WO2023274202A1 - Energy-resistant, corrosion-resistant and abrasion-resistant heat-generating substrate of thermal print head - Google Patents

Abstract

An energy-resistant, corrosion-resistant and abrasion-resistant heat-generating substrate of a thermal print head. The heat-generating substrate is provided with an insulating substrate (1), wherein a ground glaze layer (2), which is made of an amorphous glass material, is arranged on a surface portion of the insulating substrate (1); a common electrode and an individual electrode (3) are arranged on the surface of the ground glaze layer (2); a heat-generating resistor body (4) is configured between the common electrode and the individual electrode (3); the surface of the heat-generating resistor body (4), the surface of the common electrode and the surface of the individual electrode (3) are provided with a protective layer (5); and the protective layer (5) includes a first protective layer (5a) that covers the surface of the heat-generating resistor body (4), the first protective layer (5a) being a glass glaze layer having a transition point temperature ranging from 600°C to 725°C or a glass glaze layer having a softening point temperature ranging from 700°C to 870°C. The heat-generating substrate of a thermal print head has the characteristics of requiring a simple production method and being low cost, can greatly reduce the amount of damage to a heat-generating resistor body that is caused by high word-printing energy, and can improve the corrosion resistance capability of the print head in a high-temperature and high-humidity environment and the abrasion resistance performance thereof in a harsh environment, thereby significantly improving the product reliability.

Description

Energy-resistant, corrosion-resistant and wear-resistant thermal print head heating substrate technical field

The embodiment of the present application relates to the technical field of thermal printhead manufacturing, for example, a thermal printhead heating substrate that can significantly improve the energy resistance characteristics of the heating resistor in the thermal printhead and effectively improve the wear resistance and corrosion resistance of the heating substrate .

Background technique

The thermal print head in the related art includes an insulating substrate, an underglaze layer is provided on the surface of the insulating substrate, a common electrode and an individual electrode are arranged on the surface of the insulating substrate and the underglaze layer, and the heating resistor is arranged between the two electrodes, and the common One end of the electrode is connected to the heating resistor body, and the other end is used to connect to the power supply. One end of individual electrodes is connected to the heating resistor body, and the other end is connected to the pad. The surface of the glass enamel protective layer is also provided with a ceramic wear-resistant layer formed in a thin film manner.

The thermal print head in the related art has low sensitivity to the printing medium and the quality of the printing medium is poor. The heating resistor of the thermal printing head needs more Joule heat to make the printing medium develop color, and more Joule heat causes the temperature to exceed that of the heating resistor. When the temperature of the internal glass softening point or transition point is reached, the resistance value of the heating resistor is prone to rise and damage; in a high temperature and high humidity environment, the corrosion resistance of the protective layer is insufficient and the metal electrode is corroded and disconnected; in addition, the quality of the printing medium is poor. In , outdoor and other environments, the wear resistance of the protective layer is insufficient, and the resistor body or metal electrode is scratched by the medium or foreign particles, which will lead to product damage.

Contents of the invention

The following is an overview of the topics described in detail in this article. This summary is not intended to limit the scope of the claims.

The embodiment of the present application proposes a heating substrate of a thermal printing head that can significantly improve the energy resistance characteristics of the heating resistor in the thermal printing head, and effectively improve the wear resistance and corrosion resistance of the heating substrate.

The embodiment of the present application achieves through the following measures:

An energy-resistant, corrosion-resistant, and wear-resistant thermal printing head heating substrate is provided with an insulating substrate, and an underglaze layer composed of an amorphous glass material is arranged on the surface of the insulating substrate. There are common electrodes and individual electrodes on the surface, and the heating resistor is arranged between the common electrode and the individual electrodes. One end of the common electrode is connected to the heating resistor, and the other end is used to connect to the power supply; One end is connected to the pad; the surface of the heating resistor, the individual electrodes and the common electrode are provided with a protective layer, and the protective layer includes a first protective layer covering the surface of the heating resistor, and the temperature range of the transfer point of the first protective layer is A glass glaze layer at 600-725°C, or a glass glaze layer with a softening point temperature range of 700-870°C.

