AutoContac (01/99)
Manual English Version LPKF Laser & Electronics AG 1999 All rights reserved AUTOCE09(.DOC)
LPKF Laser & Electronics AG Osteriede 7 30827 Garbsen Germany Tel.: Fax: e-mail: Internet:
49-(0)5131 7095 0 49-(0)5131 7095 90
[email protected] http://www.lpkf.de
AutoContac Manual
LPKF ProtoMat is a registered trademark of LPKF Laser & Electronics AG. MS-DOS and Windows are registered trademarks of Microsoft Corporation. HP-GL is registered trademark of the Hewlett Packard Corporation. All other trademarks registered for the corresponding owners.
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AutoContac Manual CONTENTS 1 Introduction...............................................................................................................4 1.1 Requirements for operating the AutoContac system.....................................4 2 LPKF AutoContac.....................................................................................................5 2.1 Basic principle...............................................................................................5 2.2 Execution ......................................................................................................5 3 Safety rules ..............................................................................................................9 4 What is supplied with AutoContac..........................................................................10 5 LPKF DispoMat - Description and installation ........................................................11 5.1 Operator's controls and connections of the metering device ......................11 5.2 Installation...................................................................................................12 5.2.1 EPROM - version testing (Only by machines older than `97) ..........12 5.2.2 Changing the EPROM set ...............................................................13 5.2.3 Assembling the cartridge mounting on the milling-drilling head..........................................................................................................16 5.2.4 Connecting the hoses......................................................................19 5.2.5 Inserting the adapter........................................................................19 5.3 Commissioning and functional testing ........................................................20 5.3.1 Function test with BoardMaster .......................................................20 6 New functions in BoardMaster................................................................................22 6.1 The Wait - Message....................................................................................22 6.2 The Heads dialogue box .............................................................................23 6.2.1 Re-determining the offsets ..............................................................24 6.3 The Tool Edit dialogue boxes .....................................................................25 6.4 Selection of individual tools in a phase.......................................................26 6.5 Tool exchange ............................................................................................27 6.6 Raise/lower button and adjustment button ..................................................28 6.7 Waiting times for dispensing.......................................................................29 6.8 Waiting times for paste removal..................................................................31 7 Work flow................................................................................................................33 7.1 Preparing the data for working with BoardMaster .......................................33 7.2 Milling, drilling and cleaning the board .......................................................33 7.3 Fixing the board ..........................................................................................34 7.4 Filling the cartridge with paste ....................................................................35 7.5 Filling the holes with paste..........................................................................36 7.5.1 Attaching the new needle ................................................................36 7.5.2 Removing air from the needle..........................................................37 7.5.3 Preventing subsequent dripping ......................................................37 7.5.4 Setting the pressure on the metering device ...................................38 7.5.5 Starting the automatic dispensing operation ...................................38 7.6 Surplus paste removal ................................................................................38 7.6.1 Inserting the paste removal cartridge ..............................................38 7.6.2 Setting the vacuum ..........................................................................39 7.6.3 Starting the automatic paste removal operation ..............................39 7.7 Releasing the board and hardening in the oven .........................................40 7.8 Assembly and soldering ..............................................................................40 7.9 Optimising the results .................................................................................41 8 Appendix.................................................................................................................43 8.1 Technical data of the LPKF-DispoMat dispenser........................................43 2
AutoContac Manual 8.2 Default values of waiting times ...................................................................44 8.3 Data for the LPKF AutoContac Paste .........................................................45 8.4 LPKF AutoContac Paste safety data sheet .................................................46 8.5 Consumables and spare parts ....................................................................50
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AutoContac Manual 1 Introduction The DispoMat auxiliary device was specially developed to implement the new LPKF AutoContac method of through-contacting with conducting pastes. This device gives the ProtoMat circuit-board plotter the additional function of a programmable dispenser, which is particularly suitable for point application of paste media. It also provides the function of a vacuum pin for paste removal. Of course, as well as through-contacting, other dispenser applications in the prototype field can be implemented with the ProtoMat + DispoMat combination, e.g. application of solder paste or adhesive on surface-mounted printed circuit boards. To operate the DispoMat device, it is necessary to become familiar with the working method of the circuit-board plotter and the functions of the driver program. The structure of this manual is as follows: First, there is a short description of the LPKF AutoContac method of throughcontacting with a dispenser. The structure and function of the DispoMat auxiliary device and its installation on a circuit-board plotter of ProtoMat type are then described. In the following chapters, the additional functions of the BoardMaster program for dispenser control are explained. Finally, in the "Work flow" chapter, the steps of manufacturing a through-contacted printed circuit board are explained in detail. As well as specifications of the AutoContac method, the Appendix includes a safety data sheet about AutoContac paste and a list of consumables and spare parts. Important! Familiarity with this manual and the manuals of the circuit-board plotter and driver software (BoardMaster) are necessary for successful work with the AutoContac system. To enable successful guarantee claims to be made, it is absolutely necessary to read this manual carefully before using the device for the first time, and to follow the instructions exactly!
1.1 Requirements for operating the AutoContac system The following components are need for the operation of the AutoContac system: • LPKF circuit board plotter type ProtoMat • PC to control it • Supply of compressed air (6 bar) • 20- 22 °C ambient temperature (viscosity of the paste) • Forced-air oven (160°C)
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AutoContac Manual 2 LPKF AutoContac 2.1 Basic principle As an alternative to galvanic and other wet-chemical through-contacting methods, this method involves coating the walls of the drilled hole with a conducting paste which was specially developed for this application. The holes are coated with paste in two steps: First, all holes are filled with conducting paste using a dispenser. Then, in a second step, excess paste is sucked up by a vacuum pin. This achieves even covering of the hole walls with conducting paste and good lateral bonding to the pads on the top and bottom sides of the board. The paste is hardened by heating the board in a forced-air oven. By using special solderable conducting paste in this way, open through-contacts which can be populated are achieved.
2.2 Execution As before, insulating tracks are milled into the copper coating of the double-sided printed circuit board using the circuit-board plotter, and holes for populating and through-contacting are drilled. After thorough cleaning, the printed circuit board is again fixed to a frame-like base on the circuit-board plotter. Exact positioning is ensured by two locating pins. The base frame provides a hollow space between the printed circuit board and the machine bed. The holes are now filled with paste one after another. As for drilling, they are approached individually. As the milling-drilling head with the dispenser fixed to it is lowered, the metering needle settles on the printed circuit board at the edge of the hole to form a seal. Its diameter is thus greater than the diameter of the hole. A specified quantity of paste is then injected into the hole. The quantity depends on the diameter of the hole and the thickness of the board, and is controlled by the computer. The quantity is set so that the paste flows out of the hole in the form of a stalactite on the underside. Because of the reduction of pressure on the paste as it leaves the hole, the diameter of this stalactite is greater than the diameter of the hole (see Fig. 1). On the top side, because of the greater diameter of the needle, a ringshaped covering of the copper layer around the hole with paste is achieved.
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AutoContac Manual
1
2
3
4
5
(1) Conducting paste
(4) Printed circuit board
(2) Metering needle
(5) Base
(3) Cu-Pad Fig. 1: Filling holes with conducting paste
Before the excess paste can be removed by vacuum, an empty receiving cartridge must be inserted in the dispenser head. For removal, a needle with an internal diameter of about 0.2 mm greater than that of the hole is used. A defined vacuum is set on the metering device. The filled holes are approached individually. By lowering the milling-drilling head, the needle is made to settle. The vacuum ensures that the paste in the hole is pulled upwards and sucked through the needle into the receiving cartridge. On the underside of the printed circuit board, this upward movement causes the paste to shear off in the area of the extension of the stalactite. It thus leaves behind a ring-shaped swelling on the edge of the hole, which ensures secure contacting on the adjacent copper layer. Enough paste remains stuck to the hole wall to form an even coating there (see Fig. 2).
