WO2019199018A1

WO2019199018A1 - Terahertz wave-based detector and operating method therefor

Info

Publication number: WO2019199018A1
Application number: PCT/KR2019/004202
Authority: WO
Inventors: 김학성; 오경환; 박동운; 오승재; 지영빈
Original assignee: 한양대학교 산학협력단
Priority date: 2018-04-11
Filing date: 2019-04-09
Publication date: 2019-10-17
Also published as: KR102100554B1; KR20190118873A

Abstract

A terahertz wave-based detector according to one embodiment of the present invention comprises: a terahertz wave emission unit for generating a terahertz wave; a guide wire for guiding, to an object-to-be-measured in a longitudinal direction, the terahertz wave generated by the terahertz wave emission unit; and a vibration unit for vibrating the guide wire in the width direction of the guide wire.

Description

Terahertz wave-based detector and its operation method

The present invention relates to a terahertz wave based detector and a method of operating the same, and more particularly, to a terahertz wave based detector having a high speed and a high resolution and a method of operating the same.

Terahertz wave has excellent permeability to non-conductive materials except metal, and it is harmless to human body with lower energy than x-ray. Terahertzpa has received a lot of attention in high value-added services and high-tech industries such as healthcare, telecommunications and security. In addition, due to its excellent permeability to non-conductive materials and harmless properties to the human body, it is possible to be applied as a non-contact and non-destructive testing technology, which is attracting attention as a next-generation non-destructive testing technology.

However, as far as research has been conducted, there is a lack of development in terms of resolution and speed, and thus it has not reached the commercialization.

Accordingly, the inventors have invented a terahertz wave-based detector having a high speed and a high resolution and a method of operating the same.

One technical problem to be solved by the present invention is to provide a terahertz wave-based detector capable of high-speed scanning and its operation method.

Another technical problem to be solved by the present invention is to provide a terahertz wave-based detector capable of high resolution scanning and its operation method.

Another technical problem to be solved by the present invention is to provide a terahertz wave-based detector having a simple configuration and a method of operating the same.

Another technical problem to be solved by the present invention is to provide a terahertz wave-based detector easy to control and its operation method.

The technical problem to be solved by the present invention is not limited to the above.

The terahertz wave-based detector according to an embodiment of the present invention includes a terahertz wave emitter for generating terahertz waves and a terahertz wave generated from the terahertz wave emitters along the longitudinal direction to guide the measurement object. It may include a guide wire and a vibration unit for vibrating the guide wire in the width direction of the guide wire.

According to an embodiment of the present disclosure, the vibrator may include a first vibrator disposed on one side of the guide wire and a second vibrator disposed spaced apart from the first vibrator by a predetermined distance.

According to one embodiment, the first vibrating portion may be disposed inside the guide wire.

According to an embodiment, the first vibrating part may be disposed on an outer surface of the guide wire.

According to one embodiment, the first vibrating portion may be fixed to the outer surface of the guide wire by a non-conductor.

According to an embodiment, the first vibrator may be made of a magnet, and the second vibrator may be made of a coil.

According to one embodiment, the terahertz wave emitter and the guide wire further comprises a coupling substrate and a control unit for controlling the position of the coupling substrate with respect to the measurement object further comprising the control unit by the vibration The position of the coupling substrate may be controlled to correct a change in distance between the guide wire end and the measurement object.

According to one embodiment, the vibration frequency of the guide wire by the vibration unit and the correction frequency of the coupling substrate may be associated with each other.

According to one embodiment, the guide wire is conductive, the width of the guide wire tip may be a few nm to a few um.

According to an embodiment, the region where the terahertz wave is irradiated may be larger than the tip size of the guide wire due to the vibration.

According to an embodiment of the present disclosure, a method of operating a terahertz wave-based detector may include preparing a measurement object, positioning a guide wire providing a path of the terahertz wave on one side of the measurement object, and the guide. And irradiating the terahertz wave to the measurement object through a wire, wherein the irradiating step may further include oscillating the guide wire in a width direction of the guide wire.

