JP2008307873A - Bonding method, bonding body, droplet discharge head, and droplet discharge apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bonding method enabling the mutual strong and efficient bonding of two members with high dimensional accuracy, a bonding body in which the two members are bonded to each other strongly with high dimensional accuracy, a high-integrity droplet discharge head provided with the bonding body, and a droplet discharge apparatus provided with the droplet discharge head. <P>SOLUTION: The bonding method comprises a process (a first process) of forming plasma-polymerized films 3 on surfaces of two substrates, a process (a second process) of irradiating surfaces of the plasma-polymerized films 3 with ultraviolet radiation to activate the surfaces, a process (a third process) of laminating two substrates 2 to each other to obtain the bonding body 1, and a process of pressurizing the bonding body 1 while heating it. The plasma-polymerized films 3 are preferably constituted of polyorganosiloxane as main materials. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bonding method, a bonded body, a droplet discharge head, and a droplet discharge device.

When joining (adhering) two members (base materials), conventionally, a method of using an adhesive such as an epoxy adhesive, a urethane adhesive, or a silicone adhesive is often used.
The adhesive can exhibit adhesiveness regardless of the material of the member. For this reason, members composed of various materials can be bonded in various combinations.
For example, a droplet discharge head (inkjet recording head) provided in an inkjet printer is configured by bonding parts made of different materials such as a resin material, a metal material, and a silicon material using an adhesive. ing.
When the members are bonded together using the adhesive as described above, a liquid or paste adhesive is applied to the bonding surface, and the members are bonded together via the applied adhesive. Thereafter, when the adhesive is cured by the action of heat or light, the members are bonded based on a physical interaction such as an anchor effect or a chemical interaction such as a chemical bond.

However, when applying an adhesive to the bonding surface of the member, it is necessary to use a complicated method such as a printing method. Further, since the thickness of the applied adhesive is affected by many parameters such as the viscosity, temperature, humidity, and printing device conditions of the adhesive, it is extremely difficult to strictly control. For this reason, it has the problem that the dimensional accuracy of a joined body cannot fully be raised. As a result, when a structure that requires high dimensional accuracy, such as the above-described droplet discharge head, is manufactured using an adhesive, the dimensional accuracy of the droplet discharge head is reduced, and the printing result of the printer is adversely affected. This may cause problems such as
Moreover, since the hardening time of an adhesive agent becomes very long, there also exists a problem that adhesion requires a long time.
Furthermore, in many cases, it is necessary to use a primer in order to increase the bonding strength, and the cost and labor for that purpose complicate the bonding process.

On the other hand, there is a solid bonding method as a bonding method that does not use an adhesive.
Solid bonding is a method of directly bonding members without an intermediate layer such as an adhesive (see, for example, Patent Document 1).
According to such solid bonding, since an intermediate layer such as an adhesive is not used, a bonded body with high dimensional accuracy can be obtained.

However, there is a problem that the material of the member is limited. Specifically, in general, solid bonding can only be performed between the same kind of materials. In addition, materials that can be joined are limited to silicon-based materials and some metal materials.
Furthermore, there are problems in the bonding process, such as the fact that the atmosphere in which solid bonding is performed is limited to a reduced-pressure atmosphere and that high-temperature (about 700 to 800 ° C.) heat treatment is required.
In response to such problems, a method for joining two members firmly and efficiently with high dimensional accuracy is required.

JP-A-5-82404

  An object of the present invention is to provide a joining method capable of joining two members firmly and efficiently with high dimensional accuracy, a joined body obtained by joining two members firmly with high dimensional accuracy, and such a joined body. Another object of the present invention is to provide a highly reliable droplet discharge head and a droplet discharge apparatus including the droplet discharge head.

Such an object is achieved by the present invention described below.
The bonding method of the present invention includes a first step of preparing a first adherend and a second adherend each having a plasma polymerized film on a substrate,
A second step of activating the surface of each plasma polymerized film by applying energy to the surface of each plasma polymerized film of the first adherend and the second adherend,
A third step of bonding the first adherend and the second adherend to obtain a joined body so that the surfaces of the activated plasma polymerization films are brought into close contact with each other; It is characterized by.
Thereby, two base materials can be joined firmly and efficiently with high dimensional accuracy.

In the bonding method of the present invention, it is preferable that each of the plasma polymerized films is composed mainly of polyorganosiloxane.
Thereby, the water repellency and hydrophilicity of the plasma polymerized film can be easily controlled, and as a result, the adhesion can be easily controlled. Moreover, since polyorganosiloxane is comparatively rich in flexibility, it is possible to relieve stress accompanying thermal expansion that occurs between the substrates. As a result, peeling of the joined body can be reliably prevented. Furthermore, a bonded body having excellent durability can be obtained.
In the bonding method of the present invention, it is preferable that the polyorganosiloxane is mainly composed of a polymer of octamethyltrisiloxane.
Thereby, a plasma polymerization film having particularly excellent adhesiveness can be obtained.

In the bonding method of the present invention, the average thickness of each plasma polymerized film is preferably 10 to 10,000 nm.
Thereby, two base materials can be joined more firmly, preventing that the dimensional accuracy of a joined body falls remarkably. This also ensures a certain degree of shape following in the plasma polymerized film, so that the unevenness present on the bonding surface of the base material can be absorbed to reduce the height of the irregularities generated on the surface of the plasma polymerized film. it can.

In the bonding method of the present invention, it is preferable that the surface of each plasma polymerization film is irradiated with energy rays in the second step.
Thereby, the surface of a plasma polymerization film | membrane can be activated efficiently. Further, since the molecular structure in the plasma polymerized film is not cut more than necessary, it is possible to avoid deterioration of the characteristics of the plasma polymerized film.

In the bonding method of the present invention, the energy beam is preferably ultraviolet light having a wavelength of 150 to 300 nm.
Thereby, it is possible to process a wide range in a shorter time without unevenness while preventing a remarkable deterioration of the characteristics of the plasma polymerized film. For this reason, activation of the surface of a plasma polymerization film | membrane can be performed more efficiently.

In the bonding method of the present invention, it is preferable that the second step is performed in an air atmosphere.
Thereby, it is not necessary to spend time and cost to control the atmosphere, and the activation process can be performed more easily.
In the joining method of this invention, it is preferable to have the process of heat-processing the said joined body after the said 3rd process.
Thereby, the joint strength in the joined body can be further increased.

In the bonding method of the present invention, the temperature of the heat treatment is preferably 25 to 100 ° C.
Thereby, it is possible to reliably increase the bonding strength while reliably preventing the bonded body from being deteriorated and deteriorated by heat.
In the joining method of this invention, it is preferable to have the process of pressurizing the said joined body after the said 3rd process.
Thereby, the integration of the two plasma polymerized films further proceeds, and the bonding strength in the bonded body can be further increased.

