Soft magnetic composites (SMCs) which also referred as magnetic powder core, are a soft magnetic material made by applying organic or inorganic insulation agent to ferromagnetic particles and then formed by powder metallurgy process. Soft magnetic composites (SMCs) are also categorized as metal soft magnetic material due to adopt soft magnetic metal or alloy powder as its raw material. Soft magnetic material can be classified to metal soft magnetic material and soft ferrite according to electrical resistivity. Metal soft magnetic material possesses high saturated magnetic flux density, permeability and very suitable for miniaturization. However, metal soft magnetic material still be suffering from eddy current loss in high frequency owing to its low resistivity. Soft ferrite has high resistivity and suitable for high frequency applications, but as a ferrimagnetic material, it shows low saturated magnetic flux density and thus need to be increase volume in application. Due to the existence of the insulating layer, soft magnetic composites exhibit relatively high resistivity. In the meanwhile, ferromagnetic powder also provides high saturated magnetic flux density. Therefore, high frequency and miniaturization of volume are accomplished simultaneously. In addition, SMCs can be processed into ring shape, E shape and U shape to fulfill different application conditions.
Soft magnetic composites (SMCs) are typically named by soft magnetic powder it used. With the development of metal soft magnetic material, an increasing number of soft magnetic composites have come out and gradually form industrialization, standardization and serialization. The commonly used soft magnetic composites include iron cores, carbonyl iron cores, Sendust cores, XFlux cores, high flux cores, MPP cores and amorphous/nanocrystalline cores.
| Parameters | Type | ||||||
| Iron cores | Carbonyl iron cores | Sendust cores | XFlux cores | High flux cores | MPP cores | Amorphous/Nanocrystalline cores | |
| Effective permeability | 10-100 | 9 | 26-160 | 26-90 | 14-160 | 14-550 | 26-90 |
| Loss @ 50kHz, 100mT (mW/cm3) | 800-1000 | – | 200-300 | 300-500 | 260-300 | 120-200 | 200-310 |
| Loss @ 100kHz, 100mT (mW/cm3) | 1300-1800 | – | 700-800 | 800-1000 | 800-1100 | 500-650 | 550-650 |
| DC bias characteristic @ 100Oe (60μ) | 40% | 99% | 45% | 74% | 67% | 54% | 70% |
| Curie Temperature (℃) | 750 | – | 500 | 700 | 500 | 460 | 400 |
| Saturated magnetic flux density (T) | 0.5-1.4 | 0.5 | 1.05 | 1.5 | 1.5 | 0.75 | 1.05 |
| Density (g/cm3) | 3.3-7.2 | 5.1 | 6.15 | 7.5 | 7.6 | 8 | 6 |
Insulation Treatment
Mixing
Compaction
Heat Treatment
Post-process
Advantages of Soft Magnetic Composites (SMCs)
- Unique 3D magnetic and electrical properties which enable low iron loss at high frequency.
- Opening the possibilities of compact design by utilizing 3D geometry.
- Perfect for high volume mass production, enable simple net-shaping production with high material utilization ratio and reduced need for secondary operations.
- Low total cost, size, and weight.
- Enhanced assembly capabilities.