Rohm Co., Ltd.

Kyoto University

Japan Science and Technology Agency

Seita Iwahashi

Susumu Noda

Takukazu Otsuka

Katsuhiko Yoshihara

Eiji Miyai

Wataru Kunishi

Maiko Hatano

Ryuta Watanabe

Dai Ohnishi

Yoshikatsu Miura

Takui Sakaguchi

Toshiyuki Nobuoka

Yoshitaka Kurosaka

Dai Onishi

Kazuya Nagase

Kyosuke Sakai

The power semiconductor apparatus includes: a semiconductor device; a bonding layer on chipdisposed on an upper surface of the semiconductor device; and a metal leaddisposed on the upper surface of the semiconductor device and bonded to the bonding layer on chip, wherein the metal leadhas a three-laminated structure including: a second metal layerhaving a CTE equal to or less than 5×10/° C., for example; and a first metal layerand a third metal layersandwiching the second metal layer and having a CTE equal to or greater than the CTE of the second metal layer. Provided is a power semiconductor apparatus capable of improving reliability thereof by reducing a thermal stress to a bonding layer between a semiconductor power device and a metal lead positioned on an upper surface thereof, and reducing a resistance of the metal lead.

Power semiconductor apparatus and fabrication method for the same

The power semiconductor apparatus includes: a semiconductor device; a bonding layer on chipdisposed on an upper surface of the semiconductor device; and a metal leaddisposed on the upper surface of the semiconductor device and bonded to the bonding layer on chip, wherein the metal leadhas a three-laminated structure including: a second metal layerhaving a CTE equal to or less than 5&#xd7;10/&#xb0; C., for example; and a first metal layerand a third metal layersandwiching the second metal layer and having a CTE equal to or greater than the CTE of the second metal layer. Provided is a power semiconductor apparatus capable of improving reliability thereof by reducing a thermal stress to a bonding layer between a semiconductor power device and a metal lead positioned on an upper surface thereof, and reducing a resistance of the metal lead.

The power module includes: a first metallic pattern; a plurality of power devices bonded on the first metallic pattern, each of the plurality of the power devices has a thickness thinner than a thickness of the metallic pattern; a frame member disposed so as to collectively enclose a predetermined number of the power devices on the first metallic pattern; a second metallic pattern disposed outside the frame member; and a resin layer configured to seal the plurality of the power devices and the first and second metallic patterns so as to include the frame member, wherein the frame member suppresses a stress according to a difference between a coefficient of thermal expansion of the metallic pattern and a coefficient of thermal expansion of the power devices. There is provided the power module easy to be fabricated, capable of suppressing the degradation of the bonded portion and improving reliability.

Power module and inverter equipment

The 2D-PC surface emitting laser includes: a PC layer; and a lattice point for forming resonant-state arranged in the photonic crystal layer, and configured so that a light wave in a band edge in photonic band structure in the PC layer is diffracted in a plane of the PC layer, and is diffracted in a surface vertical direction of the PC layer. The perturbation for diffracting the light wave in the surface vertical direction of the PC layer is applied to the lattice point for forming resonant-state. The term 'perturbation' means that modulation is periodically applied to the lattice point for forming resonant-state. For example, the periodic modulation may be refractive index modulation, hole-diameter modulation, or hole-depth modulation.

Two dimensional photonic crystal vertical cavity surface emitting lasers

Provided is a two-dimensional photonic crystal surface emitting laser having an active layer for generating light of a predetermined wavelength range by an injection of electric current and a two-dimensional photonic crystal layer provided on one side of the active layer, the layer having a plate-shaped base member in which modified refractive index areas whose refractive index differs from that of the base member are arranged.

Two-dimensional photonic crystal surface emitting laser

A photonic crystal surface emission laser includes an active layer, and a photonic crystal layer made of a plate-shaped slab provided with modified refractive index area having a refractive index different from that of the slab, the modified refractive index areas being arranged on each of the lattice points of a first rhombic-like lattice and a second rhombic-like lattice in which both diagonals are mutually parallel and only one diagonal is of a different length, wherein a, a, a, and n satisfy the following inequality: 

Photonic crystal surface emission laser

A two-dimensional photonic crystal laser light is provided. The two-dimensional photonic crystal laser includes a two-dimensional photonic crystal made of a plate-shaped member provided with a periodic arrangement of identically-shaped modified refractive index areas having a refractive index different from that of the plate-shaped member; and an active layer provided on one side of the two-dimensional photonic crystal. The modified refractive index areas are arranged at lattice points of a lattice with a same period at least in two directions; each modified refractive index area is shaped so that a feedback strength is different with respect to directions of two primitive lattice vectors of the lattice; the two-dimensional photonic crystal has a periodic structure of a supercell, which contains a plurality of lattice points; and the sum of the feedback strengths by all modified refractive index areas in the supercell is identical in each direction of the two primitive lattice vectors.

Growing community of inventors

Kyoto, Japan

Seita Iwahashi