JP2019174249A - Method for measuring distance between holes - Google Patents

Abstract

To provide a method for measuring the distance between holes which can accurately measure the distance between holes of a porous body accurately.SOLUTION: The method for measuring the distance between holes includes the steps of: emitting an X-ray into the surface of a porous body at a minute angle; and measuring a scattering X-ray emitted from the surface.SELECTED DRAWING: None

Description

  The present invention relates to a method for measuring a distance between holes.

  The characteristics of the porous body such as the anodized film vary depending on the pore diameter and the distance between the pores. For example, Patent Document 1 describes a method in which an aluminum base material on which an anodized film is formed and a resin are bonded via the anodized film. Patent Document 1 discloses that the average inter-pore distance of the anodized film is 5 to 5 in order to allow the resin to penetrate into the pores of the porous anodized film and bond the aluminum base material and the resin more firmly. It is described that it should be 90 nm. In Patent Document 1, the average inter-pore distance is measured by observing a cross section of the anodized film with a transmission electron microscope (TEM) or a scanning electron microscope (SEM).

  Non-Patent Document 1 describes that a laminated structure of polyethylene subjected to melt crystallization and annealing treatment can be measured by a small angle incident X-ray small angle scattering (SI-SAXS) method.

JP-T-2006-522310

Sasaki et al., "In situ investigation of annealing effect on lamellar stacking structure of polyethylene thin films by synchrotron grazing-incidence small-angle and wide-angle X-ray scattering," MJ Appl. Cryst., 2007, 40, p. S642 -s644

  For observation of a fine surface shape, it is known to use TEM, SEM or the like as described in Patent Document 1. However, according to the knowledge of the present inventors, when observing the porous body with a TEM, SEM or the like and measuring the inter-hole distance, there is a large variation in the value obtained for each measurement, and the reliability of the measured value is increased. It was hard to raise.

  On the other hand, according to the GI-SAXS method as described in Non-Patent Document 1, it is expected that the minute shape of the object to be observed can be measured more accurately. However, although the GI-SAXS method is used for the measurement of thin films of polymer compounds, etc., it can be used for the measurement of porous materials that have an irregular structure and are expected to diffuse X-ray scattering. Was questioned.

  In view of the above problems, an object of the present invention is to provide a method for measuring a distance between holes, which can measure the distance between holes of a porous body with higher accuracy.

  The present invention for solving the above-mentioned problems includes a step of making X-rays incident on the surface of a porous body with an incident angle as a small angle, and a step of measuring scattered X-rays emitted from the surface. The present invention relates to a method for measuring an inter-distance.

  ADVANTAGE OF THE INVENTION According to this invention, the measuring method of the distance between holes which can measure the distance between holes of a porous body with a higher precision is provided.

  In the method for measuring the distance between pores of a porous body according to an embodiment of the present invention, first, X-rays are incident on the surface of the porous body.

  In the present embodiment, X-rays are incident on the surface of the porous body at this time with the incident angle being a minute angle. By setting the incident angle to a small angle, the X-ray penetration depth can be controlled within an appropriate range, and only the vicinity of the surface can be observed. Further, a wider area can be irradiated with X-rays, and the area that can be measured at once can be increased.

In order to observe a porous body having an irregular structure, it is preferable to adjust the optical system and measure a wide angle range (q range). Preferably _{q y} = ^{1 nm -1} from _{q y} = 0.03 nm ^-1 Specifically, more preferably _{q y} = ^{2 nm -1} from _{q y} = 0.01nm ^-1.

  According to the study by the present inventors, in the SEM and TEM described in Patent Document 1, the surface is irradiated with an electron beam whose diameter is reduced from several nm to several hundred nm. However, since the electron beam with the reduced diameter is smaller in size than the pores of the porous body, the characteristics of the incident position such as the inside or the edge of the pore greatly change due to the deviation of the irradiation position. The emitted secondary electrons (in the case of observation with the SEM) and the transmittance of the electron beam (in the case of observation with the TEM) may also vary greatly. For this reason, when the surface of the porous body is observed with SEM, TEM, etc., and the shape is measured, the measurement result may change greatly due to a slight shift of the irradiation position of the electron beam.