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AutoContac Manual
2 1
3
4
5
(1) Conductive paste
(4) Printed circuit board
(2) Metering needle
(5) Base
(3) Cu-pad Fig. 2 : Removing excess paste by vacuum
After the hole walls are lined with the conducting paste, the board is heated for half an hour at 160° C in a forced-air oven. The paste is thus hardened, and forms a coating which adheres firmly, conducts well and can be soldered. This completes the production of a through-contacted prototype. Two types of through-contact on the board should be distinguished: pure via holes and component through-contacts. For pure via holes, drills of 0.5 mm diameter are used. Although these through-contacts are not intended to be populated, they must also be sucked free, to enable solvent vapours to escape as the paste hardens.
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AutoContac Manual 1
2
3
(1) Conductive paste
(3) Printed circuit board
(2) Cu-pad Fig 3: Pure via holes
Such a through-contact is shown in cross-section in Fig. 3. It is distinguished by good lateral bonding to the pads on the top and bottom sides of the board. The diameter of the hole for through-contacts which are to be populated must be 0.3 mm greater than that of the pin to be soldered in. It is a requirement of the paste removal process that the holes are definitely open. This means that the paste on the underside of the hole edge is mostly removed. However, this disadvantage is not significant, since when a component is soldered in, the solder itself provides a good contact to the copper layer on the underside.
2
1
3
4
5
(1) Conducting paste
(4) Solder
(2) Cu-pad
(5) Component pin
(3) Printed circuit board Fig. 4: Populated through-contact
A populated through-contact is shown in cross-section in Fig. 4. The hardened conducting paste is well wetted by the solder, so that the solder can flow all the way through the hole to the populated side during the manual soldering process. On the one hand, this produces a good conducting link between the top and bottom sides, and on the other hand, the component is mechanically extremely well anchored.
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AutoContac Manual 3 Safety rules This manual on the AutoContac method and the manual on the circuit-board plotter should be read carefully. In particular, when the system is commissioned, the bold printed safety instructions in the manuals must be observed exactly! Never insert a hand into the machine when it is running! Users with long hair must wear a hair net! Warning! The machine changes speed automatically during the process! Only change tools in the tool changing position when the milling-drilling motor is stopped! When changing tools, insert the tool into the collet chuck as far as the limit stop! Never operate the control PC at the same time as tinkering with the device! Ensure that the workplace is clear. In particular, when operating the plotter, ensure free movement of the connecting cables between the control part and the mechanical part! If you modify the device yourself, the safety of the user can no longer be guaranteed, and guarantee claims are invalidated! Be aware that some materials can produce cancer-causing dusts or dangerous gases during processing (milling, drilling, heating). Find out about this from your materials supplier! Always use a dust extractor and microfilter! When working with LPKF AutoContac paste, particularly hardening in the oven, good ventilation of the workspaces must be ensured! If possible, use an extraction system! The LPKF AutoContac paste safety data sheets must be displayed at the workplace and the instructions in them must be observed! Avoid direct contact with LPKF AutoContac paste. Suitable protective clothing (gloves, overall, goggles) must be worn when working with LPKF AutoContac paste. In addition, there must be no eating or drinking at the AutoContac workplace! LPKF AutoContac paste must not come into contact with acids or oxidising materials! Put unhardened paste residues (cartridges, needles) in the special waste bin. Hardened paste can be disposed of like printed circuit board material (FR4).
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AutoContac Manual 4 What is supplied with AutoContac Dispenser: 1 LPKF DispoMat metering device with cable and adapter plug 1 5 ccm cartridge adapter head with connecting hose and fasteners 1 cartridge mounting (aluminium) complete 4 needle adapters (brass) 1 1.5 mm Allen key (needle adapters), 1 2 mm Allen key (retaining sleeve fixing) 1 3 mm Allen key (bracket arm mounting) Accessories: 1 LPKF AutoContac manual 1 diskette with BoardMaster driver software (A second installation of Boardmaster is not necessary when there is the same Version number installed yet.)
Basic provision of consumables: 4 10 10 10 10 10 5 5 1 2 2 2 1
cartridges à(25 g) of LPKF AutoContac paste cartridges 5 ccm standard metering needles pink, external diameter 0.90 mm standard metering needles green, external diameter 1.30 mm standard metering needles amber, external diameter 1.65 mm standard metering needles olive, external diameter 1.80 mm cartridge pistons 5 ccm PE white protective filters white diameter 13 mm cartridge sealing cap 5 ccm needle side sealing caps one-time syringes 5 ccm sample containers (round cans with lid) Cartridge connection (Luer)
additionally (if required) EPROM replacement set (update to version 2.00): 2 EPROMs programmed (V 2.00) 1 EPROM pliers
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AutoContac Manual 5 LPKF DispoMat - Description and installation 5.1 Operator's controls and connections of the metering device
Fig. 5: Operating and display features on front panel
The features from left to right are: 1. Manometer for output pressure (0 to 6 bar) 2. Pressure control to set output pressure 3. On/Off switch ‘Power’ for operating voltage of 24 V DC 4. Check LED ‘Pulse’ (lights yellow when solenoid valve opens) 5. Throttle valve controls the air flow throw the ejector (vacuum generator) 6. Manometer for output vacuum (0 to -0.7 bar)
Fig. 6 : Connections on the back
The connections are : 1. Cable bushing for mains cable 2. Compressed air/vacuum output with screwed fitting for connecting hose to dispenser head 3. Compressed air input with sliding valve and screwed fitting for the hose of the compressed air supply (6 bar). The screwed fitting is provided for a standard pneumatic hose with internal ∅ 4 mm and external ∅ 6 mm! 11
AutoContac Manual 5.2 Installation The following steps must be carried out to install the LPKF DispoMat dispenser on a ProtoMat circuit-board plotter: 5.2.1 EPROM - version testing (Only by machines older than `97) On the control board of the circuit-board plotter are two EPROMs, in which various input and output functions are programmed. The software with dispenser control requires EPROM version 1.38 to implement the additional new functions. In case that an „old“ Protomat machine is not able to work proper with BoardMaster it is possibly that there are eproms with the wrong version installed. • Switch on the machine and start BoardMaster • To check the eproms enter the Setting DialogBox in the machine menu. Then type OS; and press Send and leave the DialogBox with OK.
Type here!
• Press „cut log“ in the view menu. Now the whole dialogue between machine and BoardMaster will be written in the clipboard. • Open the clipboard with an editor program:
The answer to the „OS“ command must be S138, 170796 for the actual software version.
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AutoContac Manual 5.2.2 Changing the EPROM set The procedure to change the EPROMs is as follows: 1. Move the milling-drilling head in the X direction, to about the middle of the work area. 2. Important! Switch circuit-board plotter off! 3. Disconnect all plugs from the control part. 4. Unscrew the control part and separate it from the mechanical part: LPKF 9xs: The four screws in the corners of the machine bed should be loosened with a 4 Allen key and completely unscrewed. The control part is then lifted down from the mechanical part. ProtoMat 9xs: The circuit-board plotter should be tipped carefully onto the long side opposite the plugs. The screws between the rubber feet are unscrewed. Hold the control part with one hand and loosen and unscrew the rubber feet with the other hand. Remove the control part carefully. 5. Make EPROMs accessible: LPKF 9xs: Loosen the cover on the long sides and push it in the -X direction as far as the limit switch cables allow. ProtoMat 9xs: Unscrew the lid and carefully lever it down and away using a flat-headed screwdriver on a short side, if possible without removing the earth conductor and limit switch cables.
