Patent ID: 7940149

Claim:
A magnetic chuck, the magnet chuck having a structure in which elements inserted into an accommodation hole of a chuck main body are bound together by filling material and are mounted in the accommodation hole of the chuck main body, the magnetic chuck comprising: a chuck main body made of magnetic material and provided with a accommodation hole; an AlNiCo magnet inserted into the accommodation hole of the chuck main body; a coil inserted into the accommodation hole of the chuck main body and configured to surround the AlNiCo magnet; a first magnetic element inserted into the accommodation hole of the chuck main body and disposed above and adjacent to the AlNiCo magnet; and a first ferrite or rare-earth magnet inserted into the accommodation hole of the chuck main body and disposed adjacent to a circumferential surface of the first magnetic element; wherein the accommodation hole is formed to pass through the chuck main body, the first magnetic element is exposed in a direction of a top surface of the chuck main body, and the AlNiCo magnet is exposed in a direction of a bottom surface of the chuck main body.