JP2007015129A - Method of manufacturing liquid droplet discharge head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a liquid droplet discharge head which improves a yield by preventing a defect caused by etching and can manufacture an accurate head. <P>SOLUTION: The manufacturing method is designed for use in manufacturing a liquid droplet discharge head 1 having a channel forming substrate 10 in which a plurality of cavities 12 and a communicating portion 13 to make the cavities 12 communicate with each other are formed, and a reservoir forming substrate 30 in which a reservoir portion 31 communicating with the communicating portion 13 is formed. After the channel side substrate to be the precursor of the channel forming substrate 10 and the reservoir forming substrate 30 are pasted, the reservoir forming substrate 30 side is supported on the supporting substrate. By performing patterning to the channel side substrate by dry etching with the channel side substrate and the reservoir forming substrate 30 held on the support, the communicating portion 13 is formed. The cavities 12 are formed on the channel side substrate and the supporting substrate is separated from the reservoir forming substrate 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a droplet discharge head.

In the droplet discharge method, a minute wiring pattern can be formed on a substrate by discharging minute ink droplets in a dot shape from a droplet discharge head, which is used for wiring formation of a semiconductor device, for example.
In general, a droplet discharge head includes a flow path forming substrate including a cavity communicating with a nozzle opening and a communication portion that continues between the cavities, and a piezoelectric element provided on one surface side of the flow path forming substrate. And a reservoir forming substrate having a drive circuit unit that is bonded to the piezoelectric element side of the flow path forming substrate and drives the piezoelectric element.

In recent years, with the progress of miniaturization of semiconductor devices, it is desired to provide a droplet discharge head capable of forming a fine pattern for constituting such a semiconductor device. In addition, for example, by forming the droplet discharge head in a state where the cavities and the communication portions are arranged at a high density, the drawing ability of the droplet discharge head is improved, and a fine pattern can be formed.
As an example of a method for manufacturing such a droplet discharge head, a through hole is formed in a bonding substrate (reservoir forming substrate), and a drive circuit unit and a piezoelectric element are connected by a conductive wire through the through hole. A droplet discharge head in which cavities are arranged at high density is known (for example, see Patent Document 1). In Patent Document 1 described above, the flow path forming substrate is manufactured by forming the cavity and the communication portion in the substrate (the flow path side substrate) by using wet etching, but the flow path side substrate, the flow path side substrate, A method of manufacturing a droplet discharge head in which a cavity and a communication portion are formed in the flow path side substrate by performing wet etching in a state in which is attached can be considered.
JP 2003-246065 A

However, when wet etching is performed on the flow path side substrate in a state where the flow path side substrate and the bonding substrate (cavity forming substrate) are bonded as described above, a bonding substrate is obtained by using a mask or a stopper film. It is necessary to prevent damage caused by the etchant liquid wrapping around the back side of the plate.
At this time, if there is a defect in the mask and the stopper film, the etchant liquid may enter from the defective portion, resulting in a defect, which may reduce the yield of the droplet discharge head. In order to reduce the occurrence of defects due to etching, a process for repairing defects in the mask and the stopper film is required before wet etching, which complicates the manufacturing process.
In addition, as described above, the droplet discharge head is preferably provided with a flow path forming substrate in which cavities and communication portions are formed with higher processing accuracy instead of wet etching in order to cope with the formation of a fine pattern. It is rare.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a droplet discharge head, which can improve the yield by preventing defects caused by etching and can manufacture a highly accurate one. Is to provide.

  The method of manufacturing a droplet discharge head according to the present invention includes a flow path forming substrate in which a plurality of cavities and communication portions that communicate with each other are formed, and a reservoir formation in which a reservoir portion that is in communication with the communication portions is formed. In a method of manufacturing a droplet discharge head comprising a substrate, a flow channel substrate serving as a precursor of the flow channel forming substrate is bonded to the reservoir forming substrate, and then the reservoir forming substrate side is used as a support substrate. Holding the flow path side substrate and the reservoir forming substrate on the support, and performing patterning by dry etching on the flow path side substrate to form a communication portion; and A step of forming a cavity in the substrate; and a step of peeling the support substrate from the reservoir forming substrate.

According to the method for manufacturing a liquid droplet ejection head of the present invention, after the flow path side substrate, which is a precursor of the flow path forming substrate, is bonded to the reservoir forming substrate, the reservoir forming substrate side is held on the support. Therefore, the flow path side substrate and the reservoir forming substrate are in a state having higher rigidity by the support. Therefore, patterning by dry etching can be favorably performed on the flow path side substrate having high rigidity, and a communication portion can be formed. Then, for example, a cavity can be formed by the same dry etching, and a flow path forming substrate in which the communication portion and the cavity are formed can be formed.
Further, by using dry etching, the communication portion can be finely processed. Therefore, the cavities communicated by the communication portion are processed with a high density. Further, it is possible to prevent the occurrence of defects due to the etching solution flowing around the back surface side of the reservoir forming substrate as in wet etching, and the yield in the droplet discharge head can be improved.

