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:
Oct. 11, 2011
Filed:
Jun. 05, 2008
Wafer level package integrated circuit incorporating solder balls containing an organic plastic-core
Duane T. Wilcoxen, Dallas, TX (US);
Christo P. Bojkov, Plano, TX (US);
Ajay Kumar Ghai, San Jose, CA (US);
Steve Detlev Cate, Los Altos, CA (US);
Duane T. Wilcoxen, Dallas, TX (US);
Christo P. Bojkov, Plano, TX (US);
Ajay Kumar Ghai, San Jose, CA (US);
Steve Detlev Cate, Los Altos, CA (US);
Maxim Integrated Products, Inc., Sunnyvale, CA (US);
Abstract
An integrated circuit including solder balls containing an elastic or resilient material core, a hard or rigid shell substantially enclosing the core, and an electrical contact layer substantially enclosing the shell. The elastic or resilient core serves as a stress buffer layer in a wafer level package (WLP) integrated circuit. The elastic or resilient material core may include an organic plastic material, such as a Divinilbenzene cross-linked co-polymer of relatively high resistance. This material has a relatively good elongation property so that it can effectively absorb forces exerted upon the integrated circuit by, for example, the flexing of a printed circuit board (PCB) or other structure to which the integrated circuit is attached. The hard or rigid shell serves to contain the elastic or resilient core and may include copper. The electrical contact layer serve to provide a good adhesive electrical contact to an under bump metallization (UBM) layer, may include a lead free, Tin-Gold (SnAg) material.