Touch Panel External Terminal Parallel Conductive Structure
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Solution Overview
Problem
Projected capacitive touch panels face issues with high electrical resistance in external connecting terminals due to the use of transparent conductive oxides like ITO, leading to poor conduction and increased manufacturing costs.
Innovation Solution
A parallel connection structure is implemented for external connecting terminals using two layers of transparent conductive oxide films, one under and one over an interlayer insulating film, connected in parallel to the lead line, reducing electrical resistance without adding manufacturing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external connecting terminals are made of transparent conductive oxide (ITO) to maintain moisture resistance and corrosion resistance, then reliability is improved, but electrical resistance increases leading to poor conduction
Solution Approach 1:
The external connecting terminal uses a composite structure combining transparent conductive oxide (ITO) layer and metal layer. The ITO layer provides moisture and corrosion resistance, while the metal layer provides low electrical resistance. This composite material approach resolves the contradiction by integrating the beneficial properties of both materials in a single terminal structure.
2Loss of energy
If multiple layers of transparent conductive oxide are added in parallel to reduce electrical resistance, then electrical conduction is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the formation of the external connecting terminal with the existing electrode formation process. The transparent conductive oxide pattern and metal pattern are formed simultaneously in the same manufacturing step, integrating two functions into one process. This reduces manufacturing complexity while achieving the goal of reduced electrical resistance through parallel connection structure.
3Adaptability or versatility
If external connecting terminals are densely arranged in the terminal region, then adaptability is improved, but the width of each terminal decreases leading to higher electrical resistance
Solution Approach 1:
By using the composite structure of transparent conductive oxide and metal layers, the terminal can maintain low electrical resistance even when densely arranged with reduced width. The metal layer compensates for the reduced cross-sectional area, allowing high adaptability through dense terminal arrangement without sacrificing conduction performance.
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 configuration decreases the electrical resistance of external connecting terminals, enhancing touch position detection functionality while maintaining low manufacturing costs.
Implementation Method 1
a parallel connection structure of two layers connected in parallel to a lead line, and the parallel connection structure is formed of the same film as existing conductive patterns for touch position detection
Data Source
AI summary
A external connecting terminal (35) includes a first interconnect layer (36A) formed of a same film as a first conductive pattern for touch position detection under an interlayer insulating film (23), and a second interconnect layer (36B) formed of a same film as a second conductive pattern for touch position detection on the interlayer insulating film (23). the first and the second interconnect layers are electrically connected to a lead line (31) at a portion overlapping the lead line (31), and electrically connected together at a portion outside the lead line (31).