Plug Connector Structure for PCBs with Shear-Force Contact
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Solution Overview
Problem
Existing connector structures for thermocouple measurements in automotive and aircraft applications are not sufficiently stable over the long term, leading to measurement inaccuracies, especially when frequently opened and closed, due to mechanical and electrical connections that are prone to deformation and surface pressure effects.
Innovation Solution
A connector construction featuring an insulation plate with a metal layer, flat contact elements with a fastening section and a rigid contact tongue, and elastic spring tongues with a mechanical guide for centered alignment, which applies shear forces only and avoids bending moments, ensuring a stable connection using SMD technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soldering by means of push-through pins is used to connect the socket element to the printed circuit board, then mechanical and electrical connection is achieved, but long-term stability and measurement accuracy deteriorate due to deformation and surface pressure effects when the connector is opened and closed frequently
Solution Approach 1:
The contact element is divided into two distinct sections: a fastening section connected to the circuit board via SMD technology, and a rigid contact tongue that protrudes over the edge. This segmentation allows the fastening section to remain stationary while the contact tongue engages with the plug-on unit, eliminating deformation at the connection point and ensuring long-term measurement accuracy.
Solution Approach 2:
The invention replaces traditional through-hole soldering with SMD (Surface Mount Device) technology for connecting the fastening section to the circuit board. This substitution eliminates the need for push-through pins and solder joints that are prone to deformation, thereby improving long-term stability while maintaining electrical connection integrity.
2Reliability
If elastic spring tongues are used to provide mechanical preload, then good electrical contact is achieved, but bending moments act on the contact tongue causing material changes and measurement errors
Solution Approach 1:
The spring tongues are asymmetrically designed with convex sides that face each other when plugged together. This asymmetric geometry ensures that the spring tongues contact the rigid contact tongue on both sides with convex surfaces, distributing the mechanical preload symmetrically and preventing bending moments while maintaining reliable electrical contact.
Solution Approach 2:
Instead of having the spring tongues contact the contact tongue with their concave sides (which would create bending moments), the invention inverts the design so that the convex sides of the spring tongues face each other and contact the contact tongue. This inversion eliminates bending moments while providing the necessary mechanical preload for stable electrical contact.
3Ease of manufacture
If manufacturing tolerances are present, then mass production is feasible, but misalignment and tilting occur during plugging causing excessive stress on the connection point
Solution Approach 1:
The mechanical guide is designed to provide beforehand cushioning against misalignment and tilting that may occur due to manufacturing tolerances. The guide structure prevents asymmetric positioning during plugging, ensuring that the spring tongues engage the contact tongue in a centered manner without excessive stress, thereby protecting the connection strength despite manufacturing variations.
Solution Approach 2:
The invention changes the geometric parameters of the contact elements, specifically designing the spring tongues with convex sides and the contact tongue with a complementary shape. This parameter change ensures that even with manufacturing tolerances, the elements engage in a centered manner without tilting, maintaining connection strength while allowing mass production.
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 enhances measurement accuracy and long-term stability by preventing material changes and excessive errors, even with precise measurements, while accommodating manufacturing tolerances and reducing mechanical stress.
Implementation Method 1
at least two elastic spring tongues (4) which are bent at their end sections so that they face each other with their convex sides and, when plugged together, contact the rigid contact tongue (3a) on both sides by means of a contact mechanical preload
Implementation Method 2
The fastening section of the contact element connected to the circuit board is fastened to the metal layer by means of an SMD connection
Data Source
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AI summary
The invention relates to a plug-in connector structure for printed circuit boards having high long term stability with very precise measurements. Said aim is achieved by means of a plug-in connector structure with the following characteristics: an insulation plate firmly arranged on the at least one side of a metal layer; at least one flat contact element with two end sections, the first end section being designed as a securing section, and being connected to the metallic layer by means of an electrically conductive connecting material. The second end section is designed as a rigid contact tongue which protrudes over the edge of the insulation plate. The counter-piece is a plug-in device connected to a cable provided for plugging into the contact tongue, said plug-in device being provided with at least two elastic spring tongues which are curved on the end sections thereof such that the convex sides are arranged directly opposite and are in contact with the rigid contact tongue on both sides, due the mechanical stress when the connector is in the plugged-in state The two spring tongues have the same load deflection curve. The connector is also provided with a mechanical guide system enabling the incurved spring tongues to slide in a centered manner on the contact tongue.