Further, it is preferable that the communication portion and the cavity are simultaneously formed in the patterning step by dry etching on the flow path side substrate.
In this way, when dry etching is performed on the flow path side substrate, the communication portion and the cavity can be formed simultaneously. Therefore, the process for manufacturing the droplet discharge head can be simplified.

In the method of manufacturing the droplet discharge head, the flow path side substrate is thinned before the step of dry etching the flow path side substrate after the reservoir forming substrate side is attached to the support. It is preferable to have provided.
Since the thin flow path side substrate is easily cracked, it is difficult to handle it. On the other hand, for example, when a thick channel side substrate is bonded to the reservoir forming substrate, the channel side substrate becomes difficult to break and easy to handle. However, the amount of etching the channel side substrate increases, and the dry etching process is performed. take time.
Therefore, if the present invention is adopted, thin processing such as polishing is performed on the flow path side substrate before dry etching, so that even the thick flow path side substrate does not take time for the dry etching process. Thus, when manufacturing the droplet discharge head, it is possible to handle a thick flow path side substrate, prevent the flow path side substrate from being cracked during transport, and facilitate its handling.

In the method for manufacturing the droplet discharge head, it is preferable that the support substrate has a configuration in which a substrate, a release layer, and a resin layer are sequentially laminated.
In this case, when the reservoir forming substrate and the support are attached, the resin layer embeds and absorbs the uneven portion between the reservoir forming substrate and the support, and the reservoir forming substrate and the support Can be bonded firmly through the resin layer. Moreover, since the said adhesive layer contains the peeling layer, the said board | substrate can be peeled from the said reservoir | reserver formation board | substrate by removing a peeling layer.
At this time, it is preferable that the substrate constituting the support substrate is made of glass.
If it does in this way, the cost of a support substrate can be held down by using glass, and the processing cost of a flow path formation board | substrate can be reduced. In addition, by using a glass that transmits light, for example, by using a material that is peeled off by light energy, the substrate can be easily peeled from the reservoir formation substrate by irradiating the support substrate with light.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. A predetermined direction in the horizontal plane is defined as the X-axis direction, a direction orthogonal to the X-axis direction in the horizontal plane is defined as the Y-axis direction, and a direction orthogonal to the X-axis direction and the Y-axis direction (that is, the vertical direction) is defined as the Z-axis direction.

(Droplet ejection head)
FIG. 1 is an exploded perspective view showing a droplet discharge head formed by using the method for manufacturing a droplet discharge head in the present embodiment, and FIG. 2 is a perspective configuration of the droplet discharge head as viewed from below. FIG. 3 is a plan view and a sectional view of FIG. In the figure, reference numeral 1 denotes a droplet discharge head.

  The droplet discharge head 1 of the present embodiment discharges a functional liquid from a nozzle with droplets. As shown in FIG. 1, the droplet discharge head 1 includes a nozzle plate 20 having a nozzle opening 15 from which droplets are discharged, and a flow path forming substrate having an ink flow path 14 connected to the upper surface of the nozzle plate 20. 10, an elastic plate 50 connected to the upper surface of the flow path forming substrate 10 and displaced by driving the piezoelectric element 300, a reservoir forming substrate 30 connected to the upper surface of the elastic plate 50 and forming the reservoir portion 31, And a drive circuit unit 110 for driving the piezoelectric element 300 provided on the reservoir forming substrate 30.

  As will be described later, the flow path forming substrate 10 is formed from a flow path side substrate as a precursor made of a silicon single crystal substrate, and the upper surface side (+ Z direction) of the flow path forming substrate 10 is heated in advance. An elastic film 50 having a thickness of 1 to 2 μm made of silicon dioxide formed by oxidation is formed.

  On the other hand, as shown in FIG. 2, a plurality of substantially comb-shaped opening regions in a plan view are partitioned and formed in the flow path forming substrate 10 by a patterning process by dry etching as a manufacturing method described later on a silicon single crystal substrate. Of these opening regions, a portion formed extending in the X direction is surrounded by the nozzle plate 20 and the elastic plate 50 to form a pressure generation chamber (cavity) 12. During the operation of the droplet discharge head 1, the functional liquid is accommodated in the pressure generation chamber 12, and the functional liquid is discharged from the nozzle opening 15 by the pressure applied to the pressure generation chamber 12. Since the comb-shaped opening region is formed by patterning by dry etching, it is fine and highly accurate.

