JP2013000911A - Method for manufacturing liquid jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid jet head capable of inhibiting variance or lowering of liquid jetting characteristic, and inhibiting peeling of a nozzle plate and leakage of liquid.SOLUTION: In the method for manufacturing the liquid jet head, a nozzle plate 20, having a nozzle opening 21 from which liquid is jetted, and a channel formation substrate 10, on which a channel that communicates with the nozzle opening 21 is formed, are bonded through an adhesive 25. The method for manufacturing the liquid jet head includes: a step of forming resist at least on an inner surface of the nozzle opening 21 of a silicon substrate on which the nozzle opening 21 is formed; a step of dry-etching a bonded surface 20b, bonded to the channel formation substrate 10, of the silicon substrate on which the resist is formed; a step of forming the nozzle plate 20 by removing the resist on the silicon substrate subjected to dry etching; and a step of bonding the bonded surface 20b of the nozzle plate 20 to the channel formation substrate 10 through the adhesive 25.

Description

The present invention relates to a method of manufacturing a liquid ejecting head having a nozzle plate provided with nozzle openings for ejecting liquid.

A typical example of the liquid ejecting head is an ink jet recording head that ejects ink droplets from nozzle openings.

In such an ink jet recording head, a plurality of members are generally assembled through an adhesive. In addition, a nozzle opening is formed in a nozzle plate made of a silicon substrate,
The structure which joined this nozzle plate to the flow-path formation board | substrate with which the flow path was provided via the adhesive agent is disclosed (for example, refer patent document 1 and 2).

JP 2010-240854 A JP 2009-208383 A

However, when a nozzle plate made of a silicon substrate is bonded to the flow path forming substrate via an adhesive, there is a problem that peeling of the nozzle plate or leakage of liquid may occur due to insufficient bonding strength.

Such a problem exists not only in an ink jet recording head but also in a method of manufacturing a liquid ejecting head that ejects liquid other than ink.

SUMMARY An advantage of some aspects of the invention is that it provides a method for manufacturing a liquid jet head capable of suppressing variations in liquid jetting characteristics and a decrease in liquid jetting characteristics, thereby suppressing separation of a nozzle plate and liquid leakage. To do.

An aspect of the present invention that solves the above problem is that a nozzle plate having a nozzle opening through which a liquid is ejected and a flow path forming substrate on which a flow path communicating with the nozzle opening is formed are bonded via an adhesive. A method of manufacturing a liquid jet head, the step of forming a resist on at least the inner surface of the nozzle opening of the silicon substrate on which the nozzle opening is formed, and the flow path forming substrate of the silicon substrate on which the resist is formed A step of dry etching a bonding surface to be bonded to the substrate, a step of forming the nozzle plate by removing the resist of the dry-etched silicon substrate, and bonding the bonding surface of the nozzle plate to the flow path forming substrate And a step of bonding via an agent.
In this aspect, the rough surface can be formed by dry etching the bonding surface of the nozzle plate with the flow path forming substrate, and the bonding strength between the nozzle plate and the adhesive can be improved. Further, by protecting the nozzle opening from being dry-etched, it is possible to suppress variations in the liquid ejection characteristics and obtain stable liquid ejection characteristics.

Here, an oxide film is formed on at least the bonding surface of the silicon substrate,
The step of dry etching the bonding surface of the silicon substrate is preferably performed so that the oxide film remains on the bonding surface. According to this, even if the liquid enters the interface between the nozzle plate and the adhesive, it is possible to suppress the nozzle plate from being eroded by the oxide film.

Preferably, the method further includes a step of forming an oxide film on at least the bonding surface after the step of dry etching the bonding surface of the silicon substrate. According to this, even if the liquid enters the interface between the nozzle plate and the adhesive, it is possible to suppress the nozzle plate from being eroded by the oxide film.

In the step of forming the resist on the silicon substrate, it is preferable to form the resist over the surface of the flow path forming substrate that communicates with the flow path. According to this, it can suppress that durability with respect to the liquid of a nozzle plate falls.

Preferably, the method further includes a step of forming the nozzle opening by dry etching the silicon substrate before the step of forming the resist on the silicon substrate. According to this, the nozzle opening can be easily and accurately formed by dry etching.

FIG. 2 is an exploded perspective view of a recording head according to Embodiment 1 of the invention. 2A and 2B are a plan view and a cross-sectional view of the recording head according to Embodiment 1 of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view of an ink jet recording head that is an example of a liquid jet head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a cross-sectional view of the ink jet recording head.

