Heating substrate for thermal print head resistant to high energy impact and its manufacturing method

Abstract

The present invention relates to the technical field of thermal print head manufacturing, and more specifically, to a high-energy impact-resistant heating substrate for a thermal print head that can meet the requirements of high-temperature resistance and thermal shock resistance during thermal printing, and can overcome the defect of easy peeling between components caused by thermal stress, and a method for manufacturing the same. The heating substrate comprises an insulating substrate, a base glaze layer provided on the surface of the insulating substrate, and a heating resistor and electrode wires provided on the upper surface of the base glaze layer. The heating resistor is characterized in that the electrode wires within 0.3 mm from the heating resistor are high-energy impact-resistant electrode wires, the high-energy impact-resistant electrode wires comprising a lower electrode wire and an upper electrode wire, the lower electrode wire being made of a hafnium-aluminum (HfAl) alloy, having a thickness in the range of 0.1-2.0 μm, and the hafnium (Hf) content in the lower electrode wire being less than 10% of the total mass percentage.

Description

Technical field:

[0001] The present invention relates to the technical field of thermal print head manufacturing, and more specifically to a heating substrate for a thermal print head that is resistant to high temperatures and thermal shocks during thermal printing and that can overcome the defect of easy peeling between components caused by thermal stress, and a method for manufacturing the same. Background technology:

[0002] Thermal print heads use Joule heat to print. During the printing process, the temperature of the heating area is very high, reaching over 1000°C in special working environments. Existing thermal print heads have difficulty meeting this temperature requirement.

[0003] Prior literature on high-temperature-resistant materials currently includes the following: Patent document CN102815971 discloses an Hf(Ta)C ultra-high-temperature multiphase coating composed of HfC and HfTaC2, with the mole fraction of HfTaC2 ranging from 6-50% distributed uniformly or in a gradient throughout the coating. The preparation method involves placing a surface-treated substrate in a low-pressure chemical vapor deposition furnace. A mixed powder of hafnium tetrachloride and tantalum pentachloride serves as the hafnium and tantalum sources, along with methane, argon, and hydrogen as the reducing gas, is transported into the deposition furnace reactor and deposited on the substrate surface to form the Hf(Ta)C ultra-high-temperature multiphase coating.

[0004] Patent document number CN109320303 provides an ultra-high temperature oxidation-resistant and ablation-resistant coating and a preparation method thereof, relating to the field of chemical vapor deposition technology. The present invention provides an ultra-high temperature oxidation-resistant and ablation-resistant coating, including a Ta / (Ta,Hf)C multi-layer multiphase composite coating formed by alternating superposition of a metal Ta coating and a (Ta,Hf)C multiphase coating. A method for preparing an ultra-high temperature oxidation-resistant and ablation-resistant coating is also provided, the steps of which are as follows: S01, providing a pretreated substrate material; S02, preparing a (Ta,Hf)C multiphase coating on the surface of the substrate material, preparing a metal Ta transition coating on the surface of the (Ta,Hf)C multiphase coating, alternating deposition multiple times, and finally ending the deposition with a (Ta,Hf)C multiphase coating to prepare a Ta / (Ta,Hf)C multi-layer multiphase composite coating. It is suitable for preparing ultra-high temperature protective coatings on the inner pore surfaces of substrates such as graphite and C / C composite materials, and improving the oxidation resistance, ablation resistance, and thermal shock resistance of the inner pore working surface of the substrate material.

[0005] Patent document number CN109972120 proposes a method for preparing a multi-component composite carbide coating. It comprises the following steps: (1) placing a mixed powder of TaCl5, HfCl4, and ZrCl4 into a crucible under an inert atmosphere; (2) placing a substrate sample on a deposition furnace support, introducing argon gas, and heating to the deposition temperature; (3) placing the crucible containing the mixed powder on a lifting support in the low-temperature zone of a dual-temperature zone gasification furnace, connecting the crucible mouth to the high-temperature zone, setting the heating temperatures of the low and high-temperature zones, and heating to completely vaporize the mixed powder; (4) introducing H2 and CH4 into the deposition furnace, and then introducing the completely vaporized mixed gas into the deposition furnace using a carrier gas, and performing deposition under normal pressure. This preparation method can produce a multi-component composite coating with accurate stoichiometric ratios of each component, and can ensure that the coating is tightly and firmly bonded to the substrate material and has excellent stability.

