JP4326772B2 - Droplet discharge head, ink cartridge, and ink jet recording apparatus - Google Patents

Description

[0001]
[Industrial application fields]
  The present invention is a droplet discharge head,IThe present invention relates to an ink cartridge and an ink jet recording apparatus.
[0002]
[Prior art]
[Patent Document 1]
JP-A-6-8429
[Patent Document 2]
JP 2001-287371 A
[0003]
As an ink jet head constituting a recording head of an ink jet recording apparatus used as an image recording apparatus (image forming apparatus) such as a printer, a facsimile machine, a copying apparatus, a plotter, etc., as an actuator means for generating energy for pressurizing ink in an ink flow path, A piezoelectric element is used to deform the diaphragm that forms the wall surface of the ink flow path to change the volume of the ink flow path to discharge ink droplets, or a so-called piezo-type one that uses a heating resistor A so-called thermal type in which ink droplets are ejected by pressure generated by heating ink inside and generating bubbles, and a diaphragm and an electrode that form the wall surface of the ink flow path are arranged to face each other. The diaphragm is deformed by the electrostatic force generated between them, thereby changing the volume of the ink flow path and ejecting ink droplets. Such as an electrostatic type are known for.
[0004]
Among these various heads, a nozzle forming member (nozzle plate) having a nozzle opening and a vibration plate are bonded to both surfaces of a spacer (flow path forming member, flow path plate) to generate a pressure generating chamber (liquid Ink jet heads that form a chamber and deform the diaphragm with a piezoelectric element do not use thermal energy as a drive source for flying ink droplets, so there is no deterioration of the ink due to heat, and it is particularly susceptible to deterioration by heat. There is an advantage in discharging color ink. Moreover, since it is possible to freely adjust the ink amount of the ink droplet by adjusting the displacement amount of the piezoelectric vibrator, it is an optimum head for constituting an ink jet recording apparatus for high-quality color printing. .
[0005]
Thus, when manufacturing a head in which the nozzle plate, the flow path plate as the flow path forming member, and the vibration plate are laminated and bonded, the vibration plate and the flow path plate are bonded or the bonding unit and the actuator unit are bonded. Alternatively, highly accurate alignment is required for joining the flow path plate and the nozzle plate.
[0006]
Conventionally, a method using an alignment jig has been widely used, as disclosed in Japanese Patent Application Laid-Open No. 2004-260, in order to align each component member in a head having such a laminated structure. This is achieved by aligning and bonding the vibrator unit with a flow path forming member provided with an ink flow path and a pressure chamber and a reference hole formed in each of the nozzle forming members formed with nozzle holes, and then fixing the vibrator unit. The jig and the pins provided on the jig are aligned and joined with the reference hole.
[0007]
In addition, as described in [Patent Document 2], a method is also proposed in which an uneven step pattern is formed on the bonding surface of the bonding unit and the unevenness is aligned to align and bond. .
[0008]
[Problems to be solved by the invention]
However, in the above-described conventional pin and reference hole, or in a head joined with unevenness, when aligning a substrate on which a fine structure is formed in order to increase the density, it breaks due to the contact of the pin or the convex part. There was a problem that it may be damaged.
[0009]
In addition, since high density and high image quality is required in the ink jet recording apparatus, it is necessary to further improve the bonding accuracy of the head constituent members in the ink jet head having the laminated structure as described above.
[0010]
However, according to the conventional joining method described above, the positional accuracy is limited to a few tens of μm to several tens of μm. For example, in the case of a head with a nozzle pitch of 150 dpi, the positional accuracy is allowed to be about 10 to 15 μm. However, when a head with a nozzle pitch of 200 to 300 dpi is configured, there is a problem that it cannot be handled because a joining accuracy of about several μm to 5 μm is required.
[0011]
The present invention has been made in view of the above problems, and an object thereof is to improve the bonding accuracy in a high-density head.
[0014]
[Means for Solving the Problems]
  In order to solve the above problems, a liquid droplet ejection head according to the present invention includes:
  A flow path forming member made of silicon in which an alignment window including a through hole for positioning is formed;And at least one of the nozzle plate and diaphragmIn a droplet discharge head formed by bonding with an adhesive,
  The through hole that forms the alignment window is a hexagon that has a planar shape and a penetrating portion that is a parallelogram, and the joint surface side opening does not have an acute angle.The pair of opposite sides of the hexagon gradually become smaller and eventually disappear to form the parallelogram.
The configuration.
[0015]
  hereAIt can be set as the structure which has at least 2 or more windows for lements near the pressure chamber longitudinal direction centerline of a flow-path formation member. Further, the through hole forming the alignment window can be configured such that the wall portion of the through portion is entirely formed with the <111> plane.
[0016]
  Also,The flow path forming member is formed of a silicon substrate having a surface orientation (110), and information on the head is represented by a combination of patterns including a parallelogram or a hexagon that is long in the <112> direction or the <111> direction.Can be configured.
[0018]
The ink cartridge according to the present invention is obtained by integrating a droplet discharge head according to the present invention that discharges ink droplets and an ink tank that supplies ink to the head.
