Circuit package and method for making the same

• US 20030123240A1
• Filed: 12/28/2001
• Published: 07/03/2003
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Physio-Control Incorporated (Stryker Corporation)
• Original Assignee: Medtronic Physio-Control Manufacturing Corp.
• Inventors: Abbenhouse, Martin S., McIlnay, Ronald G.
• Granted Patent: US 6,885,562 B2
• Time in Patent Office: Days
• US Class Current: 361/804
• 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 positioned between the first and second circuit boards, the brace formed to affix the first circuit board to the second circuit board, wherein the brace is operable to function as a flexible spacer between the first and second circuit boards;

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

a housing formed between the first and second circuit boards, wherein the housing is formed to surround one side of the each circuit board, thereby allowing one surface of each circuit board to be exposed to the exterior surface of the circuit package.

2. The circuit package of claim 1, wherein the housing forms a bottom surface between at least two electrically conductive leads of the circuit package, wherein the bottom surface of the circuit package comprises a cavity formed therein.

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

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

an elongated body;

at least two arm portions positioned to extend from the body, wherein the arm portions are configured to affix the first circuit board to the second circuit board; and

at least two leg portions positioned to extend from the body, wherein the two leg portions are 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 positioned between the first and second circuit boards, the first and second braces affix 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, wherein the plurality of electrically conductive leads are adapted for mounting the circuit package on an external surface, and wherein the plurality of electrically conductive leads are configured to support the circuit package in an upright position.

7. The circuit package of claim 1, wherein an external surface of the housing forms a substantially flush surface with the exposed surfaces of each circuit board.

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

9. The circuit package of claim 1, further comprising an H-bridge circuit mounted on the first and second circuit boards.

10. The circuit package of claim 7, wherein the H-bridge circuit comprises:

a first switch in a first leg of the H-bridge output circuit coupled between a first lead and a first output node;

a second switch in a second leg of the H-bridge output circuit coupled between a second lead and a second output node;

a third switch in a third leg of the H-bridge output circuit coupled between the first lead and the second output node; and

a fourth switch in a fourth leg of the H-bridge output circuit coupled between the second lead and the first output node.

11. 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, wherein the first and second circuit boards are positioned against one another;

at least one brace operable to affix the first circuit board to the second circuit board;

a plurality of electrically conductive leads extending from at least one external surface of the circuit package, the plurality of electrically conductive leads adapted to mount the circuit package on an external surface in an upright position; and

a housing formed to surround at least a portion of the first and second circuit boards and a plurality of components mounted on the first and second circuit boards.

12. The circuit package of claim 11, 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.

13. The circuit package of claim 11, wherein the first and second circuit boards are made of a single-sided direct bonded copper substrate.

14. The circuit package of claim 11, wherein the brace is operable to function as a conductor between a plurality of circuit components on the first and second circuit boards.

15. The circuit package of claim 11, wherein the housing is made from an injected molded plastic.

16. The circuit package of claim 11, further comprising an H-bridge circuit mounted on the first and second circuit boards.

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

a first switch in a first leg of the H-bridge output circuit coupled between a first lead and a first output node;

a second switch in a second leg of the H-bridge output circuit coupled between a second lead and a second output node;

a third switch in a third leg of the H-bridge output circuit coupled between the first lead and the second output node; and

a fourth switch in a fourth leg of the H-bridge output circuit coupled between the second lead and the first output node.

18. A method for manufacturing a circuit package, wherein the method comprises:

positioning a first circuit board in a first plane;

positioning a second circuit board in a second plane;

affixing at least two brace members between the first and second circuit boards, thereby affixing the first circuit board to the second circuit board;

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

forming a housing by injecting a molding material between the first and second circuit boards, thereby forming a top surface and a bottom surface that extend between the first and second circuit boards, wherein the housing is configured to expose at least one surface of the first and second circuit boards.

19. The method of claim 18, further comprising the step of mounting a plurality of conductive leads to the first and second circuit boards.