JP6006992B2 - Multi nozzle plate manufacturing method - Google Patents

Description

  The present invention relates to a method for creating a nozzle plate for an electrostatic discharge type inkjet head, and more particularly to a technique for creating a nozzle plate for an inkjet head having a plurality of nozzles.

Conventionally, in the ink jet printing method, as a drop-on-demand method, a thermal ink jet method in which ink is pushed out and ejected by bubbles generated by a film boiling phenomenon caused by energization of a heating element provided in a nozzle, and a piezoelectric method are used. A piezoelectric ink jet method is known in which ink is ejected by a pressure wave resulting from displacement of an element or the like.
In the piezoelectric ink jet type ink jet head, ink is supplied to the pressure chamber at the same time as the ink is ejected. Therefore, crosstalk due to interference waves transmitted from the ink supply side cannot be eliminated.
On the other hand, the electrostatic discharge type inkjet head has an advantage that crosstalk hardly occurs because ink is drawn out and discharged using an electric field between the charged ink and the substrate.

Conventionally, in order to improve the production efficiency of an electrostatic discharge type inkjet head, a so-called multi-nozzle type nozzle plate having a plurality of nozzles has been proposed (for example, see Patent Document 1).
In this prior art, since the nozzle holes for ejecting ink are provided on the same plane, the ink in the vicinity of the nozzle holes for ejecting, for example, during patterning ejection is not ejected through the nozzle plate surface. The phenomenon of moving to the nozzle occurs.
This is a phenomenon that occurs because the charged ink moves from a nozzle hole with a high potential to a nozzle hole with a low potential due to a potential difference between the nozzle holes. This phenomenon causes variations in the amount of ink discharged between the nozzle holes and the ink. May be a factor that does not discharge.

JP 2005-74635 A

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a variation in ink discharge amount between nozzle holes in a printing apparatus having an electrostatic discharge type inkjet head. It is another object of the present invention to provide a technique capable of preventing non-ejection of ink and performing stable ink ejection.

The present invention has been made to solve the above problems, to the substrate made of semi-conductor or insulating material, forming a plurality of nozzle holes, forming an electrode layer on the inner wall surface of the nozzle hole of the substrate And a step of adhering a mask member using an adhesive on the ink discharge side opening of the nozzle hole of the substrate, and performing dry etching on the ink discharge side surface of the substrate using the mask member as a mask, A method of manufacturing a multi-nozzle plate, comprising: a step of forming a plurality of protruding nozzle portions in a region including the nozzle hole; and a step of removing a mask member on the substrate .

In the case of the multi-nozzle plate manufactured by the method of the present invention, the ink discharge ports of the plurality of nozzle holes are provided on the tops of the protruding nozzle portions provided on the ink discharge side surface of the substrate. Since the nozzle holes are not on the same plane, it is possible to prevent the charged ink from moving to the nozzle holes having a low potential.
As a result, according to the present invention, in a printing apparatus having an electrostatic discharge type inkjet head, it is possible to prevent variations in the amount of ink discharged between nozzle holes and non-discharge of ink and to perform stable ink discharge. I can .
And according to the method of this invention , the multi-nozzle plate mentioned above can be obtained reliably with a simple process.
In particular, the Rukoto to adhere the mask member with the adhesive on the opening of the ink discharge side of the nozzle hole of the substrate, in an etching process after the mask member is disengaged from the edge of the ink ejection port of the nozzle hole This can be prevented.

  According to the present invention, in a printing apparatus having an electrostatic discharge type ink jet head, it is possible to prevent variations in the amount of ink discharged between nozzle holes and ink from being discharged, and to perform stable ink discharge.

(A)-(d): Cross-sectional process drawing which shows the example of the manufacturing method of the nozzle plate which concerns on this invention (the 1) (A)-(d): Section process drawing which shows the example of the manufacturing method of the same nozzle plate (the 2) Schematic configuration diagram showing an example of an electrostatic discharge type printing apparatus according to the present invention

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
1A to 1D are cross-sectional process diagrams (part 1) showing an example of a manufacturing method of a multi-nozzle plate (hereinafter referred to as “nozzle plate”) according to the present invention, and FIG. (D) is sectional process drawing (the 2) which shows the example of the manufacturing method of the nozzle plate.

In the present invention, as shown in FIG. 1A, a substrate 10 made of, for example, glass (SiO ₂ ) is prepared, and the substrate 10 is irradiated with laser light L from one surface side to thereby obtain a substrate. A plurality of (two in this embodiment), that is, first and second nozzle holes 1 and 2 are formed through 10.

