Gradient-Filler Transfer Stamp for Precise MicroLED Placement
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Solution Overview
Problem
Existing methods for assembling semiconductor light emitting elements in large-area display devices face challenges with high arrangement errors due to deformation of the transfer stamp layer during the transfer process, which affects the precision and reliability of the assembly.
Innovation Solution
A transfer substrate is used that incorporates an organic stamp layer with varying concentrations of inorganic fillers, providing increased stiffness and adhesion to minimize deformation and improve the precision of semiconductor light emitting element transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional organic stamp layer is used for transferring semiconductor light emitting elements, then the transfer process can be performed, but the stamp layer deforms during transfer causing high arrangement errors and low precision
Solution Approach 1:
The patent applies composite materials by combining organic polymer matrix with inorganic filler particles to create a hybrid stamp layer material. This composite structure provides both the flexibility needed for transfer and the stiffness required to minimize deformation, directly resolving the contradiction between transfer capability and dimensional stability.
Solution Approach 2:
The patent implements local quality by creating a gradient distribution of inorganic filler concentration within the organic stamp layer. The filler concentration varies from the surface to the bulk, providing different mechanical properties at different locations - softer at the surface for element pickup, stiffer in the bulk for structural support, thus minimizing overall deformation during transfer.
2Manufacturing precision
If the organic stamp layer is made stiffer to reduce deformation, then arrangement precision improves, but adhesion to semiconductor light emitting elements decreases
Solution Approach 1:
The gradient filler distribution creates local quality differences where the stamp layer surface maintains lower stiffness for good adhesion to semiconductor elements, while the bulk provides high stiffness for structural support. This spatial variation in material properties simultaneously satisfies both adhesion and precision requirements.
Solution Approach 2:
The composite organic-inorganic material system allows independent optimization of adhesion and stiffness properties. The organic polymer phase provides adhesion functionality while the inorganic filler phase provides structural rigidity, enabling both requirements to be met without compromise.
3Strength
If a single organic material is used for the stamp layer, then adhesion is maintained, but stiffness is insufficient causing deformation during transfer
Solution Approach 1:
The patent transforms a single-material organic stamp layer into a composite material system by incorporating inorganic filler particles. This composite approach maintains the adhesion properties of the organic polymer while adding the stiffness contribution from the inorganic phase, resolving the contradiction between adhesion and deformation resistance.
Solution Approach 2:
The patent changes the material composition parameters by introducing inorganic filler with different mechanical properties than the organic matrix. This parameter change (adding rigid filler to flexible matrix) increases the overall stiffness of the stamp layer while the organic continuous phase preserves adhesion characteristics.
Data Source
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AI summary
Disclosed, in the present specification, is a transfer substrate for transferring a semiconductor light emitting device with high reliability and a method for manufacturing a display device by using same. Specifically, the transfer substrate includes an organic stamp layer having a protrusion, wherein the organic stamp layer contains a plurality of inorganic fillers, and the concentration of the inorganic fillers is formed so as to increase as the distance from the protrusion increases. Therefore, the protrusion of the organic stamp layer has a low concentration of the inorganic fillers so as to maintain sufficient adhesion for transferring the semiconductor light emitting device, and the stiffness of the organic stamp layer itself is formed so as to be much stronger than that of a stamp layer using a single organic material. Accordingly, it is possible to improve the accuracy of transfer by minimizing an arrangement error of the semiconductor light emitting device due to the deformation of the stamp layer occurring in a transfer process. Accordingly, it is possible to improve the accuracy of transfer by minimizing an arrangement error of the semiconductor light emitting device caused by the deformation of the stamp layer occurring during a transfer process.