Thermally Conductive MgO-Filled Epoxy Molding Compounds

Abstract

The use of magnesium oxide (MgO) as a filler in an epoxy molding compound (EMC) was considered to identify the maximum thermal conductivity that could be achieved without compromising rheological or processing control and processing flexibility. MgO is an attractive candidate filler for EMCs used in automotive and other applications because MgO is inexpensive, electrically insulative, has relatively high thermal conductivity, is nontoxic, and is a relatively soft filler material meaning it will be less abrasive to surfaces it contacts during its processing and shape molding. A maximum bulk thermal conductivity of 3 W/mK was achieved with a 56% volume fraction of MgO filler. This 56 vol% MgO-filled EMC has a thermal conductivity approximately twice that of traditional silica-filled EMCs with the same volume fraction of filler and has equivalent electrical insulative, thermal expansion, and water absorption characteristics. It is concluded that if a thermal conductivity greater than 3 W/mK is needed in an EMC, then a much more expensive filler material than MgO must be used.Index Terms-Epoxy molding compound (EMC), fillers, magnesium oxide (MgO), original equipment manufacturer, thermal conductivity, thermal management.

Thermal conductivity enhancement of liquid crystalline epoxy/MgO composites by formation of highly ordered network structure

“…In the present study, an MgO filler was dispersed in an LC epoxy resin to form a highly ordered network structure by the enhanced interfacial interaction between the filler surface and the mesogenic moieties. MgO is a promising thermal conductive filler because of its high thermal conductivity, nontoxicity, and unique dielectric property 28–29 . Our main aim is to improve the thermal conductivity of the LC epoxy composite by the synergistic effect of the high thermal conductive MgO filler and the highly ordered network polymer structure.…”

Additive Manufacturing of Dense Hexagonal Boron Nitride Objects

“…Values of the thermal conductivity of these disks in the thickness direction varied between 1.4 W/m K and 1.7 W/m K. These results are encouraging because, although these structures were not optimized for this application, these values of thermal conductivity are of the same order of magnitude of those of epoxy reinforced with 50% volume concentration of magnesium oxide particles, which is widely used for thermal management applications in power electronic modules. Values for these materials have been reported between 2.0 W/m K and 3.0 W/m K [8].…”

Morphological changes and their thermal conductivities of MgO crystals containing various impurities (B, Ca, Si)

“…Table 1 shows their physical properties and prices. As can be seen from this table, MgO is an attractive candidate filler for thermally conductive plastics used in automotive and other applications because MgO is inexpensive, electrically insulative, has relatively high thermal conductivity, is nontoxic, and is a relatively soft filler material, meaning it is less abrasive to the surface it contacts during its processing and shape molding 2 …”