A preparation method of thermal print head and thermal print head

Abstract

The embodiment of the present invention discloses a method for preparing a thermal print head and a thermal print head, wherein the thermal print head includes a heat dissipation substrate, a ceramic substrate, a heat storage layer, an electrode layer and a resistance layer; the ceramic substrate is located on one side of the heat dissipation layer, the heat storage layer is located on the side of the ceramic substrate away from the heat dissipation substrate, the electrode layer is located on the side of the ceramic substrate away from the heat dissipation substrate and covers the ceramic substrate, and the resistance layer is located on the side of the electrode layer away from the heat storage layer; wherein the heat storage layer includes a substrate and a filling material; the preparation method includes: obtaining a required printing rate; adjusting the filling condition of the filling material in the heat storage layer according to the required printing rate. The preparation method of the thermal print head provided by the embodiment of the present invention is adopted, and the filling condition of the filling material in the heat storage layer is adjusted according to the required printing rate, so as to meet the high requirements of the thermal print head for heat storage and ensure the working effect and printing effect of the thermal print head.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of thermal printing, and in particular to a method for preparing a thermal print head and a thermal print head. Background Art

[0002] As is known to all, the thermal print head includes a heat sink and a substrate made of insulating material. A base layer (heat storage layer glass) is made on the substrate, and then wire electrodes are formed on the substrate and the base surface. The wire electrodes are divided into individual electrodes and common electrodes. A heating resistor body belt along the main printing direction is formed on the wire electrode. One end of the individual electrode is connected to the heating resistor body belt along the secondary printing direction, and the other end is connected to the control IC. One end of the common electrode is connected to the heating resistor body belt along the secondary printing direction, and the other end is connected to the wire pattern. The electrical part of the thermal print head is composed of the wire electrode, heating resistor belt, control IC and PCB board on the ceramic substrate. The electrical part is adhered to the heat sink as a whole by double-sided tape or thermal conductive adhesive. The heat storage layer mainly plays the role of heat storage or heat dissipation. The heat storage or heat dissipation characteristics of the heat storage layer depend on the printing speed and printing rate. The higher the speed, the greater the printing rate, and the higher the heat dissipation requirements. Conversely, the lower the speed, the smaller the printing rate, and the higher the heat storage requirements. Summary of the invention

[0003] The embodiment of the present invention provides a method for preparing a thermal print head and a thermal print head, which adjusts the distribution of filling materials in the heat storage layer according to the required printing rate, meets the high requirements of the thermal print head for heat storage, and ensures the working effect and printing effect of the thermal print head.

[0004] In a first aspect, an embodiment of the present invention provides a method for preparing a thermal print head, which is applied to a thermal print head, wherein the thermal print head comprises a heat dissipation substrate, a ceramic substrate, a heat storage layer, a resistance layer and an electrode layer; the ceramic substrate is located on one side of the heat dissipation layer, the heat storage layer is located on a side of the ceramic substrate away from the heat dissipation substrate, the electrode layer is located on a side of the ceramic substrate away from the heat dissipation substrate and covers the ceramic substrate, and the resistance layer is located on a side of the electrode layer away from the heat storage layer; wherein the heat storage layer comprises a substrate and a filling material; the preparation method comprises:

[0005] Get the required printing rate;

[0006] The filling condition of the filling material in the heat storage layer is adjusted according to the required printing rate.

[0007] Optionally, adjusting the distribution of the filling material in the thermal storage layer according to the required printing rate includes:

[0008] Determining whether the required printing rate is less than a preset printing rate, wherein the preset printing rate is a printing rate of the thermal storage layer including the substrate;

[0009] If yes, filling the thermal storage layer with a first filling material;

[0010] If not, a second filling material is filled in the heat storage layer, wherein the thermal conductivity of the first filling material is lower than the thermal conductivity of the substrate, and the thermal conductivity of the substrate is lower than the thermal conductivity of the second filling material.

[0011] Optionally, after the first filling material is filled in the thermal storage layer, the method further comprises:

[0012] Determining the thermal time constant of the thermal storage layer according to the required printing rate;

[0013] Determining the thermal conductivity of the heat storage layer according to the thermal time constant;

[0014] Determining the proportion of the filling material according to the thermal conductivity;

[0015] After the second filling material is filled in the heat storage layer, the method further comprises:

[0016] Determining the thermal time constant of the thermal storage layer according to the required printing rate;

[0017] Determining the thermal conductivity of the heat storage layer according to the thermal time constant;

[0018] The proportion of the filling material is determined according to the thermal conductivity. Optionally, the distribution of the filling material in the thermal storage layer is adjusted according to the required printing rate, including:

[0019] Determining whether the required printing rate is less than a preset printing rate, wherein the preset printing rate is a printing rate when the heat storage layer is composed of only a substrate;

[0020] If yes, filling the heat storage layer with a third filling material;

[0021] If not, a fourth filling material is filled in the thermal storage layer, wherein the capacity of the third filling material is K1, the capacity of the substrate is K2, the capacity of the fourth filling material is K3, and K1<K2<K3, and K1, K2 and K3 are positive numbers.

