The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 14, 2002
Filed:
May. 11, 2001
Tung-Liang Shao, Taoyuan, TW;
Apack Technologies Inc., Hsinchu, TW;
Abstract
A wafer-level packaging process. A wafer having a plurality of bonding pads thereon exposed through a passivation layer formed on the wafer is provided, and an under bump metal (UBM) is formed on each bonding pad. A stress buffer layer is formed through which are formed a plurality of first openings that expose the under bump metals (UBM). Solder material is filled in the first openings of the stress buffer layer. Either a stencil or a patterned photoresist having a plurality of second openings is arranged on the stress buffer layer such that the second openings expose the first openings. A solder material is filled in the second openings. The solder material is reflowed, wherein if the stencil is used, it is removed before the reflow process while if the patterned photoresist is used, it is removed after the reflow process.