[0019]
The ink jet recording apparatus according to the present invention is equipped with the liquid droplet ejection head according to the present invention for ejecting ink droplets or the ink cartridge according to the present invention.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. An ink jet head according to an embodiment of a droplet discharge head of the present invention will be described with reference to FIGS. 1 is an exploded perspective view of the head, FIG. 2 is a cross-sectional view of the head along the longitudinal direction of the liquid chamber, and FIG. 3 is a cross-sectional view of the head along the lateral direction of the liquid chamber.
[0021]
The inkjet head includes a flow path plate 1 which is a flow path forming member formed of a single crystal silicon substrate, a vibration plate 2 bonded to the lower surface of the flow path plate 1, and a nozzle plate bonded to the upper surface of the flow path plate 1. 3, a pressure generating chamber (pressure generating chamber) 6 that is an ink flow path through which a nozzle 4 that ejects ink droplets that are droplets communicates via a nozzle communication path (communication tube) 5, pressure generation An ink supply path 7 which is a liquid supply path having a smaller cross section than the pressure generating chamber 6 communicating with the common liquid chamber 8 which is a liquid supply chamber for supplying ink to the chamber 6 via the ink supply port 9. Forming.
[0022]
An electromechanical conversion element which is a driving means (actuator means) for pressurizing the ink in the pressure generation chamber 6 corresponding to each pressure generation chamber 6 on the outer surface side (surface opposite to the liquid chamber) of the diaphragm 2. The laminated piezoelectric element 12 is bonded, and the piezoelectric element 12 is bonded to the base substrate 13. The base substrate 13 is an insulating substrate such as barium titanate, alumina, forsterite.
[0023]
Also, between the piezoelectric elements 12, support columns 14 are provided corresponding to the partition walls 6 a between the pressure generating chambers 6 and 6. Here, the piezoelectric element member is divided into comb teeth by slitting by half-cut dicing, and each piezoelectric element 12 is formed as a piezoelectric element 12 and a support post portion 14. The structure of the support 14 is the same as that of the piezoelectric element 12, but it is a simple support since no drive voltage is applied.
[0024]
Further, the outer peripheral portion of the diaphragm 12 is joined to the frame member 16 with an adhesive 17 including a gap material. The frame member 16 is formed with a concave portion serving as the common liquid chamber 8 and an ink supply hole 18 (see FIG. 5) for supplying ink to the common liquid chamber 8 from the outside. The frame member 16 is formed by injection molding with, for example, epoxy resin or polyphenylene sulfite.
[0025]
Here, the flow path plate 1 is made of, for example, a single crystal silicon substrate having a crystal plane orientation (110) that is deeply etched by dry etching and a different solution using an etching solution such as a potassium hydroxide aqueous solution (KOH) or a TMAH solution. By using in combination with isotropic etching, the nozzle communication path 5, the pressure generation chamber 6 and the ink supply path 7 are formed with recesses and holes.
[0026]
Then, the pressure generating chamber 6 that becomes a surface in contact with the ink of the flow path plate 1 (wall surface of the liquid flow path) and the wall surfaces of the ink supply path 7 are made of an organic resin film such as an oxide film, a titanium nitride film, or polyimide. A liquid thin film 10 is formed. By forming such a liquid-resistant thin film 10, the flow path plate 10 made of a silicon substrate is less likely to elute with respect to ink, and the wettability is also improved, so that bubbles are less likely to stay and stable droplet ejection is achieved. It becomes possible.
[0027]
In addition, a dummy liquid chamber 11 for releasing the adhesive is formed on the nozzle plate joint surface in the flow path plate 1.
[0028]
The diaphragm 2 is formed from a nickel metal plate, and is manufactured by, for example, an electroforming method (electroforming method). Other metal plates, resin plates, or a joining member between a metal and a resin plate are used. It can also be used.
[0029]
The diaphragm 2 has a thin portion (diaphragm portion) 21 having a thickness of 2 to 10 μm for facilitating deformation at a portion corresponding to the pressure generating chamber 6 and a thick portion (island convex portion) for joining to the piezoelectric element 12. Part) 22 and a thick part 23 is also formed at the part corresponding to the column part 14 and the joint part with the frame member 16, and the flat surface side is adhesively joined to the flow path plate 1. The portion 22 is bonded to the piezoelectric element 12 with an adhesive, and the thick portion 23 is further bonded to the support column 14 and the frame member 16 with an adhesive 17. Here, the diaphragm 2 is formed by nickel electroforming having a two-layer structure. In this case, the diaphragm portion 21 has a thickness of 3 μm and a width of 35 μm (one side).
[0030]
The nozzle plate 3 forms a nozzle 4 having a diameter of 10 to 35 μm corresponding to each pressure generating chamber 6 and is bonded to the flow path plate 1 with an adhesive. The nozzle plate 3 may be made of a metal such as stainless steel or nickel, a combination of metal and resin such as a polyimide resin film, silicon, or a combination thereof. Here, it forms with the Ni plating film | membrane etc. by the electroforming method. Further, the inner shape (inner shape) of the nozzle 4 is formed in a horn shape (may be a substantially cylindrical shape or a substantially frustum shape), and the hole diameter of the nozzle 4 is a diameter on the ink droplet outlet side of about 20 to. 35 μm. Further, the nozzle pitch of each row is 300 dpi, and 600 dpi is obtained by arranging two rows.