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AutoContac Manual The following figure should simplify finding the EPROMs: 1 4
5
6
7
8
9
702 2
701 3
10
703 704
12 11
705
13
(1) Mains filter
(8) Processor part
(2) Transformer
(9) DIL switch for baud rate setting
(3) Transformer connection
(10) Power supply units
(4) Power part for milling-drilling head
(11) Processor
(5) Z-axis power part (not fitted)
(12) EPROM L
(6) Y-axis power part
(13) EPROM H
(7) X-axis power part
701- 705 Various fuses Fig 7: View of printed circuit board of LPKF 9xs
6. Remove old EPROMs: Important! To remove the EPROMs, special PLCC pliers (which are supplied with the set of EPROMs) absolutely must be used, to avoid damaging the base or the board! Insert the metal gripping hooks of these pliers diagonally into the recesses at the corners of the base (see Fig. 9). Press the plastic handle together at the patterned parts until the EPROM becomes loose. Then lift it out carefully. Do the same with the second one. 7. Insert new EPROMs: The EPROMs are labelled H and L. The assignment to the bases on the board is simple. On the printed circuit board, next to the base for the H-EPROM, an H can be read. The other base is therefore for the L-EPROM. Put the EPROMs onto the bases the right way round: label legible upwards, marker dot over the arrow in the base. Press the EPROMs home one at a time.
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AutoContac Manual
(1) Bevelled edge
(4) Label
(2) Marker dot
(5) Recess
(3) Bevelled corner
(6) Marker arrow Fig. 8: EPROM and base
Tip: Bending of the board when the EPROMs are pressed in can be prevented by opening the pliers fully, gripping the short side of the board under its edge with one of the gripping hooks, and then holding the pliers firmly in the middle, while pressing on the EPROMs (do not pull the pliers upwards too strongly!). 8. The control unit is assembled in the opposite sequence to the disassembly described above. Important! cables!!!
Never confuse the Y stepping motor and milling-drilling head
Before switching on, always check the correct position of the head and stepping motor cables. Warning! After the circuit-board plotter is switched on, if it does not move into the -X and -Y limit switches and then into the tool changing position as usual, or there are problems in driving the plotter, switch the plotter off immediately and consult an LPKF system consultant.
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AutoContac Manual 5.2.3 Assembling the cartridge mounting on the milling-drilling head The cartridge mounting should be screwed on instead of the guide block for the depth limiter on the milling-drilling head. The procedure is as follows: 1. Move the tool head into the tool changing position.
5 6
1
7 2 8 9 10 11 3
12 12 12
12
4
(1) Shock absorber
(7) Holding part for DC motor
(2) Lifting magnet
(8) DC motor
(3) Lower head limit stop adjustment (do not move!)
(9) Adjustment screw for knurled nut (do not move!)
(4) Working depth limiter
(10) Fixing screw for guide block
(5) Motor cap
(11) Base plate for DC motor
(6) Fixing screw for motor cap
(12) Guide block Fig. 9: Milling-drilling head, front view
2. Unscrew the fixing screw (10) (3 Allen key) and remove the guide block (12). Look after them carefully. 3. Insert the mounting arm and screw it tight (see also Fig. 10). In the case of ProtoMat 93s:, if necessary tighten the springing thrust parts.
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AutoContac Manual
(1) Knurled nut for depth limiter
(5) Hole for fixing screw
(2) DC motor
(6) Hole for pen holder
(3) Adjustment screw for knurled nut
(7) Thread for fixing screw
(4) Base plate for DC motor
(8) Hole for mounting sleeve Fig 10: Fixing the mounting arm
4. Insert the mounting sleeve for the cartridge from below into the mounting arm, until the lower edge is over that of the milling-drilling head. Fix with the set screw (2 Allen key). See Fig. 11. 5. Fix a printed circuit board with underlay material to the circuit-board plotter. Move the milling-drilling head manually over the board. 6. Put a needle into a cartridge, put on a suitable needle adapter and fix it (see also Section 8.5.1). 7. Loosen the knurled screw in the mounting sleeve, insert the cartridge from above into the mounting sleeve as far as the limit stop, and fix with the knurled screw. Remove any tool located in the toolholder of the milling-drilling head. 8. Lay a piece about 1 - 1.5 mm thick of printed circuit board material on the board under the depth limiter of the milling-drilling head (not under the needle!) 9. Loosen the set screw on the mounting arm. 10. Press the milling-drilling head down by hand, until the depth limiter lies on the piece of printed circuit board. 11. Push the sleeve of the cartridge holder down until the needle settles on the printed circuit board. Finally fix in position with the set screw.
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AutoContac Manual
(1) Cartridge
(5) Mounting sleeve
(2) View window for level (fullness) check
(6) Grub screw
(3) Mounting arm
(7) Knurled screw
(4) Needle adapter
(8) Needle Fig 11: Cartridge in the mounting (front view)
The mounting is now set up so that the depth limiter of the milling-drilling head remains at least 1 mm over the printed circuit board when the needle settles. This prevents it from smearing the previously dispensed holes. When the cartridge is removed from the mounting sleeve during drilling and milling, it does not prevent the depth limiter from settling.
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AutoContac Manual 5.2.4 Connecting the hoses The connecting hose between the metering device and the cartridge is delivered with the cartridge adapter head and black fixing rings. These rings are tied firmly to the suction hose using the cable ties which are provided. The cable ties are laid around the fixing rings and the suction hose, pulled together and the remaining end is cut off as short as possible. The first ring (as seen from the adapter head) is fixed to the suction hose about 15 cm from the fitting on the lifting magnet, so that in milling-drilling operation the adapter head can be inserted into the mounting sleeve without the cartridge. The connecting hose is taken up along the suction hose and tied on. The last fixing ring is applied at the end of the suction hose, at about the height of the machine bed. The free end of the connecting hose should be fixed to the metering device using the appropriate screwed joint. For this purpose, the union nut is unscrewed and pushed over the end of the hose. The hose is then put onto the hose nozzle and secured with the union nut. The hose for the compressed air feed is fixed to the appropriate screwed joint of the sliding valve. The metering device should be set up next to the circuit-board plotter so that it is readily accessible, and so that free movement of the connecting cable when in use is not prevented. 5.2.5 Inserting the adapter Important! Switch off the circuit-board plotter! After loosening the securing screws, the plug of the head cable should be pulled out of the socket on the circuit-board plotter and replaced by the adapter plug of the metering device. The head cable is then inserted in its socket. Important! Fasten the securing screws tightly!
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AutoContac Manual 5.3 Commissioning and functional testing Functional testing takes place after the LPKF DispoMat is fully installed. The BoardMaster program or the appropriate DOS driver 9xsd can be used for this purpose. 5.3.1 Function test with BoardMaster Caution! The Circuit Board Plotter is actuated when the following actions are done! Be sure everyone is away from the Circuit Board Plotter. 1. After switching on, the circuit-board plotter approaches the -X and -Y limit switches, and then remains in the tool changing position. The Power LED lights up green. Start BoardMaster under Windows. Check under Connect in the Machine menu that the correct interface has been selected. 2. Approach all limit switches: Start a circuit-board plotter initialization run by clicking on Initialize under Settings in the Machine menu (first unlock by clicking on Unlock). The machine moves parallel to the axis. The limit switches are approached in the sequence --X, -Y, +X, +Y, -X, -Y, -X. The maximum co-ordinates of the work area (Size) are returned. Wait until the plotter comes back to the tool changing position. Tip: Determine the X and Y coordinates of the Home-point which has been used until now by calling the old BoardMaster, and enter them in the new BoardMaster driver under Home. In this way it is unnecessary to produce a new locator hole system. OK confirms. 3. Switch on the metering device. The Power-LED at the metering device lights up green. 4. Operate motor and lift manually: Select tool 1Universal cutter in the TOOL dialogue box (function panel top left). BoardMaster asks the user to: Deactivate dispenser/vacuum head! Switch the metering device off again and confirm with OK. Now the mill/drill head is activated. OK confirms the tool change. 5. Move the head out of the tool changing position. Press the motor button. On the ProtoMat 93s, wait for the HF spindle to get up to speed (around 5 minutes). Press the raise button several times with the motor running: Lower head and raise it again. Switch motor off again. 5. Query Dispenser activity: Select a dispenser tool in the tool dialogue box (function panel top left, e.g. 6Disp05Pink. A window with the prompt: Activate the Dispenser/Vacuum head! will appear. Switch the metering device on again. OK confirms. Quit tool change with OK. Caution! The circuit-board plotter may move!
