JP4428176B2 - Nozzle plate manufacturing method and droplet discharge head manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing a nozzle plate of a droplet discharge head such as an inkjet head that discharges ink droplets only when recording is required, a method of manufacturing a droplet discharge head, a droplet discharge head obtained by the manufacturing method, and The present invention relates to a droplet discharge device including the droplet discharge head.

A droplet discharge head is generally used as an inkjet head of an inkjet recording apparatus. An ink jet recording apparatus provided with an ink jet head includes a nozzle plate in which a plurality of nozzle holes for discharging droplets are formed. In the nozzle plate, in order to improve the ink ejection characteristics of each nozzle of the inkjet head, first nozzle holes and second nozzle holes having different diameters are formed in the nozzle plate and stepped from the rear end side toward the front end side. There has been proposed one in which a nozzle having a smaller cross section is formed (see, for example, Patent Document 1). In this technique, in order to adjust the length of the nozzle hole that affects the flow path resistance in the nozzle hole portion, after forming a plurality of nozzle holes having a stepped cross section in the nozzle plate, the nozzle plate is connected to the Si substrate. Only the region including the nozzle hole is dug down by anisotropic wet etching on the surface opposite to the bonding surface, so that the nozzle hole length is adjusted.

However, if the discharge surface where the nozzle hole is open is located at a position deeper than the substrate surface, paper droplets may be bent from the desired flight path or cause paper clogging of the nozzle hole. There has been a problem that wiping work for wiping the surface from the discharge surface becomes difficult.

In recent years, the entire nozzle plate is polished to a desired thickness to make it thinner, so that the nozzle hole length is first adjusted to the desired length, and then the nozzle holes that can improve the ink ejection characteristics as described above. A technique for forming by dry etching (see Patent Document 2) has been proposed. According to this technology, it is possible to solve the problem of the flight path and the problem during the wiping work.

Japanese Patent Laid-Open No. 11-288820 Japanese Patent Laid-Open No. 9-57981

In the technique of Patent Document 1, when forming the first nozzle hole and the second nozzle hole, an oxide film is formed on the surface of the nozzle plate, a resist is applied on the oxide film and patterned, and the oxide film is formed using the resist as a mask. The first nozzle hole and the second nozzle hole are formed through a process of forming an oxide film in two stages by repeating the same process after that, and the number of manufacturing processes is large and the yield is low. There were still challenges.

Further, according to the technique of Patent Document 2, since the entire nozzle plate is thinned in the initial stage of the manufacturing process, cracks are likely to occur during the subsequent manufacturing process, thereby reducing the yield and increasing the cost. There was a problem of becoming. In the dry etching process for forming the nozzle holes, the entire substrate is inserted into the chamber and the interior is kept under reduced pressure. However, at this time, the processed shape is stabilized. An operation of cooling by blowing He gas or the like from the outside of the chamber toward the back surface of the substrate is performed. For this reason, the following problems have occurred when penetrating the nozzle holes. That is, when the nozzle hole is penetrated, He gas leaks from the through-hole portion into the chamber, thereby increasing the pressure in the chamber and stopping the apparatus due to the interlock function, which makes etching impossible. .

The present invention has been made in view of the above points, and in forming a nozzle hole having a stepped cross section capable of improving discharge characteristics after thinning the Si substrate, while reducing the number of steps, and NOZZLE PLATE MANUFACTURING METHOD CAPABLE OF STABILIZING WITHOUT BREAKS, LIQUID DISCHARGE EJECTING HEAD MANUFACTURING METHOD USING THE SAME An object is to provide a discharge device.

