JPH08142325A - Ink jet head and manufacture thereof - Google Patents

Abstract

PURPOSE: To enhance a processing quality in a manufacturing process by a method wherein a tarminated piezoelectric element is divided to a plurality of laminated piezoelectric elements by applying the slitting processing utilizing a dicing saw having an electrocast blade. CONSTITUTION: Slitting processing is applied to a piezoelectric element blade 24 and a surface section of a substrate so as to form a slit groove 27 to the surface section of the substrate by utilizing a dicing saw as a processing machine and an electrocast blade 25 of an electrocast diamond blade as a processing blade. Thereby, the piezoelectric element blade 24 is divided to a plurality of laminated piezoelectric elements 26, 26 to be piezoelectric elements. At that time, electrode patterns 21, 22 are divided corresponding to the individual laminated piezoelectric elements 26, 26. Since an electrode pattern 23 has a groove 3b of the substrate, only a part thereof is polarized and is still in a united condition. The electrocast blade 25 utilized in the processing of the piezoelectric element or the like is formed by a eutectoid plating method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head and a manufacturing method thereof, and more particularly to an ink jet head using a laminated piezoelectric element and a manufacturing method thereof.

[0002]

2. Description of the Related Art The ink jet recording system has attracted attention because it can record without a head coming into contact with a recording paper, the recording process is very simple, and it is suitable for color recording. Conventionally, various methods have been proposed as this ink jet recording method, but at present, a so-called drop-on-demand (DOD) method that ejects ink only when a recording signal is input is predominant. Among the DOD methods, there is a so-called bubble jet method (Japanese Patent Publication No. 61-59913, etc.) that utilizes bubbles generated in ink by thermal energy, and a piezo actuator method that uses a piezoelectric element (Japanese Patent Publication No. 60-8953). Etc.)

In the latter method of manufacturing a piezoelectric actuator type ink jet head, after bonding a laminated piezoelectric element on a substrate, a slit is formed on the surface of the laminated piezoelectric element and the substrate by using a dicing saw to form a plurality of slits. There is known a method of dividing the piezoelectric element into a laminated piezoelectric element (see Japanese Patent Laid-Open No. 3-73347).

[0004]

In the conventional method for manufacturing an ink jet head described above, the blade or the piezoelectric element may be damaged during slit processing of the laminated piezoelectric element by dicing saw. The processing quality is not sufficiently obtained.

The present invention has been made in view of the above points, and an object thereof is to improve the processing quality in the manufacturing process of an ink jet head.

[0006]

In order to solve the above-mentioned problems, in the method of manufacturing an ink-jet head according to a first aspect, a laminated piezoelectric element is bonded to a substrate and then slit processing is performed using a dicing saw. In the method of manufacturing an inkjet head in which the laminated piezoelectric element is divided into a plurality of laminated piezoelectric elements, an electroformed blade is used as a processing blade of the dicing saw.

A method of manufacturing an ink jet head according to a second aspect is the method of manufacturing an ink jet head according to the first aspect, wherein the substrate is made of ceramics.

A method for manufacturing an ink jet head according to a third aspect is the method for manufacturing an ink jet head according to the first or second aspect, wherein the electrocutting blade having a thickness of 20 μm or more is used to make one cutting depth. Slit processing is performed by setting the thickness of the electroformed blade to 50 times or less.

According to a fourth aspect of the present invention, there is provided an ink jet head manufacturing method according to any one of the first to third aspects, wherein the electroformed blade has an abrasive grain size of 20 μm or less.

A method for manufacturing an ink jet head according to a fifth aspect is the method for manufacturing an ink jet head according to any one of the first to fourth aspects, in which a plurality of slits are simultaneously processed by a plurality of the electroformed blades.

A method of manufacturing an ink jet head according to a sixth aspect is the method of manufacturing an ink jet head according to the fifth aspect, wherein the pitch of the plurality of electroformed blades is set to an integral multiple of 2 or more of a pitch of a required slit. .

