JPS62190440A - Measurement system for in-liquid foreign matter and inorganic ion - Google Patents

Abstract

PURPOSE:To evaluate the cleanliness of components quantitatively and improve the cleanliness by removing mixed gas from liquid to be inspected and measuring securely foreign matter and inorganic ions in the liquid to be inspected continuously with high accuracy. CONSTITUTION:A body to be treated is dipped in a cleaning tank 2 which contains pure water and cleaned to remove sticking foreign matter from the surface of the body to be treated, which is put in an evaluation container 6. Such a body to be treated is supplied with cleaning liquid 4a from a cleaning tank 4 and recleaned by microwave irradiation from a microwave generating device 7 to further remove foreign matter, obtaining sample liquid 7 for clean article evaluation. Such a sample liquid 7 and standard liquid 3a for monitor calibration are switched by a changeover valve 13 for liquid measurement and guided to an ultrasonic foreign matter measurement part 20 and a laser foreign matter measurement part 30. Then, the ultrasonic foreign matter sensor 22 of the measurement part 20 detects in-liquid foreign matter of 5-100mum grain size and the leaser light foreign matter sensor 31 of the measurement part 30 detects foreign matter of 0.5-4.9mum grain size. Further, the liquid 7 and liquid 3a are guided to an inorganic ion measurement part 40 to detect ions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is directed to cleaning of components used in electron tubes, iItem devices, etc. and cleaning of foreign particles in liquid suitable for evaluating the cleanliness of components after cleaning. and inorganic ion measurement systems.

[Conventional technology]

Conventionally, this type of foreign matter measuring device in liquid has two methods: an intermittent ultrasonic irradiation type foreign matter measuring method that measures foreign matter with a particle size of approximately 5 to 100 μm, and a foreign matter measuring method that measures foreign matter with a particle size of approximately 0.5 to 60 μm. A laser beam irradiation type foreign object measurement method was used.

The structure of such a device for measuring foreign particles in liquid is based on, for example, the ``Online Measurement of Fine Particles in Liquid'' presented at the ``3rd Technical Research Conference on Air Purification and Contamination Control'' in February 1980. Are listed.

[Problem that the invention seeks to solve]

In this type of foreign matter measurement device, if mixed gases such as bubbles and gases are present in the sample liquid that has been used to clean component parts, air bubbles may adhere to the surface of the senna part when measuring foreign matter and inorganic ions. In addition, since bubbles in the liquid are also measured at the same time, the foreign matter measurement value increases and the error increases, and the measurement value of inorganic ions becomes small. could not be measured accurately. For this reason, it has been impossible to quantitatively evaluate the degree of cleanliness of component parts.

The present invention removes mixed gases from the test liquid and measures foreign substances and inorganic ions in the test liquid continuously and with high precision. The purpose of this study is to provide a system for measuring foreign substances and inorganic ions in liquid.

[Means for solving problems]

The open side system for foreign matter in liquid and inorganic ions according to the present invention includes a sampling means for preparing a test solution containing foreign matter and inorganic ions and a calibration standard solution containing a known amount of the test solution. , a laser foreign matter measurement unit that measures foreign matter with a particle size of 0.5 to 4.9 μm, an ultrasonic measurement unit that measures foreign matter with a particle size of 5 to 100 μm, an inorganic ion measurement unit that measures inorganic ions, and each measurement A vacuum degassing device is provided in front of the measurement sensor in the section.

[Function] Inorganic ions and foreign substances with a particle size of up to 100 μm are continuously and reliably measured without being affected by mixed gases in the test liquid.

〔Example〕

Next, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram showing an embodiment of a system for measuring foreign matter in liquid and inorganic ions according to the present invention.