According to an embodiment, by the vibration of the irradiation step, the terahertz wave can be irradiated to a larger area than the terahertz wave beam spot provided by the tip of the guide wire.

According to an embodiment, the method may further include a correcting step of correcting a change in distance between the tip of the guide wire and the measurement object according to the vibration of the irradiation step.

According to an embodiment of the present disclosure, if the distance between the tip of the guide wire and the measurement object is greater according to the vibration of the irradiation step, the guide wire is moved toward the measurement object, and the vibration of the irradiation step is performed. Accordingly, when the distance between the tip of the guide wire and the measurement object approaches, the guide wire may be moved in a direction away from the measurement object.

The terahertz wave-based detector according to an embodiment of the present invention is a guide for guiding the terahertz wave generated by the terahertz wave and the terahertz wave generated by the terahertz wave emitter to the measurement object along the longitudinal direction. It may include a vibration unit for vibrating a wire and the guide wire in the guide wire width direction.

The terahertz wave can be irradiated to a wider range than the terahertz wave beam spot determined by the tip of the guide wire by the vibration of the guide wire. Accordingly, high speed scanning may be enabled.

In addition, even when the distance between the end of the guide wire and the measurement object changes during the vibration of the guide wire, the coupling substrate may be controlled such that the distance between the end of the guide wire and the measurement object is kept constant. As a result, a uniform beam spot can be provided, thereby enabling detection of high resolution and high reliability.

1 is a block diagram illustrating a configuration of a terahertz wave-based detector according to an embodiment of the present invention.

2 is a view for explaining a terahertz wave-based detector according to an embodiment of the present invention.

3 to 6 are diagrams for explaining the vibration control of the terahertz wave-based detector according to an embodiment of the present invention.

FIG. 7 is a diagram for describing correction control of a terahertz wave-based detector according to an exemplary embodiment.

8 is a view for explaining a method of operating a terahertz wave-based detector according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical idea of the present invention is not limited to the exemplary embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed contents are thorough and complete, and that the spirit of the present invention can be sufficiently delivered to those skilled in the art.

In the present specification, when a component is mentioned to be on another component, it means that it may be formed directly on the other component or a third component may be interposed therebetween. In addition, in the drawings, the shape and size are exaggerated for the effective description of the technical content.

In addition, in various embodiments of the present specification, terms such as first, second, and third are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiment. In addition, the term 'and / or' is used herein to include at least one of the components listed before and after.

In the specification, the singular encompasses the plural unless the context clearly indicates otherwise. In addition, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, element, or combination thereof described in the specification, and one or more other features or numbers, steps, configurations It should not be understood to exclude the possibility of the presence or the addition of elements or combinations thereof. In addition, the term "connection" is used herein to mean both indirectly connecting a plurality of components, and directly connecting.

In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a block diagram illustrating a configuration of a terahertz wave-based detector according to an embodiment of the present invention, and FIG. 2 is a view for explaining a terahertz wave-based detector according to an embodiment of the present invention. 3 to 6 are diagrams for explaining the vibration control of the terahertz wave-based detector according to an embodiment of the present invention. FIG. 7 is a diagram for describing correction control of a terahertz wave based detector according to an exemplary embodiment.

1 and 2, the terahertz wave-based detector 100 according to an embodiment of the present invention, the terahertz wave emitter 110, terahertz wave receiver 112, guide wire 120, guide The wire vibration unit 140 (hereinafter, may be abbreviated as a vibration unit), the correction unit 150, the control unit 160, and the analysis and imaging unit 190 may be included. Hereinafter, each configuration will be described.

테라헤르츠파 방출부(110) 및 수신부(112)Terahertz wave emitter 110 and receiver 112

The terahertz wave emitting unit 110 may generate and emit terahertz waves.

According to an embodiment, the wavelength of the terahertz wave may be 3 mm to 30 μm, and the frequency of the terahertz wave may be 0.1 THz to 10 THz. As the terahertz wave has the above-described frequency range, the terahertz wave may exhibit stronger transmittance than visible or infrared rays.

