JP2010201715A - Bonding structure and bonding method for liquid flow channel, and inkjet head - Google Patents

Abstract

An object of the present invention is to improve the protection performance and sealability of a liquid contact surface of an adhesive when bonding a plurality of members having a fine flow path structure arranged at high density.
A liquid flow channel bonding structure in which a plurality of substrates are bonded together to form a fine flow channel structure, and when the plurality of substrates are bonded with an adhesive, A liquid-resistant film formed by applying a liquid-resistant film agent having liquid resistance to a liquid flowing in a flow path formed by joining the substrates so as to cover an adhesive exposed inside the flow path. It has liquid repellency with respect to the liquid-resistant film agent provided at the boundary between the film-coated part, the liquid-resistant film-coated part inside the flow path, and the non-coated part where the liquid-resistant film agent is not applied. The above-mentioned problem is solved by providing an adhesive structure for a liquid flow path characterized by comprising a liquid repellent portion.
[Selection] Figure 4

Description

  The present invention relates to a liquid flow path bonding structure, a bonding method, and an inkjet head, and more particularly to a liquid flow path bonding structure, a bonding method, and an inkjet head in an inkjet head formed by laminating a plurality of members.

  Conventionally, an ink jet head is formed by joining a plurality of members. In joining members, an adhesive may be used depending on conditions such as restrictions on applied temperature and combinations of materials of members to be joined.

  However, when each member is bonded using an adhesive, the applied adhesive protrudes into the opening of the ink flow path or the like with a minute size in the inkjet head, narrowing the opening, or in the worst case There was a risk of blocking the opening. In addition, if there is a portion where the adhesive is exposed at the joint, for example, in the case of the adhesive exposed on the inner surface of the ink flow path, the adhesive is eroded and deteriorated by the ink, resulting in a decrease in the adhesive force. There was also a risk that the joined member would be peeled off.

  On the other hand, when forming an adhesive layer by applying an adhesive to the surface of the nozzle plate, pool plate, supply hole plate, pressure chamber plate, vibration plate, etc., on which ink is not discharged, A high-viscosity adhesive is applied in the vicinity of the groove, and a low-viscosity adhesive is applied in the other areas to ensure the sealing of the ink flow path, and the amount of adhesive protruding is uniform. Is known (see, for example, Patent Document 1).

  In addition, for example, there is known an ink jet head in which joints of electrodes and members are covered with Parylene (registered trademark) to be protected from erosion by ink (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 2001-18386 JP 2002-307692 A

  However, the technique described in Patent Document 1 discloses a technique for preventing the adhesive from protruding into the ink flow path and improving the sealing performance, but both are applied when the size of the flow path structure is large. For example, the maximum length of the cross section of the flow path (or the diameter if the cross section is circular) is 1 mm or less, it is not suitable for protecting the adhesive in the fine flow path portion of the inkjet head.

  Specifically, the method of preventing the flow by partially irradiating the adhesive with ultraviolet rays before bonding causes the adhesive strength of the corresponding part to decrease, and therefore the sealing performance to prevent moisture from entering deteriorates. That is, when trying to apply the one described in Patent Document 1 above, there is no problem with the flow channel structure having a large size, but if the flow channel structure is applied to a fine and high-density one, the bonding surface portion is also narrowed. There is a problem that adhesive strength and sealability are partially reduced.

  Further, the one described in Patent Document 2 is not specifically described for protecting the adhesive at the joint portion of the member forming the fine flow path structure of the ink jet head, and cannot be applied as it is.

  In addition, as described above, in order to configure the ink jet head, it may be necessary to bond the respective constituent members. In this case, the adhesive is required to have strength and appropriate flexibility. The strength is natural, but flexibility is necessary to prevent the inkjet head from being destroyed by stress caused by deformation caused by changes in ambient temperature and pressure due to changes in the environment in which the inkjet head is placed. It is said.

  Furthermore, when adhesion is used for a portion in contact with ink, ink resistance is also required. Ink resistance is a property that can maintain the required strength even when in contact with ink components so that the adhesive itself does not deteriorate due to deterioration due to the ingress of ink components and the adhesive strength does not decrease. is there.

  In addition, when the adhesion is performed, if the adhesion state is not necessarily perfect, the ink component, particularly moisture, permeates into the adhesion interface between the adhesive and the adherend, and the adherend is peeled off by reducing the adhesive force. There is. The influence on the adhesion interface is not limited to the intrusion of ink directly into the interface, but the ink component that has entered the adhesive may reach the adhesion interface and reduce the adhesive force.

  These alterations of the adhesive and intrusion of the ink component into the adhesion interface may occur due to the invasion of the ink component into the adhesive, although there are phenomena on the surface of the adhesive. Although the diffusion rate varies depending on the substance, since the adhesive is a resin, the diffusion rate is relatively fast, and it is not possible to completely eliminate the deterioration of the adhesive and the penetration of the ink component. It is a phenomenon that progresses over time. Therefore, a function to suppress the infiltration of the ink is required for the penetration preventing agent.

  Although it is desirable if the diffusion of the ink into the adhesive can be suppressed by the physical properties of the components of the adhesive, there is a problem that it is not easy to achieve both adhesive strength and flexibility as described above.

  The present invention has been made in view of such circumstances, and an ink flow path in an inkjet head, in particular, a fine flow path structure having a maximum cross-sectional diameter of 1 mm or less is arranged at a high density. Provided are a liquid flow path bonding structure and bonding method, and an ink jet head capable of improving the protection performance and sealing performance of a liquid contact surface of an adhesive when a plurality of members are bonded to each other in the case where a head is formed. For the purpose.

  In order to achieve the above object, an invention according to claim 1 is a liquid flow channel bonding structure in which a plurality of substrates are bonded to form a fine flow channel structure, and the plurality of substrates are bonded to each other by an adhesive. In the bonding portion between the substrates, a liquid-resistant film agent having liquid resistance to the liquid flowing in the flow path formed by bonding the substrates is exposed to the inside of the flow path Provided at a boundary portion between a liquid-resistant film coating portion formed by coating so as to cover the agent, a liquid-resistant film coating portion inside the flow path, and a non-coating portion where the liquid-resistant film agent is not applied. A liquid flow path bonding structure comprising: a liquid repellent portion having liquid repellency with respect to the liquid-resistant film agent.

