阅读说明：本技术 非接触式微粒绝对质量测量装置及测量方法 (Non-contact particle absolute mass measuring device and measuring method ) 是由 金志锡 于 2020-02-18 设计创作，主要内容包括：本发明公开了一种微粒绝对质量测量装置包括：辐射管；折射所述辐射管照射出的放射线,缩小或放大图像的透镜部；包含板状的试片固定基板,所述试片固定基板搭载着入射从所述透镜部照射的放射线的试片的试片搭载部；穿过所述试片搭载部的放射线成像的图像板；以及,从成像在所述图像板上的图像中,分离提取试片图像和背景图像,通过比较所述背景图像和所述试片图像,将因所述试片发生的黑化程度转化为密度信息后,计算出所述试片的质量信息的质量计算部。(The invention discloses a device for measuring the absolute mass of particles, which comprises: a radiant tube; a lens portion for refracting the radiation irradiated from the radiation tube and reducing or enlarging the image; a test piece mounting portion including a plate-like test piece fixing substrate on which a test piece on which radiation irradiated from the lens portion is incident is mounted; an imaging plate for imaging radiation passing through the test piece mounting portion; and a quality calculating part for separating and extracting a test piece image and a background image from the image formed on the image plate, converting the blackening degree of the test piece into density information by comparing the background image and the test piece image, and calculating the quality information of the test piece.)

1. An absolute particulate mass measurement device, comprising:

a radiation tube for generating radiation inside and irradiating the radiation outside;

a lens unit which refracts the radiation irradiated from the radiation tube to reduce or enlarge an image;

a test piece mounting portion including a plate-shaped test piece fixing substrate on which a test piece on which radiation irradiated from the lens portion is incident is mounted;

an image plate on which the radiation passed through the test piece mounting portion is imaged; and the number of the first and second groups,

a quality calculating part for separating and extracting a test piece image and a background image from the image formed on the image plate, converting the blackening degree of the test piece into density information by comparing the background image and the test piece image, and calculating the quality information of the test piece,

the specimen-holding substrate is formed of a uniform material over the entire area and thickness,

the specimen mounting portion is provided with a motor for rotating the specimen fixing substrate about a line perpendicular to the radiation irradiation direction as a rotation axis, so that the mass calculating portion can calculate the same mass information for the same specimen even if the mounting direction or position of the specimen on the specimen fixing substrate varies.

2. The absolute particle mass measuring device according to claim 1, wherein the specimen image formed on the image plate is a magnified image larger than the actual size of the specimen, and the minimum distance between the specimen carrying portion and the image plate is a position where the magnified image magnifies the specimen image by a factor of 50.

3. The particle absolute mass measuring device according to claim 2,

the image plate is divided into a plurality of pixels having the same area,

the mass calculating unit calculates the area of the test piece image by calculating the number of pixels included in the test piece image formed on the image plate.

4. The particle absolute mass measuring device according to claim 1,

the mass calculating part obtains the number of photons attenuated by the difference between the number of photons irradiated from the radiation tube and incident on the test piece and the number of photons passing through the test piece, and then calculates the mass value,

and a process for the preparation of a coating,

and obtaining the actual quality value of the test piece.

5. The absolute particle mass measuring device according to claim 1, wherein the test piece holding base plate is formed by overlapping two plate surfaces with each other, and the test piece is held and inserted between the two plate surfaces.

6. The absolute particle mass measuring device according to claim 5, wherein the two plates are connected at one side by a hinge, and the two plates are rotated centering on the hinge so as to be openable between the two plates.

7. The absolute particle mass measuring device of claim 6 wherein the other side of each of said plates is provided with a counterweight of the same weight as said hinge, said counterweight being comprised of two parts fixedly mounted to each of said plates.

8. The absolute particle mass measuring device according to claim 7, wherein the balance weight is provided with a lock pin for fixing the two plates in a contact state.

9. The absolute particle mass measuring device according to claim 7, wherein the hinge and the weight are arranged in parallel in a direction perpendicular to a longitudinal direction of the rotary shaft provided for the motor to rotate the test piece-holding substrate.

10. The absolute particulate mass measurement device of claim 9, wherein the rotation shaft is detachably coupled to both of the plates constituting the specimen holding substrate at the same time, thereby preventing eccentricity when the specimen holding substrate is rotated.

11. The absolute particle mass measuring device according to claim 10, wherein a coupling plug for coupling the rotary shaft to the strip-holding substrate is provided between the rotary shaft and the strip-holding substrate,

a joint pin is projected toward the other of the side surface of the test piece fixing substrate and the joint plug, a pin hole into which the joint pin is inserted is formed in the other of the test piece fixing substrate and the joint plug,

the joint pin or the pin hole formed on the side surface of the test piece fixing substrate is formed on the side surfaces of the two plates in the same manner, and the pin hole or the joint pin correspondingly jointed with the side surface of the test piece fixing substrate is formed on the joint plug.

12. A method for measuring the absolute mass of particles,

preparing a radiation tube, an electron lens, and an image plate on which radiation irradiated from the radiation tube can be imaged, and mounting a test piece of a measured object whose quality is to be measured on a test piece fixing substrate of a test piece mounting portion formed of a uniform material;

irradiating the radiation from the radiation tube to form an image of the test piece on the image plate; and the number of the first and second groups,

a step of separating and extracting a test piece portion and a background portion from the test piece image imaged on the image plate, converting a degree of blackening caused by the shielding of the radiation by the test piece into density information by comparing the background portion with the test piece portion, and calculating quality information of the test piece,

adjusting the magnification of the electron lens and the distance between the test piece and the image plate so that the size of the image of the test piece is at least 50 times or more larger than that of the test piece,

in the imaging step, the same quality information can be obtained regardless of the direction in which the test piece is mounted on the test piece fixing substrate by rotating the test piece fixing substrate during irradiation with radiation.

13. The method of measuring absolute mass of fine particles according to claim 12, wherein in the mounting step, the minimum distance between the image plate and the test piece mounting portion is set to a position at a magnification of 50 times.

14. The method of measuring the absolute mass of fine particles according to claim 13, wherein the image plate is divided into a plurality of pixels having the same area, and the mass calculator calculates the area of the test piece image by calculating the number of pixels included in the test piece image formed on the image plate.

15. The method of measuring the absolute mass of fine particles according to claim 14, wherein the step of calculating the mass information of the test piece obtains the number of photons emitted from an X-ray tube and incident on the test piece and the number of attenuated photons of the difference between the number of photons incident on the test piece and the number of photons passing through the test piece, and then passes the number of attenuated photons through the test piece

And a process for the preparation of a coating,

and obtaining the actual quality value of the sample.

16. The method of measuring absolute mass of fine particles according to claim 12, wherein the specimen holding substrate is formed by overlapping two plates, and the two plates are hinged to each other, so that the specimen can be stably mounted while the mounting and dismounting of the specimen are simple.

17. The method of measuring absolute mass of fine particles according to claim 16, wherein when the specimen-holding substrate is connected to the motor, the rotation shaft of the motor for rotating the specimen-holding substrate is simultaneously coupled to both the plates.

18. The method for measuring absolute mass of fine particles according to claim 16, wherein in the mounting step, a weight for offsetting the weight of the hinge is provided in the test piece-holding substrate in a direction opposite to the hinge.

Technical Field

The present invention relates to a method and apparatus for measuring an absolute mass of fine particles, and more particularly, to a fine particle absolute mass measuring apparatus and method capable of measuring an absolute mass of fine particles without contacting an object to be measured.

Background

In modern society, with the development of electronic technology, parts such as various elements used in electronic products are increasingly miniaturized. In particular, as semiconductor integration technology has been developed, the size of the semiconductor device itself and the size of the package have been reduced to a mass in milligrams (mg), and in order to inspect the quality of such parts for the defect or quality, a device capable of measuring the mass in milligrams (milligram) or micrograms (microgram) is required.

However, the current devices for measuring the mass of such particles are basically the same as the principle of the conventional scale, and most of them use the gravity of the fine particles, however, the mass of the fine particles is measured by using a more sensitive sensor than the scale for measuring the mass of the macroscopic object.

In this case, the mass measurement is performed by placing fine particles on the upper part of the mass measurement sensor. Therefore, it is difficult to avoid the influence of the fine particles on the position of the sensor, the surrounding environment such as humidity and temperature, or the floating matter such as surrounding dust, and the like, and the possibility of errors is high in the fine particles having a mass size of milligram or less.

For example, in the process of producing tablets in which quantitative measurement is very important, it is difficult to precisely control the influence of air pressure, temperature, wind, etc. in a production plant because quality changes occur due to insufficient contents due to voids or cracks, etc., and very high costs are consumed for controlling the environment. In addition, since stabilization of the measuring scale requires several seconds to several tens of seconds even though the environment can be controlled, there is a limit to using the present contact type mass scale in a production process requiring a rapid inspection.

In addition, as for fine dust which has recently been a serious problem, although an attempt is made to measure the mass of fine dust, since the mass measurement of fine dust is not a mass measurement of individual particles, but a technique of measuring the total density of fine particles within a certain volume or measuring with a centrifuge, it is difficult to apply it to a technique of mass-measuring one fine particle.

As a related prior art, there can be mentioned a mass sensor and a mass detection method thereof disclosed in Japanese patent application laid-open No. P2000-321117A (published: 2000.11.24) shown in FIG. 1.

As shown in fig. 1, the conventional technique is a technique in which a connection plate 3 having a slit 5 formed therein and a diaphragm 2 are joined to each other on the side surface, two detection plates 4A and 4B are joined to the connection plate 3 on the side surface so as to sandwich the connection plate 3 in the direction perpendicular to the joining direction of the diaphragm 2 and the connection plate 3, a resonance portion formed by placing piezoelectric elements 6A and 6B on at least one flat surface of at least one of the detection plates 4A and 4B is joined to a part of the side surface of a sensor 7 to form a mass sensor 1, and the mass measurement of fine particles is performed based on the change in the resonance frequency of the resonance portion due to the change in the mass of the diaphragm 2.

However, the prior art is hardly protected from much influence of ambient temperature, humidity, dust as described above, and has problems that the quality measurement requires a clean environment, high proficiency and requires a plurality of measurements.

In addition, in particular, in a case where a micro element is already assembled as a micro electrode attached to a substrate, a difficult process of separating only the micro element is required for mass measurement, and the mass measurement itself may be difficult.

As another prior art, there can be mentioned a method and an apparatus for measuring a minute mass change of a substance disclosed in Japanese patent application laid-open No. P2002-257619A (published: 2002.09.11).

