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. 28, 2025

Filed:

Mar. 08, 2019
Applicant:

Siliconix Incorporated, San Jose, CA (US);

Inventor:

Barry Lin, Kaohsiung, TW;

Assignee:

Siliconix Incorporated, San Jose, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 21/48 (2006.01); H01L 21/56 (2006.01); H01L 23/31 (2006.01); H01L 23/495 (2006.01);
U.S. Cl.
CPC ...
H01L 21/4842 (2013.01); H01L 21/561 (2013.01); H01L 23/3107 (2013.01); H01L 23/49575 (2013.01); H01L 23/49582 (2013.01);
Abstract

Methods are disclosed herein for forming wettable flanks on quad flat no-leads semiconductor packages. The methods may begin with a package assembly having multiple non-singulated packages. The package assembly includes a lead frame assembly having dies coupled thereto. A mold encapsulation covers the dies and exposes portions of leads. An electroplating step deposits plating on the exposed portions of the leads. First and second series of parallel step cuts are made between the die packages to form sidewalls of wettable flanks. The first and second series of parallel step cuts are perpendicular to each other. These cuts are made at a depth to cut fully through the lead frame but not fully through the mold encapsulation. After the first and second series of parallel step cuts, the wettable flanks are plated using an electroless method. A third and fourth series of cuts singulates the assembly into discrete QNF semiconductor packages.


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