  As a result, the liquid-resistant film agent can be thickly applied only to necessary portions, and for example, the protection performance and the sealing performance of the ink wetted surface of the adhesive exposed in the ink flow path in the inkjet head can be improved. It becomes possible.

  According to a second aspect of the present invention, the liquid repellent portion is formed by sinking an adhesive structure member of the liquid flow path in a liquid repellent.

  In addition, as shown in claim 3, the liquid repellent portion is a large number of fine irregularities formed in a boundary portion between the application portion and the non-application portion on the inner surface of the flow path. To do.

  Thereby, by providing the liquid repellent portion, the liquid-resistant film agent can be thickly applied only to the necessary portion.

  According to a fourth aspect of the present invention, the liquid-resistant film agent is a photocurable resin and is cured by light irradiated in the flow path.

  According to a fifth aspect of the present invention, the liquid-resistant film agent is a thermosetting resin and is cured by heating.

  As described above, various liquid-resistant film agents can be used.

  Similarly, in order to achieve the object, an invention according to claim 6 provides an ink jet head comprising the liquid flow path adhesive structure according to any one of claims 1 to 5. To do.

  As a result, it is possible to obtain an ink jet head having high reliability with improved protection performance and sealing performance of the ink contact surface of the adhesive exposed in the ink flow path.

  Similarly, in order to achieve the above object, the invention according to claim 7 provides an ink jet recording apparatus comprising the ink jet head according to claim 6.

  Thereby, an inkjet recording apparatus having high reliability can be obtained.

  Similarly, in order to achieve the object, the invention according to claim 8 is a liquid channel bonding method for bonding a plurality of substrates to form a fine channel structure, wherein the plurality of substrates The adhesive is cured with an adhesive, and the inner surface of the flow path formed by bonding the substrates at the joint between the substrates has liquid resistance to the liquid flowing in the flow path. The liquid-resistant film agent has a liquid-resistant film application portion that is applied so as to cover the adhesive exposed inside the flow path, and the liquid-resistant film agent at a boundary portion between the non-application portion where the liquid-resistant film agent is not applied. A liquid flow path characterized by forming a liquid repellent portion having liquid repellency to a film agent, applying the liquid resistant film agent to the liquid resistant film application portion, and curing the liquid resistant film agent. An adhesion method is provided.

  As a result, the liquid-resistant film agent can be thickly applied only to necessary portions, and for example, the protection performance and the sealing performance of the ink wetted surface of the adhesive exposed in the ink flow path in the inkjet head can be improved. It becomes possible.

  According to a ninth aspect of the present invention, the liquid repellent portion is formed by sinking an adhesive structure member of the liquid flow path in a liquid repellent.

  In addition, as shown in claim 10, the liquid repellent portion is formed by providing a large number of fine irregularities at a boundary portion between the application portion and the non-application portion on the inner surface of the flow path. And

  In addition, according to an eleventh aspect of the present invention, the liquid-resistant film agent is a photo-curable resin and is cured by light irradiated in the flow path.

  According to a twelfth aspect of the present invention, the liquid-resistant film agent is a thermosetting resin and is cured by heating.

  Similarly, in order to achieve the object, the invention according to claim 13 is a liquid channel bonding method for bonding a plurality of substrates to form a fine channel structure, and bonding the substrates A member that closes the flow path formed by joining the substrates is provided near the portion, the plurality of substrates are bonded with an adhesive, the adhesive is cured, and the adhesive exposed inside the flow path is covered. Applying a liquid-resistant film agent having liquid resistance to the liquid flowing in the flow path so as to adhere to a member that closes the flow path, and curing the liquid-resistant film agent, A method for adhering a liquid flow path is provided, wherein a member for closing is removed.

  Thereby, when apply | coating a liquid-resistant film agent to a micro structure, it can prevent that a liquid-resistant film agent adheres to the part which is not intended.

  According to a fourteenth aspect of the present invention, the flow path structure is used for an ink flow path of an ink jet head, and a member that closes the flow path also serves as a structural material of the ink jet head.

  Thereby, the liquid-resistant film agent does not adhere to unnecessary portions, the reliability as an ink jet can be improved, and the characteristics can be stabilized.

  Furthermore, since the member that closes the flow path also serves as the structural material of the ink jet head, the manufacturing method is not complicated without increasing the number of parts, and thus can be realized at a low cost.

  Further, as shown in claim 15, in order to further form a quadrangular pyramid-shaped protrusion on the member that closes the flow path, and to cure at least the photocurable adhesive or the photocurable liquid-resistant film agent of the flow path structure. Is irradiated onto the slope of the quadrangular pyramidal projections and reflected to cure the photocurable adhesive or the photocurable liquid-resistant film agent.

  Thereby, an adhesive agent and a liquid-resistant film agent can be reliably cured in a fine channel structure.

  Similarly, in order to achieve the object, the invention according to claim 16 is a liquid channel bonding method for bonding a plurality of substrates to form a fine channel structure, wherein the plurality of substrates Is bonded with a photocurable adhesive to cure the adhesive, and the substrate is provided with a photocurable liquid-resistant film agent having liquid resistance to a liquid flowing in a flow path formed by joining the substrates. When applying and curing so as to cover the adhesive exposed in the flow path at the joint portion, light for curing the photocurable adhesive or the photocurable liquid-resistant film agent is supplied to the flow path. Provided is a method for adhering a liquid flow path, wherein the photocurable adhesive or the photocurable liquid-resistant film agent is cured by irradiating and reflecting an inner wall surface.

  Thereby, an adhesive agent and a liquid-resistant film agent can be reliably cured in a fine channel structure.

  Further, according to a seventeenth aspect of the present invention, the wall surface inside the flow path that reflects the light for curing is plated with a material having high reflectivity.

  Thereby, a reflectance can be improved and hardening efficiency can be improved.

  In addition, as shown in claim 18, the light for curing applied to the inner wall surface of the flow path is substantially parallel light.

