JP3867352B2 - Method for manufacturing piezoelectric substrate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piezoelectric substrate used for an ink jet printer head or the like, and more particularly to a method for manufacturing a piezoelectric substrate having a piezoelectric interference prevention gap on both sides of a built-in piezoelectric element.
[0002]
In recent inkjet printers, in order to enable high-definition printing, an ink flow path is independently movable, and a small and lightweight configuration with a high density ink flow path is required. Piezoelectric substrates having piezoelectric interference prevention gaps on both sides of the element have been used for inkjet printer heads.
[0003]
[Prior art]
FIG. 7 is a perspective view schematically showing the ink jet printer. The ink jet printer 1 includes a platen roller 2 for feeding the recording medium 3, two stay shafts 4a and 4b parallel to the platen roller 2, and stay shafts 4a and 4b. A carriage 5 that is guided and reciprocates in the length direction of the platen roller 2, and an inkjet head unit 6 mounted on the carriage 5. The inkjet head unit replenishes ink to be ejected from the inkjet head unit 6 to the recording medium 3. 6 and the ink reservoir 7 are connected by a flexible tube 8.
[0004]
In such an ink jet printer 1, as means for causing ink to fly from the ink jet head unit 6, a bubble jet method that utilizes a change in volume when energizing a heating element embedded in a nozzle and generating bubbles in the ink, and A piezo method using a pressure wave generated by energizing a piezoelectric element has attracted attention.
[0005]
Piezo-type ink-jet heads include: (1) an ink flow channel groove formed on the surface of a piezoelectric substrate containing a piezoelectric drive electrode, and the groove closed with an upper lid made of glass; (2) piezoelectric drive The surface of the piezoelectric substrate containing the electrodes is covered with an ink flow path plate in which ink flow path grooves are formed (flow path plate method), and (3) the upper and lower surfaces of the flow path plate in which grooves that penetrate vertically are formed. In addition, a material in which a piezoelectric body containing a piezoelectric driving electrode is attached is generally known.
[0006]
8 is an exploded perspective view of a flow path plate type ink jet head, FIG. 9 is a sectional view of the ink jet head shown in FIG. 8, FIG. 10 is an explanatory view of a piezoelectric substrate provided with a piezoelectric interference prevention slit, and FIG. It is explanatory drawing of the piezoelectric substrate which provided the clearance gap.
[0007]
8 and 9A, the inkjet head 9 incorporated in the inkjet head unit 6 includes a piezoelectric substrate 10 incorporating a plurality (four in the figure) of piezoelectric elements 16 and a plurality (four in the figure) of ink. The ink flow path plate 11 in which the flow path grooves 12 are formed is joined by the adhesive layer 21, and the nozzle plate 14 having the nozzles 13 communicating with each of the plurality of ink flow path grooves 12 is joined to the front surface thereof. Yes.
[0008]
A connecting portion 15 that connects the other end of the flexible tube 8 having one end connected to the ink reservoir 7 is formed on the upper surface of the ink channel plate 11 that is generally made of glass and has the ink channel groove 12 formed on the lower surface. It is attached.
[0009]
The piezoelectric element 16 includes a plurality of piezoelectric driving electrodes 16a and a plurality of driving layers 16b in which piezoelectric strain is generated by applying a voltage to the electrodes 16a as shown in an enlarged view in FIG. 9B.
[0010]
In the inkjet head 9, the piezoelectric substrate 10 incorporating the plurality of piezoelectric elements 16 is entirely flat, and when the specific piezoelectric elements 16 are driven by narrowing the pitch of the piezoelectric elements 16 for high-definition printing, The piezoelectric drive also compresses the adjacent ink channel groove 12 (interference occurs), and so-called close talk occurs.
[0011]
In FIG. 10, the piezoelectric substrate 10 ′ bonded with the adhesive layer 21 on the lower surface of the ink flow path plate 11 in which the ink flow path groove 12 is formed has a piezoelectric interference prevention slit 22 formed between the adjacent piezoelectric elements 16. The portion between the piezoelectric element 16 and the slit 22 is bonded to the lower surface of the ink flow path plate 11 with an adhesive layer 21.
[0012]
Such a piezoelectric substrate 10 ′ can reduce the interval between the piezoelectric elements 16 as compared with the piezoelectric substrate 10, and enables high-definition printing.
In FIG. 11, the piezoelectric substrate 10 ″ bonded to the lower surface of the ink flow path plate 11 with the adhesive layer 21 is formed between the piezoelectric elements 16 with the gaps 23 for preventing piezoelectric interference formed on both sides of the piezoelectric elements 16. A gap portion 24 sandwiched between the pair of gaps 23 is joined to the lower surface of the ink flow path plate 11 with an adhesive layer 21.
[0013]
Such a piezoelectric substrate 10 ″ can further reduce the distance between the piezoelectric elements 16 than the piezoelectric substrate 10 ′, and thus enables higher-definition printing than the piezoelectric substrate 10 ′.
[0014]
FIG. 12 is an explanatory view of a conventional method of manufacturing a piezoelectric substrate provided with a gap for preventing piezoelectric interference. In FIG. 12A, a laminate of green sheets of piezoelectric powder containing a plurality of conductor layers forming electrodes 16a. A plurality of (five in the drawing) grooves 27 are formed in the member 26, and the grooves 27 cut the plurality of conductor layers built in the laminated member 26 into a plurality, respectively. In general, the groove 27 having a width of about 100 μm is formed by mechanical processing means using a rotating slicer.
[0015]
The laminated member 26 forms a green sheet from a slurry containing piezoelectric powder, and a plurality of first green sheets and a plurality of second green sheets on which the conductor layer is formed are stacked and stacked. The second green sheet is applied by a drying process (for example, heating at 60 ° C. for about 20 minutes) performed with appropriate pressure.
[0016]
In FIG. 12B, a deposition layer 28 for forming the gap 23 is formed on the inner surface (a pair of opposing side wall surfaces and bottom surface) of the groove 27. In general, the deposited layer 28 having a thickness of about 10 μm is formed by using a composition removed by firing the laminated member 26, for example, a binder paste used for the green sheet of the laminated member 26, and injecting the binder paste into the grooves 27. I am letting.
[0017]
In FIG. 12 (c), a filler 29 is filled in the groove 27 whose surface is covered with the adherend layer 28. In general, the filler 29 is a paste made of the same quality ceramic as the laminated member 26.
[0018]
Next, after applying a drying process of heating at 60 ° C. for about 20 minutes while applying a suitable pressure, for example, a pressure of about 50 MPa, as shown in FIG. Bake in the atmosphere.
[0019]
As a result, the laminated members 26 and 30 are integrated by the baking process of heating to about 1000 ° C., and the adherend layer 28 is removed by thermal decomposition to form a gap 23 for preventing piezoelectric interference. When the unnecessary portion below is removed from the chain line 31, the piezoelectric substrate 10 ″ shown in FIG. 11 is completed.
[0020]
[Problems to be solved by the invention]
As described above, the inkjet head using the piezoelectric substrate 10 ″ can perform higher definition printing than the previous inkjet head. However, the piezoelectric interference preventing gap 23 and the electrode 16a formed from the adherend layer 28. Has a problem that it is deformed by the baking treatment of the piezoelectric substrate 10 ″.
[0021]
FIG. 13 is an explanatory view of a problem associated with the formation of a conventional piezoelectric interference prevention gap. The conventional piezoelectric interference prevention gap 23 formed from the adherend layer 28 is deformed as shown in the figure. Will also deform the electrode 16a.
[0022]
That is, the deposition layer 28 is deposited on the entire surface of the groove 27, that is, on the left and right wall surfaces and the bottom surface, and it is difficult to make the thickness uniform. There is no discharge path for the gas generated from the deposition layer 28 deposited on the bottom surface of the substrate.
[0023]
Therefore, as shown in FIG. 13, the gap 23, the gap portion 24, and the portion 25 containing the piezoelectric element 16 are deformed and missing, and the mechanical strength of the gap portion 24 and the piezoelectric element built-in portion 25 is reduced and is easily cracked. At the same time, there is a problem that the piezoelectric substrate 10 ″ is warped.
