JP5098222B2 - Ink jet head and method of manufacturing ink jet head - Google Patents

Description

  The present invention relates to an ink jet head constituting an ink jet recording apparatus and a method for manufacturing the same, and more specifically, a head plate having a nozzle plate provided with a plurality of nozzles for ejecting ink and ink channels corresponding to each of the nozzles. The present invention relates to an inkjet head having the above and a manufacturing method thereof.

  An ink jet head used in an ink jet recording apparatus that discharges ink in a plurality of ink channels divided from a plurality of nozzles formed on a nozzle plate, on a front surface of a head member in which a plurality of ink channels are formed, It is formed by joining a nozzle plate having a plurality of nozzles corresponding to each ink channel with an adhesive. The nozzles and ink channels of the nozzle plate need to be aligned at predetermined positions.

  In addition, when the head member and the nozzle plate are bonded together, if the adhesive flows into the nozzle discharge port, the clogging of the adhesive causes injection defects and injection bending, resulting in a decrease in the yield of the inkjet head manufacturing or the bonding process. Problems such as an increase in man-hours for repairs occur.

  As a method of aligning the head member and the nozzle plate, the nozzle plate is provided with an alignment through-hole for performing the alignment operation of the nozzle plate with respect to the electrostatic actuator (head member), and the alignment operation is performed on the electrostatic actuator. It is disclosed that alignment is performed by providing an alignment pattern to be performed and confirming the alignment pattern through an alignment through-hole by a CCD camera device (see, for example, Patent Document 1).

Further, a recording element substrate having a taper shape is provided between the ejection port plate and the ink supply flow path so that the supply port has an opening width larger than the ink flow path and becomes narrower toward the outlet portion, It is disclosed that ejection characteristics and supply characteristics are improved and positioning accuracy is improved by removing the protruding adhesive by curing by ultraviolet irradiation (see, for example, Patent Document 2).
JP 2002-210987 A JP 2002-254209 A

  In Cited Document 1, as described above, the nozzle plate and the head member need to be processed for alignment, such as providing an alignment pattern in the alignment hole in the nozzle plate and the electrostatic actuator. It becomes a factor of.

  Further, in Patent Document 2, one component other than the discharge port plate (nozzle plate) is required, which increases the number of bonding steps and increases man-hours, thereby increasing costs.

  The present invention has been made in view of the above situation, and in joining by bonding the head member and the nozzle plate, the head member and the nozzle plate can be easily aligned, and the nozzle is aligned with a predetermined position with respect to the head member. It is another object of the present invention to provide a high-quality and highly productive inkjet head that can easily detect the flow of adhesive into the nozzle outlet and can easily eliminate defective products.

The above object is achieved by the following configuration.
1. In an inkjet head that is formed by joining a nozzle plate having a plurality of nozzles formed by etching on a silicon substrate and a head member that forms an ink channel, and ejecting ink from the nozzle, the head member is arranged in a row of the ink channels. The nozzle plate has dummy channels having the same shape as the ink channels at both ends, and the nozzle plate has at least one dummy nozzle at a position corresponding to the dummy channels at both ends of the plurality of nozzle rows. The dummy nozzle is a circular non- penetrating hole when viewed from the ink discharge direction, and the dummy nozzle portion of the nozzle plate is smaller in thickness than the unprocessed portion, and the dummy nozzle diameter R, the width of the ink channel in the arrangement direction of the nozzles a, the ink channel When the width and is b, the ink jet head, which is a relationship a <r <(a + b).
2. 2. The inkjet head according to 1, wherein the nozzle plate has the dummy nozzle on a joint surface side with a head member.
3. The nozzle for ejecting ink of the nozzle plate has at least two nozzle diameters, ejects ink, has the smallest diameter of the penetrating ink ejection side nozzle, and is connected to the head member side The diameter of the nozzle on the joint surface side that does not pass through is defined as a <r <(a + b) where r is the nozzle diameter of the joint surface, a is the width of the ink channel in the arrangement direction of the nozzles, and b is the width of the ink channel wall. The inkjet head according to 1 or 2, wherein:
4.1. The method of manufacturing an ink jet head according to any one of claims 1 to 3, wherein when the nozzle plate and the head member are joined, the nozzle plate is irradiated with infrared rays and transmitted through the nozzle plate. A method for manufacturing an ink jet head, comprising: detecting a dummy nozzle; and performing alignment between the nozzle plate and the head member using the detected dummy nozzle for alignment.
5. 5. The method of manufacturing an ink jet head according to 4, wherein the infrared irradiation is performed from a surface opposite to a surface of the head member on which the nozzle plate is joined.