Further, the terahertz wave light source may be continuous or pulsed, and the number of light sources may be one or plural.

According to an example, the terahertz wave emitting unit 110 may be disposed above the object to be measured (S).

The terahertz wave receiver 112 may receive the terahertz wave transmitted through the measurement object S or reflected from the measurement object S. FIG. According to an embodiment, terahertz wave emission and reception may be performed in a transmissive, reflective or pitch & catch manner. If the transmission type, as shown in FIG. 2, the terahertz wave receiver 112 may be disposed under the measurement object S. FIG.

가이드 와이어(120)Guide wire (120)

The guide wire 120 may guide the terahertz wave emitted from the terahertz wave emitter 110 to the measurement object S. To this end, the guide wire 120 may have conductivity. In this case, the terahertz wave emitted from the terahertz wave emitting unit 110 may be irradiated along the longitudinal direction of the guide wire 120.

According to an example, the guide wire 120 may be made of, for example, a conductive polymer. The conductive polymer may include at least one material of olyaniline, polypyrrole and polythiophene. If the guide wire 120 is made of a conductive polymer, it may provide convenience in controlling the diameter of the guide wire 120. In another example, the guide wire 120 may be made of a metal such as copper and silver, or may be coated with a conductive metal.

In addition, the terahertz wave emitted from the terahertz wave emitting unit 110 may be coupled to the guide wire 120 in various ways. For example, the coupling may be performed in at least one of direct end-fire coupling, surface plasmon coupling, wire to wire coupling, and quasi-optical coupling.

The guide wire 120 may induce terahertz waves TH in the longitudinal direction as shown in FIG. 2. In this case, the size of the beam spot of the terahertz wave TH induced by the guide wire 120 may be proportional to the width of the tip of the guide wire 120. Accordingly, the width of the tip of the guide wire 120 may be designed according to the desired resolution. For example, the width of the tip of the guide wire 120 may be several nm to tens of um.

In addition, since the guide wire 120 should be able to vibrate in the width direction of the guide wire 120 by the vibrator 140 (V of FIG. 2), the guide wire 120 may have a predetermined flexibility.

가이드 와이어 진동부(140) Guide wire vibrator 140

The guide wire vibrator 140 may perform a function of vibrating the guide wire 120 in the width direction of the guide wire 120. In this case, since the terahertz wave irradiation area is wider than the tip area of the guide wire 120, high-speed scanning may be enabled.

To this end, the guide wire vibrator 140 is disposed spaced apart from the first vibrator 142 and the first vibrator 142 provided at one side of the guide wire 120 to be spaced apart from the first vibrator. It may include a second vibration unit 146 for vibrating the vibration unit 142.

For example, one of the first vibrator 142 and the second vibrator 146 may be a magnet and the other may be a coil. Hereinafter, for convenience of description, it will be assumed that the first vibrator 142 is a magnet and the second vibrator 146 is a coil.

As shown in FIG. 4 (a), the first vibrator 142 may be disposed inside the guide wire 120, and as shown in FIG. 4 (b), the first vibrator 142 may be disposed on an outer surface of the guide wire 120. When the first vibrator 142 is disposed on the outer surface of the guide wire 120, the first vibrator 142 may be fixed with a non-conductor. This takes into account that the insulator has a high permeability to terahertz waves. That is, it is possible to eliminate the generation of terahertz wave optical path distortion by the insulator fixing the first vibrator 142. For example, the first vibrator 142 may be fixed to the outer surface of the guide wire 120 by Teflon.

In addition, the first vibrator 142 may be disposed in an annular shape along the outer circumferential surface of the guide wire 120 in the width direction. As shown in FIG. 5, the second vibrator 146 may be disposed to be spaced apart by a predetermined interval d with respect to the guide wire 120. In another aspect, the current applied to the coil of the second vibrator 146 is controlled so that the guide wire 120 may vibrate in an annular shape.

