KR100421027B1 - Inkjet printhead and manufacturing method thereof - Google Patents

Abstract

An inkjet printhead and a method of manufacturing the same are disclosed. The disclosed inkjet printhead has a first ink chamber having a substantially hemispherical shape on the surface thereof where ink to be discharged is filled, and a manifold for supplying ink to the first ink chamber is formed on the rear side thereof. A substrate having an ink channel connecting the first ink chamber and the manifold; A nozzle plate stacked on a surface of the substrate and having a nozzle formed at a position corresponding to a central portion of the first ink chamber; A heater formed to surround the nozzle of the nozzle plate; An electrode electrically connected to the heater to apply a current to the heater; And an insulating layer formed on the top of the nozzle plate, the second ink chamber having a substantially cylindrical shape corresponding to the nozzle, and an ink discharge port through which ink is discharged from the second ink chamber.

Description

Inkjet printheads and manufacturing method thereof

The present invention relates to an inkjet printhead and a method of manufacturing the same, and more particularly, to a bubblejet inkjet printhead and a method of manufacturing the inkjet printhead in which one ink chamber is formed at the top and the bottom of the nozzle plate.

In general, 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. In such an inkjet printhead, ink is supplied from an ink reservoir into an ink chamber via an ink feed hole and a restrictor. Ink filled in the ink chamber is heated by a heating element provided therein, and is discharged in the form of droplets through the nozzle by the pressure of the bubble generated thereby.

In general, inkjet printheads require high-density and high-speed printing, requiring a structure in which a large number of nozzles are highly integrated. In this case, the shape and precision of each nozzle, the uniformity and precision between cells of the ink flow path are the most important process variables in improving printing performance and realizing excellent image quality.

1A to 1H are cross-sectional views illustrating one example of a conventional method of manufacturing an inkjet printhead of a roping shooting method. This method basically uses a photolithography process and a nickel electroforming process.

And, the method largely comprises the steps of manufacturing the nozzle plate 15 as shown in Figs. 1A to 1D, and the head chip substrate 21 provided with the heating element 23 as shown in Figs. 1E to 1G. Forming an ink flow path comprising an ink supply port 22, a restrictor, and an ink chamber 26 thereon, and attaching the nozzle plate 15 to the head chip substrate 21 as shown in FIG. 1H. The printhead can be divided into stages to complete.

In detail step by step, as shown in FIG. 1A, a seeding layer 12 for nickel electroplating is formed on a silicon substrate 11, and then a positive photoresist is formed thereon. , 13). Specifically, the seeding layer 12 is formed to a thickness of several thousand micrometers by, for example, sputtering or depositing NiV, and the photoresist 13 is spin-coated to a thickness of about several micrometers, for example, typically 4-8 micrometers. Is applied. The photoresist 13 is then selectively exposed using a photomask 14.

Next, when the exposed photoresist 13 is developed, only the unresisted photoresist 13a remains on the seeding layer 12 as shown in FIG. 1B. The remaining photoresist 13a then forms a crater 15b around the nozzle 15a shown in FIG. 1D.

FIG. 1C illustrates a state in which the nozzle plate 15 made of nickel is formed on the seeding layer 12 by carrying the patterned substrate 11 on a plating bath to perform nickel electroplating. At this time, by adjusting the total current density and the plating time applied to the plating bath can form a nozzle plate 15 of a desired thickness. At the same time, plating is suppressed on the remaining photoresist 13a to form the nozzle 15a.

After the nickel electroplating is completed, the nozzle plate 15 is separated from the substrate 11 and cleaned as shown in FIG. 1D. At this time, the crater 15b is formed around the nozzle 15a by the remaining photoresist 13a.

FIG. 1E shows a state where the negative photoresist 24 is applied onto the head chip substrate 21 on which the heating element 23 composed of the ink supply port 22 and the resistance heating element is formed. The negative photoresist 24 is a lamination for heating, pressing and compressing a solid dry film resist made of a resin such as Vacrel or Riston, commercialized by DuPont, on the head chip substrate 21. by lamination method.

Subsequently, as shown in FIG. 1F, the negative photoresist 24 is selectively exposed using the photomask 25. As a result, the exposed portion of the negative photoresist 24 is cured to form a partition 24a surrounding the ink chamber 26 as shown in FIG. 1G. The unexposed portions of the negative photoresist 24 are removed by the solvent, thereby forming the ink chamber 26 and the restrictor 27. The restrictor 27 is a connecting passage formed between the ink supply port 22 and the ink chamber 26.

