JPH0443774Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Field of Application> This invention relates to an apparatus for measuring the thickness of a thin plate having a thickness of approximately 1 mm, such as a wafer used in a semiconductor manufacturing process.

<Prior art> Thin plates are placed one by one on the table of various processing equipment and subjected to surface processing, but if the height of the upper surface varies greatly due to variations in thickness, the processing is performed at the micron level. This will affect the quality, characteristics, etc. of the manufactured thin plate. . Therefore, the thickness is measured and managed. In addition, warpage of several micrometers is likely to occur in such a thin plate during manufacture.

In conventional thickness measurements, this thin plate was placed on a surface plate, and a contact such as an electric micrometer was lowered into contact with the thin plate to measure its thickness. However, it is difficult to determine whether the lower surface of the measurement point is in close contact with the surface plate, and in some cases, the warpage of the thin plate may be included in the measured value as an error. Therefore, it was necessary to measure the pressure by applying more pressure than necessary, but this sometimes caused damage to the thin plate.

<Purpose of the present invention> The present invention improves the above-mentioned drawbacks of the conventional method, increases the measurement point by one point, eliminates the influence of warping, and easily obtains measurement values with high accuracy and no practical errors. The aim is to provide a measuring device that can.

<Example> Examples of the present invention will be described in detail below.

In the figure, reference numeral 1 denotes a base, and a column 2 is erected near one rear side of the base. The pillar 2
An arm 3 is attached horizontally in a cantilevered manner to the arm 3, which can be fixed at a vertically movable position and can be swung freely with bolts. For example, a moire scale is built in and a detector 4 connected to a display (not shown) is attached. Reference numeral 5 denotes a measuring element of the detector 4, and the tip thereof is formed into an arc shape 6 so as to make point contact with the object to be measured. The probe 5 moves up and down with respect to the main body of the detector, but if the probe escapes when not in use or when replacing an object to be measured, it should be lifted using a lever (not shown) or lifted directly with a finger. ing.

The base 1 has a mounting hole 8 in which an adjustment table 7 for positioning a reference axis, which will be described later, is mounted on the oscillation locus of the probe 5 of the detector 4 and approximately in the center of the base surface. and the pillar 2
A V-shaped notch 1a is formed on the front side of the base opposite to the base.

The adjustment table 7 is formed into a bottomed cylindrical shape with a flange 7a formed around the upper part, and the cylindrical part 7b is loosely fitted into the mounting hole 8 to provide a slight movement gap in the radial direction. It is fixed to base 1 from the top with screws. Further, the upper surface of the adjustment table is formed with a groove 7c in the diametrical direction so that a stored adjuster, which will be described later, can be easily taken out.

Reference numeral 9 denotes a reference shaft that penetrates through the bottom of the cylindrical body portion 7b of the adjustment table 7 and is screwed into it, and moves up and down.
The upper part 9a of the shaft is formed into a threadless cylinder.
Further, the tip is formed into an arc shape 9b.

When in use for measurement, the arcuate tip end thereof is adjusted so as to protrude slightly above the horizontal level of a support ball for mounting a thin plate, which will be described later.

Reference numeral 10 denotes a cylindrical adjuster used when aligning the measuring element 5 of the detector 4 and the reference shaft 9, and it is slidably fitted almost closely to the shaft portions of the measuring element and the reference shaft. The inner diameter can be formed, and the adjustment table 7
The outer diameter is such that it can slide in and out of the cylindrical body. Further, when the adjuster 10 is not in use, such as when measuring a thin piece, it is stored in the adjustment table 7 with the top surface lower than the tip of the reference shaft 9, and the reference shaft is inserted through it. A flange 10a is formed at the top.

Reference numeral 11 denotes a base plate fixed to the upper surface of the base 1 with screws, and is provided so as to surround the reference shaft 9 and the adjustment table 7 in the radial direction. Support balls 12... are arranged to protrude slightly (six in the illustrated example). As is clear from the cross-sectional view, the base plate 11 is intended to prevent the support ball 12 from coming off, and the support ball 12 is sandwiched between the top surface of the base 1 and the stepped portion of the top surface of the ball placement hole 11a of the base plate 11. .

Reference numeral 13 denotes pin mounting holes provided at appropriate radial pitches and circumferential intervals on a substantially concentric line with the measurement axis between the radial pitches in which the support balls 12 are arranged (as shown in the figure). In this case, there are eight pins), and mounting positioning pins 14 are provided in the holes 13 on the same circumference so that they can be inserted and removed according to the diameter of the thin plate A that is the object to be measured.