Referring to Figure 3 for a more detailed description, as shown in Figure 3 (a), in the initial state, the guide wire 120 may be in a state without bending. In this case, the second vibrator 146 may be in an off state. Thereafter, as shown in FIG. 3B, the second vibrating unit 146 on the left side of the guide wire 120 may be turned on, and the guide wire 120 may be bent to the left side. That is, by applying the magnetic field to the first vibration unit 142 provided on the guide wire 120, the second vibration unit 146 may bend the first guide wire 120 to the left. In addition, as shown in FIG. 3C, the second vibrating unit 146 on the right side of the guide wire 120 is turned on, and the second vibrating unit 146 on the left side of the guide wire 120 is turned off. The guide wire 120 may be bent to the right.

In this way, the second vibrating unit 146 is controlled so that the guide wire 120 can perform a predetermined vibration. Therefore, the irradiation range of terahertz waves can be extended by vibration.

Referring to FIG. 6 for a more detailed description, if the guide wire 120 does not vibrate, the terahertz wave irradiation area depends on the tip area of the guide wire 120. In this case, the scanning range is limited to Wp. In contrast, when the guide wire 120 is vibrated by the vibrator 140, the terahertz wave irradiation area is wider than the tip area of the guide wire 120. In this case, the scanning range can be extended to Wi.

보정부(150) Correction unit 150

The correction unit 150 may correct that the distance between the end of the guide wire 120 and the measurement object S is changed by vibration. When the terahertz wave emitting unit 110 is disposed on the coupling substrate 111 and the guide wire 120 is also disposed on the coupling substrate 111, the end of the guide wire 120 and the measurement object ( When the distance between the S) is far away, the coupling substrate 111 may move in the direction of the measurement object S, and conversely, when the distance between the end of the guide wire 120 and the measurement object S is closer, the coupling The substrate 111 may move in a direction away from the measurement object S. FIG. Accordingly, even when the guide wire 120 vibrates, the distance between the guide wire 120 and the measurement object S may be kept constant.

For more detailed description, referring to FIG. 7A, when the guide wire 120 is in an initial state, the distance between the guide wire 120 and the measurement object S may be determined by the coupling substrate 111 and the measurement object S. FIG. It may be DL except for the length L of the guide wire 120 in the distance (L) between.

However, when the guide wire 120 vibrates, as shown in FIG. 7B, the distance between the end of the guide wire 120 and the measurement object S may be changed to D-Lcosθ. That is, the distance between the end of the guide wire 120 and the measurement object S is greater than D-L of FIG. 7A.

Therefore, as illustrated in FIG. 7C, the coupling substrate 111 may be moved in the direction of the measurement object 111 by L (1-cosθ). Accordingly, even when the guide wire 120 is bent, the distance between the end of the guide wire 120 and the measurement object S may be maintained at D-L.

Thus, aberrations resulting from terahertz wave-based detection can be minimized.

The coupling substrate 111 may also be called a bullseye substrate.

제어부(160) Control unit 160

Referring back to FIG. 1, the controller 160 may control each component of the terahertz wave-based detector 100 according to an embodiment of the present invention. To this end, the controller 160 may include at least one of the vibration controller 170 and the correction controller 180.

The vibration controller 170 may vibrate the guide wire 120 described above with reference to FIGS. 3 to 6 in the width direction of the guide wire 120. That is, the vibration controller 170 may control the vibration direction and the vibration width of the guide wire 120 by controlling a current applied to the coil which is the second vibration unit 146.

The correction controller 180 controls the coupling substrate 111 such that the distance between the end of the guide wire 120 and the measurement object S described above with reference to FIG. 7 is kept constant even during the vibration of the guide wire 120. can do.

According to an example, the correction controller 180 may control the second vibrator 146 on / off or may be controlled by a PID method.

The analysis and imaging unit 190 may perform a function of analyzing a signal received from the terahertz wave receiver 112 and imaging the same. That is, the analysis and imaging unit 190 may detect a terahertz wave to detect a defect of the measurement object, and may display the image through the display unit.

