CN217335443U

CN217335443U - Isolated DC-DC converter module based on ceramic planar transformer

Info

Publication number: CN217335443U
Application number: CN202220856498.1U
Authority: CN
Inventors: 周少荣; 苏红娟; 杨尚兵; 杨通林; 蒋胜勇; 陈睿弘; 曾玲辉; 陈昌芃
Original assignee: Fenghua Research Institute Guangzhou Co ltd
Current assignee: Guangdong Xintao Microelectronics Co.,Ltd.
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2022-08-30
Anticipated expiration: 2032-04-14

Abstract

The utility model discloses an isolated DC-DC converter module based on ceramic planar transformer, through embedded manifold type vary voltage component in ceramic substrate, recycle ceramic substrate and carry on transformer drive device as I C support plate, a switch device, input capacitance, various components and parts such as output capacitance, set up the pad region on ceramic substrate's first surface, set up input pad on ceramic substrate's second surface, output pad and ground pad, set up the electric conductor in ceramic substrate's inside, with at least any one of input pad, output pad and ground pad through electric conductor connection to the pad region, with drive device, a switch device, input capacitance, various components and parts such as output capacitance accomplish circuit layout in the pad region in order to constitute isolated DC-DC conversion circuit topology jointly, thereby realized that isolated DC-DC converter module has miniaturized, Modularization, high reliability, low cost of batch production and the like.

Description

Isolated DC-DC converter module based on ceramic planar transformer

Technical Field

The utility model relates to a DC-DC converter technical field especially relates to an isolated DC-DC converter module based on ceramic planar transformer.

Background

The DC-DC converter is the basis of electric energy conversion, and is one of the most important power electronic devices in electric energy conversion of ICT, railway, new energy, electric vehicles, industrial control, artificial intelligence, audio and other industries.

In each market segment, the diversification and high development rhythm of the demand put higher demands on the miniaturization, modularization and high reliability of the DC-DC converter. The traditional isolated DC-DC converter module generally adopts a winding transformer, has larger size and is difficult to adapt to the miniaturization trend of the DC-DC converter module; the planar transformer based on the PCB has no traditional winding framework, has smaller volume and gradually becomes the mainstream of a miniaturized isolation type DC-DC converter module.

In recent years, the volume of the integrated die-casting coupling type transformer becomes smaller, the volume of an isolated DC-DC converter module is further reduced, but only two-dimensional rather than three-dimensional circuit layout can be carried out, and the size of the module is large; secondly, since the insulating performance of the resin type substrate is limited, the distance between the conductors needs to be increased to increase the withstand voltage, and thus there are problems of increase in the module volume and increase in the cost.

Content of application

The utility model provides an isolated DC-DC converter module based on ceramic planar transformer aims at solving the bulky problem of current DC-DC converter module.

In a first aspect, the present invention provides an isolated DC-DC converter module based on a ceramic planar transformer, which is characterized by comprising: the ceramic substrate comprises a plurality of ceramic layers, at least one layer of ceramic layer is printed with a primary coil, at least one layer of ceramic layer is printed with a secondary coil, and the plurality of ceramic layers are laminated so that the primary coil and the secondary coil are coupled to form a coupling type transformer; the ceramic substrate is provided with a first surface and a second surface which are opposite to each other, and the connecting ends of the primary side coil and the secondary side coil are connected to the first surface; a pad area formed on the first surface, the pad area being electrically connected to a connection end of the primary coil and the secondary coil; an isolated DC-DC conversion circuit topology, comprising: the primary side coil and the secondary side coil, as well as a switching element, an input capacitor, an output capacitor and a driving device, wherein the switching element, the input capacitor, the output capacitor and the driving device are all arranged in the pad area; the input bonding pad, the output bonding pad and the grounding bonding pad are arranged on the second surface; a conductor provided inside the ceramic substrate so as to penetrate the first surface and the second surface; wherein at least any one of the input pad, the output pad, and the ground pad on the second surface is connected to the pad region on the first surface through the electrical conductor to implement a circuit layout of the isolated DC-DC conversion circuit topology.

