3D low-profile Silicon interposer using Passive Integration (PICS) and Advanced Packaging Solutions EUFANET Toulouse conferences, November 28th-29th, 2011 Stéphane Bellenger, IPDiA
3D Advanced Integration trends Application requirements examples: implications for electronics modules Which solutions? IPDiA proposal general overview Passive Integrated Platform : 2D & 3D silicon usage - Deep trench capacitor : how to integrate more - Inductance : enhanced Q-factor highway PICS Silicon-Interposer. Generals 2D Interposer Platform : external components & interconnect - External Components : Chip-to-Wafer usage - 2D Connective Substrate : technical challenges & benefits - Module on Board / Flip Chip Module usages 3D Interposer Platform : how to create 3D interconnect - Via technology / Two-sides routing : - Flip Chip Module usage Conclusions
3D Advanced Integration trends Application requirements examples: implications for electronics modules Which solutions? IPDiA proposal general overview Passive Integrated Platform : 2D & 3D silicon usage - Deep trench capacitor : how to integrate more - Inductance : enhanced Q-factor highway PICS Silicon-Interposer. Generals 2D Interposer Platform : external components & interconnect - External Components : Chip-to-Wafer usage - 2D Connective Substrate : technical challenges & benefits - Module on Board / Flip Chip Module usages 3D Interposer Platform : how to create 3D interconnect - Via technology / Two-sides routing : - Flip Chip Module usage Conclusions
Aerospace application requirements From long time being, most of the following key characteristics has driven the aerospace applications development, with more intensity since last years linked to sensors & captor development and integration using advanced MEMS technologies: • Higher integration level and miniaturization (Increasing the functionality combination and the complexity within a single package) • More memory, more sensor, more calculation, more RF communication • Outisde components localization, meanings, • Extended temperature ranges (From -65°C up to 150°C ) • Rapid temperature changes during system wake-up • Resistance to external aggressions (Particles, Humidity) – Hermiticity • Packaging and product reliability (Vibration, Thermal cycling, extreme conditions,…) • Low energy consumption
Aerospace application requirements All of these previous requirements are based on the following reasons (Why), and application domains (Where): Why? • To design equipment as small as, as light as possible (Weight & space saving) • To combine a maximum of electronics into well integrated boxes • To better support high levels of vibrations • Huge thermal variations during flight, orbiting. • Having the sensors closest to the hottest areas for efficient monitoring • Improved operations when batteries or solar cells are used. Smaller energy sources are also the lighter ones. Where? • Satellite sensors, communication systems and mission control electronics, power control • Launchers flight control and communication systems • Avionic and space mechanical constraint sensors & analysers
Medical application requirements From last 5-7 years huge development activities for medical application, we recognize key factors highlighted by the main players, especially for nomad or implantable applications such as pacemaker, defibrillator, cardiac rhythm management, hearing aid (Cochlear implant, external behind-the-ear, in-the-ear, invisible canal,…), blood pressure control, glaucoma control, electronic lens, motion control, and more. -
To increase the life time of the module (More important requirement for implantable modules compared to external nomad modules). As an example, to increase from 8-10 years to 15-20 years implantable defibrillator module life time
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To increase the range and the quality of the functionalities within the same volume for the module: more computing, more memory footprint, more RF communication (WiFi, Bluetooth, etc…), more sensors for diagnostic, etc…As an example, to put autofocus capability for presbyopia dynamic recovering within bionic contact lens
-
To improve the comfort of the patient (End user). As an example, to replace behind-the-ear by in-the-ear or implantable hearing aid modules in order to decrease the equipment weight decreasing and improve the discretion
