Electronic control unit and method thereof

• US 20060171127A1
• Filed: 01/03/2006
• Published: 08/03/2006
• Est. Priority Date: 01/04/2005
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Sasaki, Masahiro, Mayuzumi, Takuya, Kadoya, Kiyoomi
• Granted Patent: US 7,417,873 B2
• Time in Patent Office: Days
• US Class Current: 361/752
• CPC Class Codes: B29C 45/14377 using an additional insert, e.g. a fastening element
• CPC Class Codes: B29C 45/14655 connected to or mounted on a carrier, e.g. lead frame
• CPC Class Codes: B60R 16/0239 Electronic boxes
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 25/165 Containers
• 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 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/09745 Recess in conductor, e.g. in pad or in metallic substrate
• CPC Class Codes: H05K 2201/10189 Non-printed connector
• CPC Class Codes: H05K 2201/10371 Shields or metal cases
• CPC Class Codes: H05K 2201/1056 Metal over component, i.e. metal plate over component mounted on or embedded in PCB
• CPC Class Codes: H05K 2203/1316 Moulded encapsulation of mounted components
• CPC Class Codes: H05K 2203/1572 Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
• CPC Class Codes: H05K 3/0061 onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 5/0034 having an overmolded housing covering the PCB

Abstract

In resin-molded engine control unit, a coil, an electrolytic capacitor, a microprocessor, electronic parts and a connector terminal are mounted on a board. Inside a cover fixed on the board, a resin-free region is formed. The coil, the electrolytic capacitor and the microprocessor, which should not be sealed with resin, are mounted in the resin-free region, while the board and the electronic parts which are not capped by the cover are sealed with a resin.

Claims

1. An electronic control unit comprising:

a board having a circuit formed thereon;

a plurality of circuit components, including at least a first component and a second component, which are mounted on the board;

a connector which is connected to the circuit formed on the board and is provided with a terminal to electrically connect the circuit to the outside; and

a cover which is fixed onto the board to cap said first component;

wherein the connector and the board are at least partially sealed with a resin, and the electronic part is sealed with the resin.

2. The electronic control unit according to claim 1, wherein said first component comprises a circuit element that generates heat or discharges gases which would adversely affect operation of the control unit.

3. The electronic control unit according to claim 1, wherein:

said first component comprises an electrolytic capacitor, and said second component comprises an electronic part; and

the inside of the cover forms a resin-free region.

4. The electronic control unit according to claim 3,

wherein the electrolytic capacitor is fixed to the cover by an adhesive.

5. The electronic control unit according to claim 1,

wherein the cover is made of a material selected from the group consisting of a plastic and metal.

6. The electronic control unit according to claim 4,

wherein the cover is made of metal, and is grounded.

7. The electronic control unit according to claim 1, further comprising a metal base fixed to the board.

8. The electronic control unit according to claim 7, wherein:

the metal base forms a resin-free region with the board; and

a second electronic part is mounted on the board in the resin-free region.

9. The electronic control unit according to claim 1,

wherein the resin has a linear expansion coefficient in the range of 8 to 24 ppm/°

C., an elastic modulus in the range of 8 to 39 GPa, and a glass transition temperature in the range of 80 to 200°

C.

10. The electronic control unit according to claim 1, wherein:

said first component comprises a microprocessor for controlling an engine;

said second component comprises an electronic part; and

an inside of the cover forms a resin-free region which is not filled with the resin.

11. The electronic control unit according to claim 10, wherein the top of the cover is detachable.

12. The electronic control unit according to claim 1, wherein:

said first component comprises a pin insertion type electronic part;

said second component comprises a surface mount type electronic part; and

an inside of the cover forms a resin-free region.

13. The electronic control unit according to claim 12, wherein the pin insertion type electronic part is a coil.

14. The electronic control unit according to claim 1, wherein:

said plurality of circuit components includes a third component, said components comprising first, second and third electronic parts, respectively, which are mounted on the board;

a first cover is fixed onto the board to cap the first electronic part;

a second cover is fixed onto the board to cap the second electronic part;

the third electronic part is sealed by said resin; and

an inside of the first cover and the inside of the second cover respectively form resin-free regions.

15. The electronic control unit according to claim 14, wherein:

the first cover is fixed onto a first main side of the board; and

the second cover is fixed onto a second main side of the board which is opposed to the first main side.

16. The electronic control unit according to claim 15, wherein the first cover and the second cover are located so as to face each other through the board.

17. The electronic control unit according to claim 15, wherein:

the first electronic part is a pin insertion type electronic part; and

the second and the third electronic parts are surface mount type electronic parts.

18. The electronic control unit according to claim 17, wherein:

the first electronic part is a coil; and

the second electronic part is a microprocessor for controlling an engine.

19. The electronic control unit according to claim 14, wherein the electronic control unit has a metal base fixed onto the board.

20. The electronic control unit according to claim 19,

wherein the first electronic part is an electrolytic capacitor, and

the second electronic part is a microprocessor for controlling an engine.

28. The electronic control unit according to claim 1, wherein:

said first component includes a wireless communication module;

the cover is made of a plastic; and

the wireless communication module comprises a wireless communication IC and a coil.

21. An electronic control unit comprising:

a metal base;

a printed board fixed onto the metal base;

at least one cover fixed onto the printed board;

an electrolytic capacitor, a coil and a microprocessor which are mounted inside the at least one cover on the printed board;

wherein,

a plurality of electronic parts which are mounted outside the at least one cover on the printed board; and

a connector which is provided with a terminal connected to the printed board;

wherein,

the printed board and the plurality of electronic parts outside the at least one cover are sealed with a resin; and

a space formed by fixing the printed board onto the metal base and the inside of the at least one cover are resin-free regions.

22. The electronic control unit according to claim 21, wherein:

the cover is made of a metal; and

the electrolytic capacitor and the coil are fixed to the cover by using an adhesive.

23. The electronic control unit according to claim 21, wherein the top of the cover is detachable.

24. The electronic control unit according to claim 21, wherein the cover is sealed with the resin.

25. The electronic control unit according to claim 21, wherein said space and the cover are located so as to face each other via the board.

26. The electronic control unit according to claim 21, wherein:

the electrolytic capacitor, the coil and the microprocessor are mounted on a first main side of the board;

a surface mount type electronic part is mounted on a second main side of the board which is opposite to the first main side;

the at least one cover comprises a first cover and a second cover;

the first cover is fixed onto the board to cap the electrolytic capacitor and the coil;

the second cover is fixed onto the board to cap the microprocessor; and

the insides of the first and second covers are respectively resin-free regions.

27. The electronic control unit according to claim 26, wherein the surface mount type electronic part is mounted in the resin-free region on the board.

29. A method of manufacturing an electronic control unit comprising the steps of:

mounting a plurality of first electronic parts and a plurality of second electronic parts on a board having a circuit formed thereon;

mounting a connector provided with a terminal to be used for connection to the circuit on the board;

attaching a metal base to the board;

applying an adhesive to the first electronic parts;

fixing a cover to the board and the first electronic parts so as to cap the first electronic parts;

preparing a molding die in order to at least partially seal the board and seal the second electronic parts; and

removing the die.

30. The method of manufacturing an electronic control unit according to claim 29, wherein:

a plurality of the first electronic parts include an electrolytic capacitor; and

the board and the second electronic parts are sealed by injecting a resin through the gate of the die.

31. The method of manufacturing an electronic control unit according to claim 29, wherein:

a plurality of the first electronic parts include an electrolytic capacitor; and

the board and the second electronic parts are sealed by placing a resin pellet on the board and performing resin molding by thermally liquefying the resin pallet and closing the molding die.