A direct current converter

Abstract

The utility model relates to a kind of direct current converters, including circuit board, controllable on-off protection device, power device and connecting point are also provided on circuit board, protection device is detachably fixed on circuit board, and the outer connection contact of protection device is electrically connected with connecting point, and the butt joint of protection device through outer connection contact and connecting point constitutes the parallel connection of power device.In addition, power device and protection device can also be packaged in ceramic substrate to form a closed module, the parallel connection of protection device and power device, and the switching of protection device between on state and off state according to the received control signal.The present application can optimize the layout and setting of the protection device for overcurrent protection of power device, meet the design requirements of different working conditions, and improve the working stability and reliability of direct current converter.

Description

Technical Field

[0001] This utility model relates to the field of electronic equipment technology, specifically to a DC-DC converter. Background Technology

[0002] DC-DC converters are the core hub of modern energy systems and are widely used in photovoltaic systems. By precisely adjusting the power of photovoltaic modules and the charging and discharging parameters of energy storage units, they enable efficient integration, safe storage, and flexible dispatch of new energy sources, significantly improving the reliability and utilization efficiency of new energy systems. In the field of DC-DC converter technology, they are divided into two categories: isolated and non-isolated. Non-isolated converters typically adopt basic topologies such as Buck, Boost, and Buck-Boost.

[0003] Taking a Boost circuit as a typical example, the power device section of an existing Boost circuit typically consists of an upper-arm diode and a lower-arm switch forming the chopper switch bridge arm. Under normal operating conditions, the reverse current of the lower-arm switch is extremely small or even negligible, so generally no additional anti-parallel diode is needed, or only a low-conductivity (high on-resistance or high forward voltage drop) anti-parallel diode is required. This configuration has no significant drawbacks in normal operation. However, under extreme conditions such as reverse input polarity, load short circuit, or lightning surge, such as... Figure 1 As shown, a high-current reverse path will force the lower bridge arm switch to pass through. Two typical failure scenarios exist: ① When using a MOSFET / HEMT device with limited reverse conduction capability, its parasitic diode will burn out directly due to overcurrent impact; ② Even with an auxiliary conduction device, if its on-resistance is too high (such as a slow recovery diode) or its current carrying capacity is insufficient, the reverse current will still preferentially flow through the switch body, leading to localized overheating and thermal breakdown failure.

[0004] In view of this, patent CN115664240A discloses an inverter protection device and a photovoltaic system. The inverter includes a power conversion circuit, a controller, and a current detection device. The power conversion circuit includes at least one bridge arm and a controllable switch. After the controllable switch is connected in parallel with at least one of the bridge arms, the conduction direction of the controllable switch in its on-state is the same as the conduction direction of the diodes in the upper and lower bridge arms. When the current detection device detects an abnormally large current, such as a short-circuit current, in the power conversion circuit, the controller controls the controllable switch to conduct, diverting the current flowing through the diodes in the upper or lower bridge arm, thus protecting the diodes or power devices in the upper or lower bridge arm. While this application proposes a strategy for protecting the switch, it does not discuss how to adapt to different application scenarios and various operating conditions, or how to arrange or expand the protection device for the bridge arm power devices to meet the needs of different operating conditions, in order to avoid redundant configurations increasing product costs or insufficient configuration affecting product reliability. Utility Model Content

[0005] One of the main objectives of this invention is to overcome at least one of the aforementioned defects and to provide a DC converter that optimizes the layout and configuration of the overcurrent protection device for power devices, meets the design requirements of different operating conditions, and improves the working stability and reliability of the DC converter.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] This utility model provides a DC-DC converter, including a circuit board on which power devices are disposed. In addition, the DC-DC converter includes a controllable on / off protection device. A connection point connected to the power devices is provided on the circuit board. The protection device is detachably fixed on the circuit board, and the external contact of the protection device is electrically connected to the connection point. The protection device is connected in parallel with the power devices through the connection of the external contact and the connection point.

