KR100897550B1 - Manufacturing method of ink-jet head - Google Patents

Abstract

Disclosed is a method of manufacturing an inkjet head. A method of forming an electrode pad for a piezoelectric element on the membrane of the inkjet head including a membrane and an ink inlet on one surface, the method comprising: shielding the ink inlet by applying a mask having a portion corresponding to the membrane on one surface of the inkjet head; An inkjet head manufacturing method comprising covering a conductive material on one surface of the inkjet head to which a mask is applied, and forming an electrode pad by removing the mask, contamination of an inkjet head that may occur during the manufacturing process of the inkjet head. Can be prevented, thereby increasing the production yield of the inkjet head.

Inkjet, head, electrode pad, mask

Description

Manufacturing method of ink-jet head

1 is a process chart showing the electrode pad formation of the inkjet head according to the prior art.

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

Figure 3 is a process chart showing the inkjet head manufacturing method according to an embodiment of the present invention.

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

310: inkjet head 311: upper substrate

312: intermediate substrate 313: lower substrate

314: ink inlet 315: membrane

316: nozzle 320: mask

330: electrode pad 331: lower electrode pad

332: upper electrode pad 340: conductive resin

350: piezoelectric element 351: piezoelectric material

352: upper electrode 353: lower electrode

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

Inkjet heads can be classified into thermal transfer methods and piezoelectric methods. The thermal transfer inkjet head is equipped with a resistance element and discharges ink by using a bubble generation phenomenon caused by temperature change. In the piezoelectric inkjet head, the piezoelectric element drives the membrane to change the volume of the ink chamber according to the application of the driving voltage, thereby discharging ink. Since the size of the nozzle from which ink is discharged is very small, nozzle clogging occurs even with fine impurities, resulting in deterioration of print quality.

1 is a process chart of the manufacturing method of the ink jet head according to the prior art. The substrates 111, 112, and 113 are combined to form a printer head chamber part 110 including an opening, and the metal thin film 120 is stacked on one surface of the chamber part. The photoresist is applied to the metal thin film 130 and then subjected to an exposure process and an etching process, leaving only the photoresist 131 and the metal thin film 121 at positions corresponding to the membrane, and then removing the photoresist. The electrode pad 121 is formed. In this case, since wet fixing such as an etching process is used, the inside of the inkjet head is more likely to be contaminated by foreign matter. In addition, since it is difficult to maintain the surface state inside the inkjet head uniformly, there is a high possibility of bubble generation during ink priming, which causes ink discharge failure.

The present invention provides a method of manufacturing a lower electrode that prevents the introduction of impurities into the inkjet head by applying a mask.

According to an aspect of the present invention, a method for forming an electrode pad for a piezoelectric element in the membrane of the inkjet head including a membrane and an ink inlet on one surface, applying a mask having a portion corresponding to the membrane on one surface of the inkjet head Thereby shielding the ink inlet, covering a conductive material on one surface of the inkjet head to which the mask is applied, and removing the mask to form the electrode pad.

The inkjet head manufacturing method may be performed by combining a piezoelectric element electrically connected to the electrode pad after formation of the electrode pad. Coupling the piezoelectric element may be performed by applying a conductive resin to the electrode pad and adhering the piezoelectric element to the conductive resin.

The conductive material covering step may include depositing a conductive material at a position corresponding to the opening of the mask, and also filling the perforated portion of the mask by screen printing, and sintering the conductive material. It may include the step.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

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

2 is a flowchart illustrating a method of manufacturing an inkjet head according to an embodiment of the present invention. 3 is a process chart showing the inkjet head manufacturing method according to an embodiment of the present invention. Referring to FIG. 3, the inkjet head 310, the substrates 311, 312, and 313, the ink inlet 314, the membrane 315, the nozzle 316, the mask 320, the electrode pad 330, and the lower electrode The pad 331, the upper electrode pad 332, the conductive resin 340, the piezoelectric element 350, the piezoelectric material 351, the upper electrode 352, and the lower electrode 353 are illustrated.

The present embodiment is characterized in that the electrode pad forming step is performed while the ink inlet is shielded during the inkjet head manufacturing process.

Shielding the ink inlet by using a mask (S210) is a step of shielding the ink inlet formed on one surface of the inkjet head by using a mask, which will be described with reference to FIGS. 3A to 3C.

The inkjet head 310 includes a nozzle 316 through which ink is discharged and a chamber which is a space where ink before discharge is stored. As shown in (a) of FIG. 3, the inkjet head 310 may form a structure necessary for two or more substrates, and then combine the substrates with each other. An ink inlet 314 and a membrane 315 are formed in the upper substrate 311.

Referring to FIG. 3B, the membrane 315 formed on the upper substrate may be deformed by the piezoelectric element to change the volume of the chamber of the inkjet head 310. The intermediate substrate 312 serves to connect the upper substrate 311 and the lower substrate 313, and a nozzle 316, which is a passage through which ink is discharged, is perforated in the lower substrate 313.

As such, each substrate 311, 312, and 313 constituting the inkjet head may be formed by processing a wafer of the same material, or may be formed of a different material. The bonding method between the substrates constituting the inkjet head 310 may be variously selected depending on the materials forming the substrate, such as silicon direct bonding in the case of silicon substrates and anodical bonding in the case of silicon-glass substrates.