  In addition, the pressure generation chambers 12 partitioned by the plurality of partition walls 11 are arranged in two rows in the X direction, and the portions formed in the Y direction in the drawing in the substantially comb-shaped opening regions in the plan view are each A communication portion 13 for communicating the pressure generating chamber 12 is formed. As shown in FIG. 1, the communication portion 13 communicates with the reservoir portion 31 of the reservoir forming substrate 30 and constitutes a part of the reservoir 100 that functions as a common ink chamber. Here, the reservoir 100 is a space that preliminarily holds the functional liquid (ink) supplied to the pressure generation chamber 12.

  Further, an ink supply path 14 which is a part of the communication portion 13 is provided at one end of each pressure generation chamber 12, and the pressure generation chambers 12 are communicated by the communication portion 13. . Each ink supply path 14 that communicates with one end of each pressure generation chamber 12 is formed shallower than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12.

  Here, as the thickness of the flow path forming substrate 10, an optimum thickness may be selected in accordance with the arrangement density of the pressure generating chambers 12. For example, if the arrangement density is about 180 dpi, the flow path forming substrate 10. However, in the case where the pressure generating chambers 12 are arranged at a relatively high density of 200 dpi or more, the thickness of the flow path forming substrate 10 should be relatively as thin as 100 μm or less. preferable. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall 11 between the adjacent pressure generation chambers 12. The size of the pressure generating chamber 12 that applies ink droplet discharge pressure to ink and the size of the nozzle opening 15 that discharges ink droplets are determined according to the amount of ink droplets to be discharged, the discharge speed, and the discharge frequency. Yes.

  As shown in FIGS. 1 and 2, the nozzle plate 20 is provided on the −Z side of the flow path forming substrate 10, and the nozzle plate 20 and the flow path forming substrate 10 are, for example, an adhesive or a heat welding film. It is fixed through etc. The nozzle plate 20 has a thickness of, for example, 0.1 to 1 mm, a linear expansion coefficient of 300 ° C. or less, and a glass ceramic of, for example, 2.5 to 4.5 [× 10 −6 / ° C.], Or it consists of non-rust steel.

  The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force. Further, the nozzle plate 20 may be formed of a material having substantially the same thermal expansion coefficient as that of the flow path forming substrate 10. In this case, since the deformation by heat of the flow path forming substrate 10 and the nozzle plate 20 is substantially the same, it can be easily joined using a thermosetting adhesive or the like.

  The plurality of nozzle openings 15 provided in the nozzle plate 20 are arranged in the Y direction. In the present embodiment, a group of nozzle openings 15 arranged in a plurality of regions on the nozzle plate 20 are respectively set to the first nozzle openings. They are referred to as group 15A, second nozzle opening group 15B, third nozzle opening group 15C, and fourth nozzle opening group 15D.

As shown in FIG. 2, the first nozzle opening group 15A and the second nozzle opening group 15B are arranged so as to face each other in the X-axis direction. The third nozzle opening group 15C is provided on the + Y side of the first nozzle opening group 15A, and the fourth nozzle opening group 15D is provided on the + Y side of the second nozzle opening group 15B. The third nozzle opening group 15C and the fourth nozzle opening group 15D are arranged so as to face each other in the X-axis direction.
In FIG. 2, each of the nozzle opening groups 15 </ b> A to 15 </ b> D is shown to be configured by six nozzle openings 15, but actually each nozzle opening group has, for example, about 720 nozzle openings. 15.

Each pressure generating chamber 12 and the nozzle opening 15 are provided so as to correspond to each other. That is, a plurality of pressure generation chambers 12 are provided side by side in the Y-axis direction so as to correspond to the plurality of nozzle openings 15 constituting each of the first to fourth nozzle opening groups 15A to 15D. A plurality of pressure generation chambers 12 corresponding to the first nozzle opening group 15A constitute a first pressure generation chamber group 12A, and a plurality of pressure generation chambers 12 formed corresponding to the second nozzle opening group 15B. Constitutes the second pressure generating chamber group 12B, and a plurality of pressure generating chambers 12 formed corresponding to the third nozzle opening group 15C constitute the third pressure generating chamber group 12C and correspond to the fourth nozzle opening group 15D. A plurality of pressure generation chambers 12 constitute a fourth pressure generation chamber group 12D.
The first pressure generation chamber group 12A and the second pressure generation chamber group 12B are arranged to face each other in the X-axis direction, and a partition wall 10K is formed between them. Similarly, a partition 10K is also formed between the third pressure generation chamber group 12C and the fourth pressure generation chamber group 12D, and they are arranged so as to face each other in the X-axis direction.

