High-reliability thermal printing head

Abstract

The utility model relates to the technical field of thermal printing head manufacturing, in particular to a high-reliability thermal printing head which is reasonable in structure, low in process cost and capable of improving the stability of an electrode of a thermal printing head product, and is provided with a ground coat layer arranged on the surface of an insulating substrate, and a heating resistor body and an electrode lead are arranged on the ground coat layer. The insulating substrate is formed by splicing a heating area insulating substrate and a COM electrode area insulating substrate, and the heating resistor and the electrode wires except the COM electrodes are arranged on the heating area insulating substrate. The COM electrode is arranged on the COM electrode area insulation substrate, the common passing electrode is arranged on the heating area insulation substrate, the COM electrode and the common passing electrode are located on the two sides of a splicing seam of the heating area insulation substrate and the COM electrode area insulation substrate respectively, and when the heating area insulation substrate and the COM electrode area insulation substrate are spliced, the COM electrode and the common passing electrode are spliced. And electrical connection is realized through contact between the plating electrode and the COM electrode.

Description

Technical field:

[0001] The utility model relates to the technical field of thermal print head manufacturing, in particular to a high-reliability thermal print head with a reasonable structure and low process cost and capable of improving the electrode stability of the thermal print head product. Background technology:

[0002] The key component of a traditional thermal printing device is the thermal print head. The heating element of the thermal print head is electrically connected via the electrode wire. In order to improve the printing effect, a COM electrode part is usually provided in the electrode wire. The COM electrode is made of metal materials with low resistivity such as Ag or Cu, and its size is significantly larger than the rest of the electrode wire to reduce the impedance of the electrode wire. During the product production process, in order to protect the heating element and the electrode wire, a protective layer will eventually be prepared on the electrode wire (including the COM electrode) and the surface of the heating element. The protective layer is generally a glass glaze layer formed by sintering. Commonly used ones include an insulating glaze layer and a conductive glaze layer. The molding temperature is high. During the preparation of the protective layer, the COM electrode made of Ag or Cu material will change due to high temperature: for example, it will react with the electrode wire or other materials in the glaze layer to cause poor resistance value and poor appearance, which reduces the product quality and affects the reliability of product use. Summary of the invention:

[0003] The utility model aims at the shortcomings and deficiencies in the prior art and proposes a thermal print head with reasonable structure, low process cost and high reliability capable of improving the electrode stability of the thermal print head product.

[0004] The utility model achieves this through the following measures:

[0005] A high-reliability thermal print head is provided with an underglaze layer arranged on the surface of an insulating substrate, a heating resistor and an electrode wire are arranged on the underglaze layer, the electrode wire includes an individual electrode, a common electrode, a COM electrode and a common pass electrode for connecting the COM electrode with the common electrode, the individual electrode and the common electrode form a comb-shaped electrode pair, the heating resistor is arranged in the middle of the comb-shaped electrode pair along the main printing direction, and a protective layer is provided on the surface of the heating resistor, the comb-shaped common electrode and the partially comb-shaped individual electrode. It is characterized in that the insulating substrate is composed of a heating area insulating substrate and a COM electrode area insulating substrate, the heating resistor and the electrode wire except the COM electrode are arranged on the heating area insulating substrate; the COM electrode is arranged on the COM electrode area insulating substrate, the common pass electrode is arranged on the heating area insulating substrate, and the COM electrode and the common pass electrode are respectively located on both sides of the joint between the heating area insulating substrate and the COM electrode area insulating substrate, and when the heating area insulating substrate and the COM electrode area insulating substrate are joined, the common pass electrode contacts the COM electrode to achieve electrical connection.

[0006] The COM electrode of the utility model is arranged on the opposite side end surface of the COM electrode area insulating substrate and the heating area insulating substrate, and the common crossing electrode is arranged on the heating area insulating substrate, and at least part of it is located on the opposite side end surface of the heating area insulating substrate and the COM electrode area insulating substrate. When the heating area insulating substrate and the COM electrode area insulating substrate are spliced ​​together, the common crossing electrode contacts the COM electrode to achieve electrical connection.

[0007] The COM electrode and the common pass electrode of the utility model are respectively arranged on the upper surface of the insulating substrate in the COM electrode area near the joint and the upper surface of the insulating substrate in the heating area near the joint. When the insulating substrate in the heating area and the insulating substrate in the COM electrode area are spliced ​​together, a conductive adhesive layer and a resistor block are provided on part of the surface of the common pass electrode and the common COM electrode, and electrical connection is achieved by attaching the resistor block with the conductive adhesive.

