Plug Contact Geometry for High Force in Small PCB Vias
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plug contacts for circuit boards face challenges in achieving a high contact normal force with small dimensions, leading to inadequate long-term electrical contact due to narrow and thin contact legs, which are difficult to manufacture and result in insufficient contact force.
Innovation Solution
The plug contact design features a recess in the connection area with contact legs that increase in distance towards their free ends, allowing for a wider contact area by spreading them apart through a knife-like separating cut, rather than punching out a corresponding area, resulting in contact legs that are significantly wider and capable of applying a higher normal force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the contact legs are made narrow and thin to fit small contact hole diameters, then the connector can be inserted into small contact holes, but the contact normal force becomes insufficient
Solution Approach 1:
The patent transitions from a two-dimensional stamped contact leg to a three-dimensional formed contact leg with increased width. By forming the contact legs from a stamped blank, the width can be increased beyond the original material thickness, allowing the contact legs to be wider than the contact hole diameter while still fitting properly, thus maintaining high contact normal force even in small contact holes
Solution Approach 2:
The patent changes the dimensional parameters of the contact legs by forming them after stamping. The contact legs are formed to have a width that is 0.5 to 2 times the contact hole diameter, and a height that is 0.5 to 2 times the material thickness, creating an optimized geometry that provides sufficient contact force while fitting small contact holes
2Force
If the contact legs are made wide to increase contact normal force, then the contact force is sufficient, but the connector cannot be inserted into small contact holes
Solution Approach 1:
The patent uses forming to create three-dimensional contact legs with optimized dimensions. The contact legs have a width (lateral dimension) that can be 0.5 to 2 times the contact hole diameter, and a height (vertical dimension) that is 0.5 to 2 times the material thickness, allowing wide contact legs to fit into small contact holes through proper dimensional control in multiple dimensions
3Ease of manufacture
If the area between contact legs is punched out to create the legs, then the manufacturing is simple, but the contact legs become narrow and thin
Solution Approach 1:
The patent performs stamping first to create a blank with the basic geometry, then forms the contact legs in a subsequent operation. This preliminary stamping action creates a blank that can be easily formed into the final shape with wide contact legs, combining the simplicity of stamping with the benefits of formed geometry
Solution Approach 2:
The patent separates the manufacturing process into two distinct operations: stamping the blank and then forming the contact legs. This segmentation allows each operation to be optimized independently, with stamping providing simplicity and forming providing the wide contact leg geometry needed for high contact force
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 design enables a higher contact normal force, ensuring good and permanent electrical contact even with small contact hole diameters, while being easier to produce and allowing for reversible connections.
Implementation Method 1
two flat, resilient contact legs relative to each other
Data Source
Figure 1~2
Figure 3a~3b
Figure 4~5
AI summary
The invention describes a plug contact (1) for electrically contacting a circuit board (2) by inserting the plug contact (1) into a via hole (3) in the circuit board (2), the plug contact having two flat contact arms (4, 5) that are resilient relative to each other, and a connecting region (6), from which the two contact arms (4, 5) extend in the plug-in direction (E) of the plug contact (1), the plug contact (1) being punched as a single piece from a flat metallic material. The plug contact (1) according to the invention permits a high normal contact force even when dimensions are compact, and thus ensures a good, lasting electrical contact even when the via holes (3) have a small diameter. The plug contact is characterized in that in the connection region (6), adjacent to the two contact arms (4, 5), a recess (7) is formed, the distance between the two contact arms (4, 5) increases from the recess (7) towards the free ends (4a, 5a) of the contact arms, the two contact arms (4, 5) being spread apart relative to each other and the two contact arms (4, 5) together having a width (B), which is the same as or only slightly smaller than the diameter (D) of the corresponding via hole (3) in the circuit board (2).