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AutoContac Manual 6. Operate Dispenser manually: Be sure that the sliding valve at the back of the device (see Fig. 6) is opened (push the black ring towards the rear wall)! Set the pressure on the pressure control (see Fig. 5) to 1 bar. Please note: the pressure control can be secured by pressing it. If it cannot be turned easily, it must be unsecured by pulling it! If it is turned clockwise, the pressure is raised; if it is turned anti-clockwise, the pressure is lowered. No cartridge should be fitted to the adapter head for the subsequent pressure test. Start a pulse by pressing the Adjustment button (arrow marked with an ‘A’): the head is lowered, the solenoid valve clicks, the Pulse LED is lit yellow, and compressed air flows out of the cartridge adapter, the pressure indicated drops to approximately 0.6 bar. Stop the pulse again using the Adjustment button: the solenoid valve clicks, the compressed air is switched off, the LED is extinguished and the head is raised again. 7. Test density: Put a cartridge on the adapter head and secure it by clockwise rotation. Seal the cartridge with the sealing cap on the needle side and insert in the mounting sleeve. Set the pressure to 6 bar. Start a pulse with the Adjustment button. Check the cartridge for escaping air. End the pulse with the Adjustment button, i.e. switch the compressed air off. Tip: If compressed air flows out at the O-ring (sealing ring on the cartridge adapter head) it can be corrected by stripping the cartridge from the adapter head and to put it on again turned by 180°. In addition special grease for plastic lubrication can be spread on the O-ring. 8. Test vacuum: Reset pressure to 1 bar. Now set the vacuum to its maximum value using the throttle valve. Warning: the throttle valve is opened by turning anti-clockwise. This produces a hissing sound. It should be possible to set a vacuum of p = -0.7 bar (at 6 bar input pressure at the feed hose). This maximum value is reached before the throttle valve is turned as far as the limit stop. Keep the vacuum for the next test. 9. Test sliding valve: Air supply at the metering device can be opened and closed using the sliding valve (see Fig. 6). Pull the black ring away from the rear wall: the valve closes and vacuum is switched off. Now push the ring towards the rear wall: the valve opens and the vacuum is switched on again. Close the throttle valve and thus switch the vacuum off. The throttle valve closes before it is turned as far as the limit stop. This completes the functional testing. Warning! If an item of this checklist does not give the expected result, the circuit-board plotter should be switched off immediately and LPKF informed without delay, to avoid consequent damage and clarify the cause of the fault. In no circumstances may the device be operated again.
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AutoContac Manual
6 New functions in BoardMaster The BoardMaster Manual gives a general description of the program. Below only those functions that have been added for controlling the dispenser will be described.
6.1 The Wait - Message As long as Boardmaster waits for a response from the circuit board plotter a box with the corresponding message is displayed:
Fig. 1: Wait - Message
This box appears when BoardMaster is started and the circuit board plotter is not switched on. When the plotter is also switched on this message disappears as soon as the tool head as reached the tool change position. If, however, you press 'Cancel' then BoardMaster sets the interface to NULL. This message is also displayed when the machine is still occupied with the last commands from the command buffer. Then this is no error message! You can change to other applications while this box is being displayed. As soon as the plotter sends the required response to the PC the box will disappear and the program is continued as normal. Caution! Clicking on ‘Cancel’ causes the machine to continue without taking into consideration the response of the circuit board plotter and may thus lead to loss of data!
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AutoContac Manual 6.2 The Heads dialogue box Open the Heads dialogue box by clicking on Heads in the Configuration menu.
Fig. 13: The Machine menu
Fig. 14: The Heads dialogue-box
The left-hand side lists the various tool heads and the right-hand side shows he offsets assigned to the various heads: Mill/Drill is the milling-drilling head. Its offsets are always X = 0 and Y = 0. Dispenser and Vacuum designate the holder for the dispensing and paste removal cartridges. Their offsets are, thus, identical.
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AutoContac Manual X offset, Y offset: These values give the distance of the dispenser needle from the drill in the X and Y directions. These values differ depending on the cartridge mountings between 32 mm and 35 mm of X and between 30 mm and 33 mm for Y. Once the offsets are determined they should only be corrected if the needle is not positioned exactly centrally over the holes in the printed circuit board for dispensing or paste removal. Increasing their amount is equivalent to moving the needle relative to the hole in the positive X or Y directions. Important! The maximum X or Y co-ordinates of the work area for dispensers are less than those for drills and cutters by this value The limited work area is shown by a white frame if a dispenser/paste removal tool is selected. Tip: This white frame can be used to place a project with dispensing and paste removal phases correctly on the circuit board. This is done by selecting a Disp/Vac tool in the Tools dialogue box (top left function bar). The white frame will then be visible.
6.2.1 Re-determining the offsets Caution! The Circuit Board Plotter is actuated when the following actions are done! Be sure everyone is away from the Circuit Board Plotter. The procedure for determining these offsets again is as follows: Select the tool 2Drill05 in the Tools combo box, insert a drill (0.5 mm), position the milling-drilling head manually over the printed circuit board (using the cursor keys or the mouse), switch on the motor and drill a hole by clicking on the lower button. Change to the Heads dialogue box, select Dispenser and click on Origin. Now select the 6Disp05Pink tool, remove the drill and insert a cartridge with needle (pink) in the mounting (see Section 5.2.3). Move manually (using the cursor keys) as precisely as possible over the hole in the printed circuit board (set the step pitch to 0.05 in the Machine Settings dialogue box for this purpose). Push the head down by hand and visually check the position of the needle in the X and Y directions and correct accordingly. Change back to the Heads dialogue box, select Dispenser and click on Head. The offsets will be calculated by BoardMaster and entered. These values should also be used for the Vacuum head. When you quit BoardMaster, these values will be saved in the INI-file and loaded again next time you open the program.
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AutoContac Manual 6.3 The Tool Edit dialogue boxes The Tools menu contains the Mill/Drill, Dispenser and Vacuum tool groups and Select.
Fig. 15: The Tools Edit dialogue-box
The Dispenser Tool Edit box contains a list of the dispenser tools available.
Fig. 17: The Dispenser Tool Edit dialogue-box
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AutoContac Manual The names of the tools are built up as follows: the ordinal number 6 is followed by the abbreviation Disp for dispenser, then comes the associated hole diameter in 1/10 mm and finally the colour of the metering needle. The dispensing tool D Green cartridge 0,8 mm, i.e. a green metering needle, is used for a 0.8 mm hole, for instance. It is clear from the list of tools that the same needle can be used for various hole diameters. The difference between these tools is in the various different Waiting times specified for them. See Section 6.7 for an explanation of the significance of these times. The user has the option of defining some tools for himself or of changing the settings for the existing tools, thus having a direct influence on their function. The Vacuum Tool Edit box contains a list of the paste removal tools available.
Fig. 18: The Vacuum Tool Edit dialogue-box
The names of the paste removal tools are made up form the ordinal number 7, followed by the abbreviation Vac, the associated hole diameter in 1/10 mm and finally the colour of the metering needle to be used. See Section 6.8 for an explanation of the waiting times.
6.4 Selection of individual tools in a phase If an operational phase which is a component of the current job is selected in the Phase combo box, it is possible to access the Select Tools box by clicking on Select... from the Tools menu. Here you can select the various tools in the phase for operations. The selection of all tools in the phase is the default setting. Tools not selected will be ignored. Selection of individual tools can be combined with the selection of a portion of the production data (graphical marking of specific areas on the printed circuit board or marking specific vector indices in the data). BoardMaster makes a logical AND association between selected data and tools selected.
