Terminal structure, and semiconductor element and module substrate comprising the same

• US 9,257,402 B2
• Filed: 08/06/2013
• Issued: 02/09/2016
• 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): Doan, Theresa T
• Application Number:
  US13/960,330
• Publication Number:
  US 20140054770A1
• Time in Patent Office: 917 Days
• Field of Search: 257/737, 438/613
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/03462 Electroplating
• 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 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05552 in top view
• CPC Class Codes: H01L 2224/05571 the external layer being disposed in a recess of the surface
• 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 2224/11462 Electroplating
• 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 2224/13006 Bump connector larger than the underlying bonding area, e.g. than the under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/13017 being non uniform along the bump connector
• CPC Class Codes: H01L 2224/13022 the bump connector being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/13076 being mutually engaged together, e.g. through inserts
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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
• CPC Class Codes: H01L 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art

Abstract

A preferred terminal structure comprises a base material; an electrode formed on the base material; an insulating covering 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 containing Ni, formed in a region in the opening on the electrode so that an upper surface of the metal layer is at a position lower than an upper surface of the insulating covering layer in a peripheral edge portion of the opening; and a dome-shaped bump containing Sn and Ti, formed in a region in the opening on the under bump metal layer, wherein an end portion of a boundary between the under bump metal layer and the bump is in contact with an inner wall of the opening portion in the insulating covering layer.

Claims

1. A terminal structure comprising:

a base material;

an electrode formed on the base material;

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

an electroless plated under bump metal layer containing Ni, formed in a region in the opening on the electrode so that an upper surface of the metal layer is at a position lower than an upper surface of the insulating covering layer in a peripheral edge portion of the opening; and

a dome-shaped bump containing Sn and Ti, formed in a region in the opening on the under bump metal layer, wherein

an end portion of a boundary between the under bump metal layer and the bump is in contact with an inner wall of the opening portion in the insulating covering layer, and

the terminal structure has an excellent bump strength property where the rupture position under shear load inn a direction lateral to the height of the bump occurs in the bump and not at interfaces between the under bump metal layer and other components.

2. The terminal structure according to claim 1, wherein the end portion of the boundary between the under bump metal layer and the bump is in contact with the inner wall over an entire circumferential direction of the inner wall.

3. A semiconductor element comprising the terminal structure according to claim 1.

4. A module substrate comprising the terminal structure according to claim 1.

5. The terminal structure according to claim 1, wherein the dome-shaped bump has a composition containing Sn and 1 to 100 ppm Ti.

6. The terminal structure according to claim 1, wherein the dome-shaped bump has a composition containing substantially no Au, Ag or Cu.

7. The terminal structure according to claim 1, wherein the dome-shaped bump has a composition containing the 1 to 100 ppm of Ti and 1 to 10 ppm of other elements total, with balance being Sn.