[0022] Optionally, after the third filling material is filled in the heat storage layer, the method further comprises:

[0023] Determining the thermal time constant of the thermal storage layer according to the required printing rate;

[0024] Determining the heat capacity of the heat storage layer according to the thermal time constant;

[0025] determining a proportion of the third filling material according to the heat capacity;

[0026] After the fourth filling material is filled in the heat storage layer, the method further includes:

[0027] Determining the thermal time constant of the thermal storage layer according to the required printing rate;

[0028] Determining the heat capacity of the heat storage layer according to the thermal time constant;

[0029] The proportion of the fourth filling material is determined according to the heat capacity. Optionally, the filling material in the heat storage layer is adjusted according to the required printing rate, including:

[0030] A fifth filling material is filled in the heat storage layer, wherein the thermal conductivity of the fifth filling material can be changed with the current temperature.

[0031] In a second aspect, an embodiment of the present invention provides a thermal print head, which is prepared according to the preparation method described in the first aspect, comprising:

[0032] Heat dissipation substrate;

[0033] A ceramic substrate, located on one side of the heat dissipation substrate;

[0034] A heat storage layer is located on a side of the ceramic substrate away from the heat dissipation substrate;

[0035] An electrode layer, located at a side of the ceramic substrate away from the heat dissipation substrate and covering the ceramic substrate;

[0036] A resistance layer, located on a side of the electrode layer away from the heat storage layer;

[0037] Wherein, the heat storage layer includes a substrate and a filling material.

[0038] Optionally, the filling material includes metal alloy particles and / or metal compound particles.

[0039] Optionally, the filling material includes solid ceramic particles and / or hollow ceramic particles.

[0040] Optionally, the base material and the filling material are evenly distributed.

[0041] The preparation method of a thermal print head provided in an embodiment of the present invention, wherein the thermal print head includes a heat dissipation substrate, a ceramic substrate, a heat storage layer, an electrode layer and a resistor layer; the ceramic substrate is located on one side of the heat dissipation layer, the heat storage layer is located on the side of the ceramic substrate away from the heat dissipation substrate, the electrode layer is located on the side of the ceramic substrate away from the heat dissipation substrate and covers the ceramic substrate, and the resistor layer is located on the side of the electrode layer away from the heat storage layer; wherein the heat storage layer includes a substrate and a filling material. The preparation method first obtains the required printing rate, and then adjusts the filling condition of the filling material in the heat storage layer according to the required printing rate. That is, the filling condition of the filling material in the heat storage layer is adjusted according to the required printing rate to meet the high requirements of the thermal print head on the heat storage layer and ensure the working effect and printing effect of the thermal print head. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required to describe the embodiments. Obviously, the drawings introduced are only drawings of a part of the embodiments to be described in the present invention, rather than all the drawings. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 It is a schematic flow chart of a method for preparing a thermal print head provided in Embodiment 1 of the present invention;

[0044] Figure 2 is a schematic structural diagram of a thermal print head provided by an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the relationship between thermal timing and printing rate provided by an embodiment of the present invention;

[0046] Figure 4 It is a schematic flow chart of a method for preparing a thermal print head provided in the second embodiment of the present invention;

[0047] Figure 5 It is a schematic flow chart of a method for preparing a thermal print head provided in Embodiment 3 of the present invention;

[0048] Figure 6 It is a schematic flow chart of a method for preparing a thermal print head provided in a fourth embodiment of the present invention;

[0049] Figure 7 It is a schematic diagram of the relationship between thermal conductivity and time provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a system, product or device comprising a series of units is not necessarily limited to those steps or units clearly listed, but may include other units that are not clearly listed or inherent to these products or devices.

[0052] Embodiment 1

[0053] Figure 1 1 is a flow chart of a method for preparing a thermal print head provided in the first embodiment of the present invention. This embodiment is applicable to the preparation process of a thermal print head. The method can be executed by a control device for preparing a thermal print head in the embodiment of the present invention, wherein the device can be implemented by software and / or hardware. Specifically, the method for preparing a thermal print head includes:

[0054] S110, obtaining a required printing rate.

