Electrical connections very often need a supplemental bond to assure that they do not disconnect in shipping or in the field. An effective method of securing these connections is to place a large dot of hot melt thermoplastic over the connection. This process is also referred to as “Overmolding” or “Potting”.
This typically is as simple as extruding one large dot of hot melt above the connection and allowing the adhesive to flow over the connector and bond to the substrate to which half of the connector is mounted.
Simple stick guns and standard hot melt systems with handguns can be used for this process but fast assembly with metered patterns are no possible. The best hot melt system for consistent metered shots of hot melt is a “Hands Free” bench-mounted system with a small capacity pressurized hot melt tank and a high speed valve with nozzle.
Consideration should be given to the hot melt used as some products do not cycle cleanly or offer sufficient temperature resistance. To determine the adhesive and system for your application you should answer the following questions:
- What size dot is needed to cover the connection?
- How many dots are needed per board?
- What is the maximum temperature the adhesive will ever see?
- What are the connectors and boards made of?