KR101835528B1 - Switching power supply with laminated structure - Google Patents

Abstract

An LLC resonant converter is used to configure a slim type switching power supply unit having a low height in a high frequency resonant switching power supply unit for converting a DC voltage into a stable DC voltage, The circuit part is divided into a primary side and a secondary side, and a ceramic layer having the same width and a same thickness as the width of the power supply device at the center and an adhesive thermally conductive sheet for facilitating thermal conduction on both sides of the ceramic, A multilayer printed circuit board constituting each circuit of the second and third circuits, a pattern using a pattern on a multilayer printed circuit board, a primary and a secondary transformer coupled through a ferrite magnetic core, and a control signal for controlling the output of the power supply Switching of laminated structure using a signal transformer coupled to a multilayer printed circuit board for transfer from the secondary to the primary Power Supply LLC Adjusts the height of the resonant converter to increase power conversion efficiency in a slim form and provides a switching power supply with high power density.

Description

[0001] SWITCHING POWER SUPPLY WITH LAMINATED STRUCTURE [0002]

The present invention relates to a switching power supply apparatus and more particularly to a switching power supply apparatus for separating a primary side and a secondary side of a power transformer and a signal transformer into a ceramic layer of a certain thickness and bonding the magnetic core to both surfaces of the ceramic layer. And the heat generated by the power semiconductor is used to induce a heat dissipation effect like a heat pipe by using the heat conduction characteristics of the ceramic layer. Thus, the slimming of the switching power supply and the high power density And more particularly to a switching power supply having a stacked structure that enables designing.

In general, switching power supplies are power converters intended for stable output voltages. In particular, an insulated switching power supply uses a transformer made of a winding having a low-conduction loss characteristic such as copper to a ferromagnetic core having a low-power-loss characteristic at a high frequency, such as a ferrite, When more than one output voltage is required, the output winding can be added to form a plurality of outputs, which is widely used in a switching power supply device requiring high efficiency.

On the other hand, since the size and volume of the switching power supply device are limited depending on the application, the various techniques for overcoming such problems have been developed. For example, when the height of the switching power supply is limited, the height of the transformer and the bobbin is lowered and the winding is made to correspond to the lowered height. In order to solve the power loss and heat generated in the core and the winding during high- A method of widening the surface area of the ferrite core or bonding the core to the case is used.

However, the heat generation of the power semiconductor and the heat generation of the device accompanied by the high frequency drive switching are obstacles to lower the height and the volume of the switching power supply.

Generally, to reduce the height of a switching power supply, it is necessary to attach components to a stacked PCB using low-profile ferrite cores and semiconductors, or to use a laminated PCB pattern to fit the transformer winding, A so-called PCB transformer using a ferrite core in a stacked PCB by routing processing is widely known.

However, the PCB transformer has advantages of simple winding structure and low height, but it can not solve the heat generated in high frequency operation. In particular, since the winding and magnetic body loss heat generated at the center of the core is difficult to be emitted outwards in the structure, Problems such as thermal runaway or thermal saturation of the magnetic core occur, and therefore, it is required to operate within a limited output range.

In addition, if there is a transformer gap in accordance with need, a material is required which provides a constant gap and maintains a uniform interval of the gap with the lapse of time, and a high electrical insulation between the primary side and the secondary side There is a problem that the electrical insulation can not be increased due to the limitation of the winding structure and manufacturing method.

CHAN, Tso-Sheng; CHEN, Chern-Lin. LLC resonant converter for wireless energy transmission system with PLL control. In: Sustainable Energy Technologies, 2008. ICSET 2008. IEEE International Conference on. IEEE, 2008. p. 136-139. HAYASHI, Yasuhiro, et al. Contactless DC connector based on ISOP-IPOS topology for high power density 380 V DC power feeding system. In: Power Electronics and Applications (EPE'14-ECCE Europe), 2014 16th European Conference on. IEEE, 2014. p. 1-10. HAYASHI, Yasuhiro, et al. Design consideration for contactless DC connector in high power density future 380 V DC distribution system. In: Energy Conversion Congress and Exposition (ECCE), 2014 IEEE. IEEE, 2014. p. 5690-5697. HAYASHI, Yasuhiro, et al. Contactless DC connector based on GaN LLC converter for next generation data centers. In: Power Electronics Conference (IPEC-Hiroshima 2014-ECCE-ASIA), 2014 International. IEEE, 2014. p. 1560-1566. ZHENG, Cong, et al. Design considerations of LLC resonant converter for contactless laptop charger. In: Applied Power Electronics Conference and Exposition (APEC), 2015 IEEE. IEEE, 2015. p. 3341-3347.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above problems and to provide a high frequency resonance type switching power supply apparatus for converting a direct current voltage into a stable direct current voltage, using an LLC resonant converter for constituting a slim type switching power supply unit having a low height A power transformer and a control circuit section are separated into a primary side and a secondary side around a transformer, a ceramic layer having the same width as the width of the power supply device and a thermosetting film A multi-layer printed circuit board constituting the primary and secondary circuits attached to the heat conductive sheet, a primary and secondary transformer combined with the patterned multi-layer printed circuit board through the ferrite magnetic core, Coupled to a multilayer printed circuit board for transferring a control signal for controlling the output of the power supply from the secondary side to the primary side Switching power supply device of the multilayer structure using a transformer hoyong adjust the height of the LLC resonant converter to enhance the power conversion efficiency in the thin state to provide a switching power supply device having a stacked structure of high power density.

