JP4852312B2 - Nozzle plate manufacturing method - Google Patents

Description

The present invention relates to a manufacturing how the nozzle plate, in particular, a method of manufacturing a nozzle plate formed of a nozzle for discharging droplets.

  In a print head of an ink jet image forming apparatus, a plurality of nozzles are formed on a nozzle plate that constitutes an ejection surface facing a recording medium. Since the shape of each nozzle that ejects ink droplets onto a recording medium tends to affect the size and ejection speed of ink droplets, the nozzles are required to be processed with high accuracy.

  As a manufacturing method of such a nozzle plate, a processing method using electroforming (hereinafter referred to as electroforming method) is known. The electroforming method has a feature that a nozzle plate can be manufactured at a lower cost than a processing method using a laser beam or a processing method using a press.

  11A to 11C show a conventional nozzle plate manufacturing method by electroforming (hereinafter referred to as a conventional first manufacturing method). First, as shown in FIG. 11A, a patterned photocurable photosensitive resin (hereinafter referred to as a resist) 202 is formed on a metal substrate 200. The planar shape of the resist 202 is circular, and its center substantially coincides with the center of the nozzle to be formed. Next, as shown in FIG. 11B, a metal layer 204 such as nickel plating is grown on the metal substrate 200 by electroforming. When the metal layer 204 exceeds the thickness of the resist 202, the metal layer 204 gradually grows so as to cover the periphery of the resist 202 to form a recess 206 having an inner wall surface having an R-shaped cross section. That is, the metal layer 204 is formed overhanging the resist 202. Finally, when the metal substrate 200 and the resist 202 are peeled from the metal layer 204, the metal layer 204 corresponding to the nozzle plate 260 can be obtained as shown in FIG. The nozzle plate 260 is formed with a nozzle (through hole) 251 having an R-shaped cross section corresponding to the concave portion 206 in FIG.

  As another method of manufacturing a nozzle plate by electroforming (hereinafter referred to as a conventional second manufacturing method), as shown in FIG. 12A, a resist 302 patterned on a metal substrate 300 is substantially omitted. After forming the metal layer 304 on the metal substrate 300 so as to be equal to or lower than the height of the resist 302, the metal substrate 300 and the resist 302 are formed from the metal layer 304 as shown in FIG. There is a method to peel off. The nozzle plate 360 thus obtained is formed with a nozzle 351 whose inner wall surface has a substantially straight cross section (straight shape).

Further, another method of manufacturing a nozzle plate by electroforming (hereinafter referred to as a conventional third manufacturing method) is disclosed in Patent Document 1. According to this document, an opaque metal film is patterned on a transparent substrate, and a resist layer having a thickness of 100 μm made of a photocurable photosensitive resin is formed on the opaque metal film. Next, the resist layer is exposed through the opaque metal film from the transparent substrate side. At this time, the exposure amount for the resist layer is strongly sensitized on the transparent substrate side, and is adjusted so that the exposure amount decreases as it is closer to the opposite side away from the transparent substrate. A tapered (tapered) resist that narrows along the surface is formed. When a metal layer is formed on the opaque metal film and the metal layer is separated from the transparent substrate and the resist, a nozzle plate corresponding to the metal layer can be obtained. The surface on the ink droplet ejection side (ink ejection surface) of such a nozzle plate is the surface opposite to the transparent substrate side of the metal layer.
Japanese Patent Laid-Open No. 10-296982

  However, the conventional nozzle plate manufacturing method using electroforming has the following problems.

  That is, in the first conventional manufacturing method, as shown in FIG. 11C, the nozzle 251 whose inner wall surface has an R-shaped cross-section must be spaced apart from the adjacent nozzles according to the shape. However, there is a limit to increasing the density of the nozzle. Also, the nozzle diameter W is likely to vary due to the variation of the metal layer 204 formed by the electroforming method beyond the thickness of the resist 202, and the flight characteristics such as the size and ejection speed of the ink droplets ejected from the nozzle 251 are likely to be affected. There's a problem.