The method and apparatus for measuring a minute mass change of a substance apply an electric signal of a frequency alternating current slightly delayed in a resonance frequency as an input signal to a piezoelectric vibration element, output a current signal corresponding to the input signal from the element as an output signal, and apply a minute mass change of a material as an emphasis change to a surface of the element, thereby converting a current change corresponding to the emphasis change from the element into a voltage change.

However, this case has a problem that, as in the above-described prior art, since the piezoelectric vibrating element must be brought into contact with the object to be measured, the fluctuation range of the result value may be large depending on the measurement environment, and the measurement requires a high degree of skill.

Therefore, there is an urgent need for a non-contact micro mass measurement method that can measure a substance having a micro mass without contacting a measured object, without requiring any effort or equipment to be refined to a very fine degree, with a great saving in the cost and effort of the measuring equipment and the measurement itself, without requiring a high level of proficiency, with which anyone can perform the measurement, with which the position is measured, for example, without causing an error due to the environment because of not being affected by the altitude of the measured position or the surrounding environment, without requiring a plurality of measurements, and with which the measured object can be subjected to mass measurement without separating the measured object even in a state where the measured object is attached to other parts.

(reference documents)

Japanese patent laid-open publication No. P2000-321117A (Kokai: 2000.11.24)

Japanese patent laid-open publication No. P2002-257619A (Kokai: 2002.09.11)

Disclosure of Invention

The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide an apparatus and a method for measuring absolute mass of fine particles, which can measure a fine-mass substance without contacting the measured object, and without requiring any effort or equipment to be refined to a very fine level, and which can greatly reduce the cost and effort of the measuring equipment and the measuring itself, and can measure the quality of the measured object without separating the measured object even in a state where the measured object is attached to other parts, and who can measure the measured position without requiring a high degree of skill, for example, because the measured position is not affected by the altitude or the surrounding environment, and without causing an error due to the environment.

An absolute mass measurement apparatus according to an aspect of the present invention includes: a radiation tube for generating radiation inside and irradiating the radiation outside; a lens unit which refracts the radiation irradiated from the radiation tube to reduce or enlarge an image; a test piece mounting portion including a plate-shaped test piece fixing substrate on which a test piece on which radiation irradiated from the lens portion is incident is mounted; an image plate on which the radiation passed through the test piece mounting portion is imaged; and a mass calculating section for separating and extracting a test piece image and a background image from an image formed on the image plate, comparing the background image with the test piece image, converting a degree of blackening caused by the test piece into density information, and calculating mass information of the test piece, wherein the test piece fixed substrate is formed of a uniform material over an entire area and thickness, and the test piece mounting section is provided with a motor for rotating the test piece fixed substrate about a line perpendicular to a radiation irradiation direction as a rotation axis, whereby the mass calculating section can calculate the same mass information for the same test piece even if a mounting direction or a position of the test piece on the test piece fixed substrate varies.

The specimen image formed on the image plate is an enlarged image larger than the actual size of the specimen, and the minimum distance between the specimen carrying section and the image plate is a position where the enlarged image enlarges the specimen image by 50 times.

The image plate is divided into a plurality of pixels having the same area, and the mass calculator calculates the number of pixels included in the sample image formed on the image plate to calculate the area of the sample image.

Further, the mass calculating section obtains an attenuation photon value which is a difference between the number of photons irradiated from the radiation tube and incident on the test piece and the number of photons passing through the test piece,

and a process for the preparation of a coating,

and obtaining the actual quality value of the test piece.

Furthermore, the test piece fixing base plate is formed by overlapping two plate surfaces, and the test piece is fixedly inserted between the two plates.

Furthermore, one side of the two plates is connected by a hinge, and the two plates rotate around the hinge, so that the two plates can be opened.

And the other sides of the two plates are provided with balance weights with the same weight as the hinge, each balance weight consists of two parts, and the two parts are respectively and fixedly arranged on the two plates.

Furthermore, the balance weight is provided with a lock pin which enables the two plates to be fixed in a contact state.

Further, a direction in which the hinge and the counter weight are arranged side by side is perpendicular to a longitudinal direction of the rotary shaft provided for the motor to rotate the test piece fixing substrate.

Furthermore, the rotation shaft is detachably coupled to both of the plates constituting the test piece fixing substrate, thereby preventing the test piece fixing substrate from being eccentric when rotating.

A joint pin for connecting the rotary shaft to the test piece fixing substrate is provided between the rotary shaft and the test piece fixing substrate, a joint pin protrudes from either one of the side surface of the test piece fixing substrate or the joint pin toward the other, a pin hole into which the joint pin is inserted is formed in the other of the test piece fixing substrate or the joint pin, the joint pin or the pin hole formed in the side surface of the test piece fixing substrate is formed in the same manner in the side surfaces of the two plates, and the pin hole or the joint pin correspondingly joined to the side surface of the test piece fixing substrate is formed in the joint pin.