  With the above configuration, when the nozzle plate and the head member are joined, the thickness of the dummy nozzle portion of the nozzle plate is smaller than that of the other portions, so that the infrared transmittance increases, and the dummy nozzle is detected by the infrared CCD camera. This can be easily performed, and the nozzle plate and the head member can be accurately aligned using the detected dummy nozzle. Further, since the dummy nozzle has no penetrating portion and uniform transmitted light with a uniform thickness, it becomes easy to confirm the position of the dummy nozzle and to easily distinguish the nozzle from which ink is ejected.

  According to the above configuration, since the thickness of the joining surface side nozzle portion is smaller than that of the other portions, the infrared transmittance is increased, and detection by the infrared CCD camera can be easily performed. Can be easily performed. In addition, it is possible to easily confirm the presence or absence of the adhesive flowing into the discharge side nozzle.

  Furthermore, since the diameter of the joining surface side nozzle is larger than the ink channel width, it is possible to suppress the adhesive from flowing into the discharge port portion of the nozzle.

  Further, by making the diameter and thickness of the dummy nozzle and the joint surface side nozzle the same, the same processing can be performed, and the processing dedicated for alignment can be made unnecessary.

  Embodiments of a nozzle plate and an inkjet head according to the present invention will be described below with reference to the drawings. The present invention is not limited to the following.

  The ink jet head according to the present invention generates energy for ejecting ink as long as the ink in the ink channel is configured to be ejected as ink droplets from an ejection port of a nozzle formed at one end of the ink channel. Any type of structure may be used, but here, the side wall (ink channel wall) constituting the ink channel is formed of a polarized piezoelectric material, and the side wall is subjected to shear deformation by applying an electric field to this side wall. An example of a so-called shear mode type recording head that discharges ink in an ink channel will be described.

  FIG. 1 is a partially cutaway perspective view showing the structure of a multichannel inkjet head.

  In FIG. 1, 1 is a head member, 2 is a nozzle plate, 3 is a back plate, and 4 is an ink manifold. The nozzle plate 2 has a configuration in which a plurality of nozzles are provided on a silicon substrate by etching.

  The head member 1 includes an actuator substrate 11 and a cover substrate 12 bonded to the upper surface of the actuator substrate 11.

  The actuator substrate 11 is formed by joining two piezoelectric material substrates 11a and 11b, which are deformed by applying an electric field, up and down using an epoxy adhesive or the like with their polarization directions opposite to each other. A plurality of rows of grooves parallel to each other at a predetermined pitch are processed over the piezoelectric material substrates 11a and 11b by using a known grinding machine such as a disc-shaped grindstone (dicing blade). Channel walls 14 are alternately formed.

  The ink channel 13 includes a channel 13a that is actually used as an ink flow path, and a dummy channel 13b that is provided at both ends of the ink channel row and is not actually used as an ink flow path. The channels 13a and 13b have the same shape.

  A metal electrode (not shown) for applying an electric field to the ink channel wall 14 is formed on the wall surface of each ink channel wall 14. As a method for forming the metal electrode, known means such as a vapor deposition method, a sputtering method, or a plating method can be used. In the illustrated embodiment, the ink channel wall 14 is composed of two piezoelectric material substrates 11a and 11b having different polarization directions, so that each metal electrode is at least each ink channel wall in order to drive the two piezoelectric material substrates 11a and 11b. 14 is formed on the entire side surface over the piezoelectric material substrates 11a and 11b constituting the substrate 14.

