Interdigital electrode embedded porous glass heating chip and preparation method thereof

Abstract

The invention relates to the technical field of electronic cigarettes, and discloses an interdigital electrode embedded type porous glass heating chip which comprises a substrate made of ultrathin high-temperature-resistant porous glass with the thickness of 30-500 microns, the pore diameter of 1-3 microns and high-temperature-resistant glass; the heating electrode is embedded into the surface of the substrate through a sputtering / electroplating process; a conductive interdigital electrode is sputtered / electroplated or printed on the heating electrode, the thickness of the conductive interdigital electrode is 1-5 microns, and the conductive interdigital electrode is made of a composite layer of Ag, Ni-Au, Pt and Sn; and the bonding pad is electrically connected with the interdigital electrode. Ultrathin high-temperature-resistant glass is adopted as a base body, through cooperative processing of laser induction (the wavelength is 355 nm) and hydrofluoric acid etching (the concentration is 8%), a porous array tar guiding channel with the aperture being 1-30 microns is formed in the surface of the glass base body, uniform tar guiding and rapid atomization of tobacco tar are achieved, and the heating efficiency and the current uniformity are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic cigarette atomization, and specifically to an interdigital electrode embedded porous glass heating chip and a preparation method thereof, which are particularly suitable for high-precision atomization, anti-oil leakage and rapid heating scenarios. Background Art

[0002] In an electronic cigarette atomizer device, the atomization core assembly plays a core role. It uses the principle of heating by electricity to atomize liquid e-liquid into smoke at high temperature and delivers it to the consumer's mouth through a specially designed smoke channel.

[0003] Currently, the main materials of electronic cigarette atomization cores include cotton cores and porous ceramics. These materials have certain advantages in oil conduction and heating, but they also have some obvious technical limitations. Although the cotton core material has low cost and good oil conduction performance, its service life is short and it is easy to burn at high temperature due to the reduction of e-liquid. The burning rate reaches 80% after continuous use for 2 hours, resulting in a deteriorated taste and the generation of bad odors. This phenomenon not only affects the user experience but also poses certain safety hazards. In the prior art, in order to solve this problem, attempts have been made to improve the burning problem by changing the material of the cotton core or adding a protective coating, but the effect is limited and the fundamental problem still exists.

[0004] In contrast, porous ceramic materials have been gradually widely used in electronic cigarette atomization cores due to their good thermal stability and long service life. However, in the manufacturing process of porous ceramics, auxiliary components such as paraffin are usually introduced, and even after high-temperature dewaxing treatment, it is difficult to completely remove the residues. The residual paraffin content in porous ceramics after dewaxing is >0.5 ppm, resulting in a 60% increase in the deterioration rate of e-liquid taste. This residue will directly affect the original taste of the e-liquid and reduce the user's smoking experience. At the same time, when the ceramic material adsorbs e-liquid, ceramic particles will be discharged and infiltrated during the heating process, posing a potential risk of inhaling harmful components by atomization. In addition, due to the difficulty in maintaining the consistency of oil-permeable pores during the forming and sintering processes of porous ceramics, there are often differences in the performance between atomization cores, making it difficult to achieve product consistency.

[0005] On the other hand, most of the atomization core structures in the prior art adopt the design of external heating wire winding or internal heating sheets. This design is difficult to achieve rapid heating in a short time, resulting in a long waiting time for the user to generate smoke when smoking. Moreover, due to the uneven distribution of the heating wire or heating sheet, there is often a problem of local overheating, which not only affects the heating efficiency but also may cause safety hazards. Some technical solutions attempt to improve the heating effect by changing the material of the heating wire or optimizing the layout method, but due to the uneven current distribution and the limitations of the material itself, this problem still cannot be completely solved. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides an interdigital electrode embedded porous glass heating chip and its preparation method, which solves the problems of uneven oil guiding, low heating efficiency, complex processing and poor taste consistency of the existing atomizing cores.

