A kind of preparation method of castor oil-based fully cross-linked UV photoreleasable adhesive for silicon wafer cutting process

Abstract

The invention provides a preparation method of castor oil-based fully cross-linked UV photoreleasable adhesive suitable for silicon wafer cutting technology: the castor oil-based castor oil containing NCO group is obtained by reacting the hydroxyl group in castor oil and the isocyanate group in diisocyanate Sesame oil-based polyurethane, and then adding hydroxylated acrylates to obtain urethane acrylate prepolymers containing ‑NCO groups and acrylate groups. The ‑NCO group in the prepolymer can cross-link with the acrylate copolymer-based adhesive containing hydroxyl and carboxyl groups before light exposure to obtain a photopolymerizable network pressure-sensitive adhesive. The diluent is cross-linked and copolymerized to form a fully cross-linked structural adhesive film. Before exposure to light, the pressure-sensitive adhesive can effectively improve the peel strength before exposure to light. The effective combination of pressure-sensitive adhesive, diluent and photoinitiator can reduce the UV dose required for photocuring; the fully crosslinked three-dimensional network structure adhesive film formed after photocuring is conducive to increasing the degree of crosslinking and increasing volume shrinkage. Reduce the amount of residual glue.

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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