Micro-Display Patching via Liquid-Layer Bonding and Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for transferring and replacing micro devices in display devices face challenges such as high cost, low efficiency, and yield, particularly when dealing with large-scale transfers of millions of devices, due to difficulties in precise bonding and removal processes.
Innovation Solution
A method involving the use of liquid layers to grip and bind micro devices to conductive pads, allowing for optical inspection and low-damage removal or replacement, utilizing liquid layer assisted binding to establish electrical contact and facilitate efficient transfer and patching operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional wafer bonding or indirect bonding methods are used for transferring micro devices, then device transfer capability is achieved, but cost increases and time efficiency decreases
Solution Approach 1:
The patent utilizes the phase transition of liquid from liquid state to vapor state through evaporation. The liquid layer is formed between the micro device electrode and conductive pad to enable bonding, then evaporated to complete the bonding process and allow for potential device removal without damage, achieving efficient transfer and replacement operations
Solution Approach 2:
The patent changes the physical state parameter of the liquid layer through evaporation. By controlling the evaporation process, the liquid transitions from a bonding medium to a vapor state, enabling secure attachment during bonding and facilitating damage-free removal afterward, thus improving both transfer efficiency and device recoverability
2Reliability
If precise bonding processes are used to ensure device attachment, then bonding reliability is improved, but device damage risk increases during removal
Solution Approach 1:
The liquid layer undergoes phase transition from liquid to vapor through controlled evaporation. During bonding, the liquid provides strong adhesion forces for reliable attachment. After evaporation completes bonding, the remaining liquid can be evaporated again to weaken bonds, enabling damage-free device removal while maintaining bonding reliability during the attachment phase
Solution Approach 2:
The liquid layer acts as an intermediary substance between the micro device electrode and conductive pad. It provides controllable bonding through evaporation while allowing reversible attachment. The liquid mediator enables reliable bonding during attachment and facilitates gentle removal afterward, reducing device damage risk while maintaining bonding reliability
3Productivity
If conventional transfer methods are used for large-scale device transfers, then transfer capability is achieved, but cost increases
Solution Approach 1:
The liquid layer is formed in advance between the micro device electrode and conductive pad before the actual bonding operation. This preliminary formation of the liquid bonding medium enables rapid subsequent evaporation and bonding, significantly reducing overall transfer time for large-scale device transfers while maintaining transfer capability
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 low or zero-damage, efficient method for replacing or patching micro devices in display devices, improving time efficiency and yield while reducing costs by using liquid layer assisted binding to securely attach and detach micro devices from conductive pads.
Implementation Method 1
a lateral length of the first micro device is equal to or smaller than 20 μm, such that the first micro device is gripped by a force produced by the first liquid layer between the first micro device and the conductive pad
Implementation Method 2
evaporating the first liquid layer such that the first electrode is bound to and is in electrical contact with the conductive pad
Data Source
AI summary
A method for replacing an element of a display device includes: forming a structure with a first liquid layer between a first micro device and a conductive pad of a substrate in which the first micro device is gripped by a sticking force produced by the first liquid layer; evaporating the first liquid layer such that the first micro device is bound to the substrate; determining if the first micro device is malfunctioned or misplaced; removing the first micro device when the first micro device is malfunctioned or misplaced; forming another structure with a second liquid layer between a second micro device and the conductive pad of the substrate in which the second micro device is gripped by a sticking force produced by the second liquid layer; and evaporating the second liquid layer such that the second micro device is bound to the substrate.