CN214251310U

CN214251310U - Temperature detection system and vehicle-mounted charger

Info

Publication number: CN214251310U
Application number: CN202022918692.1U
Authority: CN
Inventors: 周振; 尤培艾; 陈建宏
Original assignee: Delta Electronics Shanghai Co Ltd
Current assignee: Delta Electronics Shanghai Co Ltd
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2021-09-21
Anticipated expiration: 2030-12-08

Abstract

The application provides a temperature detection system and on-vehicle machine that charges, this system includes: a temperature sensor and a heat transfer element for transferring a temperature of the power device to the temperature sensor; the heat transfer element and the temperature sensor are both located on the printed circuit board; the heat transfer element is thermally connected with the temperature sensor and is also used for being thermally connected with the power device; the heat transfer element is an electrically insulating element. The heat transfer element is thermally connected with the power device and the temperature sensor, so that the temperature of the power device is quickly transferred to the temperature sensor, the heat transfer resistance between the power device and the temperature sensor is effectively reduced, the response speed of the temperature sensor to the temperature of the power device is improved, and the power device is effectively prevented from being damaged due to over-temperature.

Description

Temperature detection system and vehicle-mounted charger

Technical Field

The application relates to the technical field of vehicle-mounted chargers, in particular to a temperature detection system and a vehicle-mounted charger.

Background

With the continuous increase of the cruising ability of the electric automobile, the power of a vehicle-mounted charger is increased, and the heat management of the product becomes more and more important. The power device is a core component of the vehicle-mounted charger, so that the problem of thermal management of the power device is particularly important to solve. The stability of the power device is directly related to the reliability of the whole product. Therefore, when a product runs, the temperature of the power device needs to be monitored, and when the temperature of the power device is abnormal, a corresponding protection mechanism is started to ensure that the power device is not damaged due to overhigh temperature.

The prior art detects the temperature of the power device by placing a temperature sensor at the periphery of the power device. Due to the potential difference between the power device and the temperature sensing device, the power device and the bonding pad of the sensor need to be separated by a certain distance.

However, the heat is transferred between the power device and the sensor through the printed circuit board, the transverse heat conduction capability of the printed circuit board is poor, and a large heat transfer thermal resistance exists between the power device and the sensor, so that the temperature detection response speed is too slow.

SUMMERY OF THE UTILITY MODEL

The application provides a temperature detection system and a vehicle-mounted charger to solve the problem that the response speed of temperature detection is too low.

In a first aspect, a temperature detection system includes: a temperature sensor and a heat transfer element for transferring a temperature of the power device to the temperature sensor;

the heat transfer element and the temperature sensor are both located on the printed circuit board;

the heat transfer element is thermally connected with the temperature sensor and is also used for being thermally connected with the power device;

the heat transfer element is an electrically insulating element.

Optionally, the power device, the heat transfer element and the temperature sensor are all soldered on the printed circuit board, the pad of the heat transfer element is thermally connected with the pad of the power device, and the pad of the heat transfer element is thermally connected with the pad of the temperature sensor.

Optionally, the heat transfer element and the temperature sensor are an integrated package structure.

Optionally, the heat transfer element is a surface mount integrated package structure.

Optionally, the temperature sensor is located on the heat transfer element.

Optionally, the temperature sensor is mounted on the plating of the heat transfer member by welding.

Optionally, one temperature sensor is thermally coupled to a plurality of heat transfer elements, which are thermally coupled to one power device.

Optionally, a plurality of power devices are disposed on the printed circuit board, and the heat transfer member is thermally connected to the power device having the highest temperature.

Optionally, the material of the heat transfer element comprises aluminum oxide and/or aluminum nitride.

Optionally, the temperature detection system is arranged on the vehicle-mounted charger.

In a second aspect, a vehicle-mounted charger comprises a power device, a printed circuit board and the temperature detection system according to the first aspect and the alternative;

wherein the temperature detection system and the power device are located on the printed circuit board.

The application provides a temperature detection system and on-vehicle machine that charges, this system includes: a heat transfer element and a temperature sensor; the heat transfer element and the temperature sensor are both located on the printed circuit board; the heat transfer element is thermally connected with the temperature sensor and is also used for thermally connecting with a power device on the printed circuit board; the heat transfer element is used for transferring the temperature of the power device to the temperature sensor so that the temperature sensor detects the temperature of the power device; the heat transfer element is an electrically insulating element. The heat transfer element is thermally connected with the power device and the temperature sensor, so that the temperature of the power device is quickly transferred to the temperature sensor, the heat transfer resistance between the power device and the temperature sensor is effectively reduced, the response speed of the temperature sensor to the temperature of the power device is improved, and the power device is effectively prevented from being damaged due to over-temperature.

Drawings

In order to more clearly illustrate the technical solutions of the present application or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to the drawings without inventive labor.

FIG. 1 is a schematic diagram of a temperature sensing system provided in the prior art;

FIG. 2 is a schematic diagram of a temperature sensing system provided herein according to an exemplary embodiment;

FIG. 3 is a schematic view of a temperature sensing system provided herein according to another exemplary embodiment;

FIG. 4 is a schematic illustration of a temperature sensing system provided herein according to yet another exemplary embodiment;

FIG. 5 is a schematic view of a temperature sensing system provided herein according to yet another exemplary embodiment;

FIG. 6 is a schematic size diagram of a heat transfer element in a temperature sensing system provided herein according to yet another exemplary embodiment;

fig. 7 is a schematic diagram of a hardware structure of a vehicle-mounted charger according to an exemplary embodiment of the present application.

Description of reference numerals:

1 printed circuit board

11 power device

12 temperature sensor

13 Heat transfer element

14 integrated package structure

131 plating layer

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

To make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below with reference to the drawings in the present application, and it is obvious that the described embodiments are some, but not all embodiments of the present application.

First, it should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present application, and are not intended to limit the scope of the present application. And can be adjusted as needed by those skilled in the art to suit particular applications.

Next, it should be noted that in the description of the present application, the terms of direction or positional relationship indicated by the terms "upper", "lower", and the like are based on the direction or positional relationship shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the device or member must have a specific orientation, be configured in a specific orientation, and operate, and thus, should not be construed as limiting the present application.

In addition, it should be noted that, in the description of the present application, unless explicitly stated or limited otherwise, the terms "contacting" and "connecting" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, and the two components can be communicated with each other. The specific meaning of the above terms in the present application can be understood by those skilled in the art as the case may be.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The vehicle-mounted charger is a charger fixedly mounted on the electric vehicle, has the capability of safely and automatically charging the power Battery of the electric vehicle, and can dynamically adjust charging current or voltage parameters according to data provided by a Battery Management System (BMS), execute corresponding actions and complete the charging process. The output power of the vehicle-mounted charger can reach dozens of kilowatts to hundreds of kilowatts. Essentially, the vehicle charger is a Switching Power Supply (Switching Power Supply). The vehicle-mounted charger needs to acquire alternating current electric energy from the charging pile, convert the alternating current electric energy into high-voltage direct current electric energy and then transmit the high-voltage direct current electric energy to the BMS. The on-vehicle machine that charges is arranged between electric pile and the BMS. The vehicle-mounted charger communicates with the BMS through a Controller Area Network (CAN) bus, receives the battery charging state and the charging requirement and the like sent by the BMS, and simultaneously sends the real-time charging loop state information to the BMS.

The semiconductor power device of the vehicle-mounted charger works in a switching state, and the switching frequency reaches about 100K. Heat loss is very severe throughout the operation. For example, with an output power of 7.2kW, a loss of 5%, i.e., 360W, still occurs at 95% efficiency when the device is operated at full load, wherein about 75% (i.e., 270W) of the loss is generated by the semiconductor power device. Therefore, the power device is a key heat source of the vehicle-mounted charger. The excessively high temperature of the power device can reduce the electric energy conversion efficiency of the whole charger if the temperature is too high, and can reduce the expected service life of the charger if the temperature is too high, or even cause safety accidents caused by explosion. The stability of the power device is directly related to the reliability of the whole product. Therefore, when a product runs, the temperature of the power device needs to be monitored, and when the temperature of the power device is abnormal, a corresponding protection mechanism is started to ensure that the power device is not damaged due to overhigh temperature.

Fig. 1 is a schematic diagram of a temperature detection system provided in the prior art. As shown in fig. 1, the power device 11 and the temperature sensor 12 are soldered on the printed circuit board 1, and the power device 11 and the temperature sensor 12 need to be separated by a certain distance due to the potential difference between the power device 11 and the temperature sensor 12. Heat is transferred between the power device 11 and the temperature sensor 12 through the copper foil on the printed circuit board 1. However, the thermal conductivity of the printed circuit board 1 is about 0.3W/mK, the lateral thermal conductivity is poor, and the thermal transfer resistance between the power device 11 and the temperature sensor 12 is large. This results in too slow response speed of the temperature sensor 12 to the temperature detection of the power device 11, and the product cannot start the protection mechanism in time, and cannot effectively prevent the power device from being damaged due to too high temperature.

In order to solve the above problem, an embodiment of the present application provides a temperature detection system, which utilizes the heat conduction and insulation characteristics of a heat transfer element, and transfers the temperature of a power device to a temperature sensor through the heat transfer element, so as to effectively reduce the heat transfer resistance between the power device and the temperature sensor, improve the response speed of the temperature sensor to the temperature of the power device, and effectively prevent the power device from being damaged due to over-temperature.

Several temperature sensing systems that can be implemented are described below so that those skilled in the art can more clearly understand the technical solutions and advantages of the present application.

Fig. 2 is a schematic diagram of a temperature detection system provided herein according to an exemplary embodiment. As shown in fig. 2, the temperature detecting system provided in this embodiment includes: a heat transfer element 13 and a temperature sensor 12; the heat transfer element 13 and the temperature sensor 12 are both located on the printed circuit board 1; the heat transfer element 13 is thermally connected with the temperature sensor 13, and the heat transfer element 13 is also used for thermally connecting with the power device 11 on the printed circuit board 1; the heat transfer element 13 is used for transferring the temperature of the power device 11 to the temperature sensor 12 so that the temperature sensor 12 detects the temperature of the power device 11; the heat transfer member 13 is an electrically insulating member.

On the printed circuit board 1 of the vehicle-mounted charger, one end of the power device 11 is thermally connected with one end of the heat transfer element 13, and the other end of the heat transfer element 13 is thermally connected with one end of the temperature sensing device 12. In practical applications, the distance between the power device 11 and the temperature sensing device 12 may be determined according to the potential difference between the power device 11 and the temperature sensing device 12. The heat transfer member 13 is located between the power device 11 and the temperature sensing device 12, so that the heat transfer member 13 quickly transfers the temperature of the power device 11 to the temperature sensing device 12. The heat transfer member 13 is an electrically insulating member having a heat conductive and insulating property.

In practical applications, the power device is lost during the switching process and is dissipated as heat, which causes the temperature of the power device to rise. The heat transfer element receives the temperature of the power device and then rapidly transfers the temperature of the power device to one end of the temperature sensor. The temperature sensing device receives the temperature of the power device and judges whether the temperature of the power device exceeds the normal working temperature. And if the temperature of the power device exceeds the normal working temperature, starting a corresponding protection mechanism to ensure that the power device is not damaged due to overheating.

The temperature detection system provided by the embodiment comprises a heat transfer element and a temperature sensor. The heat transfer element and the temperature sensor are both located on a printed circuit board, on which the power device is also located. The heat transfer element is thermally coupled to the temperature sensor and also to the power device. The heat transfer element transfers the temperature of the power device to a temperature sensor for detecting the temperature of the power device. The heat transfer element has the characteristics of heat conduction and insulation. The power device and the temperature sensor have potential difference and cannot be directly connected. The system utilizes the heat conduction and insulation characteristics of the heat transfer element to place the heat transfer element between the power device and the temperature sensor, so that the temperature of the power device is quickly transferred to the temperature sensor, the heat transfer resistance between the power device and the temperature sensor is effectively reduced, and the response speed of the temperature sensor to the temperature of the power device is improved.

Fig. 3 is a schematic diagram of a temperature detection system provided herein according to another exemplary embodiment. As shown in fig. 3, the present embodiment provides a temperature detection system in which one temperature sensor 12 is thermally connected to a plurality of heat transfer members 13, and the plurality of heat transfer members 13 are thermally connected to one power device 11.

As shown in fig. 3, two heat transfer elements 13 are disposed on the right side of the power device 11, and the temperature sensor 12 is interposed between the two heat transfer elements 13 and thermally connected to the two heat transfer elements, thereby further increasing the detection speed of the temperature sensor.

In practical applications, how many heat transfer elements 13 a power device 11 is thermally connected to is determined according to specific requirements. The greater the number of heat transfer elements 13, the faster the heat transfer rate, and the faster the temperature sensor 12 responds to temperature.

Alternatively, the power device 11, the heat transfer member 13, and the temperature sensor 12 are all soldered on the printed circuit board 1, the pad of the heat transfer member 13 is thermally connected to the pad of the power device 11, and the pad of the heat transfer member 13 is thermally connected to the pad of the temperature sensor 12.