The nozzle plate manufacturing method according to the present invention includes a step of bonding the Si substrate and the support substrate, a step of polishing the Si substrate and grinding to a desired thickness, and a bonding surface of the Si substrate to the support substrate. A step of forming an oxide film by sputtering on the opposite side of the surface, etching the Si substrate, communicating with the first stage nozzle hole and the first stage hole, Forming a nozzle hole having a second-stage hole having a cross-sectional area larger than the cross-sectional area of the hole;
In the step of forming a nozzle hole, patterning the oxide film to form a second dry etching mask for forming a second-stage hole in the Si substrate, and further on The resist is patterned to form a first dry etching mask for forming a first-stage hole in the Si substrate, and dry etching processing using the first dry etching mask and the second dry etching mask as a mask. Are sequentially formed to form a nozzle hole having a first-stage hole and a second-stage hole.
As a result, when forming a nozzle hole having a stepped cross section that can improve discharge characteristics after the Si substrate is thinned, the number of steps can be reduced and the nozzle hole can be stably manufactured without cracks. It becomes possible.

In the nozzle plate manufacturing method according to the present invention, the dry etching is anisotropic dry etching.
Thereby, each of the first-stage hole and the second-stage hole can be etched vertically.

In the nozzle plate manufacturing method according to the present invention, an oxide film is formed by an ECR sputtering apparatus.
Since the ECR sputtering apparatus can form a dense and uniform film thickness, an oxide film having a dense and uniform film thickness can be formed on the Si substrate by using the ECR sputtering apparatus for forming the oxide film. Can do. For this reason, in dry etching when forming the nozzle hole, the thickness of the oxide film that should function as a dry etching mask becomes unevenly thin and the Si substrate surface other than necessary portions is etched away. it can.

Moreover, the nozzle plate manufacturing method according to the present invention is to perform bonding by a resin layer having a bonding function in the bonding process between the Si substrate and the support substrate.
A resin layer having a bonding function can be used for bonding the Si substrate and the support substrate.

In the nozzle plate manufacturing method according to the present invention, in the bonding step between the Si substrate and the support substrate, bonding is performed between the Si substrate and the support substrate with a release layer that is peeled off by light irradiation interposed therebetween. Is.
By interposing the release layer in this way, the peelability between the Si substrate and the support substrate is improved, and it is possible to perform the release in a short time.

In the nozzle plate manufacturing method according to the present invention, the Si substrate is a substrate having a plurality of nozzle regions in which a plurality of nozzle holes are formed, and the Si substrate divides the substrate into individual chips for each nozzle region. The dividing grooves are formed by dry etching simultaneously with the formation of the nozzle holes.
This eliminates the need for dicing for cutting the Si substrate into individual chips.

In addition, a method for manufacturing a droplet discharge head according to the present invention includes a plurality of nozzle holes, an independent discharge chamber communicating with each of the nozzle holes, and a vibration plate that forms a part of the discharge chamber. A method of manufacturing a droplet discharge head that discharges droplets in a discharge chamber from a nozzle hole using the deformation of
A nozzle plate having a plurality of nozzle holes is formed by the above nozzle plate manufacturing method for a droplet discharge head.
Thus, since the nozzle plate constituting the droplet discharge head is manufactured by the nozzle plate manufacturing method of the droplet discharge head, a nozzle hole having a stepped cross section that can improve discharge characteristics is formed on the Si substrate. When forming after thinning, the number of steps can be reduced, and it can be stably manufactured without cracks.

Further, a droplet discharge head according to the present invention includes an independent discharge chamber that communicates with each of a nozzle plate manufactured by the nozzle plate manufacturing method of the droplet discharge head and a plurality of nozzle holes formed in the nozzle plate. And a diaphragm constituting a part of the discharge chamber, and droplets in the discharge chamber are discharged from the nozzle holes by utilizing deformation of the diaphragm.
A droplet discharge head including a nozzle plate having stable ink discharge characteristics manufactured by the above-described nozzle plate manufacturing method for a droplet discharge head can be obtained.

A droplet discharge apparatus according to the present invention includes the above-described droplet discharge head.
It is possible to obtain a droplet discharge device that discharges droplets by a droplet discharge head that is manufactured by the above-described nozzle plate manufacturing method for a droplet discharge head and includes a nozzle plate having stable ink discharge characteristics.

FIG. 1 is a cross-sectional side view of an electrostatic inkjet head which is an example of a droplet discharge head according to the present invention. FIG. 2 is a plan view of the nozzle plate. Here, a description will be given based on an inkjet head having a stacked structure in which three substrates are stacked.

