CN113218315A - Thickness measuring method, device and system - Google Patents

Abstract

The embodiment of the invention relates to the technical field of measuring methods, and discloses a thickness measuring method, device and system.

Description

A thickness measurement method, device and system

technical field

Embodiments of the present invention relate to the technical field of measurement methods, and in particular, to a thickness measurement method, device, and system.

Background technique

Integrated circuits include a variety of semiconductor devices. Among these semiconductor devices, the chips usually use wafers such as silicon wafers as the substrate or base layer, and then are processed by lithography, etching, thin film and other semiconductor integrated circuit processes. into various electronic components and wires, so as to make a miniaturized and highly integrated semiconductor chip. In the process of manufacturing such semiconductor devices, in order to ensure the high yield of wafers such as silicon wafers, the 3D profiler measurement method has become a widely used solution due to its unique high efficiency, accuracy and non-contact. Program.

In the process of implementing the embodiments of the present invention, the inventor found that there are at least the following problems in the above related technologies: at present, the thickness measurement of the 3D profile measuring instrument relies on the monitoring of the internal temperature change of the measuring instrument, and the temperature compensation is performed on the measured value through coefficient calculation. The method is only suitable for correcting slow temperature changes, or production environments that require constant temperature, and cannot make accurate corrections for normal room temperature changes. Therefore, under certain circumstances, such methods require personnel to shut down, perform standard calibration procedures, and perform shutdown verification of high-speed pipelines, which affects production efficiency to a certain extent, and the accuracy of measurement data cannot be guaranteed.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a method, device and system for thickness measurement with high accuracy.

The purpose of the embodiment of the present invention is achieved through the following technical solutions:

In order to solve the above technical problems, in the first aspect, the embodiment of the present invention provides a thickness measurement method, which is applied to a thickness measurement system, and the method includes:

Obtain the current detection thickness of the object to be measured;

Obtain the thickness variation of the calibration object to obtain the temperature drift variation of the object to be measured;

According to the temperature drift change amount, the current detected thickness is compensated to obtain the actual thickness of the object to be detected.

In some embodiments, the thickness measurement device includes a first three-dimensional profile measuring instrument and a second three-dimensional profile measuring instrument with opposite light-emitting directions,

The obtaining the current detection thickness of the object to be measured further includes:

Collect a preset number of first height data of the object to be measured by the first three-dimensional profile measuring instrument;

Collect a preset number of second height data of the object to be measured by the second three-dimensional profile measuring instrument;

According to the first height data and the second height data, the currently detected thickness of the object to be measured is obtained by calculation.

In some embodiments, calculating the current detected thickness of the object to be measured according to the first height data and the second height data, further includes:

Select N valid pixels in the preset number of the first height data and the second height data, where from the nth pixel to the n+Nth pixel is the valid pixel, n and N are all positive integers;

The current detection thickness of the object to be measured is calculated according to the first height data and the second height data of the N valid pixels, wherein the calculation formula is as follows:

Wherein, T ₁ is the current detection thickness of the object to be measured, Z _a is the first height data, Z _b is the second height data, and N ₁ is the first height data or the first height data of the object to be measured. The number of valid pixels in the two height data, n ₁ is the serial number of the first valid pixel in the first height data or the second height data of the object to be measured.

In some embodiments, before the acquiring the current detected thickness of the object to be measured, the method further includes:

judging whether the scanning rays emitted by the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument can be completely coincident when they are directed toward each other;

If not, adjust the position or light emitting direction of the first three-dimensional profile measuring instrument or the second three-dimensional profile measuring instrument, so that the scanning rays of the two three-dimensional profile measuring instruments are completely coincident when they are directed toward each other.

In some embodiments, the number of the calibration objects is at least one, the calibration objects are arranged on both sides of the object to be measured, and the thickness direction of the object to be measured is consistent with the thickness direction of the object to be measured when placed,

The acquiring the thickness variation of the calibration object to obtain the temperature drift variation of the object to be measured further includes:

respectively acquiring the current average thickness data of the at least one calibration object;

obtaining standard thickness data of the calibration object;

According to the current average thickness data and the standard thickness data, the temperature drift change amount of the object to be measured is calculated.

In some embodiments, the calibration object includes a first calibration object and a second calibration object,

The acquiring, respectively, the current average thickness data of the at least one calibration object further includes:

The current thickness data of the at least one calibration object is obtained by the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument, respectively, so as to obtain the current average thickness data of the at least one calibration object.

In some embodiments, the calculation formula of the current thickness data of the first calibration object is as follows:

Wherein, T ₂ is the current thickness data of the first calibration object, Z _c is the first height data of the first calibration object collected by the first three-dimensional profilometer, and Z _d is the second three-dimensional The second height data of the first calibration object collected by the profile measuring instrument, N ₂ is the first height data of the first calibration object or the number of valid pixels in the second height data, and n ₂ is the first height data of the first calibration object. A serial number of the first valid pixel point in the first height data or the second height data of the calibration object.

In some embodiments, the calculation formula of the current thickness data of the second calibration object is as follows:

Wherein, T ₃ is the current thickness data of the second calibration object, Z _e is the first height data of the second calibration object collected by the first three-dimensional profilometer, and Z _f is the second three-dimensional The second height data of the second calibration object collected by the profile measuring instrument, N ₃ is the first height data of the second calibration object or the number of valid pixels in the second height data, and n ₃ is the first height data of the second calibration object. 2. The serial number of the first valid pixel point in the first height data or the second height data of the calibration object.

In some embodiments, the calculation formula for obtaining the current average thickness data of the at least one calibration object is as follows:

Wherein, T ₀ is the current average thickness data of the at least one calibration object, T ₂ is the current thickness data of the first calibration object, and T ₃ is the current thickness data of the second calibration object.

