What are some simple ways to test the treatment results of a plasma cleaner?

Plasma cleaning technology can remove particulate contaminants from material surfaces, making the surfaces better suited to bonding or printing. The contaminants removed are mainly particulate contaminants such as organic matter, epoxy resin, photoresist, oxides and micro-particle contaminants. So how can the cleaning results be tested after plasma cleaning? Are there any simple methods?

Before a plasma cleaner is used to treat products in batches, samples are usually treated first, and batch treatment of the products begins only after the results meet expectations, which better ensures efficiency. Among the many testing methods, water drop angle (contact angle) meter testing and dyne pen testing are the two most commonly used; there are also methods that use dedicated instruments or the results of special processes to reflect the cleaning results.

A water drop angle meter is a contact angle meter, and contact angle measurement is currently one of the more common methods for evaluating plasma cleaning results. The cleaning result is assessed by comparing the change in the water drop angle before and after treatment: the smaller the water contact angle, the better the cleaning result. The specific method is as follows: before and after the sample is treated, place a drop of pure water on the sample surface, perform a 3D contact angle measurement through the microscope on the instrument to measure the drop angle each time, and compare the contact angles before and after to judge the cleaning result. This method gives accurate test data, is simple and quick to operate, and has high repeatability and stability, making it one of the commonly used testing methods.

The water contact angle meter is a fairly common instrument for testing plasma treatment, but it is not suitable for testing all plasma-treated products. Materials differ in initial surface energy, and the reactions that take place on their surfaces after plasma treatment also differ. The cleaning results of most products can be tested with a water contact angle meter. One point to note is that when using the water contact angle test, the size of the water droplet should be kept similar for each test.