JPH06218918A - Droplet ejector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an inkjet printer head having an improved productivity by improving the processing speed in the cutting of the groove forming the ink flow path. [Structure] A plurality of grooves 8 are formed in a piezoelectric ceramic plate 27 by cutting. The grooves 8 are parallel and have the same depth. Then, the metal electrodes 13 are formed on the upper half of both side surfaces of the groove 8. Next, the substrate 41 is bonded to the surface of the piezoelectric ceramic plate 27 opposite to the processed side of the groove 8. A pattern 42 of a conductive layer is formed on the substrate 41 at positions corresponding to the positions of the ink flow paths. Then, the conductive paste 26 is embedded in the groove 8 by the dispenser 25, and the pattern 4 is formed.
2 is formed on. Therefore, the metal electrodes 1 on both sides of the groove 8
3 and the pattern 42 are electrically connected by the conductive paste 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a piezoelectric member,
Grooves forming an ink flow path, drive electrodes formed on both side surfaces of the groove and applied with a voltage to change the volume of the ink flow path, and a wiring pattern for applying a voltage to the drive electrodes And a liquid droplet ejecting apparatus for ejecting ink in the ink flow path by changing the volume of the ink flow path.

[0002]

2. Description of the Related Art Conventionally, as this type of droplet ejecting apparatus,
For example, there is one described in JP-A-2-150355. The schematic configuration will be described below with reference to the drawings. As shown in FIG. 4, the inkjet printer head 1 includes a piezoelectric ceramic plate 2, a cover plate 3, a nozzle plate 31, and a substrate 41.

The piezoelectric ceramic plate 2 is made of a lead zirconate titanate (PZT) -based ceramic material having ferroelectricity. The piezoelectric ceramic plate 2 is polarized in the polarization direction 5. Next, as shown in FIG.
As shown in, the diamond cutting disk 30 is rotated to perform cutting. During this cutting, the cutting direction of the diamond cutting disk 30 is 30A,
It is changed to 30B and 30C.

The groove 8 is formed by the cutting direction 30A of the diamond cutting disk 30. The width of the groove 8 is 7
The thickness is about 0 to 100 μm, and the depth is 300 to 500 μm in order to obtain a sufficient volume change of the ink flow path for ejecting an ink droplet, to the piezoelectric ceramic plate 2 having a thickness of 1 mm. It is about a meter. Subsequently, the cutting direction is changed from 30A to 30B, and the depth of cutting is changed. Then, the cutting direction is changed from 30B to 30C to form the shallow groove 16. The depth of the shallow groove 16 is about 10 to 50 micrometers.

As shown in FIG. 4, a plurality of grooves 8 and shallow grooves 16 are formed in the piezoelectric ceramic plate 2 cut in this way. The grooves 8 are of the same depth and are parallel. The shallow grooves 16 are formed near the one end surface 15 of the piezoelectric ceramic plate 2. Further, the side wall 11 which is the side surface of the groove 8 is polarized in the direction of arrow 5 by the polarization treatment.

Further, metal electrodes 13 and 9 are formed on the side surfaces of the groove 8 and the inner surface of the shallow groove 16 by a vapor deposition method. As shown in FIG. 6, when the metal electrodes 13 and 9 are formed, the piezoelectric ceramic plate 2 is inclined with respect to the vapor emission direction from a vapor deposition source (not shown). When the vapor is discharged, the upper half of the side surface of the groove 8 is generated due to the shadow effect of the side wall 11.
On the inner surface of the shallow groove 16 and the upper surface of the side wall 11, the metal electrodes 13,
9 and 10 are formed. Next, the piezoelectric ceramic plate 2 is rotated 180 degrees, and similarly, the metal electrodes 13,
9 and 10 are formed. After that, the unnecessary metal electrode 10 formed on the upper surface of the side wall 11 is removed by lapping or the like. Thus, the metal electrodes 1 formed on both sides of the groove 8
3 are electrically connected by a metal electrode 9 formed on the inner surface of the shallow groove 16.

Next, the cover plate 3 shown in FIG. 4 is made of a ceramic material, a resin material or the like.
The cover plate 3 has an ink inlet 21 and a manifold 22 formed by grinding or cutting. Then, the surface of the piezoelectric ceramic plate 2 on the groove 8 side and the manifold 22 of the cover plate 3
The surface on the processing side is bonded with an adhesive 4 such as an epoxy adhesive (see FIG. 8). Therefore, in the ink jet printer head 1, the upper surface of the groove 8 is covered, and a plurality of ink flow paths having lateral intervals are formed. Ink is filled in all the ink flow paths.