[0055] Among them, the thermal print head is generally composed of a row of heating elements, which have the same resistance. These elements are closely arranged, ranging from 200dpi to 600dpi. These elements will quickly generate high temperature when a certain current passes through them. When the medium coating encounters these elements, the temperature will rise in a very short time, and the medium coating will undergo a chemical reaction to show color.

[0056] Furthermore, the heat storage layer in the thermal print head has the functions of heat storage and heat dissipation, and the heat storage and / or heat dissipation characteristics in the heat storage layer will affect its printing rate. Specifically, in different practical scenarios or application requirements, there are different requirements for the printing rate of the thermal print head. The embodiment of the present invention can adaptively adjust the actual printing rate of the thermal print head by pre-judging the printing rate of the thermal print head, thereby ensuring the printing effect and work efficiency of the thermal print head, and at the same time, it can also avoid unnecessary waste when a lower printing rate is required.

[0057] Specifically, Figure 2 is a schematic diagram of the structure of a thermal print head provided by an embodiment of the present invention, with reference to Figure 2 As shown, the thermal print head 10 prepared by the preparation method includes a heat dissipation substrate 100, a ceramic substrate 200, a heat storage layer 300, an electrode layer 400 and a resistor layer 500, etc. Among them, the heat dissipation substrate 100 facilitates the heat dissipation of the thermal print head 10 and ensures the heat dissipation effect of the thermal print head 10. The ceramic substrate 200 is located on one side of the heat dissipation substrate 100, and the heat storage layer 300 is also arranged on the ceramic substrate 200, which can prevent the heat generated by the resistor layer 600 prepared later from being lost too quickly through the heat dissipation substrate 100 and the ceramic substrate 200, that is, the heat storage layer 300 has a certain heat preservation effect, ensuring the working efficiency of the thermal print head 10. The electrode layer 400 can be formed into an electrode structure by patterned etching. The exemplary electrode structure generally includes a common electrode, a bonding electrode and an extraction electrode, which is not specifically described in the embodiment of the present invention. By preparing the electrode layer 400, the electrical connection with the driving chip can be guaranteed, thereby realizing the transmission of electrical signals and ensuring that the resistor layer 500 in contact with it generates heat.

[0058] Optionally, the thermal print head 10 may further include an insulating protective film 600 and a wear-resistant protective layer 700, and the ceramic substrate 200 and the heat dissipation substrate 100 may be connected by a connecting adhesive 800. For example, the connecting adhesive 800 may be a double-sided adhesive or a thermally conductive adhesive, which is not specifically limited in the embodiment of the present invention.

[0059] S120, adjusting the filling condition of the filling material in the thermal storage layer according to the required printing rate.

[0060] Specifically, the materials in the heat storage layer may include a substrate and a filling material, and the substrate is the main material in the heat storage layer. The filling condition of the filling material may refer to the type of filling material, the physical properties of the filling material, and the proportion of the filling material. Exemplarily, the substrate may be made of borosilicate glass glaze material, and the filling material may be a material with different physical properties provided according to the actual printing rate. For example, when the thermal print head requires a higher printing rate, the filling material may be a material with higher thermal conductivity, thereby ensuring that the overall comprehensive thermal conductivity of the heat storage layer is larger and the higher printing rate of the thermal print head is ensured. It should be explained that, referring to Figure 3 As shown, the non-smooth connecting line segments in the figure represent the experimental tests conducted when the overall comprehensive thermal conductivity of the heat storage layer is large, and the smooth solid line in the figure can reflect the overall trend, that is, when the overall comprehensive thermal conductivity of the heat storage layer is large, that is, the thermal conductivity of the base glaze (i.e., the heat storage layer) of the thermal print head is better, the thermal timing will be smaller in combination with the attached figure, and the printing rate will be faster.

[0061] In summary, the method for preparing a thermal print head provided in an embodiment of the present invention first obtains the required printing rate, and then adjusts the distribution of the filling material in the thermal storage layer according to the required printing rate. That is, by adjusting the distribution of the filling material in the thermal storage layer according to the required printing rate, the high requirements of the thermal print head for heat storage can be met, the applicability of the thermal print head can be improved, and the working effect and printing effect of the thermal print head can be guaranteed.

[0062] Embodiment 2

[0063] Figure 4 is a schematic diagram of a method for preparing a thermal print head provided in the second embodiment of the present invention, with reference to Figure 4 As shown, the method for preparing a thermal print head provided in an embodiment of the present invention further includes:

[0064] S210, obtaining a required printing rate.

[0065] S220, determine whether the required printing rate is less than the preset printing rate, if so, execute S230, if not, execute S270.

