JP4675600B2 - Piezoelectric blank piece sorter - Google Patents

Description

  The present invention relates to an apparatus for manufacturing a piezoelectric vibrator, and more specifically, for example, a crystal blank for manufacturing an ultra-small crystal vibrator used in IT equipment or the like is selectively measured and selected. In particular, it relates to a sorter that is useful.

Crystal resonators, which are piezoelectric elements, have been used as highly accurate electro-mechanical conversion elements, and in recent years, in particular, accurate electrical constants are required for various circuits in the communications field and as control oscillators for ultra-precise equipment. It is widely used as an electronic component indispensable for the equipment to be manufactured, and its production amount has been dramatically increased.
In addition, crystal resonators that meet the demands described above are required to be miniaturized as crystal devices are miniaturized, and are automated to meet mass production.

  By the way, crystal resonators, crystal filters, ceramic resonators, etc. are generally called piezoelectric elements. In many cases, a crystal piece is cut out from a crystal and separated into small pieces (blanks) having a predetermined external dimension. The thickness of a small piece (hereinafter referred to as a blank or a blank piece) is polished so as to obtain a desired frequency characteristic, and then a vibrating electrode is formed by depositing metal or the like on the surface of the blank. After adjusting the amount of electrode deposition to finely adjust the overall vibration frequency of the piezoelectric element or the frequency characteristic of the filter to a desired value, it is housed in a package or the like to be a finished product.

FIG. 5 schematically shows a blank selection step before measuring a thickness of a small blank cut out from a crystal piece (wafer) or the like and reaching a subsequent polishing step or electrode deposition step.
The blank 2 supplied from a part feeder or the like not shown in this figure is supplied into the guide member 1 of the measurement table 4 that measures the electrical constant (impedance characteristic or resonance frequency) of the blank at the carry-in point A. The blank 2 is slid in the direction of the arrow X together with the guide member 1 and moved to the measurement point B of the blank. At the measurement point B of the blank, the measurement electrode 3 is lowered from above by a mechanism not shown, and a predetermined high frequency signal is given to the blank 2 to measure the electrical constant of the blank 2.
The measured blank 2 is further slid with the guide member 1 in the direction of the arrow Y, picked up from the guide member 1 by a pickup function at the next discharge point C, and separated into separate chambers for each measured value. Be transported.

Conventionally, the size of a blank piece cut out from a crystal piece is about 10 to 5 mm, and most of them are round, strip, and quadrangular shapes. Blank machines cut out from a crystal piece etc. Errors in vibration characteristics are relatively small, and blank thickness information is detected by the method described above, and sorting based on the results reduces the frequency of occurrence of defective products in the subsequent polishing process and electrode deposition process. Thus, it was possible to make a quartz crystal using such an alignment, conveyance, and measurement classification method.
JP-A-6-140860

By the way, in recent years, miniaturization of electronic devices and the miniaturization of crystal resonators have been demanded, and quality control has become stricter, and the external dimensions of blank pieces cut out from crystal pieces have become several mm or less. At the same time, an ultra-thin blank having a thickness of several tens of μm has been cut out.
However, when the blank cut out from the crystal piece is so small, thin, and light, it is required to have a high cutting accuracy, and when such a blank is drawn around on the measurement table as described above, In many cases, the blank surface is damaged or the blank is chipped and deformed, and it is impossible to accurately select blanks within the external dimensions that can be supplied to the next polishing process, resulting in defective products. There is a problem to do.
In addition, since it is easily affected by static electricity, the blank sorting function is not performed smoothly due to sticking of blanks in the supply, sorting, and transfer processes. When adding a polishing step, there are problems such as a problem, and a generation rate of a defective rate increases, resulting in a decrease in manufacturing yield.

  The piezoelectric blank piece sorter of the present invention is made to alleviate such problems as much as possible, and is arranged at equal intervals along the circumference of a measurement table that is intermittently rotated at a predetermined rotation angle. A plurality of stage electrode portions, a blank holding member arranged so as to surround an upper portion of the stage electrode, and a picker portion for supplying a blank into the blank holding member at a first rotation position of the measurement table A measurement electrode unit for measuring the electrical characteristics of the blank, and an upper electrode facing the blank placed on the stage electrode at a second rotational position of the measurement table, It comprises a carry-out part for sorting the blanks in the blank holding member based on the electrical characteristics measured by the measurement electrode part at the third rotational position. To.