According to a seventh aspect of the present invention, there is provided an ink jet head manufacturing method according to the fifth aspect, wherein the pitch of the plurality of electroformed blades is set to be equal to a required slit pitch.

According to another aspect of the present invention, there is provided an ink jet head in which a laminated piezoelectric element is bonded to a substrate and then slit processing is performed using a dicing saw to divide the laminated piezoelectric element into a plurality of laminated piezoelectric elements. In, the substrate is Vickers hardness (load 500g)
And is made of ceramics in the range of Hv200 to 2300.

[0014]

In the ink jet head manufacturing method of the first aspect, the processing quality is improved by using the electroformed blade as the processing blade of the dicing saw.

According to a second aspect of the present invention, there is provided a method of manufacturing an ink jet head according to the first aspect, wherein the substrate is made of ceramics. improves.

According to a third aspect of the present invention, there is provided an ink jet head manufacturing method according to the first or second aspect, wherein an electroforming blade having a thickness of 20 μm or more is used to perform electroforming at a single cutting depth. Blade thickness 50
Since the slit processing is performed by setting the number to be equal to or less than twice, the processing yield is improved.

According to a fourth aspect of the present invention, there is provided an inkjet head manufacturing method according to any one of the first to third aspects, wherein the electroformed blade has an abrasive grain size of 20 μm or less. And chipping can be reduced.

A method for manufacturing an ink jet head according to a fifth aspect is the method for manufacturing an ink jet head according to any one of the first to fourth aspects, in which a plurality of electroforming blades simultaneously perform a plurality of slits, so that the machining efficiency is improved. improves.

According to a sixth aspect of the present invention, there is provided an ink jet head manufacturing method according to the fifth aspect, wherein the pitch of the plurality of electroformed blades is set to an integral multiple of 2 or more of a required slit pitch. It is possible to improve processing efficiency while ensuring accuracy.

According to a seventh aspect of the present invention, there is provided a method of manufacturing the ink jet head according to the fifth aspect, wherein the pitch of the electroformed blades is set to be the same as the pitch of the required slits. By ensuring the pitch accuracy of the electroformed blade, it is possible to ensure the same accuracy as one blade.

In the ink jet head of claim 8, the substrate has a hardness of Vvs hardness (load of 500 g) of Hv200.
Since it is made of ceramics within the range of up to 2300, it is possible to reduce damage to the blade during slit processing by dicing saw.

[0022]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is an external perspective view of an inkjet head showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a sectional view taken along the line BB of FIG.

The ink jet head comprises an actuator unit 1 and a liquid chamber unit 2 joined on the actuator unit 1. The actuator unit 1 has two rows of piezoelectric element rows 4 and 4 formed by arranging (arranging) a plurality of laminated piezoelectric elements in rows on an insulating substrate 3.
A frame member 5 surrounding the two piezoelectric element arrays 4 and 4 is bonded by a bonding agent 6. The piezoelectric element array 4 includes a plurality of piezoelectric elements (hereinafter referred to as “driving section piezoelectric elements”) 7, 7 ... To which a driving pulse is applied to make the ink droplets and fly, and the driving section piezoelectric elements 7, 7. A bi-pitch structure in which a plurality of piezoelectric elements (which are referred to as “fixed portion piezoelectric elements”) 8, 8 ... Which are located between and which are simply liquid chamber unit fixing members without being given a drive pulse are arranged alternately. .

The liquid chamber unit 2 comprises a vibrating plate 12 having a diaphragm 11 formed thereon, and a flow of upper and lower liquid chambers using a photosensitive resin film (dry film resist) for forming a pressurized liquid chamber, a common ink flow path and the like. The liquid chamber flow path forming member 13 including the path forming members 13a and 13b is adhered, and the nozzle plate 16 having the plurality of nozzles 15 formed thereon is adhered to the liquid chamber flow path forming member 13. By the vibrating plate 12, the liquid chamber flow path forming member 13 and the nozzle plate 16, a plurality of substantially independent pressurizing liquids each having a diaphragm portion 11 facing each driving portion piezoelectric element 7, 7 ... Of the piezoelectric element array 4. The chamber 17 is formed, and the common ink flow path 18 and the fluid resistance portion 19 that communicate with each pressurized liquid chamber are also formed. The vibrating plate 12 of the liquid chamber unit 2 has the adhesive 20.
Is joined to the actuator unit 1 with high rigidity.

Here, the processing steps of the actuator unit 1 will be described. After forming predetermined electrode patterns 21 to 23 on the substrate 3 as shown in FIG. 4, then, as shown in FIG. The bonding agent 6 is used to form the piezoelectric element plates 24 and 24 formed by stacking the laminated piezoelectric elements in a plate shape.
(See FIG. 2) is used for adhesive bonding.

Then, as shown in FIGS. 6 and 2, a dicing saw is used as a processing machine, and an electroformed blade 25 which is an electroformed diamond blade is used as a processing blade to form a slit groove 27 up to the surface portion of the substrate 3. The piezoelectric element plate 24 and the surface of the substrate 3 are slit so that the piezoelectric element plates 24 and the piezoelectric elements 7 ...
Are divided into a plurality of laminated piezoelectric elements 26, 26. At this time, the electrode patterns 21 and 22 are also divided corresponding to the individual laminated piezoelectric elements 26, 26 ...
Since the electrode pattern 23 has the groove 3b of the substrate 3, only a part of the electrode pattern 23 is divided and remains in the integrated state.

The electroformed blade 25 used for processing the piezoelectric element and the like is formed by the eutectoid plating method. The principle is to put a Ni salt solution and diamond particles in an electroforming tank, to evenly disperse the diamond particles in the solution, and to apply an electric field to the electrode with a conductive base metal set on the negative electrode. Since the Ni metal layer containing diamond particles is deposited on the base metal surface, the metal layer is removed from the base metal surface when it is formed to a predetermined metal layer thickness, and formed into the shape of the blade to be used by machining. .

The electroformed blade manufactured as described above can be formed thin so that the blade thickness can be further increased by the dispersion plating technique.
Moreover, the thinner the blade, the more accurate the blade can be obtained. Further, by using Ni metal as the plating metal, the binder becomes Ni metal, and the strength and rigidity of the blade itself is high, and the abrasive grain holding power is high, and it has a long life and is hard to lose its shape. ing. Therefore, by using the electroformed blade as the processing blade for the thick electric element or the like, it becomes possible to perform precision slit processing, and the processing quality is improved.

When the piezoelectric element (piezoelectric element plate 24) and the surface of the substrate 3 are slit at the same time as described above, when the substrate 3 is made of a resin material or a metal material, a different material is used. Therefore, the damage to the blade 25 at the time of processing becomes large, and it can be said that the resin material and the metal material are not suitable for the processing by the electroformed blade.

Therefore, by using, as the material of the substrate 3, ceramics having material characteristics similar to those of the piezoelectric element, for example, alumina, barium titanate, forsterite, machinable, etc., the processing quality can be improved, and the hardness is preferably. Hv200 with Vickers hardness (load 500g)
By using ceramics within the range of 2300, the processing quality is further improved.

Next, the processing conditions and the like with the electroformed blade will be described. First, when performing fine groove slit processing under a certain fixed mechanical condition, as shown in FIG. 7, the slit width (blade thickness) a of the slit 27 and the slit depth (cutting depth) b are in a relation of a certain ratio. Then it becomes impossible to process. For example, for slit width a = 1, slit depth b = 80
In such a case, as the slit width a becomes smaller, the blade may be damaged due to deformation of the blade during processing, or the workpiece may be damaged.