  In the second conventional manufacturing method, when the patterned resist 302 is formed on the metal substrate 300, as shown in FIG. 13A, the resist layer 306 that is not patterned on the metal substrate 300 is formed. Then, the resist layer 306 is exposed from above. That is, the ultraviolet light 310 is irradiated to the resist layer 306 through the mask 308 in which the hole 308a corresponding to the desired nozzle shape is formed. At this time, part of the ultraviolet light 310 irradiated to the resist layer 306 may be diffused or reflected to the metal substrate 300 below the resist layer 306 in some cases. If development processing is performed at this time, the resist 302 does not have a straight shape like the resist 302 shown in FIG. 12A, but the metal substrate 300 side of the resist 306a becomes wide as shown in FIG. 13B, for example. End up. In such a case, there is a problem that the dimensional accuracy of the nozzle formed is poor and the flying characteristics of the nozzle are not good.

  Further, in the third conventional manufacturing method, as described above, exposure is performed by adjusting the exposure amount for the resist layer having a thickness of 100 μm so that the opposite side of the transparent substrate is smaller than the transparent substrate side. Therefore, there is a problem that the dimensional accuracy of the resist formed in a taper shape is deteriorated due to slight variations in exposure amount and variations during development, and the dimensional accuracy of the entire nozzle is deteriorated.

  In the third conventional manufacturing method, the resist dimensional accuracy is generally better on the base material side. However, in the third conventional manufacturing method, as described above, on the transparent substrate side corresponding to the base material. The surface on the opposite side is the surface on the ink droplet ejection side of the nozzle plate. Therefore, the ink droplet ejection side of the nozzle is formed based on a resist shape having inferior dimensional accuracy compared to the opposite side (transparent substrate side). Therefore, there is a problem that the dimensional accuracy on the ink droplet ejection side of the nozzle is not good, and the flight characteristics such as the ejection amount and ejection speed of the ink droplet ejected from the nozzle are easily affected.

The present invention has been made in view of such circumstances, to provide a manufacturing how the nozzle plate with improved dimensional accuracy of the liquid droplet ejection side of the nozzle.

In order to achieve the above object, the invention according to claim 1 is a method of manufacturing a nozzle plate having nozzles for discharging droplets, wherein an opaque metal film is formed on a transparent substrate by patterning the opaque metal film. A photosensitive resin forming step of forming a photosensitive resin on the opaque metal film, an exposure step of exposing the photosensitive resin from the transparent substrate side, and developing the exposed photosensitive resin a developing step, the opaque metal layer forming step of forming a metal layer on the metal film, comprising: a separation step of separating from said opaque metal layer at least the transparent substrate, wherein the nozzle plate before Symbol metal layer and the opaque metal consists film, the surface of the liquid droplet ejection side of the nozzle plate to provide a method of manufacturing a nozzle plate according to claim Rukoto consists of the opaque metal film.

  According to the present invention, the surface on the droplet discharge side of the nozzle plate is the surface on the side where the transparent substrate is separated in the separation step, and corresponds to the exposure incident side for the photosensitive resin in the exposure step. Compared with the surface, the dimensional accuracy on the droplet discharge side of the nozzle is improved. Thereby, flight characteristics such as the discharge amount and discharge speed of the droplets discharged from the nozzle are improved.

Invention of Claim 2 is a manufacturing method of the nozzle plate of Claim 1, Comprising: In the said exposure process, a wavelength area, exposure amount, and so that the light which advances the inside of the said photosensitive resin may spread At least one of the irradiation angles is controlled.
According to the aspect of claim 2, the nozzle shape having good flight characteristics can be formed by using the tapered shape.

According to a third aspect of the invention, a method of manufacturing a nozzle plate according to claim 1 or claim 2, wherein the thickness of the photosensitive resin is 10 to 50 [mu] m.

  The thickness of the photosensitive resin is preferably 10 to 50 μm, and the dimensional accuracy of the photosensitive resin on the side away from the transparent substrate is good. The dimensional accuracy when the photosensitive resin thickness is 50 μm is ± 5 μm or less, and the dimensional accuracy when the photosensitive resin thickness is 10 μm is ± 1 μm or less.

A fourth aspect of the present invention is the nozzle plate manufacturing method according to any one of the first to third aspects, wherein the opaque metal film has water repellency.

According to the aspect of the fourth aspect, it is not necessary to separately perform the water repellent treatment on the surface of the nozzle plate on the droplet discharge side.

Invention of Claim 5 is a manufacturing method of the nozzle plate of any one of Claim 1 thru | or 4 , Comprising: The thickness of the said opaque metal film is 1 micrometer or more and 5 micrometers or less, It is characterized by the above-mentioned. And

According to the aspect of the fifth aspect, since the straight portion is formed on the droplet discharge side of the nozzle, the discharge direction is stabilized.