In addition, the piezoelectric blank (piece) sorter of the present invention is provided with a lower electrode at a predetermined interval below the stage electrode at the third rotational position of the measurement table so as to improve measurement accuracy. At the same time, a discharge portion for sucking and discharging the blank in the blank holding member is provided at the fourth rotational position of the measurement table so that malfunction does not occur.
Furthermore, the picker part is configured by, for example, a thin tube, a gravity needle inserted into the thin tube, and a mechanism for sucking and releasing the gas in the thin tube, so that a small blank can be reliably transferred. did.

  In the piezoelectric blank piece sorter of the present invention, after the blank supplied from the parts feeder or the like is placed in the blank holding member arranged on the measurement table, it is carried out from the carry-in position to the measurement position and from the measurement position. Since it can be transferred smoothly without applying any external force to reach the position, the electrical measurement value of the blank is effectively utilized for the selection action, and the manufacturing process of the crystal unit can be made smoothly and quickly. The advantage is that it can be done.

FIG. 1 is a schematic view showing an outline of a piezoelectric blank piece sorter of the present invention.
In this figure, reference numeral 10 denotes a part feeder that accommodates a large number of fine blanks cut out from a crystal piece. The step part 11 is formed in a spiral shape like a feeder of a general electronic component, and the step part. There is a straight carry-out port 12 located at the end point of 11, and a microvibrator (not shown) is attached to move the accommodated work member (blank) little by little in the circumferential direction.
Then, the blank is transferred so as to be aligned without overlapping on the carry-out port 12 by the slight vibration by the fine vibrator.

  Reference numeral 20 denotes a picker (arm) that picks up the retained blanks that are transferred to the position of the carry-out port 12 one by one. As will be described later, the blanks picked up one by one by the air flow It is transferred as indicated by arrow A by an arm that rotates about the center, and is moved onto the next measurement table 30 that is at the first rotational position.

As shown in the drawing, the measurement table 30 is configured to be rotatable by a substantially disk-like disk, and for example, six blank holding members 31a, 31b, 31c, 31d, 31e, and 3f are provided on the circumference thereof. It has been. Then, the central shaft 32 is intermittently driven by, for example, 60 degrees by a drive mechanism (not shown) to rotate in the direction of the arrow B, and the blank placed in the blank holding member 31 (a) is transferred.
As will be described later, a stage electrode is placed at the center of the blank holding member, and the blank is placed on the stage electrode. The number of stage electrodes is not limited to six and can be appropriately arranged.

Reference numeral 40 denotes a measurement electrode portion provided at the second rotation position of the measurement table. As will be described later, a measurement electrode 42 that moves up and down toward the paper surface by a shaft 41 is predetermined on the upper surface side of the blank in the blank holding member 31. One of the electrical characteristics of the blank in the blank holding member 31 (c) is driven based on the measurement signal of the network analyzer that is driven so as to be in contact with each other through the gap and supplied to the measurement (upper) electrode 42. Measure one by one.
The electrical characteristics of the blank are the natural oscillation voltage of the blank that is obtained when a high-frequency signal whose frequency changes is applied to the blank, or the change characteristics of the blank's alternating current impedance. It measures the natural vibration frequency, impedance, spurious characteristics, etc. of the blank.

Reference numeral 50 denotes a carry-out arm portion for sorting and carrying out the blank based on the measured value after the electrical characteristics of the blank are measured, and the measurement table 30 is disposed at a third rotational position where the blank is further rotated.
The carry-out arm portion 50 rotates around the shaft 51 in the range of the arrow C. In the case of FIG. 1, the carry-out arm portion 50 picks up the blank whose electrical constant has been measured from the blank holding member (e) and the next sorting disk portion 60. Transport towards.

In the sorting disk portion 60, n sorting pockets 61a, 61b, 61c,... 61k,... 61n are arranged on the circumference, and any sorting pocket 61 corresponding to the electrical measurement value of the blank is selected. Is rotated by a drive mechanism provided at the lower part of the central shaft 62 so as to come to the position of the unloading point, and the measured blanks are sorted and collected in the respective sorting pockets according to the measured values. I am doing so.
Each of the plurality of sorting pockets 61 (a to n) sorts according to + error and -error values with respect to the standard measurement value of the blank, and otherwise cannot be measured (RI) And those that were outside the standard value tolerance (NG).
Reference numeral 63 denotes a clear arm for emptying the blank holding member 31, which is provided for cleaning out a blank that has already been measured at the second rotational position. The clear arm forcibly sucks and discharges the blank in the blank holding member 31 with a vacuum suction machine or the like, for example, so that the blank does not remain in the blank holding member 31 at the final position where the measurement table rotates once. It is clean.

