Film thermal printing

Abstract

The utility model provides a film thermal printing head, and relates to the technical field of printing equipment. Comprising a ceramic substrate, a heat storage layer, a resistance layer, a conductive layer, a protective layer and a connecting layer, the connecting layer is arranged between the resistance layer and the conducting layer so as to improve the binding force of the resistance layer and the conducting layer; the conductive layer comprises a copper metal layer and a nickel metal layer, and the conductive layer and the connecting layer jointly form a conductor layer used for connecting an I C assembly; and the IC assembly is welded on the conductor layer, and the IC assembly is provided with a silver finger on the heat storage layer, wherein the silver finger is used for being directly welded with an external FFC / FPC (Flexible Printed Circuit / Flexible Printed Circuit) in use, so that a film thermal printing head structure without the FFC / FPC is formed. According to the scheme, a circuit board on the ceramic substrate is omitted, the external circuit board is directly welded through the silver finger, the structure of the thin film thermal printing head can be optimized, and the size of the thin film thermal printing head is further reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of printing equipment, in particular to a thin film thermal printing head. Background Art

[0002] The existing thin film print head generally includes a ceramic substrate and a PCB board or FFC cable welded on the ceramic substrate, and the PCB board or FFC cable is welded to quickly achieve the plug-in installation.

[0003] However, when the PCB board or FFC cable is welded on the surface of the ceramic substrate, the installation thickness of the thin film print head includes the thickness of the PCB board or FFC cable, resulting in an increase in the volume of the entire thin film thermal print head. When installing the thin film print head, a larger installation space needs to be reserved on the printing device. Especially when installed on a micro-sized thermal printing device, the micro-sized thermal printing device is limited by the installation thickness of the thermal print head, and a larger installation space is also required, making it impossible to further reduce the volume of the micro-sized thermal printing device. Utility Model Content

[0004] The utility model discloses a thin film thermal print head, aiming to improve the problem of large volume of the existing thin film thermal print head.

[0005] The utility model adopts the following scheme:

[0006] The present application provides a thin film thermal print head, comprising a ceramic substrate, a heat storage layer, a resistor layer, and a conductive layer, wherein the heat storage layer is covered on the ceramic substrate, the resistor layer is formed on a side of the heat storage layer away from the ceramic substrate, and a heating component is arranged on the resistor layer along the length direction of the ceramic substrate, and the conductive layer is arranged on a side of the resistor layer away from the heat storage layer; further comprising a connecting layer; the connecting layer is arranged between the resistor layer and the conductive layer to improve the bonding force between the resistor layer and the conductive layer; the conductive layer comprises a copper metal layer and a nickel metal layer, and together with the connecting layer forms a conductor layer for connecting an IC component; the IC component is welded on the conductor layer, and the IC component is formed with silver fingers on the heat storage layer for direct welding with an external FFC / FPC when in use to form a thin film thermal print head structure without FFC / FPC.

[0007] Furthermore, the connection layer is formed of Ti metal or molybdenum metal.

[0008] Furthermore, the copper metal layer is formed on the connection layer by vacuum sputtering, and the nickel metal layer is formed on the copper metal layer by vacuum sputtering.

[0009] Furthermore, the thickness of the connecting layer is 30nm-100nm, the thickness of the copper metal layer is 0.6um-1.5um, and the thickness of the nickel metal layer is 60nm-150nm.

[0010] Furthermore, a copper common electrode layer is formed between the nickel metal layer and the copper metal layer formed by sputtering by electroplating.

[0011] Furthermore, the thickness of the copper common electrode layer is 12um-25um.

[0012] Beneficial effects:

[0013] In this embodiment, silver fingers are formed on the heat storage layer for welding with an external circuit board, so that there is no need to set a circuit board or a circuit board wiring slot structure on the ceramic substrate, eliminating the existing restriction of setting a PCB board or FFC wiring on the thin film thermal print head, optimizing the structure of the thin film thermal print head, making the structure more compact, and the thickness of the entire thin film thermal print head thinner, which can further make the volume of the micro-sized thermal printing device smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic cross-sectional structure diagram of a thin film thermal print head according to an embodiment of the utility model;

[0015] Figure 2 yes Figure 1 A local enlarged schematic diagram in FIG.

