A thin-film thermal printhead and its preparation method

Abstract

This invention discloses a thin-film thermal printhead and its fabrication method. The fabrication method includes: providing an insulating substrate, the insulating substrate including a first insulating region, a second insulating region, and a third insulating region; forming a heat-retaining glaze coating on one side of the insulating substrate and in at least the first insulating region; forming a resistive layer on the side of the heat-retaining glaze coating away from the insulating substrate; forming a common electrode on one side of the heat-retaining glaze coating and in the first insulating region, the common electrode including an electrode layer; forming a lead-out electrode on one side of the insulating substrate and in the second insulating region, the lead-out electrode including an electrode layer; forming a bond electrode on one side of the insulating substrate and in the third insulating region, the bond electrode including two electrode layers; and providing a preset opening on the side of the common electrode away from the heat-retaining glaze coating. By setting the bond electrode as two electrode layers, this invention ensures the stability of the bond electrode, thereby ensuring the overall operational stability of the thin-film thermal printhead.

Description

Technical Field

[0001] This invention relates to the field of thermal printing, and more particularly to a thin-film thermal printhead and its preparation method. Background Technology

[0002] The heating substrate for a thin-film thermal printhead includes an insulating substrate with an amorphous glaze coating on its surface, a heating resistor layer on the amorphous glaze coating, and a conductor layer covering the heating resistor layer. During the manufacturing process, the aluminum conductor layer is formed into electrode wires using photolithography, and the resistor layer is formed into several heating resistors arranged along the main printing direction.

[0003] The electrode wire bonding pads are exposed to the air for subsequent testing and bonding to the IC via gold wires. However, during later use, moisture in the environment can corrode the bonding pads, leading to increased resistance and melting of the aluminum wires when current passes through them, thus affecting the reliability of the thermal printhead. Summary of the Invention

[0004] This invention provides a thin-film thermal printhead and its preparation method. By setting the bonds and electrodes as two electrode layers, the stability of the bonds and electrodes can be guaranteed, thereby ensuring the overall working stability of the thin-film thermal printhead.

[0005] In a first aspect, embodiments of the present invention provide a method for preparing a thin-film thermal printhead, comprising:

[0006] An insulating substrate is provided, the insulating substrate including a first insulating region, a second insulating region and a third insulating region, wherein the second insulating region is located between the first insulating region and the third insulating region;

[0007] A heat-retaining glaze coating is formed on one side of the insulating substrate and in at least the first insulating region;

[0008] A resistive layer is formed on the side of the heat-storing glaze coating away from the insulating substrate;

[0009] A common electrode is formed on one side of the heat-storing glaze coating and in the first insulating region, the common electrode comprising an electrode layer; an lead-out electrode is formed on one side of the insulating substrate and in the second insulating region, the lead-out electrode comprising an electrode layer; and a bond and electrode are formed on one side of the insulating substrate and in the third insulating region, the bond and electrode comprising two electrode layers.

[0010] A pre-set opening is provided on the side of the common electrode away from the heat storage glaze coating.

[0011] Optionally, a common electrode is formed on the side of the heat-storing glaze coating and in the first insulating region, the common electrode comprising an electrode layer; a lead-out electrode is formed on the side of the insulating substrate and in the second insulating region, the lead-out electrode comprising one electrode layer; and a bond and electrode are formed on the side of the insulating substrate and in the third insulating region, the bond and electrode comprising two electrode layers, including:

[0012] The first electrode layer is prepared in the first insulating region and located on the side of the resistive layer away from the insulating substrate; the first electrode layer is also prepared in the second insulating region and the third insulating region and located on one side of the insulating substrate.

[0013] A second electrode layer is prepared, wherein the second electrode layer is in the third insulating region and located on the side of the first electrode layer away from the insulating substrate;

[0014] The first electrode layer and the second electrode layer are patterned and etched to form the common electrode on one side of the insulating substrate and in the first insulating region, the lead electrode on one side of the insulating substrate and in the second insulating region, and the bond and electrode on one side of the insulating substrate and in the third insulating region.

[0015] Optionally, a common electrode is formed on the side of the heat-storing glaze coating and in the first insulating region, the common electrode comprising an electrode layer; a lead-out electrode is formed on the side of the insulating substrate and in the second insulating region, the lead-out electrode comprising one electrode layer; and a bond and electrode are formed on the side of the insulating substrate and in the third insulating region, the bond and electrode comprising two electrode layers, including:

[0016] The second electrode layer is prepared in the third insulating region and located on one side of the insulating substrate;

[0017] The first electrode layer is prepared in the first insulating region and located on the side of the resistive layer away from the insulating substrate; the first electrode layer is in the second insulating region and located on the side of the insulating substrate; the first electrode layer is in the third insulating region and located on the side of the second electrode layer away from the insulating substrate.

[0018] The first electrode layer and the second electrode layer are patterned and etched to form the common electrode on one side of the insulating substrate and in the first insulating region, the lead electrode on one side of the insulating substrate and in the second insulating region, and the bond and electrode on one side of the insulating substrate and in the third insulating region.

[0019] Optionally, after providing a preset opening on the side of the common electrode away from the heat-storing glaze coating, the method further includes:

[0020] A wear-resistant protective layer is formed on the side of the common electrode away from the heat-storing glaze coating.

[0021] Optionally, after forming a wear-resistant protective layer on the side of the common electrode away from the insulating substrate, the method further includes:

[0022] An ink layer is formed on at least the side of the lead-out electrode away from the insulating substrate.

[0023] In a second aspect, embodiments of the present invention provide a thin-film thermal printhead, comprising:

[0024] An insulating substrate, the insulating substrate comprising a first insulating region, a second insulating region and a third insulating region, wherein the second insulating region is located between the first insulating region and the third insulating region;

[0025] A heat-storing glaze coating is located on one side of the insulating substrate and in at least the first insulating region;

[0026] A resistive layer is located on the side of the heat-storing glaze coating away from the insulating substrate;

[0027] A common electrode is located on the side of the heat-storing glaze coating away from the insulating substrate and in the first insulating region. The common electrode includes one layer of the electrode layer, and a preset opening is provided on the side of the common electrode away from the heat-storing glaze coating.

[0028] The lead-out electrode is located on one side of the insulating substrate and in the second insulating region, and the lead-out electrode includes an electrode layer;

[0029] The lead-out electrode comprises two electrode layers, located on one side of the insulating substrate and in the third insulating region, and includes a bond and an electrode.

[0030] Optionally, the electrode layer includes a first electrode layer and a second electrode layer, wherein the first electrode layer is located in the first insulating region, the second insulating region and the third insulating region, and the second electrode layer is located in the third insulating region;

[0031] The second electrode layer is located on the side of the first electrode layer away from the insulating substrate;

[0032] Alternatively, the second electrode layer may be located on the side of the first electrode layer closer to the insulating substrate.

[0033] Optionally, the first electrode layer is made of aluminum;

[0034] The material of the second electrode layer is at least one of gold, copper, nickel, titanium, chromium, and tin, or an alloy thereof.

[0035] Optionally, the thin-film thermal printhead further includes a wear-resistant protective layer;

[0036] The wear-resistant protective layer is located on the side of the common electrode away from the heat-storing glaze coating.

[0037] Optionally, the thin-film thermal printhead further includes an ink layer;

[0038] The ink layer is located on at least the side of the lead-out electrode away from the insulating substrate.

[0039] The method for fabricating a thin-film thermal printhead provided in this invention first provides an insulating substrate, which includes a first insulating region, a second insulating region, and a third insulating region, with the second insulating region located between the first and third insulating regions. A heat-storing glaze coating is formed on one side of the insulating substrate and in at least the first insulating region. A resistive layer is formed on the side of the heat-storing glaze coating away from the insulating substrate. A common electrode is formed on one side of the heat-storing glaze coating and in the first insulating region, the common electrode including one electrode layer. A lead-out electrode is formed on one side of the insulating substrate and in the second insulating region, the lead-out electrode including one electrode layer. A bond and electrode are formed on one side of the insulating substrate and in the third insulating region, the bond and electrode including two electrode layers. A pre-set opening is provided on the side of the common electrode away from the heat-storing glaze coating. By setting the bond and electrode as two electrode layers, the stability of the bond and electrode can be ensured, thereby ensuring the overall working stability of the thin-film thermal printhead. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of exemplary embodiments of the present invention, the accompanying drawings used in describing the embodiments are briefly introduced below. Obviously, the accompanying drawings described are only a portion of the drawings of the embodiments to be described in this invention, and not all of the drawings. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0041] Figure 1 This is a schematic flowchart of a method for preparing a thin-film thermal printhead according to Embodiment 1 of the present invention;

[0042] Figure 2 This is a schematic diagram of the fabrication process of a thin-film thermal printhead provided in Embodiment 1 of the present invention;

[0043] Figure 3 This is a schematic flowchart of a method for preparing a thin-film thermal printhead according to Embodiment 2 of the present invention;

[0044] Figure 4 This is a schematic diagram of the preparation process of a thin-film thermal printhead provided in Embodiment 2 of the present invention;

[0045] Figure 5 This is a schematic diagram of the preparation process of another thin-film thermal printhead provided in Embodiment 2 of the present invention;

[0046] Figure 6This is a schematic diagram of the structure of a thin-film thermal printhead provided in Embodiment 3 of the present invention;

[0047] Figure 7 This is a schematic diagram of the structure of a thin-film thermal printhead provided in Embodiment 4 of the present invention;

[0048] Figure 8 This is a schematic diagram of another thin-film thermal printhead provided in Embodiment 4 of the present invention;

[0049] Figure 9 This is a top view schematic diagram of a thin-film thermal printhead provided in Embodiment 4 of the present invention. Detailed Implementation

[0050] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort 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, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a system, product, or device comprising a series of units is not necessarily limited to those steps or units explicitly listed, but may include other units not explicitly listed or inherent to such products or devices.

[0052] Example 1

[0053] Figure 1 This is a schematic flowchart of a method for preparing a thin-film thermal printhead according to Embodiment 1 of the present invention. Figure 2 This is a schematic diagram illustrating the fabrication process of a thin-film thermal printhead according to Embodiment 1 of the present invention. (Refer to...) Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a method for preparing a thin-film thermal printhead, comprising:

[0054] S110. Provide an insulating substrate, the insulating substrate including a first insulating region, a second insulating region and a third insulating region.

[0055] The insulating substrate can be made of aluminum oxide ceramic substrate, and this embodiment of the invention does not specifically limit this. Specifically, the insulating substrate is divided into regions, including a first insulating region, a second insulating region, and a third insulating region. The second insulating region is located between the first and third insulating regions. It should be noted that the first, second, and third insulating regions are merely a geographical division. For example, refer to... Figure 2 As shown, in the process of preparing a thin-film thermal printhead, an insulating substrate 100 is first provided. The insulating substrate 100 includes a first insulating region 100A, a second insulating region 100B and a third insulating region 100C.

[0056] S120, A heat-storing glaze coating is formed on one side of the insulating substrate and in at least the first insulating region.

[0057] In this invention, forming a heat-retaining glaze coating on one side of the insulating substrate prevents the heat generated by the subsequently prepared resistive layer from being dissipated too quickly through the insulating substrate. This means the heat-retaining glaze coating has a certain heat-insulating effect, ensuring the working efficiency of the thin-film thermal printhead. For example, the heat-retaining glaze coating is preferably formed by printing and sintering a glass glaze paste, and the thickness of the heat-retaining glaze coating is preferably 20–50 μm, such as 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm. This embodiment of the invention does not specifically limit the thickness of the heat-retaining glaze coating.

[0058] Further reference Figure 2 As shown, a heat-storing glaze coating 200 is formed in the first insulating region 100A of the insulating substrate 100.

[0059] S130, A resistive layer is formed on the side of the heat storage glaze coating away from the insulating substrate.

[0060] In this process, a resistive layer is formed on the side of the heat-storing glaze coating away from the insulating substrate. This layer can be prepared using magnetron sputtering to achieve the heating effect of the thin-film thermal printhead. (Reference) Figure 2 As shown, the resistive layer 600 is disposed on the side of the heat-storing glaze coating 200 away from the insulating substrate 100. For example, the resistive layer is preferably made of cermet, more preferably a composite material of tantalum and silicon dioxide; and the thickness of the resistive layer can be 0.03–0.2 μm, specifically 0.03 μm, 0.05 μm, 0.7 μm, 0.1 μm, 0.12 μm, 0.15 μm, or 0.2 μm. This embodiment of the invention does not specifically limit the material and thickness of the resistive layer.

[0061] S140. A common electrode is formed on the heat storage glaze coating side and in the first insulating region, the common electrode including an electrode layer; an lead electrode is formed on the insulating substrate side and in the second insulating region, the lead electrode including an electrode layer; and a bond electrode is formed on the insulating substrate side and in the third insulating region, the bond electrode including two electrode layers.

[0062] In this invention, an electrode layer is formed on one side of an insulating substrate. An electrode structure is formed by patterning and etching the electrode layer. The electrode structure includes a common electrode, bonding electrodes, and lead-out electrodes. For example, the electrode layer used to fabricate the electrode structure can be formed on one side of the insulating substrate by magnetron sputtering. Further, an electrode layer is formed in a first insulating region, and patterned etching is performed on this electrode layer to form a common electrode. An electrode layer is formed in a second insulating region, and patterned etching is performed on this electrode layer to form a lead-out electrode. Two electrode layers are formed in a third insulating region, and both electrode layers are simultaneously patterned and etched to form bonding electrodes. Alternatively, the two layers can be patterned and etched sequentially, ensuring that the two etched electrode layers completely overlap, thus forming bonding electrodes. Furthermore, the metal junctions of the completely overlapping electrode layers can diffuse into each other, ensuring structural stability. The patterning etching can be performed using laser etching, etc., and this invention does not specifically limit the method used. To prevent the bonding electrodes from being affected by external factors such as moisture during testing, handling, or IC bonding, the bonding electrodes are designed as a double-layer electrode structure. This means that if the electrode layer on the side away from the insulating substrate is damaged, the electrode layer on the side closer to the insulating substrate can be used for current transmission, ensuring the reliability of the thin-film thermal printhead.

[0063] Further reference Figure 2 As shown, an electrode layer 300 is formed on one side of an insulating substrate 100. A first insulating region 100A includes a one-sided electrode layer 300A. The electrode layer 300A is covered with a heat-storing glaze coating 200 at the first insulating layer 100A, and a common electrode 330 is formed therecorrespondingly. A second insulating layer 100B includes a one-sided electrode layer 300A, and a lead-out electrode 320 is formed therecorrespondingly. A third insulating layer 100C includes two electrode layers 300A and 300B, and bonds and electrodes 310 are formed therecorrespondingly. The bonds and electrodes 310 can be connection terminals such as metal pads for electrical connection with driver chips, etc. This embodiment of the invention does not specifically limit this.

[0064] S150. A preset opening is provided on the side of the common electrode away from the heat storage glaze coating.

[0065] Furthermore, a pre-set opening is provided on the side of the common electrode away from the heat-storing glaze coating. This pre-set opening is prepared by etching the electrode layer on the side of the resistive layer away from the heat-storing glaze coating; that is, the pre-set opening is an opening formed through the electrode layer. Through this pre-set opening, the resistive layer, which is the heating resistive layer used to generate Joule heating, can be exposed. For example, refer to... Figure 2 As shown, the first electrode layer 300A at the first insulating region 100A is etched to form a preset opening K, and a portion of the resistive layer 600, i.e., the heating resistive layer used for heating, is exposed through the preset opening K. This embodiment of the invention does not specifically limit the size or dimensions of the preset opening K.

[0066] In summary, the method for preparing a thin-film thermal printhead provided in this embodiment of the invention, by setting the bonds and electrodes as two electrode layers, can ensure the stability of the bonds and electrodes, thereby ensuring the overall working stability of the thin-film thermal printhead.

[0067] Example 2

[0068] Figure 3 This is a schematic flowchart of a method for preparing a thin-film thermal printhead according to Embodiment 2 of the present invention. Figure 4 This is a schematic diagram illustrating the fabrication process of a thin-film thermal printhead according to Embodiment 2 of the present invention. Figure 5 This is a schematic diagram illustrating the fabrication process of another thin-film thermal printhead provided in Embodiment 2 of the present invention, for reference. Figure 3 Zhihe Figure 5 As shown, another method for preparing a thin-film thermal printhead provided in this embodiment of the invention further includes:

[0069] S210. Provide an insulating substrate, the insulating substrate including a first insulating region, a second insulating region and a third insulating region.

