Modelling Embedded Die Systems

Transcription

1 Modelling Embedded Die Systems Stoyan Stoyanov and Chris Bailey Computational Mechanics and Reliability Group (CMRG) University of Greenwich, London, UK 22 September 2016 IMAPS/NMI Conference on EDT

2 Content About CMRG Embedded die concepts Design for Reliability Examples: Fan-out WLP 3D-Printing and Embedded Die Conclusions

3 Computational Mechanics and Reliability Group (CMRG) Established in 2004 Staff: 2 Profs, 2 Readers, 5 Post Doc s, 7 PhD s Research Mission To develop and apply CAE technologies to predict the physical behaviour, performance, reliability, and maintainability of complex engineering components/systems.

4 Embedded Die Technology (EDT) Embedded Die is defined as a passive component or an IC that is placed or formed on an inner layer of an organic circuit board, module, or chip package, such that it is buried inside the completed structure, rather than on the top or bottom, Amcor EDT is in the heart of IoT Main embedded technologies Embedded die in PCB/substrate (based on stacking/integration approach) Fan-out Wafer Level Package (based on electrical redistribution) Source: AT&S

5 Packaging Developments for Embedded Die Miniaturisation, electrical and cost advantages Range of packaging options are developed Thermo-mechanical reliability is main challenge Embedded flip-chip Vialess solder bump QFN-like embedded package Stackable BGA package Multi chip package L. Boettcher et al, Embedding of Chips for System in Package realization Technology and Applications

6 Wafer Level Approach to Embedded Fan-Out Dice

7 Content About CMRG Embedded die concepts Design for Reliability Examples: Fan-out WLP 3D-Printing and Embedded Die Conclusions

8 Simulation driven DfX Modify Design Formulate Design Intention Computer Aided Drafting and Design Build Prototypes Testing of Prototypes Manufacturin g In-Field Operation and Maintenance Traditional DESIGN BUILD TEST Product Development Cycle Modify Design Formulate Design Intention DESIGN (CAD) MODEL and SIMULATE Fabrication Packaging Assembly Test Reliability/Performance Physical Validation Manufacturing In-Field Operation and Maintenance Numerical Design Optimisation Data Flow Simulation Driven Product Development Cycle

9 Modelling FOWLP Thermo-mechanical reliability is key challenge Due to CTE differential miss-match DfR Modelling Study: Design rules for improved reliability Wp t N i 1 ( creep Vi N dv i 1 Vi )dv

10 Impact of Fan-out Ratio

11 Impact of Mould Compound Thickness

12 Impact of Mould Compound Material Molding Compound Material CTE (ppm/ C) Young Modulus (GPa) Poisson s Ratio Mold Compound 1 Mold Compound 2 Mold Compound 3 1 =58.0 below Tg 2 =137.0 above Tg Tg=45 C 1 =10.0 below Tg 2 =45.0 above Tg Tg=130 C 1 =7.0 below Tg 2 =30.0 above Tg Tg=165 C

13 Y (response) Embedded Die Packages: How to achieve optimal and robust design? Deterministic optimum is not good enough! Need the tools to find out OPTIMUM design under UNCERTAINTY! Advanced packaging solution and miniaturisation make design ROBUSTNESS critical requirement ΔY 1 ΔY 2 X 1 X 2 X (input)

14 Design Optimisation for Embedded Die: A Demonstration Study on FOWLP Optimise aspects of embedded die design under constraints and design requirements in automated manner Use of numerical optimisation algorithms Above integrated with high fidelity FEA and Surrogate Models Most Damaged Corner Solder Joint Passive Die (PICS) Underfill Underfill for active die Active Die [J/m 3 ] Mid-Centre Plane PCB Board Level Solder Joints Diagonal Plane

15 Case Study 1: Optimal Design Design parameters for alternation (given range) Design task Results

16 Case Study 2: Optimal Probabilistic Design Design task Results

17 Design task Results Case Study 3: Robust Design

18 Content About CMRG Embedded die concepts Design for Reliability Examples: Fan-out WLP 3D-Printing and Embedded Die Conclusions

19 Why 3D-Printing Hybrid Approach Enables embedding passive and active components using additive manufacturing Advantages Design flexibility Low cost for customization Shorter lead times Less waste Can be integrated with other digitally driven processes (enables hybrid approach, pick and place of components and print circuitry) Lower barriers to entry for new businesses Decentralized manufacturing, production closer to customer Ink inlet Printhead Piezoelectric Actuator Ink droplets Printed Electronics Product Ink Reservoir + Voltage waveform -

20 NextFactory EU Funded Project ( ) Hybrid System in One machine 3D printing (Packaging) Functional/Smart materials in 3D printing Functional components (Sensors systems etc.) 3D Assembly Inspection & testing

21 Design Tools/Modelling Challenges Opportunities Physical Design Tools MCAD Tools Available 3D design rule checks Beyond 2D/2.5D Layout Rules/Checks Electrical Modelling Signal routing in 3D could be complex Physical Design Electrical Design Need for 3D rule checks (Impedance, Crosstalk, etc) Thermo-Mechanical Modelling New failure models for 3D-printed structures Material properties Electrical properties for 3D-Printed materials Thermal Design 3D- Fabrication Mechanical Design

22 Thickness of printed line (mm) NextFactory Process Models and Process Control Predicting Jetting Performance Actual ("measured") values NARX 25 step ahead predictions made at time step 150 NARX 25 step ahead predictions made at time step 175 Minimising stress due to cure shrinkage Evaluation time step number Process Monitoring Ensuring performance/reliability specs are meet

23 Embedded Components in Printed Substrates Need to understand and minimise stress in printed layers 10 layer structure of insulating material Layer thickness 25 microns 10 layer structure: 50 um conductive layer encapsulated in insulating material Embedded Components insulator insulator Conductive circuitry 0.2 MPa 25 MPa 8 MPa 30 MPa Deformed shape magnified by factor F=5 Deformed shape magnified by factor F=5

24 Need for Fast Predictive Models DoE using FEA Surrogate model for maximum stress in conductive line as damage indicator Stress sensitivity to design parameters

25 Content About CMRG Embedded die concepts Design for Reliability Examples: Fan-out WLP 3D-Printing and Embedded Die Conclusions

26 Conclusions Modelling and simulation play key role in development of EDT Underpin DfR and overall co-design activities Generate new knowledge and insights Optimise processes and embedded die designs 3D Printing processes are well placed to support advanced embedded die developments But will require a level of maturity for this application Thermal management and thermo-mechanical reliability of embedded die will remain the key challenge due to Trend of future miniaturisation Increased embedded die design complexity New processes/materials

27 Acknowledgements Wafer Level Packaging and System in Package (3D printing) Contact: Dr Stoyan Stoyanov Phone: