Insert-Molded Switch Terminal Grooves for Flux Blocking
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Solution Overview
Problem
Existing switch technologies face issues with flux entry into the contact portion of the metal member during soldering, which can compromise the integrity and functionality of the switch.
Innovation Solution
The switch design incorporates a metal terminal with groove portions on its front and rear surfaces, formed at different positions, which are embedded in the housing, to prevent flux spread during soldering by enhancing adhesiveness and creating an outflow path for flux, thereby suppressing its entry into the contact portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the metal terminal is embedded in the housing with a smooth surface, then the manufacturing process is simple, but flux can easily enter the contact portion during soldering
Solution Approach 1:
The patent applies the porous materials principle by forming groove portions (recesses) on the embedded portion of the metal terminal. These grooves create a porous-like structure that allows the resin housing to penetrate and anchor into the metal terminal, preventing flux from reaching the contact portion while maintaining manufacturing simplicity through direct formation of the grooves on the metal terminal surface
2Reliability
If groove portions are formed on the metal terminal, then flux entry is suppressed, but the manufacturing process becomes more complex
Solution Approach 1:
The patent applies the local quality principle by forming groove portions only on the embedded portion of the metal terminal that contacts the housing, while leaving the contact portion smooth and intact. This localized approach provides flux prevention exactly where needed (at the housing interface) without adding unnecessary complexity to the entire metal terminal structure
3Device complexity
If the groove portions are formed at the same position on front and rear surfaces, then the structure is symmetric and simple, but flux can still travel through the metal terminal
Solution Approach 1:
The patent applies the asymmetry principle by forming groove portions at different positions on the front surface and rear surface of the embedded portion. This asymmetric arrangement prevents flux from traveling linearly through the metal terminal by creating an interrupted path, as the grooves on one surface do not align with grooves on the opposite surface, thereby blocking flux progression
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 groove portions effectively prevent flux from reaching the contact portion, ensuring reliable electrical connections and improved adhesiveness between the housing and metal terminal, maintaining the switch's operational integrity.
Implementation Method 1
the groove portions extend in a widthwise direction that is a direction intersecting an extending direction of the embedded portion
Implementation Method 2
enhancing adhesiveness between the resin casing and the intermediate portion
Data Source
AI summary
A switch includes a housing and a metal terminal that is insert-molded into the housing. The metal terminal includes a contact portion provided on a first side of the metal terminal, an external connection portion provided on a second side of the metal terminal, and an embedded portion provided between the contact portion and the external connection portion and embedded in the housing. In the embedded portion, groove portions are formed in a front surface of the metal terminal and a rear surface of the metal terminal, the groove portions in the front surface being formed at positions different from the groove portions in the rear surface. The groove portions extend in a widthwise direction that is a direction intersecting an extending direction of the embedded portion.