[0006] Patent document CN111072388B proposes a long-lasting, ablation-resistant, ultra-high-melting-point nitrogen-containing carbide ultrahigh-temperature ceramic and its applications. The patent describes a method for producing HfCxNy ceramics with a density greater than or equal to 98% and a uniform C / N distribution using ball milling and spark plasma sintering. This novel ultra-high-melting-point ceramic overcomes the shortcomings of existing ultrahigh-temperature ablation-resistant ceramics, which suffer from excessively low ablation temperatures or rapid ablation loss at high temperatures, making it suitable for ultrahigh-temperature ablation protection at temperatures of 3000°C and above.

[0007] The above existing technologies all describe the preparation methods of Hf(Ta)C or HfCxNy high-temperature-resistant coatings. None of them provide technical means that can simultaneously meet the heat resistance and conductivity requirements of thermal print head products. The above existing materials cannot be directly used in the manufacture of thermal print heads. Summary of the invention:

[0008] In response to the shortcomings and deficiencies in the prior art, the present invention proposes a heating substrate for a thermal print head that is resistant to high energy shocks and can meet the requirements of high temperature resistance and thermal shock resistance during thermal printing, and can overcome the defect of easy peeling between components due to frequent thermal responses, and a method for preparing the same.

[0009] The present invention is achieved by the following measures:

[0010] A heating substrate for a thermal print head resistant to high-energy impacts comprises an insulating substrate, a bottom glaze layer provided on the surface of the insulating substrate, a heating resistor and an electrode wire provided on the upper surface of the bottom glaze layer, and is characterized in that the electrode wire within 0.3 mm from the heating resistor is an electrode wire resistant to high-energy impacts, and the electrode wire resistant to high-energy impacts comprises a lower electrode wire and an upper electrode wire, the lower electrode wire being made of a hafnium-aluminum (HfAl) alloy, having a thickness in the range of 0.1-2.0 μm, and a hafnium (Hf) content in the lower electrode wire accounting for less than 10% of the total mass percentage; and the upper electrode wire being made of a hafnium-iridium (HfIr) alloy, having a thickness in the range of 0.05-0.2 μm, and a hafnium (Hf) content in the upper electrode wire accounting for less than 10% of the total mass percentage.

[0011] In the high-energy impact-resistant electrode wire of the present invention, the lower electrode wire is connected to the aluminum Al wire to form an electrode wire for a thermal print head with good conductivity, wherein the high-energy impact-resistant electrode wire section is arranged close to the heating resistor area for the thermal print head. In this section, the lower electrode wire improves the temperature resistance of the electrode by adding Hf at a ratio of less than 10%, and the addition of Al can not only maintain good conductivity, but also maintain good adhesion between the electrode near the heating element and the Al electrode away from the heating element, and the cost is low; in order to obtain better anti-oxidation performance, an upper electrode wire is provided, wherein Ir has good anti-oxidation performance, and can resist oxidation up to 2100°C. The thermal expansion coefficient of Ir is 6.4±1e-6 / °C, which is similar to that of the lower electrode wire, and the resistivity is 4.7e-8Ω·m, which is also similar to that of the lower electrode wire, so that the multi-layer structure electrode wire can overcome the adverse effects of thermal stress and have an overall similar resistivity.