Among the three laminated substrates, the intermediate cavity substrate 1 is made of Si, and has a plurality of independent recess-like discharge chambers 3 having a bottom wall as the diaphragm 2 and for supplying ink to each discharge chamber 3. A concave reservoir 4 and a narrow groove-like orifice 5 connecting the reservoir 4 and each discharge chamber 3 are formed. A SiO ₂ film 6 by thermal oxidation is applied as an insulating film on the entire surface of the cavity substrate 1. This insulating film 6 is for preventing dielectric breakdown and short-circuiting during inkjet driving.

On the upper surface of the cavity substrate 1, a concave portion 11 called a crater that is recessed by about 3 μm from other regions, for example, and a plurality of nozzle holes 12 whose front ends are open on the bottom surface of the concave portions 11 and whose rear ends communicate with the discharge chambers 3 The nozzle plate 10 made of Si and formed with is bonded. As shown in FIG. 2, the recess 11 has a substantially rectangular shape, and has a configuration in which tip openings 13 of a plurality of nozzle holes 12 are arranged in a row on the bottom surface, and the bottom surface of the recess 11 is the ink discharge surface. 14
The nozzle hole 12 is a nozzle having a stepped cross section. That is, the nozzle hole 12 communicates with the first-stage hole 12a and the second-stage hole 12b communicating with the first-stage hole 12a and having a cross-sectional area larger than that of the first-stage hole 12a. It is configured. Therefore, the cross-sectional shape cut along the axial direction of the nozzle hole 12 has a cross-sectional shape that decreases stepwise from the rear end side toward the front end side from which droplets are discharged.

A glass substrate 20 is bonded to the lower surface of the cavity substrate 1, and individual electrodes 21 are formed on portions of the glass substrate 20 that face the diaphragm 2. In addition, the cavity substrate 1 and the glass substrate 20 are formed with an ink supply path 22 that penetrates both substrates from the bottom surface of the reservoir 4, and ink is supplied from an external ink supply source via the ink supply path 22. Supply to the reservoir 4 is possible.

In the ink jet head configured as described above, the diaphragm 2 that defines the bottom surface of each discharge chamber 3 formed in the cavity substrate 1 functions as a common electrode. During the ink droplet ejection operation, a pulse voltage is applied by the drive control circuit 30 between the cavity substrate 1 and the individual electrode 21 facing each diaphragm 2. As a result, the diaphragm 2 facing the individual electrode 21 to which a voltage is applied vibrates due to electrostatic force, and accordingly, the volume of the ejection chamber 3 changes, and ink droplets are ejected from the nozzle holes 12.

Hereinafter, the manufacturing method of a nozzle plate is demonstrated. 3 and 4 are diagrams showing a method for manufacturing a nozzle plate according to an embodiment of the present invention, and correspond to the AA cross section of FIG.

(A) First, a Si substrate 101 having a thickness of 525 μm is prepared, and the nozzle crater 11 is formed on the ink ejection surface 102 side of the Si substrate 101. This nozzle crater 11 is composed of an Si substrate 101
The ink discharge surface 102 is coated with a resist, patterned into a shape corresponding to the nozzle crater 11, and the Si substrate 101 is etched using the resist as an etching mask.
(B) Subsequently, the resin layer 103 having a bonding function such as a resist is coated on the ink ejection surface 102 side of the Si substrate 101, and the Si substrate 101 and the support substrate 104 are overlapped before the resin layer 103 is dried. The resin layer 103 is used for bonding. In this example, the support substrate 104 uses a transparent substrate such as a glass substrate in order to align the nozzle holes 12 in a row with respect to the rectangular pattern of the nozzle crater 11, but the nozzle crater 11 is used in the present invention. Since the nozzle crater 11 is not formed because it is not an essential configuration, a substrate made of another material such as the Si substrate 101 may be used.
(C) The surface opposite to the ink discharge surface 102 of the Si substrate 101 is ground and processed to a predetermined thickness, for example, 90 μm. Further, the crushed layer generated on the ground surface during grinding is removed by spin etching or the like, and processed to a thickness of 60 μm, for example.