  As a result, since parallel light is radiated, even when there are multiple flow path portions to be bonded, the bonding target and the light source are connected to the central axis of the flow path in order to cure the entire circumference of the adhesive end surface of the flow path inner wall. The entire circumference of each flow path portion can be cured with a single light.

  Further, according to a nineteenth aspect of the present invention, the light for curing applied to the inner wall surface of the flow path is substantially convergent light.

  Since the light is collected in this way, it is possible to irradiate only a portion where light with high illuminance is desired, and it is possible to cure efficiently.

  In addition, as shown in claim 20, the wall surface on the inner side of the flow path for irradiating and reflecting the light for curing is a paraboloid of revolution having the central axis of the flow path as a rotation axis. . The light irradiated here is substantially parallel light.

  As a result, substantially parallel light is radiated, so even when there are multiple flow path portions to be bonded, the bonding target and the light source are centered on the flow path in order to cure the entire circumference of the adhesive end surface of the flow path inner wall. By rotating relatively around an axis parallel to the axis, the entire circumference of each flow path portion can be cured with a single light. Furthermore, since the inner wall surface of the flow path is a paraboloid of revolution having the central axis of the flow path as a rotation axis, substantially parallel light can be collected, and only a portion where light with high illuminance is desired to be irradiated. The light can be converged to one point so as to be hit.

  Similarly, in order to achieve the above object, the invention according to claim 21 is characterized in that an ink channel is manufactured by using the liquid channel bonding method according to any one of claims 8 to 20. An inkjet head manufacturing method is provided.

  Thereby, an inkjet head excellent in reliability can be manufactured.

  As described above, according to the present invention, the liquid-resistant film agent can be thickly applied only to a necessary portion, for example, protection of the ink wetted surface of the adhesive exposed in the ink flow path in the inkjet head. It becomes possible to improve performance and sealing performance.

1 is a configuration diagram schematically illustrating an embodiment of an ink jet recording apparatus in which an ink jet head having a liquid flow path bonding structure according to the present invention is incorporated. It is a plane perspective view of a head body. It is a longitudinal cross-sectional view which shows schematic structure of a pressure chamber unit. FIG. 4 is an enlarged cross-sectional view illustrating a first embodiment of a liquid flow path bonding structure in which an ink introduction port portion of FIG. 3 is enlarged. FIG. 6 is an enlarged cross-sectional view of an ink introduction port portion showing a second embodiment of the adhesion structure of the liquid channel. It is an expanded sectional view of the ink introduction port part for demonstrating 3rd Embodiment of the adhesion structure of a liquid flow path. FIG. 4 is an enlarged view of an ink introduction port portion for explaining a fourth embodiment of the adhesion structure of the liquid flow path, (a) is an enlarged cross-sectional view, and (b) shows only the inside of the ink introduction port. It is a perspective perspective view. FIG. 7 is an enlarged view of an ink introduction port portion for explaining a fifth embodiment of the adhesion structure of the liquid channel, (a) is an enlarged cross-sectional view, and (b) shows only the inside of the ink introduction port. It is a perspective perspective view. FIG. 9 is an enlarged view of an ink introduction port portion for explaining a sixth embodiment of the liquid channel bonding structure, (a) is an enlarged cross-sectional view, and (b) shows only the inside of the ink introduction port. It is a perspective perspective view. It is an expanded sectional view of the ink inlet part for demonstrating 7th Embodiment of the adhesion structure of a liquid flow path.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a liquid flow path bonding structure and bonding method, and an inkjet head according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a configuration diagram schematically showing an embodiment of an ink jet recording apparatus in which an ink jet head having a liquid flow path bonding structure according to the present invention is incorporated.

  As shown in FIG. 1, the inkjet recording apparatus 100 as an image forming apparatus mainly includes a sheet feeding unit 110 that feeds a recording medium 122 and a recording surface of the recording medium 122 fed from the sheet feeding unit 110. A processing liquid applying unit 112 for applying a predetermined processing liquid, a printing unit 114 for drawing an ink droplet on the recording surface of the recording medium 122 to which the processing liquid is applied, and a recording medium on which the image is drawn A drying unit 116 that dries the recording surface 122, a fixing unit 118 that fixes an image formed on the recording surface, and a paper discharge unit 120 that collects the recording medium 122 on which the image is recorded.

  The paper feeding unit 110 includes a magazine 140 that stores the recording medium 122, and the recording medium 122 is fed from the magazine 140 to the paper feeding tray 150 one by one. The recording medium 122 fed to the paper feed tray 150 is transferred to the processing liquid drum 154 of the processing liquid applying unit 112 via the transfer drum 152.

  The treatment liquid drum 154 receives the recording medium 122 transferred from the transfer drum 152, rotates and conveys it to the first intermediate conveyance drum 124. The treatment liquid application unit 112 applies a predetermined treatment liquid to the recording medium 122 rotated and conveyed by the treatment liquid drum 154 with a constant thickness. The treatment liquid application is performed by the treatment liquid application device 156. The treatment liquid application device 156, for example, brings the treatment liquid into contact with the recording surface of the recording medium 122 by applying a coating roller having the treatment liquid applied to the surface thereof. Give. The recording medium 122 to which the treatment liquid has been applied is further dried by a dryer 158 and a heater 160 and then transferred to the first intermediate conveyance drum 124.

  Note that the treatment liquid applied by the treatment liquid application unit 112 is a treatment liquid containing a component that aggregates or thickens the color material (pigment or dye) in the ink applied by the subsequent printing unit 114. By applying such a treatment liquid before ink ejection, bleeding or the like can be prevented, and a high-quality image can be printed.

  The first intermediate transport drum 124 receives the recording medium 122 transferred from the processing liquid drum 154, rotates and transports it to the printing drum 170 of the printing unit 114.

  The printing drum 170 receives the recording medium 122 transferred from the first intermediate conveyance drum 124, rotates and conveys it to the second intermediate conveyance drum 126. In the printing unit 114, ink droplets are ejected from the inkjet heads 172C, 172M, 172Y, and 172K of cyan, magenta, yellow, and black colors onto the recording medium 122 that is rotated and conveyed by the printing drum 170. Is printed.

