Terminal Structure Anchoring via Insulation Depression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The thermal expansion mismatch between connection terminals (e.g., copper layer) and insulating layers (e.g., resin) can lead to deformation of the insulating layer during heat treatment, causing gaps and potential separation of the connection terminal from the insulating layer.
Innovation Solution
A terminal structure with a protective insulation layer, open portions, and connection terminals, where the open portions include a wall surface, depression, and projection, with the depression and projection forming a step at the bottom, allowing the connection terminal to anchor into the insulating layer and reduce stress-induced separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the insulating layer undergoes heat treatment, then the wiring substrate can be manufactured, but the insulating layer deforms due to thermal contraction causing gaps and potential separation of the connection terminal from the insulating layer
Solution Approach 1:
The patent applies preliminary action by forming the connection terminal to protrude from the insulating layer before heat treatment occurs. This protruding structure is created in advance during the manufacturing process, so that when thermal contraction and deformation occur during subsequent heat treatment, the connection terminal maintains its position and connection reliability is preserved despite the insulating layer's deformation
Solution Approach 2:
The patent employs dimensionality change by transitioning the connection terminal from a planar configuration to a three-dimensional protruding structure. The connection terminal extends outward from the insulating layer surface, creating a vertical dimension that allows it to maintain electrical connection even when the insulating layer deforms horizontally due to thermal contraction
2Reliability
If the connection terminal is formed on the wiring layer, then electrical connectivity is achieved, but gaps form between the connection terminal and insulating layer due to thermal expansion mismatch
Solution Approach 1:
The patent applies preliminary action by pre-forming the connection terminal with a protruding configuration before thermal processing. This anticipates the future gap formation issue and addresses it by creating a structure that maintains contact with the wiring layer even when gaps develop due to differential thermal expansion between the metal connection terminal and the resin insulating layer
Solution Approach 2:
The protruding structure of the connection terminal acts as a cushioning mechanism that compensates for the harmful effects of thermal expansion mismatch. The extra length of the protruding terminal provides a buffer zone that maintains electrical connection reliability even when gaps form between the terminal base and the insulating layer
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
The terminal structure enhances adhesion between the connection terminal and the insulating layer, improving connection reliability by reducing stress and inhibiting crack propagation, thereby preventing separation and ensuring reliable electrical connectivity.
Implementation Method 1
The thermal expansion coefficient differs between the connection terminal (e.g. copper layer) and the insulating layer (e.g. resin). Thus, when the insulating layer undergoes heat treatment, the insulating layer will be deformed due to thermal contraction.
Data Source
AI summary
A terminal structure includes a wiring layer, a protective insulation layer, an open portion, and a connection terminal. The protective insulation layer covers the wiring layer. The open portion extends through the protective insulation layer in a thickness-wise direction to expose part of an upper surface of the wiring layer. The connection terminal is formed on the wiring layer exposed from the open portion. The open portion includes a wall surface, a depression, and a projection. The wall surface extends downward from an upper surface of the protective insulation layer. The depression is depressed into the protective insulation layer from the wall surface toward an outer side of the open portion. The projection is formed under the depression, continuously with the depression, and projected from the depression into the open portion further inward than the wall surface in a plan view. The depression is filled with the connection terminal.