[0024]
[Means for Solving the Problems]
An object of the present invention is to incorporate a plurality of piezoelectric elements in which a piezoelectric driving electrode and a driving layer that generates a piezoelectric strain by applying a voltage to the electrode are stacked, and prevent piezoelectric interference on both sides of the piezoelectric element. In the method of manufacturing a piezoelectric substrate having a gap for use, the above-mentioned problem in the conventional piezoelectric substrate 10 ″ is solved.
[0025]
The first piezoelectric substrate manufacturing method of the present invention that achieves the above object includes a plurality of first green sheets containing piezoelectric powder and a binder, and a conductive layer comprising the piezoelectric powder and binder and constituting the electrode on the surface. step a piezoelectric powder to form a step of forming a piezoelectric member overlapping a plurality of second green sheet but is formed in the piezoelectric member, a groove for setting the width and interval of the piezoelectric element of the plurality of And a step of forming a spacer made of a third green sheet having a deposition layer deposited only on both side surfaces in the thickness direction, including the binder, the spacer, the side wall of the groove, and the deposition layer Inserting into the groove facing each other and bonding the spacer to the bottom of the groove by simultaneous firing of the first to third green sheets and at the same time thermally decomposing and removing the adherent layer configured as comprising a step That.
[0026]
The second piezoelectric substrate manufacturing method of the present invention that achieves the above object is the first piezoelectric substrate manufacturing method of the present invention, wherein the adherend layer is used for manufacturing a green sheet containing piezoelectric powder. It is characterized by comprising a binder.
[0027]
The third piezoelectric substrate manufacturing method of the present invention that achieves the above object is the method of manufacturing the first piezoelectric substrate of the present invention, wherein the first to third green sheets are manufactured using a piezoelectric powder, a binder, and a plasticizer. Use the same slurry containing
Configured as characterized by the use of a free Murrell binder to the slurry as the composition.
[0028]
In the first to third piezoelectric substrate manufacturing methods of the present invention, the deposition layer formed on the spacer to form a gap for preventing piezoelectric interference is applied to the surface facing the wall surface of the groove formed in the piezoelectric member. It is a substance that is attached and removed in the step of bonding a spacer to the bottom surface (piezoelectric member) of the groove.
[0029]
Therefore, the piezoelectric member and the spacer can be joined without being affected by the removal of the adherend layer, and the gap and the drive electrode for preventing the piezoelectric interference can be formed accurately (without deformation).
[0030]
DETAILED DESCRIPTION OF THE INVENTION
1 is an explanatory view of a piezoelectric substrate according to an embodiment of the present invention, FIG. 2 is an explanatory view of an ink jet printer head using the piezoelectric substrate of FIG. 1, FIG. 3 is an explanatory view of a green sheet used for the piezoelectric substrate of FIG. FIG. 4 is an explanatory view (No. 1) of the manufacturing method of the piezoelectric substrate of FIG. 1, and FIG. 5 is an explanatory view (No. 2) of the manufacturing method of the piezoelectric substrate of FIG.
[0031]
In FIG. 1, a piezoelectric substrate 41 has a plurality of piezoelectric drive electrodes 16a arranged in the vertical direction in the figure, and a drive in which piezoelectric strain is generated by applying a voltage to the electrodes 16a arranged between the electrodes 16a. A plurality of (four in the figure) piezoelectric elements 16 composed of the layer 16b are incorporated.
[0032]
On both sides of each piezoelectric element 16, a gap 42 for preventing piezoelectric interference is formed over the entire length of the piezoelectric element 16, and a channel plate support is provided between a pair of adjacent gaps 42 without sandwiching the piezoelectric element 16. The upper surface of the piezoelectric substrate 41 including the upper surface of the flow path plate support portion 43 is a flat surface.
[0033]
In FIG. 2, the inkjet head 45 using the piezoelectric substrate 41 has a configuration in which a flow path plate 11 ′ in which a flow path groove 12 corresponding to the piezoelectric element 16 is formed on the upper surface of the piezoelectric substrate 41 is bonded with an adhesive layer 21. When a predetermined voltage is applied to the predetermined piezoelectric element 16, the flow path groove 12 corresponding to the piezoelectric element is compressed, so that the ink filled in the compressed flow path groove 12 flies from a nozzle (not shown). become.