Furthermore, the isolated DC-DC conversion circuit topology is a flyback type, the switching element comprises a first switching tube and a first diode, the number of the grounding bonding pads is two, the two grounding bonding pads are respectively a first grounding bonding pad and a second grounding bonding pad, and the number of turns of the primary side coil is greater than that of the secondary side coil; the input pad is connected with one end of the input capacitor through a conductor, one end of the input capacitor is also connected with the dotted end of the primary coil, the first grounding pad is connected with the other end of the input capacitor through a conductor, and the other end of the input capacitor is also connected to the dotted end of the primary coil through the first switching tube; the output pad is connected with one end of the output capacitor through a conductor, one end of the output capacitor is also connected with the cathode of the first diode, the anode of the first diode is connected with the different name end of the secondary coil, the second grounding pad is connected with the other end of the output capacitor through a conductor, and the other end of the output capacitor is also connected with the same name end of the secondary coil.

Further, the first switch tube is an NMOS tube, a drain electrode of the NMOS tube is connected to the synonym terminal of the primary coil, a source electrode of the NMOS tube is connected to the other end of the input capacitor, and a gate electrode of the NMOS tube is connected to a PWM signal.

Furthermore, the isolated DC-DC conversion circuit topology is a boost type, the switching element includes a first switching tube and a first diode, the number of the ground pads is two, the two ground pads are respectively a first ground pad and a second ground pad, and the number of turns of the primary coil is less than that of the secondary coil; the input pad is connected with one end of the input capacitor through a conductor, one end of the input capacitor is also connected with the dotted end of the primary coil, the first grounding pad is connected with the other end of the input capacitor through a conductor, and the other end of the input capacitor is also connected to the dotted end of the primary coil through the first switching tube; the output pad is connected with one end of the output capacitor through a conductor, one end of the output capacitor is also connected with the cathode of the first diode, the anode of the first diode is connected with the different name end of the secondary coil, the second grounding pad is connected with the other end of the output capacitor through a conductor, and the other end of the output capacitor is also connected with the same name end of the secondary coil.

Furthermore, the isolated DC-DC conversion circuit topology is a buck type, the switching element includes a first switching tube, a second switching tube and a first diode, the number of the ground pads is three, which are respectively a first ground pad, a second ground pad and a third ground pad, and the number of the output capacitors is two, which are respectively a first output capacitor and a second output capacitor; the number of the output bonding pads is two, and the output bonding pads are respectively a first output bonding pad and a second output bonding pad; the input pad is connected with one end of the input capacitor through an electric conductor, one end of the input capacitor is also connected with the homonymous end of the primary coil through the first switch tube, the first grounding pad is connected with the other end of the input capacitor through an electric conductor, the other end of the input capacitor is also connected with the homonymous end of the primary coil through the second switch tube, the first output pad is connected with the synonym end of the primary coil through an electric conductor, the second grounding pad is connected with one end of the first output capacitor through an electric conductor, and the other end of the first output capacitor is connected with the synonym end of the primary coil; the second output pad is connected with one end of the second output capacitor through a conductor, one end of the second output capacitor is further connected with the cathode of the first diode, the anode of the first diode is connected with the different name end of the secondary coil, the third grounding pad is connected with the other end of the second output capacitor through a conductor, and the other end of the second output capacitor is further connected with the same name end of the secondary coil.

Further, the first switch tube and the second switch tube are any one of a triode, an MOS tube and an IGBT.

Further, the conductor includes a through hole penetrating the first surface and the second surface, and a conductive material filled in the through hole.

Further, the electric conductor is equivalent to an inductance element.

Further, the ceramic layers printed with the primary coil and the ceramic layers printed with the secondary coil are alternately laminated; and/or the ceramic layers printed with the primary coil are continuously laminated to form a first folding layer, the ceramic layers printed with the secondary coil are continuously laminated to form a second folding layer, and the first folding layer and the second folding layer are alternately laminated; and/or the number of the ceramic layers printed with the primary coil is greater than or less than or equal to the number of the ceramic layers printed with the secondary coil.