In the bonding method of the present invention, it is preferable that the pressure applied to the bonded body is 1 to 10 MPa.
Thereby, the joining strength of the joined body can be reliably increased without causing damage to the substrate.
In the joining method of the present invention, it is preferable to start the third step within 60 minutes after the end of the second step.
Thereby, the surface of a plasma polymerization film | membrane can be maintained in a sufficient active state, and sufficient bonding strength can be obtained when it bonds together.

In the bonding method of the present invention, each of the first adherend and the second adherend is subjected to a ground treatment with plasma on each of the substrates in advance, and then is applied to the region subjected to the ground treatment. It is preferable to form the plasma polymerized film.
Thereby, when the joining surface of a base material is cleaned and activated and a plasma polymerization film | membrane is formed on a joining surface, the joining strength of a joining surface and a plasma polymerization film | membrane can be raised.
In the joining method of the present invention, it is preferable that the two base materials have different rigidity.
Thereby, two base materials can be joined more firmly.

The joined body of the present invention is characterized in that two substrates are joined by the joining method of the present invention.
Thereby, the joined body formed by joining two base materials firmly with high dimensional accuracy is obtained.
The joined body of the present invention comprises two substrates,
A plasma polymerized film,
The two substrates are bonded via the plasma polymerization film.
Thereby, the joined body formed by joining two base materials firmly with high dimensional accuracy is obtained.
In the joined body of the present invention, the plasma polymerized film is preferably formed by joining plasma polymerized films formed in advance on the surfaces of the two base materials.
Thereby, the joined body formed by joining two base materials especially firmly with high dimensional accuracy is obtained.
In the joined body of the present invention, the joining strength between the two base materials is preferably 5 MPa or more.
Thereby, the joined body can sufficiently prevent the peeling.
The droplet discharge head of the present invention is characterized by having the joined body of the present invention.
Thereby, a highly reliable droplet discharge head can be obtained.
The liquid droplet ejection apparatus of the present invention includes the liquid droplet ejection head of the present invention.
Thereby, a highly reliable droplet discharge device can be obtained.

Hereinafter, a bonding method, a bonded body, a droplet discharge head, and a droplet discharge device according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<Join method>
The bonding method of the present invention is a method for bonding two base materials 2 to each other via a plasma polymerization film 3. According to this method, the two base materials 2 can be bonded firmly and efficiently with high dimensional accuracy.
Here, prior to describing the bonding method of the present invention, first, a plasma polymerization apparatus used to form the above-described plasma polymerization film will be described.

FIG. 1 is a longitudinal sectional view schematically showing a plasma polymerization apparatus used in the bonding method of the present invention. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.
The plasma polymerization apparatus 100 shown in FIG. 1 includes a chamber 101, a first electrode 130 that supports the substrate 2, a second electrode 140, and a power supply circuit 180 that applies a high-frequency voltage between the electrodes 130 and 140. A gas supply unit 190 that supplies gas into the chamber 101 and an exhaust pump 170 that exhausts the gas in the chamber 101 are provided. Among these parts, the first electrode 130 and the second electrode 140 are provided in the chamber 101. Hereinafter, each part will be described in detail.
The chamber 101 is a container that can keep the inside airtight, and is used with the inside being in a reduced pressure (vacuum) state. Therefore, the chamber 101 has pressure resistance that can withstand a pressure difference between the inside and the outside.

A chamber 101 shown in FIG. 1 has a substantially cylindrical chamber body whose axis is arranged in the horizontal direction, a circular side wall that seals the left-side opening of the chamber body, and a circle that seals the right-side opening. And side walls.
A supply port 103 is provided above the chamber 101, and an exhaust port 104 is provided below the chamber 101. A gas supply unit 190 is connected to the supply port 103, and an exhaust pump 170 is connected to the exhaust port 104.
In this embodiment, the chamber 101 is made of a highly conductive metal material and is electrically grounded via the ground wire 102.

The first electrode 130 has a plate shape and supports the substrate 2.
The first electrode 130 is provided on the inner wall surface of the side wall of the chamber 101 along the vertical direction, whereby the first electrode 130 is electrically grounded via the chamber 101. The first electrode 130 is provided concentrically with the chamber body as shown in FIG.

An electrostatic chuck (suction mechanism) 139 is provided on the surface of the first electrode 130 that supports the substrate 2.
As shown in FIG. 1, the electrostatic chuck 139 can support the substrate 2 along the vertical direction. Moreover, even if the base material 2 has some warpage, the base material 2 can be subjected to plasma treatment in a state in which the warpage is corrected by being attracted to the electrostatic chuck 139.

The second electrode 140 is provided to face the first electrode 130 with the base material 2 interposed therebetween. Note that the second electrode 140 is provided in a state of being separated (insulated) from the inner wall surface of the side wall of the chamber 101.
A high frequency power source 182 is connected to the second electrode 140 via a wiring 184. A matching box (matching unit) 183 is provided in the middle of the wiring 184. The wiring 184, the high-frequency power source 182 and the matching box 183 constitute a power circuit 180.
According to such a power supply circuit 180, since the first electrode 130 is grounded, a high frequency voltage is applied between the first electrode 130 and the second electrode 140. As a result, an electric field whose direction is reversed at a high frequency is induced in the gap between the first electrode 130 and the second electrode 140.

The gas supply unit 190 supplies a predetermined gas into the chamber 101.
A gas supply unit 190 shown in FIG. 1 stores a liquid storage unit 191 that stores a liquid film material (raw material liquid), a vaporizer 192 that vaporizes the liquid film material to change it into a gaseous state, and stores a carrier gas. And a gas cylinder 193. Each of these parts and the supply port 103 of the chamber 101 are connected by a pipe 194, and a mixed gas of a gaseous film material (raw material gas) and a carrier gas is supplied from the supply port 103 into the chamber 101. It is configured to supply.

The liquid film material stored in the liquid storage unit 191 is a raw material that is polymerized by the plasma polymerization apparatus 100 to form a polymer film on the surface of the substrate 2.
Such a liquid film material is vaporized by the vaporizer 192 and is supplied into the chamber 101 as a gaseous film material (raw material gas). The source gas will be described in detail later.

The carrier gas stored in the gas cylinder 193 is a gas that is discharged due to the action of an electric field and introduced to maintain this discharge. Examples of such a carrier gas include Ar gas and He gas.
A diffusion plate 195 is provided near the supply port 103 in the chamber 101.
The diffusion plate 195 has a function of promoting the diffusion of the mixed gas supplied into the chamber 101. Thereby, the mixed gas can be dispersed in the chamber 101 with a substantially uniform concentration.

The exhaust pump 170 exhausts the inside of the chamber 101, and includes, for example, an oil rotary pump, a turbo molecular pump, or the like. Thus, by exhausting the chamber 101 and reducing the pressure, the gas can be easily converted into plasma. In addition, contamination and oxidation of the base material 2 due to contact with the air atmosphere can be prevented, and reaction products resulting from the plasma treatment can be effectively removed from the chamber 101.
The exhaust port 104 is provided with a pressure control mechanism 171 that adjusts the pressure in the chamber 101. Thereby, the pressure in the chamber 101 is appropriately set according to the operation state of the gas supply unit 190.

