JPH0664176A - Manufacture of ink jet head - Google Patents

Abstract

PURPOSE:To make the state of bonding between a substrate and a vibration plate more stable in manufacture of an ink jet head that is constructed by bonding by means of heating the vibration plate to the photosensitive substrate on which ink passages are formed. CONSTITUTION:In manufacture of an ink jet head consisting of processes including an exposure process for applying exposure to a photosensitive glass substrate 10, a developing process for crystallizing the exposed part, an etching process for making recesses 12 over the crystallized part by etching and a vibration plate attaching process for bonding a vibration plate 14 to the substrate, re- exposure is applied all over the substrate 10 in the stage that follows the etching process and after that, re-developing is applied for entire crystallization. Thereby, the substrate 10 is entirely crystallized before attachment of the vibration plate thereto, and thereby coefficient of thermal expansion of the substrate can be made uniform. Therefore, it becomes easy to prepare the vibration plate and bonding material in conformity with the aforementioned coefficient, and satisfactory bonding can be achieved without making strain stress left over.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ink jet head, and more particularly, a method for manufacturing an ink jet head formed by using photosensitive glass as an ink flow path substrate and heating and bonding a vibration plate to the flow path side surface. It is about.

[0002]

2. Description of the Related Art In order to form an ink flow path portion of an inkjet head having a fine shape, it has been practiced to use a photosensitive glass which can be precisely processed as a flow path substrate.

FIG. 3 shows the structure of a photosensitive glass substrate having such an ink flow path.

[0006] In such a structure, first, SiO ₂ --Li ₂
The exposure work is performed by irradiating the portion of the O—Al ₂ O ₃ -based photosensitive glass substrate 10 where the concave portion 12 which is the ink flow path is formed with ultraviolet rays using a mask having a predetermined pattern. As a result, the photosensitive glass substrate 10 at the portion where the recess 12 is to be formed
A latent image is formed on.

Then, development is performed by heat treatment at a predetermined temperature to crystallize the latent image portion.

Next, the crystallized portion is etched to a predetermined depth by acid treatment. The etching depth is appropriately set by adjusting the time of the acid treatment. FIG. 3 shows a state in which the recess 12 is formed by these steps.

An ink jet head is manufactured by fixing a vibrating plate (not shown) formed of, for example, a glass member to the surface of the photosensitive glass substrate 10 on the side where the recess 12 is formed.

[0008]

However, when the recess 12 which is the ink flow path is formed by the above manufacturing process, the following problems occur.

That is, SiO ₂ --Li ₂ O--Al ₂ O
_{When the 3} type photosensitive glass is used as the substrate, the lower region of the recess 12 (the hatched region in the figure) is crystallized, so that the expansion coefficient α is 100 × 10 ^−7. The coefficient of expansion α of the portion, ie, the portion of the photosensitive glass substrate 10 which is not crystallized is 84 × 10 ⁻⁷ . Therefore, the expansion coefficient α of the entire photosensitive glass substrate 10 in which the ink flow path is formed is complicated in a non-uniform state.

On the other hand, when the vibrating plate is bonded to the surface of the photosensitive glass substrate 10 by heating, for example, when using heat fusion or low melting point glass, the vibrating plate and the ink flow path are connected to each other. It is necessary to make the coefficient of thermal expansion α of the formed photosensitive glass substrate 10 and that of the low melting point glass, etc. substantially equal. However, it is difficult to make the coefficient of thermal expansion α of the entire photosensitive glass substrate 10 uniform due to the presence of the crystallized portion and the non-crystallized portion as described above. Is difficult to adjust in practice. Therefore, if the joining is performed in such a state, strain stress remains in the whole, and the durability becomes unstable, which also affects the reliability of the inkjet head.

The present invention has been made to solve the above-mentioned problems, and its object is to make the coefficient of thermal expansion α of the entire photosensitive glass substrate in which the ink flow path is formed uniform, and to bond by heating. An object of the present invention is to provide a method for manufacturing an inkjet head, which can stabilize the mounting state of the diaphragm and improve the durability of the head.

[0012]

In order to achieve the above object, a method for manufacturing an ink jet head according to the present invention comprises:
An exposure step of irradiating a portion of the surface of the photosensitive glass where an ink flow path is to be formed with light, a development step of crystallizing only the portion exposed by the exposure step, and a predetermined portion only of the portion crystallized by the development step In an inkjet head manufacturing method, including an etching step of forming a concave portion as an ink flow path by etching to a depth, and a vibration plate attaching step of fixing a vibration plate to the surface of the photosensitive glass substrate on which the concave portion is formed, i) a re-exposure step of irradiating light in a wavelength range necessary for crystallizing the entire photosensitive glass substrate after the etching step, and (ii) after the re-exposure step, and of the vibration plate attaching step. A redeveloping step of crystallizing the entire photosensitive glass substrate before or at the same time is performed.

[0013]

According to the method of manufacturing an ink jet head having the above-mentioned structure, after the concave portion which is the ink flow path is formed by the etching step, the diaphragm is not directly joined, but the exposure step is performed again on the entire photosensitive glass substrate. I do.
That is, light in the wavelength range required for crystallization of the entire photosensitive glass substrate is irradiated. Then, after that, the developing process is performed again to crystallize the whole. Therefore, the photosensitive glass substrate having the recesses is not crystallized as in the conventional case, but is crystallized as a whole. Since the vibrating plate is attached and joined in that state, adjustment of the thermal expansion coefficient α of the entire photosensitive glass substrate and the vibrating plate, and in the case of using a low-melting glass, adjustment of all the thermal expansion coefficients α, that is, all Can be easily set to a close value. As a result, the vibration plate is accurately joined to the photosensitive glass substrate without leaving strain stress and the like, and the formation state thereof is stabilized.

