Hi guys, this is JRPanel! As a professional one-stop industrial manufacturer, we aim to share the most valuable contents with people who are interested in Membrane Switch, Sheet Metal, PCB and High Frequency Transformer.
In this blog, JRPanel would like to take you to explore more about Screen Printing in Membrane Switch Manufacturing. These points will help you understand more fully the screen printing process in JRPanel factory.
First let's introduce the decorative inks for the graphic layer and the tips notable during printing, summaried by JRPanel engineers.
1. The ink used on the graphic layer is solvent volatile ink. There are actually many varieties of this type of ink. However, when selecting, it is necessary to consider the ink fineness, color purity, color coverage, and bonding fastness with the substrate.
2. In multi-color printing, following the principle of printing dark colors first and then printing light colors is important. When printing light colors, it is best to print twice to ensure complete ink coverage and improve ink saturation. This way, when the color overprinting, can avoid color transmission.
In most people's mind, in screen printing of membrane panel switches, finishing the printing on the graphic layer means the whole printing process is over. But in the actual printing process, we usually also print on the back of the panel. Simply put, printing on the back side helps prevent the panel ink layer from wearing off and protect the color of the graphics.
When silkscreening the back of the panel, we should pay attention to:
1. A cleanup of the ink layer on the back of the panel is necessary. This is to improve the covering ability of the ink and effectively prevent revealing the circuit behind the panel.
2. When screen printing on the back of the panel, we usually choose silver ink. In addition to better coverage, the silver ink can also highlight the ink on the front side.
In addition, silver ink is more used in circuit printing, as well as carbon ink. When printing silver ink and carbon ink, there are also a few points to pay attention to:
1. Silver and carbon inks need to be fully stirred before screen printing, and they should be stirred up and down. Otherwise, the printed resistance and conductive properties of the same ink in different screen printing stages are different, which sometimes affects the adhesion to the film.
2. After the correct screen printing operation, the silver and carbon inks must be left on the film for a while. Wet the substrate with a bath agent and then put it in an oven and dry it as required to ensure adhesion to the film.
3. In order to accurately ensure the conductivity of silver and carbon ink, the drying degree is divided into three levels, namely low temperature, medium temperature and specified temperature. If the resistance value deviates from the requirements, it needs to be dried again until the resistance value reaches the design requirements.
4. The resistance value should be tested according to the square resistance value, because the end resistance value does not take the width and thickness of the printed line into account.
5. Do not put the silver ink that has not been printed this time back into the original can. Pour it into a clean can and use it next time to ensure the service life of the silver ink in the original can.
6. Due to the characteristics of silver and carbon ink, we should choose a softer squeegee during silk screen printing, and implement the printing principle of light squeegee and heavy re-ink.
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