On the printed circuit board 1, pad positions of the power device 11, the temperature sensing device 12, and the heat transfer member 13 are provided. In practical applications, the pad positions of the power device 11 and the temperature sensing device 12 can be set reasonably according to the potential difference between the power device 11 and the temperature sensing device 12. One end of the pad of the power device 11 is thermally connected to one end of the pad of the heat transfer member 13, and the other end of the pad of the heat transfer member 13 is thermally connected to one end of the pad of the temperature sensing device 12.

Alternatively, a plurality of power devices are provided on the printed circuit board, and the heat transfer member 13 is thermally connected to the power device having the highest temperature.

Specifically, before the welding of the heat transfer element and the temperature sensor, a simulation test is performed on a plurality of power devices on the printed circuit board, and the power device with the highest temperature in the plurality of power devices is determined. As shown in fig. 3, the power device in the figure is the power device with the highest temperature determined by simulation test. The bonding pad of the power device with the highest temperature is thermally connected with the bonding pad of the heat transfer element, and the temperature sensor detects the temperature of the power device with the highest temperature. And when the power device with the highest temperature does not exceed the normal working temperature, the temperature of other power devices is considered to be within the normal working temperature. The heat transfer element is thermally connected with the power device with the highest temperature, so that the layout of the power device, the heat transfer element and the temperature sensor on the printed circuit board is simpler and more effective.

Specifically, the material of the heat transfer element includes, but is not limited to, alumina and/or aluminum nitride, and may be alumina, or aluminum nitride, or a mixture of both. The material of the heat transfer element is not particularly limited as long as it has the characteristics of heat conduction and insulation.

For example, alumina has thermal conductive and insulating properties, and is relatively low in price, wide in source and large in filling amount. The heat transfer element made of alumina has a thermal conductivity of about 29.3W/mK and a lateral thermal conductivity about 97.7 times that of the printed circuit board. The heat transfer thermal resistance between the power device and the temperature sensor is effectively reduced, so that the temperature following capability of the temperature sensor to the power device is enhanced, and the power device can be effectively protected when the machine works.

Specifically, the temperature detection system is used for detecting the temperature of a power device of the vehicle-mounted charger, so that when the temperature of the power device of the vehicle-mounted charger is too high, the vehicle-mounted charger starts a protection mechanism in time, and the power device is prevented from being damaged due to over-temperature.

The temperature detection system provided by the embodiment transmits the temperature of the power device by arranging the plurality of heat transmission elements, so that the response speed of the temperature sensor is further improved. The pad positions of the power device, the heat transfer element and the temperature sensor are reasonably arranged on the printed circuit board, before mass production, the power device with the highest temperature in the working process is determined through simulation test, and temperature detection is carried out on the power device, so that the layout of the power device, the heat transfer element and the temperature sensor on the printed circuit board is simpler and more effective, and the power device is effectively prevented from being damaged by over-temperature.

FIG. 4 is a schematic diagram of a temperature sensing system provided herein according to yet another exemplary embodiment. As shown in fig. 4, in the temperature detecting system provided in the present embodiment, the heat transfer element 13 and the temperature sensor 12 are an integrated package structure 14.

In particular, the heat transfer element 13 may be perforated, the temperature sensor 12 placed in the hole, and the package structure 14 integrated. It is also possible to place the temperature sensor 12 on the heat transfer element 13, integrating the package structure 14. The heat transfer element 13 is integrated with the temperature sensor 12 in a specific manner, and is not particularly limited herein. The integrated package structure 14 is an integral part, and the integrated package structure 14 is directly soldered on the printed circuit board 1 in use.

Alternatively, the heat transfer element 13 in all the above embodiments may be a chip-on-package structure.

Specifically, the heat transfer member 13 is packaged in accordance with the size of an existing Surface Mounted Device (SMD). The SMD is one of Surface Mount Technology (SMT) components, has the advantage of small size, and is suitable for printed circuit boards with dense lines.

According to the temperature detection system provided by the embodiment, the heat transfer element and the temperature sensor are integrated to obtain the integrated packaging structure, and the integrated packaging structure is only required to be welded when in use, so that the layout of each device on the printed circuit board is further simplified.

FIG. 5 is a schematic view of a temperature sensing system provided herein according to yet another exemplary embodiment. As shown in fig. 5, the present embodiment provides a temperature detection system in which the temperature sensor 12 is located on the heat transfer member 13.

Specifically, the temperature sensor is of a patch type structure, the heat transfer element 13 is of a patch type structure, and the temperature sensor 12 is placed on the heat transfer element 13 to form a patch type integrated packaging structure.

Alternatively, the temperature sensor 12 is mounted on the plated layer 131 of the heat transfer member 13 by welding.