  In contrast, by irradiating a wide area with X-rays at a small angle with an X-ray incident angle being small, fluctuations in measurement results due to deviations in irradiation position can be prevented, and more reliable measurement results can be obtained. it is conceivable that.

  The X-rays can be characteristic X-rays such as CuKα rays and MoKα rays, for example.

  The X-ray beam size is such that when the incident angle is a small angle, X-rays are irradiated over a wider range of the surface of the porous body, and a sufficient number of photons are scattered when the porous body is irradiated. Any size that produces light is acceptable. For example, the X-ray beam size can be 0.05 mm to 1.0 mm in diameter, and preferably 0.1 mm to 0.5 mm.

The irradiation area irradiated at one time with X-rays may be such that a plurality of pores in the vicinity of the surface of the porous body are irradiated at once, and can be 2 mm ² or more and 8 mm ² or less, and 3 mm ² or more. It is preferably 5 mm ² or less. The irradiation area can be adjusted by the X-ray beam size.

  The incident angle of X-rays may be, for example, 0.05 ° or more and 0.5 ° or less. In SEM, TEM, etc., only the surface shape of the porous body can be measured. However, in this embodiment, the depth from the surface of the porous body to which X-rays reach can be changed by changing the incident angle. Can be adjusted. Therefore, the incident angle may be set according to the depth at which the distance between holes is desired to be observed. According to the present embodiment, it is possible to measure the inter-hole distances at a plurality of different depths in the vicinity of the surface of the porous body by irradiating the X-rays a plurality of times at different incident angles.

  When the porous body is irradiated with X-rays having a small incident angle, the irradiated porous body becomes a new wave source, and scattered X-rays are emitted from the porous body.

In the present embodiment, the distance between pores of the porous body can be obtained from the scattering intensity curve I obtained by measuring this scattered X-ray. Specifically, the peak position q _{m at} which the scattering intensity I is maximized when the measured scattered X-ray intensity is plotted with the horizontal axis as the scattering vector q _y and the vertical axis as the scattering intensity I at q _y . Is the position of the scattering vector corresponding to the average distance between the closest holes (in this specification, the average distance between the closest holes is referred to as a distance D between holes).

  At this time, the inter-hole distance D is expressed by the following formula (1).

  In order to improve the measurement accuracy of the inter-pore distance D by the above-described method, the porous body is preferably a porous body having an inter-pore distance D of 3 nm or more and 700 nm or less, and is a porous body of 5 nm or more and 250 nm or less. It is more preferable. The porous body preferably has a porous body having an average pore diameter of 3 nm or more and 700 nm or less, and more preferably a porous body having an average pore diameter of 5 nm or more and 250 nm or less.

  The porous body is preferably a surface-treated aluminum surface-treated film, and more preferably an anodized film.

  It is also known that the average particle diameter and the like can be calculated from a scattering intensity curve obtained in the same manner from a scatterer of fine particles having an average particle diameter comparable to the average pore diameter. On the other hand, according to the knowledge of the present inventors, the average pore diameter cannot be accurately determined by the method of this embodiment. This means that when calculating the average particle size, average pore size, etc., assuming the shape of the particles (pores), the above scattering intensity is represented by a scattering function that represents the scattering of a three-dimensional body (sphere, cylinder, etc.) of the shape. It is necessary to fit a curve, but in the case of a porous body whose distance between pores is the same as that of particles (pores), the fitting is strongly affected by scattering due to interference between particles (pores). As such, it is difficult to calculate the average pore diameter.

  EXAMPLES Although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples.

[Production Example 1]
7.5% of commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was added to water and dissolved in a bath at 60 ° C., immersed in an aluminum alloy plate for 5 minutes, and thoroughly washed with water. did.

