JPH0843499A - Electric-field sensor for tip-type circuit test and its electric-field detection method - Google Patents

Abstract

PURPOSE:To obtain an electric-field sensor in which an electric field can be measured by means of a simple optical system, in which a region to be measured on a circuit to be measured is not limited and whose high sensitivity can be realized. CONSTITUTION:A support 2 which is transparent with reference to light is formed of a glass material such as, e.g. synthetic quartz or the like or of a polymer material such as PMMA or the like whose refractive index is nearly equal to that of a polymer layer 1. A pyramid-shaped side face 3 which is at an angle of 25 deg. and whose side face has been worked to be pyramid-shaped in such a way that its cross section becomes square is formed, and the polymer layer 1 is fixed to a fixation face 5 which is square. In addition, an antireflection film 4 is executed to the other face which is parallel to the fixation face 5 so as not to generate a loss due to the reflection of light, an electric-field sensor 8 for testing a tip-type circuit is constituted, the polymer layer 1 is brought close to, or brought into contact with, a circuit 11, to be tested, so as to pick up an electric field from the circuit 11 to be tested, the polymer layer 1 is irradiated with a condensed luminous flux 7 via the support 2, and the electric field of the circuit 11 to be tested is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes a change in birefringence of an electro-optical material according to the electric field strength to test a circuit from the change in the polarization of light applied to the electro-optical material. For electric field sensor for electric field, and particularly to electric field sensor for dip type circuit test for conducting circuit test using polymer material in which organic nonlinear optical material is dispersed or bonded as electro-optical material, and electric field detection method using the same Is.

[0002]

2. Description of the Related Art As a means for testing a circuit, a method is known in which an electro-optical material is brought into proximity with or in contact with a circuit to be measured to couple an electric field, and the electric field generated from the circuit to be measured is detected. Since the birefringence of an electro-optical material changes according to an electric field, when the electro-optical material is irradiated with light, the electric field change can be detected as a polarization change, and the polarization can be used to detect a light intensity change. You can In particular, when laser light is used as a light source as a pulse wave and an electric field change is sampled and detected, it is possible to measure an electric signal with a time resolution corresponding to a pulse width, which is called electro-optical sampling.

As an electro-optical material used in such an electric field sensor for circuit testing, a polymer material in which an organic nonlinear material is dispersed or combined has a large electro-optical constant and a quick response as compared with an inorganic crystal material. In addition, because of its small relative permittivity, high sensitivity, high time resolution, and low disturbance are expected.

9A and 9B are views for explaining an example of a conventional electric field sensor for circuit test using an organic nonlinear optical material. FIG. 9A is a perspective view and FIG. 9B is a front view of the electric field sensor. FIG. In FIG. 9, 1 is a polymer layer made of a polymer material in which an organic nonlinear optical material is dispersed or combined,
6 is an objective lens for condensing light, 7 is a condensed light beam, 9
Is a signal line, 10 is a substrate, 11 is a circuit to be measured formed on the substrate 10, and 15 is a thin film type circuit test electric field sensor having the polymer layer 1.

The thin film type circuit test electric field sensor 15 is
The polymer layer 1 is formed by directly applying a polymer material in which an organic nonlinear optical material is dispersed or bonded to the circuit to be measured 11 (film thickness: 10 μm). The thin-film circuit test electric field sensor 15 is usually polarized in the thick film direction so that the electric field in the film thickness direction of the polymer layer 1 (z-axis direction in FIG. 9) can be detected.

