KR101020853B1 - Ink-jet head and manufacturing method thereof - Google Patents

Abstract

An inkjet head and a method of manufacturing the same are disclosed. An inkjet including a reservoir for storing ink, an inlet for supplying ink to the reservoir, a chamber for receiving ink from the reservoir, a restrictor for connecting the reservoir and the chamber, a nozzle for discharging ink, and a damper portion interposed between the chamber and the nozzle A method of manufacturing a head, comprising: preparing an SOI substrate having an insulating layer interposed between an upper silicon layer and a lower silicon layer; Etching the lower silicon layer to correspond to the top of the chamber, the restrictor, and the reservoir; Etching the upper silicon layer to correspond to an inlet in communication with the reservoir; Machining a first plate of glass material in correspondence with the damper portion and the reservoir; Processing a second plate of silicon material, corresponding to the nozzle; And bonding the SOI substrate to the top surface of the first plate, and bonding the second plate to the bottom surface of the first plate, which can improve productivity and based on a wary coupling force between the components. To ensure stable quality.

Inkjet, Head, SOI Substrates, Bipolar Bonding, Restrictors

Description

Inkjet head and manufacturing method thereof

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

The inkjet head uses a principle that converts an electrical signal into a physical force so that ink is ejected in the form of droplets through a small nozzle. Such an inkjet head is manufactured by processing various components such as a chamber, a restrictor, a nozzle, a damper, and the like on each layer, and then bonding the processed layers to each other. The inkjet technology is not only used in the graphic inkjet industry for printing on paper and textiles, but also recently, the use of inkjet technology has been expanded to manufacture electronic components such as print-based and LCD panels.

However, the inkjet printing technology for electronic components, which requires accurate and precise ejection of functional inks compared to conventional graphic printing, requires functions not required in the conventional inkjet head. For example, variations in the size and speed of discharge droplets are basically required, and in addition, high nozzle density and high frequency characteristics are required to increase production.

Conventional inkjet heads are mainly made of stainless steel (SUS), high-temperature ceramics and single crystal silicon. In the case of SUS, a head made of a single crystal silicon material has recently attracted attention because it is not easy to change the design due to the manufacture using a mold. In the production method using a single crystal silicon wafer, elements having respective functions are formed by bonding two or three wafers separately.

In general, a structure using silicon direct bonding first processes each wafer using a MEMS process, and then joins the wafers together. Unlike the semiconductor process, a general MEMS process has many rough processes, such as etching silicon from tens to hundreds of microns or performing deposition of several microns. Therefore, after performing this process, the surface becomes a lot rough or stressful state. If the silicon direct bonding is to be performed with such a wafer, the yield drops below 50 to 70%.

The present invention provides a method of manufacturing an inkjet head using a highly productive anodic bonding method without using a low yield silicon direct bonding method.

According to an aspect of the present invention, a reservoir for storing ink, an inlet for supplying ink to the reservoir, a chamber for receiving ink from the reservoir, a restrictor for connecting the reservoir and the chamber, a nozzle for discharging ink, and a chamber between the nozzle and the nozzle A method of manufacturing an inkjet head including a damper portion interposed therebetween, comprising: preparing an SOI substrate having an insulating layer interposed between an upper silicon layer and a lower silicon layer; Etching the lower silicon layer to correspond to the top of the chamber, the restrictor, and the reservoir; Etching the upper silicon layer to correspond to an inlet in communication with the reservoir; Machining a first plate of glass material in correspondence with the damper portion and the reservoir; Processing a second plate of silicon material, corresponding to the nozzle; And bonding the SOI substrate to the top surface of the first plate, and bonding the second plate to the bottom surface of the first plate.

The etching of the lower silicon layer may be performed so that the depths of the regions corresponding to the chambers, the regions corresponding to the restrictors, and the regions corresponding to the tops of the reservoirs are the same. In this case, the insulating layer or the upper silicon layer may be exposed.