[0031]
Further, a water repellent treatment layer having a water repellent surface treatment (not shown) is provided on the nozzle surface (surface in the ejection direction: ejection surface) of the nozzle plate 3. Examples of the water-repellent treatment layer include PTFE-Ni eutectoid plating, fluororesin electrodeposition coating, vapor-deposited fluororesin (e.g., fluorinated pitch), silicon resin / fluorine resin A water-repellent treatment film selected according to the ink physical properties such as baking after solvent application is provided to stabilize the ink droplet shape and flying characteristics so that high-quality image quality can be obtained.
[0032]
The piezoelectric element 12 includes a lead zirconate titanate (PZT) piezoelectric layer 31 having a thickness of 10 to 50 μm / layer, and an internal electrode layer 32 made of silver and palladium (AgPd) having a thickness of several μm / layer. The internal electrodes 32 are alternately stacked, and are electrically connected to the individual electrodes 33 and the common electrode 34 which are the end face electrodes (external electrodes) of the end faces alternately. The pressure generating chamber 6 is contracted and expanded by expansion and contraction of the piezoelectric element 12 whose piezoelectric constant is d33. The piezoelectric element 12 expands when a drive signal is applied and is charged, and contracts in the opposite direction when the charge charged in the piezoelectric element 12 is discharged.
[0033]
Note that the end face electrode on one end face of the piezoelectric element member is divided by dicing by half-cut to form the individual electrode 33, and the end face electrode on the other end face is not divided by the restriction by notching or the like and is divided by all the piezoelectric elements 12. The conductive common electrode 34 becomes conductive.
[0034]
An FPC cable 35 is connected to the individual electrode 33 of the piezoelectric element 12 by solder bonding, ACF (anisotropic conductive film) bonding or wire bonding in order to give a drive signal, and each piezoelectric element 12 is connected to the FPC cable 35. A drive circuit (driver IC) for selectively applying a drive waveform is connected. Further, the common electrode 34 is connected to the ground (GND) electrode of the FPC cable 35 by providing an electrode layer at the end of the piezoelectric element and turning it around.
[0035]
In the ink jet head configured as described above, for example, by applying a drive waveform (pulse voltage of 10 to 50 V) to the piezoelectric element 12 according to a recording signal, displacement in the stacking direction occurs in the piezoelectric element 12 and vibration occurs. Ink in the pressure generating chamber 6 is pressurized through the plate 2 to increase the pressure, and ink droplets are ejected from the nozzle 4.
[0036]
Thereafter, the ink pressure in the pressure generating chamber 6 decreases with the end of ink droplet ejection, and a negative pressure is generated in the pressure generating chamber 6 due to the inertia of the ink flow and the discharge process of the drive pulse, and the ink filling process is started. Transition. At this time, ink supplied from an ink tank (not shown) flows into the common liquid chamber 8 and is filled from the common liquid chamber 8 through the ink supply port 9 through the ink supply path 7 into the pressure generating chamber 6.
[0037]
The ink supply path (fluid resistance portion) 7 has an effect on attenuation of residual pressure vibration after ejection, but is resistant to refilling due to surface tension. By appropriately selecting the fluid resistance value of the ink supply path 7, it is possible to balance the attenuation of the residual pressure and the refill time, and to shorten the time (drive cycle) until shifting to the next ink droplet ejection operation.
[0038]
Accordingly, a structure for aligning the joining position of the flow path plate 1, the vibration plate 2, and the nozzle plate 3 in this ink jet head will be described with reference to FIGS. 4 is an enlarged perspective explanatory view as seen from the vibration plate joint surface side of the alignment mark of the flow path plate, FIG. 5 is an enlarged perspective explanatory view as seen from the nozzle plate joint surface side of the alignment mark of the flow path plate, FIG. FIG. 5 is an enlarged perspective view of an alignment window of a flow path plate.
[0039]
First, in the flow path plate 1 made of a silicon substrate having a plane orientation (110), alignment marks 32 and 32 for positioning at the time of bonding to the vibration plate 2 on the vibration plate bonding surface side are formed at diagonal corners. Each is formed (see FIG. 4), and alignment marks 33, 33 for positioning at the time of joining with the nozzle plate 3 are formed on the joint surface with the nozzle plate 3 at the corners on the diagonal line (FIG. 1). FIG. 5). These alignment marks 32 and 33 are concave or V-groove patterns formed by wet anisotropic etching.
[0040]
In addition, the flow path plate 1 has alignment windows 34 and 34 formed on the longitudinal center line formed of through holes for positioning when the piezoelectric element 12 and the base substrate 13 are bonded in advance to the diaphragm 2. Each is formed. The alignment window 34 is a through hole pattern formed by dry etching and anisotropic etching by wet.
[0041]
In the diaphragm 2, an alignment opening hole 37 for positioning with the flow path plate 1 is formed around the chip on the flow path plate joint surface so as to face the alignment mark 32 of the flow path plate 1. In addition, the nozzle plate 3 is formed with an alignment opening hole 38 for positioning with the flow path plate 1 around the chip at the flow path plate joint surface so as to face the alignment mark 33 of the flow path plate 1. Further, a through hole 39 used for positioning at the time of joining with the actuator unit is formed in the diaphragm 2 corresponding to the alignment window 34 of the flow path plate 1.
[0042]
Therefore, the alignment marks 32 and 33 will be described.
