TWI539146B - On - line concentration determination probe and concentration determination system - Google Patents

Description

Online type concentration measuring probe and concentration measuring system

The present invention relates to a measuring probe for a linear drug concentration and a concentration measuring system, and more specifically, a probe for measuring a concentrated concentration of a chemical solution in a reaction tank and a concentration of a probe using the same. Measuring system.

The present invention relates to a probe for measuring the concentration of a reaction liquid in a reaction tank, and more particularly to a probe for measuring the concentration of a reaction liquid in a reaction tank, and a description thereof. The probe concentration measuring system guides the light emitted from the light source to the reaction tank via the optical fiber, and guides the light of the reaction liquid inside the reaction reaction tank to the probe of the light receiving element via the optical fiber, and guides the light to the light receiving element. The core diameter of the optical fiber for transmitting light is larger than the core diameter of the optical fiber for guiding light emitted from the light source to guide the end portion of the optical fiber for emitting light from the light source opposite to the light source and toward the light receiving element. The core surface on which the end portion of the light-transmitting element and the light-receiving element are exposed is opposed to each other and the front end of the optical fiber is protruded.

Electroless copper plating and electrolytic copper plating can be said to be an uninterrupted process for ensuring the connection between layers when manufacturing a multilayer printed circuit board. On the other hand, it is necessary to constant the processing fluid based on this chemical reaction. The concentration management will become a cause of abnormal precipitation or non-precipitation of copper plating when it is removed from the proper management range. For the management project of the electroless copper plating liquid, for example, [Non-Patent Document 1] [Electrical Research Society, "94 June, Nikkan Kogyo Shimbun, "Non-electroless plating foundation and application (refer to P122-124) There are copper concentration, reductant concentration, pH, and distorting agent. On the other hand, in the case of electrolytic copper plating, there are copper concentration, sulfuric acid concentration, additive concentration, and the like. Among these, the copper concentration is unilaterally reduced with the reverse plating operation. The measurement of the copper concentration is generally carried out by a method of chelatometric or spectroscopy using EDTA or the like. In particular, the method of separating optics is the mainstream in such copper plating solutions. However, these are premised on the offline measurement by sampling the chemical solution from the copper plating reaction tank, and it is difficult to perform fine management in terms of the immediacy of the analysis value and the analysis frequency.

The concentration measurement of the optical separation is performed by irradiating the measurement light emitted from the light source to the object to be measured and receiving the light transmitted through the object to be measured. When the light intensity from the light source is I _O , the light intensity absorbed by the object to be measured is Ia, and the light intensity of the received light is set to It, the relationship of I _O =Ia+It is established, and the measurement Ia is based on the object to be measured. The type and concentration are inherent, and if the intensity of light absorbed by a specific substance is known, the concentration can be determined using It.

Generally, the light intensity It transmitted through the object to be measured is expressed by the absorbance A converted by the formula of A = -log (It / Io).

The absorbance A is linear with respect to the concentration when the concentration of the object to be measured is low. However, if the measured object is at a high concentration, the relationship will collapse. Further, in order to efficiently precipitate copper, the concentration of the copper plating solution described at the beginning is set to a high concentration, and it is difficult to perform concentration measurement based on the absorbance as it is.

Therefore, in the off-line concentration measurement, the sampled plating solution is diluted, and is usually diluted 10 to 100 times.

As described above, it is necessary to perform the so-called sampling and measurement operations as described above for the concentration measurement system that has passed through the off-line, and it is disadvantageous in that the copper plating solution concentration measurement is instantaneous and high frequency is analyzed.

For example, the invention described in [Patent Document 1], and the invention described in [Patent Document 2] [Patent No. 3609029] can be seen to be able to be oriented. The light irradiated by the object to be measured and the unit that receives light by the transmitted light are directly immersed in the reaction tank for measurement. Here, the absorbance of the object to be measured, the length of the optical path, and the concentration system establish the so-called Lambert-Beer law, A=α LC

(where α represents the absorption coefficient inherent to the object to be measured, L represents the optical path length, and C represents the concentration), and the optical path length is shortened for the high-concentration chemical solution, and the same effect as the dilution can be obtained. In the above-mentioned literature, it is possible to analyze a high-concentration chemical solution on-line by changing the optical path length to be variable.