  According to the present invention, the surface on the droplet discharge side of the nozzle plate is the surface on the side where the transparent substrate is separated in the separation step, and corresponds to the exposure incident side for the photosensitive resin in the exposure step. Compared with the surface, the dimensional accuracy on the droplet discharge side of the nozzle is improved. Thereby, flight characteristics such as the discharge amount and discharge speed of the droplets discharged from the nozzle are improved.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Overall configuration of inkjet recording apparatus]
FIG. 1 is an overall configuration diagram showing an outline of an ink jet recording apparatus as an image forming apparatus according to the present invention. As shown in FIG. 1, the inkjet recording apparatus 10 includes a printing unit 12 having a plurality of printing heads 12K, 12C, 12M, and 12Y provided for each ink color, and each printing head 12K, 12C, 12M, and 12Y. An ink storage / loading unit 14 for storing ink to be supplied to the paper, a paper feeding unit 18 for supplying the recording paper 16, a decurling unit 20 for removing curling of the recording paper 16, and a nozzle surface of the printing unit 12 (Ink discharge surface)
The suction belt conveyance unit 22 that conveys the recording paper 16 while maintaining the flatness of the recording paper 16, the print detection unit 24 that reads the printing result by the printing unit 12, and the printed recording paper (printed matter) are discharged to the outside. And a paper discharge unit 26 for paper.

  In FIG. 1, a magazine for rolled paper (continuous paper) is shown as an example of the paper supply unit 18, but a plurality of magazines having different paper widths, paper quality, and the like may be provided side by side. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  In the case of an apparatus configuration using roll paper, a cutter 28 is provided as shown in FIG. 1, and the roll paper is cut into a desired size by the cutter 28. The cutter 28 includes a fixed blade 28A having a length equal to or greater than the conveyance path width of the recording paper 16, and a round blade 28B that moves along the fixed blade 28A. The fixed blade 28A is provided on the back side of the print. The round blade 28B is arranged on the print surface side with the conveyance path interposed therebetween. Note that the cutter 28 is not necessary when cut paper is used.

  When multiple types of recording paper are used, an information recording body such as a barcode or wireless tag that records paper type information is attached to the magazine, and the information on the information recording body is read by a predetermined reader. Therefore, it is preferable to automatically determine the type of paper to be used and perform ink ejection control so as to realize appropriate ink ejection according to the type of paper.

  The recording paper 16 delivered from the paper supply unit 18 retains curl due to having been loaded in the magazine. In order to remove this curl, heat is applied to the recording paper 16 by the heating drum 30 in the direction opposite to the curl direction of the magazine in the decurling unit 20. At this time, it is more preferable to control the heating temperature so that the printed surface is slightly curled outward.

  After the decurling process, the cut recording paper 16 is sent to the suction belt conveyance unit 22. The suction belt conveyance unit 22 has a structure in which an endless belt 33 is wound between rollers 31 and 32, and at least a portion facing the nozzle surface of the printing unit 12 and the sensor surface of the printing detection unit 24 is flat. It is configured to make.

  The belt 33 has a width that is greater than the width of the recording paper 16, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 1, an adsorption chamber 34 is provided at a position facing the nozzle surface of the print unit 12 and the sensor surface of the print detection unit 24 inside the belt 33 spanned between the rollers 31 and 32. Then, the suction chamber 34 is sucked by the fan 35 to be a negative pressure, whereby the recording paper 16 on the belt 33 is sucked and held.

  The power of a motor (not shown) is transmitted to at least one of the rollers 31 and 32 around which the belt 33 is wound, so that the belt 33 is driven in the clockwise direction in FIG. The recording paper 16 is conveyed from left to right in FIG.

  Since ink adheres to the belt 33 when a borderless print or the like is printed, the belt cleaning unit 36 is provided at a predetermined position outside the belt 33 (an appropriate position other than the print area). Although details of the configuration of the belt cleaning unit 36 are not shown, for example, there are a method of niping a brush roll, a water absorbing roll, etc., an air blowing method of spraying clean air, or a combination thereof. In the case where the cleaning roll is nipped, the cleaning effect is great if the belt linear velocity and the roller linear velocity are changed.

Although a mode using a roller / nip transport mechanism instead of the suction belt transport unit 22 is also conceivable, when the print area is transported by a roller / nip, the roller comes into contact with the print surface of the paper immediately after printing, so that the image blurs. There is a problem that it is easy. Therefore, as in this example, suction belt conveyance that does not contact the image surface in the printing region is preferable.