  Each inkjet head 172C, 172M, 172Y, 172K is arranged to face the printing drum 170 with a predetermined gap, and arranged from the upstream side in the rotation direction of the printing drum 170 in the order of cyan, magenta, yellow, and black. Yes. In addition, each of the inkjet heads 172C, 172M, 172Y, and 172K includes a line head, and is formed corresponding to the recording width of the recording medium 122.

  The recording medium 122 on which ink has been ejected by each of the inkjet heads 172C, 172M, 172Y, 172K is transferred from the printing drum 170 to the second intermediate transport drum 126. The second intermediate transport drum 126 receives the recording medium 122 transferred from the printing drum 170, rotates and transports it to the drying drum 176 of the drying unit 116.

  The drying drum 176 receives the recording medium 122 transferred from the second intermediate conveyance drum 126, rotates and conveys it to the third intermediate conveyance drum 128. In the drying unit 116, the recording medium 122 rotated and conveyed by the drying drum 176 is dried by the first and second heaters 178 and 182 and the dryer 180.

  The dried recording medium 122 is transferred from the drying drum 176 to the third intermediate transport drum 128. The third intermediate conveyance drum 128 receives the recording medium 122 transferred from the drying drum 176, rotates and conveys it to the fixing drum 184 of the fixing unit 118.

  The fixing drum 184 receives the recording medium 122 transferred from the third intermediate transport drum 128, rotates and transports it to the conveyor 196 of the paper discharge unit 120. The fixing unit 118 heats and presses the recording medium 122 rotated and conveyed by the fixing drum 184 with the first and second fixing rollers 186 and 188 to fix the printed image.

  The recording medium 122 on which the image is fixed is transferred from the fixing drum 184 to the conveyor 196 of the paper discharge unit 120. The conveyor 196 receives the recording medium 122 from the fixing drum 184, conveys the recording medium 122 to the paper discharge tray 192 provided in the paper discharge unit 120, and collects it on the paper discharge tray 192.

  According to the ink jet recording apparatus 100 configured as described above, since the ink can be stably ejected from each ink jet head in the printing unit 114, a stable image can be formed.

  Next, the structure of the inkjet heads 172C, 172M, 172Y, and 172K disposed in the printing unit 114 will be described. Since the inkjet heads 172C, 172M, 172Y, and 172K have the same structure, an ink head (head main body) is represented by reference numeral 12 as a representative thereof.

  FIG. 2 is a perspective plan view of the head body 12. As shown in FIG. 2, a pressure chamber unit 20 that applies pressure to ink and discharges it as droplets from nozzles (not shown) is provided in the head body 12 in a predetermined arrangement pattern (in this embodiment, a staggered pattern). The ink flow paths for supplying ink to the pressure chamber units 20 are arranged with high density.

  The pressure chamber unit 20 includes a nozzle 22 that discharges ink as droplets, a pressure chamber 24 that stores ink, applies pressure to the stored ink, and discharges the ink from the nozzle 22 as droplets, and ink into the pressure chamber 24. An ink introduction (supply) port 26 (flow path) to be introduced (supplied) is provided. In this embodiment, as shown in FIG. 2, the planar shape of the pressure chamber 24 is formed in a square shape, and a nozzle 22 is formed at one end of the diagonal line, and an ink introduction port 26 is formed at the other end. . Ink is introduced into the pressure chamber 24 from a common flow path (not shown) through the ink introduction port 26, is pressurized in the pressure chamber 24, and is ejected as droplets from the nozzle 22.

  FIG. 3 is a longitudinal sectional view showing a schematic configuration of the pressure chamber unit 20. A pressure chamber 24 is formed in a silicon substrate (pressure chamber plate) 25, and the top surface (ceiling surface) of each pressure chamber 24 is configured by a common diaphragm 28. On the vibration plate 28, piezoelectric elements 30 are arranged corresponding to the pressure chambers 24. Each piezoelectric element 30 is deformed by applying a voltage between the individual electrode 32 formed on the upper surface thereof and the diaphragm 28 functioning as a common electrode. Then, when the piezoelectric element 30 is deformed, the top surface (the vibration plate 28) of the corresponding pressure chamber 24 is deformed, and an ink droplet is ejected from the nozzle 22. That is, when the top surface of the pressure chamber 24 is deformed to the pressure chamber 24 side, the volume of the pressure chamber 24 is reduced. As a result, pressure is applied to the ink in the pressure chamber 24 and ink droplets are ejected from the nozzle 22. The

  A common cover 34 is provided on the upper side of each piezoelectric element 30 to ensure and protect the free driving of each piezoelectric element 30. A common channel 36 for supplying ink to each pressure chamber 24 is formed on the upper side of the cover 34. Each pressure chamber 24 is in communication with a common flow path 36 via an ink inlet 26. When the pressure chamber 24 that has ejected ink from the nozzle 22 returns to its original state, new ink is supplied from the common flow path 36 via the ink inlet 26.

  In the present invention, when a flow path structure having a fine ink flow path or the like is formed by bonding, the bonding function and the sealing function are separated into different materials, so that the adhesive strength and the sealing performance can be reduced. The two performances are compatible.

  Therefore, here, as shown in FIG. 3, the present invention is applied to the case where the upper member composed of the cover 34 or the like is joined to the lower member composed of the pressure chamber 24 or the like in which the piezoelectric element 30 or the like is formed. The liquid channel bonding structure and bonding method will be described.

  In FIG. 3, the lower member composed of the pressure chamber 24 and the like and the upper member composed of the cover 34 and the like are joined on the surface indicated by the symbol P in the drawing.

  As described above, since the pressure chamber units 20 and the ink flow paths are arranged in the head main body 12 with high density, the bonding surface portion of the bonding surface P is relatively narrow.

  Adhesives need to guarantee a long service life with a narrow adhesive area, so adhesives that maintain bonding strength and penetration inhibitors (liquid-resistant film agents) to prevent ink components from touching the adhesive ) And the adhesive function and the sealing function, respectively. As the adhesive, an adhesive which generates an acid by ultraviolet rays or heat and is cured is used.

  In the example shown here, since silicon is used for the ink-jet head structural material, SU8, which has good adhesion to silicon, is used as the adhesive, but the present invention is not limited to this. For example, in addition to this, various things such as a thermosetting epoxy adhesive, a two-component mixed epoxy adhesive, a photocurable adhesive, or an acrylic adhesive can be applied.

