Micro Chip Mass Transfer Using Fluidic Assembly and Gap Filling

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Solution Overview

Problem

The productivity of micro LED display manufacturing decreases as the size of micro LED chips decreases and the size of display apparatus increases, due to inefficiencies in mass-transfer methods such as laser lift off or pick and place, which result in lower transfer yields.

Innovation Solution

A mass-transfer method and device that utilize fluidic self-assembly and electrostatic or electromagnetic forces to position micro semiconductor chips into grooves on a substrate, with an electromagnetic array selectively adsorbing and separating chips to improve transfer efficiency and yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If laser lift off or pick and place method is used to transfer micro LED chips, then the transfer process can be completed, but the transfer yield decreases as the size of micro LED chips decreases

Engineering Contradiction:

Improvetransfer yieldVSAvoidmass-transfer efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces traditional mechanical transfer methods (laser lift off, pick and place) with a fluidic self-assembly system that uses fluid flow to transport and position micro LED chips. This substitution eliminates the mechanical contact and positioning errors inherent in traditional methods, thereby improving transfer yield while maintaining high productivity for mass transfer operations

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs fluidic self-assembly where micro LED chips automatically position themselves into correct locations through fluid flow dynamics and substrate interactions. This self-positioning mechanism eliminates the need for precise mechanical positioning systems, improving both transfer yield and processing speed for large-scale manufacturing

Inventive Principle:

Principle #25Self-service

2Manufacturing precision

If traditional mass-transfer methods are used, then processing speed can be maintained, but transfer yield and positioning accuracy decrease

Engineering Contradiction:

Improvepositioning accuracyVSAvoidprocessing time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent incorporates a detection step that identifies empty grooves before the mass-transfer process completes. This preliminary detection allows for corrective actions to be taken while the system is still operational, improving positioning accuracy without requiring complete reprocessing or additional time-consuming post-processing steps

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent enables continuous operation by detecting and addressing missing chips during the transfer process rather than requiring batch reprocessing. The system maintains continuous fluid flow and can selectively reposition chips or adjust parameters mid-process, thereby improving positioning accuracy while minimizing processing time losses

Inventive Principle:

Principle #20Continuity of useful action

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

The method significantly enhances the transfer yield of micro semiconductor chips by accurately positioning them into grooves, reducing misplacement and increasing the efficiency of the mass-transfer process, particularly for micro LED chips used in display manufacturing.

Implementation Method 1

adsorbing the second micro semiconductor chip from the second substrate, and positioning the adsorbed second micro semiconductor chip in the empty first groove, using an electrostatic force or an electromagnetic force

Methodology Applied

Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

Methodology Applied

Scientific EffectElectromagnetic force: Electromagnet

Implementation Method 3

The plurality of first micro semiconductor chips may be transferred onto the first substrate by a fluidic self assembly method, and the plurality of second micro semiconductor chips may be transferred onto the second substrate by the fluidic self assembly method

Methodology Applied

Scientific EffectFluidic self assembly:

Data Source

PatentUS20240079395A1Mass-transfer method and mass-transfer device for micro semiconductor chips

Publication Date: 2024.03.07 SAMSUNG ELECTRONICS CO LTD

AI summary

A method of mass-transferring a plurality of micro semiconductor chips, including mass-transferring a plurality of first micro semiconductor chips onto a first substrate such that they are disposed in a plurality of first grooves of the first substrate; determining whether an empty first groove is present; and positioning a second micro semiconductor chip in the empty first groove, wherein the positioning may include transferring a plurality of second micro semiconductor chips onto a second substrate separate from the first substrate; and adsorbing the second micro semiconductor chip from the second substrate, and positioning the adsorbed second micro semiconductor chip in the empty first groove, using an electrostatic force or an electromagnetic force.