[0012] The heating substrate for the thermal print head described in the present invention is also provided with a heating resistor resistant to high-energy impact. The heating resistor resistant to high-energy impact is composed of a mixture of HfCxNy and SiC, with the proportion of HfCxNy in the total mass percentage being between 30% and 70%. The thickness of the heating resistor is 10 to 500 nm, and the resistivity is 500 to 4000E-8Ω.m. By adding the hafnium carbon nitride compound HfCxNy and utilizing the characteristic that the melting point of HfCxNy can reach above 4000°C (much higher than Ta, which has a melting point of 2996°C and an oxidation temperature of about 500°C and is commonly used in current heating elements), the finally formed heating resistor has the performance of resisting high-energy impact.

[0013] The bottom glaze layer of the heating substrate for the thermal print head of the present invention includes a bottom heat storage glaze layer and an HfO2 layer, wherein the bottom heat storage glaze layer is mainly made of SiO2, and the bottom heat storage glaze layer is made of a mixture of compounds composed of common bottom glaze materials such as Si, O, B, Zr, Ca, Al and other elements, and is prepared by a printing and sintering thick film process, with a thickness between 1um and several hundred um; the thermal conductivity of the bottom heat storage glaze layer is about 1W / mK, and the thermal expansion coefficient is 6.5±1e-6 / ℃. The HfO2 layer is made on the surface of the bottom heat storage glaze layer by PVD, CVD and other processes, with a thickness of 0.1~10um. The melting point of HfO2 is 2758℃, which can improve the power resistance and heat resistance of the print head. Temperature characteristics; the thermal conductivity of the HfO2 layer is 1.6~2W / mK, and the thermal conductivity similar to that of the lower layer can maintain similar thermal response characteristics. The thermal expansion coefficient of HfO2 is 6±1e-6 / ℃. The similar thermal expansion coefficient can avoid interlayer delamination due to thermal expansion and contraction. At the same time, the HfO2 layer can have a good bonding force with the heating resistor: the thermal expansion coefficient of HfCxNy is 6.73±1e-6 / ℃, and the thermal expansion coefficient of SIC is 4±1e-6 / ℃. The two are relatively close, and are also relatively close to the HfO2 in the lower layer. The thermal expansion coefficients of traditional heating element materials Ta and SiO2 are 15.8±1e-6 / ℃ and 6.5±1e-6 / ℃, respectively, which are quite different.

[0014] The heating substrate for the thermal print head of the present invention is further provided with a protective film, which covers the heating resistor and part of the electrode wires. The protective film is made of a mixture of HfO2 and SiN, or a mixture of HfO2 and SiON, or a mixture of HfO2 and SIALON. The protective film can be formed by PVD or CVD process.

[0015] The present invention also proposes a method for preparing a heating substrate for a thermal print head that is resistant to high-energy impact as described above, wherein the electrode wire resistant to high-energy impact is made by a sputtering film forming process combined with wet etching: a full pattern is formed by magnetron sputtering, a photolithography process is adopted, photoresist is used as a protective layer, and an electrode layer pattern is formed by wet etching, and an acid liquid is used as a wet chemical to form the electrode wire resistant to high-energy impact; or, the electrode wire resistant to high-energy impact is made by the following method: a photolithography process is adopted to protect unnecessary images with photoresist, an electrode layer of Hf+Al alloy and Hf+Ir alloy is sputtered, the photoresist and the electrode layer above are removed, and the pattern outside the photoresist is left to form an electrode layer pattern.

[0016] In the method for preparing the high-energy impact-resistant electrode conductor of the present invention, sputtering the electrode layer specifically includes the following steps:

[0017] Step 1: preparing an electrode wire target material, including a hafnium aluminum alloy target material and a hafnium iridium alloy target material, wherein the Hf content in the hafnium aluminum alloy target material is less than 10% by mass, and the hafnium Hf content in the hafnium iridium alloy target material is less than 10% by mass;

[0018] Step 2: Using the PVD magnetron sputtering process, place the substrate with the base glaze and the heating element into the cavity through direct current (DC) or radio frequency (RF), set the vacuum degree in the cavity to below 1×10-4Pa, heat the cavity temperature to 150-300°C, introduce argon gas with a pressure of 0.1-5Pa, and use magnetron sputtering technology to prepare the film layer.