[0034]
In FIG. 3, 46 is a first green sheet containing at least piezoelectric powder, 47 is a second green sheet containing at least piezoelectric powder and having a conductor layer 48 formed on the upper surface, and 49 is at least containing piezoelectric powder in the thickness direction. A spacer (third green sheet) in which the adhesion layers 50 are formed on both side surfaces, and the green sheets 46, 47, and 49 are cut into predetermined dimensions.
[0035]
On the upper surface of the green sheet 47, a conductor layer 48 for forming the piezoelectric driving electrode 16a is formed by, for example, printing of Ag-P paste, and on both side surfaces in the thickness direction of the band-shaped green sheet (spacer) 49. In this case, a deposition layer 50 of a composition that is removed by firing the green sheet 49 without adversely affecting the green sheet 49 is formed.
[0036]
The green sheet 46 containing at least piezoelectric powder includes, for example, 100 parts of a PMN-based piezoelectric powder having a particle size of about 1.0 μm, such as Pb (Mg _1/3 Nb _2/3 ) _1-x Ti _x O ₃ , and a binder, for example. 5 parts of PVB (polyvinyl petital), 5 parts of plasticizer such as DBP (dibuvinyl butyral), and 5 parts of ethanol as a dispersion medium are mixed and used as a slurry. Create to 50 μm and cut them to predetermined dimensions.
[0037]
The green sheet 47 containing at least piezoelectric powder is formed from the slurry, and a conductor layer 48, for example, an Ag-P paste is deposited on the green sheet having a thickness of 50 μm by a printing method, and the Ag-P paste is dried to form the conductor layer 48. Form.
[0038]
A green sheet 49 containing at least piezoelectric powder and having a thickness of about 100 μm, for example, is formed by stacking two green sheets formed from the slurry and cut to an appropriate width of 50 μm, and, for example, 5 at 60 ° C. while pressing to about 10 MPa. After completely removing the ethanol contained in the two stacked green sheets by lightly drying by heating for about a minute, and after lightly joining, the deposited layer 50 having a width of about ½ on both side surfaces in the thickness direction. Is formed by the usual means such as printing.
[0039]
In FIG. 4 (a), the piezoelectric member 51 is formed by laminating a plurality of green sheets 46 and 47, respectively, for example, four green sheets 46 are stacked, four green sheets 47 are stacked thereon, and further thereon. After the two green sheets 46 are stacked, the drying process is performed, for example, by heating at 60 ° C. for about 5 minutes while applying a pressure of about 10 MPa. In this drying process, the ethanol contained in the green sheets 46 and 47 is completely removed, and the plurality of green sheets 46 and 47 are lightly joined to each other.
[0040]
Next, in FIG. 4B, grooves 52 for setting the width and interval of the piezoelectric element 16 (see FIG. 1) are formed in the piezoelectric member 51. A plurality of (five in the figure) grooves 52 formed by cutting with the rotating slicer 53 have, for example, a width of 100 μm, a depth of 800 μm, and a pitch of 200 μm, and separate a plurality (four in the figure) of electrodes 16 a from the conductor layer 48. While forming, the width | variety and space | interval of the electrode 16a and the drive layer 16b are determined.
[0041]
Next, in FIG. 4C, after the green sheet 49 is inserted into each of the plurality of grooves 52, the upper surface is flattened by mechanical processing means (grinding).
Note that chipping (fine notches) may occur at the edge of the groove 52 formed by the slicer 53. In order to prevent such chipping, a mylar sheet is attached in advance to the surface of the piezoelectric member 51 that forms the groove 52, and the mylar sheet divided by the formation of the groove 52 is peeled off.
[0042]
Next, in the process of FIG. 5A, a green sheet piezoelectric member 55 is superimposed on the upper surface of the piezoelectric member 51 in which the green sheet 49 is inserted into the groove 52. The piezoelectric member 55 is formed by, for example, stacking 10 green sheets 46 and drying them at 60 ° C. for about 5 minutes while applying a pressure of, for example, about 10 MPa to completely remove ethanol contained in the green sheets 46 and a plurality of green sheets. The sheet 46 is lightly joined.
[0043]
Next, in the firing step of FIG. 5B, the stacked piezoelectric members 51 and 55 are fired at 1000 ° C. for about 20 minutes while being pressurized to, for example, about 50 MPa in the overlapping direction in the atmosphere.
