1. RF Packaging Jason Shin Fall 2007: ECEN 5004 Fundamentals of Microsystems Packaging Graduate Presentation

2. RF Packaging Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion

3. Introduction: Past RF Technology Technology focused on:  Analog communication  Short Distance Radar  < 100 [GHz]

4. Introduction: Present RF Technology RF technology today is integrated in most electronics spanning all engineering fields. Quazioptical frequencies used

5. RF Packaging Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion

6. Devices – Passives Problems with normal passives  Inductors  Capacitors  Solutions (packaging)‏ Passive uses  Matching  Filters  DC/RF choke/block  High Q Cavities (Low ESR)

7. Devices – Actives Transistors  High Power  Low Power  Various Packages Oscillators Bolometer/Diodes  Mixing  Power Measurement  Rectify RF power

8. Devices – Active Fabrication RF Transistors vs. typical CMOS transistors  Gain Product Bandwidth  Lower Capacitances Exotic Processes very small tolerances Different Materials/Structures  LDMOS

9. Devices – Active Packaging Parasitic Impedances limit performance Technologies Used  Plastic Package  Wire Bond  Flip-chip

10. Devices – Packaging Interface RF Transistor Example

11. Devices – Packaging Interface

15. RF Packaging Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion

16. Substrates - Introduction What are we looking for?  Interconnects Connecting DC Biasing Interconnects between Devices (RF and DC)‏  Microstrip Antennas  Matching 50 Ohm Impedance Transforms  Materials Flex, Brittle, Flame Retardant, etc.

17. Substrates – Materials Polytetrafluoroethylene (PTFE)‏  DuPont brand name Teflon Ceramic Woven Glass Thermoset Plastic

18. Substrates – Materials Criteria commonly used in selecting a material:  Military: Materials meet or are tested in accordance to military specifications.  Commercial: materials are designed for cost sensitive applications (military grade materials can be used in commercial applications but pricing is higher).  Multilayer: mechanical properties are such that allow for reliable multilayer (MLB, other than basic stripline) constructions  Hybrid: mechanical properties are such that allow for reliable FR4 hybrid MLB constructions  Broad Band: dielectric constant allows for very high frequency and/or high broadband use  Temp Cycling: electrical and mechanical properties allow for stable use in temperature varying environments  Surface Mount: mechanical properties allow for surface mount technology  Miniaturize dielectric constant reduces sizes of circuit elements

19. Substrates Conductors can be:  Rolled  Electro-deposited Various characteristics can be designed for Tradeoffs mostly apparent in cost Many different RF software packages used to model on substrates

20. Substrates – Flex Substrates

21. RF Packaging Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion

22. Fabrication - Introduction All techniques described in semester apply Active Antenna Laboratory  Milling  Chemical Etching

23. Fabrication - Milling Two Machines Smallest tool 5 mil

24. Fabrication – Chemical Etching Process  Design on computer  Print on Blue Paper  Iron/Press on Substrate  Peal  Pour Acid

25. RF Packaging Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion

26. μCoax Hybrid Coupler 4x4 Butler Matrix Patch Antenna

27. μCoax

29. RF Packaging Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion

30. RF usable frequencies continue to increase Passive and active devices must control unwanted parasitic effects in order to scale  Change in size/package  Change in process Substrates and fabrication techniques continue to become less expensive and more robust Interesting progress can be made with these advancements