  The ends of the plurality of pressure generating chambers 12 forming the first pressure generating chamber group 12A on the substrate center side (−X side) are closed by the partition wall 10K described above, but on the substrate outer edge side (+ X side). The ends are assembled so as to be connected to each other, and are connected to the reservoir 100. Looking at the path of the functional liquid shown in FIG. 3, the ink introduced from the ink introduction port 44 flows into the reservoir 100 via the ink introduction path 34, and constitutes the first pressure generation chamber group 12 </ b> A via the supply path 14. It is supplied to each of the plurality of pressure generating chambers 12.

  In addition, a reservoir 100 similar to that described above is connected to each of the pressure generation chambers 12 constituting each of the second, third, and fourth pressure generation chamber groups 12B, 12C, and 12D. The temporary storage part of the functional fluid supplied to the pressure generation chamber groups 12B to 12D communicated via the above is configured.

On the other hand, as shown in FIG. 3, on the elastic film 50 formed on the flow path forming substrate 10, for example, a lower electrode film 60 having a thickness of about 0.2 μm and a piezoelectric layer 70 having a thickness of about 1 μm, The upper electrode film 80 having a thickness of about 0.1 μm is laminated to form the piezoelectric element 300. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 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 distortion occurs due to application of a voltage to both electrodes is referred to as a piezoelectric active portion. In this embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed for each pressure generating chamber.
A plurality of piezoelectric elements 300 are provided so as to correspond to each of the plurality of nozzle openings 15 and the pressure generation chamber 12.

  Further, in such a piezoelectric element 300, a lead electrode 90 made of, for example, gold (Au) or the like for connection with the drive circuit 110 is formed as a lead-out wiring. In other words, each lead electrode 90 extends from the vicinity of the end of each pressure generating chamber 12 of the upper electrode film 80 on the side of the row to the elastic film 50. As will be described in detail later, each lead electrode 90 extends to a region facing the through hole 33 of the reservoir forming substrate 30, and the vicinity of the end portion and the drive circuit 110 are connected via the through hole 33. The connection wiring 120 is extended and electrically connected.

  On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, a reservoir forming substrate 30 on which a reservoir portion 31 constituting a part of the reservoir 100 is formed is joined. The reservoir portion 31 penetrates in the thickness direction (Z direction in FIG. 1) of the reservoir forming substrate 30 and is formed across the width direction (Y direction in FIG. 1) of the pressure generating chamber 12. As described above, the reservoir 100 serving as a common ink chamber of the pressure generating chambers 12 is configured by communicating with the communicating portion 13 of the flow path forming substrate 10.

  Further, in a region facing the piezoelectric element 300 of the reservoir forming substrate 30, a piezoelectric element holding portion 32 capable of sealing the space is secured in a state where a space that does not hinder the operation of the piezoelectric element 300 is secured. The piezoelectric element 300 is sealed in each piezoelectric element holding portion 32. In the present embodiment, the piezoelectric element holding portion 32 is provided for each row of the piezoelectric elements 300. However, of course, the piezoelectric element holding portion 32 may be provided independently for each piezoelectric element 300. .

  In addition, a through hole 33 that penetrates the reservoir forming substrate 30 in the thickness direction is provided in a substantially central portion of the reservoir forming substrate 30, that is, a region facing between the rows of the pressure generating chambers 12. As described above, the lead electrode 90 extending from each piezoelectric element 300 extends to a region facing the through hole 33, and the vicinity of the end is exposed.

  Further, for example, a circuit board or a semiconductor integrated circuit (IC) for driving each piezoelectric element 300 is provided on both sides of the through hole 33 of the reservoir forming substrate 30, that is, on a portion corresponding to each row of the pressure generating chambers 12. ) Etc. are respectively mounted. For example, in the present embodiment, each drive circuit 110 mounted on both sides of the through-hole 33 is for driving the piezoelectric element 300 provided in a region facing each drive circuit 110. And each drive circuit 110 and the lead electrode 90 extended from each piezoelectric element 300 are electrically connected by the connection wiring 120 which was extended through the through-hole 33, for example, consists of a conductive wire, respectively. (See FIG. 3B).

A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the reservoir forming substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir portion 31. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Thus, the flexible portion 35 can be deformed by a change in internal pressure. An ink introduction port 44 for supplying ink to the reservoir 100 is formed on the compliance substrate 40 on the outer side of the central portion of the reservoir 100 in the longitudinal direction. Further, the reservoir forming substrate 30 is provided with an ink introduction path 34 that communicates the ink introduction port 44 with the sidewall of the reservoir 100.
The droplet discharge head 1 takes in ink from an ink introduction port 44 connected to an external ink supply means (not shown), fills the interior from the reservoir 100 to the nozzle opening 15, and then records from the drive circuit 110. By applying a voltage between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generation chamber 12 according to the signal, the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 are bent and deformed, The pressure in each pressure generating chamber 12 increases and ink droplets can be ejected from the nozzle openings 15.

