JP2021139668A - Optical cell and optical analysis device - Google Patents

Abstract

To realize a cell with a short light path length with a simple structure.SOLUTION: An optical cell 10 used for optical analysis of a liquid to be tested includes: a pair of translucent members 2 and 3 provided across an internal space S into which the liquid to be tested is introduced; a spacer 6 provided so as to surround the internal space S between the pair of translucent members 2 and 3; and a seal member 9 provided so as to surround the spacer 6 between the pair of translucent members 2 and 3, and contacts each of facing surfaces 21 and 31 of the pair of translucent members 2 and 3.SELECTED DRAWING: Figure 2

Description

The present invention relates to an optical cell used for measuring the concentration of a chemical solution such as hydrofluoric acid (HF) in a manufacturing process of a semiconductor or the like, and an optical analyzer using the optical cell.

This type of optical cell is connected to a chemical solution pipe of a semiconductor manufacturing apparatus and allows the chemical solution to pass through the internal space, and has a pair of optical windows sandwiching the internal space. Then, the measurement light is irradiated to one optical window of the optical cell, and the transmitted light emitted from the other optical window is received. As a result, the concentration of a predetermined component contained in the chemical solution is calculated from the transmitted light intensity of the chemical solution flowing through the optical cell, and the concentration of the chemical solution is controlled.

Conventionally, in this optical cell, as shown in Patent Document 1, a light-transmitting member forming a pair of optical windows is considered to be composed of a liquid contact member and a reinforcing member. The wetted member is made of a material having corrosion resistance to a chemical solution such as hydrofluoric acid (HF) (for example, fluororesin), and the reinforcing member is made of a material having stronger mechanical strength than the wetted member (for example, quartz). Consists of. Further, the pair of translucent members are fixed by a fixing mechanism with a spacer arranged between them.

Here, in order to prevent the chemical liquid passing through the internal space of the optical cell from coming into contact with the reinforcing member and corroding, the reinforcing member is configured to be smaller than the wetted member, and is on the side opposite to the wetted surface of the wetted member. On the surface (outer surface), a seal member is provided so as to surround the periphery of the reinforcing member. Therefore, in the optical cell of Patent Document 1, a seal member is individually provided for each pair of light-transmitting members.

Japanese Unexamined Patent Publication No. 2016-1135

In the optical cell having the above structure, the inventor of the present application considers forming a cell having a short optical path length or the like by a simpler structure. In the optical cell having the above configuration, it is necessary to provide a seal member for each of the two wetted members, the reinforcing member is made smaller than the wetted member, and the wetted member and the reinforcing member are pressed. An inclined ring is required.

Therefore, the present invention has been made to solve the above-mentioned problems, and its main object is to realize a cell having a short optical path length or the like with a simple configuration, for example.

That is, the optical cell according to the present invention is an optical cell used for optical analysis of a test solution, and is a pair of light-transmitting members provided with an internal space into which the test solution is introduced and the pair. A spacer provided so as to surround the internal space between the light-transmitting members of the above, and a spacer provided so as to surround the spacer between the pair of light-transmitting members and contact each of the facing surfaces of the pair of light-transmitting members. It is characterized in that it is provided with a sealing member.

In this optical cell, since the sealing member is provided so as to surround the spacer between the pair of translucent members, each of the facing surfaces of the pair of translucent members can be liquid-tightly sealed by the sealing member. As a result, it is not necessary to provide a sealing member for each of the two translucent members as in the conventional case, and the two translucent members can be sealed only by pressing them from both sides. Therefore, for example, a short optical path length or the like. Cell can be realized by a simple configuration.

Specifically, it is desirable that the spacer defines the distance between the facing surfaces of the pair of translucent members.