Compared with the prior art, the beneficial effects of the utility model are that: by embedding the coupling type transformer element in the ceramic substrate and using the ceramic substrate as an IC carrier board to carry various components such as transformer driving device, switching element, input capacitor, output capacitor, etc., providing a pad region on a first surface of the ceramic substrate, providing an input pad, an output pad and a ground pad on a second surface of the ceramic substrate, an electric conductor is provided inside the ceramic substrate, at least one of the input pad, the output pad and the ground pad is connected to the pad region through the electric conductor, and various components such as driving device, switching device, input capacitor and output capacitor, etc. in the bonding pad region to complete circuit layout to form isolated DC-DC conversion circuit topology, therefore, the isolated DC-DC converter module has the advantages of miniaturization, modularization, high reliability, low cost in batch production and the like.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without any creative effort.

Fig. 1 shows a schematic diagram of an isolated DC-DC converter module according to an embodiment of the present invention;

fig. 2 shows a circuit diagram of a flyback topology of an isolated DC-DC converter module according to an embodiment of the present invention;

FIG. 3 shows the circuit diagram of FIG. 2 connected to an electrical conductor;

fig. 4 shows a circuit diagram of a boost topology of an isolated DC-DC converter module according to an embodiment of the present invention;

FIG. 5 shows a circuit diagram of FIG. 4 connected to an electrical conductor;

fig. 6 shows a circuit diagram of a buck topology of an isolated DC-DC converter module according to an embodiment of the present invention;

10. a ceramic substrate; 101. a first surface; 102. a second surface; 11. a switching element; 12. a coupling transformer; (L1, L2, L3, L4), a conductor.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts all belong to the protection scope of the present invention.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in the specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

The embodiment of the utility model provides a through providing an isolated DC-DC converter module based on ceramic planar transformer, solved current DC-DC converter module bulky and with high costs problem, through carrying on DC-DC converting circuit topology on the ceramic substrate including inlaying manifold type voltage transformation component and realized advantages such as the miniaturization of isolated DC-DC converter module, modularization, high reliability, batch production low cost.

The embodiment of the utility model provides an in technical scheme for solving above-mentioned bulky, with high costs problem, the general thinking is as follows:

by embedding the coupling type transformer element in the ceramic substrate and using the ceramic substrate as an I C carrier board to carry various components such as transformer driving device, switching device, input capacitor, output capacitor, etc., providing a pad region on a first surface of the ceramic substrate, providing an input pad, an output pad and a ground pad on a second surface of the ceramic substrate, an electric conductor is provided inside the ceramic substrate, at least one of the input pad, the output pad and the ground pad is connected to the pad region through the electric conductor, and various components such as driving device, switching device, input capacitor and output capacitor, etc. in the bonding pad region to complete circuit layout to form isolated DC-DC conversion circuit topology, therefore, the isolated DC-DC converter module has the advantages of miniaturization, modularization, high reliability, batch production, low cost and the like.

In order to better understand the technical solution, the technical solution will be described in detail with reference to the drawings and the specific embodiments.

Referring to fig. 1, the present embodiment provides an isolated DC-DC converter module based on a ceramic planar transformer, which includes: the ceramic substrate 10 comprises a plurality of ceramic layers, at least one layer of the ceramic layers is printed with a primary coil, at least one layer of the ceramic layers is printed with a secondary coil, and the ceramic layers are laminated so that the primary coil and the secondary coil are coupled to form a coupling type transformer 12; the ceramic substrate 10 has a first surface 101 (top surface) and a second surface 102 (bottom surface) opposite to each other, and connection terminals of the primary coil and the secondary coil are connected to the first surface 101; a pad area (not shown) formed on the first surface 101, the pad area electrically connecting the connection ends of the primary coil and the secondary coil; an isolated DC-DC conversion circuit topology, comprising: the primary coil and the secondary coil, as well as a switching element 11, an input capacitor and an output capacitor, wherein the switching element 11, the input capacitor and the output capacitor are all arranged in the pad area; an input pad, an output pad, and a ground pad, all disposed on the second surface 102; a conductor provided inside the ceramic substrate 10 so as to penetrate the first surface 101 and the second surface 102; wherein at least any one of the input pads, the output pads, and the ground pads on the second surface 102 are connected to the pad regions on the first surface 101 through the electrical conductors to implement a circuit layout of the isolated DC-DC conversion circuit topology.