In some embodiments, the temperature drift variation is calculated according to the current average thickness data and the standard thickness data, and the current detected thickness is compensated to obtain the actual thickness of the object to be measured ,Calculated as follows:

为所述待测物体的实际厚度，T₁为所述待测物体的当前检测厚度，T₀为所述至少一个标定物体的当前平均厚度数据，C为标定常量。in,

is the actual thickness of the object to be measured, T ₁ is the current detected thickness of the object to be measured, T ₀ is the current average thickness data of the at least one calibration object, and C is a calibration constant.

In order to solve the above technical problems, in the second aspect, the embodiment of the present invention provides a thickness measurement device, which is applied to a thickness measurement system, and the device includes:

The first acquisition module is used to acquire the current detection thickness of the object to be measured;

The second acquisition module is used to acquire the thickness variation of the calibration object, so as to obtain the temperature drift variation of the object to be measured;

The compensation module is used for compensating the current detected thickness according to the temperature drift change amount, so as to obtain the actual thickness of the object to be measured.

In some embodiments, the thickness measurement device includes a first three-dimensional profile measuring instrument and a second three-dimensional profile measuring instrument with opposite light-emitting directions,

The first acquisition module is further configured to collect a preset number of first height data of the object to be measured through the first three-dimensional profile measuring instrument, and collect a preset number of the object to be measured through the second three-dimensional contour measuring instrument. The second height data of the object to be measured is calculated according to the first height data and the second height data to obtain the currently detected thickness of the object to be measured.

In some embodiments, the first obtaining module is further configured to select N valid pixels in the preset number of first height data and the second height data, wherein, from the nth pixel to The n+Nth pixel point is an effective pixel point, and both n and N are positive integers; the current detection thickness of the object to be measured is calculated according to the first height data and the second height data of the N effective pixel points, wherein ,Calculated as follows:

Wherein, T ₁ is the current detection thickness of the object to be measured, Z _a is the first height data, Z _b is the second height data, and N ₁ is the first height data or the first height data of the object to be measured. The number of valid pixels in the two height data, n ₁ is the serial number of the first valid pixel in the first height data or the second height data of the object to be measured.

In some embodiments, the thickness measurement device further includes:

The judgment module is used to judge whether the scanning light emitted by the first three-dimensional contour measuring instrument and the second three-dimensional contour measuring instrument can be completely coincident when they are directed, and if not, adjust the first three-dimensional contour measuring instrument or The position or light-emitting direction of the second three-dimensional profile measuring instrument is such that the scanning light rays of the two three-dimensional profile measuring instruments are completely coincident when they are directed toward each other.

In some embodiments, the number of the calibration objects is at least one, the calibration objects are arranged on both sides of the object to be measured, and the thickness direction of the object to be measured is consistent with the thickness direction of the object to be measured when placed,

The second obtaining module is further configured to obtain the current average thickness data of the at least one calibration object, respectively, obtain the standard thickness data of the calibration object, and calculate the current average thickness data and the standard thickness data according to the current average thickness data and the standard thickness data. The temperature drift change of the object to be measured.

In some embodiments, the calibration object includes a first calibration object and a second calibration object,

The second acquisition module is further configured to acquire the current thickness data of the at least one calibration object through the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument, respectively, so as to calculate the thickness of the at least one calibration object. Current average thickness data.

In some embodiments, the calculation formula of the current thickness data of the first calibration object is as follows:

Wherein, T ₂ is the current thickness data of the first calibration object, Z _c is the first height data of the first calibration object collected by the first three-dimensional profilometer, and Z _d is the second three-dimensional The second height data of the first calibration object collected by the profile measuring instrument, N ₂ is the first height data of the first calibration object or the number of valid pixels in the second height data, and n ₂ is the first height data of the first calibration object. A serial number of the first valid pixel point in the first height data or the second height data of the calibration object.

In some embodiments, the calculation formula of the current thickness data of the second calibration object is as follows:

Wherein, T ₃ is the current thickness data of the second calibration object, Z _e is the first height data of the second calibration object collected by the first three-dimensional profilometer, and Z _f is the second three-dimensional The second height data of the second calibration object collected by the profile measuring instrument, N ₃ is the first height data of the second calibration object or the number of valid pixels in the second height data, and n ₃ is the first height data of the second calibration object. 2. The serial number of the first valid pixel point in the first height data or the second height data of the calibration object.

In some embodiments, the calculation formula for obtaining the current average thickness data of the at least one calibration object is as follows:

Wherein, T ₀ is the current average thickness data of the at least one calibration object, T ₂ is the current thickness data of the first calibration object, and T ₃ is the current thickness data of the second calibration object.

In some embodiments, the temperature drift variation is calculated according to the current average thickness data and the standard thickness data, and the current detected thickness is compensated to obtain the actual thickness of the object to be measured ,Calculated as follows:

为所述待测物体的实际厚度，T₁为所述待测物体的当前检测厚度，T₀为所述至少一个标定物体的当前平均厚度数据，C为标定常量。in,

is the actual thickness of the object to be measured, T ₁ is the current detected thickness of the object to be measured, T ₀ is the current average thickness data of the at least one calibration object, and C is a calibration constant.

In order to solve the above technical problems, in a third aspect, an embodiment of the present invention provides a thickness measurement system, including:

object to be tested;

at least one calibration object;

Two three-dimensional profile measuring instruments are used to obtain the thickness data of the object to be measured and the calibration object;

at least one processor connected to the two three-dimensional profilometers; and,

a memory connected to the at least one processor; wherein,

The memory stores instructions executable by the at least one processor in connection with the two three-dimensional profilometers, the instructions being executed by the at least one processor in conjunction with the two three-dimensional profilometers The connection is performed to enable the at least one processor, which is connected with the two three-dimensional profilometers, to perform the method as described in the first aspect above.

