Lead grid array integrated circuit

• US 5,210,939 A
• Filed: 04/17/1992
• Issued: 05/18/1993
• Est. Priority Date: 04/17/1992
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Mallik, Debendra, Bhattacharyya, Bidyut K.
• Primary Examiner(s): Arbes, Carl J.
• Application Number:
  US07/870,542
• Time in Patent Office: 396 Days
• Field of Search: 29/832, 29/830, 29/827, 29/739, 437/209
• US Class Current: 29/840
• CPC Class Codes: H01L 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• CPC Class Codes: H01L 23/49861 Lead-frames fixed on or encapsulated in insulating substrates H01L23/4985, H01L23/49805 take precedence
• CPC Class Codes: H01L 24/81 using a bump connector
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H05K 2201/10772 Leads of a surface mounted component bent for providing a gap between the lead and the pad during soldering
• CPC Class Codes: H05K 2201/10946 Leads attached onto leadless component after manufacturing the component
• CPC Class Codes: H05K 3/3426 characterised by the leads
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/53174 : Means to fasten electrical component to wiring board, base, or substrate

Abstract

A method for attaching an array of flexible leads to the bottom of an integrated circuit package. There is provided a sheet of electrically conductive material. A plurality of slots are punched into the sheet, such that there is formed a plurality of beams. The beams are then bent into a spring shape. The sheet is placed over an integrated circuit package which has an array of contact pads extending across a bottom surface of the package. The beams are aligned and attached to the contact pads. The beams are then cut and separated from the remainder of the sheet. The sheet is removed, wherein there is constructed an integrated circuit package that has a two dimensional array of flexible leads.

Claims

1. A method of constructing an integrated circuit package, comprising the steps of:

a) providing a module having a plurality of contact pads;

b) providing a sheet of electrically conductive material;

c) removing portions of said sheet so that there is created a two dimensional array of beams;

d) bending said beams;

e) placing said sheet adjacent to said module so that all of said beams are aligned with said contact pads;

f) attaching base portions of said beams to said contact pads;

g) cutting said base portions to separate said beams from said sheet; and

,

h) removing said sheet from said module.

2. The method as recited in claim 1, wherein each said beam is created by removing a C shaped slot in said sheet.

3. The method as recited in claim 2, wherein said beams are bent into an S shape.

4. The method as recited in claim 2, wherein said C shaped slots are etched.

5. The method as recited in claim 2, wherein said C shaped slots are punched.

6. The method as recited in claim 1, wherein each said beam is created by removing a pair of slots.

7. The method as recited in claim 6, wherein said beams are bent into a segment of a cylinder.

8. The method as recited in claim 6, wherein said slots are etched.

9. The method as recited in claim 6, wherein said slots are punched.

10. The method as recited in claim 1, wherein said sheet is removed from said beams by cutting at least one base portion of said beams.

11. The method as recited in claim 10, wherein said beams are cut with a laser.

12. The method as recited in claim 1, further comprising the steps of providing alignment means to align said beams and said contact pads, and aligning said beams to said contact pads before said beams are attached to said contact pads.

13. A method of constructing an integrated circuit package, comprising the steps of:

a) providing a module having a plurality of contact pads and at least two alignment studs;

b) providing a sheet of electrically conductive material having at least two alignment holes;

c) removing portions of said sheet so that there is created a two-dimensional array of beams;

d) bending said beams;

e) placing said sheet over said module such that said alignment studs extend through said alignment holes and said sheet is adjacent ot said module, such that all of said beams are aligned with said contact pads;

e) attaching base portions of said beams to said contact pads;

f) cutting said base portions to separate said beams from said sheet; and

,

g) removing said sheet from said module.

14. The method as recited in claim 13, wherein each said beam is created by removing a C shaped slot in said sheet.

15. The method as recited in claim 14, wherein said beams are bent into an S shape.

16. The method as recited in claim 15, wherein said C shaped slots are etched.

17. The method as recited in claim 15, wherein said C shaped slots are punched.

18. The method as recited in claim 13, wherein each said beam is created by removing a pair of slots.

19. The method as recited in claim 18, wherein said beams are bent into a segment of a cylinder.

20. The method as recited in claim 19, wherein said slots are etched.

21. The method as recited in claim 19, wherein said slots are punched.