Wire loops, methods of forming wire loops, and related processes

Patent metadata

Field	Value
Publication number	US-9455544-B2
Application number	US-201113812999-A
Country	US
Kind code	B2
Filing date	Aug 3, 2011
Priority date	Aug 10, 2010
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

A method of forming a wire loop is provided. The method includes the steps of: (1) forming a conductive bump on a bonding location using a wire bonding tool; (2) bonding a portion of wire to another bonding location using the wire bonding tool; (3) extending a length of wire from the bonded portion of wire toward the bonding location; (4) lowering the bonding tool toward the bonding location while detecting a height of a tip of the wire bonding tool; and (5) interrupting the lowering of the wire bonding tool during step (4) if the wire bonding tool reaches a predetermined height.

First claim

What is claimed:

1. A method of forming a wire loop comprising the steps of:
(1) forming a conductive bump on a bonding location using a wire bonding tool;
(2) bonding a portion of wire to another bonding location using the wire bonding tool;
(3) extending a length of wire from the bonded portion of wire toward the bonding location;
(4) lowering the wire bonding tool toward the bonding location while detecting a height of a tip of the wire bonding tool; and
(5) interrupting the lowering of the wire bonding tool during step (4) upon the tip of the wire bonding tool reaches a predetermined height, wherein step (1) includes: (a) bonding a free air ball to the bonding location using the wire bonding tool to form a bonded ball; (b) raising the wire bonding tool to a desired height, with a wire clamp open, while paying out wire continuous with the bonded ball; (c) closing the wire clamp; (d) lowering the wire bonding tool to a smoothing height with the wire clamp still closed; (e) smoothing an upper surface of the bonded ball, with the wire clamp still closed, using the wire bonding tool; and (f) raising the wire bonding tool, with the wire clamp still closed, to separate the bonded ball from wire engaged with the wire bonding tool, thereby forming the conductive bump on the bonding location.

2. The method of claim 1 wherein the predetermined height is a bonding height detected during step (1).

3. The method of claim 1 wherein the predetermined height is lower than a bonding height detected during step (1) by an amount equal to a height threshold.

4. The method of claim 3 wherein the height threshold is less than 10 micrometers.

5. The method of claim 1 wherein the predetermined height is a smoothing height used for smoothing the conductive bump formed during step (1), the smoothing height being detected during step (1).

6. The method of claim 1 wherein the predetermined height is lower than a smoothing height used for smoothing the conductive bump formed during step (1) by an amount equal to a height threshold, the smoothing height being detected during step (1).

7. The method of claim 6 wherein the height threshold is less than 10 micrometers.

8. The method of claim 1 wherein step (3) includes extending the length of wire from the bonded portion such that the length of wire is continuous with the bonded portion.

9. The method of claim 1 wherein step (b) includes raising the wire bonding tool to the desired height, the desired height being a tail height of a bumping process.

10. A method of detecting if a conductive bump is in a desired position in connection with formation of a stand-off stitch bond wire loop, the method comprising the steps of:
(1) forming a conductive bump on a bonding location using a wire bonding tool, the conductive bump being configured to be a stand-off for a stand-off stitch bond wire loop;
(2) bonding a portion of wire to another bonding location using the wire bonding tool;
(3) extending a length of wire from the bonded portion of wire toward the bonding location;
(4) lowering the wire bonding tool toward the bonding location while detecting a height of a tip of the wire bonding tool; and
(5) interrupting the lowering of the wire bonding tool during step (4) upon the wire bonding tool reaches a predetermined height, wherein step (1) includes: (a) bonding a free air ball to the bonding location using the wire bonding tool to form a bonded ball; (b) raising the wire bonding tool to a desired height, with a wire clamp open, while paying out wire continuous with the bonded ball; (c) closing the wire clamp; (d) lowering the wire bonding tool to a smoothing height with the wire clamp still closed; (e) smoothing an upper surface of the bonded ball, with the wire clamp still closed, using the wire bonding tool; and (f) raising the wire bonding tool, with the wire clamp still closed, to separate the bonded ball from wire engaged with the wire bonding tool, thereby forming the conductive bump on the bonding location.

11. The method of claim 10 wherein the predetermined height is a bonding height detected during step (1).

12. The method of claim 10 wherein the predetermined height is lower than a bonding height detected during step (1) by an amount equal to a height threshold.

13. The method of claim 12 wherein the predetermined threshold is less than 10 micrometers.

14. The method of claim 10 wherein the predetermined height is a smoothing height used for smoothing the conductive bump formed during step (1), the smoothing height being detected during step (1).

15. The method of claim 10 wherein the predetermined height is lower than a smoothing height used for smoothing the conductive bump formed during step (1) by an amount equal to a height threshold, the smoothing height being detected during step (1).

16. The method of claim 15 wherein the height threshold is less than 10 micrometers.

17. The method of claim 10 wherein step (3) includes extending the length of wire from the bonded portion such that the length of wire is continuous with the bonded portion.

18. The method of claim 10 wherein step (b) includes raising the wire bonding tool to the desired height, the desired height being a wire tail height of a bumping process.

Assignees

• Gillotti Gary S
• Kulicke & Soffa Ind Inc

Inventors

• Gillotti Gary S

Classifications

• H10W72/522

  Multilayered bond wires, e.g. having a coating concentric around a core · CPC title

• H10W72/5524

  comprising aluminium [Al] · CPC title

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W72/59

  Bond pads specially adapted therefor · CPC title