In PCB manufacturing, anti-corrosion inks need to meet the following performance requirements:
Chemical resistance: Anti-corrosion ink must have excellent chemical corrosion resistance, being able to resist the erosion of acidic etching solutions (such as ferric chloride, ammonium persulfate, etc.), alkaline etching solutions and electroplating solutions. For instance, some anti-corrosion inks can withstand the erosion of strong acid (pH 0.5) electroplating solutions for over 72 hours, ensuring that they are not dissolved or damaged during the etching and electroplating processes, thereby guaranteeing the clarity and protective effect of the circuits.
Adhesion: The anti-corrosion ink should have good adhesion to the PCB substrate to ensure that the ink does not fall off or crack during the etching and electroplating processes. Good adhesion helps maintain the accuracy and reliability of the circuit and avoids circuit defects caused by ink peeling.
Resolution and precision: Anti-corrosion ink must have high resolution and be capable of forming fine line patterns. For instance, the resolution of liquid photosensitive anti-corrosion ink can reach 50 to 100μm, making it suitable for the production of high-precision circuits. High resolution helps achieve thinner line widths and line spacings, enhancing the routing density and performance of PCBS.
Easy removal: After etching or electroplating is completed, the anti-corrosion ink needs to be easily removed to facilitate subsequent processing steps. For instance, some anti-corrosion inks can be easily dissolved and removed with a dilute alkaline solution (such as NaOH solution), and the removal process will not cause damage to the PCB substrate.
Heat resistance: During the PCB manufacturing process, anti-corrosion inks need to go through high-temperature soldering, high-temperature baking and other environments. Therefore, the ink needs to have good heat resistance to ensure that it does not fall off, change color or cause other adverse phenomena under high-temperature conditions.
Environmental friendliness: With the enhancement of environmental awareness, the environmental friendliness of anti-corrosion ink has also become an important consideration factor. The ink should be made from non-toxic or low-toxic raw materials, and the content of harmful substances should be strictly controlled. Meanwhile, during the process of ink waste treatment, harmless treatment measures should be taken to reduce pollution to the environment.
