Apparatus for detecting particle

An apparatus for detecting a particle is disclosed. The apparatus for detecting a particle in a fluid in accordance with an embodiment of the present invention can include a first light source, which emits a first beam having a wavelength of a particular band toward the fluid, a second light source, which emits a second beam having a wavelength of a band that is different from that of the first beam, a first dichroic mirror, which is placed between the fluid and the first light source and allows the first beam to permeate and reflect the second beam toward the fluid, and a detecting unit, which detects a dispersed beam of the first beam and the second beam in the fluid. An embodiment of the invention can improve the reliability of detection by detecting a particle using a beam that has an optimal permeability according to the type of solution.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2010-0031282, filed with the Korean Intellectual Property Office on Apr. 6, 2010, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The present invention is related to an apparatus for detecting a particle.

2. Description of the Related Art

Foreign particles, both organic and inorganic, in a plating solution cause defective plating of a substrate in a process of fabricating a printed circuit board. These foreign particles are introduced from the outside and/or generated within the plating solution, that is, generated by the break-down and/or coagulation of a plating additive. If it were possible to detect the presence and the size of foreign particles in real time, it would be possible to preclude the cause of the foreign particles and substantially lower the defective plating of the substrate.

In a widely known method of detecting a foreign particle in a solution, laser is irradiated into the solution in a plating tank, and the light dispersed by the foreign particle is collected to detect the foreign particle from the signal of the collected light.

However, in case it is difficult to permeate the laser beam into the solution, the detection is ether impossible or unreliable. Especially, since plating solutions are highly concentrated, it is difficult to permeate the red light, which is commonly used in commercial particle detectors, into the solution, making it difficult to detect a foreign particle reliably.

Moreover, since the permeability of laser beam is different for each different type of plating solution, the apparatus for detecting a foreign particle needs to be changed when a different plating solution is used.

SUMMARY

The present invention provides an apparatus for detecting a particle that can reliably detect the particle in various solutions.

An aspect of the present invention provides an apparatus for detecting a particle in a fluid. The apparatus for detecting a particle in a fluid in accordance with an embodiment of the present invention can include a first light source, which emits a first beam having a wavelength of a particular band toward the fluid, a second light source, which emits a second beam having a wavelength of a band that is different from that of the first beam, a first dichroic mirror, which is placed between the fluid and the first light source and allows the first beam to permeate and reflect the second beam toward the fluid, and a detecting unit, which detects a dispersed beam of the first beam and the second beam in the fluid.

The apparatus for detecting a particle in a fluid in accordance with an embodiment of the present invention can also include an adjusting lens placed, which is between the first dichroic mirror and the fluid and adjusts the first beam and the second beam incident at the fluid.

The apparatus for detecting a particle in a fluid in accordance with an embodiment of the present invention can also include a shutter, which selectively blocks the first beam or the second beam.

The apparatus for detecting a particle in a fluid in accordance with an embodiment of the present invention can also include a third light source, which emits a third beam having a wavelength of a band that is different from those of the first beam and the second beam, and a second dichroic mirror, which reflects the second beam toward the first dichroic mirror and allows the third beam to permeate through so as to be directed to the first dichroic mirror. The first dichroic mirror can reflect the third beam toward the fluid.

DETAILED DESCRIPTION

While such terms as “first” and “second,” etc., may be used to describe various components, such components must not be limited to the above terms. The above terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component without departing from the scope of rights of the present invention, and likewise a second component may be referred to as a first component. The term “and/or” encompasses both combinations of the plurality of related items disclosed and any item from among the plurality of related items disclosed.

An apparatus for detecting a particle according to a certain embodiment of the invention will be described below in more detail with reference to the accompanying drawings. Those components that are the same or are in correspondence are rendered the same reference numeral regardless of the figure number, and redundant descriptions are omitted.

FIG. 1shows an apparatus for detecting a particle in accordance with an embodiment of the present invention.

The apparatus for detecting a particle in accordance with an embodiment of the present invention detects a particle6in a fluid5and includes a first light source10, a second light source20, a first dichroic mirror40and a detecting unit70.

The first light source10and the second light source20emit a first beam12and a second beam22, respectively, each of which has a wavelength in a different band. Here, each of the first beam12and the second beam22can have an optimal permeability for the fluid5being detected. In addition, in order for the first beam12and the second beam22to be directed to the fluid5being detected, the first light source10is disposed to be directed to the fluid5directly, and the second light source20is reflected by the first dichroic mirror40, which will be described later, and directed to the fluid5.

In the present embodiment, the first beam12is configured to have an optimal permeability in a plating solution used in electrolytic plating, and the second beam22is configured to have an optimal permeability in a plating solution used in electroless plating. Accordingly, the first beam12is used when the foreign particle is to be detected in a plating solution for electrolytic plating, and the second beam22is used when the foreign particle is to be detected in a plating solution for electroless plating.

Specifically, since a beam with a wavelength of A has the highest permeability in a plating solution for electrolytic plating, as illustrated inFIG. 3, the first beam12is configured to have a wavelength in a particular band about the wavelength of A.