(Method for manufacturing droplet discharge head)
Here, an embodiment of the method for manufacturing the above-described droplet discharge head 1 will be described with reference to FIGS. The manufacturing steps shown in FIGS. 4 to 6 correspond to the cross section of the droplet discharge head 1 shown in FIG.
First, the piezoelectric element 300 is formed in advance on the flow path side substrate that is the precursor of the flow path forming substrate 10. Here, in describing the manufacturing process of the present invention, the process of forming the piezoelectric element 300 on the flow path side substrate will be described.

Here, if the flow path side substrate is thin, cracks and the like are likely to occur, which makes it difficult to handle. On the other hand, for example, it becomes difficult to break by using a thick flow path side substrate, and the handling becomes easy. However, the amount of etching the flow path side substrate increases, and the dry etching process described later takes time. .
Therefore, in this embodiment, as will be described later, since the thin film processing such as polishing is performed on the flow path side substrate before dry etching, it is possible to use a thick flow path side substrate, and the liquid droplet Handling of the flow path side substrate when manufacturing the discharge head is facilitated, and dry etching can be favorably performed on the thick flow path side substrate.

First, an elastic film 50 made of silicon dioxide is formed on one surface of a flow path side substrate made of a silicon single crystal substrate by thermal oxidation in a diffusion furnace at about 1100 ° C. Next, after forming the lower electrode film 60 on the entire surface of the elastic film 50 by sputtering, the lower electrode film 60 made of platinum (Pt) is patterned to form an entire pattern.
Then, a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied, dried and gelled, and further baked at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide, which is formed using a so-called sol-gel method. Thus, the piezoelectric layer 70 in which crystals are oriented was obtained. As a material of the piezoelectric layer 70, a lead zirconate titanate-based material is suitable when used for a droplet discharge head. Note that the thickness of the piezoelectric layer manufactured in this way in the thin film process is generally 0.2 to 5 μm.
Next, the upper electrode film 80 is formed by sputtering platinum, and then the piezoelectric element 300 is patterned by etching only the piezoelectric layer 70 and the upper electrode film 80. Here, in the present embodiment, the lead electrode 90 made of, for example, gold (Au) or the like is formed over the entire surface of the flow path forming substrate 10 and is patterned for each piezoelectric element 300. In this way, the piezoelectric element 300 is formed on the flow path side substrate 10a.
Hereinafter, a process of manufacturing a head using the flow path side substrate 10a on which the piezoelectric element 300 formed by the above-described method is formed will be described.

First, as shown in FIG. 4A, after the flow path side substrate 10a and the reservoir forming substrate 30 are bonded together, a step of holding the reservoir forming substrate 30 side on the support substrate is performed.
Here, in the reservoir forming substrate 30, the above-described through-hole 33 and the piezoelectric element holding portion 32 are formed by patterning in advance by dry etching or wet etching. Further, as the reservoir forming substrate 30, it is preferable to use a material substantially the same as the coefficient of thermal expansion of the flow path side substrate 10a, for example, glass, ceramic material, etc. In this embodiment, silicon of the same material as the flow path side substrate 10a is used. A single crystal substrate is used.

  Specifically, the reservoir forming substrate 30 and the flow path side substrate 10a are bonded together with an adhesive or the like. At this time, the reservoir forming substrate 30 is joined to the flow path forming substrate 10 with each lead electrode 90 protruding into the through hole 33 by a predetermined amount.

The support substrate 400 is configured by sequentially laminating a substrate 400a, a release layer 400b, and a resin layer 400c. Glass that is a transmissive member is used as a constituent material of the substrate 400a because light having a peeling energy applied to the back surface of the support substrate 400 when the support substrate 400 is peeled from the reservoir forming substrate 30 is applied to the peeling layer 400b. This is to ensure that it is reached.
Moreover, the cost of the support substrate 400 can be suppressed by using glass, and the processing cost of the flow path side substrate 10a can be reduced. Further, by using glass that transmits light, it is possible to easily peel the substrate 400a from the reservoir forming substrate 30 only by irradiating the substrate 400a with light.

