Electronic circuit device and method of fabricating the same

• US 6,282,092 B1
• Filed: 05/28/1999
• Issued: 08/28/2001
• Est. Priority Date: 06/12/1998
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), Shindengen Electric Manufacturing Company Limited
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), Shindengen Electric Manufacturing Company Limited
• Inventors: Okamoto, Mikio, Ebara, Katsumi
• Primary Examiner(s): THOMPSON, GREGORY D
• Application Number:
  US09/322,018
• Time in Patent Office: 823 Days
• Field of Search: 165/80.2, 165/80.3, 165/185, 174/16.3, 257/722, 361/690, 361/704-710, 361/714-715, 361/717-722, 361/752
• US Class Current: 361/704
• CPC Class Codes: H01L 23/142 Metallic substrates having insulating layers
• CPC Class Codes: H01L 23/3675 characterised by the shape of the housing
• CPC Class Codes: H01L 23/42 Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
• CPC Class Codes: H01L 25/072 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 5/0026 provided with connectors and printed circuit boards [PCB], e.g. automotive electronic control units
• CPC Class Codes: H05K 7/20854 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20863 takes precedence

Abstract

An electronic circuit device having an improved heat dissipating effect, a small size and a high reliability is provided with a metal substrate having a first surface and a second surface and a case. Electronic parts are mounted on only the first surface and the case is united with a radiating fin in one body. The metal substrate is installed in the case such that the metal substrate serves as a cap of the case and the first surface of the metal substrate faces to the case. A resin is provided to fill up a space between the metal substrate and the case, whereby heat generated from the electronic parts is dissipated to the exterior from both the radiating fin and the second surface of the metal substrate.

Claims

1. An electronic circuit device comprising:

a metal substrate having a first surface and a second surface;

electronic parts mounted on only the first surface of said metal substrate;

a case including a radiating fin which is of a one-piece structure therewith, said case having said metal substrate housed therein, wherein said metal substrate serves as a cap of said case, and the first surface of said metal substrate faces an interior region of said case; and

a resin disposed in a space between said metal substrate and said interior region of said case, wherein both said radiating fin and the second surface of said metal substrate dissipate heat generated from said electronic parts to an exterior of said case,

wherein said case defines a first area at which said case is distanced from said metal substrate with a first interval therebetween providing a least amount of space needed for enclosing said electronic parts, and a second area at which said case is distanced from said metal substrate with a second interval therebetween, said first interval being smaller than said second interval.

2. An electronic circuit device according to claim 1, wherein said case further defines a third area at which said case is brought into close contact with said metal substrate.

3. An electronic circuit device according to claim 2, wherein said first interval is not larger than one half of said second interval.

4. An electronic circuit device according to claim 3, wherein said metal substrate has a conductive pattern formed on an insulating film formed over a metal plate, and said electronic parts includes flat package parts mounted on said conductive pattern and in the first area of said case and a plurality of electrodes, mounted on said conductive pattern and in the second area of said case, for electrically connecting said electronic circuit device to an external circuit.

5. An electronic circuit device according to claim 2, wherein said case and said metal substrate have mounting holes for use of fixing said case and said metal substrate to each other, said holes being provided in the third area of said case.

6. An electronic circuit device according to claim 1, wherein said second surface of said metal substrate protrudes from said case.

7. An electronic circuit device according to claim 1, wherein said case has a guide for positionally fixing said metal substrate to prevent the positional deviation of said metal substrate, said guide bringing said case into close contact with said metal substrate along an outer periphery of said metal substrate.

9. An electronic circuit device according to claim 1, wherein said radiating fin is located at said first area of said case.

8. A method of fabricating an electronic circuit device, the method comprising the steps of:

mounting electronic parts on a metal substrate having a first surface and a second surface, said electronic parts being mounted on only the first surface of said metal substrate, said electronic parts including a plurality of electrodes for connecting said electronic circuit device to an external circuit;

installing said metal substrate in a case including a radiating fin which is of a one-piece structure therewith, wherein said metal substrate serves as a cap of said case and the first surface of said metal substrate faces an interior region of said case, said case being provided with an opening for drawing out said plurality of electrodes to an exterior;

injecting laterally a resin into said interior region between said metal substrate and said case from said opening of said case; and

inserting a member into said opening of said case to protect said plurality of electrodes.