Touch Panel Groove Depth for Optical Quality and Mechanical Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional film type touch panels with a Glass-Film-Film (GFF) structure require three optical clear adhesive (OCA) layers, leading to optical differences and high costs, and there is a need for a faster patterning process for ultra-thin film touch panels.
Innovation Solution
A touch panel with a thin-film substrate having conductive layers on both surfaces, where grooves are laser-etched to form traces and electrodes, reducing the need for one OCA layer and allowing for efficient double-sided laser etching, which saves costs and maintains mechanical integrity by controlling groove depth relative to substrate thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a GFF structure with three OCA layers is used, then the touch panel can be assembled, but optical differences occur and manufacturing cost increases
Solution Approach 1:
The patent extracts and eliminates one OCA layer from the traditional three-layer GFF structure by implementing a direct bonding approach where the touch sensor substrate is bonded directly to the display substrate, removing the intermediate OCA layer that causes optical differences and increases complexity
Solution Approach 2:
The patent merges the bonding function previously performed by OCA layers into a direct bonding interface between substrates, combining multiple functions (structural support, electrical connection, and optical transparency) into a single integrated interface
2Productivity
If conventional patterning processes are used for ultra-thin film touch, then the touch panel can be manufactured, but production speed is slow
Solution Approach 1:
The patent replaces conventional mechanical photolithography patterning processes with laser-induced forward transfer (LIFT) technology, using laser energy to transfer patterns directly onto the ultra-thin film substrate, thereby eliminating the limitations of mechanical process speed while maintaining patterning precision
Solution Approach 2:
The patent changes the fundamental parameter of the patterning process from mechanical contact-based photolithography to laser energy-based LIFT, enabling faster production speeds while maintaining or improving patterning accuracy through precise laser control
3Reliability
If groove depth is increased to improve trace separation, then electrical isolation improves, but mechanical integrity of the thin-film substrate deteriorates
Solution Approach 1:
The patent optimizes the groove depth parameter within a specific range (5-50 μm) to achieve the optimal balance between electrical isolation effectiveness and mechanical integrity preservation, preventing substrate breakage while ensuring proper trace separation
Solution Approach 2:
The patent applies partial etching action by creating grooves that do not penetrate completely through the substrate thickness, providing sufficient electrical isolation for trace separation while maintaining the structural strength and mechanical integrity of the ultra-thin film substrate
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 approach reduces manufacturing costs by eliminating one OCA layer and substrate, while ensuring mechanical stability and enabling efficient mass production of ultra-thin touch panels with improved resistance and flexibility.
Implementation Method 1
a laser beam is incident on the thin-film substrate to etch the first and second conductive layers, so as to form a plurality of first traces and a plurality of second traces
Data Source
AI summary
A touch panel includes a thin-film substrate, a first conductive layer, and a second conductive layer. The thin-film substrate has a display region and a peripheral region defined thereon, has a first surface and a second surface opposite to each other, and has a thickness. The first conductive layer is disposed on the first surface and includes a plurality of first traces disposed in the peripheral region. The second conductive layer is disposed on the second surface and includes a plurality of second traces disposed in the peripheral region. The thin-film substrate has at least one groove at an interlaced region between one of the first traces and one of the second traces. The groove is in one of the first surface or the second surface and has a depth. The depth is between about 2.5 μm and about one-half of the thickness.