Shin-etsu Chemical Co., Ltd.

On Semiconductor Trading, Ltd.

Yoshio Fujimura

Minoru Takei

Feng Xu

Tetsuo Yoshida

Toshio Shiobara

Kunio Itoh

Kazutoshi Tomiyoshi

Shinichi Yamamoto

Sumiko Komiya

A control circuit of a light-emitting element comprises a rectifying unit (), a switching element (), a transformer () having a first winding (L) which generates a magnetic field using a current controlled by switching of the switching element (), a second winding (L) which is magnetically coupled to the first winding (L) and which generates a current flowing to an LED (), and a third winding (L) which is magnetically coupled to the first winding (L) and which generates a voltage (Sfbk), and an averaging capacitor () which averages a voltage derived by superposing a voltage (Srec) rectified by the rectifying unit () and the voltage (Sfbk), and a voltage averaged by the averaging capacitor () is applied to the first winding (L), so that light is emitted from the LED ().

Control circuit of light-emitting element

A control circuit of a light-emitting element comprises a rectifying unit () which full-wave rectifies an alternating current power supply, a switching element (), a reference voltage generating unit () which generates a reference voltage (Vref), and a comparator () which receives a voltage (Srec) rectified by the rectifying unit (), compares a comparative voltage (Vcmp) corresponding to a current flowing to an LED () and the reference voltage (Vref), and controls switching of the switching element () according to a comparison result, wherein the reference voltage generating unit () comprises a voltage dividing circuit having a transistor (Q) in which a resistance value between a source and a drain is changed according to the voltage rectified by the rectifying unit (), and outputs, using the voltage dividing circuit, the reference voltage (Vref) according to the voltage (Srec) rectified by the rectifying unit ().

An epoxy resin composition comprising an epoxy resin, a curing agent, a substantially pure alpha-alumina filler, and a silicone-modified epoxy or phenol resin is useful in encapsulating semiconductor devices. The composition can be molded and cured into a product having improved thermal conductivity and moisture resistance.

Semiconductor encapsulating epoxy resin compositions and semiconductor

A silicone composition adapted for impregnation of electronic parts comprising a vinyl group-containing organopolysiloxane, an organopolysiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule and a peroxide compound. The peroxide compound is soluble in both organopolysiloxanes and is contained in an amount of from 0.1 to 10 parts by weight per 100 parts by weight of the total of the organopolysiloxanes. The composition has a viscosity which is sufficient to allow easy impregnation, and is in the range of from 20 to 400 centistokes at 25.degree. C.

Silicone composition for impregnating electric parts

The present invention provides a novel epoxy resin-based curable composition suitable for use as an encapsulating resin composition for semiconductor devices capable of being highly resistant against crack formation with low internal stress by curing and yet having very high heat conductivity and maintaining high glass transition temperature. The inventive composition comprises (a) 100 parts by weight of a curable epoxy resin blend which is a mixture of an epoxy resin and a curing agent therefor, (b) from 5 to 100 parts by weight of a block copolymer composed of at least one segment of an aromatic polymeric moiety, phenyl novolac, and at least one segment of an organopolysiloxane moiety having 30 to 200 silicon atoms and bonded to the aromatic polymeric moiety through a carbon-to-silicon linkage, and optionally (c) an inorganic filler which is preferably a silica filler such as powdered quartz in an amount not exceeding 1000 parts by weight.

Growing community of inventors

Gunma, Japan

Yoshio Fujimura