Cu Core Ball, Solder Joint, Solder Paste and Formed Solder

• US 20190375053A1
• Filed: 06/10/2019
• Published: 12/12/2019
• Est. Priority Date: 06/12/2018
• Status: Active Grant

• Current Assignee: Senju Metal Industry Company Limited
• Original Assignee: Senju Metal Industry Company Limited
• Inventors: Kawasaki, Hiroyoshi, Kondoh, Shigeki, Sudo, Hiroki, Tsuchiya, Masato, Yashima, Takashi, Roppongi, Takahiro, Soma, Daisuke
• Granted Patent: US 10,888,959 B2
• Time in Patent Office: Days
• CPC Class Codes: B22F 1/06 Metallic powder characterised by the shape of the particles nanosized particles B22F1/054
• CPC Class Codes: B22F 1/065 Spherical particles
• CPC Class Codes: B22F 1/17 Metallic particles coated with metal
• CPC Class Codes: B22F 2301/10 Copper
• CPC Class Codes: B22F 2301/30 Low melting point metals, i.e. Zn, Pb, Sn, Cd, In, Ga
• CPC Class Codes: B22F 2303/30 Coating alloy
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 7/062 involving the connection or repairing of preformed parts
• CPC Class Codes: B23K 35/025 Pastes, creams, slurries
• 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: H01L 2224/16 of an individual bump connector

Abstract

The Cu core ball contains a Cu ball and a solder layer for covering a surface of the Cu ball. The Cu ball contains at least one element selected from Fe, Ag, and Ni in a total amount of 5.0 or more to 50.0 ppm by mass or lower, S in an amount of 0 or more to 1.0 ppm by mass or lower, P in an amount of 0 or more to less than 3.0 ppm by mass, and remainder of Cu and inevitable impurities. The Cu ball contains purity which is 99.995% or higher and 99.9995% by mass or lower, and sphericity which is 0.95 or higher. The solder layer includes Ag in an amount of more than 0 to 4.0% by mass or less, Cu in an amount of more than 0 to 3.0% by mass or less, and remainder of Sn.

Claims

1. A Cu core ball comprising:

a Cu ball, and

a solder layer for covering a surface of the Cu ball,

wherein the Cu ball contains at least one element selected from a group of Fe, Ag and Ni in a total amount of 5.0 ppm by mass or more to 50.0 ppm by mass or lower, S in an amount of 0 ppm by mass or more to 1.0 ppm by mass or lower, P in an amount of 0 ppm by mass or more to less than 3.0 ppm by mass, and remainder of Cu and inevitable impurities,

wherein the Cu ball contains purity which is 99.995% by mass or higher to 99.9995% by mass or lower, and sphericity which is 0.95 or higher, and

wherein the solder layer includes Ag in an amount of more than 0% by mass to 4.0% by mass or less, Cu in an amount of more than 0% by mass to 3.0% by mass or less, and remainder of Sn.

2. The Cu core ball according to claim 1 wherein the solder layer includes Ag in an amount of 0.1% by mass or more to 2.0% by mass or less.

3. The Cu core ball according to claim 1 wherein the solder layer includes Cu in an amount of 0.1% by mass or more to 1.0% by mass or less.

4. The Cu core ball according to claim 1 wherein the sphericity thereof is 0.98 or higher.

5. The Cu core ball according to claim 1 wherein the sphericity thereof is 0.99 or higher.

6. The Cu core ball according to claim 1 wherein the Cu core ball contains alpha dose which is 0.0200 cph/cm² or lower.

7. The Cu core ball according to claim 1 wherein the Cu core ball contains alpha dose which is 0.0010 cph/cm² or lower.

8. The Cu core ball according to claim 1, further containing a metal layer which covers a surface of the Cu ball wherein the solder layer covers a surface of the metal layer and the sphericity of the Cu core ball is 0.95 or higher.

9. The Cu core ball according to claim 8 wherein the sphericity thereof is 0.98 or higher.

10. The Cu core ball according to claim 8 wherein the sphericity thereof is 0.99 or higher.

11. The Cu core ball according to claim 8 wherein the Cu core ball contains alpha dose which is 0.0200 cph/cm² or lower.

12. The Cu core ball according to claim 8 wherein the Cu core ball contains alpha dose which is 0.0010 cph/cm² or lower.

13. The Cu core ball according to claim 1 wherein the Cu ball contains a diameter which is within a range of 1 μ

m or more and 1000 μ

m or less.

14. The Cu core ball according to claim 8 wherein the Cu ball contains a diameter which is within a range of 1 μ

m or more and 1000 μ

m or less.

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

16. The solder joint according to claim 15, the Cu core ball further containing a metal layer which covers a surface of the Cu ball, wherein the solder layer covers a surface of the metal layer and the sphericity of the Cu core ball is 0.95 or higher.

17. Solder paste using the Cu core ball according to claim 1.

18. The solder paste according to claim 17, the Cu core ball further containing a metal layer which covers a surface of the Cu ball, wherein the solder layer covers a surface of the metal layer and the sphericity of the Cu core ball is 0.95 or higher.

19. Formed solder using the Cu core ball according to claim 1.

20. The formed solder according to claim 19, the Cu core ball further containing a metal layer which covers a surface of the Cu ball, wherein the solder layer covers a surface of the metal layer and the sphericity of the Cu core ball is 0.95 or higher.