The alignment marks 33 and 32 for positioning when the flow path plate 1 and the nozzle plate 3 or the vibration plate 2 are joined are arranged around the chip. In order to improve the alignment accuracy in the X and Y directions, the diagonal of the chip is arranged. At least two or more are arranged in the direction position. Thus, by providing a plurality of, preferably two, alignment marks in one flow path plate, the joining accuracy in the XY directions is improved, and the flow path plate 1 and the vibration plate 2 or the flow path plate 1 are increased. And the nozzle plate 3 can be joined with high accuracy, excellent discharge characteristics, and reduced quality variation.
[0043]
The size of the alignment marks 33 and 32 is 100 μm × 160 μm, and the shape of the silicon surface is a parallelogram or hexagon formed of <111> and <112> directions.
[0044]
When a silicon wafer having a crystal orientation (110) is used to form an etching mask pattern using a silicon oxide film or a silicon nitride film, and then etched by wet anisotropic etching, all the etched surfaces have a crystal orientation <111>. The shape of the V-shaped groove is obtained by controlling the opening size of the pattern.
[0045]
This shape depends on the size and depth of the etching mask, but as described above, when the mask size is 100 μ × 160 μm, the etching depth is about 50 μm and the V-shaped groove formed by the crystal orientation <111> Is obtained. A V-shaped groove shape is similarly formed on the other side of the alignment mark 32 with the diaphragm 2 or the dummy liquid chamber 11.
[0046]
When performing anisotropic etching on silicon, the pattern obtained by anisotropic etching is limited to those in the direction along the crystal axis, and in the silicon wafer having the crystal orientation (110), the <111> direction and <112> direction The shape is limited to a straight line. Therefore, by using a parallelogram or hexagon formed of the <111> direction and the <112> direction, a pattern can be formed without breaking the shape, and alignment can be performed accurately. Further, since the etching is spontaneously stopped by the V-shaped groove, it is possible to prevent a problem that a deep digging is formed and the strength of the chip is lowered.
[0047]
As described above, the alignment mark is formed in a hexagonal shape or a parallelogram, and all the pattern surfaces of the alignment mark are formed in the crystal orientation <111> plane, so that it is relatively easy and dimensional. An alignment mark having a stable shape can be obtained, and the flow path plate 1 and the vibration plate 2 or the flow path plate 1 and the nozzle plate 3 can be joined with high accuracy, so that the discharge characteristics are excellent and the variation in quality is reduced.
[0048]
By setting the longitudinal dimension of the alignment mark within the range of 50 to 200 μm, the V-shaped groove can be surely formed by etching for forming the pressure generating chamber 6. For this reason, the alignment mark has no (110) etched surface with a large surface roughness, and is composed of the (111) surface. Therefore, an error caused by irregular reflection at a portion with a large surface roughness during image processing for alignment, etc. In addition, high-precision alignment can be performed.
[0049]
With the alignment marks 33 and 32 and the alignment openings 38 and 37 formed by these, the nozzle plate 3 and the flow channel plate 1 or the flow channel plate 1 and the vibration plate 2 are aligned by image recognition through an optical microscope. Go and join. At this time, in order to eliminate problems such as erroneous recognition of images, other silicon etching patterns or silicon steps are not arranged in the range of 100 μm to 500 μm around the alignment marks 33 and 32. As a result, the accuracy of image recognition is improved, and there is no erroneous recognition, and stable joining can be realized.
[0050]
Next, the formation of the alignment window 34 will be described.
The alignment window 34 joins the diaphragm 2 and the flow path plate 1 to the alignment mark provided on the actuator unit when the actuator unit and the unit that joined the diaphragm 2 and the flow path plate 1 are joined. This is a through hole for positioning the unit.
[0051]
A plurality of alignment windows 34 are arranged in the direction in which the pressure generating chamber 6, the nozzle communication path 5, and the dummy liquid chamber 11 are arranged. It is preferable to arrange one on each of the left and right sides of the liquid chamber pattern as close to the center of the chip as possible so as not to reduce the mechanical strength of the chip. As described above, by providing a plurality of, preferably two, alignment windows 34 in one flow path plate, the joining accuracy in the XY directions is improved, and the unit in which the flow path plate 1 and the diaphragm 2 are joined. And the actuator unit can be joined with high accuracy. Further, by arranging the alignment window 34 near the longitudinal center line of the flow path plate, the mechanical strength of the flow path plate is not impaired, the discharge characteristics are excellent, and the quality variation can be reduced.
[0052]
The dimension of this alignment window 34 is about 400 μm × 900 μm, and a through hole is formed by dry etching and anisotropic etching by wet using a hexagonal etching mask pattern. Here, as shown in FIG. 6, the internal cross-sectional shape of the through portion 34 a in the formed through hole is a parallelogram. The silicon outermost surface, that is, the opening surface 34b of the alignment window 34 is formed in a hexagonal pattern. Further, the alignment windows 34 are all formed by the <111> plane.