[0008] In the utility model, the upper surface of the joint between the insulating substrate in the heating area and the insulating substrate in the COM electrode area is covered with an insulating protective layer. The insulating protective layer may be a glass glaze layer or a solder resist protective layer with a sintering temperature lower than 500 degrees Celsius. Furthermore, the insulating protective layer covers the upper surface and the joint of the insulating substrate in the COM electrode area. Furthermore, the thickness of the insulating protective layer ranges from 1 to 20 μm.

[0009] The thickness of the common-pass transition electrode of the utility model is in the range of 0.1-1 μm.

[0010] The distance between the edge of the heating resistor at the paper outlet side and the edge of the common transition electrode is 0.3-1 mm, so as to avoid the joint part of the insulating substrate in the heating area and the insulating substrate in the COM electrode area affecting the printing.

[0011] The thickness of the insulating substrate in the heating area and the insulating substrate in the COM electrode area of ​​the utility model ranges from 0.5 to 2 mm.

[0012] The COM electrode of the utility model is made of Ag or Cu, and has a thickness ranging from 5 to 40 μm.

[0013] The resistor block of the utility model has a thickness of 5-40 μm, a resistance value of 0.1Ω-0.5Ω, and a lower edge of the resistor block is 0.3-1 mm away from an upper edge of the heating resistor, so as to avoid the joint between the insulating substrate of the heating area and the insulating substrate of the COM electrode area affecting the printing. Furthermore, the thickness of the insulating protective layer ranges from 1-20 μm.

[0014] The thermal print head provided by the utility model has the beneficial effect that, during production, the insulating substrate in the heating area and the insulating substrate in the COM electrode area are not simultaneously subjected to high-temperature sintering, and the common COM electrode will not react with the resistor, protective layer and transition electrode of the insulating substrate in the heating area, thereby not affecting the resistance value of the insulating substrate in the heating area and the appearance of the wear-resistant protective layer, thereby ultimately improving the product yield and reliability. Description of the drawings:

[0015] Figure 1 The utility model is a schematic diagram of the cross-sectional structure of a thermal print head.

[0016] Figure 2 For this utility model Figure 1 Schematic diagram of the cross-sectional structure of the insulating substrate in the middle heating zone.

[0017] Figure 3 For this utility model Figure 1 Schematic diagram of the cross-sectional structure of the insulating substrate in the COM electrode area.

[0018] Figure 4 This is a schematic diagram of the cross-sectional structure of another thermal print head finally formed by the utility model.

[0019] Figure 5 For this utility model Figure 4 Schematic diagram of the cross-sectional structure of the insulating substrate in the middle heating zone.

[0020] Figure 6 For this utility model Figure 4 Schematic diagram of the cross-sectional structure of the insulating substrate in the COM electrode area.

[0021] Figure 7 For this utility model Figure 4 Schematic diagram of the electrical connection plan of the resistor block.

[0022] Figure markings: 1-support component, 2-heating area insulating substrate, 2-1 insulating substrate, 2-2 bottom glaze layer, 2-3a common through-electrode, 2-3b comb-shaped common electrode, 2-3c comb-shaped individual electrode, 2-4 heating resistor, 2-5 wear-resistant protective layer, 3-COM electrode area insulating substrate, 3-1 insulating substrate, 3-2 common COM electrode, 4 insulating protective layer, 5 resistor block. Specific implementation method:

[0023] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Example 1

[0025] like Figure 1As shown, this embodiment provides a low-impedance, high-reliability thermal print head, including a support component 1, on which a heating area insulating substrate 2 and a COM electrode area insulating substrate 3 are provided; the support component 1 can be a metal heat dissipation base.

[0026] The heating zone insulating substrate 2 comprises an insulating substrate 2-1, the surface of the insulating substrate 2-1 is provided with a bottom glaze layer 2-2; the surface of the bottom glaze layer 2-2 is provided with a comb-shaped individual electrode 2-3c and a comb-shaped common electrode 2-3b; the comb-shaped individual electrode 2-3c and the comb-shaped common electrode 2-3b form a comb-shaped electrode pair; the heating resistor 2-4 is arranged in the middle of the comb-shaped electrode pair along the main printing direction; one end of the comb-shaped common electrode 2-3b is connected to the heating resistor 2-4, and the other end is connected to the common crossing electrode 2-3a. The common crossing electrode 2-3a is arranged on the end surface where the insulating substrate 2 in the heating area and the insulating substrate 3 in the COM electrode area are spliced; one end of the comb-shaped individual electrode 2-3c is connected to the heating resistor 2-4, and the other end is connected to the control IC; the surfaces of the heating resistor 2-4 and the comb-shaped common electrode 2-3b and part of the surface of the comb-shaped individual electrode 2-3c are provided with a wear-resistant protective layer 2-5; the common crossing electrode 2-3a has a thickness of 0.1-1μm, and the thickness of the insulating substrate 2 in the heating area is 0.5-2mm;