Each of the translucent members comes into contact with a liquid contact member having a liquid contact surface that comes into contact with the test liquid introduced into the internal space and a surface of the liquid contact member opposite to the liquid contact surface. It is desirable to provide a reinforcing member that reinforces the wetted member.
With this configuration, the wetted member is made of a material that is corrosion resistant to the test liquid and does not generate contamination components, and the reinforcing member is made of a material that maintains the mechanical strength of the wetted member. It is possible to prevent contamination with the test solution while suppressing deformation of the translucent member forming the optical window. That is, by forming the translucent member into a plurality of sheets having at least a liquid contact member and a reinforcing member, the material is so as to prevent contamination to the test liquid while suppressing deformation of the translucent member forming the optical window. Can be selected.
Here, in the present invention, since the test liquid is hermetically sealed on the facing surfaces of the pair of translucent members, before the test liquid wraps around to the surface of the liquid contact member opposite to the liquid contact surface, That is, the test liquid is hermetically sealed before reaching the reinforcing member. This makes it possible to prevent contamination by the reinforcing member and corrosion of the reinforcing member.

As a specific embodiment, the wetted member is made of a material having corrosion resistance to the test liquid, and the reinforcing member is made of a material having stronger mechanical strength than the wetted member. Is desirable.
For example, when the liquid is hydrofluoric acid (HF), the wetted member is hydrofluoric acid (HF) such as a fluororesin such as PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer). ) Can be used, and the reinforcing member does not have corrosion resistance to hydrofluoric acid (HF) such as sapphire or quartz or produces a contamination component, but from the wetted member. Also, a material having strong mechanical strength can be used.

The effect of the present invention becomes more remarkable when the liquid contact member and the reinforcing member are adhered to each other by a translucent adhesive. That is, in the present invention, since the test liquid is hermetically sealed on the facing surfaces of the pair of translucent members, that is, before the test liquid wraps around the surface of the liquid contact member opposite to the liquid contact surface, that is, , Liquid tightly sealed before the test liquid reaches the adhesive. This makes it possible to prevent contamination due to the adhesive.

In order to arrange the sealing member so as to surround the spacer and to enable liquid-tight sealing by simply pressing a pair of translucent members against the spacer, the thickness of the spacer is set to the natural state (deformation) of the sealing member. It is desirable that it is smaller than the thickness in the previous state).

In the configuration in which the sealing member is arranged so as to surround the spacer, in order to simplify the configuration in which the test liquid is introduced into the internal space, the test liquid is placed inside the pair of translucent members on one or the other. It is desirable that an introduction port for introducing into the space is provided, and one or the other of the pair of translucent members is provided with an outlet for deriving the test liquid from the internal space.
According to this configuration, it is not necessary to provide the spacer with an introduction path for introducing the test solution from the outside and a lead-out path for leading out the test solution to the outside as in the conventional case, so that the spacer can be made thinner, and as a result, the spacer can be made thinner. , The optical path length of the optical cell can be shortened.

Further, the optical analyzer according to the present invention comes out of the above-mentioned optical cell, a light irradiation unit that irradiates light toward one of the light-transmitting members of the optical cell, and the other light-transmitting member of the optical cell. It is characterized by including an optical detection unit for detecting light.

According to the present invention described above, it is not necessary to provide a separate sealing member for each of the two translucent members as in the conventional case, and a cell having a short optical path length or the like can be realized by a simple configuration. ..

It is an overall schematic diagram of the optical analyzer which concerns on one Embodiment of this invention. It is sectional drawing of the optical cell of the same embodiment. It is an exploded perspective view of the optical cell of the same embodiment. It is a partially enlarged sectional view which shows the liquidtight seal part by the seal member of the same embodiment. It is a front view which shows the positional relationship of a spacer, a seal member and a translucent member in the optical cell of the same embodiment.

Hereinafter, the optical cell according to the embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the optical cell 10 of the present embodiment is connected to a pipe provided in a semiconductor manufacturing apparatus and is optically analyzed to measure the concentration of a chemical solution (test solution) such as hydrofluoric acid (HF). Used in device 100.

