KR100677752B1 - Ink-jet printer head and method of manufacturing thereof - Google Patents

Abstract

The present invention discloses an inkjet printhead in which a pair of nozzle holes are correspondingly arranged in a common unit ink chamber, and a method of manufacturing the inkjet printhead. The substrate is formed such that an ink flow path to which ink is supplied forms a cavity, and both sides of outlets of the ink flow path. A pair of drive heat generating units provided on the substrate so as to correspond to the ink; an ink chamber barrier stacked on the substrate so as to form sidewalls of the ink chambers filled with ink; And a nozzle plate having a nozzle hole communicating with each other and stacked on the upper surface of the ink chamber barrier, the pair of nozzle holes can discharge the ink without being influenced by the ink replenishment time, and thus the printing speed is higher than in the prior art. Can be improved by two or more times.

Description

Inkjet print head and method of manufacturing the same

1 is a perspective view of an inkjet print head having a conventional center feeding ejection structure,

2 is a cross-sectional view of an inkjet print head having a conventional edge feeding ejection structure,

3 is a cross-sectional view of an inkjet print head according to the present invention;

4 is a schematic plan view of an inkjet print head according to the present invention;

5A to 5E are process diagrams sequentially showing a method of manufacturing an inkjet print head according to the present invention.

      Explanation of symbols on the main parts of the drawings

      31 substrate 36 ink supply path

      32: manifold 37: ink chamber barrier

      33a, 33b: Heat generating resistor 38a, 38b: nozzle hole

      34: electrode layer 40: ink chamber

      35: protective layer 50, 51: drive heat generating portion

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printhead and a method of manufacturing the same, and more particularly, to an inkjet printhead and a method of manufacturing the same, which improves printing speed by increasing the number of nozzle holes corresponding to a unit ink chamber.

In general, an inkjet printhead in which a plurality of unit ejection structures are arranged in a predetermined pattern is largely divided into a center feeding and an edge feeding method according to the ink ejection structure.

In general, the center-feeding inkjet print head generates heat on both substrates of the ink supply passage 6 formed as a passage in the center of the substrate 1 so as to be connected to the ink chamber 10, as shown in FIG. The resistor 3 has a structure in which the resistors 3 are arranged in a row.

The heat generating resistor 3 converts an electrical signal applied from the outside into thermal energy to form bubbles by heating the ink thereon at a high temperature. In this way, the pressure inside the bubble formed at a high temperature reaches a high pressure of several tens of atmospheric pressure, and the bubble is expanded using this as a driving force to push the ink in the ink chamber 10 toward the nozzle hole 8 to eject and spray the ink.

When the electrical signal applied to the heat generating resistor 3 is cut off, the supply of heat energy to the bubble is blocked, and the bubble that consumes energy to drive the surrounding ink loses its expansion force and contracts, thereby allowing the ink flow direction of the ink chamber. (10) It serves to break the ink droplet pillar by changing the direction to flow into the inside to eject the ink to the print medium. After the bubble shrinking step and the complete shrinking, when the ink is refilled into the ink chamber 10 by the surface tension in the nozzle hole 8, the ejecting process of the ink is completed.                         

On the other hand, the edge-feeding inkjet print head is a space formed between the substrate 11 and the ink chamber barrier 17 without forming a separate ink supply path inside the substrate 11, as shown in FIG. It is configured to serve as an additional ink supply path 16, and ink supplied through the ink supply path 16 is temporarily filled in the ink chamber 20. As shown in FIG.

However, the above conventional technology has the following problems.

In the case of the center feeding method of FIG. 1, the ink supply path 6 is formed inside the substrate 1, which is processed by sand blasting or laser, and wet etching the bottom surface of the substrate 1 by wet etching. There is a way to form.

