JP2013190224A - Thickness measurement device and thickness measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thickness measurement device for measuring thickness of a multilayer film at high speed with high accuracy.SOLUTION: A thickness measurement device 100 for measuring thickness of a multilayer film formed on a base material to be carried is provided with a CPU 71 which compares image data of a first layer that is in a first layer on the base material with reference data pre-stored to calculate thickness of the first layer, compares image data of each layer in a second layer and above with simulation data created by applying thickness of lower layers to a prescribed theoretical formula to calculate thickness of each in the second layer and above when calculating thickness of each layer in the second layer and above which are successively formed on the first layer, and performs positioning with reference to position information about a layer one below when acquiring image data in each layer on the second layer and above.

Description

  The present invention relates to a thickness measuring apparatus and a thickness measuring method.

In recent years, the demand for large-area electronic devices typified by organic electroluminescence (EL) elements and solar cells has been increasing.
Such an electronic device includes a multilayer film in which a plurality of functional thin films are laminated on a base material. The thickness of each layer greatly affects the performance of the electronic device, such as light emission efficiency and light reception efficiency, and is physically Since it also affects properties such as strength, gas barrier properties, and adhesiveness, it is important to measure the thickness of each layer in order to control the quality of the multilayer film.

Conventionally, various methods are known as thickness measuring methods.
For example, Patent Document 1 discloses a method of calculating a thickness by comparing with master data prepared in advance using a color camera.
However, the method disclosed in Patent Document 1 is a method suitable for measuring the thickness of a single layer film. However, when applied to a multilayer film, it is necessary to prepare enormous master data or predicted values, and in addition to the comparison, The amount of calculation is large, which is not preferable for measuring the thickness of the multilayer film.
Therefore, as a method for measuring the thickness of the multilayer film, for example, Patent Document 2 uses a laser microscope to estimate the thickness of each layer based on the change in light output when the distance between the objective lens and the sample is changed. A method is disclosed.

JP 61-117404 A JP 2002-39720 A

  However, in the method of Patent Document 2, when nano-order resolution is required, high-speed processing cannot be performed due to an increase in the amount of information due to an increase in the number of steps of movement of the objective lens. It was difficult to obtain movement accuracy. That is, the method of Patent Document 2 has a problem that high-speed and high-precision measurement cannot be performed.

  An object of the present invention is to provide a thickness measuring apparatus and a thickness measuring method capable of measuring the thickness of a multilayer film at high speed and with high accuracy.

In order to solve the above problems,
The invention described in claim 1
A thickness measuring device for measuring the thickness of a multilayer film formed on a substrate to be conveyed,
Image data acquisition means for acquiring image data of the formed layer by irradiating the formed layer with light each time each layer of the multilayer film is formed;
When acquiring the image data by the image data acquisition means, identification information acquisition means for acquiring identification information for identifying the layer from which the image data was acquired;
Calculation means for calculating the thickness of each layer from the image data acquired by the image data acquisition means;
Storage means for storing the thickness of each layer calculated by the calculation means in association with the identification information acquired by the identification information acquisition means;
With
The calculating means includes
The first layer image data on the base material is compared with reference data stored in advance to calculate the thickness of the first layer,
When calculating the thickness of each of the second and subsequent layers sequentially formed on the first layer, the image data of each of the second and subsequent layers and the data relating to the thickness of the lower layer are applied to a predetermined theoretical formula. In comparison with the simulation data created in step 1, calculate the thickness of each layer after the second layer,
The image data acquisition means includes
When the image data of each layer after the second layer is acquired, alignment is performed with reference to the identification information of the lower layer.

Further, the invention according to claim 2 is the thickness measuring device according to claim 1,
The calculating means includes
When calculating the thicknesses of the second and subsequent layers sequentially formed on the first film, the image data of the second and subsequent layers is compared with the simulation data, and the difference is the smallest. The value is calculated as the thickness.

Further, the invention according to claim 3 is the thickness measuring device according to claim 1 or 2,
The image data acquisition means includes
Each time the layers of the multilayer film are formed, a linear light source that irradiates light in a line along the orthogonal direction orthogonal to the transport direction of the base material, with respect to the formed layer;
A line CCD camera that receives transmitted light or reflected light from a layer irradiated with light by the line light source, and
The thickness of each layer calculated by the calculating means is indicated by thickness distribution data along the orthogonal direction.