  As described above, the piezoelectric blank sorter of the present invention is picked up by the picker 20 or the like at the first rotation position of the measurement table and picked up by the blank holding member and held at the second rotation position. In this case, the electrical characteristics of the blank held in the blank holding member are detected by the measurement electrode unit 40, and are discharged and separated and stored by the carry-out arm unit 50 at the third rotational position. The fine blank piece can be sorted and accommodated for each frequency characteristic with almost no external force applied.

FIG. 2 shows the side surface (partial cross section) of the measurement table 30 and the configuration of the blank holding member 31 and the electrode structure for measuring the electrical characteristics of the blank in the blank holding member 31.
As shown in this figure, on the circumference of the measurement table 30, a plurality of (six in this embodiment) stage electrodes 33, which are electrically insulated from the measurement table 30 by the insulating material 32. Is embedded, and the blank holding member 31 described above is fitted so as to surround the upper portion of the stage electrode 33.
The measurement table 30 is fixed to a shaft 35 that rotates the measurement table 30 by mounting screws 34, 34, and a lower portion of the shaft 35 is fixed to a rotation driving unit 36 that rotates the measurement table 30 intermittently at a predetermined timing. ing.

Reference numeral 80 denotes a base (fixed angle) that supports the measurement electrode unit 40. A stepping motor 81 is disposed above the base (fixed angle), and a rotating shaft 82 drives the cam plate 83.
Reference numerals 84a, 84b, and 84c denote frames that support a slide shaft 75 that slides the measurement electrode (upper electrode) 71 entering the blank holding member 31 in the vertical direction.

The measurement electrode 71 descends from above into the blank holding member 31 and is fixed to the measurement electrode support member 76 so as to approach the blank placed in the blank holding member 31 (not shown). .
Therefore, the measurement electrode support member 76 is supported so as to be guided in the vertical direction by the slide shaft 75 described above, and a bearing 78 fixed by a screw 77 is in contact with the cam plate 83 described above.
Therefore, when the cam plate 83 is rotated by the stepping motor 81, the bearing 78 in contact with the cam plate 83 moves in the vertical direction, and at the same time, the measurement electrode support member 76 also moves in the vertical direction.
When the measurement electrode support member 76 is guided by the slide shaft 75 and moves in the vertical direction, the measurement electrode 71 also moves up and down via the electrode attitude adjustment screw 74 (a, b) and the electrode position adjustment member 73.
Reference numeral 72 denotes a spherical bearing that rotatably supports the electrode position adjusting member 73 with respect to the measurement electrode support member 76.

A lower electrode 85 is configured to be positioned below the stage electrode 33 embedded in the measurement table 30. The lower electrode 85 is supported by the lower electrode support member 87 so as to be positioned very close to the stage electrode 33.
The lower electrode 85 is supported so as to be slightly rotated by the spherical bearing 86 with respect to the lower electrode support portion 87, and the distance and posture (levelness) of the lower electrode 85 with respect to the stage electrode 33 are adjusted in a plurality of postures. The screws 88a and 88b can be adjusted.
Reference numeral 89 denotes a terminal plate set screw from which a lead wire is drawn.

  When measuring the electrical constant of the blank, the measurement electrode (upper electrode) support member 76 is previously measured at a height when it is closest to the blank by a micro gauge (not shown), that is, the blank and the measurement electrode 71. The approach distance is adjusted and adjusted so that the cam plate 83 is lifted upward from the position.

FIG. 3 is an enlarged side view of the stage electrode 33, the measurement electrode 71, and the lower electrode 85, and the stage electrode 33 is insulated and embedded with respect to the measurement table 30 by an insulating material 32.
The position of the lower electrode 85 located below the stage electrode 33 is adjusted by adjusting screws 88a and 88b so as to face the stage electrode 33 through a gap G1 of several tens to several hundreds of μm.
The measurement electrode approaches the blank CB placed on the stage electrode 33 from above as indicated by a one-dot chain line, and the closest approach gap G2 at this time is also set to several tens to hundreds of μm.