(D) SiO ₂ film 1 as an oxide film on the surface of the Si substrate 101 using an ECR sputtering apparatus
05 is deposited. Since the ECR sputtering apparatus can form a film at room temperature, for example, 35
Resin layer 10 such as a resist as in the case of using a CVD apparatus that forms a film at a high temperature of 0 ° C. or higher.
3 is not disassembled. Here, it is desirable to use an ECR sputtering apparatus capable of forming a dense film with good film quality for the formation of the SiO ₂ film 105. However, the ECR sputtering apparatus is not limited to the ECR sputtering apparatus. An apparatus may be used. In short, as long as the SiO ₂ film 105 can be formed at a temperature at which the resin layer 103 such as a resist is not decomposed, it may be formed by another method.
(E) A resist 106 is coated on the surface of the ground surface, and a pattern 107 for forming the second-stage hole 12b of the nozzle hole 12 is formed.

(F) Using the resist 106 on which the pattern 107 is formed as an etching mask, dry etching is performed by an REI dry etching apparatus, and the second stage hole 1 of the SiO ₂ film 105 is formed.
The portion 108 corresponding to 2b is opened to expose the Si substrate surface. This second stage hole 12
The SiO ₂ film 105 in which the portion 108 corresponding to b is opened will be described in detail in the following steps.
It becomes a dry etching mask (second dry etching mask) when the second-stage hole 12b is formed in the i substrate 101. Then, the resist 106 is removed by O ₂ plasma ashing. In addition, buffered hydrofluoric acid aqueous solution (hydrofluoric acid aqueous solution: ammonium fluoride aqueous solution = 1: 6
) To etch the SiO ₂ film 105 in the portion 108 to be the second-stage hole 12b.
May be opened.

(G) The surface of the Si substrate 101 on which the SiO ₂ film 105 is formed is coated with a resist 121 having a film thickness of 1 μm, for example, and the portion 109 for forming the first-stage hole 12a is patterned. The resist 1 in which the portion 109 to be the first-stage hole 12a is patterned
21 is a dry etching mask (first dry etching mask) for forming the first-stage hole 12b in the Si substrate 101, which will be described in detail in the following steps.
(H) Anisotropic dry etching is performed on the Si substrate 101 using the resist 121 in which the portion 109 to be the first-stage hole 12a is formed as a dry etching mask. This
The surface of the Si substrate 101 is etched vertically in a shape corresponding to the portion 109 to be the first-stage hole 12a, and, for example, a groove 112a corresponding to the first-stage hole 12a having a depth of 20 μm is formed. Here, the anisotropic dry etching can use an ICP dry etching apparatus using ICP discharge, and the groove 112a corresponding to the first-stage hole 12a has a cylindrical shape. As an etching gas in this case, for example, C ₄ F ₈ and SF ₆ are used, and these etching gases may be used alternately. Here, C ₄ F ₈ is used to protect the side surface of the groove so that the etching does not proceed to the side surface of the groove 112 a to be formed, and SF ₆ is used to promote the etching of the Si substrate 101 in the vertical direction. . In this dry etching, He gas is blown from the surface opposite to the bonding surface of the support substrate 104 so as to stabilize the processing shape as in the conventional case, and cooling is performed.

(I) The resist 121 is removed by O ₂ plasma ashing. As a result, the SiO ₂ film 105 serving as a dry etching mask appears on the surface in the next dry etching step (J). This dry etching mask is formed in the step (F), and has a portion 108 corresponding to the second-stage hole 12b.
(J) Anisotropic dry etching is performed on the Si substrate 101 using the SiO ₂ film 105 as a dry etching mask. As a result, the etching of the groove 112a corresponding to the first-stage hole 12a proceeds vertically to form the first-stage hole 12a, and has a depth of 40 μm, for example.
A cylindrical second-stage hole 12b of m is formed, and a nozzle hole 12 penetrating the Si substrate 101 is formed. The dry etching in this case also uses an ICP dry etching apparatus using ICP discharge. Here, from the viewpoint of forming the tip opening 13 of the nozzle hole 12 with high accuracy, the resin layer 103 is preferably composed mainly of a material having high resistance to dry etching. With this configuration, the nozzle hole 1 is formed by dry etching the Si substrate 101.
2 is formed, the resin layer 103 functions as an etching stop layer, and the tip opening 13 of the nozzle hole 12 can be accurately formed.

