Disclosed herein is a symmetric transformer in the context of a DC-DC isolated converter. The symmetric transformer reduces or eliminates asymmetry in the distribution of parasitic capacitance across the isolation barrier going from one end to another end of a primary coil, and as a result, undesirable electromagnetic interference (EMI) due to common mode dipole emission across the isolation barrier may be reduced.

In some embodiments, a primary winding is split into separate first and second coils, with a serial impedance connected in between the first and second coils. The transformer is symmetric in the sense that a capacitive coupling of the first coil to a secondary winding is the same as a capacitive coupling of the second coil to the secondary winding, such that common mode EMI may be reduced.

An electronic device includes a substrate, a first insulating film on the substrate, a second insulating film on the first insulating film, first and second coils respectively in the first and second insulating films, first and second terminals, and first and second connection conductors. The first and second insulating films contact each other so that the first and second coils are magnetically coupled. The first insulating film includes a first non-contact portion not contacting the second insulating film. One of the first and second insulating films includes a second non-contact portion not contacting the first or second insulating film. The first terminal is provided on the first non-contact portion and electrically connected to the first coil. The second terminal is provided on the second non-contact portion and electrically connected to the second coil. The first and second connection conductors are connected to the first and second terminals, respectively.

Provided are a transformer and a method for manufacturing a transformer. The transformer includes a magnetic core including: a top substrate and a bottom substrate arranged opposite to each other, and a plurality of winding posts located therebetween; and a winding including a primary side winding wrapped around the plurality of winding posts and a secondary side winding. The primary side winding includes two sub-windings connected in parallel, each including: a main turn including respective at least one turn wrapped on at least two winding posts, respectively, and the at least two winding posts have a single magnetic flux direction; and an additional turn including at least one turn wrapped on at least one additional winding post on which a corresponding main turn of the other sub-winding wraps, and the additional turn has a magnetic flux direction opposite to the single magnetic flux direction.

A planar transformer is disclosed. The planar transformer includes a first core, a second core, a third core, and a fourth core, which are sequentially disposed; a primary coil unit having multiple primary substrates through which the first to fourth cores penetrate and on which primary coil patterns are formed such that magnetic flux is generated in a first direction in the first and fourth cores and in a second direction in the second and third cores; and a secondary coil unit having multiple secondary substrates through which the first to fourth cores penetrate and on which secondary coil patterns are formed, the secondary coil patterns formed on a periphery of the first to fourth cores such that current induced by the magnetic flux flowing in the first to fourth cores flows therein, wherein the multiple primary and secondary substrates form a multi-layer structure.

A transformer is provided which includes an insulating sheet separating the primary-side windings and portion of split magnetic core from the secondary-side windings and portion of split magnetic core. Thin layers of conductive and semiconductive material are deposited on areas of the insulating sheet surfaces facing the primary and secondary sides. These layers are electrically referenced or tied to the potentials of the respective primary or secondary sides. This ensures that the high electric field due to primary-to-secondary potential gradient is substantially placed across the insulating sheet dielectric and avoided in the air gaps or voids in the transformer, thus reducing undesirable partial discharge effects. The two core sections on the primary and secondary side are also electrically referenced or tied to the potentials of their adjacent windings, thus reducing high electric fields and partial discharge in the space between the core sections and the windings.

A magnetic structure in a power converter includes at least two multilayer boards, such as a primary board containing the primary windings and some auxiliary windings, and a secondary board containing the secondary windings and some auxiliary windings. The primary and secondary boards are on top of each other. On the layer on the primary bard adjacent to the secondary board, is a dual function shield to reduce the total common mode noise in the converter towards zero. The controlled dual function shield can be placed on the secondary board on the layer adjacent to the primary board, and in some embodiments can be placed on both primary and secondary board on the layers adjacent to the other board. The embodiments herein offer a very good solution for cost reduction of the planar transformers and offers an avenue for total elimination of the common mode noise in a power converter.

Provided is a semiconductor device that has a configuration provided with: a driving unit for driving an upper switching element and a lower switching element according to a control signal for controlling the driving of the upper switching element and the lower switching element, which are connected in series to constitute a bridge circuit; an insulating unit having an insulating transformer; and a package for sealing at least a part of the insulating unit and the driving unit. The insulating unit transmits a signal corresponding to the control signal to the driving unit side while insulating the signal.

A high-voltage isolation withstand planar transformer and its high-voltage insulation method are provided. An insulating medium is provided between low-voltage windings and high-voltage windings. High-frequency current flows through the windings and generates a high-frequency alternating magnetic field to achieve isolated energy transmission. The low-voltage windings are connected to low-voltage side connection terminals, and the high-voltage windings are connected to high-voltage side connection terminals through a high-voltage winding leading-out foil. An annular hollow part of the low-voltage windings and the high-voltage windings is provided with a magnetic core. A stress grading method is provided to control the distribution of the electric field around the high-voltage winding leading-out foil. A voltage-balancing element group provides a voltage potential with a gradient change between the high-voltage winding leading-out foil and the low-voltage windings. The new transformer has small size, high power density and low cost.

The present disclosure is related to a power module power structure and an assembling method thereof. The power module structure includes a first printed-circuit-board (PCB) assembly, a second PCB assembly, and a conductive connection component. The first PCB assembly includes a first circuit board, a power switch and a magnetic component. The first circuit board includes a first side, a second side and a through hole. The power switch is disposed on the first circuit board. The magnetic component includes a first magnetic core and a second magnetic core fastened on the first circuit board through the through hole. The second PCB assembly includes a second circuit board having a third side, a fourth side and a hollow slot passing therethrough. The second magnetic core is exposed through the hollow slot. The conductive connection component is disposed and electrically connected between the first PCB assembly and the second PCB assembly.

A voltage regulator module includes a circuit board, a first component and a switching circuit assembly. The circuit board includes a first surface, a second surface, a concave structure and a contact pad. The first surface and the second surface are opposed to each other. The concave structure is disposed in the circuit board and concavely formed on the second surface. The contact pad is formed on the second surface and served as at least one of a positive output terminal, a negative output terminal and a positive input terminal. The concave structure and the contact pad are misaligned to each other. The first component is at least partly disposed within the concave structure. The switching circuit assembly is disposed on the first surface and electrically connected with the contact pad and the first component.