Next, an embodiment of the bonding method of the present invention will be described by taking the case of using the plasma polymerization apparatus 100 as an example.
2 and 3 are views (longitudinal sectional views) for explaining the joining method of the present invention. In the following description, the upper side in FIGS. 2 and 3 is referred to as “upper” and the lower side is referred to as “lower”.
The bonding method according to the present embodiment includes a step (first step) of forming the plasma polymerized film 3 on the surfaces of the two base materials 2, respectively, and applying energy to the surface of the plasma polymerized film 3, thereby A step of activating (second step), a step of bonding two substrates 2 together so that the activated surfaces are in contact with each other, and obtaining a joined body (third step); And pressurizing while heating. Hereinafter, each process will be described sequentially.

[1] First, two base materials 2 are prepared. In FIG. 2, one of the two base materials 2 is omitted.
Although the constituent material of such a base material 2 is not specifically limited, polyphenyl sulfide, aramid resin, polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate, Resin materials such as polyarylate, metal materials such as stainless steel, aluminum, tantalum, titanium, indium tin oxide (ITO), silicon-based materials such as single crystal silicon, polycrystalline silicon, quartz glass, and alumina A ceramic material or a composite material combining one or more of these materials can be used.
Note that the constituent materials of the two base materials 2 may be the same or different.

  Further, the thermal expansion coefficients of the two base materials 2 are preferably substantially equal, but may be different from each other. If the thermal expansion coefficient of each base material 2 is substantially equal, when the two base materials 2 are joined together, it becomes difficult to generate stress accompanying thermal expansion at the joint interface. As a result, peeling can be reliably prevented in the finally obtained bonded body 1. In addition, as will be described in detail later, even when the thermal expansion coefficients of the respective base materials 2 are different from each other, by optimizing the conditions for bonding the two base materials 2 to each other in the process described later, the two base materials The two can be firmly bonded with high dimensional accuracy.

Moreover, it is preferable that the two base materials 2 have mutually different rigidity. Thereby, two base materials 2 can be joined more firmly.
Moreover, it is preferable that at least one of the two base materials 2 is made of a resin material. The resin material can relieve stress (for example, stress accompanying thermal expansion, etc.) generated at the bonding interface when the two base materials 2 are bonded to each other due to its flexibility. For this reason, it becomes difficult to destroy the bonding interface, and as a result, the bonded body 1 having high bonding strength can be obtained.

Next, a base treatment is performed on the bonding surface 21 of the substrate 2 as necessary. Thereby, the bonding surface 21 is cleaned and activated. As a result, when the plasma polymerization film 3 is formed on the bonding surface 21 in a process described later, the bonding strength between the bonding surface 21 and the plasma polymerization film 3 can be increased.
The base treatment is not particularly limited, and examples thereof include oxygen plasma treatment, etching treatment, electron beam irradiation treatment, and ultraviolet light irradiation treatment.
In addition, especially when the base material 2 which performs a base treatment is comprised with the resin material (polymer material), a corona discharge process, a nitrogen plasma process, etc. are used suitably.

[2] Next, as shown in FIGS. 2A to 2C, the plasma polymerized films 3 are respectively formed on the two base materials 2 (one surface of the base material 2) (first step). ).
The plasma polymerized film 3 can be obtained by polymerizing molecules in the source gas by supplying a mixed gas of the source gas and the carrier gas in a strong electric field.
Specifically, first, the base material 2 is accommodated in the chamber 101 to be in a sealed state, and then the inside of the chamber 101 is depressurized by the operation of the exhaust pump 170.

Next, the gas supply unit 190 is operated to supply a mixed gas of the source gas and the carrier gas into the chamber 101. The supplied mixed gas is filled into the chamber 101 (see FIG. 2A).
The ratio (mixing ratio) of the raw material gas in the mixed gas is slightly different depending on the kind of the raw material gas and the carrier gas, the target film forming speed, and the like. It is preferable to set it to a degree, and it is more preferable to set it to about 30 to 60%. As a result, it is possible to optimize the conditions for formation (film formation) of the polymer film.
Further, the flow rate of the gas to be supplied is appropriately determined depending on the type of gas, the target film formation rate, the film thickness, etc., and is not particularly limited, but usually the flow rates of the source gas and the carrier gas are respectively , Preferably about 1 to 100 ccm, more preferably about 10 to 60 ccm.

  Next, the power supply circuit 180 is activated, and a high frequency voltage is applied between the pair of electrodes 130 and 140. As a result, gas molecules existing between the pair of electrodes 130 and 140 are ionized to generate plasma. Due to the energy of the plasma, molecules in the raw material gas are polymerized, and the polymer is deposited and deposited on the substrate 2 as shown in FIG. Thereby, the plasma polymerization film | membrane 3 is formed on the base material 2 (refer FIG.2 (c)).

  Examples of the source gas include methylsiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane, organosiloxane such as methylphenylsiloxane, trimethylgallium, triethylgallium, trimethylaluminum, Examples thereof include organometallic compounds such as triethylaluminum, triisobutylaluminum, trimethylindium, triethylindium, trimethylzinc, and triethylzinc, various hydrocarbon compounds, and various fluorine compounds.

The plasma polymerized film 3 obtained by using such a raw material gas is obtained by polymerizing these raw materials (polymer), that is, polyorganosiloxane, organometallic polymer, hydrocarbon polymer, fluorine polymer, and the like. Will be composed.
Of these, the plasma polymerized film 3 is preferably composed mainly of polyorganosiloxane. The polyorganosiloxane usually exhibits water repellency, but by performing various activation treatments, the organic group can be easily detached and can be changed to hydrophilic. That is, there is an advantage that the water repellency and hydrophilicity of the plasma polymerized film 3 can be easily controlled.

Moreover, even if the plasma polymerization film | membrane 3 comprised with the polyorganosiloxane which shows water repellency contacts each other, adhesion will be inhibited by an organic group and it will be very difficult to adhere | attach. On the other hand, the plasma-polymerized film 3 composed of polyorganosiloxane exhibiting hydrophilicity can be particularly easily bonded when they are brought into contact with each other. That is, the advantage that the water repellency and the hydrophilicity can be easily controlled leads to the advantage that the adhesion can be easily controlled. Therefore, the plasma polymerized film 3 made of polyorganosiloxane is used in the bonding method of the present invention. It will be used suitably.
In addition, since polyorganosiloxane is relatively flexible, for example, even when the constituent materials of the two base materials 2 are different, it is possible to relieve stress accompanying thermal expansion that occurs between the base materials 2. . Thereby, peeling can be reliably prevented in the bonded body 1 finally obtained.