The components in the first protective layer described in the examples of this application are based on the oxide state, and the content is as follows: SiO ₂ content 49.4mol%-56.8mol%, Al ₂ O ₃ content 13.7mol%-26.7mol%, CaO content 3.5mol%-13.8mol%, BaO content 1.5mol%-5.9mol%, PbO content 4.8mol%-17.7mol%, ZrO ₂ content 1.2mol%-5.0mol%.

In the protective layer described in the embodiment of the present application, the upper side of the first protective layer is compounded with a second protective layer, the second protective layer adopts an insulating glass glaze layer or a conductive glass glaze layer, and further, the transfer point of the second protective layer Or the softening point is lower than the transition point or softening point of the first protective layer; further, when the second protective layer is a conductive glass glaze layer, the resistivity range is 0.01Ω·m-10kΩ·m.

The protective layer in the embodiment of the present application is also provided with a thin-film ceramic wear-resistant protective layer above the glass glaze layer, and the thin-film ceramic wear-resistant protective layer is composed of one of silicon carbide, sialon or silicon nitride or is made of Composite thin-film ceramic layer composed of any two of silicon carbide, sialon, and silicon nitride; the thin-film ceramic wear-resistant layer is used to contact the external environment and printing media to improve the wear-resistant characteristics of the product.

The beneficial effect of the embodiment of the present application is that the insulating glass glaze with a high transition point (greater than 600°C) or a high softening point (greater than 700°C) is used as the first protective layer, and it partially diffuses into the heating resistor during sintering. The transfer point or softening point of the glass composition inside the heating resistor is improved, thereby improving the energy resistance of the heating resistor and reducing the resistance value increase of the heating resistor when printing at higher energy; the high transfer point or high softening point Insulating glass glaze is made by high-temperature melting and needs to be sintered at a higher temperature. It has good chemical stability and significantly enhances the corrosion resistance of the product. The surface of the glass glaze protective layer is equipped with a thin-film ceramic wear protection formed by a thin-film process. layer to further strengthen the wear resistance, the heat-generating substrate for the thermal print head of this application has the characteristics of simple production method and low cost, which can greatly reduce the damage of the heat-generating resistor caused by high printing energy, and improve the high-temperature and high-humidity environment of the print head. High corrosion resistance and wear resistance in harsh environments significantly improve product reliability.

Other aspects will be apparent to others upon reading and understanding the drawings and detailed description.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solutions herein, and constitute a part of the description, and are used together with the embodiments of the application to explain the technical solutions herein, and do not constitute limitations to the technical solutions herein.

Accompanying drawing 1 is the schematic structural diagram of embodiment 1 of the present application.

Accompanying drawing 2 is the schematic structural diagram of embodiment 2 of the present application.

Accompanying drawing 3 is the schematic structural diagram of embodiment 3 of the present application.

Reference signs: insulating substrate 1, bottom glaze layer 2, common electrode and individual electrode 3, heating resistor 4, protective layer 5, first protective layer (insulating glass glaze layer with high transfer point or high softening point) 5a, second Protective layer (low transition point or low softening point insulating glass glaze layer) 5b, third protective layer (low transition point or low softening point insulating glass glaze layer) 5c, thin-film ceramic wear-resistant protective layer 5d.

detailed description

The application will be further described below in conjunction with the accompanying drawings and embodiments.

