Next Generation System in a Package Manufacturing

1. Next Generation System in a Package Manufacturing • Lars Böttcher • FraunhoferIZM Berlin • lars.boettcher@izm.fraunhofer.de

2. Outline • Introduction to Chip Embedding Technology • HERMES Project • Technology • Process overview • QFN Package realization • Ultra fine line • Ultra Fine pitch • Applications • Conclusions

3. Interconnect Evolution µVias LDI Embedding HDI PCBs technology challenge / potential Flip Chip progress of organic substrates enabled advance in interconnect technology chip & wire 1970 1990 2010

4. Chip Embedding - Technology Progress Chip Embedding in organic substrates  use of PCB technology & material • Production started • Korea • Japan • First Standard • JPCA • EU Companies • ready Basic R&D Production Demos Production First Patent 2005 2010 2000 1968

5. Chip Embedding - Different Approaches Chip Last / Pad Connection Chip First / Via Connection core assembly embedding • use of pre-tested cores • different interconnect technologies (wires, solder, adhesives) • contact by micro vias • chip assembly in PCB flow • highest possible miniaturization pictures: Shibata, JPCA

6. Chip First Embedding - Process Alternatives Face Up Face Down die placement embedding via formation plating & etch electrical and thermal backside contact better fine pitch capability

7. HERMES High Density Integration by Embedding Chips for Reduced Size Modules and Electronic Systems Please visit: www.hermes-ect.net for more information • Project • EU funded project, FP 7 program, Started: May 2008, Duration: 36 month • Total budget (approx.): 16 M€ • Project Goal • Industrialization of the results of the HIDING DIES project • Improvement of technology towards finer pitch, use of new material developments, process innovation and equipment improvements • Strong focus on future implementing of the technology in a manufacturing environment / assembly chain • Consortium • 11 partner; technology provider, end-user, testing, research institutes • Early Adopters Group with potential end-users

8. HERMES – Technology Development Roadmap • Industrialization Goals • manufacturing panel size 18"x24" • lines/spaces 25 µm, semi-additive technology • die pitch 125 µm peripheral, 250 µm area array • stacking of 2 levels with embedded chips • Demonstrator Applications • Power module for house hold (4 ICs, large power dissipation) • Communication modem (> 10 ICs, high complexity) • Motor control unit (high-end micro controllers) • Secure phone module • Advanced Technology Goals • lines/spaces 15 µm, semi-additive technology • die pitch 60 µm • stacking of 2 levels with embedded chips

9. Outline • Introduction to Chip Embedding Technology • HERMES Project • Technology • Process overview • QFN Package realization • Ultra fine line • Ultra Fine pitch • Applications • Conclusions

10. Process Flow Face-Up Embedding • Panel format 610 x 456 mm² • 50 µm chips with 5 µm Cu or Ni/Pd pad metallization • Die attach (Dataconevo/Siplace CA3) using 20 µm DDAF (dicing die attach film) • Embedding (Lauffer) by RCC lamination (5 µm Cu, 90 µm dielectric) • UV laser drilling (Siemens Microbeam) of microvias • Cu electroplating / via filling • Dry film resist application • Laser Direct Imaging (Orbotech Paragon 9000) of circuitry pattern • Subtractive Cu etching Lamination Via drilling Cu Plating Imaging Etching

11. Process Flow Face-Up Embedding a) Die Bonding to substrate d) Copper metallization b) Vacuum lamination e) Patterning of circuitry c) Laser drilling of micro via

12. Embedded QFN • Embedded die package test vehicles • QFN type  single package • BGA type  stackable package • size 10x10 mm² / thickness approx. 140 µm • 84 I/Os, 400 µm pitch • chip size 5x5 mm / chip pitch 100 µm • Realized on panel size: 350x250 mm² BGA type QFN type

13. Embedded QFN – Process Chip preparation and Die Bond • Wafer preparation • Application of suitable pad metallization (Cu or Ni/Pd) • Thinning to 50 µm and dicing • Die bond material • Application of DDAF prior to dicing • Requirements • handling of very thin chips (50 µm) • very high placement accuracy essentially for following process steps Die bonded chips on copper substrate

14. Chip Substrate Adhesive Embedded QFN – Process Dielectric lamination • Lamination • embedding of chips by vacuum lamination of RCC • use of epoxy-based RCC • optimized lamination profile to ensure void and damage free embedding of Si chips • no chip movement during lamination process Epoxy x-section embedded Si chip

15. Embedded QFN – Process Micro via formation • Laser drilling • pulsed UV laser, enabling ablation of metal and epoxy layers • Development towards smaller via diameter needed: target 30 µm UV Laser drilled via, 30µm diameter

