On Semiconductor Trading, Ltd.

Sanyo Electric Co., Ltd.

Sanyo Semiconductor Co., Ltd.

Katsuyoshi Mino

Masami Motegi

Akira Iwabuchi

Masaru Kanakubo

Ko Nishimura

Noriaki Sakamoto

Sadamichi Takakusaki

In a circuit device of the present invention, the lower surface side of a circuit board and part of side surfaces thereof are covered with a second resin encapsulant, and the upper surface side and the like of the circuit board are covered with a first resin encapsulant. Since heat dissipation to the outside of the circuit device is achieved mainly through the second resin encapsulant, a particle size of filler contained in the second resin encapsulant is made larger than a particle size of filler contained in the first resin encapsulant. Heat dissipation to the outside of the circuit device is greatly improved.

Circuit device and method of manufacturing the same

In a circuit device of the present invention, the lower surface side of a circuit board is covered with a second resin encapsulant, and the upper surface side and the like of the circuit board are covered with a first resin encapsulant. Since heat dissipation to the outside of the circuit device is achieved mainly through the second resin encapsulant, a particle size of filler contained in the second resin encapsulant is made larger than a particle size of filler contained in the first resin encapsulant. Heat dissipation to the outside of the circuit device is greatly improved.

Circuit device

Provided is a method of manufacturing a circuit device in which a circuit element is resin-sealed with sealing resins formed integrally with each other. In the present invention, a resin sheet and a circuit board are housed in a cavity of a mold, and thereafter a first sealing resin formed of a tablet in melted form is injected into the cavity. At the time of injecting the first sealing resin, a second sealing resin formed of the resin sheet in melted form is not yet cured and is maintained in liquid form. Accordingly, the injected first sealing resin and the second sealing resin are mixed at the boundary therebetween, preventing the generation of a gap in the boundary portion and therefore preventing the deterioration of the moisture resistance and withstand voltage at the boundary portion.

Method of manufacturing circuit device

Provided is a circuit device manufacturing method for coating a bottom surface of a circuit board with a thin coating of sealing resin. In the present invention, a circuit board having a circuit element such as a semiconductor element embedded therein is placed in a molding die, and a resin sheet containing a thermosetting resin is interposed between the circuit board and a bottom surface of an inner wall of the molding die. Under this condition, the molding die is heated to about 180&#xb0; C., and a sealing resin in liquid form is injected through a gate. Thereby, the bottom surface of the circuit board can be coated with a thin coating of the sealing resin made of the molten resin sheet.

Resin sheet, circuit device and method of manufacturing the same

A circuit device having improved packaging density is provided. A circuit device of the present invention includes: a circuit board having its surface covered with an insulating layer; conductive patterns formed on a surface of the insulating layer; circuit elements electrically connected to the conductive patterns; and leads connected to pads formed of the conductive patterns. Furthermore, a control element is fixed to an upper surface of a land part formed of a part of a lead, and a back surface of the land part is spaced apart from an upper surface of the circuit board.

Growing community of inventors

Ota, Japan

Katsuyoshi Mino