JP2022090338A - Manufacturing method of liquid jet head chip, liquid jet head chip, liquid jet head and liquid jet recording device - Google Patents

Abstract

To suppress a protection film from fuzzing when removing a mask.SOLUTION: A manufacturing method of a head chip includes: a substrate preparing step of preparing a substrate for an actuator plate which has a jet channel communicated with a nozzle hole that jets ink and non-jet channels that do not jet ink; a mask arranging step of exposing a first region around the nozzle hole and masking the non-jet channels in a second region other than the first region, using a mask that can be removed by a solution, after the substrate preparing step; a protection film forming step of forming a protection film for protecting a common electrode formed on an inner surface of the jet channel from ink, after the mask arranging step; and a mask removing step of removing the mask using a solution, after the protection film forming step.SELECTED DRAWING: Figure 12

Description

The present disclosure relates to a method for manufacturing a liquid injection head tip, a liquid injection head tip, a liquid injection head, and a liquid injection recording device.

Conventionally, there is an inkjet printer provided with an inkjet head as a device for injecting droplet-shaped ink onto a recording medium such as recording paper and recording an image or characters on the recording medium.
For example, the inkjet head has a method of injecting ink by applying a voltage to a piezoelectric material such as PZT (lead zirconate titanate) to deform it. For finer printing, a method of increasing the density of nozzle holes for ejecting ink is adopted. At this time, in order to improve the density, the plurality of channels of the actuator plate (head chip structure) are also miniaturized.
For example, a protective film such as a polyparaxylylene (Parylene: registered trademark) film is formed on the portion of the inkjet head that comes into contact with the ink to ensure durability. For example, by forming a polyparaxylylene film on the channel, it is possible to prevent the electrodes formed in the channel from being corroded by the ink. Since the polyparaxylylene film has an advantage of being attached to a complicated structure, it may be formed in a place other than the necessary place (unnecessary place) such as in a channel. For example, Japanese Patent Application Laid-Open No. 2005-153510 discloses a method for removing a polyparaxylylene film formed at an unnecessary portion by an oxygen plasma etching process.
On the other hand, in the film formation of the polyparaxylylene film, there is a method of covering unnecessary portions with a masking member such as tape and removing the masking member by a physical method after the formation of the polyparaxylylene film.

Japanese Unexamined Patent Publication No. 2005-153510

However, when the polyparaxylylene film formed in an unnecessary place is removed by oxygen plasma etching treatment, ozone is generated at the time of removal, which affects the polyparaxylylene film formed in the necessary place. there is a possibility.
On the other hand, if the masking member is removed by a physical method after the formation of the polyparaxylylene film, the polyparaxylylene film may be torn and fluffing may occur when the masking member is removed.
As described above, in order to ensure durability, the area around the nozzle hole for ejecting ink is a place where a protective film such as a polyparaxylylene film is required. On the other hand, since the region other than the region around the nozzle hole includes the region to which the external substrate is connected, a protective film such as a polyparaxylylene film is unnecessary.
Therefore, it is required to suppress the occurrence of fluffing of the protective film when the mask is removed.

The present disclosure discloses a method for manufacturing a liquid injection head tip capable of suppressing the occurrence of fluffing of a protective film when removing a mask, and a highly durable liquid injection head tip, a liquid injection head and a liquid injection recording device. The purpose is to provide.

In order to solve the above problems, the present disclosure adopts the following aspects.
(1) In the method for manufacturing a liquid injection head chip according to one aspect of the present disclosure, a substrate for an actuator plate having an injection channel communicating with a nozzle hole for injecting a liquid and a non-injection channel that does not inject the liquid is prepared. After the substrate preparation step and the substrate preparation step, a mask that can be removed with a liquid is used to expose the first region around the nozzle hole, and the non-injection is performed in a second region other than the first region. After the mask placement step of covering the channel, the protective film forming step of forming a protective film that protects the electrode formed on the inner surface of the injection channel from the liquid, and the protective film forming step after the mask placement step. , A mask removing step of removing the mask with the solution.

If an unnecessary portion is covered with a masking member such as tape and the masking member is removed by a physical method after the protective film is formed, the protective film may be torn and fluffing may occur when the masking member is removed. On the other hand, according to this aspect, by removing the mask with a solution after the protective film is formed, the protective film is less likely to be torn when the mask is removed. Therefore, it is possible to suppress the occurrence of fluffing of the protective film when the mask is removed.

(2) In the method for producing a liquid injection head tip according to the above aspect (1), it is preferable that the solution contains water and the mask is made of a water-soluble resin.
According to this aspect, the mask can be easily removed with water.

(3) In the method for manufacturing a liquid injection head tip according to the above aspect (2), it is preferable that the mask contains polyvinyl alcohol.
According to this aspect, since it is easier to attach the mask to the actuator plate substrate as compared with the case where the mask is formed of a water-soluble resin other than polyvinyl alcohol, there is a gap between the mask and the actuator plate substrate. It can be suppressed from occurring.

(4) In the method for manufacturing a liquid injection head tip according to any one of (1) to (3) above, the mask is preferably formed in the form of a film.
According to this aspect, the mask can be easily placed along the surface of the actuator plate substrate.

(5) In the method for manufacturing a liquid injection head chip according to any one of (1) to (4) above, the actuator plate substrate is provided with a nozzle plate having a nozzle hole communicating with the injection channel. It has one surface and a second surface that intersects the first surface and has an end opening of the non-injection channel, and in the mask arranging step, the mask is used as the first surface of the actuator plate substrate. It is preferable to arrange the surface so as to straddle the first surface and the second surface.
If the mask is placed only on the first surface of the actuator plate substrate, scattered mist or droplets may infiltrate the non-injection channel through the end opening on the second surface. On the other hand, according to this aspect, by arranging the mask so as to straddle the first surface and the second surface of the actuator plate substrate, the end opening is covered by the mask, so that mist and droplets are not ejected. Invasion into the channel can be suppressed. Therefore, it is possible to suppress a short circuit caused by mist or droplets.

(6) In the method for manufacturing a liquid injection head chip according to any one of (1) to (5) above, it is preferable that the second region includes a connection region to which an external substrate is connected.
According to this aspect, since the formation of the protective film is suppressed in the connection region, it is possible to suppress the connection failure of the external substrate.

(7) The liquid injection head tip according to one aspect of the present disclosure includes an actuator plate having an injection channel communicating with a nozzle hole for injecting a liquid and a non-injection channel that does not inject the liquid. The protective film has a protective film that protects an electrode formed on the inner surface of the non-injection channel, and the protective film covers the opening of the non-injection channel.

According to this aspect, the protective film can protect the electrodes on the inner surface of the non-injection channel, so that the durability is improved. Therefore, it is possible to provide a liquid injection head tip having excellent durability.

(8) In the liquid injection head chip according to the embodiment (7), the actuator plate extends in the depth direction of the non-injection channel and has a pair of side walls facing in the width direction of the non-injection channel, and the said. It has a pair of side walls and a bottom wall facing the bottom of the non-injection channel, the protective film being connected to the pair of side membranes along the pair of side walls and the pair of side membranes. Moreover, it is preferable to have a bottom surface film along the bottom wall and an opening surface film connected to the pair of side surface films and arranged at the opening of the non-injection channel.
According to this aspect, since the protective film has a pair of side surface films, a bottom surface film, and an open surface film, the protective film is formed in a rectangular cross section, so that fluffing of the protective film can be suppressed more effectively.

(9) In the liquid injection head chip according to the embodiment (7) or (8), the protective film is arranged inside the opening of the non-injection channel in the depth direction of the non-injection channel. Is preferable.
According to this aspect, it is possible to suppress the protective film from being affected by disturbance from outside the opening of the non-injection channel.