By implementing the present embodiment, the planar transformer formed inside the ceramic substrate 10 has the advantages of smaller volume and mass, more flexible design, higher quality factor, better stability, higher integration level, etc., compared with the conventional wound transformer, the integral die-cast transformer, etc. The isolated DC-DC converter module formed by mounting various components such as a transformer driver, a switching device, an input capacitor, and an output capacitor on the ceramic substrate 10 embedded with the coupling transformer 12 as an IC carrier has the advantages of miniaturization, modularization, high reliability, low cost in mass production, and the like.

The ceramic substrate 10 in this embodiment is an LTCC (low temperature co-fired ceramic), which belongs to a novel material technology, and is manufactured by manufacturing low temperature sintered ceramic powder into a green ceramic tape with precise and compact thickness, manufacturing a required circuit pattern on the green ceramic tape by using processes such as laser drilling, micropore grouting, and precise conductor paste printing, and embedding a plurality of passive components (such as low-capacitance capacitors, resistors, filters, impedance converters, couplers, and the like) into the multilayer ceramic substrate 10, and then laminating the green ceramic tape and the green ceramic tape together, wherein the inner and outer electrodes can be respectively made of metals such as silver, copper, gold, and the like, and sintered at 900 ℃ to manufacture a high-density circuit with three-dimensional space without mutual interference, or a three-dimensional circuit substrate with passive elements built in, and an IC and an active device can be pasted on the surface to manufacture a passive/active integrated functional module, so as to further miniaturize and densify the circuit, particularly suitable for use in components for high frequency communications.

The ceramic substrate 10 has a coupling type transformer embedded therein, and is specifically manufactured by providing a plurality of ceramic layers, each of which is printed with a coil to obtain a primary coil or a secondary coil, in a manner that a through hole for accommodating a magnetic core is formed in the ceramic layer, the coil extends around the magnetic core (the coil is, for example, circular-arc-shaped or semi-arc-shaped), the coil is connected to a guide post, and the coils between the ceramic layers are connected by the guide post. Wherein the size of the magnetic core is in the range of 3.8mm × 3.8mm × 0.9mm and 5.4mm × 5.4mm × 1.8mm, and the shape of the magnetic core may be circular, rectangular, elongated ring-shaped, etc. Different sizes and shapes and different winding modes of the coil can reduce eddy current loss and hysteresis loss and improve pressure resistance, and the coil is specifically arranged according to actual requirements. One part of the ceramic layer is used as a primary coil, and the other part of the ceramic layer is used as a secondary coil to be coupled to form the transformation element. And finally, laminating and pressing a plurality of ceramic layers to finally form the ceramic substrate 10 embedded with the coupling type transformation element.

It should be noted that the coupling coefficient of the embedded coupling transformer 12 can be set by adjusting the coupling position and orientation of the primary coil and the secondary coil, and each parameter can be adjusted within a certain range, thereby increasing the flexibility of design. Specifically, the ceramic layers printed with the primary coil and the ceramic layers printed with the secondary coil are alternately laminated, that is, alternately laminated two by two. Or the ceramic layers printed with the primary coil are continuously laminated to form a first laminated layer, the ceramic layers printed with the secondary coil are continuously laminated to form a second laminated layer, and the first laminated layer and the second laminated layer are alternately laminated, namely after the ceramic layers of the primary coil are laminated, the ceramic layers of the primary coil and the secondary coil are alternately laminated. The lamination of the ceramic layers can be combined at will, the sequence of the lamination of the ceramic layers is changed, the coupling coefficient of the transformer can be changed, customized parameter adjustment can be realized, and the personalized requirements of customers are met. In addition, the turn ratio of the primary coil and the secondary coil can be increased or decreased by controlling the number of the ceramic layers. Specifically, the number of ceramic layers on which the primary coil is printed is greater than or equal to or less than the number of ceramic layers on which the secondary coil is printed. For example, the turn ratio can be 1:2,1:1 or 2:1, etc.