The optical analyzer 100 shown in FIG. 1 includes an optical cell 10, a light irradiation unit 11 that irradiates the optical cell 10 with light L, and a light detection unit 12 that detects light L transmitted through the optical cell 10. Has. Here, the light irradiation unit 11 includes a light source 11a, a light guide mechanism having an optical fiber 11b for guiding the light L from the light source 11a to the optical cell 10, a condenser lens 11c, and the like. Further, the photodetector 12 includes a photodetector 12a, a light guide mechanism having an optical fiber 12b for guiding the light L transmitted through the optical cell 10 to the photodetector 12a, a condenser lens 12c, and the like. Then, the calculation unit 13 that has received the light intensity signal from the photodetector 12a calculates the concentration of the predetermined component contained in the test solution. The concentration of the drug solution and the like are controlled by using the concentration obtained in this way. The light irradiation unit 11 may be configured not to include the optical fiber 11b, or the light detection unit 12 may be configured not to include the optical fiber 12b.

As shown in FIG. 2, the optical cell 10 is a flow cell having a flow path (internal space S) through which the test liquid flows. External pipes H1 and H2 are connected to the optical cell 10 by using joints J1 and J2, and here, the test liquid flows in the internal space S from the bottom to the top along the direction perpendicular to the paper surface. It is configured. In the optical cell 10, the light L from the light irradiation unit 11 irradiates the test liquid flowing through the internal space S, and the light L transmitted through the test liquid is detected by the light detection unit 12.

Specifically, as shown in FIG. 2, the optical cell 10 has a pair of translucent members 2 and 3 facing each other with the internal space S in between, and the pair of translucent members 2 and 3 from the outside into the internal space S. It is provided with a pair of pressing members 4 and 5 that press toward each other.

The pair of translucent members 2 and 3 are arranged so as to face each other at a predetermined distance via the spacer 6, one of which is the first translucent member 2 arranged on the light incident side of the internal space S, and the other. It is a second translucent member 3 arranged on the light emitting side with respect to the internal space S.

As shown in FIGS. 2 and 3, each of the translucent members 2 and 3 has a flat plate-shaped liquid contact member 7 having a liquid contact surface 7a in contact with the test liquid contained in the internal space S, and the liquid contact member 7. It has a flat plate-shaped reinforcing member 8 that comes into contact with the surface (outer surface) 7b of the member 7 opposite to the liquid contact surface 7a to reinforce the liquid contact member 7.

The wetted member 7 is made of a material that has corrosion resistance to a test solution such as hydrofluoric acid (HF) and does not generate a contamination component. In the present embodiment, the wetted member 7 is made of a material such as PTFE or PFA. It is made of fluororesin.

The reinforcing member 8 is made of a material having a higher mechanical strength than the wetted member 7, and in the present embodiment, it is made of quartz or sapphire. As described above, the reinforcing member 8 may have any corrosion resistance against a chemical solution such as hydrofluoric acid (HF) as long as it can secure a desired measurement accuracy against temperature changes and pressure fluctuations of the test solution. It may not or produce a contamination component.

The liquid contact member 7 and the reinforcing member 8 are adhered to each other by a translucent adhesive G (see FIG. 3). That is, the outer surface of the wetted member 7 and the inner surface of the reinforcing member 8 are adhered to each other by the adhesive G. The wetted member 7 and the reinforcing member 8 of the present embodiment have the same shape in a plan view, but the present invention is not limited to this, and if the reinforcing member 8 has a shape capable of reinforcing the wetted member 7, they may be mutually formed. It may have a different shape.

As shown in FIGS. 2 and 4, the spacer 6 makes the facing surfaces 21 and 31 of the pair of translucent members 2 and 3 parallel to each other, and keeps the facing surfaces 21 and 31 at a predetermined distance (for example, 0). It is for arranging facing each other at .5 mm to 3 mm).

