阅读说明：本技术 大功率平面变压器及电子设备 (High-power planar transformer and electronic equipment ) 是由 孙春阳 王猛 柳教成 于 2021-09-28 设计创作，主要内容包括：本发明涉及大功率平面变压器及电子设备,大功率平面变压器包括：电路板、第一磁芯和第二磁芯；电路板的第一面上设置有绕组区,绕组区开设有至少两个通孔,绕组区设置有第一绕组和第二绕组,第一绕组绕设于一通孔的外侧,第二绕组绕设于另一通孔的外侧,第一绕组和第二绕组耦合,第一磁芯穿过各通孔与第二磁芯连接；电路板的第二面上设置有导热PI层,导热PI层内设置相变空腔,相变空腔内设置有相变材料,导热PI层抵接于第一磁芯、第二磁芯。通过在电路板的第二面设置导热PI层,将电路板的热量吸收并且散发,导热PI层的相变空腔内设置的相变材料能够吸收热量后进行相变,提高散热效率。(The invention relates to a high-power planar transformer and an electronic device, the high-power planar transformer comprises: a circuit board, a first magnetic core and a second magnetic core; a winding area is arranged on the first surface of the circuit board, at least two through holes are formed in the winding area, a first winding and a second winding are arranged in the winding area, the first winding is wound on the outer side of one through hole, the second winding is wound on the outer side of the other through hole, the first winding is coupled with the second winding, and the first magnetic core penetrates through the through holes and is connected with the second magnetic core; the second surface of the circuit board is provided with a heat conduction PI layer, a phase change cavity is formed in the heat conduction PI layer, phase change materials are arranged in the phase change cavity, and the heat conduction PI layer is abutted to the first magnetic core and the second magnetic core. Through setting up heat conduction PI layer at the second face of circuit board, absorb the heat of circuit board and give off, the phase change material that sets up in the phase change cavity on heat conduction PI layer carries out the phase change after can absorbing the heat, improves the radiating efficiency.)

1. A high power planar transformer, comprising: a circuit board, a first magnetic core and a second magnetic core;

a winding area is arranged on a first surface of the circuit board, at least two through holes are formed in the winding area, a first winding and a second winding are arranged in the winding area, the first winding is wound on the outer side of one through hole, the second winding is wound on the outer side of the other through hole, the first winding is coupled with the second winding, the first magnetic core and the second magnetic core are respectively arranged on two sides of the circuit board, and the first magnetic core penetrates through each through hole and is connected with the second magnetic core;

the second surface of the circuit board is provided with a heat conduction PI layer, a phase change cavity is formed in the heat conduction PI layer, phase change materials are arranged in the phase change cavity, and the heat conduction PI layer is abutted to the first magnetic core and/or the second magnetic core.

2. The high power planar transformer of claim 1, wherein a projection of the thermally conductive PI layer on the first side of the circuit board at least partially coincides with the winding area.

3. The high power planar transformer of claim 2, wherein a projection of the thermally conductive PI layer onto the first side of the circuit board is entirely within the winding area.

4. The high power planar transformer of claim 1, wherein a projection of the thermally conductive PI layer on the first side of the circuit board at least partially coincides with the winding area, and wherein a projection of the thermally conductive PI layer on the first side of the circuit board at least partially deviates from the winding area.

5. The high power planar transformer of claim 1, wherein the volume of the phase change material is 85% to 90% of the volume of the phase change cavity.

6. The high power planar transformer according to claim 1, wherein the sidewalls of the phase change cavity are at least partially formed in a wave shape.

7. The high power planar transformer according to claim 6, wherein the side wall of the phase change cavity on the side close to the circuit board is wave-shaped, and the side wall of the phase change cavity on the side far from the circuit board is honeycomb-shaped.

8. The high power planar transformer according to any one of claims 1 to 6, wherein the heat conducting PI layer comprises a main heat conducting portion and a partial heat conducting portion, the main heat conducting portion is connected to the partial heat conducting portion, a projection of the main heat conducting portion on the first surface of the circuit board at least partially coincides with the winding region, a projection of the main heat conducting portion on the first surface of the circuit board is offset from the winding region, the phase change cavity is disposed in the main heat conducting portion, and a guiding cavity is disposed in the partial heat conducting portion, and the phase change cavity is communicated with the guiding cavity through a phase change channel.

