Heating substrate for thermal printing head

Abstract

The utility model relates to the technical field of thermal printing head manufacturing, in particular to a heating substrate for a thermal printing head, which can improve the compactness of a protective film in an area where a common electrode is located, improve the insulativity of a product and further improve the quality of the product, and is characterized in that the upper surface of the common electrode is provided with a common electrode protective layer with the thickness of 0.05-1.0 mu m; the protection layer and the common electrode protection layer are at least partially overlapped, the surface roughness of the common electrode can be effectively reduced by covering the electrode protection layer at the position of the common electrode, common electrode corrosion caused by etching during subsequent electrode wire preparation can be avoided, the compactness of a protection film in the area where the common electrode is located is improved, and the service life of the common electrode is prolonged. And the product stability of the thermal printing head is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to thermal printing head manufacturing technical field, specifically is a kind of heat-generating substrate for thermal printing head capable of improving the compactness of protective film in the area of common electrode, improve product insulation, to improve product quality. BACKGROUND

[0002] The existing heat-generating substrate for thermal printing head includes an insulating substrate, a heat storage underglaze layer and a substrate underglaze layer are arranged on the upper surface of the insulating substrate, a common electrode is arranged on the upper surface of the substrate underglaze layer, the heat-generating substrate for thermal printing head further comprises a heating resistor, the heating resistor is at least partially arranged on the heat storage underglaze layer, and a common electrode and a lead electrode connected to both ends of the heating resistor are further provided, the common electrode is connected to the common electrode, and a protective layer covering the heat storage underglaze layer, the heating resistor, the common electrode, at least part of the substrate underglaze layer and part of the lead electrode is arranged to protect the electrical elements. Among them, the common electrode is usually formed by printing and sintering using silver material with low resistivity, but when the silver paste forms the common electrode on the substrate underglaze layer, the surface roughness of the formed common electrode is large, and during the subsequent preparation of the heating resistor layer and the wire electrode layer, the rough surface of the common electrode seriously affects the compactness of the film, which easily leads to the problem that the etching liquid invades and corrodes during the patterning etching, and at the same time, the product insulation is poor, so that the thermal printing head is easily damaged. SUMMARY

[0003] The utility model discloses a kind of heat-generating substrate for thermal printing head capable of improving the compactness of protective film in the area of common electrode, improve product insulation, to improve product quality.

[0004] The utility model reaches by following measure:

[0005] A kind of heat-generating substrate for thermal printing head, with insulating substrate, insulating substrate surface is provided with heat storage underglaze layer and substrate underglaze layer, it is further provided with heating resistor and electrode wire, the electrode wire includes common electrode, lead electrode and common electrode, wherein common electrode is arranged on substrate underglaze layer, it is further provided with the protective layer covering heat storage underglaze layer, heating resistor and at least part of electrode wire, it is characterized in that, common electrode upper surface is provided with the common electrode protective layer with the thickness of 0.05-1.0 μm, and protective layer and common electrode protective layer at least partially overlap.

[0006] The common electrode protective layer of the utility model uses silicon target or silicon nitride, silicon oxide, silicon carbide or silicon nitride-silicon oxide composite material as target material, and is formed by radio frequency magnetron sputtering.

[0007] The protective layer includes an insulating protective layer and a conductive protective layer, wherein the conductive protective layer is arranged on the upper surface of the insulating protective layer; the insulating protective layer can be formed by sputtering of a Sylgard material, and has a thickness ranging from 2 to 10 microns; and the conductive protective layer is formed by magnetron sputtering of a carbon-silicon carbide composite material as target material, and has a thickness ranging from 2 to 10 microns.

[0008] The thickness of the heat storage base glaze layer is 20-60 microns, and the thickness of the substrate base glaze layer is arranged in the range of 5-20 microns.

[0009] The electrode protective layer is arranged on the position of the common electrode, so that the surface roughness of the common electrode can be effectively reduced, the corrosion of the common electrode caused by etching during preparation of the subsequent electrode lead can be avoided, the compactness of the protective film in the region of the common electrode is improved, and the product stability of the thermal print head is improved. BRIEF DESCRIPTION OF DRAWINGS

[0010] BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a sectional view of the utility model.

[0011] BRIEF DESCRIPTION OF DRAWINGS Figure 2 is a plan view of the utility model.

[0012] Mark: 01 is a heat-generating substrate for a thermal print head, 10 is an insulating substrate, 20 is a heat storage base glaze layer, 30 is a substrate base glaze layer, 40 is a common electrode, 50 is a heat-generating resistor, 60 is a lead electrode layer, 60a is a common electrode, 60b is a lead-out electrode, 60c is a bonding electrode, 70 is a common electrode protective layer, 80 is an insulating protective layer, and 90 is a conductive protective layer. DETAILED DESCRIPTION

[0013] The utility model will be further explained in connection with the drawings and examples.

[0014] As shown in the drawings, Figure 1 The utility model discloses a heat-generating substrate for a thermal print head, which is provided with an insulating substrate, a heat storage base glaze layer 20 and a substrate base glaze layer 30 are arranged on the surface of the insulating substrate 10, and a heat-generating resistor 50 and an electrode lead are further arranged, the electrode lead includes a common electrode 60a, a lead-out electrode 60b and a common electrode 40, the common electrode 40 is arranged on the substrate base glaze layer 30, and a protective layer covering the heat storage base glaze layer 20, the heat-generating resistor 50 and at least part of the electrode lead is further arranged, the upper surface of the common electrode 40 is provided with a common electrode protective layer 70 with a thickness of 0.05-1.0 microns, and the protective layer at least partially overlaps the common electrode protective layer 70.