To the end faces of the piezoelectric ceramic plate 2 and the cover plate 3, a nozzle plate 31 having a nozzle 32 provided at a position corresponding to the position of each ink flow path is bonded. The nozzle plate 31 is formed of a plastic such as polyalkylene (for example, ethylene), terephthalate, polyimide, polyetherimide, polyetherketone, polyethersulfone, polycarbonate, or cellulose acetate.

A substrate 41 is bonded to the surface of the piezoelectric ceramic plate 2 opposite to the processed side of the groove 8 with an epoxy adhesive or the like. Its substrate 41
The conductive layer pattern 42 is formed at a position corresponding to the position of each ink flow path. The conductive layer pattern 42
And the metal electrode 9 on the bottom surface of the shallow groove 16 are connected by a conductive wire 43 by known wire bonding or the like.

Next, the configuration of the control unit will be described with reference to FIG. 7 which is a block diagram of the control unit. The conductive layer patterns 42 formed on the substrate 41 are individually connected to the LSI chip 51. The clock line 52, the data line 53, the voltage line 54, and the ground line 55 are also LS.
It is connected to the I-chip 51. The LSI chip 51 is
Based on the continuous clock pulse supplied from the clock line 52, it is determined from which nozzle 32 the ink droplet should be ejected according to the data appearing on the data line 53. Then, the voltage V of the voltage line 54 is applied to the pattern 42 of the conductive layer electrically connected to the metal electrode 13 (FIG. 8) in the driven ink flow path 12 (FIG. 8). In addition, the metal electrode 1 other than the driven ink channel 12
A voltage of 0 V on the ground line 55 is applied to the pattern 42 of the conductive layer connected to 3.

Next, the operation of the ink jet printer head 1 will be described with reference to FIGS.

The LSI chip 51 causes the ink flow path 12 of the ink jet printer head 1 to follow the required data.
It is determined that ink is ejected from b. Then, a positive drive voltage V is applied to the metal electrodes 13e and 13f via the conductive layer pattern 42 corresponding to the ink flow path 12b and the metal electrode 9, and the metal electrodes 13d and 13g are grounded. As shown in FIG. 9, a driving electric field in the direction of arrow 14b is generated on the side wall 11b, and a driving electric field in the direction of arrow 14c is generated on the side wall 11c. Then, the driving electric field direction 14
Since b and 14c are orthogonal to the polarization direction 4, the side walls 11b and 11c are rapidly deformed inward in the ink flow path 12b due to the piezoelectric thickness slip effect.
Due to this deformation, the volume of the ink flow path 12b is reduced, the ink pressure is rapidly increased, a pressure wave is generated, and an ink droplet is ejected from the nozzle 32 (FIG. 4) communicating with the ink flow path 12b.

When the application of the driving voltage V is stopped,
Since the side walls 11b and 11c gradually return to the positions before deformation (see FIG. 8), the ink pressure in the ink flow path 12b gradually decreases. Then, ink is supplied from the ink supply port 21 (FIG. 4) through the manifold 22 (FIG. 4) into the ink flow path 12b.

In this way, in order to eject ink droplets,
The central portions of the side walls 11 on both sides of the groove 8 are simultaneously deformed toward the inside of the groove 8. Therefore, the metal electrode 13 is formed on the upper half of the side wall 11, and the side walls 11 on both sides of the groove 8 are simultaneously deformed. Side walls 11 on both sides of the groove 8
In order to simultaneously deform the metal electrodes 1 on both sides of the groove 8.
A metal electrode 9 for electrically connecting 3 is provided, and a voltage is applied to the metal electrode 9. Therefore, the shallow groove 16 is formed in order to form the metal electrode 9 for electrically connecting the metal electrodes 13 formed on the upper half of both sides of the groove 8.

[0015]

However, in the above-described ink jet printer head 1, since the shallow groove 16 is formed together with the groove 8, the machining direction of the diamond cutting disk 30 is changed at the time of cutting, so the cutting control is complicated. And the cutting speed is slow. Further, in order to electrically connect the metal electrodes 13 and the patterns 42 formed on both side surfaces of the groove 8, the shallow groove 16 for electrically connecting the metal electrodes 13 on the both side surfaces is formed. 16 of the metal electrode 9 and the pattern 4 of the substrate 41
2 is connected by a wire 43 by wire bonding. Therefore, the metal electrodes 13 and the pattern 4 on both sides are
It takes time to electrically connect the two, and the manufacturing speed of the inkjet printer head 1 slows down,
Productivity deteriorates.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a droplet ejecting apparatus which has a high manufacturing speed and excellent productivity.

[0017]

To achieve this object, according to the present invention, a groove formed in a piezoelectric member to form an ink flow path, and both side surfaces of the groove are formed, and the volume of the ink flow path is increased. A drive electrode to which a voltage is applied to change the ink flow path, and a wiring pattern for applying a voltage to the drive electrode, and by changing the volume of the ink flow path, the ink in the ink flow path is changed. In a liquid droplet ejecting apparatus for ejecting, a conductive paste is provided in a part of the groove in order to apply a voltage to the drive electrodes provided on both side surfaces of the groove at the same time. The electrically conductive paste is provided between both drive electrodes and the wiring pattern for electrical connection.