In the figure, 1 is a sampling part, and 2 has an ultrasonic irradiation device, and contains therein a cleaning liquid 2a in which an object to be inspected as a component used in an electron tube, an electronic device, etc. is immersed and cleaned. Cleaning tank 3 has a stirrer and contains 60,000 foreign particles/1001d with a particle size of 0.5 to 4.9 μm and 516 foreign particles with a particle size of 5 to 100 μm.
Standard solution 3 for monitor calibration containing 6 pieces/100ml
tLtl-Accommodated standard solution water tank, 4 is the type of cleaning liquid containing 4 m of clean parts evaluation cleaning liquid, 5 is clean parts, 6H is the cleanliness evaluation container for clean parts 5, γ is clean parts evaluation sample liquid, 8 is inside An ultrasonic cleaning tank that contains an evaluation container 6 and washing water 8a and has an ultrasonic generator 18b externally; 9 is a cleaning liquid 2;
10 is a sampling tube for the standard solution 3a, 11 is a sampling tube for the cleaning solution 4a, and 13 is a switching valve for measuring each liquid flowing in each tube 9, 10, 12. In addition, these can liquids are approximately 20 to 1
The water is sequentially fed at a flow rate of 00OR//min.

Further, 20 is an ultrasonic foreign matter measuring section, 21 is a vacuum deaerator for degassing mixed gas in the test liquid, and 22 is an ultrasonic foreign matter detecting unit for detecting foreign matter with a particle size of 5 to 100 μm in the test liquid. sensor, 23 is a power supply, 24 is a microcomputer, 25 is a display,
26 is a printer, 27 is a suction pump that suctions the test liquid at a flow rate of 20 to 10,100 O, and 28 is a drain tube after the test liquid is discharged.

Further, 30 is a laser foreign matter measuring section, and this laser foreign matter measuring section 30 has a laser light foreign matter sensor 31 that detects foreign matter with a particle size of 0.5 to 25 μm in the test liquid, and the remaining parts are as described above. It is configured similarly to the sonic foreign object measuring section 2o.

Further, 40 is an inorganic ion measuring section, 41 is an F-ion selection electrode, 42 is a recorder, 43 is a test liquid switching valve, 4
4 is a concentrator containing two concentrating columns packed with ion exchange resin, 45 is an anion separation column, 46 is a detector with 4 different needles, 47 is a standard solution, and 48 is a mixture of carbonate and sodium bicarbonate. 49 is a regenerating solution such as dilute sulfuric acid used for regenerating ion exchange resin,
The remaining parts have the same configuration as the foreign matter measuring section 20.30 described above.

The vacuum degassing device 21 described above passes a tube made of organic matter into the organic membrane chamber, creates a vacuum in the organic membrane chamber, and when the sample liquid passes through this part, the sample liquid in the organic tube is removed. A vacuum deaerator made of an organic membrane that removes mixed gases or a vacuum spray deaerator that sprays the test liquid onto a collision plate in a low vacuum and degasses the mixed gases in the liquid by low vacuum suction can be used. These deaerators remove mixed gases from 1 to 1,100 ppm in the test liquid, which is fed at a speed of 20 to 1,000 m/min.
It has the function of deaerating the air.

Further, the above-mentioned ultrasonic foreign object sensor 22 has a test liquid 22b continuously flowing inside a tube 22a as shown in FIG.
200 times per second (2 μ
SeC/time) Continuously repeat irradiation. When the ultrasonic energy is focused by the acoustic lens 22e and focused into a conical shape, the ultrasonic wave in the test liquid 22b propagates into a circular shape.
Using the reflected energy (proportional to the size of the particle) that is reflected back from the foreign object 22h in the areas 22f and 22g where the density is highest, one reflected wave from one particle is returned as an echo. Therefore, only the reflection within about 1.4 degrees φ of the reflected pulse receiving gate 221 is received by the sensor 22j. Note that 22 is an ultrasonic beam. and,
By converting the reflected pulse measurement values 22t, 22m, and 22n returned by the 1000 emitted pulses 22d into count pulses, continuous measurement of foreign particles having a particle size of 5 to 100 μm is performed.

