Case Study: Development of PCB Marking Technology for Humid Environments

Focusing on the issue of corrosion of PCBs in humid environments, it explains the process of development of PCB marking technology with high corrosion resistance.By optimizing new materials and processes, they have solved the problems of traditional labels falling off and becoming blurred. They share their anti-corrosion coating technology, their solutions for improving label accuracy, and case studies, to help electronic devices last longer and maintain stability in humid environments.

Why is a moist environment so dangerous to printed circuit boards?

Most people have probably had the experience of a printed circuit board (PCB) that has become worn out, with the text and symbols on it becoming blurred or even disappearing. This is especially noticeable in the rainy season in southern Taiwan or in industrial settings with high humidity.When traditional ink markings are exposed to moisture or salt spray, they can either reduce the efficiency of maintenance work or even cause equipment to malfunction.Our team has discovered in actual research that over 60 % of printed circuit board failures are directly related to corrosion of the printed circuit board.

The three core technological breakthroughs in the company's high corrosion resistance technology.

Material upgrade: From "fragile" to "hard core.

Ordinary ink is susceptible to expansion and flaking in damp conditions.We tested 12 types of special coating materials, and finally selected a composite of fluoropolymer and nano-ceramic particles.Not only is the material three times more waterproof than before, it is also resistant to acids and alkalis, and does not lose color even when sanded.

Optimized technology: Letting the mark grow on the board.

Good materials are not enough, as printing techniques directly affect adhesion.By improving the process of treating the surface of the board before laser engraving, the process can increase the roughness of the surface to the micron level. Combining this with high-temperature curing, the marking is embedded in the surface of the PCB.In actual testing, the labels remained clear and legible after 1000 hours of wet-heat cycling.

Customized solutions for different scenarios

Equipment for use at the seaside needs to be able to withstand salt spray, while medical equipment must be able to withstand bacteria.We have developed a database of adjustable parameters for our processes. For example, we use a two-layer coating structure for our marine monitoring equipment. The outer layer protects against salt spray, while the inner layer contains a corrosion inhibitor. This has extended the life of the equipment from an average of six months to more than five years.

A guide to pitfalls in the practical application of these concepts.

Many clients have reported that although they have used anti-corrosion materials, the results have been disappointing.After reviewing the process, it was discovered that 80 % of the problems were in the early stages of processing.

- The oxide layer on the board surface has not been completely removed.

- A curing temperature variation of more than 5 ° C causes an unstable molecular structure.

- Ignoring stress concentration points in the design.

I suggest that everyone who is upgrading their production processes should also improve their production process control, and, if necessary, introduce an AI visual inspection system, to ensure that every stage of the process meets the standards.

How can we improve in the future?

We are currently experimenting with incorporating color-changing materials into the design of signs.The technology has already been realized in the laboratory stage, and is expected to be applied to special situations such as aquaculture control boxes by next year.After all, fighting corrosion is not just a matter of "passive defense," but also one of "active offense.