Microdevice Cartridge Pad Layout for Misalignment-Tolerant Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for integrating micro devices onto system substrates face challenges in efficiently aligning and bonding micro devices without interference, particularly in cases where misalignment occurs during the transfer process.
Innovation Solution
A method involving the use of a micro device substrate with a buffer layer and planarization layer, followed by the formation of bonding layers and selective removal of the substrate, allowing for precise alignment and bonding of micro devices to a backplane using pads and electrodes, with adjustments for misalignment through pattern modifications and extensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If micro devices are transferred from substrate to backplane, then integration is achieved, but misalignment and interference between devices occur
Solution Approach 1:
The patent segments the micro device array into individually addressable units with dedicated bonding pads. Each micro device is isolated with spacing, allowing selective bonding without interference. The substrate is divided into multiple bonding regions that can be processed independently, enabling precise alignment of each device to its corresponding backplane location.
Solution Approach 2:
The patent introduces a vertical dimension by stacking multiple layers including buffer layers, planarization layers, and bonding pads at different heights. This multi-layer approach allows misaligned devices to be compensated for by adjusting bonding pad positions in the vertical dimension, eliminating interference while maintaining integration.
2Adaptability or versatility
If selective bonding of micro devices is performed, then functional integration is achieved, but alignment complexity increases
Solution Approach 1:
The patent performs preliminary actions by pre-configuring bonding pads on both the micro devices and backplane before the bonding process. Alignment marks and reference structures are pre-established, and the substrate is pre-patterned with bonding regions. This preliminary preparation simplifies the actual bonding process by reducing real-time alignment complexity.
Solution Approach 2:
The patent introduces intermediary elements including buffer layers and planarization layers that mediate between the micro devices and backplane. These intermediary layers provide tolerance for misalignment and serve as intermediate bonding surfaces, reducing the complexity of direct alignment between devices and backplane while enabling selective bonding.
3Manufacturing precision
If buffer layer and planarization layer are added, then alignment precision is improved, but manufacturing steps increase
Solution Approach 1:
The patent merges multiple functions into the buffer and planarization layers. These layers simultaneously provide mechanical support, electrical isolation, alignment reference surfaces, and stress compensation. By combining multiple functions into single layers, the patent improves precision without proportionally increasing manufacturing complexity, as the same layers serve multiple purposes throughout the fabrication process.
Data Source
AI summary
In an aspect, a method of integrating micro devices on a backplane includes; providing a micro device substrate comprising one or more micro devices; bonding a selective set of the micro devices from the substrate to the backplane by connecting pads on the micro devices and corresponding pads on the backplane; and leaving the bonded selective set of micro devices on the backplane by separating the micro device substrate.