  The cover substrate 12 is bonded to the upper surface of the actuator substrate 11 where the ink channel 13 is formed using an epoxy adhesive or the like. When the same piezoelectric material substrate as that used for the actuator substrate 11 is depolarized and used for the cover substrate 12, there is no warping, deformation, peeling due to a difference in thermal expansion coefficient, etc. when the substrates are bonded together. preferable.

  An ink manifold 4 that supplies ink into the channel 13a is bonded to the rear end surface of the head member 1 through the back plate 3 having the ink introduction holes 31 using an adhesive.

  Further, as shown in FIG. 2, the front end surface of the head member 1 has a hole that does not penetrate through the ink discharge side nozzle 21 a having discharge ports for discharging ink formed so as to correspond to the plurality of channels 13 a of the head member 1. The nozzle plate 2 having the nozzle 21 composed of the bonding surface side nozzle 21b and the dummy nozzles 22 provided at both ends of the row of the nozzles 21 so as to correspond to the dummy channel 13b is bonded using an adhesive. Ink is not supplied to the dummy channel 13b.

  The dummy nozzles 22 provided in the nozzle plate 2 have a <r <(a + b) where r is the dummy nozzle diameter, a is the width of the ink channel 13b in the nozzle arrangement direction, and b is the width of the ink channel wall 14. It is a non-penetrating hole having a relationship of

  Thus, the thickness of the dummy nozzle 22 is smaller than that of the non-processed portion. Further, when the nozzle plate 2 is overlapped at a predetermined position of the head member 1, a part of the dummy nozzle 22 becomes larger than the width a of the ink channel 13b.

  FIG. 3 is a diagram showing alignment at the time of joining by bonding the head member 1 and the nozzle plate 2.

  The infrared light is emitted from one side to the dummy nozzles 22 at both ends of the nozzle plate 2 by the infrared light emitting means 500, and the infrared light transmitted through the nozzle plate 2 by the infrared CCD camera 600 disposed on the opposite side to the irradiation side. Light is received and the dummy nozzle 22 is detected. With reference to the detected position of the dummy nozzle and the position of the head member, the nozzle plate 2 is aligned with a predetermined position of the head member 1 and adhesively bonded.

  FIG. 3 is an example of irradiating a dummy nozzle with infrared light through the ink channel 13b from the surface of the head member 1 opposite to the surface where the nozzle plate 2 is joined. is there.

  In the present embodiment, as described above, infrared irradiation is performed from the surface of the head member 1 opposite to the surface where the nozzle plate 2 is joined, but from the opposite direction, that is, from the discharge side of the nozzle plate 2. May be received on the surface opposite to the surface where the nozzle plate 2 of the ink channel 13b is joined.

  Further, as shown in FIG. 4, the dummy nozzle 22 may be provided on the discharge side of the nozzle plate 2.

  As described above, since the portion of the dummy nozzle 22 is thinner than the unprocessed portion, the transmittance increases when the nozzle plate 2 is irradiated with infrared rays, and the shape and position of the dummy nozzle 22 can be easily distinguished. become. In addition, since a part of the dummy nozzle 22 is larger than the width a of the ink channel 13b, the edge of the ink channel wall 14 can be easily confirmed, thereby easily aligning the head member 1 and the nozzle plate 2 with accuracy. Good adhesive bonding.

  Further, as shown in FIG. 3, the joining surface side nozzle 21b of the nozzle 21 has a joining surface side nozzle diameter of r, a width of the ink channel in the arrangement direction of the nozzles a, and a width of the ink channel wall 14 of b. , A <r <(a + b), which is a non-penetrating hole, that is, the same shape as the dummy nozzle 22.

