Embedment of Electronic Modules by Transfer Molding

One of the latest and most interesting techniques in the use of plastics for electronic packaging is the total embedment of an assembled circuit in a closed mold, utilizing a transfer molding press. This technique uses a combination of heat and pressure to liquefy a powdered or granular plastic compound in a transfer pot, and subsequent introduction of the plastic into the mold cavity while maintaining a carefully controlled heat and pressure on the transfer plunger. In comparison with the more recognized techniques of potting or encapsulating with liquid plastic systems, this new technique yields a better appearing product at a lower cost. While the dollar value of the new technique is of tremendous interest to the Manufacturing and Cost Accounting people, the improvement in manufacturing cycle efficiency is more dramatic, actually reducing the span from pre-molding to post molding tests, from several hours to as low as 15 minutes.