  Furthermore, since polyorganosiloxane is excellent in chemical resistance, it can be effectively used for joining members that are exposed to chemicals for a long time. Specifically, for example, when manufacturing a droplet discharge head of an industrial inkjet printer in which an organic ink that easily erodes a resin material is used, by using the plasma polymerized film 3 mainly composed of polyorganosiloxane. , Its durability can be improved.

  Further, among the polyorganosiloxanes, those mainly composed of a polymer of octamethyltrisiloxane are preferred. A plasma polymerized film containing a polymer of octamethyltrisiloxane as a main component is particularly excellent in adhesiveness, and therefore is particularly preferably used in the bonding method of the present invention. Moreover, since the raw material which has octamethyltrisiloxane as a main component is liquid at normal temperature and has an appropriate viscosity, there is an advantage that it is easy to handle.

In the plasma polymerization, the frequency of the high frequency applied between the pair of electrodes 130 and 140 is not particularly limited, but is preferably about 1 kHz to 100 MHz, and more preferably about 10 to 60 MHz.
Further, the power density of the high frequency is not particularly limited, and is preferably about 0.01 to 10 / cm ^2, more preferably about 0.1 to 1 W / cm ^2.
Further, the pressure in the chamber 101 during film formation is preferably about 133.3 × 10 ^{−5 to} 1333 Pa (1 × 10 ^{−5 to} 10 Torr), and 133.3 × 10 ^{−4 to} 133.3 Pa ( More preferably, it is about 1 × 10 ^{−4 to} 1 Torr).

The raw material gas flow rate is preferably about 0.5 to 200 sccm, and more preferably about 1 to 100 sccm. On the other hand, the carrier gas flow rate is preferably about 5 to 750 sccm, and more preferably about 10 to 500 sccm.
The treatment time is preferably about 1 to 10 minutes, more preferably about 4 to 7 minutes.
Moreover, it is preferable that the temperature of the base material 2 is 25 degreeC or more, and it is more preferable that it is about 25-100 degreeC.

By appropriately setting such conditions, the dense plasma polymerized film 3 can be formed without unevenness.
In this embodiment, the procedure for forming a plasma polymerized film on the substrate 2 using a plasma polymerization apparatus is described. However, a substrate (adhered body) provided with a plasma polymerized film is prepared in advance. In addition, the adherend may be used.
Moreover, it is preferable that the average thickness of the plasma polymerization film | membrane 3 is about 10-10000 nm, and it is more preferable that it is about 50-5000 nm. By setting the average thickness of the plasma polymerized film 3 within the above range, the dimensional accuracy of the joined body in which the two base materials 2 are joined to each other can be prevented from being significantly lowered, and the joining can be performed more firmly.

That is, when the average thickness of the plasma polymerized film 3 is less than the lower limit value, there is a possibility that sufficient bonding strength cannot be obtained. On the other hand, when the average thickness of the plasma polymerized film 3 exceeds the upper limit, the dimensional accuracy of the joined body may be significantly reduced.
Furthermore, if the average thickness of the plasma polymerized film 3 is within the above range, a certain degree of shape followability is ensured for the plasma polymerized film 3. For this reason, for example, even when unevenness is present on the bonding surface of the substrate 2 (surface adjacent to the plasma polymerization film 3), the plasma follows the shape of the unevenness depending on the height of the unevenness. The polymer film 3 can be deposited. As a result, the plasma polymerized film 3 can absorb the unevenness and reduce the height of the unevenness generated on the surface.
In addition, the degree of the shape followability as described above becomes more prominent as the thickness of the plasma polymerization film 3 increases. Therefore, in order to ensure sufficient shape followability, the thickness of the plasma polymerization film 3 should be as thick as possible.

[3] Next, energy is applied to the surface 31 of the obtained plasma polymerization film 3. Thereby, a part of molecular bond in the vicinity of the surface 31 is cut, and the surface 31 is activated (second step).
As a method for imparting energy to the surface 31 of the plasma polymerized film 3, any method may be used as long as it can activate the surface 31, but a method of irradiating energy rays is preferable. According to this method, the surface 31 of the plasma polymerization film 3 is activated efficiently. Further, according to this method, the molecular structure in the plasma polymerized film 3 is not cut more than necessary (for example, until reaching the interface of the base material 2), so that the characteristics of the plasma polymerized film 3 are prevented from deteriorating. be able to. Examples of the energy beam include ultraviolet light, electron beam, and particle beam.

In addition, it is preferable to use a method of irradiating ultraviolet rays having a wavelength of about 150 to 300 nm as energy rays, as shown in FIG. According to such ultraviolet light, a wide range can be processed in a shorter time without unevenness while preventing a significant deterioration in the characteristics of the plasma polymerized film 3. For this reason, activation of the surface 31 of the plasma polymerized film 3 can be performed more efficiently. In addition, ultraviolet light has an advantage that it can be generated by simple equipment such as an ultraviolet lamp.
The wavelength of the ultraviolet light is more preferably about 160 to 200 nm.

Further, the time of irradiation with ultraviolet light is not particularly limited as long as the molecular bond near the surface 31 of the plasma polymerized film 3 can be cut, but is preferably about 0.5 to 30 minutes. More preferably, it is about 1 to 10 minutes.
Further, the irradiation of the energy beam to the plasma polymerization film 3 may be performed in any atmosphere, but is preferably performed in an air atmosphere. Thereby, it is not necessary to spend time and cost to control the atmosphere, and the activation process can be performed more easily.

  A hydroxyl group (OH group) is naturally bonded to the surface 31 of the plasma polymerized film 3 activated in this manner by contact with surrounding moisture. The above-mentioned “activate” means a state in which the molecular bond in the vicinity of and inside the surface 31 is broken, and an unterminated bond is generated, or a hydroxyl group is bonded to the broken bond. Or a state in which these states are mixed.

[4] Next, the two base materials 2 are bonded together so that the activated surfaces are in contact with each other (see FIG. 3E). Thereby, the two plasma polymerization films 3 are integrated with each other, and the two base materials 2 are bonded to each other.
Here, this joining is presumed to be based on both or one of the following two mechanisms (i) and (ii).

(I) When two base materials 2 are bonded together, OH groups existing on the surface of each plasma polymerization film 3 are adjacent to each other. The adjacent OH groups attract each other by hydrogen bonding, and an attractive force is generated between the OH groups.
In addition, OH groups that are attracted to each other by this hydrogen bond are desorbed from the surface with dehydration condensation depending on temperature conditions and the like. As a result, at the contact interface between the two plasma polymerized films 3, the bonds in which the detached OH groups are bonded are bonded. That is, the respective base materials constituting each plasma polymerized film 3 are directly coupled and integrated to form one plasma polymerized film 30.