  The planar shape of the support substrate 400 is determined according to the bonded body 200 in which the flow path side substrate 10a and the reservoir forming substrate 30 are bonded together. In this example, the planar shape of the support substrate 400 is larger than that of the bonded body 200. The outer diameter is larger. As described above, since the outer diameter of the support substrate 400 is larger than that of the bonded body 200, even when the center position of the reservoir forming substrate 30 and the support substrate 400 is slightly shifted at the time of bonding, This is to prevent the edge of the joined body 200 from protruding from 400. In this way, in this example, by preventing the edge of the bonded body 200 from protruding, when the bonded body 200 is transported, for example, the edge of the bonded body 200 is damaged due to contact with other objects. Can be prevented.

  In addition, by providing a conductive film such as Al or a semiconductor film made of polysilicon or the like on the outer peripheral portion of the back surface of the support substrate 400, by charging such a film, an electrostatic force is used. Electrostatic adsorption on the support substrate 400 may be enabled. Such an electrostatic adsorption technique has an advantage that it is easy to achieve stabilization of conveyance, enlargement of a processed substrate, reduction of particles, and the like. In this manner, by enabling electrostatic adsorption of the support substrate 400, for example, an etching process using an etching apparatus that requires electrostatic adsorption becomes possible.

  For example, a thermosetting adhesive is used for the resin layer 400c. The resin layer 400c is preferably made of a material having high dry etching resistance. This is because the progress of etching can be stopped by the resin layer 400c in the dry etching process described later, and the end point of etching in the flow path side substrate 10a can be easily grasped. Furthermore, the resin layer 400c is preferably made of a material having high thermal conductivity. In this way, in the dry etching process described later, the thermal conductivity of the flow path side substrate 10a and the reservoir forming substrate 30 as a whole can be improved and the etching characteristics can be stabilized.

  As a method for arranging the resin layer 400c, in addition to various printing methods, various known techniques such as an inkjet method, a powder jet method, a squeezing method, a spin coating method, a spray coating method, and a roll coating method are used. . The support layer 400 is peeled off by removing the resin layer 400c after the substrate 400a is peeled from the reservoir substrate 30 and then dissolved and removed with a solvent or the like.

  The peeling layer 400b is made of a material that causes peeling (also referred to as “in-layer peeling” or “interfacial peeling”) in the layer or at the interface by irradiation light such as laser light. That is, by irradiating with a certain intensity of light, the bonding force between atoms or molecules in the atoms or molecules constituting the constituent material disappears or decreases, causing ablation or the like and causing separation. is there. In addition, when the irradiation layer is irradiated with light, the components contained in the release layer 400b are released as a gas and separated, and when the release layer 400b absorbs light and becomes a gas, the vapor is released and separated. May lead to.

  As the composition of the peeling layer 400b, for example, amorphous silicon (a-Si) is employed, and hydrogen (H) may be contained in the amorphous silicon. When hydrogen is contained, it is preferable that hydrogen is released by light irradiation to generate an internal pressure in the peeling layer 400b, which promotes peeling. In this case, the hydrogen content is preferably about 2 at% or more, more preferably 2 to 20% at%. The hydrogen content should be set appropriately for film formation conditions, such as the gas composition, gas pressure, gas atmosphere, gas flow rate, gas temperature, substrate temperature, and power to be applied when using the CVD method. Adjust by. Other release layer materials include silicon oxides or silicate compounds, nitride ceramics such as silicon nitride, aluminum nitride, titanium nitride, organic polymer materials (those whose interatomic bonds are broken by light irradiation), A metal, for example, 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.

  The method for forming the release layer 400b may be any method that can form the release layer 400b with a uniform thickness, and can be appropriately selected according to various conditions such as the composition and thickness of the release layer 400b. For example, CVD (including MOCCVD, low-pressure CVD, ECR-CVD) method, vapor deposition, molecular beam vapor deposition (MB), sputtering method, ion doping method, PVD method and other various vapor deposition methods, electroplating, immersion plating (dipping) ), Various plating methods such as electroless plating method, Langmuir ProJet (LB) method, spin coating method, spray coating method, roll coating method and other coating methods, various printing methods, transfer methods, ink jet methods, powder jet methods Applicable to etc. Of these, two or more methods may be combined.

In particular, when the composition of the peeling layer 400b is amorphous silicon (a-Si), it is preferable to form the film by a CVD method, particularly low-pressure CVD or plasma CVD. In the case where the release layer 400b is formed by using a ceramic by a sol-gel method or is made of an organic polymer material, it is preferable to form a film by a coating method, particularly by spin coating.
A support substrate 400 having such a resin layer 400c and a release layer 400b is used.