As shown in the drawing, the flow path forming substrate 10 constituting the ink jet recording head I is composed of a silicon substrate (silicon single crystal substrate) in this embodiment, and an elastic film mainly composed of silicon oxide on one surface thereof. 50 is formed. A pressure generating chamber 12 is formed on the flow path forming substrate 10 by anisotropic etching from the other surface side which is the surface opposite to the one surface. The pressure generating chambers 12 partitioned by a plurality of partition walls are arranged side by side along a direction in which a plurality of nozzle openings 21 that eject ink of the same color are arranged in parallel. Hereinafter, this direction is referred to as a juxtaposed direction of the pressure generating chambers 12 or a first direction, and a direction orthogonal to the first direction is referred to as a second direction.

Further, on the outer side in the second direction of the pressure generating chambers 12 in each row, a manifold 100 is formed which communicates with a manifold portion 31 provided on a protective substrate 30 described later and serves as a common ink chamber for the pressure generating chambers 12. A communication portion 13 is formed. The communication unit 13 includes an ink supply path 14.
And one end portion of each pressure generating chamber 12 in the second direction through the communication passage 15. That is, the flow path forming substrate 10 is formed with a flow path including the pressure generation chamber 12, the communication portion 13, the ink supply path 14, and the communication path 15.

Further, a nozzle plate 20 in which a nozzle opening 21 communicating with the side opposite to the ink supply path 14 of each pressure generating chamber 12 is formed on the opening surface side of the flow path forming substrate 10 is bonded via an adhesive 25. Has been.

The nozzle plate 20 is formed of a silicon substrate, in this embodiment, a silicon single crystal substrate. The nozzle opening 21 is provided on the bonding surface 20b side of the first nozzle opening 21a provided on the liquid ejecting surface 20a side from which the ink droplets are ejected and the flow path forming substrate 10, and from the first nozzle opening 21a. And a second nozzle opening 21b having a large inner diameter.

In the present embodiment, the surface of the nozzle plate 20 on the bonding surface 20b side and the nozzle opening 2 are also provided.
An oxide film 22 is provided over the inner surface of 1. In this embodiment, silicon oxide (SiO ₂ ) is provided as the oxide film 22.

Although not particularly illustrated, on the surface of the nozzle plate 20 on the liquid ejection surface 20a side,
A liquid repellent film (ink repellent film) is provided. The liquid repellent film is not particularly limited, and for example, a metal film containing a fluorine-based polymer, a plasma polymerized film obtained by plasma polymerization of siloxane, or the like can be used.

On the other hand, an insulating film 55 mainly composed of zirconium oxide is formed on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10. Further, the piezoelectric actuator 3 in which the first electrode 60, the piezoelectric layer 70, and the second electrode 80 are stacked on the insulator film 55.
00 (pressure generating means of this embodiment) is formed. Here, the piezoelectric actuator 3
00 is a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. In general,
One electrode of the piezoelectric actuator 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the first electrode 60 is used as a common electrode for the piezoelectric actuator 300 and the second electrode 80 is used as an individual electrode for the piezoelectric actuator 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In the above-described example, the elastic film 50, the insulator film 55, and the first electrode 60 function as a diaphragm. However, the present invention is not limited to this. For example, the elastic film 50 and the insulator film 55 are provided. Without first
Only the electrode 60 may act as a diaphragm. The piezoelectric actuator 3
00 itself may substantially double as a diaphragm.

Each second electrode 80, which is an individual electrode of the piezoelectric actuator 300, has an ink supply path 14.
A lead electrode 90 made of, for example, gold (Au) or the like, which is drawn out from the vicinity of the end on the side and extends to the insulator film 55 is connected.

On the flow path forming substrate 10 on which such a piezoelectric actuator 300 is formed, that is,
On the first electrode 60, the insulator film 55, and the lead electrode 90, a protective substrate 30 having a manifold portion 31 constituting at least a part of the manifold 100 is bonded via an adhesive 35. In this embodiment, the manifold portion 31 penetrates the protective substrate 30 in the thickness direction and is formed across the width direction of the pressure generating chamber 12. As described above, the communication portion 13 of the flow path forming substrate 10. The manifold 100 is configured as a common ink chamber for the pressure generation chambers 12. Further, the communication portion 13 of the flow path forming substrate 10 may be divided into a plurality of pressure generation chambers 12, and only the manifold portion 31 may be used as the manifold 100. Further, for example, only the pressure generation chamber 12 is provided in the flow path forming substrate 10, and a manifold and a member (for example, the elastic film 50, the insulator film 55, etc.) interposed between the flow path forming substrate 10 and the protective substrate 30 are provided. Each pressure generation chamber 12
An ink supply path 14 that communicates with each other may be provided.

