Solder material and method for die attachment

Patent metadata

Field	Value
Publication number	US-11842974-B2
Application number	US-201816612883-A
Country	US
Kind code	B2
Filing date	May 11, 2018
Priority date	May 12, 2017
Publication date	Dec 12, 2023
Grant date	Dec 12, 2023

Abstract

A solder material comprising a solder alloy and a thermal conductivity modifying component. The solder material has a bulk thermal conductivity of between about 75 and about 150 W/m-K and is usable in enhancing the thermal conductivity of the solder, allowing for optimal heat transfer and reliability in electronic packaging applications.

First claim

What is claimed is:

1. A solder material comprising:
a) a solder alloy, and
b) a thermal conductivity modifying component,
wherein the solder alloy is selected from the group consisting of high lead alloys, SnAg alloys, SnAgCu alloys, SnPb alloys, and combinations of one or more of the foregoing;
wherein the thermal conductivity modifying component is in the form of a wire;
wherein the thermal conductivity modifying component is tin over nickel over aluminum; and
wherein the solder material has a bulk thermal conductivity of between about 75 and about 150 W/m-K.

2. The solder material according to claim 1 , wherein the solder alloy has a thermal conductivity of between about 20 and about 70 W/m-K.

3. The solder material according to claim 2 , wherein the solder alloy has a thermal conductivity of between about 25 and about 60 W/m-K.

4. The solder material according to claim 1 , wherein the thermal conductivity modifying component has a thermal conductivity of at least 100 W/m-K.

5. The solder material according to claim 4 , wherein the thermal conductivity modifying component has a thermal conductivity of at least 200 W/m-K.

6. The solder material according to claim 5 , wherein the thermal conductivity modifying component has a thermal conductivity of at least 300 W/m-K.

7. The solder material according to claim 1 , wherein the solder material has a bulk thermal conductivity of between about 80 and about 110 W/m-K.

8. The solder material according to claim 1 , wherein the solder material is in the form of a solder preform.

9. The solder material according to claim 1 , wherein the lead-free solder material comprises between about 30 wt. % to about 95 wt. % of the solder alloy and about 70 wt. % to about 5 wt. % of the thermal conductivity modifying component.

10. The solder material according to claim 1 , wherein the wire comprises a plurality of wires that are used in parallel and the parallel wires are packed close together.

11. A solder joint comprising the solder material of claim 1 .

12. The solder joint according to claim 11 , wherein the solder joint is rectangular and the wire is oriented parallel to a shorter dimension of the rectangular, wherein the wire creates a shorter path for gases to escape.

13. A method of making a solder joint between a substrate and a component, the method comprising the steps of:
a) applying the solder material of claim 1 to a substrate;
b) disposing a component on the solder material; and
c) reflowing the solder material to create the solder joint between the substrate and the component.

Assignees

• Alpha Assembly Solutions Inc

Inventors

• Gulino Angelo
• Bankiewicz Bogdan
• Khaselev Oscar
• Lifton Anna
• Marczi Michael T
• Sidone Girard
• Salerno Paul
• Koep Paul J

Classifications

• H10W72/555

  of outermost layers of multilayered bond wires, e.g. material of a coating · CPC title

• H10W72/5524

  comprising aluminium [Al] · CPC title

• H10W72/07336

  Soldering or alloying · CPC title

• H10W72/073

  of die-attach connectors · CPC title

• H10W72/351

  Materials of die-attach connectors · CPC title