High-energy-impact-resistant heating substrate for thermal printing head and manufacturing method thereof

Abstract

The invention relates to the technical field of thermal printing head manufacturing, in particular to a high-energy-impact-resistant heating substrate for a thermal printing head and a manufacturing method of the high-energy-impact-resistant heating substrate, and the high-energy-impact-resistant heating substrate can meet the high-temperature-resistant and thermal-impact-resistant requirements in the thermal printing process and can overcome the defect that parts are prone to being peeled off due to thermal stress. A ground coat layer is arranged on the surface of the insulating substrate, a heating resistor body and an electrode wire are arranged on the upper surface of the ground coat layer, and the high-energy-impact-resistant electrode wire is characterized in that the electrode wire within the range of 0.3 mm away from the heating resistor body is a high-energy-impact-resistant electrode wire, and the high-energy-impact-resistant electrode wire comprises a lower-layer electrode wire body and an upper-layer electrode wire body. The lower layer electrode wire is made of hafnium aluminum HfAl alloy, the thickness range of the lower layer electrode wire is 0.1-2.0 micrometers, and the hafnium Hf content in the lower layer electrode wire accounts for 10% or below 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 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. Background technology:

[0002] Thermal print heads are devices that achieve printing through Joule heat. During the printing process, the temperature of the heating area is very high, and can reach over 1000°C in special working environments. The existing thermal print heads are difficult to meet this requirement due to their heat resistance.

[0003] At present, the prior literature on high temperature resistant materials includes the following: Patent document number CN102815971 discloses a Hf(Ta)C ultra-high temperature multiphase coating, which is composed of HfC and HfTaC2, wherein the mole fraction of HfTaC2 is 6-50%, and is evenly or gradiently distributed in the coating. Its preparation method is to place the surface-treated substrate in a low-pressure chemical vapor deposition furnace, with a mixed powder of hafnium tetrachloride and tantalum pentachloride as the hafnium source and tantalum source; methane as the carbon source; argon as the diluent gas; hydrogen as the reducing gas, and transport the mixed powder to the inside of the deposition furnace reactor, and deposit the Hf(Ta)C ultra-high temperature multiphase coating on the surface of the substrate.

[0004] The patent document number is CN109320303, which provides an ultra-high temperature oxidation-resistant and ablation-resistant coating and a preparation method thereof, and relates 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, and the steps 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 for 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 includes the following steps: (1) placing a mixed powder of TaCl5, HfCl4 and ZrCl4 in a crucible under an inert atmosphere; (2) placing a substrate sample on a support of a deposition furnace, introducing argon gas, and heating to a deposition temperature; (3) placing the crucible containing the mixed powder on a lifting support of a low-temperature zone in a dual-temperature zone gasification furnace, connecting the crucible mouth with 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 introducing the completely vaporized mixed gas into the deposition furnace with a carrier gas, and performing deposition under normal pressure. This preparation method can obtain a multi-component composite coating with an accurate stoichiometric ratio 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 number CN111072388B proposes a long-term ablation-resistant ultra-high melting point nitrogen-containing carbide ultra-high temperature ceramic and its application, and provides a method of using ball milling + spark plasma sintering to prepare HfCx Ny ceramics with a density greater than or equal to 98% and a uniform C / N content distribution. The designed and prepared new ultra-high melting point ceramic overcomes the defects of existing ultra-high temperature ablation-resistant ceramics, such as too low ablation resistance temperature or too fast high temperature ablation loss; making it suitable for ultra-high temperature ablation protection of 3000℃ and above.

[0007] The above existing technologies all describe the preparation methods of Hf(Ta)C or HfCxNy high temperature resistant coatings, and 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 view of the shortcomings and deficiencies in the prior art, the present invention proposes a 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 frequent thermal response 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 impact, comprising an insulating substrate, a bottom glaze layer being provided on the surface of the insulating substrate, a heating resistor and an electrode wire being provided on the upper surface of the bottom glaze layer, characterized in that the electrode wire within a range of 0.3 mm from the heating resistor is an electrode wire resistant to high energy impact, the electrode wire resistant to high energy impact comprises 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 accounts for 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 accounts 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 enable the electrode near the heating element to maintain good adhesion with the Al electrode far 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 the anti-oxidation can reach 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 approaching resistivity.

