Substrate structure and method for improving attachment reliability of semiconductor chips and modules

• US 6,002,172 A
• Filed: 03/12/1997
• Issued: 12/14/1999
• Est. Priority Date: 03/12/1997
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Desai, Kishor V., Sarkhel, Amit K.
• Primary Examiner(s): Fahmy, Wael M.
• Assistant Examiner(s): DUONG, HUNG V
• Application Number:
  US08/815,238
• Time in Patent Office: 1,007 Days
• Field of Search: 257/737, 257/738, 257/784, 257/786, 257/778, 257/773, 257/780, 361/774, 361/777, 174/261
• US Class Current: 257/737
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• 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 2224/13099 Material
• CPC Class Codes: H01L 2224/13111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 24/10 Bump connectors bumps on insulating substrates, e.g. chip carriers, H01L23/49816; Manufacturing methods related thereto
• CPC Class Codes: H01L 24/13 of an individual bump connector
• CPC Class Codes: H01L 24/16 of an individual bump connector
• CPC Class Codes: H01L 24/81 using a bump connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01024 Chromium [Cr]
• CPC Class Codes: H01L 2924/01027 Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01039 Yttrium [Y]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H05K 1/111 : Pads for surface mounting, e.g. lay-out
• CPC Class Codes: H05K 1/112 : directly combined with via connections
• CPC Class Codes: H05K 2201/09472 : Recessed pad for surface mounting; Recessed electrode of component
• CPC Class Codes: H05K 2201/09509 : Blind vias, i.e. vias having one side closed
• CPC Class Codes: H05K 2201/09736 : Varying thickness of a single conductor; Conductors in the same plane having different thicknesses
• CPC Class Codes: H05K 2201/09745 : Recess in conductor, e.g. in pad or in metallic substrate
• CPC Class Codes: H05K 2201/10734 : Ball grid array [BGA]; Bump grid array
• CPC Class Codes: H05K 2201/10992 : Using different connection materials, e.g. different solders, for the same connection
• CPC Class Codes: H05K 2203/041 : Solder preforms in the shape of solder balls
• CPC Class Codes: H05K 3/3436 : having an array of bottom contacts, e.g. pad grid array or ball grid array components
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

An adhesion pad for adhering a semiconductor chip or a ball grid array module to a supporting substrate includes a stepped or tapered structure. The structure is composed of at least one solder wettable metal or alloy layer having solder deposited thereon. The stepped or tapered structure prevents a fatigue crack from propagating in the X-Y plane above the adhesion pad.

Claims

1. An adhesion pad for a substrate comprising:

a first flat planar layer having a perimeter on said substrate;

a second flat planar layer on said first flat planar layer disposed within said perimeter of said first flat planar layer to form at least one raised structure with a substantially vertical sidewall on said first flat planar layer, said first and second flat planar layers being wettable for directly contacting a mass of solder;

said first flat planar layer and said second flat planar layer are substantially circular, each having a respective diameter, said diameter of said second flat planar layer is in the range of 30-70% of said diameter of said first flat planar layer, said first flat planar layer has a thickness at least 10% of said diameter of said first flat planar layer;

said substrate is one of the group consisting of an organic chip carrier, a ceramic chip carrier, and an organic circuit board, and

said thickness of said first flat planar layer is in the range of 33-41 μ

m (0.0013 to 0.0016 inches) and said second flat planar layer has a thickness in the range of 63-76 μ

m (0.0025 to 0.0030 inches).

2. The adhesion pad according to claim 1, further comprising a mass of solder on said raised structure and a portion of said first flat planar layer.

3. The adhesion pad according to claim 1, wherein said first flat planar layer is one of a metal and an alloy and said second flat planar layer is one of a metal and an alloy, said first and second flat planar layers being solder wettable.

4. The adhesion pad according to claim 3, wherein said first flat planar layer and said second flat planar layer each comprise at least one of the group consisting of copper, cobalt, nickel, platinum, palladium, and alloys thereof.

5. The adhesion pad according to claim 1, wherein said second flat planar layer is concentric with said first flat planar layer.

6. The adhesion pad according to claim 1, wherein said second flat planar layer is eccentric with said first flat planar layer.