JPH0711985Y2 - Thermal head feed line connection structure - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a feed line connecting structure for a thermal head having good connection workability.

(B) Conventional Technique FIG. 3 is a plan view showing an electrode pattern of a conventional thermal head.

The thermal head has a plurality of individual electrodes 62, a common electrode 63, and a heating resistor 64 formed on the upper surface of an insulating substrate (head substrate) 61. In this type of thermal head, power is supplied from both ends (“A” and “A” in the figure) of the common electrode 63 during use. However, in this power feeding system, the difference in resistance value from the power feeding point of the common electrode 63 to each heating resistor 64 cannot be ignored, and the heating resistors 64 located at both ends are located in the central portion (near the “B” point). The heating resistor 64 has a longer distance from the power feeding point to the common electrode 63, the electrical resistance is correspondingly larger, and the voltage drop is larger. As a result, there is a disadvantage that the printing density of the heating resistor 64 located in the central portion is lowered.

Therefore, in recent years, a thermal head as shown in FIG. 4 has been implemented. In this thermal head, a plurality of individual electrodes 62 and a heating resistor 64 are provided on the upper surface (front surface) of a head substrate 61, while the common electrode 63 is extended from the end portion of the upper surface on the heating resistor 64 side to the back surface (lower surface). Have been deployed. Then, a lead wire 67 is connected between the common electrode 63 on the back surface and the common lead pattern portion 66 of the external circuit connecting flexible substrate 65 to establish conduction. According to this feed line connection method, the common electrode 63 is provided on the entire back surface of the head substrate 61, and since it is a flat electrode, the electric resistance is small and the voltage drop at the point "B" as shown in FIG. It does not occur, and the printing accuracy can be secured.

(C) Problems to be Solved by the Invention In the power supply line connection structure of the thermal head shown in FIG. 4 described above, by soldering the lead wires, the common electrode provided on the back surface of the head substrate and the flexible substrate for external circuit connection are provided. (Common lead pattern portion). Therefore, the common electrode provided on the head substrate needs a solderable pattern, for example, a pattern of Ag-Pd, which is disadvantageous in that it increases material costs and man-hours. Moreover, since the head substrate is usually supported by the heat sink, the soldering work of the lead wires is not a troublesome task,
In order to pull out the lead wire to the outside, for example, it is necessary to provide a lead wire escape groove in the heat dissipation plate, which is disadvantageous in that the number of steps is increased.

An object of the present invention is to solve the above problems, and to provide a power supply line connection structure of a thermal head that can easily connect a common electrode with a simple configuration without causing a density difference in printing due to a voltage drop. To do.

(D) Means and Actions for Solving the Problem In order to achieve this object, the feed line connecting structure of the thermal head of the present invention has the following configuration.

The power supply line connection structure of the thermal head is such that the heating resistor array and the individual electrodes are arranged on the upper surface, the thermal head substrate is provided with a common electrode that is continuously provided from the upper surface, and the split grooves are formed on both sides. An individual lead pattern portion corresponding to the individual electrode is provided in the surface between the grooves, and both side portions located outside the split groove are extended and protruded, and the common lead pattern corresponding to the common electrode is provided on the protrusion portion. A flexible substrate having a portion, and the tip portion of the common lead pattern portion is pressure-contact connected to the common electrode on the back surface of the thermal head, and the individual lead pattern portion is pressure-contact connected to the individual electrode on the upper surface of the thermal head. ing.

In this power supply line connection structure of the thermal head, an individual lead pattern portion is provided in the center of the surface of the flexible substrate, and both sides of the individual lead pattern portion, that is, both side portions of the flexible substrate are extended by a certain length and protrude. The extension projecting portion is provided with a common lead pattern portion. The common lead pattern portion is integral with the flexible substrate and has a free end at the tip through the split groove.