The ceramic substrate 10 of the coupling transformer 12 embedded in the present embodiment can effectively reduce the volume of the isolated DC-DC converter module, realize miniaturization and low cost mass production, and fully utilize the characteristics of low thermal expansion, high voltage resistance, good heat dissipation, and the like of ceramics. And the composition of the ceramic substrate 10 can be changed, and substrates with different electrical properties can be generated according to different ingredients of the dielectric material.

In an embodiment, referring to fig. 1, the conductive body L includes a through hole penetrating through the first surface 101 and the second surface 102 and a conductive material filled in the through hole. The conductor is equivalent to an inductance element. A connection wiring line formed by connecting at least one of an input terminal, an output terminal, and a ground terminal to a land region on the first surface 101 by a conductor inside the ceramic substrate 10 has a large inductance component.

In the present embodiment, an isolated DC-DC converter circuit topology is formed by the switching element 11, the input capacitor, the output capacitor, and the input pad, the output pad, and the ground pad mounted on the ceramic substrate 10. The topology of the isolated DC-DC converter circuit topology is various, for example, Buck, Boost, flyback, forward, half bridge, full bridge, etc., and any type of topology, as long as it is implemented by using an isolated coupling transformer, falls within the protection scope of the present application, and is not limited herein. Several of these topologies are described below.

In one embodiment, referring to fig. 2 and 3, the isolated DC-DC converter circuit topology is a flyback type, the switching element includes a first switching tube Q and a first diode D, the number of the ground pads is two, the ground pads are respectively a first ground pad and a second ground pad, and the number of turns of the primary coil is greater than that of the secondary coil; the input pad is connected with one end of the input capacitor through a conductor, one end of the input capacitor is also connected with the dotted end of the primary coil, the first grounding pad is connected with the other end of the input capacitor through a conductor, and the other end of the input capacitor is also connected to the dotted end of the primary coil through the first switching tube; the output pad is connected with one end of the output capacitor through a conductor, one end of the output capacitor is also connected with the cathode of the first diode, the anode of the first diode is connected with the different name end of the secondary coil, the second grounding pad is connected with the other end of the output capacitor through a conductor, and the other end of the output capacitor is also connected with the same name end of the secondary coil. The first switch tube is an NMOS tube, the drain electrode of the NMOS tube is connected with the synonym end of the primary coil, the source electrode of the NMOS tube is connected with the other end of the input capacitor, and the grid electrode of the NMOS tube is connected with a PWM signal. In other embodiments, the first switch tube may also be a transistor, an IGBT, or other switch elements.

Specifically, the isolated DC-DC converter module may implement flyback-type (flyback-type) DC-DC conversion and is connected to the top pad region by at least one of the bottom input pad, the bottom output pad, or the bottom ground pad to form a flyback-type circuit layout. Fig. 2 is a circuit diagram of an isolated flyback type DC-DC converter module based on a ceramic planar transformer with an input voltage source connected to an input terminal VIN. The flyback type DC-DC converter is composed of a circuit including a switching device Q and a diode D, a coupling transformer (a primary winding N1, a secondary winding N2), an input filter capacitor Cin at an input end, and an output filter capacitor Cout at an output end. In fig. 1,

bottom pads

1, 2, 3, and 4 are provided on the bottom of a ceramic substrate 10, pad regions are provided on the top, and a primary coil N1 and a secondary coil N2 of a coupled transformer, which connect the bottom pads and the top pads, and conductors L1, L2, L3, and L4 are formed inside the ceramic substrate. The conductors L1, L2, L3, and L4 are formed of through holes, which are equivalent inductances L1, L2, L3, and L4 in fig. 3. An isolated flyback DC-DC converter module based on a ceramic planar transformer is characterized in that a ceramic substrate (10) internally forming a coupling transformer (a primary coil N1 and a secondary coil N2) is used as a carrier plate, an input filter capacitor Cin is carried at the input end of the top of the ceramic substrate, an output filter capacitor Cout is carried at the output end of the ceramic substrate, and a circuit comprising a switching element Q and a diode D is further arranged. The input end of the DC-DC converter module is connected with an input voltage source. In fig. 1, the input terminal VIN corresponds to the bottom terminal 1, the output terminal VOUT corresponds to the bottom terminal 3, and the ground terminal corresponds to the bottom terminals 2 and 4. The switching element 11 includes a first switching tube Q and a rectifying diode D. The main power source of the isolated flyback DC-DC converter module based on the ceramic planar transformer is that energy at an input end is stored in a coupling transformer when a first switching tube Q is switched on, and D is blocked due to the negative voltage of D for a secondary side. When the first switch Q is turned off, energy is transferred to the secondary side through the secondary side N2, forcing it D to conduct, and the secondary side will directly output a voltage to the output capacitor. Through this embodiment, realized isolation type flyback type DC-DC converter module, had advantages such as miniaturization, modularization, high reliability, batch production low cost.