In consideration of the processing margins of the above two methods, the interval between the nozzle holes 8 located at both ends of the processed ink supply passage 6 should be about 0.6 mm or more. The ink ejecting structure has a limitation in multi-array arrangement, and also a large stress is generated in the substrate 1 when the ink supply path 6 is processed, and the residual area of the substrate 1 is reduced after processing, so that the substrate 1 There is a problem that becomes very vulnerable.

On the other hand, in the edge feeding method of FIG. 2, since there is no process of forming the ink supply path 16 inside the substrate 11, there is no problem in that the substrate 11 is weak, but the substrate 11 is a nozzle plate. Since it is coupled to (19), a large bending stress is generated at both ends of the substrate 11 due to the high pressure of a bubble (not shown) that is expanded by the heat energy of the heat generating resistor 13, so that the strength of the substrate 11 is weak. You lose. In addition, due to the pressure of the ink flowing from the side of the heat generating resistor 13, the heat generating resistor 13 and the substrate 11 are subjected to a large shear force.

Therefore, in order to structurally stabilize the nozzle plate 19 and the substrate 11, the area of the adhesive layer bonded to the nozzle plate 19 should be widened. Therefore, the substrate 11 eventually becomes large, and the ink supply path 16 on the side of the substrate 11 also needs to maintain a separate space, so that the space occupied by the ink ejecting structure becomes large, so that the distance from the neighboring nozzles is increased. Since the ink jet print head has a large size, it is difficult to arrange a double nozzle, so that the printing speed cannot be improved.

The present invention has been made to improve the problems of the conventional inkjet printer head as described above, and by forming an ink supply passage having a smaller width than the conventional one to reduce the arrangement interval of the nozzle, it is formed in a compact ink ejection structure An object of the present invention is to provide an inkjet printhead and a method of manufacturing the same, which can improve the printing speed by two or more by arranging nozzles in two or more.

An inkjet printhead according to the present invention for achieving the above object, a pair of driving is provided on the substrate so as to correspond to the substrate formed so that the ink flow path is supplied ink, and respectively on both sides of the outlet of the ink flow path A pair of heat generating portions, a pair of driving heat generating portions, an ink chamber barrier stacked on the substrate to form sidewalls of an ink chamber filled with ink, and a pair of corresponding heat generating portions respectively positioned above the pair of driving heat generating portions; And a nozzle plate having a nozzle hole and stacked on an upper surface of the ink chamber barrier.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, in the inkjet printhead according to the present invention, ink passages 32 and 36 through which ink is supplied to the substrate 31 are vertically formed, and the ink passages 32 and 36 are formed of a substrate ( A manifold 32 formed to form a first cavity having a predetermined width in the lower portion of 31, and a second cavity having a narrower width than the first cavity between the ink chamber 40 and the manifold 32; It is formed by a negative ink supply path 36.

On the substrate 31 on both sides of the central axis of the ink flow paths 32 and 36, a pair of driving heat generating parts 50 and 51 are provided to correspond to each other. The driving heating parts 50 and 51 are formed by sequentially stacking the insulating layer 44 and the heating resistors 33a and 33b on the substrate 31, and on the heating resistors 33a and 33b, an etching portion having a predetermined pattern is formed on the substrate 31. As a result, the electrode layer 34 stacked to expose the upper surface thereof, and the protective layer 35 are stacked to cover the upper surface of the heating resistors 33a and 33b and the electrode layer 34. In this case, according to the present invention, the heat generating resistors 33a and 33b may have any one planar shape selected from a circle and a quadrangle of the plane shape orthogonal to the central axis of the ink flow paths 32 and 36. Here, the heat generating resistors 33a and 33b may be made of tantalum-aluminum (Ta-Al), polysilicon, and the like, and the upper surface thereof may withstand pressure generated during anti-oxidation and ink ejection. The protective layer 35 formed of a passivation layer is stacked.

The ink chamber barrier 37 is stacked on the substrate 31 to form sidewalls of the ink chamber 40 filled with ink, and a pair of nozzle holes 38a and 38b are formed on the top surface of the ink chamber barrier 37. The formed nozzle plate 39 is laminated.

