Integrated distributed heating circuit

Abstract

According to the integrated distributed heating circuit provided by the utility model, due to the introduction of the integrated distributed heating network, the LTCC substrate not only has the function of a traditional multi-layer circuit board, but also can provide a heating function to heat required components, and can effectively solve the problem that a to-be-heated component cannot work normally at a low temperature; in addition, compared with a traditional heating film for heating, the heating circuit provided by the utility model is more compact in structure, accurate in heating, lighter, smaller in size and higher in efficiency, avoids uneven heating of the substrate, really realizes low cost and light weight, and improves the energy utilization efficiency to the greatest extent.

Description

Technical Field

[0001] The utility model belongs to the technical field of microwave circuits, and in particular relates to an integrated distributed heating circuit. Background Art

[0002] The problem of RF chips not being able to work properly in extremely low temperature environments is one of the challenges facing the RF communication field. Traditional solutions usually use the method of heating the entire device, but this leads to high costs, large size, and design redundancy, which limits its application in extreme temperature conditions.

[0003] Specifically, the shortcomings of the prior art are as follows:

[0004] (1) Excessive cost: Traditional whole-machine heating solutions are expensive, especially in large-scale applications, which will significantly increase project development and operating costs.

[0005] (2) Too large: The whole machine heating solution usually requires large heating equipment, which leads to redundant equipment volume and is not suitable for application scenarios with limited space.

[0006] (3) High energy consumption: Heating the whole machine consumes a lot of energy, especially when heating for a long time in a low temperature environment, the energy consumption problem is significant.

[0007] (4) Low efficiency: Figure 1 As shown, traditional heating films have a large volume and high energy consumption, which will waste energy in some places that do not need to be heated, and the heat conduction efficiency is poor. Utility Model Content

[0008] In order to solve the problem that radio frequency chips cannot work normally in extremely low temperature environments, the utility model provides an integrated distributed heating circuit. A heating film is buried in the LTCC substrate, and a distributed heating network is used to heat the device to achieve a heating effect for the local circuit, which is more efficient and less costly.

[0009] An integrated distributed heating circuit comprises a heating film and a device to be heated which are embedded in different layers of an LTCC substrate; wherein the heating film is located in the middle layer of the LTCC substrate, and each device to be heated is located in the top layer or the bottom layer of the LTCC substrate;

[0010] The heating film is composed of multiple heating blocks connected in series and in parallel through heating wires, and each heating block is arranged in multiple S shapes through the heating wires; at the same time, the projection of each device to be heated on the middle layer overlaps or intersects with at least one heating block.

[0011] Furthermore, the heating film is powered by a direct current from an external whole system power supply, wherein the greater the difference between the current ambient temperature and the required operating temperature of each device to be heated, the higher the voltage of the external whole system power supply.

[0012] Furthermore, the number of the heating films is determined according to the number of devices to be heated and the required operating temperature of each device to be heated. At the same time, the more devices to be heated, the higher the required operating temperature of each device to be heated, the more heating films are required, and each heating film is buried in a different layer in the middle of the LTCC substrate.

[0013] Furthermore, the heating wire is a metal oxide with high resistivity.

[0014] Furthermore, the device to be heated includes a radio frequency main circuit, a temperature detection circuit and a temperature control circuit;

[0015] When the RF main circuit is started, the temperature detection circuit detects the current ambient temperature and sends the current ambient temperature to the temperature control circuit. The temperature control circuit decides whether to start the heating film based on the difference between the current ambient temperature and the operating temperature required by each device to be heated. When the difference is less than the set value, the heating film is turned off.

[0016] Beneficial effects:

[0017] 1. The utility model provides an integrated distributed heating circuit. The introduction of the integrated distributed heating network enables the LTCC substrate to not only have the functions of a traditional multi-layer circuit board, but also provide a heating function to heat the required components, which can effectively solve the problem that the components to be heated cannot work normally at low temperatures; in addition, compared with traditional heating film heating, the heating circuit structure provided by the utility model is more compact, precise heating, avoiding uneven heating of the substrate, and is more lightweight, smaller in size, and more efficient, truly achieving low cost and lightweight, and maximizing energy efficiency.

[0018] 2. The utility model provides an integrated distributed heating circuit, in which the heating film is powered by a DC power supply from an external whole machine system power supply to achieve a heating function under low temperature conditions.

[0019] 3. The utility model provides an integrated distributed heating circuit. After the radio frequency system is started, the temperature detection circuit controls the power supply of the heating network by detecting the system ambient temperature, thereby realizing dynamic management of the heating function. At the same time, the temperature control circuit is used to control the temperature so that the temperature of the LTCC substrate reaches a state that allows the chip to work. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a traditional heating film;

[0021] Figure 2 This is a schematic diagram of the buried position of the heating film of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0023] In normal and high temperature environments, the RF circuit can work normally without any problem of the device not working. However, when the ambient temperature is lower than -55℃, the system will not start or the circuit will work abnormally. At this time, the circuit needs to be heated to ensure the normal startup and operation of the system.

[0024] To achieve the above-mentioned purpose, the utility model provides an integrated distributed heating circuit, including a heating film and a device to be heated embedded in different layers of a LTCC substrate; wherein the heating film is located in the middle layer of the LTCC substrate, and each device to be heated is located in the top layer or the bottom layer of the LTCC substrate; the heating film is composed of a plurality of heating blocks connected in series and in parallel through heating wires, and each heating block is obtained by arranging the heating wires in multiple S shapes; at the same time, the projection of each device to be heated on the middle layer overlaps or intersects with at least one heating block.