[0007] To achieve the above objectives, the present invention is realized through the following technical solutions: An interdigital electrode embedded porous glass heating chip, comprising: A substrate, which is an ultra-thin high-temperature resistant porous glass with a thickness of 30-500um, a pore diameter of 1-30um, and the material is high-temperature resistant glass; A heating electrode, which is embedded on the surface of the substrate through a sputtering / electroplating process, with a thickness of 0.1-1um, and the material is a Ti-TiN composite layer; Interdigital electrodes, on the heating electrode, sputtering / electroplating or printing conductive interdigital electrodes, with a thickness of 1-5um, and the material is an Ag, Ni-Au, Pt, Sn composite layer; A support frame, which fixes the substrate through a snap structure, and the frame material is high-temperature resistant polyimide; A pad, which is electrically connected to the interdigital electrode and is used for external circuit conduction.

[0008] Preferably, the thickness of the substrate is 30-500um, the glass substrate (such as Pyrex7740 glass), its thermal expansion coefficient is (3.3×10 -6 / °C), and the heat resistance (>600°C).

[0009] Preferably, the thickness of the heating electrode is 0.1-1um, such as a Ti-TiN composite material, and the thickness of the interdigital electrode is 1-5um.

[0010] Preferably, the interdigital electrode is deposited on the surface of the substrate by a sputtering or electroplating process.

[0011] A preparation method of an interdigital electrode embedded porous glass heating chip, comprising the following steps: Thin the high-temperature resistant glass to a preset thickness to form a substrate; Form a porous array on the substrate through processing; Fabricate a heating electrode on the surface of the substrate; Deposit a conductive material in the pattern area to form interdigital electrodes; Deposit, electroplate or print lead electrodes in the lead area to form a complete heating chip.

[0012] Preferably, the glass thinning step is carried out by means of chemical mechanical thinning or directly obtained by the overflow method.

[0013] Preferably, the porous array is processed by the synergistic processing of laser marking and hydrofluoric acid etching to form a porous array oil guiding channel with a pore diameter of 1-200 um on the surface of the glass substrate. The wavelength of the laser marking is 355 nm, and the concentration of the hydrofluoric acid etching is 8%.

[0014] Preferably, the Pad of the interdigital electrode is covered with Cu surface NiAu or Ag or Sn.

[0015] Preferably, the porous array is a multi-layer structure, and the multi-layer structure includes a Ti adhesion layer, a TiN heating layer, and a SiO2 protection layer. The SiO2 protection layer is used to protect the interdigital electrode.

[0016] Preferably, the multi-layer structure includes, but is not limited to, a bottom metal adhesion layer, a heating electrode layer, a surface passivation layer, and a pad lead layer from bottom to top. The thickness of the bottom metal adhesion layer is 20 nm, including but not limited to titanium and chromium materials. The thickness of the heating metal layer is about 0.2 um, including but not limited to platinum, titanium nitride, copper, tungsten, and nickel materials. The thickness of the surface passivation layer is 0.2-0.5 um, including but not limited to silicon dioxide, gold, and silicon nitride.

[0017] The present invention provides an interdigital electrode embedded porous glass heating chip and a preparation method thereof. It has the following beneficial effects: 1. By adopting a design with a porous array pore diameter of 1-30 um and combining laser and wet etching processes, the pore diameter and processing accuracy of the oil guiding channel are precisely controlled, solving the problem of uneven oil guiding in the traditional technology. Compared with the prior art, the particle size distribution of the atomized particles is more uniform, and the proportion of particles with a size of 1-5 um exceeds 90%, significantly improving the oil guiding efficiency and atomization effect of the e-liquid, and the taste consistency is improved by 40%.

[0018] 2. The present invention adopts an interdigital electrode sputtering deposition process (deposition thickness is 1-5 um), and through an alternating arrangement structure design, the contact area between the electrode and the substrate is maximized, improving the heating efficiency and the uniformity of current distribution. Compared with the traditional heating wire or heating sheet design, it avoids the problems of local overheating and slow heating rate, realizes faster heating (only 0.5-1 second, temperature difference ±2 °C), and significantly improves the heating efficiency, ensuring the improvement of the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a top view structural schematic diagram of the chip of the present invention; Figure 2 is a cross-sectional view structural schematic diagram of the chip of the present invention; Figure 3 is a schematic flow chart of the steps of the present invention; Figure 4Schematic cross-sectional structure diagram of the porous array of the present invention.

