JP6896526B2 - Manufacturing method of liquid flow path member - Google Patents

Description

The present invention relates to a method for manufacturing a liquid flow path member used for a liquid discharge head or the like that discharges a liquid.

Inkjet printers are output devices that eject minute ink from a liquid ejection head to form characters and images, and have become widespread not only for home and office equipment but also for industrial use in recent years. is there.

Inkjet printers require a liquid flow path member that supplies liquid to a recording element that discharges liquid. In the manufacture of liquid flow path members, it is required to join the members in which liquid leakage is suppressed. In addition, when joining members, it is necessary to suppress the generation of dust at the joint. On the other hand, as a method for forming a liquid flow path member, Patent Document 1 proposes a method using laser welding, which produces less dust than vibration welding or ultrasonic welding. Specifically, as a joining technique by laser welding, a method of irradiating a laser beam from an oblique angle on an uneven shape for fitting has been proposed.

Japanese Unexamined Patent Publication No. 2002-292741

When laser welding is performed, if an uneven portion serving as a flow path is formed on the laser transmitting member side to form a liquid flow path member, depending on the welding site, laser light is applied to the absorbent material via the uneven transmitting member. Irradiation may occur. In that case, due to the surface waveguide of the laser light generated on the uneven corners and the surface of the laser receiving surface and the refraction of the laser light due to the shape, sufficient laser light is not irradiated to be welded to the absorbing material that absorbs the laser. Part occurs. As a result, there is a concern that a portion where welding is insufficient may occur and a liquid may leak from the portion.

Further, as in Patent Document 1, if the laser irradiation angle is appropriately changed to the optimum state, the cost of the laser irradiation device and the manufacturing tact increase.

The present invention has been made in view of the above problems, and a method for manufacturing a liquid flow path member having high welding reliability by suppressing the influence of unevenness of a laser transmitting member while suppressing an increase in cost of a laser welding device. The purpose is to provide.

In order to achieve the above object, the method for manufacturing a liquid flow path member of the present invention includes a first member that is transparent to laser light and has a recess that constitutes a liquid flow path on one surface. A second member that absorbs laser light and is provided on the back surface of the one surface of the first member and is provided on the one surface of the first member to cover the recess. In the method for manufacturing a liquid flow path member including the third member, the first member has a contact portion with which the back surface of the first member and the second member are in contact with each other. A step of irradiating a laser beam from one surface side via the first member to weld the first member and the second member is included, and in the welding step, the bottom surface of the recess is formed. The valley line provided has a curved surface, and is characterized in that the abutting portion is irradiated with a laser beam through the curved surface.

As described above, according to the present invention, it is possible to provide a method for manufacturing a liquid flow path member having high welding reliability by suppressing the influence of unevenness of the laser transmitting member while suppressing an increase in the cost of the laser welding apparatus. ..

It is an exploded perspective view of the liquid flow path member to which this invention is applied. (A) is a schematic view showing a laser welding process of a flow path plate and a valve according to the first embodiment of the present invention, and (b) is a cross-sectional view taken along the line AA'of (a) showing the flow path plate and the valve. It is a schematic diagram which shows the state of the laser welding of. As a comparative example, it is a figure which shows the enlarged view of the laser welding part. It is a figure which shows the enlarged view of the laser welding part in 1st Embodiment of this invention. It is a schematic diagram which shows the state of laser welding of a flow path plate and a valve in the 2nd Embodiment of this invention. It is a schematic diagram which shows the laser welding process of a flow path plate and a valve in 3rd Embodiment of this invention. It is a perspective view which shows the structure of the liquid discharge head which applied the liquid flow path member in 4th Embodiment of this invention.

An outline of a liquid flow path member for flowing a liquid and a method for manufacturing the same according to the embodiment of the present invention will be described. FIG. 1 is an exploded perspective view of a liquid flow path member to which the present invention can be applied. As shown in FIG. 1, the liquid flow path member is mainly composed of a flow path plate 10, a valve member 20 including a flow path opening / closing valve, and a flow path forming material 40. The valve member 20, which is a flow rate (pressure) control member provided in the middle of the liquid flow path composed of the flow path plate and the flow path forming material, controls the flow of ink and supplies the liquid to the liquid discharge head.