On the contrary, when the resin layer 103 is made of a material mainly composed of a material having low dry etching resistance, the resin layer 103 is also etched together with the Si substrate 101, and the tip opening 1
There is a possibility that the accuracy of 3 cannot be obtained. Further, as described in the above step (H), in dry etching for forming the nozzle holes 12, He gas is blown from the surface opposite to the bonding surface of the support substrate 104 to perform cooling. However, in this example, since the support substrate 104 is bonded to the Si substrate 101, when the nozzle hole 12 is completed through the Si substrate 101, the He gas does not leak as in the conventional case. Etching does not stop.

(K) The SiO ₂ film 105 on the surface of the Si substrate is removed by dry etching using a REI dry etching apparatus or wet etching such as a hydrofluoric acid aqueous solution.
(L) The bonded Si substrate 101 and the support substrate 104 are separated. This separation is caused by the resin layer 1
When a resist is used in 03, the resist layer 103 is dissolved by immersing the whole in a sulfuric acid hydrogen peroxide mixed solution in which sulfuric acid and hydrogen peroxide water are mixed. And finally, S
An ink-resistant protective film such as iO _{2 is} formed, an ink repellent process is performed on the ink ejection surface 14, and the like is cut into pieces by a dicing device, whereby the nozzle plate 10 is completed.

In the above description, the nozzle plate 10 is divided into pieces by cutting with a dicing apparatus. However, the nozzle plate 10 is divided into individual chips at the same time as the nozzle holes 12 are formed. The nozzle plate 10 may be separated into pieces by separating the nozzle plate 10 from the support substrate 104 so as to form grooves. The manufacturing process in this case will be described with reference to FIGS.

FIG. 6 is a plan view of a nozzle plate having divided grooves. The Si substrate 101 has a plurality of nozzle regions 110 in which a plurality of nozzle holes 12 having a stepped cross section are formed, and the Si substrate 101 is divided into individual chips for each nozzle region 110 so as to surround each nozzle region 110. A dividing groove 40 is provided for dividing into two.

7 and 8 are diagrams showing a process of forming the dividing groove, and correspond to the A′-A ′ cross section of FIG. 6. In addition, each process of (E)-(G) in FIG.7 and FIG.8 is fundamentally (E)-(G of FIGS. 3-5.
), And will be described below with a focus on differences from FIGS. 3 to 5.

(E) At the same time as forming the pattern 107 for forming the second-stage hole 12b of the nozzle hole 12 in the resist 106, the pattern 200 for forming the dividing groove 40 is formed.
(F) Using the resist 106 on which the pattern 107 and the pattern 200 are formed as an etching mask, dry etching is performed by an REI dry etching apparatus, and the SiO ₂ film 10
5 is opened by opening the portion 108 corresponding to the second-stage hole 12b and the portion 201 to be the dividing groove.
The surface of the i substrate is exposed.
(G) The portion 202 for forming the dividing groove 40 is patterned simultaneously with the patterning of the portion 109 for forming the first-stage hole in the resist 121.
(H) Dry etching is performed using the resist 121 as an etching mask to form a groove 203 corresponding to a divided groove having a depth of 20 μm, for example, similar to the first-stage hole 12a.
(I) The resist 121 is removed by O ₂ plasma ashing.

(J) Dry etching is performed using the SiO ₂ film 105 as an etching mask. As a result, the etching of the groove 203 proceeds, the tip of the groove 203 reaches the resin layer 103, and the divided groove 40 penetrating the Si substrate 101 is formed.
(K) The SiO ₂ film 105 on the surface of the Si substrate is removed by dry etching using a REI dry etching apparatus or wet etching such as a hydrofluoric acid aqueous solution.
(L) The Si substrate 101 and the support substrate 104 are separated. Here, since the dividing groove 40 penetrates the Si substrate 101, the separation of the Si substrate 101 and the support substrate 104 allows S
The i substrate 101 is in a chip state. Therefore, cutting by dicing is unnecessary. In this case, the formation of an ink-resistant protective film such as SiO ₂ and the ink discharge surface 14
The ink repellent treatment is performed on a chip basis.

