JP2005150384A - Process for producing composite piezoelectric material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing a composite piezoelectric material at a low production cost. <P>SOLUTION: In a first embodiment, the process for producing a composite piezoelectric material having piezoelectric ceramics comprises a step for forming a first resin die by means of a laser beam, a step for plating the first resin die with a layer of metallic material to form a molding die, a step for forming a second resin die by means of the molding die, and a step for filling the second resin die with ceramics slurry to form a fine piezoelectric ceramics structure. In a second embodiment, the process for producing a composite piezoelectric material comprises a step for forming a resin die by means of a laser beam, and a step for filling the resin die with ceramics slurry to form a fine piezoelectric ceramics structure. A multistage phase diffraction optical component is preferably employed for irradiation with a laser beam. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a composite piezoelectric material used for ultrasonic diagnosis or nondestructive inspection.

For example, as shown in FIG. 7, the composite piezoelectric material has a structure in which rods 71a, which are fine columnar bodies made of piezoelectric ceramics, are embedded in a resin 71b. The size of the rod is typically 20 μm to 50 μm in the maximum diameter of the cross section when the columnar body is cut by a plane perpendicular to the longitudinal direction (in the case of a circular cross section, the diameter is indicated). The length in the longitudinal direction is, for example, 40 μm to 350 μm. Such rods 71a are normally arranged in the resin 71b at 500 / mm ^{2 to} 700 / mm ² . The composite piezoelectric material 71 is used for receiving or oscillating elements such as an ultrasonic diagnostic apparatus.

  An example of a method for producing a composite piezoelectric material is shown in FIG. 8 (see Patent Document 1). First, as shown in FIG. 8A, a resist 82 sensitive to X-rays is applied to a conductive substrate 81. Next, for example, silicon nitride is used for the support film, and synchrotron radiation (hereinafter referred to as “SR light”) is irradiated through a mask 83 having tungsten as an absorber pattern to perform lithography. Thereafter, development is performed to obtain a resist structure 84 as shown in FIG.

  Next, as shown in FIG. 8C, the resist structure 84 is subjected to nickel plating, and then the resist structure 84 is removed to obtain a mold 85. Subsequently, as shown in FIG. 8D, resin mold is performed using a mold 85 to form a resin mold 86. It is also possible to use a plate-like resist or acrylic plate as a substrate, apply a resist thereon, perform lithography using SR light, and develop to obtain a similar resin mold.

  Next, except for the metal mold 85, as shown in FIG. 8E, the resin mold 86 is filled with a ceramic slurry 87 and dried to solidify. Thereafter, the resin mold 86 is burned off by heat to form a ceramic-only structure, and then fired to obtain a fine ceramic structure 88 as shown in FIG. 8F. Finally, when the resin 89 is filled, FIG. A composite piezoelectric material as shown in g) is obtained.

Apart from such a method of performing resin molding with the metal mold 85, after forming the resist 82, lithography with SR light (FIG. 8A), and formation of the resin mold 84 with development (FIG. 8B), the resin A similar composite piezoelectric material can also be obtained by filling the mold 84 with a ceramic slurry, drying and solidifying it, removing the resin mold, firing, and finally filling the resin.
JP-A-8-97483

  However, the above-described manufacturing methods using SR light all have high SR light irradiation costs, and thus the manufacturing cost of the resulting composite piezoelectric material is high.

The present invention is an invention of a method for producing a composite piezoelectric material having piezoelectric ceramics,
The first aspect is
Forming a first resin mold with laser light;
Plating a layer made of a metal material on the first resin mold to form a mold;
Forming a second resin mold with a mold;
And a step of filling the second resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure.

The second aspect of the present invention is
Forming a resin mold with laser light;
And a step of filling a resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure. An embodiment in which the laser light is irradiated using a multistage phase diffraction optical component is preferable.

The third aspect of the present invention is:
Forming a first resin mold with a micro drill;
Plating a layer made of a metal material on the first resin mold to form a mold;
Forming a second resin mold with a mold;
And a step of filling the second resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure.

The fourth aspect of the present invention is
Forming a resin mold with a micro drill; and
And a step of filling a resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure.

The fifth aspect of the present invention is:
Forming a mold by electric discharge machining;
Forming a resin mold with a mold;
And a step of filling a resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure.

  ADVANTAGE OF THE INVENTION According to this invention, the composite piezoelectric material with a low manufacturing cost can be provided.