  A heating fan 40 is provided on the upstream side of the printing unit 12 on the paper conveyance path formed by the suction belt conveyance unit 22. The heating fan 40 heats the recording paper 16 by blowing heated air onto the recording paper 16 before printing. Heating the recording paper 16 immediately before printing makes it easier for the ink to dry after landing.

  The printing unit 12 is a so-called full-line type head in which line-type heads having a length corresponding to the maximum paper width are arranged in a direction (main scanning direction) orthogonal to the paper transport direction (sub-scanning direction) ( (See FIG. 2).

  As shown in FIG. 2, the print heads 12K, 12C, 12M, and 12Y constituting the printing unit 12 discharge ink over a length that exceeds at least one side of the maximum-size recording paper 16 targeted by the inkjet recording apparatus 10. It is composed of a line type head in which a plurality of outlets (nozzles) are arranged.

  Printing corresponding to each color ink in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side (left side in FIG. 1) along the conveyance direction (paper conveyance direction) of the recording paper 16 Heads 12K, 12C, 12M, and 12Y are arranged. A color image can be formed on the recording paper 16 by discharging the color inks from the print heads 12K, 12C, 12M, and 12Y while the recording paper 16 is conveyed.

  Thus, according to the printing unit 12 in which the full line head that covers the entire width of the paper is provided for each ink color, the recording paper 16 and the printing unit 12 are relatively moved in the paper transport direction (sub-scanning direction). It is possible to record an image on the entire surface of the recording paper 16 by performing this operation only once (that is, by one sub-scan). Accordingly, high-speed printing is possible as compared with a shuttle type head in which the print head reciprocates in a direction (main scanning direction) orthogonal to the paper transport direction, and productivity can be improved.

  In this example, the configuration of KCMY standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink and dark ink are added as necessary. May be. For example, it is possible to add a print head that discharges light ink such as light cyan and light magenta.

  As shown in FIG. 1, the ink storage / loading unit 14 has tanks that store inks of colors corresponding to the print heads 12K, 12C, 12M, and 12Y, and each tank has a pipeline that is not shown. The print heads 12K, 12C, 12M, and 12Y communicate with each other. Further, the ink storage / loading unit 14 includes notifying means (display means, warning sound generating means, etc.) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. is doing.

  The print detection unit 24 includes an image sensor (line sensor or the like) for imaging the droplet ejection result of the print unit 12, and means for checking nozzle clogging and other ejection defects from the droplet ejection image read by the image sensor. Function as.

The print detection unit 24 of this example is composed of a line sensor having a light receiving element array that is wider than at least the ink ejection width (image recording width) by the print heads 12K, 12C, 12M, and 12Y. This line sensor is a photoelectric conversion element (pixel) provided with a red (R) color filter.
A color separation line CCD sensor comprising: an R sensor array in which G is arranged in a line, a G sensor array provided with a green (G) color filter, and a B sensor array provided with a blue (B) color filter It consists of Instead of the line sensor, an area sensor in which the light receiving elements are two-dimensionally arranged can be used.

  The print detection unit 24 reads the test patterns printed by the print heads 12K, 12C, 12M, and 12Y for each color, and detects the ejection of each head. The ejection determination includes the presence / absence of ejection, measurement of dot size, measurement of dot landing position, and the like.

  A post-drying unit 42 is provided following the print detection unit 24. The post-drying unit 42 is means for drying the printed image surface, and for example, a heating fan is used. Since it is preferable to avoid contact with the printing surface until the ink after printing is dried, a method of blowing hot air is preferred.

  When printing on porous paper with dye-based ink, the weather resistance of the image is improved by preventing contact with ozone or other things that cause dye molecules to break by blocking the paper holes by pressurization. There is an effect to.

  A heating / pressurizing unit 44 is provided following the post-drying unit 42. The heating / pressurizing unit 44 is a means for controlling the glossiness of the image surface, and pressurizes with a pressure roller 45 having a predetermined uneven surface shape while heating the image surface to transfer the uneven shape to the image surface. To do.