Implications for electronic modules As the main differentiators in most of the medical applications, the key electronic components as well as the general electronic architecture are directly managed by the application owner. Others components including passives, discretes, substrate and general packaging solution is also a big part of the application roadmap in order to address the following main application requirements: – To decrease the power consumptions during stand-by modes (Leakage currents) and operating mode (Global power consumption) • Reduce the component power consumption Active components this is addressed by the Medical Module Makers with their external suppliers and their internal chip development within the IC roadmap Passives components this addressed by the Medical Module makers with their external suppliers with more limitation. Passive Integration is a more interesting solution (Developed later on) • Reduce the power consumption linked to the substrate (Tracks width, length) Standard PCB roadmap (Limitation) Standard ceramic roadmap (Limitation) Silicon Interposer is an improved alternative solution (Wafer fab design rules) • Reduce the power consumption linked to external component interconnections Passive Integration on silicon (Reduce line width and length between passive) Silicon interposer as a platform to receive external components (3D packaging)
Implications for electronic modules As the main differentiators in most for the applications described, the key electronic components as well as the general electronic architecture are directly managed by the application owner. Others components including passives, discrete, substrate and general packaging solution is also a big part of the module manufacturers roadmap in order to address the following main application requirements: – Vertical integration in z axis in order to remain with the smallest footprint as possible for the module of the module (Advanced 3D packaging). This roadmap is facing some important and existing challenges or limitations • Most of the components need to be accessible at the die level. Some time, it is not possible to get sales contract. When is accessible, the wafer requires to be supplied in order to generate the die thickness and pads (Bumps) we want Wafer back-end technology access: wafer bumping, thinning and sawing • Most of the external components have an “unchanged” footprint and technology (Components on the shelf for passives, switches, Receivers, etc…) no “easy way” for a vertical integration solution with a standard stack technology 3D stacking solution with dimensional component mismatch? Interconnection strategy linked to various pad termination (Pads and the nature of the end metal, bumps and the nature of the materials)? Process development and industrial strategy linked to mixed technologies: SMD soldering, chip gluing and wire-bonding, flip-chipping, glob-top, underfill, etc… • Material mismatch between most of the external components (Silicon) and laminated, organic or ceramic substrates reliability limitation
3D Advanced Integration trends Application requirements examples: implications for electronics modules Which solutions? IPDiA proposal general overview Passive Integrated Platform : 2D & 3D silicon usage - Deep trench capacitor : how to integrate more - Inductance : enhanced Q-factor highway PICS Silicon-Interposer. Generals 2D Interposer Platform : external components & interconnect - External Components : Chip-to-Wafer usage - 2D Connective Substrate : technical challenges & benefits - Module on Board / Flip Chip Module usages 3D Interposer Platform : how to create 3D interconnect - Via technology / Two-sides routing : - Flip Chip Module usage Conclusions
Which solutions? IPDiA proposals Thanks to the 3 roadmap focuses to be worked out with external electronic suppliers, IPDiA technology and products is a-well adapted solution: – Replacing discrete Passive by Integrated passive component • • • •
Leakage current reduction during stand-by modes Better form factor for capacitors and inductors Components integration capabilities thanks to RF domain Reliability enhancement
– Using silicon substrate instead of PCB/Ceramic substrate • • •
Smallest track length between passives, and between components Higher routing density (Factor 10 reduction) Smallest footprint capability
– 2D and 3D Interposer platform • • •
More compatible for IC integration on top of (CoB or flip/chip) Better thermo-mechanical compatibility Optimized vertical integration and size at optimum footprint
IPDIA overview Company located in Caen, Normandy, France More than 50 years of success in semiconductors including 8 years in 3D silicon passive devices Dedicated campus covering 7 hectares, including • IPDiA’s headquarters • Sales and Marketing organization • Strong R&D Team • 6” wafer fab with integrated passives capacity of 150k wafers/year
, a new company based on a unique technology IPDIA’s “PICS” passive integration (IPD) technology is a highly efficient way to integrate 10’s to 100’s of passive components such as resistors, capacitors, inductors , PIN Diodes and Zener Diodes in a single Silicon die.
