Soldering a conductor to an aluminum metallization

Patent metadata

Field	Value
Publication number	US-11450642-B2
Application number	US-202017132585-A
Country	US
Kind code	B2
Filing date	Dec 23, 2020
Priority date	Jul 31, 2017
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

A method of making a semiconductor including soldering a conductor to an aluminum metallization is disclosed. In one example, the method includes substituting an aluminum oxide layer on the aluminum metallization by a substitute metal oxide layer or a substitute metal alloy oxide layer. Then, substitute metal oxides in the substitute metal oxide layer or the substitute metal alloy oxide layer are at least partly reduced. The conductor is soldered to the aluminum metallization using a solder material.

First claim

What is claimed is:

1. A method of soldering a conductor to an aluminum metallization, the method comprising:
applying a flux material to an aluminum oxide layer on the aluminum metallization, wherein the flux material is a mixture of at least flux and zeolite, the flux material having a chemical composition in percent by weight of x % wt≤zoelite ≤10% wt, with x=0.01, 0.1, 0.5, 1.0, 2.0, 4.0, 6.0, or 8.0;
disposing a solder material over the aluminum metallization, wherein the solder material has a chemical composition in percent by weight of x % wt≤Zn≤100% wt, with x=10, 30, 50, 70, 90, 95, or 100; and
soldering the conductor to the aluminum metallization.

2. The method of claim 1 , wherein x<100 and the rest of the chemical composition of the solder material contains one or more of Al, Cu, Ni, and Ti.

3. The method of claim 1 , wherein the flux material and the solder material are mixed together to form a solder paste.

4. The method of claim 1 , wherein the aluminum metallization consists of bare aluminum.

5. The method of claim 1 , wherein the aluminum metallization comprises 98.5Al-0.5Cu-1Si or 99Al-1Si.

6. The method of claim 1 , wherein the conductor comprises Cu, Ni, Cu/Ni, NiP, or Ni/NiP.

7. A method of soldering a conductor to an aluminum metallization, the method comprising:
applying a flux material to an aluminum oxide layer on the aluminum metallization,
disposing a solder material over the aluminum metallization, wherein the solder material has a chemical composition in percent by weight of x % wt≤Zn≤100% wt, with x=10, 30, 50, 70, 90, 95, or 100; and
soldering the conductor to the aluminum metallization,
wherein the flux material is a mixture of at least flux and crown ether, the flux material having a chemical composition in percent by weight of x % wt≤crown ether ≤50% wt, with x=0.01, 0.1, 0.5, 1, 5, 10, 20, 30, or 40.

8. A method of soldering a conductor to an aluminum metallization, the method comprising:
applying a flux material to an aluminum oxide layer on the aluminum metallization,
disposing a solder material over the aluminum metallization, wherein the solder material has a chemical composition in percent by weight of x % wt≤Zn≤100% wt, with x=10, 30, 50, 70, 90, 95, or 100; and
soldering the conductor to the aluminum metallization,
wherein the flux material is a mixture of at least flux, silicate, and crown ether, the flux material having a chemical composition in percent by weight of 0.01% wt≤silicate ≤10% wt and of 0.01% wt≤crown ether ≤50% wt.

9. A method of soldering a conductor to an aluminum metallization, the method comprising:
applying a flux material to an aluminum oxide layer on the aluminum metallization,
disposing a solder material over the aluminum metallization, wherein the solder material has a chemical composition in percent by weight of x % wt≤Zn≤100% wt, with x=10, 30, 50, 70, 90, 95, or 100; and
soldering the conductor to the aluminum metallization,
wherein the flux material is a mixture of at least flux, zeolite, and crown ether, the flux material having a chemical composition in percent by weight of 0.01% wt≤silicate ≤10% wt and of 0.01% wt≤crown ether ≤50% wt.

10. A method of soldering a conductor to an aluminum metallization, the method comprising:
applying a flux material to an aluminum oxide layer on the aluminum metallization wherein the flux material is a mixture of at least flux and zeolite, the flux material having a chemical composition in percent by weight of 0.01% wt≤zoelite ≤10% wt.;
disposing a solder material over the aluminum metallization, wherein the solder material has a chemical composition in percent by weight of 10% wt≤Zn≤100% wt; and
soldering the conductor to the aluminum metallization.

11. The method of claim 10 , wherein Zn<100% wt and the rest of the chemical composition of the solder material contains one or more of Al, Cu, Ni, and Ti.

12. A method of soldering a conductor to an aluminum metallization, the method comprising:
applying a flux material to an aluminum oxide layer on the aluminum metallization,
disposing a solder material over the aluminum metallization, wherein the solder material has a chemical composition in percent by weight of 10% wt≤Zn≤100% wt; and
soldering the conductor to the aluminum metallization,
wherein the flux material is a mixture of at least flux and crown ether, the flux material having a chemical composition in percent by weight of 0.01% wt≤crown ether ≤50% wt.

13. A method of soldering a conductor to an aluminum metallization, the method comprising:
applying a flux material to an aluminum oxide layer on the aluminum metallization wherein the flux material is a mixture of at least flux and crown ether, the flux material having a chemical composition in percent by weight of 0.01% wt≤crown ether ≤50% wt.;
disposing a solder material over the aluminum metallization, wherein the solder material comprises Zn and Al; and
soldering the conductor to the aluminum metallization.

14. The method of claim 13 , wherein the flux material is a mixture of at least flux and silicate, the flux material having a chemical composition in percent by weight of 0.01% wt≤silicate ≤10% wt.

15. The method of claim 13 , wherein the flux material and the solder material are mixed together to form a solder paste,
wherein the aluminum metallization comprises bare aluminum, 98.5Al-0.5Cu-1Si or 99Al-1Si, and
wherein the conductor comprises Cu, Ni, Cu/Ni, NiP, or Ni/NiP.

Assignees

• Infineon Technologies Ag

Inventors

• Riedl Edmund
• Li Wu Hu
• Heinrich Alexander
• Otremba Ralf
• Reiss Werner

Classifications

• H10W90/764

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/734

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W72/07641

  Controlling the environment, e.g. atmosphere composition or temperature · CPC title

• H10W72/07636

  Soldering or alloying · CPC title

• H10W72/07611

  Treating the bonding area before connecting, e.g. by applying flux or cleaning · CPC title