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Jason Shin Fall 2007: ECEN 5004 Fundamentals of Microsystems Packaging Graduate Presentation. RF Packaging. Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion. RF Packaging. Introduction: Past RF Technology. Technology focused on: Analog communication
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Jason Shin Fall 2007: ECEN 5004 Fundamentals of Microsystems Packaging Graduate Presentation RF Packaging
Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion RF Packaging
Introduction:Past RF Technology • Technology focused on: • Analog communication • Short Distance Radar • < 100 [GHz]
Introduction:Present RF Technology • RF technology today is integrated in most electronics spanning all engineering fields. • Quazioptical frequencies used
Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion RF Packaging
Devices – Passives • Problems with normal passives • Inductors • Capacitors • Solutions (packaging) • Passive uses • Matching • Filters • DC/RF choke/block • High Q Cavities (Low ESR)
Devices – Actives • Transistors • High Power • Low Power • Various Packages • Oscillators • Bolometer/Diodes • Mixing • Power Measurement • Rectify RF power
Devices – Active Fabrication • RF Transistors vs. typical CMOS transistors • Gain Product Bandwidth • Lower Capacitances • Exotic Processes very small tolerances • Different Materials/Structures • LDMOS
Devices – Active Packaging • Parasitic Impedances limit performance • Technologies Used • Plastic Package • Wire Bond • Flip-chip
Devices – Packaging Interface • RF Transistor Example
Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion RF Packaging
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.
Substrates – Materials • Polytetrafluoroethylene (PTFE) • DuPont brand name Teflon • Ceramic • Woven Glass • Thermoset Plastic
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
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
Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion RF Packaging
Fabrication - Introduction • All techniques described in semester apply • Active Antenna Laboratory • Milling • Chemical Etching
Fabrication - Milling • Two Machines • Smallest tool 5 mil
Fabrication – Chemical Etching • Process • Design on computer • Print on Blue Paper • Iron/Press on Substrate • Peal • Pour Acid
Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion RF Packaging
μCoax 4x4 Butler Matrix Hybrid Coupler Patch Antenna
Introduction Devices Substrates Fabrication Miscellaneous RF Packaging Conclusion RF Packaging
Conclusion • 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