Subsequently, a 10% aqueous solution of caustic soda at 50 ° C. was prepared in a separate tank, and the aluminum alloy plate was immersed in this for 1 minute and washed with water. Subsequently, a 40% nitric acid solution at 40 ° C. was prepared in another tank, and the aluminum alloy plate was immersed in it for 1 minute and washed with water. Subsequently, a 20% sulfuric acid aqueous solution at 40 ° C. was prepared in another tank, and the aluminum alloy plate and the lead plate were immersed in this tank. The anode of the DC power supply device “PPK200-18-L De (manufactured by Matsusada Precision Co., Ltd.)” is connected to a part of the aluminum alloy plate, the cathode is connected to the lead plate, and the current density is 2.5 A / A test piece 1 was manufactured by anodizing for 10 minutes under low current control at dm ² , then washing with water and placing in a hot air dryer at 80 ° C. for 20 minutes and drying.

[Production Example 2]
The aluminum alloy plate and the lead plate are immersed in a 20% sulfuric acid aqueous solution at 40 ° C., the anode of the DC power supply device is connected to a part of the aluminum alloy plate, and the cathode is connected to the lead plate. A test piece 2 was produced in the same manner as in Production Example 1 except that anodization was performed for 10 minutes under low current control to obtain a current density of 0.5 A / dm ² .

[Production Example 3]
The aluminum alloy plate and the lead plate are immersed in a 20% sulfuric acid aqueous solution at 30 ° C., the anode of the DC power supply device is connected to a part of the aluminum alloy plate, and the cathode is connected to the lead plate. A test piece 3 was produced in the same manner as in Production Example 1 except that anodization was performed for 10 minutes under low current control at a current density of 5 A / dm ² .

[Production Example 4]
The aluminum alloy plate and the lead plate are immersed in a 20% sulfuric acid aqueous solution at 20 ° C., the anode of the DC power supply device is connected to a part of the aluminum alloy plate, and the cathode is connected to the lead plate. A test piece 4 was produced in the same manner as in Production Example 1 except that anodization was performed for 10 minutes under low current control at a current density of 5 A / dm ² .

[Production Example 5]
The aluminum alloy plate and the lead plate are immersed in a 20% sulfuric acid aqueous solution at 10 ° C., the anode of the DC power supply device is connected to a part of the aluminum alloy plate, and the cathode is connected to the lead plate. A test piece 5 was produced in the same manner as in Production Example 1 except that anodization was performed for 10 minutes with low current control to obtain a current density of 0.5 A / dm ² .

[Example 1]
Using a small-angle X-ray scattering measurement device NANO-Viewer (manufactured by Rigaku Corporation) on which a grazing incidence small-angle X-ray scattering (GISAXS) measurement stage (hereinafter also referred to as a stage) is installed, GISAXS of test pieces 1 to 5 Measurements were made. The X-ray uses CuKa ray (wavelength: 0.154 nm), and the beam size is changed by the pinhole slit (first slit: φ0.2 mm, second slit: φ0.1 mm, third slit: φ0.25 mm) It was squeezed into a 0.25 mm circle. Test pieces 1 to 5 having a length of 45 mm, a width of 18 mm, and a thickness of 2 mm were placed on the stage so that the X-ray incident direction was parallel to the width direction. The stage height was adjusted using the transmitted X-ray intensity so that the test piece surface and the X-ray height matched. GISAXS measurement was performed using an X-ray incident angle θ _H of 0.1 ° and a two-dimensional detector PILATUS 100K (Decortis) as a detector. The distance between the sample and the detector was 1340 mm.

According to the method described in Non-Patent Document 1, the intensity of the obtained two-dimensional data is scanned in a direction parallel to the sample surface (in-plane direction) and plotted against the magnitude q _y of the scattering vector. An intensity curve I (q _y ) [vertical axis is I (q _y ) and horizontal axis is q _y ] was obtained. The inter-hole distance D was determined from the peak position q _m in the scattering intensity curve I (q _y ) according to the equation (1).

[Example 2]
The inter-hole distance D was determined in the same manner as in Example 1 except that θ _H was 0.2 °.

[Example 3]
The inter-hole distance D was determined in the same manner as in Example 1 except that θ _H was 0.25 °.

[Example 4]
The inter-hole distance D was determined in the same manner as in Example 1 except that θ _H was 0.3 °.