Moreover, invention of Claim 4 is the thickness measuring apparatus as described in any one of Claims 1-3,
It has a conveyance means which conveys the said base material by a roll-to-roll system, It is characterized by the above-mentioned.

The invention according to claim 5
A thickness measuring method using the thickness measuring device according to any one of claims 1 to 4,
When the first layer of the first layer is formed on the substrate, the image data acquisition unit acquires the image data of the first layer, and the identification information acquisition unit acquires the identification information of the first layer. A first acquisition step of acquiring
A first calculation step of calculating the thickness of the first layer by comparing the image data of the first layer acquired by the first acquisition step with reference data stored in advance;
A first storage step of storing the thickness of the first layer calculated in the first calculation step in the storage unit in association with the identification information of the first layer acquired by the identification information acquisition unit;
When the second layer of the second layer is formed on the first layer, the image data acquisition unit acquires the image data of the second layer, and the identification information acquisition unit identifies the second layer. A second acquisition step of acquiring information;
The second layer image data acquired in the second acquisition step is compared with simulation data created by applying data relating to the thickness stored in the storage means to a predetermined theoretical formula. A second calculation step of calculating the thickness of
A second storage step of storing the thickness of the second layer calculated by the second calculation step together with the identification information of the second layer acquired by the identification information acquisition unit;
It is characterized by having.

The invention described in claim 6 is the thickness measuring method according to claim 5,
The second calculation step includes
The image data of the second layer and the simulation data are compared, and a value with the smallest difference is calculated as the thickness.

The invention described in claim 7 is the thickness measuring method according to claim 5 or 6,
The thickness of each layer calculated by the first calculation step and the second calculation step is indicated by thickness distribution data along an orthogonal direction orthogonal to the transport direction of the base material.

Moreover, invention of Claim 8 is the thickness measuring method as described in any one of Claims 5-7,
The substrate is conveyed by a roll-to-roll method.

According to the present invention, when calculating the thickness of the first layer on the base material in the film thickness measurement of the multilayer film formed on the transported base material, the image data of the first layer is stored in advance. When calculating the thickness in comparison with the reference data obtained, and calculating the thickness of each of the second and subsequent layers that are sequentially formed on the first layer, the image data of each of the second and subsequent layers is converted to the thickness of the lower layer. The thickness is calculated by comparing with simulation data created by applying the above to a predetermined theoretical formula.
Further, when acquiring image data of each layer after the second layer, alignment is performed with reference to the position information of the lower layer.
Therefore, the thickness of the multilayer film can be measured at high speed and with high accuracy.

1 is an external perspective view of a thickness measuring apparatus according to an embodiment of the present invention. FIG. 2 is a schematic top view illustrating a multilayer film that is a measurement target of the thickness measuring apparatus in FIG. 1. It is a cross-sectional schematic diagram of a multilayer film. It is a block diagram which shows the control structure of the thickness measuring apparatus of FIG. It is an example which shows an imaging area and the image data area | region to preserve | save. It is an example which shows the preserve | saved image data and a calculation area | region. It is an example which shows the measured optical data. It is an example which shows simulation data. It is an example which shows the state which accumulated the measurement data and the simulation data. It is a flowchart which shows the thickness measuring method which concerns on embodiment of this invention. It is the external appearance perspective view which showed the modification 1 of the thickness measuring apparatus of FIG. It is the external appearance perspective view which showed the modification 2 of the thickness measuring apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Thickness measuring device>
First, the thickness measuring apparatus 100 according to the embodiment of the present invention will be described.
As shown in FIG. 1, the thickness measuring apparatus 100 is a multilayer film 10 formed on a substrate K by a film forming unit (not shown) in the process of continuously transporting the substrate K by a roll-to-roll method. Is a device for measuring the thickness of
Specifically, the thickness measuring apparatus 100 calculates the physical layer thickness of each layer by executing a thickness measurement process described later each time each layer constituting the multilayer film 10 is formed on the substrate K, Finally, the film thickness of the multilayer film 10 can be measured.
In the following description, the width direction of the base material K (the direction orthogonal to the transport direction of the base material K) is the X direction, and the transport direction of the base material K is the Y direction.

