Thermal printing head for enhancing ACF binding force

Abstract

The utility model provides a thermal printing head capable of enhancing ACF binding force, and relates to the technical field of thermal printing, the thermal printing head comprises a heating substrate, an ACF layer arranged on the upper surface of one side of the heating substrate, and a circuit board pressed on the ACF layer; the heating substrate comprises an electrode wire, pin parts of the electrode wire extend to a pressing area between the heating substrate and the circuit board and are in circuit conduction with the circuit board through an ACF layer located above the pin parts, and a plurality of protruding parts are distributed in the pressing area in the arrangement direction of the pin parts at intervals. The upper surface of each protruding part is connected with the corresponding pin part. According to the thermal printing head, the bonding strength of the ACF layer and other parts can be remarkably enhanced, connection failure is avoided, and the quality and the service life of the thermal printing head are guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of thermal printing technology, and in particular to a thermal printhead that enhances the bonding force of ACF. Background Technology

[0002] In the field of thermal printhead manufacturing, thermal printheads prepared using flip-chip bonding technology often use ACF adhesive to bond the heating substrate to the flexible circuit board. Specifically, the structure of the heating substrate mainly includes an insulating substrate, a base glaze layer, a heating resistor, and electrode wires. The insulating substrate has a base glaze layer on its surface. The heating resistor and electrode wires are set on the upper surface of the base glaze layer corresponding to the effective working area. The electrode wires are electrically connected to the heating resistor to supply power to the heating resistor. An ACF adhesive layer is attached to the surface of the electrode wire leads. The flexible circuit board is then pressed onto the ACF adhesive to complete the fixed connection with the insulating substrate.

[0003] However, in actual operation, due to factors such as the structure of the insulating substrate, unevenness of the electrode wire surface, or the characteristics of the ACF adhesive, poor contact and uneven pressure distribution may occur between the flexible circuit board and the insulating substrate. This affects the bonding strength between the insulating substrate and the flexible circuit board, ultimately leading to product connection failure and impacting the product quality of the thermal printhead. Therefore, a new technological solution is needed to enhance the bonding strength between the ACF and the insulating substrate and flexible circuit board, avoiding connection failure due to insufficient bonding strength, thereby improving the product quality of the thermal printhead. Utility Model Content

[0004] The purpose of this application is to provide a thermal printhead that enhances the adhesion of ACF.

[0005] The embodiments of this application can be implemented through the following technical solutions:

[0006] A thermal printhead for enhancing ACF adhesion includes a heating substrate, an ACF layer disposed on one upper surface of the heating substrate, and a circuit board pressed on top of the ACF layer. The heating substrate includes electrode wires, each pin of which extends to the pressing area between the heating substrate and the circuit board and is connected to the circuit board via the ACF layer above it. Several raised portions are distributed at intervals along the pin arrangement direction in the pressing area, and the upper surface of each raised portion is connected to the corresponding pin portion.

[0007] Furthermore, the material of the raised portion can be selected from either the glaze material or the film material.

[0008] Furthermore, when the material of the raised portion is a glaze material, the raised portion is formed by a printing and sintering process; when the material of the raised portion is a film material, the raised portion is formed by a film etching process.

[0009] Furthermore, the thickness of the raised portion is 0.01-0.1 mm.

[0010] Furthermore, the heating substrate includes an insulating substrate, a base glaze layer disposed on the upper surface of the insulating substrate, a heating resistor and an electrode wire disposed on the upper surface of the base glaze layer; one side of the electrode wire is connected to the heating resistor, and the other side pin is connected to the circuit board through the ACF layer.

[0011] Furthermore, the pressing area of ​​the heating substrate may or may not have a base glaze layer.

[0012] Furthermore, it also includes a metal heat sink, which is connected to the lower surface of the insulating substrate.

[0013] The thermal printhead for enhancing ACF adhesion provided by the embodiments of this application has at least the following beneficial effects:

[0014] This application increases the contact area between the ACF layer and the electrode wires by adding raised portions, and also makes the density of conductive particles in the ACF adhesive more concentrated, improving the probability of conduction between particles and ensuring stable circuit conduction. At the same time, the structure of the spaced portions of the raised portions can improve the problem of uneven pressure caused by tension differences between the circuit board and the insulating substrate, enhance the bonding strength between the ACF layer and both, avoid connection failure, and thus ensure the quality of the thermal printhead, extend its service life, and improve print quality. Attached Figure Description

[0015] Figure 1 This is a top view of a thermal printhead in the prior art;

[0016] Figure 2 for Figure 1 A schematic diagram of the cross-section of part A of the thermal printhead pressing area in the existing technology;