  Each structural material is joined after processing a flow path required for each member. In this embodiment, since silicon is used, when there is no other member having a problem with heat resistance in joining silicon, heat diffusion joining is performed by heating and pressurizing to about 1000 ° C.

  However, after forming the piezoelectric element 30 and the electrical wiring which are the actuators of the inkjet head, if the thermal diffusion bonding is used, deterioration of the piezoelectric element 30 or diffusion of the electrical wiring material occurs, and the characteristics of the inkjet head deteriorate. In this case, bonding with an adhesive is performed. Similarly, an adhesive is used to join different materials such as silicon and resin.

  Below, it demonstrates focusing on the fine flow path part joined using these adhesive agents.

  FIG. 4 is an enlarged cross-sectional view showing the first embodiment of the bonding structure of the liquid flow path, in which the ink inlet 26 portion of FIG. 3 is enlarged.

  As shown in FIG. 4, the lower member formed of the pressure chamber plate 25 in which the pressure chamber 24 is formed and the upper member formed of the cover 34 and the like are joined together by an adhesive 40. Although each of the pressure chamber plate 25 and the cover 34 is expressed as one member, it is actually formed by laminating a plurality of plate-like members. In FIG. 4, the display of the diaphragm 28 of FIG. 3 is omitted.

  As can be seen from FIG. 3, the piezoelectric element 30 and the wiring not shown are present in the very vicinity of the adhesive 40 in FIG. 4 and cannot be bonded at that portion, so the bonding area is limited. ing.

  As shown in FIG. 4, the pressure chamber plate 25 as the lower member and the cover 34 as the upper member are joined together by the adhesive 40, and then penetrates into the portion of the adhesive 40 exposed to the ink inlet 26 side. An adhesive (liquid-resistant film agent) 42 is attached to cover the exposed adhesive 40 so that the ink does not touch the adhesive 40 even if the ink is introduced into the ink inlet 26.

  At this time, as shown in FIG. 4, the permeation preventive agent 42 is applied thickly so as to rise up to the portion of the adhesive 40 exposed in the ink inlet 26, and then cured by irradiating with UV light from above. The

  In addition, when the penetration preventing agent 42 is applied, the penetration preventing agent 42 can be thickly applied to a necessary portion, and the penetration preventing agent 42 is attached to a portion where the penetration preventing agent 42 in the ink introduction port 26 is not desired. Therefore, a liquid repellent part is formed so as to sandwich the penetration preventing agent application part (liquid-resistant film application part). In this way, the position where the penetration inhibitor 42 is applied can be limited, and since the penetration inhibitor 42 does not spread due to the liquid repellency, thick coating can be performed, the penetration prevention effect is increased, and the penetration inhibitor 42 is cured. When irradiating with UV light, the UV light can be efficiently applied to the penetration inhibitor 42.

  The permeation preventive agent used here needs to be sufficiently adhered to the flow path member and the adhesive, and as a result, becomes a material that easily spreads. However, with a material that spreads easily, it is difficult to ensure the thickness of the penetration inhibitor and, as described above, it is difficult to hit the UV light when cured by irradiating with UV light.

  Therefore, in this embodiment, as described above, the portion to which the penetration preventing agent 42 is applied is regulated by the upper and lower liquid repellent portions so that the penetration preventing agent 42 does not spread to the liquid repellent portion. . As a result, as shown in FIG. 4, the amount of protrusion in the flow path can be stably increased, and the liquid penetration distance (thickness of the penetration inhibitor 42) can be increased to improve the sealing performance. In addition, the area to which the UV light hits can be increased, and the penetration inhibitor 42 can be completely cured.

  Next, a method for adhering a liquid channel in the present embodiment will be described.

  First, the pressure chamber plate 25 which is a lower member to be joined and the cover 34 which is an upper member are cleaned by plasma cleaning, and a silane coupling agent is deposited on the surface. As described above, the portions where the pressure chamber plate 25 and the cover 34 are actually joined are plate-shaped members.

  Next, the adhesive 40 is applied to the lower member (pressure chamber plate 25). Then, the upper member is bonded to the lower member, fixed with a jig, and heated to be cured.

  Next, a liquid repellent agent is applied to the upper and lower portions of the ink inlet 26 where the penetration preventing agent 42 is applied. As described above, this is performed in order to regulate the application range of the penetration preventing agent 42 to be performed next. As the liquid repellent, it is preferable to select a liquid repellent that has a surface energy that prevents the penetration inhibitor 42 from spreading. Specifically, a fluororesin material such as Cytop can be suitably used.

  Various methods are conceivable as a method of applying the liquid repellent. For example, a flow path member (a joined upper member and a lower member) joined to a bat (flat plate) containing the liquid repellent with an adhesive 40. ), And the liquid repellent material is adjusted to reach the required height in the flow path, and the flow path member is submerged. At this time, the liquid surface height in the flow path changes depending on the surface tension of the liquid repellent material, and the depth of sinking is controlled in consideration of this. This is performed for the front and back surfaces of the flow path member.

  Further, instead of applying the liquid repellent, a fine concavo-convex structure may be formed on the surface of the flow path member in a range corresponding to the liquid repellent application portion, thereby imparting liquid repellency. In this uneven shape, for example, a cross section of about 2 μ in both vertical and horizontal directions is formed in a square shape. In this case, when the flow path member is silicon, streaky irregularities parallel to the flow path direction are formed by etching. Etching is performed to each member to a depth that requires a liquid-repellent surface, and the remaining flow path that does not require the liquid-repellent surface is etched from the opposite surface to be formed without an uneven shape.

  Next, a penetration preventing agent 42 having a sealing property is applied so as to cover the end face of the adhesive 40 exposed in the ink inlet 26. Application is performed by a dispenser.

  Next, UV light is irradiated from the upper part of the ink inlet 26 to cure the penetration inhibitor 42. Since the permeation preventive agent 42 applied by the dispenser protrudes on the inner surface of the flow path, it can be cured by irradiating with UV light from the upper part of the ink inlet 26.

  The liquid repellent may be removed after the penetration preventing agent 42 is cured. For example, when the ink used is difficult to spread on the liquid repellent, it is better to remove the liquid repellent.

