Micro Device Transfer and Bonding via Infrared Adhesive Curing
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Solution Overview
Problem
Current methods for transferring and bonding micro devices, such as LEDs, are time-consuming and costly, requiring solder formation which can be difficult, and result in reduced yield due to transportation and bonding process inefficiencies.
Innovation Solution
A method involving the formation of an adhesive layer on a carrier, alignment with a substrate, and bonding using infrared light to transfer and bond multiple micro devices simultaneously without solder formation, utilizing a polymer film for electrical connection and post-curing to enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional solder formation and bonding processes are used for micro devices, then electrical connection is achieved, but manufacturing time increases and production cost rises
Solution Approach 1:
The patent extracts the solder formation step from the traditional bonding process. Instead of forming solder and then bonding, the invention uses direct adhesive bonding between the device electrode and substrate electrode, eliminating the intermediate solder material and its associated formation and reflow processes while maintaining electrical connection reliability
Solution Approach 2:
The patent merges the transfer process and bonding process into a single simultaneous operation. The device is transferred to the substrate while being bonded in one step, rather than transferring first and then bonding separately. This is achieved by using a release layer that allows the device to be released from the temporary substrate directly onto the final substrate where bonding occurs simultaneously
2Reliability
If solder formation is performed for micro devices, then electrical bonding is achieved, but manufacturing complexity and difficulty increase
Solution Approach 1:
The invention removes solder formation from the manufacturing process entirely. Instead of dealing with solder paste application, drying, reflow soldering, and inspection, the process uses direct adhesive bonding between metal electrodes, which can be performed at lower temperatures and with simpler process control
Solution Approach 2:
The patent changes the bonding parameters from high-temperature solder reflow to lower-temperature adhesive curing. This allows for simpler process equipment and better control, especially for temperature-sensitive micro devices, while achieving reliable electrical and mechanical bonding
3Manufacturing precision
If multiple devices are transferred and bonded separately, then each device can be individually positioned, but manufacturing time and cost increase significantly
Solution Approach 1:
The patent merges multiple individual transfer and bonding operations into a single batch process. Multiple devices are transferred from the temporary substrate to the final substrate simultaneously in one operation, and bonding occurs for all devices at the same time, dramatically increasing throughput while maintaining positioning accuracy through the alignment of the substrate structures
Solution Approach 2:
The patent performs preliminary arrangement of multiple devices on the temporary substrate in the correct positions before the transfer step. This preliminary positioning, combined with the rigid alignment structures of the substrates, ensures that when all devices are transferred simultaneously, they maintain their correct relative positions and align with the corresponding electrodes on the final substrate
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 significantly reduces manufacturing time and cost, increases yield by eliminating transportation-related issues, and enhances device reliability through semi-permanent polymer film hardening and controlled adhesiveness.
Implementation Method 1
forming an adhesive layer on a carrier; attaching a plurality of arranged devices onto the adhesive layer
Implementation Method 2
bonding the plurality of devices to the second electrodes respectively by radiating infrared light onto the carrier
Implementation Method 3
forming a polymer film on a plurality of second electrodes of a substrate
Data Source
AI summary
Provided is a method for transferring and bonding devices. The method includes applying an adhesive layer to a carrier, arranging a plurality of devices, attaching the arranged devices to the carrier, applying a polymer film to a substrate, aligning the carrier to which the plurality of devices are attached with the substrate, bonding the plurality of devices to the substrate by radiating laser, and releasing the carrier from the substrate to which the plurality of devices are bonded.