(10) In the liquid injection head chip according to the embodiment (9), the actuator plate includes a connection region to which an external substrate is connected, and the protective film is formed in the non-injection channel arranged in the connection region. It is preferable that it is.
According to this aspect, since the protective film is arranged in the opening of the non-injection channel, it is possible to suppress the connection failure of the external substrate.

(11) The liquid injection head according to one aspect of the present disclosure includes the liquid injection head tip according to any one of the above (7) to (10).
According to this aspect, since the liquid injection head tip of the above aspect is provided, it is possible to provide a liquid injection head having excellent durability.

(12) The liquid injection recording device according to one aspect of the present disclosure includes the liquid injection head according to the above aspect (11).
According to this aspect, since the liquid injection head of the above aspect is provided, it is possible to provide a liquid injection recording device having excellent durability.

According to one aspect of the present disclosure, a method for manufacturing a liquid injection head tip capable of suppressing the occurrence of fluffing of a protective film when removing a mask, and a highly durable liquid injection head tip and liquid injection head. And a liquid injection recorder can be provided.

The schematic block diagram of the inkjet printer which concerns on embodiment. The schematic block diagram of the inkjet head and the ink circulation mechanism which concerns on embodiment. An exploded perspective view of an actuator plate, a cover plate, and a nozzle plate according to an embodiment. Top view of the actuator plate according to the embodiment. Top view of the actuator plate and the intermediate plate according to the embodiment. FIG. 4 is a sectional view taken along line VI-VI of FIG. The bottom view of the actuator plate which concerns on embodiment. FIG. 7 is a cross-sectional view of the inkjet head taken along line VIII-VIII of FIG. FIG. 7 is a cross-sectional view of the inkjet head along the IX-IX line of FIG. FIG. 7 is a cross-sectional view of an actuator plate and a cover plate along the XX line of FIG. 7. FIG. 7 is a cross-sectional view taken along the line XI-XI of FIG. The flowchart of the manufacturing method of the inkjet head which concerns on embodiment. Explanatory drawing of the mask arrangement process which concerns on embodiment. FIG. 13 is a cross-sectional view taken along the line XIV-XIV of FIG. FIG. 13 is a cross-sectional view taken along the line XV-XV of FIG. Sectional drawing after removing the mask which concerns on a comparative example. Sectional drawing of the protective film which concerns on modification of embodiment.

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. In the embodiments and modifications described below, the corresponding configurations may be designated by the same reference numerals and description thereof may be omitted. In the following description, expressions indicating relative or absolute arrangements such as "parallel", "orthogonal", "center", and "coaxial" not only strictly indicate such arrangements, but also tolerances. It also represents a state of relative displacement at an angle or distance to the extent that the same function can be obtained. In the following embodiment, as an example of a liquid injection recording apparatus including a liquid injection head provided with the liquid injection head chip (hereinafter, simply referred to as a head chip) of the present disclosure, an ink (liquid) is used as a recording medium. An inkjet printer (hereinafter, simply referred to as a printer) for recording is described as an example. In the drawings used in the following description, the scale of each member is appropriately changed in order to make each member recognizable.

[Printer]
FIG. 1 is a schematic configuration diagram of a printer 1.
As shown in FIG. 1, the printer 1 of the present embodiment includes a pair of transport mechanisms 2 and 3, an ink tank 4, an inkjet head 5 (liquid injection head), an ink circulation mechanism 6, and a scanning mechanism 7. To prepare for. In FIG. 1, the inside of the housing is shown by showing the housing of the printer 1 with a two-dot chain line.

In the following description, the X, Y, and Z orthogonal coordinate systems will be used as necessary. The X direction coincides with the transport direction (sub-scanning direction) of the recording medium P (for example, paper or the like). The Y direction coincides with the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction indicates a vertical direction (gravity direction) orthogonal to the X direction and the Y direction. In the following description, of the X direction, the Y direction, and the Z direction, the arrow side in the figure will be referred to as a plus (+) side, and the side opposite to the arrow will be referred to as a minus (−) side. In the present specification, the + Z side corresponds to the upper side in the direction of gravity, and the −Z side corresponds to the lower side in the direction of gravity.

The transport mechanisms 2 and 3 (first transport mechanism 2 and second transport mechanism 3) transport the recorded medium P in the X direction (for example, on the + X side). Specifically, the first transport mechanism 2 includes a first grit roller 11 extending in the Y direction, a first pinch roller 12 extending in parallel with the first grit roller 11, and a motor for axially rotating the first grit roller 11. A drive mechanism (not shown) is provided. The second transport mechanism 3 is a drive mechanism for axially rotating a second grit roller 13 extending parallel to the first grit roller 11, a second pinch roller 14 extending parallel to the second grit roller 13, and a second grit roller 13. (Not shown) and.

A plurality of ink tanks 4 are provided side by side in the X direction. In the embodiment, the plurality of ink tanks 4 are ink tanks 4Y, 4M, 4C, and 4K that contain inks of four colors of yellow, magenta, cyan, and black, respectively.

FIG. 2 is a schematic configuration diagram of an inkjet head and an ink circulation mechanism.
As shown in FIG. 2, the ink circulation mechanism 6 circulates ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation mechanism 6 is connected to the ink supply pipe 21 and the ink discharge pipe 22 constituting the circulation flow path 23, the pressurizing pump 24 connected to the ink supply pipe 21, and the ink discharge pipe 22. A suction pump 25 is provided. For example, the ink supply tube 21 and the ink discharge tube 22 are composed of a flexible hose that is flexible enough to follow the operation of the scanning mechanism 7 (see FIG. 1) that supports the inkjet head 5.

The pressurizing pump 24 pressurizes the inside of the ink supply tube 21 and sends ink to the inkjet head 5 through the ink supply tube 21. As a result, the ink supply tube 21 side has a positive pressure with respect to the inkjet head 5.

The suction pump 25 decompresses the inside of the ink discharge pipe 22 and sucks ink from the inkjet head 5 through the inside of the ink discharge pipe 22. As a result, the ink discharge tube 22 side has a negative pressure with respect to the inkjet head 5. The ink can be circulated between the inkjet head 5 and the ink tank 4 through the circulation flow path 23 by driving the pressure pump 24 and the suction pump 25.

As shown in FIG. 1, the scanning mechanism 7 reciprocates the inkjet head 5 in the Y direction. Specifically, the scanning mechanism 7 includes a pair of guide rails 31 and 32 extending in the Y direction, a carriage 33 movably supported by the pair of guide rails 31 and 32, and a drive mechanism for moving the carriage 33 in the Y direction. 34 and. The transport mechanisms 2 and 3 and the scanning mechanism 7 function as a moving mechanism for relatively moving the inkjet head 5 and the recording medium P.

The drive mechanism 34 is arranged between the guide rails 31 and 32 in the X direction. The drive mechanism 34 is a drive motor that rotationally drives a pair of pulleys 35, 36 arranged at intervals in the Y direction, an endless belt 37 wound between the pair of pulleys 35, 36, and one pulley 35. 38 and.

The carriage 33 is connected to the endless belt 37. A plurality of inkjet heads 5 are mounted on the carriage 33 side by side in the Y direction. In the embodiment, the plurality of inkjet heads 5 are inkjet heads 5Y, 5M, 5C, and 5K that eject inks of four colors of yellow, magenta, cyan, and black, respectively.

[Inkjet head]
FIG. 3 is an exploded perspective view of the actuator plate 50, the cover plate 60, and the nozzle plate 41. FIG. 4 is a top view of the actuator plate 50. FIG. 5 is a top view of the actuator plate 50 and the intermediate plate 42. FIG. 6 is a sectional view taken along line VI-VI of FIG. In FIG. 3, the intermediate plate 42 is not shown. In FIG. 4, the nozzle rows Nr1 and Nr2 (first nozzle row Nr1 and second nozzle row Nr2) are shown by broken lines. In FIG. 5, the first nozzle row Nr1 is shown by a broken line.