[0066] Among them, the preset printing rate is the printing rate when the thermal storage layer is only under the substrate, that is, the printing rate of the thermal print head when no filling material is added to the thermal storage layer, or the printing rate of the thermal print head when the thermal storage layer is made of ordinary glass. By judging the relationship between the required printing rate and the preset printing rate, it can be known whether the currently required printing rate of the thermal print head is higher or lower, and the comparison standard is based on the preset printing rate. In the case where it is known that the different distribution of filling materials in the thermal storage layer will affect the printing rate, the filling material can be adjusted more accurately and purposefully based on the above judgment criteria, thereby achieving the adjustment of the comprehensive thermal conductivity of the thermal storage layer.

[0067] S230, filling the thermal storage layer with a first filling material.

[0068] Specifically, when the required printing rate is less than the preset printing rate, the first filling material can be filled in the thermal storage layer to adjust the thermal conductivity of the thermal storage layer as a whole. The thermal conductivity of the first filling material is less than the thermal conductivity of the thermal storage layer substrate, that is, the thermal storage layer is filled with a filling material with a smaller thermal conductivity on the basis of the original substrate to reduce the overall thermal conductivity. That is, through the integration of the first filling material and the substrate, the thermal conductivity of the thermal storage layer when filled with the first filling material will definitely be less than the thermal conductivity of the thermal storage layer when the first filling material is not filled, thereby reducing the printing rate of the thermal print head.

[0069] S240, determining the thermal time constant of the thermal storage layer according to the required printing rate.

[0070] Furthermore, the thermal time constant of the thermal storage layer can reflect the speed of heat conduction and heat dissipation of the thermal storage layer. Specifically, when a higher printing rate is required, the thermal time constant of the thermal storage layer should be shorter, and when a lower printing rate is required, the thermal time constant of the thermal storage layer can be longer. In general, the thermal time constant of the thermal storage layer can be selected for different required printing rates, further ensuring that the prepared thermal print head meets the expected required parameter standards.

[0071] S250, determining the thermal conductivity of the heat storage layer according to the thermal constant.

[0072] In a thermal print head, there is a certain numerical relationship between thermal conductivity and the thermal time constant, that is, the thermal conductivity in the required heat storage layer is calculated based on the cooling formula of the thermal time constant.

[0073] S260. Determine the proportion of the first filling material according to the thermal conductivity.

[0074] Specifically, the heat storage layer is filled with a first filling material on the basis of the substrate. Based on the fact that the thermal conductivity of the first filling material is less than the thermal conductivity of the substrate, the proportion of the first filling material in the entire heat storage layer can be adjusted to ensure that the heat storage layer finally presents different thermal conductivities.

[0075] Among them, when it is known that the first filling material is filled in the thermal storage layer and the thermal constant is also known, it is possible to determine how much proportion of the first filling material should be filled in the thermal storage layer at this time to achieve the thermal conductivity required by the thermal storage layer. For example, if the thermal conductivity required at this time is relatively large, a smaller content of the first filling material is filled, and if the thermal conductivity required at this time is relatively small, a larger content of the first filling material is filled, thereby reflecting the precise adjustment of the prepared thermal print head and ensuring the working effect of the thermal print head.

[0076] S270, filling the thermal storage layer with a second filling material.

[0077] Specifically, when the required printing rate is greater than the preset printing rate, a second filling material can be filled in the thermal storage layer to adjust the overall thermal conductivity of the thermal storage layer. The thermal conductivity of the second filling material is greater than the thermal conductivity of the substrate, that is, the thermal storage layer is filled with a filling material with a higher thermal conductivity on the basis of the original substrate to increase the overall thermal conductivity. That is, through the integration of the second filling material and the substrate, the thermal conductivity of the thermal storage layer when filled with the second filling material will be greater than the thermal conductivity of the thermal storage layer when the second filling material is not filled, thereby improving the printing rate of the thermal print head.

[0078] S280, determining the thermal time constant of the thermal storage layer according to the required printing rate.

[0079] Furthermore, the thermal time constant of the thermal storage layer can reflect the speed of heat conduction and heat dissipation of the thermal storage layer. Specifically, when a higher printing rate is required, the thermal time constant of the thermal storage layer should be shorter, and when a lower printing rate is required, the thermal time constant of the thermal storage layer can be longer. In general, the thermal time constant of the thermal storage layer can be selected for different required printing rates, further ensuring that the prepared thermal print head meets the expected required parameter standards.

[0080] S290. Determine the thermal conductivity of the heat storage layer according to the thermal constant.

[0081] S2100. Determine the proportion of the second filling material according to the thermal conductivity.

