JP3300664B2 - Dimension measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimension measuring device for measuring minute dimensions such as a hole diameter of a machine detail and a line width of a wiring pattern, and more particularly to a dimension of a minute part existing in a narrow place. TECHNICAL FIELD The present invention relates to a dimension measuring device suitable for measuring a size.

[0002]

2. Description of the Related Art In recent years, there has been a demand for the development of a dimension measuring device for accurately measuring the dimensions of a micro member or a micro site existing in a narrow place in a micro machine, a light emitting device, various devices, and the like. Conventionally, the measurement of the size of a minute member or a minute portion has been performed using an optical microscope, a fiberscope, or the like. Meanwhile, the optical microscope has a problem that it cannot be used because it cannot focus on a part existing in a narrow part because the focal length from the object to be measured is as large as about several mm. A normal fiberscope having a self-hoc lens at the tip is suitable for being inserted into a narrow space and performing observation and measurement of the inside, but has a low resolution of 20 μm (observation distance: about 1 mm). is there.

As a method for increasing the resolution of a fiberscope, a fiberscope having no objective lens such as a cell hook lens (hereinafter, referred to as a contactscope) is used, and an object surface at the tip of the fiberscope is measured for a size to be measured. The method of making direct contact with is well known. According to this direct contact method, a resolution up to a pixel diameter (about 4 μm) can be theoretically obtained.

However, in the direct contact method described above, since the field of view of the contact scope is extremely narrow, it is necessary to displace the relative position between the object to be measured and the object plane of the contact scope by at least the measured dimension for dimension measurement. Since the object plane of the contact scope is directly in contact with the object to be measured, there is a problem that the displacement of the relative position is difficult.

By the way, according to the study of the present inventor for the purpose of taking advantage of the high resolution of the direct contact method, unexpectedly, the object plane of the contact scope is more unexpectedly brought into contact with the object to be measured. It has been found that the resolution is slightly improved by, for example, about 1 μm. Moreover, by separating the object plane of the contact scope from the object to be measured, displacement of the relative position between the two can be facilitated, and the work of dimension measurement can be performed smoothly. Also reduces variation.

[0006]

SUMMARY OF THE INVENTION The present invention has been completed based on the above-mentioned completely unexpected new findings,
The problem to be solved by the present invention is to provide a novel dimension measuring device which can take advantage of the high resolution advantage of the direct contact method and can overcome the problem of relative position displacement. In other words, an object of the present invention is to provide a dimension measuring device that can measure a minute dimension of a dimension measurement target existing in a narrow location using a contact scope.

[0007]

SUMMARY OF THE INVENTION The above-mentioned problems are solved by the following dimension measuring device. (1) A contact scope, a sensor capable of sensing that the object plane of the contact scope approaches or comes into contact with the measured object, and a lateral displacement means capable of displacing the relative position of the measured object and the contact scope in the lateral direction. And a vertical position adjusting means for adjusting a vertical relative position between the object plane of the contact scope and the object to be measured. (2) The dimension measuring device according to (1), wherein the sensor is capable of detecting that the object plane of the contact scope has approached within a range of 0 to 5 μm from the object to be dimensioned. (3) The dimension measuring device according to (1) or (2), wherein the lateral displacement means is an X stage or an XY stage. (4) The vertical position adjusting means is a Z stage (1).
Or the dimension measuring device according to (2). (5) Any one of the above (1) to (4), wherein the vertical position adjusting means can adjust and set the distance between the object plane of the contact scope and the object to be measured within a range of 0.2 to 5 μm. The dimension measuring device described in Crab.