As shown in FIG. 3, the inkjet head 5 includes a head tip 40 and a nozzle plate 41. The inkjet head 5 is a so-called side shoot type inkjet in which ink passes in the thickness direction of the actuator plate 50, that is, in the depth direction of the injection channel 51.

[Head tip]
The head tip 40 includes an actuator plate 50 and a cover plate 60. Although not shown, a protective film such as a polyparaxylylene film is formed at a required portion on the surface (including the inner surface) of the head chip 40.

[Actuator plate]
The outer shape of the actuator plate 50 has a rectangular plate shape having a length in the X direction and a short side in the Y direction. The lower surface (-Z side surface) of the actuator plate 50 is a surface on which the nozzle plate 41 is arranged via the intermediate plate 42 (see FIG. 6).

The actuator plate 50 includes, for example, any one or more of the piezoelectric materials. The type of the piezoelectric material is not particularly limited, but is, for example, lead zirconate titanate (PZT) or the like. The actuator plate 50 of the embodiment is a so-called chevron type laminated substrate in which two piezoelectric substrates having different polarization directions in the thickness direction (Z direction) are laminated.

The actuator plate 50 has a plurality of channel rows Ch1 and Ch2 arranged at predetermined intervals in the Y direction (for example, two rows in this embodiment). Hereinafter, one of the two rows of channel rows Ch1 and Ch2 is also referred to as a first channel row Ch1 and the other is also referred to as a second channel row Ch2. When it is not necessary to distinguish between them, the two channel sequences Ch1 and Ch2 will be referred to as channel sequences.

As shown in FIG. 4, the channel sequence extends in the X direction. The channel sequence includes a plurality of channels 51, 52 extending in the Y direction and arranged at intervals in the X direction. Each channel 51, 52 is defined by a drive wall Wd containing a piezoelectric body. The plurality of channels 51 and 52 include an injection channel 51 that ejects ink and a non-injection channel 52 that does not eject ink. The injection channels 51 and the non-injection channels 52 are arranged alternately in the X direction.

The injection channel 51 and the non-injection channel 52 of the first channel row Ch1 and the injection channel 51 and the non-injection channel 52 of the second channel row Ch2 are arranged so as to be staggered in the X direction, respectively. That is, the injection channels 51 and the non-injection channels 52 of each channel sequence Ch1 and Ch2 are arranged in a staggered manner in the X direction.

FIG. 7 is a bottom view of the actuator plate 50. FIG. 8 is a cross-sectional view of the inkjet head 5 along the line VIII-VIII of FIG. 9 is a cross-sectional view of the inkjet head 5 along the IX-IX line of FIG. 7. FIG. FIG. 10 is a cross-sectional view of the actuator plate 50 and the cover plate 60 along the XX line of FIG. 7.

As shown in FIG. 7, the lower surface of the actuator plate 50 has a first region Re1 around the nozzle hole 41a (see FIG. 8) and a second region Re2 other than the first region Re1.
The first region Re1 is a region of the lower surface of the actuator plate 50 facing the nozzle plate 41 (see FIG. 8). The second region Re2 is a region on the lower surface of the actuator plate 50 that does not face the nozzle plate 41. The second region Re2 is arranged outside the first region Re1 in the Y direction. The second region Re2 includes a connection region Rc to which the external substrate 45 (see FIG. 3) is connected. The second region Re2 is provided at the end portion of the actuator plate 50 in the Y direction (hereinafter, also referred to as a tail portion 50Y).

The injection channel 51 is provided in the first region Re1. The injection channel 51 is not provided in the second region Re2. The injection channel 51 has a rectangular shape extending in the Y direction when viewed from the Z direction.

In the cross-sectional view of FIG. 8, the injection channel 51 has an extending portion 51a extending in the Y direction and a rounded portion 51b extending in the Y direction from the extending portion 51a. The extending portion 51a has a uniform groove depth over the entire Y direction. The groove depth of the cut-up portion 51b gradually becomes shallower from both ends of the extending portion 51a toward the outside in the Y direction.

As shown in FIG. 7, the non-injection channel 52 is provided so as to straddle the first region Re1 and the second region Re2. The non-injection channel 52 extends over the entire Y direction of the actuator plate 50. In the cross-sectional view of FIG. 9, the non-injection channel 52 has a uniform groove depth throughout the Y direction.

As shown in FIG. 6, drive electrodes 55 extending in the Y direction are provided on the side surfaces of the plurality of drive walls Wd. The drive electrode 55 is an electrode that electrically drives (deforms) the drive wall Wd in order to make the plurality of injection channels 51 function as pressure chambers. The drive electrode 55 includes a pair of common electrodes 56 provided on the side surface of the drive wall Wd defining the injection channel 51 (inner surface of the injection channel 51) and the side surface of the drive wall Wd defining the non-injection channel 52 (non-injection channel). Includes a pair of individual electrodes 57 provided on the inner surface of 52).

The pair of common electrodes 56 facing each other in the same injection channel 51 are electrically separated from each other. As shown in FIG. 8, the common electrode 56 is formed in a region + Z side from the lower surface (−Z side surface) of the drive wall Wd to the central position in the Z direction of the injection channel 51. The common electrode 56 extends to a position on the + Z side of the boundary (joint surface) of two piezoelectric substrates having different polarization directions, for example.

A plurality of common pads 58 electrically connected to the common electrode 56 are provided on the lower surface of the actuator plate 50. The common pad 58 electrically connects a pair of common electrodes 56 facing each other in the same injection channel 51. The common pad 58 is provided around the injection channel 51.

As shown in FIG. 6, the pair of individual electrodes 57 facing each other in the same non-injection channel 52 are electrically separated from each other. As shown in FIG. 9, the individual electrode 57 is formed in a region + Z side from the lower surface of the drive wall Wd to the center position in the Z direction of the non-injection channel 52. The individual electrode 57 extends to a position on the + Z side of the boundary (joining surface) of two piezoelectric substrates having different polarization directions, for example.

A plurality of individual pads 59 electrically connected to the individual electrodes 57 are provided on the lower surface of the actuator plate 50. The individual pads 59 electrically connect the pair of individual electrodes 57 facing each other via the injection channel 51. As shown in FIG. 7, the individual pads 59 are arranged between adjacent non-injection channels 52 with the injection channels 51 in between. The individual pad 59 is electrically separated from the common pad 58. The individual pads 59 are arranged outside the common pads 58 in the Y direction. The individual pads 59 are provided so as to straddle the non-injection channels 52 adjacent to each other in the X direction.

On the lower surface of the actuator plate 50, an electrode separating portion Sp that electrically separates the common pad 58 and the individual pad 59 is provided. The electrode separation portion Sp extends linearly along the Y direction. One end of the electrode separation groove in the Y direction is connected to the groove portion Di. The other end of the electrode separation portion Sp in the Y direction is connected to a portion (non-electrode forming portion 50N) on the lower surface of the actuator plate 50 where no electrode is formed.

As shown in FIG. 3, an external substrate 45 for electrically connecting the drive electrode 55 and the inkjet head 5 to each other is mounted on the tail portion 50Y. For example, the external substrate 45 is a flexible printed circuit board having flexibility. However, in FIG. 3, a part of the outer edge (contour) of the outer substrate 45 is shown by a broken line. The wiring pattern formed on the external substrate 45 is electrically connected to each of the above-mentioned common pad 58 and individual pad 59 (see FIG. 7). As a result, a drive voltage is applied from the inkjet head 5 to each drive electrode 55 via the external substrate 45.