Further, the piezoelectric actuator holding portion 32 having a space that does not hinder the movement of the piezoelectric actuator 300 in a region facing the piezoelectric actuator 300 of the protective substrate 30.
Is provided. The piezoelectric actuator holding part 32 only needs to have a space that does not hinder the movement of the piezoelectric actuator 300, and the space may be sealed or unsealed.

As such a protective substrate 30, it is preferable to use substantially the same material as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, ceramic material, etc. In this embodiment, the same material as the flow path forming substrate 10 is used. The silicon single crystal substrate was used.

The protective substrate 30 is provided with a through hole 33 that penetrates the protective substrate 30 in the thickness direction. The vicinity of the end of the lead electrode 90 drawn from each piezoelectric actuator 300 is provided so as to be exposed in the through hole 33.

A drive circuit 110 for driving the piezoelectric actuators 300 arranged in parallel is fixed on the protective substrate 30. As the drive circuit 110, for example, a circuit board, a semiconductor integrated circuit (IC), or the like can be used. Then, the drive circuit 110 and the lead electrode 9
0 is electrically connected via a connection wiring 111 made of a conductive wire such as a bonding wire.

In addition, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility, and one surface of the manifold portion 31 is sealed by the sealing film 41.
The fixing plate 42 is formed of a relatively hard material. Since the region of the fixing plate 42 facing the manifold 100 is an opening 43 that is completely removed in the thickness direction,
One surface of the manifold 100 is sealed only with a flexible sealing film 41.

In such an ink jet recording head I of this embodiment, after taking ink from an ink introduction port (not shown) and filling the interior from the manifold 100 to the nozzle opening 21, according to the recording signal from the drive circuit 110, Applying a voltage between each of the first electrode 60 and the second electrode 80 corresponding to the pressure generating chamber 12 to cause the elastic film 50, the insulator film 55, the first electrode 60, and the piezoelectric layer 70 to bend and deform. As a result, the pressure in each pressure generating chamber 12 increases and ink droplets are ejected from the nozzle openings 21.

Here, a method for manufacturing such an ink jet recording head, particularly a method for manufacturing a nozzle plate, will be described in detail. 3 to 6 are cross-sectional views showing a method for manufacturing the ink jet recording head.

First, as shown in FIG. 3A, a mask film 121 made of silicon oxide (SiO ₂ ) is formed on the surface of the silicon substrate 120 by thermally oxidizing the silicon substrate 120 that becomes the nozzle plate 20.

Next, as shown in FIG. 3B, the mask film 12 on the bonding surface 20 b side of the silicon substrate 120.
1 is patterned by etching. Here, the patterning of the mask film 121 is performed in accordance with the shape of the nozzle opening 21. In the present embodiment, since the nozzle opening 21 includes the first nozzle opening 21a and the second nozzle opening 21b, the opening 122 is formed in a shape matching the first nozzle opening 21a and the second nozzle opening 21b. Specifically, the opening 122 is formed by penetrating a portion that becomes the first nozzle opening 21a of the nozzle opening 21 and half-etching a portion that becomes the second nozzle opening 21b. Such patterning with different opening areas can be formed by using resists with different opening shapes twice. The mask film 121 can be etched by wet etching using a hydrofluoric acid aqueous solution or the like.

Next, as shown in FIG. 3C, the first nozzle opening 21 a is formed by anisotropically etching (dry etching) the silicon substrate 120 through the mask film 121.

Next, as shown in FIG. 3D, only the portion of the mask film 121 that becomes the second nozzle opening 21b is removed. In this embodiment, it was removed by wet etching (half etching) using a hydrofluoric acid aqueous solution or the like. Thereby, the opening part 122 opens with the same opening area as the 2nd nozzle opening 21b.

Next, as shown in FIG. 4A, the silicon substrate 120 is anisotropically etched (dry etching) through the mask film 121, whereby the first nozzle opening 21a and the second nozzle opening 2 are formed.
Nozzle opening 21 composed of 1b is formed.

Next, as shown in FIG. 4B, after removing the mask film 121 of the silicon substrate 120,
An oxide film 22 made of silicon oxide is formed over the surface of the silicon substrate 120. In the present embodiment, the oxide film is formed across both the surface of the silicon substrate 120 where the nozzle opening 21 is opened and the opposite surface, and the inner surface of the nozzle opening 21. Note that the mask film 121 can be removed using a hydrofluoric acid aqueous solution. Further, the oxide film 22 can be formed by heating the silicon substrate 120 to thermally oxidize the silicon substrate 120 over the surface thereof. Of course, the oxide film 22 may be formed by sputtering, MOD, or the like.