According to an aspect of the present invention, there is provided a switching power supply having a laminated structure including: an LLC resonant converter used as a basic circuit of the switching power supply; A power converter and a control circuit part separated into a primary side and a secondary side of the transformer; A ceramic layer inserted between the primary side and the secondary side at a width and a thickness equal to the width of the switching power supply; A thermally conductive sheet adhered to one surface or both surfaces of the ceramic layer; A multilayer printed circuit board attached to the heat conductive sheet and constituting a circuit of each of a primary side and a secondary side of the transformer; A transformer coupled to the multilayer printed circuit board through a ferrite magnetic core to form a winding pattern; And a signal transformer coupled to the multilayer printed circuit board to transmit a control signal for controlling an output of the switching power supply device from a secondary side to a primary side of the transformer, wherein the height of the LLC resonance type converter is adjusted It is characterized in that the power conversion efficiency is increased and the power density is realized in a slim type state.

In addition, the switching power supply apparatus having a laminated structure according to the present invention is characterized in that a primary side and a secondary side of a transformer are completely separated from each other by a ceramic layer, and an adhesive heat conductive sheet for filling the rough surface of the ceramic and the rough surface of the ferrite So that the physical strength is increased and the heat generated from the magnetic core is transmitted through the heat sheet and the ceramic layer to lower the heat of the core and solve the problem of thermal runaway or thermal saturation of the core, In a safe manner.

Further, since the switching power supply device having the laminated structure according to the present invention forms a transformer winding using a circuit pattern on a multilayer printed circuit board and combines with a ferrite core to constitute a primary side or a secondary side of the transformer, The bobbin used in the printed circuit board is not required and is firmly adhered to the adhesive heat conductive sheet between the printed circuit board and the ceramic layer. Therefore, the heat generated from the printed circuit board is dissipated into the ceramic layer through the pattern of the circuit, So that the heat sink of the power supply device is not separately installed, so that it is manufactured in a slim shape.

Further, the switching power supply device having the laminated structure according to the present invention is characterized in that the power semiconductor constituting the power supply device and the control circuit elements necessary for the output control are formed on the respective surfaces of the first and second multi- So that the control signal required for the output control is transmitted to the primary side control circuit through the signal transformer. Therefore, the present invention is more suitable for the laminated structure of the present invention than the photocoupler method used in the past.

In order to achieve the above-described characteristics, the switching power supply unit having a laminated structure according to the present invention uses an LLC resonant converter, separates the power conversion unit and the control circuit unit into primary and secondary sides, A multilayer printed circuit board having a ceramic layer of the same width and a certain thickness as the width of the power supply unit, an adhesive heat conductive sheet for facilitating thermal conduction on both sides of the ceramics, a primary circuit and a secondary circuit attached to the heat conductive sheet, A multilayer printed circuit board for making a winding using a pattern on a multilayer printed circuit board, a primary and a secondary transformer coupled through a ferrite magnetic core, and a control circuit for controlling the output of the power source from the secondary side to the primary side And a signal transformer coupled to the signal transformer.

As described above, according to the present invention, an LLC resonant converter having a small power conversion loss among switching power supplies using a transformer is used, and a primary side and a secondary side of the transformer are connected to a ceramic layer, ceramic An adhesive heat conductive sheet for facilitating heat conduction on both sides, a multilayer printed circuit board constituting a primary circuit and a secondary circuit attached to the heat conductive sheet, a multilayer printed circuit board on which a pattern is formed and a ferrite magnetic core And the first and second transformers are combined with each other. Therefore, the heat generated from the transformer and the power semiconductor can be dissipated to the outside through the ceramic layer.