The pair of nozzle holes 38a and 38b are disposed to face the upper sides of the driving heat generating parts 50 and 51, respectively, and the distance between the pair of nozzle holes 38a and 38b is 120 to 200 μm. It is preferable to select between.

The ink chamber 40 is a space in which bubbles generated by the heating of the heat generating resistors 33a and 33b may expand. The ink chamber 40 is divided into upper and lower surfaces by the nozzle plate 39 and the substrate 31. 37) the side walls are formed by partitioning. In addition, the ink chamber 40 may be formed in any one cross section whose outer shape of the cross section cut out to be orthogonal to the central axes of the ink flow paths 32 and 36 is selected from a circle or a rectangle. As such, the ink chamber 40 has a symmetrical cross section, so that the ink supply balance can be balanced to the driving heat generating units 50 and 51 which are bisected on the ink flow paths 32 and 36, and the bubble expands. The pressure can be effectively transmitted to the ink droplets that discharge the pressure.

The ink ejection operation of the inkjet printhead according to the present invention will be described in detail with reference to FIG. 3 as follows.

When an electrical signal applied from an external driver circuit (not shown) is applied to the heating resistor 33a through the electrode layer 34, the heating resistor 33a converts the electrical signal into thermal energy to heat the ink. As a result, the ink stopped until the bubble is generated is phase-changed by the continuous supply of thermal energy to generate bubbles, and the ink is discharged to the nozzle hole 38a by the expansion pressure of the bubble.

Then, when the bubble contracts, the ink is forced in a direction opposite to the direction of travel of the ejected droplet pillar, so that the droplet 45a is separated from the ink in the nozzle hole 38a.

The ink sucked into the nozzle hole 38a by the contraction of the bubble rises again toward the outlet of the nozzle hole 38a by the surface tension generated at the upper boundary between the nozzle hole 38a, the external atmosphere, and the ink. At this time, the ink flows into the ink chamber 40 from the ink reservoir (not shown) through the ink supply passage 36, and when power is again applied to the heat generating resistor 33a, the nozzle plate 39 through the above process. Ink is discharged to the nozzle hole 38a on the ().

Ink that has passed through one ink supply path 36 flows into the ink chamber 40, and after the ink is discharged through the nozzle hole 38a, ink can be discharged through the adjacent nozzle hole 38b after a few microseconds. As a result, the printing speed can be improved several times depending on the arrangement of the nozzle holes at twice as compared with the conventional inkjet printing.

FIG. 4 is a schematic plan view of an inkjet printhead according to the present invention, which shows that two nozzle holes are not arranged on one substrate 31 and four nozzle holes are arranged on one substrate 31 unlike the conventional art. 31) The pad 41 for applying power in the direction perpendicular to the arrangement of the nozzle holes 38 is illustrated.

A method of manufacturing an inkjet printhead according to a preferred embodiment of the present invention will be described below with reference to FIGS. 5A to 5E.

First, as shown in FIG. 5A, in the first step, a manifold 32 having a predetermined depth is formed on the bottom surface of the substrate 31 on which the insulating layer 44 is formed, and then in the second step, the manifold 32 is formed. A pair of drive heat generating parts 50 and 51 are formed on the upper surface of the substrate 31 so as to correspond to both sides of the central axis of the 32.

As shown in FIG. 5B, the driving heating units 50 and 51 sequentially stack the insulating layer 44, the heat generating resistors 33a and 33b, the electrode layer 34, and the protective layer 35 of the substrate 31. Here, the electrode layer 34 is formed by laminating aluminum or copper on the heating resistors 33a and 33b so that the upper surface thereof is exposed by an etching part of a predetermined pattern, and the protective layer 35 is formed. Is laminated to cover the top surfaces of the heating resistors 33a and 33b and the electrode layer 34.

In the third step, as shown in FIG. 5C, the substrate 31 is etched using a dry etching method to form an ink supply path 36 communicating with the manifold 32.

As shown in FIG. 5D, a dry film is laminated on the substrate 31, and then an ink chamber barrier 37 is formed by patterning. Here, the ink chamber barrier 37 may be formed using a liquid photo-definable polymer, or may be formed by laminating an adhesive layer on a polymer nozzle plate and then using dry etching.

As a next step, the nozzle chambers 38a and 38b are formed in the nozzle plate 39 by laser processing, and the ink chamber barrier 37 is formed using the nozzle plates 39 having the nozzle holes 38a and 38b formed by thermocompression bonding. By bonding to the upper surface of the fabrication of the inkjet printhead of the present invention as shown in Fig. 5E is completed.

As described above, according to the present invention, in the inkjet print head, a plurality of ink supply paths and corresponding nozzles are formed on a unit substrate by forming an ink supply path on a substrate by a dry etching method and reducing the width of the ink supply path. The hole can be formed, and the mechanical strength of the substrate can also be improved.

Also, by changing the position of the ink supply passage of the ink ejection structure to form a pair of nozzle holes having the same ink supply passage, the pair of nozzles eject the ink without being affected by the ink replenishment time, thereby printing speed. The effect can be improved by 2 times or more.

In the above, certain preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims. Such changes are intended to fall within the scope of the claims.

Claims (10)

       A substrate formed to penetrate an ink passage through which ink is supplied; A pair of drive heat generating units provided on the substrate so as to correspond to both sides of the outlet of the ink passage; An ink chamber barrier in which the pair of drive heat generating portions are inherent and stacked on the substrate to form sidewalls of the ink chamber in which ink is filled; And a nozzle plate having a pair of nozzle holes correspondingly disposed so as to be positioned above the pair of driving heat generating parts, respectively, and stacked on an upper surface of the ink chamber barrier. An ink supply having a manifold formed to form a first cavity having a predetermined width in the lower portion of the substrate, and a second cavity having a narrower width than the first cavity so as to communicate the ink chamber with the manifold An inkjet print head comprising a furnace. delete The method of claim 1, The ink flow path of the ink jet print head, characterized in that located in the center of the pair of the drive heat generating portion. The method of claim 1, wherein the drive heating portion, The insulating layer and the heat generating resistor are sequentially stacked on the substrate, and the electrode layer formed so as to expose the top surface of the heat generating resistor by an etching portion of a predetermined pattern, and a protective layer stacked to cover the top surface of the heat generating resistor and the electrode layer. Inkjet print head comprising a. The method of claim 3, wherein The planar outer shape of the heat generating resistor has an inkjet print head, characterized in that any one selected from a circle and a square. The method of claim 1, And the pair of nozzle holes are arranged to maintain a spacing between 120 and 200 μm. The method of claim 1, And the ink chamber is formed with any one selected from a circle and a quadrangle having an outer shape of a cross section cut to be orthogonal to a central axis of the ink flow path. A first step of forming a manifold having a predetermined depth by sand blasting on the bottom surface of the substrate; A second step of forming a pair of drive heating parts on an upper surface of the substrate; Etching the substrate by dry etching to form an ink supply path in communication with the manifold; Stacking a dry film on the substrate and forming an ink chamber barrier by patterning; A fifth step of forming a pair of nozzle holes in the nozzle plate by laser processing; And bonding the nozzle plate to the upper surface of the ink chamber barrier by a thermocompression bonding method. The method of claim 8, wherein the fourth step, A method of manufacturing an inkjet print head, comprising forming an ink chamber barrier by laminating a photosensitive polymer. The method of claim 8, wherein the fourth step, A method of manufacturing an inkjet print head, comprising forming an ink chamber barrier by dry etching after laminating an adhesive layer on a polymer nozzle plate.

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