  The printed matter generated in this manner is outputted from the paper output unit 26. It is preferable that the original image to be printed (printed target image) and the test print are discharged separately. The ink jet recording apparatus 10 is provided with sorting means (not shown) for switching the paper discharge path in order to select the print product of the main image and the print product of the test print and send them to the discharge units 26A and 26B. ing. Note that when the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by a cutter (second cutter) 48. The cutter 48 is provided immediately before the paper discharge unit 26, and cuts the main image and the test print unit when the test print is performed on the image margin. The structure of the cutter 48 is the same as that of the first cutter 28 described above, and includes a fixed blade 48A and a round blade 48B.

  Although not shown, the paper output unit 26A for the target prints is provided with a sorter for collecting prints according to print orders.

[Print head structure]
Next, the structure of the print head will be described. Since the print heads 12K, 12M, 12C, and 12Y provided for each ink color have the same structure, hereinafter, the print head is indicated by reference numeral 50 as a representative thereof.

  FIG. 2 is a plan perspective view showing a structural example of the print head 50. 3 is a cross-sectional view (a cross-sectional view taken along line 3-3 in FIG. 2) showing a three-dimensional configuration of one droplet discharge element (an ink chamber unit corresponding to one nozzle 51).

In order to increase the dot pitch printed on the recording paper surface, it is necessary to increase the nozzle pitch in the print head 50. As shown in FIG. 2, the print head 50 of this example includes a plurality of ink chamber units (droplet discharge elements) including nozzles 51 serving as ink droplet discharge ports and pressure chambers 52 corresponding to the nozzles 51. 53 has a structure in which 53 are arranged in a staggered matrix (two-dimensional), so that the substantial nozzle interval projected so as to be aligned along the longitudinal direction of the print head (direction perpendicular to the paper feed direction) High density (projection nozzle pitch) is achieved.

  The pressure chamber 52 provided corresponding to each nozzle 51 has a substantially square planar shape (see FIG. 2), and nozzles 51 and supply ink inlets (supply ports) are formed at both corners on the diagonal line. ) 54 is provided.

  As shown in FIG. 3, a nozzle plate 60, which is a feature of the present invention, is provided on the nozzle surface (ink ejection surface) 50A of the print head 50. As shown in FIG. A nozzle 51 is provided on the nozzle plate 60. A method for manufacturing the nozzle plate 60 will be described later.

  Further, the pressure chamber 52 communicates with the common flow channel 55 through the supply port 54. The common channel 55 communicates with an ink tank (not shown) as an ink supply source, and the ink supplied from the ink tank is distributed and supplied to each pressure chamber 52 via the common channel 55.

  An actuator 58 having an individual electrode 57 is joined to a pressure plate (common electrode) 56 constituting the top surface of the pressure chamber 52, and an actuator is applied by applying a drive voltage to the individual electrode 57 and the common electrode 56. 58 is deformed to change the volume of the pressure chamber 52, and ink is ejected from the nozzle 51 due to the pressure change accompanying this. For the actuator 58, a piezoelectric body such as a piezoelectric element is preferably used. After ink discharge, new ink is supplied from the common channel 55 to the pressure chamber 52 through the supply port 54.

  As shown in FIG. 4, the large number of ink chamber units 53 having such a structure are fixed along the row direction along the main scanning direction and the oblique column direction having a constant angle θ that is not orthogonal to the main scanning direction. The structure is an array pattern arranged in a grid pattern. With a structure in which a plurality of ink chamber units 53 are arranged at a constant pitch d along a certain angle θ with respect to the main scanning direction, the pitch P of the nozzles projected so as to be aligned in the main scanning direction is d × cos θ. .

  That is, in the main scanning direction, each nozzle 51 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a high-density nozzle configuration in which 2400 nozzle rows are projected per inch (2400 nozzles / inch) so as to be aligned in the main scanning direction.

  When driving a nozzle with a full line head having a nozzle row having a length corresponding to the entire printable width, (1) all the nozzles are driven simultaneously, (2) the nozzles are sequentially moved from one side to the other. (3) The nozzles are divided into blocks, and each block is sequentially driven from one side to the other, etc., and one line or one in the sheet width direction (direction perpendicular to the sheet conveyance direction) Nozzle driving for printing individual strips is defined as main scanning.

  In particular, when the nozzles 51 arranged in a matrix as shown in FIG. 4 are driven, the main scanning as described in the above (3) is preferable. That is, nozzles 51-11, 51-12, 51-13, 51-14, 51-15, 51-16 are made into one block (other nozzles 51-21,..., 51-26 are made into one block, Nozzles 51-31,..., 51-36 as one block,...), And the nozzles 51-11, 51-12,. One line is printed in the width direction of 20.

