摘要:
Disclosed is a field controlled thyristor in which a first semiconductor region of N.sup.+ -type, a second semiconductor region of N-type, third semiconductor regions of P-type, a fourth semiconductor region of N.sup.- -type and a fifth semiconductor region of P.sup.+ -type are formed in a semiconductor substrate having two main surfaces, the first, second and third semiconductor regions being exposed in the first main surface and the fifth semiconductor region being exposed in the second main surface; and the third semiconductor regions of P-type are spaced from each other by a predetermined spacing. The third semiconductor regions are connected with surface-exposed semiconductor regions exposed in the first main surface. The impurity concentration in the second semiconductor region decreases from the first semiconductor region toward the third semiconductor region so that a low forward voltage drop can be achieved along with a high reverse blocking voltage. Also disclosed is a method for forming the third semiconductor regions and the surface-exposed semiconductor regions through a diffusion process alone.
摘要:
A switching control circuit includes a first field controlled thyristor having a gate and a cathode between which a backward bias voltage source and a second field controlled thyristor are connected in series. Conduction of the second field controlled thyristor is controlled by controlling a voltage applied across the gate and the cathode, thereby to control conduction of the first field controlled thyristor. A large load current can be positively and safely turned on and off by a relatively small control current or voltage.
摘要:
A field controlled thyristor is disclosed which comprises a first emitter region exposed to one main surface of a semiconductor substrate and having a first conductivity type, a second emitter region exposed to the other main surface of the substrate and having a second conductivity type, a base region connecting the first and the second emitter region, and a gate region provided in the base region. The gate region consists of a slab-like first portion disposed parallel to both the emitter and a second portion connecting the first slab-like portion with one of the main surfaces of the semiconductor substrate. The impurity concentration of the base region is higher in the portion of the base region nearer to the emitter region having the same conductivity type as that of the base region than in the portion of the base region nearer to the emitter region having the opposite conductivity type to that of the base region. The field controlled thyristor has a high forward blocking voltage gain (anode-cathode voltage/gate bias voltage), a large current rating, and a high switching power capability and its switching time is very short.
摘要:
This invention relates to a thin film semiconductor device and a method for fabricating it, and more particularly a thin film semiconductor device suitably applicable to a display device in an active matrix system and a method for fabricating it. In this invention, the structure of a thin film semiconductor device for improving the characteristic thereof and particularly the structure relative to the dominant orientation of a poly-Si film as an active layer of a thin film transistor (TFT) is disclosed. A method for fabricating a thin film semiconductor device which is capable of forming a poly-Si film at a relatively low process temperature is disclosed. Further, a display device in an active matrix system which provided high performance and high image quality is disclosed. The poly-Si film having a dominant orientation of (111) is formed by forming a poly-Si film on the semiconductor substrate at a temperature up to 570.degree. C. and annealing the substrate at a temperature up to 640.degree. C.
摘要:
An improvement in a semiconductor switching device is disclosed which comprises a semiconductor substrate of a first conductivity type, an anode region of a second conductivity type formed in the semiconductor substrate adjacent to a major surface thereof, a gate region of the second conductivity type formed a distance from the anode region, and a cathode region of the first conductivity type formed in the gate region and having a higher impurity concentration than the semiconductor substrate. A channel region is formed immediately below the cathode region thereby to directly contact the cathode region to the semiconductor substrate. A current path extending from the anode region to the cathode region through the semiconductor substrate is interrupted by a depletion layer produced in the vicinity of the channel region upon application of a reverse bias across a pn-junction formed between the gate region and the cathode region. When no reverse bias voltage is applied, the anode region, the semiconductor substrate and the gate region cooperate to function as a thyristor. The semiconductor switching device has a high dv/dt capability and is easily implemented in integrated circuits.
摘要:
A heat-conducting cooling module for cooling a semiconductor substrate in an integrated circuit package assembly in which a semiconductor substrate is mounted on a base board by small solder pellets, and which contains a single substrate or laminated substrates. A heat-conducting relay member is provided between the semiconductor substrate and a housing so as to be pressed onto the semiconductor substrate. At least either one of the housing or the heat-conducting relay member is made of a sintered product which includes silicon carbide as a chief component.
摘要:
A rotating electrical machine includes a rotor, in which a plurality of magnetic poles are provided in circumferential direction, and a stator, within which the rotor is disposed. In the stator, two stator magnetic poles are formed by winding coils of one phase and by a stator core of the stator within 360° of electrical angle defined by the magnetic poles of the rotor. The coils that form respective stator magnetic poles have angular widths in circumferential direction of less than 180° of electrical angle, the coils that form the respective two stator magnetic poles are provided so as not to mutually overlap and are wound so that adjacent ones of the stator magnetic poles have mutually opposite polarities, and, in the stator, each winding of each coil consists of an external bridge wire, a turn portion, an internal bridge wire, and a turn portion, in that order.
摘要:
An electric motor comprising a rotor having plural magnetic poles in the circumferential direction; and a stator whose teeth are disposed opposite to the periphery of the rotor, with an air gap interposed between the rotor and the stator, wherein the coil conductors are wound on the stator so that two stator magnetic poles may be formed by two coil units of a phase wound around stator teeth within the range of 360 electrical degrees subtended by the magnetic poles of the rotor; each of the two coil units forming the stator magnetic poles spans an electrical angle less than 180 electrical degrees; the two coil turns forming the two stator magnetic poles are laid out so that they may not overlap each other; and the coil conductors are so wound that the adjacent stator magnetic poles exhibit opposite magnetic polarities.
摘要:
According to the present invention, a capsular endoscope having at least an image pickup optical system, an illumination unit, an image pickup portion, and a circuit board comprises a marker shooting unit that indwells a marker member in a body cavity. Consequently, a predetermined marker is indwelled in a desired region such as a lesion discovered using the capsular endoscope so that the region can be readily rediscovered during reexamination.