Shields for magnetic memory chip packages

摘要

Chip packages are described with soft-magnetic shields that are included inside or attached externally to the package containing a MRAM chip. In one group of embodiments a single shield with vias for bonding wires is affixed to the surface of the MRAM chip having the contact pads. The limitation of shield to chip distance due to bonding wire is eliminated by VIA holes according to the invention which achieves minimal spacing between the shield and chip. A second shield without vias can be positioned on the opposite side of the chip from the first shield. In one group of embodiments a hardened ferro-fluid shield can be the only shield or the structure can include a shield with or without vias. One group of embodiments includes an external shield with vias for solder access to the package contact pads affixed to the outer surface of the package.

主权项

1. A chip package including:
an MRAM chip including a set of chip contact pads formed substantially flush with a first surface of the MRAM chip; a set of package contact pads disposed on an exterior surface of the package; a set of bonding wires electrically connecting the chip contact pads to the package contact pads; a first soft-magnetic shield disposed inside the package adjacent to the first surface of the MRAM chip, a surface of the first shield confronting the MRAM chip being larger than the first surface of the MRAM chip and extending beyond the MRAM chip on opposing sides, the first shield having at least one via with at least one bonding wire passing through the via; and a second soft-magnetic shield disposed adjacent to a second surface of the MRAM chip opposite to the first surface of the MRAM chip, the second soft-magnetic shield having an edge that extends toward and contacts the first shield, thereby encapsulating the MRAM chip.