Here, the multilayer film 10 which is a measurement target of the thickness measuring apparatus 100 will be described.
As shown in FIG. 2, the multilayer film 10 has a substantially rectangular shape in a plan view extending in the longitudinal direction (Y direction) of the long base K, and the width direction (X direction) on the base K. Are provided in two rows at a predetermined interval along the longitudinal direction.
The multilayer film 10 is, for example, provided in an electronic device such as an organic electroluminescence panel or an organic thin film solar cell. As shown in FIG. 3, a plurality of thin films (first layer 10) are formed on a substrate K. ₁ to Nth layer 10 _N ) are stacked.
In the following description, the first layer of the film formed on a substrate K and the first layer 10 _1, a second layer of the film formed on the first layer and the second layer 10 _2, which Similarly, the Nth film counted from the side closer to the base material K is the Nth layer _10N .
Each layer (the first layer 10 ₁ to the Nth layer 10 _N ) constituting the multilayer film is not shown in the process in which the base material K is continuously conveyed by the roll-to-roll method along the conveyance direction (Y direction). The film is formed and laminated on the substrate K by a method such as coating, vapor deposition, or sputtering by the film forming unit.

As the base material K, for example, a resin film, glass or the like, in particular, a long material having flexibility is used.
As shown in FIG. 2, an alignment mark 11 is provided at one end in the width direction on the base material K, and a bar code 12 is provided at the other end.
Both the alignment mark 11 and the barcode 12 are provided at predetermined intervals along the transport direction (Y direction), and the two multilayer films 10 and 10 are aligned in the width direction (X direction) of the base material K. One by one.
The alignment mark 11 is provided for grasping an image data area stored for each ID given by one barcode 12 when measuring the film thickness by the thickness measuring apparatus 100. The alignment mark 11 is simultaneously imaged by a line CCD camera 42 (described later) when imaging the two multilayer films 10 and 10 aligned in the X direction of the substrate K.
Further, the barcode 12 is provided to give an ID for identifying each set of the two multilayer films 10 and 10 arranged in the X direction of the base material K at the time of measurement by the thickness measuring apparatus 100. It is a thing. The barcode 12 is read by a barcode reader 52 (described later).

  As shown in FIG. 4, the thickness measuring apparatus 100 is configured to apply a transport unit 20 that continuously transports the base material K, a transport control unit 30 that drives the transport unit 20, and a film formed on the base material K. An image data acquisition unit 40 that acquires image data by irradiating light, an interface 43 for image acquisition, an ID information acquisition unit 50 that acquires an ID of a film from which image data has been acquired by the image data acquisition unit 40, and a device The control part 60, the control part 70 which controls operation | movement of the thickness measuring apparatus 100 collectively, the display part 80, the database 90, etc. are provided.

The transport unit (transport means) 20 includes, for example, a feeding roll 21 disposed on the upstream side in the transport direction and a take-up roll 22 disposed on the downstream side in the transport direction. It is configured such that it is fed out at a constant speed and taken up by a take-up roll 22.
In the present embodiment, the transport unit 20 unwinds the base material K from the feed roll 21 and winds it with the take-up roll 22 each time a film is formed on the base material K. That is, when a film is further laminated on the thin film on the base material K, the base material K is unwound from the feeding roll 21 again.

Further, a guide roll 23 that supports the conveyed base material K on the surface is provided between the feeding roll 21 and the take-up roll 22.
The conveyed base material K is in a state in which smoothness is maintained by being supported by the surface of the guide roll 23.

  Further, a rotary encoder 24 is connected to the feeding roll 21 via a coupling or the like. The rotary encoder 24 generates a pulse in synchronization with the rotation of the feeding roll 21. In the transport unit 20, there is no slip between the base material K and the feeding roll 21, and mechanical accuracy is ensured. Therefore, the pulses of the rotary encoder 24 are synchronized with the transport of the base material K.

  The conveyance control unit (conveying means) 30 includes a motor (not shown), and drives the motor to rotate the feeding roll 21, the winding roll 22, and the guide roll 23 under the control of the control unit 70.

The image data acquisition unit (image data acquisition means) 40 includes a linear light source 41 that irradiates light in a line shape over the entire width of the substrate K along the width direction (X direction) of the substrate K, And a line CCD camera 42 that receives the transmitted light from the film irradiated with light from the light source 41.
The image data acquisition unit 40 obtains image data for each layer constituting the multilayer film 10.