Next, as shown in FIG. 4C, the support substrate 130 is bonded to the bonding surface 20b of the silicon substrate 120 on the second nozzle opening 21b side. As the support substrate 130, glass, a silicon single crystal substrate, or the like can be used. In addition, as a method for bonding the support substrate 130, for example, a double-sided tape 131 having a self-peeling layer whose adhesive strength is reduced by stimulation such as ultraviolet rays or heat can be used.

Next, as shown in FIG. 5A, the silicon substrate 120 is thinned to a predetermined thickness from the surface opposite to the surface bonded to the support substrate 130 (bonding surface 20b), and the first nozzle The tip of the opening 21a is opened. In this embodiment, the surface of the silicon substrate 120 opposite to the surface bonded to the support substrate 130 is thinned by grinding. In addition, after grinding the silicon substrate 120,
The ground surface is polished by a polisher or a CMP (Chemical Mechanical Polishing) apparatus. The surface on which the silicon substrate 120 is polished in this way is the liquid ejection surface 2 on which ink droplets are ejected.
0a. Therefore, although not particularly shown, a liquid repellent film (ink repellent film) is formed on the polishing surface (liquid ejection surface).

Next, as shown in FIG. 5B, the inner surface of the nozzle opening 21 is covered with a resist 140. In the present embodiment, when the silicon substrate 120 is bonded to the flow path forming substrate 10 as the nozzle plate 20, the resist 140 is provided on the inner surface communicating with the pressure generation chamber 12. That is, the resist 140 is provided in a region that fills the nozzle opening 21 and faces the pressure generation chamber 12 of the silicon substrate 120 (nozzle plate 20).

Next, as shown in FIG. 5C, the bonding surface 20b side of the silicon substrate 120 is dry-etched. Thereby, the bonding surface 2 not covered with the resist 140 of the silicon substrate 120.
0b can be the rough surface 20c. That is, the dry etching of the silicon substrate 120 is appropriately performed under the condition that the surface (bonding surface 20b) of the silicon substrate 120 becomes the rough surface 20c.

Further, although the oxide film 22 is provided on the bonding surface 20b, the dry etching of the silicon substrate 120 of the present embodiment is performed so that the oxide film 22 remains without being completely removed.

Next, as shown in FIG. 6A, the resist 140 on the silicon substrate 120 is removed. Thereby, the nozzle plate 20 provided with the nozzle openings 21 is manufactured.

Then, as shown in FIG. 6B, the joint surface 20b of the nozzle plate 20 manufactured in this way is bonded to the surface of the flow path forming substrate 10 where the pressure generating chamber 12 is opened via an adhesive 25.

At this time, since the region bonded to the flow path forming substrate 10 on the bonding surface 20b of the nozzle plate 20 is a rough surface 20c by dry etching, the bonding strength between the nozzle plate 20 and the adhesive 25 is increased by the anchor effect. Can be improved. In this way, by improving the bonding strength between the adhesive 25 and the nozzle plate 20 to be bonded to the flow path forming substrate 10, breakage such as peeling of the nozzle plate 20 from the flow path forming substrate 10 and ink from the bonded portion. Leakage etc. can be suppressed.

In the present embodiment, only the joint surface 20b of the nozzle plate 20 with the flow path forming substrate 10 is dry-etched to be a rough surface 20c, and at least the inner surface of the nozzle opening 21 is not roughened. For this reason, it can suppress that the tolerance with respect to the ink of the nozzle opening 21 falls, and can suppress that the discharge characteristic of an ink drop changes with the case where it does not dry-etch with the case where the joint surface 20b is dry-etched. . Incidentally, if the inner surface of the nozzle opening 21 is roughened by dry etching, the resistance to the ink on the inner surface of the nozzle opening 21 is reduced, and the behavior of the meniscus of the ink formed in the nozzle opening 21 is changed. A change occurs in the ejection characteristics of the ink droplets. In this embodiment, the nozzle opening 2
Since 1 is formed by dry etching, the inner surface of the nozzle opening 21 is a dry-etched surface. However, the dry etching that forms the nozzle opening 21 is the dry etching that forms the rough surface 20c on the bonding surface 20b described above. The processing surface is not rougher than.

In the present embodiment, the oxide film 22 remains on the bonding surface 20b. For this reason,
Even if the ink enters the interface between the nozzle plate 20 and the adhesive 25, the oxide film 22 can suppress the erosion of the nozzle plate 20 by the ink.