As shown in FIG. 4B, the reservoir forming substrate 30 side is held on the support substrate 400.
After the bonded body 200 is turned upside down, the support substrate 400 described above is held on the reservoir forming substrate 30 side. That is, the peeling layer 400b described above is formed in advance on the support substrate 400, and bonded to the bonded body 200 via the resin layer 400c described above. Here, since the through hole 33 and the piezoelectric element holding portion 32 are formed in the reservoir forming substrate 30 in advance as described above, an uneven portion is generated between the reservoir forming substrate 30 and the support body 400. Yes. At this time, the concave and convex portions between the reservoir forming substrate 30 and the support 400 are absorbed by the resin layer 400c being embedded, and the reservoir forming substrate 30 and the support 400 are intimately adhered through the resin layer 400c. Can be joined.

  Thus, since the flow path side substrate 10a and the reservoir forming substrate 30 are bonded together, the reservoir forming substrate 30 side is held by the support 400, so that the flow path side substrate 10a and the reservoir forming substrate 30 are The support body 400 has a high rigidity. Specifically, the rigidity of the flow path side substrate 10 a and the reservoir forming substrate 30 is improved by embedding the resin layer 400 c in the uneven portion of the reservoir forming substrate 30.

Here, before the step of dry etching the flow path side substrate 10a, a step of thinning the flow path side substrate 10a is performed.
Specifically, the flow path side substrate 10a of the joined body 200 held on the support substrate 400 is subjected to back grinding and thinned. As this back grinding, for example, thin processing such as grinding or polishing is performed.
Here, a crushing layer is formed on the surface of the flow path side substrate 10a subjected to the back grinding process. Since this crushed layer may cause a crack or the like in the flow path side substrate 10a, it can be removed by performing wet etching using, for example, hydrofluoric acid as shown in FIG. 4C. desirable.
In this way, the flow path side substrate 10a subjected to thin processing is obtained.

  In the present invention, since the back-grinding is performed on the thick flow path forming substrate 10a before the dry etching, the thick flow path side substrate 10a is attached to the reservoir forming substrate 30. 10a can be handled easily, and furthermore, a dry etching process to be described later can be favorably performed on the thinned flow path side substrate 10a.

  Subsequently, a process of forming the communication portion 13 is performed by performing patterning by dry etching on the flow path side substrate 10a while holding the bonded body 200 on the support body 400. In the present embodiment, the pressure generating chamber 12 is simultaneously formed during the patterning process by dry etching on the flow path side substrate 10a. Therefore, the process for manufacturing the droplet discharge head 1 can be simplified.

Specifically, as a patterning step by dry etching, as shown in FIG. 5A, a resist R is applied to the front surface of the flow path side substrate 10a, and then a mask having a desired shape is used by using a photolithography method. M is formed.
Then, by performing dry etching through the mask M, the communication portion 13 and the pressure generation chamber 12 are formed in the flow path side substrate 10a. As such an etching method, a Si high-speed etching method (for example, described in JP-A-2002-93776) or a Bosch process method (for example, described in US Pat. No. 5,501,893) is used. Can be used.

According to these etching methods, high-speed etching of 20 μm / min or more is possible, the communication portion 13 and the pressure generation chamber 12 can be formed quickly, and man-hours can be saved and formed efficiently. It becomes possible.
During the dry etching, the flow path side substrate 10a has high rigidity by being supported by the support substrate 400 as described above. Etching processing does not become defective, and it is possible to obtain the flow path forming substrate 10a in which the communication portion 13 and the pressure generation chamber 12 are well formed.

In the patterning step by dry etching, it is preferable to repeat the shape of the mask and the etching step a plurality of times. By doing so, the communication portion 13 and the pressure generating chamber 12 having the shape shown in FIG. 1 can be reliably formed. Further, when the communication portion 13 is formed, in this dry etching, the resin layer 400c embedded in the reservoir portion 31 of the reservoir formation substrate 30 functions as an etch stopper, and the etching is performed when the flow passage side substrate 10a is penetrated. Stop.
The ink supply path 14 which is a part of the communication portion 13 has a smaller etching amount than the pressure generation chamber 12. For example, a separate mask may be provided at a position corresponding to the ink supply path 14 or the etching time may be increased. It can be formed by adjusting.

In the present embodiment, when the flow path forming substrate 10 is formed, patterning is performed by dry etching, which has higher processing accuracy than wet etching, so that the communication portion 13 and the pressure generation chamber 12 having a fine shape can be processed. Become. Therefore, when the communication part 13 is processed into a fine state, the pressure generating chambers 12 communicated by the communication part 13 can be formed in a densely arranged state.
Further, the use of dry etching prevents the etching liquid from flowing around the back surface side of the reservoir forming substrate 30 as in wet etching, thereby causing a defect and improving the yield in the droplet discharge head 1.
In this manner, the flow path forming substrate 10 is formed by forming the pressure generating chamber (cavity) 12 and the communication portion 13 in the flow path side substrate 10a.
After the flow path forming substrate 10 is formed, the mask M used in the dry etching process is removed by using, for example, O ₂ plasma.