  As described above, in the first embodiment, when the penetration inhibitor is applied to a small area, the liquid-repellent portion that limits the portion to be applied is provided, so that the penetration inhibitor is thickened only in a necessary portion. It can apply | coat and can improve the penetration preventing effect. Furthermore, since the penetration inhibitor can be applied thickly, the penetration inhibitor can be efficiently cured when irradiated with curing light such as UV light.

  Next, a second embodiment of the adhesion structure of the liquid channel will be described.

  FIG. 5 shows an enlarged cross-sectional view of the ink introduction port 26 for explaining the second embodiment of the liquid flow path bonding structure.

  In this second embodiment, the permeation preventive agent can be applied only to the adhesive part that needs to be protected, and the permeation preventive agent is surely prevented from flowing into the deeper part of the flow path. is there.

  In the deeper part of the flow path (ink introduction port 26), there are flow path structures such as the pressure chamber 24 and the nozzle 22, and if the permeation preventive agent 42 enters here, it will be clogged, resulting in non-ejection or bubble adhesion. It is important that the permeation preventive agent 42 can be applied only to a necessary portion because it causes defects such as abnormal ejection.

  That is, as shown in FIG. 5, in the second embodiment, a thin silicon layer 27 is provided in the flow path (ink introduction port 26) that forms the permeation preventive layer for protecting the adhesive. There are no other members before and after the flow path portion of the silicon layer 27, and the silicon layer 27 can be easily penetrated. The silicon layer 27 may be formed so as to exist in the entire head, and may be used also as, for example, a vibration plate 28 of an actuator that discharges ink.

  As shown in FIG. 5, the lower member (pressure chamber plate 25) and the upper member (cover 34) constituting the flow path are formed in a state where the contact layer (silicon layer 27) blocks the flow path. Then, the penetration preventing agent 42 is applied in the flow path using a method such as spray coating. Then, as shown by oblique hatching in the figure, the permeation preventive agent 42 is applied in the flow path (ink introduction port 26).

  Thereafter, the penetration inhibitor 42 is cured by irradiating UV light from above. In the example shown here, the penetration inhibitor 42 is cured by UV light, but in the case of a penetration inhibitor that cures by heating, it is cured by heat treatment.

  After the penetration preventing agent 42 is cured, the abutting layer (silicon layer 27) is removed. The method for removing the silicon layer 27 is not particularly limited. For example, the silicon may be removed from the lower surface by etching, or may be removed by sandblasting.

  According to the present embodiment, the penetration inhibitor can be applied and cured only in a portion where adhesive protection is necessary, without mixing the penetration inhibitor into the flow path behind the layer to be abutted.

  As described above, according to the second embodiment, the restriction member for limiting the portion to be applied is provided so as to block the flow path portion to which the penetration preventing agent is applied, and the restriction member is removed after application and curing. Therefore, when the penetration inhibitor is applied to the microstructure, the penetration inhibitor can be prevented from being attached to an unintended portion, and the reliability of the inkjet head can be improved and the characteristics can be stabilized.

  Next, a third embodiment of the adhesion structure of the liquid channel will be described.

  FIG. 6 shows an enlarged cross-sectional view of the ink introduction port 26 for explaining the third embodiment of the liquid channel bonding structure.

  In the third embodiment, as shown in FIG. 6, a quadrangular projection of a silicon quadrangular pyramid is formed at the center of the ink inlet 26 on the contact layer (silicon layer 27) of the second embodiment described above. 29 is formed.

  Then, using the side surface 29a of the pyramidal projection 29 as a mirror, the UV light irradiated from the upper part of the ink inlet 26 is reflected by the side surface 29a and irradiated to the adhesive 40 or the permeation preventive agent 42. These are cured.

  Such a quadrangular pyramidal shape of the pyramidal protrusions 29 can be easily formed by using anisotropic etching by a crystal plane when wet etching a silicon material. Specifically, it is anisotropic etching using (1,0,0) plane of silicon by KOH, and is a generally known etching method. In this case, a (1, 1, 1) plane having an angle of 54.74 ° appears due to extreme anisotropic etching.

  The side surface 29a of the pyramidal protrusion 29 is used as a mirror, and UV light for curing the adhesive is irradiated from above the ink inlet 26 and reflected by the side surface 29a to change the direction of the UV light toward the inner surface of the flow path. Then, the adhesive 40 is irradiated. Further, as shown in FIG. 6A, a penetration inhibitor 42 is applied so as to cover the adhesive 40 exposed at the ink inlet 26, and UV light for curing the penetration inhibitor is irradiated from above the ink inlet 26. Then, the light is reflected by the side surface 29 a and irradiated to the penetration preventing agent 42.

  Thereby, according to this embodiment, an adhesive agent and a penetration inhibitor can be hardened more certainly.

  Then, after the adhesive 40 and the penetration inhibitor 42 are cured by UV light, the abutting layer (silicon layer 27) is removed together with the pyramidal protrusions 29 by the same method as in the second embodiment.

  Although FIG. 6 shows a cylindrical flow path, the method of the present embodiment can also be applied to a case where the cross section of the flow path to which the permeation preventive agent is applied is square.

  As described above, the method of the third embodiment can more reliably cure the UV light curing adhesive near the liquid contact surface of the flow path. However, in the embodiment described below, the UV light can be obtained by other configurations and methods. The cured adhesive is cured more reliably.

  Each of the embodiments described below is described with respect to the point that the UV light curing adhesive is cured more reliably, but is also applicable to the curing of the penetration inhibitor applied by the same method as that of the first embodiment described above. Is possible.

  In addition, since the UV light-curing adhesive in the vicinity of the liquid contact surface of the flow path can be cured more reliably, the resistance of the adhesive to ink can be improved. It is also effective for improving the service life.

  First, a fourth embodiment will be described.

  FIG. 7 shows an enlarged view of the ink inlet 26 for explaining the fourth embodiment of the bonding structure of the liquid flow path. FIG. 7A is an enlarged sectional view, and FIG. 7B is a perspective perspective view showing only the inside of the ink inlet 26.