A method for measuring an absolute mass of fine particles according to another aspect of the present invention includes: preparing a radiation tube, an electron lens, and an image plate on which radiation irradiated from the radiation tube can be imaged, and mounting a test piece of a measured object whose quality is to be measured on a test piece fixing substrate of a test piece mounting portion formed of a uniform material; irradiating the radiation from the radiation tube to form an image of the test piece on the image plate; and a step of separating and extracting a test piece portion and a background portion from the test piece image imaged on the image plate, converting a degree of blackening caused by the shielding of the radiation by the test piece into density information by comparing the background portion with the test piece portion, and calculating quality information of the test piece, wherein the magnification of the electron lens and the distance between the test piece and the image plate are adjusted so that the size of the test piece image is at least 50 times or more the size of the test piece, and in the imaging step, the same quality information can be obtained regardless of the direction in which the test piece is mounted on the test piece fixing substrate by rotating the test piece fixing substrate during the radiation irradiation.

In the mounting step, the minimum distance between the image plate and the test piece mounting portion is set to a position at which the magnification is 50 times.

The image plate is divided into a plurality of pixels having the same area, and the mass calculator calculates the number of pixels included in the sample image formed on the image plate to calculate the area of the sample image.

Further, the step of calculating the mass information of the test piece is carried out by obtaining the number of photons emitted from the X-ray tube and incident on the test piece and the number of attenuated photons of the difference between the number of photons incident on the test piece and the number of photons passing through the test piece, and then passing the number of attenuated photons through the test piece

And a process for the preparation of a coating,

and obtaining the actual quality value of the sample.

Furthermore, the test piece fixing base plate is manufactured into a mode that two plates are overlapped, and the two plates are hinged, so that the test piece is installed stably while the test piece is easy to install and disassemble.

When the test piece fixing substrate is connected to the motor, the rotation shaft of the motor for rotating the test piece fixing substrate is simultaneously coupled to the two plates.

In the mounting step, a weight for offsetting the weight of the hinge is provided in the test piece fixing substrate in the direction opposite to the hinge.

The invention has the beneficial effects that: the invention provides a device for measuring absolute mass of particles and a measuring method thereof, when measuring substances with micro mass, the measurement can be carried out without contacting the object to be measured, and the effort or equipment refined to a very fine degree is not required at all, the cost and the effort of the measurement equipment and the measurement are greatly saved, the high proficiency is not required, and anyone can carry out the measurement, because the device is not influenced by the surrounding environment, the device has no error caused by the environment, does not need to measure for many times, does not need to separate the measured object under the condition that the measured object is attached to other accessories, the quality of the measured object can be measured, and in addition, because the form of the measured object is not uniform, even if the measured object is the same, the difference in the size of the specimen image formed on the image plate is corrected according to the direction in which the object is placed, and the same quality can be calculated regardless of the arrangement of the object.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a conceptual diagram illustrating the prior art;

FIG. 2 is a conceptual diagram of a mass measurement device according to the present invention;

FIG. 3 is a photograph comparing image accuracy according to magnification;

FIG. 4 is a photograph comparing image sizes according to magnification;

fig. 5 is a photograph showing a boundary value setting process of a measured object;

FIG. 6 is a graph comparing the mass of the silver foil (A) with the mass of the test piece (A) measured by an electronic scale;

FIG. 7 is a graph comparing the result of measuring the weight of a printed Ag electrode according to the present invention with the result of measuring using an electronic scale;

FIG. 8 is a graph comparing the result of measuring the mass of a thin film electrode according to the present invention with the result of measuring using an electronic scale;

FIG. 9 is a conceptual diagram showing the difference (D) in the size of an image according to the arrangement direction of the test pieces (A);

FIG. 10 is a photograph showing FIG. 9;

FIG. 11 is a perspective view showing an additional example of the test piece mounting part (30) in FIG. 2;

FIG. 12 is a conceptual diagram of a virtual test piece (P) transformed into a plate shape from an actual test piece (A);

fig. 13a and 13b are conceptual views of a virtual test piece (P) deformed into a plate-like form.

Detailed Description

The specific structural and functional descriptions proposed in the embodiments of the present invention are merely exemplary for the purpose of illustrating the embodiments according to the inventive concept, which can be embodied in various forms. In addition, the present invention should not be construed as being limited to the embodiments described in the present specification, and should be construed as including all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

In the following, the present invention will be described in detail with reference to the accompanying drawings. For reference, the particle to be measured whose mass is to be measured is hereinafter referred to as "test piece (a)".

As shown in FIG. 2, the non-contact type particle absolute mass measuring device of the present invention comprises a radiation tube (10), a lens unit (20), a test piece mounting unit (30), an image plate (40), and a mass calculating unit (50) connected to receive an image signal from the image plate (40) in this order.

The radiation tube (10) is a device that generates radiation (R) and irradiates the test piece (A) with the radiation. Although the radiation (R) includes all visible rays, infrared rays, ultraviolet rays, and the like in a broad sense, in the present invention, since the measurement of the mass is performed by the attenuation amount of the radiation (R), the radiation (R) incident on the test piece (a) needs to have an intensity to a certain extent to penetrate a certain amount of things. Therefore, the radiation (R) of the present invention is limited to the X-ray or gamma ray among the ionizing radiation (R).

The basic principle of irradiation of radiation (R) in the radiant tube (10) is generated by using a filament and a metal plate as a cathode and an anode, respectively, and applying a voltage of several tens kV. The technology of the radiant tube (10) is prior art and will not be described in detail herein.

However, when the radiation (R) is X-ray, it is preferable to use about 60 to 100keV for effective mass measurement.

The lens portion (20) may be composed of one or more various lenses, and is illustrated in fig. 2 as being composed of a dust collecting lens and a magnifying lens, where the dust collecting lens is referred to as a first electron lens (21) and the magnifying lens is referred to as a second electron lens (22) for convenience. However, when the radiation (R) transmitted through the first and second electron lenses (22) passes through the test piece (a) and reaches the image plate (40) to be described later, if the test piece image (a') formed on the image plate (40) can be configured to have a magnification of at least 50 times as compared with the actual test piece (a), the configuration is not necessarily limited to the configuration of the first and second electron lenses (22) shown in fig. 2. In particular, in this case, it is important that the distance between the image plate (40) and the test piece (a) is set to satisfy a distance condition that the test piece image (a ') formed on the image plate (40) can be at least 50 times larger than the actual test piece image (a').

As shown in fig. 2, the specimen image (a ') is formed at a magnification of at least 50 times, and as shown by a comparison between the specimen diameter (a) and the specimen image diameter (b) at the magnification in fig. 2, the area of the specimen image (a') is at least 2500 times the area of the front surface of the specimen (a) in terms of area. This will be described in detail later.

As shown in FIG. 3, several tens of rectangular test pieces (A) were attached to one substrate. In this case, the lower left photograph in fig. 3 is a photograph of the specimen image (a ') when the radiation (R) is irradiated at a low magnification, and the lower right photograph in fig. 3 is a photograph of the specimen image (a') when the radiation (R) is irradiated at a high magnification.

As can be seen from fig. 3, when the fine particles are irradiated with the radiation (R), the difference in resolution is extremely large to the extent that the entire size of the specimen image (a') can be changed depending on the magnification.

More specifically, how much the difference in resolution according to the magnification causes an error in the quality measurement can be explained with reference to fig. 4.

First, before explaining fig. 4, the principle of measuring the quality by using the radiation transmittance will be explained.

The amount of the radiation (R) which cannot pass through and is blocked out among the radiation (R) incident on the test piece (A) is proportional to the atomic weight of the test piece (A) and the thickness of the test piece (A). At this time, the specimen image (A') formed on the image plate (40) is darker than the background color because the radiation (R) is blocked by the specimen (A). In this case, the degree to which the specimen image (a') has a dark color is referred to as "degree of blackening". The mass of the test piece (a) can be derived by deriving < formula 2> and < formula 3> from < formula 1> below.

< formula 1>

< formula 2>

< formula 3>

The observation of the degree of blackening is basically the same as the principle of non-destructive irradiation. Conventionally, when a substance having a certain atomic weight is irradiated with radiation (R), radiation irradiation is used for the purpose of discriminating the defective work by checking a relative attenuation difference when a product is photographed in real time in a uniform production process of a product having a two-dimensional structure of a certain thickness by using a principle that the radiation (R) portion is blocked and attenuated due to the substance.

On the contrary, focusing on the use of the degree of blackening due to attenuation of radiation (R), the absolute mass of the substance can be measured, and particularly, the mass measurement using the degree of blackening is extremely fine, and even if the substance does not contact a tray or the like in order to use gravity, although the mass measurement using the conventional technique is extremely troublesome or almost impossible. However, there has not been found a case where mass measurement using the blackening degree is applied to a substance which is extremely fine and cannot be measured by a general scale.

In addition, when the blackening degree is used for measuring the quality, two technical difficulties need to be solved. First, it is difficult to measure mass to meaningful accuracy at normal magnification, since it is an extremely fine substance. Secondly, even a fine substance may be curved or have an uneven shape in the thickness direction, and there is a difference in the conversion quality depending on the arrangement blackness of the substance.

In view of the first of the two technical difficulties mentioned above, a solution is given below by means of a measurement embodiment.

Now, measurement examples shown in the photograph of fig. 4 will be described using the above-described formulas 1, 2, and 3.

In the example of fig. 4, the test piece (a) is a particle having a fine mass of 10mg or less, and whose density, shape, and volume are not known at all, although gold is known as a material. If the volume of the test piece (A) is known and the test piece (A) is gold having a uniform density without voids, the quality can be obtained without separate measurement since the density of gold itself is known.

In fig. 4, a gold test piece (a) is attached to a plate made of a uniform material by a printing technique. In the embodiment of FIG. 4, gamma ray is selected as the radiation (R), and is Nb-93m emitting gamma of 30keV, and 10 is selected¹⁰And Bq. (for the calculation, assume that 1 gamma is emitted per 1 Bq.)

In addition, in the national Institute of Standards and Technology (NIST, Nati0nal Institute 0f Standards and Technology), when 30keV gamma rays were irradiated to gold, a mass attenuation coefficient value of 0.3744cm2/g was found.

88, see formula 4 below,

< formula 4> is

I₀Is 7.96X 10 per second⁸gamma × a, when there is no medium such as gold sample or air until the image plate (40), the same number of gamma is reached. For reference, it is calculated that the space through which the gamma ray passes is free of air.

When the probability that the gamma ray measured at the image plate (40) converts the gamma ray into a signal is defined as the efficiency of the image plate (40), the efficiency of the gamma ray image plate (40) is assumed to be 1%, the size of each pixel (41) is assumed to be 1mm X1mm, and the number of photons measurable at one pixel (41) of the image plate (40) is calculated by equation 4 as described below.

