Abstract: A thin film spiral inductor is formed on a ceramic or other suitable substrate in a manner which facilitates adjustment of the inductive value of the inductor after its fabrication on the substrate. The thin film inductor comprises a spiral conductive path having a plurality of conductive pads connected at different positions about the periphery of the spiral path. A conductive pad is also located at the center of the spiral path in electrical connection to the inner end of the path. The center pad and a selected one of the peripheral pads serve as terminals of the inductor to provide an intended value of inductance.

Abstract: A process is provided for removing slag from an aperture in a substrate, comprising the steps of: providing a protective coating on the substrate; drilling a hole through the substrate; and chemically removing slag from the aperture by complete or partial immersion of the substrate into a chemical bath. Additional process steps can include cleaning the stripped substrate and baking the substrate at a high temperature. A base coating can be provided on the substrate to promote adhesion of a chemically resistant coating to the substrate. Additionally, a protective coating can be applied to the chemically resistant coating to protect it during drilling. The chemically resistant layer can be a material, such as gold, that does not oxidize or dissolve when it is exposed to a chemical, such as phosphoric acid. Phosphoric acid can be heated to accelerate slag removal.

Abstract: An electronic circuit package in which a resistor network is readily installed and remains accessible for laser trimming after final assembly of the package. A substrate is provided having a circuit pattern on a surface thereof and terminating in electrical terminals for connection to external circuitry. The substrate includes an aperture about the periphery of which a plurality of contact pads are arranged and in connection with intended paths of the circuit pattern. A resistor network is formed on a surface of a smaller substrate, the resistors being connected to contact pads disposed about the periphery of the smaller substrate and configured to be in alignment with respective pads at the aperture of the larger substrate. The smaller substrate is placed on the larger substrate with the respective contact pads in alignment, and the engaged contact areas are bonded to mechanically retain the smaller substrate and to electrically interconnect the resistor network with the associated circuit pattern.