Inductor, transformer, and manufacturing method thereof

An electric coil manufacturing method comprising the steps of:

• processing a single bendable insulating substrate to form a plurality of strip parts having a series of alternating reverse directional bends, said plurality of strip parts including alternate strip parts and remaining strip parts, each one of said alternate strip parts being arranged adjacent to a respective one of said remaining strip parts, said plurality of strip parts having respective middle parts;
• extending an electrical conductor along said bendable insulating substrate such that said electrical conductor extends through said series of alternating reverse directional bends a plurality of times without coming into electrical contact with itself;
• placing the processed single bendable substrate including the electrical conductor material between first and second forming members;
• and
• pressing the first and second forming members together for bending said middle parts of said alternate strip parts so as to cause said middle parts of said alternate strip parts to separate from said middle parts of said remaining strip parts to form an open portion between said alternate strip parts and said remaining strip parts.