Therefore, the slit dimensions were fixed, the machining characteristics of the blade itself were changed, and the machine conditions (blade diameter, table feed, spindle rotational speed) were changed, and the following optimum machining conditions were found.

First, in order to evaluate the processing characteristics of the electroformed blade itself, as a commercially available electroformed diamond blade,
Using Ni metal used as a binder, which has a higher hardness (material characteristics) (first type) and a softer type (second type) than the first type, mechanical conditions are used. Slit processing was performed while increasing the slit depth (cutting depth) with respect to a predetermined slit width (slit width = blade thickness) with the constant value set to.

In this case, the electroforming blade of the first type has less wear of the blade itself, and the electroforming blade of the second type has greater wear than the first type. Maintains a certain cutting ability by activating the action. Then, as a result, it was confirmed that the second type electroformed blade was more suitable for deep groove machining than the first type.

Next, regarding the change of the processing conditions, a slitting depth b when processing a slit having a slit width a = 20 μm was set to a: b = 1: 1 to 50, and an experiment for confirming the processing possibility was conducted. Mechanical conditions were used as parameters. The processing conditions at this time are as follows. (1) Specifications of electroformed blade used Blade type: Second type (first type) Blade diameter: 51.2 mm (35 to 60 mm) Blade thickness: 20 μm Diamond particle size: 20 μm or less (2) Machine Conditions (Dicing saw) Spindle speed: 2K-40Krpm Table feed: 0.5-200mm / sec

In this case, the slit width a and the slit depth b
Table 1 shows the evaluation of the processing results when the ratio of 1 was set to 1 (20 μm): 20 (0.4 mm).
Table 2 shows the evaluation of the processing results when (1 mm). In each table, ⊚ indicates a yield of 98% or more, ∘ indicates a yield of 30% or more, and x indicates less than 10%.

[0037]

[Table 1]

[0038]

[Table 2]

As can be seen from these tables, the slit width (blade thickness) a is 20 μm (including 20 μm or more).
And the slit depth b (the depth of one cut) is 50
Slit processing with a (1 mm) is possible by selecting mechanical conditions. In particular, the slit width a = 1 (2
0 μm) depth of cut once (slit depth) b
= 20 (0.4 mm) when set to the ratio,
A yield of 98% or more can be obtained.

Further, according to the experiment, when slitting is performed using an electroformed blade having a thickness of 50 μm or less, the diamond grain size used for the electroformed blade is the machining performance (cutting ability) or the surface condition of the workpiece. Evaluated from 20 μm
The following were suitable for precision slit processing of piezoelectric elements and ceramics.

Next, with respect to the number of blades of the dicing saw used for slit processing, if processing is performed with one blade,
Since the cost of the blade itself becomes high and the processing efficiency is poor, a plurality of blades are used to simultaneously process a plurality of slits. When a plurality of blades, for example, two blades are used as described above, two electroformed blades 2 are formed on the flange 30 via the spacer 31 as shown in FIG. 8 or 9.
Install 5, 25. At this time, two electroformed blades 2
5,25 pitch (blade pitch) Bp and piezoelectric element 3
As for the relationship with the pitch (slit groove pitch) Sp of the slit grooves 34, 34 formed in 3 or the like, the blade pitch Bp is set to an integer multiple of 2 or more with respect to the slit groove pitch Sp (example of FIG. 8), The blade pitch Bp is set to be the same as the slit groove pitch Sp (example in FIG. 9).

Here, in the case of processing by setting the blade pitch Bp of a plurality of electroformed blades to an integer multiple of 2 or more with respect to the slit groove pitch Sp, an inkjet having a normal pitch structure as shown in FIG. A case of manufacturing a head will be described as an example. The inkjet head shown in FIG. 10 has a laminated piezoelectric element 4 on a substrate 41.
2, 42 ... are joined via slit grooves 43, 43.
The pressurizing liquid chamber 46 formed by the liquid chamber forming member 45 is pressed through the vibrating plate 44 to eject the ink droplets 48 from the nozzles 47. The piezoelectric elements 42, 42 divided by the slit groove 43. ... are all used as driving elements.