The light source 41 is disposed below the substrate K between the feeding roll 21 and the guide roll 23 and irradiates the substrate K with irradiation light having a predetermined wavelength.
Irradiation light from the light source 41 is always irradiated in a line at a predetermined position, and the film formed on the substrate K is irradiated with light when passing through the predetermined position.

The line CCD camera 42 is provided above the base material K at a position facing the light source 41 with the base material K interposed therebetween. Based on the transmitted light from the film irradiated with light from the light source 41, the line CCD camera 42 Two multilayer films 10 and 10 arranged in the width direction (X direction) are imaged to acquire image data and output to the control unit 70.
As the line CCD camera 42, a color line CCD camera is used in which dedicated CCD elements for R, G, and B are arranged in parallel, and output three primary color signals of R signal, G signal, and B signal. Therefore, the line CCD camera 42 outputs three types of image data of R, G, and B corresponding to the light intensity distribution of the transmitted light from the film on the substrate K. The output image data is used for thickness calculation processing in the control unit 70 described later.

  Specifically, the line CCD camera 42 captures an image of an imaging area having a predetermined size based on a timing signal transmitted from the device control unit 60 when the count value of pulses transmitted from the rotary encoder 24 reaches a predetermined value. Start data acquisition. Acquisition of such image data is performed for the number of lines corresponding to a predetermined distance according to the count value of the pulses transmitted from the rotary encoder 24.

At this time, the line CCD camera 42 also images the alignment mark 11 at the same time.
The alignment mark 11 is used to recognize an image data area to be stored (hereinafter referred to as “stored image data area”) in the acquired image data.
Specifically, as illustrated in FIG. 5, when the line CCD camera 42 captures an imaging area including the alignment mark 11, the center of gravity position of the alignment mark 11 is obtained based on the control of the control unit 70. An area composed of a plurality of points (0, 0) to (X _W , Y _L ) set in advance with 0 as a point is obtained as the saved image data area. Each saved image data area is given an ID by a barcode 12. For each ID, image data corresponding to each point (0, 0) to (X _W , Y _L ) is stored in the temporary memory 734.
Also, as shown in FIG. 6, a predetermined area of the stored image data area is used as a calculation area used when calculating the thickness. After the saved image data area is saved in the temporary memory 734, image data obtained by extracting only the calculation area is newly created and saved in the temporary memory 734.

  Further, the line CCD camera 42 is provided with an interface 43 for image acquisition. The interface 43 transmits the acquired image data to the control unit 70.

  The ID information acquisition unit (identification information acquisition means) 50 includes a photoelectric sensor 51 for detecting light reflected by the barcode 12 and obtaining a detection signal, a barcode reader 52 for reading the barcode 12, and the like. Yes.

The photoelectric sensor 51 includes a light projecting unit and a light receiving unit (both not shown), emits light such as visible light and infrared light from the light projecting unit, and reflects light reflected by the barcode 12 by the light receiving unit. Detect and output a detection signal.
The count of pulses transmitted from the rotary encoder 24 is started using the detection signal output from the photoelectric sensor 51 as a trigger signal.

The bar code reader 52 starts reading the bar code 12 based on the timing signal transmitted from the device control unit 60 when the count value of the pulses transmitted from the rotary encoder 24 reaches a predetermined value. get.
The barcode 12 is provided for each of the two multilayer films 10 and 10 arranged in the X direction on the substrate K, and the ID given by the barcode 12 identifies each of the set of multilayer films 10 and 10. It is used as identification information for
That is, the ID is stored in the temporary memory 734 in association with the image data (stored image data area, calculation area) acquired by the image data acquisition unit 40 or the thickness calculated by the thickness calculation process described later. .

  The device control unit 60 includes a sequencer, for counting pulses of the rotary encoder 24, generating a timing signal for starting reading of the barcode 12 by the barcode reader 52, and starting acquisition of image data by the line CCD camera 42. The timing signal is generated, the light amount of the light source 41 is controlled, and the like.

  The control unit 70 includes a CPU (Central Processing Unit) 71, a RAM (Random Access Memory) 72, a storage unit 73, and the like.

  The CPU 71 reads out a processing program stored in the storage unit 73, develops it in the RAM 72, and executes it, thereby controlling the thickness measuring apparatus 100 as a whole.

  The RAM 72 expands the processing program executed by the CPU 71 in the program storage area in the RAM 72, and stores the input data and the processing result generated when the processing program is executed in the data storage area.

