Research On Miniaturization Of DC/DC Switching Power Supply Module In LTCC Technology

Switching power supply as the energy supply for the electronic system has beenwidely used in the field of civil, military and so on. With the development of electronictechnology and demand for market, switching power supply is straightly developing tominiaturization, high frequency and modularization. The magnetic devices includinginductance and transformer as the significant part of DC/DC switching power supplyhave seriously restricted the future of miniaturization, due to its large size. So researchon magnetics integration is imperative. This paper use the most advanced passive inte-gration technology Low Temperature Co-fired Ceramic (LTCC) as the way to realize themagnetic integrated substrates and miniaturize the DC/DC switching power supply.To realize the miniaturization of supply module, this paper use fly-back circuit to-pology for example, firstly design a low power DC/DC switching power supply. Itsswitching frequency and output power is respectively1MHz and5W. Traditional PCBboard circuit of supply is finished, and the test results including different loads are pro-vided to verify the feasibility of the circuit, so the blue print of miniature supply is es-tablished. Considered of LTCC technology, starting with coupling coefficient and leak-age inductance, this paper proposed a new LTCC embedded transformer ferrite substrate,with the simulation and optimization of parameters of the new structure, finally thecoupling coefficient reached to0.93. It also deeply studied the relationship between loadcurrent and inductance of winding coil and magnetic saturation in LTCC technology andchose the right parameters to improve the performance of the miniaturized DC/DC sup-ply.According to the wiring rule of supply circuit and the parameter design of embed-ded transformer, based on the process of LTCC, produced the embedded transformerferrite substrate. All parts are assembled into a3D physical with flip chip packagingtechnology and test all the ralated parameters, prove the feasibility of LTCC switching power supply. At last we discuss the result and defect of this paper and give the sugges-tions in the next work.