9. The high power planar transformer of claim 8, wherein the width of the phase change channel gradually decreases from an end near the phase change cavity to an end near the guiding cavity.

10. An electronic device comprising a high power planar transformer as claimed in any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of transformers, in particular to a high-power planar transformer and electronic equipment.

Background

The planar transformer is a transformer in which windings are arranged on a circuit board to realize the planarization of the windings, and has the advantages of small volume, high frequency and small height.

With the continuous development of information technology, the mobile terminal is also developing towards miniaturization and convenience, and the electronic accessories of the mobile terminal are also miniaturized. For example, a charger of a mobile terminal is also miniaturized, and a transformer built in the charger needs to have a smaller size in order to reduce the size of the charger, so that a planar transformer is widely used.

In order to enable the charger to quickly charge the mobile terminal such as a mobile phone, the power of the transformer needs to be increased. However, increasing the power means a larger amount of heat generation.

The planar transformer is different from the traditional transformer, because the winding coil of the planar transformer is formed on the circuit board through printing, the line density is high, the coil is equivalently located on the same plane and is not beneficial to heat dissipation, and in addition, the coil is close to other element positions on the circuit board, so that the heat is excessively concentrated, and the traditional planar transformer has the problem of poor heat dissipation effect. For a high-power planar transformer, how to improve the heat dissipation efficiency is an urgent need to be solved at present.

Disclosure of Invention

Accordingly, there is a need for a high power planar transformer and an electronic device.

A high power planar transformer comprising: a circuit board, a first magnetic core and a second magnetic core;

a winding area is arranged on a first surface of the circuit board, at least two through holes are formed in the winding area, a first winding and a second winding are arranged in the winding area, the first winding is wound on the outer side of one through hole, the second winding is wound on the outer side of the other through hole, the first winding is coupled with the second winding, the first magnetic core and the second magnetic core are respectively arranged on two sides of the circuit board, and the first magnetic core penetrates through each through hole and is connected with the second magnetic core;

the second surface of the circuit board is provided with a heat conduction PI layer, a phase change cavity is formed in the heat conduction PI layer, phase change materials are arranged in the phase change cavity, and the heat conduction PI layer is abutted to the first magnetic core and/or the second magnetic core.

In one embodiment, a projection of the thermally conductive PI layer on the first side of the circuit board at least partially coincides with the winding area.

In one embodiment, a projection of the thermally conductive PI layer on the first side of the circuit board is entirely located within the winding area.

In one embodiment, a projection of the heat-conducting PI layer on the first side of the circuit board at least partially coincides with the winding region, and a projection of the heat-conducting PI layer on the first side of the circuit board is at least partially offset from the winding region.

In one embodiment, the volume of the phase change material accounts for 85% to 90% of the volume of the phase change cavity.

In one embodiment, the side wall of the phase change cavity is at least partially provided with a wave shape.

In one embodiment, the side wall of the phase change cavity on the side close to the circuit board is wave-shaped, and the side wall of the phase change cavity on the side far from the circuit board is honeycomb-shaped.

In one embodiment, the heat conducting PI layer comprises a main heat conducting portion and a partial heat conducting portion, the main heat conducting portion is connected with the partial heat conducting portion, a projection of the main heat conducting portion on the first surface of the circuit board at least partially coincides with the winding area, a projection of the main heat conducting portion on the first surface of the circuit board is staggered with the winding area, the phase change cavity is arranged in the main heat conducting portion, a guiding cavity is arranged in the partial heat conducting portion, and the phase change cavity is communicated with the guiding cavity through a phase change channel.

In one embodiment, the width of the phase change channel gradually decreases from one end close to the phase change cavity to one end close to the guide cavity.

An electronic device comprising a high power planar transformer as described in any of the above embodiments.