Aiming at the defects and deficiencies of the prior art, the present application proposes an energy-resistant, corrosion-resistant, and wear-resistant heat-generating substrate for thermal print heads, including an insulating substrate, and an amorphous substrate is arranged on the surface of the insulating substrate. The bottom glaze layer made of high-quality glass material is provided with a common electrode and individual electrodes on the surface of the bottom glaze layer. The heating resistor is arranged between the common electrode and the individual electrodes. One end of the common electrode is connected to the heating resistor, and the other end is It is connected to the power supply; one end of individual electrodes is connected to the heating resistor body, and the other end is connected to the pad; the surface of the heating resistor body, individual electrodes and common electrodes is provided with a glass glaze layer and a ceramic wear-resistant layer formed by thin film technology. Composite protective layer, the glass glaze protective layer at least includes a first protective layer 5a made of insulating glass glaze with a high transfer point or high softening point; the transfer point or softening point of the glass composition constituting the first protective layer 5a is higher than that of the heating resistor The transition point or softening point temperature of the glass composition in the body, the first protective layer 5a is subsequently called a high transition point or high softening point insulating glass glaze protective layer, and its transition point is 600-725 ° C or its softening point is 700-870 ℃.

Preferably, the insulating glass glaze whose transition point temperature is 600-725°C or softening point temperature is 700-870°C has a composition based on oxide state, SiO ₂ content of 49.4mol%-56.8mol%, Al ₂ O ₃ content 13.7mol%-26.7mol%, CaO content 3.5mol%-13.8mol%, BaO content 1.5-5.9mol%, PbO content 4.8mol%-17.7mol%, ZrO ₂ content 1.2mol %-5.0mol%.

Preferably, the insulating glass glaze whose transition point temperature is 600-725°C or softening point temperature is 700-870°C has a composition based on oxide state, SiO ₂ content of 49.4mol%-54.5mol%, Al ₂ O ₃ content 17.7mol%-26.7mol%, CaO content 3.5mol%-10.5mol%, BaO content 1.5mol%-5.0mol%, PbO content 8.5mol%-17.7mol%, ZrO ₂ content 1.2mol%-3.8mol%.

Preferably, the insulating glass glaze whose transition point temperature is 600-725°C or softening point temperature is 700-870°C has a composition based on oxide state, SiO ₂ content of 52.0mol%-54.5mol%, Al ₂ O ₃ content 17.7mol%-22.5mol%, CaO content 6.5mol%-10.5mol%, BaO content 2.5mol%-5.0mol%, PbO content 8.5mol%-13.5mol%, ZrO ₂ content 2.5mol%-3.8mol%.

Preferably, the first protective layer can be used independently as an insulating glass enamel protective layer, or together with other glass enamel protective layers to form a glass enamel protective layer; the other glass enamel protective layers are insulating glass enamel, or conductive glass Glaze; the resistivity of the conductive glass glaze protective layer is 0.01Ω·m-10KΩ·m.

Preferably, the transition point or softening point of the insulating glass glaze protective layer other than the first protective layer is lower than the transition point or softening point of the composition of the first protective layer, which is subsequently referred to as low transition point or low softening point insulating glass Glaze protection layer.

Preferably, the surface of the protective layer is provided with a thin-film ceramic wear-resistant protective layer 5d formed by a thin-film process, and the thin-film ceramic wear-resistant protective layer 5d is composed of one of silicon carbide, sialon or silicon nitride, or is made of silicon carbide A composite thin-film ceramic layer composed of any two of , sialon, and silicon nitride.

In the insulating glass glaze protective layer composition involved in this application, its form does not exist in various single oxides, usually in the state of composite oxides or compounds. The components of the glass composition in this application are converted in accordance with the usual practice. Single oxides are used for marking. For example, the insulating glass glaze may contain forms such as PbSiO ₃ , and single oxides are marked as PbO and SiO ₂ respectively.

The energy-resistant thermal printing head heating substrate and its manufacturing method are provided below, and a comparative example is provided:

The meanings of the parameters mentioned in the following description are as follows:

Firing appearance: (1) Use a surface roughness tester to measure the surface roughness, take 10 samples of each composition of the glass glaze for measurement, and calculate the average value; (2) Observe the surface of the glass glaze with a stereo microscope Condition: Surface leveling and defects.