In the invention described in the Japanese Patent Laid-Open Publication No. SHO-63-284454, the optical fiber is irradiated toward the object to be measured, and the method of receiving light by the scattered light is an optical fiber. In the invention described in JP-A-2000-304693, a glass crucible is used to simplify the unit.

[prior technical literature]

[Patent Document]

[Patent Document 1] JP-A-2001-228079

[Patent Document 2] Patent No. 3609029

[Patent Document 3] JP-A-63-284454

[Patent Document 4] JP-A-2000-304693

[Patent Document 5] JP-A-2008-116314

[Non-patent literature]

[Non-Patent Document 1] Electroplating Research Society, published in June 1994, Nikkan Kogyo Shimbun issued "Basic and Application of Electroless Plating" (Refer to P122-124)

In the invention described in the Japanese Patent Laid-Open Publication No. 2001-228079, the distance between the light-emitting side and the light-receiving side liquid-contacting surface is achieved by changing the optical path length and providing the unit with a movable mechanism such as a lead screw or a motor. However, the unit is complicated in order for the unit to have such a mechanism. Moreover, what kind of waterproof structure is necessary to protect these mechanisms from high-reactivity liquid chemicals. Further, since it is a movable member, there is a case where the distance between the liquid receiving surfaces is changed by an impact or the like, and as a result, the optical path length is changed and the accurate concentration measurement cannot be performed.

Further, in the invention described in [Patent Document No. 3,609,029], it is necessary to process the glass unit in such a manner that the optical path length can be changed several times, and the glass unit becomes complicated in shape and processed. Sex will cause problems. In particular, it is necessary to set the optical path length to 100 μm or less in a high concentration chemical solution, which increases the difficulty in glass processing.

Further, in the invention described in the above two documents, the flow of the transmitted light measuring unit may be slow with respect to the entire groove due to the complexity of the shape, and may not necessarily be a liquid medicine representing the entire groove. The concentration of the concentration.

In order to cope with such a problem, in the invention described in Patent Document 3, the unit is simplified by guiding the light from the light-emitting portion located outside the reaction vessel to the reaction vessel from the reaction vessel toward the light-receiving portion outside the reaction vessel by the optical fiber.

However, since the invention described in this document is a technique for measuring turbidity, it is not necessary to receive all the light scattered in the reaction tank. Generally, the core diameter coefficient of the light guiding portion of the optical fiber is ten to several hundreds μm, and when it is not appropriately selected, the measurement light leaks in the liquid, and it becomes difficult to perform accurate measurement.

Further, in the invention described in this document, the optical fiber is fixed so as to protrude inside the reaction structure, but in general, the electroless copper plating reaction tank in industrial production is as large as several square meters, and the fiber is required to be The distance, that is, the length of the light path is controlled to be 100 μm or less as described above.

In the invention described in JP-A-2000-304693, when the glass crucible is immersed in a liquid and measured, the refractive index of the glass and the chemical liquid is close to that of the glass. The light guided light in the crucible may leak from the side wall of the glass crucible which should be totally reflected, and as a result, it is difficult to perform accurate measurement.

In this regard, [Patent Document 5] [Specially Open 2008-116314 In the invention described in the Japanese Laid-Open Patent Publication, a method of bringing an optical fiber into proximity to a V-groove is disclosed. Although the optical path length of 100 μm or less can be achieved by this, it is necessary to use a plain fiber of the optical fiber in order to fix the optical fiber in the V-groove. The plain line is an optical fiber that does not have a protective coating, and has a problem of being broken due to bending or punching. In order to make the concentration of the chemical solution in the tank uniform, the reaction tank is stirred at a high speed, and when the optical fiber is immersed, it is thought that fracture or cracking may occur, and accurate measurement becomes difficult.