According to an example, the vibration frequency of the vibration controller 170 and the correction frequency of the correction controller 180 may be associated with each other. This is because a change in distance between the guide wire and the measurement object is caused by the vibration frequency in the vibration control unit 170, and the correction control unit 180 is to maintain a constant distance between the guide wire and the measurement object. . For example, the vibration frequency in the vibration controller 170 and the correction frequency in the correction controller 180 may be the same. That is, by making the vibration frequency of the guide wire 120 and the correction frequency of the coupling substrate 111 the same, the difference in the beam spot caused by the vibration can be offset by the position correction of the coupling substrate. In addition, when the vibration frequency and the correction frequency are the same, the control variable can be reduced, which can provide an advantage in terms of control.

1 to 7, a terahertz wave-based detector according to an embodiment of the present invention has been described. Hereinafter, a method of operating a terahertz wave based detector will be described with reference to FIG. 8.

Referring to FIG. 8, in the method of operating a terahertz wave-based detector according to an embodiment of the present disclosure, a preparation step (S100) of preparing a measurement object and a guide wire providing a path of the terahertz wave may be performed on one side of the measurement object. It may include at least one of the positioning step (S110) and the irradiation step (S120) for irradiating the terahertz wave to the measurement object while vibrating the guide wire in the width direction of the guide wire. Each step will be described below.

In operation S100, the measurement object may be mounted. For example, the measurement object may be a semiconductor package.

In operation S110, the guide wire 120 providing a path of the terahertz wave may be located at one side of the measurement object S. In the transmission type, the terahertz wave emitter 110 may be positioned above the measurement object S, and the terahertz wave receiver 112 may be positioned below the measurement object S. FIG.

In step S120, the terahertz wave emitting unit 110 may emit terahertz waves. The emitted terahertz wave may travel along the guide wire 120 and may be irradiated to the measurement object S.

In this case, the vibration control unit 170 may vibrate the guide wire 120 in the width direction of the guide wire 120. That is, the vibration control unit 170 may control the magnetic field provided to the first vibration unit 142 of the guide wire 120 by controlling the current applied to the second vibration unit 146. Accordingly, the guide wire 120 may be bent in a predetermined direction according to the applied magnetic field. According to an example, the vibration control unit 170 may bend the guide wire 120 in an annular direction. Therefore, as described above, the terahertz wave irradiation range may be larger than the tip area of the guide wire 120.

On the other hand, the operation method according to an embodiment may further include a correction step of correcting the change in the distance between the tip of the guide wire and the measurement object according to the vibration of the irradiation step.

That is, the correction controller 180 may control the height of the coupling substrate 111 so that the distance between the end of the guide wire 120, which varies in step S120, and the measurement object S, are kept constant. In other words, in the correcting step, when the distance between the tip of the guide wire 120 and the measurement object S increases according to the vibration of the irradiation step, the guide wire 120 is directed toward the measurement object S. If the distance between the tip of the guide wire 120 and the measurement object (S) is closer according to the vibration of the irradiation step, to move the guide wire 120 in a direction away from the measurement object (S). Can be. Therefore, the error in terahertz wave detection can be minimized.

In addition, the analysis and imaging unit 190 may image the inside of the measurement object based on the terahertz wave detected by the terahertz wave receiver 112. For example, the analysis and imaging unit 190 may provide a 2D image. Accordingly, internal analysis of the measurement object may be enabled in a non-destructive manner.

The operation method of the terahertz wave-based detector according to an embodiment of the present invention has been described above with reference to FIG. 8.

According to the terahertz wave-based detector and the method of operating the same according to an embodiment of the present invention described above, the guide wire may be bent based on the apertureless near field irradiated by the terahertz wave along the guide wire. As a result, a larger area than the size of the beam spot can be scanned, thereby enabling high-speed scanning.

On the contrary, when high-speed scanning is performed by placing a predetermined diffusion lens on the terahertz wave and the measurement object, a problem may arise in that the beam spot size at the center and the side of the diffusion lens is changed. In addition, since the beam spot at the side becomes larger, a problem may occur that the resolution is poor.