[0027] The COM electrode 3-2 is arranged on the opposite side end surface of the COM electrode area insulating substrate 3 and the heating area insulating substrate 2. When the heating area insulating substrate 2 and the COM electrode area insulating substrate 3 are assembled, the common crossing electrode 2-3a contacts the COM electrode 3-2 to achieve electrical connection; the surface of the COM electrode 3-2 and the surface of the common crossing electrode 2-3a are provided with a protective layer 4 formed by low temperature sintering; the protective layer 4 formed by low temperature sintering has a thickness of 1 to 20 μm and covers the joint;

[0028] The thermal print head provided in this example has the beneficial effect that the insulating substrate in the heating area and the insulating substrate in the COM electrode area are not simultaneously subjected to high-temperature sintering during production, and the common COM electrode will not react with the resistor, protective layer and transition electrode of the insulating substrate in the heating area, thereby avoiding affecting the resistance value of the insulating substrate in the heating area and the appearance of the wear-resistant protective layer, thereby improving the product yield and reliability. Experiments have shown that the product of this embodiment can be powered on for 1000 hours at a temperature of 85°C, a relative humidity of 85% and a power supply voltage of 8.5V without any problems.

[0029] Example 2

[0030] like Figure 4As shown, this embodiment provides a low-impedance, high-reliability thermal print head, comprising a support component 1, on which a heating area insulating substrate 2 and a COM electrode area insulating substrate 3 are provided; the support component 1 may be a metal heat dissipation base;

[0031] The insulating substrate 2 in the heating area comprises an insulating substrate 2-1, and a bottom glaze layer 2-2 is arranged on the surface of the insulating substrate 2-1; comb-shaped individual electrodes 2-3c and comb-shaped common electrodes 2-3b are arranged on the surface of the bottom glaze layer 2-2; the comb-shaped individual electrodes 2-3c and the comb-shaped common electrodes 2-3b form a comb-shaped electrode pair; the heating resistor 2-4 is arranged in the middle of the comb-shaped electrode pair along the main printing direction; one end of the comb-shaped common electrode 2-3b is connected to the heating resistor 2-4, and the other end is connected to the common pass electrode 2-3a, and the common pass electrode 2-3a is arranged near the joint on the upper surface of the insulating substrate 2 in the heating area; one end of the comb-shaped individual electrode 2-3c is connected to the heating resistor 2-4, and the other end is connected to the control IC; the surfaces of the heating resistor and the comb-shaped common electrode 2-3b and part of the surface of the comb-shaped individual electrode 2-3c are provided with a wear-resistant protective layer 2-5;

[0032] A COM electrode region insulating substrate 3 is separately provided, the COM electrode region insulating substrate 3 comprises an insulating substrate 3-1, a common COM electrode 3-2 is provided on the upper surface of the insulating substrate 3-1 near the joint, the thickness is 5-40 μm, the resistance value is 0.1Ω-0.5Ω, and the thickness of the COM electrode region insulating substrate 3 is 0.5-2 mm;

[0033] When the insulating substrate 2 in the heating area and the insulating substrate 3 in the COM electrode area are tightly spliced ​​on the upper surface of the supporting component 1, a resistor block 5 is attached to a portion of the surface of the common pass electrode 2-3a and a portion of the surface of the common COM electrode 3-2 by using conductive adhesive, so that the resistor block 5 is in contact with the common pass electrode 2-3a and the COM electrode 3-2 on both sides of the joint at the same time, so as to realize electrical connection between the insulating substrate 2 in the heating area and the insulating substrate 3 in the COM electrode area, and an insulating protective layer 4 is arranged on the surface of the joint and the portion of the surface of the common pass electrode 2-3a, the portion of the surface of the common COM electrode 3-2 and the surface of the resistor block 5. The insulating protective layer is a glass glaze layer or a solder resist protective layer with a sintering temperature lower than 500 degrees Celsius, and the thickness of the insulating protective layer 4 is 1-20μm; the thickness of the resistor block 5 is 5-40μm, and the resistance value is 0.1Ω-0.5

[0034] Ω, the distance between the lower edge of the resistor block and the upper edge of the heating resistor is 0.3-1mm to avoid the connection part affecting the printing;

[0035] The thermal print head substrate, resistor block and resistor, electrode and protective layer of the insulating substrate manufactured in the above manner are not subjected to high-temperature sintering at the same time, which will not affect the resistance value of the insulating substrate in the heating area and the appearance of the wear-resistant protective layer, thereby improving the product yield and reliability.

