Mitsubishi Denki Kabushiki Kaisha

Shigeru Hokuyo

Hideo Matsumoto

Katsumi Sato

Hiroshi Gamo

Takao Oda

Toshiyuki Fujii

Masanori Fukunaga

Takeshi Yamamoto

Yoshio Ishibashi

Takahiko Ichimura

Kiyohiko Mihara

In an overcurrent protection circuit of a power device, an analog switch (4) connects a negative input of a comparator (3) to a reference voltage VREF1 or another reference voltage VREF2 depending on a control signal (S5) from a timer (5). A positive input of the comparator (3) receives voltage drop value (VS). The timer (5) is triggered by a leading edge of an input signal (IN) to output the control signal (S5) to the analog switch (4). The control signal (S5) directs the analog switch (4) to connect the reference voltage VREF2 to the negative input of the comparator (3) only during a transient state estimated period (T) and to connect the reference voltage VREF1 to the negative input of the comparator (3) out of the transient state estimated period (T).

Overcurrent protection circuit of power device and semiconductor

A solar cell for connection in series with a plurality of like cells to provide a solar generator which can produce a desired output voltage. The cell includes a photovoltaic section of compound semiconductor layers stacked on a semiconductor substrate to form a p-n junction and a protective diode section electrically isolated from the photovoltaic section by a p-n junction. The photovoltaic and diode sections are connected in parallel and reverse polarity. The protective diode bypasses current in the solar generator when no light is incident on the photovoltaic section in parallel with the respective diode.

Solar cell

A solar cell device in which a plurality of solar cell elements are connected by interconnectors includes a metal film inserted between the electrode of the solar cell element and the interconnector, and the welded area between the metal film and the electrode is larger than the welded area between the metal film and the interconnector.

A solar cell includes a first conductivity type semiconductor substrate having two opposed surfaces, a second conductivity type first semiconductor layer disposed in the substrate at the first surface of the semiconductor substrate, a second conductivity type second semiconductor layer deposited on the first surface of the semiconductor substrate except for the first semiconductor layer production region, producing a pn junction with the semiconductor substrate having no reverse direction voltage blocking capability, a first conductivity type third semiconductor layer deposited on the second semiconductor layer, a first electrode covering the first semiconductor layer and connecting the third semiconductor layer with the first semiconductor layer, and a second electrode disposed at a second surface of the semiconductor substrate.

Solar cell and a production method therefor

According to the present invention, an electrode is formed on a first region of a light receiving surface of a solar battery element and an end portion of an interconnector is connected to a part of the surface region of the electrode, while an adhesive layer is provided on the light receiving surface, the surface of the electrode and the end portion of the interconnector. Further, one or more through holes are provided in a region of the interconnector being adjacent to the end portion. Thus, even if an adhesive agent forming the adhesive layer flows out during formation of the adhesive layer, the outflow parts of the adhesive agent are trapped in the through holes, whereby the solar battery device can be reduced in size.

Solar battery device

In the fabrication processes of a solar cell, a first p-n junction having a function required for supplying electric power to the exterior of the solar cell is formed in the vicinity of the light receiving surface, while a second p-n junction is provided in a position not reached by incident light. The two p-n junctions are interconnected in anti-parallel, so that, when a reverse voltage is applied to the first p-n junction, the second p-n junction is forward biased to have a current flow therein, thereby to prevent the solar cell from breaking down. Since the first and second p-n junctions are integrated with each other, the cost for fabricating the solar cell is decreased and the reliability thereof is increased.

Solar cell and fabrication method thereof

In the fabrication processes of a solar cell, a first p-n junction having the function of supplying electric power to the exterior of the solar cell is formed in the vicinity of the light receiving surface, while a second p-n junction is provided in a position separated from the light receiving surface. The two p-n junctions are interconnected in anti-parallel, so that, when a reverse voltage is applied to the first p-n junction, the second p-n junction is forward biased to permit current flow therein, thereby preventing the solar cell from breaking down. Since the first and second p-n junctions are integrated with each other, the cost of fabricating the solar cell is decreased and the reliability thereof is improved.

Solar cell with integral reverse voltage protection diode

A process for preparing semiconductor pellets from one sheet of a semiconductor wafer is disclosed. In the process of the invention, the semiconductor wafer is divided into a plurality of pellet-forming regions and reinforcing regions are formed between the pellet forming regions and at the peripheral part of the wafer. The reinforcing regions prevent breakage of the wafer without increasing the thickness of the pellets whereby a wafer having a large diameter can be used to obtain many pellets having suitable characteristics from one sheet of the wafer without substantial loss.

Process for preparing semiconductor device _by forming reinforcing

A process for preparing semiconductor devices by forming an insulation coating, such as a low melting point glass, on the surface of a semiconductor substrate and then forming a shaved groove through the insulation coating to the inner part of the semiconductor substrate. The insulation coating is one that is easily subject to cracking when shaved by a high speed rotating diamond blade having substantially parallel side surfaces. The low melting point glass and the semiconductor substrate are shaved by a diamond blade having a tapered edge which rotates in high speed, without forming a crack in the insulation coating or breaking a part of the semiconductor substrate. The semiconductor substrate is divided along the shaved groove in a dicing step to obtain separated semiconductor pellets.

Process for preparing semiconductor devices

The stabilization of electrical switching parameters in a semiconductor switching device is achieved by selectively doping a portion of semiconductor material with a heavy metal and irradiating the remaining semiconductor material. In an important embodiment of the invention, a center-fired four region semiconductor switching device consisting of silicon semiconductor material is prepared by gold doping the silicon in the area around the center firing gate contact where initial conduction of current is concentrated. The remainder of the active area of the device is irradiated to provide recombination centers for fast switching without the adverse effect on blocking leakage current that is attributable to indiscriminate gold doping. The gold provides recombination centers in the initial conductive area which are not subject to annealing as are the recombination centers provided by irradiation.

Growing community of inventors

Itami, Japan

Shigeru Hokuyo