Ceramic heater with micro-channel structure

Abstract

The utility model relates to the technical field of heater, especially a kind of ceramic heater with micro-channel structure, including base, heating circuit and micro-channel, the heating circuit is arranged on base, the micro-channel is the flow channel of multiple parallel and sinuously connected, the plane where the micro-channel is parallel with the plane where heating circuit is, cooling liquid is equipped in the micro-channel, and two ends are equipped with liquid inlet and liquid outlet, liquid inlet and liquid outlet are connected with liquid circulating mechanism on it.The utility model sets up micro-channel in base, realizes the active heat dissipation to high power density ceramic heater by cooling liquid forced convection heat exchange, improves the temperature uniformity and stability of ceramic heater, and micro-channel structure, heating circuit and ceramic base are integrated into one, the external cumbersome radiator is saved, and the miniaturization and light weight of device are realized.

Description

Technical Field

[0001] This utility model relates to the field of heater technology, and in particular to a ceramic heater with a microchannel structure. Background Technology

[0002] Ceramics have advantages such as high thermal conductivity, good electrical insulation properties, and a thermal expansion coefficient that matches that of silicon, making them ideal heating substrate materials for high-power electronic devices, semiconductor process equipment, lasers, and other fields.

[0003] Traditional ceramic heaters use a thick-film process to print resistance paste onto a ceramic substrate, generating heat through the Joule effect. However, with the advancement of modern technology towards miniaturization, integration, and high power, the requirements for heater power density are increasing. The thermal conductivity of the ceramic substrate alone is no longer sufficient to dissipate heat quickly, leading to several problems, such as:

[0004] 1. Localized overheating: The area directly below the heating circuit has a much higher temperature than other areas, forming a "hot spot";

[0005] 2. Thermal stress cracking: Excessive temperature gradients can generate thermal stress, leading to cracking of the ceramic matrix;

[0006] 3. Limited applications: It cannot be used in precision applications requiring rapid heating and cooling cycles or extremely stable temperatures.

[0007] Therefore, developing a novel ceramic heater structure capable of active and efficient heat dissipation has become a pressing technical challenge in this field. Utility Model Content

[0008] To address the aforementioned problems, the purpose of this invention is to provide a ceramic heater with a microchannel structure, which achieves active heat dissipation for high-power-density ceramic heaters through forced convection heat transfer, thereby improving the temperature uniformity and stability of the ceramic heaters.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a ceramic heater with a microchannel structure, comprising a substrate, a heating circuit and a microchannel, wherein the heating circuit is disposed on the substrate, and the microchannel is a series of parallel and meandering channels connected together, wherein the plane of the microchannel is parallel to the plane of the heating circuit, wherein the microchannel is provided with coolant, and both ends are provided with inlet and outlet, and a liquid circulation mechanism is connected to the inlet and outlet.

[0010] In the above technical solution, the substrate is a ceramic material of alumina or aluminum nitride.

[0011] In the above technical solution, the heating circuit is embedded inside the substrate.

[0012] In the above technical solution, the heating circuit is embedded on the surface of the substrate.

[0013] In the above technical solution, the heating circuit is provided with a connector that extends out of the substrate and is connected to an external electrode through the connector.

[0014] In the above technical solution, the microchannel is located close to the heating circuit and directly below the heating circuit.

[0015] In the above technical solution, the liquid circulation mechanism includes a liquid guide pipe connecting the liquid inlet and the liquid outlet and a circulation pump installed on the liquid guide pipe. The coolant flows along the liquid guide pipe and the microchannel under the drive of the circulation pump.

[0016] In the above technical solution, the thickness of the substrate is 5 to 20 mm.

[0017] In summary, the advantages of the technical solution of this utility model compared with traditional technical means are as follows: the heat dissipation efficiency of this utility model is 1 to 2 orders of magnitude higher than that of pure heat conduction through forced convection in the microchannel, which can support extreme power density at the level of kilowatt / square centimeter and has fast heat dissipation.

[0018] By adjusting the flow rate and temperature of the coolant flowing through the microchannel, the temperature of the ceramic heater can be dynamically adjusted while maintaining a fixed operating power, making the temperature dynamically controllable.

[0019] By designing the location and size of the microchannels, local heat can be precisely removed, and the temperature uniformity of the entire ceramic heater can be controlled within ΔTMAX < 1℃, resulting in good temperature uniformity.

[0020] By eliminating localized overheating and enormous thermal stress, the risk of material aging and failure is reduced, extending the service life of the heater and greatly improving its reliability.

