Micro-LED Bonding Electrode Layout for Thermal Expansion Offset
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Solution Overview
Problem
The existing mass transfer technologies for Micro-LED displays, such as STAMP transfer bonding, face challenges due to the thermal expansion of Polydimethylsiloxane (PDMS), which causes bonding offset between Micro-LEDs and substrates, leading to defects in the bonding process.
Innovation Solution
The solution involves designing a display panel with bonding electrodes whose size and distance between centers gradually increase from the center to the edge of the substrate, allowing for precise alignment and bonding of Micro-LEDs even after thermal expansion of the transfer material, ensuring each Micro-LED is correctly bonded to its corresponding electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PDMS is used as transfer material for STAMP transfer bonding, then the bonding process can be performed at 150°C, but thermal expansion of PDMS causes bonding offset between Micro-LEDs and substrate
Solution Approach 1:
The patent pre-calculates the thermal expansion offset of PDMS transfer material during heating and uses this information to adjust the initial positioning of bonding electrodes. By performing the offset compensation in advance before the actual bonding process, the system ensures that even after PDMS expansion, the Micro-LEDs will align correctly with their corresponding bonding electrodes, thus resolving the contradiction between using PDMS for reliable bonding and maintaining bonding precision
Solution Approach 2:
The patent changes the spatial parameters (position and/or size) of bonding electrodes based on the calculated thermal expansion characteristics of PDMS. By adjusting these parameters beforehand, the system compensates for the expected offset during heating, ensuring that the bonding process maintains both reliability and precision despite the thermal expansion of the transfer material
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 approach ensures reliable bonding between Micro-LEDs and electrodes, reducing defects and improving the quality of the display panel by accurately predicting and compensating for the thermal expansion-induced offsets, thereby enhancing the manufacturing efficiency and display performance.
Implementation Method 1
PDMS is expanded after heated for a long time, and thus a bonding offset is caused between Micro-LED and the substrate due to the increase of the expansion amount
Data Source
AI summary
Disclosed are a display panel and a display device. The display panel includes a base substrate. The base substrate is provided with bonding electrodes, Micro-LEDs are disposed on a side of the plurality of bonding electrodes facing away from the base substrate; and the plurality of Micro-LEDs are electrically connected to bonding electrodes in one-to-one correspondence. On a plane parallel to a plane where the base substrate is located, along a direction from a center of the base substrate to an edge of the base substrate, a size of each bonding electrode of the plurality of bonding electrodes gradually increases and/or a distance between centers of adjacent two of the plurality of bonding electrodes gradually increases to enable each Micro-LED of the plurality of Micro-LEDs to be bonded with a corresponding bonding electrode.