Press-Fit Pin Geometry for Alignment, Ampacity, and Crack Resistance
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Solution Overview
Problem
Power semiconductor modules face challenges with press-fit pins that are susceptible to cracking, difficult to align, and have limited ampacity, affecting their reliability and efficiency in high-power applications.
Innovation Solution
A press-fit pin design featuring a tip part with sloped sidewalls, a deformable part for elastic deformation, an elongate part with increased width for enhanced ampacity, and an anchoring part for secure insertion, manufactured through stamping and shaping of sheet metal to improve alignment and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a press-fit pin uses a uniform cross-section design, then the manufacturing process is simple, but the pin is susceptible to cracking during insertion
Solution Approach 1:
The pin is divided into multiple sections with different cross-sectional dimensions along its length. The distal region has a narrower width than the proximal region, creating segments that serve different functions: the narrower distal region reduces insertion force and cracking risk, while the wider proximal region provides structural strength and ampacity.
2Ease of operation
If a press-fit pin has a narrow tip for easy insertion, then alignment is improved, but the ampacity is reduced
Solution Approach 1:
Different regions of the pin have different cross-sectional dimensions optimized for their specific functions. The distal region (tip area) has a narrower width for improved alignment and reduced insertion force, while the proximal region has a wider width to maintain adequate ampacity and structural strength. This local differentiation resolves the contradiction between insertion ease and current carrying capacity.
3Strength
If a press-fit pin uses a constant width design, then the structural integrity is maintained, but the alignment during insertion is difficult
Solution Approach 1:
The pin structure is segmented into distal and proximal regions with different widths. The narrower distal region acts as a guide that facilitates alignment with the circuit board opening during insertion, while the wider proximal region maintains structural integrity and ampacity. This segmentation allows the pin to achieve both good alignment characteristics and structural strength.
4Reliability
If a press-fit pin has a larger cross-section for higher ampacity, then the current carrying capacity is increased, but the insertion force required increases causing cracking
Solution Approach 1:
The pin employs local quality differentiation where the distal region has a narrower cross-section to reduce insertion force and prevent cracking, while the proximal region has a wider cross-section to provide adequate ampacity and structural strength. This local optimization allows the pin to achieve both high current carrying capacity and resistance to insertion-induced cracking.
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 design reduces the likelihood of cracking, simplifies alignment, and increases ampacity, providing a robust and efficient electrical interface for power semiconductor modules, suitable for high-power applications.
Implementation Method 1
a deformable part adjoining the tip part and configured to deform upon insertion into the opening of the circuit board
Data Source
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AI summary
A press-fit pin includes: a tip part configured to guide the press-fit pin into an opening of a circuit board; a deformable part adjoining the tip part and configured to deform upon insertion into the opening of the circuit board; an elongate part adjoining the deformable part; a base part adjoining the elongate part; and an anchoring part adjoining the base part and configured for insertion into a sleeve when a force is applied to the base part. The tip part has a proximal region adjoining the deformable part and a distal region that is narrower than the proximal region. A first sidewall of the press-fit pin is sloped, with respect to a longitudinal axis of the press-fit pin, at a first acute angle in the distal region and at a second acute angle in the proximal region. The first acute angle is greater than the second acute angle.