Pixelated Microdevice Bonding With Post-Patterned Conductive Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optoelectronic solid-state array devices face challenges in achieving a reliable bonding approach for microdevice arrays to a backplane, which affects the light output profile and uniformity.
Innovation Solution
A method involving a donor substrate with deposited conductive layers and a fully or partially continuous light emitting functional layer, where the microdevices are patterned and bonded to a system substrate, with specific ohmic contacts and patterning techniques to enhance light output and connection, allowing for pixelated structures and post-processing to improve light output profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If microdevices are bonded to a backplane using conventional approaches, then the bonding process can be completed, but the light output profile and uniformity are compromised
Solution Approach 1:
The patent segments the bonding process into multiple stages: initial bonding of microdevices to the backplane, followed by subsequent patterning steps. This allows the bonding reliability to be established first, then the light output profile to be optimized through selective removal of material between devices, avoiding the trade-off between bonding reliability and light output uniformity.
Solution Approach 2:
The bonding operation is performed as a preliminary action before the patterning steps that define the light output profile. By completing the bonding first with full coverage, reliability is ensured, and then subsequent patterning steps can create the desired light output uniformity without compromising the already-established bonds.
2Ease of manufacture
If the donor substrate is removed early in the process, then microdevice separation is facilitated, but bonding reliability may be compromised
Solution Approach 1:
The bonding operation is performed as a preliminary action while the microdevices are still attached to the donor substrate, which provides mechanical support and ensures proper alignment. Only after bonding is confirmed does the process proceed to remove the donor substrate, thus facilitating separation without compromising the already-established bonding reliability.
Solution Approach 2:
The process includes preliminary bonding steps that establish reliable connections before the donor substrate removal. This beforehand cushioning ensures that even when the substrate is removed for separation, the bonding reliability is already secured and cannot be compromised by the subsequent substrate removal.
3Ease of manufacture
If continuous light emitting functional layers are used, then manufacturing is simplified, but light output profile control is reduced
Solution Approach 1:
The continuous light emitting functional layer is segmented through subsequent patterning steps that selectively remove material between microdevices. This approach maintains the manufacturing simplicity of depositing a continuous layer while achieving the manufacturing precision needed for light output profile control through the later segmentation process.
Solution Approach 2:
The continuous layer deposition is performed as a preliminary manufacturing step that simplifies the initial process. Subsequent patterning steps then refine the light output profile by removing excess material, thus maintaining both the ease of manufacture from the continuous layer approach and the precision control from the selective removal process.
Data Source
AI summary
A method of manufacturing a pixelated structure may be provided. The method may comprise providing a donor substrate comprising the plurality of pixelated microdevices, bonding a selective set of the pixelated microdevices from the donor substrate to a system substrate; and patterning a bottom conductive layer of the pixelated microdevices after separating the donor substrate from the system substrate. The patterning may be done by fully isolating the layers or leaving some thin layers between the patterns.