Motorola Corporation

Essex Group, Inc.

Essex International, Inc.

John D Shurboff

Dale W Dorinski

Bruce J Freyman

Joseph Karkoski

Kevin Douglas Moore

Lionel J Payette

Charles W McGregor

Leonard F Altman

Wendell R Hutchinson

This process uses a metal lift-off step and results in a layer of polyimide covering the surface of an integrated circuit, except at the bonding pads which are covered by metals. A layer of polyimide is applied to the surface of an integrated circuit and then partially cured. A layer of positive photo-resist is applied over the polyimide layer and then pattern exposed and developed, resulting in windows being opened up over the bonding pads of the integrated circuit. The remaining photo-resist is then flood exposed. One or more metals are then sputtered over the resist and the bonding pads. The integrated circuit is then immersed in solvent and the remaining layer of photo-resist, including the metal above it, is lifted-off. Only the metal over the bonding pads remains. The polyimide layer is then fully cured.

Integrated circuit having polyimide/metal passivation layer and method

An ultra high density pad array chip carrier is disclosed which includes a ceramic substrate having a plurality of electrical conductors each of which connect to a respective through-hole plugged with solder on its bottom surface. These solder plugs form a pad array for the chip carrier as well as provide a hermetic seal for the ceramic substrate. A polymer dielectric layer is affixed to the top surface of the ceramic substrate which provides an insulated metal die mount pad thereon. The electrical conductors on the ceramic substrate are formed using well-known vacuum metallization techniques to achieve much narrower widths. Approximately a 40 percent reduction in overall size and cost is achieved utilizing this improved arrangement, which improves reliability and facilitates post-assembly cleaning of the chip carrier when mounted to its final board.

Method of making an ultra high density pad array chip carrier

Ultra high density pad array chip carrier

An ethylene-acrylic acid copolymer can be used as a flux or a solder-through conformal coating. The copolymer can be melted and used as a coating or core for solder, or applied directly to a component, or made into a thixotropic gel with mineral spirits and/or alcohol, then applied as a coating to a component or assembly. Terpenes may be added as tackifiers in some applications. Whether used as a flux or simply solder-through coating, the material provides a self-healing moisture barrier which can safely remain on the component.

Permanent fluxing agent and solder-through conformal coating

A method of making aqueous solutions of polyesterimides and the resulting solutions are disclosed. The disclosed method is particularly adapted to making aqueous solutions of high molecular weight polyesterimides with low acid numbers. The resulting aqueous polymer solutions can also be made with high polymer solids content. Solubilization takes place utilizing a base to open imide bonds in the ester-imide polymer chain. The polymer solution has particular utility as a wire enamel.

Aqueous solutions of polyesterimides and methods of making the same

Bonding compositions are disclosed as well as bondable articles utilizing such compositions. Such bonding compositions contain a crystalline polyester material and an amorphous polyester material and exhibit thermally stable bonding properties. Such bondable articles include bondable magnet wires comprising a conductor, an insulating base coat thereon and a bonding composition coated thereover containing a crystalline polyester material and an amorphous polyester material with the wires adapted to be shaped as coils and the like and thereafter bonded together with a bond which exhibits bond strength at elevated temperatures.

Growing community of inventors

Coral Springs, FL, United States of America

John D Shurboff