Cu ball, Cu core ball, solder joint, solder paste, and solder foam

• US 10,137,535 B2
• Filed: 02/04/2014
• Issued: 11/27/2018
• Est. Priority Date: 02/04/2014
• Status: Active Grant

• Current Assignee: Senju Metal Industry Company Limited
• Original Assignee: Senju Metal Industry Company Limited
• Inventors: Kawasaki, Hiroyoshi, Roppongi, Takahiro, Soma, Daisuke, Sato, Isamu
• Primary Examiner(s): Zhu, Weiping
• Application Number:
  US15/116,271
• Publication Number:
  US 20170246711A1
• Time in Patent Office: 1,757 Days
• Field of Search: 148 24
• CPC Class Codes: B22F 1/065 Spherical particles
• CPC Class Codes: B22F 1/17 Metallic particles coated with metal
• 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 35/22 characterised by the composition or nature of the material
• CPC Class Codes: B23K 35/302 Cu as the principal constituent
• CPC Class Codes: C22C 1/0425 Copper-based alloys
• CPC Class Codes: C22C 9/00 Alloys based on copper
• CPC Class Codes: C22C 9/02 with tin as the next major constituent
• CPC Class Codes: C22F 1/00 Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working apparatus for mechanical working of metal B21, B23, B24
• CPC Class Codes: C22F 1/08 of copper or alloys based thereon

Abstract

Provided are a Cu ball, a Cu core ball, a solder joint, solder paste and foamed solder, which are superior in the impact resistance to dropping and can inhibit any occurrence of poor joints a junction defect. An electronic component 60 is constructed by joining a solder bump 30 of a semiconductor chip 10 to an electrode 41 of a printed circuit board 40 with solder paste 12, 42. The solder bump 30 is formed by joining an electrode 11 of the semiconductor chip 10 to the Cu ball 20. The Cu ball 20 according to the present invention contains purity which is equal to or higher than 99.9% and equal to or lower than 99.995%, sphericity which is equal to or higher than 0.95, and Vickers hardness which is equal to or higher than 20 HV and equal to or less than 60 HV.

Claims

1. A Cu ball containing:

purity which is equal to or higher than 99.9% and equal to or lower than 99.995%,

sphericity which is equal to or higher than 0.95, and

Vickers hardness which is equal to or higher than 20 HV and equal to or less than 60 HV,

wherein a content of U is equal to or less than 5 ppb, a content of Th is equal to or less than 5 ppb, a content of at least one of Pb and Bi is more than 1 ppm, and an alpha dose is equal to or less than 0.0200 cph/cm².

2. The Cu ball according to claim 1, wherein a diameter thereof is 1-1000 μ

m.

3. The Cu ball according to claim 1 wherein the Cu ball is coated with a flux layer.

4. The Cu ball according to claim 1, wherein the content of at least one of Pb and Bi is equal to or more than 10 ppm.

5. A solder joint using the Cu ball according to claim 1.

6. Solder paste using the Cu ball according to claim 1.

7. Foamed solder using the Cu ball according to claim 1.

8. A Cu core ball containing:

the Cu ball according to claim 1; and

a solder layer coating the Cu ball.

9. The Cu core ball according to claim 8 wherein sphericity thereof is equal to or higher than 0.95.

10. The Cu core ball according to claim 8 wherein the Cu core ball is coated with a flux layer.

11. A solder joint using the Cu core ball according to claim 8.

12. Solder paste using the Cu core ball according to claim 8.

13. Foamed solder using the Cu core ball according to claim 8.

14. A Cu core ball containing:

the Cu ball according to claim 1; and

a plating layer which includes at least one element selected from a group of Ni, Fe and Co, the plating layer coating the Cu ball.

15. The Cu core ball according to claim 14, further comprising:

a solder layer which coats the plating layer.

16. The Cu core ball according to claim 15, wherein in the solder layer coating the plating layer,

an alpha dose is equal to or less than 0.0200 cph/cm².