Therefore, in view of the above-described unsatisfactory state of the art, it is necessary to construct a correct and simple on-line concentration measuring probe that shortens the optical path length and minimizes leakage of the flow in the measuring portion without causing leakage of light. How to be good at the time is a technical problem, and the object of the present invention is to solve such a technical problem.

The present invention provides a probe for measuring the concentration of a reaction liquid in a reaction tank, and is an on-line type absorbance measurement probe. The emitted light is guided to the reaction tank via the optical fiber, and the light of the reaction liquid inside the transmission reaction tank is guided to the probe of the light-receiving element via the optical fiber, and the core diameter ratio of the optical fiber for guiding the transmitted light to the light-receiving element is guided. The core of the optical fiber for emitting light from the light source has a large core diameter to guide the end of the optical fiber for emitting light from the light source opposite to the light source and the end opposite to the light receiving element that guides the transmitted light toward the light receiving element. The exposed core faces of the parts are fixed and the front end of the optical fiber is protruded. The distance between the exposed core faces is the optical path length when the concentration of the reaction solution is measured off-line divided by the dilution ratio value in the off-line measurement. Or set it in the following ways, and The present invention provides a probe for measuring a concentration of a reaction liquid in a reaction tank as described above, wherein an end portion of a core for guiding light receiving light from the light source and a core portion exposing the liquid contact portion is provided The end portion is protected by a ferrule made of a material that is not damaged by the liquid in the reaction tank, and the present invention provides a probe for measuring the concentration of the reaction liquid in the reaction tank as described above, wherein The core diameter of the optical fiber for guiding light emitted from the light source is 62.5 μm or less, further 50 μm or less, and the core diameter of the optical fiber that transmits the transmitted light to the light receiving element is 100 μm or more, further 200 μm or more, and The present invention provides a probe for measuring a concentration of a reaction liquid in a reaction tank as described above, wherein an optical fiber for guiding light emitted from the light source and an optical fiber for guiding transmitted light toward the light receiving element are exposed The distance between the opposing core faces is 1 mm or less, further 200 μm or less, and the present invention provides a concentration measurement for measuring the concentration of the reaction liquid in the reaction tank. The system is characterized in that a probe for measuring a concentration of a reaction liquid in a reaction tank as described above is used to hold a calibration line for measuring a reaction liquid of various concentrations in a control device, and the concentration is determined by using the above concentration. The probe for measuring the absorbance of the reaction solution was measured in an on-line manner, and was immediately converted into a concentration by referring to the calibration curve held by the control device.

According to the configuration of the present invention, light is used as means for guiding light emitted from the light source and transmitted light to the light receiving element. Since the fiber is less likely to leak toward the reaction liquid, accurate concentration measurement can be performed, which is advantageous in terms of the structure of the probe being simple, the manufacturing cost, and the liquid flow. Further, it is known from the fact that the end portion of the optical fiber is protruded, and it is more advantageous for the liquid to flow, and the concentration of the entire reaction tank can be immediately reflected.

Further, according to the configuration of the present invention, by protecting the liquid-contacting end portion of the optical fiber with a ferrule, it is possible to prevent breakage of the optical fiber due to liquid flow or punching. At this time, the material of the ferrule is preferably made of a material that is not affected by the reaction liquid. When it is said that the electroless copper plating solution is used, it is possible to prevent breakage of the optical fiber by using zircon or borosilicate glass.

Further, according to the configuration of the present invention, by setting the core diameter of the optical fiber on the light-receiving side to be larger than the optical fiber on the light-emitting side, it is possible to minimize the leakage of the measurement light in the reaction liquid and to perform accurate concentration measurement.

Further, in the present invention, the facing core surface is set by dividing the optical path length at the time of measuring the concentration of the reaction liquid in the reaction tank offline by the value of the dilution ratio in the off-line measurement or less. The distance can be determined without diluting the high concentration of the reaction solution.

