Solder paste for fabricating bump

• US 6,692,581 B2
• Filed: 02/20/2003
• Issued: 02/17/2004
• Est. Priority Date: 03/01/2002
• Status: Active Grant

• Current Assignee: Advanced Semiconductor Engineering Inc (ASE Technology Holding Co., Ltd.)
• Original Assignee: Advanced Semiconductor Engineering Inc (ASE Technology Holding Co., Ltd.)
• Inventors: Lin, Chun-Hung, Horng, Ching-Fu, Wu, Tsung-Hua, Tong, Ho-Ming, Chen, Shih-Kuang, Wu, Shyh-Ing, Fang, Jen-Kuang, Lee, Chun-Chi, Tao, Su, Lee, Yung-Chi, Chou, Yu-Chen
• Primary Examiner(s): Jenkins, Daniel J.
• Application Number:
  US10/248,802
• Publication Number:
  US 20030164204A1
• Time in Patent Office: 362 Days
• Field of Search: 148/24, 752/55
• US Class Current: 148/24
• CPC Class Codes: B23K 35/0244 Powders, particles or spheres; Preforms made therefrom
• CPC Class Codes: B23K 35/025 Pastes, creams, slurries
• CPC Class Codes: B23K 35/262 Sn as the principal constituent
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05022 the internal layer being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/05572 the external layer extending out of an opening
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 24/10 Bump connectors bumps on insulating substrates, e.g. chip carriers, H01L23/49816; Manufacturing methods related thereto
• CPC Class Codes: H01L 24/13 of an individual 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 2924/0103 Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01075 Rhenium [Re]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H05K 2201/0266 Size distribution
• CPC Class Codes: H05K 2203/043 : Reflowing of solder coated conductors, not during connection of components, e.g. reflowing solder paste
• CPC Class Codes: H05K 3/3485 : Applying solder paste, slurry or powder thick film methods for applying conductive paste or ink patterns H05K3/12

Abstract

A solder paste for fabricating bumps includes a flux and metallic alloy powder. The metallic alloy powder includes a plurality of low eutectic metallic alloy granules, and the size of these metallic alloy granules is 20-60 μm and the average size of the metallic granules is 35 μm to 45 μm.

Claims

1. A solder paste for fabricating bumps comprising a flax, and

metallic alloy powder including a plurality of metallic alloy granules, wherein a size of the metallic alloy granules ranges from about 20 μ

m to about 60 μ

m.

2. The solder paste of claim 1, wherein the size of the metallic alloy granules ranges from about 35 μ

m to about 45 μ

m.

3. The solder paste of claim 1, wherein a weight percent of the metallic alloy powder ranges from about 85% to about 95% of the solder paste for fabricating the bumps.

4. The solder paste of claim 1, wherein the metallic alloy powder includes ground Sn/Pb alloy.

5. The solder paste of claim 1, wherein the metallic alloy powder includes ground low eutectic metallic alloy.

6. The solder paste of claim 4, wherein a ratio of Pb to Sn in the alloy is 95:

5.

7. The solder paste of claim 4, wherein a ratio of Pb to Sn ranges from about 94% to about 98% of a weight percentage of lead.

8. A solder paste for fabricating bumps comprising a flux, and

metallic alloy powder including a plurality of Sn/Pb alloy granules, wherein a ratio of lead to the Sn/Pb alloy ranges from about 85% to about 95% and a size of the metallic alloy granules ranges from about 20 μ

m to about 60 μ

m.

9. The solder paste of claim 8, wherein the metallic alloy powder includes ground low eutectic metallic alloy.

10. The solder paste of claim 8, wherein the size of the metallic alloy granules ranges from about 35 μ

m to about 45 μ

m.

11. The solder paste of claim 8, wherein a weight percentage of the metallic alloy powder ranges from about 85% to about 95% of the solder paste for fabricating the bumps.

12. A solder paste for fabricating bumps comprising:

a flux, and

metallic alloy powder including a plurality of metallic alloy granules, wherein an average size of the metallic alloy granules is in a range of 35-45 μ

m.