Integrally formed inductor and its manufacturing method for the same

An inductor comprising

• a core column made of a composite material composed of iron-based alloy, wherein the iron-base alloy comprises silicon (Si), aluminum (Al), and chromium (Cr);
• a coil wound around the core column;
• and
• a magnetic sheet made of the composite material composed of iron-based alloy and mounted on a bottom of the core column, wherein the coil is secured by bending to form a bottom electrode at a bottom of the magnetic sheet;
• and
• a residual magnetic body mounted around the core column and the coil and made of mixed powders composed of iron-based alloy, iron-based amorphous nanocrystals, and carbonyl iron powders, wherein the bottom electrode is exposed from the residual magnetic body;
• and
• an insulating anti-rust layer attached to an outer surface of the residual magnetic body and made of a material composed of phenoxy resin, phenolic epoxy resin, and silicon micro powders.