Heating substrate for thermal printing head
By arranging a nano-silica layer above the common reinforcing wires and electrode wires of the thermal print head, the problems of large wire surface roughness and insufficient density in the existing technology are solved, and the reliability of the thermal print head is significantly improved.
Patent Information
- Application Number
- CN202421279212.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-05
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2034-06-05
AI Technical Summary
The surface roughness of the common reinforcement wires and electrode wires of existing thermal print heads is large, the density is insufficient, and it is easy to be ions eroded and lead to failure.
A nano-silica layer is provided above the common reinforcing wires and some electrode wires as a morphology structure optimization layer, and a conductive protective layer is formed below it to improve the density of the protective layer.
Significantly improves the density of the film protective layer, prevents the electrode wires and common reinforcing wires from being corroded, and improves the reliability of the thermal print head.
Smart Images
Figure CN222372541U_ABST
Abstract
Description
Technical field:
[0001] The utility model relates to the technical field of thermal print head manufacturing, in particular to a heating substrate for a thermal print head. Background technology:
[0002] The existing thermal print head includes an insulating substrate with an amorphous glaze coating formed on the surface, a heating resistor layer is arranged on the amorphous glaze coating, and a conductor layer covers the heating resistor layer. During the manufacturing process, the conductor layer is formed into an electrode wire through photoengraving technology, and a plurality of heating resistors arranged along the main printing direction are formed on the resistor layer. The electrode wire can be divided into a common electrode wire and an individual electrode wire according to different functions. The common electrode wire is connected to an external power supply through a wiring cable, and the individual electrode wire is connected to a driver IC that controls the operation of the heating resistor. If the number of heating resistors energized by the common electrode increases at the same time, the current passing through the common electrode will increase accordingly, and the voltage at different positions on the common electrode wire will produce voltage deviations with different distances from the power supply. The greater the resistance of the common electrode wire, the greater the voltage deviation will be, that is, the voltage applied to the heating resistor through the common electrode will also deviate, resulting in the optical density of the printed sample changing regularly with the different distances from the heating resistor to the power supply.
[0003] In order to solve the above problems, the thickness of the common electrode conductor in some areas is usually increased to reduce the resistance of the common electrode conductor, so as to reduce the voltage drop loss of the common reinforcement conductor. The thickened part of the common electrode conductor is called the common reinforcement conductor. The resistivity of silver is relatively small, and it is usually made into silver paste. The common reinforcement conductor is formed by printing and sintering, which has a good effect on improving the printing concentration difference caused by the voltage drop loss of the common reinforcement conductor. However, the surface roughness of the common reinforcement conductor formed by printing and sintering the silver paste is usually greater than 0.3 microns. The thin film protective layer formed on the surface of the common reinforcement conductor by the vacuum vapor deposition film forming method will have the problem of insufficient density, and the common reinforcement conductor will be corroded after ion invasion, resulting in failure of the thermal print head. In addition, the ceramic substrate used in the thermal print head in the prior art has many pores inside, and the surface roughness is usually greater than 0.3 microns. The roughness of the electrode wire layer formed on it is usually greater than 0.3 microns. The thin film protective layer formed on the surface of the electrode wire by the vacuum vapor deposition film forming method may have the problem of insufficient density, and the electrode wire may be corroded after ion invasion, causing the thermal print head to fail. If the roughness of the ceramic substrate surface is reduced by grinding, the pores inside the ceramic substrate will be exposed, the protective layer at the gaps will be insufficiently dense, and the pores of the ceramic substrate will be exposed, resulting in problems such as short circuit or disconnection of the wire at the pores. Summary of the invention:
[0004] In order to solve the problems existing in the prior art, the utility model proposes a heating substrate for a thermal print head which can improve the reliability of the thermal print head.
[0005] The utility model achieves this through the following measures:
[0006] A heating substrate for a thermal print head is provided with an insulating substrate, a heat-resistant glaze layer is provided on the surface of the insulating substrate, a heating resistor and an electrode wire are provided on the heat-resistant glaze layer, the electrode wire includes a common electrode and individual electrodes, and a common reinforcing wire is provided along the periphery of the heating resistor and connected to the common electrode. The invention is characterized in that a protective layer is also provided, the protective layer includes a non-conductive protective layer covering at least all the heating resistors and part of the electrode wires and part of the common reinforcing wires, a conductive protective layer at least partially covering the non-conductive protective layer, and a morphology structure optimization layer at least partially provided under the conductive protective layer, wherein the morphology structure optimization layer is a nano-silicon dioxide layer.