The storage unit 73 includes, for example, a recording medium (not shown) that stores programs, data, and the like, and this recording medium is configured by a semiconductor memory or the like.
Further, the storage unit 73 stores various data, various processing programs, data processed by executing these programs, and the like for realizing the function of the CPU 71 controlling the entire thickness measuring apparatus 100.
Specifically, the storage unit 73 stores an acquisition program 731, a calculation program 732, a storage program 733, a temporary memory (storage means) 734, and the like.

  The acquisition program 731 is a program that causes the CPU 71 to acquire image data by the image data acquisition unit 40 and to acquire identification information (ID) for identifying the layer from which the image data has been acquired by the ID information acquisition unit 50. is there.

  Specifically, the CPU 71 executes the acquisition program 731 to capture the image area including the alignment mark 11 by the line CCD camera 42 to obtain the above-described image data (stored image data area and calculation area), and The barcode 12 is read by the code reader 52, and identification information (ID) for identifying the layer from which the image data is obtained is obtained.

When the CPU 71 acquires the image data of each of the second and subsequent layers 10 ₂ to 10 _N by executing the acquisition program 731, one lower layer 10 ₁ to 10 _N stored in the temporary memory 734 described later. ₋₁ identification information is referred to and alignment is performed.
For example, when acquiring the optical data of the second layer 10 _2, CPU 71 refers to the first layer 10 ₁ of the identification information stored at that time in the temporary memory 734, the first layer 10 ₁ and the same position Control is performed so that image data is measured by

The CPU 71 functions as an image data acquisition unit together with the image data acquisition unit 40 by executing the acquisition program 731.
Further, the CPU 71 functions as an identification information acquisition unit together with the ID information acquisition unit 50 by executing the acquisition program 731.

  The calculation program 732 is a program that causes the CPU 71 to realize a function of calculating the thickness of each layer using image data acquired by executing the acquisition program 731.

Specifically, when calculating the first layer 10 thickness of ₁ on the substrate K, CPU 71 executes the calculation program 732, the reference data image data of the first layer 10 ₁ was stored in advance The thickness is calculated in comparison with
And the reference data, which has been formed and stored in advance by the user based on the emission spectrum of the complex refractive index of the substrate K and the first layer 10 ₁ and a CCD receiving spectrum and the light source.

Also, when calculating the thickness of the first layer 10 ₁ on sequentially formed by the second and subsequent layers each layer ₁₀ 2 to 10 _N, CPU 71 executes the calculation program 732, stored in the temporary memory 734 Referring to the calculation area of the lower layers 10 ₁ to 10 _N-1 , the image data of each of the layers 10 ₂ to 10 _N after the second layer and the data regarding the thickness of the lower layers 10 ₁ to 10 _N-1 are as follows: The thickness of each layer is calculated by comparing with simulation data created by applying a predetermined theoretical formula.

Here, a method of creating simulation data created for calculating the thickness of each of the second and subsequent layers 10 ₂ to 10 _N will be described.

The theoretical formula of energy transmittance in the N-layer multilayer film 10 with the thickness of each layer 10 ₂ to 10 _N as a parameter is assumed that the incident angle is perpendicular (90 degrees) to the surface of the multilayer film 10, It is given by the equation of amplitude reflectance shown in (1) and the following equations (2) to (6).

Here, t in the formula (1) is expressed by the formula (2), and parameters m ₁₁ , m ₁₂ , m ₂₁ , and m ₂₂ shown in the formula (2) are all N given by the formula (3). Each element of the characteristic matrix M in the layer, which is given by the total product of M _i (i is an integer that increases by 1 from 1 to 1, as in 1, 2,...) The matrix M _i is given by equation (4). Δ _i shown in Formula (4) is represented by Formula (5), and P _Si shown in Formula (4) is represented by Formula (6). Further, n _i is the complex refractive index, d _i is the physical layer thickness of the i layer, lambda is the wavelength for obtaining the energy transmission is assigned.

  Therefore, when these equations (1) to (6) are used, the values other than the uppermost layer to be calculated are fixed values, and the layer thickness value of the uppermost layer is changed for each wavelength of the three colors to be used. The energy transmittance as well as the energy reflectance can be generated as simulation data.

