Here is the abstract you requested from the DPC_2009_Wafer technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|A Unique Process for Hermetic Wafer Level Packaging|
|Keywords: WLCSP, Hermetic, Flipchip|
|The HMIC (Heterolithic Microwave Integrated Circuit) process combines low loss expansion matched glass with micromachined silicon to make a new heterolithic substrate. The glass provides an excellent medium for high Q microwave passive elements and transmission lines. The silicon islands can be used to make diodes, transistors, and as desired for packaging, thru wafer vias. The vias are highly conductive because a metal layer is incorporated between the silicon and glass.The glass metal and silicon are fused together at a temperature greater than 700 C. creating hermetic vertical feedthroughs for RF, DC, and thermal vias. To create a hermetic package start with a HMIC substrate wafer that has been processed to create interconnects and passive components, then flip chip die attach silicon, GaAs, or InP die, and finally solder seal a silicon lid wafer etched to create pockets to accommodate the flip chip die. The back surface of the HMIC substrate can be processed to include redistribution of the thru vias to solder bumps. Final test can be performed in wafer form or as packages after singulation. This paper will describe the progress to date for substrate formation, flip chip die attach with AuSn solder, lid alignment and attach, and backside lithography and metallization.|
|Joel Goodrich, Fellow
M/A-COM Technology Solutions