Inspection Probe Copper Alloy Plunger Low Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inspection probes face challenges in reducing resistance values for signal transmission, stability, and suitability for large-current use due to limitations in material choice and manufacturing processes, particularly with coil spring units and dimensional adjustments.
Innovation Solution
The design incorporates a copper alloy first and second plunger with an integral spring portion and a cylindrical support stem, allowing sliding contact and reducing resistance, along with a plating process using non-magnetic metals like gold and copper to enhance conductivity and stability, while omitting the need for dimensional adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thickening plating is performed on the coil spring unit using low-resistance materials like gold, copper, or silver, then the resistance value is reduced, but the manufacturing complexity increases and the coil spring units are apt to fix together during plating
Solution Approach 1:
The invention extracts the plating function from the coil spring unit itself and applies it only to the contact pieces. This selective approach reduces resistance at the critical contact points without requiring the entire spring unit to be plated, thereby avoiding the manufacturing complications of handling and fixing entire spring units during plating processes.
Solution Approach 2:
Instead of uniformly plating the entire coil spring unit, the invention applies plating locally only to the contact pieces where electrical contact occurs. This local quality approach reduces resistance where it matters most while avoiding the manufacturing complexity and fixing issues associated with plating the entire spring unit.
2Reliability
If the wound tight portion is brought into close contact to reduce resistance, then the resistance value is reduced, but the manufacturing precision requirements increase and stability decreases
Solution Approach 1:
The invention removes the wound tight portion from the spring unit and replaces it with a separate support stem structure. This extraction eliminates the need for precise dimensional adjustments and close contact arrangements, providing stable electrical connection without manufacturing precision issues.
Solution Approach 2:
The invention segments the spring unit by removing the wound tight portion and introducing a separate support stem with contact pieces. This segmentation allows the support stem to be independently positioned and fixed, eliminating the need for precise dimensional adjustments between components while maintaining low resistance through proper contact piece design.
3Manufacturing precision
If dimensional adjustment is performed on the clearance between the fixing portion and the spring portion end, then assembly precision is improved, but productivity decreases
Solution Approach 1:
The invention segments the structure by removing the wound tight portion and introducing a separate support stem. This segmentation allows the support stem to be independently fixed at a predetermined position without requiring dimensional adjustments, thereby improving assembly productivity while maintaining precision through the predetermined positioning design.
Solution Approach 2:
The support stem is designed with predetermined positioning features that allow it to be fixed at the correct position without requiring dimensional adjustments during assembly. This preliminary action approach ensures assembly precision is built into the design rather than requiring post-design adjustments, thereby maintaining high productivity.
4Device complexity
If the short-circuit piece is configured to come into contact at one point, then the structure is simplified, but reliability decreases due to instability in internal contact and resistance value
Solution Approach 1:
The invention replaces the fixed one-point contact configuration with a dynamic spring-based contact mechanism. The spring portion provides elastic force that ensures continuous and stable contact between the contact pieces, accommodating variations in position and maintaining reliable electrical connection without requiring complex multi-point contact structures.
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 signal transmission resistance, prevents spring buckling, and supports large-current applications, while being suitable for non-magnetic metal usage to avoid interference with magnetic sensors.
Implementation Method 1
a coil spring unit configured to bias the plunger
Implementation Method 2
transmitting an electric signal from the plunger via the coil spring unit
Implementation Method 3
a plating process using non-magnetic metals like gold and copper to enhance conductivity
Data Source
AI summary
An inspection probe 16Ai is formed by subjecting a thin sheet material made of a copper alloy to press working. The inspection probe 16Ai includes: a device side plunger 16A having a contact point which selectively comes into contact with an electrode portion DVb of a semiconductor device DV; a board side plunger 16B having a contact point which selectively comes into contact with a contact pad of a printed wiring board 18; a spring portion 16D which biases the device side plunger 16A and the board side plunger 16B in a direction away from each other; and a cylindrical support stem 16C being disposed inside the spring portion 16D, making the spring portion 16D slidable thereon, and being configured to retain straight advancing property of the spring portion 16D.