[0018]

In the present invention having the above structure, the conductive paste provided in a part of the groove and provided between the drive electrodes and the wiring pattern electrically connects the drive electrodes and the wiring pattern. Connecting.

[0019]

An embodiment of the present invention will be described in detail below with reference to the drawings. For convenience, the same parts as those of the conventional example and the equivalent parts are given the same reference numerals,
Detailed description thereof will be omitted.

The piezoelectric ceramic plate 27 shown in FIG.
Is lead zirconate titanate (PZT) with ferroelectricity
Manufactured from ceramic materials. The piezoelectric ceramic plate 27 is a plate having a thickness of about 1 mm which is polarized in the direction of arrow 5. A plurality of grooves 8 are formed on the piezoelectric ceramic plate 27 by cutting the diamond cutting disk 30 (see FIG. 5) by rotation. The grooves 8 are parallel,
And it is the same depth. The grooves 8 have a depth of about 400 μm, a width of about 80 μm, and a pitch of 169 μm.

Then, as described above, the metal electrodes 13 and 10 are formed on the upper halves of both side surfaces of the groove 8 and the upper surface of the side wall 11. Aluminum is used for the metal electrodes 13 and 10.
Nickel or the like is used.

Next, as shown in FIG. 1, a substrate 41 is adhered to the surface of the piezoelectric ceramic plate 27 opposite to the processed side of the groove 8 with an epoxy adhesive or the like. A pattern 42 of a conductive layer is formed on the substrate 41 at positions corresponding to the positions of the ink flow paths.

Then, the conductive paste 26 is filled in the groove 8 by the dispenser 25, and the pattern 42 is formed.
Formed on. At this time, a plurality of dispensers 25 are provided, and the dispensers 25 are arranged above each groove 8. Then, in the conductive paste 26,
Heat is applied by a device (not shown), and the heat causes solidification. As the conductive paste 26, gold paste, silver paste, copper paste or the like is used. The conductive paste 26 is the end portion 15 of the piezoelectric ceramic plate 27.
(See FIG. 4). In addition, the conductive paste 2
6 fills the entire depth of the groove 8. Then, the surplus portion of the conductive paste 26 and the metal electrode 10 on the upper surface of the side wall 11 are formed.
Are removed by wrapping or the like.

Therefore, the metal electrodes 13 and the patterns 42 on both side surfaces of the groove 8 are electrically connected by the conductive paste 26. Therefore, when a voltage is applied to the pattern 42, a voltage is simultaneously applied to the metal electrodes 13 on both sides of the groove 8 through the conductive paste 26, and at the same time, the sidewalls 11 on both sides of the groove 8 are formed as described above. The ink droplets are ejected by deforming inward.

The surface of the piezoelectric ceramic plate 27 on the side where the groove 8 is processed and the surface of the cover plate 3 (FIG. 4) on the side where the manifold 22 (FIG. 4) is processed are formed by an adhesive 4 (see FIG. 8) made of epoxy or the like. To be glued. Therefore, the ink jet printer head 1 has a plurality of ink flow paths 12 (FIG.
Reference) is configured. Then, the ink is filled in all the ink flow paths 12.

Next, a nozzle plate 31 (FIG. 4) having nozzles 32 (FIG. 4) provided at positions corresponding to the positions of the respective ink flow paths 12 is adhered to the end faces of the piezoelectric ceramic plate 27 and the cover plate 3. It

Next, the construction of the ink jet printer will be described with reference to FIG. The ink jet printer head 1 and the ink container 61 described above are joined so that the ink introduction port 21 (FIG. 4) of the ink jet printer head 1 and the inside of the ink container 61 communicate with each other. When the ink inside the ink container 61 is consumed, the ink container 61 is removed from the carriage 62 and replaced with a new one. The carriage 62 reciprocates on the slider 63, and the inkjet printer head 1 prints and records on the recording paper 66 held by the platen 64. The recording paper 66 is moved by the paper feed rollers 65a and 65b in a direction orthogonal to the moving direction of the carriage 62. As a result, the inkjet printer head 1 can print and record on the entire surface of the recording paper 66.

In such an ink jet printer, when ink droplets are ejected, small ink droplets are generated, and a part of the ink droplets adheres to the ink ejection surface of the ink jet printer head 1. If left unattended, ink gradually accumulates on the ink ejection surface, making it impossible to eject ink droplets. Therefore, the carriage 62 moves to the leftmost non-printing area for a proper period after the printing is completed or when the use of the inkjet printer is completed. At this time, the ink ejection surface is engaged with the wiper member 68 provided on the support member 69 fixed to the non-printing area and formed of resin or fiber such as cotton, and moves to the left. By this sliding operation, the ink droplets adhering to the ink ejection surface are removed by the wiper member 68. When a large amount of ink adheres to the wiper member 68, the wiper member 68 is replaced with a new one.