  (Ii) When the two base materials 2 are bonded to each other, the unterminated bonds generated on the surface 31 and the inside of each plasma polymerized film 3 are recombined. Since this recombination occurs in a complicated manner so as to overlap (entangle) with each other, a network-like bond is formed at the bonding interface. Thereby, the respective base materials constituting each plasma polymerized film 3 are directly joined and integrated to form one plasma polymerized film 30.

With the above mechanism, the joined body 1 is obtained as shown in FIG. 3 (f) (third step).
Note that the active state of the surface of the plasma polymerized film 3 activated in the step [3] relaxes with time. For this reason, this process [4] is performed as soon as possible after the completion of the process [3]. Specifically, after the completion of the step [3], the step [4] is preferably performed within 60 minutes, and more preferably within 5 minutes. Within this time, the surface of the plasma polymerized film 3 maintains a sufficiently active state, so that a sufficient bonding strength can be obtained when bonded.

In other words, the plasma polymerization film 3 before activation is chemically stable and excellent in weather resistance. For this reason, the plasma polymerized film 3 at the time when the step [2] is completed is suitable for long-term storage. Therefore, a large amount of the base material 2 (adhered body) provided with such a plasma polymerized film 3 is manufactured or purchased and stored, and just before the bonding in this step [4], only the necessary number is performed. If the step [3] is performed, it is effective from the viewpoint of the manufacturing efficiency of the joined body.
In the conventional solid bonding such as silicon direct bonding, even if the surface is activated, the active state is maintained for only a very short time of several seconds to several tens of seconds in the atmosphere. For this reason, after the surface was activated, there was a problem that it was not possible to ensure sufficient time for performing operations such as bonding the two members to be joined together.

On the other hand, according to the present invention, the active state can be maintained for a relatively long time of several minutes or more by the action of the plasma polymerized film. For this reason, the time required for the work can be sufficiently secured, and the efficiency of the joining work can be increased.
In the bonded body 1 obtained in this manner, the bonding occurs in a short time like a covalent bond, not an adhesive based on a physical bond such as an anchor effect, like an adhesive used in a conventional bonding method. Based on a strong chemical bond, the two substrates 2 are joined together. For this reason, the joined body 1 is extremely difficult to be peeled off, and joining unevenness or the like hardly occurs.
Further, according to the bonding method of the present invention, unlike the conventional solid bonding, a heat treatment at a high temperature (about 700 to 800 ° C.) is not required. Can be used for joining. Thereby, the range of selection of the constituent material of a base material can be expanded.

The joined body (joined body of the present invention) 1 can be obtained as described above.
The bonded body 1 thus obtained preferably has a bonding strength between the substrates 2 of 5 MPa (50 kgf / cm ² ) or more, more preferably 10 MPa (100 kgf / cm ² ) or more. The bonded body 1 having such bonding strength can sufficiently prevent the peeling. As will be described later, when the droplet discharge head is configured using the joined body 1, a droplet discharge head having excellent durability can be obtained. Moreover, according to the joining method of the present invention, the joined body 1 in which the two base materials 2 are joined with such a large joining strength can be efficiently produced.
In addition, after obtaining the joined body 1, you may make it perform either one or both of the following two processes [5A] and [5B] with respect to this joined body 1 as needed.

[5A] As shown in FIG. 3G, the obtained bonded body 1 is pressurized in a direction in which the base materials 2 approach each other.
Thereby, the surfaces of the respective plasma polymerization films 3 are closer to each other. As a result, dehydration condensation and recombination of binding activity in the step [4] are promoted. Then, the integration of the two plasma polymerized films 3 further proceeds, and the bonding strength in the bonded body 1 can be further increased.
At this time, the pressure when pressurizing the bonded body 1 is preferably as high as possible. Thereby, the joint strength in the joined body 1 can be increased in proportion to the pressure.

In addition, what is necessary is just to adjust this pressure suitably according to conditions, such as a constituent material and thickness of the base material 2, and a joining apparatus. Specifically, although it is slightly different depending on the constituent material and thickness of the substrate 2, it is preferably about 1 to 10 MPa, and more preferably about 1 to 5 MPa. Thereby, the joining strength of the joined body 1 can be reliably increased. In addition, although this pressure may exceed the said upper limit, depending on the constituent material of the base material 2, there exists a possibility that damage etc. may arise in the base material 2. FIG.
The time for pressurization is not particularly limited, but is preferably about 10 seconds to 30 minutes. In addition, what is necessary is just to change suitably the time to pressurize according to the pressure at the time of pressurizing. Specifically, the higher the pressure at which the bonded body 1 is pressed, the shorter the pressing time.

[5B] As shown in FIG. 3G, the obtained bonded body 1 is heated.
Thereby, dehydration condensation of OH groups further proceeds at the interface of each plasma polymerized film 3. Thereby, the joint strength in the joined body 1 can be further increased.
At this time, the temperature at the time of heating the bonded body 1 is not particularly limited as long as it is higher than room temperature and lower than the heat resistance temperature of the bonded body 1, but is preferably about 25 to 100 ° C., more preferably 50 to 100 ° C. About ℃. By heating at a temperature in such a range, it is possible to reliably increase the bonding strength while reliably preventing the bonded body 1 from being altered or deteriorated by heat.

The heating time is not particularly limited, but is preferably about 1 to 30 minutes.
Moreover, when performing both said process [5A] and [5B], it is preferable to perform these simultaneously. That is, as shown in FIG. 3G, it is preferable to heat the bonded body 1 while applying pressure. Thereby, the effect by pressurization and the effect by heating are exhibited synergistically, and the joint strength of the joined body 1 can be particularly increased.

In addition, when the thermal expansion coefficients of two base materials 2 are substantially equal, it is preferable to heat the joined body 1 as described above, but when the thermal expansion coefficients of the two base materials 2 are different from each other. Is preferably performed at as low a temperature as possible. By performing the bonding at a low temperature, it is possible to further reduce the thermal stress generated at the bonding interface.
Specifically, although it depends on the difference in thermal expansion coefficient between the two base materials 2, it is preferable to perform the bonding at a temperature of about 25 to 50 ° C, and it is more preferable to perform the bonding at a temperature of about 25 to 40 ° C. . Within such a temperature range, even if the difference in thermal expansion coefficient between the two base materials 2 is large to some extent, the thermal stress generated at the bonding interface can be sufficiently reduced. As a result, it is possible to reliably prevent warpage, peeling, and the like in the joined body 1.
In this case, when the difference in thermal expansion coefficient between the two base materials 2 is 5 × 10 ⁻⁵ / K or more, it is strongly recommended that the bonding be performed at the lowest possible temperature as described above. .
By performing the steps as described above, the two plasma polymer films 3 are almost completely integrated into one plasma polymer film 30. As a result, a bonded body 1 ′ with higher bonding strength can be obtained.

