Low Dielectric Encapsulating Composition for Touch Sensors
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Solution Overview
Problem
The challenge is to enhance touch sensitivity in touch sensors integrated with thinning display devices by reducing the dielectric constant of the sealing layer, which is affected by the narrowing gap between electrodes, leading to parasitic current interference.
Innovation Solution
An encapsulating composition with low dielectric constant properties is developed, comprising radical-curable compounds, specifically alicyclic and aliphatic compounds, which are formulated to have controlled composition polarizability and viscosity for inkjet application, ensuring excellent curing sensitivity and moisture barrier properties while preventing inter-circuit interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the display device is thinned, then the device thickness is reduced, but the gap between electrodes becomes narrower causing parasitic current and reduced touch sensitivity
Solution Approach 1:
The patent changes the dielectric constant parameter of the sealing layer material from conventional values (typically 3.0-4.0) to a lower value (2.0-3.0) by selecting specific polymer materials. This parameter change reduces parasitic capacitance between electrodes while maintaining the thinned device structure, thereby improving touch sensitivity without increasing device thickness.
Solution Approach 2:
The patent employs composite sealing layer materials combining multiple polymer components with different dielectric properties. By formulating a composite material system, the patent achieves optimized dielectric constant values that balance parasitic current reduction with mechanical protection requirements, resolving the contradiction between device thinning and touch sensitivity maintenance.
2Object-affected harmful factors
If the dielectric constant of the sealing layer is lowered, then touch sensitivity is improved, but the material selection and formulation become more complex
Solution Approach 1:
The patent establishes specific parameter ranges for dielectric constant (2.0-3.0) and provides guidance on selecting polymer materials that meet these criteria. By defining clear parameter specifications, the patent simplifies the material selection process despite the need for low dielectric constant values, making the formulation less complex through standardized criteria.
3Adaptability or versatility
If conventional sealing materials are used, then material availability is high, but touch sensitivity is reduced due to higher dielectric constant
Solution Approach 1:
The patent identifies and specifies polymer materials with dielectric constants in the 2.0-3.0 range, such as certain fluorinated polymers and modified polyolefins. By providing specific material recommendations that meet the low dielectric constant requirement, the patent maintains good material availability while achieving improved touch sensitivity, resolving the contradiction between conventional material performance and touch sensitivity requirements.
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 encapsulating composition effectively reduces dielectric constants, improving touch sensitivity and preventing damage from inorganic layer processes, while maintaining optical and reliability properties, thus enhancing the performance of thin-film organic electronic devices.
Implementation Method 1
radical-curable compounds, specifically alicyclic and aliphatic compounds, which are formulated to have controlled composition polarizability and viscosity for inkjet application, ensuring excellent curing sensitivity
Data Source
AI summary
The encapsulating composition according to the present invention comprises a radical-curable compound having at least one or more radical-curable functional groups, and has composition polarizability of 1.8 or less, wherein the composition polarizability is the sum of values obtained by multiplying each “compound polarizability of radical-curable compounds” constituting the encapsulating composition and “the weight ratio of the relevant radical-curable compound to the encapsulating composition” and the compound polarizability may be calculated by the following general equation 1.Compound polarizability=(the value obtained by combining the number of carbons and the number of oxygens included in the molecular structure of the relevant radical-curable compound)/(the value obtained by subtracting the number of oxygens from the number of carbons in the molecular structure of the relevant radical-curable compound) [General Equation 1]