Semiconductor Light Emitter Transfer Using Cleavable Covalent Bonding
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Solution Overview
Problem
The challenge in manufacturing large-area display devices using semiconductor light emitting elements is the difficulty in transferring millions of these elements due to their small size and fragility, which leads to low yield and efficiency in self-assembly processes.
Innovation Solution
A method is developed where semiconductor light emitting elements are seated on an assembly substrate using electric and magnetic fields, forming a covalent bond between the elements and the substrate to secure them during self-assembly. This bond is then cleaved to allow easy detachment and transfer of the elements to a wiring substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If semiconductor light emitting elements are assembled on an assembly substrate and then transferred to a wiring substrate, then the structure for self-assembly can be added without limitation, but the process complexity increases due to the additional transfer process
Solution Approach 1:
The patent applies preliminary action by forming a covalent bond between the semiconductor light emitting element and the assembly substrate before the transfer process. This pre-established bond ensures the element remains securely fixed during subsequent handling and transfer operations, preventing dislodgement while maintaining process flexibility
Solution Approach 2:
The assembly substrate serves as an intermediary between the semiconductor light emitting element and the final wiring substrate. The covalent bond mechanism acts as a mediator that temporarily secures the element during assembly and transfer, then can be selectively cleaved to enable clean detachment at the appropriate stage
2Productivity
If semiconductor light emitting elements are directly assembled to the final substrate, then the process is more efficient, but there is no flexibility to add self-assembly structures
Solution Approach 1:
The patent segments the assembly process into two distinct stages: first assembling the semiconductor light emitting element to an intermediate assembly substrate with full self-assembly structure flexibility, then transferring it to the final wiring substrate. This segmentation allows both structural flexibility and final process efficiency
3Ease of manufacture
If semiconductor light emitting elements are transferred using conventional methods, then the transfer process is simple, but the yield is low due to element dislodgement and damage
Solution Approach 1:
The patent employs a curved or flexible PDMS stamp that conforms to the surface topology during transfer. This curvature allows the stamp to maintain contact and adhesion across the transfer interface, preventing element dislodgement while keeping the transfer process relatively simple
Solution Approach 2:
The patent changes the physical and chemical parameters of the transfer stamp by treating the PDMS surface with oxygen plasma. This treatment modifies the surface energy and adhesion properties, enabling strong temporary bonding during transfer that can be later released, thereby improving transfer yield without complicating the 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 method improves the transfer yield of semiconductor light emitting elements by preventing them from being dislodged during self-assembly and subsequent handling, thereby enhancing the efficiency of the display device manufacturing process.
Implementation Method 1
seating semiconductor light emitting elements placed into a chamber containing a fluid at preset positions of an assembly substrate including assembly electrodes using electric and magnetic fields
Implementation Method 2
seating semiconductor light emitting elements placed into a chamber containing a fluid at preset positions of an assembly substrate including assembly electrodes using electric and magnetic fields
Implementation Method 3
forming a covalent bond between the semiconductor light emitting elements and a surface of the assembly substrate such that the semiconductor light emitting elements are fixed to the assembly substrate
Data Source
AI summary
A method of manufacturing a display device according to the present invention involves assembling a semiconductor light emitting element to an assembly substrate and then transferring the same to a wiring substrate, wherein, during self-assembly using magnetic and electric fields, the semiconductor light emitting element is fixed to the assembly substrate by forming a covalent bond between the semiconductor light emitting element and the assembly substrate so that the semiconductor light emitting element does not become separated from the assembly substrate, and when transferring the assembled object to the wiring substrate, the formed covalent bond is broken down so that the semiconductor light emitting element can be easily detached from the assembly substrate.