In one embodiment, referring to fig. 3 and 5, the isolated DC-DC conversion circuit topology is a boost type, the switching element includes a first switching tube Q and a first diode D, the number of the ground pads is two, the ground pads are respectively a first ground pad and a second ground pad, and the number of turns of the primary coil is less than that of the secondary coil; the input pad is connected with one end of the input capacitor through a conductor, one end of the input capacitor is also connected with the dotted end of the primary coil, the first grounding pad is connected with the other end of the input capacitor through a conductor, and the other end of the input capacitor is also connected to the dotted end of the primary coil through the first switching tube; the output pad is connected with one end of the output capacitor through a conductor, one end of the output capacitor is also connected with the cathode of the first diode, the anode of the first diode is connected with the different name end of the secondary coil, the second grounding pad is connected with the other end of the output capacitor through a conductor, and the other end of the output capacitor is also connected with the same name end of the secondary coil. The first switch tube is an NMOS tube, the drain electrode of the NMOS tube is connected with the synonym end of the primary coil, the source electrode of the NMOS tube is connected with the other end of the input capacitor, and the grid electrode of the NMOS tube is connected with a PWM signal. In other embodiments, the first switch tube may also be a transistor, an IGBT, or other switch elements.

Specifically, the isolated DC-DC converter module may implement a boost type DC-DC conversion and is connected to the top pad region by at least one of a bottom input pad, a bottom output pad, or a bottom ground pad to form a boost type circuit layout. Fig. 4 is a circuit diagram of an isolated boost-type DC-DC converter module based on a ceramic planar transformer with an input voltage source connected to the input terminal VIN. The boost type DC-DC converter is composed of a circuit including a switching device Q and a diode D, a coupling transformer (a primary winding N1, a secondary winding N2, N1< N2), an input filter capacitor Cin at an input end, and an output filter capacitor Cout at an output end. In fig. 1,

bottom terminals

1, 2, 3, and 4 are provided on the bottom of a ceramic substrate 10, a top electrode (the pattern of which is not specifically shown) is provided on the top, and a primary coil N1 and a secondary coil N2 of a coupling transformer, which connect the bottom and the top, and conductors L1, L2, L3, and L4 are formed inside the ceramic substrate. The conductors L1, L2, L3, and L4 are formed of through holes, which in fig. 5 are equivalent inductances L1, L2, L3, and L4. An isolated boost-type DC-DC converter module based on a ceramic planar transformer is composed of a ceramic substrate (10) which is internally provided with a coupling transformer (a primary coil N1, a secondary coil N2 and N1< N2) as a carrier plate, an input filter capacitor Cin is arranged at the input end of the top of the ceramic substrate, an output filter capacitor Cout is arranged at the output end of the ceramic substrate, and a circuit which comprises a switching element Q and a diode D. The input end of the DC-DC converter module is connected with an input voltage source. In fig. 1, the input terminal VIN corresponds to the bottom terminal 1, the output terminal VOUT corresponds to the bottom terminal 3, and the ground terminal corresponds to the bottom terminals 2 and 4. The switching element includes a first switching tube Q and a rectifying diode D. Through the embodiment, the isolated boost type DC-DC converter module is realized, and the isolated boost type DC-DC converter module has the advantages of miniaturization, modularization, high reliability, low cost in batch production and the like.

