MgO Heat Dissipating Fillers: Production Processes
(1) Spray-drying Mg(OH)2 or MgO Slurry -> Sintering Granules to Dense Spherical MgO
| Manufacturer | YU (한국 Academic Research) | Soul Material (한국) | Tateho / Denka (일본) |
| Raw Materials | Mg(OH)2 + Sintering Additives1) | Mg(OH)2 + Sintering Additives2) | MgO + Sintering Additive3) |
| Slurry (Solvent) | DI Water | DI Water | Alcohol (Organic) |
| Mixing | Wet Milling (Ball-Milling) | Wet Milling | Wet Milling |
| Granulation | Aqeuous Spray Drying4) | Aqeuous Spray Drying | Non-aq. Spray Drying3) |
| Granules | Mg(OH)2 phase | Mg(OH)2 phase | MgO phase |
| Sintering Temp. | 1350 oC | ~1400 oC | >1600 oC |
| Shape of Fillers | Spherical | Spherical | Spherical |
| Surface Treatment*) | Coupling Agent <0.25~0.5% | - | - |
|
Moisture Absorption |
0.00% | <0.1% | 0.1% |
|
Remarks |
Humidity Test : 85oC/85% 72h |
85oC/85% 72h | 85oC/85% 168h |
1) Patent Pending, 2) Kor. Patent 10-2143817 & 10-2205178, 3) US Patent 8518536, Kor. Patent 10-2404942 & PCT/JP2021/033639
4) Patent Pending
*) Surface treatment not only improves the moisture resistance of the magnesium oxide heat dissipation filler, but also has the advantage of facilitating heat transfer by strengthening the bond between the filler surface and the resin in TIM. Furthermore, as the heat dissipation fillers come to be reduced in their size, they stick together during sintering, and thus a large amount of rare surfaces are exposed during the process of separating them, so surface treatment is an unavoidable process.
A. Yeungnam University (Korea)
B. Soul Material (Korea)
C. Denka / Tateho (Japan)
(2) High Temperature Heat-treatment and then crushing of MgO
| Manufacturer | Ube Industries5) (일본) | Remarks |
| Raw Materials | Mg(OH)2 + CaO, SiO2 | Impurity B2O3 < 0.5% |
| Sintering Temp. | 1800~2000oC | Rotary Kiln |
| Shape of Fillers | Roundish | not spherical |
| Moisture Absorption | 0.18~0.36% | 85oC/85% 48h |
| Surface Treatment | Halogen e.g. NH4F + Silanes | 120~200oC |
| Moisture Absorption | 0.0 ~ 0.1% | After Surface Treatment |
| Humidity Test | 121oC/100% 24h |
5) PCT/JP2021/044152, Kor. Patent 10-1981636 & 10-1933142
A. Ube Industries (Japan)
(3) Flame Sintering of MgO Powders
- Under research