Microdevice Backplane Bonding With Planarization Layer Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a challenge in conducting a reliable and selective transfer and bonding of micro devices to a backplane, particularly in optoelectronic solid-state array devices, where existing methods lack effectiveness in ensuring a stable and consistent connection.
Innovation Solution
The method involves forming bumps on micro devices and a backplane, using a planarization layer to align and connect them, and curing the adhesive layer to create a stable bond, which can be facilitated by applying pressure, temperature, light, or microwave exposure to fuse the adhesive layers, ensuring mechanical and electrical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bonding methods are used to transfer micro devices to a backplane, then the bonding process can be completed, but the connection stability and reliability are insufficient
Solution Approach 1:
A planarization layer is introduced as an intermediary between the micro devices and the backplane. This layer fills surface profile non-uniformities and provides a flat bonding surface, enabling both high connection stability and precise alignment. The planarization layer acts as a mediator that accommodates surface irregularities while maintaining accurate device-to-backplane registration.
Solution Approach 2:
The backplane surface is pre-planarized before the bonding process by filling surface profile non-uniformities with the planarization layer. This preliminary action creates a flat, uniform bonding surface in advance, ensuring that subsequent alignment and bonding operations achieve high precision and reliable connections without being affected by surface irregularities.
2Reliability
If a planarization layer is added to improve bonding reliability, then connection stability improves, but the device complexity increases
Solution Approach 1:
The planarization function and bonding adhesive function are merged into a single integrated layer. This multi-functional layer simultaneously provides surface flattening, bonding adhesion, and stress distribution, thereby improving bonding reliability without adding multiple separate process steps or layers that would increase fabrication complexity.
Solution Approach 2:
The planarization layer is designed to perform multiple functions: it planarizes the backplane surface, serves as a bonding adhesive layer, and accommodates surface profile non-uniformities. This multi-functionality approach achieves high bonding reliability while minimizing the number of additional process steps required.
3Strength
If pressure and temperature are applied to cure the adhesive layer, then bonding strength improves, but energy consumption increases
Solution Approach 1:
The curing process utilizes controlled changes in temperature and pressure parameters to achieve optimal bonding strength. By precisely controlling these parameters and their application duration, the process achieves high bonding strength while minimizing energy consumption through efficient, time-limited exposure rather than prolonged high-energy input.
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 a reliable and efficient bonding process that provides mechanical stability and electrical contact between micro devices and the backplane, accommodating surface profile non-uniformities and ensuring a durable connection.
Implementation Method 1
curing the adhesive layer, which can be facilitated by applying pressure, temperature, light, or microwave exposure to fuse the adhesive layers
Implementation Method 2
curing the adhesive layer, which can be facilitated by applying pressure, temperature, light, or microwave exposure to fuse the adhesive layers
Implementation Method 3
aligning and bringing the micro devices and the backplane in contact, and curing the at least one planarization layer
Data Source
AI summary
Structures and methods are disclosed for fabricating optoelectronic solid state array devices. In one case a backplane and array of micro devices is aligned and connected through bumps.