[0008]

The distance between the sensor and the vertical position adjusting means can improve the resolution of the contact scope (the vertical relative position between the object plane of the contact scope and the object to be measured), for example, 0.2 to 5 μm. The size of the desired portion to be measured can be measured from the lateral displacement of the lateral displacement means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a conceptual sectional view of an apparatus according to an embodiment of the present invention. FIGS. 2 to 4 are explanatory diagrams for explaining a method of measuring dimensions by the apparatus of the embodiment of FIG. FIG. 5 is an explanatory view of the visual field of the contact scope in FIG.
FIG. 5 is an explanatory diagram of a field of view of a contact scope in FIG. 4. FIG. 7 is an enlarged view of an example of the object plane of the contact scope. FIG. 8 is an enlarged view of another example of the object plane of the contact scope. FIG. 9 is an explanatory diagram for explaining a method of measuring dimensions by the apparatus according to another embodiment of the present invention. FIG.
It is an explanatory view explaining a method of size measurement by a device of another example of the present invention.

In FIGS. 1 to 4 and FIGS. 7 to 10,
1 is a contact scope, 2 is a vertical position adjusting means, 3
Is a contact sensor as one embodiment of the sensor, and 5 is a lateral displacement means.

As the contact scope 1, an ordinary fiber scope formed of a bundle of optical fiber wires can be used. Each optical fiber in the bundle is
It may be made of glass such as quartz glass or multi-component glass, or made of synthetic resin. Also, the refractive index distribution of each core in the optical fiber may be a step index type, a multi-mode type, or the like. Although the number of pixels of the bundle is not particularly limited, it is 2,000 to 10
A suitable value is about 0000, especially about 5,000 to 50,000.

The vertical position adjusting means 2 is preferably capable of adjusting and installing the position (height) of the contact scope 1 with an accuracy of at least about 0.5 μm, preferably at least about 0.1 μm. The same gear operation mechanism as the vertical movement means of the lens barrel as used in the optical microscope described above, the Z stage in which various X stages for the lateral displacement means 5 described later are assembled for the vertical direction, and the like are exemplified. obtain.

The contact sensor 3 comprises a main body portion 32 and a tactile projection 33 having a constant height h. The tactile projection 33 is provided around the tip of the contact scope 1 and can move up and down as indicated by an arrow A. When the distal end surface 31 of the projection 33 moves upward in the direction of the arrow A by contacting with another object, an electric system or an optical system (for example, an electric system or an optical system) that transmits the movement distance to, for example, a programmable controller PC described later in FIG. (Not shown) in the contact scope 1. The tactile projection 33 always protrudes below the objective surface 11 of the contact scope 1 (see FIG. 1), and when the tip surface 31 is pressed against the surface of the object 4, the tactile projection 33 moves upward in the direction of arrow A. The object plane 11 can directly contact the surface of the object 4 (see FIG. 2). Therefore, by measuring the amount of movement of the tactile projection 33 of the contact sensor 3 by the vertical position adjusting means 2, the object plane 11 of the contact scope 1 approaches the surface of the object 4 within the range of the height h. Further, it can be known that the object plane 11 of the contact scope 1 has directly contacted the surface of the object 4. Specific examples of the contact sensor 3 include those described in JP-A-6-190050. In the present invention, a non-contact sensor using laser light may be used as the sensor other than the contact sensor such as the contact sensor 3.

Examples of the lateral displacement means 5 include an X stage and an XY stage with a micrometer, an automatic X stage and an automatic XY stage with a positioning function using a stepping motor, a DC servo motor, an AC servo motor, and the like. Is done. In particular, it is preferable to be able to measure the moving distance in the X direction or the X direction and the Y direction with an accuracy of at least about 0.5 μm, preferably at least about 0.1 μm.

Next, referring to FIGS. 1 to 6, the diameter of the circular hole 41 existing on the surface of the object 4 placed on the lateral displacement means 5, that is, the distance between a and b (that is, the object to be measured). The measurement method of will be described. First, in FIG. 1, the lateral displacement means 5 is operated so that the entire circular hole 41 substantially enters the field of view of the contact scope 1, and then the object plane 11 of the contact scope 1 is operated by operating the vertical position adjusting means 2. After approaching the surface of the object 4 and the front end surface 31 of the contact sensor 3 comes into contact with the surface of the object 4, the contact scope 1 is gradually lowered in accordance with a signal from the contact sensor 3 to gradually lower the object surface 11.
Is once brought into contact with the surface of the object 4. FIG.
Shows a state in which is in contact with the surface of the object 4.

