Circuit forming method of outer layer of circuit board

Abstract

The invention relates to a circuit forming method of an outer layer of a circuit board. The method comprises: a circuit board with an outer layer circuit needing to be processed is provided; pouring and coating of deep-curing UV ink are carried out on a hole needing protection and/or a predetermined region needing protection at a circuit board surface on the circuit board; exposure is carried out on the condition of 100-300mJ/cm<2>; and development, etching, and membrane removing are carried out on the exposed circuit board to form an outer layer circuit of the circuit board. According to the invention, the deep-curing UV ink is used for manufacturing the circuit board and the inside of the hole and the region with the surface needing protection are coated with the ink; and deep curing can be realized after UV light source irradiation. Therefore, chemical impacts on a weak base developing solution with the pH being approximately equal to 10 and an acid etching solution with the pH being 2 to 3 and thus the anti-etching effect is realized.

Description

technical field [0001] The invention relates to a method for forming the outer circuit of a circuit board. Specifically, the invention relates to a method for using deep-cured UV ink instead of a dry film as a temporary protective film layer in the forming process of the outer circuit of a circuit board. Background technique [0002] Circuit boards are regarded as an indispensable and important part in the rapidly developing electronics industry. The continuous improvement of circuits is to make continuous breakthroughs in the function and volume of electronic products. With the popularization of electronic products such as mobile phones and the ever-increasing functional requirements, the precision and complexity of circuit boards are also increasing day by day. All types of electronic products require circuit boards of varying complexity. [0003] In the prior art, two processes are usually used to manufacture the outer layer circuit of the circuit board. The first proce...

AI Technical Summary

Problems solved by technology

[0005] The use of dry film has been used in the circuit board process for more than 30 years. Although the dry film is better than the liquid wet film in terms of use and precision, however, since the dry film must be fused with photosensitive coating and PVC film, The production cost has been unable to decrease, and the development of dry film has not been able to break through in the last ten years. As mentioned above, the price has reached the limit of the cost, and there are also inevitable waste of materials in different degrees during application (such as There is excess dry film on the four sides of the board), therefore, in order to reduce waste and reduce the impact on the overall environment (disposal of the PVC sheet that protects the dry film also leads to environmental problems) and cost savings, the introduction and use of a new type of deep curing UV Photosensitive ink replaces dry film technology is a very valuable solution

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