Further, according to the present invention, the reaction liquid set to various concentrations is measured by the probe to be used as a calibration curve, and is input to a control device, and the measurement result of the absorbance measured by the control device or the probe from the line can be measured. Output the correct concentration. Thereby, the concentration of the reaction liquid can be monitored instantaneously.

As described above, according to the effects of the invention, according to the present invention, the measurement can be carried out correctly and on the line under the measurement of the concentration of the undiluted reaction solution which is usually diluted, and the concentration of the reaction solution can be measured immediately. The reaction liquid is finally managed in a good state. As a result, the use of the reaction liquid can stably produce the product to be manufactured, which can bring about a reduction in the manufacturing cost of the product and a reduction in the cost of the product. Great usefulness.

1‧‧‧ ferrule

2‧‧‧through holes for the front end of the ferrule provided on the plate 3

3‧‧‧ boards

4a‧‧‧Flange flange

4b‧‧‧ body part of the fiber (mesh)

4a'‧‧‧ ferrule flange

4b'‧‧‧ body part of the fiber (mesh)

5‧‧‧Fiber support

5'‧‧‧Fiber support

6‧‧‧Inter-fiber gap

7‧‧‧Bridge components

8‧‧‧Absorbance measuring probe

9‧‧‧Reaction tank

10‧‧‧Light source

11‧‧‧Detector

12‧‧‧Amplifier

13‧‧‧Control PC

14‧‧‧Low-pass filter

Fig. 1 is a perspective view schematically showing a configuration of a member for forming a fiber holder in the first embodiment.

Fig. 2 is a perspective view schematically showing a state in which the optical fiber support in the embodiment 1 is assembled.

FIG. 3 is a perspective view schematically showing an aspect in which the optical axes of the two optical fiber supports in the first embodiment are aligned.

Fig. 4 is a perspective view schematically showing the probe in the first embodiment.

Fig. 5 is a block diagram showing the configuration of a measurement system based on the probes assembled in the first embodiment.

The present invention is achieved by providing a probe for carrying out a concentration of a reaction liquid in a reaction tank, that is, an on-line type absorbance measuring probe, and light emitted from a light source is guided to a reaction tank via an optical fiber. And guiding the light of the reaction liquid inside the reaction cell to the light receiving element via an optical fiber, wherein the probe is characterized in that the core diameter of the optical fiber for guiding the light to the light receiving element is greater than the light emitted from the light source. The core diameter of the optical fiber is also large to guide the end face of the optical fiber emitted from the light source opposite to the light source and the core surface exposed to the end of the light receiving element and the end opposite to the light receiving element. And the way the fiber front end protrudes The distance between the exposed core faces is set by dividing the optical path length when the concentration of the reaction solution is measured off-line by the dilution ratio value in the off-line measurement or the following. Further, the embodiments of the present invention are shown below in the drawings, but the present invention is not limited thereto.

[Example 1]

First, as shown in Fig. 1, a connector having the same end as the optical connector prepared by the spectrophotometer is prepared, and the other end is a diameter of 1.249 mm, and the distance from the front end to the flange 4a is 4.95 mm. a ferrule (optical fiber) 1 with a coated optical fiber (NA = 0.21, a core diameter of 50 μm, a coated diameter of 0.9 mm, a GI multimode fiber), and a through hole 2 is provided through the front end of the ferrule. A plate 3 of SUS316 having a thickness of 1 mm and a width of 1 mm. In the same figure, as described above, 4a is the flange of the ferrule 1, and 4b is the body (mesh) of the main fiber of the ferrule.

Further, as shown in FIG. 2, the optical fiber support 5 in which the ferrule 1 is a stopper of the ferrule 4a as a stopper through the through hole 2 of the plate 3 of the SUS316, and the both are fixed. Further, only the ferrule is shown in each drawing, and the coated optical fiber is not shown.

The optical fiber support 5' similar to the above-described optical fiber support 5 is produced by using the coated optical fiber 1' having a core diameter of 118 μm and the optical fiber supporting plate 3 (the optical fiber support 5' is not separately shown). The production of the absorbance measurement probe was performed by using the two support bodies 5 and 5' as one set.