[0015] The common electrode protective layer 70 adopts a silicon target or a silicon nitride, silicon oxide, silicon carbide or silicon nitride-silicon oxide composite material as target material and is formed by radio frequency magnetron sputtering.

[0016] The protective layer includes an insulating protective layer 80 and a conductive protective layer 90, wherein the conductive protective layer 90 is arranged on the upper surface of the insulating protective layer, the insulating protective layer 80 can be formed by sputtering of a Sylgard material, and the thickness ranges from 2 to 10 microns; the conductive protective layer is formed by magnetron sputtering of a carbon-silicon carbide composite material as target material, and the thickness ranges from 2 to 10 microns.

[0017] Embodiment:

[0018] The heating substrate for the thermal print head includes an insulating substrate 10 composed of aluminum trioxide material, glass paste is printed on part of the insulating substrate 10, and a heat storage base glaze layer 20 is formed on part of the side surface of the insulating substrate 10 by sintering at a temperature of 1200-1300 DEG C, the thickness of the heat storage base glaze layer 20 is 20-60 microns, and the width is 0.4-1.0 mm; a lead-free amorphous glaze paste is printed on the insulating substrate 10 to form a substrate base glaze layer, the sintering temperature is about 600-850 DEG C, and the thickness of the substrate base glaze layer after sintering is set to be in the range of 5-20 microns; a common electrode 40 is formed on the surface of the substrate base glaze layer 30, the common electrode 40 is mainly printed by conductive paste containing silver powder, glass powder, carrier resin and solvent, and sintered at a temperature of 600-850 DEG C, and the thickness of the common electrode after sintering is 5-30 microns according to different wire resistance requirements.

[0019] A tantalum-silicon dioxide composite target is sputtered by a sputtering method to form a heating resistor layer on the heat storage base glaze layer 20, the substrate base glaze layer 30 and the common electrode 40 by controlling process conditions, and the thickness of the heating resistor layer is 30-400 nm; a wire electrode layer 60 with a thickness of 0.5-1 micron is formed on the surface of the heating resistor 50 by using a metal aluminum target and a magnetron sputtering method;

[0020] A silicon target, silicon nitride, silicon oxide, silicon carbide or silicon nitride-silicon oxide composite material is used as target material to form a common electrode protective layer 70 on the surface of the wire electrode layer 60 by a radio frequency magnetron sputtering method, the thickness of the electrode protective layer is 0.05-1 micron, and the electrode protective layer is formed by pattern processing by means of photoengraving and etching, and only exists on the upper side of the common electrode 40;

[0021] Based on information such as printing resolution, a photomask for photolithography is designed and manufactured. Photolithography and etching techniques are used to pattern the conductive electrode layer 60 and the heating resistor layer 50. After patterning, a common electrode 60a, a lead electrode 60b, and a bonding electrode 60c are formed on the conductive electrode layer 60. The common electrode 60a and the lead electrode 60b are respectively connected to both ends of the heating resistor layer 50 to form a heating resistor unit. The common electrode 60a is connected to a common electrode 40 and is used to connect to an external power supply. The bonding electrode pattern 60c is used to connect to external logic control signals.

[0022] Using a cerium ionomer as the target material, an insulating protective layer 80 is formed on the surface of the heat storage base glaze layer 20, the substrate base glaze layer 30, the heating resistor layer 50, the wire electrode 60 and the electrode protective layer 70 by radio frequency magnetron sputtering. The thickness of the insulating protective layer is 2 to 10 μm.

[0023] Using carbon-silicon carbide composite material as the target, a conductive protective layer 90 is formed locally on the insulating protective layer by magnetron sputtering. The thickness of the conductive protective layer is 2-10 μm.

[0024] This invention effectively reduces the surface roughness of the common electrode by covering the common electrode with an electrode protective layer, and avoids corrosion of the common electrode caused by etching during subsequent electrode wire fabrication. It also improves the density of the protective film in the area where the common electrode is located, thereby enhancing the product stability of the thermal printhead.

Claims

1. A heating substrate for a thermal printhead, comprising an insulating substrate, a heat-storing base glaze layer and a substrate base glaze layer disposed on the surface of the insulating substrate, and further comprising a heating resistor and electrode wires, wherein the electrode wires include a common electrode, a lead-out electrode and a common electrode, wherein the common electrode is disposed on the substrate base glaze layer, and further comprising a protective layer covering the heat-storing base glaze layer, the heating resistor and at least a portion of the electrode wires, characterized in that, The upper surface of the common electrode is provided with a common electrode protective layer with a thickness of 0.05-1.0 μm, and the protective layer overlaps with the common electrode protective layer at least partially; the common electrode protective layer is formed by radio frequency magnetron sputtering using a silicon target or silicon nitride, silicon oxide, silicon carbide or silicon nitride-silicon oxide composite material as the target material; the thickness of the heat storage base glaze layer is 20~60 μm, and the thickness of the substrate base glaze layer is set in the range of 5~20 μm.

2. The heating substrate for a thermal printhead according to claim 1, characterized in that, The protective layer includes an insulating protective layer and a conductive protective layer, wherein the conductive protective layer is disposed on the upper surface of the insulating protective layer, and the insulating protective layer is formed by sputtering of a silane material.

3. The heating substrate for a thermal printhead according to claim 2, characterized in that, The thickness of the insulating protective layer ranges from 2 to 10 μm, and the conductive protective layer is formed by magnetron sputtering using a carbon-silicon carbide composite material as the target material. The thickness ranges from 2 to 10 μm.

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