Quantitative test method for absorption of UV light by solder resist ink

Abstract

The invention relates to a quantitative test method for absorption of UV light by solder resist ink. The quantitative test method comprises the following steps that S1, the solder resist ink with H thickness is coated on a first light-transmitting thin film, and a first UV energy meter is arranged on the solder resist ink to obtain a test sample; and S2, the test sample is placed under an exposuremachine for exposure treatment, wherein the side, far away from the first UV energy meter, of the first light-transmitting thin film faces the light incident direction of the exposure machine, and the first UV energy meter measures the transmission energy value I1 of the test sample. The quantitative testing method for the absorption of UV light by the solder resist ink can quantitatively test the transmission energy value of a bottom layer of the solder resist ink after the H-thickness solder resist ink absorbs the UV light, testing is accurate, and operation is simple.

Description

technical field [0001] The invention relates to the technical field of PCB processing, in particular to a quantitative test method for UV light absorption of solder resist ink. Background technique [0002] With the continuous development of the electronics industry in the direction of thinner and shorter, the spacing between the pads of the printed circuit board (PCB) is constantly shrinking, so the requirements for the ability to manufacture solder-resisting bridges between the pads are also getting higher and higher. For PCB, solder resist ink plays an important role in preventing soldering short circuit, corrosion, and insulation, and its reliability is the basis for ensuring the normal performance of PCB. [0003] Generally, during the UV curing exposure process of solder resist ink, since the solder resist ink will absorb UV light, the energy of UV light will continue to attenuate with the thickness of the solder resist ink layer, so it is necessary to set the exposure...

AI Technical Summary

Problems solved by technology

When the exposure energy is set too low, the bottom layer of the solder resist ink will be seriously etched by the developer solution due to insufficient curing, resulting in the solder resist bridge falling off on the PCB after development, resulting in a short circuit where the non-conductive position is interconnected by tin material during the soldering process Phenomenon, the production will face the risk of rework or scrap; when the exposure energy is set too high, it will lead to the phenomenon that the top curing width of the top layer of the solder resist ink caused by excessive energy saturation is greater than the design value, so that it should be exposed after development. There is still residual ink on the pads, which brings quality problems that the pads cannot be developed cleanly, and electronic components cannot be well mounted on the pads, which leads to poor production quality and high defective scrap rate.

When determining the exposure energy of a suitable exposure machine, it is necessary to first determine the degree of energy received by the bottom layer of the solder resist ink. The traditional method generally uses a qualitative evaluation method, which is less accurate.

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