Nec Corporation

Tatsuya Miya

Kazuhiro Tahara

Seiji Ichikawa

Takeshi Umemoto

Yoshikazu Nishimura

Kazunari Sato

Toshiaki Nishibe

Keita Okahira

Masato Suga

Kunihiko Tsubota

Toru Kitakoga

Kazuyoshi Uemura

Tsutomu Noguchi

Sadayoshi Yoshida

Kunihiko Tubota

Tooru Kitakoga

A semiconductor device having lead terminals bent in a J-shape is disclosed. A radiating plate having a recess formed on an outer peripheral portion thereof is exposed to a lower face of a resin member and free ends of outer portions of the lead terminals are positioned in the recess of the radiating plate. The free ends of the outer portions of the lead terminals and the recess of the radiating plate are isolated from each other by projections of the resin member. Since the radiating plate is exposed to the lower face of the resin member, the heat radiating property is high whereas the radiating plate and the lead terminals are not short-circuited to each other at all.

Semiconductor device having lead terminals bent in J-shape

A semiconductor device having a pellet mounted on a radiating plate thereof is disclosed. The radiating plate is formed in such a shape that a central portion thereof is positioned higher than both end portions thereof. A pellet is mounted on a lower face of the central portion of the radiating plate, and an upper face of the central portion of the radiating plate is exposed to the top of a resin member. Since the upper face of the central portion of the radiating plate which has the pellet mounted on the lower face thereof is exposed from the resin member, heat generated by the pellet can be radiated efficiently.

Semiconductor device having pellet mounted on radiating plate thereof

A semiconductor device is disclosed wherein a pair of radiating terminals and a plurality of lead terminals are formed from a single lead frame. A hole or holes in each radiating terminal are formed with an equal width and in an equal pitch to those of gaps between the lead terminals, and the opposite sides of each hole of the radiating terminal are connected to each other by a support element. The support elements of the radiating terminals and support elements which interconnect the lead terminals are formed with an equal length and in an equal pitch to allow the support elements to be cut away by a plurality of punches which are arranged in an equal pitch and have an equal width.

Method of manufacturing a semiconductor device with a pair of radiating terminals and a plurality of lead terminals formed from a single lead frame

A plastic-encapsulated semiconductor device is provided, which is capable of efficient heat dissipation without upsizing while preventing the moisture from reaching an IC chip. This device is comprised of an electrically-conductive island having a chip-mounting area, an IC chip fixed on the chip-mounting area of the island, leads electrically connected to bonding pads of the chip through bonding wires, a plastic package for encapsulating the island, the chip, the bonding wires, and inner parts of the leads. The package has an approximately flat bottom face. Outer parts of the leads are protruded from the package and are located in approximately a same plane as the bottom face of the package. The island has an exposition part exposed from the package at a location excluding the chip-mounting area. A lower face of the exposition part of the island is located in approximately a same plane as the bottom face of the package. The chip and the chip-mounting area of the island are entirely buried in the package. Apart of the island excluding the chip-mounting area is bent toward the bottom face of the package to be exposed therefrom.

Plastic-encapsulated semiconductor device and fabrication method thereof

Method of manufacturing a semiconductor device with a pair of radiating

A semiconductor device of the present invention comprises a semiconductor pellet, a radiation plate mounted with the semiconductor pellet, a plurality of lead terminals electrically connected with the semiconductor pellet, and a resin member for encapsulating the above items. The resin member has a first surface and a second surface, and the radiation plate has a first portion exposed to the outside from the first surface of the resin member and a second portion exposed to the outside from the second surface of the resin member.

Semiconductor device with radiation plate for high radiation character

Disclosed is a semiconductor switch which has: a first resonance circuit which is composed so that a variable capacitance element and an inductor are in series connected and a series circuit composed of an inductor and a capacitor are in parallel connected to the variable capacitance element and the inductor, the first resonance circuit having one end connected to an input terminal and the other end connected to a first output terminal; a second resonance circuit which is composed like the first resonance circuit and is grounded to the first output terminal; a third resonance circuit which is composed like the first resonance circuit and is connected to the input terminal in parallel with the first resonance circuit, the third resonance circuit having a second output terminal on the reverse side of the input terminal; and a fourth resonance circuit which is composed like the first resonance circuit and is grounded to the second output terminal.

Semiconductor switch having plural resonance circuits therewith

A high frequency switching circuitry comprising the following elements. At least one input signal terminal is provided into which an input signal is inputted. An output signal terminal is also provided, from which an output signal is outputted. A first resistive switching circuit is connected between the input signal terminal and a first node. The first resistive switching circuit has first and second signal transmission channels having first and second resistances. The second resistance of the second channel is much higher than the first resistance of the first channel. The first resistive switching circuit switches the first and second signal transmission channels. A first switching element is connected between the first node and the output terminal. A second switching element is connected in series between the first node and a ground line. It is important that the second resistance of the second signal transmission channel of the first resistive switching circuit is almost equal to a difference of an ON-resistance of the second switching element from an impedance of a signal source of the high frequency switching circuitry.

High frequency switching circuit

A frequency converter has low noise figure and high conversion gain characteristics, and can drive directly a 50 Ohm load. In one embodiment, a dual-gate FET is employed that is composed of a first and second FET as the frequency mixing elements, and a third FET is connected in parallel to the first. The gate voltage of the first FET is set to be substantially equal to the pinch-off voltage in order to thereby ensure low noise figure. The second FET is set to a high g.sub.m, from which a frequency-converted signal is outputted. The gate bias of the third FET is set to provide a path for the current flowing through the second FET. As a result, the second FET can be set to a high g.sub.m regardless of the gate voltage of the first FET, in order to ensure high conversion gain.

Frequency converter circuit structure having two sources

A 3-element series parallel resonator, which performs series resonance and parallel resonance at a predetermined frequency by a combination of three elements including an inductor and a capacitor of concentrated constants, is used as a filter. This design can reduce the circuit constant and permits a filter to be formed on a semiconductor substrate. Accordingly, various micro-wave devices, such as an amplifier which requires a filter, a frequency converter, a multiplier and signal switcher, can be designed into an MMIC on a single chip.

Semiconductor device with a filter formed of 3-element

In a microwave oscillation apparatus including a negative resistance element, a microstrip line having a first end connected to the negative resistance element and a second end connected to a terminating resistor, and a dielectric resonator magnetically coupled to the microstrip line, a capacitive stub is provided on the microstrip line at a distance (1/4) .lambda..sub.s (2N-1) from the first end thereof, where .lambda..sub.s is a wavelength of a spurious oscillation frequency component and N is a positive integer.

Microwave oscillation apparatus capable of suppressing spurious

A microwave oscillator circuit is provided for decreasing the number of passive elements such as inductance, etc. in microwave oscillators and frequency doublers. A microwave oscillator circuit is connected to a resonator circuit generating a signal at a frequency f, and produces at its output a signal of frequency nf, and comprises a first field effect transistor having a gate connected to the resonator circuit, a second field effect transistor whose source/drain path is connected in series with the source/drain path of the first field effect transistor and a connecting circuit for coupling either the gate or source of the first field effect transistor to the gate of the second field effect transistor. A signal of frequency nf is output at a node corresponding to a connection point between the source of the first field effect transistor and the drain of the second field effect transistor.

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Tokyo, Japan

Tatsuya Miya