The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
As a first embodiment of the invention, a schematic structure and a forming method of a nozzle plate will be described with reference to the following drawings. The nozzle plate includes a truncated cone shape as a tapered shape part and a cylindrical columnar shape disposed at a side adjacent to a small opening diameter of the truncated cone shape.
As shown in
Next, a method for manufacturing the truncated cone shape part 11 and the cylindrical columnar part 12 shown in
First, the nozzle plate material 10a is set to the die 22. Then, the punch 21 is touched to the nozzle plate material 10a and the cylindrical columnar shape part of the punch 21 is forced to penetrate the nozzle plate material 10a. The punched slug 23 produced during the penetration is passed through the hole 23. Through the step, the cylindrical columnar part 12 is formed. Simultaneously, the truncated cone shape part 11 is formed by being pressed with the truncated cone shape of the punch 21. As a result, the nozzle plate 10 (refer to
Since the tip of the droplet guidance part 13 is positioned in the truncated cone shape part 11, a droplet is released at the tip of the droplet guidance part 13 and discharged when the droplet is discharged. The influence of the shape of the droplet guidance part 13 is relaxed in discharging a droplet and a droplet is disposed at a position to be discharged by the droplet guidance part 13 since the droplet is released at the tip. Thus, the droplet is discharged with having straight flying property. As a result, variation in a droplet discharging direction can be suppressed.
An example in which two cylindrical columnar parts, each having a different radius, are disposed in a nozzle plate will be described as a second embodiment with reference to the accompanying drawings.
As shown in
A droplet guidance part 33 having a cylindrical columnar shape as an axisymmetric pattern, shown in
As shown in
Next, a method for manufacturing the first cylindrical columnar part 31 and the second cylindrical columnar part 32, both of which are shown in
First, as shown in
Next, the photoresist layer 36 is removed and a photoresist layer 37 is anew formed as shown in
Additionally, they may be formed, by using a technique described in the first embodiment, with a punch and a die. In this case, a ductile material such as a stainless steel is preferably used as a material for the nozzle plate.
The volume difference or a step at the border between the first cylindrical columnar part 31 and the second cylindrical columnar part 32 may cause an occurrence and gathering of bubbles, adversary affecting discharge stability. Positioning the tip of the droplet guidance part 33 inside the first cylindrical columnar part 31 can reduce the volume difference and control the change of a meniscus position smoothly. As a result, discharge performance and continuous discharge performance can be improved. When a structure is employed in which a bulging part is provided inside the first cylindrical columnar part 31, the volume difference between the first cylindrical columnar part 31 and the second cylindrical columnar part 32 can be suppressed. Further, a tapered shape extending toward a discharging direction of a droplet in the structure can more stabilize the discharging direction.
A third embodiment of the invention will be described below. In the embodiment, a wiring material used for forming a wiring pattern by a droplet discharge method, the droplet discharge method, and a hardening treatment of the wiring material will be described in this order before describing a distinctive method for manufacturing a droplet discharging head.
Wiring Material
As a wiring material for forming a wiring pattern by a droplet discharge method, a dispersed solution is used in which conductive fine particles are dispersed in a dispersion medium. According to the embodiment, examples of the conductive fine particles may include: metal fine particles containing any of gold, silver, copper, iron, chromium, manganese, molybdenum, titanium, palladium, tungsten, and nickel; their oxides; and fine particles of a conductive polymer or a super-conductive material. These conductive fine particles may be used by coating their surfaces with an organic matter or the like to improve their dispersibility. The diameter of the conductive fine particle is preferably in the range from 1 nm to 0.1 μm inclusive. Using conductive fine particles having a diameter 0.1 μm or less can prevent the discharge part of a droplet discharging head from being clogged. Using conductive fine particles having a diameter 1 nun or more can control the volume ratio of a coating agent to the conductive fine particles in an adequate range. As a result, the proportion of an organic matter contained in the resulting film can be controlled in an adequate range.
Here, any dispersion medium can be used as long as it is capable of dispersing the above conductive fine particles and suppressing the aggregation of the particles. As the dispersion medium, the following hydrocarbon compounds can be exemplified: alcohols such as methanol, ethanol, propanol, and butanol; n-heptane, n-octane, decane, dodecane, tetradecane, toluene, xylene, cymene, durene, indene, dipentene, tetrahydronaphthalene, decahydronaphthalene, and cyclohexylbenzene, in addition to water,
The following ether type compounds also can be exemplified: ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, 1,2-dimethoxyethane, bis(2-methoxyethyl) ether, and p-dioxane.
Further, the following polar compounds can be exemplified: propylene carbonate, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethyl formamide, dimethyl sulfoxide, and cyclohexanone.