In some embodiments, the at least one calibration object is fixed on one of the two three-dimensional profile measuring instruments, and is arranged within the field of view of the two three-dimensional profile measuring instruments.

In order to solve the above technical problems, in a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, where the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to cause a computer to execute The method of the first aspect above.

In order to solve the above technical problems, in a fifth aspect, an embodiment of the present invention further provides a computer program product, the computer program product includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions, when The program instructions, when executed by a computer, cause the computer to perform the method described in the first aspect above.

Compared with the prior art, the beneficial effects of the present invention are: different from the prior art, the embodiment of the present invention provides a thickness measurement method, device and system, the method first obtains the current detection thickness of the object to be measured , then obtain the thickness change of the calibration object to obtain the temperature drift change of the object to be measured, and finally compensate the current detected thickness according to the temperature drift change to obtain the actual thickness of the object to be measured. Thickness, the thickness measurement method provided by the embodiment of the present invention can solve the problem of inaccurate thickness measurement data caused by changes in ambient temperature, and improve production efficiency.

Description of drawings

One or more embodiments are exemplified by the pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations to the embodiments, and the elements/modules and steps with the same reference numerals in the drawings represent For similar elements/modules and steps, the figures in the accompanying drawings do not constitute a scale limitation unless otherwise stated.

1 is a schematic diagram of an application environment of a thickness measurement method provided by an embodiment of the present invention;

2 is a schematic flowchart of a thickness measurement method provided in Embodiment 1 of the present invention;

Fig. 3 is a sub-flow schematic diagram of step 110 in the thickness measurement method shown in Fig. 2;

4 is a schematic flowchart of another thickness measurement method provided in Embodiment 1 of the present invention;

Fig. 5 is a sub-flow schematic diagram of step 120 in the thickness measurement method shown in Fig. 2;

6 is a schematic structural diagram of a thickness measurement device provided in Embodiment 2 of the present invention;

7 is a schematic structural diagram of another thickness measurement device provided in Embodiment 2 of the present invention;

FIG. 8 is a schematic diagram of a hardware structure of a thickness measurement system according to Embodiment 3 of the present invention.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

It should be noted that, if there is no conflict, various features in the embodiments of the present invention may be combined with each other, which are all within the protection scope of the present application. In addition, although the functional modules are divided in the schematic diagram of the device, and the logical sequence is shown in the flowchart, in some cases, the modules in the device may be divided differently, or the sequence shown in the flowchart may be performed. or the described steps. In addition, the words "first" and "second" used herein do not limit the data and execution order, but only distinguish the same or similar items with substantially the same function and effect.

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the technical field of the present invention. The terms used in the description of the present invention in this specification are only for the purpose of describing specific embodiments, and are not used to limit the present invention. As used in this specification, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

In order to solve the problem of inaccurate measurement data of the thickness of the substrate actually measured by the thickness measuring instrument due to the temperature drift of the silicon wafer and other chip substrates caused by the ambient temperature and the heating of the machine itself, the embodiment of the present invention provides a A thickness measurement method, device and system capable of ensuring measurement accuracy for a long time and avoiding the influence of room temperature changes on measurement data.

FIG. 1 is a schematic diagram of one application environment of the thickness measurement method provided by an embodiment of the present invention. The application environment includes: a first three-dimensional contour measuring instrument 11, a second three-dimensional contour measuring instrument 12, an object to be measured 13, and a calibration object 14.

The first three-dimensional contour measuring instrument 11 and the second three-dimensional contour measuring instrument 12 are measuring instruments that use the contour lines of a series of objects to form a three-dimensional shape, and are also called 3D contour measuring instruments. The first three-dimensional contour measuring instrument 11 and the second three-dimensional profile measuring instrument 12 can be two identical three-dimensional profile measuring instruments, and the two three-dimensional profile measuring instruments need to be set so that the light emitting directions are opposite and the emitted light rays can be completely coincident.

The object to be measured 13 is an object whose thickness needs to be measured, which can be various types of semiconductor devices used in integrated circuits, or components of semiconductor devices. The example shown in FIG. 1 of the present invention takes a silicon wafer as an example. Further, the thickness measurement method provided by the embodiment of the present invention can also be used to measure other dimension data such as the length and width of the object to be measured 13 .

The calibration object 14 is arranged on both sides within the field of view of the first three-dimensional profile measuring instrument 11 and the second three-dimensional profile measuring instrument 12 and is fixed on the first three-dimensional profile measuring instrument 11, and the thickness direction is the same as that of the first three-dimensional profile measuring instrument 11. The objects to be measured 13 are consistent, and the calibration object 14 is a standard part used to compensate the error of calibrating the object to be measured 13. Therefore, preferably, the calibration object 14 can choose to use the object to be measured 13 , the calibration object 14 in the example of the present invention is also a silicon wafer, and further, the object to be measured 13 with a size standard can also be selected as the calibration object 14 . In some other embodiments, the calibration object 14 may not be placed on the same level as the object to be measured 13, but only needs to be placed on the first three-dimensional profile measuring instrument 11 and the second three-dimensional profile Within the effective measurement range of the measuring instrument 12, there is no need to be bound by the limitations of the embodiments of the present invention.

Moreover, in the embodiment of the present invention, the data to be measured is the thickness of the object to be measured 13 , therefore, the object to be measured 13 and the calibration object 14 are placed in the thickness direction as shown in FIG. 1 . between the first three-dimensional profile measuring instrument 11 and the second three-dimensional profile measuring instrument 12 .

Specifically, the embodiments of the present invention are further described below with reference to the accompanying drawings.