16. Embedded QFN – Process Desmear and Cu plating • Strong increase of via diameter after desmear process by more than 50% • Adaption of process parameters • Defect free copper filling of micro via Improvement in desmear process Desmear + Copper plating

17. Embedded QFN – Process • Fine Line copper structuring • Wiring structure sizes 50µm lines/space (subtractive): • Use of laser direct imaging system with local alignment option • 25µm thick DFR • Acidic spray etching of structures Etched wiring structure Etched wiring structure (detail) Resist mask

18. Embedded QFN • Test vehicle for: • Reliability testing • Easy electrical testing • Processing on large panel format • overall thickness 160 µm • standard QFN footprint • Automated testing using QFN test board: • daisy chain • four point Detail

19. QFN Package reliability • Reliability testing • Passed: preconditioningwith MSL3 (192h, 30°C/60%RH) (JEDS22-113-E) • Passed: TC (-55 ° C/125 ° C, 1000cycles), HTS (150 ° C, 1000h), THS (85 ° C/85%, 1000h) • Delamination at resin/chip and DAF/chip at PCT (168h, 121C, 100%RH, 2 atm) PCT Resin/chip delamination PCT DAF/FR4 delamination

20. QFN Package reliability • Warpage • No symmetrical lamination • Improvement with 100µm FR4 • Embedding resins with high Tg and fibers 100µm FR4 50µm FR4 • Warpage reduction from 200µm to 20µm with increased substrate thickness

21. Ultra fine line development • Exposure by Laser Direct Imaging (LDI) • Maskless processing capable of large substrate sizes • 25µm thick dry film resist (DFR) • Goal: 15 µm L/S pattern on PCB • Reliable development of resist structures Resist removal Cu base etched

22. Ultra fine line development • Ultra fine line copper structuring • Goal: 15 µm line/space • Thin (2 µm) base copper foil • Suitable dry film resist and substrate preparation (resin thickness & adhesion) • Dry film resist removal • Use of thin copper foils to enable reliable differential etch of initial Cu layer x-section 15 µm L/S after Cu plating x-section 15 µm L/S after differential etch

23. Ultra fine pitch development Future Development  Via-less Embedding • Cu lines are formed indirect contact to Cu bumps • no drilled vias • much less constraints in tolerances • expectation 50 µm pitch • under development

24. Outline • Introduction to Chip Embedding Technology • HERMES Project • Technology • Process overview • QFN Package realization • Ultra fine line • Ultra Fine pitch • Applications • Conclusions

25. Where to use Embedding? Complex Systems Packages / System in Packages / Modules one / few components many different components  high risk in yield

26. top RCC 2 top RCC 1 top chip adhesive adhesive bottom chip bottom RCC 1 bottom RCC 2 Applicatio - Dual chip package • Dual Chip package • Two + two build up layer • Package outline 15 x 15 mm² • 120 µm Pad pitch • Min. L/S: 50 µm • Challenges • Die bonding on both substrate sides • High wiring complexity and density • Multiple build up layer cross-section of dual chip SiP

27. Application - Dual chip package • System in Package BGA Module • Two embedded Si chips of 50µm thickness • Five Cu routing layers • stacked micro vias • Overall package thickness: 450µm • JEDEC Level 2A passed • 1000 cycles -55 / + 125 °C passed • 1000 h 85 °C / 85 % r. h. passed cross-section of complete SiP

28. Application - Power Packages • Cooperation with Infineon Technologies • Embedding offers a technology platformenabling a large variety of packages • different package types realized • reliability qualification passed • advantages • low inductances • low resistance • reduced cost SMD package with embedded MOSFET

29. Multi Chip Package • Package containing two power IC and a logic IC • Challenge: Combination of required thick Cu metallization for power chip with fine pitch requirement of logic chip

30. Outline • Introduction to Chip in Polymer - Embedding Technology • HERMES Project • Technology • Process overview • QFN Package realization • Ultra fine line • Ultra Fine pitch • Applications • Conclusions

31. Conclusion • Embedded Chip Technology • Next generation package realization by embedding of bare dies into laminate layers • Industrialization of the technology within the “HERMES” project • Realization of different packages: • Single and multi die packages • reliability comparison to conventional packages • Further developments target: • Ultra fine pitch chips with peripheral pad pitch down to 60 µm • Ultra fine line development towards 15 µm lines/space using semi additive processing • Wide range of laminate materials for embedding • Transfer of technology to new process line, capable of substrate sizes up 610 x 456 mm²

32. Thank you very much for your attention! Contact: Lars.Boettcher@izm.fraunhofer.de