[0020] Among them, 1 is the substrate; 2 is the interdigital electrode; 4 is the pad; 5 is the heating electrode. Specific embodiments

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] Embodiment 1: Please refer to the attached Figure 1 - attached Figure 3 , the embodiment of the present invention provides an interdigital electrode-embedded porous glass heating chip, including: A substrate 1, which is an ultra-thin high-temperature resistant porous glass with a thickness of 30-500 um, a pore diameter of 1-30 um, and the material is high-temperature resistant glass; A heating electrode 5, which is embedded on the surface of the substrate through a sputtering / electroplating process, with a thickness of 0.1-1 um, and the material is a Ti-TiN composite layer; An interdigital electrode 2, on the heating electrode, a conductive interdigital electrode is sputtered / electroplated or printed, with a thickness of 1-5 um, and the material is a composite layer of Ag, Ni-Au, Pt, and Sn; A support frame, which fixes the substrate 1 through a snap structure, and the frame material is high-temperature resistant polyimide; A pad 4, which is electrically connected to the interdigital electrode 2 for external circuit conduction.

[0023] Specifically, the substrate 1 adopts an ultra-thin high-temperature resistant porous glass, which has good heat conduction performance and mechanical strength. A uniformly distributed porous array is processed on its surface for guiding and storing e-liquid. The interdigital electrode 2 and the heating electrode 5 are embedded on the surface of the substrate 1, designed in an alternating finger-like structure, which can maximize the contact area with the heating area, thereby improving the heating efficiency. The pad 4 is the input / output interface of the chip, and the internal circuit of the chip and the external circuit are connected through the pad 4 to realize the input / output function.

[0024] In some embodiments, the pore diameter and pore density of the porous array on the substrate 1 can be adjusted according to specific usage requirements. Generally, the pore diameter range is 1 to 200 um, which can ensure the full penetration and e-liquid guiding performance of the e-liquid. In another possible implementation, the pore density can be set to 100 to 3000 pores per square millimeter to meet the usage requirements of different types of e-liquid. As an option, these pores can be processed by laser-induced and wet etching processes to ensure processing accuracy and pore diameter consistency.

[0025] Specifically, the interdigital electrode 2 is made of a highly conductive metal material or alloy, and the materials can be copper, chromium, aluminum and their alloys. These materials have good electrical conductivity and high temperature resistance characteristics, which can ensure the stability of the chip in a long-term high-temperature working environment. In a possible implementation, the thickness of the interdigital electrode 2 can be controlled between 1 and 5 μm. By depositing the interdigital electrode 2 on the surface of the substrate 1 by sputtering, electroplating or coating process, the adhesion and electrical conductivity of the electrode can be effectively improved. Experimental verification shows that at a power of 8 W, the chip only needs 0.5 to 1 second to heat up to 200 °C, and the temperature uniformity is ±2 °C (±15 °C for the traditional solution). The proportion of atomized particle sizes of 1-5 μm is >95%, and the taste consistency is improved by 50%.

[0026] In this embodiment, the support frame is used to provide mechanical support for the substrate 1 and the interdigital electrode 2, and to ensure that the entire chip has sufficient structural strength during use. The material of the support frame can be selected from high-temperature resistant engineering plastics, metals or ceramic materials. These materials can not only meet the use requirements in high-temperature environments, but also effectively reduce the loss during the chip assembly process. In a possible application scenario, the support frame is fixed around the substrate 1 by snap or gluing methods to ensure simple and firm assembly.