  The first embodiment of the method for manufacturing a composite piezoelectric material according to the present invention includes a step of forming a first resin mold by laser light, and a metal mold is formed by plating the first resin mold with a layer made of a metal material. , Forming a second resin mold with a mold, and filling the second resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure. When the resin mold is formed by lithography using SR light, the SR light irradiation cost is high, and thus the manufacturing cost of the composite piezoelectric material is increased. In the first embodiment of the present invention, since the resin mold is formed using a laser device that is less expensive than the SR device, the manufacturing cost of the composite piezoelectric material can be reduced. Further, by forming the mold and repeatedly using the mold, the second resin mold can be mass-produced, so that the laser running cost can be reduced.

  A first embodiment of the manufacturing method of the present invention is shown in FIG. First, as shown in FIG. 1A, the resin layer 12 is formed on the conductive substrate 11. The conductive substrate is a metal substrate made of copper, nickel, stainless steel (SUS) or the like, or a silicon substrate on which a metal such as titanium or chromium is sputter-deposited. The material for forming the resin layer is polymethacrylate such as polymethyl methacrylate (PMMA). The thickness of the resin layer is, for example, 10 μm to 500 μm in consideration of the height of the piezoelectric columnar body to be formed.

  Next, as shown in FIG.1 (b), the resin layer 12 is irradiated with the laser beam L, and the 1st resin type | mold 12a is formed. By utilizing the difference in threshold value in the ablation between the conductive substrate 11 and the resin layer 12, only the resin layer 12 is heated and evaporated to form the second resin mold 12a. For example, the laser light can be set to an intermediate value between the threshold values of the conductive substrate 11 and the resin layer 12, and only the resin layer can be evaporated without affecting the conductive substrate.

  As the laser, a carbon dioxide laser, a YAG laser, an excimer laser, or the like can be used. However, a carbon dioxide laser is preferable because it is easy to increase the output and can make a small-diameter, high-speed and high-precision drilling. An example of the laser beam irradiation mechanism is shown in FIG. In the example shown in FIG. 6, the incident laser light L is branched into a plurality of beams by a multilevel phase diffractive optical element (hereinafter referred to as “DOE”) 63, and is reflected by a telecentric lens 64. The condensed light is applied to the resin layer 62 on the substrate 61.

  DOE is an optical component made of ZnSe, etc., has a fine concavo-convex pattern of μm order on the surface, and functions such as beam branching, shape conversion, and uniform intensity by changing the phase of incident light Demonstrate. By using DOE, multipoint irradiation can be performed simultaneously on the target position of the resin layer on the substrate, and the laser processing cost can be reduced.

  Subsequently, as shown in FIG. 1C, a metal mold 13 is formed by plating a layer made of a metal material on the first resin mold 12a. A metal layer can be easily deposited using the conductive substrate 11 as a plating electrode. Examples of the metal material include nickel, copper, gold, and alloys thereof. Next, the substrate 11 is removed by wet etching or the like, and the first resin mold 12a is removed by wet etching or plasma etching to obtain a mold 13 as shown in FIG. The shape of the first resin mold 12 a is transferred to the mold 13.

  Subsequently, as shown in FIG. 1E, the second resin mold 14 is formed by molding using the mold 13. For example, the second resin mold 14 is formed by performing press or injection molding using the mold 13. Or after inject | pouring a syrup-like resin liquid, it hardens | cures and the 2nd resin type | mold 14 is formed. These molds are preferably in the form of press or injection molding because mass production of resin molds is easy. As the resin, an acrylic resin such as polymethyl methacrylate, a thermoplastic resin such as a polyurethane resin or a polyacetal resin such as polyoxymethylene, a thermosetting resin such as an epoxy or syrupy acrylic, or the like is used. After the second resin mold 14 is formed, the mold 13 is separated.

  After removing the mold 13, as shown in FIG. 1 (f), the second resin mold 14 is filled with a ceramic slurry to form a fine piezoelectric ceramic structure 15. The ceramic is preferably a piezoelectric ceramic. Piezoelectric ceramics refer to ceramic materials that exhibit a piezoelectric effect. Piezoelectric ceramics include, for example, crystals of perovskite type structure such as barium titanate or lead zirconate-lead titanate solid solution, such as lead zirconate titanate (PZT) and lead lanthanum zirconate titanate (PLZT). Zirconate titanate such as) is preferably used. Furthermore, lead titanate or the like can be used as the piezoelectric ceramic. Further, ceramics other than piezoelectric ceramics may be used. The content of ceramic in the slurry is typically 25% to 57% by volume, and the content of a solvent such as water is typically 40% to 45% by volume. Moreover, the aspect which mix | blends 3 volume%-30 volume% of binders, such as polyvinyl alcohol, is preferable.