26
AutoContac Manual
Fig. 19: Select Tools
6.5 Tool exchange If a new tool is requested through the Tool combo box (in the toolbar, top left) when a new phase is started or on manual tool exchange, BoardMaster first queries the position of the switch on the adapter plug. If the switch is down, this means Dispenser active, if the switch is up, this means Dispenser inactive, i.e. the milling-drilling motor is switched off. If this dispenser status is not compatible with the tool selected, the user is prompted to change the switch position. If, for instance, the dispenser is inactive and a dispenser or paste removal tool has been selected, the prompt Activate the Dispenser/Vacuum head will appear. If, on the other hand, the dispenser is active and a drilling or milling tool is selected, the prompt Deactivate the Dispenser/Vacuum head will appear.
Fig. 20: Switch status
Important! Always quit by clicking on OK. Then BoardMaster will check the position of the switch again and if necessary, ask the user again to really execute the switch. When Cancel is clicked, the tool change will be performed without control of the dispenser activity. The short switching pulses which are meant to control the solenoid valve at the metering device are passed on to the motor when the metering device is switched on and a dispensing tool has been selected just the same. In the Tool Exchange box, the user is prompted to insert a new tool in the appropriate tool head. In the case of a tool exchange at the start or during the course of a phase, the user can choose between two options: continue operations Continue after tool exchange or interrupt processing for adjustment Stop after tool exchange for adjustment. The default setting is to continue, which corresponds to the feature previously used of tool exchange without interruption of the operational phase.
27
AutoContac Manual
Fig. 21: Tool Exchange
If Stop after tool exchange for adjustment is selected, the BoardMaster interrupts the current phase, i.e. it is possible to move to any point and lower the head. The details of the actions to be carried out at this point in a dispensing or paste removal phase are described in detail in the “Workflow” Section. The phase is then continued after adjustment of the newly inserted tool with the Start button. Instead of this, however, the phase can also be completely aborted at this point.
6.6 Raise/lower button and adjustment button On a milling machine, pressing the raise/lower button (when the motor is running) causes the head to be lowered. The head remains lowered until the raise/lower button is clicked again. Clicking on the raise/lower button when a drilling, dispensing or paste removal tool is selected causes the execution of a single drilling, dispensing or paste removal operation. There is a special adjustment key (‘A’+arrow) for adjusting the dispensing and paste removal tools. Pressing this key when a paste removal tool is selected causes the head to be lowered, pressing again causes it to be raised again. If a dispensing tool is selected, the compressed air is also switched on or off.
28
AutoContac Manual 6.7 Waiting times for dispensing All the waiting times required for controlling the dispensing operation are listed in ms (milliseconds) under Waiting times in the Dispenser Tool Edit dialogue box. They have different values depending on the diameter of the holes and the metering needles to be used. The meaning of the individual waiting times is now explained. Before Down (BD): After a hole is approached, the waiting time BD is used to steady the millingdrilling head before lowering the needle. A very short time can be chosen, about BD = 10 ms. After Down (AD): Waiting time AD after the command to lower the head takes account of the fact that the needle requires about 180 ms until it settles on the printed circuit board. It can therefore be fixed at AD = 200 ms. Dispens (D): The time D between the solenoid valve opening and closing is the duration of the compressed air pulse. Together with the pressure set, it determines the quantity of paste pressed into the hole, and must be appropriate for the hole diameter and the needle in use. Before Up (BU): The waiting time BU between the solenoid valve closing and the needle raising takes into account the paste which continues to flow after the end of the compressed air pulse, because of the relatively slow reduction of pressure in the cartridge. It is intended to ensure that the needle is raised from the printed circuit board cleanly, and can be fixed at BU = 400 ms. After Up (AU): The purpose of time AU is also clean process execution. Particularly with larger needle diameters (amber needles), it can happen that the paste pulls into threads when the needle is raised. The waiting time AU after the raise command is to wait for the thread to break, and to prevent the tool head from moving immediately, which would result in the paste thread being laid over the insulation track. AU can be chosen to be less for small needle diameters than for large ones.
29
AutoContac Manual The following diagram is intended to clarify the function of waiting times in the dispensing process:
Fig. 22: Waiting times in the dispensing process
In Fig. 22, the position of the tool head, pressure changes in the cartridge and exit speed of the paste are shown schematically against the process time. The steepness of the flanks of the pressure pulse is determined by the buffer effect of the air volume in the hose and cartridge. Min is used instead of 0 to signify that even for dispensing, to prevent subsequent dripping, a weak vacuum can be set (see Section 8.5.3). If the solenoid valve is closed, the vacuum affects the cartridge.
30
AutoContac Manual 6.8 Waiting times for paste removal The waiting times required for the paste removal operation are listed in ms under Waiting times in the Vacuum Tool Edit dialogue box. The Before Down time BD is exactly as for dispensing. Vacuum (V): Time V is the time between the commands to lower and raise the tool head, and indirectly determines the resting time of the suction needle. The time of about 180 ms to lower the head must be subtracted. After Up (AU): Waiting time AU gives the removed paste time to pass through the needle into the receiving cartridge. This ensures that the needle is free again before the next removal process. AU can be fixed at 500 ms. The following diagram is intended to clarify the function of waiting times in the paste removal process:
Fig. 23: Times in the paste removal process
In Fig. 23, the head position, negative pressure in the cartridge and flow speed of the paste in the hole are shown schematically over the process time.
31
AutoContac Manual The vacuum is fixed at the metering device. If the needle is sealed, a maximum negative pressure can build up in the cartridge. However, if air is sucked through the needle, the negative pressure in the cartridge drops more or less depending on the size of the volume flow. If the needle is completely free, a minimum negative pressure is set. This situation is given if the head is up. When the suction needle settles on the hole, which is filled with paste, the negative pressure in the cartridge increases to the pre-set maximum negative pressure. The paste in the hole thus moves upwards into the needle. When the hole finally opens and air is sucked through it, the negative pressure falls again. The paste on the hole wall is driven further upwards by the air flow in the hole, until the needle is raised and the air flow through the hole stops.
32
AutoContac Manual
7 Work flow This Section describes the individual operations to be carried out in producing a through-contacted printed circuit board with the LPKF AutoContac system.
7.1 Preparing the data for working with BoardMaster LMD format: The UserDisp script file supplied with the program is used to allow output of an LMD file with the Dispense and Vacuum phases from the CircuitCAM program. The UserDataFormat LpkfDispVacTool and the UserDataOutput job PcbLmdOut is imported using the Mix Scripts function. The data output can then be read and processed directly by BoardMaster. Placing the projects: In order to place a project with dispens and vacuum phases correctly on the basis material, select a dispensing or vacuum tool from the tool dialog box (function bar top left), e.g. 6Disp05Pink. The limited working area for the dispense or vacuum phase is displayed on the screen by means of a white frame. All holes to be throughcontacted must be located within this frame as spots outside of the frame cannot be approached by the dispenser or suction needles. This must be taken into consideration during placing, displacing and copying of projects. For drilling, milling and cutting the whole working area of the machine is of course available.
7.2 Milling, drilling and cleaning the board Caution! Follow the safety-rules of the Circuit Board Plotter manual and pay attention to the section 5 of this manual! The double-sided printed circuit board is drilled and milled according to the instructions in the circuit-board plotter manual. This is done by inserting the cartridge adapter head in the empty sleeve and tightening the knurled screw to the stop, to prevent damage from loose parts. After drilling and milling the circuit board is then thoroughly cleaned on both sides, either with a printed circuit board brushing machine, or by hand.
33
AutoContac Manual To clean the printed circuit board by hand, it is laid on a level base. Before further processing, burrs which may be present on the edges of the holes are removed using fine abrasive paper (1000 grain). The board is then brushed in the primary direction of the tracks with a wet board cleaner (e.g. LPKF PAD board cleaner). The brushing is intended to remove the oxidation layer and splinters in the insulation channel. After brushing, the printed circuit board must have a metallic gloss. From now on, the board should only be held at the edges. It is now best to rinse the board under running hot water and then to dry it using a drier or compressed air. After drying, the board is rubbed off with isopropanol (chemist), to remove grease and the slightest impurities. Warning! Use only fluff-free (paper) cloths to wipe the printed circuit board!
