Irvine Sensors Corporation

Other

David M Reinker

Angel Antonio Pepe

Joseph A Minahan

Paul Wojtuszewski

A self-aligning optical beam system is disclosed in which optical alignment of two beam-carrying portions, such as a laser beam generated by a chip, and a light guide formed as a waveguide in a polymeric material, is precisely controlled by plug-and-socket connection between a substrate and a chip. Plugs in the form of solder bumps are formed on one surface of a laser chip, and are inserted in sockets provided in a substrate. The optical alignment is precisely controlled in three axes, two of which guarantee alignment for laser beam transmission into a waveguide, and one of which minimizes the gap across which the beam travels. A powerful waveguide division multiplexer may be provided by having numerous converging waveguides on a single substrate, and by stacking a number of substrates, all of whose waveguides feed into a single optical output channel.

Self-aligning optical beam system

There is disclosed an efficient, cost effective production method to bond layers of electronic devices into an integral stack, or for joining electronic devices to other devices or substrates with use of an adhesive material, preferably an appropriate polyimide, to provide, in effect, a two-stage bonding process. In the first stage, the electronic device is coated, preferably at the wafer level, with a liquid solution of the adhesive material, the coated device is heated to remove solvent, forming a dry adhesive coating of sufficient thickness to fill all spaces between metal traces on the electronic device. Coated wafers can be stacked and bonded, or preferably diced to yield individual chips, which are cut and stacked in a suitable fixture, and heat and pressure are applied in a second stage, to cause viscous flow of the adhesive, filling all voids, and to cure the adhesive, creating an integral, adhesively bonded stack. The adhesive selected for use in the process is one which can be dried to a solvent free layer, which has good B stage properties, exhibits viscous flow at temperatures below its curing temperature, and which is substantially free of volatile release during curing to form a substantially void-free adhesive bond having high film strength, high adhesion, chemical resistance and good dielectric properties.

Dry adhesive joining of layers of electronic devices

A method and product are disclosed in which multiple solder bumps on a first planar surface are guided into engagement with terminals on a second planar surface by means of holes formed (by a photolithographic process) in a dielectric layer, which has been added to the second surface to provide the holes (or sockets) through which the solder bumps (or plugs) extend. The perforated (hole-providing) layer may be formed of one of several materials. The preferred perforated layer material is a photo-definable polyimide, which is hardened by heating after the holes have been formed. Small solder bumps may be formed inside the holes on the second surface, in order to facilitate bonding between the solder bumps on the first surface and the terminals on the second surface.

Growing community of inventors

Yorba Linda, CA, United States of America

David M Reinker