Here, the number of pixels (41) in the test piece region is counted, and the number X1mm of pixels (41) in the test piece region is calculated²The area of the sample image is calculated 2500. Then, assuming a degree of blackening of an image expressed when the number of photons is 31.8 per second, if it is regarded as being expressed in proportion to the number of photons to 0 to 255, an average gray of a background regionThe value is 200 and the average gray value for the sample area is 100. In this case, the attenuation amount x per second was calculated to be 15.9 according to the following proportional equation.

x＝15.9

By substituting this result into the above equation 2, the area density is obtained, and a value of 0.2595 can be obtained. The obtained areal density value was substituted by formula 3, and the mass of the unit pixel was as follows.

0.2595XA(1mm²X1000/multiplying power is 10cm²(2500) ═ 1.038X10^-4g

The number of pixels measured in the image of the sample specimen (a) was 4994, and the number multiplied by the mass of the unit pixel was found to be 51.84mg in actual mass of the sample specimen (a).

The actual mass of the sample specimen (A) was 60.6mg, which was calculated to be 51.84 mg.

Therefore, the reason why there is a difference between the actually measured mass of the sample specimen (a) and the mass calculated from the blackening degree is that the resolution of the image information on the form of the sample specimen (a) is low.

Therefore, in order to minimize such an error, it is necessary to acquire an image of the specimen of the test piece (a) at a magnification of at least 50 times or more. The results relating to this, as the magnification increases, the mass error becomes much smaller, are shown in the following table and in the photograph of fig. 4.

[ TABLE 1 ]

	Multiplying power	Quality estimation value
			1	50.000	60.602
2	6.900	64.11483058
			3	3.700	62.24315643
4	2.530	63.45449395
			5	1.923	63.27824239
6	1.550	64.47896087
			7	1.300	51.84388244

Referring to the photograph of fig. 4, the lower right photograph is a specimen image (a') obtained by a magnification of 50 times. In conclusion, it can be seen from examining the table that, in the case of the quality evaluation of the image with the magnification of 50 times, there is a difference of 14% in accuracy compared with the quality evaluation of the image with the magnification of 1.3 times.

The reason why the quality estimation using the high magnification image is more accurate is that the area measurement accuracy and the transmission data in the specimen image (a') are more.

Then, although not shown in the drawings, in the mass measuring device according to the present invention, more photons can reach the target specimen (a) while the inside is kept at vacuum, and more stable and accurate data can be obtained. Therefore, the mass measurement device according to the present invention can be provided with a small vacuum pump for maintaining the internal vacuum.

Fig. 6 shows the result of mass estimation of the silver foil test piece (a). Since the silver foil test piece (a) was manufactured by a punch press, it was measured to have no constant pattern, with a deviation of about 2mg, and represented by a rectangle. The weight evaluation results using the radiation (R) are indicated by circles, and it can be seen that the deviation of the comparative mass value using the electronic scale is well reflected. The maximum relative error is 3.82%, and the average relative error is 1.81%.

The silver foil test piece (a) test is characterized in that although there is no process of separating the silver foil test piece (a) from the fixed substrate when measuring the weight, there is no error in the process of separating the silver foil test piece (a), but there are error factors with different shapes. If the shapes are different, it may be a large error factor depending on the X-ray transmission power, but the X-rays used in the present study are considered to have sufficient transmission power at a maximum of 70keV, and thus the shape variable factor is not considered.

However, since the shape variable factor may cause a large error depending on the situation, a composition and a method capable of overcoming the shape variable factor and estimating an accurate mass will be described later.

Fig. 7 is a weight evaluation result of Ag electrodes printed on a substrate in a size similar to that of the silver foil test piece (a). Similar to the results of the silver foil test piece (a), the weight deviation between the different Ag electrodes was well reflected. The maximum relative error is 4.07%, and the average relative error is 1.99%.

The reason why the weight deviation of the printed Ag electrodes occurs regularly is presumed that additional pressure is applied without releasing the applied pressure when the Ag electrodes (P) are printed in an arrangement of 5 × 5 using a jetting dispenser. Can see the Ag electricity of the same rowThe coating weight of the poles is gradually increased, releasing the pressure and returning to the original coating weight when changing the columns. For reference, the apparatus used for printing is a jetting dispenser (not shown). The Ag electrode test piece (A) as a measurement object made by a jetting dispenser has a thickness of 50 to 250 μm per 1mm²The area is at a level of 0.01 to 10 mg.

Fig. 8 shows the analysis result of the thin film electrode used as the semiconductor element. The maximum relative error of the 3mg horizontal electrode was 3.05%, and the average relative error was 1.70%. The maximum relative error of the 1mg horizontal electrode was 6.57%, and the average relative error was 2.51%. Although it has been confirmed that effective evaluation can be performed in quality inspection at a level of several mg, it can be judged that an error is significantly increased when a small weight at a level of 1mg is inspected. In evaluating the quality of the small electrodes, the most suspected error factor is human error in weighing the reference weight with a scale. Therefore, the measured mass as the reference mass cannot be an accurate reference point, and the smaller the mass, the more accurate the mass calculated by the blackening degree according to the present invention.

For reference, the printed Ag electrode (P) was separated from the teflon substrate after X-ray microscope photographing, and measured 3 times using an electronic balance (error 0.005mg) to calculate a comparative mass value, and normalized using the average of the comparative mass values as a standard for comparison using the mass evaluation value of gamma ray.