The spacer 6 forms an internal space S together with the pair of translucent members 2 and 3. The spacer 6 of the present embodiment has a configuration that surrounds the entire circumference of the internal space S, and has a closed shape around the internal space S. By sandwiching the spacer 6 between the pair of translucent members 2 and 3, the space surrounded by the inner peripheral surface 6a of the spacer 6 and the facing surfaces 21 and 31 of the pair of translucent members 2 and 3 becomes the internal space S. .. The spacer 6 has a shape that is one size smaller than the pair of translucent members 2 and 3 in a plan view.

Further, the spacer 6 is made of a material that has corrosion resistance to the test liquid and does not generate a contamination component like the wetted member 7, and in the present embodiment, the spacer 6 is made of a material such as PTFE or PFA. Formed from fluororesin.

Further, as shown in FIG. 2 and FIG. 5, a seal member 9 is provided around the spacer 6. The seal member 9 is, for example, an O-ring, and is provided so as to surround the spacer 6 between the pair of light-transmitting members 2 and 3. Then, the seal member 9 comes into contact with the facing surfaces 21 and 31 of the pair of translucent members 2 and 3, respectively. The seal member 9 is made of a material that has corrosion resistance to the test liquid and does not generate a contamination component. In this embodiment, the seal member 9 is made of, for example, PTFE, FKM (fluororubber), or the like. Will be done.

Here, the thickness of the seal member 9 in the natural state is larger than the thickness of the spacer 6. That is, in a state where the facing surfaces 21 and 31 of the pair of translucent members 2 and 3 are in contact with the spacer 6, the seal member 9 is crushed and pressed against the facing surfaces 21 and 31 of the pair of translucent members 2 and 3. Will come into contact. In the present embodiment, as shown in FIG. 4, the outer peripheral surface 6b of the spacer 6 and the inner peripheral surface 4a (inner peripheral surface of the accommodating recess 41) of the first pressing member 4 to be described later are also pressed and contacted. As a result, the seal member 9 exerts a function of positioning the spacer 6 with respect to the first pressing member 4.

As shown in FIGS. 2 and 3, the pair of pressing members 4 and 5 press the pair of translucent members 2 and 3, and one of them is arranged on the light incident side of the first translucent member 2. The first pressing member 4 is the second pressing member 5, and the other is the second pressing member 5 arranged on the light emitting side of the second translucent member 3. The pair of pressing members 4 and 5 are made of, for example, a material that has corrosion resistance to the test liquid and does not generate a contamination component. Formed from fluororesin.

The first pressing member 4 has an accommodating recess 41 accommodating a pair of translucent members 2, 3 and a spacer 6 and a sealing member 9. The accommodating recess 41 has a shape corresponding to the pair of translucent members 2 and 3, and specifically, the accommodating recess 41 has a shape in which the pair of translucent members 2 and 3 fit in the accommodating recess 41 without rattling. There is. Further, the depth of the accommodating recess 41 is about the same as the total thickness of the pair of translucent members 2, 3 and the spacer 6. Further, a first opening 411 for passing the light L is formed on the bottom wall of the accommodating recess 41. The light L from the light irradiation unit 11 is irradiated to the first light transmitting member 2 through the first opening 411.

The second pressing member 5 presses the pair of translucent members 2, 3 and the spacer 6 and the sealing member 9 with the first pressing member 4. The second pressing member 5 is formed with a second opening 51 for passing the light L. The light L that has passed through the second translucent member 3 is detected by the photodetector 12 through the second opening 51.

Further, the second pressing member 5 is fixed to the first pressing member 4 by the fixing screws 14a constituting the fixing mechanism 14. Therefore, the second pressing member 5 is formed with a through hole (stupid hole) 14b into which the threaded portion of the fixing screw 14a is inserted, and the first pressing member 4 is screwed with the threaded portion of the fixing screw 14a. A female threaded portion 14c to be inserted is formed.

