Semiconductor Device External Terminal with Variable Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor device experiences high thermal stress at the joint between the inner conductor layer and the external connection terminal due to differing thermal expansion rates, which can reduce the device's durability.
Innovation Solution
The external connection terminal is designed with a thin section for reduced thermal stress and a thick section for strength, with the thin section being smaller than the inner conductor layer to mitigate expansion differences and the thick section extending outside the encapsulant for additional support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the external connection terminal has uniform thickness, then it maintains structural simplicity and ease of manufacture, but it generates high thermal stress at the joint portion due to thermal expansion difference
Solution Approach 1:
The external connection terminal is designed with non-uniform thickness, featuring a thin section at the joint portion with the insulated substrate and a thick section at the external connection end. This local variation in geometry allows the thin section to accommodate thermal expansion differences and reduce stress concentration at the joint, while the thick section maintains mechanical strength for external connections.
2Strength
If the external connection terminal has large thickness, then it maintains connection strength for external components, but it increases thermal stress due to greater thermal expansion
Solution Approach 1:
The terminal structure implements different thickness sections: a thin section at the joint portion that minimizes thermal stress, and a thick section at the external connection end that provides sufficient mechanical strength for connecting external components.
Solution Approach 2:
The external connection terminal is divided into distinct sections along its length - a thin section for stress reduction at the joint and a thick section for strength at the external connection point. This segmentation allows each portion to be optimized for its specific functional requirement.
3Stress or pressure
If the external connection terminal has small thickness at the joint, then it reduces thermal stress, but it may compromise connection strength
Solution Approach 1:
The terminal is designed with a thin section specifically at the joint portion where thermal stress occurs, while maintaining a thick section at the external connection end. This localized thickness variation ensures stress reduction where needed without compromising overall connection strength.
Solution Approach 2:
The terminal structure is segmented into a thin section for stress management and a thick section for strength, allowing each segment to fulfill its specific mechanical requirement independently.
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 configuration effectively reduces thermal stress at the joint while maintaining the necessary strength for connection, enhancing the durability and heat dissipation of the semiconductor device.
Implementation Method 1
When a temperature of the semiconductor device increases, the inner conductor layer of the insulated substrate and the external connection terminal respectively expand thermally. During this time, the thermal expansion of the inner conductor layer in the insulated substrate is suppressed by the adjacent insulator layer, and thus becomes smaller than the thermal expansion of the external connection terminal.
Data Source
AI summary
A semiconductor device includes a semiconductor element, an insulated substrate on which the semiconductor element is located, and an external connection terminal electrically connected to the semiconductor element via the insulated substrate. The insulated substrate includes an insulator layer, an inner conductor layer located on one side of the insulator layer and electrically connected to the semiconductor device, and an outer conductor layer located on the other side of the insulator layer. The external connection terminal includes, along a longitudinal direction of the external connection terminal, a thin section and a thick section that is thicker than the thin section, and the external connection terminal is joined to the inner conductor layer of the insulated substrate at the thin section.