Finally, as shown in FIG. 1H, the inkjet printhead is completed by heating, pressing, and adhering the nozzle plate 15 prepared in advance on the partition wall 24a.

The nozzle manufacturing method described above is well known as the Mandrel Type Nozzle Electro Forming Method. This method is currently employed by a number of manufacturers, primarily for color inkjet printheads and mono inkjet printheads with fewer nozzles.

However, the manufacturing method shown in FIGS. 1A to 1H causes various problems in accordance with the increase in the number of nozzles 15a and the degree of integration of a cell expressed in cells per inch (CPI). First, since the nozzle plate 15 must be manufactured separately and bonded to the head chip substrate 21, high precision is required in this process. Second, when thermally bonding the nozzle plate 15 to the head chip substrate 21, the thermal expansion coefficients of the nozzle plate 15 are different, and misalignment of the nozzle 15a and the heating element 23 may occur. Third, since the electroplating process, the two photolithography process and the bonding process are performed, the manufacturing process is very complicated.

Accordingly, recently, a manufacturing method for integrally forming components such as an ink flow path and a nozzle on a head chip substrate has been introduced.

FIG. 2 is a cross-sectional view schematically showing one of the conventional inkjet printheads disclosed in US Pat. No. 6,019,457, illustrating a back shooting in which a heater and an ink chamber are formed as opposed to the up-discharge method of FIG. 1.

Referring to the drawings, a hemispherical ink chamber 65 is formed on an upper portion of a substrate 60 made of silicon or the like, and a manifold 66 for supplying ink to the ink chamber 65 is formed below. In the center of the bottom of the ink chamber 65, an ink channel 63 connecting the ink chamber 65 and the manifold 66 is formed.

On the surface of the substrate 60, a nozzle plate 70 on which a nozzle 61 through which ink droplets 68 are discharged is formed is located, and forms an upper wall of the ink chamber 65. The nozzle plate 70 includes a thermal insulation layer 70a and a CVD chemical vapor deposition overcoat layer 70b thereon.

The nozzle plate 70 is formed with an annular heater 62 adjacent to and surrounding the nozzle 61, and the heater 62 is located at an interface between the insulating layer 70a and the overcoating layer 70b. On the other hand, the heater 62 is connected to an electric wire (not shown) for applying a pulsed current.

In the above structure, when the pulsed current is applied to the annular heater 62 while the ink supplied through the manifold 66 and the ink channel 63 is filled in the ink chamber 65, the heater 62 Heat generated in the heat transfer) is transferred through the insulating layer 70a below, and ink below the heater 62 is boiled to generate bubbles B. Then, when the bubble B expands as the heat generated from the heater 62 continues, pressure is applied to the ink filled in the ink chamber 65 so that the ink near the nozzle 61 passes through the nozzle 61. It is ejected in the form of the ink droplet 68 to the outside. Then, ink is refilled in the ink chamber 65 while the ink is sucked through the ink channel 63.

In the conventional inkjet printhead, components such as a flow path and a nozzle are integrally formed on the head chip substrate, so that a misalignment problem between the nozzle and the heater does not occur.

However, these conventional inkjet printheads have a problem in that the ejection performance is deteriorated because they obtain a force for ejecting ink in the ink chamber by generating bubbles by using only one direction of heat from the heater.

In order to solve the above problems, the present invention provides a bubble jet inkjet printhead of which a single ink chamber is formed on the top and bottom of the nozzle plate, and the ejection performance is good by using both the heat of the top and the bottom of the heater. The purpose is to provide a method of manufacturing the same.

1A to 1H are cross-sectional views showing one example of a conventional method of manufacturing an inkjet printhead of a roar shooting method.

2 is a cross-sectional view showing an example of a conventional inkjet print head of a back shooting method.

3 is a schematic plan view of the bubble jet inkjet printhead according to the present embodiment.

4 is an enlarged plan view of a portion A of FIG. 3, which is a feature of the present invention;

FIG. 5 is a cross-sectional view illustrating a vertical structure of the inkjet printhead viewed along the line VV of FIG. 4.