Next, the contact scope 1 is slightly moved upward by the vertical position adjusting means 2 and stopped. The distance between the object plane 11 and the surface of the object 4 in the stopped state is X
Then, the interval X may be 0, but the contact scope 1
Is preferably about 0.2 to 5 μm, particularly about 0.5 to 2 μm, from the viewpoint of improving the resolution of the image. Next, in a state where the interval X is kept within the above range, while observing the visual field of the contact scope 1, the lateral displacement means 5 is precisely operated to form a cross-shaped mark on the object plane 11 of the contact scope 1. Peripheral edge 42 of circular hole 41 on vertical line 122 of sign 12
The arc on the left side (point a side) is in contact with the horizontal line 1 of the marker 12.
The upper part of the peripheral edge 42 of the circular hole 41 is in contact with 21. Thus, the vertical line 122 comes over the point a, and the exact coordinate position of the point a is determined by the vertical line 122. 3 and 5 show this state.

Next, while keeping the distance X within the above range, the horizontal displacement means 5 is operated in the same manner as described above while observing the visual field of the contact scope 1 so that a circular hole is formed in the vertical line 122 of the marker 12. The arc on the right side (point b side) of the peripheral edge 41 of the edge 41 is in contact with the arc above the peripheral edge 42 with the horizontal line 121. Then, a vertical line 122 comes on point b,
The exact coordinate position of point b is determined by vertical line 122. 4 and 6 show this state. Thus, the distance between a and b can be accurately measured from the moving distance of the lateral displacement means 5 in the X direction.

As shown in FIGS. 5 and 6, when the circular hole 41 to be measured is small and fits entirely within the field of view of the contact scope 1, the coordinate positions of the points a and b are set. By determining that the horizontal line 121 and the arc above the peripheral edge 42 are in contact with each other, the distance between a and b passing through the center of the circle of the peripheral edge 42 can be measured, and thus the diameter of the correct circle can be measured. On the other hand, when the circular hole to be measured is larger than the field of view of the contact scope 1, the lateral displacement means 5 is first installed so that the horizontal line 121 of the marker 12 passes through the center of the circular hole. The intersection of the horizontal line 121 and the vertical line 122 is aligned with the point of the circular hole corresponding to the point a, and then the horizontal displacement means 5 is moved to move the horizontal line 121 and the vertical line to the point of the circular hole corresponding to the point b. 12
What is necessary is just to match the intersection of 2 and measure the moving distance between them.

FIGS. 1 to 4 show an example of the operation of the vertical position adjusting means 2 and the horizontal displacement means 5 of the contact scope 1. In summary, the object plane 11 of the contact scope 1 is formed by an arbitrary method or procedure. The distance between the object and the object to be measured such as the circular hole 41 of the object 4 is set to the fine distance X (FIG. 3).
And the state shown in FIG. 4) to perform necessary measurement.

When the state shown in FIGS. 3 and 4 is obtained through the procedure shown in FIGS. 1 and 2 or other procedures,
Since the interval X is on the order of submicron to micron, it is practically difficult without a sensor such as the contact sensor 3. The reason is as follows.

In setting the interval X, it is necessary to recognize the degree of closeness when the object plane 11 is close to the object to be measured or the state of direct contact (X = 0).
This is because it is necessary to inform the vertical position adjusting means 2 of the degree of closeness and the state of direct contact, or to know from the vertical position adjusting means 2. A known height h as the contact sensor 3
When the one having the tactile projection 33 having the following is used, the interval X can be accurately measured on the order of submicron to micron from the amount of movement of the tactile projection 33 in the upward direction of the arrow A (see FIG. 1).