Therefore, the apparatus for detecting a particle in accordance with the present embodiment can improve the reliability of detecting the particle in a plating solution even though the type of plating solution, which is the fluid5being detected, is changed, by providing a beam having the optimal permeability for the changed plating solution. In other words, by using a beam having a high permeability for the plating solution, the probability and angular resolution of detecting the particle6can be improved.

The first dichroic mirror40is a part that controls the path of a beam such that both the first beam12and the second beam22can be directed to the fluid5. Accordingly, a beam of a certain wavelength can be permeated while a beam of other wavelengths can be reflected.

FIG. 2is a graph illustrating the property of the first dichroic mirror40in the apparatus for detecting a particle in accordance with an embodiment of the present invention.

As illustrated inFIG. 2, the first dichroic mirror40of the present embodiment is configured to allow the first beam12having the wavelength of A to permeate and the second beam22having the wavelength of a different band to reflect.

Accordingly, as illustrated inFIG. 1, the first dichroic mirror40is placed between the fluid5and the first light source10to allow the first beam12, which is emitted toward the fluid5, to reach the fluid5. By being slanted on the path of the second beam22, the first dichroic mirror40allows the second beam to reflect toward the fluid5.

The apparatus for detecting a particle in accordance with the present embodiment can emit a plurality of beams through a single path. In addition, by controlling the first light source10and the second light source20, the apparatus for detecting a particle in accordance with the present embodiment can selectively emit the first beam12and the second beam22. Accordingly, even though the plating solution is changed, it is not required to change the apparatus for detecting a particle to a different apparatus, and it is possible to detect a particle in the changed plating solution by controlling the kind of light source.

Here, the apparatus for detecting a particle in accordance with the present embodiment can additionally include shutters15and25that selectively block the first beam12or the second beam22, in order to make the control of the first beam12and the second beam22easier. The shutters15and25can block the first beam12or the second beam22or allow the first beam12or the second beam22to pass through.

In the present embodiment, the shutters15and25are placed in front of the first light source10and the second light source20, respectively, thereby allowing the first beam12and the second beam22to be selectively incident at the fluid5.

The detecting unit70detects how much the first beam12or the second beam22permeated into the fluid5is dispersed by the particle6in the fluid5. That is, by detecting a dispersed beam7, the presence of the particle6and the size of the particle6in the fluid5are detected.

Here, the signal strength of the dispersed beam7is related to the size of the particle6. Thus, if a beam permeated into the fluid5is not properly permeated and absorbed by the plating solution, a detection error can occur, and the relation between the signal strength of the dispersed beam and the size of the particle becomes unreliable. To prevent this, the present embodiment selects a beam that has the optimal permeability for a particular plating solution in order to secure the reliability of detection, as described earlier.

Moreover, the apparatus for detecting a particle in accordance with the present embodiment can further include an adjusting lens80that adjusts the first beam12and the second beam22that are incident at the fluid5, so as to facilitate the formation of the dispersed beam7. The adjusting lens80is placed between the first dichroic mirror40and the fluid5and allows the first beam12and the second beam22passing through the adjusting lens80to converge or diverge so as to adjust the first beam12and the second beam22to a form that is easier for detection.

The apparatus for detecting a particle in accordance with an embodiment of the present invention can additionally include a third light source30or a plurality of light sources, in addition to the first light source10and the second light source20. Specifically, as illustrated inFIG. 1, the apparatus for detecting a particle in accordance with an embodiment of the present invention can additionally include the third light source30, which emits a third beam32having a wavelength of a band that is different from those of the first beam12and the second beam22, and a second dichroic mirror50, which reflects the second beam22toward the first dichroic mirror40and allows the third beam32to permeate toward the first dichroic mirror40. Here, the first dichroic mirror40is configured to reflect the third beam32together with the second beam22.

Accordingly, the first beam12permeates through the first dichroic mirror40and is directed toward the fluid5directly, and the second beam22is reflected by the second dichroic mirror50and then reflected by the first dichroic mirror40to be directed toward the fluid5. Moreover, the third beam32permeates through the second dichroic mirror50and then is reflected by the first dichroic mirror40to be directed toward the fluid5. Here, the third beam32can be guided by a reflective mirror60so as to permeate through the second dichroic mirror50and be directed to the first dichroic mirror40. In addition, the third beam32can be also blocked or allowed to pass through by a shutter35.

Therefore, by selectively using a plurality of light sources in one apparatus for detecting a particle, an optimal beam for a particular particle can be used to improve the reliability of detection.

The present invention can improve the reliability of detection by detecting the particle using a beam that has an optimal permeability according to the type of solution.

Moreover, it is possible to detect the particle in various solutions, without changing the apparatus.

While the spirit of the invention has been described in detail with reference to a certain embodiment, the embodiment is for illustrative purposes only and shall not limit the invention. It is to be appreciated that those skilled in the art can change or modify the embodiment without departing from the scope and spirit of the invention.

As such, many embodiments other than that set forth above can be found in the appended claims.