However, even if the specimen image (a') is obtained at a magnification of at least 50 times or more, if the image of the specimen (a) is not symmetrical with respect to the front, rear, left, right, and top and bottom, and is not uniform from one another, variations in quality may occur depending on the arrangement direction of the specimen (a). The principle of occurrence of such mass deviation is conceptually shown in fig. 9, and as shown in the photograph of fig. 10, the arrangement of the test pieces (a) shown in fig. 9 causes a difference in the size of the test piece image (a'), and as a result, the mass calculated value changes. For example, as shown in fig. 9 and 10, due to gamma rays irradiated from the radiation tube (10) to the hemispherical test piece (a), the test piece image projected to the image plate (40) is disposed closer to the radiation tube (10) with the maximum cross section of the test piece (a) perpendicular to the irradiation direction, which forms a larger image.

Even for the same test piece (a), the diameters of the projected images were imaged as b2 and b1 as shown in fig. 10, and the difference between the two diameters may be 2D.

In particular, such a difference may increase as the magnification of the specimen image (a') is higher. In order to solve such a quality difference according to the specimen image (A'), the same amount of radiation (R) shielding should occur even if the arrangement direction or the arrangement position of the specimen (A) is determined in various cases. However, it is impossible to form a uniform shape with a constant thickness by carving the shape of the fine test piece (A).

In order to solve the above problems, the present invention proposes a method for obtaining the same radiation (R) shielding value for a specific test piece (a) regardless of the arrangement position or the arrangement direction of the test piece (a) by rotating the test piece (a) at a constant speed, and a structure realized thereby.

In order to rotate the test piece (A), it is necessary to prevent the test piece (A) from being displaced by a centrifugal force generated by high-speed rotation. The test piece (A) is mounted on the test piece carrying part (30), a test piece fixing substrate (31) is arranged in the test piece carrying part (30), and the test piece (A) is fixedly mounted on the test piece fixing substrate (31).

In one embodiment of the present invention, as shown in fig. 11, the test piece fixing substrate (31) is formed by two plates in a relatively overlapped manner, and the test piece (a) is fixedly inserted between the two plates, so long as the two plates are not separated by an external force, the test piece (a) does not deviate from the mounting position.

However, since the test piece (A) itself must be easily attached and detached, the two plates constituting the test piece fixing substrate (31) are connected to one side by a hinge (312) as shown in FIG. 11, so that the two plates can be opened with the hinge (312) as a center.

As shown in fig. 11, a counter weight 313 having the same weight as the hinge 312 is attached to the other side of the two plates, that is, the side opposite to the direction in which the hinge 312 is provided, with the two plates interposed therebetween, and the counter weight 313 is composed of two parts, and the two parts are respectively fixed to the two plates.

When the hinge 312 is provided on either side, the test piece fixing substrate 31 formed of the two plates rotates at a high speed, and the mass is biased toward the hinge 312, so that an excessive centrifugal force is generated on the hinge 312, resulting in a problem of stability of rotation, and a problem of durability of the device itself may occur. Therefore, by installing a weight (313) having a weight equal to that of the hinge (312) on the opposite side of the hinge (312), the rotation of the test piece fixing substrate (31) can be stably performed.

In particular, in this case, when the balance weight (313) is formed in half as shown in fig. 11, the center of gravity is balanced in the width direction of the two plates constituting the test piece fixing base plate (31), and not only the rotation is stabilized, but also the lock device can be attached to the balance weight (313) so that the two plates at the center portion thereof are held in a closed state. Although a lock pin is formed as the lock device in fig. 11, the lock device is not necessarily limited to the lock pin (312) in fig. 11, and if it is a known technique, it is not limited in specific form.

In this case, for reference, the rotation axis direction of the motor for rotating the test piece holding substrate (31) may be a horizontal axis direction as shown in FIG. 11 or a vertical axis direction although not shown. However, the line connecting the hinge (312) and the counterweight and the axis of rotation are at right angles to each other.

The rotation axis rotates the center of the test piece fixing substrate (31) in the width direction and the length direction. However, as described above, since the test piece fixing substrate (31) is made of two plates, it is difficult to provide a means for connecting the rotation shafts at the center of the two plates.

Therefore, the center of the rotation shaft in the present invention coincides with the center of gravity when two plates are regarded as one block, and structurally, in order to connect the two plates to the rotation shaft, respectively, an engagement plug for engaging the rotation shaft and the two plates is provided on the rotation shaft. At this time, either one of the side surface of the test piece fixing substrate (31) or the joint plug projects toward the other joint pin (311), and the other of the test piece fixing substrate (31) or the joint plug is formed with a pin hole (321) into which the joint pin (311) can be inserted.

Specifically, the joint pin (311) or the pin hole (321) formed on the side surface of the test piece fixing substrate (31) is similarly formed on the side surfaces of the two plates constituting the test piece fixing substrate (31), and the joint plug is formed with the pin hole (321) or the joint pin (311) joined to the side surface of the test piece fixing substrate (31) correspondingly.

Here, as shown in fig. 11, when a plurality of plates are formed at regular intervals in the longitudinal direction of the side surface of each plate, the joint pin (311) and the pin hole (321) can make the joint of the joint plug and the test piece fixing substrate (31) more firm and stable.

Thus, when the test piece fixing substrate (31) rotates, the test piece (A) disposed between the two plates forming the test piece fixing substrate (31) also rotates together. In this case, referring to fig. 12, the actual test piece (a) may have a semicircular shape as shown in the upper left corner of fig. 12. When the semicircular test piece (A) is rotated, as shown in FIG. 12(b), both sides of the center are vertical planes, and the upper and lower portions thereof are in an illusion of a circular shape.