Tg (glass transition point temperature), Ts (glass softening point temperature): Differential thermal analysis (DTA) was used to measure 10 samples of glass frits of each composition, and the average value was calculated.

STOL (energy resistance test): Apply 1.5-2 times the rated heating energy to the resistor, measure the resistance value change rate of the heating resistor, measure 192 heating resistors for each glass glaze protective layer sample, and calculate its average.

Corrosion resistance test: Under the conditions of fixed temperature and fixed humidity, the thermal print head is powered on and standby in the actual working state, and the time for corrosion damage of the insulating glass glaze protective layer is measured.

First, mix various oxides according to the metering ratio, and melt at high temperature to obtain glass frit, take each sample for Tg and Ts measurement; take an appropriate amount of glass frit and pulverize to obtain glass glaze powder, add fillers, organic solvents and resins, After mixing, a high transfer point or high softening point insulating glass glaze protective layer slurry is prepared.

Calculated by oxides, the contents of various components of the high transfer point or high softening point insulating glass glaze composition are shown in Table 1:

Table 1

Secondly, the insulating glass glaze protective layer slurry prepared above is printed on the surface of the substrate on which the electrode and the ruthenium dioxide heating resistor have been prepared, and sintered to form the first insulating glass glaze protective layer, which is made into a thermal print head substrate , to carry out the power resistance test and the corrosion resistance test, and the results are recorded in Table 2.

Table 2:

The first protective layer of insulating glass glaze	Sintered surface state	STOL(%)	Corrosion Resistance (Hr)
Sample 1 (Prior Art)	smooth	-7.5%	264
Sample 2	dull, rough	-5.0%	twenty four
Sample 3	smooth, glossy	-2.5%	168
Sample 4	smooth, glossy	-2.0%	192
Sample 5	smooth, glossy	-1.9%	192
Sample 6	dull	-2.2%	144
Sample 7	dull	-2.3%	144
Sample 8	dull	-1.5%	48

In addition, select sample 3-sample 7 insulating glass glaze protective layer paste with STOL<-3%, print on the surface of the substrate that has already prepared electrodes and ruthenium dioxide heating resistors, and sinter to make a high transfer point or softening point The first glass glaze protective layer sample, and then a part of the sample surface is formed with a silicon carbide wear-resistant layer by thin film technology to make a thermal print head substrate; the other part of the sample surface is printed and sintered with the second glass glaze protective layer slurry to make the second glass Glaze protective layer, and then use thin film technology to form a silicon carbide wear-resistant layer on the surface of the second glass glaze protective layer to make a thermal print head substrate, and further conduct energy resistance and corrosion resistance tests. Combining the dot insulating glass protective layer with other glass glaze protective layers, the energy resistance and corrosion resistance of the thermal print head of the present application are significantly improved compared with the prior art, and the results are recorded in Table 3.

table 3

Example 1:

As shown in Figure 1, the energy-resistant and corrosion-resistant heat-generating substrate for a thermal print head involved in this example includes an insulating substrate 1, and an underglaze made of an amorphous glass material is provided on the surface portion of the insulating substrate 1. Layer 2; a common electrode and an individual electrode 3 are provided on the surface of the bottom glaze layer 2, and a heating resistor 4 is arranged between the common electrode and the individual electrode 3 along the main printing direction as a heating element that generates Joule heat. One end of the common electrode is connected to the heating resistor 4 along the secondary printing direction, and the other end is used to connect to the power supply; one end of the individual electrode is connected to the heating resistor 4 along the secondary printing direction, for protection The heating substrate is covered with a protective layer 5 on the surface of the heating resistor 4, the common electrode and the individual electrodes 3. The protective layer 5, as shown in Table 3, selects sample 3 with a transfer point of 600 ° C and a softening point of 700 ° C. Insulating glass glaze 5a constitutes the first protective layer and the silicon carbide ceramic protective layer formed by thin film technology.