Meanwhile, the polishing of the upper silicon layer may be further performed, and the nozzle may include an inclined portion connected to the damper portion and a straight portion connected to the inclined portion.

According to another aspect of the present invention, a reservoir for storing ink, an inlet for supplying ink to the reservoir, a chamber for receiving ink from the reservoir, a restrictor for connecting the reservoir and the chamber, a nozzle for discharging ink, and a chamber and the nozzle between the nozzles An inkjet head including a damper part interposed therebetween, wherein the inkjet head has an insulating layer interposed between an upper silicon layer and a lower silicon layer, and an upper part of a chamber, a restrictor, and a reservoir is formed on the lower silicon layer, and an upper silicon. An SOI substrate having an inlet in communication with the reservoir in the layer; A first plate of glass material bonded to a bottom surface of the SOI substrate and having a damper portion and a reservoir formed thereon; And a second plate bonded to a lower surface of the first plate and having a nozzle formed thereon.

The depths of the chamber and the restrictor may be the same, and an insulating layer or an upper silicon layer may be exposed on the upper surfaces of the chamber and the restrictor.

The nozzle may include an inclined portion connected to the damper portion, and a straight portion connected to the inclined portion.

According to a preferred embodiment of the present invention, the productivity can be improved, and stable quality can be ensured based on the warning coupling force between the respective components.

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.

Hereinafter, preferred embodiments of an inkjet head and a method of manufacturing the same 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 numbers Duplicate description thereof 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 7 are views illustrating respective processes of the method of manufacturing an inkjet head according to an embodiment of the present invention. 2 to 7, the chamber 12, the reservoir 13, the restrictor 14, the damper portion 15, the inlet 16, the nozzle 17, the SOI substrate 20, the upper silicon layer 21, insulating layer 22, lower silicon layer 23, first plate 30, and second plate 40 are shown.

Before describing the inkjet head manufacturing method according to the present embodiment in detail, the components of the above-described inkjet head will be briefly described with reference to FIG. 7.

The chamber 12 accommodates ink and, when pressure is applied by an actuator (not shown) formed on the upper surface of the diaphragm 21, means for moving the contained ink toward the nozzle 17 so that the ink can be discharged. to be.

The reservoir 13 is a means for receiving ink from the outside through the inlet 16 and the like, storing the ink, and supplying ink to the chamber 12 described above.

The restrictor 14 communicates the reservoir 13 and the chamber 12 described above, and is a means for controlling the flow of ink generated between the reservoir 13 and the chamber 12. The restrictor 14 is formed to have a smaller cross-sectional area than the reservoir 13 and the chamber 12, and is supplied from the reservoir 13 to the chamber 12 when the diaphragm 21 vibrates by an actuator (not shown). The amount of ink to be adjusted can be adjusted.

The nozzle 17 is connected to the chamber 12 to receive ink from the chamber 12 and to eject ink. When the vibration generated by the actuator is transmitted to the chamber 12 through the diaphragm 21, pressure is applied to the chamber 12, and the nozzle 17 can eject ink by the pressure.

On the other hand, the damper portion 15 is formed between the chamber 12 and the nozzle 17 described above. The damper unit 15 may function to concentrate energy generated in the chamber 12 toward the nozzle 17 and buffer a sudden pressure change.

In order to form the above-described components, the present embodiment proposes a method of using two silicon substrates 20 and 40 and one glass substrate 30. That is, the above components are formed by dividing the two components on the silicon substrates 20 and 40 and the glass substrate 30 and then bonding them to manufacture the inkjet head. Hereinafter, this will be described in more detail.

First, an SOI substrate 20 having an insulating layer 22 is interposed between the upper silicon layer 21 and the lower silicon layer 23 (S110), the chamber 12, the restrictor 14, And etching the lower silicon layer 23 to correspond to the top of the reservoir 13 (S120), and etching the upper silicon layer 21 to correspond to the inlet 16 communicating with the reservoir 13 ( S130). That is, as shown in FIG. 2, both surfaces of the SOI substrate 20 are processed according to the shape of the chamber 12, the restrictor 14, the inlet 16, and the part of the reservoir 13. As a method of etching the upper silicon layer 21 and the lower silicon layer 23, a dry reactive ion etching (DRIE) process, which is advantageous for vertical shape control, may be used, and various other physical / chemical etching methods may be used. Of course.

