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:
Oct. 19, 2021

Filed:

May. 24, 2018
Applicant:

International Business Machines Corporation, Armonk, NY (US);

Inventors:

Kevin O'Connell, Rochester, MN (US);

Mark Plucinski, Toms River, NJ (US);

Timothy Tofil, Rochester, MN (US);

Joseph Kuczynski, North Port, FL (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K 1/00 (2006.01); H05K 3/34 (2006.01); B23K 1/005 (2006.01); G02B 5/08 (2006.01);
U.S. Cl.
CPC ...
H05K 3/3494 (2013.01); B23K 1/0053 (2013.01); G02B 5/08 (2013.01);
Abstract

A method and structure are provided for implementing manufacture of a printed circuit board (PCB) with one of an infrared (IR) reflective mask or a novel solder mask to minimize coefficient of thermal expansion (CTE) mismatch between PCB laminate and plated through hole (PTH) copper. At least one of an IR-reflective mask and a solder mask composition for use in IR reflow processes is created such that radiant heat is reflected away from the major portion of the PCB yet permitted to impinge upon the PTHs. The copper within the PTH expands due to radiant heating while the bulk laminate expansion is significantly reduced due to the reflected IR radiation. Consequently, the CTE mismatch is minimized and tensile strain of the copper in the PTH is reduced, providing enhanced reliability.


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