Elastic bladder method of fabricating an integrated circuit package having bonding pads in a stepped cavity.

摘要

An integrated circuit package is fabricated by assembling a stack which is comprised of a plurality of thin flat epoxy-glass layers (lla-llc), adhesive layers (l2a-l2d) between the epoxy-glass layers, and a staircase-shaped cavity. This cavity extends from an outer epoxy-glass layer to an internal epoxy-glass layer, goes parallel along a portion of the flat surface of the internal epoxy-glass layer, and then penetrates through it. Conductors lie on the internal epoxy-glass layer including bonding pads on the flat surface portion. After the stack is assembled, the outer epoxy-glass layer and the cavity are covered with an elastic bladder (40). Subsequently, the stack is laminated by forcing a fluid (42) into the bladder at a temperature and pressure which causes the bladder's membrane to stretch and push against all the surfaces of the cavity. This dams the adhesive from flowing onto the bonding pads.