Adhesive Film with Photothermal Separation for Substrate Processing
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Solution Overview
Problem
The existing processes for working with thin or flexible substrates, such as in semiconductor wafer thinning and flexible display manufacturing, face challenges in efficiently separating these substrates from hard supporters without damaging the substrates or the elements formed on them, while also requiring complex and costly adhesive application and curing processes.
Innovation Solution
An adhesive film with a photothermal conversion layer containing a light absorber and thermally decomposable resin, along with an adhesive layer, is used. This film includes high and low molecular weight acrylic resins and an inorganic filler, allowing for easy bonding and subsequent laser-induced separation from the supporter, reducing damage and simplifying the peeling process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a thin or flexible substrate is used to reduce thickness and increase flexibility, then the substrate can be processed at smaller thickness levels and enhanced aesthetic functions are achieved, but the substrate becomes difficult to convey by track equipment or robots and requires complex adhesive application and curing processes
Solution Approach 1:
The adhesive film uses thermally decomposable resin that changes its properties based on temperature. At processing temperatures, the resin decomposes and releases gas to create separation, while at normal temperatures it maintains adhesive properties. This parameter-based transformation simplifies the overall process by eliminating the need for separate adhesive application and curing steps.
Solution Approach 2:
The adhesive film integrates multiple functions into a single component: adhesion, thermal response, and separation mechanism. By extracting the separation function from a complex multi-step adhesive process and incorporating it directly into the adhesive film structure, the overall process complexity is reduced while maintaining substrate thickness reduction capabilities.
2Strength
If conventional adhesive is applied and cured to bond substrate to supporter, then the substrate can be firmly fixed, but the process becomes complicated and costs and time are added
Solution Approach 1:
The adhesive film combines the adhesive layer and photothermal conversion layer into a single integrated structure. This merging eliminates the need for separate adhesive application, curing, and activation steps that would otherwise be required, significantly reducing process time while maintaining strong bond strength through the adhesive layer's design.
Solution Approach 2:
The adhesive film acts as an intermediary between the substrate and supporter, providing both mechanical bonding and thermal response functions. The adhesive layer ensures firm fixation while the photothermal conversion layer enables controlled separation, eliminating the need for complex multi-step adhesive processes and reducing overall processing time.
3Productivity
If the substrate is separated from the hard supporter after processing, then the processed substrate can be obtained, but the substrate or circuit may be damaged by physical force
Solution Approach 1:
The invention replaces mechanical separation force with a photothermal-based separation mechanism. The photothermal conversion layer absorbs laser energy and converts it to thermal energy, which decomposes the thermally decomposable resin and generates gas to create separation. This substitution eliminates the need for physical force that could damage thin or flexible substrates, maintaining substrate integrity while achieving efficient separation.
Solution Approach 2:
The photothermal conversion layer utilizes phase transitions through thermal decomposition of the thermally decomposable resin. When exposed to laser energy, the resin decomposes and releases gas, causing a phase change that creates separation between the substrate and supporter. This phase transition-based separation mechanism avoids mechanical stress that could damage the substrate or its circuits.
4Ease of operation
If laser irradiation is used to separate the photothermal conversion layer, then easy separation is achieved, but heat may damage the substrate or elements formed on it
Solution Approach 1:
The photothermal conversion layer is positioned specifically between the adhesive layer and substrate, creating a localized thermal response zone. The thermally decomposable resin in this layer absorbs laser energy and decomposes to generate gas pressure that separates the layers. This localized quality ensures that thermal effects are confined to the separation interface, protecting the substrate and its elements from widespread thermal damage while maintaining ease of separation.
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 adhesive film enables easy and damage-free separation of substrates from supporters, provides excellent heat resistance and light blocking, and simplifies the processing by omitting the need for pre-applying adhesives, thereby reducing costs and time.
Implementation Method 1
a photothermal conversion layer comprising a light absorber and a thermally decomposable resin
Implementation Method 2
the thermally decomposable resin is decomposed by irradiation of laser energy so that the photothermal conversion layer is separated from the substrate
Data Source
AI summary
The present invention relates to an adhesive film including a photothermal conversion layer including a light absorber and a thermally decomposable resin; and an adhesive layer, in which the thermally decomposable resin has a —COOH or —OH functional group and includes two kinds of acrylic resins having different weight average molecular weights, and an adhesive substrate including the adhesive film and a substrate to be processed. In the adhesive film and the adhesive substrate according to the present invention, it is possible to simplify a processing process of the substrate and reduce costs and time, and prevent damage to a substrate and a circuit or an element formed on the substrate.