Next, the optical fiber supports 5, 5' are held by a aligning machine in an appropriate manner, and the optical axes of the two optical fiber supports are adjusted as shown in FIG. At this time, the optical axis adjustment and the distance between the end portions of the optical fibers can be accurately performed by using the alignment machine of the optical component assembly mechanism, that is, at the end of the alignment The distance between the ends of the fibers 6 will be 100 μm. The reaction liquid which was usually subjected to absorbance measurement at 100-fold dilution was measured without dilution by setting the distance between the end portions of the optical fibers to 100 μm and using a unit of 1 cm. Further, since the exit angle of the fiber exit based on the NA is 12°, the beam diameter of the light emitted from the 50 μm core at 100 μm becomes about 100 μm, but compared with the refractive index of the fiber core (1.4 to 1.6). When the refractive index of the electroless copper plating solution is low, the core diameter of the optical fiber on the light receiving side may be 100 μm or less. However, since the refractive index also varies depending on the concentration of the reaction liquid, an optical fiber having a core diameter of 118 μm is used here. This corresponds to a refractive index of the liquid of 2.3 or more, and usually, the aqueous solution does not become such a refractive index.

After the core adjustment is completed, the state in which the fiber holders 5 and 5' are held by the core adjusting machine is maintained, and as shown in Fig. 4, the bridge members 7 are fixed by bridging the two supports. The structural system absorbance measuring probe 8 is obtained by arranging the optical fiber supports 5 and 5' and the bridge member 7. As the bridging member 7, a plate of SUS316 having a thickness of 1 mm was used. In the case of a fixed method, it is possible to apply a backing or mechanical fixing, welding, etc., but here it is fixed by laser welding. When using the backing material, it is necessary to protect the material from the reaction liquid. When mechanically fixing, it is necessary to consider that the positional relationship between the optical fiber supports is not abnormal when fixed. This is not required by the application of laser fusion. Further, although resistance fusion can be applied, it is necessary to consider that the positional relationship between the supports does not become abnormal when the fusion probe is pressed against the support or the bridge member.

After the fixation was completed, the absorbance measuring probe 8 was attached to a spectrophotometer, and the absorbance measurement based on the blank was performed. In the air, there will be transmission loss or Fresnel reflection at the end of the fiber, etc. When white, not all of the input light can be received.

Since this blank value is affected by the manufacturing error of the probe, the probe is individually measured.

A concentration measuring system for measuring the concentration of the reaction liquid in the reaction tank was constructed using the probes shown in these examples. Figure 5 shows a schematic block diagram thereof. In the same figure, the 9-series reaction tank is a plating bath for performing concentration detection using the probe 8 for on-line detection or the like. A laser light source 10 that emits light of a measurement wavelength, a detector 11 that detects laser light that transmits the reaction liquid, an amplifier 12 that amplifies a signal from the detector 11, and a signal for controlling and receiving the detector of the laser light source The control is constituted by the PC 13. The measurement results of the blank and two or more standard concentration reaction liquids are input to the PC 13 in advance, and are held as a calibration curve. This is done each time the probe 8 is changed. Since the fibers of the probe 8 are free spaces, it is conceivable that foreign matter in the reaction liquid passes between the optical fibers, so that a signal path from the amplifier 12 to the PC 13 is inserted into the low-pass filter 14 to remove a sudden signal change. Further, in response to a constant change in absorbance due to foreign matter adhesion or liquid deterioration, the PC 13 issues an alarm when the upper and lower limits of the absorbance received by the PC 13 are exceeded. Further, by accumulating the measurement result in the PC 13, it is possible to perform concentration detection while tracking the successive concentration changes of the reaction liquid in the reaction tank 9.

[Example 2]

It is assumed that the dilution ratio of the offline measurement of the reaction liquid in the above-described Example 1 is 100 times, and the distance 6 between the ends of the optical fibers is set to 100 μm. When the dilution ratio at the offline is low, when the copper concentration of the measurement unit of 1 cm is measured by 10-fold dilution, the concentration of copper is a relatively thin reaction solution, and the end of the fiber is applied. In the case of a probe having a distance of 100 μm, since the measured absorbance is low, it is affected by a decrease in the resolution.

