JPS5828117B2 - netsukiruquinsatsuyohead - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a planar type thermal recording printing head, in which a heat-generating portion formed on a surface of a silicon substrate that is to be in contact with a heat-sensitive recording material is made to be a convex portion with respect to the silicon substrate. A thermally conductive film is deposited on the substrate, and an abrasion-resistant hard film is formed through this heat-conductive film, thereby improving print quality and the quality of the abrasion-resistant hard film.

One of the planar type thermal recording printing heads is a type in which a heating resistor is formed on the surface of a silicon substrate that contacts a heat-sensitive recording material, and this will be explained with reference to FIG.

1 is an N type (or P type) silicon substrate, 2 is a P type (or N type)
type) heating resistor consisting of a diffusion layer, 3 is a thermal oxide film, 4 is M
o metal electrode, 5 is a 5i02 film formed by sputtering or CVD, 6 is a wear-resistant hard film of SiC, 2H is a heating resistor 2, a thermal oxide film 3.5i02 film 5, a wear-resistant hard film 6, etc., and 7 is a heat-sensitive recording material.

As shown in the figure, in this head, the surface of the heat generating part 2H is concave with respect to the surrounding surface, so there is insufficient contact between the heat sensitive recording material 7 and the surface of the heat generating part 2H, resulting in poor printing quality. It is.

In addition, the adhesion strength between the 5i02 film 5 and the wear-resistant hard film 6 is not sufficient, and the heat-generating resistor 2 reaches a high temperature especially during printing, so the wear-resistant hard film 6 is stronger than the Si02 film 5. Problems such as peeling occurred.

The present invention eliminates the drawbacks of the prior art as described above.

FIG. 2 is a partial cross-sectional view of one embodiment of the present invention.

8 is an N type (or P type) silicon substrate, 9 is an N type (or P type)
type) P+ (or N+) formed in the silicon substrate 8
A heating resistor consisting of a diffusion layer, 10 a hole penetrating the front and back surfaces of a silicon substrate 8, 11 a thermal oxide film, 12 a low resistance polycrystalline silicon film, 13 a metal electrode such as Mo, 14 an electrical insulating film, and 15 a High-resistance polycrystalline silicon film, 16 is a wear-resistant hard film, 9H is a heating resistor 9. Thermal oxide film 11. Electrical insulation film 14. High resistance polycrystalline silicon film 15. A heat-generating portion 17 made of a wear-resistant hard film 16 and the like is a heat-sensitive recording material.

Hereinafter, the construction method of the thermal recording printing head of the present invention will be explained with reference to FIG.

As shown in figure a, N type (100 to 200 μm thick)
Phosphorus (or boron) is diffused on one surface of the silicon substrate 8 to form a heating resistor 9 (or P type).

In this case, the silicon oxide film 1
It is natural to protect it with 8th grade.

Next, as shown in the figure, a hole 10 penetrating both sides of the silicon substrate 8 is formed using the gold vapor deposited film 19 and the photoresist 20 as a mask.

Then, as shown in Figure C, an insulating silicon oxide film 11 is formed on the entire surface of the silicon substrate 8, and CVD
After forming a low-resistance polycrystalline silicon film 12 by a method, and protecting the hole 10 and its surrounding area with a film resist or photoresist, the unprotected portion of the low-resistance polycrystalline silicon film 12 is removed by chemical etching. .

Next, as shown in FIG. d, a part of the silicon oxide film 11 is removed using a photoresist as a protective film, metal electrodes 13 are formed on both sides, and the heating resistor 9, metal electrode 13 and low resistance polycrystalline silicon are formed. The two sides are connected through membrane 12.

Next, as shown in FIG. 5E, an electrical insulating film 14 is formed by sputtering and CVD, and a high-resistance polycrystalline silicon film 15 is formed by sputtering and CVD.

Next, using a photoresist film as a protection film, the high resistance polycrystalline silicon film 1 is
A part of 5 is chemically etched, and Si is further deposited on top of these.
A wear-resistant hard film 16 such as C is formed.

Next, metal bumps (Cu solder) 21 are formed by electroplating etc.
form.

The thermal recording printing head thus produced is bonded to a ceramic substrate that has been previously metalized in a predetermined pattern by a flip-chip method or the like.

Further, the present invention is applicable not only to planar type thermal recording printing heads but also to thick film and thin film type thermal printing heads, or when the polycrystalline silicon layer 15 is left only on the top of the heating resistor 9 as shown in FIG. Also included.

Since the present invention is constructed as described above, in the thermal recording printing head as shown in FIG. Good contact with the top surface.

This improves thermal efficiency and print quality.

Furthermore, since the base of the wear-resistant hard film is polycrystalline silicon, a stable and high-quality wear-resistant hard film with strong adhesion can be obtained.

Furthermore, by using a high-resistance polycrystalline silicon film as the heat conductive film that forms the convex portions, defects such as pinholes and cracks may occur in the electrical insulating film that is the base of the heat conductive film, resulting in metal electrodes that are the base of the electrical insulating film. Alternatively, even if the heating resistor and the heat conductive film come into contact, by using a high resistance polycrystalline silicon film as the heat conductive film, an electrical short circuit will not occur, and problems such as a decrease in yield due to the addition of the heat conductive film will occur. Therefore, it is possible to provide a thermal recording printing head with good thermal efficiency and excellent printing quality.

Further, in the thermal recording printing head having the structure as shown in FIG. 4, by forming a heat conductive film only on the heat generating portion, it is possible to provide a thermal recording printing head with even better thermal efficiency and excellent printing quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of a conventional thermal recording printing head, FIG. 2 is a sectional view of the main parts of an embodiment of the thermal recording printing head of the present invention, and FIGS. FIG. 2 is a sectional view showing the manufacturing process of the thermal recording printing head, and FIG. 4 is a sectional view of the main part showing another embodiment of the thermal recording printing head of the present invention. 8. Semiconductor substrate, 9... Heat generating resistor, 4... Electrical insulating film, 15... High resistance polycrystalline silicon film, 16... Hard film.

Claims (1)

[Claims] 1. A heat-generating resistor is provided on the substrate along the main surface of the substrate to be in contact with the heat-sensitive recording material, and a heat-conducting film made of a high-resistance polycrystalline silicon film is provided at least on the heat-generating resistor via an electrical insulating film. A thermal recording printing head comprising a film formed on the heat generating resistor in a convex part and a wear-resistant hard film on the heat conductive film to provide a convex heat generating part.