Then, in the present embodiment, as shown in FIG. 2, the second translucent member 3 is provided with an introduction port P1 for introducing the test liquid into the internal space S, and the first translucent member 2 is provided with an introduction port P1. , A lead-out port P2 for leading out the test liquid from the internal space S is provided. Here, the introduction port P1 is composed of the first joint J1, and the out-licensing port P2 is composed of the second joint J2.

The first joint J1 is provided by being screwed into the second pressing member 5, and an external pipe H1 is inserted therein. Specifically, the first joint J1 has a ferrule made of a fluororesin such as ETFE (tetrafluoroethylene / ethylene copolymer). Further, the reinforcing member 8 of the second translucent member is formed with a through hole 81 having a diameter that does not contact the first joint J1, and the liquid contact member 7 of the second transmissive member communicates with the external pipe H1. An introduction hole 71 is formed. The introduction hole 71 is open to the internal space S. Then, by screwing the first joint J1 into the second pressing member 5, the external pipe H1 or the first joint J1 (ferral) presses against the introduction hole 71 of the liquid contact member 7 and comes into contact with the second joint member 7. As a result, the space between the external pipe H1 and the wetted member 7 is hermetically sealed.

The second joint J2 is provided by being screwed into the first pressing member 4, and an external pipe H2 is inserted therein. Specifically, the second joint J2 has a ferrule made of a fluororesin such as ETFE (tetrafluoroethylene / ethylene copolymer). Further, the reinforcing member 8 of the first translucent member 2 is formed with a through hole 81 having a diameter that does not contact the second joint J2, and the liquid contact member 7 of the first transmissive member 2 has an external pipe H2. An introduction hole 71 for communication is formed. The introduction hole 71 is open to the internal space S. Then, by screwing the second joint J2 into the first pressing member 4, the external pipe H2 or the second joint J2 (ferral) presses against the introduction hole 71 of the liquid contact member 7 and comes into contact with the second joint J2. As a result, the space between the external pipe H2 and the wetted member 7 is hermetically sealed.

<Effect of this embodiment>
According to the optical cell 10 of the present embodiment configured in this way, since the seal member 9 is provided so as to surround the spacer 6 between the pair of light-transmitting members 2, 3, the seal member 9 provides a pair of light-transmitting members. The facing surfaces 21 and 31 of the members 2 and 3 can be hermetically sealed. As a result, it is not necessary to provide a sealing member for each of the two translucent members 2 and 3 as in the conventional case, and the two translucent members 2 and 3 can be sealed only by pressing them from both sides. For example, a cell having a short optical path length or the like can be realized by a simple configuration.

Further, in the present embodiment, the wetted member 7 is made of a material that has corrosion resistance to the test liquid and does not generate a contamination component, and the reinforcing member 8 is made of a material that maintains the mechanical strength of the wetted member 7. Therefore, it is possible to prevent contamination with the test solution while suppressing deformation of the translucent member forming the optical window. That is, by forming the translucent members 2 and 3 into a plurality of sheets having at least the wetted member 7 and the reinforcing member 8, the translucent members 2 and 3 forming the optical window can be suppressed from being deformed and into the test liquid. The material can be selected to prevent contamination.

Here, in the present embodiment, since the test liquid is hermetically sealed on the facing surfaces 21 and 31 of the pair of translucent members 2 and 3, respectively, the test liquid is liquid-tightly sealed with the liquid contact surface 7a of the liquid contact member 7. Is liquidtightly sealed before wrapping around the opposite surface 7b, that is, before the test liquid reaches the reinforcing member 8 and the adhesive G. As a result, contamination by the reinforcing member 8 and corrosion of the reinforcing member 8 can be prevented, and contamination by the adhesive G can be prevented.