[0016] Figure 3 It is a schematic diagram of the planar structure of a thin film thermal print head according to an embodiment of the utility model;

[0017] Icon: ceramic substrate 1, heat storage layer 2, resistance layer 3, connection layer 4, copper metal seed layer 5, copper common electrode layer 6, nickel metal layer 7, protective layer 8, IC component 9, silver finger 10. DETAILED DESCRIPTION

[0018] Example 1

[0019] Combination Figures 1 to 3As shown, this embodiment provides a thin film thermal print head, including a ceramic substrate 1, a heat storage layer 2, a resistor layer 3, a conductive layer and a protective layer 8, wherein the heat storage layer 2 is covered on the ceramic substrate 1, the resistor layer 3 is formed on the side of the heat storage layer 2 away from the ceramic substrate 1, and a heating component is arranged on the resistor layer 3 along the length direction of the ceramic substrate 1, the conductive layer is arranged on the side of the resistor layer 3 away from the heat storage layer 2, and a protective layer 8 is arranged on the side of the conductive layer away from the resistor layer 3; further comprising a connecting layer 4; the connecting layer 4 is arranged between the resistor layer 3 and the conductive layer to improve the bonding force between the resistor layer 3 and the conductive layer; the conductive layer includes a copper metal layer and a nickel metal layer 7, and together with the connecting layer 4 forms a conductor layer for connecting an IC component 9, the IC component 9 is welded on the conductor layer, and the IC component 9 is formed with a silver finger 10 on the heat storage layer 2 for direct welding with an external FFC / FPC when in use to form a thin film thermal print head structure without FFC / FPC.

[0020] In this embodiment, the ceramic substrate 1 and the heat storage layer 2 are made of existing materials. For example, the heat storage layer 2 may be made of glass glaze.

[0021] The connection layer 4 is formed of Ti metal or molybdenum metal, preferably Ti metal. The connection layer 4 formed of Ti metal is used as the bottom layer of the conductive layer to improve the connection force of the conductive layer and prevent the conductive layer from falling off. The thickness of the connection layer 4 is 30nm-100nm, and can be formed on the resistor layer 3 by vacuum sputtering or evaporation. The resistor layer 3 is provided with heating components for heating.

[0022] The copper metal layer is formed on the connecting layer 4 by vacuum sputtering, and the nickel metal layer 7 is formed on the copper metal layer by vacuum sputtering. The thickness of the nickel metal layer 7 is 60nm-150nm; the sputtering thickness of the copper metal layer is 0.6um-1.5um. Since the copper metal layer, the nickel metal layer 7 and the connecting layer 4 have a certain line resistance value, when the printing rate is high, it is easy to cause a voltage drop and uneven printing density. Therefore, in a preferred embodiment, the line resistance can be reduced by thickening the thickness of the copper metal layer. However, only a thickness of 2um can be achieved by vacuum sputtering, and the line resistance is still relatively high. Therefore, in a preferred embodiment, a copper common electrode layer 6 can be formed by electroplating between the nickel metal layer 7 and the copper metal layer formed by sputtering. The thickness of the copper common electrode layer 6 is 12um-25um, preferably 20um. The copper metal layer can be quickly thickened by electroplating, and the cost is low compared to the usual silver metal material.

[0023] In the present embodiment, a conductor layer is formed by a connection layer 4 formed by Ti metal and a copper metal layer and a nickel metal layer 7, a pad of an IC component 9 is formed on the conductor layer for directly welding the IC component 9, and a silver finger 10 structure is provided on the conductor layer for direct welding connection with an external FFC / FPC. There is no need to provide a circuit board structure or an interface socket of a circuit board on the ceramic substrate 1. Compared with the existing ceramic substrate + PCB / hard board FPC structure by welding the FFC / FPC, the solution of the present embodiment is more compact and concise in structure, and is more suitable for use in micro thermal printers.