Product range •
3D Silicon Submounts / Interposers – 2D and 3D interposer products for hih tech industrial and Medical – Submount for HB LED Packaging + ESD Protection – TVS (transient voltage suppressor) for HB LED
•
3D Silicon RF – A range a standard products such as filter, balun, coupler… – Customized component network (Application Specific Integrated Passives) for RF applications.
•
3D Silicon Capacitors – A range a standard products • High stability for “demanding application” • Low Profile for ”height constraint application “ • Wire bonding for near decoupling in IC packaging – Customized component network ASIP (Application Specific Integrated Passives) for advanced decoupling applications.
3D Advanced Integration trends Application requirements examples: implications for electronics modules Which solutions? IPDiA proposal general overview Passive Integrated Platform : 2D & 3D silicon usage - Deep trench capacitor : how to integrate more - Inductance : enhanced Q-factor highway PICS Silicon-Interposer. Generals 2D Interposer Platform : external components & interconnect - External Components : Chip-to-Wafer usage - 2D Connective Substrate : technical challenges & benefits - Module on Board / Flip Chip Module usages 3D Interposer Platform : how to create 3D interconnect - Via technology / Two-sides routing : - Flip Chip Module usage Conclusions
Passive Integration technology platform •
High or Low Ohmic Silicon substrate
•
High Quality Factor Inductors and superior selfresonance frequency Q>80 @ 10GHz
•
Polysilicon Resistors up to 100kOhms with excellent matching capabilities (10V and ESD Capability 15KV Air discharge (IEC 6100-4-2, level4)
•
PIN diodes for RF switch applications Isolation > -21dB @0.5GHz
C=
ε 0ε S ⋅ S e
PICS High Density Capacitors Trench capacitor technology
C=
ε 0ε S ⋅ S e
PICS1
PICS2
PICS3
Density (nF/mm²)
20
80
250
Depth
17µm
30µm
> 45µm
Capacitance technology roadmap PICS4 « HV »
400 nF/mm², 30 BV PICS5
1000 nF/mm², 12 BV PICS3 « HV »
250 nF/mm², 30 BV PICS4 400 nF/mm², 12 BV
Production
PICS3 R&D
250 nF/mm², 12 BV 2010
2011
2012
2013
PICS Inductances : Q factors Q-factor : RFCMOS, PICS1, Qexceed & Qexceed+ Qexceed+8 Qexceed+4
Qexceed Copper
PCS1 Aluminum RFCMOS45n Aluminum
Comparison based on a 4 nH coil
PICS Inductances: Q factors
Maximum Quality factor Inductance (nH)
Qexceed
Qexceed+8
Qmax
0.8
80@18GHz
100@18GHz
>
2,4
[email protected]
[email protected]
>
4,2
[email protected]
[email protected]
>
6
33@2GHz
55@2GHz
>
3D Advanced Integration trends Application requirements examples: implications for electronics modules Which solutions? IPDiA proposal general overview Passive Integrated Platform : 2D & 3D silicon usage - Deep trench capacitor : how to integrate more - Inductance : enhanced Q-factor highway PICS Silicon-Interposer. Generals 2D Interposer Platform : external components & interconnect - External Components : Chip-to-Wafer usage - 2D Connective Substrate : technical challenges & benefits - Module on Board / Flip Chip Module usages 3D Interposer Platform : how to create 3D interconnect - Via technology / Two-sides routing : - Flip Chip Module usage Conclusions
PICS Silicon-Interposer, generals •
Integration of passive component (Wafer processing) – To build /adapt a full system module (adding Passives and Diodes) – To miniaturize the system thanks to PICS form factor & performances
•
A platform to receive external components (Chip-to-Wafer processing) – External IC’s in picked & placed or flipped technologies – SMD’s or discrete packages in surface mount technology
•
To interconnect integrated passives & external components (2D-interposer) – Interconnection factor prepared from packages to advanced IC’s – Interconnection dimensions thanks to wafer processing – Optimized performances thanks to small interconnection dimension