Further, in the present embodiment, since the introduction port P1 is provided in the second translucent member 3 and the outlet port P2 is provided in the first translucent member 2, the test liquid is introduced into the spacer from the outside as in the conventional case. It is not necessary to provide an introduction path and a lead-out path for leading out the test liquid to the outside, and the spacer 6 can be made thin, and as a result, the optical path length of the optical cell can be shortened reasonably.

<Other modified embodiments>
The present invention is not limited to the above embodiment.

For example, both of the pair of translucent members 2 and 3 have a liquid contact member 7 and a reinforcing member 8, but one of the translucent members 2 and 3 has a liquid contact member 7 and a reinforcing member 8. Alternatively, the pair of translucent members 2 and 3 may be made of a single material (for example, fluororesin or quartz).

Further, in the above-described embodiment, the liquid contact member 7 and the reinforcing member 8 are bonded to each other by the adhesive G, but the structure may be such that the liquid contact member 7 and the reinforcing member 8 are simply brought into contact with each other without using the adhesive G.

Further, in the above-described embodiment, the introduction port P1 and the extraction port P2 are provided on different translucent members 2 and 3, but the ports P1 and P2 are shared with the translucent member (first translucent member 2). Alternatively, the configuration may be provided on only one of the second translucent members 3).

Further, in the above-described embodiment, the openings 411 and 51 are formed in the pair of pressing members 4 and 5, if the pressing members 4 and 5 are made of a translucent material, the openings 411 and 51 are formed. It may be configured not to have.

Further, the pair of pressing members 4 and 5 is not limited to the above embodiment as long as the pair of light transmitting members 2, 3 and the spacer 6 and the sealing member 9 can be pressed.

Furthermore, the optical cell of the present invention can be used not only for optical analysis of the test solution but also for optical analysis of gas.

In addition, various embodiments may be modified or combined as long as they do not contradict the gist of the present invention.

100 ... Optical analyzer L ... Light 10 ... Optical cell 11 ... Light irradiation unit 12 ... Light detection unit S ... Internal space 2, 3 ... A pair of translucent members 21 , 31 ... Facing surface 6 ... Spacer 7 ... Liquid contact member 7a ... Liquid contact surface 8 ... Reinforcing member 9 ... Seal member P1 ... Introduction port P2 ... Derivation port

Claims (8)

An optical cell used for optical analysis of a test solution.
A pair of translucent members provided across the internal space into which the test solution is introduced,
A spacer provided between the pair of translucent members so as to surround the internal space,
An optical cell provided between the pair of light-transmitting members so as to surround the spacer, and provided with a seal member that comes into contact with each of the facing surfaces of the pair of light-transmitting members. The optical cell according to claim 1, wherein the spacer defines a distance between facing surfaces of the pair of translucent members. Each of the translucent members
A wetted member having a wetted surface that comes into contact with the test liquid introduced into the internal space,
The optical cell according to claim 1 or 2, further comprising a reinforcing member that comes into contact with a surface of the wetted member opposite to the wetted surface to reinforce the wetted member. The wetted member is made of a material having corrosion resistance to the test liquid.
The optical cell according to claim 3, wherein the reinforcing member is made of a material having a higher mechanical strength than the wetted member. The optical cell according to claim 3 or 4, wherein the liquid contact member and the reinforcing member are adhered to each other by a translucent adhesive. The optical cell according to any one of claims 1 to 5, wherein the sealing member has a thickness in a natural state larger than the thickness of the spacer. An introduction port for introducing the test liquid into the internal space is provided on one or the other of the pair of translucent members.
The optical cell according to any one of claims 1 to 6, wherein a lead-out port for leading out the test liquid from the internal space is provided on one or the other of the pair of light-transmitting members. The optical cell according to any one of claims 1 to 7.
A light irradiation unit that irradiates light toward one of the light transmitting members of the optical cell, and a light irradiation unit.
An optical analyzer comprising a photodetector that detects light emitted from the other translucent member of the optical cell.

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