[Comparative Example 1]
Scanning electron microscope (SEM) observation of test piece 1 to test piece 5 was performed using JEOL JSM-6701F. The acceleration voltage was 5.0 kV and the observation magnification was 100,000 times. Ten pairs of adjacent holes were randomly selected from within a 500 nm square field of view, the distance between the holes was measured, and the average value was defined as the distance between the holes (Comparative Example 1-1). Different fields of view having the same size were evaluated in the same manner to obtain an inter-hole distance D (Comparative Example 1-2).

  Table 1 shows the evaluation area, the observation depth, and the inter-hole distance D measured for each of the test pieces 1 to 5 in Examples 1 to 4, Comparative Example 1-1, and Comparative Example 1-2. Shown in

  As is clear from Table 1, a wider area can be evaluated by measuring the scattered X-rays emitted from the surface by making X-rays incident on the surface of the test piece with a small angle of incidence, and For anodized with a larger inter-hole distance D, a larger inter-hole distance value is measured, and for an anodized with a smaller inter-hole distance D, a smaller inter-hole distance value is measured. It was. This is probably because a wider area could be evaluated.

  In addition, by changing the incident angle by measuring the scattered X-rays emitted from the surface by entering X-rays on the surface of the test piece with a small incident angle, the distance between holes in the depth direction can also be changed. It was possible to evaluate.

  On the other hand, in the observation by SEM, even if it measured about the same test piece, the value of the distance between holes obtained for every measurement was changing. This is probably because only a relatively narrow range could be measured with respect to the opening diameter of the holes.

[Comparative Example 2]
It is a scattering function of isolated spherical particles in order to obtain the pore diameter from the scattering intensity curves I (q _y ) obtained in Examples 1 to 4 (the vertical axis is I (q _y ) and the horizontal axis is q _y ). We tried curve fitting using equation (2). For curve fitting, Igor Pro manufactured by WaveMetrics, which is data analysis software, was used.

In the formula (2), A is an arbitrary constant, R is the radius of a sphere approximating the spherical particles, it is q = q _x.

  However, curve fitting was not possible. This is thought to be because the distance between the holes is small and the scattering from each hole interferes with each other.

[Comparative Example 3]
Curve fitting was attempted in the same manner as in Comparative Example 2 except that Formula (2) was replaced by Formula (3), which is the scattering function of an isolated cylinder.

式（３）において、Ｂは任意の定数であり、Ｂ_１は第一種ベッセル関数であり、Ｒは円柱の断面の半径であり、Ｌは円柱の長さである。

In Expression (3), B is an arbitrary constant, B ₁ is a first-type Bessel function, R is a radius of the cross section of the cylinder, and L is the length of the cylinder.

  However, curve fitting was not possible. This is thought to be because the distance between the holes is small and the scattering from each hole interferes with each other.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to measure the distance between holes of a porous body more accurately. Therefore, the present invention can be effectively used for nondestructive evaluation of a porous body, inspection before shipment, and the like.

Claims (6)

A step of entering X-rays on the surface of the porous body with an incident angle as a minute angle;
Measuring scattered X-rays emitted from the surface;
A method for measuring a distance between holes.   In the scattering intensity curve obtained by the measurement of the scattered X-ray, the peak position where the scattering intensity is maximized is the position of the scattering vector corresponding to the inter-hole distance, and the distance corresponding to the scattering vector of the position is the porous The method for measuring a distance between holes according to claim 1, wherein the distance between holes in the material is a distance between holes. Injecting X-rays to the surface of the porous body multiple times at different incident angles,
Measure scattered X-rays emitted from the surface by each of the multiple incidences;
Measuring the inter-hole distances at a plurality of positions having different depths from the surface of the porous body,
The method for measuring a distance between holes according to claim 1 or 2.   The interporous distance measurement method according to any one of claims 1 to 3, wherein the porous body is a porous body having an interpore distance of 3 nm to 700 nm.   The said porous body is a surface treatment film | membrane of the surface-treated aluminum, The measuring method of the distance between holes of any one of Claims 1-4.   The method for measuring a distance between holes according to claim 1, wherein the porous body is an anodized film.