Multilayer Substrate Via Structure to Reduce Boundary Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multilayer substrates face damage to interlayer connection conductors due to large forces applied at the boundaries between insulator layers.
Innovation Solution
The multilayer substrate design includes through-holes with tapered shapes and spaces between insulator layers to reduce contact with the interlayer connection conductors, minimizing the application of large forces and preventing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the interlayer connection conductor passes through the boundary between insulator layers, then electrical connection between layers is achieved, but large forces are applied to the conductor causing damage
Solution Approach 1:
The through-hole is divided into two distinct sections: a first through-hole in the first insulator layer and a second through-hole in the second insulator layer. The interlayer connection conductor passes through both holes but is relieved of stress at the insulator layer boundary by the space created between the holes, segmenting the force path and preventing concentrated stress on the conductor.
Solution Approach 2:
A space is introduced as an intermediary element between the first and second insulator layers at the boundary region. This space acts as a mediator that prevents direct contact between the insulator layer boundary and the interlayer connection conductor, thereby eliminating the source of damaging forces while maintaining electrical connectivity.
2Ease of manufacture
If the through-holes are aligned directly, then manufacturing is simplified, but the interlayer connection conductor experiences large forces at the insulator layer boundary
Solution Approach 1:
The local geometry of the through-holes is modified to create a space at the insulator layer boundary. The first through-hole and second through-hole are positioned and sized such that they create a gap region, giving different local properties to different sections of the conductor path: direct alignment for ease of manufacturing, but with a localized space at the critical boundary region to protect the conductor.
3Strength
If the insulator layers are pressed tightly together, then bonding strength is improved, but large forces are transmitted to the interlayer connection conductor
Solution Approach 1:
The space between the first and second insulator layers at the boundary is effectively 'taken out' from the direct compression path. By creating this void or gap region where the through-holes do not fully overlap, the pressing force is distributed around the space rather than being transmitted directly to the interlayer connection conductor, allowing strong bonding without conductor damage.
Data Source
AI summary
A multilayer substrate includes a first insulator layer including a first through-hole penetrating the first insulator layer along a Z-axis, a second insulator layer including a second through-hole penetrating the second insulator layer along the Z-axis. The second through-hole overlaps the first through-hole when viewed downward. When viewed in a positive direction of the Z-axis, an area of an end portion of the second through-hole on a positive side of the Z-axis is larger than an area of an end portion of the first through-hole on a negative side of the Z-axis. A first interlayer connection conductor extends along the Z-axis inside the first through-hole and the second through-hole and electrically connects first and second conductor layers. A space exists between a boundary of the first insulator layer and the second insulator layer and the first interlayer connection conductor.