Abstract: In a high-frequency variable attenuator for variably attenuating an input high-frequency signal in response to a control voltage to produce an output high-frequency signal, a reference voltage generating circuit generates a controllable reference voltage in response to the control voltage. Connected to the reference voltage generating circuit, an attenuating circuit attenuates the input high-frequency signal on the basis of the control voltage in reference with the controllable reference voltage to produce the output high-frequency signal.

Abstract: 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.

Abstract: In a high-frequency variable attenuator for variably attenuating an input high-frequency signal in response to a control voltage to produce an output high-frequency signal, a reference voltage generating circuit generates a controllable reference voltage in response to the control voltage. Connected to the reference voltage generating circuit, an attenuating circuit attenuates the input high-frequency signal on the basis of the control voltage in reference with the controllable reference voltage to produce the output high-frequency signal.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.