In the above-described embodiment, the resin layer 103 is interposed between the Si substrate 101 and the support substrate 104.
In the above description, the case of joining with only the intervening layer is described as an example, but a peeling layer may be further interposed.

FIG. 9 is an explanatory diagram of a peeling process in the case where a peeling layer is further interposed when the Si substrate and the support substrate are bonded with a resin layer.
FIG. 9 shows that after bonding the two substrates with the resin layer 301 and the release layer 302 interposed between the Si substrate 101 and the support substrate 104, the first-stage holes 12 a and the second-stage holes are formed in the Si substrate 101. The state which formed the nozzle hole 12 which consists of this hole 12b is shown. Note that when the Si substrate 101 and the support substrate 104 are bonded when the release layer 302 is interposed, the support substrate 104 alone is inserted into, for example, a CVD apparatus before the two substrates are bonded by the resin layer 301. A release layer 302 is formed on 104, and the surface of the support substrate 104 on the release layer side, and S
The i substrate 101 is bonded with the resin layer 301.

Here, the resin layer 103 absorbs irregularities on the surface of the Si substrate 101 and joins the Si substrate 101 and the support substrate 104, and has a function of joining the Si substrate 101 and the support substrate 104. If it is, it will not specifically limit, Various resin can be used. In particular,
For example, a resin such as a curable adhesive such as a thermosetting adhesive or a photocurable adhesive can be used.

The release layer 302 is for peeling the support substrate 104 from the Si substrate 101. The release layer 302 receives light such as a laser beam and peels off inside the release layer 302 and at the interface with the Si substrate 101 ("
It has a function of causing “in-layer peeling” or “interfacial peeling”). That is,
The peeling layer 302 receives light of a certain intensity, whereby the interatomic or intermolecular bonding force in the atoms or molecules of the constituent material disappears or decreases, causing ablation, etc., and facilitating peeling. It is. The separation layer 302 undergoes separation by receiving light of a certain intensity so that the components in the constituent material of the separation layer 302 are released as a gas, leading to separation, and the separation layer 302 absorbs light. In some cases, it becomes a gas, and its vapor is released, leading to separation.

The material constituting the release layer 302 is not particularly limited as long as it has the above-described function. For example, amorphous silicon (a-Si), silicon oxide or silicate compound, silicon nitride, Nitride ceramics such as aluminum nitride and titanium nitride, organic polymer materials (those whose atomic bonds are broken by light irradiation), metals such as Al, Li, Ti,
Mn, In, Sn, Y, La, Ce, Nd, Pr, Gd, or Sm, or an alloy containing at least one of them can be given.

Among these, it is particularly preferable to use amorphous silicon (a-Si), and it is preferable that hydrogen (H) is contained in the amorphous silicon. This is because when light is received, hydrogen is released and an internal pressure is generated in the peeling layer 302, which can promote peeling. In this case, the hydrogen content in the release layer 302 is preferably about 2 at% or more, and more preferably 2 to 20 at%. In addition, the hydrogen content is determined depending on the film formation conditions of the release layer 302, such as the gas composition, the gas pressure, the gas atmosphere, the gas flow rate, the gas temperature, the substrate temperature, and the power to be applied when using the CVD method. It can be adjusted by appropriately setting the conditions.

When peeling the Si substrate 101 and the support substrate 104 bonded via the resin layer 301 and the release layer 302, a laser having release energy from the back side of the support substrate 104 as shown in FIG. Irradiate light such as light. As a result, peeling (also referred to as “in-layer peeling” or “interfacial peeling”) occurs inside the peeling layer 302 or at the interface with the Si substrate 101, and S
The i substrate 101 can be detached from the support substrate 104. Note that the resin layer 301 is peeled off by hand.

Note that, as described above, when the Si substrate 101 and the support substrate 104 are bonded to each other via the release layer 302, the light emitted from the back side of the support substrate 104 needs to surely reach the release layer 302. For example, a glass substrate is used.

