Flexible Circuit Board Passivation Layer Surface Roughness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display device manufacturing processes face challenges with adhesive layers and release layers during automation, leading to defects and difficulties in removing these layers without damaging the components.
Innovation Solution
A display device design featuring a flexible printed circuit board with a passivation layer having a first region with increased surface roughness for improved adhesive bonding and a second region with reduced surface roughness for easier adhesive removal, facilitating process automation and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If adhesive layers and release layers are used for automated assembly processes, then productivity is improved, but defects occur during removal of these layers
Solution Approach 1:
The passivation layer is designed with different surface roughness characteristics in different regions: a first region with greater surface roughness for strong adhesive bonding during automated assembly, and a second region with lesser surface roughness for easy adhesive removal. This local differentiation resolves the contradiction by enabling both high productivity through automation and high reliability through defect-free removal.
2Strength
If adhesive bonding is strengthened for reliable attachment, then bonding force is improved, but removal of adhesive becomes difficult
Solution Approach 1:
The passivation layer exhibits spatially varying surface roughness: the first region has greater roughness to maximize adhesive bonding strength for permanent attachments, while the second region has smoother surface to facilitate easy removal of temporary adhesives. This local quality differentiation allows the same surface to provide both strong bonding and easy removal properties in different locations.
3Strength
If surface roughness is increased for better adhesive bonding, then bonding force is improved, but adhesive removal becomes more difficult
Solution Approach 1:
Different regions of the passivation layer are engineered with different surface roughness levels: the first region has increased roughness (Ra≥50nm) to provide strong adhesive bonding for permanent components, while the second region has reduced roughness (Ra<50nm) to enable easy detachment of temporary adhesives. This local differentiation resolves the contradiction between bonding strength and ease of removal.
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 solution enhances the bonding force of adhesives in critical areas while allowing for easier detachment of temporary elements, thereby reducing defects and improving the efficiency of process automation in display device manufacturing.
Implementation Method 1
the first region has greater surface roughness than the second region
Implementation Method 2
improved adhesive bonding
Data Source
AI summary
A display device includes a display panel including a display surface and a rear surface opposite to each other; and a flexible printed circuit board attachable to the display panel at the rear surface of the display panel. The flexible printed circuit board includes a conductive layer, a passivation layer defining an outer surface of the flexible printed circuit board, and a base film between the conductive layer and the passivation layer, the outer surface includes a first region at which the rear surface of the display panel is attachable to the flexible printed circuit board and a second region at which the rear surface of the display panel is not attached to the flexible printed circuit board, and the first region has greater surface roughness than the second region.