7.3 Fixing the board First, from the 2 mm thick underlay (which was previously used for drilling), two supporting strips, which are about 1.5 cm wide and somewhat longer than the printed circuit board in the X direction, are cut. From the same material, two supporting slabs measuring about 3 cm by 1.5 cm are prepared. Move the milling-drilling head into the Pause-position. Align the printed circuit board as for drilling with the component side upward and lay it on the locating pins. Push the supporting strips in the X direction under the edges of the printed circuit board and parallel to them, so that the strips show about 5 mm beyond the board. The supporting slabs are laid next to the locating pins under the edges of the printed circuit board in the Y direction. Now press the board down and let the locating pins engage with the locating holes. Then fix the printed circuit board, on the sides where the supporting strips are, with adhesive tape (Tesakrepp 5250 is recommended). It is important that there is no dirt (adhesive tape residues, drilling or milling splinters) between the layers, so that the base material lies exactly flat. The locating pins form the reference for through-contacting the printed circuit board. Since the same data is used for drilling and through-contacting, the printed circuit board must be in exactly the same position for these processes. The adhesive tape is used to hold the printed circuit board down at the edges. 2
3
1
4
5
6
1.
Machine bed (aluminium base plate)
4.
Base material about 1.6 mm thick
2.
Adhesive tape
5.
Supporting strips 2 mm thick
3.
Locating pins 3 mm diameter
6.
Locating hole strips
Fig. 26: Fixing the printed circuit board
34
AutoContac Manual This kind of support has the advantage that the gap under the printed circuit board can be seen from the front in the X direction, so that an optical check on the dispensing process is possible.
7.4 Filling the cartridge with paste Note: While the entire described process do never pull at one of the Cartridge piston to avoid air bubble inclusions in one of the cartridges! Furthermore an cartridge fitting (Luer to Luer-connector) is necessary for the following process. If this part not available, it can be ordered under part number: 106281 from the LPKF AG. Working process: Remove the sealing cover from one of the cartridges filled with AutoContac paste. Fasten this cartridge and th empty 12 ml cartridge to the cartridge fittin (Luer to Luer connector). Cartridge (12 ml) filled with AutoContac - paste
empty cartridge (12 ml)
Luer to Luer Connector
Move the AutoContac - paste from the filled to the empty Cartridge by pushing the cartridge piston down. Repeat this process back and forth from one to the other cartridge a couple of times. By pressing the paste back and forth it will be mixed. It has to be repeated till the paste shows an even colored mixture (beige color). If you get this propertionate shade, move the paste back to the original, labeled cartridge for further use. Keep the syringe, it can be used several times! Now push the cartridge-piston from the empty small 5 ml - cartridge up to the plot in the cartridge (e.g. with the help of a pencil). 5 ml cartridge
Cartridge piston
35
AutoContac Manual Now solve the Luer to Luer - connection to the empty 12 ml cartridge and move the small 5 ml cartridge at equal place.. Press the required quantity of AutoContac - paste in the small cartridge (approx. 1,5 cm of the cartridge for one European standard size board). Remove both cartridges of the Luer to Luer connection. After that lock the used cartridges immediately to prevent a drying up.
7.5 Filling the holes with paste The printed circuit board, once milled, drilled and cleaned, is fixed on a frame of supporting strips on the circuit-board plotter. BoardMaster: Load the job to be executed. Set the Dispense phase. Select the required production data with All+ or by graphically marking an area and pressing +. Press Start. BoardMaster prompts the user to fit the appropriate dispensing tool. Select Stop after tool exchange for adjustment when exchanging the tool.
7.5.1 Attaching the new needle The tool head is in the tool changing position and is left there for the further operations. After filling the cartridge, twist off the sealing cap on the needle side. Hold the cartridge firmly. Put the new needle on and fasten it by rotating it by 180° clockwise. Push the suitable needle adapter on the needle as far as the limit stop and fasten the set screw with a 1.5 mm Allen key. Important! Before putting the cartridge on the adapter head make sure that the vacuum is switched off at the metering device. Otherwise you run the risk of sucking air into the cartridge! Hold the cartridge adapter head firmly. Push the cartridge over the O-ring (sealing ring) and secure it by rotating it by 90° clockwise. Insert the cartridge in the mounting sleeve and fix the needle adapter with the knurled screw. To change the needle, loosen the knurled screw and pull the cartridge upward out of the sleeve. Hold the adapter head firmly, release the cartridge by rotating it by 90° anti-clockwise, and pull it off the adapter head. Hold the cartridge firmly and twist and pull the metering needle and needle adapter off. Needles can be used several times, as long as the paste residues have not dried too much. Important! When the amber needle is used it is important that the adjusting nut for the upper head stop (at the top between the Z guides) is set in a way that the maximum lift is possible.
36
AutoContac Manual 7.5.2 Removing air from the needle After the metering needle on the cartridge has been exchanged, the air must be removed from the new needle to ensure that the holes at the beginning of the subsequent dispensing procedure will be filled with paste and not only with air. To do this, proceed as follows: Hold the sample container under the needle and dispense manually until the paste thread has no more air bubbles as it comes out. The needle is then completely filled with paste. Strip the paste off the needle smoothly with the edge of the sample container. BoardMaster: Dispense manually using the Adjustment button. Tip: With the amber metering needle use the single pulse function to save paste.
7.5.3 Preventing subsequent dripping It is imperative that subsequent dripping of the paste, i.e. formation of a drip at the metering needle after the end of a compressed air pulse, be avoided to ensure that no paste is pressed into the insulation tracks around the holes when the needle is moved. Dripping can be prevented by setting a suitably weak vacuum (around -0.05 bar). The vacuum is applied to the cartridge between the pulses of compressed air. It should not be so great that the paste is sucked back up into the cartridge, so that the metered amount at the next pulse is too small. Hold the sample container under the needle again and trigger a single pulse. Strip the paste off the needle smoothly with the edge of the container. Set the vacuum so that the paste does not flow after the end of the pulse, i.e. that no drop forms at the tip of the needle. Trigger another single pulse and control the setting. BoardMaster: Use the Raise/Lower key to trigger single pulses.
37
AutoContac Manual 7.5.4 Setting the pressure on the metering device This procedure only has to be carried out once at the start of a working day. 10 to 20 test holes with the smallest diameter of the printed circuit boards to be processed later are used to adjust the pressure during dispensing correctly to the viscosity of the paste. This can change as the result of solvent evaporation and changing ambient temperatures. Set the pressure on the metering device to 1 bar. Dispense a few test holes (see also Section 8.5.5) and set the pressure so that the length of the paste stalactite on the underside of the printed circuit board is a good 1 mm (check by eye). The pressure which is set in this way is maintained for all hole diameters, and does not need to be changed again. The metering of different quantities of paste for the different hole and needle diameters is done using the waiting time Dispense in the dispenser tool library (Edit dispenser-tool dialog box).
7.5.5 Starting the automatic dispensing operation The dispensing operation can be started once the air has been removed from the metering needle and a suitable weak vacuum has been set to prevent dripping. BoardMaster: Recommence processing of the dispense phase by selecting Start.
7.6 Surplus paste removal The paste should be removed about 15 to 20 min after a hole is filled to prevent the paste drying too well. Dispensing processes which last longer should be interrupted for a paste removal phase for the holes which have been filled earlier. BoardMaster: Select the Vacuum phase and select for paste removal holes into which paste has already been dispensed. Press Start and select Stop after tool exchange for adjustment in the subsequent tool exchange. 7.6.1 Inserting the paste removal cartridge Remove the cartridge with the paste out of the mounting sleeve. Insert a protective filter into an empty cartridge so that the fabric side forms the outside. The protective filter prevents the hose and the metering device from becoming dirty by drops of the sucked-in paste. Put the needle which corresponds to the desired vacuum tool onto the cartridge and fasten it by rotating. Push the suitable needle adapter on the needle as far as the limit stop and fasten the set screw with a 1.5 mm Allen key. Important! Needles which have been used for dispensing should not be used for removal since dried paste residue may diminish the size of the removal channel in the needle! Hold the cartridge adapter head firmly. Push the cartridge over the O-ring (sealing ring) and secure it by rotating it by 90° clockwise. Now the protective filter is positioned directly before the inlet opening of the adapter head. The cartridge is big 38
AutoContac Manual enough to take up the paste to be removed. Insert the cartridge in the mounting sleeve and fix the needle adapter with the knurled screw.
