Cast cast ball grid with flexible circuit and manufacturing process

摘要

A grid array assembly method uses a flex circuitry substrate and includes providing a series of conforming flex circuitry substrates, the flex circuitry substrates include bonding pads and metallization on a first surface and, holes or vias in the substrate which define a contact pad array on the opposite surface. The substrates are tested and acceptable, then mounted on a carrier strip with longitudinally aligned apertures. The carrier strip is typically a metal such as copper. The strip with mounted substrates is then passed to a station where an IC die is mounted on the substrate first surface, wire bonds are placed from the die to the bonding pads, and the assembly is encapsulated by auto-molding to form a package body. Subsequently, interconnecting bumps are placed on the contact pads and the assembly is removed from the strip.