US Patent No. 11,116,071

METHOD FOR PRODUCING A PRINTED CIRCUIT BOARD HAVING THERMAL THROUGH-CONTACTS


Patent No. 11,116,071
Issue Date September 07, 2021
Title Method For Producing A Printed Circuit Board Having Thermal Through-contacts
Inventorship Erik Edlinger, Vienna (AT)
Assignee ZKW Group GmbH, Wieselburg (AT)

Claim of US Patent No. 11,116,071


1. A method for producing thermal vias (19) in a printed circuit board, proceeding from a substrate plate (101) with a plurality of boreholes (11, 12, 13, 14) preformed therein, which are formed between a lower surface (A) and an upper surface (B) of the substrate plate (101) and are located at positions where thermal vias are to be produced respectively, the method comprising the following steps:applying a first and a second solder resist mask (21, 31) onto the lower surface (A) and the upper surface (B) respectively, wherein the first solder resist mask (21) has, at the preformed boreholes (11-14), respective regions (23) free from solder resist around the edges (22) of each bore on the lower surface, and wherein the second solder resist mask (31) extends to at least the edges (32) of the boreholes on the upper surface for at least a majority of the preformed boreholes (11-14);
applying solder (16) onto the lower surface (A) and reflow soldering of the solder, wherein the solder penetrates into the bores (11-14) and forms on the lower surface (A) convex menisci (26) protruding beyond the edge (22) of the respective boreholes; and then
clearing regions (35) on the upper surface (B), which regions are predetermined for the contacting of at least one electronic component (18) on the upper surface and respectively comprise at least one of the thermal vias, by removal of the second solder resist mask (31) at least in said regions on the upper surface.