Regarding the distance X between the object plane 11 and the object to be measured, the shape of the object plane 11 can be artificially formed and controlled. In many cases, it is not strictly parallel to the plane (for example, the center plane of the objective plane 11). Therefore, in the present invention, in such a case, the object plane 1 for each portion of the dimension measurement target is
What is necessary is just to take the average value of the interval with one specific surface (for example, the center surface of the objective surface 11). Alternatively, when the level difference between the portions to be measured is large, the interval X may be set to the above range for each portion.

If the interval X is slightly increased as described above rather than 0 μm, the illumination in the field of view of the contact scope 1 becomes good and the image of the portion to be measured is sharpened. The resolution is improved, and as a result, the cross-shaped marker 12 engraved on the object plane 11 of the contact scope 1 can be made to exactly match the measurement point (such as the point a in FIG. 3) to be measured. More accurate dimensional measurements are achieved. The interval X is 0 μm
Assuming that the MTF (modulation transfer function) value in the case of (1) is 1, the value when the interval X is, for example, 1 μm is about 1.5.

The illuminating means in the contact scope 1 may be any of those commonly used in the art. For example, a mode in which a plurality of illuminating fibers are provided on the outer periphery of a bundle of fiber strands, individual optical fiber elements constituting the bundle A mode in which part or all of the core or cladding layer of the wire is also used as a transmission path for illumination light, an aspect in which an individual optical fiber constituting a bundle has a transmission layer for illumination light, or other May be adopted.

Among the above-mentioned lighting means, a mode in which a part or all of the cores and cladding layers of the individual optical fiber wires forming the bundle are also used as a transmission path of the light for illumination, the individual light forming the bundle In an embodiment using a fiber having a transmission layer for illuminating light as a fiber, the illuminating light is radiated from the entire surface of the object plane 11 of the contact scope 1, so that the illumination at the time of measurement is more effective. On the other hand, in the aspect in which a plurality of illumination fibers are provided on the outer periphery of the bundle of the fiber strands, if the objective surface 11 is flat, the illumination of the central portion of the objective surface 11 is likely to be insufficient.
The objective surface 11 is made convex as shown in FIG. 8, or the objective surface 11 is made concave as shown in FIG. 8, so that the circular hole 41 of the object 4 is illuminated with the illumination light component L shown in those drawings. Is preferred.

In FIG. 9, the object 4 has a wiring pattern 43 to be measured on its surface, and the entire object 4 is housed in a perforated package 6. 61 is
An approximately square small hole with one side d provided on the upper wall of the package 6. It is not possible to measure each line width W of the wiring pattern 43 with a normal optical microscope because the objective lens of the optical microscope cannot approach the wiring pattern 43 due to the presence of the upper wall of the package 6. According to the present invention, the line width W can be measured. In this case, the contact scope 1 is inserted into the package 6 through the small hole 61, and the object plane 11 is held on the wiring pattern 43. On the other hand, the object 4 is placed on the lateral displacement means 5 with the package 6 and Let me move to. However, it is sufficient that the left and right moving distance is equal to or slightly larger than the line width W of the wiring pattern 43, which is usually much smaller than one side d of the small hole 61 of the package 6. Therefore, the contact scope 1 only has to be inserted into the small hole 61 and moved vertically by the vertical position adjusting means 2. When the package 6 is moved left and right by the lateral displacement means 5 in such a state, the contact scope 1 can be relatively displaced left and right in the small hole 61 and the line width W can be measured.

FIG. 10 shows an example of an automatic dimension measuring apparatus using an automatic stage as an example of the vertical position adjusting means and the horizontal position adjusting means. In the figure, 1 is a contact scope, 2 is an automatic Z stage, 4 is an object having a surface to be measured (not shown), 5 is an automatic XY stage, S is a controller, PC is a programmable controller, CN Is a contact measuring device, J is a johnite provided at one end of the contact scope 1, LS is a light source, and C is a CCD.
Camera and M are monitors. Illumination light from the light source LS is transmitted to the contact scope 1 via the Joid J, and the transmitted light is emitted from the object plane 11 to illuminate the object 4 to be measured. Contact scope 1
The presence or absence of contact of a contact sensor (not shown) provided on the object plane 11 with the object to be measured is measured by an electric system or an optical system (not shown) provided in the contact scope 1. It is transmitted to the device CN and then to the programmable controller PC.

