Membrane Circuit Board Light-Guiding Spacer Layer
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Solution Overview
Problem
Existing keyboards face challenges in achieving a low profile design while maintaining functionality, as they often require complex assembly processes and suffer from issues like edge chipping and light leakage due to the use of silver paste, which affects luminous performance.
Innovation Solution
A membrane circuit board with a light-guiding spacer layer that separates the upper and lower layers, featuring tapered through holes for electrical connection and light guidance, minimizing the number of components and assembly steps, and preventing erosion from silver paste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a traditional keyboard structure with separate light guide plate and membrane circuit board is used, then the keyboard can achieve light-emitting function, but the profile height increases and assembly complexity increases
Solution Approach 1:
The patent combines the light guide plate and membrane circuit board into a single integrated structure where the light-guiding spacer layer serves dual purposes: it guides light from the light-emitting component while simultaneously providing the necessary spacing and structural support for the membrane circuit board layers. This merging eliminates the need for a separate light guide plate, reducing profile height while maintaining light-emitting functionality.
Solution Approach 2:
The light-guiding spacer layer performs multiple functions: it acts as a light guide to transmit light from the light-emitting component to the key cap, provides structural spacing between the upper and lower layers of the membrane circuit board, and serves as a template for forming the through holes that enable electrical connection. This multi-functionality reduces the total number of components and assembly steps.
2Reliability
If silver paste is used for electrical connection between layers, then electrical connectivity is achieved, but edge chipping and light leakage occur reducing luminous performance
Solution Approach 1:
The patent extracts and removes the silver paste from the system, replacing it with a through-hole electrical connection structure. The through holes pass directly through the light-guiding spacer layer, allowing electrical contacts to connect the upper and lower layers without using silver paste. This eliminates the edge chipping and light leakage problems associated with silver paste while maintaining reliable electrical connectivity.
3Adaptability or versatility
If multiple separate components are used for light guiding and circuit board structure, then functional requirements are met, but manufacturing cost increases and assembly steps increase
Solution Approach 1:
The patent merges the light guide plate and membrane circuit board structure into a single integrated component. The light-guiding spacer layer is formed as an integral part of the membrane circuit board assembly, eliminating the need for separate light guide plate, spacer layer, and circuit board components. This reduces the number of components and assembly steps while maintaining all necessary functions.
4Length of stationary object
If the membrane circuit board is designed with through holes for electrical connection, then low profile is achieved, but light leakage may occur through the holes
Solution Approach 1:
The patent applies different properties to different regions of the through holes. The inner walls of the through holes are treated with a light-blocking coating or structure that prevents light from leaking through the holes while allowing electrical contacts to pass through. This local modification maintains the low-profile advantage of through-hole design while eliminating the light leakage problem.
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 solution results in a low-profile light-emitting keyboard with enhanced luminous performance, reduced manufacturing costs, and minimized light leakage, maintaining the integrity of the light-guiding spacer layer and improving the overall brightness and durability of the product.
Implementation Method 1
a light-guiding spacer layer arranged between the lower layer and the upper layer... The light-guiding spacer layer is formed with a tapered through hole... the light emitted from the light-emitting component E can go into the inside of the light guide plate B and then be guided out or transmitted
Implementation Method 2
the light-guiding spacer layer is formed with a tapered through hole that provides room for a triggering stroke for enabling a second circuit of the upper layer to electrically connect to a first circuit of the lower layer... When one key assembly D is pressed, the upper layer of the membrane circuit board C is forced to deform elastically
Data Source
AI summary
A light-emitting keyboard includes a membrane circuit board including a lower layer, an upper layer and a light-guiding spacer layer arranged between lower layer, an upper layer and defining therein a tapered through hole, a substrate holding membrane circuit board, a key assembly including key cap, a linkage coupled between key cap and substrate and an elastic element supported between key cap and membrane circuit board, and a light source for emitting light into the light-guiding spacer layer. The light-guiding spacer layer uses its thickness to isolate the lower layer and the upper layer and its tapered through hole to provide room for a triggering stroke for enabling the upper layer to electrically contact the lower layer second circuit in producing a corresponding switching signal each time the key assembly is pressed. Thus, the light-emitting keyboard achieves the characteristics of low profile, low manufacturing cost, and simple assembly process.