Example 1

An embodiment of the present invention provides a thickness measurement method, which is applied to a thickness measurement system. Please refer to FIG. 2 , which shows the flow of the thickness measurement method provided by the embodiment of the present invention. The thickness measurement method includes but is not limited to the following steps:

Step 110: Obtain the current detection thickness of the object to be measured;

In the embodiment of the present invention, first, it is necessary to measure and obtain the current detected thickness of the object to be measured by a measuring instrument, and the current detected thickness is the measured thickness of the object to be measured under the current ambient temperature that can be measured by the measuring instrument in the current environment. Thickness data.

Step 120: Obtain the thickness variation of the calibration object to obtain the temperature drift variation of the object to be measured;

Since the ambient temperature changes at any time, and the measuring instrument may also cause changes in the ambient temperature around the object to be measured due to the heating of its own machine, in order to obtain the influence of the ambient temperature on the object to be measured, a calibration object needs to be set. The standard part of the same material of the object to be measured can determine the influence of the ambient temperature on the measured current detected thickness of the object to be measured by detecting the thickness change between the current thickness of the calibration object and the standard size, that is, the The amount of temperature drift change. Preferably, in the embodiment of the present invention, the thickness of the calibration object can be measured each time a piece of the object to be measured is measured. compensate for this.

Step 130: Compensate the currently detected thickness according to the temperature drift change amount to obtain the actual thickness of the object to be detected.

In the embodiment of the present invention, the variation of the temperature drift is determined by the variation of the thickness of the calibration object, so that the deviation between the current detected thickness and the actual thickness of the object to be measured can be obtained, and the variation of the temperature drift can be calculated by calculating the variation of the temperature drift. As a compensation value, the actual thickness of the object to be measured can be obtained by compensating the currently detected thickness.

Further, the thickness measuring device includes a first three-dimensional contour measuring instrument and a second three-dimensional contour measuring instrument with opposite light-emitting directions, please refer to FIG. The current detected thickness of the object, further including:

Step 111 : collecting a preset number of first height data of the object to be measured by the first three-dimensional profile measuring instrument;

Preferably, in the embodiment of the present invention, a silicon wafer is used as the object to be measured, and a three-dimensional profile measuring instrument is used as an example. For details, please refer to the application scenario shown in FIG. 1 above. The first height data is obtained from the distance from the three-dimensional profile measuring instrument 11 to the surface of the object to be measured that faces the first three-dimensional profile measuring instrument 11 .

Step 112 : collecting a preset number of second height data of the object to be measured by the second three-dimensional profile measuring instrument;

Then, the second three-dimensional contour measuring instrument 12 collects the distance from the second three-dimensional contour measuring instrument 12 to the surface of the object to be measured facing the second three-dimensional contour measuring instrument 12 to obtain the second height data.

Step 113: Calculate the current detected thickness of the object to be measured according to the first height data and the second height data.

Finally, according to the first height data and the second height data collected above, since the two three-dimensional profile measuring instruments are in opposite directions, in a system, the height data measured by the two machines is one positive and the other negative. , add the two, and the sum of the heights can get the current detection thickness of the object to be measured at the current scanning point.

Specifically, select N valid pixels in the preset number of first height data and the second height data, wherein, from the nth pixel to the n+Nth pixel are valid pixels, Both n and N are positive integers; the current detection thickness of the object to be measured is calculated according to the first height data and the second height data of the N effective pixels, wherein the calculation formula is as follows:

Wherein, T ₁ is the current detection thickness of the object to be measured, Z _a is the first height data, Z _b is the second height data, and N ₁ is the first height data or the first height data of the object to be measured. The number of valid pixels in the two height data, n ₁ is the serial number of the first valid pixel in the first height data or the second height data of the object to be measured.

Taking the output light width of the first three-dimensional profile measuring instrument 11 and the second three-dimensional profile measuring instrument 12 as an example of 16 mm, the left and right sides of the light output light of the measuring instruments each block the 4 mm field of view, and the remaining 8 mm line width in the middle of the field of view is used. For thickness measurement of silicon wafers. During the measurement, since the length of the conventional silicon wafer is about 160mm, the laser line is parallel to the movement direction, and the number of pixels for each two contours is 3200, and the sampling distance is kept at 2mm. The number of sampling contours is 80. Therefore, the calculation formula of the current detection thickness of the object to be measured can be expressed as:

Among them, Z _a and Z _b are the height data collected by the upper and lower three-dimensional profile measuring instruments respectively, and the average value of the sum of the two at each collection position is the final currently detected thickness data of the object to be measured.

Further, please refer to FIG. 4 , which shows a flow of another thickness measurement method provided by an embodiment of the present invention. Before obtaining the currently detected thickness of the object to be measured, the method further includes:

Step 141: Determine whether the scanning rays emitted by the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument can be completely coincident when they are directed; if not, go to step 142; if so, go to step 142 110;

Step 142 : Adjust the position or light emitting direction of the first three-dimensional profile measuring instrument or the second three-dimensional profile measuring instrument, so that the scanning rays of the two three-dimensional profile measuring instruments are completely coincident when they are directed toward each other.

In the process of thickness measurement, the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument also need to be physically aligned front and rear and left and right. Among them, a standard silicon wafer is used as a light correction tool to correct the upper and lower light levels, so that the aurora light emitted by the two measuring instruments can be completely coincident when they are directed toward each other. After the light profile is corrected, the silicon wafer is placed in the field of view of the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument, and the lateral positions of the upper and lower laser lines are aligned by the edge point positions.

