KR100708142B1 - Inkjet printhead and method of manufacturing the same - Google Patents

Abstract

An inkjet printhead and a method of manufacturing the same are disclosed. The disclosed inkjet printhead includes a substrate formed through the ink feed hole; A chamber layer provided on the substrate, the chamber layer defining an ink chamber filled with ink flowing from the ink feed hole; It is provided on the chamber layer, and has a nozzle layer in which the nozzle which discharges ink in an ink chamber is provided, Comprising: A chamber layer and a nozzle layer consist of a solid film resist.

Description

Inkjet printhead and method of manufacturing the same

1 to 6B are views for explaining a method of manufacturing a conventional inkjet printhead.

7 to 9B are diagrams for explaining a method of manufacturing another conventional inkjet printhead.

FIG. 10 is a SEM photograph showing a state in which a nozzle layer is swollen when an ink jet print head formed by penetrating an ink feed hole is manufactured by a conventional method of manufacturing an ink jet print head.

11A and 11B are cross-sectional views of inkjet printheads cut in a direction perpendicular to each other according to an embodiment of the present invention.

12 to 15 are views for explaining a method of manufacturing an inkjet printhead according to an embodiment of the present invention.

16 is a SEM photograph showing a cross section of an inkjet printhead manufactured by an inkjet printhead according to an embodiment of the present invention.

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

110 ... substrate 111 ... ink feed hole

112 chamber layer 113 ink chamber

116 ... Nozzle Layer 117 ... Nozzle

The present invention relates to an inkjet printhead and a method of manufacturing the same, and more particularly, to a thermally driven inkjet printhead and a method of manufacturing the same, which can precisely control the thickness of the chamber layer and the nozzle nozzle and simplify the manufacturing process. It is about.

An inkjet printhead is an apparatus for ejecting a small droplet of printing ink to a desired position on a recording sheet to print an image of a predetermined color. Such inkjet printheads can be largely classified in two ways depending on the ejection mechanism of the ink droplets. One is a heat-driven inkjet printhead which generates bubbles in the ink by using a heat source and ejects ink droplets by the expansion force of the bubbles, and the other is ink due to deformation of the piezoelectric body using a piezoelectric body. A piezoelectric drive inkjet printhead which discharges ink droplets by a pressure applied thereto.

The ink droplet ejection mechanism of the thermally driven inkjet printhead will be described in detail as follows. When a pulse current flows through a heater made of a resistive heating element, heat is generated in the heater and the ink adjacent to the heater is instantaneously heated to approximately 300 ° C. Accordingly, as the ink boils, bubbles are generated, and the generated bubbles expand and apply pressure to the ink filled in the ink chamber. This causes the ink near the nozzle to be discharged out of the ink chamber in the form of droplets through the nozzle.

Here, the thermal driving method is further classified into a top-shooting, side-shooting, and back-shooting method according to the bubble growth direction and the ink droplet ejection direction. Can be. In the top-shooting method, the growth direction of the bubble and the ejection direction of the ink droplets are the same. In the side-shooting method, the growth direction of the bubble and the ejection direction of the ink droplets are perpendicular to each other. An ink droplet ejecting method in which the growth direction and the ejecting direction of the ink droplets are opposite to each other.

Such thermally driven inkjet printheads generally must meet the following requirements. First, the production should be as simple as possible, inexpensive to manufacture, and capable of mass production. Second, in order to obtain a high quality image, the distance between adjacent nozzles should be as narrow as possible while suppressing cross talk between adjacent nozzles. In other words, in order to increase dots per inch (DPI), it is necessary to be able to arrange a plurality of nozzles at high density. Third, for high speed printing, the period of refilling ink in the ink chamber after the ink is ejected from the ink chamber should be as short as possible, and at the same time, the heated ink and the heater should be cooled quickly to increase the driving frequency.

1 through 6B are cross-sectional views schematically showing a method of manufacturing a conventional thermally driven inkjet printhead.