[0007] The common reinforcing wire of the utility model is arranged on the surface of the insulating substrate, including a Y-direction segment arranged parallel to the length direction of the heating resistor, and an X-direction segment vertically connected to the end of the Y-direction segment. The common reinforcing wire is arranged around the outside of the heating resistor and close to the edge of the insulating substrate, and is connected to the common electrode.
[0008] The morphology structure optimization layer of the utility model adopts a nano silicon dioxide layer formed by spraying perhydropolysilazane. Specifically, it is realized by spraying a substrate with perhydropolysilazane produced by Anzhi Company. This is a prior art and will not be described in detail.
[0009] The thickness of the morphology structure optimization layer of the utility model ranges from 10 to 2000 nm, and more than two morphology structure optimization layers may be provided.
[0010] The morphology structure optimization layer at least partially arranged below the conductive protection layer of the utility model is arranged above the common reinforcing wire and part of the electrode wire.
[0011] In the utility model, the morphology structure optimization layer at least partially arranged below the conductive protective layer is located above the non-conductive protective layer, that is, at least one morphology structure optimization layer is arranged between the conductive protective layer and the non-conductive protective layer, and the morphology structure optimization layer overlaps with the setting area of the non-conductive protective layer; further, the non-conductive protective layer includes an upper non-conductive protective layer and a lower non-conductive protective layer, and the morphology structure optimization layer is arranged between the upper non-conductive protective layer and the lower non-conductive protective layer.
[0012] The morphology structure optimization layer at least partially arranged under the conductive protective layer of the utility model is arranged between the non-conductive protective layer and the electrode wire, that is, after the morphology structure optimization layer covers the electrode wire, the non-conductive protective layer is sputtered on the upper surface of the morphology structure optimization layer.
[0013] The beneficial effect of the utility model is that a morphology structure optimization layer is arranged below the conductive protection layer above the common reinforcement wire and the electrode wire part, and the nano silicon dioxide layer in the morphology structure optimization layer is utilized to significantly improve the compactness of the thin film protection layer, thereby achieving the effect of improving the reliability of the thermal print head. Description of the drawings:
[0014] Figure 1 It is a partial front perspective schematic diagram of a heating substrate for a thermal print head involved in Example 1 of the utility model.
[0015] Figure 2 yes Figure 1 Schematic diagram of the cross section along the Y direction.
[0016] Figure 3 It is a schematic cross-sectional view of a heating substrate for a thermal print head according to Embodiment 2 of the present utility model.
[0017] Figure 4 It is a schematic cross-sectional view of a heating substrate for a thermal print head according to Embodiment 3 of the present utility model.
[0018] Figure 5 It is a partial front perspective schematic diagram of a heating substrate for a thermal print head involved in Example 3 of the utility model.
[0019] Figure markings: 01-heating substrate, 10-insulating substrate, 20-heat-resistant glaze layer, 30-common reinforcing wire, 41-heating resistor layer, 40-heating resistor, 50f-electrode wire layer, 50-electrode wire, 50a-common electrode, 50b-individual electrode, 60-non-conductive protective layer, 60a-lower non-conductive protective layer, 60b upper non-conductive protective layer, 70-morphology structure optimization layer, 80-conductive protective layer, 90-resin protective layer. Specific implementation method:
[0020] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings.