As shown in FIG. 7, a groove portion Di extending along the X direction is provided between the common pad 58 and the individual pads 59 on the lower surface of the actuator plate 50. The width of the groove portion Di in the Y direction is larger than the width of the connection wiring (not shown) formed on the external substrate 45 in the Y direction. As a result, when the external board 45 is connected to the actuator plate 50, the connection wiring of the external board 45 is arranged at the position corresponding to the groove Di of the actuator plate 50, so that the connection wiring of the external board 45 and the actuator plate 50 can be arranged. It is possible to prevent the individual pads 59 from coming into contact with each other. Therefore, it is possible to prevent an electrical short circuit between the connection wiring of the external board 45 and the individual pads 59 of the actuator plate 50 and the individual electrodes 57 connected to the individual pads 59.

As shown in FIG. 9, it is preferable that the length (depth) of the groove Di in the Z direction is smaller than the length of each electrode provided on the side surface of the drive wall Wd in the Z direction. As a result, the groove Di can be formed on the side surface of the drive wall Wd without dividing each electrode.

As shown in FIG. 11, the actuator plate 50 has a pair of side walls 54a facing the width direction (X direction) of the non-injection channel 52 and a bottom wall 54b facing the bottom of the non-injection channel 52. The side wall 54a extends in the depth direction (Z direction) of the non-injection channel 52. The bottom wall 54b is connected to a pair of side walls 54a. The bottom wall 54b extends in the width direction of the non-injection channel 52.

The actuator plate 50 has a protective film 70 that protects the electrodes 56 and 57 formed on the inner surfaces of the channels 51 and 52. FIG. 11 shows a protective film 70 that protects the individual electrodes 57 formed on the inner surface of the non-injection channel 52. The protective film 70 covers the opening of the non-injection channel 52. The protective film 70 is arranged in the non-injection channel 52 arranged in the connection region Rc.

In the cross-sectional view of FIG. 11, the protective film 70 is formed in a rectangular cross section. The protective film 70 has a pair of side surface films 71 along the pair of side walls 54a, a bottom surface film 72 along the bottom wall 54b, and an open surface film 73 arranged at the opening of the non-injection channel 52. The bottom surface film 72 is connected to the + Z side ends of the pair of side surface films 71. The open surface film 73 is connected to the −Z side end of the pair of side surface films 71. The lower surface (-Z side surface) of the opening surface film 73 is arranged on substantially the same surface as the lower surface (electrode surface) of the actuator plate 50.

[Cover plate]
As shown in FIG. 3, the outer shape of the cover plate 60 has a rectangular plate shape having a length in the X direction and a short side in the Y direction. For example, the length of the length and the length of the cover plate 60 are substantially the same as the length of the length and the length of the actuator plate 50.

The cover plate 60 is a plate that introduces ink into the actuator plate 50 (a plurality of injection channels 51) and discharges ink from the actuator plate 50. As shown in FIG. 6, the actuator plate 50 is arranged between the intermediate plate 42 and the cover plate 60. The lower surface of the cover plate 60 is joined to the upper surface of the actuator plate 50.

As shown in FIG. 3, the cover plate 60 has ink flow paths Lp1 and Lp2 (liquid flow paths) communicating with the injection channel 51. The ink flow paths Lp1 and Lp2 do not communicate with the non-injection channel 52 (see FIG. 9). The ink flow paths Lp1 and Lp2 are provided with two sets of a first flow path Lp1 corresponding to the injection channel 51 of the first channel row Ch1 and a second flow path Lp2 corresponding to the injection channel 51 of the second channel row Ch2. Has been done.

The ink flow paths Lp1 and Lp2 extend in the X direction. When it is not necessary to distinguish between them, the two sets of flow paths will be referred to as ink flow paths. As shown in FIG. 10, the ink flow path has a manifold 60a that opens the cover plate 60 to the + Z side, and a slit 60b that communicates with the manifold 60a and opens to the −Z side. The manifold 60a communicates with the injection channel 51 through the slit 60b. The manifold 60a does not communicate with the non-injection channel 52.

As shown in FIG. 3, the ink flow path includes an ink supply flow path 61 that supplies ink to the injection channel 51, and an ink discharge flow path 62 that discharges ink from the injection channel 51. The ink supply flow path 61 of the first flow path Lp1 and the ink supply flow path 61 of the second flow path Lp2 may be arranged at positions adjacent to each other in the Y direction.

As shown in FIG. 8, the ink supply flow path 61 communicates with one end of the injection channel 51 in the Y direction. The ink supply flow path 61 extends in the X direction across one end of each injection channel 51 in the Y direction. The ink is supplied to each injection channel 51 via the ink supply flow path 61.

The ink discharge flow path 62 communicates with the other end of the injection channel 51 in the Y direction. The ink discharge flow path 62 extends in the X direction across the other end of each injection channel 51 in the Y direction. The ink is discharged from each injection channel 51 via the ink discharge flow path 62.

The cover plate 60 is preferably made of a material having an insulating property and having a thermal conductivity equal to or higher than the thermal conductivity of the material for forming the actuator plate 50. For example, when the actuator plate 50 is formed of PZT, the cover plate 60 is preferably formed of PZT or silicon. As a result, the temperature variation in the actuator plate 50 can be alleviated and the ink temperature can be made uniform. As a result, the ink ejection speed can be made uniform and the printing stability can be improved.

[Nozzle plate]
As shown in FIG. 3, the outer shape of the nozzle plate 41 has a rectangular plate shape having a length in the X direction and a short side in the Y direction. As shown in FIG. 6, the nozzle plate 41 is arranged to face the actuator plate 50 via the intermediate plate 42. As shown in FIG. 4, the nozzle plate 41 has a plurality of nozzle rows Nr1 and Nr2 (for example, two rows in the present embodiment) arranged at predetermined intervals in the Y direction. The inkjet head 5 is a so-called two-row type inkjet head. The two rows of nozzle rows Nr1 and Nr2 are a first nozzle row Nr1 corresponding to the first channel row Ch1 and a second nozzle row Nr2 corresponding to the second channel row Ch2. When it is not necessary to distinguish between them, the two nozzle rows will be referred to as nozzle rows.

The nozzle row extends in the X direction. The nozzle row has a plurality of nozzle holes 41a arranged at predetermined intervals in the X direction. The nozzle hole 41a is an ink injection port. The nozzle hole 41a penetrates the nozzle plate 41 in the Z direction. The opening shape of the nozzle hole 41a (the shape of the nozzle hole 41a seen from the Z direction) is, for example, circular.

As shown in FIG. 6, the direction in which ink is ejected from the nozzle hole 41a (ink ejection direction) is the −Z side. In other words, the ink ejection direction is the direction from the actuator plate 50 toward the nozzle plate 41. The inner diameter of the nozzle hole 41a gradually decreases in the ink ejection direction. That is, the nozzle hole 41a is a tapered through-hole whose diameter is reduced toward the −Z side.

The nozzle hole 41a communicates with the injection channel 51 via the communication hole 42a. As a result, the ink supplied from each injection channel 51 is ejected from each nozzle hole 41a.
On the other hand, the nozzle hole 41a does not communicate with the non-injection channel 52. The non-injection channel 52 is covered from below by the nozzle plate 41.

As shown in FIG. 5, the nozzle hole 41a is arranged at a position corresponding to a substantially central region of the injection channel 51 in the Y direction. The pitch of the plurality of nozzle holes 41a in the X direction (distance between the two nozzle holes 41a adjacent to each other) is the pitch of the plurality of injection channels 51 in the X direction (the pitch between the two injection channels 51 adjacent to each other). Distance) is almost the same. As shown in FIG. 4, the nozzle holes 41a of the first nozzle row Nr1 and the nozzle holes 41a of the second nozzle row Nr2 are arranged so as to be staggered in the X direction. That is, the nozzle holes 41a of each nozzle row Nr1 and Nr2 are arranged in a staggered manner in the X direction.