[0027] In some other embodiments, in order to further improve the service life and safety of the chip, a passivation protection layer can be added to the surface of the interdigital electrode 2. The passivation layer can be made of a corrosion-resistant material, such as silicon oxide or silicon nitride. Through this design, the corrosion resistance of the electrode can be significantly improved, and the service life of the chip can be extended. Durability experiments verify that after continuous operation for 1000 times, the change rate of the electrode resistance is <3%, and there is no residual e-liquid.

[0028] In another implementation of the present invention, in order to adapt to different power requirements, the pattern design of the interdigital electrode 2 can be adjusted. For example, the coverage area of the heating region can be expanded by increasing the number of electrode fingers, so as to achieve higher power output. At the same time, the thickness of the substrate 1 can also be appropriately adjusted according to the power requirements to ensure that the chip can maintain good heat conduction performance and mechanical strength under different power conditions.

[0029] Generally, in order to improve the processing efficiency and consistency of the entire chip, an automated batch production process can be adopted. In some embodiments of the present invention, the thinning of the substrate 1 and the processing of the porous array can be completed by the combined operation of a laser device and a chemical etching device. Specifically, after the glass is induced by a laser device, wet etching with hydrofluoric acid can be used to ensure the high precision and high consistency of the porous array.

[0030] The present invention realizes an efficient, safe and well - consistent heating chip by embedding interdigital electrodes 2 and heating electrodes 5 on an ultra - thin high - temperature - resistant porous glass substrate 1 and combining the design of the peripheral support frame. Through the combination of the above - mentioned various technical features, the present invention can not only significantly improve the use experience of electronic cigarettes, but also reduce the manufacturing cost through an automated mass - production process and enhance the market competitiveness.

[0031] Embodiment 2: Please refer to the attached Figure 2 , based on Embodiment 1, the present invention provides a preparation method for an interdigital - electrode - embedded porous - glass heating chip, including the following steps: Thin the high - temperature - resistant glass to a preset thickness to form the substrate 1; Form a porous array on the substrate 1 through processing. The porous array is a multi - layer structure for protecting the interdigital electrode 2. The multi - layer structure includes, but is not limited to, a bottom metal adhesion layer, a heating electrode layer, and a surface passivation layer. The bottom metal adhesion layer includes, but is not limited to, titanium and chromium materials. The heating electrode layer includes, but is not limited to, platinum, titanium nitride, copper, tungsten, silver, and nickel - chromium alloy materials. The surface passivation layer includes, but is not limited to, silicon dioxide and silicon nitride; Specifically, in this embodiment, the high - temperature - resistant glass is thinned to a preset thickness to form the substrate 1. Generally, the thickness of the glass is controlled between 30 and 500 um, and the specific thickness can be selected according to the requirements of different application scenarios. In a possible implementation, to ensure the mechanical strength and heat conduction efficiency of the substrate 1, glass with a thickness of 100 to 300 um is preferred.

[0032] In actual processing, the glass thinning can be carried out by physical grinding, chemical thinning, or a combination of both. In some embodiments, physical grinding is suitable for quickly thinning the glass, but there may be problems with insufficient surface flatness. To improve the surface flatness and thickness consistency of the glass, a chemical thinning process can be selected. Specifically, by immersing the glass in a specific chemical solution for etching, the surface material can be removed and the glass thickness can be gradually reduced. The advantage is that the glass surface is flatter after processing. In another possible implementation, to balance efficiency and precision, physical grinding can be used for preliminary thinning first, and then chemical thinning can be used to precisely control the final thickness.

[0033] In the actual preparation process, the heating electrode layer can be connected to the interdigital electrode and serve as a heating electrode. The surface passivation layer is designed with multi - layer coating using materials such as silicon dioxide and silicon nitride, which can effectively protect the heating electrode as a protective layer and prevent the oxidation of the heating electrode.

[0034] In order to further ensure the accuracy of subsequent porous array processing and the electrode deposition effect, the thinned glass surface needs to be cleaned. In this embodiment, deionized water and absolute ethanol are used to jointly clean the glass surface, and then a vacuum drying device is used for drying. In some embodiments, a surfactant can also be added during the cleaning process to improve the cleanliness of the glass surface, thereby providing better processing conditions for subsequent processes.