The high softening point or transition point glass glaze 5a partly diffuses into the heating resistor body during sintering, which increases the glass softening point temperature of the heating resistor body and enhances the power resistance characteristics of the heating resistor body; the high softening point or transfer point insulating glass glaze 5a, has a certain fluidity during sintering, and has good surface smoothness after sintering. The surface of 5a has very few defects, which improves the corrosion resistance of the product. The silicon carbide ceramic layer strengthens the wear resistance of the thermal print head substrate and obtains energy resistance. , Corrosion-resistant, wear-resistant thermal print head substrate.

Example 2:

As shown in Figure 2, the energy-resistant and corrosion-resistant heat-generating substrate for a thermal print head involved in this example includes an insulating substrate 1, and an underglaze made of an amorphous glass material is provided on the surface portion of the insulating substrate 1. Layer 2. A common electrode and an individual electrode 3 are arranged on the surface of the underglaze layer 2, and a heating resistor 4 is disposed between the common electrode and the individual electrode 3 along the main printing direction, as a heating element generating Joule heat, and the common electrode One end is connected to the heating resistor 4 along the secondary printing direction, and the other end is used to connect to the power supply; one end of the individual electrode is connected to the heating resistor 4 along the secondary printing direction, in order to protect the heating substrate, The protective layer 5 is covered on the surface of the heating resistor 4, the common electrode and the individual electrodes 3. The protective layer 5, as shown in Table 3, uses sample 5, which is made of insulating glass glaze with a transfer point of 683°C and a softening point of 812°C. 5a constitutes the first protective layer, the insulating glass glaze 5b constitutes the second protective layer and the silicon carbide ceramic protective layer formed by thin film technology;

The high softening point glass glaze 5a partially diffuses into the heating resistor body during sintering, which increases the glass softening point temperature of the heating resistor body and enhances the energy resistance characteristics of the heating resistor body. The glass protective layer 5b has good fluidity during sintering, After sintering, the insulating glass glaze 5 has good surface smoothness, improves the compactness of the surface of the high softening point glass glaze 5a, and further improves the corrosion resistance of the product. The silicon carbide ceramic layer strengthens the wear resistance of the substrate of the thermal print head to obtain energy resistance , Corrosion-resistant, wear-resistant thermal print head substrate.

Example 3:

As shown in FIG. 3 , the energy-resistant and corrosion-resistant heat-generating substrate for a thermal print head involved in this example includes an insulating substrate 1, and an underglaze made of an amorphous glass material is provided on the surface portion of the insulating substrate 1. Layer 2. A common electrode and an individual electrode 3 are arranged on the surface of the underglaze layer 2, and a heating resistor 4 is disposed between the common electrode and the individual electrode 3 along the main printing direction, as a heating element generating Joule heat, and the common electrode One end is connected to the heating resistor 4 along the secondary printing direction, and the other end is used to connect to the power supply; one end of the individual electrode is connected to the heating resistor 4 along the secondary printing direction, in order to protect the heating substrate, The protective layer 5 is covered on the surface of the heating resistor 4, the common electrode and the individual electrodes 3. The protective layer 5, as shown in Table 3, uses sample 5, which is made of insulating glass glaze with a transfer point of 683°C and a softening point of 812°C. 5a constitutes the first protective layer, the second protective layer composed of conductive glass glaze 5b with a resistivity of 10Ω·m, and a silicon carbide ceramic protective layer formed by thin film technology;

In this example, the high softening point glass glaze 5a partly diffuses into the heating resistor body during sintering, which increases the glass softening point temperature of the heating resistor body and enhances the energy resistance characteristics of the heating resistor body. The conductive glass glaze protective layer 5b reduces the surface potential of the substrate , reduce the electrochemical corrosion of the wear-resistant protective layer under high temperature and high humidity, reduce the corrosion effect of the electrode on the high temperature and high humidity environment, and improve the corrosion resistance of the product. The silicon carbide ceramic layer strengthens the wear resistance of the thermal print head substrate and obtains energy resistance , Corrosion-resistant, wear-resistant thermal print head substrate.

