JPH04200098A - Manufacturing method of composite piezoelectric material - Google Patents

Abstract

PURPOSE:To improve the characteristics of the composite piezoelectric by completely cutting the piezoelectric provided with a resin layer on one surface in its thickness direction and forming grooves arriving at a part of the resin layer like a grid therein, then packing an org. high polymer in the grooves and curing the high polymer. CONSTITUTION:The resin layer 2 is formed on one surface of the piezoelectric 1. The piezoelectric 1 is completely cut from the opposite side surface of the resin layer 2 of the piezoelectric 1 and further, the grooves 3 are formed like the grid (network) down to the depth arriving at a part of the resin layer 2 to form two-dimensionally arranged columnar piezoelectric elements 4. The org. high polymer 5 is then packed into the grooves 3. The resin layer 2 and the org. high polymer 5 are partly removed by polishing or grinding. Further, the columnar piezoelectric elements 4 and the org. high polymer 5 are polished or ground, by which the composite piezoelectric 6 meeting the desired frequency is produced. The characteristics of the composite piezoelectric 6 are improved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a composite piezoelectric material used in sensors such as sonar and ultrasonic diagnostic equipment.

Conventional technology Recently, piezoelectric ceramics and organic materials have been combined as piezoelectric materials used in transducers (ultrasonic probes), which are sensors such as sonar and ultrasound diagnostic equipment for water and living organisms. Composite piezoelectric materials are being studied. Conventionally, in order to manufacture this composite piezoelectric material, for example, Japanese Patent Laid-Open No. 60
The method described in JP-A-85699 is known. The method for manufacturing the conventional composite piezoelectric material described above will be explained below as shown in Fig. 2 (
This will be explained with reference to the schematic perspective views for explaining the manufacturing process shown in a) and (bl).

First, as shown in FIG. 2(a), the piezoelectric ceramic plate 20 is temporarily bonded with wax or the like to a holding table (not shown [3') with good parallelism and flatness, and the piezoelectric ceramic plate 21 is attached to a dicing machine or the like. A cutting et21 is formed in a lattice shape to a depth of about half the thickness, and this cutting groove 2 is
1 is filled with an organic polymer 22 and heated to harden it. Next, this piezoelectric ceramic plate 20 is removed from the holding base. Next, as shown in FIG. 2 (bl), by polishing and removing the uncut plate portion 23 of the piezoelectric ceramic plate 20 as shown by the dotted line, a two-dimensional array of columnar piezoelectric ceramic elements is formed. A composite piezoelectric body can be produced by bonding 24 with an organic polymer 22.

Problems to be Solved by the Invention However, in such a conventional method for manufacturing a composite piezoelectric body, the organic polymer (resin) 22 filled in the groove 21 formed in the piezoelectric ceramic plate 20 is heated and hardened. Therefore, when the organic polymer 22 is returned to room temperature after hardening, the organic polymer 22 contracts with respect to the piezoelectric ceramic, and a force acts to distort the uncut plate-like portion 23. This causes the piezoelectric ceramic to deform or crack, making it difficult to obtain good flatness during polishing. In addition, the vibration form changes due to deformation and breakage of the piezoelectric ceramic, resulting in deterioration of characteristics as a composite piezoelectric body.

The present invention solves these conventional problems, and enables columnar piezoelectric elements to be accurately and accurately two-dimensionally arranged, thereby improving the characteristics of a composite piezoelectric material. It is an object of the present invention to provide a method for manufacturing a composite piezoelectric material, which can improve manufacturing yield.

Means for Solving the Problem The technical solution of the present invention to achieve the above object is as follows:
A resin layer is provided on one side of a plate-shaped piezoelectric body, the piezoelectric body is completely cut in the thickness direction, grooves are formed in a lattice shape reaching a part of the resin layer, and an organic polymer is applied to the grooves. The resin layer is filled and cured, and after curing, the resin layer is removed.

It is preferable to use materials having the same or equivalent thermal properties for the resin layer and the organic polymer.

Therefore, according to the present invention, since the plate-shaped piezoelectric body is completely cut in the thickness direction and held by the resin layer, the grooves formed by the cutting process are filled with an organic polymer. It is possible to prevent the piezoelectric body from being deformed or damaged due to strain even if the organic polymer and resin layer shrink after curing by heating.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 1(a) to (di) show a method for manufacturing a composite piezoelectric material in one embodiment of the present invention, FIGS. 1(a) and (bl) are schematic cross-sectional views for explaining the manufacturing process, and FIG. , (di is a schematic perspective view for explaining the manufacturing process.