[0053]
Thus, by forming the surface shape of the alignment window 34 in a hexagonal shape, the adhesive is bonded via the alignment window 34 by capillary action when the flow path plate 1 and the vibration plate 2 or the nozzle plate 3 are joined. It is possible to prevent the adhesive from flowing into the surface (for example, the nozzle plate bonding surface) opposite to the surface (for example, the vibration plate bonding surface). If the adhesive flows into the surface opposite to the adhesive surface, it will cause application failure when the adhesive is applied to the opposite surface, which will cause poor bonding, but it should be shaped as described above. Therefore, it is possible to perform adhesive application and joining without causing such a problem, and the joining reliability is improved.
[0054]
In addition, all the through-holes that make up the alignment window are formed by the crystal orientation <111> plane, so that through-holes with relatively stable dimensions and shapes can be formed with high accuracy with the actuator unit. Bonding becomes possible, excellent discharge characteristics, and variations in quality are reduced.
[0055]
Furthermore, by setting the alignment window 34 to a size of 300 μm or more and 1200 μm or less, highly accurate and stable bonding is possible, excellent discharge characteristics, and variation in quality are reduced.
[0056]
The ink jet head is formed by joining the flow path plate 1, the vibration plate 2, the nozzle plate 3, and the actuator unit as described above. As a generally well-known nozzle arrangement of an ink jet head, each liquid chamber (pressure generating chamber) communicating with the nozzle 4 is arranged in the column direction (short side direction) via a partition wall of 20 μm to 30 μm. In order to improve or stabilize discharge characteristics such as reduction in crosstalk between adjacent pressure generation chambers, it is necessary to join the members and units with high accuracy. On the contrary, there is a margin in positional accuracy in the long side direction of the bit compared with that in the short side direction.
[0057]
Therefore, an example of joining each member and unit on which the alignment mark is formed will be described.
First, the flow path plate 1 and the diaphragm 2 are joined by adhesion. At this time, the alignment mark 32 formed on the flow path plate 1 is positioned and joined through the alignment opening hole 37 provided in the diaphragm chip. Thereafter, positioning is performed by the alignment opening hole 39 of the vibration plate 2 and the alignment mark 40 (see FIG. 1) formed in the actuator unit through the alignment window 34 formed in the flow channel plate 1. 2 joining units and an actuator unit are joined. In this case, since there is a margin in accuracy in the long side direction of the chip, positioning is performed using an attachment jig or the like.
[0058]
Note that the alignment mark of the actuator unit can be provided on the piezoelectric element 12 or the column 14 or can be aligned with the piezoelectric element 12 or the column 14 itself. In the case of alignment with the alignment mark provided on the piezoelectric element or the piezoelectric element itself, the distance in the depth direction from the alignment mark 39 of the diaphragm 2 is small, so that the defocus of the alignment microscope is small and alignment can be performed with higher accuracy. .
[0059]
Next, the nozzle plate 3 is joined to the flow path plate 1 to which the actuator unit is joined. The nozzle plate 3 is positioned and joined by the alignment mark 33 formed on the flow path plate 1 through the alignment opening hole 38 formed in the nozzle plate 3 in the same manner as when the diaphragm 2 is joined. Thereby, the ink jet head of the present invention is constituted.
[0060]
Thus, by providing alignment marks for alignment on the diaphragm joint surface and / or nozzle plate joint surface on the flow path plate, the flow path plate and the diaphragm can be finely joined, and the joining position accuracy is improved. High precision bonding within several μm to 5 μm can be performed, and the flow path plate and nozzle plate can be finely bonded, and the bonding position accuracy can be performed within several μm to 5 μm. And a high-density head with excellent discharge characteristics can be realized.
[0061]
Further, by providing the flow path plate with an alignment window for positioning the joint with the actuator unit, for example, the joining accuracy when joining the unit in which the flow path plate and the vibration plate are joined to the actuator unit can be improved. When joining the actuator unit, the flow path plate, and the unit in which the diaphragm is joined, there is a relatively large margin of joining accuracy in the long side direction of the bit, but joining accuracy within a few μm to 5 μm is required in the short side direction. However, according to the above alignment method, a bonding accuracy within several μm to 5 μm can be realized, a head having excellent ejection characteristics and no variation in quality can be obtained.
[0062]
Next, an embodiment in which a code for chip identification, which is information about the head, is formed on the flow path plate will be described with reference to FIG.
The flow path plate 1 is formed by a wafer process using a silicon wafer. After the structure is formed by the wafer process, it is separated into individual flow path plate chips by the dicing method, but a code is provided in the chip area to identify and manage the individual flow path plate chips after the chip separation. ing.
[0063]
That is, as shown in FIG. 7, a pattern 41 representing a code is formed in the chip area. The pattern 42 is configured by a combination of parallelograms and hexagons that are long or short in the <112> direction or the <111> direction.
[0064]
The formation method of the code pattern 41 is formed by anisotropic etching by wet after forming a parallelogram or hexagonal etching mask pattern in the same manner as the formation method of the alignment marks 32 and 33 described above.
[0065]
In this case, since it is formed in a parallelogram or hexagon that is long in the <112> direction or the <111> direction, the pattern is etched into a V-shaped groove shape by anisotropic etching by wet. In addition, the planes to be constructed are all formed by the crystal orientation <111> plane, and the shape does not collapse. In addition, since the code pattern 41 is configured by a pattern including a long parallelogram or hexagon, the code area can be made smaller than when a number is represented by dots.
