Electronic component unit and manufacturing method thereof

• US 20110194255A1
• Filed: 02/09/2011
• Published: 08/11/2011
• Est. Priority Date: 02/09/2010
• Status: Active Grant

• Current Assignee: Honda Elesys Co., Ltd. (Nidec Corporation)
• Original Assignee: Honda Elesys Co., Ltd. (Nidec Corporation)
• Inventors: Honda, Takashi, Kuroyanagi, Hitoshi, Masubushi, Tomoyuki, Murao, Amane, Teshima, Tamotsu, Ishizaki, Hiroshi, Yamashita, Seiji
• Granted Patent: US 8,737,075 B2
• Time in Patent Office: Days
• US Class Current: 361/711
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 37/003 Cooling means
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/83385 Shape, e.g. interlocking features
• CPC Class Codes: H01L 2924/15151 the die mounting substrate comprising an aperture, e.g. for underfilling, outgassing, window type wire connections
• CPC Class Codes: H01L 2924/19105 in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H05K 13/0465 by soldering H05K13/0469 takes precedence
• CPC Class Codes: H05K 7/20 Modifications to facilitate cooling, ventilating, or heating
• CPC Class Codes: H05K 7/20472 Sheet interfaces
• CPC Class Codes: H05K 7/20509 Multiple-component heat spreaders; Multi-component heat-conducting support plates; Multi-component non-closed heat-conducting structures
• CPC Class Codes: H05K 7/20854 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20863 takes precedence

Abstract

According to embodiments, there is provided an electronic component unit, including: a circuit board including: a heat generating element that generates a heat; and a bonding metal foil layer formed on a face thereof; a heat transfer board including: a board body having a thermal conductivity higher than that of the circuit board; an insulative layer formed on a first face of the board body; and a heat transfer metal foil layer formed to cover the insulative layer; and a heat sink, wherein the circuit board is assembled with the heat sink via the heat transfer board such that (1) the heat transfer metal foil layer is soldered to the bonding metal foil layer and (2) the second face of the board body is superimposed on the heat sink.

Claims

1. An electronic component unit, comprising:

a circuit board including;

electronic components mounted on the circuit board, the electronic components including a heat generating element that generates a heat; and

a bonding metal foil layer formed on a face of the circuit board;

a heat transfer board including;

a board body having a thermal conductivity higher than that of the circuit board, the board body having a first face and a second face opposite to the first face;

an insulative layer formed on the first face; and

a heat transfer metal foil layer formed to cover the insulative layer on the first face; and

a heat sink configured to externally dissipate the heat generated in the heat generating element,

wherein the circuit board is assembled with the heat sink via the heat transfer board such that

(1) the heat transfer metal foil layer on the first face of the board body is soldered to the bonding metal foil layer on the circuit board and

(2) the second face of the board body is superimposed on the heat sink.

2. The electronic component unit of claim 1,

wherein the board body is a metal flat plate,

wherein the insulative layer is an insulative covering film printed on the first face of the flat plate, and

wherein the heat transfer metal foil layer is a copper foil layer printed to cover the covering film.

3. The electronic component unit of claim 1,

wherein the bonding metal foil layer includes a circuit pattern for the heat generating element,

wherein the heat transfer metal foil layer has a pattern similar to the circuit pattern, and

wherein both the patterns are electrically connected to each other.

4. The electronic component unit of claim 1,

wherein the circuit board has a through hole therein at amounting area for mounting the heat generating element, and

wherein a solder is filled in the through hole so as to be connected with the bonding metal foil layer.

5. The electronic component unit of claim 1,

wherein the circuit board has a plurality of mounting areas for respectively mounting a plurality of heat generating elements, and

wherein the heat transfer board is divided so as to each correspond to a respective one of the plurality of mounting areas.

6. An electronic component unit manufacturing method, comprising:

preparing;

a circuit board including a heat generating element mounted thereon and a bonding metal foil layer formed thereon;

a heat transfer board including an insulative layer formed on one face thereof and a heat transfer metal foil layer formed on the insulative layer; and

a heat sink;

applying a cream solder to form a solder layer on the board bonding metal foil layer or the heat transfer metal foil layer;

superimposing the bonding metal foil layer and the heat transfer metal foil layer with each other via the solder layer;

re-melting the solder layer to solder the bonding metal foil layer and the heat transfer metal foil layer; and

superimposing the other face of the heat transfer board with the heat sink to thereby assemble the circuit board with the heat sink via the heat transfer board.