Display Substrate Bonding Pad Insulation for Step Stress Relief
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Solution Overview
Problem
The uneven distribution of force during the bonding process of display substrates due to step differences between contact pads and peripheral regions leads to stress concentration and potential breakage of film layers, resulting in damaged substrates and increased manufacturing costs.
Innovation Solution
A display substrate design featuring a first insulation layer in the bonding region that covers the edges of contact pads, ensuring even force distribution and reducing step differences, thereby preventing substrate damage during bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If contact pads are made larger to facilitate bonding, then bonding ease is improved, but step differences between contact pads and peripheral regions increase causing stress concentration and film layer breakage
Solution Approach 1:
A buffering layer is introduced as an intermediary structure between the contact pads and the bonding pad. This buffering layer has a gradient thickness design that gradually transitions from the contact pad region to the peripheral region, acting as a stress buffer that prevents stress concentration and film layer breakage while maintaining bonding ease
Solution Approach 2:
The thickness parameter of the buffering layer is changed to create a gradient structure. The buffering layer thickness varies continuously from the contact pad region to the peripheral region, which changes the mechanical properties of the structure to reduce stress concentration and prevent film layer breakage during bonding
2Area of stationary object
If contact pads are made larger to improve bonding, then bonding area is increased, but step differences cause stress concentration leading to substrate damage
Solution Approach 1:
The buffering layer serves as a mediator that connects the large-area contact pads to the bonding pad while gradually reducing the step difference. This intermediary structure distributes the mechanical stress across a gradient thickness profile, preventing stress concentration that would otherwise cause film layer breakage
Solution Approach 2:
The buffering layer exhibits local quality variation through its gradient thickness design. Different regions of the buffering layer have different thicknesses, creating locally optimized mechanical properties that reduce stress concentration at the interface between contact pads and bonding pad while maintaining overall structural integrity
3Ease of manufacture
If conventional bonding processes are used on substrates with step differences, then manufacturing simplicity is maintained, but substrate breakage occurs increasing manufacturing costs
Solution Approach 1:
The buffering layer is formed in advance during the substrate manufacturing process, before the bonding operation. This preliminary action creates a stress-buffering structure that prevents substrate breakage during subsequent bonding, thereby improving manufacturing yield without significantly complicating the manufacturing process
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 insulation layer evenly distributes pressure, preventing substrate breakage and improving yield while reducing manufacturing costs by allowing larger contact pad designs and easier manufacturing processes.
Implementation Method 1
a light-emitting element including: a first electrode; a second electrode disposed opposite to the first electrode; and an organic EL layer including a light-emitting dopant and a host compound interposed between the first electrode and the second electrode
Data Source
Figure 1A~1C
Figure 1D~3
Figure 4~5A
AI summary
A display substrate and a manufacturing method therefor, and a display device are provided. The display substrate includes a base substrate (1100), a plurality of sub-pixels (1110), a plurality of data lines (11011), a plurality of data lead lines (1400), at least one group of contact pads (1200), and a first insulation layer (1310). The base substrate (1100) includes a display region (1101) and a bonding region (1102) on at least one side of the display region (1101); the plurality of data lines (11011) are in the display region, and are configured to provide data signals to the plurality of sub-pixels (1110); the plurality of data lead lines (1400) are in the bonding region (1102) and are electrically connected to the plurality of data lines (11011), respectively; the at least one group of contact pads (1200) is in the bonding region, and the at least one group of contact pads (1200) includes a first group of contact pads (1200') and a second group of contact pads (1200); the first insulation layer (1310) is in the bonding region, and the first insulation layer (1310) is in gaps between the plurality of contact pads (1200) and covers edges of the plurality of contact pads (1200), and is configured to expose surfaces, away from the base substrate (1100), of the plurality of contact pads (1200).