The nozzle plate 41 may be made of a conductive material. The type of the conductive material is not particularly limited, but is preferably a metal material such as stainless steel (SUS). Since the metal material has high scratch resistance, the inclusion of the metal material in the nozzle plate 41 improves the physical strength of the nozzle plate 41. The type of SUS is not particularly limited, and examples thereof include SUS316L and SUS304.

[Intermediate plate]
As shown in FIG. 6, the head tip 40 further includes an intermediate plate 42. The outer shape of the intermediate plate 42 has a rectangular plate shape having a length in the X direction and a short side in the Y direction. For example, the outer shape of the intermediate plate 42 is substantially the same as the outer shape of the nozzle plate 41. The intermediate plate 42 is arranged between the nozzle plate 41 and the actuator plate 50. The intermediate plate 42 is a plate for aligning the nozzle plate 41 and the actuator plate 50 with each other.

The intermediate plate 42 has a plurality of communication holes 42a at positions corresponding to each of the plurality of injection channels 51 and the plurality of nozzle holes 41a. Each communication hole 42a is arranged in the same manner as each injection channel 51. As shown in FIG. 5, each communication hole 42a extends in the Y direction and is arranged at a predetermined interval in the X direction. The communication hole 42a is not provided at a position overlapping the non-injection channel 52 when viewed from the Z direction.

The width of the communication hole 42a in the X direction is preferably larger than the width of the injection channel 51 in the X direction. As a result, the flow of ink supplied from the injection channel 51 to the nozzle hole 41a is less likely to be obstructed by the actuator plate 50. Therefore, problems related to ink ejection characteristics such as deflection of the ink ejection direction are less likely to occur. More preferably, the injection channel 51 is arranged in a region defined by the width of the communication hole 42a when viewed from the Z direction.

The intermediate plate 42 is preferably made of an insulating material. The type of the insulating material is not particularly limited, and examples thereof include glass, polyimide, polypropylene, and polyethylene terephthalate. For example, when the base material of the intermediate plate 42 is formed of the above-mentioned material, a structure in which the base material is covered with polyparaxylylene or the like is also possible.
Further, examples of the material of the intermediate plate 42 include alumina and the like. The intermediate plate 42 is not limited to the material described above, and may be formed of a piezoelectric material such as PZT as in the actuator plate 50.

As shown in FIG. 6, the nozzle plate 41 and the actuator plate 50 are attached to each other via the intermediate plate 42. As a result, the conductive nozzle plate 41 and the conductive actuator plate 50 are electrically separated (insulated) via the insulating intermediate plate 42. When the nozzle plate 41 and the actuator plate 50 are insulated from each other via the intermediate plate 42, a conductive material can be used as a forming material for the nozzle plate 41, and a piezoelectric material can be used as a forming material for the actuator plate 50. become. Therefore, a metal material having high scratch resistance can be used as the forming material of the nozzle plate 41. As a result, the nozzle plate 41 is less likely to be damaged (wear, etc.) while suppressing a short circuit between the nozzle plate 41 and the actuator plate 50.

For example, the intermediate plate 42 preferably has a linear expansion coefficient E1 (E2 <E1 <E3 or E3 <E1 <E2) between the linear expansion coefficient E2 of the nozzle plate 41 and the linear expansion coefficient E3 of the actuator plate 50. .. By satisfying the above relationship, when each of the nozzle plate 41, the intermediate plate 42 and the actuator plate 50 is thermally deformed, each of the nozzle plate 41 and the actuator plate 50 due to the difference in the linear expansion coefficient (thermal expansion coefficient). The displacement is absorbed by the intermediate plate 42. Therefore, as compared with the case where the intermediate plate 42 is not interposed between the nozzle plate 41 and the actuator plate 50, it is possible to suppress the peeling of the nozzle plate 41 and the actuator plate 50 due to thermal deformation. Therefore, problems such as deflection are less likely to occur when the ink is ejected.

[Printer operation]
As shown in FIG. 1, in the printer 1 of the present embodiment, the recording paper P is conveyed in the X direction, and the carriage 33 reciprocates in the Y direction. The inkjet head 5 on the carriage 33 reciprocates in the Y direction to eject ink onto the recording paper P. As a result, an image or the like is recorded on the recording paper P.

[Operation of inkjet head]
In the inkjet head 5 of the present embodiment, ink is ejected onto the recording paper P using the shear (share) mode according to the following procedure.

First, when the carriage 33 reciprocates, a drive voltage is applied to the drive electrodes 55 (common electrode 56 and individual electrodes 57) via the external substrate 45. Specifically, a drive voltage is applied to each drive electrode 55 provided on the pair of drive walls Wd defining the injection channel 51. As a result, each of the pair of drive walls Wd is deformed so as to project toward the non-injection channel 52 adjacent to the injection channel 51.

Here, as described above, in the actuator plate 50, two piezoelectric substrates set so that the polarization directions in the Z direction are different from each other are laminated. In addition, the drive electrode 55 extends from the lower surface of the drive wall Wd to a region on the + Z side of the center position of the drive wall Wd in the Z direction. In this case, when the drive voltage is applied to the drive electrode 55, the drive wall Wd is bent and deformed starting from the substantially center position of the drive wall Wd in the Z direction due to the piezoelectric thickness slip effect. As a result, each injection channel 51 is deformed as if it swells by utilizing the bending deformation of the drive wall Wd described above.

The volume of each injection channel 51 is increased by utilizing the bending deformation of the pair of drive walls Wd based on the piezoelectric thickness slip effect. As a result, the ink supplied to each ink supply flow path 61 is guided to the inside of each injection channel 51.

Subsequently, the ink induced inside each injection channel 51 propagates inside each injection channel 51 as a pressure wave. In this case, the drive voltage applied to the drive electrode 55 becomes zero (0 V) at the timing when the pressure wave reaches the nozzle hole 41a provided in the nozzle plate 41. As a result, the bent and deformed drive wall Wd returns to the original state, so that the volume of each injection channel 51 returns to the original state.

Finally, when the volume of each injection channel 51 returns to the original volume, the pressure increases inside each injection channel 51, so that the ink guided to the inside of each injection channel 51 is pressurized. As a result, droplet-shaped ink is ejected from each nozzle hole 41a to the outside (recording paper P).

In this case, for example, as described above, since the inner diameter of the nozzle hole 41a is gradually reduced toward the ink ejection direction, the ink ejection speed is increased and the straightness of the ink is improved. As a result, the quality of the image recorded on the recording paper P is improved.

[Manufacturing method of inkjet head]
FIG. 12 is a flowchart of a method for manufacturing an inkjet head.
As shown in FIG. 12, the manufacturing method of the inkjet head 5 of the present embodiment includes a substrate preparation step, a cover plate joining step, a channel forming step, an electrode forming step, an electrode separating step, a groove forming step, a mask placement step, and a protective film. It includes a forming step, a mask removing step, an intermediate plate joining step, a nozzle plate joining step, and an external substrate connecting step.

In the substrate preparation step (step S1 in FIG. 12), a wafer or the like for obtaining the components of the inkjet head 5 is prepared in advance. Hereinafter, the substrate (for example, a wafer) for obtaining the actuator plate 50 is referred to as an actuator plate substrate AW. In the substrate preparation step, a groove including a plurality of channels is formed in the actuator plate substrate AW. In the substrate preparation step, a cover plate 60 (see FIG. 3) having an ink flow path is prepared. After the substrate preparation step, the process proceeds to the cover plate joining step (step S2 in FIG. 12).

In the cover plate joining step, the cover plate 60 is joined to the upper surface of the actuator plate substrate AW. As a result, a bonded wafer in which the actuator plate substrate AW and the cover plate 60 are bonded is obtained. After the cover plate joining step, the process proceeds to a channel forming step (step S3 in FIG. 12).

