High-insulation multilayer planar transformer and circuit board integration thereof

A high-insulation multilayer planar transformer, comprising:

• a pair of iron cores, comprising a first iron core and a second iron core arranged oppositely, the first iron core comprising a first base and a first core pillar connected to the first base, and the second iron core comprising a second base and a second core pillar connected to the second base;
• and
• a circuit board integration, stacked between the first iron core and the second iron core, comprising:
• a first insulating layer, consisting of two first insulating plates stacked with each other;
• a second insulating layer, consisting of two second insulating plates stacked with each other;
• a first coil winding in a U-shape with two distal ends both located at a first side, disposed between the first insulating layer and the second insulating layer, and surrounding a through hole planarly;
• a third insulating layer, consisting of two third insulating plates stacked with each other;
• and
• a second coil winding in a U-shape with two distal ends both located at a second side opposite to the first side, disposed between the second insulating layer and the third insulating layer, and surrounding the through hole planarly;
• wherein the through hole is inserted with the first core pillar and the second core pillar;
• wherein a thickness of the first insulating layer, a thickness of the second insulating layer and a thickness of the third insulating layer are equal to or greater than 0.05 mm and equal to or less than 1 mm respectively, a distance of a periphery of the first coil winding to a periphery of the first insulating layer is equal to or greater than 0.1 mm and equal to or less than 1 mm;
• and a distance of a periphery of the second coil winding to a periphery of the second insulating layer is equal to or greater than 0.1 mm and equal to or less than 1 mm.