The principle and operation procedure of the dimension measurement by the automatic dimension measuring apparatus shown in FIG. 10 are basically the same as the method described with reference to FIGS. 1 to 6 above. The controller S, the programmable controller PC, and the It is only performed automatically by the CCD camera C. Therefore, in the following, description will be made using the description of FIGS. The dimension measurement target is
The distance between the points a and b of the circular hole 41 on the surface of the object 4 is set.

First, upon receiving a signal from the contact measuring device CN and a signal from the CCD camera C and the monitor M, the programmable controller PC operates the automatic Z stage 2,
The contact scope 1 is brought to the state of FIG. At this time, the programmable controller PC detects that the object plane 11 of the contact scope 1 has come into contact with the surface of the object 4 via the contact measuring device CN, and then activates the automatic Z-stage 2 to plot the contact scope 1. Bring to state 3. In this state, the programmable controller PC operates the automatic XY stage 5 via the controller S to align the marker 12 with the end of the circular hole 41 on the monitor M as shown in FIG. Next, the programmable controller PC is connected to the automatic XY stage 5 via the controller S.
To operate the contact scope 1 in FIGS. 4 and 6.
Bring to the state. Thus, the dimension between points a and b is automatically measured.

[0030]

By using a sensor such as a contact sensor and a vertical position adjusting means such as a Z stage, the object plane of the contact scope can be set slightly away from the object to be measured, and as a result, the resolution of the contact scope can be improved. Is improved. Further, by separating the two, the lateral relative position between the object plane of the contact scope and the object to be measured can be easily displaced by using a lateral displacement means such as an X stage or an XY stage. Can more accurately measure the dimensions of the measurement target.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional view of an apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a method of dimension measurement by the apparatus of the embodiment of FIG. 1;

FIG. 3 is an explanatory diagram for explaining a method of measuring dimensions by the apparatus of the embodiment of FIG. 1;

FIG. 4 is an explanatory diagram for explaining a method of dimension measurement by the apparatus of the embodiment of FIG. 1;

FIG. 5 is an explanatory diagram of a field of view of a contact scope in FIG. 3;

FIG. 6 is an explanatory view of a field of view of a contact scope in FIG. 4;

FIG. 7 is an enlarged view of an example of an object plane of a contact scope.

FIG. 8 is an enlarged view of another example of the object plane of the contact scope.

FIG. 9 is an explanatory diagram for explaining a method of dimension measurement by the apparatus according to another embodiment of the present invention.

FIG. 10 is an explanatory diagram for explaining a method of dimension measurement by an apparatus according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Contact scope 2 Longitudinal position adjustment means 3 Contact sensor 4 Object, 41 Circular hole provided in object 4 and subjected to dimension measurement 5 Lateral displacement means

Claims (5)

(57) [Claims] 1. A contact scope, a sensor capable of sensing that an object plane of the contact scope approaches or comes into contact with a measurement target, and a lateral direction capable of displacing a relative position of the measurement target and the contact scope in a horizontal direction. A dimension measuring device comprising: a displacement unit; and a vertical position adjusting unit that can adjust a vertical relative position between an object plane of a contact scope and a measurement target. 2. The dimension measuring apparatus according to claim 1, wherein the sensor is capable of detecting that the object plane of the contact scope has approached within a range of 0 to 5 μm from the dimension measurement target. 3. The apparatus according to claim 1, wherein the lateral displacement means is an X stage or an X stage.
3. The dimension measuring device according to claim 1, wherein the dimension measuring device is a Y stage. 4. The dimension measuring device according to claim 1, wherein the vertical position adjusting means is a Z stage. 5. The vertical position adjusting means sets the distance between the object plane of the contact scope and the object to be measured to 0.2 to 5 μm.
The dimension measuring apparatus according to any one of claims 1 to 4, wherein the dimension measuring apparatus can be adjusted and installed within a range of m.