Further, the number of the calibration objects is at least one, and the calibration objects are arranged on both sides of the object to be measured and the thickness direction of the object to be measured is consistent with the thickness direction of the object to be measured. A sub-process as described in the above step 120 is shown, the obtaining the thickness variation of the calibration object to obtain the temperature drift variation of the object to be measured, further comprising:

Step 121: respectively acquiring the current average thickness data of the at least one calibration object;

Wherein, the current thickness data of the at least one calibration object is obtained by the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument, respectively, so as to calculate the current average thickness data of the at least one calibration object. Specifically, in the example shown in FIG. 1 , two calibration objects 14 are set as an example below, and the first calibration object and the second calibration object are obtained by the first three-dimensional contour measuring instrument and the second three-dimensional contour measuring instrument, respectively. The current thickness data of the object.

The calculation formula of the current thickness data of the first calibration object is as follows:

Wherein, T ₂ is the current thickness data of the first calibration object, Z _c is the first height data of the first calibration object collected by the first three-dimensional profilometer, and Z _d is the second three-dimensional The second height data of the first calibration object collected by the profile measuring instrument, N ₂ is the first height data of the first calibration object or the number of valid pixels in the second height data, and n ₂ is the first height data of the first calibration object. A serial number of the first valid pixel point in the first height data or the second height data of the calibration object.

The calculation formula of the current thickness data of the second calibration object is as follows:

Wherein, T ₃ is the current thickness data of the second calibration object, Z _e is the first height data of the second calibration object collected by the first three-dimensional profilometer, and Z _f is the second three-dimensional The second height data of the second calibration object collected by the profile measuring instrument, N ₃ is the first height data of the second calibration object or the number of valid pixels in the second height data, and n ₃ is the first height data of the second calibration object. 2. The serial number of the first valid pixel point in the first height data or the second height data of the calibration object.

Still taking the number of pixels per two contours as 3200 in the above step 113 and keeping the collection distance of 2mm as an example, the obtained calculation formulas of the first calibration object and the second calibration object can be expressed as:

Among them, considering the stability, in the above calculation process, 300 pixels at both ends of the field of view are eliminated, and the actual number of effectively used pixels is 2600.

Step 122: obtaining standard thickness data of the calibration object;

The standard thickness data is a standard thickness value of the calibration object at a certain temperature, which is a set data, which may be data designed by software, or a standard value of a standard part actually measured. Preferably, the first calibration object and the second calibration object set in the thickness measurement system may be two identical calibration objects, and in this case, the standard thickness data of the two are the same.

Step 123: Calculate the temperature drift change of the object to be measured according to the current average thickness data and the standard thickness data.

The calculation formula for obtaining the current average thickness data of the at least one calibration object by the calculation is as follows:

Wherein, T ₀ is the current average thickness data of the at least one calibration object, T ₂ is the current thickness data of the first calibration object, and T ₃ is the current thickness data of the second calibration object.

Based on this, for the step 130, specifically, the temperature drift variation is calculated and obtained according to the current average thickness data and the standard thickness data, and the current detected thickness is compensated to obtain the The actual thickness of the object to be measured, the calculation formula is as follows:

为所述待测物体的实际厚度，T₁为所述待测物体的当前检测厚度，T₀为所述至少一个标定物体的当前平均厚度数据，C为标定常量。in,

is the actual thickness of the object to be measured, T ₁ is the current detected thickness of the object to be measured, T ₀ is the current average thickness data of the at least one calibration object, and C is a calibration constant.

Embodiment 2

An embodiment of the present invention provides a thickness measurement device, which is applied to a thickness measurement system. Please refer to FIG. 6 , which shows the structure of the thickness measurement device provided by the embodiment of the present invention. The thickness measurement device 200 includes: a first acquisition module 210 , a second acquisition module 220 and a compensation module 230 .

The first acquisition module 210 is used to acquire the current detected thickness of the object to be measured;

The second acquisition module 220 is configured to acquire the thickness variation of the calibration object to obtain the temperature drift variation of the object to be measured;

The compensation module 230 is used for compensating the currently detected thickness according to the temperature drift change amount, so as to obtain the actual thickness of the object to be detected.

In some embodiments, the thickness measurement device includes a first three-dimensional profile measuring instrument and a second three-dimensional profile measuring instrument with opposite light-emitting directions, and the first acquisition module 210 is further configured to collect data from the first three-dimensional profile measuring instrument a preset number of first height data of the object to be measured; collect a preset number of second height data of the object to be measured by the second three-dimensional profile measuring instrument; according to the first height data and the The second height data is calculated to obtain the currently detected thickness of the object to be measured.

In some embodiments, the first obtaining module 210 is further configured to select N valid pixels in the preset number of first height data and the second height data, wherein the nth pixel is obtained from the The n+Nth pixel is an effective pixel, and both n and N are positive integers; according to the first height data and the second height data of the N effective pixels, the current detection thickness of the object to be measured is calculated, Among them, the calculation formula is as follows:

Wherein, T ₁ is the current detection thickness of the object to be measured, Z _a is the first height data, Z _b is the second height data, and N ₁ is the first height data or the first height data of the object to be measured. The number of valid pixels in the two height data, n ₁ is the serial number of the first valid pixel in the first height data or the second height data of the object to be measured.

In some embodiments, please refer to FIG. 7 , which shows the structure of another thickness measurement device provided by the embodiment of the present invention. The thickness measurement device 200 further includes: a judgment module 240 for judging the first three-dimensional thickness Whether the scanning light emitted by the contour measuring instrument and the second three-dimensional contour measuring instrument can be completely coincident when they are directed toward each other; if not, adjust the position of the first three-dimensional contour measuring instrument or the second three-dimensional contour measuring instrument or The direction of light output, so that the scanning rays of the two 3D profile measuring instruments are completely coincident when they are directed toward each other.

In some embodiments, the number of the calibration objects is at least one, the calibration objects are arranged on both sides of the object to be measured, and the thickness direction of the object to be measured is consistent with the thickness direction of the object to be measured when placed, the second The obtaining module 220 is further configured to obtain the current average thickness data of the at least one calibration object respectively; obtain the standard thickness data of the calibration object; and calculate the to-be-measured data according to the current average thickness data and the standard thickness data The amount of change in temperature drift of an object.

