VHDI Vacuum Lamination JC Yun 6106 Lamination Procedure

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 2 x 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 N 2 gas – 5”sq cylinder. • Safety features: --- relief valve (260 psi) --- flow restrictor (100 cc/min) --- vacuum pump will remove accidental pressure buildup in the oven and for faster pressure build up the

VHDI Preproduction • 5 VHDI were laminated and 1 VHDI is being laminated. - 4 VHDI laminated with identical process ( two 2 x 4, two 2 x 5) - 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 (2 x 3) laminated with the simplified method - 1 VHDI (2 x 3) 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.