•
To interconnect top and bottom sides (3D-interposer) – Conductive vias (Wafer processing) – Double-side patterning process (Various metal finishing options)
Advantages of Si-Interposer for Advanced Packaging solutions for Medical modules Substrate
Printed Circuit Board (PCB)
Thick/thin flex
Ceramic
Silicon Interposer
Line width / Spacing
90µm down to 65µm for advanced PCB technologies
75µm down to 50µm for advanced thin flex technologies
75 µm to 50µm for advanced LTCC technologies
5µm
Accuracy around 25µm
Accuracy around 15µm
Accuracy around 15µm or less for LTCC
Below 1µm
Metal layers for signal and routing management
One metal layer inbetween 2 thick laminated layer
Two layers for advanced flex technology
One layer
No limitation (2 to 3 layer)
Via diameter
200µm or below for advanced PCB
150µm for the best in class
120µm for advanced LTCC
75µm or below
Comparison on main dimensions aspects
Advantages of Si-Interposer for Advanced Packaging solutions for Medical modules Substrate
CTE1
Printed Circuit Board (PCB) ~ 20 ppm/°K
Thick flex
~ 20 ppm/°K
Ceramic
~ 10 ppm/°K
Silicon Interposer ~ 2 ppm/°C
Big CTE mismatch with DSP and memories die set
Big CTE mismatch with DSP and memories die set
Slight CTE mismatch with DSP and memories die set
No CTE mismatch with DSP and memories die set
Temperature
Limited to 250°C with warpage
Lower than 200°C with polymer degradation
Higher than 400°C
Process compatibility
Very good with SMD
Intermediate with SMD
Good with SMD
Good with SMD
Critical with silicon die set
Intermediate with silicon die set
Good with silicon die set
Perfectly adjusted for silicon die set
Higher than 400°C
Comparison on main thermal, thermo-mechanical and material aspects
General 2D-Interposer Platform
Die 1
Die 2
Interposer
Interposers only
Die 1
Interposers with IPD
Die 2
Interposer + passive devices PICS IPD
Page 8
General 3D-Interposer Platform
Die 1
Die 2
Interposers only
Interposer
Die 1 Die 1
PICS IPD Die 1
Interposers with IPD
Interposer + passive devices
Page 9
3D Advanced Integration trends Application requirements examples: implications for electronics modules Which solutions? IPDiA proposal general overview Passive Integrated Platform : 2D & 3D silicon usage - Deep trench capacitor : how to integrate more - Inductance : enhanced Q-factor highway PICS Silicon-Interposer. Generals 2D Interposer Platform : external components & interconnect - External Components : Chip-to-Wafer usage - 2D Connective Substrate : technical challenges & benefits - Module on Board / Flip Chip Module usages 3D Interposer Platform : how to create 3D interconnect - Via technology / Two-sides routing : - Flip Chip Module usage Conclusions
2D-PICS Interposer Platform •
Active components to be mounted onto the PICS interposer – Silicon die (Digital IC’s, Analog IC’s, low power discrete) – Small packages (Passive SMD, Oscillators, Diodes, Transistors, etc…) Die 1
Die 2
Passive Integrated Die (PICS)
•
Interconnection processes : Wafer level package C2W – Vertical die : die pick & place, wire-bond, dam&fill – Planar die : flip-chip and underfill – packages pick & place : solder print, pick&place, reflow
•
Silicon die to be reported : main characteristics – Die size : 250µm x 250µm up to 15mmx15mm – Die thickness : 80µm min – Pad size / pitch min : 40µm / 60µm – Aluminum based end-metal
2D-PICS Interposer Platform •
Stacked die design : Necessary for vertical die technologies • Specific die-pad design onto interposer (Adhesion / reliability) • Thermal dissipation requirement as an option o Conductive glue : Raw Silicon or metalized back-side o Solder material : Back-side metalized die • Conductive/non conductive glue characteristics • Low stress, lower CTE as possible • Low bleeding effect (Jetting technology is preferred) • Thickness control for reliability (Thermal cycling) • Gold ball bonding (20µm diameter min, ball size 45µm) • Reverse ball stitch on ball (rbsob) for low profile modules • Aluminum based metal on die pad and interposer patterns • Protection required with glob-top or dam & fill (Better definition)