  In the case of the present invention, although not particularly limited, the inner wall surfaces 1a and 2a of the first and second nozzle holes 1 and 2 are formed in a tapered shape from the viewpoint of ease of drilling, and the substrate 10 More preferably, the diameter of the opening of the surface 10A on the ink supply side is larger than the diameter of the opening of the surface 10B on the ink discharge side of the substrate 10.

Specifically, the diameter of the opening of the surface 10B on the ink ejection side of the substrate 10 is, for example, 0.04 to 0.15 mm, and the diameter of the opening of the surface 10A on the ink supply side of the substrate 10 is, for example. For example, it is 0.08-0.3 mm.
Moreover, the pitch of the 1st and 2nd nozzle holes 1 and 2 can be applied to 0.05-1 mm between each center.

  Next, for example, by performing sputtering in vacuum, as shown in FIG. 1B, the inner wall surfaces 1a and 2a of the first and second nozzle holes 1 and 2 of the substrate 10 and the surface 10A on the ink supply side. A bonding layer 4 made of, for example, Cr (chrome) is formed thereon.

Here, the reason why Cr is used as the material of the bonding layer 4 is that the adhesiveness with the surface of the substrate 10 is good.
In the case of the present invention, although not particularly limited, it is preferable to set the bonding layer 4 to have a thickness of 100 to 200 nm from the viewpoint of ensuring stable adhesion.

  Further, by performing sputtering in vacuum, as shown in FIG. 1C, the inner wall surfaces 1a and 2a of the first and second nozzle holes 1 and 2 of the substrate 10 and the surface 10A on the ink supply side are formed. A conductive layer 5 made of, for example, Au (gold) is formed on the bonding layer 4.

Here, Au is used as the material of the conductive layer 5 in consideration of organic solvent resistance and resistivity.
In the present invention, although not particularly limited, the thickness of the conductive layer 5 is 200 to 300 nm from the viewpoint of preventing disconnection at the boundary between the ink supply side surface 10A and the ink supply side opening. It is preferable to set so.

  In this embodiment, the bonding layer 4 and the conductive layer 5 constitute an electrode layer 6. Also in this case, the diameter of the opening on the ink supply side of the first and second nozzle holes 1 and 2 is set to be larger than the diameter of the opening on the ink discharge side.

In the case of the present invention, although not particularly limited, from the viewpoint of ensuring more stable ink ejection, the ink in the first and second nozzle holes 1 and 2 is formed after the electrode layer 6 is formed. It is preferable to set so that a conductive layer having a thickness such that the diameter of the opening on the discharge side is 0.01 mm to 0.05 mm, more preferably 0.01 mm to 0.03 mm.
On the other hand, from the same viewpoint, it is preferable to set the diameter of the opening on the ink supply side to be 0.04 to 0.15 mm.

  Thereafter, the electrode layer 6 between the first and second nozzle holes 1 and 2 is cut by dicing (indicated by reference numeral 11), and the first and second insulating layers are insulated from each other as shown in FIG. Two electrode layers 61 and 62 are formed.

  Next, as shown in FIG. 2 (a), the substrate 10 is turned upside down. Further, as shown in FIG. 2 (b), the openings on the ink discharge side of the first and second nozzle holes 1 and 2 are formed. The mask member 20 having a size larger than the diameters of the ink discharge ports 21 and 22 of the first and second nozzle holes 1 and 2 is placed on the edges of the ink discharge ports 21 and 22, respectively.

In the case of the present invention, it is preferable to use beads made of the same material as the substrate 10 serving as a nozzle plate.
The shape of the mask member 20 is not particularly limited, and various shapes such as a spherical shape, an egg shape, a polygonal column shape, a mushroom shape, and the like can be used.

Furthermore, the mask member 20 can be adhered and fixed to the edge portions of the ink discharge ports 21 and 22 of the first and second nozzle holes 1 and 2 using an adhesive. In this case, it is possible to prevent the mask member 20 from being detached from the edge portions of the ink discharge ports 21 and 22 of the first and second nozzle holes 1 and 2 in the next etching step.
In addition, as an adhesive agent, an epoxy type thing can be used suitably, for example.

Thereafter, dry (plasma) etching is performed on the surface 10B on the ink discharge side on the substrate 10 in a vacuum using the above-described mask member 20 as a mask and using, for example, CF ₄ as a reaction gas, as shown in FIG. As shown in c), protruding first and second nozzle portions 31 and 32 are formed in a region including the first and second nozzle holes 1 and 2.

  In the case of the present invention, there is no particular limitation, but from the viewpoint of using beads made of the same material as the nozzle plate, the first and second nozzle portions are formed by isotropic etching with a selection ratio of 1: 1. Preferably, 31 and 32 are formed.