Specifically, the heat transfer element 13 is provided with plating 131 at both ends, which has the advantages of increasing the surface hardness of the heat transfer element, improving friction, reducing wear, improving electrical conductivity, reducing contact resistance, enhancing magnetic properties, preventing diffusion, and preventing infiltration or repairing worn parts. The temperature sensor 12 is placed on the plating layer, and the temperature sensor 12 is mounted on the plating layer 131 of the heat transfer element 13 by welding to form a patch type integrated package structure.

FIG. 6 is a dimensional schematic of a heat transfer element in a temperature sensing system provided herein according to yet another exemplary embodiment. As shown in FIG. 6, the heat transfer member 13 has a length of 5.0. + -. 0.1mm, a width of 2.5. + -. 0.1mm and a height of 1.0. + -. 0.1 mm. The length of the plating layer 131 is 2.5 + -0.1 mm, and the width is 0.75 + -0.25 mm.

The temperature detection system provided by the embodiment integrates the heat transfer element and the temperature sensor into a surface mount type integrated packaging structure, and the integrated packaging structure is only required to be welded when in use, so that the layout of each device on the printed circuit board is further simplified.

Fig. 7 is a schematic diagram of a hardware structure of a vehicle-mounted charger according to an exemplary embodiment of the present application. As shown in fig. 7, an embodiment of the present application provides a vehicle-mounted charger, including: power device, printed circuit board and temperature detection system as all embodiments relate to above.

The vehicle-mounted charger is a device which is fixedly installed on the electric automobile, converts electric energy of a public power grid into direct current required by the vehicle-mounted energy storage device and charges the vehicle-mounted energy storage device.

The vehicle-mounted charger comprises an alternating current input interface, a power unit, a control unit, a direct current output interface and the like. The vehicle-mounted charger has the function of communicating with the BMS through the high-speed CAN and judges whether the connection state of the battery is correct or not; and acquiring parameters of a battery system and real-time data of the whole set of batteries and the single batteries before and during charging. The vehicle-mounted charger CAN be communicated with a vehicle monitoring system through the high-speed CAN, upload the working state, working parameters and fault warning information of the charger and receive a charging starting or stopping control command. The vehicle-mounted charger has complete safety protection measures, for example, in the charging process, the charger can ensure that the temperature, the charging voltage and the current of the power battery do not exceed allowable values, and has a single battery voltage limiting function, and the charging current is dynamically adjusted automatically according to the battery information of the BMS.

It should be understood that in some embodiments, the thermal connections may not be direct connections, the power device 11, the heat transfer element 13, and the temperature sensor 12 are all soldered on the printed circuit board by pads, the pads of the heat transfer element 13 and the pads of the power device 11 are connected or directly connected by copper foils of the printed circuit board, and the pads of the heat transfer element 13 and the pads of the temperature sensor 12 are connected or directly connected by copper foils of the printed circuit board.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A temperature sensing system, comprising: a temperature sensor and a heat transfer element for transferring a temperature of a power device to the temperature sensor;

the heat transfer element and the temperature sensor are both located on a printed circuit board;

the heat transfer element is thermally connected with the temperature sensor and is also used for being thermally connected with a power device;

the heat transfer element is an electrically insulating element.

2. The temperature sensing system of claim 1, wherein the power device, the heat transfer element, and the temperature sensor are all soldered to a printed circuit board, the pads of the heat transfer element are thermally connected to the pads of the power device, and the pads of the heat transfer element are thermally connected to the pads of the temperature sensor.

3. The temperature sensing system of claim 1, wherein the heat transfer element and the temperature sensor are an integrated package structure.

4. The temperature sensing system of claim 1, wherein the heat transfer element is a surface mount integrated package structure.

5. The temperature sensing system of claim 3, wherein the temperature sensor is located on the heat transfer element.

6. The temperature sensing system of claim 5, wherein the temperature sensor is mounted to the plating of the heat transfer member by welding.

7. The temperature sensing system of claim 1, wherein one of said temperature sensors is thermally coupled to a plurality of said heat transfer elements, said plurality of heat transfer elements being thermally coupled to one of said power devices.

8. The temperature sensing system of claim 1, wherein a plurality of power devices are disposed on the printed circuit board, and the heat transfer element is thermally coupled to the power device having the highest temperature.

9. The temperature detection system of claim 1, wherein the temperature detection system is disposed on a vehicle-mounted charger.

10. A vehicle-mounted charger characterized by comprising a power device, a printed circuit board and a temperature detection system according to any one of claims 1 to 9;