In the channel forming step, the lower surface of the actuator plate substrate AW is ground by, for example, a grinder. As a result, the channels 51 and 52 (see FIG. 7) are opened on the lower surface of the actuator plate substrate AW. The lower surface (first surface) of the actuator plate substrate AW is the surface on which the nozzle plate 41 (see FIG. 8) is arranged. After the channel forming step, the process proceeds to the electrode forming step (step S4 in FIG. 12).

In the electrode forming step, a conductive film is formed on the inner surface of each of the channels 51 and 52 and the lower surface of the actuator plate substrate AW by, for example, an orthorhombic vapor deposition method. After the electrode forming step, the process proceeds to the electrode separation step (step S5 in FIG. 12).

In the electrode separation step, the conductive film is separated into a common pad 58 and an individual pad 59 on the lower surface of the actuator plate substrate AW by, for example, laser patterning (see FIG. 7). After the electrode separation step, the process proceeds to the groove forming step (step S6 in FIG. 12).

In the groove forming step, a groove Di extending in the X direction is formed by, for example, a dicer (see FIG. 7). After the groove forming step, the process proceeds to a mask arranging step (step S7 in FIG. 12).

As shown in FIG. 13, in the mask arranging step, the mask Ma that exposes the first region Re1 and covers the non-injection channel 52 in the second region Re2 is arranged. In the mask arranging step, the mask Ma is arranged in the connection region Rc on the lower surface of the actuator plate substrate AW. In the mask arranging step, the mask Ma is arranged on the tail portion 50Y on the lower surface of the actuator plate substrate AW.

The mask Ma can be removed with a solution containing water. For example, the mask Ma is made of a water-soluble resin. For example, examples of the water-soluble resin include resole-type phenol resin, methylolated urea (urea) resin, methylolated melamine resin, polyvinyl alcohol, polyethylene oxide, polyacrylamide, carboxymethyl cellulose (CMC) and the like. In this embodiment, the mask Ma contains polyvinyl alcohol. The mask Ma is formed in the form of a film.

For example, it is preferable that the mask Ma can be processed (laminated) in which a plurality of materials are laminated and laminated. By forming the mask Ma into a laminated structure, the strength can be increased as compared with the single-layer structure.

For example, if the temperature at which the mask Ma is laminated (hereinafter referred to as the laminating temperature) is a high temperature exceeding 150 degrees, it may affect the polarization of the actuator plate (PZT). Therefore, the laminating temperature is preferably 150 degrees or less.

For example, if the amount of gas emitted from the mask Ma (film) is too large, the quality of the protective film may deteriorate. Therefore, it is preferable that the amount of gas emitted from the mask Ma is as small as possible.

In the mask arranging step, the mask Ma is arranged so as to straddle the lower surface of the actuator plate substrate AW and the side surface of the actuator plate substrate AW in the Y direction. The side surface (second surface) of the actuator plate substrate AW in the Y direction is orthogonal (crossed) to the lower surface of the actuator plate substrate AW, and the end opening 52h (see FIG. 14) of the non-injection channel 52 is formed. It's a certain aspect.

For example, as shown in FIG. 14, in the mask arranging step, the mask Ma is moved from the Y-side end of the lower surface of the actuator plate substrate AW to the position on the + Z side of the joint surface between the actuator plate substrate AW and the cover plate 60. extend. In the mask arranging step, the mask Ma may be arranged so as to straddle the lower surface of the actuator plate substrate AW and the side surface of the actuator plate substrate AW in the X direction.

As shown in FIG. 13, by the mask arrangement step, the injection channel 51 and the non-injection channel 52 are exposed in the first region Re1 and the non-injection channel 52 is covered with the mask Ma in the second region Re2. .. After the mask placement step, the process proceeds to the protective film forming step (step S8 in FIG. 12).

In the protective film forming step, a protective film 70 is formed to protect the common electrode 56 (see FIG. 8) formed on the inner surface of the injection channel 51 from ink. In the protective film forming step, the protective film 70 is formed on the injection channel 51 in a state where the first region Re1 is exposed and the second region Re2 is covered with the mask Ma.

In the protective film forming step, a fluid for forming the protective film 70 in the injection channel 51 is supplied to the first region Re1. For example, the paraxylylene-based dimer is heated to form a monomer vapor, and the monomer is reacted on the inner surface of the injection channel 51, which is an object, to form the protective film 70. Since the polyparaxylylene film has an advantage of being attached to a complicated structure, the protective film 70 can also be formed on the non-injection channel 52. For example, as shown in FIG. 15, the protective film 70 is formed in a rectangular cross section across the inner surface of the non-injection channel 52 of the connection region Rc and the inner surface of the mask Ma. After the protective film forming step, the process proceeds to a mask removing step (step S9 in FIG. 12).

In the mask removing step, the mask Ma is removed from the lower surface of the actuator plate substrate AW with a solution. In the present embodiment, since the mask Ma is formed of a water-soluble resin, the mask Ma is removed with a solution containing water. When the mask Ma is removed, the protective film 70 is in a state of covering the opening of the non-injection channel 52 in the connection region Rc (see FIG. 11). After the mask removing step, the process proceeds to an intermediate plate joining step (step S10 in FIG. 12).

In the intermediate plate joining step, the intermediate plate 42 is joined to the first region Re1 on the lower surface of the actuator plate substrate AW. After the intermediate plate joining step, the process proceeds to the nozzle plate joining step (step S11 in FIG. 12).

In the nozzle plate joining step, the nozzle plate 41 is joined to the lower surface of the intermediate plate 42 (see FIG. 8). After the nozzle plate joining step, the process proceeds to the external substrate connecting step (step S12 in FIG. 12).

In the external board connection step, the external board 45 (see FIG. 3) is connected to the connection region Rc (see FIG. 7) on the lower surface of the actuator plate 50.
As described above, the inkjet head 5 of the present embodiment is completed (see FIG. 8).

The method for manufacturing the inkjet head is not limited to the above example, and various methods can be adopted.
For example, the method of manufacturing the inkjet head may be performed in the following order.
First, the channels 51 and 52 are formed on the actuator plate substrate AW. Next, electrodes are formed on the inner surfaces of the channels 51 and 52. Next, the cover plate substrate is bonded to the actuator plate substrate AW to form a bonded wafer. Next, the bonded wafer is fragmented (chip division). Next, a protective film is formed at necessary points on the individualized wafer. Next, the nozzle plate 41 is joined to the wafer on which the protective film is formed.

For example, the method of manufacturing the inkjet head may be performed in the following order.
First, the channels 51 and 52 are formed on the actuator plate substrate AW. Next, electrodes are formed on the inner surfaces of the channels 51 and 52 from the upper surface side of the actuator plate substrate AW. Next, the cover plate substrate is bonded to the actuator plate substrate AW to form a bonded wafer. Next, the lower surface of the bonded wafer (the lower surface of the actuator plate substrate AW) is ground. As a result, the channels 51 and 52 are opened on the lower surface of the actuator plate substrate AW. Next, electrodes are formed on the inner surfaces of the channels 51 and 52 from the lower surface side of the actuator plate substrate AW. Next, a protective film is formed at the required location. Next, the nozzle plate 41 is joined to the wafer on which the protective film is formed.
The electrode formation direction with respect to the actuator plate substrate AW is either the direction from the upper surface side to the lower surface side of the actuator plate substrate AW or the direction from the lower surface side to the upper surface side of the actuator plate substrate AW. You may.