[0025] That is to say, when the LTCC board is made, the utility model has an integrated distributed heating network built under the device to be heated, such as the RF chip that needs to be heated, instead of the traditional integral heating network; the heating film is powered by a DC power supply from an external whole system power supply, wherein the greater the difference between the current ambient temperature and the operating temperature required by each device to be heated, the higher the voltage of the external whole system power supply, thereby realizing the heating function under low temperature conditions.

[0026] Furthermore, the number of the heating films is determined according to the number of devices to be heated and the required operating temperature of each device to be heated. At the same time, the more devices to be heated, the higher the required operating temperature of each device to be heated, the more heating films are required, and each heating film is buried in a different layer in the middle of the LTCC substrate. Figure 2 As shown, there are two layers of heating films distributed on two layers of LTCC substrate. The setting position of the heating block corresponds to the device that needs to be heated, so as to achieve precise heating, avoid uneven heating of the substrate, and improve energy utilization efficiency.

[0027] It should be noted that the device to be heated includes a radio frequency main circuit, a temperature detection circuit and a temperature control circuit; when the radio frequency main circuit is started, the temperature detection circuit detects the current ambient temperature and sends the current ambient temperature to the temperature control circuit, and the temperature control circuit determines whether to start the heating film according to the difference between the current ambient temperature and the required working temperature of each device to be heated, wherein when the difference is less than the set value, the heating film is turned off. In other words, after the radio frequency main circuit is started, the temperature detection circuit controls the power supply to the heating film by detecting the system ambient temperature, thereby realizing dynamic management of the heating function.

[0028] It should be noted that the temperature control circuit is flexible and the system power supply voltage can be selected according to the specific temperature range.

[0029] The embedded heating film is a special process introduced in the LTCC board making process to achieve the heating function. The following is the process flow of the embedded heating film:

[0030] 1. Substrate preparation: Prepare the LTCC substrate, which can be a classic multilayer ceramic substrate.

[0031] 2. Slurry preparation: Prepare a slurry containing a metal oxide with a high resistivity of thousands of ohms;

[0032] 3. Printing and coating of integrated distributed heating network: adding the slurry at a designated position on a designated layer of the LTCC substrate using printing or coating technology;

[0033] 4. Sintering: Sintering the LTCC substrate with the slurry added to solidify the high resistivity metal oxide and bond it to the LTCC substrate;

[0034] 5. Conductive layer preparation and welding through-holes: Add conductive materials to other layers of the LTCC substrate and create through-holes or welding holes to achieve circuit connection between the heating film and the device to be heated;

[0035] 6. Re-sintering: The LTCC substrate is sintered at high temperature for the second time to ensure the firmness of the entire structure;

[0036] 7. External connection: Add external connectors or pins to the LTCC substrate after secondary sintering to connect the LTCC substrate with other external electronic components.

[0037] 8. Testing: The manufactured LTCC substrates are tested with special attention paid to the performance of the heating elements and the overall heating function.

[0038] It can be seen that the utility model adopts LTCC substrate, embeds heating film inside it, and sets the heating network to open or close through the temperature control circuit system, so that components can work normally at extremely low temperatures, and make the whole system lightweight, miniaturized and low power consumption. Compared with the traditional heating film heating, the embedded heating film provided by the utility model has higher heat conversion efficiency. After detailed thermal simulation results, it can be seen that under the condition of heating film heating, the heating power is 30W, and the substrate temperature has risen from -90℃ to -38.7℃ after preheating for ten minutes, while the traditional heating film heating method requires 45W heating power, so the embedded heating film form has higher heating efficiency than the traditional heating film method. In addition, the integrated distributed heating network can heat the RF chip faster and more fully, has higher thermal conductivity, and can start the chip normally in a low-energy and high-efficiency manner; therefore, the utility model can effectively reduce the design and production costs, reduce the volume of microwave components, reduce the weight of modules, and can well meet the heating needs of RF circuits.

[0039] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field can certainly make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. An integrated distributed heating circuit, characterized in that: It includes heating films and devices to be heated that are embedded in different layers of the LTCC substrate; wherein the heating film is located in the middle layer of the LTCC substrate, and each device to be heated is located in the top layer or the bottom layer of the LTCC substrate; The heating film is composed of multiple heating blocks connected in series and in parallel through heating wires, and each heating block is arranged in multiple S shapes through the heating wires; at the same time, the projection of each device to be heated on the middle layer overlaps or intersects with at least one heating block.

2. An integrated distributed heating circuit as claimed in claim 1, characterized in that: The heating film is powered by a direct current from an external whole-machine system power supply, wherein the greater the difference between the current ambient temperature and the required operating temperature of each device to be heated, the higher the voltage of the external whole-machine system power supply.

3. An integrated distributed heating circuit as claimed in claim 1, characterized in that: The number of the heating films is determined according to the number of devices to be heated and the required operating temperature of each device to be heated. At the same time, the more devices to be heated, the higher the required operating temperature of each device to be heated, the more heating films are required, and each heating film is buried in a different layer in the middle of the LTCC substrate.

4. An integrated distributed heating circuit as claimed in claim 1, characterized in that: The heating wire is a metal oxide with high resistivity.

5. An integrated distributed heating circuit as claimed in any one of claims 1 to 4, characterized in that: The device to be heated includes a radio frequency main circuit, a temperature detection circuit and a temperature control circuit; When the RF main circuit is started, the temperature detection circuit detects the current ambient temperature and sends the current ambient temperature to the temperature control circuit. The temperature control circuit decides whether to start the heating film based on the difference between the current ambient temperature and the operating temperature required by each device to be heated. When the difference is less than the set value, the heating film is turned off.

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