Optical Bond Research Articles

A numerical methodology to support the development of liquid adhesive spreading patterns on display bonding process

A numerical methodology was implemented to support the development of adhesive spreading patterns for the Optical Bonding (OB) material on display bonding process, in order to reduce the experimental trial and error effort, being this iterative process done mainly through numerical simulations. These simulations were performed using the commercial software Abaqus, more specifically the Abaqus/Explicit module, which includes the Coupled Eulerian-Lagrangian method (CEL), used in cases where extreme deformations of the material are observed. This way, it was possible to obtain a methodology capable of predicting the spreading behaviour of a predefined OB material pattern. These results were initially compared to experimental results for a simple validation case and later for two more complex real cases. The numerical approach developed provided results very close to what was observed in experimental tests. This methodology can be a useful tool to optimize OB material patterns for display bonding process, but the simulation time needed is still a concern to have in mind.

Analysis of the bonding process and materials optimization for mitigating the Yellow Border defect on optically bonded automotive display panels

The Optical Bonding (OB) technology has become a critical aspect of the performance of displays, and an essential requisite of their supply chain. This paper presents the development and the implementation of a technological solution to the OB of automotive instrument panel displays. The goal is to select and develop the adequate materials and bonding techniques that can meet the rigorous performance, quality, cost and productivity of OB displays for the automotive industry. The implementation of a display wet-OB production line is firstly presented. The process is then optimised by selecting the adequate silicone based OB materials that can eliminate defects such as Yellow Border, YB (a type of MURA defect), meeting the application requirements at reduced cycle time.