Further, since the present invention is combined with an adhesive thermally conductive sheet that fills the rough surface of the ceramic layer between the primary side and the secondary side of the transformer and the rough surface of the ferrite core, the physical strength is increased, The heat is transmitted through the heat sheet and the ceramic layer, so that the heat of the core can be lowered and the thermal runaway or heat saturation of the core can be prevented.

Further, since the transformer winding is formed by using the pattern of the circuit on the multilayer printed circuit board and the transformer winding is formed and combined with the ferrite core to constitute the primary side or the secondary side of the transformer, the bobbin used in the normal winding type transformer becomes unnecessary, The heat generated from the printed circuit board is dissipated through the pattern of the circuit and the through hole into the ceramic layer. Therefore, the heat radiation plate of the power supply device is installed separately So that it can be manufactured in a slim shape.

Further, since the control circuit elements are attached to the respective surfaces of the first and second multi-layer printed circuit boards described above, there is no mutual interference, and in particular, a control signal required for output control is supplied to the primary side control circuit It is suitable for the laminated structure of the present invention as compared with the conventional photocoupler method. As a result, due to the effective lamination structure and the heat dissipation structure, internal heat generation of the switching power supply is lowered, , And a high efficiency power supply device can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a basic configuration diagram of a full bridge LLC resonant converter having a synchronous rectifier to which the present invention is applied;
FIG. 2 is a main operation waveform diagram of a full bridge LLC resonant converter of FIG. 1,
FIG. 3 is a basic circuit diagram of a full bridge LLC resonant converter separated around a gap of a transformer to which the present invention is applied.
FIG. 4 is a conceptual diagram of a full bridge LLC resonant converter and a control circuit separated from each other by a gap of a transformer to which the present invention is applied and a ceramic layer,
5 is a view showing a stacked structure of a full bridge LLC resonant converter and a control circuit separated from each other by a gap of a transformer to which the present invention is applied and a ceramic layer,
6 is a diagram showing the outline of a switching power supply apparatus having a laminated structure according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a switching power supply apparatus having a laminated structure according to the present invention will be described in detail with reference to the drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS The same features of the Figures represent the same reference symbols wherever possible. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, the attached drawings are exaggerated or simplified in order to facilitate understanding and clarification of the structure and operation of the technology, and it is to be understood that each component does not exactly coincide with the actual size.

The terms first, second, etc. may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In addition, when an element is referred to as including an element, it is understood that the element may include other elements, not the other element, unless specifically stated otherwise, and the meaning of the term " Means a unit or module type that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It is to be understood that the same terms as those defined in the commonly used terms are defined in consideration of the functions of the present invention and are to be construed in accordance with the technical idea of the present invention and the meaning commonly understood or commonly recognized in the technical field And is not to be construed as an ideal or overly formal sense unless expressly defined to the contrary.

FIG. 1 is a basic configuration diagram of a full bridge LLC resonant converter having a synchronous rectifier to which the present invention is applied, FIG. 2 is a main operation waveform diagram of a full bridge LLC resonant converter of FIG. 1 Fig.

1, a full bridge LLC resonant converter having a synchronous rectifier to which the present invention is applied includes a DC input voltage Vs and four switches Q1 to Q4 constituting a full bridge, Two resonance inductors L _R and L _M and one resonance capacitor C _R1 are constituted on the primary side of the transformer T 1 and four switches Q a through Q d are connected on the secondary side of the single- One output capacitor (C _O ) for stabilizing the output voltage, and a load resistor (R _L ) for consuming the output power constitute a full-wave rectifier.

2, when the control signals V _G1 and V _G2 for driving the four switches Q1 to Q4 are applied by an external control circuit, three resonance elements L _R , L _M , The primary current i _LP and the resonant current i _LR of the transformer T1 are generated by C _R1 and the two currents appear as sinusoidal waveforms due to the resonance. On the other hand, currents i _DR1 and i _DR2 , which are rectified in the half-wave rectification mode, are supplied to the respective switches on the secondary side of the transformer T1 due to the rectifying function of the full-wave rectifier, At the same time, since the switch voltages V _DR1 and V _{DR2 take the} same voltage as the output voltage V _O during the current does not flow, the two rectifier switch voltages V _DR1 , V _DR2 ) is divided.

Therefore, as can be seen from the circuit diagram and operation waveform of the full bridge LLC resonant converter having the synchronous rectifier of FIGS. 1 and 2, the four rectifier switches Qa-Qd existing on the secondary side of the transformer T1 are switched The current flows only during the half period, and it is understood that the voltage equivalent to the output voltage is applied while the current does not flow.