In some embodiments, the calibration object includes a first calibration object and a second calibration object, and the second acquisition module 220 is further configured to pass the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument, respectively The current thickness data of the at least one calibration object is acquired, so as to obtain the current average thickness data of the at least one calibration object.

In some embodiments, the calculation formula of the current thickness data of the first calibration object is as follows:

Wherein, T ₂ is the current thickness data of the first calibration object, Z _c is the first height data of the first calibration object collected by the first three-dimensional profilometer, and Z _d is the second three-dimensional The second height data of the first calibration object collected by the profile measuring instrument, N ₂ is the first height data of the first calibration object or the number of valid pixels in the second height data, and n ₂ is the first height data of the first calibration object. A serial number of the first valid pixel point in the first height data or the second height data of the calibration object.

In some embodiments, the calculation formula of the current thickness data of the second calibration object is as follows:

Wherein, T ₃ is the current thickness data of the second calibration object, Z _e is the first height data of the second calibration object collected by the first three-dimensional profilometer, and Z _f is the second three-dimensional The second height data of the second calibration object collected by the profile measuring instrument, N ₃ is the first height data of the second calibration object or the number of valid pixels in the second height data, and n ₃ is the first height data of the second calibration object. 2. The serial number of the first valid pixel point in the first height data or the second height data of the calibration object.

In some embodiments, the calculation formula for obtaining the current average thickness data of the at least one calibration object is as follows:

Wherein, T ₀ is the current average thickness data of the at least one calibration object, T ₂ is the current thickness data of the first calibration object, and T ₃ is the current thickness data of the second calibration object.

In some embodiments, the temperature drift variation is calculated according to the current average thickness data and the standard thickness data, and the current detected thickness is compensated to obtain the actual thickness of the object to be measured ,Calculated as follows:

为所述待测物体的实际厚度，T₁为所述待测物体的当前检测厚度，T₀为所述至少一个标定物体的当前平均厚度数据，C为标定常量。in,

is the actual thickness of the object to be measured, T ₁ is the current detected thickness of the object to be measured, T ₀ is the current average thickness data of the at least one calibration object, and C is a calibration constant.

Embodiment 3

An embodiment of the present invention further provides a thickness measurement system, please refer to FIG. 8 , which shows the hardware structure of the thickness measurement system capable of executing the thickness measurement method described in FIGS. 2 to 5 . The thickness measurement system 10 may be the thickness measurement system shown in FIG. 1 .

The thickness measurement system 10 includes: an object to be measured 13; at least one calibration object 14; and two three-dimensional profile measuring instruments (11 and 12) for acquiring thickness data of the object to be measured and the calibration object.

In some embodiments, the at least one calibration object 14 is fixed on one of the two three-dimensional profile measuring instruments (11 and 12), and is arranged on the two three-dimensional profile measuring instruments (11 and 12). ) within the field of view. Specifically, in the embodiment of the present invention, the calibration object 14 is fixed on the extension plate of the first three-dimensional profile measuring instrument 11, and is arranged on both sides of the first three-dimensional profile measuring instrument 11. In some embodiments, the position of the calibration object 14 can be set according to actual needs, and does not need to be bound by the limitations of the embodiments of the present invention.

The thickness measurement system 10 further includes: at least one processor 15, which is connected to the two three-dimensional profile measuring instruments 11 and 12; and, a memory 16 connected to the at least one processor 15. The processor 15 is taken as an example. The memory 16 stores instructions executable by the at least one processor connected to the two three-dimensional profilers 15, the instructions being executed by the at least one processor connected to the two three-dimensional profilers. The measuring instrument connection 15 is performed so that the at least one processor, which is connected with the two three-dimensional profile measuring instruments 15, can perform the thickness measurement method described above in FIGS. 2 to 5 . The processor 15 and the memory 16 may be connected by a bus or in other ways, and the connection by a bus is taken as an example in FIG. 8 .

The memory 16, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs and modules, such as program instructions corresponding to the thickness measurement method in the embodiments of the present application /modules, for example, the individual modules shown in Figures 6 to 7. The processor 15 executes various functional applications and data processing of the server by running the non-volatile software programs, instructions and modules stored in the memory 16, that is, to implement the thickness measurement method in the above method embodiment.

The memory 16 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the thickness measuring device, and the like. Additionally, memory 16 may include high speed random access memory, and may also include nonvolatile memory, such as at least one magnetic disk storage device, flash memory device, or other nonvolatile solid state storage device. In some embodiments, memory 16 may optionally include memory located remotely from processor 15, which remote memory may be connected to the thickness measurement device via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

The one or more modules are stored in the memory 16, and when executed by the one or more processors 15, perform the thickness measurement method in any of the above method embodiments, for example, perform the above-described FIG. 2 to The method steps in FIG. 5 realize the functions of each module and each unit in FIG. 6 to FIG. 7 .

The above product can execute the method provided by the embodiments of the present application, and has functional modules and beneficial effects corresponding to the execution method. For technical details not described in detail in this embodiment, reference may be made to the methods provided in the embodiments of this application.

Embodiments of the present application also provide a non-volatile computer-readable storage medium, where the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are executed by one or more processors, for example, executing The method steps in FIGS. 2 to 5 described above implement the functions of the modules in FIGS. 6 to 7 .

Embodiments of the present application also provide a computer program product, including a computer program stored on a non-volatile computer-readable storage medium, where the computer program includes program instructions, when the program instructions are executed by a computer, The computer executes the thickness measurement method in any of the above method embodiments, for example, executes the method steps of FIGS. 2 to 5 described above to realize the functions of each module in FIGS. 6 to 7 .

