Terminal structure and semiconductor device

• US 9,640,500 B2
• Filed: 08/06/2013
• Issued: 05/02/2017
• Est. Priority Date: 08/24/2012
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Yoshida, Kenichi, Orikasa, Makoto, Seike, Hideyuki, Horikawa, Yuhei, Abe, Hisayuki
• Primary Examiner(s): King, Joshua
• Assistant Examiner(s): Alam, Mohammed R
• Application Number:
  US13/960,173
• Publication Number:
  US 20140054767A1
• Time in Patent Office: 1,365 Days
• CPC Class Codes: H01L 2224/0345 Physical vapour deposition [PVD], e.g. evaporation, or sputtering
• CPC Class Codes: H01L 2224/03462 Electroplating
• CPC Class Codes: H01L 2224/03464 Electroless plating
• CPC Class Codes: H01L 2224/0347 using a lift-off mask
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/05022 the internal layer being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/05552 in top view
• CPC Class Codes: H01L 2224/05572 the external layer extending out of an opening
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/11464 Electroless plating
• CPC Class Codes: H01L 2224/1147 using a lift-off mask
• CPC Class Codes: H01L 2224/11849 Reflowing
• CPC Class Codes: H01L 2224/13005 Structure
• CPC Class Codes: H01L 2224/13006 Bump connector larger than the underlying bonding area, e.g. than the under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/13023 the whole bump connector protruding from the surface
• CPC Class Codes: H01L 2224/13111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 24/03 Manufacturing methods
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/13 of an individual bump connector
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

The present invention relates to a terminal structure comprising; a base material 10; an external electrode 20 formed on the base material; an insulating coating layer 30 formed on the base material and on the electrode and having an opening exposing at least part of the electrode; an under-bump metal layer 70 filling the opening and covering part of the insulating coating layer; and a dome-shaped bump 85 covering the under-bump metal layer, wherein in a cross section along a lamination direction, the under-bump metal layer has a convex shape toward the bump, and the thickness T_u0 of the under-bump metal layer at a center of the opening is equal to or greater than the thickness T_u1 of the under-bump metal layer at an end portion of the opening.

Claims

1. A terminal structure comprising:

a base material;

an electrode formed on the base material;

an insulating coating layer formed on the base material and on the electrode and having an opening exposing at least part of the electrode;

an under-bump metal layer filling the opening and covering part of the insulating coating layer; and

a dome-shaped bump (i) covering the under-bump metal layer, (ii) being in direct contact with and covering part of the insulating coating layer, and (iii) continuously tapering inward from the insulating coating layer to a top of the dome-shaped bump, wherein;

in a cross section along a lamination direction, the under-bump metal layer has a convex shape toward the dome-shaped bump, and a thickness of the under-bump metal layer at a center of the opening is equal to or greater than the thickness of the under-bump metal layer at an end portion of the opening; and

a ratio R between distance AB from point A to point B and distance BC from point B to point C satisfies the following expression;

R=0.50≧

BC/AB≧

0.05.

(i) on an upper surface of the insulating coating layer, point A being a position of an end on the opening side of the insulating coating layer, (ii) point B being a position of an end of the under-bump metal layer, and (iii) on a basis of the upper surface of the insulating coating layer, point C being a position where the thickness of the under-bump metal layer is half the thickness of the under-bump metal layer at point A.

2. The terminal structure according to claim 1, wherein the dome-shaped bump contains tin as a main component.

3. The terminal structure according to claim 1, wherein the under-bump metal layer contains nickel as a main component.

4. The terminal structure according to claim 1, wherein the dome-shaped bump contains titanium.

5. A semiconductor device comprising the terminal structure according to claim 1.

6. The terminal structure according to claim 1, wherein the cross-sectional diameter of the dome-shaped bump is the greatest at the insulating coating layer.

7. The terminal structure according to claim 1, wherein in the cross section along the lamination direction, an upper surface of the under-bump metal layer includes curved portions and a substantially flat portion therebetween.

8. The terminal structure according to claim 3, wherein the under-bump metal layer contains phosphorous.

9. The terminal structure according to claim 8, wherein the under-bump metal layer contains 5 to 15 mass % of phosphorous.