[0012] The heating substrate for the thermal print head of 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, the proportion of HfCxNy in the total mass percentage is between 30% and 70%, the thickness of the heating resistor is 10 to 500nm, and the resistivity is 500 to 4000E-8Ω.m. By adding hafnium carbon nitride compound HfCxNy and utilizing the characteristic that the melting point of HfCxNy can reach above 4000°C (much higher than Ta with a melting point of 2996°C and an oxidation temperature of about 500°C, which 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 comprises a bottom heat storage glaze layer and a HfO2 layer, wherein the bottom heat storage glaze layer is made of SiO2 as the main material, 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 printing and sintering thick film processes, with a thickness of 1um to 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 to 10um, and 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 also 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 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, a photoresist is used as a protective layer, an electrode layer pattern is formed by wet etching, and an acid liquid is used as a wet chemical to form an 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 a photoresist, an electrode layer Hf+Al alloy and an Hf+Ir alloy are 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 electrode wire resistant to high energy impact of the present invention, sputtering the electrode layer specifically comprises the following steps:

[0017] Step 1: preparing electrode wire targets, including hafnium aluminum alloy targets and hafnium iridium alloy targets, wherein the Hf content in the hafnium aluminum alloy targets is less than 10% by mass, and the hafnium Hf content in the hafnium iridium alloy targets 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 by 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 the sputtering efficiency is higher. 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 pulsed 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 preparing 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 according to the 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%, and the prepared HfC powder, HfN powder and SIC powder are refined by ball milling and mixed evenly, and the powder after mixing evenly is filtered to obtain a powder with a particle size of less than 5 μm;

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

[0023] S3: The sintered material is cut to the required size 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 with a pressure of 0.1~5Pa, and use magnetron sputtering technology to prepare the film layer in order to improve the density and adhesion of the material.

[0025] In S4 of the present invention, since the material is conductive, direct current (DC) sputtering is selected, which has higher sputtering efficiency, and 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.

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

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

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

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

[0030] Reference numerals: insulating substrate 1 , base glaze layer 2 , base glaze 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 in conjunction with the accompanying drawings and embodiments.

[0032] Example:

[0033] This example provides a thermal print head resistant to high energy impact, which is provided with a heating substrate for the thermal print head, an integrated circuit (IC), a circuit board, a heat sink, and a socket, wherein the heating substrate for the thermal print head includes an insulating substrate and a base glaze layer, a heating resistor layer, an electrode layer, and a protective layer arranged on the insulating substrate, wherein the electrode layer is provided with electrode wires, and the electrode wires include individual electrodes 4b and a common electrode 4a; the protective layer includes an insulating protective layer, and a wear-resistant protective layer can be added on the insulating protective layer as needed;

[0034] The bottom glaze layer 2 in this example adopts a composite structure of a bottom 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, and the components include at least two kinds of conductive materials and insulating materials, and the resistivity can be adjusted by proportion;

[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 a 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, and is prepared by printing and sintering thick film technology with a thickness of several um to 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 / ℃. On the surface of the base glaze heat storage layer 2-1, a HfO2 layer 2-2 is made by PVD, CVD and other processes with a thickness of 0.1 to 10 um. 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. Similar thermal expansion coefficients can avoid interlayer peeling 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 proportion 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 more than 4000℃, which is much higher than the melting point of Ta, which is 2996℃ and the oxidation temperature is about 500℃, which is commonly used in heating elements. , it has been verified that after ultra-long (300s) ablation, HfCxNy ceramics still maintain a near-zero ablation rate and a continuous and stable anti-oxidation protection structure; the thermal expansion coefficient of HfCxNy is 6.73±1e-6 / ℃, and the thermal expansion coefficient of SIC is 4±1e-6 / ℃, which are relatively close, and are also relatively close to the HfO2 in the lower layer, while 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, and are also quite different from the HfO2 in the lower layer. The resistivity of HfCxNy is about 36.33e-8Ω·m, and SIC is insulating. The two can obtain different square resistances by adjusting different proportions to meet different resistance requirements. The traditional heating element materials Ta (resistivity is 15e-8Ω·m) and SiO2 (insulation) are also relatively similar and can be replaced.