In order to manufacture the inkjet head according to the present embodiment, first, as shown in FIG. 3C, a mask 320 is used to shield the ink inlet 314. The mask may be made of various materials. If the material suitable for the process used in the subsequent electrode pad forming step (S230) may be a mask 320, for example, may be made of quartz glass or metal.

The mask 320 is positioned in contact with the upper substrate 311 where the ink inlet 314 is located, and prevents foreign substances from flowing through the ink inlet 314 during the manufacturing process of the inkjet head. In this embodiment, a membrane portion is perforated in the mask 320 that shields the ink inlet 314.

Covering the conductive material to the mask in contact with the upper substrate (S220), the mask is applied so as to shield the ink inlet located on one side of the inkjet head, that is, with the surface of the inkjet head and the mask on or attached to the inkjet head Depositing a conductive material on the applied mask.

In the present embodiment, 'applying a mask' is a concept including a case in which a conductive material, which will be described later, is selectively masked on one surface of an inkjet head by a mask.

The conductive material covering step S220 is described with reference to FIG. Since the mask 320 has openings perforated at the location of the membrane 315, the inkjet corresponding to the location of the membrane 315 even when the mask 320 is applied to the inkjet head to shield the ink inlet 314. One side of the head is exposed. Therefore, the conductive material may be bonded to one surface of the exposed inkjet head through a process such as vapor deposition and sputtering.

Meanwhile, screen printing may be used to stack conductive materials to have a shape corresponding to the perforated pattern of the mask.

Removing the mask to form the electrode pad (S230) is a step of forming the electrode pad on one surface of the inkjet head. Forming an electrode pad (S230) will be described with reference to FIG. In this embodiment, when the mask 320 is removed after the conductive material is deposited, the conductive material corresponding to the perforation pattern of the mask remains on one surface of the inkjet head, which forms the electrode pad 330.

The formed electrode pad 330 includes a lower electrode pad 331 and an upper electrode pad 332. The lower electrode pad may serve as a common electrode in the piezoelectric inkjet head, and the upper electrode pad may serve as a passage for applying power to the upper electrode of the piezoelectric element. The electrode pad may be designed in various forms at different positions according to the position or shape of the electrode of the piezoelectric element.

On the other hand, when the screen printing technique is used, the conductive material in the form of a paste is cured through a high temperature sintering process to form the electrode pad 330.

Joining the piezoelectric elements (S240) is a step of coupling the piezoelectric elements to be electrically connected to the electrode pads formed on one surface of the inkjet head. Coupling the piezoelectric elements is described with reference to FIGS. 3F and 3G.

The conductive resin 340 is applied to the electrode pad 330. In this embodiment, since the piezoelectric element 350 is coupled to the lower electrode pad 331, a conductive resin is coated on the lower electrode pad for electrical connection with the lower electrode pad. The piezoelectric element 350 has a structure in which electrodes 352 and 353 are formed on both surfaces of the piezoelectric material 351, and the upper electrode 352 and the lower electrode 353 respectively have an upper electrode pad 332 and a lower electrode pad ( 331 may be electrically connected. The piezoelectric element 350 is bonded to the lower electrode pad 331 by the conductive resin 340.

As the conductive resin 340, a kind of resin in which a conductive filler is blended may be used. For example, epoxy, polyimide, acrylic resin, etc. may be used as the resin in which the conductive filler is blended. Materials used as conductive fillers include gold, silver, copper, palladium, and carbon. In addition, an intrinsically conductive polymer (ICP) having conductivity in the material itself may be used as the conductive resin 340.

Although not directly shown in FIG. 3, a wire bonding process or a process of stacking a separate conductive material may be additionally performed to electrically connect the upper electrode 352 and the upper electrode pad 332.

So far, the present invention has been described with reference to the embodiments. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

As described above, according to the preferred embodiment of the present invention, it is possible to prevent contamination inside the inkjet head which may occur during the manufacturing process of the inkjet head, thereby increasing the manufacturing yield of the inkjet head.

In addition, the printer head may be manufactured without a high temperature sintering process by forming a print head by attaching a piezoelectric element in a bulk state in which upper and lower electrodes are formed on the piezoelectric material by using a conductive resin layer. This ensures that the lower electrode is not limited to a paste type that can withstand the high temperature sintering process.

Claims (5)

A method of forming an electrode pad for a piezoelectric element on the membrane of the inkjet head comprising a membrane and an ink inlet on one surface, Shielding the ink inlet by applying a mask in which a portion corresponding to the membrane is perforated on one surface of the inkjet head; Covering a conductive material on one surface of the inkjet head to which the mask is applied; And Removing the mask to form the electrode pads. The method of claim 1, After the electrode pad forming step, Coupling the piezoelectric element electrically connected to the electrode pad to the membrane. The method of claim 2, The piezoelectric element coupling step, Applying a conductive resin to the electrode pad; And And attaching the piezoelectric element to the conductive resin. The method according to claim 1 or 3, The conductive material cover step, And depositing the conductive material at a position corresponding to an opening of the mask. The method of claim 1 or 3. The conductive material cover step, Filling the conductive material in the perforated portion of the mask by screen printing; And Inkjet head manufacturing method comprising the step of sintering the conductive material.

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