  In the fourth embodiment, when a UV-curing adhesive is used for a portion that is difficult to be irradiated with UV light after being bonded, in particular, in order to allow the curing polymerization to proceed more in the adhesive on the liquid contact side of the flow path. This is a method of irradiating UV light.

  As shown in FIGS. 7A and 7B, in this embodiment, UV light, which is parallel light, is obliquely incident on the ink introduction port 26 and is formed on the side wall 26a inside the ink introduction port 26. Reflected and irradiated to the adhesive end face in the flow path (ink inlet 26). The side wall 26a is formed by etching a silicon member, reflects UV light even with the etched surface, and allows the UV light to reach the adhesive 40 at a position deeper than the flow path inlet.

  In the configuration of FIG. 7, the side wall 26a is a cylindrical surface, so that it has a light condensing property in a plane (horizontal direction) perpendicular to the central axis of the cylinder, and the intensity of the irradiated UV light can be increased.

  Note that the channel side wall formed by etching the silicon member may remain the etched surface, but it is desirable to make it a mirror surface by plating with a highly reflective material such as aluminum or silver. Further, this plating is removed in a later step if it is a member eroded by the ink used.

  Although FIG. 7 is applied to a cylindrical flow path, this method can also be applied to a case where the cross section of the flow path to which the permeation inhibitor is applied is a square. In the case of a quadrangle, the light collecting property in the horizontal direction is lost as compared with the case of a cylindrical shape, and the light is irradiated over a wide range.

  Next, a fifth embodiment will be described.

  FIG. 8 is an enlarged view of the ink introduction port 26 for explaining the fifth embodiment of the adhesion structure of the liquid flow path. FIG. 8A is an enlarged cross-sectional view, and FIG. 8B is a perspective perspective view showing only the inside of the ink inlet 26.

  In the fifth embodiment, as shown in FIG. 8, UV light that is parallel light in the fourth embodiment described above is incident obliquely and reflected by the side wall 26a inside the ink inlet 26. As shown in FIG. The difference is that the incident light is condensed in the vertical direction and concentrated on the portion to be irradiated with UV light, and the intensity of the UV light is further increased than in the fourth embodiment.

  As shown in FIG. 8A and FIG. 8B, the light condensed vertically from the upper side of the ink introduction port 26 is incident and reflected by the side wall 26a inside the ink introduction port 26, and the opposite side. The adhesive 40 exposed on the side wall is irradiated.

  Thus, since light was condensed up and down, only the part which wants to irradiate light can be irradiated, and the adhesive agent 40 can be hardened efficiently.

  As in the fourth embodiment described above, this fifth embodiment can also be applied to the case where the channel cross section is a square, but the light collecting property in the horizontal direction is lost, and the wide range is irradiated. Become.

  In the fourth and fifth embodiments, in order to cure the entire circumference of the adhesive end face of the inner wall of the flow path, the head and the light source are rotated relative to each other around an axis parallel to the central axis of the flow path, The entire circumference along the road inner wall can be hardened.

  However, in the fifth embodiment, since the UV light is condensed, the degree of concentration of the UV light changes at each position, so the relative positions of the head and the UV light are averaged at each bonding portion. As described above, when the head and the light source are rotated relative to each other, the distance between the head and the light source is changed, or the optical system of the UV light source is adjusted to change the condensing position.

  Next, a sixth embodiment will be described.

  FIG. 9 shows an enlarged view of the ink inlet 26 portion for explaining the sixth embodiment of the liquid flow path bonding structure. FIG. 9A is an enlarged cross-sectional view, and FIG. 9B is a perspective perspective view showing only the inside of the ink inlet 26.

  In the sixth embodiment, the UV light irradiation portion is the same as that in the case where the UV light that is parallel light in the fourth embodiment described above is incident obliquely and reflected by the side wall 26a. , The side wall 26a of the ink inlet 26 is formed on a rotating paraboloid. Since the side wall 26a is formed on the rotating paraboloid, the UV light to be irradiated is parallel light, and the reflected light on the side wall 26a converges to one point.

  In FIG. 9, since the convergence position (focal point) is set slightly inside the adhesive from the adhesive surface, the reflected light is irradiated over the entire thickness of the adhesive 40 in a slightly expanded state before converging to one point. In addition, even if there is an angle error of incident light or a manufacturing error of a paraboloid of revolution, the adhesive 40 can be reliably irradiated with UV light.

  In addition, since the sixth embodiment emits parallel light in the same manner as the fourth embodiment described above, even when there are a plurality of head flow path portions to be bonded, the adhesive end face of the flow path inner wall In order to cure the entire circumference, the entire circumference of each flow path can be cured with a single UV light by rotating the head and the light source relatively around an axis parallel to the central axis of the flow path. it can.

  In addition, when there are a plurality of head flow path portions to be bonded, the condensed UV light is simultaneously irradiated as parallel light, and the head and the light source are relative to each other around an axis parallel to the central axis of the flow path. May be rotated to cure the entire circumference.

  Similar to the fourth embodiment described above, the sixth embodiment can be applied even when the flow path cross section is a quadrangle. However, the light collecting property in the horizontal direction is lost, and a wide range is irradiated.

  Next, a seventh embodiment will be described.

  FIG. 10 is an enlarged view of the ink inlet 26 for explaining the seventh embodiment of the liquid flow path bonding structure.

  In the seventh embodiment, as shown in FIG. 10, immediately after the UV light that cures the adhesive 40 is irradiated, the liquid fine particles 31 are sprayed into the flow path (ink inlet 26), and then the UV light. Irradiate. Then, the UV light is diffused by the liquid fine particles 31 and the adhesive 40 is cured.

  In addition, it is more effective if the liquid for making fine particles is a liquid that accelerates the curing of the adhesive. For example, since the curing reaction of SU8 proceeds with an acid, an acid solution meets this purpose. A part of the atomized fine particles 31 adheres to the surface of the adhesive and penetrates to promote the curing of the adhesive 40.

  As described above, in the third to seventh embodiments, the reflective member for irradiating the UV light to the minute part that is difficult to irradiate the UV light is provided. The penetration inhibitor can be reliably cured.