Subsequently, a process of peeling the support substrate 400 from the reservoir forming substrate 30 is performed. As described above, the support substrate 400 includes the release layer 400b. Therefore, irradiation light such as laser light is irradiated from the substrate 400a side. At this time, light is transmitted through the substrate 400a made of glass, causing the peeling layer 400b to peel off, and the substrate 400a is peeled off from the reservoir forming substrate 30 as shown in FIG.
Thereafter, the resin layer 400b in close contact with the reservoir forming substrate 30 was dissolved using a solvent or the like, so that the support substrate 400 was completely peeled from the reservoir forming substrate 30 as shown in FIG. 6B. It becomes a state.

Subsequently, as shown in FIG. 6C, the nozzle plate 20 having the nozzle openings 15 formed on the surface of the flow path forming substrate 10 opposite to the reservoir forming substrate 30 is joined, and the reservoir forming substrate 30. A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded thereon.
Further, the drive circuits 110 for driving the piezoelectric elements 300 are mounted on the reservoir forming substrates 30 on both sides of the through hole 33, respectively. Then, for example, the connection wiring 120 is formed by wire bonding or the like, and each drive circuit 110 and each lead electrode 90 are electrically connected.
Thereby, the droplet discharge head 1 is manufactured.

According to the method of manufacturing the droplet discharge head 1 of the present embodiment, the flow path side substrate 10a that is the precursor of the flow path forming substrate 10 and the reservoir forming substrate 30 are bonded together, and then the reservoir forming substrate side 30 is supported. By holding the body 400 and patterning the flow path side substrate 10a having high rigidity by dry etching, the communication portion 13 and the pressure generating chamber 12 can be formed satisfactorily.
Further, by using dry etching, the communication portion 13 can be finely processed. Therefore, the pressure generating chambers 12 communicated by the communication portion 13 are arranged at a high density. Furthermore, since wet etching is not used when the flow path forming substrate 10 is formed, it is possible to prevent the occurrence of defects due to the wraparound of the etchant and improve the yield of the droplet discharge head 1.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention. For example, in the present embodiment, the pressure generation chamber 12 is formed at the same time in the dry etching process when forming the communication portion 13, but the present invention is not limited to this, for example, the pressure generation chamber is formed in another etching process. You may make it form in.

It is a disassembled perspective view of the droplet discharge head of this embodiment. It is the perspective view which looked at the droplet discharge head from the lower side. (A) is a top view of a droplet discharge head, (b) is a sectional side view of (a). It is a figure explaining the manufacturing process of a droplet discharge head. FIG. 5 is a diagram illustrating a manufacturing process of the droplet discharge head following FIG. 4. FIG. 6 is a diagram illustrating a manufacturing process of the droplet discharge head following FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Droplet discharge head, 10 ... Channel formation substrate, 10a ... Channel side substrate, 12 ... Pressure generation chamber (cavity), 13 ... Communication part, 30 ... Reservoir formation substrate, 31 ... Reservoir part, 400 ... Support substrate, 400a ... substrate, 400b ... release layer, 400c ... resin layer

Claims (5)

Manufacture of a droplet discharge head comprising a flow path forming substrate in which a plurality of cavities and a communication portion for communicating between the cavities are formed, and a reservoir forming substrate in which a reservoir portion communicating with the communication portion is formed In the method
A step of holding the reservoir-forming substrate side on a support substrate after bonding the channel-forming substrate serving as a precursor of the channel-forming substrate and the reservoir-forming substrate;
Forming a communicating portion by patterning the flow path side substrate by dry etching while holding the flow path side substrate and the reservoir forming substrate on the support;
Forming a cavity in the flow path side substrate;
Peeling the support substrate from the reservoir forming substrate;
A method of manufacturing a droplet discharge head, comprising:   2. The method of manufacturing a droplet discharge head according to claim 1, wherein the communication portion and the cavity are simultaneously formed in a patterning step by dry etching on the flow path side substrate.   3. The method according to claim 1, further comprising a step of thinly processing the flow path side substrate after the reservoir forming substrate side is attached to a support and before the step of dry etching the flow path side substrate. A manufacturing method of a droplet discharge head described in 1.   The method for manufacturing a droplet discharge head according to claim 1, wherein the support substrate has a configuration in which a substrate, a release layer, and a resin layer are sequentially laminated.   The method of manufacturing a droplet discharge head according to claim 4, wherein the substrate constituting the support substrate is made of glass.

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