[0066]
Thus, by providing a code (representing information about the head) pattern on the flow path plate chip, it becomes possible to manage the flow path plate chip after separation into chips, and in the subsequent head assembly process, Since the history of the manufacturing process of the plate can also be collated, quality can be stabilized, and the crystal orientation <111> plane is used as the plane on which the code pattern is formed, and the dimensions and shape are relatively stable. A pattern can be formed.
[0067]
Next, a manufacturing process according to an embodiment of the method for manufacturing a droplet discharge head of the present invention will be described with reference to FIGS.
First, as shown in FIGS. 8A and 8B, a silicon wafer 61 having a crystal orientation (110) of 400 μm thickness, a silicon oxide film 62 having a thickness of 1.5 μm, and a silicon nitride film having a thickness of 0.1 μm. 63 and a polysilicon film 64 having a thickness of 0.35 μm are sequentially formed. Here, the silicon oxide film 63 is formed by a thermal oxidation method, and the silicon nitride film 63 and the polysilicon film 64 are formed by a low pressure CVD method.
[0068]
Next, as shown in FIG. 4C, wet anisotropic processes such as the nozzle communication path 5, the dummy liquid chamber 11, the alignment mark 33, the alignment window 34, etc. with respect to one wafer surface of the silicon wafer 61 by photolithography. A resist pattern 65 is formed on the portion to be patterned by reactive etching, and then the silicon nitride film 63 and the polysilicon film 64 are etched by dry etching. Then, the resist pattern 65 is peeled off, and a step pattern (required opening 66) is formed in the silicon nitride film 63 and the polysilicon film 64 as shown in FIG.
[0069]
Next, as shown in FIG. 9A, a resist pattern 67 of a portion where through holes such as the nozzle communication path 5 and the alignment window 34 are formed is formed by photolithography. Then, as shown in FIG. 6B, the exposed silicon oxide film 62 is etched by dry etching, and as shown in FIG. 6C, the step pattern of the silicon oxide film 62 (required opening 68). ).
[0070]
Next, as shown in FIGS. 10A to 10D, the pressure generating chamber 6 or ink is applied to the other wafer surface of the silicon wafer 61 using the resist pattern 69 in the same process as described above. A step pattern (required opening 70) is formed in the silicon nitride film 63 and the polysilicon film 64 where the flow path and the alignment mark 32 are formed, and the nozzle communication path 5 and the alignment window are formed using the resist pattern 71. A step pattern (required opening 72) of the silicon oxide film 62 is formed in the part where the through-holes 34 are formed.
[0071]
After that, as shown in FIG. 11A, a resist pattern 73 having an opening in the portion where the nozzle communication path 5 and the alignment window 34 are formed is formed, and etching is performed by dry etching to form a dig 74. . In this case, the etching depth is about 280 μm to 320 μm. Thereafter, the resist pattern 73 is removed as shown in FIG.
[0072]
Next, as shown in FIG. 3C, anisotropic etching of silicon with a potassium hydroxide aqueous solution is performed. As a result, a through hole 75 is formed in a portion where the nozzle communication path 5 and the alignment window 34 are formed, and the outermost polysilicon film 64 is removed and the etching is stopped by the lower silicon nitride film 63. Further, in the portion where the silicon oxide film 62 is exposed, the silicon oxide film 62 has the film-slipping portion 76 to the extent that the etching does not reach the lower silicon surface.
[0073]
Therefore, as shown in FIG. 4D, the silicon oxide film of the above-mentioned film verify portion 76 is removed by dilute hydrofluoric acid to form an opening 77 to expose the surface of the silicon wafer 61.
[0074]
Next, as shown in FIG. 12A, anisotropic etching of silicon with a potassium hydroxide aqueous solution is performed again. As a result, the exposed silicon is etched.
[0075]
In this case, by controlling the dimension of the exposed pattern and the etching depth, it is possible to form a V-shaped groove shape constituted by a region where the crystal orientation <110> plane recedes entirely and the crystal orientation <111> plane. . Depending on the former, the pressure generating chamber 6 or the ink flow path is formed, and depending on the latter, the dummy liquid chamber 11 and the alignment marks 32 and 34 (or the code pattern 41) are formed. In the figure, the pressure generation chamber 6, the nozzle communication path 5, and the dummy liquid chamber 11 are illustrated.
[0076]
Thereafter, as shown in FIG. 6B, the silicon nitride film 63 and the silicon oxide film 62 that have become etching mask layers are removed by phosphoric acid or dilute hydrofluoric acid, and then, as shown in FIG. The silicon oxide film 10 is formed on the outermost surface by thermally oxidizing them.
[0077]
The flow path plate is formed by the manufacturing flow as described above. Thereafter, the silicon wafer state is separated into chips by a dicing method, and individual flow path plates 1 (flow path plate chips) are taken out.
[0078]
Thereafter, using the alignment marks 32 and 33 or the alignment window 34 formed on the flow path plate 1 as described above, the vibration plate chip or the actuator unit is bonded, and the nozzle plate chip is bonded. Complete.
[0079]
In this way, by using dry etching and anisotropic wet etching together to form an alignment mark, alignment window, and code pattern, a head with excellent dimensional control and reproducibility and excellent productivity can be obtained. Can do. That is, in the case of forming only by dry etching, etching characteristics such as variation in etching shape and reproducibility remarkably affect the shape of the through hole. However, by using anisotropic wet etching together, the <111> plane Through holes are formed, and it is possible to form through holes with excellent dimensional control and reproducibility. Further, only dry etching requires a long etching time, but productivity can be improved by using wet etching together.