In the above description, the resin layer 301 and the release layer 302 are separate layers.
They may be grouped into two layers. That is, as a layer for bonding the Si substrate 101 and the support substrate 104, the layer has an adhesive force (bonding force) and causes peeling by light, thermal energy, or the like (
You may use what has the effect | action which reduces a joining force. In this case, for example, JP-A-200
The technology described in Japanese Patent No. 2-373771 can be applied.

As described above, according to the present embodiment, the following effects can be obtained.
(1) Since the Si substrate 101 to be the nozzle plate is bonded to the support substrate 104 and the Si substrate 101 is thinned, the substrate in the manufacturing process is compared with the case where the nozzle processing is performed after the Si substrate 101 is thinned in advance. Can be prevented.
(2) Because the nozzle hole 12 formed in the nozzle plate 10 has a stepped cross section,
It can be set as the nozzle with the big effect | action which arranges the direction of the pressure transmitted to the nozzle hole 12 from the discharge chamber 3 side to a nozzle axial direction. For this reason, it is possible to obtain a stable ink discharge characteristic, and to obtain a nozzle plate 10 that can eliminate variations in the flying direction of ink droplets, eliminate scattering of ink droplets, and suppress variations in the amount of ink droplets. be able to.
(3) Since dry etching is performed in a state where the support substrate 104 is bonded to the nozzle, it is possible to prevent the He gas as a cooling gas from leaking from the penetrating nozzle hole 12 and making etching impossible.
(4) When forming the nozzle hole 12 having a stepped cross section on the Si substrate 101, a dry etching mask made of an oxide film (SiO ₂ film) 105 on the Si substrate 101 and the resist 10
6 is combined with the dry etching mask according to No. 6, and the number of steps is reduced as compared with the case of forming a nozzle hole having a stepped cross section after forming an oxide film in two steps as in the prior art. Is possible. That is, in the prior art, the first nozzle hole (
In this example, the resist pattern for forming the etching mask for forming the first stage hole) on the oxide film can be used as a pattern for forming the first stage hole itself on the Si substrate. In addition, the step of forming an etching mask for forming the first-stage hole in the oxide film can be omitted, and the number of steps can be reduced. As described above, in this example, the dry etching mask for forming the first-stage hole 12a is formed of a resist instead of the conventional oxide film, but the resist 121 is compared with the oxide film. Since the etching resistance is low, the dry etching is gradually performed in the same manner as the Si substrate 101. However, the depth of the first-stage hole 12a is about 20 μm here, and the film thickness (here, 1 μm) that can resist the resist 121 to form this depth on the Si substrate 101.
Therefore, the first-stage hole 12a can be formed without any inconvenience.
(5) Since the resin layer 103 relieves stress generated between these substrates during processing due to a difference in linear expansion coefficient due to a difference in material, cracking due to a temperature change during the manufacturing process can also be prevented.

As described above, according to the present invention, when forming the nozzle hole 12 having a stepped cross section capable of improving the discharge characteristics after the Si substrate 101 is thinned, the number of steps is reduced, and It is possible to manufacture stably without cracks.

Also, since anisotropic dry etching is used for dry etching when forming the nozzle holes 12, the surface of the Si substrate 101 is etched vertically to form the first-stage holes 12a and the second-stage holes. 12b can be formed.

Since the SiO ₂ film (oxide film) is formed by the ECR sputtering apparatus, S
A dense SiO ₂ film (oxide film) having a uniform thickness can be formed on the i substrate 101. For this reason, when dry etching is performed when the nozzle holes 12 are formed, the thickness of the SiO ₂ film that should function as a dry etching mask becomes unevenly thin, so that the Si substrate 10 other than the necessary portions is formed.
The inconvenience of etching one surface can be prevented.