Figure 7 is an example of an optical data measured in the second layer 10 _2, FIG. 8 shows an example of a simulation data created for the second layer 10 _{and second} layer thickness calculation.
7 and 8, the vertical axis represents energy transmittance (%), and the horizontal axis represents layer thickness (nm). A broken line, a solid line, and an alternate long and short dash line indicate R, B, and G, respectively.

FIG. 9 is an example of fitting data obtained by superimposing (comparing) actual measurement data and simulation data.
As shown in FIG. 9, the layer thickness where the difference between the R, B, and G values is the smallest between the measured data and the simulation data (140 nm in FIG. 9) is calculated as the layer thickness.
The calculated layer thickness is stored in the temporary memory 734 and the database 90 in association with the position information.

The wavelength used for the thickness calculation process may be limited to a plurality of discontinuous wavelengths, and the range of the layer thickness to be compared may be limited to a predetermined range including a desired layer thickness.
In order to increase the reliability of the measurement, it is preferable to weight the wavelength with less noise, or to narrow the layer thickness range as much as possible in a stable process.

  The CPU 71 functions as a calculation unit by executing the calculation program 732.

  The storage program 733 is a program for realizing a function of causing the CPU 71 to store the layer thickness calculated by the execution of the calculation program 732 in the temporary memory 734 in association with the identification information acquired by the execution of the acquisition program 731.

Specifically, CPU 71 is the execution of the calculation program 732, for example, when the thickness of the first layer 10 ₁ is calculated, and stores the thickness of the first layer 10 ₁ together with the identification information, the temporary memory 734 .
Further, CPU 71 is the execution of the calculation program 732, for example, when the thickness of the second layer 10 ₂ is calculated, the first layer 10 ₁ of the thickness and the identification information stored in the already temporary memory 734, the storing the thickness of the two layers 10 ₂ to the temporary memory 734.

  The CPU 71 functions as a storage unit together with the temporary memory 734 by executing the storage program 733.

The temporary memory (storage means) 734 stores data acquired and calculated in the thickness measurement process.
This temporary memory 734 stores all data acquired and calculated in the thickness measurement procedure until the thickness measurement procedure for all layers of the thickness measurement target lot is completed. Is overwritten or erased.

The display unit 80 includes, for example, a monitor such as a CRT (Cathode Ray Tube) or an LCD (Liquid Crystal Display), and displays various screens according to instructions of a display signal input from the control unit 70.
For example, the display unit 80 displays image data, simulation data, fitting data for comparing them, and the like.

The database 90 is configured by an HDD (Hard Disk Drive) or the like, and can store all data acquired and calculated in the thickness measurement processing of a plurality of lots even when the thickness measurement processing of a plurality of lots is executed. It is a capacity database.
That is, the same data as the temporary memory 734 is stored in the database 90. In the temporary memory 734, data is overwritten or deleted when the lot is changed, whereas in the database 90, the data is overwritten even if the lot is changed. It is accumulated without being erased.
Accordingly, the data can be restored by referring to the database 90 as necessary, for example, when data is damaged.

<Thickness measurement method>
Next, a thickness measurement method according to an embodiment of the present invention will be described with reference to the flowchart of FIG.
In the following flowchart, a case where two layers of films (first layer 10 ₁ , second layer 10 ₂ ) are formed on the substrate K will be described as an example.
Further, as a premise of the thickness measuring method, the feeding roll 21, the winding roll 22, and the guide roll 23 are rotated and the base material K is conveyed, and the irradiation light from the light source 41 is always guided by the guide roll 23. The line CCD camera 42 can receive transmitted light.

First, when the first layer 10 ₁ is formed on a substrate K, the control unit 70 by a line CCD camera 42 acquires image data of the first layer 10 ₁ by the bar code reader 52, the first layer acquires 10 ₁ identification information (first acquisition step: step S1).

Then, the control unit 70, the image data of the first layer 10 _1, compared with the previously stored reference data, calculates the thickness of the first layer 10 ₁ (first calculation step: step S2).

Then, the control unit 70 stores the first layer 10 thickness of ₁ calculated in the temporary memory 734 in association with the first layer 10 ₁ of the identity (first storage step: Step S3).

Then, when the second layer 12 is formed on the first layer 10 _1, the control unit 70 by a line CCD camera 42 acquires image data of the second layer 10 _2, the bar code reader 52, the second acquiring identification information of the layer 10 ₂ (second acquisition step: step S4).
At this time, the control unit 70 refers to the first layer 10 ₁ of the identification information stored in the temporary memory 734 in step S3, is performed alignment of image data acquisition position.

