CN213519559U

CN213519559U - Shielding layer for planar transformer

Info

Publication number: CN213519559U
Application number: CN202021982314.3U
Authority: CN
Inventors: 马奇; 蔡祖亲
Original assignee: Salcomp Shenzhen Co ltd
Current assignee: Salcomp Shenzhen Co ltd
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2021-06-22
Anticipated expiration: 2030-09-11

Abstract

The utility model discloses a shielding layer for a planar transformer, which comprises a magnetic core opening and a shielding coil, wherein the magnetic core opening is arranged in the middle of the shielding layer and can be passed by the magnetic core of the planar transformer; the shielding coil is arranged around the opening of the magnetic core, at least one copper removing area is arranged on the shielding coil, and the shielding coil in the copper removing area is not covered by copper foil. The utility model discloses a setting up the area of removing copper, adjusting transformer primary level's voltage balance reaches the effect of balanced conduction transmission and radiation emission, reduces the use of peripheral EMI suppression device, and reduction in production cost improves switching power supply's efficiency, obtains the effect of more ideal suppression electromagnetic interference, shortens switching power supply's development cycle, improves development efficiency.

Description

Shielding layer for planar transformer

Technical Field

The utility model relates to a switching power supply technical field especially relates to a shielding layer for planar transformer.

Background

Switching power supplies have been developed rapidly with their advantages of high efficiency, small size, and good output stability. The transformer is an indispensable basic component in the switching power supply. Compared with the traditional transformer taking the electric wire as the winding, the winding of the planar transformer is generally formed by winding a plurality of layers of Printed Circuit Boards (PCBs), and the planar transformer is designed to have lower direct-line resistance, smaller leakage inductance, smaller height and higher working frequency.

The planar transformer generally adopts the shielding layer to reduce the influence of electromagnetic interference, and the effect of suppressing the electromagnetic interference is usually adjusted by adjusting the number of turns of the shielding winding on the shielding layer, but the effect of transmitting and radiating cannot be effectively balanced by adjusting the number of turns of the shielding winding, so that an ideal effect of suppressing the electromagnetic interference cannot be obtained, the development period of the switching power supply is prolonged, and the development efficiency is reduced.

SUMMERY OF THE UTILITY MODEL

The utility model is directed to the above-mentioned technical problem, provide a shielding layer for planar transformer.

In order to solve the technical problem, the utility model provides a following technical scheme:

a shielding layer for a planar transformer includes a magnetic core opening and a shielding coil,

the opening of the magnetic core is arranged in the middle of the shielding layer and can be used for the magnetic core of the planar transformer to pass through;

the shielding coil is arranged around the opening of the magnetic core, at least one copper removing area is arranged on the shielding coil, and the shielding coil in the copper removing area is not covered by copper foil.

In some embodiments, the decoppering region is a circular region, and the decoppering region is disposed at an intermediate position of the shield coil.

In some embodiments, the copper removing area is an elongated area, and the copper removing area is disposed in a middle position of the shielding coil.

In some embodiments, when the shielding coil is a multi-turn coil, the line width of each turn of the shielding coil is not equal.

In some embodiments, the width of the line width of the shield coil furthest from the core opening is greatest.

In some embodiments, the shield coil comprises N1 turns in clockwise winding and N2 turns in counterclockwise winding, and the ratio of N1 to N2 is adjustable.

In some embodiments, the sum of N1 and N2 is equal to 1.

In some embodiments, the device further comprises a connection node for making an electrical connection.

The utility model has the advantages that: by setting the copper removing area, the point position distribution of the copper foil of the shielding layer is changed, so that the high-frequency signal voltages at two ends of a parasitic capacitor between the primary winding and the secondary winding are balanced, the common-mode voltage between the shielding layer and the other winding of the adjacent layer is reduced, and the high-frequency energy is restrained, thereby achieving the effect of balancing conducted emission and radiated emission, reducing the use of peripheral EMI restraining devices, reducing the production cost, improving the efficiency of the switching power supply, obtaining the ideal effect of restraining electromagnetic interference, shortening the development period of the switching power supply, and improving the development efficiency.

Drawings

Fig. 1 is a schematic structural diagram of a shielding layer for a planar transformer according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a shielding layer for a planar transformer according to another embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a shielding layer for a planar transformer according to another embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Fig. 1 schematically shows a shielding layer (hereinafter referred to as shielding layer) for a planar transformer, the shielding layer is generally located at an adjacent layer of a primary level of the transformer, the shielding layer includes a magnetic core opening 1 and a shielding coil 2, the magnetic core opening 1 is disposed in the middle of the shielding layer, and a magnetic core of the planar transformer can pass through the magnetic core opening; the shielding coil 2 is arranged around the magnetic core opening 1, at least one copper removing area 3 is arranged on the shielding coil 2, and the shielding coil of the copper removing area 3 is not covered by copper foil.

