Toshiyuki Nagase

Bio: Toshiyuki Nagase is an academic researcher from MITSUBISHI MATERIALS CORPORATION. The author has contributed to research in topics: Power module & Substrate (printing). The author has an hindex of 17, co-authored 110 publications receiving 1024 citations.

Ceramic circuit board with heat sink

Abstract: A ceramic circuit board with a heat sink which has a long life under heat cycles. First and second aluminum plates are laminated and bonded onto both sides of a ceramic substrate through Al--Si-based brazing solders, respectively. A heat sink formed of an AlSiC-based composite material is laminated and bonded onto a surface of the first aluminum plate. The ceramic substrate is formed of AlN, Si 3 N 4 or Al 2 O 3 . An Al alloy in the heat sink has an Al purity of 80-99% by weight, and the first or second aluminum plate has an Al purity not less than 99.98% by weight. The heat sink is laminated and bonded onto the first aluminum plate through the Al alloy in the heat sink.

Liquid-cooled heat sink and manufacturing method thereof

Abstract: A heat sink is obtained that has high thermal conductivity as well as satisfactory moldability and corrosion resistance by using a malleable material made of aluminum or aluminum alloy. Liquid cooled heat sink 11 has a passage 23 in which coolant is able to pass, and is joined to a ceramic substrate. A plurality of through holes 12 extending from one end to the other end are formed by a plurality of dividing walls 13 through 15 in flat casing 12 of which both ends are open, and notches 16 are formed on one or both ends of the plurality of dividing walls. Corrugated fins 17 are respectively inserted into each of the plurality of through holes, and each through hole is demarcated into a plurality of slots 12 b extending from one end to the other end of the casing by these fins. Both ends of the casing are closed by a pair of covers 18 and 19, and coolant inlet 18 a and outlet 18 b are formed in the covers. The above passage is formed by communication of the notches and slots, and the above inlet and outlet are positioned on both ends of the passage.

Power module and power module with heat sink

Abstract: The present invention relates to a power module in which an insulated circuit board is fixed to one main surface of a heat discharge plate. It is an object thereof to provide a power module in which the heat discharge characteristics are improved without any marked warping being generated, and that has an extended heat cycle longevity. In the power module 10 of the present invention, a square insulated circuit board 12 is fixed to one main surface of a heat discharge plate 11. The heat discharge plate 11 is formed of an Al based alloy plate having a thickness A of 3 to 10 mm, and the insulated circuit board 12 having a side B of 30 mm or less in length is brazed directly onto the heat discharge plate 11. It is-preferable that the brazing material used is one or two or more brazing materials selected from Al—Si, Al—Ge, Al—Cu, Al—Mg, and Al—Mn based brazing materials. It is also preferable that the insulated circuit board 12 is formed by a ceramic substrate 12 a and Al plates 12 b and 12 c that are bonded to both surfaces thereof, and that the Al plate 12 b has a purity of 99.98 or greater percent by weight.

Highly heat-radiating ceramic package

Abstract: Highly heat-radiating ceramic packages comprising a multi-layer ceramic wiring board 11 to one surface of which is bonded a heat-radiating ceramic base plate 13 with first and second aluminum plates 31 and 32 bonded to both surfaces thereof, via the first aluminum plate 31 are free from warping and cracking, and have improved heat-radiation performance and lower weight and manufacturing cost. The ceramic base plate 13 and the multi-layer ceramic wiring board 11 may be constructed with the same or different types of ceramic which are selected from the group consisting of alumina, glass ceramic, aluminum nitride, mullite, and silicon carbide. The two aluminum plates 31 and 32 are bonded to the ceramic base plate 13 with an Al-Si brazing material. Improved levels of heat radiation performance are accomplished by bonding a heat-radiating ceramic base plate with an aluminum plate bonded thereto, to a multi-layer wiring board prepared even by low-temperature sintering.