2D-PICS Interposer Platform •
Flip-Chip design : Space saving • Bumping and thinning processes o Thinning down to 80µm thickness o 30µm bump diameter (Min), 50µm bump pitch o [5µm;80µm] bump height (Gold, SAC Solder, Gold-Tin, CuSn) Stencil printing (Solder bumps) Pitch > 150µm Gold stud bumping Opening pad > 50µm Galvanic growing (Solder / Gold) Pitch min 40µm • Flip-chip processes o Flux dipping + reflow + flux cleaning (Solder bumps) o Thermo-compression (Gold-Gold Interco, ACF, NCF) • Underfilling process o Adapted material (Low stress, lower CTE as possible) o Controlled volume and bleeding effect (Jetting technology)
2D-PICS Interposer Platform Constraints to anticipate: • Mixed technologies (Chip-on wafer / Flip-chip on wafer) – Interposer end metal suitable for o Die pad (vertical technologies) : ENiG (Low cost) o Gold ball bonding metallization : Aluminum o Solder bump flip-chip : ENiG (Low cost) o Gold bump, gold stud bump : Aluminum / Gold Low cost : ENiG maskable process for both wire bond (Al) and solder flip-chip (NiAu) Medium cost : TiW/Au full metallization for wire bond and thermocompression • Mixed glue/solder pick & place and flip-chip processing – Operational flow to manage o Solder print on wafer o Package pick & place, then vertical die pick & place o Reflow soldering and flux cleaning o Flip-chip : thermo-compression / Flux dipping-reflow o Wire bonding, then dam & fill (vertical die) Thermal process influences on material and components
2D-PICS Interposer Examples Market Application: AC/DC converter in CSP package Frequency range: 100 MHz Components: Resistors, capacitors, Inductor, Interconnects Cin
PICS die
L Active die flip-chipped on the IPD
Cout
CMOS die
Module architecture
Market Application : Cellular in HVQFN package IPD RF module (with 73 SMD embedded) for W-CDMA & GSM RF transceiver 850-950MHz & 1.7-1.9GHz RF Silicon carrier flip chipped on lead frame (SIP) Active die flip-chipped on the IPD
5 mm x 5 mm
Components: RF capacitors, RF inductors, RF baluns, loop filters, decoupling capacitors and RF ESD protections.
2D-PICS Interposer Examples Digital TV (Dual TV Tuner) 2 tuners flipped over PICS Interposer SnAg galvanic bumps on actives die Capacitors, Resistor on PICS, interconnection External Aluminum pads 3 Active dies flip-chipped on the IPD 7.00 mm x 7.00 mm
Module picked and place over laminated substrate (LGA package)
Medical (In-vivo T° monitoring)
IPD Sensor
3 die flipped over PICS Interposer
TX
Gold stud bumps on actives die Capacitors, Resistor and PIN Diode on PICS, interconnection
µCTRL
External solder balls (WLCSP) 3 Active dies flip-chipped on the IPD
7.00 mm x 7.00 mm
2nd interconnect bumps on IPD
Double flip-chip on foil
Module flipped over flex substrate
2D-PICS Interposer Examples
Defibrillator (RF Module demonstrator) Shown during MiNaPAD Grenoble 2011 by SORIN PRIIM Project (French government subsidies) SORIN, CEA-LETI, IPDiA Partnership PICS Technology in 2D-interposer Platform
2D architecture exemple for hearing aids EEPROM
DSP
All compoents are reported to the upper interposer side
Interposer Passive Integartion technology for R, L and C
Pad distrib ution suitbale for wire bonding technology to interconnect the module to the external applicative substrate
EEPROM
DSP
EEPROM
Interposer size depend on the number of external SMD, the Passive Integration scenario (Passive component values) and the external die set dimension
