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.

Date of Patent:
Jan. 09, 2018

Filed:

Apr. 15, 2016
Applicant:

Avago Technologies General Ip (Singapore) Pte. Ltd., Singapore, SG;

Inventors:

Wei-Shun Wang, Palo Alto, CA (US);

Li Sun, Fremont, CA (US);

Ashish Alawani, San Jose, CA (US);

Lea-Teng Lee, Sunnyvale, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 21/44 (2006.01); H01L 21/48 (2006.01); H01L 21/50 (2006.01); H01L 21/60 (2006.01);
U.S. Cl.
CPC ...
H01L 21/4853 (2013.01); H01L 21/4864 (2013.01); H01L 2021/6009 (2013.01); H01L 2021/6024 (2013.01); H01L 2021/60135 (2013.01);
Abstract

A method is provided for attaching components to pads on a PCB, where total accumulated tolerances are reduced by separating accumulated tolerances into multiple processes. The method includes performing first and second processes having first and second accumulated tolerances, respectively. The first process includes placing a first stencil over the PCB, the first stencil defining first apertures corresponding to the pads; printing solder paste onto the pads using the first stencil; and reflowing the printed solder paste to form corresponding solder bumps on the pads. The second process includes placing a second stencil over the PCB, the second stencil defining second apertures corresponding to the pads; printing flux onto the solder bumps using the second stencil; placing at least one component on the printed flux; and reflowing the printed flux and the solder bumps to form corresponding solder joints between the at least one component and the first pads, respectively.


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