[0082] Specifically, the heat storage layer is filled with a second filling material on the basis of the substrate. Based on the fact that the thermal conductivity of the second filling material is greater than the thermal conductivity of the substrate, the proportion of the second filling material in the entire heat storage layer can be adjusted to ensure that the heat storage layer finally presents different thermal conductivities.

[0083] Among them, when it is known that the heat storage layer is filled with the second filling material and the thermal constant is also known, it is possible to determine how much proportion of the second filling material should be filled in the heat storage layer at this time to achieve the thermal conductivity required by the heat storage layer. For example, if the thermal conductivity required at this time is relatively large, a larger content of the second filling material is filled, and if the thermal conductivity required at this time is relatively small, a smaller content of the second filling material is filled, thereby reflecting the precise adjustment of the prepared thermal print head and ensuring the working effect of the thermal print head.

[0084] In summary, the method for preparing a thermal print head provided in an embodiment of the present invention compares the required printing rate with the preset printing rate, selects filling materials with different thermal conductivities to be filled in the heat storage layer, and selects the proportion of the filling materials, thereby ensuring that the actual printing rate of the prepared thermal print head is closer to the required printing rate, thereby ensuring the working accuracy of the thermal print head.

[0085] Embodiment 3

[0086] Figure 5 is a schematic diagram of a method for preparing a thermal print head provided in Embodiment 3 of the present invention, with reference to Figure 5 As shown, the method for preparing a thermal print head provided in an embodiment of the present invention further includes:

[0087] S310, obtaining a required printing rate.

[0088] S320, determine whether the required printing rate is less than the preset printing rate. If yes, execute S330, if no, execute S370.

[0089] S330, filling the thermal storage layer with a third filling material.

[0090] Specifically, when the required printing rate is less than the preset printing rate, a third filling material can be filled in the heat storage layer to adjust the overall thermal conductivity of the heat storage layer. Among them, the heat capacity of the third filling material is K1, the heat capacity of the substrate is K2, and K1<K2, and the heat capacity is the product of density and specific heat capacity. That is, the heat capacity of the third filling material is smaller than the heat capacity of the substrate, and the heat capacity will affect its thermal conductivity. In the case where the heat capacity of the third filling material is smaller than the heat capacity of the substrate, that is, the heat storage layer is filled with a filling material with a smaller heat capacity on the basis of the original substrate, thereby reducing the overall thermal conductivity. That is, through the integration of the third filling material and the substrate, the thermal conductivity of the heat storage layer when filled with the third filling material will definitely be smaller than the thermal conductivity of the heat storage layer when the third filling material is not filled, thereby reducing the printing rate of the thermal print head.

[0091] S340, determining the thermal time constant of the heat storage layer according to the required printing rate.

[0092] Furthermore, the thermal time constant of the thermal storage layer can reflect the speed of heat conduction and heat dissipation of the thermal storage layer. Specifically, when a higher printing rate is required, the thermal time constant of the thermal storage layer should be shorter, and when a lower printing rate is required, the thermal time constant of the thermal storage layer can be longer. In general, the thermal time constant of the thermal storage layer can be selected for different required printing rates, further ensuring that the prepared thermal print head meets the expected required parameter standards.

[0093] S350, determining the heat capacity of the heat storage layer according to the thermal time constant.

[0094] S360. Determine the proportion of the third filling material according to the heat capacity.

[0095] Specifically, the heat storage layer is filled with a third filling material on the basis of the substrate. Based on the fact that the heat capacity of the third filling material is smaller than the heat capacity of the substrate, by adjusting the proportion of the third filling material in the entire heat storage layer, it can be ensured that the heat storage layer finally presents different thermal conductivities and achieves different printing rates.

[0096] Among them, when it is known that the third filling material is filled in the heat storage layer and the thermal constant is also known, it is possible to determine how much percentage of the third filling material should be filled in the heat storage layer at this time to achieve the required heat capacity of the heat storage layer. For example, if the required heat capacity at this time is relatively large, a smaller content of the third filling material is filled, and if the required heat capacity at this time is relatively large, a larger content of the third filling material is filled, thereby reflecting the precise adjustment of the prepared thermal print head and ensuring the working effect of the thermal print head.

[0097] S370, filling the heat storage layer with a fourth filling material.