[0019] In step 2 of the present invention, since the material is conductive, direct current (DC) magnetron sputtering is preferred, as it has higher sputtering efficiency. In order to improve the density and adhesion of the material, a direct current (DC) pulse mode is further adopted on the basis of the direct current (DC) mode, with the conditions of a frequency of 50-150k, a pulse power density of 4-7w / cm2, a duty cycle of 20-45%, and an air pressure of 0.2-0.8Pa; or high-power pulse magnetron sputtering (HIPIMS) technology is adopted, with a pulse power density of 400-1000w / cm2, a frequency of 0.1-5kHz, a duty cycle of 5-20%, and an air pressure of 0.2-1Pa.

[0020] The method for manufacturing the heating resistor of the heating substrate for the thermal print head of the present invention is specifically as follows:

[0021] S1: Prepare HfC powder, HfN powder, and SIC powder in a mass ratio of HfC:HfN:SIC = (1-3):(1-3):(1-2), wherein the purity of HfC, HfN, and SIC is greater than or equal to 99.9%. Use a ball milling method to refine the particles of the prepared HfC powder, HfN powder, and SIC powder, and mix them uniformly. After mixing, filter the powder to obtain a powder with a particle size of less than 5 μm.

[0022] S2: Plasma sintering the obtained mixed powder. The plasma sintering conditions are as follows: the temperature in the sintering furnace is 2100-2500°C, the temperature is kept for 15-20 minutes, the pressure is 35-50 MPa, and the vacuum degree is less than 2 Pa;

[0023] S3: The sintered material is cut into required sizes and welded to the target base to make a PVD target.

[0024] S4: Using PVD magnetron sputtering technology, direct current (DC) or radio frequency (RF) is used to place the substrate with the base glaze into the cavity, set the vacuum degree in the cavity to below 1×10-4Pa, heat the cavity temperature to 150-300℃, introduce argon gas, and the pressure is 0.1-5Pa. The film layer is prepared using magnetron sputtering technology to improve the density and adhesion of the material.

[0025] In S4 of the present invention, since the material is conductive, DC sputtering is selected, which has higher sputtering efficiency. On the basis of the DC mode, a DC pulse method is further adopted. The conditions are a frequency of 50-150k, a pulse power density of 4-7w / cm2, a duty cycle of 20-45%, and an air pressure of 0.2-0.8Pa.

[0026] Compared with the prior art, the present invention can meet the requirements of high temperature resistance and thermal shock resistance during thermal printing, and can overcome the defect of easy peeling between components caused by thermal stress. Description of the drawings:

[0027] Attachment Figure 1 It is a cross-sectional view of a heating substrate for a thermal print head according to the present invention.

[0028] Attachment Figure 2 It is a partial structural schematic diagram of the electrode wire in the present invention.

[0029] Attachment Figure 3 This is a partial cross-sectional view of the heating resistor area on the heating substrate for the thermal print head of the present invention.

[0030] Reference numerals: insulating substrate 1 , underglaze layer 2 , underglaze heat storage layer 2 - 1 , HfO 2 layer 2 - 2 , heating resistor 3 , electrode layer 4 , lower electrode layer 4 - 1 , upper electrode layer 4 - 2 , common electrode 4 a , individual electrode 4 b , protective layer 5 . Specific implementation method:

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] Example:

[0033] This example provides a thermal print head resistant to high-energy impact, comprising a heating substrate for the thermal print head, an integrated circuit (IC), a circuit board, a heat sink, and a socket. The heating substrate for the thermal print head comprises an insulating substrate, an underglaze layer, a heating resistor layer, an electrode layer, and a protective layer disposed on the insulating substrate. The electrode layer comprises electrode conductors, which include individual electrodes 4b and a common electrode 4a. The protective layer comprises an insulating protective layer, and a wear-resistant protective layer may be added to the insulating protective layer as needed.

