PCB Via Fill-Plating Structure to Prevent Dimple Defects
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Solution Overview
Problem
Existing printed circuit boards face challenges in achieving high-quality fill-plating within via holes due to the occurrence of dimples, particularly at low plating thicknesses.
Innovation Solution
The printed circuit board design includes conductor layers that extend beyond the via hole, with non-contact portions protruding from the contact portions to act as walls during fill-plating, stabilizing the plating thickness and preventing dimple defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fill-plating is performed within the via hole under low plating thickness conditions, then plating thickness is reduced, but dimples occur in the via formed by the plating
Solution Approach 1:
The conductor layer is extended to protrude into the via hole before the fill-plating process. This preliminary structural preparation provides a foundation that guides the plating process and prevents dimple formation during low-thickness plating, thereby resolving the contradiction between achieving low plating thickness and maintaining via hole fill-plating quality
Solution Approach 2:
The conductor layer is selectively extended only in the regions adjacent to the via hole, creating a localized protruding structure. This local modification provides enhanced plating control precisely where needed (at the via hole interface) without requiring changes to the entire conductor layer, thus improving via hole fill-plating quality while maintaining overall low plating thickness
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances fill-plating quality by ensuring stable plating thickness and reduces dimple defects, improving the electrical connectivity and reliability of the circuit board.
Implementation Method 1
a metal layer filling the via hole
Implementation Method 2
fill-plating within a via hole
Data Source
AI summary
A printed circuit board includes an insulating layer having first and second surfaces opposite to each other with respect to a first direction; a via hole penetrating a region between the first and second surfaces; a first conductor layer including a first contact portion in contact with the first surface and a first non-contact portion protruding from the first contact portion and disposed on the via hole with respect to a second direction perpendicular to the first direction; and a metal layer filling the via hole.