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:
Jun. 17, 2008
Filed:
Apr. 13, 2006
Woong-sun Lee, Daejeon, KR;
Jin Yu, Daejeon, KR;
Woong-Sun Lee, Daejeon, KR;
Jin Yu, Daejeon, KR;
Korea Advanced Institute of Science and Technology, Daejeon, KR;
Abstract
Disclosed herein is a method of bonding solder pads of a flip-chip package. This invention relates to a method of bonding solder pads having different sizes to each other, when a bonding operation is executed between a chip and a PCB, between chips, or between PCBs. On a side having a larger solder pad, a general solder ball is used. Conversely, on a side having a smaller solder pad, a solder ball having a core is used. The core serves to maintain a predetermined interval between the chip and the PCB or between the chips, after the bonding operation has been completed. The solder bonded parts are aligned with each other so as to perform a final bonding operation. In a conventional flip-chip package, solder pads provided on a bonded part must have the same or similar size. According to this invention, even if the size difference between the solder pads is large, bonding is possible, thus ensuring electrical and mechanical reliability.