  The liquid channel bonding structure and bonding method and the ink jet head of the present invention have been described in detail above. However, the present invention is not limited to the above examples, and various improvements can be made without departing from the gist of the present invention. It goes without saying that or may be modified.

  DESCRIPTION OF SYMBOLS 12 ... Ink head, 20 ... Pressure chamber unit, 22 ... Nozzle, 24 ... Pressure chamber, 25 ... Pressure chamber plate, 26 ... Ink inlet (flow path), 27 ... Silicon layer (butting layer), 28 ... Vibration plate , 29 ... Pyramid projections, 30 ... Piezoelectric element, 34 ... Cover, 40 ... Adhesive, 42 ... Penetration inhibitor, 100 ... Inkjet recording device, 110 ... Paper feed unit, 112 ... Treatment liquid application unit, 114 ... Printing 116, drying unit, 118, fixing unit, 120, paper discharge unit

Claims (21)

A liquid flow path bonding structure in which a fine flow path structure is formed by bonding a plurality of substrates,
When the plurality of substrates are bonded with an adhesive, a liquid-resistant film agent having liquid resistance to a liquid flowing in a flow path formed by bonding the substrates at a bonding portion between the substrates, A liquid-resistant film coating portion formed by coating so as to cover the adhesive exposed inside the flow path;
A liquid-repellent portion having liquid repellency with respect to the liquid-resistant film agent, provided at a boundary portion between the liquid-resistant film-coated portion and the non-coated portion where the liquid-resistant film agent is not applied, inside the flow path,
A liquid channel bonding structure characterized by comprising:   2. The liquid channel adhesive structure according to claim 1, wherein the liquid repellent portion is formed by sinking the liquid channel adhesive structure member in a liquid repellent. 3.   The liquid channel according to claim 1, wherein the liquid repellent portion has a number of fine irregularities formed at a boundary portion between the application portion and the non-application portion on the inner surface of the flow channel. Adhesive structure.   The said liquid-resistant film agent is photocurable resin, and is hardened | cured by the light irradiated in the said flow path, The adhesion structure of the liquid flow path in any one of Claims 1-3 characterized by the above-mentioned.   The liquid channel adhesive structure according to claim 1, wherein the liquid-resistant film agent is a thermosetting resin and is cured by heating.   An ink jet head comprising the liquid channel adhesive structure according to claim 1.   An ink jet recording apparatus comprising the ink jet head according to claim 6. A liquid channel bonding method for bonding a plurality of substrates to form a fine channel structure,
Bonding the plurality of substrates with an adhesive to cure the adhesive;
On the inner surface of the flow path formed by bonding the substrates at the joint portion between the substrates, a liquid-resistant film agent having liquid resistance to the liquid flowing in the flow path is exposed to the inner side of the flow path. A liquid-repellent part having liquid repellency with respect to the liquid-resistant film agent is formed at a boundary portion between the liquid-resistant film-coated part applied so as to cover the adhesive and the non-coated part where the liquid-resistant film agent is not applied. And
Applying the liquid-resistant film agent to the liquid-resistant film application part,
A method for adhering a liquid flow path, wherein the liquid-resistant film agent is cured.   The method for adhering a liquid channel according to claim 8, wherein the liquid repellent part is formed by submerging an adhesive structure member of the liquid channel in a liquid repellent.   The liquid flow according to claim 8, wherein the liquid repellent portion is formed by providing a large number of fine irregularities at a boundary portion between the application portion and the non-application portion on the inner surface of the flow path. Road bonding method.   The method for adhering a liquid channel according to claim 8, wherein the liquid-resistant film agent is a photocurable resin and is cured by light irradiated in the channel.   11. The liquid channel bonding method according to claim 8, wherein the liquid-resistant film agent is a thermosetting resin and is cured by heating. A liquid channel bonding method for bonding a plurality of substrates to form a fine channel structure,
Providing a member that closes the flow path formed by bonding the substrate in the vicinity of the bonding portion of the substrate,
Bonding the plurality of substrates with an adhesive to cure the adhesive;
Covering the adhesive exposed on the inside of the flow path, and applying a liquid-resistant film agent having liquid resistance to the liquid flowing in the flow path so as to adhere to the member closing the flow path,
A method for adhering a liquid flow path, comprising: removing a member blocking the flow path after curing the liquid-resistant film agent.   14. The method for adhering a liquid flow path according to claim 13, wherein the flow path structure is used for an ink flow path of an inkjet head, and a member that closes the flow path also serves as a structural material of the inkjet head.   Further, a quadrangular pyramidal protrusion is formed on the member that closes the flow path, and at least light for curing the photocurable adhesive or the photocurable liquid-resistant film agent of the flow path structure is emitted from the quadrangular pyramidal protrusion. The method for adhering a liquid flow path according to claim 13 or 14, wherein the photo-curing adhesive or the photo-curing liquid-resistant film agent is cured by irradiating and reflecting the inclined surface. A liquid channel bonding method for bonding a plurality of substrates to form a fine channel structure,
A photocurable liquid-resistant film having liquid resistance against a liquid flowing in a flow path formed by bonding the plurality of substrates with a photocurable adhesive, curing the adhesive, and joining the substrates. When applying and curing the agent so as to cover the adhesive exposed in the flow path at the joint of the substrate,
By irradiating and reflecting the light for curing the photocurable adhesive or the photocurable liquid-resistant film agent on the inner wall surface of the flow path, the photocurable adhesive or the photocurable liquid-resistant liquid A method for adhering a liquid channel, wherein the film agent is cured.   The method for adhering a liquid channel according to claim 16, wherein a wall surface inside the channel for reflecting the light for curing is plated with a highly reflective material.   The method for adhering a liquid flow path according to claim 16 or 17, wherein the light for curing irradiated to the inner wall surface of the flow path is substantially parallel light.   The method for adhering a liquid flow path according to claim 16 or 17, wherein the light for curing applied to the inner wall surface of the flow path is substantially convergent light.   18. The liquid flow according to claim 16, wherein a wall surface inside the flow path that irradiates and reflects the light for curing is a paraboloid of revolution having a central axis of the flow path as a rotation axis. Road bonding method.   21. A method of manufacturing an ink jet head, wherein an ink flow path is manufactured using the liquid flow path bonding method according to claim 8.

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