In addition, the laser beam foreign object sensor 31 described above also includes a test liquid 3 that continuously flows inside the sensor cell 31a as shown in FIG.
1b, a laser beam 31e that is reflected by a prism 31d and focused by a focusing lens 31-f is irradiated with a He-Ne laser 31c to detect foreign substances (particle size 0.
5 to 60 μm) is collected by a condenser lens 31j.
The particle size is 0.5 to 25μ by collecting the particles with a 31g high-sensitivity photodiode and detecting their size and quantity.
Continuous measurement of foreign matter of m. Note that the non-scattered light is reflected by the prism 31h and is not incident on the photodiode 31g.

In such a configuration, first, a manufactured object to be inspected, such as an electron gun assembly (not shown), is placed in a cleaning tank 2 and immersed therein for cleaning treatment. in this case,
This pure water contains cleaning liquid 2 after removing foreign substances of various particle sizes that had adhered to the surface of the object to be inspected! It becomes L. Next, the cleaned object to be tested is stored in the evaluation container 6 as a clean part, and the cleaning liquid tank 4 is passed through the sampling tube 1.
1. A cleaning liquid 4a such as pure water is supplied throughout the cleaning part 5, and the ultrasonic generator 17 continuously irradiates ultrasonic waves for re-cleaning, thereby further removing all foreign matter remaining on the cleaning part 5. This is used as clean product evaluation test liquid 7. Next, the clean product evaluation test liquid 7 and the monitor calibration standard liquid 3m are passed through the sampling tubes 12 and 10t, respectively, and switched by the switching valves 13 for measuring each liquid, and the ultrasonic foreign matter measuring section 20 and the Each suction pump 27 of the measurement unit 30 introduces mixed gases such as bubbles and gases contained in the test liquid 7 and the standard liquid 3a into each vacuum deaerator 21 at a flow rate of approximately xooml/min. After degassing, in the ultrasonic foreign matter measurement section 20, the test liquid T and the standard solution 3a are introduced into the ultrasonic foreign matter sensor 22, and as explained in FIG.
Only foreign objects in the liquid of ~100 μm are measured. On the other hand, in the laser foreign matter measuring section 30.

Similarly, the degassed test liquid 7 and standard solution 3a are respectively introduced into the laser light foreign object sensor 31, and as explained in FIG. 3, only foreign objects in the liquid with a particle size of 0.5 to 4.9 μm are measured. . As a result, the standard solution 3a has the above-mentioned standard value (particle size 0
．． Number of foreign particles of 5 to 4.9 μm: 60,000/10Qd
, the number of foreign particles with a particle size of 5 to 100 μm: 51667100
ml), the coefficient of variation is within ±15 coefficients, and the total water flow rate of the above-mentioned treated object is approximately 20 to 101.
When cleaning at 000/min, the number of foreign substances in the clean evaluation test liquid I in the evaluation container 6 is 13,000 to 16,000 pieces/100.
It was d. Furthermore, the 10 processed objects to be tested after fabrication are not re-cleaned by ultrasonic cleaning in the evaluation container 6 in the sampling section 1.

After initial cleaning using only the cleaning tank 2, measurement by the ultrasonic foreign matter measuring unit 20 through the vacuum deaerator 21 revealed that the particle size was 5.
The total amount of attached foreign matter of ~100μm is 30,000~5ooo
o pieces/piece (X = 46,000 pieces/piece), whereas in the case of re-cleaning by ultrasonic cleaning in the evaluation container 6 as in this example, the number was 3,100 to 6,200 pieces/piece (X
= 3,700 pieces/piece), making it possible to continuously measure foreign substances. Next, the clean product evaluation test liquid 7 and the monitor calibration standard liquid 31 are switched by the switching valve 13 for each liquid measurement.
is introduced into the inorganic ion measuring section 40, and the vacuum degassing device 2
1 causes bubbles.