In FIG. 1(a), 1 is a piezoelectric material, for example, P
ZT series, PbTl0. piezoelectric ceramics, LINb
O,, LiTa0. A plate-shaped material such as a single crystal is used. First, a resin layer 2 is formed on one side of the piezoelectric body 1. For this resin layer 2, a resin having the same thermal properties as the organic polymer 4, such as an epoxy resin made of bisphenol A type epoxy resin and an amine hardening agent, is used, and an appropriate mold is used. It is formed on one side of the piezoelectric body 1. Next, as shown in FIG. Grooves 3 are formed in a grid pattern (mesh pattern) by mechanical processing using a wire saw or processing using a laser.
A two-dimensional array of columnar piezoelectric elements 4 is formed. Next, as shown in FIG. 1 (C1), the groove 3 is filled with an organic polymer 5.As the organic polymer 5, for example, a bisphenol A type epoxy resin and an amine-based hardened epoxy resin are used. A material such as an epoxy resin consisting of 70% is used.
It hardens by leaving it for 90 minutes or more at a temperature of about ℃,
After curing, when the temperature is returned to room temperature, shrinkage will occur due to cooling. However, the piezoelectric body 1 is completely cut into columnar elements 4, and at the same time, the resin layer 2 is made of epoxy resin having the same material. Since the piezoelectric element 4 undergoes a large amount of contraction, there is almost no possibility that the piezoelectric element 4 will be deformed or damaged due to strain. Next, as shown in Figure 1 (dl),
A portion of the resin layer 2 and the organic polymer 5 are removed by polishing or grinding. Furthermore, by polishing or grinding the columnar piezoelectric elements 4 and the organic polymer 5, the two-dimensional array of columnar piezoelectric elements 4 is bonded with the organic polymer 5, and the desired thickness is achieved. A composite piezoelectric material 6 suitable for the frequency to be used is manufactured. This composite piezoelectric body 6 can be formed into a desired shape by heating and pressurizing, if necessary. Then, a transducer can be constructed by providing electrodes on both sides, connecting lead wires to these electrodes, and providing a back load material, an acoustic matching layer, an acoustic lens, etc. as necessary.

As described above, according to the above embodiment, in the composite piezoelectric body 6 composed of the two-dimensionally arranged columnar piezoelectric elements 4 and the organic polymer 5 joining them, the columnar piezoelectric elements 4 are prevented from being distorted or damaged. Less likely to occur. Therefore, the piezoelectric elements 4 can be accurately arranged in a desired shape.

In the above embodiment, as shown in FIG. 1(a), the resin layer 2 was directly provided on one side of the piezoelectric body 1 using a mold. Prepared in advance, the resin layer 2 is adhered to one side of the piezoelectric body 1 using an adhesive having the same thermal properties as the organic polymer 5 used for filling, and the composite piezoelectric body 6 is produced by the method described above. You can also get the same effect. Furthermore, in the above embodiment, the piezoelectric body 1 shown in FIG. 1(a) is made thicker than the desired final composite piezoelectric body 6, but If the thickness is made equal to the thickness of the target composite piezoelectric body 6, only the resin layer 2 needs to be removed by polishing, grinding, or the like.

As described in detail, according to the present invention, a resin layer is provided on one side of a plate-shaped piezoelectric body, and the piezoelectric body is completely cut in the thickness direction, and a part of the resin layer is reached. Grooves are formed in a lattice shape, the organic polymer is filled into the grooves and cured, and then the resin layer is removed. In this way, since there is no uncut portion in the thickness direction of the piezoelectric body, it is possible to prevent the piezoelectric body from being deformed or damaged due to distortion due to contraction of the organic polymer due to temperature changes. Therefore, the columnar piezoelectric elements can be accurately and accurately two-dimensionally arranged, the characteristics of the composite piezoelectric body can be improved, and the manufacturing yield can be improved.

In addition, by using materials with the same or equivalent thermal properties for the resin layer and the organic polymer, it is possible to further reduce distortions applied to the columnar piezoelectric elements, and to make the piezoelectric elements even more It is possible to perform two-dimensional arraying accurately and with high precision.

[Brief explanation of the drawing]

FIGS. 1(a) to (di) show a method for manufacturing a composite piezoelectric material in one embodiment of the present invention, FIGS. 1(a> and (b) are schematic cross-sectional views for explaining the manufacturing process, C1, (dl is a schematic perspective view for explaining the manufacturing process, and FIG. 2(a), (bl) is a schematic diagram for explaining the manufacturing process showing an example of a conventional method for manufacturing a composite piezoelectric material. 1... Piezoelectric body, 2... resin layer, 3... groove, 4...
・Piezoelectric element, 5...Organic polymer, 6...Composite piezoelectric material. Name of agent: Patent attorney Osamu Koebi Akira Baka 2 Figure 1 Figure 2 (4a) (b)

Claims (2)

[Claims] (1) A resin layer is provided on one side of a plate-shaped piezoelectric material, the piezoelectric material is completely cut in the thickness direction, and grooves reaching a part of the resin layer are formed in a lattice shape. A method for manufacturing a composite piezoelectric material, which comprises filling a polymer with the resin, curing the material, and removing the resin layer after curing. (2) The method for manufacturing a composite piezoelectric material according to claim 1, wherein the resin layer and the organic polymer are made of materials having the same or equivalent thermal properties.