IIIIIIIH
US006268114B1
(12) United States Patent ao) Patent No.: us 6,268,114 Bi
Wen et al. (45) Date of Patent: Jul. 31,2001
(54) METHOD FOR FORMING FINE-PITCHED SOLDER BUMPS
(75) Inventors: Ying-Nan Wen; Ling-Chen Kung;
Szu-Wei Lu; Ruoh-Huey Uang, all of
Hsinchu (TW)
(73) Assignee: Taiwan Semiconductor
Manufacturing Company, Ltd, Hsin
Chu (TW)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/156,353
(22) Filed: Sep. 18, 1998
(51) Int. C I. G03C 5/00
(52) U.S. CI 430/314; 430/312; 430/318;
430/319
(58) Field of Search 430/311, 312,
430/313, 314, 315, 318, 319; 427/96, 98,
99
(56) References Cited
U.S. PATENT DOCUMENTS
4,950,623 * 8/1990 Dishon 437/183
A method for forming solder balls that have larger spacings between them and electronic devices containing such solder balls are disclosed. In the method, an additional layer of a leachable metal such as gold or silver is used between an under bump metallurgy layer and a solder bump subsequently formed. This allows the formation of the under bump metallurgy layer prior to the deposition of the solder material into a window formed in a photoresist layer. The present invention allows the underfill of a solder window, instead of an overfill which is normally required in a conventional method.
22 Claims, 3 Drawing Sheets
