The function of potting material is  to strengthen the integrity of electronic devices,to improve the resistance to external impact,vibration  and insulation between internal components and lines, which is conducive to miniaturization and lightweight of devices,Avoiding direct exposure of components and lines and improvinf  the waterproof and moisture-proof performance of devices.It consists of resin, curing agent, toughening agent, filling agent and so on.

The commonly used fillers in epoxy resin potting materials contain silica, alumina, aluminum hydroxide, magnesium hydroxide and so on.

Aluminium hydroxide and magnesium hydroxide is a kind of inorganic filler flame retardant of environmental protection, when heated (325 degrees 235 degrees aluminium hydroxide, magnesium hydroxide),they will release water molecules to acheive the flame retardant effect of cooling and smoke suppression, at the same time they  could  produce Alumina, magnesia and they can form a layer of dense film coated other substances, so as to cut off oxygen, which have the effect of flame retardant.Therefore, adding this type of material into potting material has the dual functions of filling and flame retardant, and the price is lower than Alumina, and the product cost can be reduced.

Alumina hydroxide and magnesium hydroxide used in Epoxy Resin Potting  Material are required to have low oil absorption rate, uniform particle size, laser particle size D50=15 micron is better, and D90 should not exceed 40, otherwise the product is easy to precipitate, and the gloss of the surface after curing is not enough, which affects the appearance.Add aluminum hydroxide, the product liquidity is better, the surface gloss is good, oil absorption rate relative to magnesium hydroxide is also lower.The disadvantage is that the price is higher than magnesium hydroxide.The advantage of magnesium hydroxide is its low price, which is inferior to aluminum hydroxide in other aspects.It is recommended that magnesium hydroxide can be added for some small potting.For large area potting, aluminum hydroxide can be used.