JPS5954038B2 - Thermal head and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal head used in a thermal printing device and a method for manufacturing the same.

In conventional thermal heads, the head substrate on which the heating elements are arranged is warped, so one side of a thick mounting substrate is processed to have good straightness, and the head substrate is attached to this surface to correct the warp.

However, the head substrate has not only overall warpage but also thickness unevenness, and although the conventional configuration can correct the overall warpage of the head substrate, the thickness unevenness of the head substrate remains and its effects are This resulted in a drawback that unevenness remained on the heating element arrangement surface of the head substrate.

As a result, the heating elements located in the recesses on the heating element array surface of the head board cannot make sufficient contact with the recording paper, resulting in low print density and uneven printing in the direction perpendicular to the feeding direction of the recording paper. Was.

The present invention aims to solve such problems with a simple configuration and manufacturing method, and will be explained in detail below using the drawings of FIGS. 1 to 3 showing one embodiment of the present invention. Explain.

1 to 3, 1 is an adhesive jig, and this adhesive jig 1 is composed of an adhesive jig main body 1a, a plurality of pressing screws lb, and an elastic body IC. The A side of the tool body 1a serves as a jig reference surface and is machined with good straightness.

Reference numeral 2 denotes a head substrate, the mouth surface of which serves as a heating element arrangement surface on which a plurality of heating elements 3 are arranged.

Reference numeral 74 indicates a plurality of thin plates, and these thin plates 4 constitute a mounting board.

When manufacturing a thermal head according to the present invention, as shown in FIG. The thin plates 4 are stacked one after another in a layered manner with a thermosetting adhesive (not shown) such as an epoxy adhesive between them.

Thereafter, as shown in FIG. 2, the plurality of pressing screws 1b are tightened with approximately equal torque until the heating element array surface opening of the head board 2 comes into close contact with the jig reference surface A of the adhesive jig main body 1a. , the adhesive is pressed almost evenly through the elastic body 1C, and the adhesive is cured in this state. After the adhesive has hardened, it is removed from the thermal head bonding jig 1 to obtain a thermal head as shown in FIG. That is,
In the thermal head of the present invention, since the head substrate 2 and the plurality of thin plates 4 are bonded together by pressure, it is possible to correct the overall warpage of the head substrate 2, and also to prevent uneven thickness of the head substrate 2 from appearing on the back surface of the head substrate 2. , the plurality of thin plates 4 are deformed correspondingly.

Then, in this state, the adhesive is cured, and after the adhesive is cured, the thermal tube is removed from the bonding jig 1.
As shown in FIG. 3, the heat generating element arrangement surface of the head substrate 2 has a flat surface with good straightness. Here, as an example of the specific dimensions of the thermal head according to the present invention in case of A4 size, the thickness of the two-head substrate 2 is about 2 mm, the thickness of the thin plate 4 is about 1 mm, and the number of thin plates 4 is 5 to 5 mm. There are about 6 pieces.

As described above, according to the thermal head and its manufacturing method of the present invention, even if the head substrate has overall warpage and uneven thickness, the heat generating element array surface of the head substrate can be kept in a flat plane with good straightness. Therefore, it is possible to easily obtain an excellent thermal head that can always produce clear prints without causing uneven printing or non-printing when printing. Furthermore, since the mounting board is constructed from a plurality of thin plates, the flat surface of the mounting board to which the head board is attached does not need to be processed to have good straightness, so it can be manufactured at a lower cost than conventional thermal heads. In addition, in the manufacturing method of the present invention, the case where pressing is performed using a plurality of pressing screws and an elastic body has been explained as an example, but the jig reference surface of the adhesive jig body and the head board The same results as the present invention can be obtained as long as the pressing means can press almost evenly from the back surface of the thin plates stacked in layers so that the heating element arrangement surface and the heating element array surface are in close contact with each other.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a state before pressure bonding in a method for manufacturing a thermal head according to an embodiment of the present invention;
The figure is a front view showing the state of pressure bonding, and FIG. 3 is a perspective view showing the thermal head obtained according to the present invention. 2...Head board, 3...Heating element,
4...Thin plate.

Claims (1)

[Claims] 1. A head substrate with a plurality of heating elements arranged on its surface;
Thermal system is characterized by comprising a mounting board made up of a plurality of thin plates, all of which are thinner than the thickness of the head board, which are pasted in layers with an adhesive on the back surface of the head board to reinforce the head board. head. 2. The surface of the head substrate on which a plurality of heat generating elements are arranged on its surface faces the heating element array side, and the surface of the head substrate facing the adhesive reference surface is heated between each thin plate, which is thinner than the thickness of the head substrate, on the back surface of the head substrate. They are stacked with a curable adhesive interposed therebetween, and then pressure is applied uniformly to the entire stack, and the curable adhesive is cured while the heating element arrangement surface of the head substrate is brought into close contact with the adhesion reference surface. A method for manufacturing a thermal head characterized by: