Fitting Type Connecting Terminal Groove Design for Abrasion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Miniaturization of connecting terminals for automotive vehicles and other applications leads to decreased contact load and reliability due to minute sliding abrasion, with existing solutions either being costly or ineffective in preventing oxide accumulation and electrical resistance increase.
Innovation Solution
A fitting type connecting terminal with male and female terminals featuring a tin plating layer on a conductive base material, where the contact surface has grooves or recessed portions spaced to control sliding distance and oxide accumulation, preventing abrasion powder from accumulating and reducing electrical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the contact load is decreased due to miniaturization, then the terminal size is reduced, but the contact reliability deteriorates due to minute sliding abrasion
Solution Approach 1:
The invention applies a specific surface structure (grooves or recessed portions) only to the contact surface of the terminal, while the rest of the terminal maintains its miniaturized design. This localized modification allows the contact surface to effectively contain abrasion powder through the groove structure, preventing contact reliability deterioration without compromising the overall miniaturization of the terminal
Solution Approach 2:
The invention converts the harmful effect of abrasion powder generation during sliding into a beneficial effect by designing grooves that guide and contain the abrasion powder within specific regions. The abrasion powder that would normally degrade contact reliability is instead channeled into the grooves, preventing its accumulation at the contact interface and maintaining reliable electrical connection
2Reliability
If an Ag-Sn alloy layer is formed on the tin plating layer, then the electric connection reliability is enhanced, but the manufacturing cost increases due to expensive noble metal plating
Solution Approach 1:
The invention replaces the expensive Ag-Sn alloy plating with a simple groove structure formed on the existing tin plating layer. Instead of using costly noble metals, the invention uses a geometric surface modification that is inexpensive to manufacture and can be easily integrated into existing terminal production processes, thereby maintaining reliability enhancement while significantly reducing manufacturing cost
3Device complexity
If the contact point is allowed to move, then the terminal structure is simpler, but minute sliding abrasion occurs due to vibration
Solution Approach 1:
The invention accepts the natural movement and sliding of the contact point during vibration and assembly, rather than attempting to prevent it through complex structures. By providing grooves on the contact surface, the invention converts the harmful sliding motion into a beneficial effect where abrasion powder is continuously guided into the grooves, preventing accumulation and maintaining contact reliability without increasing structural complexity
Data Source
Figure 1A~1B
Figure 1C~2A
Figure 2B~3A
AI summary
In a fitting type connecting terminal having male and female terminals, each of which has a tin plating layer formed on an electrically conductive base material, a surface of a contact portion of one of the male and female terminals with the other thereof has a plurality of grooves or recessed portions which are spaced from each other in longitudinal directions, and the grooves or recessed portions are formed so as to satisfy d ≦b, d≦a≦L and a+c≦L assuming that the width of each of the grooves or recessed portions is a (µ m), the depth thereof being b (µm), the distance between two of the grooves or recessed portions adjacent to each other in the longitudinal directions being c (µm), the sliding distance producible between the male terminal and the female terminal in a state that the male terminal is fitted into and fixed to the female terminal being L (µ m), and the maximum grain size of the oxide of abrasion powder producible due to sliding between the male terminal and the female terminal being d (µm).