[0080]
Next, an ink cartridge in which an ink jet head and an ink tank according to the present invention are integrated will be described with reference to FIG.
This ink cartridge (ink tank integrated head) 200 is obtained by integrating an ink jet head 202 according to the present invention having nozzle holes 201 and the like, and an ink tank 203 for supplying ink to the ink jet head 202. .
[0081]
In this way, in the case of an ink tank integrated head, the reliability of the head immediately leads to the overall reliability, so by integrating the head that can be aligned with high accuracy, the reliability that is excellent in ejection characteristics at low cost A highly efficient ink cartridge can be obtained.
[0082]
Next, an example of an ink jet recording apparatus equipped with an ink jet head composed of a droplet discharge head according to the present invention will be described with reference to FIGS. FIG. 14 is a perspective explanatory view of the recording apparatus, and FIG. 15 is a side explanatory view of a mechanism portion of the recording apparatus.
[0083]
This ink jet recording apparatus includes a carriage movable in the main scanning direction inside the recording apparatus main body 211, a recording head comprising the ink jet head according to the present invention mounted on the carriage, an ink cartridge for supplying ink to the recording head, and the like. A paper feed cassette (or a paper feed tray) 214 on which a large number of sheets 213 can be stacked from the front side is detachably attached to the lower part of the apparatus main body 211. In addition, the manual feed tray 215 for manually feeding the paper 213 can be opened, the paper 213 fed from the paper feed cassette 214 or the manual feed tray 215 is taken in, and required by the printing mechanism unit 212. After the image is recorded, it is discharged to a discharge tray 216 mounted on the rear side.
[0084]
The printing mechanism 212 holds the carriage 223 slidably in the main scanning direction with a main guide rod 221 and a sub guide rod 222 which are guide members horizontally mounted on left and right side plates (not shown). (Y), cyan (C), magenta (M), and black (Bk), each of which has a plurality of ink discharge ports, is a head 224 composed of an inkjet head that is a droplet discharge head according to the present invention. They are arranged in a direction crossing the scanning direction and mounted with the ink droplet ejection direction facing downward. Also, each ink cartridge 225 for supplying ink of each color to the head 224 is replaceably mounted on the carriage 223. Note that the ink cartridge according to the present invention, which is the above-described ink tank integrated head, may be mounted.
[0085]
The ink cartridge 225 has an air port that communicates with the atmosphere upward, a supply port that supplies ink to the inkjet head below, and a porous body filled with ink inside, and the capillary force of the porous body. Thus, the ink supplied to the inkjet head is maintained at a slight negative pressure.
[0086]
Further, although the heads 224 of the respective colors are used here as the recording heads, a single head having nozzles for ejecting ink droplets of the respective colors may be used.
[0087]
Here, the carriage 223 is slidably fitted to the main guide rod 221 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the secondary guide rod 222 on the front side (upstream side in the paper conveyance direction). is doing. In order to move and scan the carriage 223 in the main scanning direction, a timing belt 230 is stretched between a driving pulley 228 and a driven pulley 229 that are rotationally driven by a main scanning motor 227, and the timing belt 230 is attached to the carriage 223. The carriage 223 is reciprocally driven by forward and reverse rotation of the main scanning motor 227.
[0088]
On the other hand, in order to convey the sheet 213 set in the sheet feeding cassette 214 to the lower side of the head 224, the sheet feeding roller 231 and the friction pad 232 for separating and feeding the sheet 213 from the sheet feeding cassette 214 and the sheet 213 are guided. A guide member 233, a conveyance roller 234 that inverts and conveys the fed paper 213, a conveyance roller 235 that is pressed against the circumferential surface of the conveyance roller 234, and a leading end that defines a feeding angle of the sheet 213 from the conveyance roller 234 A roller 236 is provided. The transport roller 234 is rotationally driven by a sub-scanning motor 237 via a gear train.
[0089]
A printing receiving member 239 is provided as a paper guide member for guiding the paper 213 fed from the transport roller 234 below the recording head 224 corresponding to the range of movement of the carriage 223 in the main scanning direction. On the downstream side of the printing receiving member 239 in the sheet conveyance direction, a conveyance roller 241 and a spur 242 that are rotationally driven to send the sheet 213 in the sheet discharge direction are provided, and the sheet 213 is further discharged to the sheet discharge tray 216. A roller 243 and a spur 244, and guide members 245 and 246 that form a paper discharge path are disposed.
[0090]
At the time of recording, the recording head 224 is driven according to the image signal while moving the carriage 223, thereby ejecting ink onto the stopped sheet 213 to record one line, and after the sheet 213 is conveyed by a predetermined amount, Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 213 reaches the recording area, the recording operation is terminated and the sheet 213 is discharged.
[0091]
A recovery device 247 for recovering defective ejection of the head 224 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 223. The recovery device 247 includes a cap unit, a suction unit, and a cleaning unit. The carriage 223 is moved to the recovery device 247 side during printing standby and the head 224 is capped by the capping means, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant and stable ejection performance is maintained.
