Right-Angle Connector Leg-Blade Restriction for Reflow Stability
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Solution Overview
Problem
Existing right-angle electrical connectors face issues with leg-portion blades deforming during reflow oven heating, leading to potential detachment from the circuit board due to thermal expansion differences, which can result in poor solder connections.
Innovation Solution
The design incorporates guiding and restricting portions within the housing to prevent excessive displacement of leg-portion blades, ensuring they do not lift off the circuit board by abutting them from the front and rear during heating, thus maintaining stable connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the connector is heated in a reflow oven for solder connection, then the solder connection process can be completed, but the leg-portion blades deform and displace forward due to thermal expansion differences
Solution Approach 1:
The patent applies preliminary anti-action by providing restricting portions in the housing that prevent forward displacement of leg-portion blades before thermal expansion can cause detachment. These restricting portions are positioned to abut the front faces of the leg-portion blades, creating a counteracting force that offsets the harmful thermal expansion effect during reflow heating.
Solution Approach 2:
The patent changes the physical state and constraints of the leg-portion blades by introducing restricting portions that modify the boundary conditions during heating. The restricting portions create mechanical constraints that change the thermal expansion behavior, preventing the blades from displacing forward while still allowing controlled movement in other directions.
2Object-affected harmful factors
If the leg-portion blades are allowed to move freely during heating, then thermal expansion is accommodated, but the connecting portions lift off the circuit board mounting face
Solution Approach 1:
The patent applies local quality by providing different degrees of freedom to different parts of the blade structure. The leg-portion blades are constrained in the forward-backward direction by restricting portions but remain free to expand thermally in other directions. This localized constraint strategy allows thermal stress accommodation while preventing connection detachment.
Solution Approach 2:
The patent segments the movement constraints by applying restrictions only to the leg-portion blades while leaving other parts of the connector structure free to expand. The restricting portions are selectively positioned to constrain only the critical leg-portion blades, allowing differential movement that accommodates thermal expansion without compromising connection reliability.
3Reliability
If restricting portions are added to prevent blade displacement, then connection reliability is maintained, but device complexity increases
Solution Approach 1:
The restricting portions are designed to serve multiple functions: they prevent forward displacement of leg-portion blades, guide blade insertion, and maintain structural integrity during heating. By combining multiple functions into a single structural feature, the patent minimizes the increase in device complexity while achieving reliable connection maintenance.
Solution Approach 2:
The patent merges the restricting portions with the existing housing structure, integrating the displacement prevention function into the housing itself rather than adding separate components. This merging approach reduces overall device complexity by consolidating functions into existing structural elements.
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 solution effectively restricts forward and rearward displacement of leg-portion blades, ensuring reliable solder connections and maintaining an excellent connection between the connector and the circuit board even under thermal stress.
Implementation Method 1
the leg-portion blades of the heated connector may be subject to deformation and displaced forward because of the difference in the coefficients of thermal expansion between the resin board and the leg portions of the terminals
Data Source
AI summary
Blades 60A, 60B are formed due to the fact that arm-portion blades 60A-1, 60B-1, by which arm portions of electroconductive elongated members are retained in place, and leg-portion blades 60A-2, 60B-2, by which leg portions are retained in place, are coupled via bend portions of the electroconductive elongated members such that the respective major faces of the blades form an angle with one another, a housing 10 has formed therein a holding portion 10G holding the blades 60A, 60B, said holding portion 10G has formed therein restricting portions 17K, 17J positioned in a face-to-face relationship with the front faces of the leg-portion blades 60A-2, 60B-2 in front of said leg-portion blades 60A-2, 60B-2, and said restricting portions 17K, 17J can restrict forward displacement of the leg-portion blades 60A-2, 60B-2.