A high frequency signal applied to measure the electrical constant of the blank is placed on the stage electrode 33 from the measurement electrode 71 via the gap G2 and from the lower electrode 85 via the gap G1. A measurement result obtained when the frequency of the alternating signal is swept within a certain range is supplied to the blank CB and analyzed by the network analyzer.
According to the measurement result of the electrical constant (AC impedance, phase change characteristics, etc.) analyzed by the network analyzer, the sorting of the carry-out destination by the next carry-out arm unit is converted into the rotation control signal of the sorting disk 60, Each blank approximated according to electrical characteristics is dropped into each sorting pocket 61 (an) and classified and collected.

FIG. 4 shows a blank grasping mechanism that is arranged at the tip of the picker (arm) 20 or the carry-out arm unit 50 shown above and is used to place a blank in the blank holding member 31 or carry it out of the blank holding member. It is explanatory drawing.
As shown in FIG. 2A, the tip of the picker arm or carry-out arm is composed of a narrow tube 23 extending downward and a gravity needle 24 inserted into the narrow tube 23, and the side wall of the narrow tube 23. Are formed with pores 25.
When picking up the workpiece w, as shown in FIG. 4 (b), when the thin tube 23 is guided above the workpiece w (blank) and the air in the tube is pulled upward at this position, the gravity needle 24 is drawn by the flow of the arrow shown in the drawing. Is lifted upward, and the workpiece w is adsorbed to the tip of the thin tube.
Next, when the flow of air in the tube is released, air flows in from the pores 25 as shown in FIG. 4C, and the gravity needle 24 hangs downward and is adsorbed on the tip of the narrow tube 23. The workpiece w is pushed downward and falls. By changing the size of the pores 25, it is possible to obtain an optimum adsorption force for the workpiece w.

  The above sorter can be applied to the process of processing a blank cut out from a crystal piece as a vibrator, but the material constituting the vibrator is an artificial material whose shape is deformed in response to an electrical signal. It goes without saying that it can be applied to blanks cut out from piezoelectric material.

The crystal resonator sorting apparatus according to the present invention sorts a blank obtained by cutting a piezoelectric element into a predetermined size for each electrical characteristic in the process of manufacturing a crystal resonator from a crystal piece. It is useful as a pre-process when performing polishing, etching, or attaching electrodes so as to obtain vibration conditions.
In addition, since the crystal blank selection process to which the present invention is applied can perform highly accurate selection, the accuracy of the final product as a device can be improved and the manufacturing yield can be improved.

It is a schematic diagram which shows the outline | summary of the piezoelectric blank piece sorter of this invention. It is the side view which looked at the structure of the measurement electrode part from the side as a partial cross section. It is an enlarged view which shows the positional relationship of a blank holding member, a measurement electrode, and a lower electrode. It is a side view which shows the principle of the picker for picking up a blank. It is explanatory drawing for demonstrating the selection process of a crystal piece.

Explanation of symbols

10 parts feeder, 20 picker arm, 30 measurement table, 31 blank holding member, 32 insulating material, 33 stage electrode, 40 measurement electrode section, 71 measurement electrode,
85 Lower electrode, 50 Unloading arm

Claims (3)

A plurality of stage electrode portions arranged at equal intervals along the circumference of the measurement table that is rotationally driven intermittently at a predetermined rotation angle;
A blank holding member disposed so as to surround the upper portion of the stage electrode portion ;
A picker section for supplying a blank into the blank holding member at a first rotational position of the measurement table;
A measurement electrode unit for measuring an electrical characteristic of the blank, in proximity to an upper electrode facing the blank placed on the stage electrode unit at a second rotational position of the measurement table;
A carry-out unit for sorting the blanks in the blank holding member based on the electrical characteristics measured by the measurement electrode unit at a third rotational position of the measurement table;
A piezoelectric blank piece sorter characterized in that a lower electrode is disposed on the stage electrode portion with a predetermined gap at a second rotational position of the measurement table .   2. The piezoelectric blank piece according to claim 1, further comprising a discharge portion that sucks and discharges the blank in the blank holding member at a fourth rotation position that has passed through the third rotation position of the measurement table. Sorting machine.   The picker part includes a thin tube and a gravity needle inserted into the thin tube, and is configured by a mechanism for sucking and releasing the gas in the thin tube through an opening drilled above the thin tube. The piezoelectric blank piece sorter according to claim 1, wherein the piezoelectric blank piece sorter is provided.

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