Referring to FIG. 1, a chamber layer 12 defining an ink chamber filled with ink to be ejected on a substrate 10 is formed. The chamber layer 12 may be formed by applying a first photoresist on a substrate 10 to a predetermined thickness and patterning the first photoresist. Referring to FIG. 2, the sacrificial layer 15 is formed on the substrate 10 and the chamber layer 12 to fill the ink chamber formed in the chamber layer 12. Here, the sacrificial layer 15 may be formed by applying a second photoresist on the substrate 10 and the chamber layer 12 to a predetermined thickness. Referring to FIG. 3, the sacrificial layer 15 and the chamber layer 12 are planarized by a chemical mechanical polishing (CMP) process. Referring to FIG. 4, a nozzle layer 16 having a nozzle 17 is formed on upper surfaces of the chamber layer 12 and the sacrificial layer 15. Specifically, when the nozzle 17 is formed by applying a third photoresist to a predetermined thickness on the upper surface of the chamber layer 12 and the sacrificial layer 15, and patterning it by a photolithography process, the nozzle layer 16 is completed. Subsequently, when the sacrificial layer 15 is removed with a solvent, an ink chamber 13 is formed in the chamber layer 12 as shown in FIG. 5. 6A and 6B, the inkjet printhead is completed by forming an ink feedhole 11 for supplying ink to the ink chamber 13 by vertically etching the substrate 10. . 6A and 6B are cross-sectional views of the finished inkjet printhead cut in a direction perpendicular to each other.

In the inkjet printhead manufacturing method as described above, the thickness of the chamber layer 12 is determined only by a chemical mechanical polishing (CMP) process. The chemical mechanical polishing process makes the thickness of the chamber layer 12 uniform. It is known to be very difficult, and also increases the process cost. In addition, since the application and removal process of the sacrificial layer 15 is required, the manufacturing process is complicated and the yield is also reduced.

A conventional method for manufacturing a thermally driven inkjet printhead to solve this problem is illustrated in FIGS. 7 to 9B.

Referring to FIG. 7, an ink chamber filled with ink to be ejected on the substrate 20 and a chamber layer 22 defining an ink feed hole for supplying ink to the ink chamber are stacked. The chamber layer 22 may be formed by laminating a first solid film resist on a substrate 20 by a lamination method and then patterning the first solid film resist. Referring to FIG. 8, a second solid film resist 26 ′ is laminated on the upper surface of the chamber layer 22 by a lamination method. 9A and 9B, when the second solid film resist 26 ′ is patterned by a photolithography process to form the nozzle 27, the nozzle layer 26 is formed on the upper surface of the chamber layer 22. ) Is formed. 9A and 9B are cross-sectional views of the finished inkjet printhead cut in a direction perpendicular to each other.

In the inkjet printhead manufacturing method as described above, in order to form the chamber layer 22 and the nozzle layer 26, a solid film resist is used instead of the conventional liquid resist sheet to form the chamber layer 22 and the nozzle layer 26. The thickness can be precisely adjusted, and the manufacturing process is simple.

On the other hand, most of the inkjet printheads currently commercialized have a structure in which ink feed holes for supplying ink to the ink chambers are vertically penetrated to the substrate. However, in order to manufacture an inkjet printhead having such a structure using a solid film resist, process problems arise. Specifically, in the inkjet printhead having a structure in which the ink chamber and the ink feed hole as described above are formed in the chamber layer, the ink chamber is formed when the nozzle layer of the solid film resist is formed on the upper surface of the chamber layer. Through and through. Therefore, no problem arises by the heat treatment process required during lamination and exposure of the solid film resist. However, in an inkjet printhead having a structure in which ink feed holes penetrate perpendicularly to a substrate, air in the ink chamber is not formed when ink feed holes are first formed through the substrate when the nozzle layer is formed on the upper surface of the chamber layer. Is isolated from the outside. Therefore, the air in the ink chamber is expanded during the heat treatment process, thereby causing a phenomenon in which the nozzle layer swells as shown in FIG. 10.

The present invention has been devised to solve the above problems, and provides a thermally driven inkjet printhead and a method of manufacturing the same, which can precisely control the thickness of the chamber layer and the nozzle nozzle and simplify the manufacturing process. There is a purpose.

In order to achieve the above object,

Inkjet printhead according to an embodiment of the present invention,

A substrate formed through the ink feed hole;

A chamber layer provided on the substrate, the chamber layer defining an ink chamber filled with ink flowing from the ink feed hole;

A nozzle layer provided on the chamber layer, the nozzle layer having a nozzle through which ink in the ink chamber is discharged,

The chamber layer and the nozzle layer are made of solid film resist.

