Heating substrate for thermal printing head and 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 and a thermal printing head, which can overcome the defect of poor printing effect caused by large roughness of a substrate base layer of the thermal printing head and poor fluctuation of a heating body part, and is characterized in that a ceramic substrate is provided with a groove, a filling layer is arranged in the groove, and the ceramic substrate is provided with a ceramic layer. The upper surface of the filling layer is not lower than the upper surface of the ceramic substrate, the roughness of the upper surface of the filling layer is smaller than 1 micrometer, the groove and the filling layer are located under the heating resistor, and the width of the groove and the width of the filling layer are larger than the width of the heating resistor. Therefore, when different substrates are spliced, the heating body part is not limited by fluctuation of the bottom ceramic substrate, and the problem that the printing effect is poor due to the fact that the roughness of the base layer of the ceramic substrate is large and the fluctuation of the heating body part is poor can be solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to thermal printing head manufacturing technical field, concretely is a kind of thermal printing head with heating substrate and thermal printing head that can overcome the poor printing effect caused by the roughness of thermal printing head substrate base layer, heating body site undulation. BACKGROUND

[0002] It is known that thermal printing head is controlled by printer control chip to control printing data to make heating body selectively heat printing consumables, such as thermal paper or ribbon, to realize printing graphics and text.In the field of thermal material science, the heating body of thermal printing head is usually arranged on the heat storage layer of ceramic substrate.The heating body in thermal printing head is arranged on ceramic substrate and is electrically connected with control IC and common electrode through individual electrode wire, and graphics and text printing is realized by external signal data control.The key component of thermal printing head is heating substrate, and the basic raw material of heating substrate is ceramic.Ceramic substrate is formed by more than 96% of alumina or aluminum nitride powder through high-temperature sintering.Ceramic substrate is prone to bending during sintering process, and ceramic substrate has defects such as unevenness, pinhole and bubble, so that the heating body arranged on the upper surface of ceramic substrate will undulate, causing inconsistent pressure between rubber roller and heating body during printing process and poor printing effect.This problem is particularly prominent in wide-format printing equipment. SUMMARY

[0003] The utility model proposes a kind of thermal printing head with heating substrate and thermal printing head that can overcome the poor printing effect caused by the roughness of thermal printing head substrate base layer, heating body site undulation in view of the shortcomings and deficiencies in the prior art.

[0004] The utility model reaches by following measure:

[0005] A kind of thermal printing head with heating substrate, it is equipped with ceramic substrate, the upper surface of ceramic substrate is equipped with bottom glaze layer, bottom glaze layer is equipped with heating resistor and electrode wire, the upper surface of heating resistor and at least part electrode wire is also equipped with protective layer, it is characterized in that, recess is opened on ceramic substrate, filling layer is arranged in recess, the upper surface of filling layer is not lower than the height of the upper surface of ceramic substrate, the roughness of the upper surface of filling layer is less than 1 μm, the recess and filling layer are located in the direct below of heating resistor, the width of the recess and filling layer is greater than the width of heating resistor.

[0006] The upper surface of the filling layer of the utility model is equipped with bottom glaze layer, bottom glaze layer selects comprehensive bottom glaze layer or partial bottom glaze layer according to product specification, heating resistor is arranged on bottom glaze layer, preferably, heating resistor is located on the central axis of the recess and filling layer, further, the thickness of the recess and filling layer is greater than 15 μm, and the width is greater than 90 μm.

[0007] The filling groove is filled with a filling layer slurry, and the sintering temperature of the filling layer slurry is greater than 500 DEG C.

[0008] The utility model discloses in order to respond to the high heat dissipation demand in high speed printing process, the width of slot is greater than the width of partial bottom glaze layer, and the filling layer adopts the thermal conductivity material of the thermal conductivity of bottom glaze layer, wherein when printing resolution is 4ips below, can select the material of 1-2w / m.k of thermal conductivity coefficient, when resolution 10ips above, the thermal conductivity of filling layer selected slurry is greater than 2w / mk of high thermal conductivity insulation material, such as beta-Si3N4, guarantee the thermal conductivity of filling layer vertical direction for 57-169W / m.k, can realize high speed printing of quick heat dissipation.