In the present embodiment, the flow path forming substrate 10 side is not particularly described. However, if the bonding surface to which the nozzle plate 20 of the flow path forming substrate 10 is bonded is roughened by dry etching, the flow path forming substrate 10 side is formed. Improving the bonding strength between the forming substrate 10, the adhesive 25 and the nozzle plate 20,
Destruction such as peeling or ink leakage can be more reliably suppressed.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above. For example, in Embodiment 1 described above, the oxide film 22 is provided on the silicon substrate 120 so that the oxide film 22 remains when the bonding surface 20b is dry-etched. However, the present invention is not particularly limited thereto. After the dry etching of 20b, the oxide film 22 may not be present on the bonding surface 20b. In this case, a step of forming the oxide film 22 on the bonding surface 20b after dry-etching the bonding surface 20b may be added. In addition,
The state in which the oxide film 22 is not present on the bonding surface 20b after the bonding surface 20b is dry-etched means that the oxide film 22 is completely removed by dry-etching the bonding surface 20b, or the bonding surface 20b is dry-etched. This includes the case where the step of removing the oxide film 22 has been performed before the process.

Of course, after the bonding surface 20b is dry-etched and the oxide film 22 is not formed on the bonding surface 20b, the bonding surface 20b is dry-etched to the rough surface 20c, so that the nozzle plate 20 and the adhesive can be used. The bonding strength with 25 can be improved.

Furthermore, in Embodiment 1 described above, the thin film type piezoelectric actuator 300 has been described as the pressure generating means for causing a pressure change in the pressure generating chamber 12, but the present invention is not particularly limited thereto. For example, a green sheet is attached. It is possible to use a thick film type piezoelectric actuator formed by such a method, a longitudinal vibration type piezoelectric actuator in which piezoelectric materials and electrode forming materials are alternately stacked and expanded and contracted in the axial direction. In addition, as a pressure generating means, a heating element is arranged in the pressure generating chamber, and droplets are ejected from the nozzle by bubbles generated by heat generation of the heating element, or static electricity is generated between the diaphragm and the electrode. A so-called electrostatic actuator that deforms the diaphragm by electrostatic force and discharges droplets from the nozzle can be used.

In addition, the present invention is intended for a wide range of liquid ejecting heads in general, for example, for manufacturing recording heads such as various ink jet recording heads used in image recording apparatuses such as printers, and color filters such as liquid crystal displays. The present invention can also be applied to a coloring material ejecting head, an organic EL display, an electrode material ejecting head used for forming electrodes such as an FED (field emission display), a bioorganic matter ejecting head used for biochip manufacturing, and the like.

I ink jet recording head (liquid jet head), 10 flow path forming substrate, 12
Pressure generation chamber, 20 nozzle plate, 20a liquid ejection surface, 20b joint surface,
20c rough surface, 21 nozzle opening, 21a first nozzle opening, 21b second nozzle opening, 22 oxide film, 30 protective substrate, 40 compliance substrate, 50 elastic film, 55 insulator film, 60 first electrode, 70 piezoelectric layer 80 Second electrode,
90 lead electrode, 100 manifold, 110 drive circuit, 120 silicon substrate, 300 piezoelectric actuator

Claims (5)

A nozzle plate having nozzle openings through which liquid is ejected;
A flow path forming substrate in which a flow path communicating with the nozzle opening is formed, and a manufacturing method of a liquid ejecting head bonded with an adhesive,
Forming a resist on at least an inner surface of the nozzle opening of the silicon substrate on which the nozzle opening is formed;
Dry etching a bonding surface bonded to the flow path forming substrate of the silicon substrate on which the resist is formed;
Removing the resist of the dry-etched silicon substrate to form the nozzle plate;
And a step of bonding the bonding surface of the nozzle plate to the flow path forming substrate via an adhesive. An oxide film is formed on at least the bonding surface of the silicon substrate, and the step of dry etching the bonding surface of the silicon substrate is performed so that the oxide film remains on the bonding surface. The method of manufacturing a liquid jet head according to claim 1. The method of manufacturing a liquid jet head according to claim 1, further comprising a step of forming an oxide film on at least the bonding surface after the step of dry etching the bonding surface of the silicon substrate. 4. The liquid jet according to claim 1, wherein in the step of forming the resist on the silicon substrate, the resist is formed over a surface of the flow path forming substrate that communicates with the flow path. Manufacturing method of the head. 5. The method according to claim 1, further comprising a step of forming the nozzle opening by dry etching the silicon substrate before the step of forming the resist on the silicon substrate. Manufacturing method of liquid jet head of

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