At this time, the shape shown in fig. 12(b) is enlarged, and when the test piece image (a ') is formed on the image plate (40), the area occupied by the test piece image (a') can be extracted by calculating the number of pixels (41) occupied by the shape itself shown in fig. 12(b), but since the actual shape of the test piece (a) may be quite various and irregular, here, as shown in fig. 12(c), it is assumed that the area of one rectangle is the same as the area of the test piece (a) for convenience of explanation. Thus, as shown in FIG. 12 (d), it is assumed that the virtual test piece (P) has the same mass as the actual test piece (A), but has a uniform rectangular shape.

However, there is a possibility that the quality value calculated by the blackening degree may be changed depending on the mounted position of the test piece (a). That is, when the test piece (a) is rotated, the volume of the space formed by the rotation trajectory of the test piece (a) is small when the test piece (a) is mounted at a position close to the rotation axis, and the volume of the space formed by the rotation trajectory of the test piece (a) is large when the test piece (a) is mounted at a position away from the rotation axis, and the size of the test piece image (a') formed on the image plate (40) changes, so that there is a possibility that the quality measured depending on the mounting position of the test piece (a) changes.

For example, referring to fig. 12 (a), the test piece (a) may be disposed closer to or farther from the rotation axis, and the shape during rotation may be a shape close to a circular shape or a vertically elongated shape as illustrated in fig. 12 (b).

However, since the test pieces (a) themselves are the same, even if the test pieces (a) are disposed at positions close to or away from the rotation axis, the sum of the probabilities of the test pieces (a) existing per unit time in the space composed of the trajectory drawn by the test pieces (a) is the same as long as the rotational angular velocities are the same.

In addition, as shown in fig. 13a, the rotation image of each part of the test piece (a) formed on the image plate (40) is different depending on the direction in which the radiation (R) travels and the angle of the test piece (a), and finally, even if it is actually a uniform flat test piece (a), in the test piece image (a'), the higher the blackening degree is, the deeper it is, and the problem can be raised that the region near the center (0) of the rotation axis is erroneously represented as thick.

For example, in fig. 13a, as the virtual test piece (P) is closer to the horizontal direction of the proceeding direction of the radiation (R), the thickness of the test piece (a) through which the radiation (R) has to pass becomes thicker (T2), and as the virtual test piece (P) is closer to the vertical direction, the thickness (T1) of the test piece (a) through which the radiation (R) has to pass becomes smaller, and finally, the closer to the rotation axis, the deeper the center of the test piece (a) is expressed in the test piece image (a') displayed on the image plate (40), and it is possible to question whether the center portion quality of the test piece (a) can be displayed greatly.

However, as shown in fig. 13b, when the specimen (P) is observed in front of the virtual specimen (P) in the same visual direction as the direction of the radiation (R), although the sizes of d1, d2, d3 and d4 in the observation direction are the same, the angle of rotation of the actual specimen (a) gradually increases from d1 to d4, and the time of passing d4 is much longer than the time of passing d1 when the specimen (a) is rotated at a constant angular velocity, and the specimen image (a') observed as a final result is uniformly represented.

Therefore, even if the shape of the test piece (A) is not uniform, by rotating the test piece (A), the same mass value of the test piece (A) can be calculated regardless of the arrangement position or direction of the test piece (A).

In addition, as described above, the method of calculating the mass value of the test piece (a) by rotating the test piece (a) has been described, but when the rotation center of the test piece mounting portion (30) and the centroid of the test piece are difficult to match, the mass value can be calculated by rotating the test piece 180 degrees.

On the other hand, since the methods for measuring the absolute mass of the particles according to the present invention are included in the above description, they are not repeated for avoiding redundant descriptions.

On the other hand, according to the apparatus and method for measuring the absolute mass of fine particles of the embodiments of the present invention, it is possible to measure the mass of a material having a minute mass without contacting the measured object.

Such a non-contact quality estimation technique can evaluate, for example, uniformity of metal circuits (wirings) or the like provided on a printed circuit board.

Conventionally, it is difficult to quantify intermittent quality abnormalities and quality deviations from the line width and line pitch of a metal circuit having a plurality of lines on a printed circuit board and from the shape of wiring to evaluate the overall print quality. However, when the quality evaluation method of the present invention is used, the printing uniformity can be quantified.

The apparatus and method for measuring the absolute mass of fine particles can also evaluate defects such as internal voids in a metal circuit, impurities, and material potential in a metal circuit, which cannot be observed only by the shape inspection method.

In addition, the apparatus and the measuring method for measuring the absolute mass of fine particles according to an embodiment of the present invention can be used in quantitatively measuring the mass of an extremely important tablet. For example, it is possible to quickly measure a change in tablet quality due to a phenomenon such as insufficient content or breakage due to a void that may be formed in the tablet, using the measuring apparatus according to the present embodiment. In this case, the quality of measurement can be free from the influence of the air pressure, temperature, wind, etc. of the measurement site, and the defect of the tablets in the tablet production process can be judged very effectively because the rapid quality measurement can be performed.

The present invention described above is not limited to the above-described embodiments and drawings, and it is obvious to those skilled in the art of the present invention that various substitutions, modifications, and changes are possible without departing from the technical spirit of the present invention.