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Robust LGA PTH structure having single sided Partial hard Ni/Au

IP.com Disclosure Number: IPCOM000015988D
Original Publication Date: 2002-Aug-01
Included in the Prior Art Database: 2003-Jun-21
Document File: 1 page(s) / 37K

Publishing Venue

IBM

Abstract

This unique structure provides planar copper surface on back side and overcomes E-lytic Ni/E-Lytic Au throwing limitation in high aspect boards. It is applicable to mass production with lower cost. It also provides conformal hard gold on LGA site. This invention in general relates to precious metal plated electrical contact and soldering pads on printed circuit boards (PCB's) or PWB's (FIG. 1). These connection pads typically include electrical connections to circuit lines internal to the PCB formed by a plated through hole (PTH) or conductive stud.

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Robust LGA PTH structure having single sided Partial hard Ni/Au

    This unique structure provides planar copper surface on back side and overcomes E-lytic Ni/E-Lytic Au throwing limitation in high aspect boards. It is applicable to mass production with lower cost. It also provides conformal hard gold on LGA site. This invention in general relates to precious metal plated electrical contact and soldering pads on printed circuit boards (PCB's) or PWB's (FIG. 1). These connection pads typically include electrical connections to circuit lines internal to the PCB formed by a plated through hole (PTH) or conductive stud.

FIG. 2 is the industry standard structure achieved by Pattern Plating. The sidewalls are exposed copper and during flash etching of the commoning layer the copper can be galvanically undercut. This undercut region may be deformed and/ or broken loose of the pad during handling, cleaning, or mating a Land Grid Array (LGA) type connector with the PCB/ PWB shown in attachment .

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