Membrane Keyboard Spacer Alignment for Smooth Keystroke Response
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current membrane keyboard manufacturing methods face issues with assembly tolerances, leading to misalignment of conductive circuits and hollow portions, which affects the smoothness of keystroke and input signal generation.
Innovation Solution
The method involves forming specific positioning holes on the upper and lower circuited layers of the membrane circuit board, where the minimum diameter of the second positioning hole is smaller than the first and third holes, allowing precise alignment of restoring members with hollow portions, even with assembly tolerances, by using a restoring member assembly fixture with locating pillars.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional single positioning hole method is used, then manufacturing process is simple, but assembly tolerance causes misalignment between restoring members and hollow portions
Solution Approach 1:
The single positioning hole is segmented into three separate positioning holes located at different positions (first positioning hole at upper circuited layer, second positioning hole at spacer layer, third positioning hole at lower circuited layer). Each positioning hole independently constrains a different degree of freedom, collectively achieving precise alignment between the restoring member and hollow portion while compensating for assembly tolerances.
Solution Approach 2:
The second positioning hole at the spacer layer acts as an intermediary element that directly abuts the locating pillar of the assembly fixture. This intermediary positioning hole with smaller minimum diameter provides the critical constraint that ensures the restoring member's central position corresponds to the hollow portion's central position, mediating between the fixture and the final assembly precision.
2Manufacturing precision
If positioning hole diameter is reduced for better precision, then alignment accuracy improves, but manufacturing difficulty increases
Solution Approach 1:
Different positioning holes have different minimum diameters tailored to their specific functions. The second positioning hole has a smaller minimum diameter than the first and third positioning holes. This local differentiation optimizes positioning accuracy where needed (at the spacer layer) while maintaining ease of manufacture at other positions, balancing precision requirements with manufacturing feasibility.
Data Source
AI summary
A membrane keyboard and manufacturing method thereof, the manufacturing method comprises the following steps: forming a first positioning hole on an upper circuited layer, forming a second positioning hole and a plurality of hollow portions on a spacer layer, forming a third positioning hole on a lower circuited layer, wherein a minimum diameter of the second positioning hole is smaller than a minimum diameter of the first positioning hole and a minimum diameter of the third positioning hole; adhering the upper circuited layer, the spacer layer and the lower circuited layer, to form a restoring member positioning hole; placing the membrane circuit board in the restoring member assembly fixture and passing the restoring member positioning hole through a locating pillar of the restoring member assembly fixture, with an inner wall of the second positioning hole abutting the locating pillar.