Connector Gold Layer Relocation to Prevent Solder Wicking
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Solution Overview
Problem
Conventional connectors require a large amount of gold to prevent damage to the conductive layer in through holes, leading to high manufacturing costs and the phenomenon of solder wicking, which reduces the size or causes disappearance of solder balls.
Innovation Solution
A connector manufacturing method involving a substrate with through holes filled with filler posts, where a conductive elastic cantilever with a gold layer is formed over the substrate surface instead of within the through holes, reducing gold usage and preventing solder wicking by not forming the gold layer over the solder ball area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gold layer completely covers the second conductive layer in the through holes to prevent damage, then the electrical reliability is improved, but the manufacturing cost increases due to large gold consumption
Solution Approach 1:
The patent extracts the gold layer from the through hole region and relocates it to form gold rings only on the second surface of the substrate. This removes the unnecessary gold coverage inside the through holes while maintaining the protective function where solder balls are formed, thereby reducing gold consumption without compromising electrical reliability
Solution Approach 2:
The patent applies gold layer selectively only in the region where solder balls are formed (on the second surface), rather than uniformly covering the entire second conductive layer including the through holes. This localized application maintains protection where needed while reducing overall gold usage
2Area of stationary object
If the gold rings are placed close to the solder balls to improve layout density, then the available layout area is increased, but solder wicking occurs causing solder balls to become smaller or disappear
Solution Approach 1:
The patent introduces a non-conductive layer positioned between the gold rings and the solder balls. This intermediary layer prevents direct contact between the solder material and gold rings, thereby eliminating the solder wicking phenomenon while allowing the gold rings to remain close to the solder balls for improved layout density
Data Source
AI summary
A method of manufacturing a connector is provided. Firstly, a substrate having a first surface, a second surface opposite to the first surface and a through hole is provided. Next, a first conductive layer covering the inside wall of the through hole is formed on the substrate. Then, a filler is filled in the through hole to form a filler post. Next, a conductive elastic cantilever is formed over the first surface and electrically connected to the first conductive layer. Then, a gold layer is formed on the conductive elastic cantilever and over the first surface. A solder ball electrically connected to the first conductive layer is formed over the second surface.