  Next, when the second resin mold 14 is removed and fired, a fine piezoelectric ceramic structure 15 as shown in FIG. 1G is obtained. The removal of the resin mold can be performed by thermal decomposition, but in order to prevent the protrusions of the fine structure from being overturned by the high-viscosity melt of the molten resin, the resin mold can be evaporated or evaporated without being melted A mode of removing by sublimation or dissolving in a suitable solvent is preferable. For example, the resin mold can be removed by etching with plasma such as oxygen plasma.

  After firing, the fine piezoelectric ceramic structure 15 is impregnated with a resin 16 and cured, and then the surface is polished to obtain a composite piezoelectric material as shown in FIG. For the resin material, use is made of a copolymer of vinylidene fluoride and trifluoroethylene, a copolymer of vinylidene fluoride and vinylidene trifluoride, or a piezoelectric polymer material such as vinylidene fluoride resin, or an epoxy resin. However, by combining a piezoelectric ceramic sintered body and a piezoelectric polymer, a material having higher ultrasonic reception sensitivity than a composite piezoelectric material impregnated with an epoxy resin can be obtained.

  The second embodiment of the method for manufacturing a composite piezoelectric material of the present invention includes a step of forming a resin mold by laser light and a step of forming a fine piezoelectric ceramic structure by filling a ceramic slurry in the resin mold. It is characterized by providing. Since a resin mold is formed by laser processing without using an expensive SR light irradiation device, an inexpensive composite piezoelectric material can be provided.

  A second embodiment of the manufacturing method of the present invention is shown in FIG. First, as shown in FIG. 2A, the resin layer 24 is irradiated with laser light L to form a resin mold 24. As the resin, acrylic resin such as polymethyl methacrylate, polyurethane resin, thermoplastic resin such as polyacetal resin such as polyoxymethylene, thermosetting resin such as epoxy, and the like are used. The laser, the laser beam irradiation mechanism, and the DOE are the same as those in the first embodiment.

  Next, as shown in FIG. 2B, the resin mold 24 is filled with a ceramic slurry to form a fine piezoelectric ceramic structure 25. Thereafter, when the resin mold 24 is removed and fired, a fine piezoelectric ceramic structure 25 as shown in FIG. 2C is obtained. After firing, the resin film 26 is impregnated into the fine piezoelectric ceramic structure 25 and cured to obtain a composite piezoelectric material as shown in FIG. The ceramic slurry, the resin mold removing method, the resin material, and the like are the same as those in the first embodiment.

  The third embodiment of the method for manufacturing a composite piezoelectric material of the present invention includes a step of forming a first resin mold by a micro drill, and a mold formed by plating a layer made of a metal material on the first resin mold. , Forming a second resin mold with a mold, and filling the second resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure. Since the resin mold is formed by the micro drill without using an expensive SR light irradiation apparatus or laser light irradiation apparatus, the manufacturing cost of the composite piezoelectric material can be reduced. In addition, since the second resin mold can be mass-produced by molding by repeatedly using the mold, the processing cost can be reduced.

  In the third embodiment of the manufacturing method of the present invention, as shown in FIG. 3A, after forming the resin layer 32 on the conductive substrate 31, as shown in FIG. A hole is made in the resin layer 32 with a drill 33 to form a first resin mold 32a. As the micro drill, for example, a drill having a blade diameter of 10 μm or more and a blade length of 20 μm or more (a carbide micro drill SCMMR manufactured by Daiwa Seiko Co., Ltd.) is used. The conductive substrate and the resin layer are the same as those in the first embodiment. Each process after the formation of the mold is the same as that of the first embodiment.

  The fourth embodiment according to the method of manufacturing a composite piezoelectric material of the present invention includes a step of forming a resin mold with a micro drill and a step of forming a fine piezoelectric ceramic structure by filling a resin slurry with a ceramic slurry. It is characterized by providing. Since a resin mold is manufactured by a micro drill without using an expensive SR light irradiation device or laser light irradiation device, an inexpensive composite piezoelectric material can be provided.