[0034] The base glaze layer 2 in this example adopts a composite structure of a base glaze heat storage layer 2-1 with SiO2 as the main material and HfO2; the heating resistor is composed of a mixture of HfCxNy and SIC, which includes at least two types of conductive materials and insulating materials, and the resistivity can be adjusted by the ratio;

[0035] The electrode layer 4 in this example adopts a double-layer structure, the lower electrode layer 4-1 is composed of Hf+Al alloy, and the upper electrode layer 4-2 is composed of Hf+Ir alloy; the insulating protective film is composed of at least one of a HfO2&SiN mixture, a HfO2&SiON mixture, or a HfO2&SIALON mixture.

[0036] The bottom glaze layer 2 adopts a composite structure of a bottom glaze heat storage layer 2-1 with SiO2 as the main material and an HfO2 layer 2-2. The bottom glaze heat storage layer 2-1 with SiO2 as the main material adopts a mixture of compounds composed of common bottom glaze materials such as Si, O, B, Zr, Ca, Al and other elements. It is prepared by printing and sintering thick film technology, and the thickness is between several um and several hundred um; the thermal conductivity of the bottom glaze heat storage layer 2-1 is about 1W / mK, and the thermal expansion coefficient is 6.5±1e-6 / ℃. The HfO2 layer 2-2 is made on the surface of the base glaze heat storage layer 2-1 using PVD, CVD and other processes. The thickness is 0.1 to 10 μm. The melting point of HfO2 is 2758°C, which can improve the power resistance and temperature resistance of the print head. The thermal conductivity of the HfO2 layer is 1.6 to 2 W / mK, and the thermal conductivity similar to that of the lower layer can maintain similar thermal response characteristics. The thermal expansion coefficient of HfO2 is 6±1e-6 / °C. The similar thermal expansion coefficient can avoid interlayer delamination due to thermal expansion and contraction.

[0037] The heating resistor layer has a good bonding force with the base glaze layer and the protective layer. The selected heating resistor layer is composed of a mixture of HfCxNy and SiC. The ratio of HfCxNy is between 30% and 70%, the thickness is 10 to 500nm, and the resistivity of the mixture is 500 to 4000E-8Ω.m. The selected heating resistor layer is made by PVD or CVD processes. The melting point of HfCxNy can reach above 4000℃, which is much higher than the melting point of Ta commonly used in current heating elements, which is 2996℃ and the oxidation temperature is about 500℃. It has been verified that after ultra-long (300s) ablation, HfCxNy ceramics still maintain a near-zero ablation rate and a continuous, stable anti-oxidation protective structure. The thermal expansion coefficient of HfCxNy is 6.73±1e-6 / °C, and the thermal expansion coefficient of SIC is 4±1e-6 / °C. The two are relatively close, and are also relatively close to the underlying HfO2. The thermal expansion coefficients of traditional heating element materials Ta and SiO2 are 15.8±1e-6 / °C and 6.5±1e-6 / °C, respectively, which are quite different, and also differ significantly from the underlying HfO2. The resistivity of HfCxNy is approximately 36.33e-8Ω·m, and SIC is insulating. By adjusting different ratios, the two have different square resistances to meet different resistance requirements. The traditional heating element materials Ta (resistivity of 15e-8Ω·m) and SiO2 (insulating) are also relatively similar, and can form a substitute.

[0038] In this example, the resistance pattern of the heating resistor is a mixture of sputtered resistance layer HfCxNy and SiC. The photolithography process is adopted, photoresist is used as a protective layer, and dry etching is used to form the resistance layer pattern. Commonly used etching gases include Ar, CF4, CHF3, O2, etc.