[0044]
Then, the deposited layer 50 deposited on the green sheet 46 is thermally decomposed and disappears, and the piezoelectric members 51 and 55 and the green sheet (spacer) 49 are completely integrated, and the front surface and the rear surface (not shown) of the electrode 16a are formed. The piezoelectric fired substrate 56 in which the end face and the end face of the gap 57 formed by thermal decomposition of the adherend layer 50 are exposed is completed.
[0045]
Therefore, when the upper surface of the piezoelectric fired substrate 56 shown in FIG. 5B is repeatedly polished in the thickness direction so that the uppermost electrode 16a is positioned at a predetermined depth from the polished surface, FIG. The piezoelectric substrate 41 as shown in c), that is, the piezoelectric substrate 41 including a plurality of piezoelectric elements 16 having a uniform width and no distortion 42 on both sides is completed.
[0046]
【The invention's effect】
As described above, the piezoelectric substrate manufacturing method of the present invention accurately forms gaps and piezoelectric elements for preventing piezoelectric interference, increases the definition of the ink jet printer, increases the conversion rate of gradation control, and is mass-productive. To improve the performance and stabilize the performance.
[Brief description of the drawings]
1 is an explanatory diagram of a piezoelectric substrate according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of an inkjet printer head using the piezoelectric substrate of FIG. 1. FIG. 3 is an explanatory diagram of a green sheet used for the piezoelectric substrate of FIG. 4 is an explanatory diagram of a method for manufacturing the piezoelectric substrate of FIG. 1 (part 1);
FIG. 5 is an explanatory diagram of a method for manufacturing the piezoelectric substrate of FIG. 1 (part 2).
6 is an enlarged view of a gap for preventing piezoelectric interference in an embodiment of the present invention. FIG. 7 is a perspective view schematically showing an ink jet printer. FIG. 8 is an exploded perspective view of a flow path plate type ink jet head. FIG. 10 is an explanatory view of a piezoelectric substrate provided with a piezoelectric interference prevention slit. FIG. 11 is an explanatory view of a piezoelectric substrate provided with a piezoelectric interference prevention gap. FIG. 12 is a piezoelectric interference prevention gap. Explanatory drawing of the conventional manufacturing method of a piezoelectric substrate provided with FIG. 13 Explanatory drawing of problems associated with the formation of a conventional gap for preventing piezoelectric interference
16 Piezoelectric element 16a Electrode 16b of piezoelectric element Drive layer 41 of piezoelectric element Piezoelectric substrate 42 Clearance 43 for preventing piezoelectric interference Flow path plate support 46 First green sheet 47 Second green sheet 48 Conductor layer 49 Third green Sheet (spacer)
50 Spacer Deposited Layer 51 Piezoelectric Member 52 Groove

Claims (3)

A piezoelectric element having a plurality of piezoelectric elements in which a piezoelectric driving electrode and a driving layer that generates a piezoelectric strain by applying a voltage to the electrode are stacked, and a gap for preventing piezoelectric interference is provided on both sides of the piezoelectric element. A method for manufacturing a substrate, comprising:
A plurality of first green sheets containing piezoelectric powder and a binder, and a plurality of second green sheets containing a piezoelectric powder and a binder and having a conductive layer constituting the electrode formed on the surface are stacked to form a piezoelectric member Forming a step;
To the piezoelectric member, forming a groove for setting the width and interval of the piezoelectric element of the plurality of,
Forming a spacer composed of a third green sheet including a piezoelectric powder and a binder, and having an adhesion layer attached only on both side surfaces in the thickness direction ;
Inserting the spacer into the groove with the side wall of the groove facing the deposition layer; and
The co-firing of said second and third green sheets, at the same time to bond the spacer to the bottom of the groove, piezoelectric, characterized in including that a bonding step of removing the該被adhesive layer is thermally decomposed A method for manufacturing a substrate. The method for manufacturing a piezoelectric substrate according to claim 1, wherein the deposition layer is made of a binder used for manufacturing a green sheet containing piezoelectric powder. Using the same slurry containing piezoelectric powder, binder and plasticizer in the production of the first to third green sheets,
Method of manufacturing a piezoelectric substrate according to claim 1, wherein the use of free Murrell binder to the slurry as the composition.

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