Preparation method of castor oil-based fully-crosslinked UV (Ultraviolet) photoinduced peelable glue for silicon wafer cutting process

Abstract

The invention provides a preparation method of castor oil-based fully-crosslinked UV (Ultraviolet) photoinduced peelable glue suitable for a silicon wafer cutting process. The preparation method comprises the following steps: reacting hydroxyl in castor oil with isocyanate groups in diisocyanate to obtain castor oil-based polyurethane containing -NCO groups; and then adding hydroxylated acrylate to prepare the urethane acrylate prepolymer containing the -NCO group and the acrylate group. The -NCO group in the prepolymer can be subjected to a cross-linking reaction with an acrylate copolymer-based adhesive containing hydroxyl and carboxyl before illumination so as to obtain a photopolymerizable reticular pressure-sensitive adhesive, and the acrylate group is subjected to cross-linking copolymerization with a functional diluent during illumination so as to form a fully cross-linked structural adhesive film. Before illumination, the pressure-sensitive adhesive can effectively improve the peel strength before illumination. The effective combination of the pressure-sensitive adhesive, a diluent and a photoinitiator can reduce the UV dosage required by photocuring; and the fully-crosslinked three-dimensional network structure adhesive film formed after photocuring is beneficial to improving the crosslinking degree, increasing the volume shrinkage and reducing the residual adhesive amount.

Description

technical field [0001] The invention belongs to the technical field of adhesives, in particular to a method for preparing a castor oil-based fully crosslinked UV photoreleasable adhesive used in a silicon wafer cutting process. Background technique [0002] In the early stage, it is similar to pressure-sensitive adhesive, which has a certain adhesive force, and in the later stage, it can be irradiated with ultraviolet rays to make it lose its adhesive force instantly when needed. It is called UV photoreleasable adhesive. UV photoreleasable adhesives require the performance of pressure-sensitive adhesives before exposure to light, and can quickly lose viscosity after exposure to light. Currently, they are widely used in silicon wafer cutting and other fields. During the silicon wafer cutting operation, the UV photo-releasable adhesive tape fixes the large wafer through a sufficiently large adhesive force. The adhesive force is greatly reduced to prevent damage and contaminat...

AI Technical Summary

Problems solved by technology

However, the existing fully cross-linked UV photoreleasable adhesives do not have a network structure before illumination, and it is difficult to improve the peeling strength before illumination, and the photocuring process is crosslinking and polymerization between macromolecules, making photocuring difficult.

In addition, the current prepolymers used for the preparation of UV photoreleasable adhesives for silicon wafer dicing use petroleum-based polyether polyols such as polyethylene glycol. The raw materials are non-renewable resources, and organic solvents need to be added during the preparation process.

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