  In the fourth embodiment of the manufacturing method of the present invention, as shown in FIG. 4, the resin layer 44 is formed by making holes in the resin layer with a micro drill 43. The micro drill is the same as that of the third embodiment. Each process after forming the resin layer and the resin mold is the same as that of the second embodiment.

  The fifth embodiment of the method for manufacturing a composite piezoelectric material of the present invention includes a step of forming a mold by electric discharge machining, a step of forming a resin mold by molding using the mold, and a ceramic in the resin mold. And a step of filling the slurry to form a fine piezoelectric ceramic structure. Since the mold is formed by electric discharge machining, the machining accuracy is higher than that by laser machining or micro drilling, and it is suitable for finer machining. Moreover, since the mold can be repeatedly used and the resin mold can be mass-produced by the mold, the processing cost can be reduced.

  In the fifth embodiment of the manufacturing method of the present invention, as shown in FIG. 5, a metal layer made of nickel or the like is electrodischarge processed using an electrode 53 to form a mold 54. The process after the mold formation is the same as in the first embodiment.

Example 1
In this example, first, as shown in FIG. 1A, an acrylic syrup is applied on a conductive substrate 11 made of SUS and cured to form a resin layer (acrylic plate) 12 having a thickness of 300 μm. Formed. Next, as shown in FIG. 1B, the resin layer 12 is irradiated with UV-YAG laser light L having a wavelength of 355 nm, and the first resin having a diameter of 40 μm, a depth of 300 μm, and a circular cross section. A mold 12a was formed. The conductive substrate 11 was placed on a slide stage, and each time laser processing was completed, the substrate was slid to form 40000 holes (200 × 200 holes) at an 80 μm pitch.

  Subsequently, as shown in FIG. 1C, a mold 13 was formed by plating a nickel layer on the first resin mold 12 a. Next, the substrate 11 was removed by wet etching, and the first resin mold 12a was removed by plasma etching to obtain a mold 13 as shown in FIG. After the mold is formed, as shown in FIG. 1 (e), acrylic syrup is injected into the mold 13 and cured to form the second resin mold 14. When the mold 13 is separated, the diameter is 40 μm, A second resin mold 14 in which holes having a depth of 300 μm and a pitch of 80 μm were formed was obtained. After forming the resin mold, as shown in FIG. 1 (f), the second resin mold 14 was filled with PZT slurry. For PZT slurry, 40% by volume of PZT was added to the slurry, and polyvinyl alcohol was added as a binder.

  Next, the second resin mold 14 was removed by oxygen plasma and baked to obtain a fine piezoelectric ceramic structure 15 as shown in FIG. When the obtained fine piezoelectric ceramic structure 15 was impregnated with an epoxy resin 16 and cured, and then the surface was polished, a composite piezoelectric material as shown in FIG. 1 (h) was obtained. This composite piezoelectric material had 40,000 cylindrical protrusions having a diameter of 40 μm and a height of 250 μm.

Example 2
In this embodiment, first, as shown in FIG. 2A, the acrylic plate is irradiated with carbon dioxide laser light L (wavelength: 10.6 μm), and 40,000 holes with a diameter of 40 μm, a depth of 300 μm, and a circular cross section ( 200 × 200) was formed. The laser beam irradiation mechanism is shown in FIG. The incident carbon dioxide laser beam L was branched by the DOE 63, collected by the telecentric lens 64, and simultaneously irradiated to the resin layer 62 on the substrate 61 at multiple points. Subsequently, as shown in FIG. 2B, the resin mold 24 was filled with a ceramic slurry to form a fine piezoelectric ceramic structure 25. Thereafter, when the resin mold 24 was removed and baked, a fine piezoelectric ceramic structure 25 as shown in FIG. 2C was obtained. After firing, the fine piezoelectric ceramic structure 25 was impregnated with the resin 26, cured, and then the surface was polished to obtain a composite piezoelectric material as shown in FIG. The ceramic slurry, the resin mold removing method and the resin material were the same as in Example 1. The obtained composite piezoelectric material had 40000 cylindrical protrusions having a diameter of 40 μm and a height of 250 μm.