[0024] In this embodiment, the copper metal layer and the nickel metal layer 7 are used as the conductive layer, and the connection layer 4 of the Ti metal can prevent the circuit from being oxidized, and the production cost can be saved by soldering the IC component 9. The structure breaks the existing thin film ceramic substrate 1 plus PCB structure, and the silver finger 10 is directly constructed on the conductor layer for welding and connecting with the external circuit board, so that the structure and process are simple and the production efficiency is high.

[0025] Example 2

[0026] The utility model also provides a method for processing the above-mentioned thin film thermal print head, comprising the following steps:

[0027] S1, firing a heat storage layer 2 on a ceramic substrate 1 at 1200° C.;

[0028] S2, performing vacuum sputtering of TaN / Tas i o 2 on the heat storage layer 2 to form a resistance layer 3;

[0029] S3, forming a connecting layer 4 on the resistor layer 3 by vacuum sputtering or evaporation of a conductive metal;

[0030] S4, vacuum sputtering of Cu / Ni is performed on the connection layer 4 to form conductive layers of a copper metal layer and a nickel metal layer 7, respectively, and then the connection layer 4 and the conductive layer are etched away by wet etching to expose the heating components in the resistance layer 3;

[0031] S5, vacuum sputtering is performed on the upper part of the conductive layer within the range of the heating component to form a wear-resistant protective layer 8;

[0032] S6, printing and curing the oxide layer on the part other than the protective layer 8;

[0033] S7, connecting the IC component 9 to the conductive layer by reflow soldering on the conductive layer of the ceramic substrate 1;

[0034] S8. Cover the outside of the IC with a layer of epoxy resin for protection.

[0035] In a preferred embodiment, in step S4, a copper metal seed layer 5 with a thickness of 0.6um-1.5um is first formed on the connection layer 4 by vacuum sputtering, and then a copper common electrode layer 6 with a thickness of 12um-25um is formed on the copper metal seed layer 5 by electroplating. This solution can reduce the line resistance of the conductor layer.

[0036] It should be understood that the above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0037] The above description of the drawings used in the implementation manner only shows certain embodiments of the utility model and should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

Claims

1. A thin film thermal print head, comprising a ceramic substrate, a heat storage layer, a resistor layer, and a conductive layer, wherein the heat storage layer is covered on the ceramic substrate, the resistor layer is formed on a side of the heat storage layer away from the ceramic substrate, and a heating component is arranged on the resistor layer along the length direction of the ceramic substrate, and the conductive layer is arranged on a side of the resistor layer away from the heat storage layer; characterized in that: Also includes connection layer; The connecting layer is disposed between the resistance layer and the conductive layer; The conductive layer includes a copper metal layer and a nickel metal layer, and together with the connecting layer forms a conductor layer for connecting IC components; The IC component is soldered on the conductor layer, and the IC component is provided with silver fingers on the heat storage layer suitable for achieving electrical connection with an external FFC / FPC through direct soldering.

2. The thin film thermal print head according to claim 1, characterized in that: The connection layer is formed of Ti metal or Mo metal.

3. The thin film thermal print head according to claim 1, characterized in that: The copper metal layer is formed on the connection layer by vacuum sputtering, and the nickel metal layer is formed on the copper metal layer by vacuum sputtering.

4. The thin film thermal print head according to claim 3, characterized in that: The thickness of the connecting layer is 30nm-100nm, the sputtering thickness of the copper metal layer is 0.6um-1.5um, and the sputtering thickness of the nickel metal layer is 60nm-150nm.

5. The thin film thermal print head according to claim 3, characterized in that: A copper common electrode layer is formed between the nickel metal layer and the copper metal layer formed by sputtering by electroplating.

6. The thin film thermal print head according to claim 5, characterized in that: The thickness of the copper common electrode layer is 12um-25um.

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