<Droplet ejection head>
Next, an embodiment in which the joined body of the present invention is applied to an ink jet recording head will be described.
FIG. 4 is an exploded perspective view showing an ink jet recording head (droplet discharge head) obtained by applying the joined body of the present invention, and FIG. 5 shows a configuration of a main part of the ink jet recording head shown in FIG. FIG. 6 is a schematic view showing an embodiment of an ink jet printer including the ink jet recording head shown in FIG. Note that FIG. 4 is shown upside down from the state of normal use.

An ink jet recording head (droplet discharge head of the present invention) 10 shown in FIG. 4 is mounted on an ink jet printer (droplet discharge apparatus of the present invention) 9 as shown in FIG.
The ink jet printer 9 shown in FIG. 6 includes an apparatus main body 92, a tray 921 in which the recording paper P is installed at the upper rear, a paper discharge port 922 for discharging the recording paper P in the lower front, and an operation panel on the upper surface. 97.

The operation panel 97 includes, for example, a liquid crystal display, an organic EL display, an LED lamp, and the like, and a display unit (not shown) for displaying an error message and the like, and an operation unit (not shown) configured with various switches. And.
Further, inside the apparatus main body 92, mainly a printing apparatus (printing means) 94 provided with a reciprocating head unit 93 and a paper feeding apparatus (paper feeding means) for feeding recording paper P to the printing apparatus 94 one by one. 95 and a control unit (control means) 96 for controlling the printing device 94 and the paper feeding device 95.

  Under the control of the control unit 96, the paper feeding device 95 intermittently feeds the recording paper P one by one. The recording paper P passes near the lower part of the head unit 93. At this time, the head unit 93 reciprocates in a direction substantially orthogonal to the feeding direction of the recording paper P, and printing on the recording paper P is performed. That is, the reciprocating motion of the head unit 93 and the intermittent feeding of the recording paper P are the main scanning and sub-scanning in printing, and ink jet printing is performed.

The printing apparatus 94 includes a head unit 93, a carriage motor 941 that is a drive source of the head unit 93, and a reciprocating mechanism 942 that reciprocates the head unit 93 in response to the rotation of the carriage motor 941.
The head unit 93 includes an ink jet recording head 10 (hereinafter simply referred to as “head 10”) having a large number of nozzle holes 111 at a lower portion thereof, an ink cartridge 931 that supplies ink to the head 10, the head 10 and And a carriage 932 on which the ink cartridge 931 is mounted.
Ink cartridge 931 is filled with four color inks of yellow, cyan, magenta, and black (black), thereby enabling full color printing.

The reciprocating mechanism 942 includes a carriage guide shaft 943 whose both ends are supported by a frame (not shown), and a timing belt 944 extending in parallel with the carriage guide shaft 943.
The carriage 932 is supported by the carriage guide shaft 943 so as to be able to reciprocate and is fixed to a part of the timing belt 944.
When the timing belt 944 travels forward and backward via a pulley by the operation of the carriage motor 941, the head unit 93 reciprocates as guided by the carriage guide shaft 943. During this reciprocation, ink is appropriately discharged from the head 10 and printing on the recording paper P is performed.

The sheet feeding device 95 includes a sheet feeding motor 951 serving as a driving source thereof, and a sheet feeding roller 952 that is rotated by the operation of the sheet feeding motor 951.
The paper feed roller 952 includes a driven roller 952a and a drive roller 952b that are vertically opposed to each other with a recording paper P feeding path (recording paper P) interposed therebetween. The drive roller 952b is connected to the paper feed motor 951. As a result, the paper feed roller 952 can feed a large number of recording sheets P set on the tray 921 one by one toward the printing apparatus 94. Instead of the tray 921, a configuration in which a paper feed cassette that stores the recording paper P can be detachably mounted may be employed.

The control unit 96 performs printing by controlling the printing device 94, the paper feeding device 95, and the like based on print data input from a host computer such as a personal computer or a digital camera.
Although not shown, the control unit 96 mainly includes a memory that stores a control program for controlling each unit, a piezoelectric element driving circuit that drives the piezoelectric element (vibration source) 14 to control the ink ejection timing, A driving circuit for driving the printing device 94 (carriage motor 941), a driving circuit for driving the paper feeding device 95 (paper feeding motor 951), a communication circuit for obtaining print data from the host computer, and these electrically And a CPU that is connected and performs various controls in each unit.
Further, for example, various sensors that can detect the remaining ink amount of the ink cartridge 931, the position of the head unit 93, and the like are electrically connected to the CPU.

  The control unit 96 obtains the print data via the communication circuit and stores it in the memory. The CPU processes the print data and outputs a drive signal to each drive circuit based on the process data and input data from various sensors. The piezoelectric element 14, the printing device 94, and the paper feeding device 95 are each activated by this drive signal. As a result, printing is performed on the recording paper P.

Hereinafter, the head 10 (the droplet discharge head of the present invention) will be described in detail with reference to FIGS.
The head 10 includes a head main body 17 including a nozzle plate 11, an ink chamber substrate 12, a vibration plate 13, and a piezoelectric element (vibration source) 14 bonded to the vibration plate 13, and a base body that houses the head main body 17. 16. The head 10 constitutes an on-demand piezo jet head.

The nozzle plate 11 is made of, for example, a silicon-based material such as SiO ₂ , SiN, or quartz glass, a metal-based material such as Al, Fe, Ni, Cu, or an alloy containing these, or an oxide-based material such as alumina or iron oxide. The material is composed of carbon-based materials such as carbon black and graphite.
A number of nozzle holes 111 for discharging ink droplets are formed in the nozzle plate 11. The pitch between these nozzle holes 111 is appropriately set according to the printing accuracy.

An ink chamber substrate 12 is fixed (fixed) to the nozzle plate 11.
The ink chamber substrate 12 includes a plurality of ink chambers (cavities, pressure chambers) 121 and a reservoir chamber that stores ink supplied from the ink cartridge 931 by the nozzle plate 11, side walls (partition walls) 122, and a vibration plate 13 described later. 123 and a supply port 124 for supplying ink from the reservoir chamber 123 to each ink chamber 121 are partitioned.

Each ink chamber 121 is formed in a strip shape (cuboid shape), and is disposed corresponding to each nozzle hole 111. Each ink chamber 121 has a variable volume due to vibration of a diaphragm 13 described later, and is configured to eject ink by this volume change.
As a base material for obtaining the ink chamber substrate 12, for example, a silicon single crystal substrate, various glass substrates, various resin substrates and the like can be used. Since these substrates are general-purpose substrates, the manufacturing cost of the head 10 can be reduced by using these substrates.

On the other hand, a vibration plate 13 is bonded to the ink chamber substrate 12 on the side opposite to the nozzle plate 11, and a plurality of piezoelectric elements 14 are provided on the vibration plate 13 on the side opposite to the ink chamber substrate 12.
A communication hole 131 is formed at a predetermined position of the diaphragm 13 so as to penetrate in the thickness direction of the diaphragm 13. Ink can be supplied from the ink cartridge 931 to the reservoir chamber 123 through the communication hole 131.