6 to 14 are cross-sectional views illustrating a process of manufacturing an inkjet printhead of the structure shown in FIG. 5.

<Brief description of symbols for the main parts of the drawings>

100 ... substrate 101 ... bonding pad

102 ... Manifold 103 ... Ink ejection

104 ... Nozzle 105 ... Ink Supply Hole

106 ... First Ink Chamber 108 ... Heater

110 ... ink channel 112 ... electrode

114 ... Nozzle plate 116 ... Heater protection layer

118 ... electrode protection layer 120 ... metal layer

120 channel forming layer 121 insulating film

122 ... polyimide 126 ... ink discharge outlet

128. 2nd Ink Chamber

In order to achieve the above object, the inkjet printhead according to the present invention is formed with a first ink chamber having a substantially hemispherical shape on the surface thereof where ink to be discharged is filled, and ink into the first ink chamber. A substrate having a manifold for supplying the ink and having an ink channel connecting the first ink chamber and the manifold;

A nozzle plate stacked on a surface of the substrate and having a nozzle formed at a position corresponding to a central portion of the first ink chamber;

A heater formed to surround the nozzle of the nozzle plate;

An electrode electrically connected to the heater to apply a current to the heater; And

And an insulating layer formed on the nozzle plate, the second ink chamber having a substantially cylindrical shape corresponding to the nozzle, and an ink discharge port through which ink is discharged from the second ink chamber.

In addition, in order to achieve the above object, the inkjet printhead manufacturing method according to the present invention, (a) forming a nozzle plate on the surface of the substrate;

(b) forming a heater on the nozzle plate;

(c) forming an electrode electrically connected to the heater on the nozzle plate;

(d) etching the nozzle plate to form a nozzle;

(e) forming a conductive layer on the substrate to cover the exposed substrate and the heater;

(f) forming an insulating layer covering the conductive layer on the nozzle plate;

(g) forming an ink discharge port corresponding to the nozzle by etching the insulating layer;

(h) etching the conductive layer to form a second ink chamber;

(i) forming a first ink chamber by etching the substrate exposed by the nozzle; And

(j) forming a manifold by etching the back surface of the substrate to a predetermined depth, and forming an ink channel on the back surface of the etched substrate.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments exemplified below are not intended to limit the scope of the present invention, but are provided to fully explain the present invention to those skilled in the art. Like reference numerals in the drawings refer to like elements, and the size or thickness of each element in the drawings may be exaggerated for convenience of explanation. 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.

First, FIG. 3 is a schematic plan view of a bubble jet inkjet printhead according to the present embodiment.

3, the inkjet printhead according to the present embodiment has two rows of ink ejecting portions 103 arranged on the manifold 102 for ink supply shown in dotted lines, and is electrically connected to each ink ejecting portion 103. Bonding pads 101 are arranged to be connected to each other and to which the wire is to be bonded. Manifold 102 is connected with an ink container (not shown) containing ink. Although the ink ejecting portions 103 are arranged in two rows in the drawing, they may be arranged in one row or may be arranged in three or more rows to further increase the resolution. In addition, one manifold 102 may be formed for each column of the ink ejecting portions 103. Further, although an inkjet printhead using only one color of ink is shown in the drawing, three or four groups of ink ejecting portions may be arranged for each color for color printing.

4 is an enlarged plan view of a portion A of FIG. 3, which is a feature of the present invention, and FIG. 5 is a cross-sectional view illustrating a vertical structure of the inkjet printhead along the line VV of FIG. 4.

The structure of the inkjet printhead according to the present embodiment will be described in detail with reference to FIGS. 4 and 5 as follows.

First, the substrate 100 is formed with a substantially hemispherical first ink chamber 106 filled with ink on its surface side, and a manifold 102 for supplying ink to each ink chamber 106 on its back side. ) Is formed. Here, the substrate 100 is preferably made of silicon widely used in the manufacture of integrated circuits.

An ink channel 110 connecting the ink chamber 106 and the manifold 102 is formed between the ink chamber 106 and the manifold 102.

A nozzle plate 114 having a nozzle 104 is formed on the surface of the substrate 100 to form an upper wall of the first ink chamber 106. When the substrate 100 is made of silicon, the nozzle plate 114 may be made of a silicon oxide film formed by oxidizing the silicon substrate, or may be made of an insulating film such as a silicon nitride film deposited on the substrate 100.