[0021] Example 1
[0022] like Figure 1 and Figure 2As shown, this example provides a heating substrate 01 for a thermal print head with a high surface protection layer density, including an insulating substrate 10. The insulating substrate 10 can be a flat plate-shaped or long strip-shaped insulating substrate 10. A heat-resistant glaze layer 20 is locally provided on the surface of the insulating substrate 10 along the X direction. The heat-resistant glaze layer 20 is an amorphous glaze layer formed by printing with a lead-free amorphous glaze slurry and sintering at about 1200°C to 1300°C. A common reinforcing wire 30 is locally formed on the surface of the insulating substrate 10 along the X direction and the Y direction. In order to reduce the wire resistance of the common reinforcing wire 30 as much as possible, the film thickness of the common reinforcing wire 30 after sintering is set in the range of 5-20 microns. On the surfaces of the insulating substrate 10, the heat-resistant glaze coating 20, and the common reinforcing wire 30, a metal ceramic target is used. A heating resistor layer 41 with a film thickness of 50 to 400 nanometers is formed by sputtering, and an electrode wire layer 50f with a film thickness of 500 to 1000 nanometers is formed by sputtering or evaporation using an aluminum target. Then, the electrode wire layer 50f and a portion of the heating resistor layer 40f are removed according to a preset width by a yellow light process and an etching method to form a heating resistor 40 and an electrode wire 50 including at least a common electrode 50a and an individual electrode 50b. A non-conductive protective layer 60 is formed by sputtering using a target in a set area on the surface of the insulating substrate 10, the heat-resistant glaze layer 20, the common reinforcing wire 30, the heating resistor 40, and the electrode wire 50. The thickness of the non-conductive protective layer 60 can be set within a range of 1 to 20 micrometers.
[0023] Using a perhydropolysilazane spray material, a perhydropolysilazane liquid coating is sprayed on a set area on the surface of the non-conductive protective layer 60 to form a morphology structure optimization layer 70 whose component is SiO2;
[0024] Using a conductive target material, a conductive protective layer 80 is formed on the morphology structure optimization layer 70 and the non-conductive protective layer 60 by magnetron sputtering, and an organic resin layer 90 is formed at least in a set area on the insulating substrate 10 by printing and then heating and curing the solder resist material with epoxy resin as the main component;
[0025] In this example, a perhydropolysilazane liquid coating is formed by spraying on a set area on the surface of the non-conductive protective layer 60, and finally a morphology structure optimization layer 70 composed of SiO2 is formed. Figure 2 As shown, in this example, the morphology structure optimization layer 70 partially covers the surface of the non-conductive protective layer 60, and the conductive protective layer 80 completely covers the morphology structure optimization layer 70. This structure can effectively compensate for the tiny defects of the non-conductive protective layer 60 on the surface of the electrode wire, and can improve the density of the conductive protective layer above the morphology structure optimization layer to prevent the electrode wire from being corroded.
[0026] Example 2
[0027] In this example, the structure and implementation method before the non-conductive protective layer 60 is formed are the same as those in the above example. The non-conductive protective layer 60 is formed by using SiO2, SiON, Si3N4, or SiAlON target material and sputtering to first form a lower non-conductive protective layer 60a. On a set area on the surface of the lower non-conductive protective layer 60a (specifically, above the common reinforcing wire and part of the electrode wire), a perhydropolysilazane spray material is used to form a perhydropolysilazane liquid coating, and finally a morphology structure optimization layer 70 composed of SiO2 is formed.
[0028] In a set area on the surface of the morphology structure optimization layer 70 and the lower non-conductive protective layer 60a, an upper non-conductive protective layer 60b is formed by sputtering using SiO2, SiON, Si3N4, or SiAlON target material. The composition of the upper non-conductive protective layer 60b may be the same as or different from that of the lower layer 60a. In this way, the lower non-conductive protective layer 60a, the morphology structure optimization layer 70, and the upper non-conductive protective layer 60b are combined to form the non-conductive protective layer 60. The method for forming the conductive protective layer 80 and the organic resin layer 90 above the non-conductive protective layer and the area in which they are located are the same as those in Example 1.
