Circuit package and method for making the same

• US 6,885,562 B2
• Filed: 12/28/2001
• Issued: 04/26/2005
• Est. Priority Date: 12/28/2001
• Status: Expired due to Fees

• Current Assignee: Physio-Control Incorporated (Stryker Corporation)
• Original Assignee: Medtronic Physio-Control Manufacturing Corp. (Medtronic Plc)
• Inventors: McIlnay, Ronald G., Abbbenhouse, Martin S.
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): DINH, TUAN T
• Application Number:
  US10/033,595
• Publication Number:
  US 20030123240A1
• Time in Patent Office: 1,215 Days
• Field of Search: 174 521- 522, 174260-262, 174/35.R, 361801-802, 361/772, 361/760, 361/764, 361/781, 439/76.1, 29840-846, 257/692
• US Class Current: 361/772
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 23/5385 Assembly of a plurality of insulating substrates
• CPC Class Codes: H01L 25/0652 the devices being arranged next and on each other, i.e. mixed assemblies
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/13034 Silicon Controlled Rectifier [SCR]
• CPC Class Codes: H01L 2924/1305 Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/13055 Insulated gate bipolar transistor [IGBT]

Abstract

A circuit package with improved heat dissipation properties for high-power circuits. In one embodiment, the circuit package comprises two circuit boards positioned in different planes, at least one brace affixed between the two circuit boards, a molded housing enclosing an area between the circuit boards, and a plurality of electrically conductive leads extending from the sides of the circuit package. The molded housing is configured to expose at least one surface of the circuit boards to the exterior surface of the circuit package. The leads are configured in a J-shape, which allows the circuit package to be mounted in an upright position. The brace functions as a flexible spacer for holding the two circuit boards in position during the application of the molded housing. In one embodiment, a H-bridge circuit is configured on the first and second circuit boards of the circuit package.

Claims

1. A circuit package for an electronic device, comprising:

a first circuit board positioned in a first plane;

a second circuit board positioned in a second plane;

at least one brace coupled to the first circuit board and the second circuit board;

at least two electrically conductive leads extending from at least one surface of the circuit package; and

a housing formed between the first and second circuit boards that covers at least one surface of each circuit board and leaves another surface of each circuit board substantially uncovered to thereby expose the uncovered surface to an environment exterior of the circuit packages,

wherein the housing includes an external surface that is flush with the uncovered surfaces of each circuit board.

2. The circuit pads of claim 1, wherein the housing comprises a bottom surface that includes a cavity formed therein.

3. The circuit package of claim 1, wherein the first and second circuit boards are each made of a single sided direct bonded copper substrate.

4. The circuit package of claim 1, wherein the brace comprises:

an elongate body;

at least two arm portions extending from the body at least one of the arm portions coupled to the first circuit board and another of the arm portions coupled to the second circuit board; and

at least two leg portions extending from the body each leg portion operable to function as a flexible spacer between the first and second circuit boards.

5. The circuit package of claim 1, wherein the circuit package comprises a first brace and a second brace, each brace positioned between the first and second circuit boards and coupling the first circuit board to the second circuit board, the first and second braces are operable to function as a flexible spacer between the first and second circuit boards.

6. The circuit package of claim 1, further comprising:

a plurality of electrically conductive leads adapted to mount the circuit package on an external surface, and configured to support the circuit package in an upright position relative to the external surface.

7. The circuit package of claim 1, wherein the housing is made from an injected molded plastic.

8. The circuit package of claim 1, further comprising:

an H-bridge circuit mounted on at least one of the first and second circuit boards.

9. The circuit package of claim 8, wherein the H-bridge circuit comprises:

a first leg including a first lead and a first output node, and a first switch coupled therebetween;

a second leg including a second lead and a second output node, and a second switch coupled therebetween;

a third leg including the first lead and the second output node, and a third switch coupled therebetween;

a fourth leg including the second lead and the first output node, and a forth switch coupled therebetween.

10. A circuit package for an electronic device, comprising:

a first circuit board positioned in a first plane;

a second circuit board positioned in a second plane and in contact with the first circuit board;

at least one brace coupled to the first circuit board and the second circuit board;

a plurality of electrically conductive leads extending from the circuit package and adapted to mount the circuit package on an external surface; and

a housing formed to surround at least a portion of the first and second circuit boards;

a plurality of components mounted on the first and second circuit boards in a region that is surrounded by the housing.

11. The circuit package of claim 10, wherein the housing forms a surface between at least two electrically conductive leads of the circuit package, wherein the surface of the circuit package comprises a cavity formed therein.

12. The circuit package of claim 10, wherein the first and second circuit boards are made of a single-sided direct bonded copper substrate.

13. The circuit package of claim 10, wherein the brace is an electrical conductor.

14. The circuit package of claim 10, wherein the housing is made from an injected molded plastic.

15. The circuit package of claim 10, further comprising

an H-bridge circuit mounted on at least one of the first and second circuit board.

16. The circuit package of claim 15, wherein the H-bridge circuit comprises:

a first leg including a first lead and a first output node, and a fist switch coupled therebetween;

a second leg including a second lead and a second output node, and a second switch coupled therebetween;

a third leg including the first lead and the second output node, and a third switch coupled therebetween;

a fourth leg including the second lead and the first output node, and a fourth switch coupled therebetween.

17. A method of manufacturing a circuit package comprising the steps of:

positioning a first circuit board in a first plane;

positioning a second circuit board in a second plane;

coupling at least two brace members to the first and second circuit boards;

mounting at least two electrically conductive leads to at least one of the first and second circuit boards; and

injecting a molding material between the first and second circuit boards to form a housing that substantially covers at least one surface of each of the circuit boards and leaves another surface of each circuit board substantially uncovered to thereby expose at least one surface of the first and second circuit boards.

18. The method of claim 17, further comprising the step of:

coupling the plurality of conductive leads to the first and second circuit boards.