Water, alcohols, hydrocarbon compounds, and ether compounds are preferably used in terms of particle dispersibility, dispersed solution stability, and applicability to a droplet discharge method. Among others, water and hydrocarbon compounds are more preferably used.
The surface tension of the dispersed solution of the conductive fine particles is preferably within the range from 0.02 N/m to 0.07 N/m inclusive. When a droplet L is discharged by a droplet discharge method, maintaining the surface tension 0.02 N/m or more can suppress the wettability of a functional liquid composition with respect to the surface of the discharge part. As a result, an occurrence of a flight curve can be prevented. In contrast, maintaining the surface tension 0.07 N/m or less can stabilize the meniscus shape at the tip the discharge part. As a result, a discharge amount and discharge timing can be precisely controlled.
In order to adjust the surface tension, a fluorine-, silicone- or nonionic-based surface tension adjuster, for example, may be added in a small amount to the dispersed solution in a range not largely lowering a contact angle with respect to a substrate. The nonionic surface tension adjuster enhances the wettability of a liquid with respect to a substrate, improves the leveling property of a film, and serves to prevent minute concavities and convexity of the film from being formed. The surface tension adjuster may include, if necessary, organic compounds, such as alcohol, ether, ester, and ketone.
The viscosity of the dispersed solution is preferably within the range from 1 mPa·s to 50 mPa·s inclusive. When a liquid material is discharged as the droplet L by using a droplet discharge method, maintaining the viscosity 1 mPa·s or more can prevent a functional liquid from flowing out to the periphery of the discharge part. As a result, contamination can be prevented. In contrast, maintaining the viscosity 50 mPa·s or less prevents the discharge part from being clogged. As a result, a smooth discharge can be achieved.
Droplet Discharge Method
As the discharge technique of a droplet discharge method, an inkjet method is preferably used that can form fine patterns in an on-demand manner. Examples of the inkjet method include electromechanical converting and electrostatic driving methods. The electromechanical converting method utilizes the characteristic of a piezo element (piezoelectric element) that it is deformed in response to a pulsed electric signal. In the method, the deformation of the piezo element applies pressure, via an elastic material, to a space storing a material, pushing the material out of the space to discharge it from a discharge part. In the electrostatic driving method, pressure produced by attractive and repulsive forces of electrostatic charges is applied to a space in which a material is stored via a flexible material so as to push out the material from the space, thereby discharging the material from a discharge part. Other than the above methods, a thermal method using a heater can be used as a droplet discharge method.
The droplet discharge method has an advantage in that a desired amount of a material can be adequately disposed to a desired location with little waste of the material. An amount of a liquid material droplet discharged by the droplet discharge methods is, for example, from 1 to 300 nanograms.
Hardening Treatment of the Wiring Material
A hardening treatment of the wiring material, called as a firing treatment, is usually carried out in the atmosphere. The treatment also can be performed in an environment of an inert gas, such as nitrogen, argon, and helium, if necessary. The processing temperature for the firing treatment will be determined at an appropriate level, taking into account the boiling point (vapor pressure) of the dispersion medium., the type and pressure of the atmospheric gas, thermal behavioral properties such as the dispersibility and oxidizability of fine particles, the existence and volume of coating material, and the base material heat resistance temperature, or the like. In the embodiment, the wiring material is subjected to a firing treatment under the following conditions: at 200° C., for about 60 minutes, and with a clean oven in the atmosphere. Through the above treatment, wiring layers (not shown) can be formed to secure an electrical contact between fine particles.
Such firing treatment can be conducted with a hot plate or an electric furnace. Alternatively, lamp annealing can also be employed. Examples of light sources for lamp annealing are not limited to but include: an infrared lamp, a xenon lamp, YAG laser, argon laser, carbon dioxide laser, and excimier laser of XeF, XeCl, XeBr, KrF, IrCl, ArF, ArCl, or the like. The light sources generally have a power ranging from 10 W to 5000 W inclusive, but for the embodiment it is sufficient to provide the range from 100 W to 1000 W inclusive. As described above, a wiring material is disposed by using a droplet discharge method, and then the wiring material is hardened to form a desired wiring pattern.
As a fourth embodiment, a method for manufacturing a droplet guidance part by using a dry etching method will be described below with reference to the accompanying drawings.
First, as step 1 shown in
Next, as step 2 shown in
Next, as step 3 shown in
With the above etching condition, a droplet guidance part 43 having a conical shape, and a first support 44 are formed as an axisymmetric pattern having a peaked shape. Here, a circular constructional member of the first support 44 can be omitted. For example, it can be removed simultaneously when the silicon substrate 40 is etched in a fun shape of step 2. The constructional member can employ another shape, which will be described later as the fourth modification. When the photoresist layer 42 remains since it is not thoroughly etched during processing the silicon substrate 40 in a tapered form, the remains is removed by an additional step. The droplet guidance part 13, used in the first embodiment and shown in
Alternatively, dry etching may be employed in which used are silicon oxide as a substitute for the silicon substrate 40, a nickel mask as a substitute for the photoresist layer 42, and a mixed gas of carbon tetrafluoride, difluoromethane, and oxygen as an etching gas. Using such materials and gases also can achieve a tapered shape.