[0029] Example 3
[0030] like Figure 4 and Figure 5 As shown, this example provides a heating substrate 01 for a thermal print head with a high surface protection layer density, including an insulating substrate 10, the insulating substrate 10 can be a flat plate or a long strip insulating substrate 10, and a heat-resistant glaze layer 20 is partially provided on the surface of the insulating substrate 10 along the X direction. The heat-resistant glaze layer 20 is an amorphous glaze layer formed by printing with a lead-free amorphous glaze slurry and sintering at about 1200°C to 1300°C. On the surface of the insulating substrate 10 and the heat-resistant glaze coating 20, a gold A ceramic target is used to form a heating resistor layer 41 with a film thickness of 50 to 400 nanometers by sputtering, and an aluminum target is used to form an electrode wire layer 50f with a film thickness of 500 to 1000 nanometers by sputtering or evaporation. Then, a part of the electrode wire layer 50f and the heating resistor layer 40f is removed according to a preset width by a yellow light process and an etching method to form a heating resistor 40 and an electrode wire 50 including at least a common electrode 50a and an individual electrode 50b.
[0031] In the set area on the surface of the insulating substrate 10, the heat-resistant glaze layer 20, the heating resistor 40, and the electrode wire 50, a sputtered non-conductive protective layer 60 is formed by sputtering using a target material. The film thickness of the non-conductive protective layer 60 can be set in the range of 1-20 microns;
[0032] In this example, perhydropolysilazane liquid is used to form a morphology structure optimization layer 70 on the surface of the non-conductive protective layer 60, corresponding to the set area of the electrode wire, and further, a conductive protective layer 80 covering the morphology structure optimization layer 70 is provided on the upper surface of the morphology structure optimization layer 70;
[0033] Compared with the prior art, this example helps to improve the density of the protective layer above the corresponding area by setting the morphology structure optimization layer, thereby achieving the effect of improving the reliability of the thermal print head.
Claims
1. A heating substrate for a thermal print head, comprising an insulating substrate, a heat-resistant glaze layer on the surface of the insulating substrate, a heating resistor and an electrode wire on the heat-resistant glaze layer, wherein the electrode wire comprises a common electrode and an individual electrode, characterized in that: A protective layer is also provided, which includes a non-conductive protective layer that at least covers all heating resistors and part of the electrode wires, a conductive protective layer that at least partially covers the non-conductive protective layer, and a morphology structure optimization layer that is at least partially arranged under the conductive protective layer, and the morphology structure optimization layer is a nano-silicon dioxide layer.
2. A heating substrate for a thermal print head according to claim 1, characterized in that: A common reinforcing wire connected to the common electrode is also provided along the periphery of the heating resistor, and the non-conductive protective layer covers part of the common reinforcing wire.
3. A heating substrate for a thermal print head according to claim 1, characterized in that: The morphology structure optimization layer is a nano silicon dioxide layer formed by spraying perhydropolysilazane.
4. The heating substrate for a thermal print head according to claim 1, characterized in that: The thickness of the morphology structure optimization layer ranges from 10 to 2000 nm, and more than two morphology structure optimization layers are provided.
5. The heating substrate for a thermal print head according to claim 2, characterized in that: The common reinforcing wire is arranged on the surface of the insulating substrate, including a Y-direction segment arranged parallel to the length direction of the heating resistor, and an X-direction segment vertically connected to the end of the Y-direction segment. The common reinforcing wire is arranged around the outside of the heating resistor and close to the edge of the insulating substrate, and is connected to the common electrode.
6. A heating substrate for a thermal print head according to claim 5, characterized in that: The morphology structure optimization layer at least partially arranged below the conductive protection layer is arranged above the common reinforcing wire and part of the electrode wire.
7. A heating substrate for a thermal print head according to claim 6, characterized in that: The morphology structure optimization layer at least partially disposed under the conductive protective layer is located above the non-conductive protective layer, that is, at least one morphology structure optimization layer is disposed between the conductive protective layer and the non-conductive protective layer, and the morphology structure optimization layer overlaps with the non-conductive protective layer.
8. The heating substrate for a thermal print head according to claim 6, characterized in that: The non-conductive protective layer comprises an upper non-conductive protective layer and a lower non-conductive protective layer, and the topography structure optimization layer is arranged between the upper non-conductive protective layer and the lower non-conductive protective layer.
9. The heating substrate for a thermal print head according to claim 3, characterized in that: The morphology structure optimization layer at least partially disposed under the conductive protective layer is disposed between the non-conductive protective layer and the electrode wire, that is, after the morphology structure optimization layer covers the electrode wire, the non-conductive protective layer is sputtered on the upper surface of the morphology structure optimization layer.