However, in the present invention, because the guide wire vibrates, the irradiation area can be widened without causing a problem of non-uniformity of the size of the beam spot.

In addition, according to an embodiment of the present invention, since the size of the beam spot depends on the tip area of the guide wire, it may be possible to reduce the frequency of the terahertz wave while minimizing the beam spot. When the frequency of the terahertz wave is lowered, the power of the terahertz wave can be increased, so that the penetration rate can be improved and the accuracy of the measurement can be improved.

Furthermore, according to an embodiment of the present invention, even if the distance between the end of the guide wire and the measurement object is changed by the vibration of the guide wire, the change in distance can be corrected by moving the coupling substrate, thereby improving the reliability of the measurement. .

According to a terahertz wave substrate detector and an operation method thereof according to an embodiment of the present invention, defects such as chip-to-chip spacing and pattern defects and defects such as peeling / pores in a high-density and miniaturized semiconductor package in a non-contact and non-destructive manner are detected. can do.

As mentioned above, although this invention was demonstrated in detail using the preferable embodiment, the scope of the present invention is not limited to a specific embodiment, Comprising: It should be interpreted by the attached Claim. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

Claims

A terahertz wave emitting unit generating terahertz waves;

A guide wire for guiding the terahertz wave generated by the terahertz wave emitting unit along a longitudinal direction to a measurement object; And

The terahertz wave-based detector comprising a vibration unit for vibrating the guide wire in the width direction of the guide wire.
According to claim 1,

The vibrating unit,

A first vibrator disposed on one side of the guide wire;

And a terahertz wave-based detector including a second vibration unit disposed to be spaced apart from the first vibration unit by a predetermined distance.
The method of claim 2,

The terahertz wave-based detector of which the first vibration unit is disposed inside the guide wire.
The method of claim 2,

The terahertz wave based detector is disposed on the outer surface of the guide wire.
The method of claim 4, wherein

The terahertz wave-based detector is fixed to the outer surface of the guide wire by the first vibrating portion insulator.
The method of claim 2,

The first vibrating portion is made of a magnet,

The terahertz wave-based detector, the second vibrating portion is made of a coil.
According to claim 1,

A coupling substrate on which the terahertz wave emitting portion and the guide wire are disposed; And

The controller may further include a controller configured to control a position of the coupling substrate with respect to a measurement object.

And the control unit controls the position of the coupling substrate to correct a change in distance between the guide wire end and the measurement object caused by the vibration.
The method of claim 7, wherein

The terahertz wave-based detector of the guide wire vibration frequency by the vibration unit and the correction frequency of the coupling substrate are associated with each other.
According to claim 1,

The guide wire is conductive,

The terahertz wave-based detector, the width of the guide wire tip is a few nm to several um.
According to claim 1,

And a region where the terahertz wave is irradiated is larger than the tip size of the guide wire by the vibration.
A preparation step of preparing a measurement object;

Positioning the guide wire on one side of the measurement object providing a path of the terahertz wave; And

And irradiating a terahertz wave to a measurement object through the guide wire.

The irradiating step further comprises the step of vibrating the guide wire in the width direction of the guide wire, the method of operating a terahertz wave-based detector.
The method of claim 11, wherein

By vibration of the irradiation step,

The terahertz wave is irradiated to an area larger than the terahertz wave beam spot provided by the tip of the guide wire, the method of operating a terahertz wave-based detector.
The method of claim 11, wherein

And a correction step of correcting a change in distance between the tip of the guide wire and the measurement object according to the vibration of the irradiation step.
The method of claim 13,

The correction step,

When the distance between the tip of the guide wire and the measurement object is far away according to the vibration of the irradiation step, the guide wire is moved in the direction of the measurement object,

When the distance between the tip of the guide wire and the measurement object is closer according to the vibration of the irradiation step, the guide wire is moved in a direction away from the measurement object, the method of operating a terahertz wave-based detector.