[0008] According to one embodiment of the present invention, the circuit board is provided with a soldering seat, the protective device is soldered and fixed to the soldering seat, and the connection point is located on the side of the soldering seat.

[0009] According to one embodiment of the present invention, the external contact is disposed on the contact surface where the protective device and the welding seat are mated, the area where the contact surface is welded and fixed to the welding seat is the welding surface, and the external contact is disposed on the outside of the welding surface.

[0010] According to one embodiment of the present invention, the circuit board is provided with a fixed socket, and the side of the protective device is provided with a fixed plug, and the protective device is plugged into the fixed socket through the fixed plug.

[0011] According to one embodiment of the present invention, the connection point is disposed in the fixed socket or on the side of the fixed socket, and the corresponding external contact is disposed in the fixed plug or on the side of the fixed socket.

[0012] According to one embodiment of the present invention, the protection device includes a circuit board, a controllable switch tube disposed on the circuit board, and an external contact disposed on the side of the circuit board.

[0013] The external contacts include high-current contacts and control contacts. The high-current contacts are connected in parallel across the main power terminals of the protected power device in the circuit, and the control contacts are connected to signal pins used to input control signals.

[0014] According to one embodiment of the present invention, a copper layer is laid on the back of the circuit board, and the thickness of the copper layer is 30μm~80μm.

[0015] According to one embodiment of the present invention, a radiator is included, which is fixed to the side of the protective device.

[0016] In particular, this application also provides a DC-DC converter, which includes a circuit board, power devices and protection devices, wherein the power devices and protection devices are encapsulated in a ceramic substrate to form a closed module, and the protection devices are connected in parallel with the power devices.

[0017] According to one embodiment of the present invention, the protection device switches between an on state and an off state based on a received control signal. The protection device includes a controllable switch transistor, the gate of which is connected to a signal pin for inputting a control signal, the source of which is connected to the source of the power device, and the drain of which is connected to the drain of the power device.

[0018] Compared with the prior art, the advantages and beneficial effects of the DC converter in this utility model patent application are as follows:

[0019] The DC-DC converter of this application allows for the independent modular design of the protection device for parallel protection of power devices. This protection device can be soldered or plugged into the circuit board, or integrated directly into the circuit board, with heat dissipation achieved through the circuit board. An additional copper layer on the back of the circuit board can further enhance heat dissipation. Alternatively, the heat sink of the power device or a separate heat sink can be used to cool the protection device. This makes the protection device component of the DC-DC converter more flexible, structurally simple, highly expandable, and relatively inexpensive. Furthermore, the layout of this protection device is not limited by the area of ​​the circuit board and can be flexibly adjusted to adapt to the working requirements of different operating conditions. Attached Figure Description

[0020] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of a Boost circuit in the prior art;

[0022] Figure 2 This is a schematic diagram of the circuit structure of a protection device for shunt protection of a Boost circuit according to one embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of a DC-DC converter according to Embodiment 1 of this utility model;

[0024] Figure 4 This is a schematic diagram of the structure of a DC-DC converter according to Embodiment 2 of this utility model;

[0025] Figure 5 This is a schematic diagram of the DC-DC converter according to Embodiment 3 of this utility model.

[0026] The annotations in the attached figures are explained as follows:

[0027] 1. Circuit board; 11. Soldering base; 12. Socket; 13. Thick copper layer for heat dissipation on the back of the circuit board.

[0028] 2. Connection point; 21. Source connection point; 22. Drain connection point;

[0029] 3. Power devices;

[0030] 4. Protection device; 41. Circuit board; 42. Controllable switch tube; 43. Plug;

[0031] 5. External contact; 51. Source contact; 52. Drain contact;

[0032] 6. Enclosed module containing power devices and protection devices; 61. Ceramic substrate. Detailed Implementation

[0033] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0034] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0035] The DC converter of this application, such as Figure 2 As shown, the protection device used is connected in parallel with the power device S1 (such as a transistor, triode, diode, etc.), thereby constructing an auxiliary conduction path in parallel with the power devices in the DC-DC converter that require key protection, achieving dynamic shunt protection. Furthermore, as... Figure 2 As shown, the current conduction direction of the protection device is the same as the current direction when the power device S1 is reverse-conducting.

