10-10/11 :: October/November 2010

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Figure 1 shows the pressure indicating film positioned on the top surface of the PCB. The top surface location measures the cavity pressure distribution. Separately, the pressure indicating film may be placed on the top or bottom of the substrate to measure mold wall contact pressure. Three steps are involved in transfer molding with pressure indicating film, as described below.

Step 1: Mount the multilayer stack on the PCB and insert it into the mold cavity; Step 2: Close the mold cavity and preheat the PCB and the EMC pellet; Step 3: Depress the plunger to press the epoxy molding compound into the cavity.