功率磁性器件是开关电源变换器中必不可少的关键器件，而采用平面变压器可以显著降低磁性器件的高度，减小磁性器件的体积和重量，提高磁性器件的功率密度，从而实现平面磁集成技术。 本文设计了一种微型平面变压器，具有体积小、重量轻、容易表面贴装的优点，可以和平面电感、平面电容等进行磁集成制成平面集成磁件。与常规设计平面变压器方法不同的是，本文以NiCuZn软磁铁氧体磁介质材料作为变压器的基体，以Ag导体作为绕组材料，采用先进的厚膜丝网印刷技术和叠层生产工艺把导体绕组叠积在扁平的高频铁氧体磁性材料介质上，通过交替印刷、叠层、低温共烧形成闭合磁路。本文建立了微型平面变压器的仿真数学模型，进行了电磁仿真和电路仿真。根据仿真结果对所设计的绕组结构进行了优化，通过研究矩形、倒角形和圆形三种结构的电磁特性，确定了圆形结构为最佳微型平面变压器绕组结构。本文采用了在微型平面变压器绕组层之间使用低磁导率介质的方法来提高变压器初级和次级之间的耦合程度，耦合系数达到0.8以上。最后，制作了微型平面变压器的样机，并对样机的电气特性进行了测试，测试结果表明，本文设计微型平面变压器的思路正确，样机工作特性良好。 通过本文的研究工作，作者探索了微型平面变压器的设计理论和方法，并对后续研究工作内容和平面集成磁技术进行了展望。

The power magnetic device is the essential key device in the converter of switch power. The planar transformer can reduce the volume and weight of the magnetic device, improve the power density of the magnetic device, and realize the planar integrated magnetic technology. In this paper, a micro planar transformer has been designed, which is with the advantage of small volume, light weight, easily surface mounting. This kind of planar transformer integrates electrical components into planar magnetism, including planar inductance, planar capacity etc. The design idea in this paper is different from routine. In this paper, NiCuZn, a kind of soft magnetic ferrite, is used as magnetic medium material of the transformer, and Ag is used as the winding material. The thick membrane silk screen printing technology and laminar technology are also used. The product method is piling the conductor winding on the flat high-frequency ferrite magnetic material medium, printing and laminar alternatively. In low temperature the close magnetic way is formed after sintering. This paper has developed a simulation mathematics model of the micro planar transformer. Electromagnetic and circuit simulation are also presented. The winding structure has been optimized according to the simulation results. The electromagnetic characteristics of three structure, such as, rectangle, bevel, and round have been studied, the round structure has been confirmed as optimal micro planar transformer winding structure. This paper raises the coupling level between elementary and secondary windings in planar transformer by using low permeability medium. The coupling coefficient is more than 0.8. Finally, prototype of a micro planar transformer has been produced. Results of the electrical experiments on this prototype have indicated that the design in this paper is correct, and the prototype also has high performances. Refer to the study in this paper, author explored the design theory of the planar transformer, put forward the prospects of the following study and planar integrated magnetic technology at the end of this paper.