Then, the distance between the end portions of the optical fibers set at the time of setting the probe assembly was set to 1 mm in accordance with the dilution ratio of 10 times. In the case where the above-mentioned optical fiber having a core diameter of 50 μm is applied, the beam diameter at the light receiving end becomes 460 μm. Therefore, the core diameter of the optical fiber on the light receiving side is also 460 μm or more, and preferably 680 μm or more (corresponding to a refractive index of the reaction liquid of 2 or more).

In addition, the present invention can be variously modified without departing from the spirit of the invention, and the invention can of course be applied to the changer.

[Industrial Applicability]

The present invention can be expected to bring about concentration measurement in a reaction tank, and in particular, it can be used for measurement of copper concentration in the field of copper concentration in copper plating solution, concentration measurement in electroless copper plating bath, and the like. Excellent utility.

3‧‧‧ boards

4a'‧‧‧ ferrule flange

4b'‧‧‧ body part of the fiber (mesh)

5‧‧‧Fiber support

5'‧‧‧Fiber support

6‧‧‧Inter-fiber gap

Claims (2)

A probe for measuring the concentration of a reaction liquid in a reaction tank is an on-line type absorbance measurement probe, and light emitted from a light source is guided to a reaction tank via an optical fiber, and a reaction liquid inside the reaction tank is transmitted through the optical fiber. The light is guided to the light-receiving element, and the probe is characterized in that the core diameter of the optical fiber for guiding the transmitted light toward the light-receiving element is larger than the core diameter of the optical fiber for guiding the light emitted from the light source to guide The end portion of the optical fiber for light emitted from the light source on the side opposite to the light source and the core surface exposed to the end of the light-receiving element that is opposite to the light-receiving element are opposite to each other, and the front end of the optical fiber is protruded. The distance between the core faces exposed thereto is set by dividing the optical path length at the time of offline measurement of the concentration of the reaction solution by the dilution ratio value in the off-line measurement or the following thereof; wherein the guidance is from the above-mentioned light source The end of the core of the optical fiber containing the exposed liquid receiving portion, the end portion of which is protected by a ferrule made of a material that is not damaged by the liquid in the reaction tank; wherein the light source is guided from the light source The core diameter of the optical fiber for light emission is 62.5 μm or less, further 50 μm or less, and the core diameter of the optical fiber that transmits the transmitted light to the light receiving element is 100 μm or more, further 200 μm or more; wherein the light source is guided from the light source The distance between the emitted optical fiber and the opposing core surface of the optical fiber for guiding the transmitted light to the light receiving element is 1 mm or less, and further 200 μm or less. A probe for measuring the concentration of a reaction liquid in a reaction tank is an on-line type absorbance measurement probe, and light emitted from a light source is guided to a reaction tank via an optical fiber, and a reaction liquid inside the reaction tank is transmitted through the optical fiber. The The light is guided to the light receiving element. The probe is characterized in that the core diameter of the optical fiber for guiding the transmitted light toward the light receiving element is larger than the core diameter of the optical fiber for guiding the light emitted from the light source to guide the light source. The end portion of the emitted optical fiber opposite to the light source and the core surface exposed to the end opposite to the light receiving element that is transmitted to the light receiving element face each other, and are fixed by the front end of the optical fiber. The distance between the exposed core faces is set by dividing the optical path length when the concentration of the reaction solution is measured off-line by the dilution ratio value in the off-line measurement or the following; wherein the light emitted from the light source is guided The core diameter of the optical fiber used is 62.5 μm or less, further 50 μm or less, and the core diameter of the optical fiber that transmits the transmitted light to the light receiving element is 100 μm or more, further 200 μm or more; wherein the light emitted from the light source is guided The distance between the optical fiber and the opposing core surface of the optical fiber for guiding the transmitted light to the light receiving element is 1 mm or less, and further 200 μm or less.