  On the other hand, by moving the full line head and the paper relative to each other, it is possible to repeatedly print one line formed by the main scanning described above (a line composed of a single row of dots or a line composed of a plurality of rows of dots). This is defined as sub-scanning.

  In implementing the present invention, the nozzle arrangement structure is not limited to the illustrated example. In this embodiment, a method of ejecting ink droplets by deformation of an actuator 58 typified by a piezo element (piezoelectric element) is employed. However, the present invention is limited to a method for ejecting ink. Instead of the piezo method, a thermal jet method in which ink is heated by a heating element such as a heater to generate bubbles and ink droplets are ejected by the pressure may be used.

[Nozzle plate manufacturing method]
Next, a method for manufacturing a nozzle plate, which is a feature of the present invention, will be described.

  FIGS. 5A to 5F are explanatory views showing the manufacturing process of the nozzle plate 60 in the first embodiment. First, as an opaque metal film forming step, as shown in FIG. 5A, an opaque metal film 102 that blocks ultraviolet light is formed on a transparent substrate 100 that transmits ultraviolet light, such as a glass substrate, according to the nozzle shape and nozzle arrangement. Pattern. As a method for patterning the opaque metal film 102, known means such as a photolithography technique is used. The opaque metal film 102 is thin and has a thickness of about 1 μm or less, and its dimensional accuracy is about ± 0.1 μm or less.

  In the next resist layer forming step, as shown in FIG. 5B, a photocurable photosensitive resin layer (resist layer) 104 is formed on the surface of the transparent substrate 100 on the opaque metal film 102 side. In the present embodiment, the thickness of the resist layer 104 is about 10 to 50 μm.

  In the next exposure step, as shown in FIG. 5C, the ultraviolet light 108 is passed through the diffusion plate 106 from the opposite side (transparent substrate side) of the transparent substrate 100 to the side where the opaque metal film 102 is formed. Irradiate. The diffusing plate 106 has a function of converting light passing therethrough into diffused light, and is composed of, for example, a combination of frosted glass or a lens system. Accordingly, the ultraviolet light 108 a that has passed through the diffusion plate 106 becomes diffused light and passes through the transparent substrate 100. The patterned opaque metal film 102 on the transparent substrate 100 functions as a mask and blocks the ultraviolet light 108a in accordance with the patterning shape. On the other hand, since the ultraviolet light 108a that has passed without being blocked by the opaque metal film 102 is diffused light, it passes through the resist layer 104 so as to spread along the irradiation direction.

  Next, as a development step, development processing of the resist layer 104 is performed. Since the exposed portion of the resist layer 104 irradiated with the ultraviolet light 108a undergoes a curing reaction in the exposure step, the unexposed portion of the resist layer 104 is removed when development processing is performed. That is, as shown in FIG. 5D, a reverse-tapered resist 104a is formed on the transparent substrate 100 so that the transparent substrate 100 side is narrow and the opposite side is widened by development processing.

  Next, as a metal layer forming step, a metal layer 110 is formed on the opaque metal film 102 as shown in FIG. The metal layer 110 is formed using a known electroforming method, and is formed of nickel or the like, for example.

  Next, as a separation step, as shown in FIG. 5F, the metal layer 110 and the opaque metal film 102 are separated from the transparent substrate 100 and the resist 104a. In this example, since the shape of the resist 104a is inversely tapered (see FIG. 5E), the transparent substrate 100 is separated after separating the resist 104a. As a result, the nozzle plate 60 composed of the metal layer 110 and the opaque metal film 102 can be obtained. In the nozzle plate 60, a through hole (nozzle) 51 corresponding to the shape of the reverse tapered resist 104a is formed.

Note that the separation order of the transparent substrate 100 and the resist 104a is not particularly limited, and may be appropriately changed according to the shape of the resist 104a. For example, when the resist 104a has a substantially cylindrical shape with almost no taper, the metal layer 110 and the opaque metal film 10 are formed.
The transparent substrate 100 and the resist 104a may be separated from 2 at a time.

  Alternatively, the opaque metal film 102 may be removed from the metal layer 110 as necessary to form the nozzle plate 60 made of the metal layer 110.