Here, the solid film resist is preferably made of an epoxy-based polymer.

Preferably, the ink feed hole is formed perpendicular to the surface of the substrate, and a heater and a conductor for applying a current to the heater are formed on the surface of the substrate forming the bottom surface of the ink chamber.

On the other hand, the manufacturing method of the inkjet printhead according to the embodiment of the present invention,

Forming an ink feed hole through the substrate;

Defining an ink chamber in which ink flowing from the ink feed hole is filled, and forming a chamber layer formed of a first solid film resist on the substrate; And

And forming a nozzle layer on the chamber layer, wherein the nozzle in which the ink in the ink chamber is discharged is formed, and a second solid film resist is formed.

Here, the first and second solid film resist is preferably made of an epoxy-based polymer.

The ink feed hole may be formed by dry etching or wet etching the substrate.

Forming the chamber layer,

Laminating the first solid film resist on the substrate by a lamination method; And

And patterning the first solid film resist by a photolithography process to form the ink chamber.

Forming the nozzle layer,

Laminating the second solid film resist on the chamber layer by a lamination method; And

And forming the nozzle by patterning the second solid film resist by a photolithography process.

The method may further include forming a heater and a conductive wire for applying current to the heater on the substrate forming the bottom surface of the ink chamber before forming the ink feed hole on the substrate.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings refer to like elements, and the size or thickness of each element may be exaggerated for clarity. In addition, when one layer is described as being on top of a substrate or another layer, the layer may be present over and in direct contact with the substrate or another layer, with a third layer in between.

11A and 11B are cross-sectional views of inkjet printheads cut in a direction perpendicular to each other according to an embodiment of the present invention.

11A and 11B, an ink feed hole 111, which is a passage for supplying ink, is formed in the substrate 110 to penetrate perpendicularly to the surface of the substrate 110. In general, a silicon substrate is used as the substrate 110. In addition, a chamber layer 112 is formed on the substrate 110 to define an ink chamber 113 filled with ink flowing from the ink feed hole 111. Here, the chamber layer 112 may be formed by stacking and patterning a solid film resist of a predetermined thickness on a substrate. Here, the solid film resist is preferably made of an epoxy-based polymer having excellent chemical resistance and adhesion. On the other hand, although not shown in the drawing on the surface of the substrate 110 forming the bottom surface of the ink chamber 113, a heater for heating the ink in the ink chamber 113 to generate bubbles and for applying a current to the heater A conductor is formed.

On the chamber layer 112, a nozzle layer 116 having a nozzle 117 through which ink in the ink chamber 113 is discharged to the outside is formed to have a predetermined thickness. Like the chamber layer 112 described above, the nozzle layer 116 may be formed by stacking and patterning a solid film resist having a predetermined thickness. Here, the solid film resist is preferably made of an epoxy-based polymer having excellent chemical resistance and adhesion.

As described above, in the inkjet printhead according to the exemplary embodiment of the present invention, the chamber layer 112 and the nozzle layer 116 are formed by stacking solid film resists having a specified thickness, respectively, so that the chamber layer 112 and the nozzle layer 116 are formed. The thickness of can be adjusted precisely.

Hereinafter, a method of manufacturing an inkjet printhead according to an embodiment of the present invention will be described. 12 to 15 are views for explaining a method of manufacturing an inkjet printhead according to an embodiment of the present invention.

First, referring to FIG. 12, the substrate 110 is prepared. In general, a silicon substrate is used as the substrate 110. Subsequently, the substrate 110 is formed to vertically penetrate the ink feed hole 111 for supplying ink to the ink chamber (113 in FIG. 11A). In this case, the ink feed hole 111 may be formed by dry etching or wet etching the substrate 110. On the other hand, although not shown in the drawing, before forming the ink feed hole 111 in the substrate 110, a current is applied to the heater and the heater on the upper surface of the substrate 110 forming the bottom surface of the ink chamber 113. Lead wires may be formed.