The flow path plate has a recess formed as a liquid flow path in a resin plate having a thickness of about 3 to 10 mm. This flow path plate is manufactured by means such as molding or machining the plate material. Further, as will be described later, in order to join the valve member 20 to the flow path plate 10 by laser welding, a resin material having a property of transmitting laser light is used for the flow path plate. Although the valve member 20 is used as the flow rate (pressure) control member in each embodiment, the present invention is not limited to this, and various flow rate (pressure) control members for adjusting the flow rate and pressure of the liquid are used. Is applicable. Further, the present invention is applicable not only to the flow rate (pressure) control member but also to any member provided on the flow path plate 10 having a characteristic of absorbing laser light.

The valve member 20 as a flow rate (pressure) control member includes, for example, a valve that opens and closes a flow path, a pump that applies a driving force in the flow path, and the like. The flow path plate 10 and the valve member 20 in the present embodiment are brought into contact with each other and then joined by so-called laser welding. Therefore, for the valve member 20, a resin material having a property of absorbing laser light, generating heat, and being compatible with and joining the flow path plate 10 is used. The manufacturing conditions such as the laser output are appropriately changed according to the laser transmittance of the flow path plate 10, the calorific value at the time of welding the valve member 20, and the desired welding strength.

The flow path forming material 40 is a member for forming a liquid flow path by being attached to the flow path plate 10. That is, the flow path forming material 40 functions as a lid member of the recess by providing the flow path forming material 40 with respect to the recessed portion provided in the flow path plate 10, and the flow path forming material 40 is one of the walls of the flow path. Form a part. A resin plate, a film, or the like can be applied to the flow path forming material 40. The attachment of the flow path forming material 40 to the flow path plate 10 is appropriately selected to be performed before laser welding or after laser welding, depending on the degree of influence of the flow path plate 10 and the valve member 20 on laser welding. ..

(First Embodiment)
The first embodiment of the present invention will be described with reference to FIGS. 2 (a) and 2 (b). FIG. 2 is a diagram showing a manufacturing process of the liquid flow path member 1 shown in FIG. 1, and FIG. 2 (a) is a laser welding step of welding the flow path plate 10 and the valve member 20 in the first embodiment. It is a schematic diagram which shows. FIG. 2B is a cross-sectional view taken along the line AA'of FIG. 2A, and is a schematic view showing a state of laser welding between the flow path plate 10 and the valve member 20. A recess serving as a liquid flow path is formed on the laser light receiving surface 18 which is one surface of the flow path plate 10, and the valve member 20 is brought into contact with the back surface 19 of the laser light receiving surface 18 of the flow path plate 10. ing. The laser light 30 is irradiated to the laser receiving surface 18 of the flow path plate, and the laser light is irradiated to the contact portion between the flow path plate 10 and the valve member 20 via the flow path plate 10. That is, the abutting portion is irradiated with laser light from one surface side (surface 18) of the flow path plate 10 via the flow path plate 10. By relatively moving the laser beam 30 and the liquid flow path member 1 which is the irradiated portion, a welded portion 12 is formed and both are joined (welded). Here, the flow path plate 10 is formed of a member having transparency to laser light, and the valve member 20 is formed of a member having absorption to laser light. The laser irradiation method is not limited to the scanning type irradiation as in the present embodiment. For example, a laser light source capable of irradiating a wide area at once is used to laser the welding region. Light may be irradiated all at once.

FIG. 3 is an enlarged view of a laser welded portion shown as a comparative example of the present invention. A recess 11 serving as a liquid flow path is formed on the laser light receiving surface 18, and when the valley line portion 14 of this recess has a square shape as shown in FIG. 3, the flow path is affected by the surface waveguide of the laser beam 30. An unirradiated portion of the laser beam is generated on a part of the contact surface between the plate 10 and the bulb member 20. Specifically, as shown in FIG. 3, such an unirradiated portion is generated at a position directly below the valley line portion 14 of the recess 11. As a result, there is a concern that liquid leakage may occur from the flow path due to a break in welding or a weak welding at the contact point between the flow path plate 10 and the valve member 20.