Therefore, at the time of connecting the power supply line, the tips of the common lead pattern portions that extend from both sides of the flexible substrate are inserted and inserted into the lower surface of the thermal head substrate, that is, between the heat sink and the thermal head substrate. . This allows
The tip of the common lead pattern portion is electrically connected to the common electrode on the lower surface (rear surface) of the thermal head substrate, and the common lead pattern portion is pressed and fixed between the thermal head substrate and the heat dissipation plate. In this state, the individual lead pattern portions of the flexible substrate correspond to the individual electrodes on the upper surface of the thermal head substrate, and are superposed and conductive. This superposition state is fixed by pressure using a conventionally used metal cover for pressure contact (a metal cover that pressure contacts via silicone rubber).

Thus, the common electrodes of the thermal head substrate are connected to the power supply by a very simple operation by the common lead pattern portions extending on both sides of the flexible substrate, and the lead wires are soldered to the conventional common electrode connection. Such difficult work can be eliminated.

(E) Embodiment FIG. 1 is an enlarged perspective view of an essential part showing a power supply line connection structure of a thermal head according to the present invention.

The thermal head feed line connection structure has individual electrodes 11 on the top surface.
And a thermal head substrate 1 including a heating resistor (not shown), and a common electrode 12 continuously provided from the upper surface to the lower surface (rear surface), and the individual electrodes of the thermal head substrate 1.
The flexible substrate 2 is provided with the individual lead pattern portions 21 and the common lead pattern portions 22 respectively corresponding to 11 and the common electrode 12.

The thermal head substrate 1 has the same structure as that shown in FIG. 4 in which the individual electrodes 11 and the heating resistors (not shown) are arranged on the upper surface, and the common electrode 12 is formed from the upper surface to the lower surface (rear surface). It is placed and fixed on the upper surface of the plate 3. The heat dissipation plate 3 mounts the thermal head substrate 1 on one end side of the upper surface, and has a notch 31 corresponding to a common lead pattern portion 22 of the flexible substrate 2 described later on the other end side (from the center of the length). It is provided. Further, the reinforcing plate 4 having a cutout portion 41 corresponding to the cutout portion 31 is superposed on the upper surface of the heat dissipation plate 3 on the other end side,
A flexible substrate (external circuit connecting flexible substrate) 2 to be described later is placed on the reinforcing plate 4.

A feature of the present invention is that both side portions of the flexible substrate 2 are extended and protruded in the forward direction, that is, in the direction of the thermal head substrate 1, and the common lead pattern portions 22 are provided on the protrusions.

The flexible substrate 2 is formed in a flat plate shape having a constant width and a three-layer structure by superposing the conductor 2b on the insulating film (base film) 2a and the insulating film 2c on the conductor 2b. This flexible substrate 2 is provided with split grooves 23 on both sides, and the conductor 2b located in the plane between the split grooves 23.
Is the individual lead pattern portion 21. And the split groove 23
Outside, that is, both side portions of the flexible substrate 2 are projected forward (to the side of the thermal head substrate 1) by a certain length, and the conductor 2b located on this projecting portion is connected to the common lead pattern portion.
It is set to 22. The individual lead pattern portion 21 is formed by notching the lower insulating film (base film) 2a at the tip portion, that is, at the portion corresponding to the individual electrode 11 of the thermal head substrate 1, and forming the conductor (individual lead pattern 21) 2b.
Are set so that they can come into contact with the individual electrodes 11 correspondingly. Further, the common lead pattern 22 is provided on the upper side of the insulating film at the tip of the extension projecting portion, that is, at the portion corresponding to the lower surface common electrode 12 of the thermal head substrate 1.
2c is cut out, and the conductor (common lead pattern 22) 2b is exposed so that it can be brought into contact with the common electrode 12 in a corresponding manner.