[0009] The utility model discloses still be equipped with control IC, the one end of electrode wire links with heating resistance body, and the other end links with control IC, and through epoxy resin glue will wire, control IC and the circuit such as connecting pad encapsulation protection, further, the top of insulating protective film can still be equipped with more than 20GPa's hard protective film.

[0010] Compared with the prior art, the utility model has reasonable structure, reliable technology, can avoid the different base plate splicing, and the heating body part is not restricted by the fluctuation of bottom ceramic substrate, and can solve the problem of poor printing effect caused by the roughness of base layer and the fluctuation of heating body part of ceramic substrate. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a plane structure schematic diagram of the utility model.

[0012] Figure 2 It is a full glaze section structure schematic diagram of the utility model.

[0013] Figure 3 It is a partial glaze section structure schematic diagram of the utility model.

[0014] Figure 4 It is a partial glaze section structure schematic diagram of the utility model with hard protective film.

[0015] Figure 5 It is a full glaze section structure schematic diagram of the utility model with hard protective film.

[0016] Reference signs: insulating substrate 1, groove 2, electrode wire layer 3, heating resistance body 4, first insulating protective layer 5, bottom glaze layer 6, second layer hard protective film 7. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the patent. Obviously, the described embodiments are only part of the embodiments of the patent, not all the embodiments.

[0018] Example 1

[0019] As shown in the accompanying Figure 1 The example provides a heat-generating substrate for a thermal print head, wherein a rectangular groove 2 is formed in the position corresponding to the heat-generating resistor 4 on the surface of the insulating substrate 1 by laser cutting or scribing cutting, the width of the groove 2 is 300-1300 μm, and the depth is 100 μm, a filling layer is provided in the groove 2, the filling layer fills the groove by printing, and the filling layer with a flat upper surface is formed after drying and sintering, then a full or partial underglaze layer 6 as shown in the accompanying Figure 2 or 3 is provided on the surface of the insulating substrate 1, and then a conductive layer is formed by printing, the material can be gold, silver or gold-silver alloy, the common electrode and individual electrode and electrode pad are formed by etching and imaging, the heat-generating resistor 4 is printed or drawn at the intersection of the common electrode and individual electrode, the width of the heat-generating resistor 4 is 130-250 μm, an insulating protective layer is formed on the electrode layer and heat-generating body to avoid the pad, the thickness of the protective layer is 5-8 μm, and a high-hardness protective film is formed near the heat-generating resistor 4 by magnetron sputtering, the thickness is 2 μm.

[0020] The example is aimed at the existing technology that the relief or density of the ceramic substrate itself directly affects the printing quality, especially the flatness of the substrate surface at the heat-generating body part, the ceramic has the characteristics of high hardness and easy bending during sintering, the relief of individual substrate is more than 0.5 mm, which seriously affects the printing effect, by slotting at the heat-generating body part and the width range being greater than the width of the heat-generating body, and by filling and sintering with low-roughness slurry, the flatness of the heat-generating body part can meet the high-quality printing requirements.

[0021] Example 2

[0022] The example provides a heat-generating substrate for a thermal print head, wherein the position corresponding to the heat-generating resistor 4 on the surface of the heat-generating substrate for a thermal print head is formed with a rectangular groove 2 by laser cutting or scribing cutting, the width is 300-1300 μm, and the depth is 100 μm, the groove 2 is filled by point coating, and a flat filling layer is formed after drying and sintering at 700°C, then a conductive layer is formed by magnetron sputtering, the material can be AL, a heat-generating body coating is formed on the conductive layer by sputtering tantalum silicon dioxide or tantalum silicon carbide, a common electrode, individual electrode, electrode pad and resistor layer are formed by etching and imaging, the heat-generating resistor 4 at the intersection of the common electrode and individual electrode, the width of the heat-generating resistor 4 is 90-110 μm, an insulating protective layer is formed on the electrode layer and heat-generating body to avoid the pad, the thickness of the protective layer is 5-8 μm, preferably 8 μm, a high-hardness protective film is formed near the heat-generating resistor 4 by magnetron sputtering, the thickness is 2-4 μm, preferably 3.5 μm.