[0036] The accompanying drawings of the following embodiments are only for more clearly illustrating the configuration structure and layout of power devices and protection devices in the DC converter of this application. There are differences in the component ratios and circuit board ratios. Please be aware of this in advance.

[0037] Example 1:

[0038] This embodiment describes a DC-DC converter, including a circuit board 1 on which a power device 3 is disposed. The DC-DC converter also includes a controllable on / off protection device 4. A connection point 2 connected to the power device 3 is disposed on the circuit board 1. The protection device 4 is detachably fixed to the circuit board 1, and its external contact 5 is electrically connected to the connection point 2. The protection device 4 is connected in parallel with the power device 3 via the connection of the external contact 5 and the connection point 2.

[0039] like Figure 3 As shown, the circuit board 1 is provided with a soldering seat 11, the protective device 4 is soldered and fixed to the soldering seat 11, and the connection point 2 is located on the side of the soldering seat 11. The external contact 5 is located on the contact surface where the protective device 4 and the soldering seat 11 meet. The area where the contact surface and the soldering seat 11 are soldered and fixed is called the soldering surface, and the external contact 5 is located on the outside of the soldering surface.

[0040] The protection device 4 includes a circuit board 41, a controllable switch 42 encapsulated in the circuit board 41, and external contacts 5 disposed on the side of the circuit board 41. The external contacts include high-current contacts and control contacts. The high-current contacts are connected in parallel to the two ends of the main power terminal of the protected power device in the circuit, and the control contacts are connected to the signal pins used to input control signals.

[0041] The external contact 5 includes a gate contact, a source contact 51, and a drain contact 52. In this embodiment, the gate contact is the control contact, and the source contact 51 and drain contact 52 are high-current contacts among the external contacts. The gate contact is connected to a signal pin used for inputting control signals. The connection point 2 includes a source connection point 21 connected to the source of the power device 3 and a base connection point 2 connected to the base of the power device 3. The source contact 51 is electrically connected to the source connection point 21, and the base contact is electrically connected to the base connection point 2. The accompanying drawings of this embodiment only show the source contact 51, drain contact 52, source connection point 21, and drain connection point 22, focusing on the connection relationship between the power device 3 and the protection device 4. As for the gate contact of the controllable switch 42 of the protection device 4 being electrically connected to the input signal pin of the control signal on the circuit board 1, this is a conventional setting and is not described in detail here.

[0042] In this embodiment, the DC-DC converter welds and fixes the protection device 4, which provides parallel protection for the power device 3, to the circuit board 1. Heat dissipation is then achieved through the circuit board 1, or other methods can be used to enhance or assist heat dissipation. Generally speaking, in terms of thermal management, in low-power scenarios, the natural heat dissipation from the copper layer on the circuit board 1 itself is sufficient. In medium-to-high-power scenarios, a thick copper layer 13 (30μm~80μm thick, which can provide some heat dissipation for the protection device) or an embedded heatsink can be added to the back of the circuit board 1 to improve thermal conductivity. Adding a copper layer to the back of the circuit board 1 allows for heat dissipation based on the overall plane of the circuit board 1, thus improving heat dissipation performance. Alternatively, a shared heatsink with the main power device 3 or an independent heatsink can be added, employing external active heat dissipation devices to cool the protection device 4.

[0043] As can be seen, the protection device 4 of the DC-DC converter in this embodiment is more flexible in its design, simple in structure, highly expandable, and relatively inexpensive. Furthermore, the layout of this protection device 4 can be adjusted flexibly, not limited by the area of ​​the circuit board 1, to adapt to the working requirements of different operating conditions.