In this case, the lower silicon layer 23 may be etched so that the depth of the region corresponding to the chamber 12, the region corresponding to the restrictor 14, and the region corresponding to the upper portion of the reservoir 13 are the same. . In other words, the restrictor 14 is arranged in a straight line between the chamber 12 and the reservoir 13.

On the other hand, considering that the resistance of the fluid, such as ink, is generated by the wall effect (viscosity effect of the fluid sliding on the wall), as shown in Figure 3, narrow the distance between both side walls of the restrictor 14 Can be designed. At this time, the resistance of the fluid such as ink is also increased by the narrower length, so that the length of the restrictor 14 can be relatively short. The restrictor 14 produced in such a shape has a rectangular parallelepiped shape as shown in FIG. 3.

The rectangular parallelepiped restrictor 14 is formed in a straight line between the chamber 12 and the reservoir 13, thereby minimizing a crosstalk phenomenon which greatly affects the ejection characteristics of the ink. In addition, a step is not formed between the restrictor 14 and the reservoir 13, so that the discharge deviation can also be minimized.

As described above, in order to ensure that the depth of the region corresponding to the chamber 12, the region corresponding to the restrictor 14, and the region corresponding to the top of the reservoir 13 are equally formed, the lower silicon layer ( 23 may be used to perform etching so that the insulating layer 22 or the upper silicon layer 21 is exposed. In this case, the insulating layer 22 located between the upper and lower silicon layers 23 can function as an etch stop, so that the depths of the chamber 12 and the restrictor 14 and the like can be more stably provided. It can be secured.

Meanwhile, as shown in FIG. 2, since the upper silicon layer 21 functions as a diaphragm, when the upper silicon layer 21 is thicker than the diaphragm to be formed, the thickness of the intended diaphragm is polished by polishing it. Can be secured. As a method of polishing the upper silicon layer 21, a chemical mechanical polishing (CMP) process or the like may be used.

Separately, as shown in FIG. 4, the first plate 30 made of glass is processed in correspondence with the damper part 15 and the reservoir 13 (S140). In order to process the first plate 30, methods such as sandblasting and drilling may be used.

Thereafter, a process of trimming the roughness of the inner wall of the first plate 30 may be performed, and the thickness of the first plate 30 may be adjusted using a CMP process or the like. In order to refine the roughness of the inner wall of the first plate 30, a method of introducing the first plate 30 into an aqueous solution containing HF may be used.

In this case, since the roughness of the inner wall of the first plate 30 is refined and the surface of the first plate 30 may also be etched, a change in state may occur. The process of adjusting the roughness of the surface may be further performed.

Separately, as shown in FIG. 5, the second plate 40 made of silicon is processed in correspondence to the nozzle 17 (S150). To this end, a method of preparing a second plate 40 of silicon material having a suitable thickness, processing the desired thickness using a CMP process, or the like, and then forming a nozzle 17 may be used.

 Meanwhile, as shown in FIG. 5, the nozzle 17 may include an inclined portion 17a connected to the damper portion 15 and a straight portion 17b connected to the inclined portion 17a. That is, the angle of the interface between the nozzle 17 and the damper portion 15 is formed at an obtuse angle. Through such an obtuse structure, it is possible to reduce the possibility of micro bubbles being formed at the interface between the nozzle 17 and the damper portion 15. Further, by forming only a part of the nozzle 17 as the inclined surface 17a and forming the remaining part as the straight surface 17b, the straightness of the ejected ink can also be ensured. Based on the above, it is possible to expect the effect of improving the quality of printing.