As another manner in step 3, a droplet guidance part 45 and a first support 46 shown in
Here, a circular constructional member of the first support 46 can be omitted. For example, it can be removed simultaneously when the silicon substrate 40 is etched in a fun shape of step 2. The constructional member can employ another shape, which will be described later as the fourth modification.
As shown in
Likewise, as shown in
As a fifth embodiment, a method for manufacturing a droplet guidance part by using a light-forming method or an ion beam method will be described below with reference to the accompanying drawings.
First, as step 1 shown in
Next, as step 2 shown in
Then, as step 3 shown in
By repeating the above steps shown in
Here, an ion beam etching may be used for forming complicated structures. Using a transport-positioning mechanism that relatively changes an ion beam irradiation position can form complicated structures. Processing by using ion beams makes it possible to choose metal as a material to be etched. Since metal shows less aging change, a higher reliable droplet guidance part can be formed.
As a sixth embodiment, a structure of a droplet discharging head mounted in a droplet discharging device will be described below with reference to the accompanying drawings.
As shown in
The vibration plate 61 has a material supply hole 66. A material supply device 67 is connected to the material supply hole 66. The material supply device 67 supplies a material N containing a wiring material and the like to the material supply hole 66. The supplied material N fully fills in the liquid reservoir 64 and further fully fills the pressure chambers 63 after passing though the passage 68. In
As shown in
Instead of the first support 75, a support 76 can be used for fixing the droplet guidance part 74 to the vibration plate 61 as shown in
Additionally, the second support 76 can be fixed to a sidewall facing the nozzle plate 59 by changing the position of the vibration plate 61 facing the nozzle plate 59. In this case, a mass addition is avoided that is caused by providing the droplet guidance part 794 and the second support 76 to the vibration plate 61. The droplet guidance part 74 can be supported without influencing a droplet discharge movement.
Additionally, as shown in
A material pressurization member 69 is fixed on a surface, opposite to a surface facing the pressure chamber 63, of the vibration plate 61 so as to correspond the pressure chamber 63. The material pressurization member 69 includes a piezoelectric element 71, and a pair of electrodes 72a and 72b sandwiching the piezoelectric element 71. The piezoelectric element 71 deforms to bulge outwardly as shown with the arrow C by energizing the electrodes 79a and 72b. The deformation increases the volume of the pressure chamber 63. As a result, the material N flows in the pressure camber 63 from the liquid reservoir 64 though the passage 68 by an amount equivalent to the increased volume.
Upon stopping energization to the piezoelectric element 71, the piezoelectric element 71 and the vibration plate 61 are put back to the original shape, resulting in the volume of the pressure chamber 63 being put back to the original. This recovery increases the pressure of the material N inside the pressure chamber 63. As a result, the material N is discharged from the penetration part 70 as a droplet.
Here, the material pressurization member 69 may employ a structure of using electrostatic charges instead of the piezoelectric element. In order to avoid the occurrence of flight curve of the droplet L, and clogging the penetration part 70 and the like, a repellent material layer 73 composed of Ni-tetrafluoroethylene eutectoid plating layer, for example, is formed in the vicinity of the penetration part 70.
Next, a method for manufacturing the droplet discharging head of the embodiment will be simply described with reference to
While the penetration part 710 composed by combining a truncated cone shape and a cylindrical columnar shape is used in the embodiment, the penetration part 70 composed by combining two cylindrical columnar shapes may be used as described in the second embodiment. In addition, the shapes described in a first modification (described later) may also be used. Further, the shape of the droplet guidance part 74 is not limited to a conical shape or a cylindrical columnar shape. The shapes described in the second modification (described later) may also be used.
A droplet discharging device according to a seventh embodiment of the invention will now be described.
The table 103 placing the substrate P is allowed to move and to be positioned in the Y direction by a first moving means 102, and is allowed to oscillate and to be positioned in a θz direction by a motor 104. On the other hand, the droplet discharging head 80 is allowed to move and to be positioned in the X direction by a second moving means, and is allowed to move and to be positioned in the Z direction by a linear motor 108. The droplet discharging head 80 is allowed to oscillate and to be positioned in α,β, and γ directions by motors 105, 106, and 107, respectively. Accordingly, the droplet discharging device 100 can accurately control the position and attitude of a discharge face 81 of the droplet discharging head 80 relative to the substrate P on the table 103.