As described above, the method for manufacturing the head chip 40 according to the embodiment is a substrate AW for an actuator plate having an injection channel 51 communicating with a nozzle hole 41a for injecting ink and a non-injection channel 52 for not injecting ink. After the substrate preparation step and the substrate preparation step, a mask Ma that can be removed with a solution is used to expose the first region Re1 around the nozzle hole 41a and the second region Re2 other than the first region Re1. After the mask placement step of covering the non-injection channel 52 and the mask placement step, a protective film forming step of forming a protective film 70 that protects the common electrode 56 formed on the inner surface of the injection channel 51 from ink, and a protective film. After the forming step, a mask removing step of removing the mask Ma with a solution is included.
If an unnecessary part is covered with a masking member such as tape and the masking member is removed by a physical method after the protective film 70 is formed, the protective film 70 may be torn and fluffing may occur when the masking member is removed. There is (see FIG. 16). On the other hand, according to the method for manufacturing the head chip 40 according to the embodiment, by removing the mask Ma with a solution after forming the protective film 70, the protective film 70 is less likely to be torn when the mask Ma is removed. Therefore, it is possible to suppress the occurrence of fluffing of the protective film 70 when the mask Ma is removed.
Further, if the protective film 70 formed on an unnecessary portion is removed by oxygen plasma etching treatment after the protective film 70 is formed on the entire surface without arranging the mask Ma, ozone is generated when the protective film 70 is removed. It may affect the protective film 70 formed at the required location. On the other hand, according to the method for manufacturing the head chip 40 according to the embodiment, removing the mask Ma with a solution after forming the protective film 70 affects the protective film 70 formed at a required position. Can be suppressed.
In addition, by forming a protective film on the exposed first region Re1 with the non-injection channel 52 of the second region Re2 covered, the protective film 70 is formed on the non-injection channel 52 of the second region Re2. It can be suppressed. For example, even when the protective film 70 is formed on the non-injection channel 52 of the second region Re2, the film thickness of the protective film 70 can be reduced.

The solution of the embodiment comprises water. The mask Ma is made of a water-soluble resin.
According to this method, the mask Ma can be easily removed by water.

The mask Ma of the embodiment contains polyvinyl alcohol.
According to this method, it is easier to attach the mask Ma to the actuator plate substrate AW as compared with the case where the mask Ma is formed of a water-soluble resin other than polyvinyl alcohol. It is possible to suppress the formation of a gap between the two.

The mask Ma of the embodiment is formed in the form of a film.
According to this method, the mask Ma can be easily aligned with the surface of the actuator plate substrate AW.

The actuator plate substrate AW of the embodiment intersects the lower surface on which the nozzle plate 41 having the nozzle hole 41a communicating with the injection channel 51 is arranged and the lower surface of the actuator plate substrate AW, and is at the end of the non-injection channel 52. It has a side surface having a portion opening 52h. In the mask arranging step, the mask Ma is arranged so as to straddle the lower surface and the side surface of the actuator plate substrate AW.
If the mask is arranged only on the lower surface of the actuator plate substrate AW, scattered mist and droplets may infiltrate into the non-injection channel 52 through the side end opening 52h. On the other hand, according to the method for manufacturing the head chip 40 according to the embodiment, by arranging the mask Ma so as to straddle the lower surface and the side surface of the actuator plate substrate AW, the end opening 52h is covered with the mask Ma. It is possible to suppress the infiltration of mist and droplets into the non-injection channel 52. Therefore, it is possible to suppress a short circuit caused by mist or droplets.

The second region Re2 of the embodiment includes a connection region Rc to which the external substrate 45 is connected.
According to this method, since the formation of the protective film 70 is suppressed in the connection region Rc, it is possible to suppress the connection failure of the external substrate 45.

The head tip 40 of the embodiment includes an actuator plate 50 having an injection channel 51 communicating with a nozzle hole 41a for injecting ink and a non-injection channel 52 for not injecting ink. The actuator plate 50 has a protective film 70 that protects the individual electrodes 57 formed on the inner surface of the non-injection channel 52. The protective film 70 covers the opening of the non-injection channel 52.
According to this configuration, the protective film 70 can protect the individual electrodes 57 on the inner surface of the non-injection channel 52, so that the durability is improved. Therefore, it is possible to provide the head tip 40 having excellent durability. For example, when the mist of the ejected ink reaches the non-injection channel 52, the individual electrode 57 can be protected. For example, when the mask Ma is removed by a solution after the protective film 70 is formed, the mask Ma is protected when the mask Ma is removed as compared with the case where the mask member is removed by a physical method after the protective film 70 is formed. Since the film 70 is unlikely to be torn, it is possible to suppress the occurrence of fluffing of the protective film 70. In addition, since the protective film 70 covers the opening of the non-injection channel 52, when the external substrate 45 is connected to the actuator plate 50, the electrode on the external substrate 45 is also protected at the joint surface of the external substrate 45. can do.

The actuator plate 50 of the embodiment extends in the depth direction of the non-injection channel 52 and is connected to the pair of side walls 54a facing the width direction of the non-injection channel 52 and the pair of side walls 54a, and the non-injection channel 52. With a bottom wall 54b, which faces the bottom of the. The protective film 70 is connected to the pair of side surface films 71 along the pair of side walls 54a and the pair of side surface films 71, and is connected to the bottom surface film 72 along the bottom wall 54b and the pair of side surface films 71, and is non-injection. It has an open surface film 73 arranged in the opening of the channel 52.
According to this configuration, since the protective film 70 has a pair of side surface films 71, a bottom surface film 72, and an open surface film 73, the protective film 70 is formed in a rectangular cross section, so that the fluffing of the protective film 70 is more effectively suppressed. Can be done.

The actuator plate 50 of the embodiment includes a connection region Rc to which the external substrate 45 is connected. The protective film 70 is formed on the non-injection channel 52 arranged in the connection region Rc.
According to this configuration, since the protective film 70 is arranged in the opening of the non-injection channel 52, it is possible to suppress poor connection of the external substrate 45.

Since the inkjet head 5 and the printer 1 of the embodiment include the head chip 40 described above, it is possible to provide the inkjet head 5 and the printer 1 having excellent durability.

The technical scope of the present disclosure is not limited to the above-described embodiment, and various changes can be made without departing from the spirit of the present disclosure.

For example, in the above-described embodiment, the inkjet printer 1 has been described as an example of the liquid injection recording device, but the printer is not limited to the printer. For example, the liquid injection recording device may be a fax machine, an on-demand printing machine, or the like.
In the above-described embodiment, the case where the recording medium P is paper has been described, but the present invention is not limited to this configuration. The recording medium P is not limited to paper, but may be a metal material, a resin material, food, or the like.
In the above-described embodiment, the configuration in which the liquid injection head is mounted on the liquid injection recording device has been described, but the configuration is not limited to this. That is, the liquid ejected from the liquid injection head is not limited to the one that lands on the recording medium, for example, a chemical solution to be blended in a preparation, a food additive such as a seasoning or a fragrance to be added to a food, or an injection into the air. It may be a fragrance or the like.

In the above-described embodiment, the side shoot type head tip 40 has been described as an example, but the present invention is not limited to this. For example, the present disclosure may be applied to a so-called edge shoot type head tip in which ink is ejected from the tip of the injection channel in the channel extending direction.
Further, the present disclosure may be applied to a so-called roof chute type head chip in which the direction of the pressure applied to the ink and the direction of ejection of the ink are the same.

In the above-described embodiment, the configuration in which the Z direction coincides with the gravity direction has been described, but the configuration is not limited to this configuration. For example, the Z direction may be along the horizontal direction.

In the above-described embodiment, the two-row type inkjet head 5 in which the nozzle holes 41a are arranged in two rows has been described, but the present invention is not limited to this. For example, an inkjet head having three or more rows of nozzle holes 41a may be used, or an inkjet head having one row of nozzle holes 41a may be used.

In the above-described embodiment, the configuration in which the injection channels 51 and the non-injection channels 52 are alternately arranged has been described, but the present invention is not limited to this. For example, the present disclosure may be applied to a so-called three-cycle inkjet head in which ink is sequentially ejected from all channels.

