A semiconductor device includes a semiconductor element, a base plate, and a plurality of contact materials. The base plate has a front surface holding the semiconductor element and a rear surface to which a cooling body to cool the semiconductor element is attachable. The plurality of contact materials are discretely arranged on the rear surface of the base plate. The plurality of contact materials are materials for bridging a gap on a heat dissipation path between the base plate and the cooling body. The plurality of contact materials each have a volume based on a bowed shape of the rear surface of the base plate. From among the plurality of contact materials, a contact material at a concave of the bowed shape has a greater volume than a contact material at a convex of the bowed shape.

A high efficiency satellite transmitter comprises an RF amplifier chip in thermal contact with a radiant cooling element via a heat conducting element. The RF amplifier chip comprises an active layer disposed on a high thermal conductivity substrate having a thermal conductivity greater than about 1000 W/mK, maximizing heat conduction out of the RF amplifier chip and ultimately into outer space when the chip is operating within a satellite under normal transmission conditions. In one embodiment, the active layer comprises materials selected from the group consisting of GaN, InGaN, AlGaN, and InGaAlN alloys. In one embodiment, the high thermal conductivity substrate comprises synthetic diamond.

In a general aspect, a method for producing a semiconductor device assembly can include defining a cavity in a conductive spacer, and electrically and thermally coupling a semiconductor die with the conductive spacer, such that the semiconductor die is at least partially embedded in the cavity. The semiconductor die can have a first surface having active circuitry included therein, a second surface opposite the first surface, and a plurality of side surfaces each extending between the first surface of the semiconductor die and the second surface of the semiconductor die. The method can also include electrically coupling a direct bonded metal (DBM) substrate with the first surface of the semiconductor die.

A method of joining a metal-ceramic substrate having metalization on at least one side to a metal body by using a metal alloy is disclosed. The metal body has a thickness of less than 1.0 mm, and the metal alloy contains aluminum and has a liquidus temperature of greater than 450° C. The resulting metal-ceramic module provides a strong bond between the metal body and the ceramic substrate. The resulting module is useful as a circuit carrier in electronic appliances, with the metal body preferably functioning as a cooling body.

The invention relates to a composition for forming an adhesive layer, an adhesive layer, a manufacturing method for the adhesive layer, a composite material, a sheet, a heat dissipation member, an electronic device, a battery, a capacitor, an automobile component and a machine mechanism component, and the composition for forming the adhesive layer contains a polyvinyl acetal resin and a compound having an oxazoline group.

The present invention provides a high thermal conductive silicon nitride sintered body having a thermal conductivity of 50 W/m.Math.K or more and a three-point bending strength of 600 MPa or more, wherein when an arbitrary cross section of the silicon nitride sintered body is subjected to XRD analysis and highest peak intensities detected at diffraction angles of 29.3±0.2°, 29.7±0.2°, 27.0±0.2°, and 36.1±0.2° are expressed as I.sub.29.3°, I.sub.29.7°, I.sub.27.0°, and I.sub.36.1°, a peak ratio (I.sub.29.3°)/(I.sub.27.0°+I.sub.36.1°) satisfies a range of 0.01 to 0.08, and a peak ratio (I.sub.29.7°)/(I.sub.27.0°+I.sub.36.1°) satisfies a range of 0.02 to 0.16. Due to above configuration, there can be provided a silicon nitride sintered body having a high thermal conductivity of 50 W/m.Math.K or more, and excellence in insulating properties and strength.

A circuit board includes a metal circuit plate, a metallic heat diffusing plate disposed below the metal circuit plate and having an upper surface and a lower surface, a metallic heat dissipating plate below the heat diffusing plate, an insulating substrate disposed between the metal circuit plate and the heat diffusing plate, and an insulating substrate disposed between the heat diffusing plate and the heat dissipating plate. A grain diameter of metal grains contained in the heat diffusing plate decreases from each of the upper surface and the lower surface of the heat diffusing plate toward a center portion of the heat diffusing plate in a thickness direction.

Electronic devices are manufactured using a collective (wafer-scale) fabrication process. Electronic chips are mounted onto one face of a collective substrate wafer. A collective flexible sheet made of a heat-conductive material comprising a layer containing pyrolytic graphite is fixed to extend over a collective region extending over the electronic chips and over the collective substrate wafer between the electronic chips. The collective flexible sheet is then compressed. A dicing operation is then carried out in order to obtain electronic devices each including an electronic chip, a portion of the collective plate and a portion of the collective flexible sheet.

Electronic devices are manufactured using a collective (wafer-scale) fabrication process. Electronic chips are mounted onto one face of a collective substrate wafer. A collective flexible sheet made of a heat-conductive material comprising a layer containing pyrolytic graphite is fixed to extend over a collective region extending over the electronic chips and over the collective substrate wafer between the electronic chips. The collective flexible sheet is then compressed. A dicing operation is then carried out in order to obtain electronic devices each including an electronic chip, a portion of the collective plate and a portion of the collective flexible sheet.

To improve a TCT characteristic of a circuit substrate. The circuit substrate comprises a ceramic substrate including a first and second surfaces, and first and second metal plates respectively bonded to the first and second surfaces via first and second bonding layers. A three-point bending strength of the ceramic substrate is 500 MPa or more. At least one of L1/H1 of a first protruding portion of the first bonding layer and L2/H2 of a second protruding portion of the second bonding layer is 0.5 or more and 3.0 or less. At least one of an average value of first Vickers hardnesses of 10 places of the first protruding portion and an average value of second Vickers hardnesses of 10 places of the second protruding portion is 250 or less.