Subsequently, referring to FIG. 13, a chamber layer 112 defining an ink chamber 113 is formed on the substrate 110 formed by penetrating the ink feed hole 111. Specifically, the first solid film resist having a predetermined thickness is laminated on the substrate 110 by a lamination method, and then the first solid film resist is patterned by a photolithography process to form an ink chamber 113. The chamber layer 112 is completed. Here, the first solid film resist is preferably made of an epoxy-based polymer having excellent chemical resistance and adhesion. In the present invention, by forming the chamber layer 112 using a first solid film resist having a predetermined thickness, it is possible to more precisely control the thickness of the chamber layer 112.

Next, referring to FIG. 14, a second solid film resist 116 ′ having a predetermined thickness is stacked on the chamber layer 112 on which the ink chamber 113 is formed. Here, the second solid film resist 116 ′ is deposited on the chamber layer 112 by a lamination method. As described above, the second solid film resist 116 ′ is preferably made of an epoxy polymer having excellent chemical resistance and adhesion.

Finally, referring to FIG. 15, when the second solid film resist 116 ′ is formed with a nozzle 117 for discharging ink in the ink chamber 113 to the outside using a photolithography process, the chamber layer 112 may be formed. ), The nozzle layer 116 is completed. In the present invention, the thickness of the nozzle layer 116 can be more precisely controlled by forming the nozzle layer 116 using the second solid film resist 116 ′ having a predetermined thickness. In addition, since the ink feed hole 111 is formed through the substrate 110 before the nozzle layer 116 is formed, the ink chamber 113 may be formed by the ink feed hole when the nozzle layer 116 is formed. 111) through the outside. Therefore, even if the heat treatment process required for lamination and exposure of the second solid film resist 116 ′ is performed, the phenomenon that the nozzle layer 116 does not swell does not occur. 16 is a SEM photograph showing a cross section of an inkjet printhead made in accordance with the present invention. In FIG. 16, ink feed holes are not shown for convenience. Referring to FIG. 16, it can be seen that the inkjet printhead manufactured according to the present invention did not cause swelling of the nozzle layer 116, which may occur in the conventional method of manufacturing the inkjet printhead.

Although the preferred embodiment according to the present invention has been described above, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

As described above, the inkjet printhead and the manufacturing method thereof according to the present invention have the following effects.

First, an inkjet printhead excellent in chemical resistance and adhesion may be obtained by forming a chamber layer and a nozzle layer using a solid film resist made of an epoxy-based polymer.

Second, as compared with the manufacturing method of a conventional inkjet printhead which forms a sacrificial layer by applying a liquid resist and flattens it, in the present invention, a solid film resist is laminated by a lamination method to form a chamber layer and a nozzle layer. The manufacturing process can be simplified and the yield can be improved.

Third, the solid film resist having a predetermined thickness may be laminated to form the chamber layer and the nozzle layer, thereby precisely controlling the thickness of the chamber layer and the nozzle layer.

Fourth, since the nozzle layer is formed after the ink feed hole is formed in the substrate, the swelling phenomenon of the nozzle layer can be prevented.

Claims (11)

delete delete delete delete Forming an ink feed hole through the substrate; Defining an ink chamber in which ink flowing from the ink feed hole is filled, and forming a chamber layer formed of a first solid film resist on the substrate; And And forming a nozzle layer on the chamber layer, wherein a nozzle is formed to discharge ink in the ink chamber, and a nozzle layer formed of a second solid film resist is formed on the chamber layer. The method of claim 5, Wherein the first and second solid film resists are made of an epoxy-based polymer. The method of claim 5, The ink feed hole is a method of manufacturing an inkjet printhead, characterized in that formed by dry etching or wet etching the substrate. The method of claim 7, wherein And the ink feed hole is formed perpendicular to the surface of the substrate. The method of claim 5, Forming the chamber layer, Laminating the first solid film resist on the substrate by a lamination method; And And patterning the first solid film resist by a photolithography process to form the ink chamber. The method of claim 5, Forming the nozzle layer, Laminating the second solid film resist on the chamber layer by a lamination method; And And forming the nozzle by patterning the second solid film resist by a photolithography process. The method of claim 5, And forming a heater and a conductive wire for applying current to the heater on the substrate forming the bottom surface of the ink chamber before the ink feed hole is formed on the substrate. Manufacturing method.

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