Cu ball

• US 9,668,358 B2
• Filed: 12/06/2012
• Issued: 05/30/2017
• Est. Priority Date: 12/06/2012
• Status: Active Grant

• Current Assignee: Senju Metal Industry Company Limited
• Original Assignee: Senju Metal Industry Company Limited
• Inventors: Kawasaki, Hiroyoshi, Hattori, Takahiro, Roppongi, Takahiro, Soma, Daisuke, Sato, Isamu
• Primary Examiner(s): Kastler, Scott
• Assistant Examiner(s): LUK, VANESSA TIBAY
• Application Number:
  US14/649,439
• Publication Number:
  US 20150313025A1
• Time in Patent Office: 1,636 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: B23K 35/0222 for use in soldering, brazing B23K35/0205 takes precedence
• CPC Class Codes: B23K 35/0244 Powders, particles or spheres; Preforms made therefrom
• CPC Class Codes: B23K 35/302 Cu as the principal constituent
• CPC Class Codes: C22C 9/00 Alloys based on copper
• CPC Class Codes: H01L 23/488 consisting of soldered or bonded constructions bump connectors H01L24/01
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 2203/041 Solder preforms in the shape of solder balls
• CPC Class Codes: H05K 3/3463 Solder compositions in relation to features of the printed circuit board or the mounting process
• 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 Cu ball that has low α dose and high sphericity even when containing at least a certain amount of impurity elements other than Cu. Even when the purity thereof is 99.995% or less and U and Th contents are 5 ppb or less in order to suppress any software errors and decrease connection failure, α dose is 0.0200 cph/cm² or less. Further, the sphericity of the Cu ball is unexpectedly improved by making the purity not more than 99.995%.

Claims

1. A Cu ball characterized in that the Cu ball contains a Pb content of 1 ppm or more, and has a sphericity of 0.95 or more, a purity from 99.9% or more to 99.995% or less, an α

dose of 0.0200 cph/cm² or less, a U content of 5 ppb or less, a Th content of 5 ppb or less, and a diameter in the range of 1 μ

m through 1000 μ

m.

2. The Cu ball according to claim 1 wherein the α

dose is 0.0020 cph/cm2 or less.

3. The Cu ball according to claim 1 wherein the α

dose is 0.0010 cph/cm2 or less.

4. A Cu core ball including:

the Cu ball according to claim 1, and

solder plating which covers the Cu ball.

5. A Cu core ball including:

the Cu ball according to claim 2, and

solder plating which covers the Cu ball.

6. A Cu core ball including:

the Cu ball according to claim 1,

Ni plating which covers the Cu ball; and

solder plating which covers the Ni plating.

7. A Cu core ball including:

the Cu ball according to claim 2,

Ni plating which covers the Cu ball; and

solder plating which covers the Ni plating.

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

9. A solder joint using the Cu ball according to claim 2.

10. A solder joint using the Cu core ball according to claim 4.

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

12. A solder joint using the Cu core ball according to claim 6.

13. A solder joint using the Cu core ball according to claim 7.