Power module substrate

Abstract: The present invention for solving the problem of suppressing the load caused by heat stress applied on an insulation substrate, reducing the manufacturing coat of a power module substrate, and improving productivity provides a power module substrate in which a buffer layer having a surface area one to three times as large as the surface area of the insulation substrate is laminated and bonded between the insulation substrate and the heat sink, wherein the buffer layer is formed using a material having a thermal expansion coefficient between the thermal expansion coefficients of the insulation substrate and the heat sink, the insulation substrate being preferably formed using AlN, Si3N4 or Al2O3, the buffer layer being preferably formed using AlSiC, and a carbon plate or a composite material of AlC, besides the thickness of the buffer layer being preferably 1.5 to 50 times as large as the thickness of the insulation substrate, and the insulation substrate, the buffer layer and the heat sink being preferably laminated via a brazing foil by bonding.

Semiconductor device, and manufacturing method thereof

Abstract: An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

A high temperature multi-layered alloy heater assembly and related methods

Abstract: The present invention provides systems, methods and apparatus for heating substrates in a processing chamber to temperatures up to at least 700 °C. In accordance with an embodiment of the invention a heater assembly with an inner core of high thermal conductivity in encased in a shell of lower thermal conductivity, creating a nearly isothermal interface between the core and shell. The inner core is brazed to the shell, promoting thermal transfer, and acts as a thermal short between opposing surfaces of the shell. The heater assembly is designed to minimize thermal stresses arising from the difference in the thermal expansion coefficients of the various components of the multi-layered heater assembly. In one embodiment of the invention, two independently-powered heating elements are arranged concentrically to each other to create a dual zone heater. A thermal gap in the inner core between the inner and outer heating elements de-couples the zones and provides a more controllable temperature profile at the surface of the heater, including excellent temperature uniformity. In one embodiment, an RF isolator is placed between a heater and a support shaft, allowing the heater to be powered as an electrode in a plasma process.

A review of SiC power module packaging: Layout, material system and integration

Abstract: Silicon-Carbide (SiC) devices with superior performance over traditional silicon power devices have become the prime candidates for future high-performance power electronics energy conversion. Traditional device packaging becomes a limiting factor in fully realizing the benefits offered by SiC power devices, and thus, improved and advanced packaging structures are required to bridge the gap between SiC devices and their applications. This paper provides a review of the state-of-art advanced module packaging technologies for SiC devices with the focuses on module layout, packaging material system, and module integration trend, and links these packaging advancements to their impacts on the SiC device performances. Through this review, the paper discusses main challenges and potential solutions for SiC modules, which is critical for future SiC applications.

A Review of SiC Power Module Packaging Technologies: Challenges, Advances, and Emerging Issues

Abstract: Power module packaging technologies have been experiencing extensive changes as the novel silicon carbide (SiC) power devices with superior performance become commercially available. This article presents an overview of power module packaging technologies in this transition, with an emphasis on the challenges that current standard packaging face, requirements that future power module packaging needs to fulfill, and recent advances on packaging technologies. The standard power module structure, which is a widely used current practice to package SiC devices, is reviewed, and the reasons why novel packaging technologies should be developed are described in this article. The packaging challenges associated with high-speed switching, thermal management, high-temperature operation, and high-voltage isolation are explained in detail. Recent advances on technologies, which try to address the limitations of standard packaging, both in packaging elements and package structure are summarized. The trend toward novel soft-switching power converters gave rise to problems regarding package designs of unconventional module configuration. Potential applications areas, such as aerospace applications, introduce low-temperature challenges to SiC packaging. Key issues in these emerging areas are highlighted.

Ceramic circuit board

Abstract: The present invention provides a ceramic circuit board comprising: a ceramic substrate and a metal circuit plate bonded to the ceramic substrate through a brazing material layer; wherein the brazing material layer is composed of Al-Si group brazing material and an amount of Si contained in the brazing material is 7 wt% or less. In addition, it is preferable to form a thinned portion, holes, or grooves to outer peripheral portion of the metal circuit plate. According to the above structure of the present invention, there can be provided a ceramic circuit board having both high bonding strength and high heat-cycle resistance, and capable of increasing an operating reliability as electronic device.