Then, the SOI substrate 20 is bonded to the upper surface of the first plate 30, and the second plate 40 is bonded to the lower surface of the first plate 30 (S160). When the glass substrate 30 is bonded between two silicon substrates 20 and 40 as in the present embodiment, the anodic bonding between the silicon and the glass can be realized at each bonding surface. It is possible to expect improved product reliability based on strong bonding force. Of course, the bonding order between the substrates can be variously changed according to the process needs.

7 is a view illustrating an ink jet head manufactured through the process described above. The inkjet head is bonded by arranging the glass substrate 30 between the two silicon substrates 20 and 40, thereby improving reliability of the product based on a firm bonding force.

In addition, through the obtuse angle structure of the interface between the nozzle 17 and the damper portion 15, it is possible to reduce the possibility of the microbubble is formed at the interface between the nozzle 17 and the damper portion 15. Further, by forming only a part of the nozzle 17 as the inclined surface 17a and forming the remaining part as the straight surface 17b, the straightness of the ejected ink can also be ensured. Based on the above, it is possible to expect the effect of improving the quality of printing.

In addition, the rectangular parallelepiped restrictor 14 is formed in a straight line between the chamber 12 and the reservoir 13, thereby minimizing the crosstalk phenomenon which greatly affects the ejection characteristics of the ink, and the restrictor 14 ), And a step is not formed between the reservoir 13 and the discharge deviation can also be minimized.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

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 7 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>

12: chamber 13: reservoir

14: List 15: Damper

16: inlet 17: nozzle

20: SOI substrate 21: upper silicon layer

22: insulating layer 23: lower silicon layer

30: first plate 40: second plate

Claims (9)

A reservoir for storing ink, an inlet port through which ink is supplied to the reservoir, a chamber for receiving ink from the reservoir, a restrictor connecting the reservoir and the chamber, a nozzle for discharging ink, and an interposition between the chamber and the nozzle A method of manufacturing an inkjet head comprising a damper portion, Preparing an SOI substrate having an insulating layer interposed between an upper silicon layer and a lower silicon layer; Etching the lower silicon layer to correspond to an upper portion of the chamber, the restrictor, and the reservoir; Wherein the depth of the region corresponding to the chamber, the region corresponding to the restrictor, and the region corresponding to the top of the reservoir are etched to be equal. Etching the upper silicon layer to correspond to the inlet in communication with the reservoir; Machining a first plate of glass material corresponding to the damper part and the reservoir; Processing a second plate of silicon material corresponding to the nozzle; And Bonding an SOI substrate to an upper surface of the first plate, and bonding the second plate to a lower surface of the first plate. delete The method of claim 1, Etching the lower silicon layer, And the insulating layer or the upper silicon layer is exposed. The method of claim 1, And polishing the upper silicon layer. The method of claim 1, The nozzle, An inclined portion connected to the damper portion, and Inkjet head manufacturing method comprising a straight portion connected to the inclined portion. A reservoir for storing ink, an inlet port through which ink is supplied to the reservoir, a chamber for receiving ink from the reservoir, a restrictor connecting the reservoir and the chamber, a nozzle for discharging ink, and an interposition between the chamber and the nozzle An inkjet head comprising a damper portion, An insulating layer is interposed between an upper silicon layer and a lower silicon layer, and an upper portion of the chamber, the restrictor, and the reservoir is formed in the lower silicon layer, and the upper silicon layer is in communication with the reservoir. An SOI substrate on which the inlet is formed; Wherein the depths of the chamber and the restrictor are the same. A first plate of glass material bonded to a bottom surface of the SOI substrate and having the damper portion and the reservoir formed thereon; And An inkjet head bonded to a lower surface of the first plate and including a second plate made of a silicon material on which the nozzle is formed. delete The method of claim 6, And the insulating layer or the upper silicon layer is exposed on upper surfaces of the chamber and the restrictor. The method of claim 6, The nozzle, An inclined portion connected to the damper portion, and And a straight portion connected to the inclined portion.

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