[0044] Example 2:

[0045] The main structure of the DC converter in this embodiment is the same as that in embodiment 1. The difference is that the protection device 4 is pluggable and installed on the circuit board 1.

[0046] Specifically, such as Figure 4 As shown, the circuit board 1 is provided with a fixed socket 12, and the side of the protection device 4 has a fixed plug 43. The protection device 4 is plugged into the fixed socket 12 through the fixed plug 43. The connection point 2 is provided in the fixed socket 12 or on the side of the fixed socket 12, and the corresponding external contact 5 is provided in the fixed plug 43 or on the side of the fixed socket 12.

[0047] The DC-DC converter provided in this embodiment features a modular design for the protection device 4 that provides parallel protection for the power devices 3. This protection device 4 is then plugged into the circuit board 1. This design supports plug-and-play replacement, facilitating future upgrades or fault repairs. Furthermore, vertical stacking or lateral mounting significantly reduces the board area occupied. Therefore, the protection device 4 in this embodiment is more flexible, has a simpler structure, stronger expandability, and is also more cost-effective.

[0048] Furthermore, heat dissipation is achieved through circuit board 1, and an additional copper layer can be added to the back of circuit board 1 to improve heat dissipation performance. This can meet the requirements of transient overcurrent scenarios such as lightning strikes, focusing on controlling the instantaneous temperature rise rate rather than long-term steady-state heat dissipation capacity, thus balancing cost and operational reliability. As for operating scenarios where continuous conduction occurs, such as when the input terminals are reversed, the heat sink of power device 3 or an additional independent heat sink can be used to dissipate heat from the protection device 4 to cope with the high current temperature rise.

[0049] Example 3:

[0050] This embodiment describes a DC-DC converter, such as... Figure 5 As shown, the device includes a circuit board 1, a power device 3, and a protection device 4. The power device 3 and the protection device 4 are encapsulated in a ceramic substrate 61 to form a closed module 6. The protection device 4 is connected in parallel with the power device 3, and the protection device 4 switches between a conducting state and a cut-off state according to the received control signal.

[0051] In this embodiment, the DC-DC converter encapsulates the protection device 4 and the main power device 3 within a single module, utilizing a ceramic substrate 61 to achieve electrical isolation and efficient heat dissipation (for thermal management, device layout is optimized using simulation tools in the early stages to avoid localized overheating caused by thermal coupling). When the protection device 4 and the main power device 3 share a heat sink substrate, the independence of the heat dissipation path for the main power device 3 in the DC-DC converter must be prioritized to ensure that its heat dissipation efficiency is not affected by a failure of the protection device 4. Furthermore, the temperature resistance difference between the protection device 4 and the main power device 3 needs to be quantified, and thermal stress decoupling is achieved through the selection of heat dissipation materials and layout design.

[0052] The protection device 4 includes a controllable switch 42. The gate of the controllable switch 42 is connected to a signal pin for inputting control signals. The source of the controllable switch 42 is connected to the source of the power device 3, and the drain of the controllable switch 42 is connected to the drain of the power device 3. To improve the shunt protection effect, a protection resistor can be connected in series with the source or drain of the controllable switch 42. When the controllable switch 42 is turned on, the protection resistor is connected in parallel with the power device 3, thereby improving the protection effect.

[0053] The DC-DC converter in this embodiment adopts an integrated design, directly encapsulating the protection device 4 and power device 3 together. Heat dissipation is achieved through circuit board 1. An additional copper layer on the back of circuit board 1 can be added to improve heat dissipation performance. Alternatively, the heat sink of power device 3 or an additional independent heat sink can be used to dissipate heat from the protection device 4. This makes the design of the protection device 4 component more flexible, structurally simple, highly expandable, and relatively inexpensive. Furthermore, the layout of this protection device 4 is not limited by the area of ​​circuit board 1 and can be flexibly adjusted to adapt to the working requirements of different operating conditions.

