KR100637426B1 - Method of the nozzle for ink jet head - Google Patents

Abstract

A method of manufacturing a nozzle for an ink jet head is provided to prevent a wetting phenomenon caused at the nozzle and improve uniformity in the droplet size of ink. A method of manufacturing a nozzle for an ink jet head includes a step of coating a photo resist at the ink jet head structure containing a nozzle unit(50); a step of controlling the exposure condition, exposing the light to the nozzle unit, and removing a part of the photo resist(60); a step of combining a water repellent layer at the removed part of the photo resist of the nozzle unit(70); and a step of removing the photo resist remaining at the nozzle unit(80). The head structure contains more than one of a pressure chamber, an ink injection channel, and a manifold, and the photo resist is liquid.

Description

Method for manufacturing nozzle for ink jet head {Method of the nozzle for ink jet head}

1 is a conceptual view showing a water repellent treatment method of a nozzle for an ink jet head by a conventional composite plating method.

2 is a conceptual view showing a water repellent treatment method of a nozzle for an ink jet head by a conventional vacuum deposition method.

Fig. 3 is a sectional view of the nozzle unit of the nozzle for inkjet head.

Figure 4 is a flow chart showing a manufacturing method of a nozzle for an ink jet head according to an embodiment of the present invention.

5 is a conceptual diagram showing a manufacturing process of a nozzle for an ink jet head according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

120 nozzle part 122 nozzle hole

124: photoresist 141: water repellent layer

The present invention relates to a nozzle, and more particularly to a nozzle for an ink jet head and a method of manufacturing the same.

An inkjet printer is a device that performs printing by applying a driving force to a pressure chamber formed inside the head so that ink droplets are ejected through the nozzle. Ink sprayed through the nozzle of the inkjet head is usually ejected in the form of droplets, and in order to increase the printing function of the inkjet head, the ink must be stably ejected in the form of complete droplets.

To this end, a water repellent (Hydrophobicity) treatment is required at the nozzle portion of the inkjet head, and through this water repellent treatment, a meniscus of the ink droplets is smoothly formed in the nozzle.

In general, the problem that the nozzle surface of the inkjet head does not have water repellency is caused by a wetting phenomenon in which the nozzle surface is wetted by repeated ejection of ink. When such a wetting phenomenon occurs, the ejected ink forms agglomerates with the wet ink on the surface of the nozzle, and the ejected ink flows down without having a complete droplet form. As a result, the printing quality is lowered and the meniscus formed after the ejection of the ink droplets is also unstable. In other words, in order to secure the reliability of printing through the inkjet, it is essential to effectively water repellent the nozzle surface of the inkjet head.

In order to perform a water repellent treatment on a nozzle of an inkjet head, conventionally, a method of forming a nozzle by electroplating, a method of forming a nozzle by micropunching and polishing, and the like have been used. The outlet portion of the nozzle formed by the above methods is an important factor in the size of the ink droplets ejected from the inkjet head, the ink ejection performance, the ink ejection stability, and the continuous ejection.

The conventional electroplating method is a method of semi-permanently plating a water repellent material in a plating bath subjected to a certain length in order to water repellent the nozzle surface of an inkjet printer head. In this case, Teflon-based materials are mainly used for the water repellent material, and PTFE (Polytetrafluroethylene) is representative of Teflon-based materials.

In order to use a water-repellent treatment of the surface of the nozzle using the PTFE, a method of complex plating the PTFE in a plating bath in which a certain length is applied is used. Since the water-repellent treatment method by the composite plating is not directed, the water-repellent layer is formed by plating not only the surface of the nozzle on which the water-repellent layer should be formed, but also the rear surface of the nozzle on which the water-repellent layer should not be formed.

Therefore, when the water repellent treatment is performed by the composite plating method, a pretreatment for preventing the water repellent layer from being formed on the rear surface of the nozzle is further required. That is, in order to water-repellent process only on the surface of the nozzle, conventionally, an insulating film was formed on the rear surface of the nozzle and an insulating film was formed on the rear surface of the nozzle to plate the water repellent layer so that the water-repellent layer was not formed on the rear surface of the nozzle.

Here, the representative material used as the insulating film is a photoresist, and a method of forming an insulating film on the back of the nozzle using the photoresist is illustrated in FIG. 1. 1 is a conceptual diagram showing a water repellent treatment method for a nozzle for an ink jet head by a conventional composite plating method.