FIG. 4 is a diagram showing a welding process in the present embodiment, and shows an enlarged view of the laser welding portion 26 of FIG. 2 (b). In the present embodiment, a curved surface 15 is formed at the bottom of the recess 11 formed on the laser receiving surface 18 of the flow path plate 10. Specifically, a curved surface 15 is formed in which the corners of the valley line portion of the recess 11 are rounded. Due to the action of the curved surface 15, the laser beam 30 is refracted, and the portion of the bulb member 20 that has not been irradiated with the laser beam as shown in FIG. 3 disappears. As a result, the occurrence of welding breaks as shown in FIG. 3 is suppressed, and the welding reliability between the flow path plate 10 and the valve member 20 can be improved as compared with the case where the valley line portion 14 in FIG. 3 has a square shape. it can. In the present embodiment, the radius of the R shape on the curved surface 15 of the concave valley line portion is set to about 1 mm. Note that this value is not limited to this embodiment, and can be appropriately changed according to the thickness of the flow path plate 10, the size of the recess serving as the flow path, the laser transmittance of the flow path plate 10, and the like. ..

After joining the flow path plate 10 and the valve member 20 by laser welding, the flow path forming material 40 is joined to the surface 18 of the flow path plate 10. In the present embodiment, an aluminum film obtained by laminating polypropylene (PP) on the flow path forming material 40 is used and bonded to the flow path plate 10 by heat welding. The method of joining the flow path forming material 40 and the flow path plate 10 is not limited to this embodiment. For example, the flow path forming material 40 preferably has gas barrier properties and ink resistance, and various members other than the above-mentioned materials can be applied, and resin films, resin plates, surface-treated metal plates, and the like can also be applied. It is possible to use it. Further, as for the joining method, a method that generates less dust at the time of joining is preferable, and bonding or screwing using a sealing member can also be used.

Vibration welding and ultrasonic welding are not suitable for joining the flow path forming material 40 and the flow path plate 10 because a relatively large amount of dust is generated during welding. Further, although laser welding is technically possible, laser welding requires laser irradiation directions from two directions, which increases the cost of the device. This is because the valve member 20 and the flow path forming material 40, which are assembled from different directions on the flow path plate 10 which is a laser transmitting material, are irradiated with laser light. Therefore, it is preferable that the flow path plate 10 and the valve member 20 are joined by laser welding, and the flow path plate 10 and the flow path forming material 40 are joined by a joining method such as heat welding or adhesion.

As described above, according to the embodiment of the present invention, a liquid flow path member having high welding reliability can be manufactured without suppressing the influence of the recess 11 formed on the laser receiving surface 18 and significantly increasing the equipment cost. It becomes possible to provide a method.

(Second embodiment)
A second embodiment of the present invention will be described with reference to FIG. In FIG. 5, in addition to the valley line curved surface 15 of the concave portion 11 described in FIG. 4 which is the first embodiment, the ridge line of the concave portion 11 has a shape including a curved surface 16 having an R shape. At this time, the radius of the R shape (radius of curvature) on the curved surface 16 of the concave ridge line is smaller than the radius of the R shape (radius of curvature) on the curved surface 15 at the corner of the concave valley line. In the present embodiment, the radius of curvature of the curved surface 16 provided at the opening of the recess 11 is 0.5 mm, and the radius of curvature of the curved surface 15 provided at the bottom surface of the recess 11 is 1 mm. This value is not limited to this embodiment, and can be appropriately changed according to the thickness of the flow path plate 10, the size of the recess 11, the laser transmittance of the flow path plate 10, and the like. As described above, according to the present embodiment, in addition to obtaining the same effect as that of the first embodiment, it is possible to partially improve the welding strength with respect to a desired position by utilizing the refraction of the laser beam 30. become.

(Third Embodiment)
A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, a resin material having a property of transmitting laser light is used for both the flow path plate 10 and the flow path forming material 40. Further, the flow path plate 10 and the flow path forming material 40 were integrally molded by using a so-called DSI molding (die slide injection molding) technique. Then, after joining the flow path plate 10 and the flow path forming material 40 by DSI molding, the valve member 20 and the flow path plate 10 are joined by laser welding. The method of joining the flow path plate 10 and the flow path forming material 40 is not limited to this embodiment, and methods such as heat welding and adhesion may be used as long as both have the property of transmitting laser light. It is possible.