[0098] Specifically, when the required printing rate is greater than the preset printing rate, a fourth filling material can be filled in the thermal storage layer to adjust the overall thermal conductivity of the thermal storage layer. The heat capacity of the fourth filling material is K3, the heat capacity of the substrate is K2, and K2 < K3, that is, the heat capacity of the fourth filling material is greater than the heat capacity of the substrate. In other words, when the heat capacity of the fourth filling material is greater than the heat capacity of the substrate, the thermal storage layer is filled with a filling material with a larger heat capacity on the basis of the original substrate to enhance the overall thermal conductivity. That is, through the integration of the fourth filling material and the substrate, the thermal conductivity of the thermal storage layer when filled with the fourth filling material will definitely be greater than the thermal conductivity of the thermal storage layer when the fourth filling material is not filled, thereby enhancing the printing rate of the thermal print head.

[0099] S380, determining the thermal time constant of the thermal storage layer according to the required printing rate.

[0100] Furthermore, the thermal time constant of the thermal storage layer can reflect the speed of heat conduction and heat dissipation of the thermal storage layer. Specifically, when a higher printing rate is required, the thermal time constant of the thermal storage layer should be shorter, and when a lower printing rate is required, the thermal time constant of the thermal storage layer can be longer. In general, the thermal time constant of the thermal storage layer can be selected for different required printing rates, further ensuring that the prepared thermal print head meets the expected required parameter standards.

[0101] S390. Determine the heat capacity of the heat storage layer according to the thermal time constant.

[0102] S3100. Determine the proportion of the fourth filling material according to the heat capacity.

[0103] Specifically, the heat storage layer is filled with a fourth filling material on the basis of the substrate. Based on the fact that the heat capacity of the fourth filling material is greater than the heat capacity of the substrate, by adjusting the proportion of the fourth filling material in the entire heat storage layer, it can be ensured that the heat storage layer finally presents different thermal conductivities and achieves different printing rates.

[0104] Among them, when it is known that the heat storage layer is filled with the fourth filling material and the thermal constant is also known, it is possible to determine how much of the fourth filling material should be filled in the heat storage layer at this time to achieve the required heat capacity of the heat storage layer. For example, if the required heat capacity at this time is relatively large, a larger content of the fourth filling material is filled, and if the required heat capacity at this time is relatively small, a smaller content of the fourth filling material is filled, thereby reflecting the precise adjustment of the prepared thermal print head and ensuring the working effect of the thermal print head.

[0105] In summary, the method for preparing a thermal print head provided in an embodiment of the present invention compares the required printing rate with the preset printing rate, selects filling materials with different density and specific heat capacity products to be filled in the heat storage layer, and selects the proportion of the filling materials, thereby ensuring that the actual printing rate of the prepared thermal print head is closer to the required printing rate, thereby ensuring the working accuracy of the thermal print head.

[0106] Embodiment 4

[0107] Figure 6 is a schematic diagram of a process for preparing a thermal print head provided by a fourth embodiment of the present invention, with reference to Figure 6 As shown, the method for preparing a thermal print head provided in an embodiment of the present invention further includes:

[0108] S410, obtaining a required printing rate.

[0109] S420, filling the heat storage layer with a fifth filling material.

[0110] Specifically, the fifth filling material may be a material whose thermal conductivity changes with the current temperature, that is, the higher the temperature, the higher the thermal conductivity of the filling material, and thus the greater the comprehensive thermal conductivity of the heat storage layer. Figure 7 is a schematic diagram of the relationship between thermal conductivity and time provided by an embodiment of the present invention, with reference to Figure 7 As shown in the figure, the color development temperature refers to the color change caused by the chemical reaction between the color developer and the colorless dye at the place where the thermal print head prints at the current temperature to form a picture. For example, the embodiment of the present invention does not limit the specific value of the color development temperature. Further, Figure 7 There are also two curves, curve a1 represents the situation that the thermal conductivity can be changed when the fifth filling material is filled in the heat storage layer, and curve a2 represents the situation that the thermal conductivity is fixed when the fifth filling material is not filled in the heat storage layer. The color development temperature + (30-80°C) is taken as the turning point. When the temperature of the heat storage layer is less than the color development temperature + (30-80°C), the lower the thermal conductivity is, the more conducive it is to raise the base temperature as soon as possible in the case of low base temperature (such as Figure 7 (t3-t2) < (t3-t1)), the purpose of saving energy can be achieved; when the temperature of the heat storage layer > the color temperature + (30 ~ 80 ° C) or above, the higher the thermal conductivity, the more conducive it is to reduce the temperature of the heating element as soon as possible in high temperature situations (such as Figure 7 (t4-t3)<(t5-t3)), which can avoid tailing caused by high temperature time for too long.