Example 3
In this example, first, as shown in FIG. 3A, acrylic syrup was applied on a conductive substrate 31 made of SUS and dried to form a resin layer 32 having a thickness of 300 μm. Next, as shown in FIG. 3B, a hole is formed in the resin layer 32 by using a micro drill 33 having a blade diameter of 50 μm and a blade length of 500 μm (a carbide micro drill SCMMR90005 manufactured by Daiwa Seiko Co., Ltd.), and the first resin mold is formed. 32a was formed. The holes formed in the first resin mold 32a had a diameter of 50 μm, a depth of 300 μm, and a pitch of 100 μm, and 40000 (200 × 200) were formed. Subsequent steps, such as a mold forming step, a second resin mold forming step, and a fine piezoelectric ceramic structure forming step, formed a composite piezoelectric material in the same manner as in Example 1. The obtained composite piezoelectric material had 40000 (200 × 200) cylindrical protrusions having a diameter of 50 μm, a height of 250 μm, and a pitch of 100 μm.

Example 4
In this example, as shown in FIG. 4, a hole was made in the acrylic plate with a micro drill 43 to form a resin mold 44. The specifications of the micro drill and the shape of the hole were the same as in Example 3. A composite piezoelectric material was manufactured in the same manner as in Example 2 except that a resin mold was formed using a micro drill instead of the laser beam. The obtained composite piezoelectric material had 40000 (200 × 200) cylindrical protrusions having a diameter of 50 μm, a height of 250 μm, and a pitch of 100 μm.

Example 5
In this example, electric discharge machining was performed on a nickel plate, and 40,000 (200 × 200) holes having a diameter of 50 μm, a depth of 300 μm, a pitch of 100 μm, and a circular cross section were formed. A mold 54 as shown was formed. The steps after forming the mold, such as a step of forming a resin die by molding using the formed die and a step of forming a fine piezoelectric ceramic structure by filling a ceramic slurry in the resin die, are the same as in Example 1. A composite piezoelectric material was produced in the same manner. The obtained composite piezoelectric material had 40000 (200 × 200) cylindrical protrusions having a diameter of 50 μm, a height of 250 μm, and a pitch of 100 μm.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the present invention, a piezoelectric element used for ultrasonic diagnosis or non-destructive inspection can be provided at low cost.

It is process drawing which shows 1st Embodiment of the manufacturing method of this invention. It is process drawing which shows 2nd Embodiment of the manufacturing method of this invention. It is process drawing which shows 3rd Embodiment of the manufacturing method of this invention. It is a figure which shows the resin mold formation process in 4th Embodiment of the manufacturing method of this invention. It is a figure which shows the metal mold | die formation process in 5th Embodiment of the manufacturing method of this invention. It is a schematic diagram which shows the laser beam irradiation mechanism used in this invention. It is a schematic diagram which shows the structure of the composite piezoelectric material of this invention. It is process drawing which shows the manufacturing method of the conventional composite piezoelectric material.

Explanation of symbols

  11 conductive substrate, 12 resin layer, 12a first resin mold, 13 mold, 14 second resin mold, 15 fine piezoelectric ceramic structure, 16 resin, 63 DOE, 64 telecentric lens, L laser beam.

Claims (6)

A method of manufacturing a composite piezoelectric material having piezoelectric ceramics,
Forming a first resin mold with laser light;
Plating the first resin mold with a layer made of a metal material to form a mold;
Forming a second resin mold with the mold;
And a step of filling the second resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure. A method of manufacturing a composite piezoelectric material having piezoelectric ceramics,
Forming a resin mold with laser light;
And a step of forming a fine piezoelectric ceramic structure by filling the resin mold with a ceramic slurry.   3. The method of manufacturing a composite piezoelectric material according to claim 1, wherein the laser light is irradiated using a multi-stage phase diffraction type optical component. A method of manufacturing a composite piezoelectric material having piezoelectric ceramics,
Forming a first resin mold with a micro drill;
Plating the first resin mold with a layer made of a metal material to form a mold;
Forming a second resin mold with the mold;
And a step of filling the second resin mold with a ceramic slurry to form a fine piezoelectric ceramic structure. A method of manufacturing a composite piezoelectric material having piezoelectric ceramics,
Forming a resin mold with a micro drill; and
And a step of forming a fine piezoelectric ceramic structure by filling the resin mold with a ceramic slurry. A method of manufacturing a composite piezoelectric material having piezoelectric ceramics,
Forming a mold by electric discharge machining;
Forming a resin mold with the mold;
And a step of forming a fine piezoelectric ceramic structure by filling the resin mold with a ceramic slurry.

Images