Therefore, if 64 slit grooves 43 are processed at a slit groove pitch Sp = 0.25 mm using two electroformed blades, the blade pitch Bp is 0.2.
If 5 mm × 32 = 8 mm is set, it suffices to process 32 slit grooves 34 with one electroformed blade 25, and the total feed amount of the electroformed blade 25 at this time is halved. When three electroformed blades are used, the blade pitch Bp is similarly 0.25 mm × 22 = 5.5 m.
If m is set, 22 slit grooves 34 are processed by one electroforming blade 25, and the total feed amount of the electroforming blade 25 at this time is about 1/3. In this case, two extra slit grooves 34 are processed, but there is no practical problem.

In this way, when machining is performed with the blade pitch Bp of a plurality of electroformed blades set to an integer multiple of 2 or more with respect to the slit groove pitch Sp, when two blades are used, one blade is used. On the other hand, the processing time becomes 1/2, and when three blades are used, the processing time becomes 1/3 similarly. In these cases, there are two or three places where an error occurs depending on the size and accuracy of the spacer 31.
It can be done in some places.

Next, a case will be described in which the blade pitch Bp of a plurality of electroformed blades is made equal to the slit groove pitch Sp to manufacture the ink jet head having the bi-pitch structure as in the above-mentioned embodiment. At this time, as shown in FIG. 3, each width A of the driving portion piezoelectric element 7 and the fixed portion piezoelectric element 8
Assuming that w and Pw are 0.075 mm, the width a of the slit groove 27 is 0.05 mm, and the pitch of the piezoelectric elements 7, 7 is 0.25 mm, the two blades 25, 2
The width of the spacer 31 between the five is adjusted to the width Pw of the fixed portion piezoelectric element 8 so that the width Aw of the drive portion piezoelectric element 7 is determined by mechanical feeding. Although there is an error in the width, the width of the driving portion piezoelectric element 7 is not affected, so that it is possible to perform processing with high accuracy. Since the precision of the feed amount of the blade of the dicing saw is 1 μm or less, the drive unit piezoelectric element 7 is controlled by the mechanical feed amount.
There is no inconvenience even if you decide the width of.

In the above embodiment, the ink jet head using the displacement of the laminated piezoelectric element in the d33 direction, which is the same direction as the electric field direction, has been described. However, in the manufacture of the ink jet head using the d31 direction displacement of the direction orthogonal to the electric field direction. Can also be applied. In addition, the description has been given of the example applied to the side shooter type inkjet head in which the opening direction of the nozzle is coaxial with the displacement direction of the piezoelectric element.
The invention can also be applied to an edge shooter type inkjet head in which the nozzle opening direction is orthogonal to the displacement direction of the piezoelectric element.

[0047]

As described above, according to the method of manufacturing an ink jet head of claim 1, since the electroforming blade is used as the processing blade of the dicing saw for slitting the laminated piezoelectric element, the processing quality is high. improves.

According to the manufacturing method of the ink jet head of the second aspect, since the substrate for slit processing together with the piezoelectric element in the dicing saw is made of ceramics, damage of the electroformed blade is reduced and the processing quality is improved.

According to the method of manufacturing an ink jet head of claim 3, an electroforming blade having a thickness of 20 μm or more is used, and the depth of one cut is set to 50 times or less the thickness of the electroforming blade. Since the slit processing is performed, the processing yield is improved.

According to the method of manufacturing an ink jet head of claim 4, since the abrasive grain size of the electroformed blade is set to 20 μm or less, the surface roughness of the machined surface can be improved and the chipping can be reduced, and the yield and further processing can be improved. The quality can be improved.

According to the ink jet head manufacturing method of the fifth aspect, since a plurality of electroforming blades simultaneously perform a plurality of slits, the processing time is shortened and the processing efficiency is improved.