  In general, in the resist layer forming step shown in FIG. 5B, the dimensional accuracy tends to decrease as the resist layer 104 formed on the transparent substrate 100 becomes thicker. In the above-described conventional third manufacturing method, the thickness of the resist layer is 100 μm, and the dimensional accuracy of the resist layer on the side away from the transparent substrate is expected to be about ± 10 μm. The thickness of the resist layer 104 in the embodiment is as thin as about 10 to 50 μm, and the dimensional accuracy on the side of the resist layer 104 away from the transparent substrate 100 is about ± 5 or less when the thickness of the resist layer 104 is 50 μm, and 10 μm In this case, it is ± 1 μm or less. Thus, in this embodiment, it is possible to manufacture the nozzle plate 60 with good dimensional accuracy.

  The dimensional accuracy of the resist layer 104 is better on the transparent substrate 100 side than on the side away from the transparent substrate 100. In the present embodiment, the surface on the opaque metal film 102 side of the nozzle plate 60, that is, the surface in contact with the transparent substrate 100 in FIG. 5E is the surface on the ink droplet ejection side of the nozzle plate 60 (ink ejection). Surface) 60A, which is a feature of the present invention. Thus, the dimensional accuracy on the ink droplet ejection side of the nozzle 51 is better than that of the third conventional manufacturing method in which the surface opposite to the transparent substrate 100 side is the ink ejection surface.

  In this embodiment, the patterned opaque metal film 102 on the transparent substrate 100 is used as a mask function in the exposure process. However, the dimensional accuracy is good, and the subsequent development process, metal layer formation process, and separation process. The dimensional accuracy of the nozzle 51 formed through the above process is good.

  Furthermore, in this embodiment, since the ink discharge surface 60A of the nozzle plate 60 is constituted by the opaque metal film 102, the opaque metal film 102 preferably has liquid repellency. When ink mist generated when ink droplets are ejected from the nozzle 51 adheres to the ink ejection surface 60A, it becomes easy to remove with an unillustrated blade or the like. Therefore, the nozzle caused by the ink mist adhering to the ink ejection surface 60A The ejection failure 51 can be prevented.

  FIG. 6 is an explanatory view showing the characteristic part of the exposure process in the method for manufacturing a nozzle plate according to the second embodiment of the present invention. FIG. 7 is a modification of FIG. Since steps other than the exposure step are the same as those in the first embodiment, illustration is omitted.

  In the present embodiment, as shown in FIG. 6, the transparent substrate 100 or the like is disposed substantially perpendicular to the irradiation direction from the light source 112. The light source 112 emits ultraviolet light 108 as parallel light and is controlled by the control means 114. The control means 114 adjusts the wavelength and emission amount of the ultraviolet light 108 emitted from the light source 112 and the irradiation angle according to the material of the resist layer 104 and the like. This makes it possible to form the nozzle 51 having an arbitrary taper angle.

  As shown in FIG. 7, the control unit 114 may control the resist layer 104 side so that the transparent substrate 100 forms a predetermined angle α with respect to the irradiation direction of the light source 112. In this case, the same effect as that shown in FIG. 6 can be obtained.

  FIG. 8 is a side sectional view showing a nozzle plate according to a third embodiment of the present invention. FIG. 9 is a modification of FIG.

In the present embodiment, as shown in FIG. 8, the ink ejection surface 60 </ b> A of the nozzle plate 60 has
A liquid repellent film 116 having liquid repellency is provided. The manufacturing method of the nozzle plate 60 is performed in the same manner as in the first embodiment shown in FIGS. 5A to 5F, and is applied to the surface of the opaque metal film 102 after the separation step (see FIG. 5F) is completed. A liquid repellent film 116 may be formed.

  Further, after removing the opaque metal film 102 together with the metal substrate 100 in the separation step shown in FIG. 5F, a liquid repellent film 116 may be formed on the surface of the metal layer 104 as shown in FIG.

  Due to the liquid repellent film 116 formed on the ink discharge surface 60A of the nozzle plate 60, even if ink mist generated during ink discharge adheres to the ink discharge surface 60A, it can be easily removed by a blade (not shown), and the ink discharge surface 60A. It is possible to prevent the ejection failure of the nozzle 51 due to contamination of the nozzle.

  Although not shown, the opaque metal film 102 may be configured to have liquid repellency. In this case, the step of forming the liquid repellent film 114 as shown in FIGS. 8 and 9 can be omitted. Can be made more efficient.

