Internal-Pillar Cartridge for Aligned Microdevice Transfer

Solution Overview

Problem

Existing methods for transferring microdevices face challenges in efficiently separating them from donor substrates while maintaining alignment and integrity during the bonding process, particularly due to strong adhesion forces between the microdevices and pillars.

Innovation Solution

The method involves modifying the interface between the pillars and microdevices through chemical processes, temperature adjustments, or structural weaknesses to facilitate separation, using materials like organic or inorganic impurities, and employing techniques such as dry etching to reduce pillar width or angle, allowing for the microdevices to float and be transferred to a system substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If strong adhesion is used between pillars and microdevices to maintain alignment, then alignment precision is improved, but separation difficulty increases

Engineering Contradiction:

Improvealignment precisionVSAvoidseparation difficulty

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The pillar structure incorporates a modified interface at its base with different material properties or structural characteristics compared to the main pillar body. This local modification creates a weak point that facilitates separation while the rest of the pillar maintains its alignment function. The modified interface can have reduced adhesion strength or altered mechanical properties to enable easy separation after alignment.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The pillar interface is pre-modified during manufacturing to include a weak point or reduced adhesion zone before the actual separation process. This preliminary structural preparation ensures that when separation is needed, the microdevice can be easily detached from the pillar without requiring excessive force that would damage the alignment precision achieved during the bonding process.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If pillar width is reduced to facilitate separation, then separation ease is improved, but structural strength decreases

Engineering Contradiction:

Improveseparation easeVSAvoidpillar strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The pillar structure incorporates a modified interface at its base with different material properties or structural characteristics compared to the main pillar body. This local modification creates a weak point that facilitates separation while the rest of the pillar maintains its alignment function. The modified interface can have reduced adhesion strength or altered mechanical properties to enable easy separation after alignment.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The pillar is divided into distinct segments with different properties: a main body portion that maintains structural strength for alignment, and a base interface portion that has reduced strength for easy separation. This segmentation allows each portion to fulfill its specific function optimally without compromising the other.

Inventive Principle:

Principle #1Segmentation

3Productivity

If chemical processes are used to modify interfaces, then separation efficiency is improved, but process complexity increases

Engineering Contradiction:

Improveseparation efficiencyVSAvoidprocess complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent modifies the physical or chemical parameters of the pillar interface during manufacturing to create a weak point. This can involve changing material composition, surface energy, or structural parameters at the interface region. By pre-adjusting these parameters, the separation process becomes more efficient and less complex, as the modified interface naturally facilitates detachment without requiring additional chemical treatment steps.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250304435A1Cartridge with internal pillar

Publication Date: 2025.10.02 VUEREAL INC

AI summary

The present invention discloses a process to transfer microdevices. The method involves coupling a microdevice to a donor substrate by a pillar layer, aligning the microdevice, bonding the microdevice and breaking the pillar layer with various scenarios. Also disclosed are various configurations of pillars within the structure such as edges and floating layers. Further, the method also discloses use and formation of nano-pillars to achieve the transfer of microdevices.