摘要:
A heat dissipating pad or support member for mounting a semiconductor device in an electrical circuit has a metal core with a relatively low coefficient of thermal expansion preferably lower than that of the semiconductor device and has a thermally conducting, corrosion resistant metal coating with relatively greater thermal conductivity than the core. The thermally conducting coating is metallurgically bonded to top, bottom and two lateral surfaces of the core with a selected thickness to cooperate with the core in providing an outer surface portion of the member over the top of the core having an effective coefficient of thermal expansion substantially corresponding to the semiconductor device to reliably mount the semiconductor device thereon. The coating is thicker on at least one of the two lateral core surfaces so that heat collected from the semiconductor device at the top surface of the thermally conducting coating is efficiently transferrred via the lateral surface or surfaces on the core to the portion of the thermally conducting coating on the bottom surface of the member.
摘要:
Ceramic to metal stock or substrates having a relatively large and thick metal core and a relatively thin ceramic layer or layers are bonded to the metal core or a selected portion thereof by providing a metal core material having a temperature coefficient of expansion which is tailored to the temperature coefficient of expansion of the ceramic layer to be bonded thereto. The typical core materials include multilayer composite metal laminates embodying Cu/Mo/Cu, Cu/Kovar/Cu, Cu/Invar/Cu and the like and including powdered metal composites embodying Cu-W, Ag-Mo, Ag-W, Al-Si, Cu/Mo/Cu, Cu/Kovar/Cu, SiC-Cu, Ni-Fe alloys having from about 20% Ni to about 80% Ni, etc. The ceramic layer is chosen primarily for the properties of dielectric strength and isolation properties and typically include such ceramics as alumina, beryllium oxide, aluminum nitride, silicon carbide, etc. Where the core composite includes copper outer surface materials or is plated to have copper outer surface materials, the core and ceramic materials and particularly multiple sections of the ceramic materials are provided in spaced relation on the metal cores of relatively large area and are preferably bonded to the core using a copper oxide eutectic formed on the core surface.
摘要:
Adhesion between a heat spreader (15) and a substance (19) to be adhered to the heat spreader can be enhanced by using thermal spray deposition to apply a coating (23) to the heat spreader. The substance to be adhered is applied to the coated heat spreader.
摘要:
Discrete powder particles of copper 14 and INVAR 12 are mixed together in a container 16 and packed into a powder metal article. This article is hot vacuum degassed and vacuum sealed and then heated to temperature well below the sintering temperature of copper or INVAR. Immediately after heating the article, it is subjected to a high pressure, high strain force such as extrusion through a die thereby yielding a fully dense, strong composite material 10 with excellent combined thermal expansion and conductivity properties.
摘要:
A circuit system has a semiconductor device mounted on a substrate which includes a composite metal material comprising a plurality of discrete elements of ferrous metal material such as an alloy of 36 percent nickel and the balance iron having a relatively low coefficient of thermal expansion, the discrete elements being copper-coated by electroless copper plating or the like and being pressed together and heated for sintering or diffusion-bonding the copper coatings together to form a continuous copper matrix having the discrete elements secured in dispersed relation therein for providing the composite metal material with a coefficient of thermal expansion relatively much lower than that of the copper material, the heating of the coated particles for diffusion bonding thereof being regulated for forming the continuous copper matrix while leaving the copper material of the matrix substantially free of nickel, ferrous or other constituents diffused therein from the discrete elements for providing the composite material with improved thermal conductivity.
摘要:
A layer of ceramic material such as alumina is plasma-deposited on a sheet member such as molybdenum or a composite laminate of molybdenum and graphite or other material of low thermal expansion to form a circuit unit substrate having a thick, adherent, electrically-insulating coating on a light, rigid and thermally-conducting base. Thick and thin film materials are deposited and fired on the insulating coating to provide conductors, insulators or resistors or the like in a circuit unit. The materials of the sheet member and of the insulating coating are selected to have matching thermal expansion coefficients so that the substrate remains flat and free of bowing during the firing of the thick and thin film materials. The plasma-deposited electrically-insulating layer is sealed to prevent moisture absorption during use.
摘要:
A method of forming enclosures for microwave and hybrid devices and the enclosure itself wherein the metals to be joined are thin (i.e., less than 40 mils thick) and/or thick (up to several inches) and wherein metallurgical hermetic bonds are provided between adjacent metals which are generally difficult to bond to each other and may be bonded by a select number of bonding processes.
摘要:
A circuit having a semiconductor device therein has a novel and improved circuit substrate comprising a layer of organic electrically insulating material having a layer of metal of relatively high electrical conductivity adhered to and supported on one side of the organic material layer forming electrically conductive circuit paths and forming a pad mounting the semiconductor device. A heat sink metal layer is adhered to and supported on an opposite side of the organic material layer for withdrawing heat from the semiconductor device. A multiplicity of particles of materials of relatively higher thermal conductivity than the organic layer material is dispersed in the organic material for enhancing heat withdrawal from the semiconductor device, and the heat-sink metal layer comprises a layer of a first metal of relatively low coefficient of thermal expansion having a plurality of apertures in therethrough and a second metal of relatively much higher thermal conductivity which is disposed in the apertures and on the opposite sides of the low expansion layer and which is metallurgically bonded to the low expansion layer material. The first and second metals in the heat-sink layer provide the heat-sink layer with heat-transferring properties and with an effective coefficient of thermal expansion which cooperates with the particles enhancing heat withdrawal from the semiconductor device for conducting withdrawn heat through the heat-sink layer to be rapidly dissipated while also providing improved reliability in the mounting and interconnection of the semiconductor device and the circuit during such enhanced heat withdrawal from the circuit.
摘要:
A substrate for semiconductor and integrated circuit components including: a core plate containing a Group VIB metal from the periodic table of the elements and/or an anisotropic material, having a first major surface and a second major surface and a plurality of openings extending, at least partially, from the first major surface to the second major surface; and a Group IB metal from the periodic table of the elements or other high thermally conductive material filling at least a portion of the space encompassed by at least some of the openings; and optionally, a layer containing a Group IB metal from the periodic table or other high thermally conductive material disposed over at least a portion of the first major surface and at least a portion of the second major surface.
摘要:
Adhesion between a heat spreader (15) and a substance (19) to be adhered to the heat spreader can be enhanced by using thermal spray deposition to apply a coating (23) to the heat spreader. The substance to be adhered is applied to the coated heat spreader.