Printed circuit boards are an important part of electronic circuits. Today, you can turn on any electronic device to see its appearance. In addition to the electronic components required for connection, they also need to carry recognizable text information.
Then you might be thinking, how is the information printed in a small area on the PCB? This involves PCB screen printing (Also called PCB silk screen printing) and PCB inkjet printing technology. Before discussing the differences between PCB screen printing and PCB inkjet printing, let's look at the silkscreen layer closely related to them?
PCB silkscreen layer overview
Silkscreen is a layer of ink traces used to identify PCB components, marks, logos, symbols, etc. PCB screen printing helps manufacturers and engineers to identify different parts quickly.
Next, let's talk about the advantages and disadvantages of PCB screen printing and PCB inkjet printing.
PCB inkjet printing is highly flexible
Compared with traditional pcb screen printing, the most significant advantage of pcb inkjet printing lies in its flexibility. pcb inkjet printing does not need to make a plate, there is no limit to the print volume, and all the pre-press processes of pcb screen printing are omitted.
We only need to input the file as usual and use a computer to print the pcb silkscreen. Therefore, on-demand printing can greatly adapt to market changes and reduce waste in the pcb printing industry. With variable printing, pcb printing companies can print a small number of products on the market.
If the market is good, the output can be increased immediately. Print again according to the customer's needs, reducing a lot of waste. At present, in some countries with relatively small populations in Europe and America, pcb inkjet printing has become more popular.
PCB Inkjet Printing simplifies the production process of PCB silkscreen
The traditional PCB screen printing process involves the following process steps when making a pcb silkscreen:
1. PCB pretreatment
2. Full board coating (such as curtain coating)
3. Pattern laminated film manufacturing (photomask)
4. Ultraviolet exposure
5. Development
6. Post curing
Use the most advanced pcb inkjet printing technology to make silkscreen on PCB, which can reduce the number of process steps:
1. PCB pretreatment
2. Digital inkjet printing, including in-situ UV curing
3. Post curing
Using this simplified pcb printing process, the benefits are apparent. In addition to the required equipment to take up capital and the related labor cost reduction, pcb inkjet printing also significantly reduces the use of chemicals in the pcb printing process; therefore, it also reduces the related management and processing costs.
In general, the environmental benefits of pcb inkjet printing are huge. Finally, and most importantly, pcb inkjet printing reduces the manufacturing time of pcb silkscreen; this is an essential capability in today's rapidly developing electronic business.
PCB inkjet printing saves cost-efficiency
As always, in the challenging manufacturing industry, "cost is king". Based on the operational data of the PCB manufacturer, we can directly explore the actual costs associated with the production of pcb silkscreen.
Obviously, when compared with the above-mentioned pcb screen printing process, pcb inkjet printing dramatically influences the cost factors of the pcb printing process.
First of all, the fixed asset investment of pcb printing equipment is a big head. Secondly, the traditional pcb screen printing process includes more consumption material costs; including additional chemicals required for photomasks and dry films and its waste disposal costs. In most operations, the cost of water consumption, wastewater treatment, and solvent recovery is high. Less significant cost factors are labor costs and floor space.
In addition to saving costs, pcb inkjet printing can also increase output with the same labor and factory space. The impact of traditional pcb screen printing on the environment is challenging to quantify, so it is not considered a direct cost factor. However, it would be very difficult to obtain permission for a new factory space for large-scale lithography work to give an example. Coupled with the ability to eliminate the increased cost of the aforementioned pcb screen printing, the cost advantage of pcb inkjet printing has been further strengthened.
PCB inkjet printing is more environmentally friendly
With the development of the times and people's attention to low-carbon environmental protection, the concept of green environmental protection has received more and more attention from the pcb printing process industry.
Compared with similar devices of traditional pcb screen printing, pcb inkjet printing technology has unparalleled advantages in environmental protection.
First of all, from the point of view of printing consumables; most of the inks for pcb screen printing contain substances that are not friendly to the environment. The books and newspapers we read every day have some flavors, which are often produced when organic solvents evaporate.
At the same time, in addition to ink, pcb screen printing also needs to use plates. PCB screen printing uses many other consumables in the process of plate making and plate material use and produces a large amount of waste liquid and waste residue.
pcb inkjet printing takes place in the pcb printing industry chain under its advanced technology, a massive potential for environmental protection, and broad market prospects.
However, the currently widely used pcb inkjet printing equipment is far inferior to traditional pcb screen printing in production capacity. At the same time, there is a certain gap between the quality of pcb inkjet printing and the effect of traditional pcb screen printing.
It is more typical than in the pcb printing process. PCB inkjet printing will have the phenomenon of poor quality of characters dropping ink.
The character quality of pcb screen printing is better
The huge difference in viscosity between pcb inkjet printing ink and pcb screen printing ink is manifested in the character production of PCB. We will find that pcb inkjet printing is very sensitive to the surface state of the PCB. If the surface tension of the substrate is slightly different from that of pcb inkjet printing, the ejected ink dots will spread or shrink, thereby affecting the print quality. The pcb screen printing ink has an extremely high viscosity, and it will behave "inert" on the PCB substrate. It is not easy to spread or shrink by itself, which is generally caused by improper pressure and speed of the scraper.
In addition, due to the extremely low viscosity of pcb inkjet printing, the ink composition is very different from pcb screen printing. The whiteness and three-dimensional effect are shown on the PCB substrate tend to be weaker than the existing pcb screen printing inks. Sometimes you feel that the characters of pcb screen printing under the same thickness and size of characters may be more apparent. But because pcb inkjet printing ink's leveling will be better, pcb inkjet printing characters will feel smoother.
PCB Inkjet Printing has high requirements for ink
For pcb inkjet printing, the fluidity required by the ink is excellent. Its viscosity will be very low. Otherwise, the ink will not be ejected from the nozzle of the print head. So the pcb inkjet printing we have seen is more appropriate to say that it is ink. Its viscosity is close to water, and the viscosity is generally about ten cps when printing.
Compared with pcb screen printing, the requirement for ink is lower. The ink for pcb screen printing needs to be very viscous. Otherwise, the ink will easily ooze out of the screen mesh. And if the ink of pcb screen printing is too fluid, it will be difficult to control, and the area where there should be no ink will be penetrated by the ink that has been "pressed over", and the desired printing pattern cannot be obtained. Compared with pcb inkjet printing, the ink viscosity of typical pcb screen printing will be 4000-10000cps, which is very different.
