Photocurable composition for PCB containing alkenyl ether and/or oxetane compounds and free radical polymeric compounds

Abstract

The invention discloses a photocurable composition for a printed circuit board, which contains the following components: (a) a photopolymerizable compound, (b) at least one infrared absorbing photosensitizer and (c) at least one photopolymerization initiator, wherein the photopolymerizable compound as the component (a) contains (a1) at least one free radical polymeric compound and (a2) at least one cationic polymeric compound, and is selected from alkenyl ether compounds and / or oxetane compounds, and the infrared absorbing photosensitizer as the component (b) comprises at least one polymethinecyanine compound.

Description

technical field [0001] The present invention relates to a photocurable composition for printed circuit boards (PCB), which contains (a) a photopolymerizable compound, (b) at least one infrared absorbing photosensitizer and (c) at least one photopolymerization initiator agent. The photocurable composition for PCB of the present invention is suitable for preparing photosensitive ink. The photosensitive ink of the present invention is also suitable for the preparation of printed circuit boards (PCB). Background technique [0002] In recent years, the emerging digital inkjet printing technology has replaced the traditional screen printing technology and has been promoted and applied in PCB production, especially for the production of multi-variety and low-volume PCB products. As a brand-new printing tool, inkjet printing is a fully digital printing. When forming resist, solder resist, and symbol marks on the printed circuit board, it can perform precise area printing without t...

AI Technical Summary

Problems solved by technology

But the disadvantage is that in the current technology of photocurable ink for PCB, the curing light source used is ultraviolet lamp (UV) or UV-LED, which is still not satisfactory in terms of safety and production cost.

At the same time, the penetration of ultraviolet light is weak, and some components with conjugated structures or pigment substances in the photocuring formula have strong absorption of ultraviolet light, resulting in serious light intensity attenuation, incomplete curing, and poor performance of photocurable films; easy to generate ozone pollute the environment, etc.

In addition, ultraviolet light is harmful to the human body, the life of the light source is short, and the price is higher

[0003] Photocuring technology mainly has two mechanisms: free radical curing and cationic curing. The former has a wide source of raw materials, high formula adjustability, and is widely used. However, due to the oxygen inhibition effect, the curing volume shrinks greatly (resulting in poor imaging accuracy) , poor adhesion and other issues, its use is subject to certain restrictions

[0004] For example, patent CN201780018493.3 discloses a curable composition for inkjet, a cured product and a printed circuit board. The ink obtained has good surface curability and film properties, but due to the design of a separate free radical curing system, resulting in The volume is easy to shrink during curing, which seriously affects the adhesion of the film layer to the substrate

In addition, as a curing light source, the UV mercury lamp has poor penetration, which will lead to incomplete curing of the bottom layer.

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