Bottom-Anchored Printable Wafers for Reliable Micro-Device Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for an efficient, robust, and cost-effective method to micro-assemble micro-devices from a native source wafer onto a target substrate and electrically connect them on the target substrate.
Innovation Solution
The method involves a printable-component structure with a carrier substrate, a bonding layer, a solid weak-adhesion layer, and a release layer, where micro-components are weakly adhered to the carrier wafer and lifted off using a stamp, transported, and printed onto the target substrate, with electrically conductive posts for connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If micro-devices are assembled using traditional methods with lateral tethers and stabilization posts, then the micro-devices can be released and transferred, but the process complexity increases and source wafer space is wasted
Solution Approach 1:
The patent removes the complex lateral tether and stabilization post structures from the micro-device assembly process. Instead, it uses a simple release layer that can be etched away to free the micro-devices, which are then picked up directly by stamp posts. This extraction of unnecessary components simplifies the overall process while maintaining functionality.
Solution Approach 2:
The patent segments the adhesion function into two distinct layers: a bonding layer for strong attachment during fabrication, and a release layer for easy separation during transfer. This segmentation allows each layer to perform its specific function optimally without the complexity of integrated stabilization structures.
2Reliability
If stabilization posts and bonding layers are used to secure micro-devices during transfer, then transfer reliability improves, but source wafer space is consumed and costs increase
Solution Approach 1:
The patent eliminates stabilization posts and extensive bonding layer structures that consume source wafer space. The micro-devices are secured only by the minimal release layer area needed for fabrication, and then released by etching away this layer. This extraction of space-consuming structures maintains transfer reliability while maximizing source wafer utilization.
Solution Approach 2:
The patent applies bonding and release functions only where locally necessary - the release layer is present only at the interface between the micro-device and the carrier, rather than requiring extensive stabilization structures across the entire device area. This localized approach reduces space consumption while maintaining reliability.
3Ease of manufacture
If traditional release methods with lateral tethers are used, then micro-devices can be released from the source wafer, but the pick-up yield decreases and process robustness is reduced
Solution Approach 1:
Instead of using lateral tethers that extend outward from the micro-device to enable release, the patent inverts the approach by using a release layer that is etched away from beneath the micro-device. This allows the micro-device to be released vertically upward, making it easier to pick up with stamp posts and significantly improving pick-up yield and process robustness.
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 enables efficient micro-assembly and electrical connection of micro-devices on the target substrate, reducing the use of expensive source wafer space and improving pick-up yield, while being cost-effective and robust.
Implementation Method 1
releasing the micro-devices from the native source substrate by etching the release layer
Implementation Method 2
contacting the micro-devices with stamp posts of a stamp to adhere the micro-devices to the stamp posts
Implementation Method 3
a bonding layer disposed on the carrier substrate, a solid weak-adhesion layer disposed on the bonding layer
Data Source
AI summary
A printable-component structure includes a carrier substrate, a bonding layer disposed on the carrier substrate, a solid weak-adhesion layer disposed on at least a portion of the bonding layer, at least a portion of a component disposed directly on and in contact with at least a portion of the weak-adhesion layer, and a release layer disposed in contact with at least a portion of the component. The component is adhered to the weak-adhesion layer with a force that is less than the adhesion between the component and a stamp, such as a PDMS stamp. The component can include a protruding post in sole contact with the weak-adhesion layer.