On the nozzle plate 114, an annular bubble generation heater 108 surrounding the nozzle 104 is formed. The heater 108 is made of a resistive heating element such as polycrystalline silicon, tantalum-aluminum alloy, or tungsten silicide (WSi) doped with impurities, and an electrode 112 for applying a pulsed current is connected to the heater 108. . This electrode 112 is usually made of the same material as the bonding pad (101 in FIG. 2) and the necessary wiring (not shown), such as a metal such as aluminum or an aluminum alloy. Meanwhile, in order to protect the heater 108 and the electrode 112, the heater protection layer 116 and the electrode protection layer 118 are formed on the heater 108 and the electrode 112, respectively.

On top of the nozzle plate 114, a second ink chamber 128, which is a feature of the present invention, is formed. The ink chamber 128 is a cylindrical chamber formed thereon with an ink discharge port 126 corresponding to the nozzle 104. In addition, an ink supply hole 105 for supplying ink from the manifold 102 and the first ink chamber 106 to the outside of the second ink chamber 128 is formed outside the heater 108. The ink supply hole 105 may be formed to be modified in various shapes.

In the above structure, after the ink supplied through the ink channel 110 from the manifold 102 by the capillary phenomenon fills the first ink chamber 106, the nozzle 104 and the ink supply hole 105 When the pulsed current is applied to the annular heater 108 while the second ink chamber 128 is filled through the second ink chamber 128, the heat generated from the heater 108 is transferred through the nozzle plate 114 below and the heater 108. The ink below boils and bubbles B 'are generated, and heat of the heater 108 forms bubbles B ″ in the second ink chamber 128 through the insulating layers 116 and 118 thereon. At this time, the shapes of the bubbles B 'and B "become substantially donut shapes.

As bubbles B 'and B "expand over time, the ink in the first ink chamber 106 is discharged through the nozzle 104 by the pressure of the expanding bubbles B' and B". The liquid is discharged into the chamber 128 and is discharged into the droplets through the ink discharge port 126 together with the ink of the second ink chamber 128.

Next, when the applied current is cut off, the bubbles B 'and B " are reduced or burst before the first and second ink chambers 106 and 128 are released from the manifold 102. The ink is filled again through the ink channel 110 and the ink supply hole 105.

In the inkjet printhead described above, the volume of the bubbles B ′ and B ″ is rapidly grown by using heat generated from both sides of the heater 108 in both the first 106 and the second ink chamber 128. By discharging the ink, the heater 108 can be cooled more efficiently by filling with new ink after the ink is discharged, thereby improving the discharge characteristics such as the ink discharge speed, the droplet amount, and the like.

Next, a method of manufacturing the inkjet printhead of the present invention will be described.

6 to 14 are cross-sectional views illustrating a process of manufacturing an inkjet printhead of the structure shown in FIG. 5.

Referring to FIG. 6, first, in this embodiment, the substrate 100 uses a silicon substrate having a thickness of approximately 500 mu m. This is because silicon wafers widely used in the manufacture of semiconductor devices can be used as they are and are effective for mass production.

Subsequently, when the silicon substrate 100 is placed in an oxidation furnace and wet or dry oxidized, a silicon oxide film that becomes the nozzle plate 114 is formed on the surface of the silicon substrate 100, and a nozzle is formed later on the nozzle plate 114. do.

On the other hand, as shown in Figure 6 shows a very small portion of the silicon wafer, the printhead according to the present invention is manufactured in a state of tens to hundreds of chips on one wafer.

Next, the annular heater 108 is formed on the nozzle plate 114. The heater 108 is formed by depositing polycrystalline silicon, tantalum-aluminum alloy, or tungsten silicide doped with impurities on the nozzle plate 114, which is a silicon oxide film, and then patterning it in an annular shape. The doped polycrystalline silicon may be formed to a thickness of about 0.7 to 1 μm by low pressure chemical vapor deposition (LPCVD), for example, by depositing with a source gas of phosphorus (P) as an impurity. In the case where the heater 108 is formed of a tantalum-aluminum alloy, the tantalum-aluminum alloy film is approximately 0.1 to 0.3 mu m by depositing by sputtering with a target of tantalum-aluminum alloy or a separate target of tantalum and aluminum. It may be formed in a thickness. When the heater 108 is formed of a tungsten silicide layer, the heater 108 may be formed to a thickness of about 0.5 to 0.8 μm by chemical vapor deposition. The deposition thickness of this polycrystalline silicon film, tantalum-aluminum alloy film, or tungsten silicide may be set in another range so as to have an appropriate resistance value in consideration of the width and length of the heater 108. Next, the polycrystalline silicon film, tantalum-aluminum alloy film, or tungsten silicide film deposited on the entire surface of the silicon oxide film, which is the nozzle plate 114, is etched by using a photomask and a photoresist and a photoresist pattern as an etching mask. Patterned by the process.

FIG. 7 illustrates a state in which an electrode is formed after depositing a heater protection layer protecting the heater on the entire surface of the resultant of FIG. 6, and an electrode protection layer is deposited on the front surface of the electrode protection layer.

Specifically, a heater protective layer 116, such as a silicon nitride film, is deposited by low pressure chemical vapor deposition to, for example, approximately 0.5 [mu] m thick. Next, the heater protection layer 116 deposited on the heater 108 is etched to expose the heater 108 of the portion to be connected to the electrode 112. Subsequently, the electrode 112 is formed by depositing and patterning a metal having good conductivity and easy patterning, such as aluminum or an aluminum alloy, by sputtering to a thickness of approximately 1 탆. In this case, the metal film constituting the electrode 112 is patterned to simultaneously form a wiring (not shown) and a bonding pad (101 in FIG. 3) at other portions of the substrate 100. Next, an electrode protective layer 118 such as a tetraethylerthosilane (TEOS) oxide film is deposited on the entire surface of the substrate 100 on which the electrode 112 is formed. The TEOS oxide layer, which is the electrode protective layer 118, may be deposited by a chemical vapor deposition method at a low temperature, for example, 400 ° C. or less, in a range where the electrode and the bonding pad of aluminum or its alloy are not deformed to a thickness of about 1 μm.

FIG. 8 illustrates a state in which an ink supply hole is formed at an outside of the nozzle and the heater in the state shown in FIG. 7. In detail, the electrode protection layer 118, the heater protection layer 116, and the nozzle plate 114 are sequentially etched to a diameter smaller than the diameter of the heater 108 into the heater 108 to form the nozzle 104. Exposing the substrate 100. In addition, the electrode protection layer 118, the heater protection layer 116, and the nozzle plate 114 are sequentially etched on the outer side of the heater 108 to expose the substrate 100 of the portion forming the ink supply hole 105.

9 covers the substrate 100 exposed by the nozzle 104 and the ink supply hole 105 with the metal layer 120. Specifically, a metal layer 120 such as aluminum is deposited by a flow metal process at approximately 530 to 560 ° C. At this time, the process is repeated several times in consideration of the height of the second ink chamber 128 to be formed in the future. Subsequently, the patterning process leaves only the portion to be the second ink chamber 128.

FIG. 10 deposits an insulating film 121 covering the surface of the patterned metal layer 120 to a thickness of approximately 0.7 to 1 μm by the CVD method. Subsequently, polyimide is deposited by CVD method to a thickness of several tens of micrometers.

FIG. 11 develops the polyimide formed in FIG. 10 by a photographic process to form an upper portion of the ink discharge port 126. Subsequently, the insulating layer 121 is dry-etched to form the lower portion of the ink discharge port 126 formed therein. Subsequently, the metal layer 120 stacked in multiple layers is selectively etched by wet etching to form the second ink chamber 128, the nozzle 104, and the ink supply hole 105.

FIG. 12 shows the hemispherical first ink chamber 106 having a predetermined depth by supplying etching gas from the nozzle 104 to the nozzle 104 by a dry etching apparatus, for example, an XeF2 etching apparatus. At this time, the ink supply hole 105 is etched to a predetermined depth so as to penetrate the first ink chamber 106.

FIG. 13 illustrates a step of forming a manifold on the back side of the substrate by obliquely etching the back side of the substrate. Specifically, a silicon oxide film having a thickness of about 1 μm is deposited on the back surface of the silicon substrate 100 using an etching mask material, and patterned to form an etching mask 132 that defines an area to be etched. Next, the silicon substrate 100 exposed by the etch mask 132 is wet-etched for a predetermined time by using tetramethyl ammonium hydroxide (TMAH) as an etchant to have a thickness of, for example, approximately 30 to 40 μm. Dry etching is performed by inductively coupled plasma-reactive ion etching (ICP-RIE) to form a manifold 102 on the back side of the substrate 100.

Meanwhile, the manifold 102 may be formed by etching the substrate 100 before forming the nozzle 104 of FIG. 8. In addition, although the manifold 102 is illustrated and described as being formed by obliquely etching the rear surface of the substrate 100, the manifold 102 may be formed by anisotropic etching instead of oblique etching.

14 shows a photoresist pattern 134 having a thickness of approximately 1 to 2 [mu] m by applying and patterning photoresist on the surface of the manifold 102 of the substrate, for example, by photoresist spray coating. In this case, the photoresist pattern 134 is formed such that the surface of the manifold of the portion where the ink channel 110 is to be formed is exposed. Next, the back surface of the substrate exposed by Reactive Ion Etching (RIE) or the like is etched to form the ink channel 110. The ink channel 110 may be formed using a laser.

Although the preferred embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and equivalent other embodiments are possible. For example, the materials used to construct each element of the inkjet printhead in the present invention may use materials not illustrated. That is, the substrate may be replaced with another material having good processability even if it is not necessarily silicon. The same applies to a heater, an electrode, a silicon oxide film, and a nitride film. In addition, as a method of laminating and forming each material is merely illustrated, various deposition methods and etching methods may be applied.

In addition, the order of each step of the inkjet printhead manufacturing method of the present invention may be different from that illustrated, and the specific values exemplified in each step may be illustrated within the range in which the manufactured inkjet printhead can operate normally. Adjustable out of range.

As described above, according to the present invention, by forming the ink chamber in a cylindrical shape, it is possible to increase the amount that can contain ink per unit area than the conventional hemispherical ink chamber. In addition, by using both the front and the back of the heater, it is possible to improve the discharge characteristics, such as discharge rate, droplet amount.

Claims (8)

Where ink to be discharged is filled, a first ink chamber having a substantially hemispherical shape is formed on the surface thereof, and a manifold for supplying ink to the first ink chamber is formed on the rear side thereof and the first ink chamber is formed. And a substrate on which an ink channel connecting the manifold is formed. A nozzle plate stacked on a surface of the substrate and having a nozzle formed at a position corresponding to a central portion of the first ink chamber; A heater formed to surround the nozzle of the nozzle plate; An electrode electrically connected to the heater to apply a current to the heater; And And an insulating layer having a second ink chamber substantially cylindrical in correspondence with the nozzle and an ink discharge port through which ink is discharged from the second ink chamber on an upper portion of the nozzle plate. The method of claim 1, The insulating layer is an inkjet printhead, characterized in that the polyimide (polyimide). The method of claim 1, The inkjet printhead, characterized in that the ink supply hole is further provided in the nozzle plate to the second ink chamber from the first ink chamber on the outside of the heater. The method of claim 1, And the ink discharge port and the nozzle are arranged on the same line. (a) forming a nozzle plate on the surface of the substrate; (b) forming a heater on the nozzle plate; (c) forming an electrode electrically connected to the heater on the nozzle plate; (d) etching the nozzle plate to form a nozzle; (e) forming a conductive layer on the substrate to cover the exposed substrate and the heater; (f) forming an insulating layer covering the conductive layer on the nozzle plate; (g) forming an ink discharge port corresponding to the nozzle by etching the insulating layer; (h) etching the conductive layer to form a second ink chamber; (i) etching the substrate exposed by the nozzle to form a first ink chamber; And (j) forming a manifold by etching the back surface of the substrate to a predetermined depth, and forming an ink channel on the back surface of the etched substrate. The method of claim 5, wherein In the step (d), by etching the nozzle plate on the outside of the nozzle to form an ink supply hole for supplying ink from the first ink chamber to the outside of the second ink chamber; The step (e) is a step of forming a conductive layer covering the substrate including the ink supply hole; inkjet printhead manufacturing method characterized in that. The method of claim 5, wherein Wherein the step (i) comprises forming the substantially hemispherical first ink chamber by isotropically etching the substrate exposed by the nozzle. The method of claim 7, wherein The step (i) is a step of etching including the lower portion of the ink supply hole; inkjet printhead manufacturing method characterized in that.