3D Advanced Integration trends Application requirements examples: implications for electronics modules Which solutions? IPDiA proposal general overview Passive Integrated Platform : 2D & 3D silicon usage - Deep trench capacitor : how to integrate more - Inductance : enhanced Q-factor highway PICS Silicon-Interposer. Generals 2D Interposer Platform : external components & interconnect - External Components : Chip-to-Wafer usage - 2D Connective Substrate : technical challenges & benefits - Module on Board / Flip Chip Module usages 3D Interposer Platform : how to create 3D interconnect - Via technology / Two-sides routing : - Flip Chip Module usage Conclusions
3D-PICS Interposer with Via +/-PICS
- Reduced RC delays
- Low power consumption
- Low resistivity
- Short connection
- Smallest area
- High density
- High routing density
- Good heat dissipation
3D-PICS PICS Interposer : Via structure Finition 1 - Ni-Au Passivation 1 – Organic passivation layer metal 2 - Copper metal 1 - Aluminium
Dielectric 2 – Nitride
dielectric 1 - Oxide
Silicon dielectric in vias - Oxide dielectric 0 - Oxide Via – Copper filling metal 0 - Copper Passivation 0 – Organic passivation Layer
Finition 0 - Ni-Au
Via structure on Integrated Passive (PICS2 Cu generation)
3D-PICS Interposer : Vias
3D interposer main characteristics Integrated Passive (PICS2 Cu generation)
3D-PICS Interposer : Vias Electrical performances
Series resistors of vias versus frequency
Results on through silicon vias with a 75µm diameter and a 300µm depth Parasitic Inductors of vias versus frequency
3D-PICS Interposer : Examples
Interposer with TSV and Cu routing on the wafer backside
Interposer for lighting platform
3D-PICS Interposer : Examples
Top side
Cross section
Bottom side
- PICS2 Cu (Passive Integration generation) - Top side with one µ-controller flipped + underfill (Jetting) - Bottom side with one RF-die flipped + underfill (Jetting) - WL-CSP Module with end 300µm Leadfree solder balls
3D architecture exemple for hearing aids EEPROM
Interposer
All SMD components and EEPROM are reported to the upper interposer side DSP is reported to the bottom side Vias technologie to redistribute the solder ball at the interposer bottom side
DSP
Solder ball diameter & pitches could be 100µm / 300µm depending on DSP die thickness EEPROM
DSP EEPROM
Interposer size depend on the number of external SMD, the Passive Integration scenario (Passive component values) and the external die set dimension
3D architecture exemple for higher integration requirements (PoP) +
Interposer DSP
Interposer EEPROM
+ Interposer DSP
+ ….. +
Interposer size depend on the number of external SMD, the Passive Integration scenario (Passive component values) and the external die set dimension
Interposer DSP EEPROM
1,20mm EEPROM
EEPROM
DSP
DSP
0,80mm
3D Advanced Integration trends Application requirements examples: implications for electronics modules Which solutions? IPDiA proposal general overview Passive Integrated Platform : 2D & 3D silicon usage - Deep trench capacitor : how to integrate more - Inductance : enhanced Q-factor highway PICS Silicon-Interposer. Generals 2D Interposer Platform : external components & interconnect - External Components : Chip-to-Wafer usage - 2D Connective Substrate : technical challenges & benefits - Module on Board / Flip Chip Module usages 3D Interposer Platform : how to create 3D interconnect - Via technology / Two-sides routing : - Flip Chip Module usage Conclusions
Conclusions Passive integration technologies coupled with 2D/3D-interposers bring differentiations and miniaturization 3D Silicon and IPD platforms are now fully visible in Medical applications Main driver is the packaging integration density, the number of passive components and external IC integration Lower vias diameter and pitches, as well as thinner interposer platforms will is achievable
Thanks for your attention