In the power supply line connection structure of the thermal head having such a configuration, the individual lead pattern portion 21 is provided in the center of the in-plane of the flexible substrate 2, and the common ends are free ends via the split grooves 23 on both side portions. The lead pattern portion 22 is provided so as to extend for a certain length. Therefore, when connecting the power supply line,
As shown in the figure, the leading end of the common lead pattern portion 22 located on both sides of the flexible substrate 2 that is localized on the reinforcing plate 4 and the leading end of which is a free end, is connected to the heat sink 3 and the thermal plate 3 via the notch 31. The head substrate 1 and the head substrate 1 are interposed. As a result, the common lead pattern portion 22 becomes the thermal head substrate 1
Corresponding to the common electrode 12 located on the lower surface of the surface of the electrode, and is electrically connected. Then, the common lead pattern portion 22 is pressure-bonded and fixed between the heat dissipation plate 3 and the thermal head substrate 1, so that the conductive state (pressure contact connection state) is maintained. In this state, the individual lead pattern portion 21 of the flexible substrate 2 is superposed on and in contact with the individual electrode 11 located on the upper surface of the thermal head substrate 1, and the individual lead pattern portion 21 and the individual electrode 11 are electrically connected. The overlapping state (conduction state) of the individual lead pattern 21 and the individual electrode 11 is, for example, a conventionally used pressure-contacting metal cover (a metal cover that is pressure-contacted via a silicone rubber).
Is pressed and fixed by.

Thus, the individual electrodes 11 of the thermal head substrate 1 are connected to the individual lead pattern portions 21 of the flexible substrate 2 as in the conventional case, and the common electrodes 12 of the thermal head substrate 1 are integrally extended from both side portions of the flexible substrate 2. The common lead pattern portion 22 that is provided and has a free end is attached to the heat sink 3
The common electrode 12 and the common lead pattern portion 22 are electrically connected to each other in a pressure contact state by a simple work of simply introducing them between the thermal head substrate 1 and the thermal head substrate 1. Therefore, the soldering work for connecting the common electrode 12 via the lead wire unlike the conventional case is completely unnecessary.

(F) Advantageous effect of the invention In this invention, as described above, the split grooves are provided on both sides of the flexible substrate, and the individual lead pattern portions that come into contact with the individual electrodes of the thermal head substrate are provided between the split grooves. Since both sides of the flexible substrate are extended and protruded through the split groove, and the common lead pattern portion that faces the common electrode of the thermal head substrate is formed on this protrusion, the tip is a free end. By introducing the common lead pattern part which is between the thermal head substrate and the heat sink,
The common lead pattern portion is pressed and fixed between the heat dissipation plate and the thermal head substrate in a state of being electrically connected to the common electrode. Further, the individual lead pattern portions are superposed on the individual electrodes of the thermal head substrate to be electrically connected, and this electrically connected state is fixed by pressure contact with the metal cover for pressure contact. Therefore, it is not possible to connect the power feeding pattern by an extremely simple work, and the density difference due to the voltage drop of the common lead pattern does not occur, and the conventional lead wire soldering work and the soldering pattern No formation is required. Further, the common lead pattern portion has a structure in which both side portions of the flexible substrate are extended and integrally projected, so that the structure is simple, the manufacturing is easy, and the connection workability is good. Has excellent effect achieved.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view of an essential part showing a power supply line connection structure of an embodiment thermal head, FIG. 2 is an enlarged view of an essential part showing a power supply line connection structure of an example thermal head, and FIG. FIG. 4 is a plan view showing an electrode pattern of the thermal head of FIG. 4, and FIG. 4 is a perspective view showing a pattern connection structure of the thermal head which has been recently implemented. 1: Thermal head substrate, 2: Flexible substrate, 11: Individual electrode, 12: Common electrode, 21: Individual lead pattern part, 22: Common lead pattern part, 23: Split groove.

Claims (1)

[Scope of utility model registration request] 1. A thermal head substrate having a heating resistor array and individual electrodes arranged on an upper surface, and a common electrode continuous from the upper surface to a back surface, and split grooves formed on both side portions, and between the split grooves. An individual lead pattern portion corresponding to the individual electrode is provided in the surface of the, and both side portions located outside the split groove are extended and projecting, and a common lead pattern portion corresponding to the common electrode is provided on the projecting portion. Consisting of a flexible board with
A thermal head power supply line connecting structure in which the tip portion of the common lead pattern portion is press-contacted to a common electrode on the back surface of the thermal head and the individual lead pattern portion is press-contacted to an individual electrode on the upper surface of the thermal head.