JP2002228409A - Electrode structure for measuring flatness of resonator blank wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a resonance frequency in a plurality of places on a quarts blank without relatively moving an electrode and the quartz blank. SOLUTION: Pair electrodes 22a1, 22a2 to 22e1, 22e2 are distributed and formed on a measuring stage 21. The quartz blank 11 is arranged on the stage 21. The pair electrodes 22a1, 22a2 to 22e1, 22e2 are connected respectively to connecting electrodes 23a1, 23a2 to 23e1, 23e2 through respective through holes 24. Contact pins 26a1, 26a2 to 26e1, 26e2 are brought into contact with the electrodes 23a1, 23a2 to 23e1, 23e2. One pair electrode from among the pair electrodes is changed over by switches 28, 29 so as to be connected to a measuring device 14, and the resonance frequency of each part on the blank 11 is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrode structure for measuring the flatness of a resonator blank wafer such as a quartz blank wafer or a ceramic blank wafer.

[0002]

2. Description of the Related Art As a crystal blank wafer such as a multi-electrode crystal becomes larger, it is necessary to measure the uniformity, that is, the flatness of each part of the crystal blank wafer. FIG. 3 shows a conventional quartz blank wafer flatness measurement technique.
The crystal blank wafer 11 is placed on the pair of electrodes 1 from above and below, for example.
2 and 13, the electrodes 12 and 13 are connected to a resonance frequency measuring device 14 such as a network analyzer, and a frequency sweep signal is applied from the measuring device 14 between the electrodes 12 and 13. The characteristic, for example, the current flowing between the electrodes 12 and 13 with respect to the frequency change is displayed on the display surface 15 including the polarity, and the resonance frequency of the crystal blank wafer 11 is measured at a plurality of locations of the crystal blank wafer 11, If the same resonance frequency is always obtained, it is determined that the crystal blank wafer 11 is flat.

In order to measure the resonance frequency at each part of the crystal blank wafer 11, the electrodes 12 and 13 and the crystal blank wafer 11 are conventionally moved relatively. Therefore, when the crystal blank wafer 11 is fixed and the electrodes 12 and 13 are moved, a gap of several tens of microns is provided between the electrodes 12 and 13 and the crystal blank wafer 11, and the gap is measured for the crystal blank wafer 11. It is necessary to maintain the same value at the point. Since the current between the electrodes 12 and 13 flows through the capacitive coupling in the gap, when the gap changes, the measured resonance frequency changes, and the flatness of the quartz blank wafer 11 cannot be measured correctly.

On the other hand, when the measurement is performed by moving the quartz blank wafer 11 with the electrodes 12 and 13 fixed, conventionally, the quartz blank wafer 11 is moved while the lower electrode 13 and the quartz blank wafer 11 are in close contact with each other. As a result, the quartz blank wafer 11 will be damaged. In order to move the quartz blank wafer 11 while keeping the gap between the electrodes 12 and 13 constant without bringing the quartz blank wafer 11 into close contact with the electrode 13, a very high-precision mechanism was required.

[0005]

As is apparent from the above, when the electrodes 12 and 13 and the quartz crystal blank wafer 11 are manually moved relative to each other, the gap between the electrodes and the quartz blank wafer is kept constant. And there is a problem in reproducibility, and it is difficult to put it to practical use in a production line. In order to mechanically perform relative movement between the electrode and the quartz blank wafer, the parallelism between the electrodes 12 and 13 needs to be about 1 μm or less, and when the quartz blank wafer is moved,
It is necessary to maintain the gap between the electrodes 12 and 13 with high precision. In any case, a high-precision mechanism is required, which is expensive, and the relative movement to each measurement position is mechanically performed. In order to achieve high accuracy,
The movement requires a certain amount of time and is not suitable for high-speed measurement. Further, as described above, there is a possibility that the quartz crystal blank wafer may be damaged.

[0006]

According to one aspect of the present invention, a resonator blank wafer is mounted on a plate-like measuring stage made of an electrically insulating material, and a pair of measuring blanks close to each other are mounted on the mounting surface. A plurality of pairs of plane electrodes are formed so as to be in surface contact with the mounted resonator blank wafer, and a plurality of pairs of measurement plane electrodes are connected to a measuring device for connection to a resonance frequency measuring device for each counter electrode. Means are provided. According to another embodiment of the present invention, a resonator blank wafer is mounted on a plate-like measuring stage made of an electrically insulating material, and at least one concave portion is formed on a surface opposite to the mounting surface, and a bottom surface of the concave portion is formed. A plurality of pairs of measuring electrodes approaching each other are formed. A plurality of measurement electrodes forming this pair may be provided in one recess, or one may be provided in one recess. Therefore, in the latter case, the plurality of recesses is always provided. Each measurement electrode is connected to a resonance frequency measuring device for each pair.