Before the water repellent treatment is performed on the nozzle as shown in FIG. 1, the photoresist is first applied to the rear surface of the nozzle 10 by screen printing or the like to form an insulating film 12. After the insulating film 12 is formed, a water repellent layer 14 of PTFE is formed on the surface of the nozzle 10 by a complex plating process which is a general method.

FIG. 2 is a conceptual view illustrating a water repellent treatment method of a nozzle for an ink jet head by a conventional vacuum deposition method. A method of forming a uniform non-conductive thin film using the straightness of vacuum deposition on a rear surface of a nozzle and plating a water repellent material on the entire surface of the nozzle. It is shown.

As shown in FIG. 2, before the water repellent treatment is performed on the front surface of the nozzle 30, the non-conductive thin film 32 is formed on the rear surface of the nozzle by vacuum deposition. The water repellent layer 34 is formed by plating a Teflon-based water repellent material on the entire surface of the nozzle 30 on which the non-conductive thin film 32 is formed. After the water repellent layer 34 is formed, the nozzle 30 is heat treated to complete the water repellent treatment.

Generally, the water repellent layer of the nozzle for inkjet heads is located at the inlet of the nozzle, and is formed to several micrometers inside the nozzle. The above-described methods for forming a water repellent layer of the nozzle for an inkjet head are difficult to completely prevent the water repellent layer from being deposited on the back of the nozzle, and it is difficult to control the water repellent layer to be formed to a uniform depth inside the nozzle. For this reason, there is a problem that the size of the droplets is not uniform or the reliability of repeat printing is lowered during the spraying of the droplets after the water repellent treatment.

In addition, the above-described prior art has a problem that it is difficult to manage the process conditions due to the complicated process, and the yield of the coated nozzle plate for water repellent treatment is low or the degree of coating for each nozzle is uneven.

As a conventional technique related to the water repellent treatment of the nozzle for an inkjet head, first, in the case of a technique of forming a water repellent layer stably by using a contact printing method, there is a problem that it is difficult to form a water repellent layer to a uniform depth inside the nozzle.

Second, in the case of controlling the depth of the water repellent layer by forming an insulating film only on the rear surface of the nozzle, the depth of the water repellent layer is determined during the formation of the insulating film.

Third, in the prior art using the photolithography method, there is a limitation that a process of adjusting exposure conditions in order to uniformly control the depth of the water repellent layer is not disclosed. That is, from the prior art, the present invention of uniformly controlling the depth of the water repellent layer cannot be easily derived by applying a liquid photoresist to the entire nozzle part and removing the photoresist layer by adjusting exposure conditions. There is a limit.

The present invention makes it easy to uniformly control the depth of the water repellent layer by forming a water repellent layer on the nozzle of the inkjet head using a photolithography method, and evenly deposit the depth of the water repellent layer even if the shape of the nozzle back surface is complicated. It is to provide a manufacturing method of a nozzle for an ink jet head that can be controlled.

According to one aspect of the invention, (a) coating a photo resist (Photo Resist) on the inkjet head structure including the nozzle portion, (b) exposure and development of the nozzle portion by adjusting the exposure conditions to a portion of the photoresist There is provided a method of manufacturing a nozzle for an ink jet head, comprising the steps of: removing; (c) bonding the water repellent layer to the portion of the photoresist from which the nozzle portion has been removed; and (d) removing the photoresist remaining in the nozzle portion. do.

The head structure may further include any one or more of a pressure chamber, an ink injection channel, and a manifold. Photoresist is preferably liquid. The exposure conditions may include an exposure time or an exposure amount.

The water repellent layer may include a Teflon-based material or parylene. The water repellent layer is preferably bonded by vacuum deposition or plating.

Step (b) may further include adjusting exposure conditions such that the photoresist coated on the outer surface of the nozzle portion is exposed. Step (b) may further comprise adjusting exposure conditions such that the photoresist is exposed to a predetermined depth of the nozzle. The predetermined depth is preferably uniform along the inner circumferential surface of the nozzle.

