Method and apparatus for joining printed circuit boards

• US 6,234,820 B1
• Filed: 07/21/1997
• Issued: 05/22/2001
• Est. Priority Date: 07/21/1997
• Status: Expired due to Fees

• Current Assignee: Rambus Inc.
• Original Assignee: Rambus Inc.
• Inventors: Perino, Donald V., Dillon, John B.
• Primary Examiner(s): VU, HIEN D
• Application Number:
  US08/898,141
• Time in Patent Office: 1,401 Days
• Field of Search: 439/67, 439/73, 439/326-329, 439/492, 439/493, 439/499, 439/496
• US Class Current: 439/326
• CPC Class Codes: H01R 12/7005 Guiding, mounting, polarizing or locking means; Extractors for printed circuit boards H05K
• CPC Class Codes: H01R 12/725 containing contact members presenting a contact carrying strip, e.g. edge-like strip
• CPC Class Codes: H01R 13/2414 conductive elastomers

Abstract

A method and apparatus for joining printed circuit boards is provided. A socket is attached to a mother board. A connector is attached to a daughter board. The traces on the daughter board are connected to signal leads, which are wrapped around an elastomer. The socket and the connector are engaged, such that the mother board is coupled to a daughter board, and the traces on the mother board are coupled to the signal leads of the daughter board.

Claims

1. An electrical apparatus comprising:

(1) a first connector coupled to a first circuit board, wherein the first connector comprises;

(a) an elastomer;

(b) a first flex circuit coupled to the first circuit board and having a first connection portion coupled to the elastomer for spring force;

(c) a cam follower positioned at one end of the first connector;

(2) a second connector coupled to a second circuit board, wherein the second connector comprises;

(a) a second flex circuit coupled to the second circuit board and having a second connection portion;

(b) a socket with an opening that comprises;

(i) an insertion portion with a side angled from a plane of the second circuit board;

(ii) a central portion with a side substantially parallel to the plane of the second circuit board, wherein the opening allows the cam follower to be inserted laterally and then rotated when the first connector is rotated with respect to the second connector in order to provide a wiping action between the first and second connection portions of the first and second flex circuits when the first connector is coupled to the second connector.

2. The electrical apparatus of claim 1, wherein the second connector further comprises a latch for keeping the first circuit board in place.

3. The electrical apparatus of claim 1, wherein the first flex circuit of the first connector is electrically coupled to a dynamic random access memory (DRAM) coupled to the first circuit board.

4. The electrical apparatus of claim 3, wherein the second flex circuit of the second connector is electrically coupled to a DRAM controller coupled to the second circuit board.

5. The electrical apparatus of claim 1, wherein the first connection portion of the first flex circuit of the first connector comprises:

a flexible layer in contact with the elastomer;

a conductive layer comprising a plurality of signal traces;

a plurality of layers residing over the signal traces.

6. The electrical apparatus of claim 5, wherein the flexible layer comprises polymide, wherein the signal traces are comprised of copper, and wherein the plurality of layers residing over the signal traces comprise a first layer of nickel and a second layer of gold.

7. The electrical apparatus of claim 1, wherein the second connection portion of the second flex circuit of the second connector comprises:

a first layer in contact with the second board;

a conductive layer comprising leads;

a plurality of layers residing over the leads.

8. The electrical apparatus of claim 7, wherein the first logic layer comprises polymide, wherein the leads of the conductive layer are comprised of copper, and wherein the plurality of layers residing over the leads comprise a nickel layer and a gold layer.

9. The electrical apparatus of claim 1, wherein the elastomer is selected from the group consisting of fluorosilicone, silicone rubber, and fluoroelastomer.

10. An electrical apparatus comprising:

(1) a first connector coupled to a first circuit board, wherein the first connector comprises;

(a) an elastomer residing at an end of the first circuit board;

(b) first signal leads wrapped around the elastomer;

(c) a cam follower coupled to a side of the first circuit board positioned at one end of the fir connector;

(2) a second connector coupled to a second circuit board, wherein the second connector comprises;

(a) second signal leads wrapped around an end of the second circuit board;

(b) a socket with an opening that comprises;

(i) an insertion portion with a side angled from a plane of the second board;

(ii) a central portion with a side substantially parallel to the plane of the second board, wherein the opening allows the cam follower to be inserted laterally and then rotated when the first connector is rotated with respect to the second connector in order to provide a wiping action between the first and second signal leads when the first connector is coupled to the second connector.

11. The electrical apparatus of claim 10, wherein the cam follower and the socket are comprised of plastic.

12. The electrical apparatus of claim 10, wherein the cam follower and the socket are comprised of metal.

13. An electrical apparatus comprising:

(1) a first connector coupled to a first circuit board, wherein the first connector comprises;

(a) a base;

(b) an elastomer residing at an end of the base of the first connector;

(c) first signal leads wrapped around the elastomer;

(d) a protrusion coupled to the first circuit board and having a curved end;

(2) a second connector coupled to a second circuit board, wherein the second connector comprises;

(a) a base;

(b) second signal leads wrapped around an end of the base of the second connector;

(c) a hook coupled to the second circuit board to engage the curved end of the protrusion of the first connector in order to connect the first signal leads of the first connector to the second signal leads of the second connector when the first connector couples to the second connector.

14. The electrical apparatus of claim 13, wherein the curved end of the protrusion of the first connector is substantially oval-shaped.

15. The electrical apparatus of claim 13, wherein the curved end of the protrusion of the first connector is substantially shaped like a knob.

16. The electrical apparatus of claim 13, wherein the elastomer to glued to the end of the base of the first connector.