Resin Multilayer Substrate Via Structure for Stronger Interlayer Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resin multilayer substrates face issues with weak connectivity and insufficient strength at the boundary surface between conductive portions such as paste vias and plated vias, leading to inadequate interlayer connection conductors.
Innovation Solution
The resin multilayer substrate design includes an interlayer connection conductor with a first portion having lower conductivity and a second portion closer to the second conductor layer, where the second portion wraps around the first portion in a recessed shape, enhancing the bonding strength between the conductor layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If portions having different conductivities (paste via and plated via) are mixed as interlayer connection conductor in the insulating layer, then connectivity between the plated via and paste via can be improved, but the strength of the interlayer connection conductor becomes insufficient
Solution Approach 1:
The interlayer connection conductor is divided into multiple portions (first portion with lower conductivity and second portion with higher conductivity). This segmentation allows each portion to serve different functions: the first portion ensures connectivity while the second portion provides structural strength, thereby resolving the contradiction between connectivity and strength.
Solution Approach 2:
Different portions of the interlayer connection conductor are assigned different conductivity characteristics. The first portion has lower conductivity (paste via material) while the second portion has higher conductivity (plated via material). This local differentiation allows the conductor to simultaneously achieve connectivity through the first portion and strength through the second portion.
2Strength
If the second portion wraps around the first portion in a recessed shape, then the strength of the interlayer connection conductor is increased, but the device complexity increases
Solution Approach 1:
The second portion is formed to wrap around the first portion in a recessed shape, creating a nested structure. This nesting configuration enhances the mechanical interlocking between the two portions, significantly improving the strength of the interlayer connection conductor while maintaining a relatively compact design.
Solution Approach 2:
The second portion is formed with a curved, recessed shape that wraps around the first portion. This curvature provides better mechanical interlocking compared to a straight configuration, enhancing the strength of the connection while the wrapping structure naturally accommodates the different materials.
Data Source
AI summary
A resin multilayer substrate includes a resin insulating layer, first and second conductor layers, and an interlayer connection conductor penetrating the resin insulating layer in a stacking direction of the first and second conductor layers and connecting the first and second conductor layers. The interlayer connection conductor includes first and second portions. The first portion has lower conductivity than the second portion. The first conductor layer is not in contact with the second portion. The second conductor layer is in contact with the second portion. A distance between two corner portions at which a distal end portion of the second portion is most separated is longer than a distance between two corner portions at which a proximal end portion of the second portion is in contact with the second conductor layer.