Generally, when the transformer is constructed, the coupling ratio of the transformer does not become an ideal state, so there is a leakage inductance as low as the coupling ratio. Therefore, by appropriately adjusting the coupling ratio of the transformer, the two resonant inductors L _R and L _M mentioned in FIG. 1 can be made in the transformer T 1, so that the number of external elements can be reduced, . For this purpose, a gap is formed between the ferrite magnetic core used in the transformer to control the coupling ratio and the inductance of the transformer.

FIG. 3 is a basic circuit diagram of a full bridge LLC resonant converter separated around a gap of a transformer according to the present invention. FIG. 4 is a schematic circuit diagram of a full bridge LLC resonant converter, A full bridge LLC resonant converter and a control circuit will be described in detail with reference to FIGS. 3 and 4. FIG.

As described above with reference to FIGS. 1 and 2, by appropriately providing a gap in the core of the transformer and controlling it, two resonant inductors L _R and L _M become unnecessary. Therefore, as shown in FIG. 3, And a simple structure in which only the primary winding and the secondary winding exist is possible. At this time, a material of a material which does not deform the magnetic flux is inserted between the magnetic cores of the transformer to control the coupling ratio and to make a gap that matches the design value with the inductance and the winding ratio.

4, a ceramic layer 115 is inserted as much as the required thickness of the gap between the primary side and the secondary side of the transformer separated by the air gap in FIG. 3, and the area of the ceramic layer 115 is connected to the power source As shown in FIG.

4, when a DC voltage is applied to the input voltage terminals 111 and 112 of the full bridge LLC resonant converter, four switches Q1 to Q4 are controlled and switched by the primary side control circuit 121 And a resonance circuit 113 required for resonance is configured in series between the four switches Q1-Q4 and the primary-side transformer 114. [

The winding of the transformer primary side 114 is formed by using a pattern of a multilayer printed circuit board, and the core is formed by inserting a magnetic core into the printed circuit board by grooving a groove with a router or the like. The transformer secondary side 116 is formed in the same manner as the transformer primary side 114 and the ceramic layer 115 is formed between the cores of the transformer primary side 114 and the transformer secondary side 116.

At this time, an adhesive heat conductive sheet is preferably attached to one side or both sides of the ceramic layer 115 to smooth the heat conduction between the core of the transformer primary 114 and the multilayer printed circuit board on which the windings are formed.

An impedance coupling circuit 117 for stabilizing the output waveform is connected in series to the transformer secondary side 116 and a rectifying element such as a diode or a MOSFET is connected between the impedance coupling circuit 117 and the output voltage terminals 118 and 119, A power conversion circuit using an element is constituted.

In order to stabilize the output voltage, it is preferable that the secondary side control circuit 124 for transferring necessary output information to the primary side control circuit 121 and the communication port 125 for transferring information to the outside are further provided .

The switching power supply apparatus having the laminated structure according to the present invention may be configured such that the primary side control circuit 121 and the secondary side control circuit 124 ) Using a transformer (122, 123). Thus, the lamination structure of the switching power supply unit is realized by sharing the ceramic layer 115. [

5 is a view showing a laminate structure of a full bridge LLC resonant converter 110 and its control circuit 120 separated from each other with respect to a gap of a transformer and a ceramic layer according to the present invention, And FIG. 6 is a diagram showing the outline of a switching power supply apparatus having a laminated structure according to the present invention. Hereinafter, the configuration of a switching power supply apparatus having a laminated structure according to the present invention will be described in detail with reference to FIGS. 5 and 6. FIG.

The full bridge LLC resonant converter 110 and the control circuit 120 separated from each other by the gap of the transformer described above can be divided into separate functions and separated into separate layers. Hereinafter, from the uppermost layer to the lowermost layer 211 to 233 ).

5, the switching power supply unit having a laminated structure according to the present invention is broadly divided into a power transformer primary power control circuit unit 210, a transformer secondary power control circuit unit 230, And a power conversion transformer unit 220.

First, the first layer of the transformer primary power control circuit portion 210 is a printed circuit board layer 211 for coupling the transformer primary components with circuit elements and control circuit elements required for primary power conversion, and the second layer A multilayer printed circuit board layer 212 for connecting the transformer primary circuit to each of the elements according to a circuit, and a third layer is a primary electromagnetic shielding layer 213 for preventing interference of signals generated from the magnetic body.

