JPH0547100B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a method for aligning a thermal print head.

(B) Prior Art In the mask alignment process when manufacturing a thermal print head, it is generally a practice to adjust the deviation in the extension direction and the deviation in the orthogonal direction using the glaze layer formed on the main surface of the substrate as a reference. desirable.

Here, conventionally, the deviation in the direction perpendicular to the glaze layer is adjusted in relation to the alignment key provided on the mask and the pitch of the glaze layer. can be suppressed to about ±20μ. However, the deviation in the extension direction of the glaze layer is caused by the fact that the deviation of the glaze layer is adjusted by bringing the edge of the substrate into contact with a plurality of pins fixed to a pin alignment device. The deviation differs depending on the dimensional accuracy. Further, such a shift in the extension direction of the glaze layer can be avoided, for example, as described in Japanese Patent Application Laid-Open No.
It is also possible to apply the optical mark generally used for semiconductor wafers as shown in Publication No. 51-140638, but since this optical mark is formed by etching technology, thermal It was also unsuitable for application to print heads.

That is, in the case of the semiconductor wafer mentioned above, in order to determine the X, Y, and θ directions of the wafer, two or more optical marks are formed on the wafer and each optical mark is optically recognized. The purpose is achieved. However, in the case of a thermal print head, when the glaze layer is formed by printing and firing, its cross section becomes mountain-like. When recognizing a shift in the extension direction of the glaze layer formed in a mountain shape on such a ceramic substrate, a difference in height occurs between the optical mark formed by the etching and the glaze layer. However, even if the target glaze layer is adjusted using optical marks having different heights, there is a problem in that the positional shift cannot be sufficiently corrected. The above-mentioned substrate is generally made of ceramic, and its dimensional accuracy has an error of about ±200 μm. That is, there is a certain limit to improving the alignment precision of the deviation in the extension direction of the glaze layer.

If it is not possible to improve the alignment accuracy of such deviation in the extension direction of the glaze layer, it may be difficult to improve the alignment accuracy when forming a heating resistor band on the glaze surface in the post-manufacturing process or when forming electrode wiring from this heating resistor band. It could not be formed at the desired location, resulting in misalignment. In the thermal print head, the partial glaze applied to the ceramic substrate by screen printing and fired is formed in a mountain-like cross-section, so when forming the above-mentioned heating resistor band on the glaze layer, the glaze layer is If misalignment occurs in the longitudinal direction, the height of the formation position of the heat-generating resistor band will be uneven, resulting in uneven contact pressure on the printing material during printing.
There is a problem with uneven printing.

Furthermore, if the electrode wiring that selectively generates heat by supplying electricity to the heating resistor band is misaligned with respect to the extending direction of the glaze layer, the printing area of the heating resistor formed between the electrode wirings will be deformed. There is a problem that omission occurs or the resistance between wirings in the wiring area of the printing area changes, making it impossible to obtain a predetermined amount of heat generation, resulting in printing defects.

(c) Purpose This invention was made in view of the above circumstances,
It is an object of the present invention to provide a method for aligning a thermal print head that can improve the alignment accuracy of a glaze layer to be formed on a substrate in the extending direction and the orthogonal direction, and can significantly shorten the alignment time.

(D) Structure The thermal print head positioning method according to the present invention is characterized by forming a band-shaped glaze layer on the surface of the substrate by printing and baking, and aligning the band-shaped glaze layer in the extending direction. In the thermal print head alignment method, the band-shaped glaze layer is formed near the substrate, and at the same time, a glaze similar to the glaze layer is printed and fired to form an alignment glaze, and the alignment glaze is and an alignment key provided on the mask to align the glaze layer formed on the substrate and the mask.

(e) Example FIG. 1a is an explanatory diagram showing the formation of a glaze layer and alignment glaze on a substrate.
FIG. b is an explanatory diagram showing an alignment key formed on a mask.

In Figure a, 1 indicates a substrate made of ceramic or the like, 2 a glaze layer coated and fired by screen printing, and 3 a circular alignment glaze formed at the same time as the glaze layer 2. . In this embodiment, the alignment glaze 3 is formed near the ends of two opposing sides corresponding to the extending direction of the glaze layer 2. In Figure b, numeral 4 indicates a photomask made of ultra-transparent glass, and numeral 5 indicates a concentric alignment key. This alignment key 5
are formed on the photomask 4 corresponding to the positions of the alignment glaze 3.

Therefore, the alignment method in this embodiment is to set the substrate 1 on which the glaze layer 2 and the alignment glaze 3 have been formed in advance in a pin alignment device, and to set the photomask 4 in relation to the substrate 1. In the pin alignment device, the alignment glaze 3 and the alignment key 5 of the photomask 4 are
By comparing the glaze layer 2 with the glaze layer 2 formed on the substrate 1, the deviation in the extension direction and the orthogonal direction is adjusted. In other words, this alignment glaze 3
Since it is circular, the displacement of the glaze layer 2 in the extension direction and the orthogonal direction can be adjusted by simply forming one alignment glaze 3 on each of the two opposing sides of the substrate 1.

Note that the position where the alignment glaze 3 is formed is not limited to the above-described embodiment, and may be formed near the ends of two opposing sides corresponding to the orthogonal direction of the glaze layer 2. Of course.

(F) Effects According to the present invention, since the alignment glaze is formed at the same time as the glaze layer is formed on the substrate, the possibility of misalignment between the glaze layer and the alignment key can be eliminated. Therefore, the alignment of the mask and the glaze layer, especially in the extending direction, can be performed with high precision, so that, for example, in a later process, the mask can be used to form the heat generating resistor and the electrode wiring that conducts electricity to the heat generating resistor with high precision. It is possible to stably manufacture thermal print heads with good printing quality.

Moreover, since the alignment glaze is formed of glaze in the same way as the glaze layer, the alignment glaze and the glaze layer have almost the same height, so there is a risk of misalignment of the mask due to the height difference between them. It can be resolved.

[Brief explanation of drawings]

FIG. 1a is an explanatory diagram showing the formation of a glaze layer and an alignment glaze on a substrate;
FIG. b is an explanatory diagram showing alignment keys formed on a photomask. 1...Substrate, 2...Glaze layer, 3...Glaze for alignment, 4...Photomask, 5...Alignment key.

Claims (1)

[Claims] 1. In a thermal print head alignment method in which a band-shaped glaze layer is formed on the surface of a substrate by printing and baking, and alignment is performed in the extending direction of the band-shaped glaze layer, the band-shaped glaze layer is formed near the substrate. At the same time as forming the layer, a glaze similar to the glaze layer is printed and fired to form an alignment glaze, and this alignment glaze and an alignment key provided on the mask align the glaze layer formed on the substrate with the alignment key. A method for aligning a thermal print head, characterized by aligning it with a mask.