[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 Hf+Al alloy, the Hf ratio is less than 10%, and the thickness is 0.1~2um; the upper electrode layer 4-2 is composed of Hf+Ir alloy, the Hf ratio is less than 10%, and the thickness is 0.05~0.2um. The selected electrode layer is made by PVD or CVD and other processes. The melting point of Hf is 2227℃, which is much higher than the melting point of about 600℃ of Al commonly used now. The addition of Hf can improve the temperature resistance of the electrode. The thermal expansion coefficient of Hf is 5.8e-6 / ℃, which is less than 23e-6 / ℃ of Al. The addition of Hf can reduce the thermal expansion coefficient of the electrode and relieve thermal stress to a certain extent. The resistivity of Hf is 35.7e-8Ω·m, which is greater than 2.83e-8Ω·m of Al, so it is limited to use near heating elements with higher temperature requirements, and the proportion of Hf cannot 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 far 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 is made outside the Hf+Al alloy with a thickness of 0.05~0.2um. Ir has good 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 by a variety of process methods. Method 1 is to sputter the electrode layer of Hf+Al alloy and Hf+Ir alloy, adopt the photolithography process, use photoresist as a protective layer, and wet-etch to form the electrode layer pattern. The wet chemicals use various acid liquids. Method 2 is to use the photolithography process. The photoresist protects the unnecessary image, sputter the electrode layer of 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, a HfO2&SiON mixture, or a HfO2&SIALON mixture, with a proportion of HfO2 below 20% and a total thickness between 1 and 20um. SiN is electrically insulating, with a temperature resistance of about 1900°C and a thermal expansion coefficient of 2.35±0.5e-6 / °C; SIALON is electrically insulating, with a melting point greater than 1500°C, a heat shock resistance greater than 900°C, and a thermal expansion coefficient of 2.6±0.5e-6 / °C. They are all relatively excellent temperature-resistant materials, and their expansion coefficients are close to those of the HfO2 of the lower glaze 2 and the HfCxNy of the heating element.

[0042] The insulating protective film can be made by using the 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 the insulating protective film 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: HfC powder, HfN powder and SIC powder are prepared 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%. The prepared HfC powder, HfN powder and SIC powder are refined by ball milling and mixed evenly. The mixed powder is filtered to obtain a powder with a particle size of less than 5um;

[0046] S2: The obtained mixed powder is subjected to plasma sintering. The conditions for plasma sintering are: the temperature in the sintering furnace is 2100-2500°C, where 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 material. Spark plasma sintering (SPS) allows the powder particles to be quickly densified at a temperature below the melting point, and the temperature is kept for 15-20 minutes, the pressure is 35-50MPa, and the vacuum degree is less than 2Pa;

[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. Due to the conductivity of the material, 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°C, 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 underglaze heat storage layer 2 (HfO2) and the electrode (Hf+Al alloy, Hf+Ir alloy) refers to the method of the heating element. The underglaze heat storage layer 2 and the electrode are directly sputtered by the corresponding target material; the electrode is a conductive material and can be prepared by DC or RF magnetron sputtering process; the underglaze heat storage layer 2 is a non-conductive material and is prepared by RF magnetron sputtering process.

[0050] The preparation method of protective film (HfO2&SiN or HfO2&SiON or HfO2&SIALON) etc. refers to the method of heating element. The target material can be a single target, which is made by mixed plasma sintering, or two independent double targets. When two independent targets are sputtered, they can be sputtered once in the same cavity according to different proportions. Because the target material is not conductive, the protective film is made by RF magnetron sputtering process.

[0051] Compared with the prior art, the present invention can meet the requirements of high temperature resistance and heat 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 is provided on the surface of the insulating substrate, an electrode wire and a heating resistor are provided on the upper surface of the base glaze layer, and a protective layer is covered above the heating resistor and part of the electrode wire, characterized in that: The electrode wire within 0.3mm from the heating resistor is an electrode wire resistant to high-energy impact, and 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 range of the lower electrode wire is 0.1-2.0μm, and the hafnium Hf content in the lower electrode wire accounts for less than 10% of the total mass percentage; the upper electrode wire is made of hafnium iridium HfIr alloy, the thickness range of the upper electrode wire is 0.05-0.2μm, and the hafnium Hf content in the upper electrode wire accounts for 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, characterized in that: The lower electrode wire in the high-energy impact-resistant electrode wire is connected to the aluminum Al wire to form an electrode wire for a thermal print head with good conductivity.

3. The heat generating substrate for a thermal print head resistant to high energy impact according to claim 1, characterized in that: The heating substrate for the thermal print head 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, the proportion of HfCxNy in the total mass percentage is between 30% and 70%, the thickness of the heating resistor is 10 to 500nm, and the resistivity is 500 to 4000E-8Ω.m.

4. The heat generating substrate for a thermal print head resistant to high energy impact according to claim 1, characterized in that: 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, with a thickness ranging from 1um to several hundred um, a thermal conductivity of the bottom heat storage glaze layer of 1±0.2W / mK, and a thermal expansion coefficient of 6.5±1e-6 / ℃; an HfO2 layer is provided on the surface of the bottom heat storage glaze layer, with a thickness of 0.1 to 10um, a melting point of HfO2 of 2758℃, a thermal conductivity of 1.6 to 2W / mK, and a thermal expansion coefficient of HfO2 of 6±1e-6 / ℃.

5. The heat generating substrate for a thermal print head resistant to high energy shock according to claim 1, characterized in that: 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 as claimed in any one of claims 1 to 5, characterized in that: 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, a photoresist is used as a protective layer, an electrode layer pattern is formed by wet etching, and an acid liquid is used as a wet chemical to form an 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 a photoresist, an electrode layer Hf+Al alloy and an Hf+Ir alloy are sputtered, the photoresist and the electrode layer above are removed, and the pattern outside the photoresist is left to form an 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, characterized in that: In the method for preparing the electrode wire resistant to high energy impact, sputtering the electrode layer specifically comprises the following steps: Step 1: preparing electrode wire targets, including hafnium aluminum alloy targets and hafnium iridium alloy targets, wherein the Hf content in the hafnium aluminum alloy targets is less than 10% by mass, and the hafnium Hf content in the hafnium iridium alloy targets is less than 10% by mass; Step 2: Use PVD magnetron sputtering technology to place the substrate with base glaze and heating element into the cavity through direct current (DC) or radio frequency (RF) method, 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.

8. The method for preparing a heat-generating substrate for a thermal print head resistant to high energy impact according to claim 6, characterized in that: 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 according to the 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%, and the prepared HfC powder, HfN powder and SIC powder are refined by ball milling and mixed evenly, and the powder after mixing evenly is filtered to obtain a powder with a particle size of less than 5 μm; S2: The obtained mixed powder is subjected to plasma sintering. The conditions of plasma sintering are: the temperature in the sintering furnace is 2100-2500°C, the temperature is kept for 15-20 minutes, the pressure is 35-50MPa, and the vacuum degree is less than 2Pa; S3: The sintered material is cut to the required size and welded to the target base to make a PVD target. 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, the pressure is 0.1~5Pa, and use magnetron sputtering technology to prepare the film layer in order to improve the density and adhesion of the material.

9. The method for manufacturing 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 a DC pulse method is used. The conditions are a frequency of 50-150k, a pulse power density of 4-7w / cm2, a duty cycle of 20-45%, and a gas pressure of 0.2-0.8Pa.

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