[0035] After the glass thinning and surface cleaning are completed, a uniformly distributed porous array needs to be processed on the substrate 1. These holes can not only achieve the functions of guiding and storing e-liquid, but also serve as the embedding area for the interdigital electrodes 2, ensuring the overall heating efficiency and service performance of the chip. In this embodiment, the porous array is processed by combining laser induction and wet etching processes. Specifically, first, a high-precision laser device is used to induce the preset hole array positions on the glass surface, and then the induced area is exposed to hydrofluoric acid solution for etching to form high-precision through holes.

[0036] Generally, the concentration of hydrofluoric acid is controlled at 5% to 10%, and the etching time is 10 to 30 minutes. The specific parameters can be adjusted according to actual needs. In one possible implementation, in order to improve the processing accuracy and aperture consistency, the etching solution can be circulated and stirred to ensure a uniform corrosion process. In some other embodiments, in order to further improve the flatness and mechanical strength of the through holes, the substrate 1 can be subjected to high-temperature annealing treatment after etching to eliminate the microcracks generated during the etching process.

[0037] Table 1 shows the parameter comparison between the laser induction + hydrofluoric acid wet etching process and the traditional mechanical drilling.

[0038] Process parameter comparison table: A porous array is formed on the substrate 1 through processing; As an option, in specific applications, the aperture and hole density of the hole array can be adjusted. For example, the aperture can be controlled between 1 and 200 um, and the hole density can be set to 100 to 3000 holes per square millimeter to meet the usage requirements of different types of e-liquids. In one possible application scenario, in order to handle high-viscosity e-liquid, the aperture can be appropriately increased or the hole density can be decreased to ensure that the e-liquid can be smoothly introduced into the channels and fully atomized.

[0039] After the porous array is processed, the pore walls can be further treated to improve their oil conduction performance and anti-pollution ability. In this embodiment, plasma treatment is used to modify the surface of the pore walls. By performing short-time plasma discharge treatment in an oxygen or nitrogen environment, a dense oxide film can be formed on the surface of the pore walls, improving the wettability and corrosion resistance of the pore walls. In some other embodiments, a hydrophobic or lipophilic coating can also be formed on the surface of the pore walls by means of coating, thereby optimizing the guiding effect of the e-liquid.

[0040] Fabricate interdigital electrodes 2 on the surface of substrate 1, and the Pad of the interdigital electrodes 2 is covered with NiAu or Ag or Sn on the Cu surface; Specifically, in this embodiment, first fabricate the pattern of the interdigital electrodes 2 on the surface of substrate 1. Generally, photolithography technology or laser-induced technology can be used. In one possible implementation, by coating a layer of photoresist on the surface of substrate 1, and then using photolithography equipment to expose and develop the photoresist, a pattern area of the interdigital electrodes 2 is formed. Photolithography technology has the advantages of high pattern accuracy and being suitable for the processing of um-level structures, which can ensure the accurate size and position of the pattern of the interdigital electrodes 2.

[0041] For the Pad of the interdigital electrodes, covering with NiAu or Ag on the Cu surface can meet Snsolder (soldering), enabling the Pad to support mechanical contact with a flat-top pin, allowing the chip to be used without the need for a dedicated wirebond, and achieving the highest space utilization rate.

[0042] As an option, in some embodiments, laser-induced technology can be used to directly induce the pattern of the interdigital electrodes 2 on the surface of substrate 1. Laser induction is simple in operation and high in flexibility, and is particularly suitable for small-batch production or customized design scenarios. In another possible implementation, in order to improve the edge clarity of the interdigital electrodes 2, the laser induction and chemical etching processes can be combined to further optimize the pattern quality.

[0043] After the pattern is fabricated, a highly conductive material needs to be deposited in the induced area to form the interdigital electrodes 2. In this embodiment, a sputtering process is used to deposit a highly conductive metal material in the pattern area on the surface of substrate 1. The sputtering process is suitable for the deposition of metals with fine structures and can form a metal layer with uniform thickness and good adhesion on the surface of substrate 1. In some other embodiments, electroplating or chemical coating processes can also be selected for deposition, and a suitable conductive material is selected according to actual application requirements.

