Silkscreen is a layer of ink traces used to identify components, test points, portions of the PCB, warning signals, logos, and markings, among other things. Silkscreen is also used to print on. Silkscreening is often done on the component side; however, it is sometimes done on the solder side. This is not an extremely popular practice, however. However, this may result in a price rise. A thorough printed circuit board (PCB) silkscreen may, in essence, assist the manufacturer and the engineer locate and identify all of the components.

Epoxy ink that does not conduct electricity makes up the ink. The ink utilized to make these marks is of a very specific formulation. Yellow, black, and white are the colors that are most often seen in everyday life. PCB software uses conventional typefaces in silkscreen layers; however, you are also given the option to choose different fonts from the system. To carry out conventional silk-screening, you will need a laser photo plotter, spray developer, curing ovens, and a polyester screen stretched across metal frames.

Silkscreen coating may be applied to a printed circuit board (PCB) in one of these three primary ways:

Manual screen-printing: Screen printing may be done by hand when the line widths are higher than 7 millimetres, and the registration tolerance is 5 millimeters. This is the procedure known as manual screen printing.

Liquid Photo Imaging (LPI): When line widths are more than 4 millimeters, this method, which offers better precision and readability than manual screening, is the one that is used.

Direct Legend Printing (DLP): Adding a silkscreen pcb in this manner is the method with the highest level of precision; nevertheless, it is also the most costly.

What are the several ways that silk screen printing may be done?

You may choose from various Silk Screen printing techniques when you go with the Silkscreen PCB printing.

• When the line widths are more than four miles, you should consider using liquid photo imaging instead of traditional photo printing. It is comparable to the method used to apply the solder mask, and it even has some of the same characteristics. After the Silk Screen Circuit Board is created, the lamination will be covered with a liquid photo-imageable epoxy, which will then be put through ultraviolet light exposure. 
• Direct Legend Printing is the option you should go with if you choose quality above cost and are looking for a printing method that can deliver on both fronts. This method would use acrylic ink extensively and place it directly on a raw PCB using CAD data. The curing of the printed ink is accomplished by ultraviolet radiation. The PCB Silk Screen Printing is done by the customers while the boards are fabricated. Nevertheless, DLP is mostly useful for processing the PCB assembly phases, which refers to installing the components on the board.
• Manual Screen Printing: You can use manual screen printing if the line width is more than 0.007 inches or the tolerance level of registration is equivalent to 0.005 inches. The manual screen printing process is carried out with stencils, which include both text and traces.

The traces would need to be converted to nylon to complete the operation. After that, the stencil placed on the layer or laminate will appropriately guide the ink. The drying of the ink is the following phase, and it takes place in the baking oven. The silkscreen pcb that supports any sort of text may be created using one of the simplest ways, manual screen printing.