Each piezoelectric element 14 has a piezoelectric layer 143 interposed between the lower electrode 142 and the upper electrode 141, and is disposed corresponding to the substantially central portion of each ink chamber 121. Each piezoelectric element 14 is electrically connected to a piezoelectric element drive circuit and is configured to operate (vibrate, deform) based on a signal from the piezoelectric element drive circuit.
Each piezoelectric element 14 functions as a vibration source, and the diaphragm 13 vibrates due to vibration of the piezoelectric element 14 and functions to instantaneously increase the internal pressure of the ink chamber 121.
The base body 16 is made of, for example, various resin materials, various metal materials, and the like, and the nozzle plate 11 is fixed and supported on the base body 16. That is, the edge of the nozzle plate 11 is supported by the step 162 formed on the outer periphery of the recess 161 in a state where the head body 17 is housed in the recess 161 provided in the base body 16.

Among the above-described bonding between the nozzle plate 11 and the ink chamber substrate 12, bonding between the ink chamber substrate 12 and the vibration plate 13, and bonding between the nozzle plate 11 and the substrate 16, the bonding according to the present invention is performed. The method is used.
In other words, the present invention is provided in at least one place among the joined body of the nozzle plate 11 and the ink chamber substrate 12, the joined body of the ink chamber substrate 12 and the vibration plate 13, and the joined body of the nozzle plate 11 and the substrate 16. The joined body is applied.

Such a head 10 is joined by interposing a plasma polymerization film at the joining interface. For this reason, the bonding strength and chemical resistance of the bonding interface are increased, and thereby the durability and liquid tightness with respect to the ink stored in each ink chamber 121 are increased. As a result, the head 10 becomes highly reliable.
In addition, since highly reliable bonding can be performed at a very low temperature, it is advantageous in that a large-area head can be formed even with materials having different linear expansion coefficients.
Such a head 10 is in a state where a predetermined ejection signal is not input via the piezoelectric element driving circuit, that is, in a state where no voltage is applied between the lower electrode 142 and the upper electrode 141 of the piezoelectric element 14. The piezoelectric layer 143 is not deformed. For this reason, the vibration plate 13 is not deformed, and the volume of the ink chamber 121 is not changed. Therefore, no ink droplet is ejected from the nozzle hole 111.

  On the other hand, in a state where a predetermined ejection signal is input via the piezoelectric element driving circuit, that is, in a state where a constant voltage is applied between the lower electrode 142 and the upper electrode 141 of the piezoelectric element 14, the piezoelectric layer 143 is applied. Deformation occurs. As a result, the diaphragm 13 is greatly deflected, and the volume of the ink chamber 121 is changed. At this time, the pressure in the ink chamber 121 increases instantaneously, and ink droplets are ejected from the nozzle holes 111.

When the ejection of one ink is completed, the piezoelectric element driving circuit stops applying the voltage between the lower electrode 142 and the upper electrode 141. As a result, the piezoelectric element 14 returns almost to its original shape, and the volume of the ink chamber 121 increases. At this time, a pressure (pressure in the positive direction) from the ink cartridge 931 toward the nozzle hole 111 acts on the ink. Therefore, air is prevented from entering the ink chamber 121 from the nozzle hole 111, and an amount of ink corresponding to the amount of ink discharged is supplied from the ink cartridge 931 (reservoir chamber 123) to the ink chamber 121.
In this manner, in the head 10, arbitrary (desired) characters and figures can be printed by sequentially inputting ejection signals to the piezoelectric elements 14 at the positions to be printed via the piezoelectric element driving circuit. it can.

The head 10 may have an electrothermal conversion element instead of the piezoelectric element 14. That is, the head 10 may have a configuration (so-called “bubble jet method” (“bubble jet” is a registered trademark)) that ejects ink using thermal expansion of a material by an electrothermal transducer.
In the head 10 having such a configuration, the nozzle plate 11 is provided with a coating 114 formed for the purpose of imparting liquid repellency. Thus, when ink droplets are ejected from the nozzle holes 111, it is possible to reliably prevent ink droplets from remaining around the nozzle holes 111. As a result, the ink droplets ejected from the nozzle hole 111 can be reliably landed on the target area.
As described above, the bonding method, the bonded body, the droplet discharge head, and the droplet discharge apparatus of the present invention have been described based on the illustrated embodiments, but the present invention is not limited thereto.
For example, in the bonding method of the present invention, one or more optional steps may be added as necessary.

Next, specific examples of the present invention will be described.
1. Production of laminated body (joined body) (Example 1)
First, a single crystal silicon substrate having a length of 20 mm × width of 20 mm × an average thickness of 1 mm is prepared as the first base material, and a glass substrate of length 20 mm × width 20 mm × average thickness of 1 mm is prepared as the second base material. did.
Subsequently, these base materials were accommodated in the chamber 101 of the plasma polymerization apparatus 100 shown in FIG. 1, and the base treatment by oxygen plasma was performed.
Next, a plasma polymerization film having an average thickness of 200 nm was formed on the surface subjected to the base treatment. The film forming conditions are as shown below.

<Film formation conditions>
-Source gas composition: Octamethyltrisiloxane-Source gas flow rate: 50 sccm
Carrier gas composition: Argon Carrier gas flow rate: 100 sccm
・ High frequency power output: 100W
-Chamber pressure: 1 Pa (low vacuum)
・ Processing time: 15 minutes ・ Substrate temperature: 20 ° C.

Next, the obtained plasma polymerization film was irradiated with ultraviolet rays under the following conditions.
<Ultraviolet irradiation conditions>
-Atmospheric gas composition: Air (air)
・ Atmospheric gas temperature: 20 ℃
・ Atmospheric gas pressure: Atmospheric pressure (100 kPa)
UV wavelength: 172 nm
-Irradiation time of ultraviolet rays: 5 minutes Subsequently, one minute after the irradiation of ultraviolet rays, the respective substrates were superposed so that the surfaces irradiated with the ultraviolet rays contacted each other.
And each base material was heated at 80 degreeC, pressurizing at 3 Mpa, and maintained for 15 minutes. Thereby, each base material was joined and the laminated body (joined body) was obtained.

(Example 2)
A laminate was obtained in the same manner as in Example 1 except that the heating temperature was changed from 80 ° C to 25 ° C.
(Examples 3 to 12)
A laminate was obtained in the same manner as in Example 1 except that the constituent material of the first base material and the constituent material of the second base material were changed to the materials shown in Table 1, respectively.

(Examples 13 to 15)
A laminate was obtained in the same manner as in Examples 1, 3, and 4 except that the raw material gas was changed to the gas having the composition shown in Table 1 and the composition of the plasma polymerized film was changed.
(Comparative Examples 1-3)
The constituent materials of the first base material and the constituent materials of the second base material are the materials shown in Table 1, respectively, except that each base material is bonded with an epoxy-based adhesive, respectively in Examples 1, 3, and In the same manner as in Example 4, a laminate was obtained.