The invention has the beneficial effects that: through set up heat conduction PI layer at the second face of circuit board, absorb the heat of circuit board and give off, in addition, the phase change material that sets up in the phase change cavity on heat conduction PI layer carries out the phase change after can absorbing the heat, further improves the radiating efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a schematic perspective exploded view of a high power planar transformer according to an embodiment;

fig. 2 is a schematic partial cross-sectional view of a heat-conducting PI layer of the high-power planar transformer according to an embodiment;

FIG. 3 is a schematic diagram illustrating a partial cross-sectional structure of a circuit board and a heat conductive PI layer according to an embodiment;

fig. 4 is a schematic partial cross-sectional view illustrating a circuit board and a heat conductive PI layer according to another embodiment.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 2, a high power planar transformer 10 according to an embodiment of the present invention includes: circuit board 100, first magnetic core 210, and second magnetic core 220; a winding area 150 is arranged on the first surface 110 of the circuit board 100, at least two through holes are formed in the winding area 150, a first winding and a second winding are arranged in the winding area 150, the first winding is wound on the outer side of one through hole, the second winding is wound on the outer side of the other through hole, the first winding and the second winding are coupled, the first magnetic core 210 and the second magnetic core 220 are respectively arranged on two sides of the circuit board 100, and the first magnetic core 210 penetrates through each through hole to be connected with the second magnetic core 220; the second surface 120 of the circuit board 100 is provided with a heat-conducting PI layer 300, a phase-change cavity 301 is arranged in the heat-conducting PI layer 300, a phase-change material 400 is arranged in the phase-change cavity 301, the heat-conducting PI layer 300 abuts against the first magnetic core 210 and/or the second magnetic core 220, and the second surface 120 and the first surface 110 of the circuit board 100 are arranged in a reverse manner.

In this embodiment, the first surface 110 of the circuit board 100 is printed to form a first winding, a second winding, and a circuit on the circuit board 100, and the first winding and the second winding are electrically connected to the electrical components on the circuit board 100 through the circuit on the circuit board 100. The first winding may also be referred to as a first coil and the second winding may also be referred to as a second coil. The circuit board 100 may be a single-layer board or a multi-layer board, in an embodiment, the circuit board 100 includes multiple layers of circuit daughter boards, each circuit daughter board is provided with a first sub-coil, each circuit daughter board is respectively provided with a first via hole, the first via hole is plated with copper, so that the first sub-coils on different circuit daughter boards are connected with each other to form a first winding, each circuit daughter board is provided with a second sub-coil, each circuit daughter board is respectively provided with a second via hole, and the second via holes are plated with copper, so that the second sub-coils on different circuit daughter boards are connected with each other to form a second winding, therefore, the circuit board 100 in this embodiment can set the first winding and the second winding with different turns number according to a required transformation ratio.

In this embodiment, the first and second magnetic cores 210 and 220 may be provided as E-shaped magnetic cores, and one of the first and second magnetic cores 210 and 220 may be provided as E-shaped magnetic cores, and the other may be provided as I-shaped magnetic cores. In this embodiment, the first magnetic core 210 is E-shaped, the second magnetic core 220 is I-shaped, the winding area 150 has a first through hole 101, a second through hole 102 and a third through hole 103, one end of the first magnetic core 210 has a first connection portion 211 protruding toward the second magnetic core 220, the other end of the first magnetic core 210 has a third connection portion 213 protruding toward the second magnetic core 220, the middle of the first magnetic core 210 has a second connection portion 212 protruding toward the second magnetic core 220, the first connection portion 211 of the first magnetic core 210 passes through the first through hole 101 to be connected with the second magnetic core 220, the second connection portion 212 of the first magnetic core 210 passes through the second through hole 102 to be connected with the second magnetic core 220, the third connection portion 213 of the first magnetic core 210 passes through the third through hole 103 to be connected with the second magnetic core 220, in this embodiment, the first connection portion 211, the second connection portion 212 and the third connection portion 213 are connected with the second magnetic core 220 by an adhesive, the first winding is wound outside the first through hole 101, the second winding is wound outside the third through hole 103, so that the first winding and the second winding can be disposed around the magnetic core, and the first winding and the second winding are coupled.

In this embodiment, the heat conduction PI (Polyimide) layer that the second face of circuit board 100 set up, heat conduction PI layer 300 cladding is in phase change material's outside, the material of heat conduction PI layer 300 is PI, heat conduction PI layer 300 has the thermal conductivity of preferred, can absorb the heat of circuit board 100 fast, conduct to the outside, and set up phase change cavity 301 in the heat conduction PI layer 300, phase change material 400 that holds in the phase change cavity 301 can be along with the rising of temperature, and change the form after reaching phase change temperature, thereby play the heat absorption effect well, thereby make the heat of winding district 150 on circuit board 100 can be absorbed fast, and give off.