[0092]
When a discharge failure occurs, the discharge port (nozzle) of the head 224 is sealed with a capping unit, and bubbles and the like are sucked out together with ink from the discharge port with a suction unit through the tube. Is removed by the cleaning means to recover the ejection failure. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.
[0093]
As described above, since this inkjet recording apparatus is equipped with a highly reliable inkjet head (or ink cartridge) having excellent ejection characteristics according to the present invention, high-quality recording can be performed.
[0094]
In the above embodiment, the liquid droplet ejection head according to the present invention is applied to an ink jet head. However, a liquid droplet other than ink, for example, a liquid droplet ejection head for ejecting a liquid resist for patterning, a gene analysis sample The present invention can also be applied to a droplet discharge head for discharging.
[0096]
【The invention's effect】
  As described above, according to the droplet discharge head according to the present invention,AThe through-hole forming the window for the lining is a hexagon that has a planar shape and a penetrating portion that is a parallelogram, and the opening on the joint surface side does not have an acute angle.A pair of opposite sides of the hexagon gradually becomes smaller and eventually disappears to form a parallelogram.Since the configuration is adopted, the positioning accuracy is improved, and a highly reliable high-density head excellent in ejection characteristics can be realized.
[0098]
According to the ink cartridge of the present invention, since the liquid droplet ejection head according to the present invention for ejecting ink droplets and the ink tank for supplying ink to this head are integrated, a highly reliable and high density with excellent ejection characteristics An ink cartridge having a head is obtained.
[0099]
According to the ink jet recording apparatus of the present invention, since the liquid droplet ejection head for ejecting ink droplets or the ink cartridge of the present invention is mounted, high quality recording can be performed.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an inkjet head according to an embodiment of a droplet discharge head of the present invention.
FIG. 2 is an explanatory cross-sectional view of the head along the longitudinal direction of the liquid chamber.
FIG. 3 is a cross-sectional explanatory view of a main part along the liquid chamber short direction of the head
FIG. 4 is an enlarged perspective explanatory view of a main part for explaining an alignment mark on the diaphragm joint surface side of the flow path plate of the head.
FIG. 5 is an enlarged perspective explanatory view of a main part for explaining an alignment mark on the nozzle joint surface side of the flow path plate of the head.
FIG. 6 is an enlarged perspective explanatory view of a main part for explaining an alignment window of a flow path plate of the head.
FIG. 7 is an enlarged perspective explanatory view of a main part for explaining a code pattern of a flow path plate of the head.
FIG. 8 is a cross-sectional explanatory view of a flow path forming member manufacturing process illustrating an embodiment of a method of manufacturing a droplet discharge head according to the present invention.
FIG. 9 is an explanatory cross-sectional view illustrating a process following FIG.
FIG. 10 is a cross-sectional explanatory diagram illustrating a process following FIG.
11 is an explanatory cross-sectional view illustrating a process following FIG.
12 is a cross-sectional explanatory diagram illustrating a process following FIG.
FIG. 13 is an explanatory perspective view for explaining the ink cartridge according to the present invention.
FIG. 14 is an explanatory perspective view showing an example of an ink jet recording apparatus equipped with a droplet discharge head according to the present invention.
FIG. 15 is an explanatory side view of a mechanism unit of the recording apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Channel plate, 2 ... Vibration plate, 3 ... Nozzle plate, 4 ... Nozzle, 5 ... Nozzle communication path, 6 ... Pressure generation chamber, 7 ... Ink supply path, 8 ... Common liquid chamber, 10 ... Liquid-resistant thin film , 12 ... piezoelectric element, 13 ... base substrate, 32, 33 ... alignment mark, 34 ... alignment window, 41 ... code pattern, 200 ... ink cartridge, 214 ... recording head.

Claims (6)

It has a flow path forming member made of silicon in which an alignment window consisting of a through hole for positioning is formed, and is formed by joining at least one of the flow path forming member , the nozzle plate and the vibration plate with an adhesive. In the droplet discharge head
Through holes forming the alignment window is a through portion is a parallelogram in plan shape, the bonding surface side opening hexagons having no sharp corners, a pair of sides facing each of said hexagon The droplet discharge head is characterized in that the parallelogram is formed by gradually becoming smaller and finally disappearing .   2. The droplet discharge head according to claim 1, wherein the flow path forming member is sandwiched between a vibration plate and a nozzle plate and laminated and bonded with an adhesive. 3. The droplet discharge head according to claim 1, wherein the through-hole forming the alignment window has a wall portion of the through-portion all formed in a <111> plane. . In the liquid droplet ejecting head according to any one of claims 1 to 3, wherein the flow path forming member is formed of a silicon substrate of plane orientation (110), <112> direction or <111> direction in a long parallelogram or A droplet discharge head, wherein information about the head is represented by a combination of patterns including a hexagon. 5. An ink cartridge in which an ink jet head for ejecting ink droplets and an ink tank for supplying ink to the ink jet head are integrated, wherein the ink jet head is the liquid droplet ejecting head according to any one of claims 1 to 4. Ink cartridge. 6. An ink jet recording apparatus for recording an image by ejecting ink droplets, wherein the droplet ejecting head according to any one of claims 1 to 4 or the ink cartridge according to claim 5 is mounted. An ink jet recording apparatus.

Images