[0070] S220, A heat-storing glaze coating is formed on one side of the insulating substrate and in at least the first insulating region.

[0071] S230, A resistive layer is formed on the side of the heat storage glaze coating away from the insulating substrate.

[0072] S240. Prepare a first electrode layer. The first electrode layer is in the first insulating region and is located on the side of the resistive layer away from the insulating substrate. The first electrode layer is in the second and third insulating regions and is located on the side of the insulating substrate.

[0073] S250. Prepare a second electrode layer, which is located in the third insulating region and on the side of the first electrode layer away from the insulating substrate.

[0074] Furthermore, the electrode layer fabricated on one side of the insulating substrate is patterned and etched to form bonds, electrodes, lead-out electrodes, and common electrodes. Specifically, a first electrode layer is first formed on one side of the insulating substrate by magnetron sputtering. The first electrode layer covers a heat-storing glaze coating in a first insulating region, and the first electrode layer covers the insulating substrate in a second and a third insulating region. Based on the fabrication of the first electrode layer, a second electrode layer is formed in the third insulating region by magnetron sputtering. The second electrode layer is located on the side of the first electrode layer away from the heat-storing glaze coating and is disposed in the third insulating region. In other words, the first electrode layer and the second electrode layer provided in this embodiment of the invention are fabricated by first fabricating the first electrode layer by magnetron sputtering, and then fabricating the second electrode layer by magnetron sputtering based on the fabricated first electrode layer.

[0075] For example, refer to Figure 4 As shown, after a heat-storing glaze coating 200 is prepared on one side of the insulating substrate 100, a first electrode layer 300A is prepared in the first insulating region 100A, the second insulating region 100B, and the third insulating region 100C by magnetron sputtering. The first electrode layer 300A covers the heat-storing glaze coating 200 in the first insulating region 100A. Further, a second electrode layer 300B is formed on the first electrode layer 300A in the third insulating region 100C by magnetron sputtering. For example, the material of the first electrode layer 300A can be aluminum, etc., and the thickness of the first electrode layer 300A can be 0.2-1 μm. This embodiment of the invention does not specifically limit the material and thickness of the first electrode layer 300A. Further, the material of the second electrode layer 300B can be at least one alloy selected from gold, copper, nickel, titanium, chromium, and tin, and the thickness of the second electrode layer 300B can be 0.1-1 μm. This embodiment of the invention does not specifically limit the material and thickness of the second electrode layer 300B.

[0076] S260. Prepare a second electrode layer, which is located in the third insulating region and on one side of the insulating substrate.

[0077] S270. Prepare a first electrode layer, wherein the first electrode layer is in a first insulating region and located on the side of the resistive layer away from the insulating substrate, the first electrode layer is in a second insulating region and located on the side of the insulating substrate, and the first electrode layer is in a third insulating region and located on the side of the second electrode layer away from the insulating substrate.

[0078] Furthermore, the electrode layer fabricated on one side of the insulating substrate is patterned and etched to form bonds, electrodes, lead-out electrodes, and common electrodes. Specifically, a second electrode layer is first formed on one side of the insulating substrate by magnetron sputtering, and the second electrode layer is located in the third insulating region. Based on the fabrication of the second electrode layer, the first insulating region, the second insulating region, and the third insulating region are formed into the first electrode layer by magnetron sputtering. Furthermore, in the third insulating region, the first electrode layer is located on the side of the second electrode layer away from the heat-storing glaze coating. In other words, the first electrode layer and the second electrode layer provided in this embodiment of the invention are fabricated by first fabricating the second electrode layer by magnetron sputtering, and then fabricating the first electrode layer by magnetron sputtering based on the already fabricated second electrode layer.

[0079] For example, refer to Figure 5 As shown, after a heat-storing glaze coating 200 is prepared on one side of the insulating substrate 100, a second electrode layer 300B is formed in the third insulating region 100C by magnetron sputtering. Then, a first electrode layer 300A is formed in the first insulating region 100A, the second insulating region 100B, and the third insulating region 100C by magnetron sputtering, and the second electrode layer 300B is covered by the first electrode layer 300A in the third insulating region 100A. For example, the material of the first electrode layer 300A can be aluminum, and the thickness of the first electrode layer 300A can be 0.2-1 μm. This embodiment of the invention does not specifically limit the material and thickness of the first electrode layer 300A. Further, the material of the second electrode layer 300B can be at least one alloy selected from gold, copper, nickel, titanium, chromium, and tin, and the thickness of the second electrode layer 300B can be 0.1-1 μm. This embodiment of the invention does not specifically limit the material and thickness of the second electrode layer 300B.

[0080] It should be noted that S240 and S250, or S260 and S270, can be used to prepare the first electrode layer and the second electrode layer. After performing S250 or S260, S280 is performed.

[0081] S280. Pattern etching is performed on the first electrode layer and the second electrode layer to form a common electrode on the side of the insulating substrate and in the first insulating region, a lead-out electrode on the side of the insulating substrate and in the second insulating region, and a bond and electrode on the side of the insulating substrate and in the third insulating region.

[0082] Specifically, based on the fabrication of the first and second electrode layers, bond and electrode, lead-out electrode, and common electrode are formed by patterning and etching the first and second electrode layers. Further, along the thickness direction of the insulating substrate, the common electrode is located in the first insulating region, the lead-out electrode is located in the second insulating region, and the bond and electrode is located in the third insulating region. The bond and electrode located in the third insulating region comprises two electrode layers.