In the present invention, the vibration plate can be joined after the re-developing step, but it can also be performed at the same time. That is, it may be possible to join the diaphragm at the same time as the redevelopment step by using a low melting point glass or the like that can be joined at the heat treatment temperature in the redevelopment step. By taking such steps, it is possible to reduce the number of processing steps as much as possible.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an explanatory view showing a characteristic process portion of a method of manufacturing an ink jet head according to an embodiment.

FIG. 1A shows a state in which the recess 12 is formed in the glass substrate 10 by the same process as the conventional process described in FIG. In addition, also in this embodiment, as the photosensitive glass substrate 10, SiO ₂ —Li ₂ O—
An Al ₂ O ₃ based photosensitive glass is used. As shown in the figure, in this state, the concave portion 12 of the photosensitive glass substrate 10 is
Only the lower part of the part where the slab is formed is in a crystallized state.

Next, a re-exposure step is performed to expose the entire photosensitive glass substrate 10 again as shown in FIG. In this re-exposure step, the entire photosensitive glass substrate 10 is irradiated with light, and this light has a wavelength range of ultraviolet light (310 nm) necessary to crystallize the entire photosensitive glass substrate 10.
Neighborhood) is used. Next, a redevelopment process is performed as shown in FIG. This is carried out by subjecting the entire photosensitive glass substrate 10 to a latent image in the re-exposure step shown in (B) above to heat treatment in the range of 450 ° C to 620 ° C. Thereby, as shown in the drawing, the photosensitive glass substrate 1
The whole 0 is crystallized. The crystal at this time is lithium metasilicate (Li ₂ O-SiO ₂ ), and the shrinkage rate due to crystallization is about 0.1%. If heat treatment is further performed at about 800 ° C. to 900 ° C. here, it changes to a lithium disilicate (Li ₂ O-2SiO ₂ ) crystal, and the shrinkage ratio of the entire substrate is very large, 2 to 3%. turn into. Therefore, the heat treatment temperature should be 450 ° C to 6 ° C.
It is preferable to carry out the treatment in the range of 20 ° C. and suppress it to the lithium metasilicate crystal.

Then, finally, a vibration plate attaching step of bonding the vibration plate 14 to the surface of the photosensitive glass substrate 10 on which the concave portion 12 is formed is performed. This attachment is performed by direct heat fusion or adhesion through a low melting point glass.

By performing the re-exposure step and the re-development step as described above, it is possible to clearly measure the thermal expansion coefficient of the photosensitive glass substrate 10 at the stage of joining the vibrating plate 14. That is, the photosensitive glass substrate 1
Since 0 is entirely crystallized, its coefficient of thermal expansion can be easily grasped. Therefore, when the diaphragm 14 is bonded, the coefficient of thermal expansion of the diaphragm 14 formed of a glass member and the coefficient of thermal expansion of the bonding agent are set to the coefficient of thermal expansion α of the photosensitive glass substrate 10 that is entirely crystallized.
It becomes easy to adjust to suit. As a result, the bonding state becomes good without strain stress, and the formation state is stabilized.

FIG. 2 is an explanatory view showing main process parts of another embodiment of the present invention.

Since FIGS. 1A and 1B are the same as FIGS. 1A and 1B and the steps are the same, the description thereof will be omitted.

The characteristic feature of this embodiment is that the redeveloping step and the vibrating plate 14 attaching step are carried out simultaneously as shown in FIG.

The heat treatment temperature in the redevelopment step is carried out within the range of 450 ° C. to 620 ° C. as described above. For example, the vibrating plate 14 is provided through a low melting point glass having a melting point within the range.
As a result, the vibrating plate 14 can be simultaneously joined at the stage when the entire photosensitive glass substrate 10 is crystallized. With such a process, it becomes possible to attach the diaphragm 14 in a shorter time than the processing process shown in FIG.

Note that the embodiment of FIG. 2 also has the effect that the stable bonding state of the diaphragm to the photosensitive glass substrate 10 can be maintained, as in the case of the embodiment of FIG.

[0026]

As described above, according to the method of manufacturing an ink jet head of the present invention, the photosensitive glass substrate having the concave portion is not in a partially crystallized state as in the conventional case, but is Since the whole can be crystallized, the coefficient of thermal expansion α can be made uniform. Thus, when the diaphragms are joined by heating, it is possible to adjust both of them and the members used for joining to have a thermal expansion coefficient α that is as equal as possible, and stable joining work can be performed without leaving strain stress. . Therefore, the formation state of the inkjet head is stabilized, and the durability is improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing main steps of a manufacturing method according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the main steps of another embodiment.

FIG. 3 is a cross-sectional view showing a state before being joined to a diaphragm of a photosensitive glass substrate having a concave portion which is an ink flow path in a conventional inkjet head manufacturing process.

[Explanation of symbols]

 10 Photosensitive glass substrate 12 Recessed portion 14 Vibration plate

Claims (1)

[Claims] 1. An exposing step of irradiating a portion of a surface of a photosensitive glass where an ink flow path is to be formed with light, a developing step of crystallizing only a portion exposed by the exposing step, and a crystallization by the developing step. Of the ink jet head, which includes an etching step of forming a concave portion as an ink flow path by etching only the formed portion to a predetermined depth, and a vibrating plate attaching step of fixing the vibrating plate to the surface of the photosensitive glass substrate in which the concave portion is formed. In the manufacturing method, after the etching step, a re-exposure step of irradiating light in a wavelength range necessary for crystallizing the entire photosensitive glass substrate, and after the re-exposure step and before the vibration plate attaching step. Alternatively, at the same time, a redevelopment step of crystallizing the entire photosensitive glass substrate, and a method for manufacturing an inkjet head are performed.