[0036] The product of this embodiment was subjected to a reliability test at a temperature of 85° C., a relative humidity of 85%, and a power supply voltage of 8.5V, and was powered on for 1000 hours without any damage.

Claims

1. A highly reliable thermal print head, comprising an underglaze layer arranged on the surface of an insulating substrate, a heating resistor and an electrode lead arranged on the underglaze layer, the electrode lead comprising an individual electrode, a common electrode, a COM electrode and a common transition electrode for connecting the COM electrode to the common electrode, the individual electrode and the common electrode forming a comb-shaped electrode pair, the heating resistor being arranged in the middle of the comb-shaped electrode pair along the main printing direction, the heating resistor, the comb-shaped common electrode and the surface of the partially comb-shaped individual electrode being provided with a protective layer, characterized in that: The insulating substrate is composed of two parts, a heating area insulating substrate and a COM electrode area insulating substrate. The heating resistor and the electrode wires except the COM electrode are arranged on the heating area insulating substrate; the COM electrode is arranged on the COM electrode area insulating substrate, and the common pass electrode is arranged on the heating area insulating substrate, and the COM electrode and the common pass electrode are respectively located on both sides of the joint between the heating area insulating substrate and the COM electrode area insulating substrate. When the heating area insulating substrate and the COM electrode area insulating substrate are assembled, the common pass electrode contacts the COM electrode to realize electrical connection.

2. A highly reliable thermal print head according to claim 1, characterized in that: The COM electrode is arranged on the opposite side end surface of the COM electrode area insulating substrate and the heating area insulating substrate. The common crossing electrode is arranged on the heating area insulating substrate and is at least partially located on the opposite side end surface of the heating area insulating substrate and the COM electrode area insulating substrate. When the heating area insulating substrate and the COM electrode area insulating substrate are spliced ​​together, the common crossing electrode contacts the COM electrode to achieve electrical connection.

3. A highly reliable thermal print head according to claim 1, characterized in that: The COM electrode and the common pass electrode are respectively arranged on the upper surface of the insulating substrate in the COM electrode area near the joint and the upper surface of the insulating substrate in the heating area near the joint. When the insulating substrate in the heating area is spliced ​​with the insulating substrate in the COM electrode area, a conductive adhesive layer and a resistor block are provided on part of the surface of the common pass electrode and the common COM electrode, and electrical connection is achieved by attaching the resistor block with the conductive adhesive.

4. A highly reliable thermal print head according to claim 1, characterized in that: The upper surface of the joint between the heating area insulating substrate and the COM electrode area insulating substrate is covered with an insulating protective layer, and the insulating protective layer can be a glass glaze layer or a solder resist protective layer with a sintering temperature lower than 500 degrees Celsius.

5. A highly reliable thermal print head according to claim 4, characterized in that: The insulating protection layer covers the upper surface of the insulating substrate in the COM electrode area and the joint part, and the thickness of the insulating protection layer is in the range of 1-20 μm.

6. A highly reliable thermal print head according to claim 1, characterized in that: The thickness of the common-pass transition electrode is in the range of 0.1-1 μm.

7. A highly reliable thermal print head according to claim 1, characterized in that: The distance between the edge of the heating resistor at the paper outlet side and the edge of the common transition electrode is 0.3-1 mm.

8. A highly reliable thermal print head according to claim 1, characterized in that: The thickness of the heating area insulating substrate and the COM electrode area insulating substrate ranges from 0.5 to 2 mm.

9. A highly reliable thermal print head according to claim 1, characterized in that: The COM electrode is made of Ag or Cu and has a thickness ranging from 5 to 40 μm.

10. A highly reliable thermal print head according to claim 3, characterized in that: The resistor block has a thickness of 5-40 μm, a resistance value of 0.1Ω-0.5Ω, and a distance between the lower edge of the resistor block and the upper edge of the heating resistor body of 0.3-1 mm.

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