电路板是不是必须要刷三防漆?那三防漆的浸涂有哪些要点及注意事项？

湿气是破坏电路板性的主要因素。过多的湿气会大幅降低导体间的绝缘抵抗性、加速高速分解、降低Q值、及腐蚀导体。我们常常看到PCB电路板金属部分起了铜绿就是没有涂覆三防漆金属铜与水蒸气、氧气共同其化学反应引起的。

三防漆具有优越的绝缘、防潮、防漏电、防尘、防腐 蚀、防老化、防霉、防零件松脱及绝缘耐电晕等性能。三防漆涂覆在印刷电路板及零组件上，可以降低或消除电子操作性能衰退状况。

  三防漆操作中的浸涂法一直有较广泛的使用，适用于需完全涂覆的场合；就涂覆的效果而言，浸涂方法是比较有效的方法之一。

    浸涂法的要点是：

    应以密度计随时监控溶剂的损失，以保证合理的配比；浸入及抽出速度应加以控制。以获得满意的涂覆厚度并可减少气泡等缺陷；应在洁净而

    且温度/湿度受控的环境下操作。

    浸涂法的注意事项：

    线路板表面会形成一层均匀膜层。应让大部分涂料残留物从线路板上流回浸膜机。

    连接器不要浸入，除非经过仔细遮盖，线路板或者元器件应浸入1分钟，直至气泡消失，然后缓慢拿出。

    线路板组件或者元器件应垂直浸入涂料糟中。

    浸涂结束后再次使用时，若表面有结皮现象，将表皮除去，可继续使用。

    线路板或元器件浸入速度不宜太快，以免产生过多气泡。

Moisture is the main factor to destroy the circuit board. Excessive moisture will greatly reduce the insulation resistance between conductors, accelerate high-speed decomposition, reduce Q value, and corrode conductors. We often see that the metal part of PCB board is green, which is caused by the chemical reaction of copper with water vapor and oxygen without coating three proofing paint.

Three proofing paint has excellent insulation, moisture-proof, anti leakage, dust-proof, anti-corrosion, anti-aging, anti mildew, anti loose parts and insulation corona resistance properties. The application of three proofing paint on printed circuit boards and components can reduce or eliminate the deterioration of electronic operation performance.

The dip coating method is widely used in the operation of three proofing paint, which is suitable for the situation of complete coating; In terms of coating effect, dip coating method is one of the more effective methods.