Structure and method for packaging stress-sensitive micro-electro-mechanical system stacked onto electronic circuit chip

A method for packaging an integrated micro-electro-mechanical system (MEMS) device comprising:

• attaching a semiconductor chip on an assembly pad of a substrate, the substrate including leads, the chip including first and second terminals, a surface of the chip including a closed structure of polyimide;
• attaching the MEMS device on an area of the chip inside the closed structure using a first layer of silicone material;
• spanning bonding wires from terminals of the MEMS device to the first terminals;
• forming a glob by dispending a second layer of silicone material over the MEMS device and the bonding wires, restricting the glob to a chip surface area inside the closed structure;
• curing the glob;
• dispensing a layer of epoxy compound onto a surface of the glob;
• curing the layer of epoxy;
• and
• covering the MEMS device embedded by the glob, the chip, and portions of the substrate in a polymeric molding compound.

A packaged micro-electro-mechanical system (MEMS) device comprising:

• a pad of a substrate including leads;
• a semiconductor chip including circuitry with first and second terminals, the second terminals wire bonded to the leads;
• a MEMS device attached to a surface of the chip by a layer of silicone compound, terminals of the MEMS device bonded by wire spans to the first terminals;
• a closed structure of polyimide on the surface of the chip surrounding the MEMS device and the first terminals;
• a glob of silicone material covering the MEMS device and the wire spans, the glob restricted to the surface of the chip inside the closed structure;
• and
• molding compound covering portions of the glob, the chip, and the substrate, the molding compound non-adhering to the glob.