[0017] Figure 3 This is a top view of the internal structure of the heating substrate according to an embodiment of this application;

[0018] Figure 4 This is a schematic cross-sectional view of part A of the thermal printhead pressing area according to an embodiment of this application;

[0019] Figure 5 This is a schematic cross-sectional view of part A of the thermal printhead pressing area according to another embodiment of this application;

[0020] Figure 6 This is a schematic cross-sectional view of part A of the thermal printhead pressing area according to another embodiment of this application;

[0021] Numbers in the diagram

[0022] Heating substrate 1, insulating substrate 11, base glaze layer 12, heating resistor 13, electrode wire 14, common electrode 141, individual electrode 142, lead portion 143, encapsulating glue 15, circuit board 2, socket 3, metal heat sink 4, ACF layer 5, raised portion 6. Detailed Implementation

[0023] The present application will now be further described based on preferred embodiments and with reference to the accompanying drawings.

[0024] Furthermore, for ease of understanding, various components on the drawings have been enlarged or reduced, but this is not intended to limit the scope of protection of this application.

[0025] Singular forms of words also include plural meanings, and vice versa.

[0026] In the description of the embodiments of this application, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, in the description of this application, in order to distinguish different units, the terms "first," "second," etc. are used in this specification, but these are not limited by the manufacturing order, nor should they be construed as indicating or implying relative importance. Their names may differ in the detailed description and claims of this application.

[0027] The vocabulary used in this specification is for illustrative purposes and is not intended to limit the scope of this application. It should also be noted that, unless otherwise expressly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection via an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of these terms in this application.

[0028] To better illustrate the technical solution of this application, we will first combine it with Figure 1 and Figure 2The prior art is described in the figure. A prior art thermal printhead includes a heating substrate 1, an ACF layer 5 disposed on one upper surface of the heating substrate 1, and a circuit board 2 pressed onto the ACF layer 5. The heating substrate 1 includes an insulating substrate 11, a base glaze layer 12 disposed on the upper surface of the insulating substrate 11, and a heating resistor 13 and an electrode wire 14 disposed on the base glaze layer 12. One side of the electrode wire 14 is connected to the heating resistor 13, and the other side is electrically connected to the circuit board 2 through the ACF layer disposed on its surface. As described in the background art, in actual operation, due to the structure of the insulating substrate, unevenness of the electrode wire surface, or the characteristics of the ACF adhesive, poor contact and uneven pressure distribution may occur between the circuit board and the insulating substrate, affecting the bonding strength between the insulating substrate and the circuit board, ultimately causing product connection failure and affecting the product quality of the thermal printhead. Therefore, this application provides a thermal printhead that can enhance the ACF bonding force.

[0029] Combination Figure 1 , Figure 3 and Figure 4 As shown, an embodiment of this application provides a thermal printhead with enhanced ACF bonding force, specifically including a heating substrate 1, an ACF layer 5 disposed on the upper surface of one side of the heating substrate 1, and a circuit board 2 pressed on top of the ACF layer 5. The heating substrate 1 includes electrode wires 14, and each pin portion 143 of the electrode wires 14 extends to the pressing area between the heating substrate 1 and the circuit board 2, and achieves circuit conduction with the circuit board 2 through the ACF layer 5 located above it; a plurality of raised portions 6 are distributed at intervals along the arrangement direction of the pin portions 143 (i.e., the main printing direction) in the pressing area, and the upper surface of each raised portion 6 is in contact with the corresponding pin portion 143.

[0030] Specifically, the heating substrate 1 includes an insulating substrate 11, a base glaze layer 12 disposed on the upper surface of the insulating substrate 11, and a heating resistor 13 and an electrode wire 14 disposed on the upper surface of the base glaze layer 12, wherein the heating resistor 13 is connected to the electrode wire 14; specifically, as Figure 3 and Figure 4 As shown, the electrode wire 14 includes a common electrode 141, individual electrodes 142, and a pin portion 143 connected in sequence along the sub-printing direction. The pin portion 143 extends to the pressing area between the heating substrate 1 and the circuit board 2. An ACF layer 5 is attached to the upper surface of the pin portion 143. The circuit board 2 is fixedly connected to the heating substrate 1 by pressing on the top of the ACF layer 5. On the other hand, the circuit of the circuit board 2, the heating resistor 13, and the electrode wire 14 is made conductive through the conductive particles in the ACF layer 5, ensuring that the current can be smoothly transmitted from the circuit board 2 to the heating resistor 13 so that it can heat up and work normally.