[0021] By integrating the microfluidic structure, heating circuit, and ceramic substrate into one unit, the bulky external heat sink is eliminated, achieving miniaturization and weight reduction of the device. Attached Figure Description

[0022] Other objects, features and advantages of this invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0023] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0024] Figure 2 This is a side sectional view of the present invention;

[0025] Figure 3 This is a cross-sectional schematic diagram of the microchannel of this utility model;

[0026] The following labels are used: 100, substrate; 200, heating circuit; 300, microchannel; 310, liquid inlet; 320, liquid outlet; 400, liquid circulation mechanism. Detailed Implementation

[0027] Based on the preferred embodiments of this utility model, and through the following description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

[0028] The present invention will be further described with reference to the following figures:

[0029] like Figures 1-3 As shown, a ceramic heater with a microchannel structure includes a substrate 100, a heating circuit 200, and a microchannel 300. The heating circuit 200 is disposed on the substrate 100. The microchannel 300 consists of multiple parallel and meandering channels. The plane of the microchannel 300 is parallel to the plane of the heating circuit 200. Coolant is disposed inside the microchannel 300, and inlet 310 and outlet 320 are provided at both ends. Liquid circulation mechanisms are connected to the inlet 310 and outlet 320.

[0030] The substrate 100 is made of alumina or aluminum nitride ceramic material, providing structural support, electrical insulation, and basic thermal conductivity.

[0031] The heating circuit 200 is embedded inside the substrate 100 or disposed on the surface of the substrate 100.

[0032] The cross-section of the microchannel 300 is a regular shape such as a circle, rectangle, or trapezoid.

[0033] The heating circuit 200 is provided with a connector 210 extending out of the substrate 100, and is connected to an external electrode through the connector 210.

[0034] like Figure 2 As shown, the microchannel 300 is disposed close to the heating circuit 200 and located directly below the heating circuit 200.

[0035] The liquid circulation mechanism includes a liquid guide pipe connecting the liquid inlet 310 and the liquid outlet 320 and a circulation pump installed on the liquid guide pipe. The coolant flows along the liquid guide pipe and the microchannel under the drive of the circulation pump. A small condenser can also be installed on the liquid guide pipe to accelerate the cooling of the coolant.

[0036] The thickness of the substrate 100 is 5-20 mm, while the thickness of the substrate 100 in the prior art is 1-5 mm. In order to increase the microchannel 300, the thickness needs to be increased.

[0037] The preparation method of this utility model is as follows:

[0038] S1 casting: Aluminum nitride or aluminum oxide powder, sintering aid, binder and plasticizer are mixed into a slurry and then cast to prepare a ceramic tape.

[0039] S2 graphical processing:

[0040] On some green ceramic strips, microchannel structures are prepared by laser etching or precision die stamping. On some green ceramic strips, resistive paste is prepared into specific patterns by screen printing or inkjet printing technology to initially form a heating circuit.

[0041] S3 stacking: The green ceramic tape with microchannel structure, the green ceramic tape with heating circuit, and the complete green ceramic tape as ceramic matrix are stacked in a preset order.

[0042] S4 isostatic pressing: After lamination, cold isostatic pressing is performed to make each layer of green ceramic tape dense and firmly bonded together.

[0043] S5 Debinding and Co-firing: In a protective atmosphere, the isostatically pressed multilayer green ceramic strip is placed in an atmosphere furnace and heated to initially remove the organic binder. Then, it is sintered at a high temperature of 1600℃~1850℃ to densify the ceramic matrix and co-fire it with the internal heating circuit and microchannel structure to form a solid whole.

[0044] S6 Post-processing: After sintering, the inlet and outlet of the microchannel are made by precision machining, and the electrode positions of the heating circuit are metallized and external electrodes are welded for power supply.

[0045] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A ceramic heater with a microchannel structure, characterized in that: It includes a substrate, a heating circuit, and microchannels. The heating circuit is disposed on the substrate. The microchannels are multiple parallel and meandering channels connected together. The plane of the microchannels is parallel to the plane of the heating circuit. Coolant is disposed in the microchannels, and inlet and outlet are provided at both ends. Liquid circulation mechanism is connected to the inlet and outlet.

2. The ceramic heater with a microchannel structure according to claim 1, characterized in that: The substrate is a ceramic material of alumina or aluminum nitride.

3. The ceramic heater with a microchannel structure according to claim 1, characterized in that: The heating circuit is embedded inside the substrate.

4. The ceramic heater with a microchannel structure according to claim 1, characterized in that: The heating circuit is embedded on the surface of the substrate.

5. The ceramic heater with a microchannel structure according to claim 1, characterized in that: The heating circuit is provided with a connector that extends out of the substrate and is connected to an external electrode through the connector.

6. The ceramic heater with a microchannel structure according to claim 1, characterized in that: The microchannel is positioned close to the heating circuit and directly below it.

7. The ceramic heater with a microchannel structure according to claim 1, characterized in that: The liquid circulation mechanism includes a liquid guide pipe connecting the liquid inlet and the liquid outlet, and a circulation pump installed on the liquid guide pipe. The coolant flows along the liquid guide pipe and the microchannel under the drive of the circulation pump.

8. The ceramic heater with a microchannel structure according to claim 1, characterized in that: The thickness of the substrate is 5–20 mm.

Images