[0044] In general, the material of the interdigital electrode 2 can be selected from copper, gold, silver, aluminum or their alloys. These materials have low resistivity and good high-temperature resistance, which can ensure that the interdigital electrode 2 maintains good conductivity and stability during long-term operation. In a possible implementation, in order to improve the corrosion resistance of the interdigital electrode 2, after the metal deposition is completed, its surface can be oxidized or passivated to form a protective film, thereby extending the service life of the interdigital electrode 2.

[0045] In practical applications, the thickness of the interdigital electrode 2 is generally controlled between 1 and 5 μm. An overly thin electrode may result in excessive resistance, thereby reducing the heating efficiency, while an overly thick electrode may increase the processing cost. In this embodiment, by adjusting the deposition time and power of the sputtering process, the thickness of the interdigital electrode 2 is precisely controlled to meet specific heating power requirements.

[0046] To further improve the stability and conductivity of the interdigital electrode 2, after the electrode deposition is completed, its endpoints can be conductively connected. In this embodiment, the micro-welding technique is used to connect the endpoints of the interdigital electrode 2 to the external power supply connection area to ensure the stability of current transmission. In some embodiments, conductive adhesive can also be selected for endpoint bonding, and the advantage is that the process is simple and suitable for connecting different materials.

[0047] Fabricate the heating electrode 5 on the surface of the substrate 1; Deposit a conductive material in the pattern area to form the interdigital electrode 2; Specifically, in this embodiment, a conductive material is deposited in the pattern area of the substrate 1 through a process to form the interdigital electrode 2. Specifically, in the sputtering process, in a vacuum environment, high-energy ions bombard the conductive target, and the conductive material is deposited on the surface of the substrate 1 in the form of atoms or molecules. Generally, the conductive material can be selected from copper, chromium, aluminum or their alloys. These materials have low resistivity and high heat resistance, which can ensure the stability of the interdigital electrode 2 and the heating electrode 5 in a long-term working environment.

[0048] As an option, in some embodiments, electroplating can also be used for the deposition of the conductive material. The electroplating process is suitable for large-area metal deposition, and its advantages are low cost and fast deposition speed. In another possible implementation, in order to improve the uniformity of the deposited layer, a thin metal seed layer can be first formed by the sputtering process, and then the interdigital electrode 2 can be deposited to a preset thickness by the electroplating process.

[0049] Generally, the thickness of the interdigital electrode 2 is controlled between 1 and 5 μm to balance the conductivity and processing cost. In some specific applications, the thickness of the electrode can be adjusted according to the heating power requirement. For example, for a chip with high power output requirements, the electrode thickness can be appropriately increased to reduce the resistance loss and improve the heating efficiency. In another possible implementation, by controlling the sputtering power and deposition time, the thickness of the interdigital electrode 2 can be precisely adjusted to ensure that the thickness uniformity of the processed electrode meets the design requirements.

[0050] After the deposition of the conductive material is completed, generally, the surface of the interdigital electrode 2 needs to be cleaned and dried to remove impurities or residues that may adhere during the deposition process, so as to improve the surface cleanliness of the interdigital electrode 2. In some embodiments, to further improve the corrosion resistance of the interdigital electrode 2, a passivation film or protective coating can be added to its surface. For example, by using plasma deposition technology or chemical coating treatment, a dense oxide film can be formed on the surface of the interdigital electrode 2, thereby enhancing its antioxidant and corrosion resistance capabilities.

[0051] Please refer to the appendix Figure 4 , the multi-layer structure of the porous array includes, from bottom to top, but is not limited to, a bottom metal adhesion layer, a heating electrode layer, a surface passivation layer, and a pad lead layer. The thickness of the bottom metal adhesion layer is 20 nm and includes, but is not limited to, using titanium and chromium materials. The thickness of the heating metal layer is about 0.2 μm and includes, but is not limited to, using platinum, titanium nitride, copper, tungsten, and nickel materials. The thickness of the surface passivation layer is 0.2 - 0.5 μm and includes, but is not limited to, using silicon dioxide, gold, and silicon nitride.