[0023] Example 3

[0024] The heat-sensitive printing head heating substrate is formed by laser cutting or scribing cutting to form a rectangular groove with a width of 300 microns and a depth of 100 microns on the surface heating body position of the heat-sensitive printing head heating substrate, the groove is filled by point coating, a flat layer is formed by drying and sintering at 700 DEG C, a heat-accumulating bottom glaze layer 6 is printed on the substrate, the printing thickness is 5-15 microns, then a conductive layer is formed on the bottom glaze layer 6 by magnetron sputtering, the material can be AL, a heating body coating layer is formed on the conductive layer by sputtering tantalum silicon dioxide or tantalum silicon carbide, a common electrode and individual electrodes and electrode pads and a resistance layer are formed by etching imaging, the heating resistance body 4 at the intersection of the common electrode and the individual electrodes has a width of about 90-110 microns, an insulating protective layer is formed on the electrode layer and the heating resistance body 4 to avoid the pads, the thickness of the protective layer is 5-10 microns, preferably 8 microns, a high-hardness protective film is formed near the heating resistance body 4 by magnetron sputtering, the thickness is 2-4 microns, preferably 3 microns.

[0025] Compared with the prior art, the utility model discloses a structure is reasonable, process is reliable, can avoid the different substrate splicing, heating body part is not restricted by the undulation of bottom ceramic substrate, can solve the problem of bad printing effect caused by the roughness of base layer and the undulation of heating body part of ceramic substrate.

Claims

1. A heat-generating substrate for a thermal printhead, comprising a ceramic substrate, a ground glaze layer provided on the upper surface of the ceramic substrate, a heat-generating resistor and electrode leads provided on the ground glaze layer, and a protective layer provided on the upper surface of the heat-generating resistor and at least part of the electrode leads, characterized in that, A groove is opened on a ceramic substrate, a filling layer is arranged in the groove, the upper surface of the filling layer is not lower than the upper surface of the ceramic substrate, the roughness of the upper surface of the filling layer is less than 1 μm, the groove and the filling layer are located directly below a heating resistor, the width of the groove and the filling layer is greater than the width of the heating resistor.

2. The heat generating substrate for a thermal printhead according to claim 1, wherein The upper surface of the filling layer is provided with a bottom glaze layer, the bottom glaze layer is selected from a full bottom glaze layer or a partial bottom glaze layer, the heating resistor is arranged on the bottom glaze layer, and the heating resistor is located on the central axis of the groove and the filling layer.

3. The heat generating substrate for a thermal printhead according to claim 1, wherein The thickness of the groove and the filling layer is greater than 15 μm, and the width is greater than 90 μm.

4. The heat generating substrate for a thermal printhead according to claim 1, wherein The sintering temperature of the filling layer slurry filling the groove is greater than 500 ℃.

5. The heat generating substrate for a thermal printhead according to claim 2, wherein The width of the groove is greater than the width of the partial bottom glaze layer.

6. The heat generating substrate for a thermal printhead according to claim 5, wherein The high-thermal-conductivity insulating material of the filling layer slurry has a thermal conductivity greater than 2 w / mk.

7. The heat generating substrate for a thermal printhead according to claim 1, wherein A control IC is further arranged, one end of the electrode lead wire is connected with the heating resistor, the other end is connected with the control IC, the lead wire, the control IC and the connecting pad are encapsulated by epoxy resin glue, and a hard protective film with a hardness greater than 20 GPa is further arranged above the insulating protective film.

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