KR20110050205A - Manufacturing method for inkjet head - Google Patents

Abstract

PURPOSE: An ink-jet head manufacturing method is provided to prevent the inflow of foreign materials flowing in a head body in an etching process for patterning an upper electrode. CONSTITUTION: An ink-jet head manufacturing method comprises the following steps. A head body which is formed with a vibration plate on the top thereof is prepared. The upper side of the vibration plate is coated with a lower electrode(S110). Photoresist is patterned so that an open area is formed on the upper part of the vibration plate(S120). The open area is filled with the piezoelectric(S130). The upper side of the piezoelectric and the upper side of the photoresist are coated with a conductive layer(S140). The photoresist is etched, a part of a conductive layer coated on the photoresist is removed, and an upper electrode is patterned on the upper side of the piezoelectric(S150).

Description

Manufacturing method for inkjet head

The present invention relates to a method of manufacturing an inkjet head.

The inkjet head has a structure of various elements such as a pressure chamber, a reservoir, a damper, and a nozzle therein, and each element is individually processed into several layers to complete the manufacturing process by bonding the respective layers. In general, a piezoelectric material (PZT) is used to drive the diaphragm. When a voltage is applied to both surfaces of the piezoelectric body, the crystal structure inside the piezoelectric body changes, causing displacement of the piezoelectric body. This displacement is used to drive the thin film driver bonded to the lower portion.

In keeping with the increasing nozzle density of inkjet heads, which are increasing year by year, the spacing between unit cells for discharging each ink droplet must also be narrowed, and the diaphragm must be thinner, and the piezoelectric thickness must be thinner for this purpose. do.

According to the prior art, in order to form a piezoelectric body in accordance with each cell, after depositing a lower electrode on the upper side of the head body, the piezoelectric body is completely coated using epoxy, and the applied piezoelectric body is applied to each cell using a blade or the like. Will be divided accordingly. At this time, since the lower electrode is thin, a defect in which the blade is cut to the diaphragm when the blade touches the lower electrode occurs, so that the residual layer is present in the piezoelectric body to prevent this.

This residual layer eventually acts as a cause of crosstalk in which the driving force of the piezoelectric body is transferred to the neighboring cells, which causes a poor ejection of ink.

The present invention provides an inkjet head manufacturing method which can prevent crosstalk and can shorten the manufacturing time.

According to an aspect of the invention, the step of preparing a head body provided with a diaphragm; Coating a lower electrode on an upper surface of the diaphragm; Patterning the photoresist such that an open area is formed above the diaphragm; Filling a piezoelectric material in the open area; Coating a conductive layer on an upper surface of the piezoelectric body and an upper surface of the photoresist; And patterning an upper electrode on the upper surface of the piezoelectric material by etching the photoresist to remove a portion of the coated conductive layer on the photoresist.

The method may further include forming an ink injection hole in the head body after the patterning of the upper electrode.

In the meantime, the filling of the piezoelectric material may include depositing the piezoelectric material in the open area and on the upper surface of the resist; And removing a portion of the deposited piezoelectric body so that the top surface of the photoresist is exposed.

According to a preferred embodiment of the present invention, it is possible to prevent crosstalk and to shorten the manufacturing time.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, a preferred embodiment of the inkjet head manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings, in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and Duplicate explanations will be omitted.

1 is a flowchart illustrating a method of manufacturing an inkjet head according to an embodiment of the present invention, and FIGS. 2 to 10 are views illustrating respective processes of the method of manufacturing an inkjet head according to an embodiment of the present invention.

First, as shown in FIG. 2, after preparing the head body 10 having the diaphragm 16 provided thereon, the lower electrode 20 is coated on the upper surface of the diaphragm 16 (S110). In order to coat the lower electrode 20, a method of depositing gold on the upper surface of the diaphragm 16 may be used, but the material and the method are not limited thereto.

The head body 10 is formed with a chamber 13, an reservoir 11, a restrictor 12, a damper 14, a nozzle 15, and the like for drawing ink. The function of each of the components formed on the head body 10 will be described briefly as follows.

The chamber 13 accommodates ink, and when pressure is applied by a driving unit using a piezoelectric body (see 42 in FIG. 10) or the like formed on the upper surface of the diaphragm 16, the contained ink is moved in the direction of the nozzle 15 to inks Means to be discharged. These chambers 13 are arranged in parallel, such as 128 or 256 in one inkjet head, the number of driving units are also provided to provide pressure to each of these chambers 13 .

The reservoir 11 is a means for receiving ink from the outside through the inlet 12 or the like, storing the ink, and supplying ink to the chamber 13 described above.

