Single chip molded magnetic bubble memory package

Abstract

A magnetic bubble domain package in which a magnetic bubble domain chip is bonded to conductors disposed on a thin film interconnect member which is formed to allow a reduction in the volume of the drive coils of the package. The conductors of the interconnect member are bonded to a lead frame which provides signal leads for the magnetic bubble domain chip and the drive coils. The interconnect member with magnetic bubble domain chip and lead frame bonded thereto is encapsulated with a molding compound, the chip being located precisely within the mold in order to insure placement of the chip in the geometric center of the drive coils. The drive coils are prewound and slipped onto the premolded package through slots formed during the molding process to reduce the volume of the coils, and the coils terminated directly onto the signal leads of the lead frame. This chip substructure is supplied with the magnetic field prependicular to the planar surface of the chip by means of a bias field structure formed by permanent magnets secured within an open ended tubular housing which acts as a shield to shunt stray magnetic fields in the external operating environment of the device. A second molding operation encapsulates the chip substructure within the bias field structure to complete the package.