Photocurable Adhesive for LCD Panel Bonding
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Solution Overview
Problem
Existing adhesive compositions struggle to provide sufficient adhesive strength and viscosity for bonding liquid crystal display (LCD) panels to backlight units in mobile devices, especially when dealing with different materials like glass and polycarbonate, which limits the enlargement of display windows due to mechanical and adhesion issues.
Innovation Solution
A photocurable adhesive composition comprising a urethane (meth)acrylate binder, photocurable monomers, adhesion enhancing monomers, and a photoinitiator, with specific properties such as viscosity, modulus, and surface energy, applied to adjacent sides of the LCD panel and backlight unit to ensure strong bonding and reworkability, and cured using UV irradiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional adhesive compositions are used to bond LCD panels to backlight units, then the assembly process can proceed, but the adhesive strength is insufficient and viscosity is not suitable for proper bonding
Solution Approach 1:
The patent modifies the adhesive composition by adjusting the molecular weight of the urethane (meth)acrylate binder to 10,000-50,000 g/mol and controlling the viscosity to 3,000-6,000 cps, which optimizes both adhesive strength and bonding reliability for LCD panel assembly
Solution Approach 2:
The invention uses a composite adhesive system combining urethane (meth)acrylate binder with specific photoinitiators and additives, creating a multi-component formulation that achieves superior adhesive strength (30-50 N/cm²) compared to conventional single-component adhesives
2Area of stationary object
If the display window is enlarged in mobile devices, then the display area increases, but mechanical and adhesion issues arise that limit further enlargement
Solution Approach 1:
By optimizing the viscosity parameter to 3,000-6,000 cps and modulus to 2,000-6,000 Pa, the adhesive can properly bond larger display components together, enabling enlarged display windows while maintaining structural integrity
Solution Approach 2:
The adhesive composition is designed with specific local properties including surface energy control and targeted molecular weight distribution, allowing it to bond different materials (glass LCD panels to polycarbonate backlight units) effectively across large display areas
3Stability of the object's composition
If adhesive composition with high viscosity is used, then the adhesive maintains position better, but the adhesive strength and reworkability are compromised
Solution Approach 1:
The patent identifies an optimal viscosity range of 3,000-6,000 cps that balances position stability during application with reworkability after curing, allowing the adhesive to maintain components in place while still permitting adjustment if needed
Solution Approach 2:
The adhesive exhibits dynamic properties where it remains relatively fluid during application for easy positioning, then transitions to a stable bonded state after UV curing, providing both ease of assembly and structural stability
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 composition achieves an adhesive strength of 30 to 50 N/cm² and suitable viscosity, ensuring robust bonding between the LCD panel and backlight unit, facilitating the assembly of larger display windows in mobile devices while maintaining reworkability and preventing light leakage.
Implementation Method 1
a photocurable adhesive composition including a urethane (meth)acrylate binder, a photocurable monomer, an adhesion enhancing monomer, and a photoinitiator
Data Source
AI summary
A photocurable adhesive composition, a module apparatus, and a method of assembling a module, the composition including a urethane (meth)acrylate binder, the composition having a viscosity of about 3,000 to about 6,000 cps at 25° C., and providing an adhesive film having an adhesive strength of about 30 N/cm2 or more.