In any of the above embodiments, a plurality of pairs of electrodes are provided so as to be distributed so as to correspond to each position to be measured on the resonator blank wafer mounted on the measurement stage.

[0008]

FIG. 1 shows an embodiment of the present invention. A plate-like measurement stage 21 made of an electrically insulating material such as sapphire or ceramic is provided. Measurement stage 2
The upper surface 1 is a mounting surface 21a on which the crystal blank wafer 11 is mounted, and a pair of measurement plane electrodes 22a1 and 22a2, 22b1 and 22 close to the mounting surface 21a.
For example, b2 to 22e1 and 22e2 are formed. The measuring electrodes 22a1, 22a2 to 22e1, 22e2 have a size of, for example, about 1 mm × 1 mm to 2 mm × 2 mm, and the interval between the electrodes, for example, 22a1 and 22a2 is about a few mm. These electrodes are formed by photolithography, for example, after forming a metal layer on one surface of the mounting surface 21a by vacuum evaporation or the like. These planar electrodes for measurement 22 a 1, 22 a 2 to 22 e 1 and 22 e 2 are provided when the quartz crystal blank wafer 11 is mounted on the measurement stage 21.
The flatness of the mounting surface 21a is maintained so that the entire surface is in contact with the crystal blank wafer 11, and the thickness of each electrode is uniform. The measurement plane electrode pairs are distributed and arranged such that the measurement plane electrodes are in contact with each other. The mounting of the crystal blank wafer 11 on the measurement stage 21 is automatically performed by a handler mechanism, so that the crystal blank wafer 11 is placed at a desired position on the measurement stage 21.
Can be easily mounted.

Each of these measurement plane electrode pairs 22a1, 22
Measuring device connecting means for connecting to the resonance frequency measuring device 14 such as a network analyzer is provided for each of a2 to 22e1 and 22e2. In this example, FIG.
As shown in the cross section taken along the line 1B-1B of FIG. 1, the plane electrodes 22a1, 22a1 for measurement are provided on the surface opposite to the mounting surface 21a of the measurement stage 21.
The connection electrodes 23a1, 23a2 to 22a2 are opposed to the electrodes 22a2 to 22e1, 22e2 via the measurement stage 21, respectively.
23e1 and 23e2 are formed, and the measurement plane electrodes 22a1 and 22a2 to 22e1 and 22e2 and the connection electrode 2 are formed.
3a1, 23a2 to 23e1, 23e2 (23b in the figure)
1, 23b2, 23e1, and 23e2 are not shown) are connected to each other by respective through holes 24 formed through the measurement stage 21.

Further, in this example, the measurement stage 21 can be replaced according to the type (size) of the quartz blank wafer to be measured and the required accuracy of the measured flatness. That is, the contact pin holding substrate 25 is provided to face the connection electrode forming surface of the measurement stage 21. Each connection electrode 23 is provided on the contact pin holding substrate 25.
The contact pins 26a1, 26a2 to 26e1, 26e2 (26b1, 26b2, 26e1, 26e2 are not shown in the figure) are vertically erected in opposition to the contact pins 26a1, 23a2 to 23e1, 23e2.
Connection electrodes 23a1, 23a2 to 23e1, 23e2 are located on the tips of 1, 26a2 to 26e1, 26e2, respectively, and these are connected by contact. Contact pin 26a
1, 26a2 to 26e1 and 26e2 are inserted into and held by the contact pin holding substrate 25, and are held between the cylindrical portions held by the contact pin holding substrate 25 so as to be able to move in and out, and come out by a spring. The contact pin portions are biased in the direction, and each contact pin portion is elastically pressed against the corresponding connection electrode and is brought into contact therewith, so that reliable and good electrical connection with each electrode is obtained. I have. Such contact pins are known as pogo pins and are commercially available. That is, the contact pin 26a
Connection electrode 23a on 1, 26a2 to 26e1, 26e2
If the measurement stage 21 is arranged with the 1,23a2 to 23e1,23e2 positioned, good contact can be obtained between the contact pins and the connection electrodes. Although not shown in the drawing, the measuring stage 21 is detachably fixed to the contact pin holding substrate 25 by fixing means so as to obtain such a state.

Further, in this example, each measurement plane electrode 22a
1, 22a2 to 22e1 and 22e2 are connected to the resonance frequency measuring device 14 for each pair to measure the resonance frequency. The switch box 27 is provided with two changeover switches 28 and 29,
The other ends of 6a1 to 26e1 are lead wires 31a1 to 31e.
1, the fixed contacts 28a to 28 of the changeover switch 28
e, the other ends of the contact pins 26a2 to 26e2 are connected to the fixed contacts 29a to 29e of the changeover switch 29 through the lead wires 31a2 to 31e2, respectively, and the movable contacts 28v and 29v of the switches 28 and 29 resonate. It is connected to a pair of measuring terminals 16 and 17 of the frequency measuring device 14, respectively.

According to this configuration, the quartz blank wafer 1
1 is mounted on the measurement stage 21 and a changeover switch 2
8 and 29 are linked, for example, fixed contacts 28a and 29a
By connecting a movable contact to the
A frequency sweep signal is applied between 1,2a2 and this signal flows through that portion of the quartz blank wafer 11 so that the resonance frequency of this portion of the quartz blank wafer 11 can be measured. Similarly, by switching the switches 28 and 29, the measurement plane electrodes 22b1, 22b2
The resonance frequency of the crystal blank wafer 11 in each of the portions 22e1 and 22e2 can be measured. That is, the resonance frequency of each desired portion of the quartz blank wafer 11 can be measured without moving any of the quartz blank wafer 11 and the measurement electrodes, and the flatness of the quartz blank wafer 11 can be known.

The resonance frequency of each part can be measured by electrically switching the switch without mechanically moving the electrode and the quartz blank wafer relative to each other, thereby shortening the measurement time as compared with the case of mechanical movement. be able to. Next, another embodiment of the present invention will be described with reference to FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals. In this example, no measurement electrode is provided on the upper surface of the measurement stage 21, that is, on the mounting surface 21a. Measuring electrodes 41a1, 41a2 to 41e1, 41e2 are formed in pairs on the surface opposite to the mounting surface 21a of the measuring stage 21, respectively. In this example, the concave portions 42 are respectively formed in the measurement electrode formation portions of the measurement stage 21 by etching or the like, and the measurement electrodes 41a1, 41a2
41e1 and 41e2 are formed respectively, and the thickness between the bottom surface of the concave portion 42 and the mounting surface 21a is made as thin as possible, for example, 100
μm or less, each pair of measuring electrodes, for example, 41
The frequency sweep signal applied between a1 and 41a2 is made to easily pass through that portion of the crystal blank wafer 11 by capacitive coupling. The arrangement of these pairs of measurement electrodes is determined in the same manner as in the above-described embodiment.

In this example, each pair of measurement electrodes 41a
A through-hole 43 is formed in the measurement stage 21 between slits 1 and 41a2 to 41e1 and 41e2 in a slit shape in FIG. As in the example shown in FIG. 1, a contact pin holding substrate 25 is arranged so as to face the measurement electrode side of the measurement stage 21, and the contact pins 2 are provided on the contact pin holding substrate 25.
6a1, 26a2 to 26e1 and 26e2 are erected, and their respective tips are measured electrodes 41a1, 41a2 to 41e, respectively.
1, 41e2. The contact pins 26a1, 26a2 to 26e1, 26e2 are configured to be connected to the resonance frequency measuring device 14 via the changeover switches 28, 29.

Also in this case, it is possible to measure the resonance frequency of the corresponding portion of the crystal blank wafer 11 by applying a frequency sweep signal to each pair of measurement electrodes, and to measure the flatness of the crystal blank wafer 11. Is easy to understand. In this embodiment, since the quartz crystal blank wafer 11 does not directly contact the measurement electrodes 41a1, 41a2 to 41e1, 41e2, there is no possibility that the quartz crystal blank wafer directly contacts the measurement electrodes and wears the measurement electrodes. In addition, when air enters between the crystal blank wafer 11 and the mounting surface 21a and the resonance frequency cannot be measured due to inability to adhere, or conversely, the crystal blank wafer 11 and the mounting surface 21a are in a state of being closely attached and adsorbed. It may be difficult to remove the crystal blank wafer 11 from the measurement stage 21, but these problems do not occur when the through hole 43 is formed as in the example shown in FIG. In addition, as shown in FIG.
Are formed so as to separate them from each other, the lines of electric force between the pair of measurement electrodes pass through the quartz crystal blank wafer 11 without passing through the inside of the measurement stage 21, and are affected by the measurement stage 21. Can be minimized.

When only the problem of the close contact of the crystal blank wafer 11 with the measuring stage 21 is to be solved, the position of the through hole 43 need not be provided between the electrodes. In addition, even when provided between the electrodes, it is not always necessary to provide between all the electrodes. If there is a possibility that the problem of adhesion of the measurement stage 21 of the quartz crystal blank wafer 11 may occur in the example shown in FIG. In the example shown in FIG. 2, the concave portion 42 is formed for each pair of the measurement electrodes. However, the concave portion 42 having a relatively large area is formed, and a plurality of pairs of the measurement electrodes are formed into one concave portion 42.
May be formed on the bottom surface. One extreme electrode for all measurements
It may be formed on the bottom surface of the two concave portions 42. Further, the measurement stage 21 is a sufficiently thin plate of, for example, about 100 μm or less, and is provided with measurement electrodes 41a1, 41a2 to 41a.
The e1 and 41e2 may be formed, and the measurement stage 21 may be reinforced with an appropriate frame if necessary.

In any of the embodiments shown in FIGS. 1 and 2, the measuring stage 21 does not necessarily have to be replaceable.
In this case, the connection electrodes 23a1, 23a2 to 23e1,
23e2, measuring electrodes 41a1, 41a2 to 41e1, 4
1e2, the frequency measuring device 14 or the switches 28, 2
9 may be directly connected to one end of the lead wire. Alternatively, a plurality of resonance frequency measuring devices 14 may be provided to simultaneously measure the resonance frequencies at a plurality of locations on the quartz crystal blank wafer 11. Electronic switches can be used as the switches 28 and 29, and a computer can execute a program to automatically switch and connect each pair of electrodes to the measuring instrument 14. Further, the present invention can be applied to the measurement of flatness of not only a quartz crystal blank wafer but also other resonator blank wafers such as a ceramic resonator.

[0018]

As described above, according to the present invention, it is possible to measure the resonance frequency of each part of the resonator blank wafer without relatively moving the resonator blank wafer and the electrodes. It is not necessary to control the gap between the daughter blank wafer and the electrode, the structure as a whole becomes very simple, and the measurement can be performed with high accuracy. Further, there is no possibility of damaging the resonator blank wafer.

[Brief description of the drawings]

1 shows an embodiment of the present invention, wherein A is a plan view, and B is a cross-sectional view taken along the line 1B-1B in FIG. 1A.

FIG. 2 shows another embodiment of the present invention, wherein A is a plan view,
FIG. 2B is a sectional view taken along line 2B-2B of FIG. 2A.

FIG. 3 is a diagram showing a configuration of a conventional flatness measuring device for a quartz crystal blank wafer.

Claims (7)

[Claims] 1. A resonator comprising: a plate-like measurement stage made of an electrically insulating material on which a resonator blank wafer is mounted; and a resonator which is formed close to a surface of the measurement stage on which the resonator blank wafer is mounted; A plurality of pairs of measurement plane electrodes that are in surface contact with the blank wafer, and measurement device connection means connected to the plurality of pairs of measurement plane electrodes and connected to a resonance frequency measurement device for each counter electrode. Resonator blank wafer flatness measurement electrode structure. 2. The measurement device connection means includes a plurality of connection electrodes connected to each of the plurality of pairs of electrodes and formed on a surface of the measurement stage opposite to a surface on which a resonator blank wafer is mounted. 2. The electrode structure for measuring flatness of a resonator blank wafer according to claim 1, wherein: 3. The measuring device connecting means includes: a contact pin holding substrate arranged opposite to the connection electrode side of the measurement stage; and a standing member mounted on the contact pin holding substrate. 3. The electrode structure for measuring flatness of a resonator blank wafer according to claim 2, further comprising a plurality of contact pins connected in contact. 4. A plate-like measurement stage made of an electrical insulating material on which a resonator blank wafer is mounted, and a plurality of pairs of a plurality of pairs formed close to each other on a surface of the measurement stage opposite to the resonator blank wafer mounting surface. A resonator blank wafer flatness measurement electrode structure comprising: a measurement electrode. 5. The resonance according to claim 4, wherein at least one concave portion is formed on the measurement electrode forming surface of the measurement stage, and the measurement electrode is formed on a bottom surface of the concave portion. Substrate blank wafer flatness measurement electrode structure. 6. A hole penetrating the measurement stage between at least one pair of electrodes of the plurality of pairs of measurement electrodes.
The electrode structure for flatness measurement of a resonator blank wafer as described in the above. 7. A contact pin holding substrate arranged to face the measurement electrode of the measurement stage, and a plurality of contact pins erected on the contact pin holding substrate and connected to the measurement electrodes. The electrode structure for measuring flatness of a resonator blank wafer according to any one of claims 4 to 6, wherein the electrode structure is provided.