A capping unit 56, shown in
The droplet discharging device 100 can achieve highly accurate drawings since the droplet discharging head 80 is mounted that can improve the landing position accuracy of the droplet L. When the droplet discharging device 100 is used for a printing device such as an inkjet printer that uses the droplet L as ink, the printing device can improve its printing quality.
First Modification
In the first embodiment, the shape of combining the truncated cone shape part 11 and the cylindrical columnar part 12 shown in
Instead of the above examples, the following exemplified shapes may be employed: a polygon, including a regular polygon, pyramid; a conical shape having a star shape cross-section; and a shape excluding the tip part of a conical shape having a oval shape cross-section. The shape is not limited to a conical shape. A polygon prism including a regular polygon prism, a column having a star shape cross-section, and a column having an oval shape cross-section may be used. Additionally, a shape of connecting columnar and conical shapes in a plurality of numbers may be employed. In this regard, connecting them so as to form a shape tapering towards a droplet discharge side is preferable since the shape allows a droplet to flow without interruption. Further, a uniform or nonuniform groove may de formed inside the conical or columnar shapes.
A shape of connecting a columnar shape having the same cross-section of an area exposed from the above conical shape after cutting off the tip part thereof may be employed for substituting the cylindrical columnar part 12 shown in
Furthermore, the axisymmetric pattern is not necessarily required. A pattern having no symmetric axis of rotation can be used. In this case, a droplet is released from a fixed position of the penetration part upon discharging the droplet. As a result, repeatability of landing position can be improved.
Second Modification
In the first and second embodiments, the droplet guidance part having a conical or a cylindrical columnar shape is described. However, another shape such as a truncated cone shape, which is a shape of excluding the tip part of a conical shape, may be used. Additionally, the following shapes may be used: pyramids of polygons including regular polygons; a conical shape having a star shape cross-section; a conical shape having an oval shape cross-section; and a shape excluding the tip part of the conical shapes. Further, the following shapes may be used: cylindrical columns; polygon columns including regular polygon columns; a column having a star shape cross-section; a column having an oval shape cross-section; and a shape having a bulging part. Furthermore, the axisymmetric pattern is not necessarily required. A pattern having no symmetric axis of rotation can be used. In this case, a droplet is released from a fixed position of the droplet guidance part upon discharging the droplet. As a result, repeatability of landing position can be improved. Further, the above shapes may be used by additionally forming a uniform or nonuniform groove inside thereof. The formed groove enhances a droplet releasing property, making it possible to discharge a droplet with high straight flying property.
Third Modification
In the fourth embodiment, the manufacturing method for forming the droplet guidance part by dry etching is described. The droplet guidance part has a pattern with a peak such as a conical shape or an axisymmetric pattern such as a cylindrical columnar shape. Using the dry etching technique can form various patterns. For example, by only changing the plane shape of the photoresist layer 42 used in step 9, the following shapes can be achieved: polygons including regular polygons; a conical shape having a star shape cross-section, an oval shape cross-section, or the like; and a shape excluding the tip part of a conical shape. Additionally, using a pattern asymmetric to rotation for the shape of the photoresist layer 42, a conical pattern asymmetric to rotation can be achieved.
Likewise, various columnar shapes, each having a cross-section of such as polygons including regular polygons, a star, and an oval shapes can be achieved by performing an anisotropic etching without removing the side surface of the photoresist layer 42 in step 3 of the fourth embodiment. Additionally, using a pattern asymmetric to rotation for the shape of the photoresist layer 42, a columnar pattern asymmetric to rotation can be achieved.
Fourth Modification
The first and second supports are exemplified each of which supports the droplet guidance part mainly with three beams. The number of beams, however, is not limited to three. The droplet guidance part can be supported by other than three beams. For example, single beam, two beams, or more than three beams may be employed. Additionally, the first and second supports are not limited to a shape having a beam. For example, a plane shape having a through hole for a droplet passing through it may be employed.
Each of the first and second supports includes the circular constructional member at a fixing end thereof. The circular constructional member is not essential. For example, employing a shape excluding the constructional member for supporting the droplet guidance part can reduce a fixing area. The shape of the constructional member is not limited to a round shape, a polygon shape such as a triangle and a quadrangle shapes may be used. Additionally, the following exemplified shapes may be used: rectangle, trapezoid, inequilateral triangle, and oval. Among them, quadrangle and rectangular shapes are preferably used since the droplet guidance part can be cut off together with the support by dicing or the like.
The entire disclosure of Japanese Patent Application No. 2006-2811,34, filed on Oct. 16, 2006, is expressly incorporated by reference herein.
Number | Date | Country | Kind |
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2006-281134 | Oct 2006 | JP | national |