Heavy-current planar transformer

Abstract

The invention relates to a planar transformer, in particular to a heavy-current planar transformer manufactured on a multilayer printed circuit board (PCB). The heavy-current planar transformer disclosed by the invention comprises magnetic cores and coil windings. The invention relates to magnetic core shapes, a coil topological structure and a winding method of the planar transformer. The heavy-current planar transformer is characterized in that a primary winding is formed by connecting a large coil surrounding two magnetic cores and a small coil surrounding a magnetic core in series; a secondary winding is formed by connecting a plurality of coils in parallel; different windings are in circulating staggered arrangement on all layers of the PCB; and a signal winding and a power winding are wound on different magnetic core columns. The planar transformer has small size, low height and heavy current. The heavy-current planar transformer is generally integrated on the PCB of a switch power supply for being used as a power transmission transformer in the switch power supply.

Description

technical field [0001] The invention relates to a planar transformer, in particular to a large-current planar transformer fabricated on a printed circuit board (PCB). Background technique [0002] With the development of switching power supply, small size and high power density are more and more called the pursuit target list and development direction of switching power supply. Various technologies for reducing the size of the power supply and improving the power density of the power supply have emerged. Planar transformer technology is one of them. one. In the switching power supply of traditional technology, the power transformer is realized by multiple groups of wires wound on the magnetic core. Such a transformer occupies a large volume, making it difficult to make the switching power supply module small and thin. Moreover, due to the relatively large spacing between the windings, the leakage inductance of the transformer is also relatively large, the degree of coupli...

AI Technical Summary

Problems solved by technology

There are two main problems in this structure of planar transformers: first, the insulation distance required by safety regulations is difficult to achieve, especially the reinforced insulation required by AC / DC converter safety regulations, which is more complicated to implement and often requires a special skeleton The second is that due to the multi-layer superposition, the structure and technology are complicated, and the processing and production are difficult

However, since the transformer itself is a part of the PCB, it must be limited by the number of layers and copper thickness of the PCB.

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