Integrated structure of passive elements in LLC resonance converter realized by flexible circuit boards

Integrated structure of passive elements in an LLC resonance converter realized by flexible circuit boards, comprising:

• a closed magnetic circuit, including a first magnetic core and a second magnetic core;
• a tubular, double-sided, flexible circuit board;
• a tubular magnetic-material layer;
• and
• a tubular, single-sided, flexible circuit board coaxially sleeved in turn from inside outwards on a magnetic core column of the closed magnetic circuit, wherein
• the tubular, double-sided, flexible circuit board includes a first wound, laminated plate material having in turn a first insulating layer, a first copper foil, an insulating medium layer, a second copper foil and a second insulating layer,
• the leading end of the first copper foil and the tail end of the second copper foil each have a respective pad for connecting with an external circuit, and
• the tubular, single-sided, flexible circuit board includes a second wound, laminated plate material having in turn a third insulating layer, a third copper foil and a fourth insulating layer, respective ends of the third copper foil each having an external circuit connecting pad.