In one embodiment, referring to fig. 6, the isolated DC-DC conversion circuit topology is a buck type, the switching element includes a first switching tube Q1, a second switching tube Q2 and a first diode D, the number of the ground pads is three, and the ground pads are respectively a first ground pad, a second ground pad and a third ground pad, and the number of the output capacitors is two, and the output capacitors are respectively a first output capacitor and a second output capacitor; the number of the output bonding pads is two, and the output bonding pads are respectively a first output bonding pad and a second output bonding pad; the input pad is connected with one end of the input capacitor through an electric conductor, one end of the input capacitor is also connected with the homonymous end of the primary coil through the first switch tube, the first grounding pad is connected with the other end of the input capacitor through an electric conductor, the other end of the input capacitor is also connected with the homonymous end of the primary coil through the second switch tube, the first output pad is connected with the synonym end of the primary coil through an electric conductor, the second grounding pad is connected with one end of the first output capacitor through an electric conductor, and the other end of the first output capacitor is connected with the synonym end of the primary coil; the second output bonding pad is connected with one end of the second output capacitor through a conductive body, one end of the second output capacitor is further connected with the cathode of the first diode, the anode of the first diode is connected with the different name end of the secondary coil, the third grounding bonding pad is connected with the other end of the second output capacitor through a conductive body, and the other end of the second output capacitor is further connected with the same name end of the secondary coil. The first switch tube and the second switch are any one of a triode, an MOS tube and an IGBT.

Specifically, the isolated DC-DC converter module can realize a flybuck type DC-DC conversion, and is connected with a top pad area by at least one of a bottom input pad, a bottom output pad or a bottom grounding pad to form a flybuck type circuit layout. Fig. 6 is a circuit diagram of an isolated flybuck type DC-DC converter module based on a ceramic planar transformer with an input voltage source connected to an input terminal VIN. The flybuck type DC-DC converter module is composed of a circuit including switching devices Q1, Q2 and a diode D, a coupling transformer (a primary coil N1, a secondary coil N2), an input filter capacitor Cin at an input end, and an output filter capacitor Cout (including Cout1 and Cout2) at an output end. The ceramic substrate 10 has bottom terminals 1 (input pads), 2 (first ground pads), 3 (first output pads), 4 (second ground pads), 5 (second output pads), and 6 (third ground pads) provided on the bottom thereof, a top electrode (a pattern of which is not specifically shown) provided on the top thereof, and primary and secondary windings N1 and N2 of a coupling transformer connecting the bottom and the top together, and conductors L1, L2, L3, L4, L5, and L6 (not shown in fig. L5 and L6) formed therein. Conductors L1, L2, L3, L4, L5, and L6 are formed of through holes, and equivalent inductances L1, L2, L3, L4, L5, and L6. An isolated buck-type DC-DC converter module based on a ceramic planar transformer is formed by taking a ceramic substrate (10) with a coupling transformer (a primary coil N1 and a secondary coil N2) inside as a carrier plate, mounting an input filter capacitor Cin at the top input end of the carrier plate, mounting output filter capacitors Cout1 and Cout2 at the output end of the carrier plate, and mounting a circuit comprising switching elements Q1, Q2 and a diode D. The input end of the DC-DC converter module is connected with an input voltage source. Through the embodiment, the isolated boost type DC-DC converter module is realized, and the isolated boost type DC-DC converter module has the advantages of miniaturization, modularization, high reliability, low cost in batch production and the like.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. An isolated DC-DC converter module based on a ceramic planar transformer, comprising:

the ceramic substrate comprises a plurality of ceramic layers, at least one layer of ceramic layer is printed with a primary coil, at least one layer of ceramic layer is printed with a secondary coil, and the plurality of ceramic layers are laminated so that the primary coil and the secondary coil are coupled to form a coupling type transformer; the ceramic substrate is provided with a first surface and a second surface which are opposite to each other, and the connecting ends of the primary side coil and the secondary side coil are connected to the first surface;

a pad area formed on the first surface, the pad area being electrically connected to a connection end of the primary coil and the secondary coil;

an isolated DC-DC conversion circuit topology, comprising: the primary side coil and the secondary side coil, as well as a switching element, an input capacitor, an output capacitor and a driving device, wherein the switching element, the input capacitor, the output capacitor and the driving device are all arranged in the pad area;

the input bonding pad, the output bonding pad and the grounding bonding pad are arranged on the second surface;

a conductor provided inside the ceramic substrate;

wherein at least any one of the input pad, the output pad, and the ground pad on the second surface is connected to the pad region on the first surface through the electrical conductor to implement a circuit layout of the isolated DC-DC conversion circuit topology.