In the above embodiment configuration, when measuring the thickness of the thin plate A, when aligning the axis of the measuring stylus 5 of the detector 4 and the shaft upper part 9a of the reference shaft 9, first tighten the fixing screw of the adjustment table 7. Loosen it, move the adjustment table 7 slightly to position the reference shaft 9 on the circumference of the travel radius of the probe 5 of the detector, and fix it with screws at the matching position. This adjustment can be easily performed since the length of the arm 3, the position of the probe 5, etc. are clear.

Next, the detector support arm 3 is allowed to move freely relative to the column 2, the probe 5 of the detector 4 is positioned approximately coaxially with the reference axis 9, and the adjuster 10 is pulled up from within the adjustment table 7, and its upper end is The tip of the probe 5 is faced. Then, the arm 3 is adjusted by slightly moving so that the gauge head is inserted into the adjuster 10, and when the gauge head 5 and the shaft upper part 9a of the reference shaft 9 face into the adjuster, both axes are aligned. This means that the arm 3 is tightened and fixed to the support column 2. Therefore, the adjuster 10 has a cylindrical length that does not come off the reference shaft 9 during alignment. (See FIG. 3) After the above-mentioned axis alignment is completed, the adjuster 10 is stored in the adjustment table 7 again.

The above axis alignment has been explained for the case where the detector 4 is finally moved and adjusted by the arm 3, but it is also possible to fix the detector side and finally move and adjust the adjustment table 7 side. Needless to say, it can be decided arbitrarily.

After the axis alignment adjustment as described above, the thickness of the thin plate A as the object to be measured is measured. Depending on the content of the measurement, for example, when measuring the individual thickness of each thin plate, the reference axis It is sufficient to butt the gauge head 5 against the gauge head 5 and set the displacement amount indication value at that time to zero.Also, when making comparative measurements by setting the thickness tolerance range, measure a master piece whose value is known in advance. Adjust the reference value as necessary, such as by using the indicated value as the reference.

With the above adjustment, when the thin plate A as the object to be measured is placed on the base 1, the tip end arc shape 9 of the reference shaft 9
Since point b slightly protrudes from the horizontal plane of the support ball 12 on the base, the thin plate A will be slightly tilted in either direction, as shown in FIG.
However, the average thickness of the thin plate A is, for example, 1 mm.
In the case of a slope of a few degrees or less, the theoretical thickness measurement error can be reduced to a value that does not cause any problem in practice, even if the slope is a few degrees at most.

In the above embodiment, point support is provided by the support ball 12, but this is to prevent dirt or scratches from forming on the thin plate.The support ball and base plate are not required, and an adjustment table is provided on the base surface. It may be installed flush.

<Effects> As described in detail above, according to the main proposal,
Even if the thin plate has some warpage and is tilted when placed on the base, the tip of the reference shaft that supports the thin plate from below and the measuring head should be adjusted so that the measurement error is not a practical problem. It is stored in the adjustment table when not in use so that it can be held in alignment with the tip, and when in use, it is pulled up and the probe is inserted to align the axis with the reference axis. Since the adjuster is provided, the axis can be aligned easily and with high precision, and therefore the thickness of the thin plate can be measured with high precision.

[Brief explanation of the drawing]

The figures relate to one embodiment of the present invention, in which Fig. 1 is a partially sectional side view of the entire device taken along the line X-X shown in Fig. 2, Fig. 2 is a plan view of the base surface, and Fig. 3 is FIG. 4 is an explanatory diagram of the axis alignment, and FIG. 4 is an explanatory diagram of the measurement state of the thin plate. 1... Base, 2... Support, 3... Arm, 4
...detector, 5...measuring point, 6...arc-shaped part, 7...
...Adjustment table, 9...Reference axis, 9a...Axis upper part, 9b
...Arc-shaped portion, 10...Adjuster, A...Thin plate.

Claims (1)

[Scope of utility model registration request] When placing and supporting a thin plate, which is an object to be measured, on the base of a measuring device, a reference shaft is provided that protrudes an appropriate amount above the horizontal level of the support, and has an arcuate tip, and a reference shaft is placed opposite to the tip of the shaft. provided,
A thin plate thickness measuring device that measures the thickness of a thin plate by sandwiching the thin plate between the arcuate ends of the measuring tip of a detector supported by an arm, and the device slides almost closely on the reference shaft and the shaft of the measuring tip. When not in use, the reference shaft is inserted and stored at a position lower than the tip of the reference shaft into an adjustment table that has an inner diameter that can be freely fitted, supports the reference shaft, and adjusts its position in the horizontal direction of the base. A thin plate thickness measuring device equipped with an adjuster for axis alignment.