A moving means for moving the wiper member 68 is provided, and the wiper member 68 is provided on the surface of the nozzle plate 31 of the ink jet head 1 moved to the non-printing area.
May be moved and slid.

As described above, since the groove 8 having a constant depth is formed in the piezoelectric ceramic plate 27,
Easy control in cutting and high processing speed.
Therefore, such an inkjet printer head 1
High productivity in mass production.

Further, since the metal paste 13 and the pattern 42 on both sides of the groove 8 are electrically connected by the conductive paste 26, the pattern 42 and the metal electrode 1 on both sides of the groove 8 are electrically connected.
It is easy to electrically connect with 3, and the time required for the connection is short. Therefore, the mass productivity of the inkjet printer head 1 is high.

Furthermore, since the groove 8 is closed at the end portion 15 of the piezoelectric ceramic plate 27 by the conductive paste 26, even if the ink flow path 12 (see FIG. 8) is filled with the ink, the ink is not discharged from the end portion 15. It is never discharged.

Further, since the metal paste 13 and the pattern 42 on both side surfaces of the groove 8 are electrically connected by the conductive paste 26, the connection method can be diversified.

The present embodiment can be modified without departing from the gist of the present invention. For example, the pitch, width, and depth of the grooves 8 formed in the piezoelectric ceramic plate 27 are not specified and are arbitrary.

In this embodiment, the conductive paste 26 is formed in the groove 8 at the end 15 of the piezoelectric ceramic plate 27.
Although it is filled in the groove 42 and provided on the pattern 42 of the substrate 41, it may be filled in a part of the groove 8 and provided on the pattern 42.

Further, in the present embodiment, the conductive paste 26 fills the entire depth of the groove 8 of the piezoelectric ceramic plate 27. However, even if the conductive paste 26 does not fill the entire depth of the groove 8, metal on both side surfaces of the groove 8 is formed. The electrodes 13 may be formed so as to be electrically connected. For example, the conductive paste 26 may be formed up to the sixth minute of the depth of the groove 8. However, in this way, when the ink flow path 12 (see FIG. 8) is filled with ink,
The piezoelectric paste 2 is formed by the conductive paste 26.
Since the effect of not discharging the ink from the end 15 of the groove 7 cannot be obtained, a member for closing the end 15 of the groove 8 is required.

[0037]

As is apparent from the above description, according to the present invention, the drive electrode and the wiring pattern provided in a part of the groove formed in the piezoelectric member and formed on both side surfaces of the groove. Since the conductive paste provided between the two electrically connects the both drive electrodes and the wiring pattern, the cutting speed of the groove is high. In addition, electrical connection between both drive electrodes and the wiring pattern is easy, and the time required for the connection is short. Therefore, the production speed of the liquid ejecting apparatus is high and the productivity is excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a conductive paste forming process of an example of the present invention.

FIG. 2 is an explanatory view showing a forming process of the piezoelectric ceramic plate of the embodiment.

FIG. 3 is a perspective view showing a schematic configuration of an inkjet printer including the inkjet printer head of the embodiment.

FIG. 4 is a perspective view showing the configuration of a conventional inkjet printer head.

FIG. 5 is an explanatory view showing a cutting process of a conventional piezoelectric ceramic plate.

FIG. 6 is an explanatory view showing an electrode forming step of a conventional piezoelectric ceramic plate.

FIG. 7 is an explanatory diagram showing a control unit of a conventional inkjet printer head.

FIG. 8 is a cross-sectional view of a conventional inkjet printer head.

FIG. 9 is an explanatory diagram showing an operating state of a conventional inkjet printer head.

[Explanation of symbols]

 8 groove 12 ink flow path 13 metal electrode 26 conductive paste 27 piezoelectric ceramic plate 32 nozzle 41 substrate 42 pattern

Claims (1)

[Claims] 1. A groove formed in a piezoelectric member to form an ink flow path, a drive electrode formed on both side surfaces of the groove and to which a voltage is applied to change the volume of the ink flow path, A droplet ejecting device that has a wiring pattern for applying a voltage to a drive electrode and ejects ink in the ink flow path by changing the volume of the ink flow path, wherein both side surfaces of the groove are provided. A conductive paste is provided in a part of the groove in order to apply a voltage to the provided drive electrodes at the same time. To electrically connect the drive electrodes and the wiring pattern, both drive electrodes and a wiring pattern are formed. A liquid droplet ejecting apparatus, characterized in that the conductive paste is provided between.