Solder material and connected structure

Patent metadata

Field	Value
Publication number	US-9656351-B2
Application number	US-201415101306-A
Country	US
Kind code	B2
Filing date	Dec 1, 2014
Priority date	Dec 3, 2013
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

Provided is a solder material that has a high melting point and exhibits superior mechanical characteristics, and therefore can form a connecting portion with high heat-resistant reliability.

First claim

The invention claimed is:

1. A solder material comprising, as a solder alloy, a second alloy obtainable by using a first alloy and a Bi—Ag alloy at a ratio of 5 to 80% by weight for the Bi—Ag alloy relative to a total amount of the first alloy and the Bi—Ag alloy, the first alloy being obtainable by using a Bi—Cu alloy and a Bi—Ge alloy at a ratio of 30 to 70% by weight for the Bi—Cu alloy relative to a total amount of the Bi—Cu alloy and the Bi—Ge alloy, wherein
the Bi—Cu alloy consists of 0.2 to 0.8% by weight of Cu and a balance of Bi,
the Bi—Ge alloy consists of 0.7 to 1.3% by weight of Ge and a balance of Bi,
the Bi—Ag alloy consists of 2.2 to 20.3% by weight of Ag and a balance of Bi, and
the second alloy comprises 0.06% by weight or more of Ge.

2. The solder material according to claim 1 , wherein
the Bi—Cu alloy is a Bi—Cu eutectic alloy,
the Bi—Ge alloy is a Bi—Ge eutectic alloy, and
the Bi—Ag alloy consists of 2.5 to 20% by weight of Ag and a balance of Bi.

3. The solder material according to claim 2 , comprising, as the solder alloy, instead of the second alloy, a third alloy obtainable by using the second alloy and at least one of Ni and P at a ratio of 0.05 to 2.0% by weight for the at least one of Ni and P relative to a total amount of the second alloy and the at least one of Ni and P.

4. The solder material according to claim 2 , further comprising, in the solder alloy, at least one of Cu particles and Ni particles having an average particle diameter of 1 to 40 μm at 1 to 20% by weight relative to a total amount of the solder alloy and the at least one of the Cu particles and the Ni particles.

5. The solder material according to claim 2 , wherein the solder alloy has a solidus-line temperature of 250 to 350° C.

6. The solder material according to claim 2 , wherein the solder alloy is in a form of particles, and a surface of the particles is coated with a material that has a melting point higher than the solidus-line temperature of the solder alloy.

7. The solder material according to claim 1 , comprising, as the solder alloy, instead of the second alloy, a third alloy obtainable by using the second alloy and at least one of Ni and P at a ratio of 0.05 to 2.0% by weight for the at least one of Ni and P relative to a total amount of the second alloy and the at least one of Ni and P.

8. The solder material according to claim 7 , further comprising, in the solder alloy, at least one of Cu particles and Ni particles having an average particle diameter of 1 to 40 μm at 1 to 20% by weight relative to a total amount of the solder alloy and the at least one of the Cu particles and the Ni particles.

9. The solder material according to claim 7 , wherein the solder alloy has a solidus-line temperature of 250 to 350° C.

10. The solder material according to claim 7 , wherein the solder alloy is in a form of particles, and a surface of the particles is coated with a material that has a melting point higher than the solidus-line temperature of the solder alloy.

11. The solder material according to claim 1 , further comprising, in the solder alloy, at least one of Cu particles and Ni particles having an average particle diameter of 1 to 40 μm at 1 to 20% by weight relative to a total amount of the solder alloy and the at least one of the Cu particles and the Ni particles.

12. The solder material according to claim 11 , wherein the solder alloy has a solidus-line temperature of 250 to 350° C.

13. The solder material according to claim 11 , wherein the solder alloy is in a form of particles, and a surface of the particles is coated with a material that has a melting point higher than the solidus-line temperature of the solder alloy.

14. The solder material according to claim 1 , wherein the solder alloy has a solidus-line temperature of 250 to 350° C.

15. The solder material according to claim 14 , wherein the solder alloy is in a form of particles, and a surface of the particles is coated with a material that has a melting point higher than the solidus-line temperature of the solder alloy.

16. The solder material according to claim 1 , wherein the solder alloy is in a form of particles, and a surface of the particles is coated with a material that has a melting point higher than the solidus-line temperature of the solder alloy.

17. A connected structure formed by connecting two members with each other between parts for connection of the respective two members by the solder material of claim 1 .

18. The connected structure according to claim 17 , wherein the parts for connection of the respective two members have an Sn content of less than 0.5% by weight in a material constituting at least a surface part of the parts for connection.

19. The connected structure according to claim 17 , wherein the part for connection of at least one of the two members is plated with any one selected from a group consisting of Bi plating, Ni plating, Au plating, and Ni-based and Au-flash plating.

Assignees

• Univ Hiroshima

Inventors

• Matsugi Kazuhiro
• Suetsugu Kenichiro

Classifications

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W72/5363

  the connected ends being wedge-shaped · CPC title