[0031] Furthermore, the pin portion 143 includes a plurality of pins spaced apart along the main printing direction. Each pin has a corresponding raised portion 6 on its lower surface. The raised portion 6 can effectively compensate for the height difference caused by factors such as the structure of the insulating substrate and the unevenness of the electrode wire surface. When the circuit board 2 is pressed on top of the ACF layer 5, the raised portion 6 can ensure that the contact between the pin portion 143 and the circuit board 2 is tighter and more uniform, avoiding poor circuit conduction caused by poor contact. During the pressing process, the raised portion 6 can transmit the pressure more concentratedly to the contact position between the pin portion 143 and the ACF layer 5, avoiding the problem of uneven pressure distribution caused by different tensions between the circuit board 2 and the insulating substrate 11, thereby significantly enhancing the bonding force of the ACF and greatly improving the stability and reliability of the connection between the heating substrate 1 and the circuit board 2 in the thermal printhead.

[0032] Furthermore, in some specific embodiments, such as Figure 4 As shown, the material of the raised portion 6 is the same as that of the base glaze layer, and can specifically use glaze materials well known in the art; no specific limitation is made here. The raised portion 6 is formed using a printing and sintering process, and its cross-section has a convex arc-shaped structure. In some other optional embodiments, such as... Figure 5 As shown, the material of the raised portion 6 is the same as the film material. Specifically, it can be a film material well known in the art. No specific limitation is made here. The raised portion 6 is formed by film etching process. The cross-section of the raised portion is rectangular.

[0033] In some other alternative embodiments, such as Figure 6 As shown, the pressing area of ​​the heating substrate 1 may not have a base glaze layer 12, that is, the base glaze layer 12 can be replaced by the raised part 6 to simplify the structure and reduce production costs.

[0034] Furthermore, in some preferred embodiments, the thickness of the raised portion 6 is 0.01-0.1 mm. On the one hand, this ensures sufficient thickness to achieve effects such as compensating for height differences and improving pressure distribution. On the other hand, it avoids other problems such as excessive compression and affecting the distribution of conductive particles caused by excessive thickness.

[0035] In some specific embodiments, the heating resistor 13 is disposed between the common electrode 141 and the individual electrode 142 and extends along the main printing direction. One end of the common electrode 141 along the secondary printing direction is connected to the heating resistor 13, and the other end is used to connect to the printing power supply. One end of the individual electrode 142 along the secondary printing direction is connected to the heating resistor 13, and the other end is provided with a control IC part between it and the pin part 143. The control IC part is also provided with encapsulating glue 15 for encapsulation and protection.

[0036] In some specific embodiments, the thermal printhead further includes a metal heat sink 4, which is connected to the lower surface of the insulating substrate 11.

[0037] In some specific embodiments, the circuit board 2 is also provided with a socket 3 that is connected to the printer body.

[0038] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A thermal printhead for enhancing ACF bonding strength, comprising a heating substrate (1), an ACF layer (5) disposed on one upper surface of the heating substrate (1), and a circuit board (2) pressed on top of the ACF layer (5); the heating substrate (1) includes electrode wires (14), each pin (143) of the electrode wires (14) extending to the pressing area between the heating substrate (1) and the circuit board (2), and achieving circuit communication with the circuit board (2) through the ACF layer (5) located above it, characterized in that, The pressing area has a number of raised portions (6) spaced apart along the arrangement direction of the pin portion (143), and the upper surface of each raised portion (6) is connected to the corresponding pin portion (143).

2. The thermal printhead according to claim 1, characterized in that, The material of the raised portion (6) can be selected from either glaze material or film material.

3. The thermal printhead according to claim 2, characterized in that, When the material of the raised portion (6) is a glaze material, the raised portion (6) is formed by printing and sintering process; When the material of the raised portion (6) is a film material, the raised portion (6) is formed by a film etching process.

4. The thermal printhead according to claim 2, characterized in that, The thickness of the raised portion (6) is 0.01-0.1 mm.

5. The thermal printhead according to claim 1, characterized in that, The heating substrate (1) includes an insulating substrate (11), a base glaze layer (12) disposed on the upper surface of the insulating substrate (11), a heating resistor (13) disposed on the upper surface of the base glaze layer (12), and an electrode wire (14); one side of the electrode wire (14) is connected to the heating resistor (13), and the other side pin (143) is connected to the circuit board (2) through the ACF layer (5).

6. The thermal printhead according to claim 5, characterized in that, The heating substrate (1) may or may not have a base glaze layer (12) in the pressing area.

7. The thermal printhead according to claim 5, characterized in that, It also includes a metal heat sink (4), which is connected to the lower surface of the insulating substrate (11).

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