Thermoplastic Adhesive Peripheral Crown for Ultra-Thin Substrate Handling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Ultra-thin semiconductor substrates in microelectronics are difficult to handle due to flexibility issues, leading to deformation during heat treatment, which complicates precise alignment and planarization processes.

Innovation Solution

A method involving a thermoplastic polymer adhesive with a peripheral crown of rigid material at the bonding interface, which maintains rigidity during heat treatment, preventing substrate deformation by distributing peeling forces and minimizing deflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a thermoplastic polymer adhesive is used to bond ultra-thin substrates, then adhesion and flexibility are improved, but substrate deformation occurs during heat treatment above glass transition temperature

Engineering Contradiction:
ImproveadhesionVSAvoidsubstrate deformation
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The adhesive layer is segmented into two distinct regions: a central cavity region providing flexibility and adhesion for the ultra-thin substrate, and a peripheral crown region providing rigidity during heat treatment. This segmentation allows each region to perform its specific function without interfering with the other, resolving the contradiction between adhesion/flexibility and deformation resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the adhesive layer are given different physical properties: the central region uses thermoplastic polymer for flexibility and adhesion, while the peripheral crown uses rigid material for structural support during heating. This local differentiation of material properties allows the system to simultaneously achieve adhesion, flexibility, and deformation resistance.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the substrate is thinned to ultra-thin dimensions, then flexibility and adaptability are improved, but handling difficulty and mechanical stability worsen

Engineering Contradiction:
ImproveflexibilityVSAvoidhandling difficulty
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The bonding structure is divided into a central cavity for substrate flexibility and a peripheral crown for mechanical stability. This segmentation allows the ultra-thin substrate to maintain its flexibility for adaptability while the rigid peripheral crown provides the mechanical stability needed for easy handling during processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The adhesive system combines thermoplastic polymer material in the central region with rigid material in the peripheral crown, creating a composite structure that exhibits both flexibility and mechanical stability. This composite approach resolves the contradiction between substrate thinness for flexibility and handling ease.

Inventive Principle:
Principle #40Composite materials

3Strength

If heat treatment above glass transition temperature is applied, then adhesion promotion is improved, but substrate deformation increases

Engineering Contradiction:
Improveadhesion promotionVSAvoidsubstrate deformation
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The adhesive layer is divided into a central cavity region that allows substrate deformation during heat treatment for adhesion promotion, and a peripheral crown region that maintains rigidity to prevent excessive deformation. This segmentation enables heat treatment to proceed effectively while controlling substrate shape stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The peripheral crown region is given rigid material properties specifically to resist deformation during heat treatment, while the central region maintains thermoplastic properties for adhesion. This local quality differentiation allows heat treatment to promote adhesion without causing harmful substrate deformation.

Inventive Principle:
Principle #3Local quality

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 allows for stable handling and processing of ultra-thin substrates without deformation, ensuring precise alignment and improved planarization performance.

Implementation Method 1

when the assembly is heated beyond the glass transition temperature of the thermoplastic polymer (for example beyond approximately 100° C. for polymethyl methacrylate), the polymer becomes rubbery and very flexible

Methodology Applied
Scientific EffectGlass transition:

Implementation Method 2

a central cavity surrounded by a peripheral crown having an upper level and a lower level, the peripheral crown being made of material rigid at the treatment temperature

Methodology Applied
Scientific EffectThermal stability of rigid materials:

Data Source

PatentEP3623437B1Method for temporary gluing with thermoplastic adhesive including a rigid crown
Publication Date: 2021.12.29 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3623437B1 patent drawingFigure 1A~1G
  • EP3623437B1 patent drawingFigure 2A~2B
  • EP3623437B1 patent drawingFigure 3A~3D

AI summary

The invention relates to a method for temporarily bonding a substrate of interest (40) to a manipulation substrate (20), comprising a step of creating an assembly by bringing the bonding faces of the substrate of interest and the manipulation substrate into contact via a thermoplastic polymer (30), and a step of treating the assembly at a processing temperature above the glass transition temperature of the thermoplastic polymer. Prior to the assembly step, this method comprises: a step of manufacturing, at the bonding face of one of the substrates of interest and the manipulation substrate, a central cavity surrounded by a peripheral ring (50-A) of a material rigid at the processing temperature, and a step of forming a layer of said thermoplastic polymer (30) filling the central cavity.