According to the method of manufacturing an ink jet head of claim 6, the pitch of the plurality of electroformed blades is set to an integral multiple of 2 or more of the pitch of the required slits, so that the machining efficiency is improved while ensuring the accuracy. it can.

According to the ink jet head manufacturing method of the seventh aspect, the pitch of the plurality of electroformed blades is set to be the same as the pitch of the required slits, so that the pitch accuracy of the plurality of electroformed blades is ensured. Therefore, it is possible to secure the same accuracy as one blade.

According to the ink jet head of the eighth aspect, the hardness of the substrate is Vickers hardness (load: 500 g).
Since ceramics in the range of Hv200 to 2300 are used, damage to the blade during slit processing by dicing saw can be reduced.

[Brief description of drawings]

FIG. 1 is an external perspective view of an inkjet head showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a perspective view of a substrate used for explaining the processing and assembling steps of the actuator unit.

FIG. 5 is a perspective view showing a state where a piezoelectric element plate is bonded to a substrate used for explaining the same process.

FIG. 6 is a perspective view for explaining the same process.

FIG. 7 is an explanatory diagram for explaining processing conditions for slit processing.

FIG. 8 is an explanatory view of an example using a plurality of electroformed blades.

FIG. 9 is an explanatory view of another example using a plurality of electroformed blades.

10 is a sectional view of an inkjet head having a normal pitch structure, similar to FIG.

[Explanation of symbols]

1 ... Actuator unit, 2 ... Liquid chamber unit, 3 ...
Substrate, 4 ... Piezoelectric element array, 5 ... Frame member, 6 ... Adhesive agent, 7 ... Driving section piezoelectric element, 8 ... Fixed section piezoelectric element, 11 ...
Diaphragm part, 12 ... Vibration plate, 13 ... Liquid chamber flow path forming member, 15 ... Nozzle, 16 ... Nozzle plate, 17 ... Pressurized liquid chamber, 25 ... Electroformed blade, 26 ... Piezoelectric element plate,
27 ... Slit groove, 30 ... Flange of dicing saw,
31 ... Spacer, 33 ... Piezoelectric element, 34 ... Slit groove.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideyuki Makita 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (8)

[Claims] 1. After bonding a laminated piezoelectric element on a substrate,
In an inkjet head manufacturing method for dividing a laminated piezoelectric element into a plurality of laminated piezoelectric elements by performing slit processing using a dicing saw, an inkjet characterized by using an electroformed blade as a processing blade of the dicing saw Head manufacturing method. 2. The method of manufacturing an inkjet head according to claim 1, wherein the substrate is made of ceramics. 3. The method for manufacturing an inkjet head according to claim 1, wherein the electroforming blade having a thickness of 20 μm or more is used, and a cutting depth is 50 times the thickness of the electroforming blade. A method for manufacturing an inkjet head, wherein slit processing is performed by setting the number to be equal to or less than twice. 4. The method of manufacturing an inkjet head according to claim 1, wherein the electroformed blade has an abrasive grain size of 20 μm or less. 5. The method for manufacturing an inkjet head according to claim 1, wherein a plurality of slits are simultaneously formed by a plurality of the electroforming blades. 6. The ink jet head manufacturing method according to claim 5, wherein the pitch of the plurality of electroformed blades is set to an integer multiple of 2 or more of a required slit pitch. Head manufacturing method. 7. The method of manufacturing an inkjet head according to claim 5, wherein the pitch of the electroformed blades is set to be the same as the pitch of the required slits. . 8. After bonding a laminated piezoelectric element on a substrate,
In an inkjet head in which the laminated piezoelectric element is divided into a plurality of laminated piezoelectric elements by performing slit processing using a dicing saw, the substrate has a Vickers hardness (load of 500 g) of ceramics within a range of Hv200 to 2300. An inkjet head characterized by comprising.