Abstract:
An SMT electronic component is mounted to a solder-bearing floatation plate by fusible or other heat-responsive releasable mounting means which suspend the component above the floatation plate. The bottom of the floatation plate is effectively substantially the mirror image of a component-positioning pad formed on the board surface adjacent the solder-bearing contact pads corresponding to the electrical contacts on the component. In the assembly process, the floatation plate is placed on the positioning pad. The solder on the bottom of the floatation plate has a melting point lower than the release temperature of the mounting means and the melting point of the solder on the contact pads. With the floatation plate on the component-positioning pad, on heating the solder on the floatation plate liquifies first, wetting the component-positioning pad and floating the floatation plate and component on a thin film of molten solder. Surface tension forces bring the floatation plate into registry with the component-positioning pad. On further heating, the solder on the contact pads liquifies, and the heat-responsive mounting means allows the component to fall freely onto the contact pads. Guide means are provided to prevent rotational and lateral displacement of the component during the fall. The disclosure includes alternative floatation plate constructions and component mounting arrangements.
Abstract:
A circuit package 2 is provided for heat dissipating power semiconductors and the like. Circuit means 10, including lead frames 12 and power conditioning components 13, is mounted on an electrically insulating thermally conductive substrate 4 and covered by an electrically insulating housing 6. Power lead frames 14 extend integrally externally of the housing 6 and have external portions 22 bent laterally across the to surface of the housing 6 to cooperate with terminal connection means 28 there below in the top wall 24 of the housing 6. Internal connection means 50 is provided for selectively connecting a peripheral power lead frame portion 46 to a central portion 52 of circuit means 10 and insulatively bypassing designated portions 54 of circuit means 10 therebetween. In one embodiment, circuit package 2 is provided in combination with an external printed circuit board 40 extending across the top surface 24 of the housing and connected to control lead frames 18 and power lead frames 14.
Abstract:
A microwave integrated circuit includes a mounting device surrounding a lead adapted to be electrically connected to a circuit board. The mounting device comprises electrically conductive material spaced from the lead to form a coaxial structure suitable for microwave operation. Apertures, grooves, or the like extend from the space defined between the mounting device and the lead to the outside of the mounting device to provide an exit for a flux gas evolved during soldering of the microwave integrated circuit to a circuit board. The mounting device may exist separately from the microwave integrated circuit.
Abstract:
A system for connecting a semiconductor chip carrier to a printed circuit card is described. The semiconductor chip carrier has a flexible, extendable wiring membrane attached to the bottom thereof which extends beyond the periphery of the semiconductor chip carrier and in the area beyond the periphery is provided with electrical contacts. The electrical contacts are mated to complementary contacts in a printed circuit card which is biased from the semiconductor chip carrier by electrical and thermal contact means. The membrane, inter alia, provides high density electrical contact between the semiconductor and printed circuit card. Various elements thereof and a process for forming the same are described.
Abstract:
An integrated circuit heat dissipator is provided which will additionally hold the integrated circuit in a printed circuit board prior to soldering. The heat dissipator is comprised of a single elastic piece of metallic material having oppositely facing sides joined by a fold at the top. A tab is located at the bottom of each of the sides which is suitable for insertion into a printed circuit board. The tabs have a width which allows them to contact only the heat-conducting pins of the integrated circuit. The heat dissipator is mounted adjacent to the integrated circuit with one of the tabs contacting the heat-conducting pins. The elastic material gives the heat dissipator a spring-like property which causes the tabs to press outwardly from each other when inserted in a board so as to fixedly hold the heat dissipator and the integrated circuit in the printed circuit board prior to soldering.
Abstract:
A semiconductor integrated circuit means comprising a semiconductor substrate having a plurality of circuit elements formed therein and a package enclosing said substrate, wherein the wires for leading out the electrodes of said circuit elements from said package are formed of strip lines and the grounded conductor for said strip lines is made of a common metal plate.