2. The isolated DC-DC converter module according to claim 1, wherein the isolated DC-DC converter circuit topology is a flyback type, the switching element comprises a first switching tube and a first diode, the number of the ground pads is two, the ground pads are a first ground pad and a second ground pad, respectively, and the number of turns of the primary coil is greater than that of the secondary coil;

the input pad is connected with one end of the input capacitor through a conductor, one end of the input capacitor is also connected with the dotted end of the primary coil, the first grounding pad is connected with the other end of the input capacitor through a conductor, and the other end of the input capacitor is also connected to the dotted end of the primary coil through the first switching tube;

the output pad is connected with one end of the output capacitor through a conductor, one end of the output capacitor is also connected with the cathode of the first diode, the anode of the first diode is connected with the different name end of the secondary coil, the second grounding pad is connected with the other end of the output capacitor through a conductor, and the other end of the output capacitor is also connected with the same name end of the secondary coil.

3. The isolated DC-DC converter module of claim 1, wherein the isolated DC-DC converter circuit topology is a boost type, the switching element comprises a first switching tube and a first diode, the number of the ground pads is two, and the ground pads are a first ground pad and a second ground pad, respectively, and the number of turns of the primary coil is less than that of the secondary coil;

4. The isolated DC-DC converter module of claim 1, wherein the isolated DC-DC converter circuit topology is a buck type, the switching element includes a first switching tube, a second switching tube and a first diode, the number of the ground pads is three, respectively a first ground pad and a second ground pad and a third ground pad, the number of the output capacitors is two, respectively a first output capacitor and a second output capacitor; the number of the output bonding pads is two, the output bonding pads are respectively a first output bonding pad and a second output bonding pad, and the number of turns of the primary side coil is greater than that of the secondary side coil;

the input pad is connected with one end of the input capacitor through an electric conductor, one end of the input capacitor is also connected with the homonymous end of the primary coil through the first switch tube, the first grounding pad is connected with the other end of the input capacitor through an electric conductor, the other end of the input capacitor is also connected with the homonymous end of the primary coil through the second switch tube, the first output pad is connected with the synonym end of the primary coil through an electric conductor, the second grounding pad is connected with one end of the first output capacitor through an electric conductor, and the other end of the first output capacitor is connected with the synonym end of the primary coil;

the second output pad is connected with one end of the second output capacitor through a conductor, one end of the second output capacitor is further connected with the cathode of the first diode, the anode of the first diode is connected with the different name end of the secondary coil, the third grounding pad is connected with the other end of the second output capacitor through a conductor, and the other end of the second output capacitor is further connected with the same name end of the secondary coil.

5. The isolated DC-DC converter module according to claim 4, wherein the first and second switching tubes are any one of a triode, a MOS tube, and an IGBT.

6. The isolated DC-DC converter module according to any one of claims 2 to 4, wherein the conductor includes a through hole and a conductive material, the through hole penetrates through the first surface and the second surface, and the conductive material is filled in the through hole.

7. The isolated DC-DC converter module according to claim 6, wherein the electrical conductor is equivalent to an inductive element.

8. The isolated DC-DC converter module of claim 1, wherein the ceramic layers printed with the primary coil are alternately laminated with the ceramic layers printed with the secondary coil.

9. The isolated DC-DC converter module according to claim 1, wherein the ceramic layers printed with the primary coil are sequentially stacked to form a first folded layer, the ceramic layers printed with the secondary coil are sequentially stacked to form a second folded layer, and the first folded layer and the second folded layer are alternately stacked.

10. The isolated DC-DC converter module according to claim 1, wherein the number of ceramic layers on which the primary coil is printed is greater than or less than or equal to the number of ceramic layers on which the secondary coil is printed.