7.6.2 Setting the vacuum The procedure for setting a defined vacuum value is as follows. Move the head to a place without a hole and lower it so that the needle settles tightly on the board. Now set the vacuum to the value of -0.3 bar using the throttle valve on the metering device. Raise and lower the head again and correct the setting as necessary. BoardMaster: Move manually to a position without a hole using the cursor keys or the mouse and lower the head by pressing the Adjustment button. Set the vacuum on the metering device. Raise the head again (Adjustment button).
7.6.3 Starting the automatic paste removal operation Now start the processing. After this work step ends, keep the used cartridge. It can be used several times, until it is about 1/4 filled with removed paste: BoardMaster: Start execution of the Vacuum phase with Start.
39
AutoContac Manual 7.7 Releasing the board and hardening in the oven Pre-heat the forced-air oven to a temperature of 160 °C. Pull the adhesive tape off the edges of the board. Secure the board against unwanted lifting. Now release the board and lift it carefully from the machine bed by holding it only at the edges. Warning! The paste can easily be smeared, as long as it is not yet hardened. This may cause insulation to be bridged or holes which have had paste removed to close again! Lay the printed circuit board with its edges on a suitable mounting in the oven. The paste must not come into contact with the mounting. Leave the board in the oven for 30 min. After cooling, abrade only the underside (= solder side) with a dry board cleaner, to remove residues of resin, which might prevent the pads from being wetted by the solder. Then coat both sides of the board with flux to make sure that the flux reaches the paste coating in the holes.
7.8 Assembly and soldering The components should be fitted with suitable care, to avoid damaging the paste sleeve within the hole! In manual soldering, care should be taken that the component pins are heated for long enough to allow the solder to flow through the hole as far as the populated side. Populated through-contacts have a very low resistance after soldering, and are also mechanically particularly stable.
40
AutoContac Manual 7.9 Optimising the results The following chapter describes how the user can influence the result of the throughcontacting: 1) The paste cone on the underside of the board is either too long/too short during dispensing: First set the dispense pressure at the metering device for the smallest hole diameter (see section 7.5.4) and keep this setting for the other diameters. Then correct the amount of paste by changing the waiting time Dispense in the Edit dispense tool dialog box until the length of the cone is about 1 mm (see section 6.3). 2) A hole has not sufficiently been filled with paste: The cause of the error is an air bubble within the metering needle. When ventilating the needle (see section 7.5.2) make sure that the dispensing phase is sufficiently long so that no air is left within the needle! Graphically and individually select the incorrect hole using BoardMaster and repeat the dispensing. Prior to it remove any present paste or work with a shorter waiting time dispense at the second time. 3) Paste is smeared past the external needle diameter: This can have the following causes: It happens that paste continues to flow between two dispen7.5.3sing processes and forms a drop at the metering needle. This drop is then squashed at the following settling of the needle on the board. This dripping can be avoided by setting a suitably weak vacuum (about -0.05 bar)(see section 7.5.3). When the offsets for dispenser (and vacuum) in the Heads dialog box have been determined incorrectly (see section 6.2.1) so that the needle does not cover the hole completely when it settles on the board paste may be pressed out at the top of the hole and form a drop on the board. In this case correct the offsets in the Heads dialog box correspondingly (see section 6.2). Always take care that a newly inserted metering needle is free from paste residues at the outside. 4) The paste forms strings which do not tear off in time before the head moves on: This problem may occur when using the amber needle for dispensing. Setting the maximum lift of the tool head helps tearing the string. The adjustment nut for the top head limit stop is located between the Z-guides at the tool head (see Manual circuit board plotter). Additionally, the waiting time after up can be extended in the edit dispenser tool dialog box. The tool head then stays longer before starting up again.
41
AutoContac Manual 5) Too little or too much paste is removed in the vacuum phase: When paste is left for too long (> 30 min.) in the hole after dispensing it dries and becomes more viscous. Low ambient temperatures also increase the viscosity of the paste (see section 8.3). Thus too much paste may remain in the hole and the inserting of component pins becomes more difficult or is even impossible. On the other hand higher temperatures cause the paste to become more fluid and thus too little paste remains after removal, especially on the underside. To determine how much paste is removed, use the waiting time vacuum in the Edit vacuum-tool dialog box (see section 6.3). 6) The rings of paste on the upper side of the board are not formed symmetrically around the hole.: When the offsets for (dispenser and) vacuum were not determined correctly in the Heads dialog box (see section 6.2.1) so that the needle does not cover the holes centrally then paste settles in irregular shape at the upper rim of the hole during paste removal. In this case the offsets must be corrected accordingly in the Heads dialog box (see section 6.2).
42
AutoContac Manual 8 Appendix 8.1 Technical data of the LPKF-DispoMat dispenser Metering device: Metering is done on the pressure-time principle. Dimensions :
230 x 210 x 70 mm
Weight :
2.3 kg
Power supply :
No separate mains connection. The metering device is connected by a special adapter plug directly to the circuitboard plotter, and controlled from it.
Internal voltage :
24 V DC / 72 V DC
Power consumption : Compressed air connection :
6 VA (solenoid valve) The hose for the compressed air supply is screwed to the rear wall of the metering device. (Hose external diameter: 6 mm, internal diameter: 4 mm )
Operating pressure : 6 bar Output pressure :
0 to
+ 6.0 bar
Output vacuum :
0 to
- 0.7 bar
Dispenser head: mounted on the tool head of the plotter. cartridge size :
5 cm3
(for 4.5 cm3 = 20 g paste)
The dispenser head is connected to the metering device via a transparent hose. Metering needles: Standard metering needles with Luer-Lock thread, nylon / high-grade steel, capillary length 1/2'': Needle colour
Internal diameter
External diameter
pink
0.60 mm
0.90 mm
green
0.84 mm
1.30 mm
amber
1.35 mm
1.65 mm
olive
1.53 mm
1.80 mm
This needle set is suitable for hole diameters from 0.5 mm to 1.4 mm.
43
AutoContac Manual 8.2 Default values of waiting times The following default values for waiting times were determined for paste that has just been filled at an ambient temperature of 20 °C. Dispensing: before down =
0.01 s
after down
=
0.2 s
pulse
=
see table
before up
=
0.4 s
after up
=
see table
Paste removal: before down =
0.01 s
vacuum
=
see table
after up
=
0.5 s
LPKF 9xsd driver: The times before down in dispense and vacuum modes are always the same. The time after up in vacuum mode is called after vacuum. Drill hole dia. [mm]
Dispensing (1 bar) needle
pulse [s]
Paste removal (-0.3 bar)
after up [s]
needle
vacuum [s]
0.5
pink
0.240
0.1
green
0.270
0.6
pink
0.320
0.1
green
0.270
0.7
pink
0.430
0.1
green
0.270
0.8
green
0.170
0.4
amber
0.230
0.9
green
0.220
0.4
amber
0.220
1.0
green
0.265
0.4
amber
0.210
1.1
amber
0.055
0.9
olive
0.200
1.2
amber
0.062
1.0
olive
0.190
1.3
amber
0.075
1.1
olive
0.180
1.4
amber
0.085
1.2
olive
0.180
Due to the paste coating the final diameter of the through contact is by mm smaller than the diameter of the drilled hole! 44
0,3
AutoContac Manual 8.3 Data for the LPKF AutoContac Paste LPKF AutoContac paste is a single-component polymer copper conducting paste which can be soldered, and has outstanding adhesion to FR-4 base material and to copper. Durability:
6 months if stored between 0° and +6° C
Hardening:
30 minutes at 160° C in forced-air oven (protective gas not required)
Capacity:
(100g) 25 g paste per cartridge is enough to through-contact about 35,000
holes with ∅ 0.5 mm or
15,000
holes with ∅ 0.8 mm or
8,000
holes with ∅ 1.1 mm.