Hereinafter, a preferred embodiment of a method of manufacturing a nozzle for an inkjet head according to the present invention will be described in detail with reference to the accompanying drawings, and in the following description with reference to the accompanying drawings, the same or corresponding components regardless of reference numerals The same reference numerals will be given, and redundant description thereof will be omitted.

Fig. 3 is a sectional view showing the nozzle portion of the nozzle for inkjet head. Referring to FIG. 3, the nozzle unit 120a, the nozzle hole 122, and the water repellent layer 141 are illustrated. The present invention is to uniformly control the depth of the water repellent layer formed in the nozzle of the inkjet head, and precisely the depth that the water repellent layer is formed to the inside of the nozzle hole compared to the conventional technique for plating the water repellent layer after depositing an insulating film It is characterized by using a photolithography method to control.

That is, as shown in FIG. 3, the water repellent layer is formed to the inside of the nozzle hole to a predetermined depth so that meniscus formation of ink droplets can be smoothly performed. After coating the photo resist, the exposure conditions such as the exposure time and the exposure amount are adjusted to precisely control the photoresist of the photoresist to a predetermined depth inside the nozzle surface and the inside of the nozzle hole to remove the photoresist layer, and then deposit the water repellent layer. As a result, the depth at which the water repellent layer is deposited is controlled.

4 is a flowchart illustrating a method of manufacturing an inkjet head nozzle according to an exemplary embodiment of the present invention.

In order to form the water repellent layer on the nozzle for the inkjet head according to the present embodiment, first, a photoresist is entirely coated on the surface of the inkjet head structure (50). The inkjet head structure includes a nozzle unit, and in addition, a pressure chamber, an ink injection channel, and a manifold may be included.

The present invention is to control the depth to which the water repellent layer is deposited by coating the photoresist on the surface of the inkjet head structure as a whole, and selectively removing only the portion where the water repellent layer is to be deposited. Even when the structure is already formed, the water repellent layer can be easily formed uniformly.

That is, according to the present invention, the nozzle part of the inkjet head is formed, the water repellent layer is deposited, and the various structures of the head are formed, and the case of depositing the water repellent layer in the nozzle part in the state where the structure of the head is formed is the same. Since the process proceeds, not only the process of depositing the water repellent layer in the nozzle part in the state where the head structure is formed, but also can be easily proceeded without any special technical difficulties.

In order to easily coat the photoresist on the head structure, a photoresist coating layer is formed on the outer surface of the ink jet head structure by applying, spraying, or depositing the entire surface of the ink jet head structure including the nozzle part using a liquid photoresist. It is good to be formed. However, the present invention is not necessarily limited to the methods described above as the coating method of the photoresist, and of course, other methods are also included so that the coating layer is evenly formed on the outer surface of the inkjet head structure within a range apparent to those skilled in the art.

Next, part of the photoresist is removed by exposing and developing the nozzle portion (60). When the photoresist is a photosensitive material and exposed to ultraviolet rays or the like, its properties change to selectively remove or remain only a specific site. In general, the photoresist has exposure conditions such as exposure time and exposure amount determined by the manufacturer in order to reduce the amount by the required amount.

Therefore, by exposing and developing the surface of a nozzle part under appropriate exposure conditions, only the photoresist of a required part can be selectively removed. In addition, as shown in FIG. 3, in order to deposit the water repellent layer to the inside of the nozzle to a predetermined depth, the photoresist must be removed to the inside of the nozzle to the predetermined depth before depositing the water repellent layer, by adjusting the exposure time or the exposure amount. It is possible.

The proper depth at which the water repellent layer is formed to the inside of the nozzle hole depends on the shape of the nozzle part, and in some cases, it may be desirable to prevent the water repellent layer from being formed only on the surface around the nozzle hole, that is, inside the nozzle hole. In this case, the exposure conditions are adjusted so that only the photoresist coated on the outer surface of the nozzle portion is exposed.

On the other hand, in order to deposit the water repellent layer to a predetermined depth at the end of the nozzle hole, the exposure conditions are adjusted so that the photoresist is exposed to a predetermined depth of the nozzle. Of course, in order to make the meniscus shape of the ink droplets smooth, exposure conditions are adjusted such that the depth at which the photoresist is exposed, that is, the depth at which the water repellent layer is deposited, is uniform along the inner circumferential surface of the nozzle.