In this embodiment, since the heat conducting PI layer 300 is disposed on the second surface of the circuit board 100, the heat conducting PI layer 300 can guide heat from the back surface of the circuit board 100 where the winding area 150 is disposed, the heat conducting PI layer 300 has an insulating property, which can effectively avoid short circuit caused by disposing a heat conducting material, and in addition, the heat conducting PI layer 300 abuts against the first magnetic core 210 and/or the second magnetic core 220, which can further conduct heat, in this embodiment, the first magnetic core 210 is disposed on the first surface of the circuit board 100, the second magnetic core 220 is disposed on the second surface of the circuit board 100, the first connecting portion 211, the second connecting portion 212, and the third connecting portion 213 respectively have the first through hole 101, the second through hole 102, and the third through hole 103 penetrating through and connected with the second magnetic core 220 located on the second surface of the circuit board 100, the heat conducting PI layer 300 is located between the second magnetic core 220 and the second surface of the circuit board 100, the heat-conducting PI layer 300 abuts against the first connection portion 211, the second connection portion 212, and the third connection portion 213 of the first magnetic core 210, and the heat-conducting PI layer 300 abuts against the second magnetic core 220, so that the heat-conducting PI layer 300 can better conduct heat.

It should be understood that when the transformer stops working, the temperature drops, and the phase change material 400 in the phase change cavity 301 returns to the original shape after dropping to the phase change temperature, so that the next time the transformer works, the heat can be better absorbed.

To better dissipate heat from the circuit board 100, the projection of the thermally conductive PI layer 300 onto the first side of the circuit board 100 at least partially coincides with the winding area 150 in one embodiment, due to the denser routing of the coil windings within the winding area 150, resulting in more concentrated heat and higher temperatures.

In this embodiment, the position of the heat-conducting PI layer 300 on the circuit board 100 corresponds to the position of the winding area 150, and because the heat generation amount of the winding area 150 is large, the heat-conducting PI layer 300 and the winding area 150 are at least partially overlapped, so that the heat of the winding area 150 on the circuit board 100 can be better conducted, and an efficient heat dissipation effect is achieved.

In one embodiment, the projection of the thermally conductive PI layer 300 onto the first side of the circuit board 100 is entirely located within the winding area 150. In the present embodiment, the heat conducting PI layer 300 completely overlaps the winding region 150, and in one embodiment, the projection of the heat conducting IP layer on the first surface of the circuit board 100 has the same shape and area as the winding region 150, so that the heat conducting PI layer 300 can absorb the heat of the winding region 150 of the circuit board 100 more sufficiently.

In one embodiment, the projection of the thermally conductive PI layer 300 on the first side of the circuit board 100 is at least partially coincident with the winding region 150, and the projection of the thermally conductive PI layer 300 on the first side of the circuit board 100 is at least partially offset from the winding region 150.

In this embodiment, the heat conducting PI layer 300 is partially located in the winding region 150 and partially located outside the winding region 150, and the portion located in the winding region 150 absorbs heat from the winding region 150 and dissipates heat through the portion located outside the winding region 150. It should be understood that the phase change material 400 is in a solid state below the phase change temperature, changes into a liquid after being heated to the phase change temperature, and absorbs heat during the phase change process, since the heat conductive PI layer 300 is not located outside the winding region 150, and the phase change cavity 301 extends to the outside of the winding region 150 along with the heat conductive PI layer 300, so that the phase change material 400 changing into a liquid can take away heat when flowing to the phase change cavity 301 of the portion outside the winding region 150, thereby performing a better heat conduction function.

In addition, as the phase change material 400 changes from a solid phase to a liquid phase, the phase change material 400 can flow in the phase change cavity 301, so that the mass distribution of the phase change material 400 in the phase change cavity 301 is more uniform, and thus, the heat can be more uniformly dissipated.

In order to further improve the heat dissipation efficiency and make the heat dissipation effect better, in an embodiment, the projection of the heat-conducting PI layer 300 on the first surface of the circuit board 100 completely covers the winding region 150, and the projection of the heat-conducting PI layer 300 on the first surface of the circuit board 100 is at least partially located outside the winding region 150, so that the heat-conducting PI layer 300 can not only sufficiently absorb the heat of the winding region 150, but also guide the heat to the outside of the winding region 150, which is beneficial to further diffusion of the heat.

In order to enable the phase change of the phase change material 400 within the phase change cavity 301, in one embodiment, the volume of the phase change material 400 is 85% to 90% of the volume of the phase change cavity 301. In this embodiment, the volume of the phase change material 400 in the phase change cavity 301 is relatively large, which is beneficial for the phase change material 400 to be able to fully contact with the sidewall of the phase change cavity 301, and is beneficial for heat conduction, and in addition, the phase change material 400 does not completely fill the heat conduction PI layer 300, and can provide space for the phase change of the phase change material 400. In each embodiment, the phase change material 400 is in a powder or bulk shape when in a solid state, and therefore, the phase change material may also be referred to as a phase change powder or a phase change layer. It should be understood that, when the phase change material 400 changes from a solid phase to a liquid phase or from a liquid phase to a solid phase, the volume of the phase change material 400 changes, and the volume of the phase change material 400 is set to be 85% to 90% of the volume of the phase change cavity 301, so that the phase change material 400 can be in sufficient contact with the side wall of the phase change cavity 301 before and after the phase change, the heat conduction efficiency is improved, and in addition, a redundant space can be provided for the phase change of the phase change material 400. It should be understood that, because the phase change cavity 301 is configured as a sealed cavity, the phase change material 400 will cause a volume change during the phase change process, thereby causing a change in the air pressure inside the phase change cavity 301, and because the material of the heat conducting PI layer 300 is PI, which has flexibility and elasticity, a local deformation can be generated during the phase change process of the phase change material 400, so as to adapt to the volume change of the phase change cavity 301 affected by the air pressure.

In one embodiment, as shown in FIG. 3, the sidewalls of the phase change cavity 301 are at least partially configured in a wave shape. In this embodiment, the side wall of the phase change cavity 301 is set to be wavy, which is beneficial to increase the contact area between the phase change material 400 and the side wall of the phase change air, and is beneficial to heat conduction.

In one embodiment, referring to fig. 3 again, the side wall of the phase change cavity 301 is corrugated, in this embodiment, the side wall of the phase change cavity 301 is provided with two corrugated structures, the cross-sectional shape of the corrugated structure is corrugated, the corrugated structures are arranged in a circular corrugated manner with the geometric center of the first winding as the center, the other corrugated structure is arranged in a circular corrugated manner with the geometric center of the second winding as the center, the positions of the troughs 311 of the corrugated structure 310 correspond to the positions of the coils 151 of the first winding, and the positions of the peaks 312 of the corrugated structure 310 correspond to the gaps 152 between the coils of the first winding, so that, as the troughs 311 can accommodate more phase change materials 400, more heat absorption is facilitated, and the troughs 311 can enable the phase change materials 400 to be closer to the first side of the circuit board 100, which is more beneficial for absorbing heat, and the peaks 312 corresponding to the gaps 152 between the coils 151, the phase change material 400 can be distributed more uniformly after being changed into liquid.

In one embodiment, the side wall of the phase change cavity 301 close to the circuit board 100 is wave-shaped, and the side wall of the phase change cavity 301 far from the circuit board 100 is honeycomb-shaped.

In this embodiment, the side wall of one side of the phase change cavity 301 is corrugated, and the cross-sectional shape of the side wall is wavy, while the side wall of the other side of the phase change cavity 301 is honeycomb-shaped, in this embodiment, the side wall of one side of the phase change cavity 301 far away from the circuit board 100 is provided with a plurality of honeycomb grooves 304, so as to form a honeycomb-shaped structure. Therefore, the contact area between the phase change material 400 and the side walls on the two fixed sides of the phase change cavity 301 is increased, and heat dissipation is facilitated.

In one embodiment, the phase change material 400 is an alkane ester, and the alkane ester changes from a solid phase to a liquid phase during the absorption process, so that a large amount of heat can be absorbed during the absorption process, and a good heat dissipation effect is achieved. In one embodiment, the phase change material 400 is paraffin, and paraffin changes from a solid phase to a liquid phase during the absorption process, so that a large amount of heat can be absorbed during the absorption process, and a good heat dissipation effect is achieved. In other embodiments, the phase change material may also be a phase change material in other prior arts, which is not described in detail in this embodiment.

