JP4039613B2 - Plano convex piezoelectric element manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing method for converting a quartz resonator, for example, into a plano-convex as a small piezoelectric element plate.
[0002]
[Prior art]
Conventionally, the plano-convex type piezoelectric element plate has been put into practical use in AT plate crystal resonators for special measurement and communication devices, and its outer shape is more than 10 mm in diameter, and the number of production is also small. Then, after rounding the crystal piezoelectric element plate, abrasive grains were attached to a dish whose inner surface was recessed in a spherical shape, and the quartz crystal element plate was pressed against the rotated dish and processed by a polishing method.
[0003]
As an example of the specific processing, as shown in FIG. 4, mechanical processing is performed in which a piezoelectric base plate is attached to a semi-convex spherical plate and polishing is performed using a semi-concave spherical polishing dish. .
[0004]
[Problems to be solved by the invention]
In the above-described processing method, the external dimensions of recent piezoelectric base plates tend to be small, and it is very difficult to perform a miniaturized piezoelectric base plate by a conventional processing method. Examples of such phenomena include variations in machining accuracy, troublesome handling of the piezoelectric substrate, and frequency variations due to processing accuracy. Convex processing is performed. In addition, since the demand for mass production is strengthened against these backgrounds, in addition to the improvement of the above-mentioned variations in various characteristics, an improvement in yield in mass production is also demanded.
[0005]
On the other hand, there is a convex processing technique aiming at improvement of mass productivity as described in, for example, Japanese Patent Application Laid-Open No. 58-217262. According to the publication, a process of alternately bonding wafers showing piezoelectric results with an adhesive, a process of processing the outer periphery of the bonded wafer, and peeling the peripherally processed wafer into a set of two. A processing method for a small planar convex vibrating piece comprising a step, a step of processing the wafer into a biconvex vibrating piece by piping, and a step of separating the vibrating piece into one piece. Here, the piping is named by the inventor, and the vibrating piece is put in a cast iron pipe together with abrasive grains and processed by rotating the pipe.
[0006]
As described above, in this publication, although it is an improvement measure for processing a small piece of vibrating piece, there is a problem that it is difficult to manage the processing amount and processing time for performing the convex processing.
[0007]
[Means for Solving the Problems]
The present invention solves the above-described problems and is a processing method in which convex processing is mass-produced at low cost. Specifically, at least one side of at least one of the two piezoelectric element plates has a central portion on one side. A step of disposing a metal piece having a concave shape, a step of adhering and bonding the two piezoelectric element plates with an adhesive with the metal piece interposed therebetween, and an opposite bonding of the bonded piezoelectric element plates A method for processing a small plano-convex piezoelectric element plate comprising: a step of convex-processing the main surface of the substrate; a step of measuring the frequency of the piezoelectric element plate; and a step of peeling the piezoelectric element plate processed with the main surface. .
[0008]
In short, in the process of convex processing, the amount of processing of the piezoelectric base plate is measured by measuring the frequency of the piezoelectric base plate, so that the desired convex processing amount can be confirmed in real time with the plano convex piezoelectric base plate processing method. is there. As described above, according to the present invention, it is possible to further improve the conventional processing method, realize mass production in the processing process of the piezoelectric element plate, and improve the process yield. In addition, since the frequency of the piezoelectric element plate is directly measured with the object to be processed, the processing time can be improved, and the problem is solved.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. In each figure, the same numerals indicate the same objects. An example of convex processing as one embodiment of the present invention will be described with reference to FIG. FIG. 1A to FIG. 1F show the process flow of the convex piezoelectric element plate 1 according to the present invention.
[0010]
