KR20040041886A - Inkjet printhead and method of manufacturing thereof - Google Patents

Abstract

PURPOSE: An ink jet print head and a method for manufacturing the same are provided to perform precise patterning work with respect to a conductive wire and a heater through a dry etching process. CONSTITUTION: An ink jet print head includes a base plate(110), a fluid path plate(120) and a nozzle plate(130), which are sequentially stacked. The fluid path plate(120) defines an ink chamber(122) receiving ink therein, and an ink path for feeding ink from an ink reservoir to the ink chamber(122). The fluid path plate(120) forms a sidewall surrounding the ink chamber(122) and the ink path. The nozzle plate(130) has a nozzle(132) positioned corresponding to a position of the ink chamber(122). The base plate(110) is formed by depositing a plurality of material layers on a substrate(111). An insulation layer(112) is formed on an upper surface of the substrate(111).

Description

Inkjet printhead and method of manufacturing the same

The present invention relates to an inkjet printhead, and more particularly, to an inkjet printhead of a thermal drive type and a method of manufacturing the same.

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. 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. As a result, the ink near the nozzle is discharged out of the ink chamber in the form of droplets through the nozzle.

FIG. 1 is a schematic partial cutaway perspective view showing a configuration of a conventional thermal inkjet printhead, and FIG. 2 is a cross-sectional view illustrating a vertical structure of the conventional inkjet printhead shown in FIG.

Referring to FIG. 1, an inkjet printhead includes a base plate 10 formed by stacking a plurality of layers of materials on a substrate, and an ink chamber 22 and an ink flow path 24 stacked on the base plate 10. It consists of a flow path plate 20 and a nozzle plate 30 stacked on the flow path plate 20. Ink is filled in the ink chamber 22, and a heater (13 in FIG. 2) is provided below the ink chamber 22 for heating the ink to generate bubbles. The ink passage 24 is connected to an ink reservoir (not shown) as a passage for supplying ink into the ink chamber 22. The nozzle plate 30 is provided with a plurality of nozzles 32 through which ink is discharged at positions corresponding to the respective ink chambers 22.

Referring to FIG. 2, a vertical structure of a conventional inkjet printhead having the above configuration is described. On the substrate 11 made of silicon, an insulating layer 12 for insulating and insulating between the heater 13 and the substrate 11 is provided. ) Is formed. The insulating layer 12 is mainly formed by depositing a silicon oxide film on the substrate 11. On the insulating layer 12, a heater 13 for generating bubbles by heating the ink in the ink chamber 22 is formed. The heater 13 is formed by, for example, depositing tantalum nitride (TaN) or tantalum-aluminum alloy (TaAl) on the insulating layer 12 in the form of a thin film. On the heater 13 there is provided a conductor 14 for applying a current thereto. This lead wire 14 is made of aluminum or an aluminum alloy, for example. Specifically, the conductive wire 14 is formed by stacking aluminum and the like on the heater 13 to a predetermined thickness and then patterning the same into a predetermined shape.

A passivation layer 15 is formed on the heater 13 and the conductive wire 14 to protect them. The protective layer 15 is for preventing the heater 13 and the conductor 14 from being oxidized or coming into direct contact with ink, and is mainly formed by depositing a silicon nitride film. In addition, an anticavitation layer 16 is formed on a portion where the ink chamber 22 is formed on the protective layer 15. The cavitation prevention layer 16 is for preventing the heater 13 from being damaged by the high air pressure generated when the upper surface forms the bottom surface of the ink chamber 22 and the bubbles in the ink chamber 22 disappear. Mainly tantalum thin films are used.

In this way, on the base plate 10 formed by stacking several material layers on the substrate 11, the flow path plate 20 for forming the ink chamber 22 and the ink flow path 24 is stacked. The flow path plate 20 is formed by applying a photosensitive polymer by a lamination method of heating, pressing and compressing the photosensitive polymer onto the base plate 10 and then patterning the photosensitive polymer. At this time, the coating thickness of the photosensitive polymer is determined by the height of the ink chamber 22 required according to the volume of the ink droplets to be ejected.

The nozzle plate 30 in which the nozzle 32 is formed is laminated on the flow path plate 20. The nozzle plate 30 is made of polyimide or nickel, and is heated and pressed onto the flow path plate 20 by using the adhesiveness of the photosensitive polymer forming the flow path plate 20.

In the structure of the conventional inkjet printhead, since the conductors 14 are formed on the heater 13, when etching, for example, aluminum or the like for the patterning of the conductors 14, according to the dry etching, under the conductors 14, The heater 13 may also be etched together. Thus, conventionally, the patterning of the conductors 14 will depend on wet etching. However, according to the wet etching, the surface of the etched portion is rough, and fine and precise patterning is difficult, and thus, uniformity of the electric wire 14 corresponding to each of the plurality of nozzles 32 is lowered, resulting in unevenness of the electric field. And there is a problem that the variation in the resistance heating characteristics in each heater 13 is increased.

The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide an inkjet printhead of a thermal drive type, in which a heater is formed on a conductive wire and the interface resistance between the conductive wire and the heater is reduced.

Another object of the present invention is to provide a method of manufacturing an inkjet printhead capable of precisely patterning a conductive wire and a heater by dry vision, and reducing an interface resistance between the conductive wire and the heater.

1 is a schematic partial cutaway perspective view showing the configuration of a conventional thermal drive inkjet printhead.

FIG. 2 is a cross-sectional view illustrating a vertical structure of the conventional inkjet printhead shown in FIG. 1.

3 is a cross-sectional view showing a vertical structure of the inkjet printhead according to the present invention.

4A to 4J are cross-sectional views for explaining step by step of a method of manufacturing an inkjet printhead according to the present invention.

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

110 ... base plate 111 ... substrate

112 Insulation layer 113 Heater

114 ... conductor 115 ... protective layer

116 cavitation prevention layer 118 ion implantation layer

120 ... Euro Plate 122 ... Ink Chamber

130 Nozzle plate 132 Nozzle

The present invention to achieve the above technical problem,

A substrate, an insulating layer formed on the substrate, a heater formed on the insulating layer to generate thermal energy, a conductive wire formed on the insulating layer so as to be connected below both end portions of the heater, and at least the heater and the conductive wire. A base plate including an ion implantation layer formed at an interface therebetween to reduce interfacial resistance, a protective layer formed on the entire surface of the substrate to cover the heater and the conductive wire, and a cavitation prevention layer formed on the protective layer;

A flow path plate stacked on the base plate and defining an ink chamber in which ink is filled and an ink flow path for supplying ink to the ink chamber; And

And a nozzle plate stacked on the flow path plate and having nozzles through which ink is discharged at a position corresponding to the ink chamber.

Here, the ion implantation layer may be formed in the interface between the heater and the conductive wire, the interface between the heater and the insulating layer and in the conductive wire.

In addition, the heater and the conductive wire may be formed by dry etching.

In addition, the present invention provides a method of manufacturing an inkjet printhead having the above structure.

The manufacturing method of the inkjet printhead according to the present invention,

(A) forming an insulating layer on the surface of the substrate;

(B) depositing a predetermined metal material on the insulating layer and patterning the metal material by dry etching to form a conductive wire;

(C) depositing a predetermined resistance heating material on the insulating layer and the conductive wire, and patterning the resistive heating material by dry etching to form a heater connected to the conductive wire;

(D) forming an ion implantation layer at least at an interface between the heater and the lead;

(E) forming a protective layer on the entire surface of the substrate to cover the heater and the conductive wire;

(F) forming a cavitation prevention layer on the protective layer at a position corresponding to the heater;

(G) forming a flow path plate defining an ink chamber and an ink flow path on the substrate; And

(H) forming a nozzle plate having a nozzle corresponding to the ink chamber on the flow path plate.

In the step (b), the metal material is preferably any one selected from the group consisting of aluminum, aluminum alloy and tungsten.

In the step (c), the resistance heating material is preferably any one selected from the group consisting of tantalum nitride, tantalum-aluminum, titanium nitride, and tungsten silicide.

In the step (d), it is preferable to form the ion implantation layer in the interface between the heater and the conductive wire, the interface between the heater and the insulating layer, and in the conductive wire by implanting ions into the entire surface of the substrate.

In the step (d), the ion implantation layer may be made of any one material selected from the group consisting of B, BF ₂ , P, and Ar.

In addition, the step (d) preferably comprises performing annealing after ion implantation. In this case, the annealing may be performed at a temperature of 200 ° C. or higher.

Further, in the step (d), it is preferable to inject ions in a direction perpendicular to the surfaces of the heater and the conducting wire, and then perform ion implantation again by tilting the substrate at an angle. In this case, the inclination angle of the substrate is preferably 7 ° to 40 °.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the examples 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. In the drawings, like reference numerals refer to like elements, and the size of each element may be exaggerated for clarity and convenience of description. 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.

3 is a cross-sectional view showing a vertical structure of the inkjet printhead according to the present invention. Although only the unit structure of the inkjet printhead is shown in the drawing, in the inkjet printhead manufactured in a chip state, a plurality of ink chambers and a plurality of nozzles are arranged in one row or two rows, and may be arranged in three or more rows for further resolution. have.

Referring to FIG. 3, the inkjet printhead of the thermal driving method according to the present invention has a structure in which the base plate 110, the flow path plate 120, and the nozzle plate 130 are sequentially stacked. The flow path plate 120 defines an ink chamber 122 in which ink is filled therein and an ink flow path (not shown) for supplying ink into the ink chamber 122 from an ink reservoir (not shown). That is, the flow path plate 120 forms sidewalls surrounding the ink chamber 122 and the ink flow path. The nozzle plate 130 is provided with a nozzle 132 through which ink is discharged at a position corresponding to the ink chamber 122.

The base plate 110 is formed by stacking a plurality of material layers on the substrate 111. As the substrate 111, a silicon wafer widely used in the manufacture of integrated circuits may be used. An insulating layer 112 is formed on the upper surface of the substrate 111. The insulating layer 112 functions not only as insulation between the substrate 111 and the heater 113, but also as a heat insulating layer for suppressing the escape of thermal energy generated by the heater 113 toward the substrate 111. The insulating layer 112 may be formed of a silicon oxide film or a silicon nitride film.

On the insulating layer 112, a heater 113 for heating the ink in the ink chamber 122 to generate bubbles, and a conducting wire 114 for applying a current to the heater 113 are provided. The heater 113 may be formed of, for example, tantalum nitride (TaN), tantalum-aluminum alloy (TaAl), titanium nitride (TiN), tungsten silicide, or the like as a resistance heating element. Under the both sides of the heater 113, that is, the conductive wire 114 is provided between both ends of the heater 113 and the insulating layer 112. The conductive wire 114 may be made of a metal having good conductivity such as aluminum, aluminum alloy, or tungsten. As described above, in the present invention, since the conductive wires 114 are provided under both ends of the heater 113, the conductive wires 114 are first formed in the manufacturing process described later, and then the heaters 113 are formed. The same stacked structure enables the conductive wire 114 and the heater 113 to be formed by dry etching, thereby enabling uniform and fine patterning of the conductive wire 114 and the heater 113. This will be described in more detail in the manufacturing process described later.

An ion implantation layer 118 is formed at the interface between the heater 113 and the conductive wire 114. As the dopant used in the ion implantation process, boron (B), BF ₂ , phosphorus (P) or Ar may be used. The ion implantation layer 118 lowers the interface resistance between the heater 113 and the conductive wire 114. Specifically, in the patterning step of the conductive wire 114 as described below, foreign substances such as photoresist may partially remain on the surface of the conductive wire 114, and a natural oxide film may be formed on the surface of the conductive wire 114 made of aluminum. The interfacial resistance between the heater 113 and the conductive wire 114 is increased. Therefore, in the present invention, as described above, by forming the ion implantation layer 118 at the interface between the conductive wire 114 and the heater 113, the oxide film on the surface of the conductive wire 114 is destroyed to lower the interface resistance. Meanwhile, the ion implantation layer 118 may be formed not only at the interface between the conductive wire 114 and the heater 113, but also between the heater 113 and the insulating layer 112 and inside the conductive wire 114 as shown. have. The ions implanted in the conductive wire 114 also reduce the resistance of the wiring 114 itself.

A protective layer 115 is formed on the heater 113 and the conductive wire 114 to protect them. The protective layer 115 is to prevent the heater 113 and the conductive wire 114 from being oxidized or in direct contact with the ink, and may be formed of silicon nitride (SiN).

In addition, an anticavitation layer 116 is formed on the passivation layer 115 at a portion where the ink chamber 122 is formed. The cavitation prevention layer 116 is for preventing the heater 113 from being damaged by the high pressure generated when the upper surface forms the bottom surface of the ink chamber 122 and the bubbles in the ink chamber 122 disappear. The cavitation prevention layer 116 may be formed of a tantalum thin film.

Hereinafter, a preferred manufacturing method of the inkjet printhead according to the present invention having the structure as described above will be described.

4A to 4J are cross-sectional views for explaining stepwise steps of a preferred method of manufacturing an inkjet printhead according to the present invention.

First, referring to FIG. 4A, in the present embodiment, a silicon wafer is processed to a thickness of about 300 to 500 μm as the substrate 111. Silicon wafers are widely used in the manufacture of semiconductor devices and are effective for mass production.

On the other hand, as shown in Figure 4a shows a very small portion of the silicon wafer, the inkjet printhead according to the present invention can be manufactured in a state of tens to hundreds of chips on one wafer.

Then, the insulating layer 112 of the prepared silicon substrate 111 is formed. When the surface of the substrate 111 is oxidized at a high temperature, the insulating layer 112 may be formed of a silicon oxide film having a thickness of about 1 to 3 μm. The insulating layer 112 may be made of another insulating material such as a silicon nitride film deposited on the substrate 111.

Subsequently, as shown in FIG. 4B, the metal layer 114 ′ for forming the conductive wire (114 in FIG. 4C) is formed on the insulating layer 112 formed on the upper surface of the substrate 111. The metal layer 114 ′ may be formed by depositing a metal material having good conductivity, such as aluminum, an aluminum alloy, or tungsten, to a thickness of about 5,000 μm to 2 μm by sputtering. Then, the photoresist is applied to the surface of the metal layer 114 ′ thus formed, and then patterned by photolithography to form an etching mask M. FIG. Subsequently, a portion of the metal layer 114 ′ exposed by the etching mask M is removed by dry etching, and the etching mask M is removed by ashing and strip, which is a conventional photoresist removing process. As shown in FIG. 1, a conductive line 114 is formed.

Next, as illustrated in FIG. 4D, a heat generating material layer 113 ′ for forming a heater (113 in FIG. 4E) is formed on the conductive wire 114 and the insulating layer 112. The heating material layer 113 ′ may be formed by sputtering or chemical vapor deposition (CVD) on a resistive heating material such as tantalum nitride (TaN), tantalum-aluminum alloy (TaAl), titanium nitride (TiN), or tungsten silicide. vapor deposition) to form a predetermined thickness, for example, a thickness of about 0.1 to 0.3 μm. The deposition thickness of the resistive heating material may be in a different range so as to have an appropriate resistance value in consideration of the kind of material and the width and length of the heater 113. The photoresist is applied to the surface of the heat generating material layer 113 ′ with a predetermined thickness and then patterned to form an etching mask M ′. Subsequently, a portion of the heating material layer 113 ′ exposed by the etching mask M ′ is removed by dry etching, and the etching mask M ′ is removed by the same method as described above. Heater 113 is formed as shown.

As described above, according to the present invention, the conductive wire 114 and the heater 113 are formed by dry etching. Accordingly, the conductive wire 114 and the heater 113 can be uniformly and finely patterned. When a plurality of nozzles are formed on one substrate, the conductive wire 114 and the heater 113 corresponding to each of the plurality of nozzles are formed. It has an overall uniform pattern and electrical and thermal properties.

As shown in FIG. 4F, ions are implanted into the entire surface of the resultant product of FIG. 4E to form an ion implantation layer 118. In this case, boron (B), BF ₂ , phosphorus (P), or Ar may be used as an implanted dopant. In addition, the implantation depth of the ions is controlled by controlling energy so that the ion implantation layer 118 is formed at the interface between the heater 113 and the conductive wire 114.

On the other hand, the ion implantation can be made in two steps. That is, after performing the ion implantation process in a vertical direction with respect to the surface of the heater 113 and the conducting wire 114, as shown in Figure 4f, the substrate 111 is inclined by about 7 ° to 40 ° to perform the ion implantation process As a result, ions can be effectively implanted into the vertical interface at the end of the conductive wire 114.

The resultant of FIG. 4F is then annealed at 200 ° C. or higher. The annealing temperature may vary depending on the melting point of the material forming the conductive wire 114. For example, when the lead 114 is made of aluminum having a relatively low melting point, the annealing temperature is about 200 ° C. to about 400 ° C., and when the lead 114 is made of a metal having a high melting point such as tungsten, at least about 800 ° C. It could be Such annealing improves the uniformity of the interface resistance by uniformizing the ion distribution in the ion implantation layer 118.

As described above, the present invention is characterized in that the ion implantation layer 118 is formed at the interface between the conductive wire 114 and the heater 113. The ion implantation layer 118 serves to reduce the interface resistance between the conductive wire 114 and the heater 113.

Next, as shown in FIG. 4G, the protective layer 115 is formed on the entire surface of the resultant product of FIG. 4F. The protective layer 115 is to protect the heater 113 and the conductive wire 114, and may be formed by depositing a silicon nitride film (SiN) to a thickness of about 1 μm to 3 μm by chemical vapor deposition.

4H illustrates a state in which the cavitation prevention layer 116 is formed on the protective layer 115. Specifically, the cavitation prevention layer 116 may be formed by depositing a tantalum thin film on the protective layer 115 by sputtering to a thickness of about 0.1 to 1.0 μm and then patterning it by photolithography as described above. This completes the base plate 110 composed of a plurality of material layers.

Next, as illustrated in FIG. 4I, an ink chamber 122 and an oil passage plate 120 defining an ink passage (not shown) are stacked on the base plate 110. The flow path plate 120 may be formed by applying a photosensitive polymer such as polyimide to the base plate 110 to a predetermined thickness and then patterning the same by photolithography. The coating thickness of the photosensitive polymer is approximately 25 to 35 μm, which is appropriately determined by the height of the ink chamber 122 required according to the volume of the ink droplets to be ejected, and has a height in a range different from the illustrated height. It may be. Specifically, the photosensitive polymer may be dried or filmed or liquid. When the photosensitive polymer is a dry film, it is applied by a lamination method of heating, pressing and compressing the same on the base plate 110. When the photosensitive polymer is a liquid, the base plate ( 110 is applied by a spin coating method. When the photosensitive polymer coated on the base plate 110 is selectively exposed using the photomask protecting the ink chamber 122 and the portion where the ink flow path is to be formed, the exposed portion is cured so that chemical resistance and high mechanical Strength. Subsequently, when the uncured portion of the photosensitive polymer is dissolved and removed by using a solvent, the ink chamber 122 and the ink flow path are formed, and the portion cured by exposure forms the flow path plate 120 surrounding them. .

Finally, as shown in FIG. 4J, the nozzle plate 130 having the nozzle 132 is formed on the flow path plate 120. The nozzle plate 130 is made of polyimide or nickel, and is heated and pressed onto the flow path plate 120 by using the adhesiveness of the photosensitive polymer forming the flow path plate 120. This completes the inkjet printhead according to the present invention.

Although the preferred embodiments of the present invention have 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 printhead in the present invention may use materials not illustrated. In addition, the specific numerical values exemplified in each step may be adjusted beyond the exemplified ranges within the range in which the manufactured printhead can operate normally. In addition, as a method of laminating and forming each material is merely illustrated, various deposition methods may be applied. In particular, since the present invention has a main feature in the laminated structure and method of the base plate, the flow path plate and the nozzle plate laminated thereon can be formed by various other methods known from the above method. For example, the nozzle plate may be integrally formed using the same material as the flow path plate. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

As described above, according to the present invention, since the heater is formed after the formation of the conductive wire, both the conductive wire and the heater can be formed by dry etching. Accordingly, the conductive wire and the heater can be patterned uniformly and finely, and the conductive wire and the heater have a uniform pattern and electrical and thermal characteristics as a whole. In addition, an ion implantation layer is formed at the interface between the conductive wire and the heater, thereby reducing the interface resistance.

Claims (15)

A substrate, an insulating layer formed on the substrate, a heater formed on the insulating layer to generate thermal energy, a conductive wire formed on the insulating layer so as to be connected below both end portions of the heater, and at least the heater and the conductive wire. A base plate including an ion implantation layer formed at an interface therebetween to reduce interfacial resistance, a protective layer formed on the entire surface of the substrate to cover the heater and the conductive wire, and a cavitation prevention layer formed on the protective layer; A flow path plate stacked on the base plate and defining an ink chamber in which ink is filled and an ink flow path for supplying ink to the ink chamber; And And a nozzle plate stacked on the flow path plate and having nozzles through which ink is discharged at a position corresponding to the ink chamber. The method of claim 1, And the ion implantation layer is formed in an interface between the heater and the conductive wire, an interface between the heater and the insulating layer, and in the conductive wire. The method according to claim 1 or 2, The ion implantation layer is inkjet printhead, characterized in that made of any one material selected from the group consisting of B, BF ₂ , P and Ar. The method of claim 1, And the heater and the conductive wire are formed by dry etching. The method of claim 1, The heater is inkjet printhead, characterized in that made of any one material selected from the group consisting of tantalum nitride, tantalum-aluminum, titanium nitride and tungsten silicide. The method of claim 1, And the conductive wire is made of any one material selected from the group consisting of aluminum, aluminum alloy, and tungsten. (A) forming an insulating layer on the surface of the substrate; (B) depositing a predetermined metal material on the insulating layer and patterning the metal material by dry etching to form a conductive wire; (C) depositing a predetermined resistance heating material on the insulating layer and the conductive wire, and patterning the resistive heating material by dry etching to form a heater connected to the conductive wire; (D) forming an ion implantation layer at an interface between at least the heater and the lead; (E) forming a protective layer on the entire surface of the substrate to cover the heater and the conductive wire; (F) forming a cavitation prevention layer on the protective layer at a position corresponding to the heater; (G) forming a flow path plate defining an ink chamber and an ink flow path on the substrate; And (H) forming a nozzle plate having a nozzle corresponding to the ink chamber on the flow path plate. The method of claim 7, wherein In the step (b), the metal material is an inkjet printhead manufacturing method, characterized in that any one selected from the group consisting of aluminum, aluminum alloy and tungsten. The method of claim 7, wherein In the step (c), the resistance heating material is any one selected from the group consisting of tantalum nitride, tantalum-aluminum, titanium nitride and tungsten silicide. The method of claim 7, wherein In the step (d), the ion implantation layer is implanted into the entire surface of the substrate to form the ion implantation layer in the interface between the heater and the conductive wire, the interface between the heater and the insulating layer and the conductive wire. Manufacturing method. The method according to claim 7 or 10, In the step (d), the ion implantation layer is a method of manufacturing an inkjet printhead, characterized in that made of any one material selected from the group consisting of B, BF ₂ , P and Ar. The method of claim 7, wherein The step (d) comprises the step of performing annealing after ion implantation. The method of claim 12, And the annealing is performed at a temperature of 200 ° C. or higher. The method of claim 7, wherein In the step (d), after the ion is implanted in a direction perpendicular to the surface of the heater and the conductive wire, the substrate is inclined by a predetermined angle to perform ion implantation, characterized in that the ion implantation again. The method of claim 14, The inclination angle of the substrate is a manufacturing method of the inkjet printhead, characterized in that 7 ° ~ 40 °.