[0054] In summary, the DC-DC converter of this application has the following advantages compared with the prior art:

[0055] 1. Diversified protection device structure configuration strategy

[0056] Results: By employing three configuration options—onboard, modular pluggable, and integrated power modules—the system enables flexible deployment of protection devices in various application scenarios (basic / high maintainability / high power density), balancing cost and reliability, and avoiding resource waste or performance deficiencies caused by the "one-size-fits-all" approach of existing technologies.

[0057] 2. Differentiated thermal management solutions based on operating conditions

[0058] Effect: The strategy of forced heat dissipation for persistent faults (such as reversed input) and flexible heat dissipation for transient faults (such as lightning strikes) solves the problem of insufficient heat dissipation for persistent faults or excessive heat dissipation for transient faults caused by the uniform configuration of existing technologies, thereby improving reliability and reducing costs.

[0059] 3. Modular design improves maintainability and power density

[0060] Effects: The independently packaged functional modules and circuit board socket interface design support quick plug-and-play replacement. The vertical stacking layout reduces the board area occupied, improves system maintenance efficiency, and increases power density, making it suitable for highly integrated photovoltaic equipment.

[0061] 3. Integrated design enhances reliability and thermal dissipation

[0062] Effect: The protection device and the main power device are co-packaged on a ceramic substrate. The layout of the two is optimized by combining thermal simulation to ensure system stability under harsh environments.

[0063] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the protection scope of this utility model.

Claims

1. A DC-DC converter, comprising a circuit board, wherein power devices are disposed on the circuit board, characterized in that, The DC-DC converter includes a controllable on / off protection device. A connection point connected to the power device is provided on the circuit board. The protection device is detachably fixed on the circuit board, and the external contact of the protection device is electrically connected to the connection point. The protection device is connected in parallel with the power device through the docking of the external contact and the connection point.

2. The DC-DC converter according to claim 1, characterized in that, The circuit board is provided with a soldering base, the protective device is soldered and fixed to the soldering base, and the connection point is located on the side of the soldering base.

3. The DC-DC converter according to claim 2, characterized in that, The external contact is located on the contact surface where the protective device and the welding seat meet. The area where the contact surface is welded and fixed to the welding seat is the welding surface, and the external contact is located on the outside of the welding surface.

4. The DC-DC converter according to claim 1, characterized in that, The circuit board is provided with a fixed socket, and the side of the protection device has a fixed plug. The protection device is plugged into the fixed socket through the fixed plug.

5. The DC-DC converter according to claim 4, characterized in that, The connection point is located in the fixed socket or on the side of the fixed socket, and the corresponding external contact is located in the fixed plug or on the side of the fixed socket.

6. The DC-DC converter according to claim 1, characterized in that, The protection device includes a circuit board, a controllable switch tube disposed on the circuit board, and external contacts disposed on the side of the circuit board; The external contacts include high-current contacts and control contacts. The high-current contacts are connected in parallel across the main power terminals of the protected power device in the circuit, and the control contacts are connected to signal pins used to input control signals.

7. The DC-DC converter according to claim 1, characterized in that, A copper layer with a thickness of 30μm to 80μm is laid on the back of the circuit board.

8. The DC-DC converter according to claim 1, characterized in that, It includes a radiator, which is fixed to the side of the protective device.

9. A DC-DC converter, characterized in that, It includes a circuit board, power devices, and protection devices. The power devices and protection devices are encapsulated in a ceramic substrate to form a closed module, and the protection devices are connected in parallel with the power devices.

10. The DC-DC converter according to claim 9, characterized in that, The protection device switches between a conduction state and a cutoff state according to the received control signal. The protection device includes a controllable switch transistor. The gate of the controllable switch transistor is connected to a signal pin for inputting control signals. The source of the controllable switch transistor is connected to the source of the power device. The drain of the controllable switch transistor is connected to the drain of the power device.

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