Cu core ball, solder paste, formed solder, Cu core column, and solder joint

Patent metadata

Field	Value
Publication number	US-10322472-B2
Application number	US-201415034194-A
Country	US
Kind code	B2
Filing date	Nov 4, 2014
Priority date	Nov 5, 2013
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

Provided are a Cu core ball and a cu core column, which achieve dropping strength and strength against heat cycle. The Cu core ball ( 1 ) contains a Cu ball ( 2 ) made of Cu or a Cu alloy and a solder layer ( 3 ) which is made of a solder alloy composed of Sn and Cu and covers the Cu ball ( 2 ). The solder layer ( 3 ) contains not less than 0.1% through not more than 3.0% of Cu and the remainder is composed of Sn and impurities.

First claim

The invention claimed is:

1. A Cu core ball comprising:
a spherical core layer; and
a solder layer made of a solder alloy composed of Sn and Cu, the solder layer covering the core layer,
wherein in the core layer, purity of Cu is not less than 99.9% through not more than 99.995%;
a content of Pb is 10 ppm to 50 ppm;
a content of Bi is 10 ppm to 50 ppm;
a content of U is 5 ppb or less;
a content of Th is 5 ppb or less;
sphericity is 0.95 or more; and
an emitting α dose is 0.0200 cph/cm2 or less;

wherein in the solder layer, a content of U is 5 ppb or less; and
a content of Th is 5 ppb or less; and

wherein an α dose emitting from the Cu core ball is 0.0200 cph/cm2 or less.

2. The Cu core ball of claim 1 , wherein the solder layer comprises not less than 0.1% through not more than 3.0% of Cu, the remainder being composed of Sn and impurities.

3. The Cu core ball of claim 2 , wherein the core layer covered by a layer made of at least one element selected from Ni and Co is covered by the solder layer.

4. A solder paste comprising the Cu core ball of claim 1 .

5. A solder joint comprising the Cu core ball of claim 1 .

Assignees

• Senju Metal Industry Co

Inventors

• Hattori Takahiro
• Soma Daisuke
• Roppongi Takahiro
• Sato Isamu

Classifications

• H10W72/952

  comprising metals or metalloids, e.g. PbSn, Ag or Cu · CPC title

• H10W72/29

  Bond pads specially adapted therefor · CPC title

• H10W72/07236

  Soldering or alloying · CPC title

• H10W72/07234

  Using a reflow oven · CPC title

• H10W72/016

  of strap connectors · CPC title