In addition, the height h of the first and second nozzle portions 31 and 32, that is, the distance h between the etched surface 10C of the substrate 10 on the ink ejection side and the top portions of the first and second nozzle portions 31 and 32. Is not particularly limited, but is preferably set to 50 μm or more from the viewpoint of preventing ink flow between the nozzles.
Further, it is preferable that the etched surface 10C of the substrate 10 has a contact angle of 30 degrees or more with respect to the ink to be used (by fluorine resin coating or the like).

  Finally, the substrate 10 is washed with an organic material, and when an adhesive is used, the mask member 20 is removed together with the adhesive, thereby removing the first and first layers as shown in FIG. The ink discharge ports 21 and 22 of the two nozzle holes 1 and 2 obtain the nozzle plate 30 provided on the tops of the protruding nozzle portions 31 and 32 on the etched surface 10C of the substrate 10.

  As described above, according to the nozzle plate 30 of the present embodiment, the ink discharge ports 21 and 22 of the first and second nozzle holes 1 and 2 are etched surfaces 10C on the ink discharge side of the substrate 10. Since the first and second nozzle holes 1 and 2 are not on the same plane, the charged ink moves to the nozzle hole having a low potential. Can be prevented.

FIG. 3 is a schematic configuration diagram illustrating an example of an electrostatic discharge printing apparatus according to the present invention.
As shown in FIG. 3, the electrostatic discharge printing apparatus 50 according to the present embodiment has an inkjet head 53 that is disposed to face a substrate 52 that is placed on a stage 51.

  Here, the stage 51 is grounded, and the substrate 52 placed on the stage 51 is made of a semiconductor (for example, a silicon substrate) or an insulating material (for example, a sapphire substrate or a glass substrate).

The ink-jet head 53 has a main body portion 56 to which ink 55 is supplied from an ink tank 54 having a pressurizing function. The main body portion 56 is provided with the nozzle plate 30 described above.
The first and second nozzle portions 31 and 32 provided on the nozzle plate 30 are filled with ink 55 up to the tip ends of the ink discharge ports 21 and 22 of the first and second nozzle holes 1 and 2.

  As described above, the first and second electrode layers 61 and 62 of the nozzle plate 30 are insulated from each other, and the pulse sources 73 and 74 and the high voltage circuit are connected via the first and second switches 71 and 72. 75 is electrically connected. As a result, a high pulse voltage (for example, about 1 kV) is applied to the first and second electrode layers 61 and 62.

  According to the electrostatic discharge type printing apparatus 50 of the present embodiment, since the nozzle plate 30 described above is included, the variation in the discharge amount of the ink 55 between the first and second nozzle holes 1 and 2 The non-ejection of the ink 55 can be prevented, and the stable ejection of the ink 55 can be performed.

The present invention is not limited to the above-described embodiment, and various changes can be made.
For example, in the above-described embodiment, the case where two nozzle portions are provided on the substrate has been described as an example. However, three or more nozzle portions may be provided.
In this case, the nozzle portions can be arranged linearly or in a staggered manner.

  In the above-described embodiment, the nozzle hole is formed in the substrate by laser irradiation. However, the present invention is not limited to this, and the nozzle hole can be formed in the substrate by etching or die press. .

Furthermore, in the above-described embodiment, the electrode layer is formed by sputtering. However, the present invention is not limited to this, and can be formed by electroless plating, electrolytic plating, vacuum deposition, or CVD.
However, from the viewpoint of ease of processing, it is preferable to form the electrode layer by sputtering as in the above embodiment.

DESCRIPTION OF SYMBOLS 1 ... 1st nozzle hole 1a ... Inner wall surface 2 ... 2nd nozzle hole 2a ... Inner wall surface 4 ... Bonding layer 5 ... Conductive layer 6 ... Electrode layer 10 ... Substrate 21 ... Ink ejection port 22 ... Ink ejection port 30 ... Multi Nozzle plate 31 ... first nozzle part 32 ... second nozzle part 50 ... electrostatic discharge type printing apparatus 61 ... first electrode layer 62 ... second electrode layer

Claims (1)

Forming a plurality of nozzle holes on a substrate made of a semiconductor or an insulating material;
Forming an electrode layer on the inner wall surface of the nozzle hole of the substrate;
A step of adhering the mask member with the adhesive on the opening of the ink discharge side of the nozzle hole of the substrate,
Performing dry etching on the surface of the substrate on the ink ejection side using the mask member as a mask, and forming a plurality of protruding nozzle portions in a region including the nozzle holes;
Removing the mask member on the substrate;
The manufacturing method of the multi-nozzle plate which has.

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