2. 2. Evaluation of Laminate (Joint) 2.1 Evaluation of Bond Strength (Split Strength) For the laminates obtained in each Example and each Comparative Example, the bond strength was measured.
The measurement of the bonding strength was performed by measuring the strength immediately before each substrate was peeled off. Then, the bonding strength was evaluated according to the following criteria.

<Evaluation criteria for bonding strength>
◎: 10 MPa (100 kgf / cm ² ) or more ○: 5 MPa (50 kgf / cm ² ) or more, less than 10 MPa (100 kgf / cm ² ) Δ: 1 MPa (10 kgf / cm ² ) or more, less than 5 MPa (50 kgf / cm ² ) ×: Less than 1 MPa (10 kgf / cm ² )

2.2 Evaluation of dimensional accuracy The dimensional accuracy in the thickness direction was measured for each of the laminates obtained in each Example and each Comparative Example.
The measurement of the dimensional accuracy was performed by measuring the thickness of each corner of the square laminate and calculating the difference between the maximum value and the minimum value of the thickness at four locations. This difference was evaluated according to the following criteria.
<Evaluation criteria for dimensional accuracy>
○: Less than 10 μm ×: 10 μm or more

2.3 Evaluation of chemical resistance The laminates obtained in each Example and each Comparative Example were immersed in ink for inkjet printers (manufactured by Epson Corporation, HQ4) maintained at 80 ° C. for 3 weeks under the following conditions. Thereafter, each base material was peeled off, and it was confirmed whether or not ink entered the bonding interface. The results were evaluated according to the following criteria.

<Evaluation criteria for chemical resistance>
◎: Not penetrated at all ○: Slightly penetrated into the corner △: Infiltrated along the edge ×: Intruded inside As described above, each evaluation result of 2.1 to 2.3 Is shown in Table 1.

As is clear from Table 1, the laminates obtained in each example exhibited excellent characteristics in any of the items of bonding strength, dimensional accuracy, and chemical resistance.
On the other hand, the laminates obtained in the respective comparative examples have insufficient bonding strength and chemical resistance, and the tendency of the dimensional accuracy is particularly remarkable.

It is a longitudinal cross-sectional view which shows typically the plasma polymerization apparatus used for the joining method of this invention. It is a figure (longitudinal sectional view) for demonstrating the joining method of this invention. It is a figure (longitudinal sectional view) for demonstrating the joining method of this invention. It is a disassembled perspective view which shows the inkjet recording head (droplet discharge head) obtained by applying the conjugate | zygote of this invention. FIG. 5 is a cross-sectional view illustrating a configuration of a main part of the ink jet recording head illustrated in FIG. 4. It is the schematic which shows embodiment of an inkjet printer provided with the inkjet recording head shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1 '... Assembly 2 ... Base material 21 ... Joining surface 3, 30 ... Plasma polymerization film 31 ... Surface 100 ... Plasma polymerization apparatus 101 ... Chamber 102 ... Grounding wire 103 ... Supply port 104 …… Exhaust port 130 …… First electrode 139 …… Electrostatic chuck 170 …… Pump 171 …… Pressure control mechanism 180 …… Power supply circuit 182 …… High frequency power supply 183 …… Matching box 184 …… Wiring 190 …… Gas supply unit 191 ... Liquid storage unit 192 ... Vaporizer 193 ... Gas cylinder 194 ... Pipe 195 ... Diffusion plate 10 ... Inkjet recording head 11 ... Nozzle plate 111 ... Nozzle hole 114 ... Coating 12 ... ... Ink chamber substrate 121 ... Ink chamber 122 ... Side wall 123 ... Reservoir chamber 124 ... Supply port 13 ... Diaphragm 131 …… Communication hole 14 …… Piezoelectric element 140 …… Second electrode 141 …… Upper electrode 142 …… Lower electrode 143 …… Piezoelectric layer 16 …… Substrate 161 …… Concavity 162 …… Step 17 …… Head body 9. Inkjet printer 92 ... Main body 921 ... Tray 922 ... Paper discharge port 93 ... Head unit 931 ... Ink cartridge 932 ... Carriage 94 ... Printing device 941 ... Carriage motor 942 ... Reciprocating mechanism 943 …… Carriage guide shaft 944 …… Timing belt 95 …… Feeding device 951 …… Feeding motor 952 …… Feeding roller 952a …… Driving roller 952b …… Driving roller 96 …… Control unit 97 …… Operation panel P ……Recording sheet

Claims (20)

A first step of preparing a first adherend and a second adherend each having a plasma polymerized film on a substrate;
A second step of activating the surface of each plasma polymerized film by applying energy to the surface of each plasma polymerized film of the first adherend and the second adherend,
A third step of bonding the first adherend and the second adherend to obtain a joined body so that the surfaces of the activated plasma polymerization films are brought into close contact with each other; The joining method characterized by this.   The bonding method according to claim 1, wherein each of the plasma polymerized films is composed of polyorganosiloxane as a main material.   The joining method according to claim 2, wherein the polyorganosiloxane is mainly composed of a polymer of octamethyltrisiloxane.   The joining method according to any one of claims 1 to 3, wherein an average thickness of each plasma polymerization film is 10 to 10,000 nm.   5. The bonding method according to claim 1, wherein, in the second step, the surface of each plasma polymerization film is irradiated with energy rays.   The bonding method according to claim 5, wherein the energy beam is ultraviolet light having a wavelength of 150 to 300 nm.   The joining method according to claim 1, wherein the second step is performed in an air atmosphere.   The joining method according to claim 1, further comprising a step of performing a heat treatment on the joined body after the third step.   The bonding method according to claim 8, wherein a temperature of the heat treatment is 25 to 100 ° C.   The joining method according to claim 1, further comprising a step of pressurizing the joined body after the third step.   The bonding method according to claim 10, wherein a pressure when the bonded body is pressurized is 1 to 10 MPa.   The joining method according to any one of claims 1 to 11, wherein the third step is started within 60 minutes after the end of the second step.   Each of the first adherend and the second adherend is preliminarily subjected to a base treatment with plasma on each of the substrates, and then the plasma polymerized film is formed in the region subjected to the base treatment. The joining method according to any one of claims 1 to 12, wherein the joining method is as follows.   The joining method according to claim 1, wherein the two base materials have different rigidity.   Two bonded substrates are bonded by the bonding method according to any one of claims 1 to 14. Two substrates,
A plasma polymerized film,
The joined body, wherein the two base materials are joined via the plasma polymerized film.   The joined body according to claim 16, wherein the plasma polymerized film is formed by joining plasma polymerized films formed in advance on the surfaces of the two base materials.   The joined body according to any one of claims 15 to 17, wherein a joining strength between the two base materials is 5 MPa or more.   A droplet discharge head comprising the joined body according to claim 15.   A droplet discharge apparatus comprising the droplet discharge head according to claim 19.

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