Spring Terminal Constriction for Semiconductor Contact Reliability
Solution Overview
Problem
Existing semiconductor modules face contact failures due to stress relaxation issues in the planar direction, particularly when positional deviations occur in the control substrate, and there is a risk of damaging the substrate during external connection, leading to unreliable electrical connections.
Innovation Solution
A semiconductor apparatus with a spring terminal design featuring a first connection portion fixed to the case and connected to the semiconductor device, and a second connection portion with an elastic force and a constriction structure, including notches along the longitudinal direction, which allows for stress distribution and improved positional flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a spring terminal with spring property only in height direction is used, then the structure is simple, but it cannot relax stress in planar direction causing contact failure when positional deviation occurs
Solution Approach 1:
The spring terminal is divided into multiple functional segments: a first connection portion extending along the side surface, a second connection portion on the top surface with elastic force, and an intermediate portion connecting them. This segmentation allows each part to perform its specific function - the first portion provides structural support while the second portion provides elastic contact pressure, resolving the contradiction between structural simplicity and contact reliability.
Solution Approach 2:
The spring terminal transitions from a single-dimension (vertical) spring structure to a multi-dimensional structure by adding the first connection portion extending along the side surface and the second connection portion on the top surface. This dimensional expansion enables the terminal to accommodate positional deviations in both vertical and planar directions, improving contact reliability without significantly increasing complexity.
2Ease of manufacture
If the second connection portion has constant width, then manufacturing is simple, but stress concentrates causing contact failure
Solution Approach 1:
The second connection portion features a variable width design where the width changes along its length, creating different local properties. The narrower region provides flexibility and stress distribution, while wider regions provide structural support. This local quality variation allows the terminal to distribute stress effectively during contact, improving reliability while remaining manufacturable through standard forming processes.
3Reliability
If external connection terminal tip is pressed against semiconductor device, then electrical connection is established, but the substrate or semiconductor device may be damaged
Solution Approach 1:
The spring terminal acts as an intermediary element between the external connection and the semiconductor device/substrate. Instead of directly pressing the terminal tip against the fragile substrate, the elastic second connection portion provides a compliant interface that establishes electrical connection while absorbing mechanical stress, preventing damage to the substrate or semiconductor device.
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 solution enhances the reliability of contact between the spring terminal and the control substrate by distributing stress and accommodating positional deviations, reducing the risk of contact failure and substrate damage, while maintaining reliable electrical connections.
Implementation Method 1
the second connection portion being a flat plate and having an elastic force using the first end as a supporting point, the second end contacts the control substrate with an elastic force
Data Source
AI summary
According to the present invention, a semiconductor apparatus includes a semiconductor device, a case surrounding the semiconductor device, a spring terminal including a first connection portion extending to a top surface of the case, and a second connection portion provided on the top surface of the case and a control substrate provided on the second connection portion, wherein the first connection portion is connected to the semiconductor device, the second connection portion includes a first end connected to an end of the first connection portion, and a second end opposite to the first end, the second connection portion being a flat plate and having an elastic force using the first end as a supporting point, the second end contacts the control substrate with an elastic force, and the second connection portion has a constriction structure having a notch formed in a side surface along a longitudinal direction.