  FIGS. 10A to 10F are explanatory views showing manufacturing steps of the nozzle plate according to the fourth embodiment. In the fourth embodiment, the thickness of the opaque metal film 102 formed on the transparent substrate 100 in the step shown in FIG. 10A is 1 μm or more and 5 μm or less. The nozzle plate 60 manufactured using such an opaque metal film 102 has a height corresponding to the thickness of the opaque metal film 102 on the ink ejection surface 60A side of the nozzle 51, as shown in FIG. Since the (depth) straight portion 51A is formed, there is an effect that the discharge direction is stabilized.

  When the thickness of the opaque metal film 102 is smaller than 1 μm as in the first embodiment, it does not function as the straight portion 51A and contributes little to the stability in the ejection direction. On the other hand, when the thickness of the opaque metal film 102 is larger than 5 μm, the dimensional variation at the time of patterning increases, and the ink discharge amount and discharge speed of the nozzle 51 are adversely affected. In addition, if the height (depth) of the straight portion 51A is large, the fluid resistance increases, so that the discharge efficiency is deteriorated. Therefore, an embodiment in which the thickness of the opaque metal film 102 is 1 μm or more and 5 μm or less as in the present embodiment is preferable.

  In addition, the resist layer 104 in this embodiment is the same thickness (about 10-50 micrometers) as 1st Embodiment. Further, as in the third embodiment, a liquid repellent film may be formed on the surface of the opaque metal film 102 after the step of FIG. The other steps are the same as those in the first embodiment (see FIG. 5), so the same numbers are assigned and the description is omitted.

Has been described in detail with the production how the nozzle plate of the present invention, the present invention is not limited to the above examples, without departing from the scope of the present invention, it performs various improvements and modifications Of course it is also good.

1 is an overall configuration diagram showing an outline of an embodiment of an ink jet recording apparatus as an image forming apparatus according to the present invention. FIG. 3 is a plan perspective view illustrating a structural example of a print head. It is sectional drawing which follows the 3-3 line in FIG. FIG. 3 is an enlarged detailed view of a part of the print head shown in FIG. 2. (A)-(f) is explanatory drawing showing the manufacturing process of the nozzle plate which concerns on 1st Embodiment. It is explanatory drawing showing the characterizing part of the exposure process in the manufacturing method of the nozzle plate which concerns on 2nd Embodiment. It is a modification of FIG. It is side surface sectional drawing which showed the nozzle plate which concerns on 3rd Embodiment. It is a modification of FIG. (A)-(f) is explanatory drawing showing the manufacturing process of the nozzle plate which concerns on 4th Embodiment. (A)-(c) is explanatory drawing which showed the 1st conventional manufacturing method. (A), (b) is explanatory drawing which showed the 2nd conventional manufacturing method. (A), (b) is explanatory drawing of the problem in the 2nd conventional manufacturing method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device 50 ... Print head 50A ... Nozzle surface 51 ... Nozzle 52 ... Pressure chamber 54 ... Ink supply port 55 ... Common liquid chamber 60 ... Nozzle plate 100 ... Transparent substrate 102 ... Opaque Metal film 104... Resist layer 104 a. Resist 106. Diffuser 108 108 Ultraviolet light 110 Metal layer 112 Light source 114 Control means 116 Liquid repellent film

Claims (5)

A method of manufacturing a nozzle plate on which nozzles for discharging droplets are formed,
An opaque metal film forming step of patterning an opaque metal film on a transparent substrate;
A photosensitive resin forming step of forming a photosensitive resin on the opaque metal film;
An exposure step of exposing the photosensitive resin from the transparent substrate side;
A development step of developing the exposed photosensitive resin;
A metal layer forming step of forming a metal layer on the opaque metal film;
Separating at least the transparent substrate from the opaque metal film,
The nozzle plate is composed of the metal layer and the opaque metal film,
The surface of the liquid droplet ejection side of the nozzle plate production method of Roh nozzle plate characterized in that it is constituted by the opaque metal film. 2. The nozzle plate production according to claim 1, wherein in the exposure step, at least one of a wavelength region, an exposure amount, and an irradiation angle is controlled so that light traveling through the photosensitive resin travels in a spreading direction. Method. The method for producing a nozzle plate according to claim 1 or 2 , wherein the photosensitive resin has a thickness of 10 to 50 µm. Said opaque metal film production method of a nozzle plate according to any one of claims 1 to 3 characterized by having a water repellency. Method of manufacturing a nozzle plate according to any one of claims 1 to 4, wherein the thickness of said opaque metal film is 1μm or more 5μm or less.

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