The restrictor 13 communicates the reservoir 11 and the chamber 13 described above, and is a means for controlling the flow of ink generated between the reservoir 11 and the chamber 13. The restrictor 13 is formed to have a smaller cross-sectional area than the reservoir 11 and the chamber 13, and the amount of ink supplied from the reservoir 11 to the chamber 13 when the diaphragm 16 vibrates by the driving unit. Can be adjusted.

The nozzle 15 is connected to the chamber 13 to receive ink from the chamber 13 and to eject ink. When the vibration generated by the driving unit is transmitted to the chamber 13 through the diaphragm, pressure is applied to the chamber 13, and the nozzle 15 can eject ink by the pressure.

On the other hand, a damper 14 is formed between the chamber 13 and the nozzle 15 described above. The damper 14 may perform a function of concentrating energy generated in the chamber 13 toward the nozzle 15 and buffering a sudden pressure change.

The head body 10 having the respective components described above may be formed by stacking a plurality of substrates made of a material such as silicon or ceramic, but may also be formed of a single substrate.

Then, as shown in FIG. 3, the photoresist 30 is patterned such that the open area 32 is formed above the lower electrode 20 (S120). The open area 32 is an area in which a piezoelectric body (see 42 in FIG. 10), which will function as a driver later, is charged.

Next, the piezoelectric body 42 is filled in the open area 32 (S130). To this end, after depositing the piezoelectric body 40 on the inside of the open area 32 and the upper surface of the photoresist 30 by using a sputtering or E-beam method (see FIG. 4), the upper surface of the photoresist 30 is formed. A part of the piezoelectric body 40 deposited to be exposed may be removed (for example, polished). In order to remove a part of the piezoelectric body 40, a CMP process may be used.

Next, as shown in FIG. 6, the conductive layer 52 is coated on the upper surface of the piezoelectric body 42 and the upper surface of the photoresist 30 (140). To this end, a method of depositing a conductive material that can be used as an upper electrode (see 50 in FIG. 7) on the upper surfaces of the piezoelectric body 42 and the photoresist 30 by sputtering or the like may be used. However, the material and the formation method of the conductive layer 52 are not limited thereto.

Next, as shown in FIG. 7, the photoresist 30 is etched to pattern the upper electrode 50 (S150). When the photoresist 30 is selectively etched while the conductive layer 52 is coated on the upper surface of the piezoelectric body 42 and the photoresist 30, the conductive layer coated on the upper surface of the photoresist 30 is exposed. A portion of 52 can be separated and removed. That is, the upper electrode 50 is patterned by using a lift-off method.

At this time, the photoresist 30 has different reactivity with the piezoelectric material 42, the metal lower electrode 20, the conductive layer 52, and the like, and thus the piezoelectric material 42, the lower electrode 20, and the conductive layer. It is possible to selectively etch only the photoresist 30 without damaging the 52 or the like. As a result, only a part of the conductive layer 52 coated on the upper surface of the piezoelectric body 42 remains, and this part can finally function as the upper electrode 50.

After etching the photoresist 30 to pattern the upper electrode 50, an ink injection hole (see 17 in FIG. 10) is formed in the head body 10 (S160). To this end, the resist 60 is formed so that only the portion of the head body 10 on which the ink injection hole 17 is to be formed is selectively opened (see FIG. 8), and then the head body 10 of the corresponding portion is selectively etched. Can be used (see FIG. 9). After that, the resist 60 is removed (see Fig. 10). As such, when the injection hole is formed after the upper electrode 50 is patterned through the etching of the photoresist 30, foreign substances are introduced into the head body 10 during various etching processes for patterning the upper electrode 50. Can be prevented.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention.

1 is a flow chart showing a method of manufacturing an inkjet head according to an embodiment of the present invention.

2 to 10 is a view showing each step of the inkjet head manufacturing method according to an embodiment of the present invention.

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

10: head body

16: diaphragm

20: lower electrode

30: photoresist

40, 42: piezoelectric

50: upper electrode

52: conductive layer

Claims (3)

Preparing a head body provided with a diaphragm at an upper portion thereof; Coating a lower electrode on an upper surface of the diaphragm; Patterning the photoresist such that an open area is formed above the diaphragm; Filling a piezoelectric material in the open area; Coating a conductive layer on an upper surface of the piezoelectric body and an upper surface of the photoresist; And Etching the photoresist to remove a portion of the coated conductive layer on the photoresist, thereby patterning an upper electrode on the top surface of the piezoelectric body. The method of claim 1, After patterning the upper electrode, An inkjet head manufacturing method comprising the step of forming an ink injection hole in the head body. The method of claim 1, Filling the piezoelectric body, Depositing the piezoelectric body in the open region and on an upper surface of the resist; And Removing a portion of the deposited piezoelectric body so that the top surface of the photoresist is exposed.

Images