In one embodiment, as shown in fig. 4, the heat conducting PI layer 300 includes a main heat conducting portion 320 and a partial heat conducting portion 330, the main heat conducting portion 320 is connected to the partial heat conducting portion 330, a projection of the main heat conducting portion 320 on the first side of the circuit board 100 at least partially coincides with the winding region 150, a projection of the main heat conducting portion 320 on the first side of the circuit board 100 is offset from the winding region 150, the phase change cavity 301 is disposed in the main heat conducting portion 320, a guiding cavity 331 is disposed in the partial heat conducting portion 330, and the phase change cavity 301 is partially communicated with the guiding cavity 331 through a phase change channel 302.

In this embodiment, the projection of the main heat conducting portion 320 is located inside the winding region 150, which is favorable for sufficiently absorbing heat of the dense coils 151 of the winding region 150, while the projection of the partial heat conducting portion 330 is located outside the winding region 150, which is favorable for conducting and radiating heat of the main heat conducting portion 320 to the outside, and in addition, the partial heat conducting portion 330 is located outside the first magnetic core 210 and the second magnetic core 220, which is more favorable for radiating heat. In addition, after the phase change material 400 in the phase change cavity 301 is heated to be changed into liquid, the liquid flows to the guiding cavity 331 along the phase change channel 302, which is beneficial to heat diffusion and enables the heat dissipation effect to be better.

In one embodiment, the width of the phase change channel 302 gradually decreases from the end near the phase change cavity 301 to the end near the guide cavity 331.

In this embodiment, because the width of the phase change channel 302 near the one end of the phase change cavity 301 is large, and the width near the one end of the guiding cavity 331 is small, which is beneficial for the liquid phase change material 400 to flow from the phase change cavity 301 to the guiding cavity 331, and is beneficial for the heat diffusion, and the liquid phase change material 400 in the guiding cavity 331 is not easy to enter the phase change cavity 301, and when the transformer stops working, and the temperature gradually decreases, the backflow of the phase change material 400 to the phase change cavity 301 can be reduced, so that more phase change materials 400 in the guiding cavity 331 are obtained. And when the transformer works again and the temperature rises again, the phase-change material 400 in the phase-change cavity 301 obtains more heat, the phase-change material is firstly changed into liquid and flows to the guide cavity 331 through the phase-change channel 302, after the phase-change material 400 in the guide cavity 331 absorbs the heat of the liquid phase-change material 400 entering from the phase-change cavity 301, the phase-change material 400 in the guide cavity 331 is also changed into liquid along with the phase-change material, so that the phase-change material 400 in the guide cavity 331 can also absorb the heat, and along with the increase of the working time of the transformer, the phase-change material 400 in the phase-change cavity 301 and the guide cavity 331 gradually changes into liquid, so that the heat absorption can be distributed along with the increase of the time, thereby the heat dissipation is more durable, and the heat dissipation effect is better.

In one embodiment, the planar transformer further includes a metal heat sink, a jack is formed in a side wall of the phase change cavity 301 at an end outside the winding region, the metal heat sink is at least partially inserted into the jack, and the metal heat sink is connected to the side wall of the jack to seal the jack. In this embodiment, the metal conducting strip is connected with heat conduction PI layer, and through setting up the metal conducting strip, leads the heat on heat conduction PI layer to the outside for the radiating effect is better. In addition, through sealing the jack, the phase change material in the phase change cavity can be in contact with the metal radiating fin, and heat dissipation is further facilitated. The metal radiating fin is made of metal, the metal has high heat conductivity and can efficiently radiate heat to the outside, and in one embodiment, the metal radiating fin is made of at least one of aluminum alloy, copper and stainless steel. In this embodiment, since the metal heat sink is connected to the outer side of the heat conducting PI layer, the metal heat sink can be away from the winding area on the circuit board and also away from the electrical component on the circuit board, thereby effectively avoiding the short circuit caused by the contact of the metal heat sink.

In one embodiment, there is provided an electronic device comprising the high power planar transformer described in any of the above embodiments.

In the above-mentioned embodiment, through setting up heat conduction PI layer at the second face of circuit board, absorb the heat of circuit board and give off, the phase change material that sets up in the phase change cavity on heat conduction PI layer carries out the phase change after can absorbing the heat, further improves the radiating efficiency, avoids planar transformer during operation high temperature for electronic equipment work is more stable, and is more safe.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.