[0039] In this example, the electrode layer adopts a double-layer structure. The lower electrode layer 4-1 is composed of a Hf+Al alloy with an Hf ratio of less than 10% and a thickness of 0.1 to 2 μm. The upper electrode layer 4-2 is composed of a Hf+Ir alloy with an Hf ratio of less than 10% and a thickness of 0.05 to 0.2 μm. The selected electrode layers are produced using processes such as PVD or CVD. Hf has a melting point of 2227°C, far higher than the currently commonly used Al, which has a melting point of approximately 600°C. The addition of Hf improves the temperature resistance of the electrode. The thermal expansion coefficient of Hf is 5.8e-6 / °C, which is lower than Al's 23e-6 / °C. The addition of Hf can reduce the thermal expansion coefficient of the electrode and alleviate thermal stress to a certain extent. The resistivity of Hf is 35.7e-8Ω·m, which is higher than Al's 2.83e-8Ω·m. Therefore, it is limited to use near heating elements with high temperature requirements, and the Hf ratio should not be too high. The retention of Al in the alloy electrode can not only maintain good conductivity, but also maintain good adhesion between the electrode near the heating element and the Al electrode away from the heating element, and the cost is low; in order to obtain better anti-oxidation performance, a thin Hf+Ir alloy conductive layer with a thickness of 0.05~0.2um is made outside the Hf+Al alloy. Ir has excellent anti-oxidation performance and can resist oxidation up to 2100℃. The thermal expansion coefficient of Ir is 6.4±1e-6 / ℃, which is similar to the lower electrode 1, and the resistivity is 4.7e-8Ω·m, which is also similar to the lower electrode 1.

[0040] The electrode layer can be realized through a variety of process methods. Method 1 is to sputter the electrode layer Hf+Al alloy and Hf+Ir alloy, adopt photolithography process, use photoresist as a protective layer, and wet etching to form the electrode layer pattern. Various acid liquids are used as wet chemicals; Method 2 is to adopt photolithography process, use photoresist to protect unnecessary images, sputter the electrode layer Hf+Al alloy and Hf+Ir alloy, remove the photoresist and the electrode layer above, and leave the pattern outside the photoresist to form the electrode layer pattern.

[0041] The insulating protective film is composed of at least one of a HfO2 & SiN mixture, an HfO2 & SiON mixture, or an HfO2 & SIALON mixture, with the HfO2 ratio being less than 20% and a total thickness between 1 and 20 μm. SiN is an electrical insulator with a temperature resistance of approximately 1900°C and a thermal expansion coefficient of 2.35±0.5e-6 / °C. SIALON is an electrical insulator with a melting point greater than 1500°C, thermal shock resistance greater than 900°C, and a thermal expansion coefficient of 2.6±0.5e-6 / °C. Both are relatively high-temperature-resistant materials, and their expansion coefficients are similar to those of the HfO2 of the underlying base glaze 2 and the HfCxNy of the heating element.

[0042] The insulating protective film can be made by using a lift-off process to prepare bentonite powder into a special slurry, using a printing process to cover the electrode pattern that needs to be exposed, sputtering an insulating protective film of HfO2&SiN mixture or HfO2&SiON mixture or HfO2&SIALON mixture, and finally removing the bentonite and the insulating protective film above to form an insulating protective film pattern.

[0043] From the heat storage layer to the heating element, to the electrode, and then to the protective layer, the Hf element runs through the entire process, which can maintain the fusion between the layers.

[0044] The preparation method of HfCxNy&SIC in the heating element,

[0045] S1: Prepare HfC powder, HfN powder, and SIC powder in a mass ratio of HfC:HfN:SIC = 2:3:2. The specific ratio is adjusted according to the resistance value of the print head to be made. The purity of HfC, HfN, and SIC is greater than or equal to 99.9%. Use ball milling to refine the prepared HfC powder, HfN powder, and SIC powder and mix them evenly. After mixing evenly, filter the powder to obtain a powder with a particle size of less than 5 μm.

[0046] S2: The resulting mixed powder is plasma sintered under the following conditions: a sintering furnace temperature of 2100-2500°C. The melting points of HfC, HfN, and SIC are 3928°C, 3305°C, and 2827°C, respectively. The plasma sintering temperature does not necessarily need to reach the melting point of the sintered materials. Spark plasma sintering (SPS) allows for rapid densification of powder particles at temperatures below their melting point. The process is held for 15-20 minutes at a pressure of 35-50 MPa and a vacuum of less than 2 Pa.