The embodiments of the present invention provide a thickness measurement method, device and system. The method first obtains the current detection thickness of the object to be measured, and then obtains the thickness change of the calibration object, so as to obtain the temperature drift change of the object to be measured. , and finally compensate the current detected thickness according to the temperature drift change to obtain the actual thickness of the object to be measured. The thickness measurement method provided by the embodiment of the present invention can solve the thickness measurement caused by the change of the ambient temperature. The problem of inaccurate data improves production efficiency.

It should be noted that the device embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physically separated unit, that is, it can be located in one place, or it can be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

From the description of the above embodiments, those of ordinary skill in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, and certainly can also be implemented by hardware. Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and the program can be executed when the program is executed. , may include the flow of the above-mentioned method embodiments. The storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM), or a random access memory (Random Access Memory, RAM) or the like.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, The steps may be carried out in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the invention has been The skilled person should understand that it is still possible to modify the technical solutions recorded in the foregoing embodiments, or to perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the implementation of the present invention. scope of technical solutions.

Claims (23)

1. A thickness measuring method is applied to a thickness measuring system, and comprises the following steps:

acquiring the current detection thickness of an object to be detected;

obtaining the thickness variation of a calibration object to obtain the temperature drift variation of the object to be measured;

and compensating the current detection thickness according to the temperature drift variation to obtain the actual thickness of the object to be detected.

2. The thickness measuring method according to claim 1,

the thickness measuring device comprises a first three-dimensional profile measuring instrument and a second three-dimensional profile measuring instrument which have opposite light emitting directions,

the obtaining of the current detection thickness of the object to be detected further includes:

acquiring first height data of a preset number of objects to be measured through the first three-dimensional profile measuring instrument;

acquiring second height data of a preset number of objects to be measured through the second three-dimensional profile measuring instrument;

and calculating to obtain the current detection thickness of the object to be detected according to the first height data and the second height data.

3. The thickness measuring method according to claim 2,

the calculating according to the first height data and the second height data to obtain the current detection thickness of the object to be detected further includes:

selecting N effective pixel points in the preset number of first height data and the second height data, wherein the pixel points from the nth pixel point to the (N + N) th pixel point are effective pixel points, and N and N are positive integers;

calculating the current detection thickness of the object to be detected according to the first height data and the second height data of the N effective pixel points, wherein the calculation formula is as follows:

wherein, T₁Is the current detected thickness, Z, of the object to be measured_aIs said first height data, Z_bFor the second height data, N₁The number n of effective pixel points in the first height data or the second height data of the object to be detected₁And the serial number of the first effective pixel point in the first height data or the second height data of the object to be detected is used as the serial number of the first effective pixel point in the first height data or the second height data of the object to be detected.

4. The thickness measuring method according to claim 2,

before the obtaining of the current detection thickness of the object to be detected, the method further includes:

judging whether the scanning light rays emitted by the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument can be completely overlapped during correlation;

if not, adjusting the position or the light emitting direction of the first three-dimensional profile measuring instrument or the second three-dimensional profile measuring instrument so as to enable the scanning light rays of the two three-dimensional profile measuring instruments to be completely overlapped when being oppositely emitted.

5. The thickness measuring method according to claim 2,

the number of the calibration objects is at least one, the calibration objects are arranged on two sides of the object to be measured, the thickness direction of the calibration objects is consistent with the thickness direction of the object to be measured when the calibration objects are placed,

the obtaining of the thickness variation of the calibration object to obtain the temperature drift variation of the object to be measured further includes:

respectively acquiring current average thickness data of the at least one calibration object;

acquiring standard thickness data of the calibration object;

and calculating the temperature drift variation of the object to be measured according to the current average thickness data and the standard thickness data.

6. The thickness measuring method according to claim 5,

the calibration objects comprise a first calibration object and a second calibration object,

the respectively obtaining the current average thickness data of the at least one calibration object further includes:

and respectively acquiring the current thickness data of the at least one calibration object through the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument so as to calculate and obtain the current average thickness data of the at least one calibration object.

7. The thickness measuring method according to claim 6,

the calculation formula of the current thickness data of the first calibration object is as follows:

wherein, T₂Is the current thickness data, Z, of the first calibration object_cFirst height data, Z, of the first calibration object acquired by the first three-dimensional profile measuring instrument_dSecond height data, N, of the first calibration object acquired by the second three-dimensional profile measuring instrument₂The number n of effective pixel points in the first height data or the second height data of the first calibration object₂And the serial number of the first effective pixel point in the first height data or the second height data of the first calibration object is used as the serial number of the first effective pixel point.

8. The thickness measuring method according to claim 6,

the calculation formula of the current thickness data of the second calibration object is as follows:

wherein, T₃Is the current thickness data, Z, of the second calibration object_eFirst height data, Z, of the second calibration object acquired by the first three-dimensional profile measuring instrument_fSecond height data, N, of the second calibration object acquired by the second three-dimensional profile measuring instrument₃The number n of effective pixel points in the first height data or the second height data of the second calibration object₃And the serial number of the first effective pixel point in the first height data or the second height data of the second calibration object is used as the serial number of the first effective pixel point in the second height data.

9. The thickness measuring method according to claim 7 or 8,

the calculation formula for obtaining the current average thickness data of the at least one calibration object by calculation is as follows:

wherein, T₀Is the current average thickness data, T, of the at least one calibration object₂Is the current thickness data, T, of the first calibration object₃And the current thickness data of the second calibration object.

10. The thickness measuring method according to claim 9,

calculating to obtain a temperature drift variation according to the current average thickness data and the standard thickness data, and compensating the current detection thickness to obtain the actual thickness of the object to be detected, wherein the calculation formula is as follows:

wherein,

is the actual thickness, T, of the object to be measured₁Is the current detected thickness, T, of the object to be measured₀And C is a calibration constant, and is the current average thickness data of the at least one calibration object.

