Micro Semiconductor Mass Transfer via Photosensitive Layer Segmentation

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Solution Overview

Problem

The existing methods for transferring micro semiconductor elements from a donor substrate to a receiver substrate face challenges, including the sacrifice of epitaxial structures in direct transfer and the need for high-temperature resistant transfer means in indirect transfer, resulting in unsatisfactory success rates, especially when using polymers for micro pillar-based positioning techniques.

Innovation Solution

A method involving a transfer unit with a photosensitive layer on a substrate, where micro semiconductor elements are picked up and supported by an element structure, and the photosensitive layer is partially removed to form connecting structures that interconnect the elements with the substrate, allowing for subsequent separation and transfer to a package substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If direct transfer bonding is used to transfer micro semiconductor elements from donor substrate to receiver substrate, then the transfer process is simplified, but the epitaxial structure of each micro semiconductor element is sacrificed undesirably

Engineering Contradiction:

Improvetransfer process simplicityVSAvoidepitaxial structure

Core Design Contradiction:

Ease of manufactureVSLoss of substance

Solution Approach 1:

The invention segments the transfer process into two distinct stages: first bonding the micro semiconductor elements to a transfer substrate while preserving their epitaxial structures, then separately transferring them to the receiver substrate. This segmentation allows the epitaxial structure to be preserved during the initial bonding phase, avoiding the sacrifice that occurs in direct transfer methods.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces a transfer substrate as an intermediary carrier between the donor substrate and the receiver substrate. This intermediary enables the micro semiconductor elements to be transferred without direct bonding to the final substrate, thereby preserving their epitaxial structures while achieving the desired transfer function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of substance

If indirect transfer using a transfer means is used to preserve epitaxial structures, then the epitaxial structure is maintained, but the transfer means must be resistant to high temperature which increases device complexity

Engineering Contradiction:

Improveepitaxial structureVSAvoidtransfer means requirements

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The invention employs a transfer substrate that can be discarded after a single use. This disposable transfer substrate eliminates the need for expensive, high-temperature resistant transfer means, as the transfer substrate itself is designed to be consumed in the process, simplifying the overall device requirements while preserving epitaxial structures.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Productivity

If micro pillars are used to pick up micro semiconductor elements through positioning technique, then the elements can be transferred, but the success rate is unsatisfactory when high precision positioning cannot be achieved

Engineering Contradiction:

Improvemass transfer capabilityVSAvoidtransfer success rate

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The invention replaces the mechanical positioning system with a chemical bonding system. Instead of relying on precise mechanical alignment of micro pillars with micro semiconductor elements, the invention uses a photosensitive layer that forms adhesive bonds across the entire surface, enabling mass transfer without requiring high-precision positioning and thereby significantly improving the transfer success rate.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 method enhances the success rate of micro semiconductor element transfer by eliminating the need for high-precision positioning and reducing costs, while maintaining the integrity of the epitaxial structures and allowing for mass transfer with improved precision and efficiency.

Implementation Method 1

the semiconductor layer adheres to the photosensitive layer

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS11557580B2Method and device for mass transfer of micro semiconductor elements

Publication Date: 2023.01.17 HUBEI SANAN OPTOELECTRONICS CO LTD

AI summary

A mass transfer method includes providing a transfer unit and a semiconductor carrying unit connected therewith, removing an element supporting structure of the semiconductor carrying unit from micro semiconductor elements of the semiconductor carrying unit, partially removing the photosensitive layer to form connecting structures, connecting a package substrate with electrodes of the micro semiconductor elements, breaking the connecting structures to separate the micro semiconductor elements from the transfer substrate. A mass transfer device is also disclosed.