In alternative embodiments, the copper removal area 3 may be a circular area, an elongated area, or other suitable shape. The decoppering area 3 may be arranged in the middle of the shielding coil.

In an alternative embodiment, the shape, size and position of the decoppered areas 3 can be adjusted to suit different requirements of the balance of conductive emission and radiative emission in practical applications. The utility model provides a shielding layer for planar transformer, regional 3 through setting up the decoppering, the copper foil point position that changes the shielding layer distributes, make just, the high frequency signal voltage at parasitic capacitance both ends between the secondary winding is balanced, reduce the common mode voltage between another level winding of shielding layer and adjacent layer, and restrain high frequency energy, thereby reach balanced conduction emission and radiation emission's effect, reduce the use of peripheral EMI suppression device, and the production cost is reduced, switching power supply's efficiency is improved, obtain the more ideal effect of suppressing electromagnetic interference, shorten switching power supply's development cycle, and the development efficiency is improved.

Referring to fig. 1 and 2 of the specification, in an alternative embodiment, the shield coil 2 includes N1 turns of the clockwise winding and N2 turns of the counterclockwise winding, the starting point 5 is where the clockwise winding and the counterclockwise winding start, and the winding opening 6 is where the clockwise winding and the counterclockwise winding end. The ratio of N1 to N2 is adjustable. Therefore, the ratio of N1 to N2 is adjusted to change the potential distribution of the shielding layer, so that the common-mode current between the primary winding and the secondary winding is adjusted, the effect of balancing conducted emission and radiated emission is achieved, the production cost is reduced, the efficiency of the switching power supply is improved, the ideal effect of suppressing electromagnetic interference is obtained, the development period of the switching power supply is shortened, and the development efficiency is improved.

In an alternative embodiment, the shield coil 2 may be a single turn coil, in which case the sum of N1 and N2 may be equal to 1.

Referring to fig. 3 in the description, in an alternative embodiment, when the shielding coil 2 is a multi-turn coil, the line width of each turn of the shielding coil 2 may be unequal.

In alternative embodiments, the shield coil 2 may have more than three different line widths. Therefore, the shielding coil 2 comprises copper foils with different line widths, and the potential distribution of the shielding layer can be reasonably adjusted to inhibit primary and secondary common mode voltages.

In an alternative embodiment, the width of the line width of the shield coil 2 farthest from the core opening 1 is largest. Therefore, the outermost line width of the shielding coil 2 is wider, and radiation emission shielding is facilitated.

In an alternative embodiment, the shielding layer further comprises a connection node 4, the connection node 4 being used for making an electrical connection. For example, the shield coil 2 may be electrically connected to the connection node 4.

In an alternative embodiment, the starting point 5 may be a dead or moving point of the switching power supply.

The above are only some embodiments of the present invention. For those skilled in the art, without departing from the inventive concept, several modifications and improvements can be made, which are within the scope of the invention.

Claims

1. Shielding layer for a planar transformer, characterized in that,

comprises a magnetic core opening and a shielding coil,

the magnetic core opening is arranged in the middle of the shielding layer and can be penetrated by a magnetic core of the planar transformer;

the shielding coil surrounds the magnetic core opening, set up at least one area of copper that removes on the shielding coil, remove the copper area the shielding coil does not have the copper foil to cover.

2. The shielding layer for a planar transformer according to claim 1, wherein the decoppering region is a circular region, and the decoppering region is disposed at a middle position of the shielding coil.

3. The shielding layer for planar transformer as claimed in claim 1, wherein the copper removing region is an elongated region, and the copper removing region is disposed at a middle position of the shielding coil.

4. The shielding layer for planar transformer as claimed in claim 1, wherein when the shielding coil is a multi-turn coil, the line width of each turn of the shielding coil is not equal.

5. The shield for planar transformers according to claim 4, wherein a line width of said shield coil farthest from said core opening is largest.

6. The shielding layer for planar transformer as claimed in claim 1, wherein said shielding coil comprises N1 turns clockwise and N2 turns counterclockwise, and the ratio of N1 to N2 is adjustable.

7. The shielding layer for planar transformers according to claim 6, characterized in that the sum of N1 and N2 is equal to 1.

8. The shielding layer for planar transformer of claim 1, further comprising a connection node for making electrical connection.