In the above-described embodiment, the configuration using the chevron type as the actuator plate 50 has been described, but the present invention is not limited to this. That is, a monopole type actuator plate (polarization direction is one direction in the thickness direction) may be used.

In the above-described embodiment, the actuator plate 50 includes a connection region Rc to which the external substrate 45 is connected, but the present invention is not limited to this. For example, the actuator plate 50 may not include the connection region Rc. For example, the connection region Rc may be provided on a substrate other than the actuator plate 50 such as the cover plate 60.

In the above-described embodiment, the configuration in which the head tip 40 is joined to the actuator plate 50 and includes a cover plate 60 having ink flow paths Lp1 and Lp2 communicating with the injection channel 51 has been described, but the present invention is not limited to this. For example, the head tip 40 does not have to include the cover plate 60. For example, the head tip 40 may include a flow path plate that is joined to the actuator plate 50 and has an ink flow path that communicates with the injection channel 51.

In the above-described embodiment, an example of using a mask Ma formed of a water-soluble resin that can be removed with a solution containing water has been described in the method for producing a head chip, but the present invention is not limited to this. For example, a release agent may be used as the solution, and a resist film may be used as the mask. For example, when an alkaline aqueous solution such as an aqueous NaOH solution or an organic solvent such as an organic amine or N-methylpyrrolidone is used as the release agent, a dry film resist can be used as the resist film. From the viewpoint of not affecting the protective film, it is preferable to use a solution containing water as the solution and a water-soluble film as the mask.

In the above-described embodiment, an example in which the mask Ma is formed in a film shape has been described, but the present invention is not limited to this. For example, the mask Ma does not have to be formed in the form of a film. For example, the mask Ma may be formed of a liquid or a gas. When forming a mask with a liquid or gas, it is necessary to set up a tent (form a film) on the groove by the tenting method.

In the above-described embodiment, an example in which the mask Ma is arranged so as to straddle the lower surface and the side surface of the actuator plate substrate AW in the mask arrangement step has been described, but the present invention is not limited to this. For example, in the mask arranging step, the mask Ma may be arranged only on the lower surface of the actuator plate substrate AW.

In the above-described embodiment, the protective film 70 is connected to the pair of side surface films 71 along the pair of side walls 54a and the pair of side surface films 71, and is connected to the bottom surface film 72 along the bottom wall 54b and the pair of side surface films 71. Although the description has been given with reference to an example having an open surface film 73 which is connected and is arranged at the opening of the non-injection channel 52, the present invention is not limited to this. For example, the protective film 70 does not have to have at least a part of the pair of side surface films 71, the bottom surface film 72, and the open surface film 73.

In the above-described embodiment, the protective film 70 has been described with reference to an example in which the protective film 70 is formed in the non-injection channel 52 arranged in the connection region Rc, but the present invention is not limited to this. For example, the protective film 70 may not be formed on the non-injection channel 52 arranged in the connection region Rc.

In the above-described embodiment, the head tip 40 has been described with reference to an example including an intermediate plate 42 having an intermediate plate 42 joined to the actuator plate 50 and having a communication hole 42a communicating with the injection channel 51, but the present invention is not limited to this. For example, the head tip 40 may not include the intermediate plate 42.

In the following modification, the same components as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 17 is a cross-sectional view of the protective film 170 according to the modified example of the embodiment. FIG. 17 is a cross-sectional view corresponding to FIG.
In the above-described embodiment, an example (see FIG. 11) in which the lower surface (-Z side surface) of the opening surface film 73 is arranged on substantially the same surface as the lower surface (electrode surface) of the actuator plate 50 has been described. Not limited to. For example, as shown in FIG. 17, the protective film 170 may be arranged inside (+ Z side) in the depth direction of the non-injection channel 52 with respect to the opening of the non-injection channel 52. Specifically, the protective film 170 includes a pair of side surface films 171 along the + Z side of the opening of the non-injection channel 52 in the pair of side walls 54a, a bottom surface film 172 along the bottom wall 54b, and the non-injection channel 52. It may have an opening surface film 173 arranged on the + Z side of the opening.

According to this modification, the protective film 170 is arranged inside the non-injection channel 52 in the depth direction with respect to the opening of the non-injection channel 52, so that the protective film 170 is from outside the opening of the non-injection channel 52. It is possible to suppress the influence of disturbance.

In addition, it is possible to replace the constituent elements in the above-described embodiment with well-known constituent elements without departing from the gist of the present disclosure. Further, each of the above-mentioned modification examples may be combined.

1 ... Inkjet printer (liquid injection recording device)
5,5K, 5C, 5M, 5Y ... Inkjet head (liquid injection head)
40 ... Head tip (liquid injection head tip)
41 ... Nozzle plate 41a ... Nozzle hole 45 ... External board 50 ... Actuator plate 51 ... Injection channel 52 ... Non-injection channel 52h ... End opening 54a ... Side wall 54b ... Bottom wall 56 ... Common electrode (electrode)
57 ... Individual electrode (electrode)
70, 170 ... Protective film 71, 171 ... Side film 72, 172 ... Bottom film 73, 173 ... Open surface film AW ... Actuator plate substrate Ma ... Mask Re1 ... 1st area Re2 ... 2nd area Rc ... Connection area

Claims (12)

A substrate preparation step for preparing a substrate for an actuator plate having an injection channel communicating with a nozzle hole for injecting a liquid and a non-injection channel that does not inject the liquid.
After the substrate preparation step, a mask placement step of using a mask that can be removed with a solution to expose the first region around the nozzle hole and covering the non-injection channel in a second region other than the first region. When,
After the mask placement step, a protective film forming step of forming a protective film that protects the electrode formed on the inner surface of the injection channel from the liquid, and a protective film forming step.
A method for manufacturing a liquid injection head tip, comprising a mask removing step of removing the mask with the solution after the protective film forming step. The solution contains water and
The method for manufacturing a liquid injection head tip according to claim 1, wherein the mask is made of a water-soluble resin. The method for manufacturing a liquid injection head tip according to claim 2, wherein the mask contains polyvinyl alcohol. The method for manufacturing a liquid injection head tip according to any one of claims 1 to 3, wherein the mask is formed in a film shape. The substrate for the actuator plate is
A first surface on which a nozzle plate with a nozzle hole communicating with the injection channel is arranged,
It has a second surface that intersects the first surface and has an end opening of the non-injection channel.
The method for manufacturing a liquid injection head chip according to any one of claims 1 to 4, wherein in the mask arranging step, the mask is arranged so as to straddle the first surface and the second surface of the actuator plate substrate. .. The method for manufacturing a liquid injection head chip according to any one of claims 1 to 5, wherein the second region includes a connection region to which an external substrate is connected. An actuator plate comprising an injection channel communicating with a nozzle hole for injecting a liquid and a non-injection channel that does not inject the liquid.
The actuator plate has a protective film that protects the electrodes formed on the inner surface of the non-injection channel.
The protective film is a liquid injection head tip that covers the opening of the non-injection channel. The actuator plate extends in the depth direction of the non-injection channel and is connected to a pair of side walls facing in the width direction of the non-injection channel and the pair of side walls, and faces the bottom of the non-injection channel. With a bottom wall,
The protective film is
A pair of side membranes along the pair of side walls,
A bottom membrane connected to the pair of side membranes and along the bottom wall,
The liquid injection head tip according to claim 7, further comprising an open surface film connected to the pair of side surface films and arranged at the opening of the non-injection channel. The liquid injection head tip according to claim 7 or 8, wherein the protective film is arranged inside the opening of the non-injection channel in the depth direction of the non-injection channel. The actuator plate includes a connection area to which an external substrate is connected.
The liquid injection head chip according to claim 9, wherein the protective film is formed in the non-injection channel arranged in the connection region. A liquid injection head comprising the liquid injection head tip according to any one of claims 7 to 10. A liquid injection recording device including the liquid injection head according to claim 11.

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