PCB circuit board ink is generally divided into three kinds, respectively, PCB line etching ink, welding ink and text ink. Some are conductive carbon oil (also called conductive carbon ink), conductive silver oil (also called conductive silver paste), the latter two kinds of general dosage are less.

PCB photosensitive etching ink

First of all, the etching ink of PCB line. The base material of PCB board is copper clad plate, and there is a layer of copper foil on it. It needs the sensitive etching ink on screen printing, and then it is cured by exposure development, etched away the unexposed place, and then it is inked. This line etching ink, mainly for protection, etching a good line, behind the use of sodium hydroxide aqueous solution to remove ink. Most of the circuit board etching ink is blue, so it is also called line blue oil or sensitive blue oil, some hardware stainless steel etching will also use this ink, individual people will call it sensitive glue, in fact, it is very different from printing plate with sensitive glue.

Two, PCB welding ink

The second kind of ink is to focus on, that is, PCB circuit board welding ink, also known as welding ink. Solder ink is a very common PCB board is the main use of ink. The layer of green paint that we see on the circuit board is actually solder blocking ink.

According to the curing mode, solder ink has photographic developing ink, heat curing heat setting ink, and UV light curing UV ink. And according to the plate classification, and PCB hard plate welding ink, FPC soft plate welding ink, and aluminum plate welding ink, aluminum plate ink can also be used in ceramic plate.

Photosensitive solder ink is uv light curing, screen printing, need to pre-bake after exposure developed. Generally used to make all kinds of PCB hard board, soft board with precision pad circuit board in addition to dry film will also use sensitive solder ink. And thermosetting ink, is directly printed after baking out. Common is mobile phone antenna board ink, light strip board white welding ink. UV ink, UV green oil is more common, general requirements are not too high circuit boards or large output of automatic production circuit boards will be used. UV ink, photosensitive ink, thermosetting ink three contrast, photosensitive ink requirements are relatively high, followed by thermosetting ink, and then UV ink, generally speaking, UV ink adhesion will be poor, photosensitive ink precision is higher.

Three, PCB text ink

The third kind of ink is text ink, text ink in circuit board printing, mainly to print characters and marks. The common character ink is white and black, white is used more, almost all of the circuit board in addition to the white solder layer are printed with white text ink. Aluminum substrate, lamp strip board, backlight, etc., due to the use of white solder ink, so the above characters used black text ink.

Individual circuit board manufacturers because of the needs of customers, will use a yellow or other color ink, but due to the circuit board writing ink dosage is too little, a lot of ink manufacturers are not willing to go to production, so the text will want special color ink is very difficult to find, recommend welding ink to make proof, defect is the welding ink when writing ink is used, There will be a phenomenon of oil loss.

Text ink is mainly thermosetting text ink, some will use UV curing text ink. Most ink manufacturers have produced white UV text ink, such as Kawashima UVM-5 is a UV curing text white oil.

PCB circuit board production is mainly used in the above three kinds of ink, so what are the roles of these three kinds of ink?

A photographic etching ink is mainly used to protect the copper foil on the circuit board that does not need to be etched. It has the effect of etching resistance, acid and alkali resistance and electroplating resistance.

Two, welding ink is also used as a protective role, insulation, reflow resistance, resistance to gold, gold, tin, silver and salt spray. It can also protect the copper foil circuit on the circuit board in the future use and increase the life of the circuit board.

Three, the role of text ink compared to the previous two, the role is not too big, mainly as a mark character or graphics to use.