[0111] Exemplarily, such a material whose thermal conductivity changes with temperature, such as MgB2 polycrystalline sample, is prepared by solid-state reaction method, such as mixed physical and chemical vapor deposition method, pulsed laser deposition method, magnetron sputtering method, molecular beam epitaxy method and electron beam evaporation method. For example, when preparing MgB2 thin film by magnetron sputtering, DC or radio frequency magnetron sputtering is used, and the target material is mostly a single Mg, B dual target or a composite target with B block embedded in the Mg target. Dual-target sputtering can more conveniently adjust the amount of MgB atoms deposited on the substrate by their respective sputtering powers, while the composite target can only determine the content of Mg and B in the effective sputtering area during preparation. If the ratio of Mg to B in the target is optimized, the dual-target sputtering effect is better. The Mg / B precursor film B uses a radio frequency magnetron source, and the Mg uses a direct current magnetron source. The precursor film is then in-situ annealed in an argon atmosphere at 500-700°C to obtain MgB2 with a smooth surface. The film quality obtained by in-situ annealing at 680°C is the best, and then stripping and grinding methods are used to obtain micron-sized particles, which are used as filling materials for the substrate.

[0112] In summary, the preparation method provided in the embodiment of the present invention can fill the fifth filling material in the heat storage layer, that is, fill the filling material whose thermal conductivity can change with temperature, thereby better ensuring the working effect and working efficiency of the thermal print head.

[0113] Embodiment 5

[0114] Based on the same inventive concept, an embodiment of the present invention further provides a thermal print head. Figure 2 is a schematic diagram of the structure of a thermal print head provided by an embodiment of the present invention, with reference to Figure 2 As shown, the thermal print head 10 provided by the embodiment of the present invention includes a heat dissipation substrate 100; a ceramic substrate 200, which is located on one side of the heat dissipation substrate 100; a heat storage layer 300, which is located on the side of the ceramic substrate 200 away from the heat dissipation substrate 100; an electrode layer 400, which is located on the side of the ceramic substrate 200 away from the heat dissipation substrate 100 and covers the ceramic substrate 200; a resistor layer 500, which is located on the side of the electrode layer 400 away from the heat storage layer 300; wherein the heat storage layer 300 includes a base material and a filling material.

[0115] Among them, the thermal print head 10 is generally composed of a row of heating elements, which have the same resistance. These elements are closely arranged, ranging from 200dpi to 600dpi. These elements will quickly generate high temperature when a certain current passes through them. When the medium coating encounters these elements, the temperature will rise in a very short time, and the medium coating will undergo a chemical reaction to show color.

[0116] Among them, the heat dissipation substrate 100 facilitates the heat dissipation of the thermal print head 10 and ensures the heat dissipation effect of the thermal print head 10. The ceramic substrate 200 is located on one side of the heat dissipation substrate 100, and a heat storage layer 300 is also arranged on the ceramic substrate 200, which can prevent the heat generated by the resistor layer 600 prepared later from being lost too quickly through the heat dissipation substrate 100 and the ceramic substrate 200, that is, the heat storage layer 300 has a certain heat preservation effect, ensuring the working efficiency of the thermal print head 10. The electrode layer 400 can form an electrode structure by patterned etching. The exemplary electrode structure generally includes a common electrode, a bonding electrode and an extraction electrode, which is not described in detail in the embodiment of the present invention. By preparing the electrode layer 400, the electrical connection with the driver chip can be guaranteed, thereby realizing the transmission of electrical signals and ensuring that the resistor layer 600 in contact with it generates heat.

[0117] Optionally, the thermal print head 10 may further include an insulating protective film 600 and a wear-resistant protective layer 700, and the ceramic substrate 200 and the heat dissipation substrate 100 may be connected by a connecting adhesive 800. For example, the connecting adhesive 800 may be a double-sided adhesive or a thermally conductive adhesive, which is not specifically limited in the embodiment of the present invention.

[0118] Optionally, the substrate in the heat storage layer 300 may be made of borosilicate glass glaze material.

[0119] Optionally, the filling material in the heat storage layer 300 includes alloy particles.

[0120] Optionally, the filling material in the thermal storage layer 300 may be solid ceramic particles and / or hollow ceramic particles.

[0121] Specifically, the filling material can be modified high-temperature resistant alloy particles or metal compound particles, and can also be ceramic particles. The base metal of the alloy can be silver, aluminum, gold, iron, copper, zinc and other materials. The thermal conductivity of silver can reach up to 429W / mK, and the product of the density of silver (g / cm3) and the specific heat (J / g*k) can reach a maximum of 2.52. Ceramic particles can be Al2O3 (≈20w / mK) or SIC (≈270w / mK). Ceramic particles are of two types: solid and hollow. The solid comprehensive thermal conductivity is high, and the hollow comprehensive thermal conductivity is low. The filling material is adaptively adjusted according to the actual parameter requirements.

