Mounting structure and manufacturing method for same

Patent metadata

Field	Value
Publication number	US-9373595-B2
Application number	US-201214342935-A
Country	US
Kind code	B2
Filing date	Aug 8, 2012
Priority date	Sep 16, 2011
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

In a provided mounting structure, an electronic component such as a semiconductor chip having a fragile film is mounted on a substrate such as a circuit board with higher connection reliability. A junction that connects an electrode terminal ( 4 ) of an electronic component ( 1 ) and an electrode terminal ( 5 ) of a substrate ( 2 ) contains an alloy ( 8 ) and a metal ( 9 ) having a lower modulus of elasticity than the alloy ( 8 ). The junction has a cross section structure in which the alloy ( 8 ) is surrounded by the metal ( 9 ) having the lower modulus of elasticity.

First claim

The invention claimed is:

1. A mounting structure comprising:
an electronic component having a plurality of first electrode terminals;
a substrate having a plurality of second electrode terminals; and
a plurality of junctions, each of which contains an alloy and a metal, the metal having a lower modulus of elasticity than the alloy, each of the junctions connecting a respective one of the first electrode terminals to a respective one of the second electrode terminals,
wherein each of the plurality of junctions has a cross section structure containing a plurality of cross sections that are parallel to a plane of the substrate, and including the alloy that is surrounded by the metal having the lower modulus of elasticity,
a first maximum proportion of the metal in any of the plurality of cross sections for a first one of the plurality of junctions disposed toward an outer periphery relative to the electronic component is greater than a second maximum proportion of the metal in any one of the plurality of cross sections for a second one of the plurality of the junctions disposed toward a center relative to the electronic component, and the electronic component is curved, and
a first thickness of the first one of the plurality of the junctions is greater than a second thickness of the second one of the plurality of the junctions, the first and second thickness being perpendicular to the plane of the substrate.

2. The mounting structure according to claim 1 , wherein at least one junction among the plurality of junctions has a portion connecting an alloy grown from the first electrode terminal and an alloy grown from the second electrode terminal, and the connecting portion contains an alloy surrounded by the metal having the lower modulus of elasticity.

3. The mounting structure according to claim 1 , wherein the plurality of junctions include a first junction and a second junction, and
if the first junction has a current value larger than a current value of the second junction per unit time, a content of the metal having the lower modulus of elasticity in the first junction is smaller than a content of the metal having the lower modulus of elasticity in the second junction.

4. The mounting structure according to claim 1 , wherein the plurality of junctions include a first protruding electrode that is provided on the first electrode terminal of the electronic component and has a curvature on an edge of the first protruding electrode.

5. The mounting structure according to claim 4 , wherein the plurality of junctions further include a second protruding electrode that is provided on the second electrode terminal of the substrate and has a curvature on an edge of the second protruding electrode.

6. The mounting structure according to claim 5 , wherein the metal having the lower modulus of elasticity is solder.

7. The mounting structure according to claim 4 , wherein the junction further contains a flat electrode provided on the second electrode terminal of the substrate.

8. The mounting structure according to claim 7 , wherein the metal having the lower modulus of elasticity is solder.

9. The mounting structure according to claim 4 , wherein the plurality of junctions further include a cylindrical electrode provided on the second electrode terminal of the substrate.

10. The mounting structure according to claim 9 , wherein the metal having the lower modulus of elasticity is solder.

11. The mounting structure according to claim 1 , wherein the alloy contains a nickel-tin alloy, and the metal having the lower modulus of elasticity contains tin.

12. The mounting structure according to claim 4 , wherein the first protruding electrode contains nickel, the alloy contains a nickel-tin alloy, and the metal having the lower modulus of elasticity contains tin.

13. The mounting structure according to claim 5 , wherein the first protruding electrode contains nickel, the second protruding electrode contains nickel, the alloy contains a nickel-tin alloy, and the metal having the lower modulus of elasticity contains tin.

14. The mounting structure according to claim 7 , wherein the first protruding electrode contains nickel, the flat electrode contains nickel, the alloy contains a nickel-tin alloy, and the metal having the lower modulus of elasticity contains tin.

15. The mounting structure according to claim 9 , wherein the first protruding electrode contains nickel, the cylindrical electrode contains copper, the alloy contains a nickel-tin alloy, a tin-copper alloy, and a nickel-tin-copper alloy, and the metal having the lower modulus of elasticity contains tin.

16. The mounting structure according to claim 1 , wherein the alloy has fine irregularities on a surface of the alloy.

Assignees

• Sakurai Daisuke
• Usirokawa Kazuya
• Hagihara Kiyomi
• Panasonic Ip Man Co Ltd

Inventors

• Sakurai Daisuke
• Usirokawa Kazuya
• Hagihara Kiyomi

Classifications

• H10W90/724

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

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/07255

  changes in materials · CPC title

• H10W72/07236

  Soldering or alloying · CPC title

• H10W72/07234

  Using a reflow oven · CPC title