After mixed gases such as dissolved gases are degassed, only F- is selectively detected by the F- ion selection electrode 41, and an output voltage is counted in proportion to its content, which is determined in advance. The F- ion is measured based on the calibration curve. On the other hand, the clean product evaluation test liquid 7 degassed by the X air deaerator 21 is introduced by switching the changeover valve 43, and is subjected to concentration and elution operations in the concentrator 44. In this case: In this elution operation, the anionic eluent 48 is added to one of the concentration columns in the concentrator 44, and during the elution operation, the test solution 7 is concentrated in the other concentration column, and the sample solution 7 is successively and alternately concentrated. It is separated into positive ions and residual ions. Next, regeneration i49 is added to this test liquid γ in an anion separation column 45, and only cations are separated, resulting in ct- and pop-.

The analyte ions are sequentially eluted in the order of No''3r So;-.

The conductivity of these test ions is measured by the conductivity detector 46, and the relationship between concentration and conductivity is created in advance, and each test ion is quantitatively determined using a calibration curve. Measured continuously. Here, the test liquid I used to clean the clean part 5
From CL-, F-, No;.

As a result of measuring SO knee * PO”4-1,
Ct- is 5 pPI, F- is 1 ppm+NO;
is less than lppm, so'; - is 2 ppm + po
;- could be detected at lppm or below.

Here, when using the vacuum deaerator 21 (!-) to continuously measure foreign substances and inorganic ions in the liquid, use a known sample whose particle number and size of the foreign substances have been measured in advance.

Using a sample with known ion content, create a relationship curve between the reflected energy of the irradiated ultrasonic wave and the size and number of foreign particles. The number of foreign particles and inorganic ions in the test liquid is calculated by the foreign particle sensor and the inorganic ion sensor, and the number and size of foreign particles and the inorganic ion content are displayed and tabulated in a graph, and simultaneously printed out on the printer 26. Foreign matter and inorganic ions in the liquid are continuously measured by displaying the information on the display 25.

〔Effect of the invention〕

As explained above, according to the present invention, inorganic ions and foreign particles with a particle size of up to 100 μm can be measured continuously and reliably without being affected by mixed gases mixed in the test liquid, so that the component parts can be cleaned. The cleanliness can be quantitatively evaluated, and extremely excellent effects such as improved quality due to improved cleanliness can be obtained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the foreign matter and inorganic ion measurement system in liquid according to the present invention, FIG. 2 is a diagram explaining an ultrasonic foreign matter sensor, and FIG. 3 is a diagram explaining a laser beam foreign matter sensor. It is. 1...Sampling section, 2...Cleaning tank, 2&...
...Cleaning liquid, 3...Standard liquid storage tank. 3&°...Standard solution, 4...Cleaning liquid tank, 4a. ... Clean parts evaluation cleaning liquid, 5 ... Clean parts, 6
...Cleanliness evaluation container, 7..Clean parts evaluation test liquid, 8..Ultrasonic cleaning tank, 8a..Cleaning water, 8b
...Ultrasonic generator, 9゜10.11.12...
- Sampling tube, 13... Switching valve for each liquid measurement, 20... Ultrasonic foreign matter measuring section, 21... Vacuum deaerator, 22... Ultrasonic foreign matter sensor, 23...・
·power supply. 24...Microcomputer, 25...Display, 2
6...Printer, 2γ...Pump, 28...
・Drainage tube, 30... Laser foreign matter measurement unit, 31
... Laser light foreign object sensor, 40 ... Inorganic ion measuring section, 41 ... F-ion selection electrode, 42 ...
・Recorder, 43...Switching valve, 44...Concentrator, 45...Anion separation column, 46...Detector conductivity liver, 47...Standard solution, 48... ... Anion eluent, 49... Regeneration liquid.

Claims (1)

[Claims] 1. Sampling means for preparing a test solution containing various foreign substances and inorganic ions having different particle sizes and quantities, and a calibration standard solution containing a known amount of the test solution; a foreign matter measuring means for measuring foreign matter, an inorganic ion measuring means for measuring inorganic ions contained in the test liquid, and a vacuum degassing device disposed upstream of the measurement sensor section of each of the measuring means. A system for measuring foreign substances and inorganic ions in liquid, which is characterized by: