JP2002067327A - Liquid drop jet recording apparatus and manufacturing method for its structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid drop jet apparatus equipped with liquid discharge openings having different depths in the same tip. SOLUTION: In an ink-jet recording head 10, a rectangular big ink discharge opening 20 and a rectangular small ink discharge opening 22 which have different depths on a laminated edge face 18 are formed. When individual channels including these ink discharge openings is manufactured, the shallow small ink discharge opening 22 is protected by a etching protective film, while RIE operation is applied only to the big ink discharge 20. After this operation, the etching protective film is removed, and RIE operation is applied to both the big ink discharge opening and the small ink discharge opening. Thus, the ink discharge openings having different depths are formed with high precision. The ink discharge openings of the different depths provided like these enables printing with the big ink drop by priority of speed and printing with the small ink drop by priority of image quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid droplet ejection recording apparatus for applying energy to a liquid held in a liquid flow path and ejecting the liquid from a nozzle, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a method of manufacturing a droplet jet recording head by forming a silicon substrate into a desired shape by etching and stacking the silicon substrates.

For example, Japanese Patent Application Laid-Open No. 11-227208 (hereinafter referred to as a conventional example) discloses that a print head chip having an aperture shape with good manufacturing accuracy can be manufactured before and after a bubble generation region, and the ejection energy efficiency can be improved. It is disclosed that it is possible to manufacture a droplet jet recording apparatus capable of coping with high resolution.

[0004] This conventional example will be described with reference to FIGS. 19 to 24.

The head chip 100 is formed by laminating a heating element substrate 102 and a flow path substrate 104 as shown in FIG. 19, and as shown in FIG. Ink supply port 1 formed in
The ink supplied from 06 enters the individual flow channel 110 via the common liquid chamber 108 having the step 107, is heated by the heating element 112, and is discharged from the ink discharge port 114 as an ink droplet. The individual flow path 11
At 0, a front stop 116, a rear stop 118, and a recess 132 are formed so that ink droplets are ejected with high energy efficiency by heating by the heating element 112.

A method of manufacturing the flow path substrate 104 constituting the head chip 100 will be described with reference to FIGS.

An SiO ₂ film 122 is formed as a first etching resistant masking layer on a Si substrate 120 (see FIG. 21A) serving as a flow path substrate 104 by a thermal oxidation method (FIG. 21B). Then, the portions of the SiO ₂ film 122 serving as the individual flow channels 110 including the nozzles and the portions serving as the common liquid chambers 108 are patterned using photolithography and dry etching (see FIG. 21C). Si
As shown in FIG. 22A, the mask pattern formed by the O ₂ film 122 is such that the common liquid chamber 108 and the portion that becomes the step portion 107 and the portion that becomes the individual flow channel 110 are connected to each other. A front stop shape 124 serving as a front stop 116 and a rear stop shape 126 serving as a rear stop 118 are provided. Subsequently, low pressure CVD (Chemical vapor D)
An SiN film 128 is formed as a second etching-resistant masking layer by an eposition method (see FIG. 21D). This SiN film 128 is patterned by photolithography and dry etching on a portion serving as the common liquid chamber 108 and the step portion 107 and a portion serving as the concave portion 132 provided in the individual flow channel 110 (FIG. 21).
(E)). The SiN film 128 is formed on the individual channel 110
This serves as a mask for performing preliminary processing for forming a shape in the depth direction to become the concave portion 132 therein, and the SiN film 128 in the portion of the concave portion pattern 130 is removed (see FIG. 22B). ). Further, in this example, since the step 107 is formed together with the concave portion 132, the common liquid chamber 108 and the portion of the SiN film 128 serving as the step 107 are removed.

Subsequently, an SiO ₂ film 134 serving as a phosphoric acid etching protection protective film (third etching resistance masking layer) is formed by a low pressure CVD method (see FIG. 21F). The SiO ₂ film 134 is patterned using photolithography and dry etching (see FIG. 21G). This SiO ₂ film 134 is formed to cover the SiN film 128.

Subsequently, a second SiN film 136 to be a fourth etching resistant masking layer is formed by a low pressure CVD method (see FIG. 21H). A region to be the common liquid chamber 108 is patterned on the SiN film 136 by using a photolithography method and a dry etching method (FIG. 2).
1 (I)). This SiN film 136 is formed as shown in FIG.
As shown in (1), only the portion that becomes the common liquid chamber 108 is removed, and the common liquid chamber pattern 138 is formed.

Here, the Si substrate 120 is etched with a KOH aqueous solution using the SiN film 136 as an etching mask (see FIG. 21 (J)). This etching is performed until the silicon substrate 120 penetrates, and this through hole becomes the ink supply port 106. In this processing, the side wall is formed as a slope having a predetermined angle from the characteristic of wet anisotropic etching similar to the conventional one. The Si substrate 12
The crystal orientation of 0 is the <100> plane. Here, since the processing is performed from one surface of the Si substrate 120, a through hole having a smaller cross-sectional area toward the ink supply port 106 is formed.

Subsequently, the SiN film 136 is selectively removed by etching with a phosphoric acid aqueous solution (see FIG. 21K). At this time, SiO 2 serving as a phosphoric acid etching protection protective film
_Since there are _two films 134, the SiN film 128 thereunder is not eroded.

Next, the SiO ₂ film 134 is selectively removed by etching with an HF solution (see FIG. 21 (L)). Subsequently, wet anisotropic etching using a KOH aqueous solution is performed on the Si substrate 120 using the SiN film 128 as an etching mask (see FIG. 21M). In this wet anisotropic etching, processing is performed to a desired depth without penetrating. As shown in FIG. 22B, the SiN film 128
Since the portions serving as the common liquid chamber 108 and the step 107 are removed, a step having a predetermined depth can be formed on the side wall of the common liquid chamber 108. Also, the SiN film 12
Since the portion to be the concave portion 132 in the individual channel 110 of No. 8 has been removed, the portion to be the concave portion 132 is also etched. As shown in FIG.
Can be formed as a rectangular pattern. By performing wet anisotropic etching using the SiN film 128 having such a pattern formed thereon as an etching mask, a three-dimensional concave portion 132 as shown in FIG. 23 is formed.

Subsequently, the SiN film 128 is selectively removed by etching with a phosphoric acid solution (see FIG. 21N). Subsequently, using the SiO ₂ film 122 as an etching mask,
RIE (Reactive Ion Etching) processing of the substrate 120 is performed (see FIG. 21O). In this RIE processing,
As described above, the portion other than the masked portion can be uniformly etched in the thickness direction without depending on the crystal orientation of Si. In other words, according to the mask pattern shape shown in FIG. 22A, the cross section to become the individual flow path 110 forms a substantially rectangular groove, and the shape formed in the steps up to that point is etched as it is to the processing depth. . For this reason, the concave portion formed at a position in the individual flow channel 110 in the step of FIG. 21M is formed almost as it is at the bottom of the groove to be the individual flow channel 110 while substantially maintaining the shape of the concave portion 132.

Finally, the SiO ₂ film 122 is selectively removed by etching with a hydrofluoric acid solution to complete the processing of the Si substrate 120 to be the flow path substrate 104 (see FIG. 21 (P)). FIG. 24 is a plan view showing an example of a Si substrate 120 serving as a flow path substrate manufactured by this method. By dicing the Si substrate 120 along the dicing line, the ends of the individual flow paths 110 are opened to form the ink discharge ports 114.

As described above, the feature of the present manufacturing method is that, unlike the wet anisotropic etching, by using the RIE method, as shown in FIG.
The individual flow channel 110 having a complicated shape in a plane including 8 and the like can be processed with high accuracy, and desired injection characteristics can be secured.

The groove formed by the RIE process has the same depth over the entire surface of the chip. Therefore, the ink ejection port 114 has a rectangular shape with the same depth (see FIG. 19).

[0017]

In recent years, printers have been required to have a function of ejecting ink droplets having different volumes from the same print head. This includes, for example, how to print high-density characters by ejecting large ink droplets when printing black-and-white characters, and ejecting small ink droplets when ejecting color printing. This is because a method such as “use thinned-out printing with large ink droplets when performing high-speed draft printing, and use small ink droplets when performing high-quality printing” is used.

To meet these demands, a print head may be formed by combining head chips formed according to the volume of each ink droplet. However, the size of the print head increases and the cost increases. .

Further, in the thermal type ink jet system, a slight difference in ink droplet volume can be obtained by adjusting the design dimensions of the heating resistor for generating bubbles and the width of the nozzle, but a sufficiently large difference cannot be obtained.

On the other hand, Japanese Patent Application Laid-Open No. Hei 10-138483
Japanese Patent Application Laid-Open No. H11-163,086 discloses a configuration in which a drive voltage and a pulse width applied to a heating resistor are changed to change a re-ink temperature rising speed, and to change an ink amount contributing to foaming to change an ink ejection amount. I have. In this method, since a plurality of drive voltages are applied to the heating resistor, the cost is increased and the fluctuation range of the ink droplet volume is small.

Japanese Patent Application Laid-Open No. H11-99637 proposes a method of driving a heating resistor for controlling the volume of ink droplets by providing a plurality of heating resistors in the same flow path. Further, Japanese Patent Application Laid-Open No. 10-16221 discloses that a plurality of heating resistors are provided in the same channel, and two heating resistors are driven in the case of a large capacity drop, and one of them is driven in the case of a small capacity drop. A method has been proposed. These methods can also provide an ink volume difference, but have a small fluctuation range.

Further, in the conventional example, the individual flow path (ink ejection port) having a complicated shape can be accurately formed into a cross-sectional shape having a predetermined depth by RIE, but can be formed only at a certain depth. Therefore, the volume of ink droplets ejected from the same chip cannot be changed.

When an individual flow path (ink ejection port) is formed in a silicon substrate using wet anisotropic etching, the cross-section (depth) of a different cross-sectional area (depth) is changed by changing the width of the mask opening. Although a triangular individual flow path can be formed, an ink discharge port having a large cross-sectional area has a disadvantage that the ink discharge ports cannot be densely arranged due to a large width. In addition, it is difficult to accurately form the individual flow path into a complicated shape such as a throttle shape, and the injection energy efficiency cannot be sufficiently increased.

The present invention has been made in view of such problems, and has the advantages of fine processing by RIE (high injection energy efficiency and can respond to high resolution).
It is an object of the present invention to provide a method for manufacturing a droplet ejecting apparatus and a structure in which ink ejection ports having different depths are formed in the same chip.

[0025]

According to the first aspect of the present invention,
A liquid droplet which is formed by laminating a plurality of silicon substrates, a liquid supplied from a liquid supply port reaches a plurality of individual flow paths, and is ejected as a liquid droplet from a liquid discharge port formed at the tip of each individual flow path. An ejection recording apparatus, characterized in that the silicon substrate has a plurality of liquid ejection ports having different depths in a lamination direction in a lamination end face of the silicon substrate.

The operation of the first aspect of the present invention will be described.

In the droplet jet recording apparatus, at least two types of rectangular liquid ejection ports having different stacking depths are formed on the stacking end surface of the stacked silicon substrates. Therefore, when an image is formed using ink as a liquid, by selecting a liquid ejection port and ejecting ink droplets,
Image formation can be switched to image quality priority or speed priority. That is, high-quality image formation can be performed by discharging ink droplets from the liquid discharge ports having a small lamination depth (cross-sectional area), and ink droplets can be discharged from the liquid discharge ports having a large lamination depth (cross-sectional area). By doing so, an image can be formed quickly.

Since the liquid discharge port has a rectangular shape,
The cross-sectional area of the liquid discharge port can be adjusted by the depth in the stacking direction. Therefore, the liquid ejection ports can be arranged at a high density on the lamination end face, and a high-resolution droplet ejecting apparatus can be obtained.

According to a second aspect of the present invention, in the first aspect of the present invention, the first end area in which the liquid discharge ports having the first depth in the stacking direction are arranged on the end face of the stack. There is a second region in which liquid ejection ports having a second depth greater than the first depth in the direction are arranged.

The operation of the second aspect of the present invention will be described.

With this configuration, a relatively small volume droplet is ejected from the liquid ejection port in the first area, and a relatively large volume droplet is ejected from the liquid ejection port in the second area. . Therefore, when ink is used for the liquid, a relatively large-volume ink droplet is ejected from the liquid ejection ports arranged in the second area, so that black character printing with a high density can be performed. On the other hand, high-quality color printing can be performed by discharging relatively small-volume ink droplets using the color ink to the liquid discharge ports arranged in the first area.

According to a third aspect of the present invention, in the first aspect of the present invention, the first liquid discharge port having the first depth in the stacking direction and the first liquid discharge port having the first depth in the stacking direction are deeper than the first depth. 2
The second liquid discharge ports having a depth are alternately arranged on the laminated end face.

The operation of the third aspect of the present invention will be described.

With this configuration, a relatively small volume droplet is discharged from the first liquid discharge port, and the second liquid discharge port is discharged.
Droplets having a relatively large volume are discharged from the liquid discharge ports.

When ink is used as the liquid, the volume of the ink droplet ejected from the second liquid ejection port is large.
Sufficient print density can be achieved without overprinting. Further, if printing is performed using ink droplets having a relatively small volume from the first liquid ejection port, high-quality printing can be achieved.

According to a fourth aspect of the present invention, a plurality of silicon substrates are stacked, and the liquid supplied from the liquid supply port reaches the plurality of individual flow paths, and the liquid formed at the tip of each individual flow path. A droplet ejection recording device ejected as droplets from a discharge port, wherein the individual flow path has a rectangular cross section, and a pressure generating area for applying pressure to a liquid in order to eject a droplet from the liquid discharge port A first throttle portion provided on the liquid supply side with respect to the pressure generation region to reduce the cross-sectional area of the individual flow channel; and a cross-sectional area of the individual flow channel provided on the liquid discharge port side with respect to the pressure generation region. And a second constricted portion that reduces the depth of the second constricted portion in the stacking direction is smaller than the first constricted portion.

The operation of the fourth aspect of the present invention will be described.

By providing the first throttle portion and the second throttle portion on the liquid supply side and the liquid discharge port side with respect to the pressure generation region in the individual flow path, respectively, the pressure efficiently acts on the liquid in the pressure generation region, and Droplets are discharged from the discharge ports.
At this time, since the depth of the second throttle portion in the stacking direction is smaller than that of the first throttle portion, the flow resistance of the second throttle portion is higher than the flow resistance of the first throttle portion. As a result, the refill speed of the liquid with respect to the individual flow path (the pressure generation region) is improved, and the droplet discharge frequency can be improved.

According to a fifth aspect of the present invention, a plurality of silicon substrates are stacked, and the liquid supplied from the liquid supply port reaches the plurality of individual flow paths, and the liquid formed at the tip of each individual flow path. A droplet ejection recording device ejected as droplets from a discharge port, wherein the individual flow path has a rectangular cross section, and a pressure generating area for applying pressure to a liquid in order to eject a droplet from the liquid discharge port A first throttle portion provided on the liquid supply side with respect to the pressure generation region to reduce the cross-sectional area of the individual flow channel; and a cross-sectional area of the individual flow channel provided on the liquid discharge port side with respect to the pressure generation region. And a second constricted portion that reduces the depth of the second constricted portion in the stacking direction is greater than the first constricted portion.

The operation of the invention will be described.

By providing the first throttle portion and the second throttle portion on the liquid supply side and the liquid discharge port side with respect to the pressure generation region in the individual flow path, respectively, the pressure efficiently acts on the liquid in the pressure generation region, and Droplets are discharged from the discharge ports.
At this time, since the depth of the second throttle portion in the stacking direction is deeper than that of the first throttle portion, the flow resistance of the first throttle portion is higher than the flow resistance of the second throttle portion. As a result, the flying speed of the droplet discharged from the liquid discharge port can be further increased.

According to a sixth aspect of the present invention, there is provided the first type having different depths.
A method for manufacturing a structure having a concave portion and a second concave portion, wherein the etching-resistant protective film formed on a silicon substrate includes:
A first step of removing the etching-resistant protective film located on the silicon substrate in a region where the first concave portion is formed by etching using the first mask, and by etching using a second mask different from the first mask A second step of reducing the thickness of the etching-resistant protective film formed on the silicon substrate in a region where the second concave portion is formed, and a region where the first concave portion exposed in the first step is formed; A third step of etching the silicon substrate, a fourth step of etching the etching-resistant protective film over the entire surface of the silicon substrate, and removing the etching-resistant protective film having a reduced thickness in the second step; And a fifth step of etching the silicon substrate exposed in the fourth step.

The operation of the invention according to claim 6 will be described.

In the third step, an etching-resistant protective film (for example, a silicon oxide film) is formed only in a region where the first concave portion is formed.
The silicon substrate is etched in a state in which the first concave portion and the second concave portion are formed in the silicon substrate after the second concave portion is formed. The region to be formed is etched. That is, the region where the first concave portion is formed is etched in the third and fifth steps, and the region where the second concave portion is formed is etched only in the fifth step. It is formed.

The second recess is formed in the fourth step in order to reduce the thickness of the etching-resistant protective film located on the silicon substrate in the region where the second recess is formed in the second step. Even if the etching protection film is etched to remove only the etching protection film in the region, other portions of the etching protection film remain without being removed.

According to an eighth aspect of the present invention, in the first aspect of the invention, a plurality of the liquid discharge ports having different depths in the stacking direction are formed using the silicon substrate formed by the manufacturing method of the sixth or seventh aspect. It is characterized by having been formed.

The operation of the eighth aspect of the present invention will be described.

By forming in this manner, liquid discharge ports having different depths can be formed on the substrate with high accuracy.

[0049]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet recording head (droplet ejection device) according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of an ink jet recording head, and FIGS. 2 and 3 are AA in FIG.
It is a line sectional view and a BB line sectional view.

As shown in FIG. 1, the ink jet recording head 10 has a heating element substrate 12 and a flow path substrate 14 laminated with a protective film 16 interposed therebetween. Large ink ejection ports 20 and small ink ejection ports 22 are formed alternately.

The ink supply port 24 is provided on the upper surface of the flow path substrate 14.
And communicates with a common liquid chamber 28 having a step 26 formed therein (see FIGS. 2 and 3). The common liquid chamber 28 has an individual flow path 30 communicating with the large ink ejection port 20 and an individual flow path 31 communicating with the small ink ejection port 22.
Is in communication with Each of the individual flow paths 30 and 31 has a wide pressure generating region 35 in which a heating element 32 is disposed and a concave portion 34 is formed, and the ink discharge ports 20 and 22 whose widths are reduced with respect to the pressure generating region 35. And a rear throttle 38 on the common liquid chamber 28 side (see FIG. 12).

Therefore, the ink supplied from the ink supply port 24 into the ink jet recording head 10 is:
The ink flows into the individual flow paths 30 and 31 via the common liquid chamber 28, generates bubbles in the pressure generation area 35 by heating the heating element 32, and ink droplets having different volumes from the large ink ejection port 20 or the small ink ejection port 22. Is discharged.

As described above, the ink jet recording head 1
0 indicates that the small ink ejection ports 22 and the large ink ejection ports 20 are alternately arranged. Therefore, when high-speed draft printing is performed, the signal of the address corresponding to the heating element 32 of the individual flow path 30 is selected, so that the large ink ejection port 22 is selected. What is necessary is just to print by discharging a large volume ink droplet from the ink discharge port 20. This is because a sufficient print density can be achieved without overprinting because the volume of the ink droplet is large. On the other hand, by selecting a signal of an address corresponding to the heating element 32 of the individual flow path 31 and printing by discharging a small volume ink droplet from the small ink discharge port 22, high quality printing can be performed.

Next, a method of manufacturing the ink jet recording head 10 will be described with reference to FIGS. FIG.
FIG. 5 is a cross-sectional view of a position of the lamination end face 18 (dicing) in the manufacturing process of the flow path substrate 14, and FIGS. 8 to 10 show the steps of manufacturing the flow path substrate 14 as B
-It is what looked at the B cross section. 4A to 10 show the same manufacturing steps.

Specifically, the depth d as shown in FIG.
A process of manufacturing a Si substrate (flow path substrate 14) in which three large grooves 62 and small grooves 64 having a depth d2 are alternately arranged will be described. The crystal orientation of the Si substrate 40 is the <100> plane.

First, a Si substrate 40 serving as the flow path substrate 14
Against (see FIG. 4 (A) refer), the SiO ₂ film 42 is formed by a thickness t1 as a first etch resistant masking layer by thermal oxidation (Fig. 4, 5, 8 see each (B) ).

Next, the large ink discharge port 2 of the SiO ₂ film 42
The portions that become the individual flow paths 30 including the “0” and the common liquid chamber 28 are patterned using the photolithography method and the dry etching method (see FIGS. 4, 5, and 8C). The mask shape formed by this patterning is shown in FIG.
(A) shows a solid line. That is, the portions of the Si substrate 40 corresponding to the common liquid chamber 28 and the individual flow channel 30 and the portion corresponding to the concave portion 34 of the individual flow channel 31 are exposed.

Subsequently, the individual channels 31 including the small ink discharge ports 22 of the SiO ₂ film 42 are patterned by photolithography and dry etching (FIGS. 4 and 8).
Each (D)). However, at this time, the SiO ₂ film 42 is not entirely removed by etching, but is left by the film thickness t2.

This patterning is shown by a broken line in FIG. As a result, the thickness of the portion of the SiO ₂ film 42 (the cross-hatched portion inside the broken line in FIG. 11A) corresponding to the individual flow channel 31 excluding the concave portion 34 is set to t2.
Hereinafter, the portion having the thickness t2 is referred to as a thin film portion 42A.

Note that, as shown in FIG.
_{In the} mask pattern formed by the _two films 42, the portion serving as the common liquid chamber 28 and the portion serving as the individual flow path 30 are connected to each other. A front throttle shape 44 is provided in the vicinity of a portion to be formed, and the individual flow path 30 at a position to be an ink discharge port is formed in a narrowed pattern. Thin film section 4 corresponding to individual flow path 31
The same applies to the shape of 2A. Subsequently, SiN is used as a second etching resistant masking layer by a low pressure CVD (Chemical vapor Deposition) method.
A film 48 is formed (see FIGS. 5 and 8E). The thickness of the SiN film 48 formed at this time can be, for example, about 300 mm.

The common liquid chamber 28 is
In addition, the portions that become the step portions 26 and the portions that become the concave portions 34 in the individual flow paths 30 and 31 are patterned using photolithography and dry etching (see FIGS. 5 and 8 (F)). An example of the pattern of the SiN film 48 is shown in FIG. The recess pattern 50 formed in the SiN film 48 serves as a mask for performing preliminary processing for forming a shape in the depth direction to be the recess 34 of the individual flow paths 30 and 31. Unless the SiO ₂ film 42 in this portion is completely removed by the concave pattern 50, the Si substrate 40 cannot be anisotropically etched in the steps of FIGS. 6 (N) and 9 (N). In this example, since the common liquid chamber pattern 51 is formed together with the concave pattern 50,
The portion serving as the common liquid chamber 28 and the step 26 is removed.

Subsequently, an SiO ₂ film 52 serving as a phosphoric acid-resistant etching protective film (third etching-resistant masking layer) is formed by a low pressure CVD method (see FIGS. 5 and 8 (G)). The thickness of the SiO ₂ film 52 formed at this time can be, for example, about 500 nm.

The SiO ₂ film 52 is patterned using photolithography and dry etching. The SiO ₂ film 52 is formed to cover the SiN film 48 (see FIGS. 5 and 8 (H)).

Subsequently, a second SiN film 54 to be a fourth etching resistant masking layer is formed by a low pressure CVD method. The thickness of the SiN film 54 formed at this time can be, for example, about 300 nm (see FIGS. 6 and 9 (I)).

With respect to the SiN film 54, the common liquid chamber 28
Is patterned by using photolithography and dry etching (see FIGS. 6 and 9 (J)). An example of the pattern of the SiN film 54 is shown in FIG. In the SiN film 54, a common liquid chamber pattern 56 is formed in which only a portion serving as the common liquid chamber 28 is removed. At this time, the area where the SiN film 54 is to be removed is preferably set to be smaller than the actual size of the common liquid chamber 28 by a predetermined amount.

Subsequently, the Si substrate 40 is etched with a KOH aqueous solution using the SiN film 54 as an etching mask (see FIGS. 6 and 9 (K)). This etching is performed until the silicon substrate 40 penetrates, and the through hole becomes the ink supply port 24. In this process, the side wall is formed as a slope having a predetermined angle due to the characteristics of wet anisotropic etching. Here, since the processing is performed from one surface of the Si substrate 40, a through hole having a smaller sectional area toward the ink supply port 24 is formed. The wet anisotropic etching used here has a higher processing speed than RIE (Reactive lon Etching) and is suitable for processing with a deep processing depth such as to penetrate the Si substrate 40.

Subsequently, the SiN film 54 is selectively removed by etching with a phosphoric acid aqueous solution (see FIGS. 6 and 9 (L)). At this time, SiO 2 serving as a phosphoric acid etching protection protective film
_Since there are _two films 52, the underlying SiN film 48 is not eroded.

Next, the SiO ₂ film 52 is selectively removed by etching with an HF solution (see FIGS. 6 and 9 (M)).

Subsequently, K is applied to Si substrate 40 using SiN film 48 (see FIG. 11B) as an etching mask.
A wet anisotropic etching using an OH aqueous solution is performed (see FIGS. 6 and 9 (N)). In this wet anisotropic etching, processing is performed to a desired depth without penetrating. The processing depth can be, for example, about 200 μm. However, it shall be set shallower than the finishing depth. FIG. 11 (B)
As shown in FIG. 7, the SiN film 48 has a common liquid chamber pattern 51 in which portions that become the common liquid chamber 28 and the step 26 are removed.
Therefore, a step having a predetermined depth can be formed on the side wall of the common liquid chamber 28.

The individual flow paths 30, 31 of the SiN film 48
Since the concave portion pattern 50 in which the concave portion is removed is formed, the concave portion 34 provided in the individual flow channels 30 and 31 is also etched to form the individual flow channel 30 in the depth direction. Is done.

Subsequently, the SiN film 48 is selectively removed by etching with a phosphoric acid solution (see FIGS. 4, 7, and 10 (O)).

Next, a portion of the Si substrate 40 which becomes the individual flow channel 30 including the large ink discharge port 20 and a portion which becomes the concave portion 34 of the individual flow channel 31 is subjected to RIE using the SiO ₂ film 42 as an etching mask to a depth d1. (See FIGS. 4, 7, and 10 (P)). The processing depth can be, for example, about 20 μm. In this RIE processing, the portions other than the masked portions can be uniformly etched in the thicker direction without depending on the crystal orientation of Si. That is, along the mask pattern shape (solid line portion) shown in FIG. 11A, the cross section to be the individual flow path 30 forms a substantially rectangular groove, and the shape formed in the previous steps is also processed as it is. It is etched to the depth.

At this time, the individual flow path 31 including the small nozzle 22
The portion of the Si substrate 40 (excluding the concave portion 34) is shown in FIG.
0 (P), as shown in FIG.
It is not etched because it is covered by the (SiO ₂ film 42). However, as shown in FIG. 4 (P), SiO ₂ film 4
2 is also slightly etched, the film thickness decreases, and the film thickness t1
Is t1 ', and the thickness t2 is t2'.

Subsequently, the SiO ₂ film 42 is etched by RIE, and the individual channels 31 including the small ink discharge ports 22 are etched.
The portion of the SiO ₂ film 42 (thin film portion 42A) which is to be removed is completely removed (see FIGS. 4 and 10 (Q)). Where Si
The remaining portion of the O ₂ film 42 (the portion having the thickness tl ′) is left by the thickness tl ″, that is, FIG.
In the mask pattern shown in (A), the Si substrate 40 is exposed in a form in which the thin film portion 42A has been removed.

At this time, the depth of this portion remains d1 in order to set a condition such that the portion of the Si substrate 40 which becomes the individual flow path 30 including the large ink discharge port 20 is hardly etched.

Further, the Si substrate 40 is etched to a depth d2 by the RIE method (see FIGS. 4, 7, and 10 (R)). At this time, the depth of the part that becomes the individual flow path 31 including the small ink discharge ports 22 is d2, and the depth of the part that becomes the individual flow path 30 that includes the large ink discharge ports 20 is d3.
(= Dl + d2). As a result, rectangular large grooves 62 and small grooves 64 having different depths are formed in the Si substrate 40.

Finally, the SiO ₂ film 42 is selectively etched and removed with a hydrofluoric acid solution to remove the Si 2 serving as the flow path substrate 14.
The processing of the substrate 40 is completed (see FIG. 4 (S)).

By dicing the Si substrate 40 having the large grooves 62 and the small grooves 64 formed in this manner along the dicing lines shown in FIG. 12, the large grooves 62 and the small grooves 64 having different depths are opened at the end faces. The flow path substrate 14 is formed (see FIGS. 13A and 13B). In FIG. 12, in the individual flow channel 31, the portion of the small channel 64 (the concave portion 34) where the portion applied in black is formed shallower than the large groove 62.
Except).

By laminating the flow path substrate 14 and the heat generating element substrate 12 with the protective layer 16 interposed therebetween, the large grooves 62 and the small grooves 64 become the individual flow paths 30 and 31, respectively, and the opening in the lamination end face 18 becomes the ink discharge port. Exits 20 and 22 are provided.

As described above, in this embodiment, first, the large groove 6
Si substrate 4 in a region 2 (see the solid line in FIG. 11A)
Then, the SiO ₂ film 42 on the Si substrate 40 is removed.
The thickness of the O ₂ film 42 is reduced to form a thin film portion 42A. Thereby, first, only the region to be the large groove 62 of the Si substrate 40 can be etched by RIE. Next, S
By etching the iO ₂ film 42 to a predetermined depth,
Only the thin film portion 42A can be removed. By etching the Si substrate 40 again by RIE in this state, the large groove 62 already etched can be formed deeper and the small groove 64 can be formed shallower.

Therefore, the front stop 36 and the rear stop 38
In addition, the individual channels 30 and 31 having complicated shapes can be formed with high accuracy, and rectangular grooves (large grooves 62 and small grooves 64) having different depths can be formed in the silicon substrate 40.

Another advantage of the manufacturing method according to the present embodiment is that the material (SiO ₂ film 42) serving as an etching resistant mask of the Si substrate 40 only needs to be formed once, and the large groove 6 is used.
In order to increase the depth, the Si substrate 40 is etched twice, but the same etching resistant mask (SiO ₂ film 42) is used, so that a shape defect due to misalignment does not occur. (Second Embodiment) Next, an ink jet recording head according to a second embodiment of the present invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The only difference from the first embodiment is the arrangement of the individual flow channels of the flow channel substrate 14, and only the relevant portions will be described.

As shown in FIG. 14, in the ink jet recording head 60, a first area A 1 in which the small ink discharge ports 22 are arranged and a large ink discharge port 2
0 is divided into a second region A2 in which the 0s are arranged.

Therefore, printing is performed using only the second area A2 when ejecting a large volume ink drop, and printing is performed using the first area A1 when ejecting a small volume ink drop.

For example, the large ink ejection port 2 in the first area A1
By discharging black ink from 0, black character printing with high density can be performed, and high quality color printing can be performed by using color ink in the second area A2.

In the first and second embodiments, the ink jet recording head having the ink discharge ports having two kinds of depths has been described. However, it is possible to form the ink discharge ports having three or more kinds of depths in the same way. Can also. (Third Embodiment) Next, an ink jet recording head according to a third embodiment of the present invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The only difference from the first embodiment is the individual flow channel shape of the flow channel substrate 14, and only the relevant portions will be described.

The difference from the first embodiment is that the individual channels 31
Is that the shallow groove region is only on the small ink ejection port 22 side (see FIGS. 15A and 15D). Si
The mask pattern of the O ₂ film 42 can be manufactured by forming the thin film portion 42A only on the front stop side as shown in FIG.

The Si substrate 40 thus formed
By manufacturing the ink jet recording head using the (flow path substrate 14), the flow resistance of the rear stop 38 in the individual flow path 31 can be reduced, the ink refill speed can be improved, and the printing frequency can be improved.

On the other hand, the shallow groove basin in the individual flow path 31 may be provided only on the rear throttle 38 side. In this case, the ink discharge ports in the individual flow paths 31 are the same as the large ink discharge ports 20. By forming in this manner, the flow path resistance on the front throttle 36 side is increased, and the flying speed of the ink droplet ejected from the ink ejection port can be improved.

As described above, by making either the front stop 36 side or the rear stop 38 side shallow in the individual flow path 31, desired ink flying characteristics (ink volume, ink flying speed, frequency characteristics, etc.) are secured. can do.

In these two embodiments, the case where the large ink discharge ports 20 (individual flow paths 30) and the small ink discharge ports 22 (individual flow paths 31) coexist has been described. In view of the flow path resistance adjustment, the present invention can be applied to a case where individual flow paths having the same depth are provided.

For example, as shown in FIG. 16, by forming all of the individual flow paths as individual flow paths 31 (small grooves 64), the sectional area of the individual flow path 31 can be made relative to the volume of the common liquid chamber 28. Can be made smaller. FIG.
As shown in (1), by making all the individual flow paths 72 shallower only on the front throttle 36 side, it is possible to form an ink jet recording head having an improved ink refill speed and an improved printing frequency. Further, the front throttle 3 is relatively high.
When it is desired to sufficiently reduce the flow path resistance on the 6 side, FIG.
As shown in FIG. 8, a shallow groove can be formed only on the rear throttle 38 side of the individual flow path 74.

[0093]

According to the present invention, by forming ink discharge ports having different depths in the same chip, it is possible to eject ink droplets having greatly different volumes, and the ink discharge ports can be arranged at a high density. It is possible to provide a droplet jet recording apparatus capable of achieving high quality printing at low cost. High-speed, high-quality printing is possible with a single head by allocating black ink to relatively deep (large sectional area) ink discharge ports and color ink to shallow (small sectional area) ink discharge ports. A full-color droplet ejection recording apparatus can be provided. Further, by adjusting the flow path resistance before and after the pressure generation region in the individual flow path by the depth of the groove, it is possible to manufacture a droplet jetting apparatus having higher jetting efficiency and good frequency response.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ink jet recording head (head chip) according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a view showing a manufacturing process at a position of a stacked end surface of a silicon substrate.

FIG. 5 is a manufacturing process diagram of the flow path substrate at a cross-sectional position along the line AA in FIG. 1;

FIG. 6 is a manufacturing process diagram of the flow path substrate at a cross-sectional position along the line AA in FIG. 1;

FIG. 7 is a manufacturing process diagram of the flow path substrate at a cross-sectional position along the line AA in FIG. 1;

FIG. 8 is a manufacturing process diagram of the flow channel substrate at a cross-sectional position along line BB of FIG. 1;

FIG. 9 is a manufacturing process diagram of the flow path substrate at a cross-sectional position along the line BB of FIG. 1;

FIG. 10 is a manufacturing process diagram of the flow path substrate at a cross-sectional position along line BB of FIG. 1;

FIG. 11A shows a mask pattern of a SiO ₂ film 42,
(B) is a mask pattern of the SiN film 48, and (C) is Si
6 is a mask pattern of the N film 54.

FIG. 12 is a plan view of an Si substrate in which a large groove and a small groove are formed.

13A is a sectional view taken along line CC in FIG. 12, and FIG. 13B is a sectional view taken along line DD in FIG.

FIG. 14 is a perspective view of an ink jet recording head according to a second embodiment of the present invention.

FIG. 15A is a plan view of a flow path substrate constituting an inkjet recording head according to a third embodiment of the present invention, FIG. 15B is a mask pattern diagram used for manufacturing a flow path substrate, (C) is a sectional view taken along line EE in (A), and (D) is a sectional view taken along line FF in (A).

FIG. 16 is a plan view of a flow path substrate constituting an ink jet recording head according to another example.

FIG. 17 is a plan view of a flow path substrate constituting an inkjet recording head according to another example.

FIG. 18A is a plan view of a flow channel substrate constituting an ink jet recording head according to another example, FIG. 18B is a mask pattern diagram used for manufacturing a flow channel substrate, and FIG.
FIG. 2 is a sectional view taken along line GG in FIG.

FIG. 19 is a perspective view of an ink jet recording head (head chip) according to a conventional example.

20 is a sectional view taken along line HH in FIG. 19;

21 is a process drawing of a flow path substrate at a cross-sectional position taken along the line HH in FIG. 19;

22A is a mask pattern of a SiO ₂ film 122, FIG. 22B is a mask pattern of a SiN film 128, and FIG.
Denotes a mask pattern of the SiN film 136.

FIG. 23 is a cutaway perspective view of the vicinity of a portion serving as an individual flow channel 110 in the Si substrate when the second wet anisotropic etching is performed.

FIG. 24 is a plan view of a flow path substrate constituting an ink jet recording head according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Ink-jet recording head (droplet ejection device) 12 ... Heat generating element substrate 14 ... Flow path substrate 20 ... Large ink discharge port 22 ... Small ink discharge port 24 ... Ink supply port (liquid supply port) 28 ... Common liquid chamber 30, 31 ... individual channel 35 ... pressure generating area 36 ... front aperture (second aperture portion) 38 ... rear stop (first diaphragm portion) 40 ... Si substrate 42 ... SiO ₂ film (anti-etching protective film)

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takayuki Takeuchi 2274 Hongo, Ebina-shi, Kanagawa Fuji Xerox Co., Ltd. On-site F-term (reference) 2C057 AF01 AF06 AF21 AF51 AF93 AG08 AG13 AG30 AG46 AP02 AP34 AP35 AP53 AP56 BA13

Claims (8)

[Claims] A liquid supplied from a liquid supply port reaches a plurality of individual flow paths, and is formed as liquid droplets from a liquid discharge port formed at the tip of each individual flow path. A droplet ejection recording apparatus for ejecting, comprising: a plurality of liquid ejection ports having a rectangular shape having different depths in a lamination direction, on a laminated end surface of the silicon substrate. 2. A first region in which liquid ejection ports having the first depth in the stacking direction are arranged, and a second depth in which the stacking direction depth is greater than the first depth. 2. The droplet ejection recording apparatus according to claim 1, wherein there is a second area in which the liquid ejection ports are arranged. 3. The method according to claim 1, wherein the depth in the stacking direction is a first depth.
2. The droplet jet recording according to claim 1, wherein the liquid discharge ports and the second liquid discharge ports having the second depth whose depth in the lamination direction is greater than the first depth are alternately arranged on the lamination end surface. apparatus. 4. A plurality of silicon substrates are stacked, and a liquid supplied from a liquid supply port reaches a plurality of individual flow paths, and forms liquid droplets from a liquid discharge port formed at the tip of each individual flow path. A droplet ejection recording apparatus that is ejected, wherein the individual flow path has a rectangular cross section, and a pressure generation area for applying pressure to a liquid to eject liquid droplets from the liquid ejection port; and the pressure generation area. A first restrictor provided on the liquid supply side to reduce the cross-sectional area of the individual flow path, and a second restrictor provided on the liquid discharge port side with respect to the pressure generation region to reduce the cross-sectional area of the individual flow path And a depth of the second narrowed portion in the stacking direction is smaller than that of the first narrowed portion. 5. A plurality of silicon substrates are stacked, and a liquid supplied from a liquid supply port reaches a plurality of individual flow paths, and forms a liquid droplet from a liquid discharge port formed at the tip of each individual flow path. A droplet ejection recording apparatus that is ejected, wherein the individual flow path has a rectangular cross section, and a pressure generation area for applying pressure to a liquid to eject liquid droplets from the liquid ejection port; and the pressure generation area. A first restrictor provided on the liquid supply side to reduce the cross-sectional area of the individual flow path, and a second restrictor provided on the liquid discharge port side with respect to the pressure generation region to reduce the cross-sectional area of the individual flow path A liquid ejecting recording apparatus, comprising: a second constricted portion having a greater depth in the stacking direction than the first constricted portion. 6. A method of manufacturing a structure having a first concave portion and a second concave portion having different depths, the method comprising: forming a region of the etching-resistant protective film formed on a silicon substrate where the first concave portion is formed. A first step of removing the etching-resistant protective film located on the silicon substrate by etching using the first mask; and etching using a second mask different from the first mask, thereby forming the second concave portion. A second step of reducing the thickness of the etching-resistant protective film formed on the silicon substrate in the region halfway, and a third step of etching the silicon substrate in the region where the first concave portion exposed in the first step is formed A fourth step of performing etching of the etching-resistant protective film on the entire surface of the silicon substrate and removing the etching-resistant protective film having a reduced thickness in the second step; The method of the structure, characterized in that it comprises a fifth step of etching the silicon substrate exposed in the first step and the fourth step. 7. The method according to claim 6, wherein the etching-resistant protective film is a silicon oxide film. 8. A plurality of liquid discharge ports having different depths in a stacking direction are formed using a silicon substrate formed by the manufacturing method according to claim 6. Description:
The droplet ejection recording apparatus according to the above.