[0083] For example, refer to Figure 4 and Figure 5 As shown, the lead electrode 320, bonding electrode 310, and common electrode 330 are all located on one side of the insulating substrate 100. The lead electrode 320 is located in the second insulating region 100B, and the common electrode 330 is located in the first insulating region 100A. The lead electrode 320 and the common electrode 330 can be fabricated by patterning etching of the first electrode layer 300A. The bonding electrode 310 is located in the third insulating region 100C and is fabricated by patterning etching of both the first electrode layer 300A and the second electrode layer 300B. (Refer to...) Figure 4 As shown, the first electrode layer 300A is closer to the heat storage glaze coating 200 than the second electrode layer 300B. (Reference) Figure 5 As shown, the second electrode layer 300B is closer to the heat storage glaze coating 200 than the first electrode layer 300A. This indicates that the preparation processes for the bonds and electrodes 330 are diverse.

[0084] S290. A preset opening is provided on the side of the common electrode away from the heat storage glaze coating.

[0085] S2100, a wear-resistant protective layer is formed on the side of the common electrode away from the heat storage glaze coating.

[0086] Furthermore, a wear-resistant protective layer is formed on the side of the common electrode away from the insulating substrate, and the wear-resistant protective layer is located in the first insulating region to prevent the common electrode and resistive layer in the first insulating region from being worn by external factors, thereby affecting the overall working performance.

[0087] For example, refer to Figure 4 and Figure 5 As shown, the wear-resistant protective layer 500 is located on the side of the common electrode 330 away from the heat-storing glaze coating 200, and the wear-resistant protective layer 500 is only located in the first insulating region 100A. That is, the wear-resistant protective layer 500 located in the first insulating region 100A is used to protect the common electrode 330 and the resistor layer 600. The safety and stability of the resistor layer 600 have certain precision requirements. That is, by setting the wear-resistant protective layer 500, the common electrode 330 can be protected at the same time as the resistor layer 600, further improving the working stability of the thin-film thermal printhead.

[0088] S2110, An ink layer is formed on at least the side of the lead-out electrode away from the insulating substrate.

[0089] Furthermore, an ink layer is formed on the side of the lead-out electrode away from the insulating substrate. This ink layer provides certain protection, such as protection against friction, wear, and corrosion. By providing an ink layer at least on the side of the lead-out electrode away from the insulating substrate, the operational stability of the lead-out electrode can be ensured, thereby ensuring the operational stability of the thin-film thermal printhead. Furthermore, the ink layer can also be extended to the side of the bond and electrode and the wear-resistant protective layer away from the insulating substrate, thus increasing the protection range of the ink layer. This embodiment of the invention does not specifically limit this aspect.

[0090] For example, refer to Figure 4 and Figure 5 As shown, the ink layer 400 covers the lead-out electrode 320, meaning the ink layer 400 is mainly located in the second insulating region 100B, thus protecting the lead-out electrode 320 and ensuring the operational stability of the thin-film thermal printhead. Furthermore, the ink layer 400 can also extend to the bond and electrode 310 and the wear-resistant protective layer 500, as shown in the reference diagram. Figure 4 As shown, ink layer 400 covers a portion of the second electrode layer 300B in the third insulating region 100C, and ink layer 400 covers a portion of the wear-resistant protective layer 500 in the first insulating region 100A. (Refer to...) Figure 5 As shown, the ink layer 400 covers a portion of the first electrode layer 300A in the third insulating region 100C, and the ink layer 400 covers a portion of the wear-resistant protective layer 500 in the first insulating region 100A. This embodiment of the invention does not impose specific limitations on this.

[0091] In summary, the method for preparing a thin-film thermal printhead provided in this embodiment of the invention enriches the preparation methods of the electrode structure, including a double-layer electrode structure with bonds and electrodes, and further improves the working stability of the thin-film thermal printhead by adding a wear-resistant protective layer and an ink layer.

[0092] Example 3

[0093] Based on the same inventive concept, embodiments of the present invention also provide a thin-film thermal printhead. Figure 6 This is a schematic diagram of the structure of a thin-film thermal printhead provided in Embodiment 3 of the present invention, as shown below. Figure 6As shown, an embodiment of the present invention provides a thin-film thermal printhead 10 comprising: an insulating substrate 100, the insulating substrate 100 including a first insulating region 100A, a second insulating region 100B and a third insulating region 100C, the second insulating region 100B being located between the first insulating region 100A and the third insulating region 100C; a heat-storing glaze coating 200 located on one side of the insulating substrate 100 and at least in the first insulating region 100A; a resistive layer 600 located on the side of the heat-storing glaze coating 200 away from the insulating substrate 100; and a common electrode 330. Located on the side of the heat storage glaze coating 200 away from the insulating substrate 100 and in the first insulating region 100A, the common electrode 330 includes an electrode layer 300, and a preset opening K is provided on the side of the common electrode 330 away from the heat storage glaze coating 200; the lead electrode 320 is located on the side of the insulating substrate 100 and in the second insulating region 100B, and the lead electrode 320 includes an electrode layer 300; the bond electrode 310 is located on the side of the insulating substrate 100 and in the third insulating region 100C, and the lead electrode 310 includes two electrode layers 300.

[0094] Specifically, the thin-film thermal printhead 10 includes an insulating substrate 100, a heat-storing glaze coating 200, a resistive layer 600, a bonding electrode 310, a lead-out electrode 320, a common electrode 330, and a pre-set opening K on the common electrode 330. The insulating substrate 100 can be made of an alumina ceramic substrate; this embodiment of the invention does not specifically limit its material. Specifically, the insulating substrate 100 is divided into three regions: a first insulating region 100A, a second insulating region 100B, and a third insulating region 100C. The second insulating region 100B is located between the first insulating region 100A and the third insulating region 100C. It should be noted that the first insulating region 100A, the second insulating region 100B, and the third insulating region 100C are merely geographically defined.