The present application can also adopt other combinations, such as adopting high softening point or high transfer point glass glaze as the first protective layer, adopting low softening point or low transfer point glass glaze as the second protective layer and the third protective layer, and using thin film The silicon carbide ceramic protective layer formed by the process together constitutes the protective layer, and a thermal print head substrate with energy resistance, corrosion resistance and wear resistance is obtained.

Claims (8)

1. An energy-resistant, corrosion-resistant, and wear-resistant thermal printing head heating substrate is provided with an insulating substrate, and an underglaze layer composed of an amorphous glass material is arranged on the surface of the insulating substrate. There are common electrodes and individual electrodes on the surface, and the heating resistor is arranged between the common electrode and the individual electrodes. One end of the common electrode is connected to the heating resistor, and the other end is used to connect to the power supply; One end is connected to the pad; the surface of the heating resistor, the individual electrodes and the common electrode are provided with a protective layer, wherein the protective layer includes a first protective layer covering the surface of the heating resistor, and the first protective layer is the transfer point temperature A glass enamel layer in the range of 600-725°C, or a glass enamel layer with a softening point temperature in the range of 700-870°C.
2. An energy-resistant, corrosion-resistant and wear-resistant thermal printing head heating substrate according to claim 1, wherein the components in the first protective layer are calculated as oxides, and the content is as follows: SiO ₂ content 49.4mol %-56.8mol%, _Al2O3 content _13.7mol %-26.7mol%, CaO content 3.5mol%-13.8mol%, BaO content 1.5mol%-5.9mol%, PbO content 4.8mol%-17.7 mol%, ZrO ₂ content 1.2mol%-5.0mol%.
3. An energy-resistant, corrosion-resistant, and wear-resistant thermal printing head heating substrate according to claim 1, wherein the outer side of the first protective layer in the protective layer is compounded with a second protective layer, and the second protective layer adopts Insulating glass glaze layer or conductive glass glaze layer.
4. An energy-resistant, corrosion-resistant and wear-resistant thermal printing head heating substrate according to claim 3, wherein the transfer point or softening point of the second protective layer is lower than the transfer point or softening point of the first protective layer .
5. An energy-resistant, corrosion-resistant and wear-resistant thermal printing head heating substrate according to claim 3, wherein the second protective layer is a conductive glass glaze layer, and the resistivity range is 0.01Ω·m-10kΩ·m .
6. An energy-resistant, corrosion-resistant and wear-resistant thermal printing head heating substrate according to claim 1, wherein the protective layer is also provided with a thin-film ceramic wear-resistant protective layer, and the thin-film ceramic wear-resistant protective layer is formed by carbonization One of silicon, sialon, or silicon nitride, or a composite thin-film ceramic layer composed of any two of silicon carbide, sialon, and silicon nitride.
7. An energy-resistant, corrosion-resistant and wear-resistant thermal printing head heating substrate according to claim 2, wherein the insulating glass glaze with a transfer point temperature of 600-725°C or a softening point temperature of 700-870°C, Its composition is based on the oxide state, _SiO2 content 49.4mol%-54.5mol%, _Al2O3 content _17.7mol %-26.7mol%, CaO content 3.5mol%-10.5mol%, BaO content 1.5 mol%-5.0mol%, PbO content 8.5mol%-17.7mol%, ZrO ₂ content 1.2mol%-3.8mol%.
8. An energy-resistant, corrosion-resistant and wear-resistant thermal printing head heating substrate according to claim 2, wherein the insulating glass glaze with a transfer point temperature of 600-725°C or a softening point temperature of 700-870°C, Its composition is based on the oxide state, _SiO2 content 52.5mol%-54.5mol%, _Al2O3 content _17.7mol %-22.5mol%, CaO content 6.5mol%-10.5mol%, BaO content 2.5 mol%-5.0mol%, PbO content 8.5mol%-13.5mol%, ZrO ₂ content 2.5mol%-3.8mol%.

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