In the processing step of the present invention shown in FIG. 1, (1) a step of placing a metal piece 2 on at least one surface of the piezoelectric element plate 1, and (2) one or two piezoelectric element plates A step of bonding the metal pieces 2 with an adhesive 3 and bonding them together, and (3) a process of convex-working the opposite main surface of the bonded piezoelectric element plate 1 to which the metal pieces 2 are bonded, (4) A step of placing the metal plate 4 on the main surface of the piezoelectric element plate 1 on which the convex processing is performed, and measuring the frequency of the piezoelectric element plate 1 between the metal plate 4 and the metal piece 2; (5) After measuring the frequency of the piezoelectric base plate 1, the metal plate 4 is removed from the piezoelectric base plate 1 and the piezoelectric base plate 1 is peeled off from the metal piece 2. The base plate 1 is processed. Convex processing is performed by a barrel method.
[0011]
In short, as a feature of the present invention, in the course of the convex processing, the processing amount of the piezoelectric base plate 1 is measured by measuring the frequency of the piezoelectric base plate 1, thereby repeating the convex processing and frequency measurement to obtain the desired convex processing amount. 1 is a method of processing the piezoelectric base plate 1 capable of simultaneously obtaining two desired convex vibrators, and by repeating the frequency measurement step in FIG. 1 several times, the desired convex processing (measured as a frequency) is performed. ) Can be realized.
[0012]
On the other hand, the side sectional view shown in FIG. 2 shows the form of the piezoelectric element plate 1 that performs the convex processing of the present invention. FIG. 2A shows, as an example, a state in which the piezoelectric element plate 1 is an element plate of a crystal resonator having an outer dimension of about 10 mm, and the two element plates are bonded together to form one set. A metal piece 2 serving as an electrode is disposed between the two quartz crystal resonators (piezoelectric element plate 1), and includes a step of performing frequency measurement in the process of convex processing. At this time, the metal piece 2 is shaped such that there is a gap between the metal piece 2 and the piezoelectric element plate 1 at the central part of the metal piece because at least the central part of one side is concave.
[0013]
FIG. 2B shows an example of frequency measurement. The upper piezoelectric element plate 11 measures the frequency between the sandwiched metal piece 2 and the metal plate 4 by, for example, a network analyzer method. This confirms the progress of the convex processing amount.
Similarly, the progress of the amount of convex processing can be confirmed by measuring the frequency between the metal piece 2 and the metal plate 4 sandwiched between the upper piezoelectric element 12 and the network analyzer method, for example. it can.
The metal piece 2 to be an electrode may be a metal material such as a gold material, silver material, or aluminum material, and a low melting point adhesive 3 or the like is used for bonding the piezoelectric element plate 1. It is. Moreover, the enlarged view of the state which bonded the piezoelectric element | base_plate 1 is shown in FIG.
[0014]
As described above, according to the present invention, the conventional processing method can be further improved, mass production in the processing step of the piezoelectric element plate 1 can be realized, and the process yield can be improved. Moreover, since the frequency of the piezoelectric element plate 1 is directly measured with the object to be processed, the processing time can be improved and the problem is solved.
[0015]
【The invention's effect】
According to the present invention, it is possible to reduce the convex processing time with respect to the miniaturization of the piezoelectric element plate, and it is possible to maintain the quality of the vibrator itself by improving the processing accuracy. In addition, the yield in the manufacturing process can be improved and quality control can be enhanced.
[Brief description of the drawings]
FIG. 1 is a process flow diagram showing an embodiment of the present invention.
FIG. 2 is a side sectional view showing a state of the piezoelectric element plate of the present invention.
FIG. 3 is an enlarged view showing a state in which the piezoelectric element plates of the present invention are bonded together.
FIG. 4 shows an example of conventional convex processing.
[Explanation of symbols]
1 Piezoelectric substrate

Claims (2)

A step of disposing a metal piece on at least one surface of the two piezoelectric element plates, a step of bonding the two metal element plates with an adhesive with the metal piece interposed therebetween, and affixing them; Convexing the opposite main surface of the bonded piezoelectric element plate to which the metal pieces are bonded , and arranging the metal plate on the convex surface of the piezoelectric element plate, the metal plate and the metal plate Measuring the frequency of the piezoelectric element plate with a metal piece, and measuring the frequency of the piezoelectric element plate, then removing the metal plate from the piezoelectric element plate and removing the piezoelectric element plate from the metal piece A method of processing a branoconvex piezoelectric element plate comprising: a peeling step . The method for processing a plano-convex piezoelectric element plate according to claim 1, wherein at least one central portion of the metal piece has a concave shape.

Images