[0047] S3: The sintered material is cut into required sizes and welded to the target base to make a PVD target.

[0048] S4: PVD magnetron sputtering process, the specific steps are: direct current (DC) or radio frequency (RF) can be used. Since the material is conductive, the DC method is preferred, and the sputtering efficiency is higher. The substrate with the base glaze is placed in the cavity, and the vacuum degree in the cavity is set to below 1×10-4Pa. The cavity temperature is heated to 150-300℃, and argon gas is introduced with a pressure of 0.1-5Pa. The film layer is prepared using magnetron sputtering technology. In order to improve the density and adhesion of the material, a DC pulse method can be further used on the basis of the DC mode. The conditions are a frequency of 50-150k, a pulse power density of 4-7w / cm2, a duty cycle of 20-45%, and an air pressure of 0.2-0.8Pa. The resulting film is dense and has excellent performance.

[0049] The preparation method of the bottom glaze heat storage layer 2 (HfO2) and the electrode (Hf+Al alloy, Hf+Ir alloy) refers to the method of the heating element. The bottom glaze heat storage layer 2 and the electrode are directly sputtered by the corresponding target material; the electrode is a conductive material and can be made by DC or RF magnetron sputtering process; the bottom glaze heat storage layer 2 is a non-conductive material and is made by RF magnetron sputtering process.

[0050] The preparation method for protective films (HfO2 & SiN, HfO2 & SiON, or HfO2 & SIALON) is similar to that for heating elements. The target can be a single target, produced using hybrid plasma sintering, or two independent targets can be used. These two independent targets can be sputtered simultaneously in the same chamber at varying ratios. Because the target is non-conductive, the protective film is produced using RF magnetron sputtering.

[0051] Compared with the prior art, the present invention can meet the requirements of high temperature resistance and thermal shock resistance during thermal printing, and can overcome the defect of easy peeling between components caused by thermal stress.

Claims

1. A heating substrate for a thermal print head resistant to high energy impact, comprising an insulating substrate, a base glaze layer provided on the surface of the insulating substrate, an electrode wire and a heating resistor provided on the upper surface of the base glaze layer, and a protective layer covering the heating resistor and part of the electrode wire, characterized in that: The electrode wire within 0.3 mm from the heating resistor is an electrode wire resistant to high-energy impact. The electrode wire resistant to high-energy impact includes a lower electrode wire and an upper electrode wire. The lower electrode wire is made of hafnium-aluminum HfAl alloy, the thickness of the lower electrode wire is in the range of 0.1-2.0 μm, and the hafnium Hf content in the lower electrode wire is less than 10% of the total mass percentage; the upper electrode wire is made of hafnium-iridium HfIr alloy, the thickness of the upper electrode wire is in the range of 0.05-0.2 μm, and the hafnium Hf content in the upper electrode wire is less than 10% of the total mass percentage.

2. The high-energy impact-resistant heating substrate for a thermal print head according to claim 1, wherein: The lower electrode wire in the high-energy impact-resistant electrode wire is connected to the aluminum wire to form an electrode wire for a thermal print head with good conductivity.

3. The high-energy impact-resistant heating substrate for a thermal print head according to claim 1, wherein: The heating substrate for the thermal print head is also provided with a heating resistor resistant to high energy impact, and the heating resistor resistant to high energy impact is made of HfC x N y Composition of mixture with SiC, HfC x N y The proportion of the total mass percentage is between 30% and 70%, the thickness of the heating resistor is 10 to 500 nm, and the resistivity is 500 to 4000E-8Ω·m.

4. The high-energy impact-resistant heating substrate for a thermal print head according to claim 1, wherein: The bottom glaze layer includes a bottom heat storage glaze layer and a HfO2 layer, wherein the bottom heat storage glaze layer is mainly made of SiO2, the thermal conductivity of the bottom heat storage glaze layer is 1±0.2W / mK, and the thermal expansion coefficient is 6.5±1e -6 / ℃, a HfO2 layer is provided on the surface of the bottom heat storage glaze layer, with a thickness of 0.1~10um, the melting point of HfO2 is 2758℃, the thermal conductivity is 1.6~2W / mK, and the thermal expansion coefficient of HfO2 is 6±1e -6 / ℃.