[0095] Furthermore, by forming a heat-storing glaze coating 200 layer on one side of the insulating substrate 100, the heat generated by the subsequently prepared resistive layer 600 can be prevented from dissipating too quickly through the insulating substrate 100. That is, the heat-storing glaze coating 200 has a certain heat-insulating effect, ensuring the working efficiency of the thin-film thermal printhead 10. For example, the heat-storing glaze coating 200 is preferably formed by printing and sintering glass glaze paste, and the thickness of the heat-storing glaze coating 200 is preferably 20-50 μm, for example, it can be 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, etc. The embodiments of the present invention do not specifically limit the thickness of the heat-storing glaze coating 200.

[0096] A resistive layer 600 is formed on the side of the heat-storing glaze coating 200 away from the insulating substrate 100. This layer can be prepared by magnetron sputtering and is used to achieve the heating effect of the thin-film thermal printhead 10. (Reference) Figure 6As shown, the resistive layer 600 is disposed on the side of the heat storage glaze coating 200 away from the insulating substrate 100. For example, the resistive layer 600 is preferably made of cermet, more preferably a composite material of tantalum and silicon dioxide; and the thickness of the resistive layer 600 can be 0.03–0.2 μm, specifically 0.03 μm, 0.05 μm, 0.7 μm, 0.1 μm, 0.12 μm, 0.15 μm, or 0.2 μm. This embodiment of the invention does not specifically limit the material and thickness of the resistive layer 600.

[0097] Furthermore, an electrode layer 300 is formed on one side of the insulating substrate 100. An electrode structure can be formed by patterning and etching the electrode layer 300. The electrode structure includes a common electrode 330, a bonding electrode 310, and a lead-out electrode 320. Exemplarily, the electrode layer 300 used to fabricate the electrode structure can be formed on one side of the insulating substrate 100 by magnetron sputtering. Further, an electrode layer 300 is formed in the first insulating region 100A, and the electrode layer 300 is patterned and etched to form a common electrode 330 having an electrode layer. An electrode layer 300 is formed in the second insulating region 100B, and a lead-out electrode 320 with the electrode layer 300 is formed by patterning etching. Two electrode layers 300 are formed in the third insulating region 100C, and the two electrode layers 300 are simultaneously patterned and etched to form bonds and electrodes 310 with the two electrode layers 300. Alternatively, the two layers can be patterned and etched sequentially, ensuring that the two electrode layers 300 completely overlap after etching. This also allows for the formation of bonds and electrodes 310 with the two electrode layers 300, and the metal junctions of the completely overlapping electrode layers 300 after etching can diffuse into each other, ensuring structural stability. The patterning etching can be performed using laser etching, etc., and this embodiment of the invention does not specifically limit the method used. To prevent the bonding electrodes 310 from being affected by external factors such as moisture during testing, handling, or IC bonding, the bonding electrodes 310 are configured with a double-layer electrode structure. This means that if the electrode layer 300 on the side away from the insulating substrate 100 is damaged, the electrode layer 300 on the side closer to the insulating substrate 100 can still be used for current transmission, ensuring the reliability of the thin-film thermal printhead 10. Furthermore, a preset opening K is provided on the side of the common electrode 330 away from the heat-storing glaze coating 200. This preset opening K is formed by etching the electrode layer 300 on the side of the resistive layer 600 away from the heat-storing glaze coating 200. In other words, the preset opening K is an opening that penetrates the electrode layer 300, exposing the resistive layer 600, which is the heating resistive layer 600 used to generate Joule heating. For example, refer to... Figure 6As shown, the first electrode layer 300A at the first insulating region 100A is etched to form a preset opening K, and a portion of the resistive layer 600, i.e., the heating resistive layer used for heating, is exposed through the preset opening K. This embodiment of the invention does not specifically limit the size or dimensions of the preset opening K.

[0098] In summary, the thin-film thermal printhead provided in this embodiment of the invention has a two-layer electrode configuration for its bonds and electrodes, which can ensure the stability of the bonds and electrodes, thereby ensuring the overall working stability of the thin-film thermal printhead.

[0099] Example 4

[0100] Figure 7 This is a schematic diagram of the structure of a thin-film thermal printhead provided in Embodiment 4 of the present invention. Figure 8 This is a schematic diagram of another thin-film thermal printhead provided in Embodiment 4 of the present invention. Figure 9 This is a top view schematic diagram of a thin-film thermal printhead provided in Embodiment 4 of the present invention, for reference. Figures 7 to 9 As shown, the electrode layer 300 includes a first electrode layer 300A and a second electrode layer 300B. The first electrode layer 300A is located in the first insulating region 100A, the second insulating region 100B and the third insulating region 100C, and the second electrode layer 300B is located in the third insulating region 100C. The second electrode layer 300B is located on the side of the first electrode layer 300A away from the insulating substrate 100; or, the second electrode layer 300B is located on the side of the first electrode layer 300A close to the insulating substrate 100.

[0101] Furthermore, the electrode layer 300 prepared on one side of the insulating substrate 100 is patterned and etched to form bonds and electrodes 310, lead-out electrodes 320, and common electrodes 330. Specifically, a first electrode layer 300A is first formed on one side of the insulating substrate 100 by magnetron sputtering. The first electrode layer 300A is covered with a heat-storing glaze coating 200 in the first insulating region 100A, and the first electrode layer 300A is covered with the insulating substrate 100 in the second insulating region 100B and the third insulating region 100C.

[0102] For example, refer to Figure 7 As shown, based on the preparation of the first electrode layer 300A, a second electrode layer 300B is formed in the first insulating region 100B by magnetron sputtering. The second electrode layer 300B is located on the side of the first electrode layer 300A away from the heat storage glaze coating 200, and is disposed in the third insulating region 100C. In other words, the first electrode layer 300A and the second electrode layer 300B provided in this embodiment of the invention are prepared by first preparing the first electrode layer 300A by magnetron sputtering, and then preparing the second electrode layer 300B based on the preparation of the first electrode layer.

[0103] For example, refer to Figure 8 As shown, based on the fabrication of the second electrode layer 300B, the first electrode layer 300A is formed by magnetron sputtering in the first insulating region 100A, the second insulating region 100B, and the third insulating region 100C. The first electrode layer 300A is located on the side of the second electrode layer 300B away from the heat-storing glaze coating 200. In other words, the first electrode layer 300A and the second electrode layer 300B provided in this embodiment of the invention are prepared by first fabricating the second electrode layer 300B by magnetron sputtering, and then fabricating the first electrode layer 300A based on the already prepared second electrode layer 300B.

[0104] Furthermore, the first electrode layer 300A is made of aluminum; the second electrode layer 300B is made of at least one of gold, copper, nickel, titanium, chromium, and tin, or an alloy thereof. For example, the first electrode layer 300A can be made of aluminum, and its thickness can be 0.2-1 μm. This embodiment of the invention does not specifically limit the material and thickness of the first electrode layer 300A. Furthermore, the second electrode layer 300B can be made of at least one of gold, copper, nickel, titanium, chromium, and tin, or an alloy thereof, and its thickness can be 0.1-1 μm. This embodiment of the invention does not specifically limit the material and thickness of the second electrode layer 300B.

[0105] Furthermore, based on the fabrication of the first electrode layer 300A and the second electrode layer 300B, bond and electrode 310, lead-out electrode 320, and common electrode 330 are formed by patterning and etching the first electrode layer 300A and the second electrode layer 300B. Further, along the thickness direction of the insulating substrate 100, the lead-out electrode 320 is located in the second insulating region 100B, the bond and electrode 310 is located in the third insulating region 100C, and the common electrode 330 is located in the first insulating region 100A. That is, the lead-out electrode 320 and the common electrode 330 can be fabricated by patterning and etching the first electrode layer 300A, while the bond and electrode 310 is located in the third insulating region 100C, meaning that the bond and electrode 310 are formed by patterning and etching both the first electrode layer 300A and the second electrode layer 300B.

[0106] Further reference Figures 7 to 9 As shown, the thin-film thermal printhead 10 also includes a wear-resistant protective layer 500; the wear-resistant protective layer 500 is located on the side of the common electrode 330 away from the heat storage glaze coating 200.

[0107] Specifically, a wear-resistant protective layer 500 is formed on the side of the common electrode 330 away from the insulating substrate 100, and the wear-resistant protective layer 500 is located in the first insulating region 100A to prevent the common electrode 330 and the resistive layer 600 in the first insulating region 100A from being worn by external factors, thereby affecting the overall working effect.

[0108] For example, refer to Figure 7 and Figure 8 As shown, the wear-resistant protective layer 500 is located on the side of the common electrode 330 away from the heat-storing glaze coating 200, and the wear-resistant protective layer 500 is only located in the first insulating region 100A. That is, the wear-resistant protective layer 500 located in the first insulating region 100A is used to protect the common electrode 330 and the resistor layer 600. The safety and stability of the resistor layer 600 have certain precision requirements. That is, by setting the wear-resistant protective layer 500, the common electrode 330 can be protected at the same time as the resistor layer 600, further improving the working stability of the thin-film thermal printhead.

[0109] Continue to refer to Figures 7 to 8 As shown, the thin-film thermal printhead 10 also includes an ink layer 400; the ink layer 400 is located on the side of at least the lead-out electrode 320 away from the insulating substrate 100.

[0110] Furthermore, an ink layer 400 is formed on the side of the lead-out electrode 320 away from the insulating substrate 100. The ink layer 400 has a certain protective function, such as preventing friction, wear, and corrosion. By providing the ink layer 400 on at least the side of the lead-out electrode 320 away from the insulating substrate 100, the operational stability of the lead-out electrode 320 can be ensured, thereby ensuring the operational stability of the thin-film thermal printhead 10. Furthermore, the ink layer 400 can also extend to the side of the bond and electrode 310 and the wear-resistant protective layer 500 away from the insulating substrate 100, thereby increasing the protection range of the ink layer 400. This embodiment of the invention does not specifically limit this aspect.

[0111] For example, refer to Figure 7 and Figure 8 As shown, the ink layer 400 covers the lead-out electrode 320, meaning the ink layer 400 is mainly located in the second insulating region 100B, thus protecting the lead-out electrode 320 and ensuring the operational stability of the thin-film thermal printhead. Furthermore, the ink layer 400 can also extend to the bond and electrode 310 and the wear-resistant protective layer 500, as shown in the reference diagram. Figure 7 As shown, ink layer 400 covers a portion of the second electrode layer 300B in the third insulating region 100C, and ink layer 400 covers a portion of the wear-resistant protective layer 500 in the first insulating region 100A. (Refer to...) Figure 8 As shown, the ink layer 400 covers a portion of the first electrode layer 300A in the third insulating region 100C, and the ink layer 400 covers a portion of the wear-resistant protective layer 500 in the first insulating region 100A. This embodiment of the invention does not impose specific limitations on this aspect. For example, refer to... Figure 9 As shown, the thin-film thermal printhead 10 is viewed from a top-down angle. It should be noted that... Figure 9 In order to avoid the ink layer 400 from blocking the lead electrode 320, etc., the ink layer 400 is not shown to be filled.