[0122] Furthermore, in some embodiments, the filling material in the heat storage layer may also include alloy particles and ceramic particles at the same time. Based on the specific setting conditions, the embodiments of the present invention do not limit this one by one.

[0123] Furthermore, the base material and the filling material in the thermal storage layer 300 may be evenly distributed.

[0124] Specifically, adding filling material to the heat storage layer 300 can adjust the comprehensive thermal conductivity of the heat storage layer 300. By evenly distributing the substrate and the filling material, the balance of the overall heat storage and heat dissipation effects of the heat storage layer 300 can be ensured, which is beneficial to ensuring the working stability of the thermal print head 10.

[0125] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for preparing a thermal print head, applied to a thermal print head, the thermal print head comprising a heat dissipation substrate, a ceramic substrate, a heat storage layer, an electrode layer and a resistance layer; the ceramic substrate is located on one side of the heat dissipation substrate, the heat storage layer is located on a side of the ceramic substrate away from the heat dissipation substrate, the electrode layer is located on a side of the ceramic substrate away from the heat dissipation substrate and covers the ceramic substrate, and the resistance layer is located on a side of the electrode layer away from the heat storage layer; in, The heat storage layer comprises a substrate and a filling material; characterized in that the preparation method comprises: Get the required printing rate; Adjusting the filling condition of the filling material in the heat storage layer according to the required printing rate; Adjusting the filling condition of the filling material in the heat storage layer according to the required printing rate includes: Determining whether the required printing rate is less than a preset printing rate, wherein the preset printing rate is a printing rate when the heat storage layer is composed of only a substrate; If yes, filling the thermal storage layer with a first filling material; If not, filling the thermal storage layer with a second filling material, wherein the thermal conductivity of the first filling material is less than the thermal conductivity of the substrate, and the thermal conductivity of the substrate is less than the thermal conductivity of the second filling material; After the first filling material is filled in the heat storage layer, the method further includes: Determining the thermal time constant of the thermal storage layer according to the required printing rate; Determining the thermal conductivity of the heat storage layer according to the thermal time constant; determining a proportion of the first filling material according to the thermal conductivity; After the second filling material is filled in the heat storage layer, the method further comprises: Determining the thermal time constant of the thermal storage layer according to the required printing rate; Determining the thermal conductivity of the heat storage layer according to the thermal time constant; determining a proportion of the second filling material according to the thermal conductivity; Or adjusting the distribution of the filling material in the thermal storage layer according to the required printing rate, including: Determining whether the required printing rate is less than a preset printing rate, wherein the preset printing rate is a printing rate when the heat storage layer is composed of only a substrate; If yes, filling the heat storage layer with a third filling material; If not, fill the heat storage layer with a fourth filling material, wherein the heat capacity of the third filling material is K1, the heat capacity of the substrate is K2, the heat capacity of the fourth filling material is K3, and K1<K2<K3, and K1, K2 and K3 are positive numbers; After the third filling material is filled in the heat storage layer, the method further includes: Determining the thermal time constant of the thermal storage layer according to the required printing rate; Determining the heat capacity of the heat storage layer according to the thermal time constant; determining a proportion of the third filling material according to the heat capacity; After the fourth filling material is filled in the heat storage layer, the method further includes: Determining the thermal time constant of the thermal storage layer according to the required printing rate; Determining the heat capacity of the heat storage layer according to the thermal time constant; The proportion of the fourth filling material is determined according to the heat capacity.

2. The preparation method according to claim 1, It is characterized in that Adjusting the filling condition of the filling material in the heat storage layer according to the required printing rate includes: A fifth filling material is filled in the heat storage layer, wherein the thermal conductivity of the fifth filling material can be changed with the current temperature.

3. A thermal print head, prepared according to the method for preparing a thermal print head according to claim 1 or 2, It is characterized in that include: Heat dissipation substrate; A ceramic substrate, located on one side of the heat dissipation substrate; A heat storage layer is located on a side of the ceramic substrate away from the heat dissipation substrate; An electrode layer, located at a side of the ceramic substrate away from the heat dissipation substrate and covering the ceramic substrate; A resistance layer, located on a side of the electrode layer away from the heat storage layer; Wherein, the heat storage layer includes a substrate and a filling material.

4. The thermal print head according to claim 3, It is characterized in that The filling material includes metal alloy particles and / or metal compound particles.

5. The thermal print head according to claim 3, It is characterized in that The filling material includes solid ceramic particles and / or hollow ceramic particles.

6. The thermal print head according to claim 3, It is characterized in that The base material and the filling material are evenly distributed.

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