Electronic encapsulation

[prelmes]

I'm currently researching methods to encapsulate electronic components to meet ATEX approval.

I'm keen to understand what materials are typically used for this application and the type of processing techniques employed.

I would be particularly interested to hear from anyone who has used low pressure injection moulding for this purpose.

 

[BOPdesigner]

Are you using encapsulation as the primary means of protection in the hazardous location per IEC 60079-18? We use encapsulation in conjunction with the IS standard (-11) and the Non sparking standard (-15) to allow us to use tigher creepage and clearance spacing between traces and conductive parts of the PWA. Potting materials we use are Epoxy based or Polyurethane. We have used low pressure injection molding but only as a preprocess to seal off where a connector exits the products housing so that we can fill the cavity without the encapsulant leaking out. I think the important part is to make sure that the material you use meets the CTI and other parameters called out in whatever IEC 60079-XX document you are basing your ATEX design from. Aside from that, we have found this site to be helpful with some of the problems we have experienced on the processing side:

http://www.pottingsolutions.com/my site/Technology/overview_of_potting.htm