Temporary protection coating for UV illumination demolding and application of temporary protection coating

Abstract

The invention relates to the technical field of coating materials, in particular to a temporary protection coating for UV illumination demolding and application of the temporary protection coating. When holes are directly drilled in the surface of a multi-layer PCB, copper cuttings are easily generated, and the drilling precision is influenced. In order to solve the problems, the invention provides a temporary protection coating material for UV illumination demolding, wherein a free photoinitiator in the coating material absorbs energy under a specific emission wavelength to initiate photocuring of the coating material system, so that a temporary protection coating is formed on the surface of a PCB multilayer circuit board, wherein the specific emission wavelength perfectly avoids the absorption wavelength range of the photoinitiator 2959, after drilling, the PCB multilayer circuit board is placed under a high-pressure mercury lamp for high-energy irradiation, the photoinitiator 2959 fragment of the modified polyurethane structure in the temporary protection coating can absorb a large amount of energy to break, the temporary protection coating is fragmented, and finally, strong shrinkage occurs under the action of high energy, so that automatic stripping from the surface of the PCB multilayer circuit can be realized.

Description

technical field [0001] The invention relates to the technical field of coatings, in particular to a temporary protective coating for film removal by UV light and its application. Background technique [0002] As the core component of electronic products such as mobile phones, PCB circuit boards are constantly developing in the direction of high precision. In order to increase the density of fixed-volume circuits in the electronics manufacturing industry, high-density interconnected printed circuit boards have been developed. Through the superposition of multi-layer circuit boards, they are separated from each other by insulating layers. The traditional method is to drill holes between the insulating layers, and then plate the holes with metal to realize the conduction of the circuits between the layers of circuits, so as to greatly increase the circuit density. [0003] Laser drilling directly on the surface of the circuit board is very easy to produce copper scraps, which ...

AI Technical Summary

Problems solved by technology

[0003] Laser drilling directly on the surface of the circuit board is very easy to produce copper scraps, which will affect the accuracy of the drilling, and this method can only be applied to multi-layer circuits with fewer layers. For multi-layer boards with more layers , it can only be carried out with drill pins, but at present, almost all multi-layer boards with many layers are drilled directly, and there is no auxiliary coating on the copper surface, which seriously affects the accuracy of drilling. In order to solve this problem, the present invention Prepared a temporary protective coating for UV light stripping, which is coated on the surface of the circuit board before drilling to form a temporary protective coating. When drilling, the temporary protective coating can prevent the circuit board from producing copper scraps. After the drilling is completed , put the circuit board under the ultraviolet light to achieve complete peeling off of the temporary protective coating and the circuit board

Images