Note that the Si substrate 101 to be the nozzle plate 10 and the support substrate 104 can be easily peeled off by using a sulfuric acid hydrogen peroxide mixed solution or the like when a resist is used as the resin layer 103 having a bonding function. In addition, when the resin layer 301 and the release layer 302 are joined as illustrated in FIG. 9, the peelability between the Si substrate and the support substrate is higher than when the resin layer 301 alone is interposed. It becomes good and can be easily peeled off by light irradiation with a laser or the like. Further, in the case of peeling by light irradiation, it is possible to peel in a short time compared to a method using a sulfuric acid hydrogen peroxide mixed solution.

In the present embodiment, an inkjet head used in an inkjet printer has been described. However, the present invention is not limited to this, and the present invention is applied to a nozzle of a droplet discharge device including a nozzle for ejecting / spraying liquid or gas. Can be applied. Further, in this example, the electrostatic driving type is described as the driving method for discharging droplets. However, the present invention is not limited to this, and the present invention is applied to all driving methods such as a piezoelectric driving type and a thermal type. Applicable.

FIG. 3 is a cross-sectional side view of an inkjet head. The top view of the nozzle plate of one embodiment of this invention. The figure which shows the nozzle plate manufacturing method of one embodiment of this invention (the 1). The figure which shows the nozzle plate manufacturing method of one embodiment of this invention (the 2). The figure which shows the nozzle plate manufacturing method of one embodiment of this invention (the 3). The top view of the nozzle plate which has a division groove. The figure which shows the manufacturing process of a division | segmentation groove | channel (the 1). The figure which shows the manufacturing process of a division groove | channel (the 2). Explanatory drawing of the peeling process at the time of interposing a peeling layer between Si substrate and a support substrate.

Explanation of symbols

2 Diaphragm, 3 Discharge chamber, 10 Nozzle plate, 12 Nozzle hole, 12a First stage nozzle hole, 12b Second stage nozzle hole, 40 dividing groove, 101 Si substrate, 103
Resin layer, 104 Support substrate, 105 SiO ₂ film (oxide film), 110 Nozzle region, 12
1 resist, 301 resin layer, 302 release layer.

Claims (7)

Joining the Si substrate and the support substrate;
Polishing the Si substrate and grinding to a desired thickness;
Forming an oxide film by sputtering on a surface of the Si substrate opposite to the bonding surface with the support substrate;
Etching the Si substrate, communicating with the first stage nozzle hole and the first stage hole, the second stage hole having a cross-sectional area larger than the cross-sectional area of the first stage hole Forming a nozzle hole comprising:
Separating the support substrate from the Si substrate,
In the step of forming the nozzle hole, the oxide film is patterned to form a second dry etching mask for forming the second-stage hole in the Si substrate, and a resist is patterned thereon. Forming a first dry etching mask for forming the first-stage hole in the Si substrate, and performing a dry etching process using the first dry etching mask and the second dry etching mask as a mask. A nozzle plate manufacturing method comprising forming the nozzle holes including the first-stage holes and the second-stage holes by sequentially performing the steps.   The nozzle plate manufacturing method according to claim 1, wherein the dry etching is anisotropic dry etching.   3. The nozzle plate manufacturing method according to claim 1, wherein the oxide film is formed by an ECR sputtering apparatus.   The nozzle plate manufacturing method according to claim 1, wherein in the bonding step between the Si substrate and the support substrate, bonding is performed using a resin layer having a bonding function.   5. The nozzle plate according to claim 4, wherein, in the bonding step between the Si substrate and the support substrate, the Si substrate and the support substrate are bonded together with a release layer that is peeled off by light irradiation interposed therebetween. Production method. The Si substrate is a substrate having a plurality of nozzle regions in which a plurality of nozzle holes are formed,
The Si substrate includes a dividing groove for dividing the substrate into individual chips for each nozzle region,
The nozzle plate manufacturing method according to claim 1, wherein the division grooves are formed by dry etching simultaneously with the formation of the nozzle holes.   A plurality of nozzle holes; an independent discharge chamber communicating with each of the nozzle holes; and a diaphragm constituting a part of the discharge chamber. 2. A droplet discharge head manufacturing method for discharging droplets in a chamber, wherein the nozzle plate having the plurality of nozzle holes is formed by the nozzle plate manufacturing method according to claim 1. Manufacturing method.

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