5. The high-energy impact-resistant heating substrate for a thermal print head according to claim 1, wherein: The heating substrate for the thermal print head is also provided with a protective film, which covers the heating resistor and part of the electrode wires. The protective film is a HfO2 and SiN layer or a HfO2 and SiON layer, or a HfO2 and SiALON layer, and is formed by magnetron ion sputtering.

6. A method for preparing a heating substrate for a thermal print head resistant to high energy impact according to any one of claims 1 to 5, characterized in that: The electrode conductor resistant to high-energy impact is manufactured by a sputtering film-forming process combined with wet etching: a full pattern is formed by magnetron sputtering, a photolithography process is adopted, photoresist is used as a protective layer, and an electrode layer pattern is formed by wet etching. A wet chemical uses an acid liquid to form the electrode conductor resistant to high-energy impact; or, the electrode conductor resistant to high-energy impact is manufactured by the following method: a photolithography process is adopted to protect unnecessary images with photoresist, an electrode layer of Hf+Al alloy and Hf+Ir alloy is sputtered, the photoresist and the electrode layer above are removed, and the pattern outside the photoresist is left to form the electrode layer pattern.

7. The method for preparing a heat-generating substrate for a thermal print head resistant to high energy impact according to claim 6, wherein: In the method for preparing the electrode wire resistant to high energy impact, sputtering the electrode layer specifically includes the following steps: Step 1: preparing electrode wire targets, including a hafnium aluminum alloy target and a hafnium iridium alloy target, wherein the Hf content in the hafnium aluminum alloy target is less than 10% by mass, and the hafnium Hf content in the hafnium iridium alloy target is less than 10% by mass; Step 2: Using PVD magnetron sputtering technology, place the substrate with the base glaze and heating element into the cavity by DC or RF method, and set the vacuum degree in the cavity to 1×10 -4 Pa, the heating chamber temperature is 150~300℃, argon gas is introduced, the pressure is 0.1~5Pa, and the film layer is prepared using magnetron sputtering technology.

8. The method for preparing a heat-generating substrate for a thermal print head resistant to high energy impact according to claim 6, wherein: The method for preparing the heating resistor of the heating substrate for the thermal print head is specifically as follows: S1: Prepare HfC powder, HfN powder, and SiC powder in a mass ratio of HfC:HfN:SiC = (1-3):(1-3):(1-2), wherein the purity of HfC, HfN, and SiC is greater than or equal to 99.9%. Use a ball milling method to refine the prepared HfC powder, HfN powder, and SiC powder and mix them uniformly. After mixing, filter the powder to obtain a powder with a particle size of less than 5 μm. S2: Plasma sintering of the obtained mixed powder. The plasma sintering conditions are as follows: a temperature in a sintering furnace of 2100-2500°C, holding temperature for 15-20 minutes, a pressure of 35-50 MPa, and a vacuum degree of less than 2 Pa. S3: The sintered material is cut into required sizes and welded to the target base to make a PVD target. S4: Using PVD magnetron sputtering technology, DC or RF method, the substrate with the base glaze is placed in the cavity, and the vacuum degree in the cavity is set to 1×10 -4 Pa, the heating chamber temperature is 150~300℃, argon is introduced, the pressure is 0.1~5Pa, and the film layer is prepared using magnetron sputtering technology to improve the density and adhesion of the material.

9. The method for preparing a heat-generating substrate for a thermal print head according to claim 8, wherein: In S4, due to the conductivity of the material, DC sputtering is selected, which has higher sputtering efficiency and adopts DC pulse method with the conditions of frequency of 50~150kHz and pulse power density of 4-7w / cm 2 , the duty cycle is 20~45%, and the air pressure is 0.2~0.8Pa.

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