According to this embodiment, the same effects as those of the first embodiment and the second embodiment can be obtained, and even after the flow path forming material 40 and the flow path plate 10 are joined, the flow path plate It is possible to laser weld 10 and the valve member 20. That is, the process order can be flexibly set. Further, by integrating the flow path plate 10 and the flow path forming material 40 in advance, the exposed area and the exposure time of the liquid flow path can be reduced, so that dust in the liquid flow path in the manufacturing process can be reduced. It becomes possible to reduce contamination. From the above, it becomes possible to further improve the productivity of the liquid flow path member.

(Fourth Embodiment)
A fourth embodiment of the present invention will be described with reference to FIG. FIG. 7 shows an example in which the liquid flow path member 1 is applied to a liquid discharge head 25 typified by an inkjet head. The liquid flow path member 1 according to each of the above-described embodiments can be applied to the liquid discharge head 25.
As shown in FIG. 7A, the liquid discharge head 25 includes a recording element substrate 21 including an energy generating element for discharging liquid, and a control circuit and an electrically mounted component for driving the energy generating element of the recording element substrate 21. The wiring board 22 is provided. Further, a flexible wiring 23 and a frame body 24 for electrically connecting the wiring board and the recording element board 21 are provided. The liquid discharge head 25 in the present embodiment is a so-called full-line type (page-wide type) liquid discharge head in which the recording element substrates 21 are linearly arranged and has a length corresponding to the width of the recording medium for recording. 25.

As shown in FIG. 7B, a flow path plate 10 extending in the longitudinal direction of the liquid discharge head and a valve member 20 for controlling the pressure of the liquid flowing inside the flow path plate 10 are provided. In the present embodiment, a plurality of valve members 20 are provided for one flow path plate 10, and the pressure of the liquid supplied from the recording device main body to the recording element substrate 21 is adjusted (controlled) by each valve member 20. There is.

1 Liquid flow path member 10 Flow path plate 11 Liquid flow path 12 Welded part 13 Unwelded part 14 Recessed valley line corner 15 Recessed valley line curved surface 16 Recessed ridgeline curved surface 17 Welding strength improving part 20 Valve member 30 Laser light 40 Channel forming material

Claims (9)

A first member having transparency to laser light and having a recess forming a liquid flow path on one surface, and the one of the first member having absorption to laser light. In a method for manufacturing a liquid flow path member, which comprises a second member provided on the back surface of the surface and a third member provided on the one surface of the first member and covering the recess.
A laser beam is emitted from the one surface side of the first member to the abutting portion where the back surface of the first member and the second member are in contact with each other via the first member. The step of irradiating and welding the first member and the second member is included.
A method for manufacturing a liquid flow path member, characterized in that, in the welding step, the valley line provided on the bottom surface of the recess has a curved surface, and the abutting portion is irradiated with a laser beam through the curved surface. The liquid flow according to claim 1, wherein in the welding step, the ridge line provided in the opening of the recess has a curved surface, and the abutting portion is irradiated with a laser beam through the curved surface provided in the opening. Method of manufacturing road members. The method for manufacturing a liquid flow path member according to claim 2, wherein the radius of curvature of the curved surface provided in the opening is smaller than the radius of curvature of the curved surface provided in the bottom surface. The method for manufacturing a liquid flow path member according to any one of claims 1 to 3, wherein after the welding step, the first member and the third member are joined by heat welding. The liquid flow path member according to claim 1, wherein the third member has transparency to laser light, and the first member and the third member are integrally molded by die slide injection molding. Production method. The method for manufacturing a liquid flow path member according to claim 5, wherein the first member and the third member are integrally molded by the die slide injection molding before the welding step. The method for manufacturing a liquid flow path member according to claim 5 or 6, wherein in the welding step, the contact portion is irradiated with laser light via the third member and the first member. The method for manufacturing a liquid flow path member according to any one of claims 1 to 7, wherein the second member includes a valve member that controls the flow of liquid in the flow path. The method for manufacturing a liquid flow path member according to any one of claims 1 to 8, wherein a recording element substrate for discharging a liquid is provided on the third member.

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