Then, the control unit 70, simulations image data of the second layer 10 _2, which is created by fitting the data relating to the thickness of the first layer 10 ₁ was stored in the temporary memory 734 in step S3 a predetermined theoretical expression compared to the data, calculates the thickness of the second layer 10 ₂ (second calculation step: step S5).

Then, in step S6, the control unit 70, a second layer 10 of ₂ thickness calculated and stored in the temporary memory 734 together with the identification information of the second layer 10 ₂ (second storage step).

  In the above flowchart, the case where two layers of films are formed on the substrate K has been described as an example. However, when three or more layers of films are formed, the above steps S4 to S6 are repeated. That is, when forming a film of three or more layers, the image data of the outermost layer is acquired in the same manner, and the data and identification information regarding the thickness of the lower layer already stored in the temporary memory 734 at that time are used. Thus, the thickness of the outermost layer is calculated while aligning.

As described above, according to the present embodiment, when calculating the first layer 10 thickness of ₁ on the substrate K, the image data of the first layer 10 _1, compared with the previously stored reference data calculating the thickness of the image data of the first layer 10 when calculating the thickness of the successively formed by the second and subsequent layers of the layers ₁₀ 2 to 10 _N on _1, 2 and subsequent layers of the layers ₁₀ 2 to 10 _N Is compared with the simulation data created by applying the thicknesses of the lower layers 10 ₁ to 10 _N-1 to a predetermined theoretical formula, and a value having the smallest difference is calculated as the thickness.
Also, when acquiring the image data of the second and subsequent layers each layer ₁₀ 2 to 10 _N, performs alignment with reference to one identification information of the lower layer ₁₀ 1 _{to 10 N-1.}
Therefore, the thickness of the multilayer film can be measured at high speed and with high accuracy.

In addition, according to the present embodiment, the calculated layer thickness data for each layer is thickness distribution data along the width direction of the substrate K.
For this reason, the thickness of the multilayer film can be measured with higher accuracy.

Moreover, according to this embodiment, the base material K is conveyed by a roll-to-roll system.
For this reason, it is possible to efficiently measure the thickness of the base material K produced by a more productive method.

The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.
Below, the modification of the thickness measuring apparatus which concerns on this invention is demonstrated.

<Modification 1>
As shown in FIG. 11, in the thickness measuring apparatus 100 </ b> A of the first modification, the light source 41 is disposed above the guide roll 23, irradiates the substrate K with light, and the line CCD camera 42 includes the light source 41. Based on the reflected light from the film irradiated with more light, the two multilayer films 10 and 10 arranged in the width direction (X direction) of the base material K are imaged to acquire image data and output to the control unit 70. It has a configuration.
In addition, the irradiation light from the light source 41 is always irradiated in a line at a predetermined position of the guide roll 23, and the film formed on the base material K passes through the predetermined position of the guide roll 23. In the case of light.
Further, when the transported base material K is supported by the guide roll 23, the image data acquisition unit 40 acquires the image data of the film formed on the base material K.

<Modification 2>
As shown in FIG. 12, the thickness measuring apparatus 100B according to Modification 2 includes three light sources 41a to 21c and three monochrome line CCD cameras 42a to 22c corresponding to the three light sources 41a to 21c. It is a configuration.
The three light sources 41a to 21c emit light of different wavelengths corresponding to R, B, and G, respectively, and each monochrome line CCD camera 42 receives image data corresponding to R, B, and G. Can be acquired.
A filter corresponding to R, B, and G may be provided in each of the three monochrome line CCD cameras 42a to 22c, and light having the same wavelength may be emitted from the three light sources 41a to 21c. .

  Even in the configurations of the first modification and the second modification, image data similar to that of the thickness measurement apparatus 100 can be acquired, and a thickness measurement process similar to that of the thickness measurement apparatus 100 can be performed. .

  In addition, in the said embodiment and the modifications 1 and 2, although the conveyance part 20 was the structure wound up whenever it forms a film | membrane once, between a supply roll 21 and the winding roll 22, a film-forming part and A plurality of sets of the image data acquisition unit 40 and the ID information acquisition unit 50 may be provided to perform continuous processing.

