Semiconductor Wafer Temporary Fixing Film with Modulus Control
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Solution Overview
Problem
Current sticking materials for semiconductor wafers, particularly those used for temporary fixing during processing, face challenges such as variations in thickness, difficulty in peeling from surfaces with unevenness, and inefficiencies in peeling methods like solvent dissolution or laser irradiation, which affect productivity and heat resistance.
Innovation Solution
A film for temporary fixing composed of a high molecular weight component and silicone-modified resin, with a modulus of elasticity between 0.1 to 1000 MPa, that can be easily peeled off from semiconductor wafers with unevenness, using a combination of (meth)acrylic copolymer and silicone-modified alkyd resin, and optionally including a curing accelerator, to ensure adequate adhesion and separation without residue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a BG tape is used to support a thinned semiconductor wafer, then the wafer can be supported during processing, but the tape becomes unable to adequately support the wafer due to warping caused by circuit influence
Solution Approach 1:
The patent changes the material parameters of the support from soft BG tape to hard silicon wafer or glass, which have higher stiffness and can maintain wafer flatness even when thinned. This parameter change resolves the contradiction by providing sufficient support capability while preventing warping.
Solution Approach 2:
The patent uses composite structures where a sticking material (resin composition) is applied between the semiconductor wafer and the hard support (silicon wafer or glass). This composite approach combines the adhesive properties of the resin with the structural stability of the hard support, achieving both reliable support and warping prevention.
2Ease of manufacture
If a liquid sticking material is used for temporary fixing, then the material can be applied by spin coating, but the coating variation causes thickness variation in the stuck wafer and scattered material must be discarded
Solution Approach 1:
The patent employs a film-shaped sticking material that is pre-formed with uniform thickness and disposed of after single use. This disposable film eliminates the need for precise spin coating control and material thickness management, resolving the contradiction between ease of application and manufacturing precision.
Solution Approach 2:
The patent uses a thin film-shaped sticking material that can be laminated onto the semiconductor wafer. This film approach provides uniform thickness without requiring precise coating control, and the flexible nature allows for easy application and removal, solving both the ease of manufacture and manufacturing precision issues.
3Ease of operation
If solvent dissolution is used to peel the sticking material, then the material can be removed from the wafer, but the process takes time and productivity decreases
Solution Approach 1:
The patent replaces the chemical dissolution process with a mechanical peeling method. The film-shaped sticking material is designed to be peelable by mechanical force without requiring solvent treatment, thus resolving the contradiction between ease of operation and productivity by enabling rapid removal.
Solution Approach 2:
The patent introduces a specially designed film-shaped sticking material as an intermediary between the wafer and support that facilitates easy mechanical peeling. This intermediary material is engineered with appropriate adhesion properties to allow simple removal without solvents, improving both ease of operation and productivity.
4Ease of operation
If heating is used to decrease stickiness for peeling, then the sticking material can be removed, but the method is poor in heat resistance and cannot be used in through electrode formation
Solution Approach 1:
The patent replaces thermal peeling with mechanical peeling of a film-shaped sticking material. This substitution eliminates the need for heating, thereby resolving the contradiction between peeling capability and heat resistance, and enabling use in heat-sensitive processes like through electrode formation.
Solution Approach 2:
The patent uses a disposable film-shaped sticking material that is designed for single-use mechanical peeling. This approach eliminates the need for heat-resistant properties in the sticking material itself, as the film is removed mechanically before subsequent high-temperature processing, resolving the heat resistance limitation.
5Ease of operation
If laser irradiation is used to modify or eliminate the sticking material, then the material can be removed for peeling, but expensive laser equipment is required and considerable investment is essential
Solution Approach 1:
The patent replaces laser-based sticking material removal with simple mechanical peeling of a film-shaped material. This substitution eliminates the need for expensive laser equipment, resolving the contradiction between peeling capability and device complexity by using a low-cost mechanical approach.
Solution Approach 2:
The patent employs a disposable film-shaped sticking material that can be easily peeled off mechanically without requiring any special equipment. This approach eliminates the need for expensive laser systems, resolving the contradiction between effective peeling and equipment cost.
6Stability of the object's composition
If a hard support like silicon wafer or glass is used instead of BG tape, then the support can maintain wafer flatness, but the sticking material must provide adequate adhesion and easy peeling
Solution Approach 1:
The patent uses a composite structure combining a film-shaped sticking material (resin composition) with a hard support (silicon wafer or glass). The resin composition is specifically formulated to provide adequate adhesion to the wafer while allowing easy mechanical peeling, thus resolving the contradiction between maintaining wafer flatness and enabling easy peeling.
Solution Approach 2:
The patent changes the physical state of the sticking material from liquid to film-shaped solid, and formulates the resin composition with specific mechanical properties that enable easy peeling from hard supports. This parameter change in the sticking material's properties resolves the contradiction between adhesion strength and peeling ease.
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 film effectively fixes and separates semiconductor wafers from supports with minimal residue and cracking, maintaining adhesive properties during processing and facilitating easy peeling, even from surfaces with significant unevenness, while ensuring low peel strength and adequate fluidity for smooth processing.
Implementation Method 1
a film for temporary fixing which is used in a processing method of a semiconductor wafer, the method including a temporary fixing step of temporarily fixing the semiconductor wafer to a support via the film for temporary fixing
Implementation Method 2
a separation step of separating the processed semiconductor wafer from the support and the film for temporary fixing
Data Source
AI summary
The film for temporary fixing of the present invention is a film for temporary fixing which is used in a processing method of a semiconductor wafer, the method including a temporary fixing step of temporarily fixing the semiconductor wafer to a support via the film for temporary fixing, a processing step of processing the semiconductor wafer that is temporarily fixed to the support, and a separation step of separating the processed semiconductor wafer from the support and the film for temporary fixing, contains (A) a high molecular weight component and (B) a silicone-modified resin, and has a modulus of elasticity of from 0.1 to 1000 MPa at 23° C. after being heated for 30 minutes at 110° C. and for 1 hour at 170° C.