11. A thickness measuring device is characterized by being applied to a thickness measuring system, and the device comprises:

the first acquisition module is used for acquiring the current detection thickness of the object to be detected;

the second acquisition module is used for acquiring the thickness variation of the calibration object so as to obtain the temperature drift variation of the object to be measured;

and the compensation module is used for compensating the current detection thickness according to the temperature drift variation so as to obtain the actual thickness of the object to be detected.

12. The thickness measuring apparatus according to claim 11,

the thickness measuring device comprises a first three-dimensional profile measuring instrument and a second three-dimensional profile measuring instrument which have opposite light emitting directions,

the first acquisition module is further used for acquiring a preset number of first height data of the object to be detected through the first three-dimensional profile measuring instrument, acquiring a preset number of second height data of the object to be detected through the second three-dimensional profile measuring instrument, and calculating to obtain the current detection thickness of the object to be detected according to the first height data and the second height data.

13. The thickness measuring apparatus according to claim 12,

the first obtaining module is further configured to select N effective pixels in the preset number of first height data and the second height data, where N and N are positive integers from the nth pixel to the N + nth pixel; calculating the current detection thickness of the object to be detected according to the first height data and the second height data of the N effective pixel points, wherein the calculation formula is as follows:

wherein, T₁Is the current detected thickness, Z, of the object to be measured_aIs said first height data, Z_bFor the second height data, N₁The number n of effective pixel points in the first height data or the second height data of the object to be detected₁And the serial number of the first effective pixel point in the first height data or the second height data of the object to be detected is used as the serial number of the first effective pixel point in the first height data or the second height data of the object to be detected.

14. The thickness measuring device according to claim 12, further comprising:

and the judging module is used for judging whether the scanning light rays emitted by the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument can be completely overlapped during the correlation, and if not, adjusting the position or the light emitting direction of the first three-dimensional profile measuring instrument or the second three-dimensional profile measuring instrument so as to ensure that the scanning light rays of the two three-dimensional profile measuring instruments are completely overlapped during the correlation.

15. The thickness measuring apparatus according to claim 12,

the number of the calibration objects is at least one, the calibration objects are arranged on two sides of the object to be measured, the thickness direction of the calibration objects is consistent with the thickness direction of the object to be measured when the calibration objects are placed,

the second obtaining module is further configured to obtain current average thickness data of the at least one calibration object, obtain standard thickness data of the calibration object, and calculate the temperature drift variation of the object to be measured according to the current average thickness data and the standard thickness data.

16. The thickness measuring apparatus according to claim 15,

the calibration objects comprise a first calibration object and a second calibration object,

the second obtaining module is further configured to obtain current thickness data of the at least one calibration object through the first three-dimensional profile measuring instrument and the second three-dimensional profile measuring instrument, so as to obtain current average thickness data of the at least one calibration object through calculation.

17. The thickness measuring apparatus according to claim 16,

the calculation formula of the current thickness data of the first calibration object is as follows:

wherein, T₂Is the first calibration objectFront thickness data, Z_cFirst height data, Z, of the first calibration object acquired by the first three-dimensional profile measuring instrument_dSecond height data, N, of the first calibration object acquired by the second three-dimensional profile measuring instrument₂The number n of effective pixel points in the first height data or the second height data of the first calibration object₂And the serial number of the first effective pixel point in the first height data or the second height data of the first calibration object is used as the serial number of the first effective pixel point.

18. The thickness measuring apparatus according to claim 16,

the calculation formula of the current thickness data of the second calibration object is as follows:

wherein, T₃Is the current thickness data, Z, of the second calibration object_eFirst height data, Z, of the second calibration object acquired by the first three-dimensional profile measuring instrument_fSecond height data, N, of the second calibration object acquired by the second three-dimensional profile measuring instrument₃The number n of effective pixel points in the first height data or the second height data of the second calibration object₃And the serial number of the first effective pixel point in the first height data or the second height data of the second calibration object is used as the serial number of the first effective pixel point in the second height data.

19. The thickness measuring apparatus according to claim 17 or 18,

the calculation formula for obtaining the current average thickness data of the at least one calibration object by calculation is as follows:

wherein, T₀Is the current average thickness data, T, of the at least one calibration object₂Is the current thickness data, T, of the first calibration object₃And the current thickness data of the second calibration object.

20. The thickness measuring device according to claim 19,

and calculating to obtain the temperature drift variation according to the current average thickness data and the standard thickness data, and compensating the current detection thickness to obtain the actual thickness of the object to be detected, wherein the calculation formula is as follows:

wherein,

is the actual thickness, T, of the object to be measured₁Is the current detected thickness, T, of the object to be measured₀And C is a calibration constant, and is the current average thickness data of the at least one calibration object.

21. A thickness measuring system, comprising:

an object to be measured;

at least one calibration object;

the two three-dimensional profile measuring instruments are used for acquiring the thickness data of the object to be measured and the calibrated object;

at least one processor connected with the two three-dimensional profile measuring instruments; and

a memory coupled to the at least one processor; wherein,

the memory stores instructions executable by the at least one processor in connection with the two three-dimensional profilometers, the instructions being executable by the at least one processor in connection with the two three-dimensional profilometers to cause the at least one processor, in connection with the two three-dimensional profilometers, to perform the method of any one of claims 1-10.

22. The thickness measuring system of claim 21,

the at least one calibration object is fixed on one of the two three-dimensional profile measuring instruments and is arranged in the visual field range of the two three-dimensional profile measuring instruments.

23. A computer-readable storage medium having stored thereon computer-executable instructions for causing a computer to perform the method of any one of claims 1-10.

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