  In the present embodiment, the thickness of the nozzle plate 22 (t dimension in FIG. 2) is 200 μm, and the depth of the holes of the dummy nozzle 22 and the nozzle 21b (t1 dimension in FIG. 2) is 150 μm.

  As described above, the joining surface side nozzle 21b portion has a thickness smaller than that of the non-processed portion, so that the transmittance increases when the nozzle plate 2 is irradiated with infrared rays. Further, when the nozzle plate 2 is overlapped at a predetermined position of the head member 1, a part of the nozzle 21b becomes larger than the width a of the ink channel 13b. As a result, the infrared light emitting means 500 emits infrared light from one side as in the detection of the dummy nozzle 22 described above, and the position of the nozzle 21 is confirmed by receiving it with the infrared CCD camera 600 disposed on the opposite side to the irradiation side. In addition, the edge of the ink channel wall 14 can be easily confirmed, and the suitability of the entire nozzle can be confirmed. In addition, it is possible to easily confirm the presence or absence of the adhesive flowing into the discharge side nozzle.

  Furthermore, since there is a portion where the diameter of the joining surface side nozzle 21b is larger than the ink channel width 13a, it is possible to prevent the portion from becoming a pool of adhesive protruding and flowing into the discharge port portion of the nozzle 21.

  With the above, it is possible to produce a high-quality and highly productive inkjet head.

1 is a schematic perspective view of a multi-channel inkjet head according to the present invention. It is a figure which shows the shape of a head member and a nozzle plate. It is a figure which shows the position alignment of the adhesive joining of a head member and a nozzle plate. It is a figure which shows an example of the shape of a dummy nozzle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Head member 2 Nozzle plate 3 Back plate 4 Ink manifold 11 Actuator board | substrate 11a, 11b Piezoelectric material board | substrate 12 Cover board | substrate 13, 13a, 13b Channel 14 Ink channel wall 21 Nozzle 21a Ejection side nozzle 21b Joint surface side nozzle 22 Dummy nozzle 500 Infrared Light emitting means 600 Infrared CCD camera

Claims (5)

In an inkjet head formed by joining a nozzle plate provided with a plurality of nozzles by etching on a silicon substrate and a head member that forms an ink channel, and discharging ink from the nozzles,
The head member has dummy channels having the same shape as the ink channels at both ends of the row of ink channels,
The nozzle plate has at least one dummy nozzle at a position corresponding to the dummy channel at both ends of the plurality of nozzle rows, and the dummy nozzle penetrates in a circular shape when viewed from the ink discharge direction. Is not a hole, the portion of the dummy nozzle in the nozzle plate is smaller than the unprocessed portion,
An ink jet head having a relationship of a <r <(a + b), where r is the dummy nozzle diameter, a is the width of the ink channel in the arrangement direction of the nozzles, and b is the width of the ink channel wall. The inkjet head according to claim 1, wherein the nozzle plate has the dummy nozzle on a joint surface side with a head member. The nozzle for ejecting ink of the nozzle plate has at least two nozzle diameters, ejects ink, has the smallest diameter of the penetrating ink ejection side nozzle, and is connected to the head member side The diameter of the nozzle on the joint surface side that does not pass through is defined as a <r <(a + b), where r is the nozzle diameter on the joint surface side, a is the width of the ink channel in the nozzle arrangement direction, and b is the width of the ink channel wall. The inkjet head according to claim 1, wherein the inkjet head has a relationship of A method for manufacturing an inkjet head according to any one of claims 1 to 3,
When the nozzle plate and the head member are joined, the nozzle plate is irradiated with infrared light, transmitted through the nozzle plate, the dummy nozzle is detected by an infrared CCD camera, and the detected dummy nozzle is used for alignment. And a method of manufacturing the ink jet head, wherein the head member is aligned. The method of manufacturing an inkjet head according to claim 4, wherein the infrared irradiation is performed from a surface opposite to a surface of the head member on which the nozzle plate is joined.

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