Next, the power conversion transformer unit 220 includes a primary-side transformer layer 221 coupled with a winding core and a magnetic-material core using a multilayer printed circuit board to constitute a transformer winding, And a secondary side transformer layer 223 having a winding core and a magnetic material core coupled to each other using a multilayer printed circuit board for constituting the secondary side winding of the transformer.

The transformer secondary power control circuit unit 230 includes a secondary electromagnetic wave shielding layer 231 for preventing interference of signals generated by the magnetic body, a multilayer printed circuit board layer 232 for coupling the secondary circuit to be coupled to each element, And a printed circuit board layer 233 for secondary-side element bonding with circuit elements and control circuit elements required for power conversion on the vehicle side.

FIG. 6 is an external view of a switching power supply apparatus having a laminated structure according to the present invention. The transformer primary power control circuit unit 210, the power conversion transformer unit 220, and the transformer secondary power control circuit unit 230 are stacked Lt; / RTI > switching power supply. 6, a switching power supply unit having a stacked structure according to the present invention is provided with an input / output terminal 240 for transmitting power of an input and an output, and ultimately uses a switching power supply as a single component And the heat generated from the power conversion element, the transformer, and the winding is discharged to the outside through the ceramic layer 222 to reduce the internal heat generation of the switching power supply unit, thereby providing a high efficiency power supply unit having high reliability and high durability.

6, a coating layer for sealing the outside of the stacked switching power supplies may be further formed.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

Claims (9)

DC input voltage terminal,
A bridge type switching circuit,
The resonance circuit,
A power conversion transformer,
Rectifiers and
An LLC resonant converter configured by a DC output voltage terminal;
A primary side control circuit for controlling the bridge type switching circuit,
A secondary side control circuit for transmitting output information necessary for the primary side control circuit and
A control circuit part comprising a signal transformer for transmitting the output information from the secondary side control circuit to the primary side control circuit; And
The power conversion transformer and the signal transformer are inserted with the same thickness as the thickness of the gap formed between the primary side and the secondary side of the transformer for power conversion and the signal transformer with the same width as the width of the board formed with the converter and the control circuit portion, And a ceramic layer to which an adhesive thermally conductive sheet for thermal conduction with the primary side core of the transformer and the printed circuit board on which the winding is formed is attached.
delete 2. The apparatus of claim 1,
And an impedance coupling circuit for stabilizing a waveform of a secondary output signal of the power conversion transformer is further provided in series.
2. The secondary battery according to claim 1, wherein the secondary-
And a communication port for transmitting information to the outside is further provided.
An LLC resonant converter configured by a DC input voltage terminal, a bridge type switching circuit, a resonant circuit, a power conversion transformer, a rectifier and a DC output voltage terminal; A primary side control circuit for controlling the bridge type switching circuit; a secondary side control circuit for transmitting output information necessary for the primary side control circuit; and a secondary side control circuit for transmitting the output information from the secondary side control circuit to the primary side control circuit And a control circuit part composed of a signal transformer,
A printed circuit board layer for primary side element attachment with circuit elements and control circuit elements required for primary side power conversion;
A printed circuit board layer for connecting the primary side circuit to connect the elements mounted on the primary side element coupling printed circuit board layer according to a circuit;
A primary electromagnetic wave shielding layer for shielding signal interference generated from the following primary magnetic core;
A primary transformer layer formed with the primary winding and the magnetic core of the power conversion and signal transformer;
A ceramic layer for providing a gap necessary for the power conversion and the signal transformer and facilitating attachment of the core;
A secondary-side transformer layer formed with a secondary-side winding of the power conversion and signal transformer and a magnetic material core;
A secondary electromagnetic wave shielding layer for shielding signal interference generated from the secondary magnetic body core;
A printed circuit board layer for connecting a secondary side circuit for connecting the elements mounted on the printed circuit board layer for secondary side element bonding according to a circuit;
And a printed circuit board layer for coupling a secondary side element with circuit elements and control circuit elements required for secondary side power conversion.
6. The method of claim 5,
And an adhesive heat conductive sheet for thermal conduction with the primary-side transformer layer is further formed on one surface of the ceramic layer.
6. The apparatus of claim 5,
And an impedance coupling circuit for stabilizing a waveform of a secondary output signal of the power conversion transformer is further provided in series.
6. The secondary-side control circuit according to claim 5,
And a communication port for transmitting information to the outside is further provided.
6. The printed wiring board according to claim 5, wherein the printed circuit board layer for secondary-
And an input / output terminal for transmitting power of an input and an output.

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