100, 100A, 100B Thickness measuring device K Base material 10 Multilayer film 10 ₁ to 10 _N 1st film to Nth film 11 Alignment mark 12 Bar code 20 Conveying section (conveying means)
21 Feeding roll 22 Winding roll 23 Guide roll 24 Rotary encoder 30 Transport control unit (transport means)
40 Image data acquisition unit (image data acquisition means)
41 Light source 42 Camera 43 Interface 50 ID information acquisition unit (identification information acquisition means)
51 Photoelectric Sensor 52 Barcode Reader 60 Device Control Unit 70 Control Unit 71 CPU (Image Data Acquisition Unit, Identification Information Acquisition Unit, Calculation Unit, Storage Unit)
72 RAM
73 storage unit 731 acquisition program 732 calculation program 733 storage program 734 temporary memory (storage means)
80 Display 90 Database

Claims (8)

A thickness measuring device for measuring the thickness of a multilayer film formed on a substrate to be conveyed,
Image data acquisition means for acquiring image data of the formed layer by irradiating the formed layer with light each time each layer of the multilayer film is formed;
When acquiring the image data by the image data acquisition means, identification information acquisition means for acquiring identification information for identifying the layer from which the image data was acquired;
Calculation means for calculating the thickness of each layer from the image data acquired by the image data acquisition means;
Storage means for storing the thickness of each layer calculated by the calculation means in association with the identification information acquired by the identification information acquisition means;
With
The calculating means includes
The first layer image data on the base material is compared with reference data stored in advance to calculate the thickness of the first layer,
When calculating the thickness of each of the second and subsequent layers sequentially formed on the first layer, the image data of each of the second and subsequent layers and the data relating to the thickness of the lower layer are applied to a predetermined theoretical formula. In comparison with the simulation data created in step 1, calculate the thickness of each layer after the second layer,
The image data acquisition means includes
The thickness measuring apparatus according to claim 1, wherein when acquiring image data of each of the second and subsequent layers, positioning is performed with reference to identification information of one lower layer. The calculating means includes
When calculating the thicknesses of the second and subsequent layers sequentially formed on the first film, the image data of the second and subsequent layers is compared with the simulation data, and the difference is the smallest. The thickness measuring apparatus according to claim 1, wherein the value is calculated as a thickness. The image data acquisition means includes
Each time the layers of the multilayer film are formed, a linear light source that irradiates light in a line along the orthogonal direction orthogonal to the transport direction of the base material, with respect to the formed layer;
A line CCD camera that receives transmitted light or reflected light from a layer irradiated with light by the line light source, and
The thickness measuring apparatus according to claim 1 or 2, wherein the thickness of each layer calculated by the calculating means is indicated by thickness distribution data along an orthogonal direction.   The thickness measuring apparatus according to any one of claims 1 to 3, further comprising transport means for transporting the base material by a roll-to-roll method. A thickness measuring method using the thickness measuring device according to any one of claims 1 to 4,
When the first layer of the first layer is formed on the substrate, the image data acquisition unit acquires the image data of the first layer, and the identification information acquisition unit acquires the identification information of the first layer. A first acquisition step of acquiring
A first calculation step of calculating the thickness of the first layer by comparing the image data of the first layer acquired by the first acquisition step with reference data stored in advance;
A first storage step of storing the thickness of the first layer calculated in the first calculation step in the storage unit in association with the identification information of the first layer acquired by the identification information acquisition unit;
When the second layer of the second layer is formed on the first layer, the image data acquisition unit acquires the image data of the second layer, and the identification information acquisition unit identifies the second layer. A second acquisition step of acquiring information;
The second layer image data acquired in the second acquisition step is compared with simulation data created by applying data relating to the thickness stored in the storage means to a predetermined theoretical formula. A second calculation step of calculating the thickness of
A second storage step of storing the thickness of the second layer calculated by the second calculation step together with the identification information of the second layer acquired by the identification information acquisition unit;
A thickness measuring method comprising: The second calculation step includes
The thickness measurement method according to claim 5, wherein the image data of the second layer and the simulation data are compared, and a value with the smallest difference is calculated as the thickness.   The thickness of each layer calculated by the first calculation step and the second calculation step is indicated by thickness distribution data along an orthogonal direction orthogonal to the transport direction of the base material. The thickness measuring method as described in.   The thickness measurement method according to any one of claims 5 to 7, wherein the substrate is conveyed by a roll-to-roll method.

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