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:
Jan. 28, 2003
Filed:
May. 18, 2001
Tan Kim Hwee, Singapore, SG;
Romeo Emmanuel P. Alvarez, Singapore, SG;
Advanpack Solutions Pte. Ltd., Singapore, SG;
Abstract
An oxidized ( ) copper leadframe and a semiconductor die with copper posts extending from die pads, and with solder balls coated ( ) with flux on the end of the copper posts, are provided. The semiconductor die is placed ( ) on the oxidized copper leadframe, with the solder balls abutting portions of the layer of oxide, above and aligned with, interconnect locations on the leadframe. When reflowed ( ), the flux on the abutting portions of the oxide layer selectively cleans these portions of the oxide layer, away from the interconnect locations. In addition, the solder balls change to molten state and adhere to the cleaned copper surfaces at the interconnect locations. Advantageously, the rest of the oxide layer that is not cleaned away provides a passivation layer that advantageously contains and prevents the molten solder from flowing away from the interconnect locations.