[0112] In summary, the thin-film thermal printhead provided by the embodiments of the present invention, with a double-layer electrode structure including bonds and electrodes, enriches the preparation methods of electrode structure, and further improves the working stability of the thin-film thermal printhead by adding a wear-resistant protective layer and an ink layer.

[0113] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for preparing a thin-film thermal printhead, characterized in that, include: An insulating substrate is provided, the insulating substrate including a first insulating region, a second insulating region and a third insulating region, wherein the second insulating region is located between the first insulating region and the third insulating region; A heat-retaining glaze coating is formed on one side of the insulating substrate and in at least the first insulating region; A resistive layer is formed on the side of the heat-storing glaze coating away from the insulating substrate; A common electrode is formed on one side of the heat-storing glaze coating and in the first insulating region, the common electrode comprising an electrode layer; an lead-out electrode is formed on one side of the insulating substrate and in the second insulating region, the lead-out electrode comprising an electrode layer; and a bond and electrode are formed on one side of the insulating substrate and in the third insulating region, the bond and electrode comprising two electrode layers. A pre-set opening is provided on the side of the common electrode away from the heat-storing glaze coating; A common electrode is formed on one side of the heat-storing glaze coating and in the first insulating region, the common electrode comprising an electrode layer; a lead-out electrode is formed on one side of the insulating substrate and in the second insulating region, the lead-out electrode comprising one electrode layer; and a bond and electrode are formed on one side of the insulating substrate and in the third insulating region, the bond and electrode comprising two electrode layers, including: A first electrode layer is prepared, wherein the first electrode layer is in the first insulating region and located on the side of the resistive layer away from the insulating substrate, and the first electrode layer is in the second insulating region and the third insulating region and located on one side of the insulating substrate; A second electrode layer is prepared, wherein the second electrode layer is located in the third insulating region and on the side of the first electrode layer away from the insulating substrate; The first electrode layer and the second electrode layer are patterned and etched to form the common electrode on one side of the insulating substrate and in the first insulating region, the lead electrode on one side of the insulating substrate and in the second insulating region, and the bond and electrode on one side of the insulating substrate and in the third insulating region. Alternatively, a common electrode is formed on one side of the heat-storing glaze coating and in the first insulating region, the common electrode comprising an electrode layer; a lead-out electrode is formed on one side of the insulating substrate and in the second insulating region, the lead-out electrode comprising one electrode layer; and a bond and electrode are formed on one side of the insulating substrate and in the third insulating region, the bond and electrode comprising two electrode layers, including: The second electrode layer is prepared in the third insulating region and located on one side of the insulating substrate; The first electrode layer is prepared in the first insulating region and located on the side of the resistive layer away from the insulating substrate; the first electrode layer is in the second insulating region and located on the side of the insulating substrate; the first electrode layer is in the third insulating region and located on the side of the second electrode layer away from the insulating substrate. The first electrode layer and the second electrode layer are patterned and etched to form the common electrode on one side of the insulating substrate and in the first insulating region, the lead electrode on one side of the insulating substrate and in the second insulating region, and the bond and electrode on one side of the insulating substrate and in the third insulating region.

2. The preparation method according to claim 1, characterized in that, After providing a preset opening on the side of the common electrode away from the heat-storing glaze coating, the method further includes: A wear-resistant protective layer is formed on the side of the common electrode away from the heat-storing glaze coating.

3. The preparation method according to claim 2, characterized in that, After forming a wear-resistant protective layer on the side of the common electrode away from the insulating substrate, the method further includes: An ink layer is formed on at least the side of the lead-out electrode away from the insulating substrate.

4. A thin-film thermal printhead, characterized in that, The thin-film thermal printhead is prepared by the method described in any one of claims 1-3, and the thin-film thermal printhead comprises: An insulating substrate, the insulating substrate comprising a first insulating region, a second insulating region and a third insulating region, wherein the second insulating region is located between the first insulating region and the third insulating region; A heat-storing glaze coating is located on one side of the insulating substrate and in at least the first insulating region; A resistive layer is located on the side of the heat-storing glaze coating away from the insulating substrate; A common electrode is located on the side of the heat-storing glaze coating away from the insulating substrate and in the first insulating region. The common electrode includes one layer of the electrode layer, and a preset opening is provided on the side of the common electrode away from the heat-storing glaze coating. The lead-out electrode is located on one side of the insulating substrate and in the second insulating region, and the lead-out electrode includes an electrode layer; The bonds and electrodes are located on one side of the insulating substrate and in the third insulating region, and the bonds and electrodes comprise two electrode layers.

5. The thin-film thermal printhead according to claim 4, characterized in that, The electrode layer includes a first electrode layer and a second electrode layer, wherein the first electrode layer is located in the first insulating region, the second insulating region and the third insulating region, and the second electrode layer is located in the third insulating region; The second electrode layer is located on the side of the first electrode layer away from the insulating substrate; Alternatively, the second electrode layer may be located on the side of the first electrode layer closer to the insulating substrate.

6. The thin-film thermal printhead according to claim 5, characterized in that, The first electrode layer is made of aluminum; The material of the second electrode layer is at least one of gold, copper, nickel, titanium, chromium, and tin, or an alloy thereof.

7. The thin-film thermal printhead according to claim 4, characterized in that, The thin-film thermal printhead also includes a wear-resistant protective layer; The wear-resistant protective layer is located on the side of the common electrode away from the heat-storing glaze coating.

8. The thin-film thermal printhead according to claim 4, characterized in that, The thin-film thermal printhead also includes an ink layer; The ink layer is located on at least the side of the lead-out electrode away from the insulating substrate.

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