Two options of potting epoxy resin to PCB assembly devices.

What is the potting epoxy resins?

Potting epoxy resin is to pot polyurethane, silicone, and epoxy resin into the devices with electronic components and PCBs by automatic equipment (tool) or by manual work with a tool.

The electronics devices potted with epoxy resin can be supremely protected from water, chemicals, shock, voltage discharge, vibration, and physical damage.

Which material is the best option for potting process?

Actually,there is no best material for electric device potting process. It depends on your production application,budgetary cost, etc. But for out door application electric devices, there are 2 better potting material options: 3M-DP270 from 3M Corporate, and EPIC S7302 from Epic Resins.

What is the difference between 3M-DP270 and EPIC-S7302?

Epic S7302 is a compound urethane material (A+B) designed for electronic devices potting applications. The chemistry feature of S7302 lends itself well for electronic products that are exposed to a wide range of temperatures. S7302 is an ideal potting material for applications that are thermal cycled between -40C and 135C with excursions up to 160C. S7302 also has excellent features of good moisture resistance and good adhesion to various metals and plastics. Weak points is that it needs potting process by machine which could save time and ensure good quality, as the potting work by manual process is very complexity due to that you have to compound A and B together before ready for potting work. So, it is not an ideal potting material for small volume production. But it will be more economic in cost for mass production and potting by machine due to it is package is by “barrel”.

3M-DP270 is a Potting Compound material with low viscosity for easy dispensing and potting. It’s advantages is non-corrosive to copper, minimal exotherm and very low shrinkage – making it well-suited for potting and bonding electronic and electrical components.It has excellent features of good resistance to medical sterilization and is available color in black opaque and transparent amber. Good points is that by 3M dispensing equipment,it provide more convenient and accurate metering, mixing and dispensing which is time saved and quality ensured by manual potting work in small volumes production.Weak points is that the price will be not so good for mass productions.

Below table would be a good reference for your choice of protecting your electronic devices by 3M-DP270 or EPIC S7302?

Product Identification:Potting CompoundPotting Compound
Product Resin:UrethaneUrethane
Component Count:BlackClear or Black
Color, Part A:AmberClear or Black
Color, Part B:BlackClear or Black
Color, Mixed:BlackClear or Black
Flammability (UL):Recognized UL94 HB @ 1.5 mmUL94 HB
UL File Number:E55516 Plastics ComponentE61941
Shelf Life 25C, Part A:12 Months12 Months
Shelf Life 25C, Part B:12 Months12 Months
Pot Life, minutes:35 -50 minutes @ 25°C (100 grams)60-70 minutes @ 23°C (73°F)
The comparison: 3M-DP270 & EPIC-S7302

So, if it is only some small volumes and prototypes productions,3M-DP270 could be a good option.But if you have mass production with larger quantities, maybe EPIC-S7302 is good reference.

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