The paste viscosity strongly depends on temperature! It is therefore recommended to keep ambient temperature as constant as possible, i.e. work in air-conditioned rooms if possible.
35
Visc (Pa.s)
30
25
20
15
10 15
20
25
30
35
Temp (°C) Fig. 27: Temperature dependence of the paste viscosity
45
40
AutoContac Manual 8.4 LPKF AutoContac Paste safety data sheet Page 1 of 4
LPKF AutoContac Paste safety data sheet
1.
Identification of the substance / preparation and of the company
1.1
Identification of the substance or preparation:
Date : 02 / 95
ECCOCOAT™ M 8503 ECCOCOAT™ is a registered trademark of W. R. Grace & Co. Trade name: 1.2
LPKF-AutoContac-Paste
Manufacturer identification: Emerson & Cuming Nijverheidsstraat 7 B-2260 Westerlo - Belgium
Tel: ++32 14 57 56 42 Fax: ++32 14 58 56 50 Telex: 31500
Supplier identification: LPKF CAD CAM Systeme GmbH Osteriede 7 D-30827 Garbsen - Germany 1.3
Tel: ++49 51 31 70 95-0 Fax: ++49 51 31 70 95-90 Telex: 921542 lpkf d
Company emergency telephone number: Official advisory body: Not yet appointed
2.
Composition / information on ingredients Solderable copper conductor Hazardous Ingredients*
CAS-Number
Quantity
Hazard Class
Risk Phrases
None * See also Section 8.2. 3.
Hazards identification None
4.
First aid measures
4.1
Eye Contact: Moderately irritating upon direct contact. Keep lids open and rinse eyes with water for a sufficiently long time. Get medical attention.
4.2
Skin Contact: Moderately irritating. Wash affected area with plenty of water. Get medical attention if irritated.
4.3
Inhalation: Heating can generate vapors that may cause respiratory irritation, nausea and headache. At room temperature inhalation hazard is unlikely. At elevated temperatures: remove to fresh air if effects occur and get medical attention.
4.4
Ingestion:
Harmful if swallowed. Drink water, rinse mouth out repeatedly. Do not induce vomiting. Get medical attention.
46
AutoContac Manual Page 2 of 4
LPKF AutoContac Paste safety data sheet
5.
Fire-fighting measures
5.1
Suitable extinguishing media:
5.2
Extinguishing media which must not be used for safety reasons:
Water [X]
Foam [X]
CO2 [X]
Date : 02 / 95
Other [ ]
Never use strong water jet 5.3
Special exposure hazards: Toxic fumes may be evolved upon exposure to heat or open flames.*
5.4
Special protective equipment for firefighters: Wear breathing apparatus with independent air supply. * See also Section 10.4
6.
Accidental release measures*
6.1
Personal precautions:
Prevent contact with eyes, skin and clothing.
6.2
Environmental precautions:
Prevent from entering sewers or effluents
6.3
Methods for cleaning up: Dam with absorbent material,e.g. sand. Remove mechanically and collect in suitable container which can be sealed. Residual resin may be removed using steam or hot soapsuds. * See also Section 13
7.
Handling and storage
7.1
Handling:
Practice good caution and personal cleanliness to avoid skin / eye contact.
7.2
Storage:
Store dry in closed original container at low temperature.
8.
Exposure controls/personal protection
8.1
Recommended engineering controls:
8.2
Control parameters:
Ensure effective extraction.
Hazardous Ingredients
%
Exposure Limits
References
-
-
-
-
8.3
Monitoring procedures:
8.4
Recommended personal protection: Eyes: Hands: Skin: Respiration:
None known
Close fitting goggles Protective rubber gloves Protective clothes (apron) Extraction
47
AutoContac Manual Page 3 of 4
LPKF AutoContac Paste safety data sheet
9.
Physical and chemical properties
9.1
Appearance:
Gray-brown fluid
9.2
Odour:
Very slight ether
9.3
pH (concentrate):
9.4
Boiling point / boiling range:
190° C
9.5
Melting point / melting range:
N. A.
9.6
Flash point:
90° C
9.7
Flammability:
Combustible
9.8
Autoflammability:
9.9
Explosive properties:
N. A.
9.10 Oxidising properties:
N. A.
Neutral
Unknown
9.11 Vapour pressure:
< 1 mm Hg (20° C)
9.12 Relative density:
4,2
9.13 Solubility:
Date : 02 / 95
Water: no,
Fat: no
9.14 Partition coefficient (n-octanol / water):
Low
9.15 Further data: 10.
Stability and reactivity
10.1 Stability:
Product is stable. Hazardous polymerisation will not occur by itself.
10.2 Conditions to avoid: Exposure to open flames or uncontrolled exposure to heat. 10.3 Materials to avoid: Bases, Lewis acids and strong oxidizers. 10.4 Hazardous decomposition products (in a fire): Carbon monoxide, carbon dioxide, phenol, formaldehyde, hydrocarbons and other organic substances 11.
Toxicological information
11.1 Acute LD50 Oral Rat:
Unknown
11.2 Acute LD50 Dermal Rabbit:
Unknown
11.3 Acute LD50 Inhalation Rat (4 hr): Unknown 11.4 Effects of exposure and symptoms: 11.5 Other data: 12.
Ecological information
12.1 Aquatic Toxicity: LC50 (96 hr) Rainbow Trout: Unknown EC50 (48 hr) Daphnia Magna: Unknown 12.2 Environmental effects:
Unknown
48
AutoContac Manual Page 4 of 4 13.
LPKF AutoContac Paste safety data sheet
Date : 02 / 95
Disposal considerations
13.1 Disposal of material: Burn in an adequate incinerator or bury in an approved landfill, in accordance with local and national regulations 13.2 Disposal of packaging: Uncleaned empty containers should be treated like the contents. 14.
Transport information
14.1 Labelling for transportation:
None
14.2 Substance Identification Number (SIN) (UN Number): 14.3 ADR/RID:
None
14.4 IMDG:
None
14.5 IATA/ICAO:
None
None
14.6 Further information: 15.
Regulatory information
15.1 Labelling according to EC Directives 67/548/EEC and 88/379/EEC: Classification:
None
Risk Phrases:
None
Safety Phrases:
None
15.2 EINECS number: All ingredients of this product are listed in EINECS unless specifically exempted under the EC Directive 67/548/EEC 15.3 Specific provisions: 16.
Other information Nature of revision: Requirements of EC Directive 91/155/EEC. All information for this data sheet was taken from the safety data sheet of the paste manufacturer.
49
AutoContac Manual 8.5 Consumables and spare parts Consumables for dispenser: Item
Supply unit
Order number
AutoContac paste
100 g
106280
Cartridges 5 ccm
50
101203
Standard metering needles pink
50
101225
Standard metering needles green
50
101223
Standard metering needles amber
50
101222
Standard metering needles olive
50
101224
Cartridge pistons 5 ccm PE white
40
101206
Protective filters white ∅ 13 mm
50
101218
Cartridge seals 5 ccm
10
101207
Needle side sealing caps
10
101226
Sample containers
10
101214
When ordering spare parts, please give the type of circuit-board plotter in use and the machine number (stamped into the machine bed)! Spare parts for the AutoContac system: Item
Order number
Needle adapter for metering needle pink
101449
Needle adapter for metering needle green
101447
Needle adapter for metering needle amber
101446
Needle adapter for metering needle olive
101448
O-ring for cartridge adapter
101213
Cartridge adapter 5 ccm complete with connecting hose and fasteners
101443
Cartridge mounting complete with a set of 4 needle adapters
101762
EPROMs replacement set version 1.38)
(update to
50
101441
