Novel heating substrate for thermal printing head

Abstract

The utility model relates to the technical field of thermal printing head manufacturing, in particular to a novel heating substrate for a thermal printing head, which is reasonable in structure, simple and convenient to operate and capable of effectively preventing a silver bonding pad part on the substrate for the printing head from being corroded so as to remarkably prolong the service life of a product. The upper surfaces of the more than two silver bonding pads are provided with thermocuring ink protection layers, the thermocuring ink protection layers are provided with welding windows corresponding to the arrangement areas of the silver bonding pads, the welding windows and the corresponding silver bonding pads are concentrically arranged, and the area of the welding windows is smaller than that of the silver bonding pads. And the service life of the product can be obviously prolonged.

Description

Technical field:

[0001] The utility model relates to the technical field of thermal print head manufacturing, in particular to a novel heating substrate for thermal print heads which has a reasonable structure, is easy to operate and can effectively prevent corrosion of silver pad components on a substrate for the print heads, thereby significantly improving the service life of the product. Background technology:

[0002] At present, the print head is connected to the external flexible circuit board through the pad on the ceramic substrate, so as to use the external functional circuit to drive the thermal print head. The pad is generally printed into a pattern with silver paste and then sintered at high temperature. Usually, after the silver pad is sintered, a layer of glass paste will be printed on the substrate, and a protective layer will be formed by sintering. However, when the thickness of the glass paste printing is less than 8 microns, there will be defects such as holes after sintering, resulting in the exposed circuit to be protected. Water vapor will enter through the holes. Due to the unstable nature of silver and the potential difference between the silver pads, silver migration will occur. However, if the thickness of the glass paste printing is increased, it will be unfavorable for the connection between flexible cables such as FPC and FFC and the pad. In view of the above reasons, the silver pad is basically unprotected and is in a bare state. In the subsequent use process, it is easy to damage the pad components and affect the product quality and service life. Summary of the invention:

[0003] In view of the shortcomings and deficiencies in the prior art, the utility model proposes a novel heating substrate for a thermal print head, which can effectively protect the silver pad and reduce silver migration while meeting the requirements of pad welding, thereby increasing the service life of the product.

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

[0005] A novel heating substrate for a thermal print head is provided with an insulating substrate, a base glaze layer is provided on the insulating substrate, a heating resistor and an electrode wire are provided on the base glaze layer, and two or more silver pads connected to the electrode wires and arranged at equal intervals are provided on the base glaze layer. The invention is characterized in that a thermosetting ink protective layer is provided on the upper surfaces of the two or more silver pads, a welding window is provided in the thermosetting ink protective layer corresponding to each silver pad setting area, the welding window is concentrically arranged with the corresponding silver pad, and the area of ​​the welding window is smaller than the area of ​​the silver pad.

[0006] The thickness of the thermosetting ink protective layer of the utility model ranges from 1.0 to 10 μm, and is used to effectively fill the gaps between adjacent silver pads and cover the junction between the silver pads and the base glaze layer to prevent water vapor or other corrosive ions from entering.

[0007] In order to ensure the welding stability between the silver pad and the external flexible circuit board and the cable, the edge width of the thermosetting ink layer covering the silver pad is in the range of 0.1mm-0.5mm, so that the central effective welding area of ​​the silver pad is connected to the external cable through the welding window.

[0008] The utility model arranges a thermosetting ink protection layer with a thickness of 1.0-10 μm above the area where the silver pad is located, and opens a welding window concentrically arranged with the silver pad corresponding to the silver pad below the thermosetting ink protection layer. Under the premise of ensuring welding requirements, the silver migration of the silver pad caused by potential difference or water vapor intrusion can be effectively reduced, and the connection stability between the silver pad and the base glaze layer can be further enhanced, so as to avoid the silver pad being peeled off from the heating substrate along with the external flexible circuit board and the cable as a whole during subsequent assembly and use.

[0009] Compared with the prior art, the utility model has the advantages of reasonable structure, simple operation, and the ability to significantly improve the service life of the product. Description of the drawings:

[0010] Attached Figure 1 It is a structural schematic diagram of the utility model.

[0011] Reference numerals: insulating substrate 1 , heating resistor 2 , encapsulating adhesive layer 3 , base glaze layer 4 , silver pad 5 , thermosetting ink protective layer 6 . Specific implementation method:

[0012] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0013] Example:

[0014] As attached Figure 1 As shown, this example provides a high-quality heating substrate for a thermal print head, which is provided with an insulating substrate 1, a base glaze layer 4 is provided on the insulating substrate 1, a heating resistor 2 and an electrode wire and a driver IC component packaged and cured by a packaging glue layer 3 are provided on the base glaze layer 4, and two or more silver pads 5 connected to the electrode wire are also provided on the base glaze layer 4, which are arranged at equal intervals, and a thermosetting ink protective layer 6 is provided on the upper surface of the two or more silver pads 5, and a welding window is provided in the thermosetting ink protective layer 6 corresponding to each silver pad setting area, and the welding window is concentrically arranged with the corresponding silver pad 5, and the area of ​​the welding window is smaller than the area of ​​the silver pad;

[0015] The thickness of the thermosetting ink protective layer 6 in this example is in the range of 1.0-10 μm. The thermosetting ink protective layer is formed by printing ink containing epoxy resin components. This is a prior art and will not be described in detail. The thickness of the thermosetting ink protective layer 6 can effectively fill the gap between adjacent silver pads and cover the junction between the silver pad 5 and the base glaze layer 4 to prevent water vapor or other corrosive ions from entering.

[0016] Furthermore, in this example, in order to ensure the welding stability between the silver pad 5 and the external flexible circuit board and the cable, the edge width Y and length X of the thermosetting ink layer 6 covering the silver pad 5 are set in the range of 0.1mm-0.5mm, so that the central effective welding area of ​​the silver pad 5 is connected to the external cable through the welding window;

[0017] In this example, a thermosetting ink protective layer with a thickness of 1.0-10 μm is arranged above the area where the silver pad 5 is located, and a welding window is opened concentrically with the silver pad 5 corresponding to the silver pad 5 below the thermosetting ink protective layer 6. Under the premise of ensuring welding requirements, the silver migration of the silver pad 5 caused by the potential difference or water vapor intrusion can be effectively reduced, and the connection stability between the silver pad 5 and the base glaze layer 4 can be further enhanced, so as to avoid the silver pad from being peeled off from the heating substrate along with the external flexible circuit board and the cable as a whole during subsequent assembly and use.

[0018] Compared with the prior art, the utility model has the advantages of reasonable structure, simple operation, and the ability to significantly improve the service life of the product.

Claims

1. A novel heating substrate for a thermal print head, comprising an insulating substrate, an underglaze layer on the insulating substrate, a heating resistor and an electrode wire on the underglaze layer, and two or more silver pads connected to the electrode wire arranged at equal intervals on the underglaze layer, characterized in that: A thermosetting ink protective layer is provided on the upper surfaces of two or more silver pads, and a welding window is provided in the thermosetting ink protective layer corresponding to each silver pad setting area, the welding window is concentrically arranged with the corresponding silver pad, and the area of ​​the welding window is smaller than the area of ​​the silver pad.

2. A novel heating substrate for a thermal print head according to claim 1, characterized in that: The thickness of the heat curing ink protective layer is in the range of 1.0-10 μm.

3. A novel heating substrate for a thermal print head according to claim 1, characterized in that: The edge width of the silver pad covered by the thermosetting ink layer is in the range of 0.1 mm to 0.5 mm, so that the central effective welding area of ​​the silver pad is connected to the external cable through the welding window.

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