Abstract: A method of adhering a polyimide to a substrate includes first placing the substrate in a dilute acid solution. The substrate is then placed in a palladium and tin solution followed by a rinse with water. The rinsed substrate is placed in an accelerator solution to substantially remove the tin from the substrate. The palladium which remains on the substrate surface provides nucleation sites for adhesion promotion and enhanced wetting of polyimide which is applied in a liquid form as by spraying or spinning. Adhesion of polyimide to metals such as gold, ceramics, alumina or polyimide is thereby provided.

Abstract: A method of producing a metallized pattern on a substrate includes the steps of providing a substrate having a high aspect ratio groove defining a desired metallization pattern and applying metallization to the substrate. The high aspect ratio groove is utilized to prevent metallization across the groove boundary thereby producing electrically isolated areas. The substrate can be a circuit board, hybrid module or other component carrying structure. Also the substrate can be a resonator or a stripline device in which the groove is used to electrially isolate a lead or wire extending from the substrate in the ground plane portion of the structure.

Abstract: A method of fabricating an electronic device on a carrier (14) is provided wherein the method comprises forming a hole pattern in the carrier (14), and providing a metallization pattern on the carrier, and through the holes (16, 22, etc.) to define the electronic device.

Abstract: A method of forming solder bumps includes the steps of applying a thick layer of solder resist to a substrate. The resist is selectively removed to provide wells at solder pads on the substrate. The solder paste is applied to the substrate in the wells. The solder paste is reflowed to form solder bumps on the pads. A socket for a solder bumped member is obtained by first providing a substrate having metalized pads corresponding to the solder bumps of the member. A thick layer of photo definable solder resist is applied to the substrate. The resist is selectively removed to provide wells at the metalized pads of the substrate. Solder paste is then deposited in the wells. The solder bumped member can then be positioned so that the solder bumps are located in the wells. The solder paste is reflowed to bond to the solder bumps and the metalized pads. The solder paste can be selected to have a lower melting temperature than the solder bumps.

Abstract: A method of laser drilling a substrate includes the steps of placing a sacrificial member over the substrate, and then laser drilling through the sacrificial member. This method produces a substantially uniform hole in the substrate.

Abstract: 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.