Assembly Substrate Surface Structure for Micro-LED Transfer Accuracy
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Solution Overview
Problem
The existing methods for transferring semiconductor light-emitting devices to a transfer substrate face challenges such as low transfer rate, high misassembly rate, and inefficient assembly process, particularly due to the difficulty in concentrating the contact force between the transfer substrate and the semiconductor light-emitting devices.
Innovation Solution
An assembly substrate is designed with a base part, pair electrodes, a dielectric layer, and partition walls that define cells for placing semiconductor light-emitting devices. The substrate includes recess portions and concave and convex portions on its surface to reduce the contact area with the transfer substrate, thereby improving the transfer efficiency. Additionally, the substrate is made of materials with different surface energies to optimize the contact forces during the transfer process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the assembly substrate has a large contact area with the transfer substrate, then the contact force is distributed, but the transfer rate decreases and misassembly rate increases
Solution Approach 1:
The assembly substrate incorporates recess portions and convex portions that create localized variations in surface topology. These local structural differences concentrate contact force specifically at the convex portions where semiconductor light-emitting devices are positioned, while the recess portions reduce overall contact area with the transfer substrate. This local quality differentiation enables precise force concentration without requiring the entire substrate surface to have high contact pressure, thereby improving both transfer rate and positioning accuracy.
2Productivity
If the contact area between assembly substrate and transfer substrate is reduced, then the transfer efficiency improves, but the contact force concentration becomes difficult
Solution Approach 1:
The assembly substrate features convex portions with curved surfaces that naturally concentrate contact force. When the transfer substrate contacts the assembly substrate, the curved convex portions create point or line contact rather than surface contact, concentrating the mechanical force onto small areas where semiconductor light-emitting devices are located. This curvature-based force concentration mechanism achieves effective force transmission even with reduced overall contact area, thereby improving transfer efficiency while maintaining adequate contact force at critical locations.
3Ease of manufacture
If the assembly substrate uses uniform material properties, then the manufacturing is simple, but the contact force distribution during transfer is not optimized
Solution Approach 1:
The assembly substrate is divided into distinct functional regions: recess portions and convex portions, each serving different purposes during the transfer process. The convex portions are designed to concentrate contact force and support semiconductor light-emitting devices, while the recess portions reduce overall contact area and minimize unwanted adhesion. This segmentation of the substrate surface into functionally differentiated zones enables optimized contact force distribution without requiring complex material compositions, maintaining manufacturing simplicity while achieving superior transfer performance.
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 proposed assembly substrate structure enhances the transfer rate of semiconductor light-emitting devices by reducing the energy acting between the assembly substrate and the transfer substrate, thereby improving the assembly rate and reducing misassembly errors.
Implementation Method 1
a plurality of pair electrodes extending in one direction and disposed in parallel on the base part
Implementation Method 2
applying a magnetic force to the semiconductor light-emitting devices put into the fluid chamber to cause the semiconductor light-emitting devices to move in one direction
Data Source
AI summary
Discussed in an assembly substrate used in a display manufacturing method for placing semiconductor light-emitting devices to predetermined positions thereof using an electric field and a magnetic field, the assembly substrate including: a base part; a plurality of pair electrodes extending in one direction and disposed in parallel on the base part; a dielectric layer disposed on the base part to cover the plurality of pair electrodes; and partition walls disposed on the dielectric layer and defining cells at predetermined intervals along the one direction of the plurality of pair electrodes so as to overlap portions of the plurality of pair electrodes, and the semiconductor light-emitting devices being placed into the cells, respectively, wherein at least one of a recess portion and a concave and convex portion is formed on an upper surface of each of the partition walls.