[0052] After implementation verification, the aperture deviation of the existing laser direct engraving process is ±5 μm, and the roughness of the hole wall Ra > 1 μm, resulting in uneven oil conduction; while the laser-induced + wet etching process of the present invention has an aperture deviation of ±0.2 μm and a roughness Ra < 0.1 μm.

[0053] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A porous glass heating chip with interdigital electrodes embedded therein, characterized in that: include: The substrate (1) is an ultra-thin high temperature resistant porous glass with a thickness of 30-500 μm and a pore size of 1-30 μm, and is made of high temperature resistant glass; The heating electrode (5) is embedded in the surface of the substrate through a sputtering / electroplating process, has a thickness of 0.1-1 μm, and is made of a Ti-TiN composite layer; Interdigital electrode (2), on the heating electrode, a conductive interdigital electrode is sputtered / electroplated or printed, with a thickness of 1-5 μm and a material of Ag, Ni-Au, Pt, Sn composite layer; The soldering pad (4) is electrically connected to the interdigital electrodes (2) and is used for external circuit conduction.

2. The interdigital electrode embedded porous glass heating chip according to claim 1, characterized in that: The thickness of the substrate (1) is 30-500 μm, and the thermal expansion coefficient is 3.3×10 -6 / ℃.

3. The interdigital electrode embedded porous glass heating chip according to claim 1, characterized in that: The thickness of the heating electrode (5) is 0.1-1 um, and the thickness of the interdigital electrode (2) is 1-5 um.

4. The interdigital electrode embedded porous glass heating chip according to claim 1, characterized in that: The interdigitated electrodes (2) are deposited on the surface of the substrate (1) by sputtering or electroplating.

5. A method for preparing an interdigital electrode embedded porous glass heating chip, according to any one of claims 1 to 4, characterized in that: The following steps are involved: Thinning the high temperature resistant glass to a preset thickness to form a substrate (1); Forming a porous array on a substrate (1) by processing; A heating electrode (5) is fabricated on the surface of the substrate (1); Depositing a conductive material in the pattern area to form interdigitated electrodes (2); depositing a surface passivation layer on the heated area; Lead electrodes are deposited, electroplated or printed on the pad (4) area to form a complete heating chip.

6. The method for preparing a porous glass heating chip with embedded interdigital electrodes according to claim 5, characterized in that: The glass thinning step is performed by chemical mechanical thinning or overflow method.

7. The method for preparing a porous glass heating chip with interdigital electrodes embedded therein according to claim 5, characterized in that: The porous array processing is carried out by co-processing laser marking and hydrofluoric acid etching to form a porous array oil guide channel with a pore size of 1-200um on the surface of the glass substrate. The laser marking wavelength is 355nm, and the hydrofluoric acid etching concentration is 8%.

8. The method for preparing a porous glass heating chip with embedded interdigital electrodes according to claim 5, characterized in that: The Pad of the interdigital electrode (2) is covered with NiAu, Ag or Sn on the Cu surface.

9. The method for preparing a porous glass heating chip with interdigital electrodes embedded therein according to claim 5, characterized in that: The porous array is a multi-layer structure, which comprises a Ti adhesion layer, a TiN heating layer, and a SiO2 protective layer, wherein the SiO2 protective layer is used to protect the interdigital electrodes (2).

10. The method for preparing a porous glass heating chip with embedded interdigital electrodes according to claim 9, characterized in that: The multilayer structure includes but is not limited to a bottom metal adhesion layer, a heating electrode layer, and a surface passivation layer. The bottom metal adhesion layer includes but is not limited to titanium and chromium materials. The heating electrode layer includes but is not limited to platinum, titanium nitride, copper, tungsten, silver, and nickel materials. The surface passivation layer includes but is not limited to silicon dioxide and silicon nitride.

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