Conductive Materials in Electronics Packaging. Radesh Jewram The Bergquist Company Chanhassen, MN

Transcription

1 Emerging Trends for Thermally Conductive Materials in Electronics Packaging Radesh Jewram The Bergquist Company Chanhassen, MN

2 Outline Introduction Low outgassing and Silicone sensitive applications Liquid Dispensable TIM s Summary

3 Introduction Several electronics market segments are requiring TIM material with low volatility and/or silicone free There is a shift from Pad based to liquid dispensable TIM s because of cost and performance and manufacturing reasons.

4 Low Outgassing and Silicone Sensitive Applications

5 Silicone Free TIM Environments Open electrical contacts Opticaland and Hard Disc drive assemblies Clean room assemblies silicone is not allowed in clean rooms Dewetting of paints Adhesion of solder and conformal coat

6 Low Outgassing Application Automotive windshield fogging Automotive lighting application for fogging of lenses Disc drives for smearing on rotating media LED lighting gfor fogging g of lenses

7 Silicone vs. Silicone Free Outgassing Low silicone outgassing does not mean low volatility Silicone free material also has low molecular weight unreacted polymeric materials that can migrate out of the TIM

8 Manufacturing Approaches for Low Outgassing Products Post Baking Finished Product: Not feasible for high volume production, long times at high temperatures required Selection of raw materials: raw materials with low outgassing specifications used.

9 Liquid Dispensable TIM s

10 Future Direction for TIM Materials Development There is a market shift towards liquid dispensable thermally conductive materials Improved thermal performance Reduced assembly stress in application Lower cost Lower part count High volume

11 Improved Thermal Performance Typical viscosity of thermally conductive liquid ~10 Pa.s Liquid Typical viscosity of thermally conductive pad Pad ~ Pa.s Better wet out with liquids Lower interfacial/contact resistance Improved thermal performance

12 Lower Assembly Stress Typical modulus of thermallyconductive liquid ~10 2 Pa Typical modulus of thermally conductive pad ~ Pa Pressure Less force required to wet out material il Lower stress on components during assembly

13 Conformability bl Liquid materials conform to intricate surfaces, including multi level surfaces Can fill highly variable gaps with large tolerances High conformability Design flexibility

14 Efficient Use of Material Cost Benefits Place precise amount of material directly in key areas Minimal waste Easy to automate Single dispensing line can be used for multiple programs/platforms

15 Logistics Simplification lf Same material can be used for multiple platforms/programs Single qualification process One part number One PPAP

16 Liquid Dispensing Techniques High Volume Highvolume automated pattern dispensing Very precise, repeatable material placement Shortest cycle times Cartridge or pail feed Minimal waste Minimal process variation

17 Total Cost Benefits / Transitioning to Liquids: Maximize Product Design Efficiency Minimize Part Number Counts / Lower Systems Costs: Design Leverage Piece Part Qualifications Improved Inventory Management Labor, Cost of Inventory, Inspection. Minimize Variable Costs: Packaging Costs, Shipping & Handling Costs, Eliminate Converting Costs.

18 Additional Benefits / Transitioning to Liquids: Production Control / Maximize Flexibility: Controlled Dispense Multiple Platform Enables Automated Dispensing: Semi Automated to Automated Highly Repeatable Application Higher Throughput Rates.

19 Challenges With Liquid Dispensable TIM s High performance liquid dispensable TIMS ate typically highly filled systems High viscosity i dispensingi Shelf life loss of reactivity Separation and settling Abrasion

20 Summary Low outgassing materialsdoes not only mean low silicone outgassing Silicone sensitive applications require low/no silicone migration Outgassing can occur in both silicone and organic TIM s Shift to Liquid dispensing materials allows for: Significant cost savings opportunities Significant performance advantages Potential for automation and HVM Many more manufacturing options becoming available Material manufacturer, CMs and OEMs need to work in close partnership for success

21 Thank You Questions?