VHDI Vacuum Lamination JC Yun 6/1/06

Lamination Procedure For details refer to Doc DB #1009 Plasma Cleaning for VHDI dropped ---simple tests show the weak link is wafer to glue Plasma Cleaning is also dropped for Si wafer --- John’s tests show no peel strength improvement for Si wafer to glue bonding

Overpressure heating process Since the vacuum pressure alone could not remove some deformations of 2x VHDI’s – we built a press to remove deformation as much as we could. 3 atmospheric over pressure at 70 degree Celsius at peak. ( 3 hour preheat, 4 hour ramping, overnight cool down under pressure – no vacuum) The press uses 230 psi N2 gas – 5”sq cylinder. Safety features: --- relief valve (260psi) --- flow restrictor (100cc/min) --- vacuum pump will remove accidental pressure buildup in the oven and for faster pressure build up the door latch is removed.

VHDI Preproduction 5 VHDI were laminated and 1 VHDI is being laminated. - 4 VHDI laminated with identical process ( two 2x4, two 2x5) - Minor changes in technique clam shell vacuum fixture was replaced by the existing lamination station – this eliminates transfer operations between the lamination station to clam shell vacuum fixture 8 times a day - 1 VHDI (2x3) laminated with the simplified method - 1 VHDI (2x3) is being laminated in oven

Discussions The process is tuned to be 1 person operation for 2 laminations a day. The preproduction VHDI laminations show improvement with more pressure (before dicing) -- creases became smaller Heat sink with water layer between a glass plate and a VHDI when soldering capacitors --- seems helping We need to dice, visual inspection and electrical test ASAP.