Next, the water repellent layer is bonded to the portion where the photoresist of the nozzle portion is removed (70). The water repellent layer may be bonded according to the conventional art such as vacuum deposition or plating, but it is apparent to those skilled in the art that a physical bonding method that may be implemented as one step of the photolithography process may be applied without the need for a separate plating process. Since the bonding process of the water repellent layer is obvious to those skilled in the art, detailed description thereof will be omitted.

As described above, the water repellent layer may include Teflon-based material or parylene. Since the material of the water repellent layer is also obvious to those skilled in the art, a detailed description thereof will be omitted.

Finally, the process of forming the water repellent layer in the inkjet head nozzle is completed by removing the photoresist remaining in the nozzle portion (80). The method of removing the photoresist is also apparent to those skilled in the art, so a detailed description thereof will be omitted.

5 is a conceptual diagram illustrating a manufacturing process of a nozzle for an ink jet head according to an exemplary embodiment of the present invention. Referring to FIG. 5, the nozzle unit 120, the nozzle hole 122, the photoresist 124 and 124a, and the water repellent layer 141 are illustrated.

Referring to FIG. 5, the process of forming the water repellent layer 141 on the nozzle unit 120 of the ink jet head according to the present embodiment will be described with reference to FIG. 5. The liquid surface photoresist 124 is entirely coated on the surface as shown in FIG.

Next, in consideration of the depth to be deposited to the water repellent layer 141 to the inside of the nozzle hole 122, the outer surface of the nozzle unit 120 is exposed and developed as shown in FIG. In this process, the depth of formation of the water repellent layer 141 of the nozzle for the inkjet head is determined. As such, when the photolithography process including exposure and development is performed, a part of the photoresist 124 coated on the surface of the nozzle unit 120, that is, the portion where the water repellent layer 141 is to be formed is removed.

The water repellent layer 141 is bonded to a portion where the photoresist 124 of the nozzle unit 120 is removed, that is, a portion where the water repellent layer 141 is to be formed, as shown in FIG. . In this process, as many water repellent layers 141 as necessary for the nozzle for the inkjet head are formed.

Finally, the process of forming the water repellent layer 141 of the nozzle for inkjet head is completed by removing the photoresist 124a remaining on the surface of the nozzle unit 120 as shown in FIG.

Although the technical spirit of the present invention has been described in detail according to the above-described embodiments, the above-described embodiments are for the purpose of description and not of limitation, and a person of ordinary skill in the art will appreciate It will be understood that various embodiments are possible within the scope.

According to the present invention having such a configuration, it is easy to uniformly control the depth of the water repellent layer, and even if the shape of the nozzle rear surface is complicated, the depth of the water repellent layer can be controlled, so that the uniformity of the water repellent nozzles can be controlled. And reproducibility is improved. In addition, since the water-repellent nozzles are uniform, the size of the ink droplets to be ejected is uniform, and the printing performance is improved because a wetting phenomenon does not occur in the nozzle of the inkjet head by the water repellent treatment.

Claims (9)

(a) coating a photoresist on the inkjet head structure including the nozzle portion; (b) exposing and developing the nozzle part to adjust exposure conditions to remove a portion of the photoresist; (c) bonding a water repellent layer to a portion from which the photoresist is removed; And (d) removing the photoresist remaining in the nozzle unit. The method of claim 1, The head structure is a method of manufacturing a nozzle for an ink jet head further comprises any one or more of a pressure chamber, an ink injection channel, a manifold. The method of claim 1, The photoresist (Photo Resist) is a liquid inkjet head nozzle manufacturing method. The method of claim 1, And said exposure conditions include an exposure time or an exposure amount. The method of claim 1, The water repellent layer is a method of manufacturing a nozzle for an ink jet head containing a Teflon-based material or parylene (Parylene). The method of claim 1, The water repellent layer is a method of manufacturing a nozzle for an ink jet head is bonded by a vacuum deposition method or a plating method. The method of claim 1, The step (b) further comprises the step of adjusting the exposure conditions so that the photoresist coated on the outer surface of the nozzle portion is exposed. The method of claim 1, The step (b) further comprises adjusting the exposure conditions such that the photoresist is exposed to a predetermined depth of the nozzle. The method of claim 8, And the predetermined depth is uniform along the inner circumferential surface of the nozzle.

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