Liquid Crystal Display Substrate Concave Portions for Seal Stability
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Solution Overview
Problem
The existing One Drop Fill (ODF) method for manufacturing liquid crystal display devices faces challenges in maintaining a uniform and narrow cell gap and frame size due to variations in seal material application, which affects the display's response characteristics, viewing angle, and external form size, leading to instability and defects like pattern cuts.
Innovation Solution
The proposed solution involves a liquid crystal display device structure with a first substrate having a concave portion in the peripheral area and a second substrate with a corresponding concave portion, both overlapping with a pillar-shaped spacer, allowing for increased application of seal material and expanded contact areas, thereby stabilizing the seal material application and enhancing the bonding strength between substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cell gap is narrowed to improve response characteristic and alignment characteristic, then the viewing angle characteristic improves, but the amount of seal material application is reduced
Solution Approach 1:
The invention transitions from controlling seal material application in a two-dimensional plane to utilizing three-dimensional space by forming concave portions on substrate surfaces. This allows increased seal material application volume without increasing the planar width of the seal material, thereby maintaining narrow frame size while improving response and alignment characteristics.
2Length of stationary object
If the width of seal material is reduced to achieve narrow frame size, then the external form size is reduced, but the stability of seal material application is reduced
Solution Approach 1:
The invention moves from two-dimensional seal material control to three-dimensional control by forming concave portions on substrates. This enables increased seal material volume within the same planar footprint, improving application stability without increasing frame size.
Solution Approach 2:
The concave portions are formed specifically in the peripheral area where seal material is applied, creating localized depth variations that enhance seal material retention and stability without affecting the overall narrow frame design.
3Productivity
If high velocity material is used to shorten tact time, then the productivity improves, but the variation in applied amount of seal material increases
Solution Approach 1:
The concave portions are formed on substrate surfaces before seal material application. This preliminary structural preparation allows high-velocity material deposition to be performed with reduced variation, as the concave portions provide physical constraints that guide and stabilize the seal material application process.
4Manufacturing precision
If the amount of seal material is reduced to achieve narrow cell gap, then the cell gap precision improves, but the bonding strength between substrates is reduced
Solution Approach 1:
The invention utilizes the vertical dimension by forming concave portions on substrates, enabling increased seal material volume without increasing planar dimensions. This maintains narrow cell gap precision while providing sufficient bonding strength through increased material quantity.
Solution Approach 2:
The seal material is formulated as a composite containing both adhesive components for bonding and filler particles for structural integrity. This composite structure enables the seal material to provide both precise cell gap control and strong bonding strength simultaneously.
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 configuration increases the applied amount of seal material by approximately 20% and reduces defects, improving manufacturing yield and maintaining the narrow cell gap and frame size requirements, while also controlling air bubbles and surplus liquid crystal material distribution.
Implementation Method 1
the pair of substrates is pressed by a difference in the pressure between an inner region surrounded with the seal material and outside by returning to an atmospheric pressure state from the vacuum state
Implementation Method 2
As the seal material applied to the One Drop Fill ODF method, ultraviolet curing type adhesives are used widely
Data Source
AI summary
In a first substrate, a first organic insulating film is arranged in an active area, and includes a first surface and a first concave portion in a peripheral area outside the active area. The first concave portion is located more close to a substrate end side than the first surface. In a second substrate, a shield layer is arranged in the peripheral area facing the first substrate. A second organic insulating film includes a second surface facing the first surface and a second concave portion facing the first concave portion. The second organic insulating film overlaps the shield layer in the peripheral area. A pillar-shaped spacer is arranged between the first surface and the second surface in the peripheral area. A seal material contains the pillar-shaped spacer and is arranged between the first surface and the second surface, and between the first concave portion and the second concave portion.