In the method of conducting a circuit test using the thin film type circuit test electric field sensor 15, a condensed light beam 7 is obliquely incident at an incident angle θ 1 and reflected at a position where a signal of the circuit under test 11 is desired to be detected. This is done by detecting the electric field from the polarization state of light. The thin-film circuit test electric field sensor 15 of FIG. 9 is formed by directly coating the polymer layer 1 made of a polymer material in which an organic nonlinear optical material is dispersed or bonded onto the circuit to be measured 11. However, in addition to this, for example, as shown in FIG. 10, the polymer layer 1 is formed on the film 13 as a large-area thin film by spin coating to be used as the thin film type circuit test electric field sensor 15, or FIG.
As shown in FIG. 1, a structure in which the polymer layer 1 is formed as a large-area thin film on the transparent flat plate 14 by spin coating and is adhered to the circuit under test 11 to be used as the thin film circuit test electric field sensor 15 is also known.

[0007]

However, such a polymer layer 1 is directly applied to the circuit 11 to be measured, or a structure in which it is fixed to a film 13 or a flat plate 14 which is transparent to light is produced, and When the thin film type circuit test electric field sensor 15 is adhered to the measuring circuit 11 and used as the electric field sensor 15, the following problems occur.

In order to convert the change in the birefringence of the polymer layer 1 according to the electric field generated from the circuit to be measured 11 into the change in polarization, the light is normally projected at an angle of 30 to 50 degrees as shown in FIG. It is incident at an angle of (θ 1). Therefore, the polymer layer 1 is directly applied to the circuit to be measured 11, or a thin film type circuit test electric field sensor 15 formed as a large area thin film by spin coating on the film 13 or the flat plate 14 which is transparent to light. 2 for collecting and collimating light
A dedicated and complicated optical system using one objective lens 6 is required.

In addition, in this optical system, light is obliquely incident from above the circuit under test 11, so that the circuit under test 11 is measured.
If parts having large unevenness are integrated in the area, the parts may interfere with the optical path, or the jig of the circuit under test 11 may interfere with the objective lens 6, resulting in a region where the circuit under test 11 cannot be irradiated with light. Occurrence may occur and the measured area may be limited.

Further, even though the light is incident at an angle of 30 to 50 degrees, the angle of light (θ 2) in the polymer layer 1 becomes small due to refraction, and the birefringence changes. There is a problem that the efficiency of conversion into polarization change is reduced, and high sensitivity cannot be achieved.

Further, the thin film type circuit test electric field sensor 15
When the thin film type circuit test electric field sensor 15 has a spatial non-uniformity in sensitivity because it is applied to or bonded to the circuit under test 11, a signal having the same intensity is measured depending on the measurement position of the circuit under test 11. May be detected as signals of different intensities. However, it is difficult to evaluate and correct the spatial nonuniformity of the sensitivity of the thin-film circuit test electric field sensor 15 that has been applied or adhered once.

Particularly, in the case of the thin film type circuit test electric field sensor 15 formed on the film 13 as shown in FIG. 10, when the thin film type circuit test electric field sensor 15 is bonded to the circuit under test 11, it is difficult to handle. However, there is a problem that the thin-film circuit test electric field sensor 15 itself is deformed to cause spatial nonuniformity of sensitivity.

On the other hand, in the case of the thin film type circuit test electric field sensor 15 formed on the flat plate 14 as shown in FIG. 11, the polymer layer 1 and the film 13 are solved although the above-mentioned problems are solved.
The condensing light beam 7 is transmitted through a flat plate 14 (thickness of about 200 μm or more) that is thicker than the optical axis, and as a result, astigmatism makes it difficult to condense and the spatial resolution deteriorates. There is.

Further, there is a problem that an oblique light path in the flat plate 14 causes a region 16 which cannot be irradiated with light at an end portion of the thin film type circuit test electric field sensor 15. Therefore, when the thin-film circuit test electric field sensor 15 is adhered, it becomes impossible to measure the portion to be measured that must be the end of the thin-film circuit test electric field sensor 15, for example, the vicinity of the bonding pad. The area 16 that cannot be irradiated with light is 8 times the thickness of the flat plate 14 when the angle θ1 is 50 degrees.
It will be about 0% (about 160 μm).

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and an object thereof is a dip type circuit test electric field sensor capable of measuring an electric field by a simple optical system and its electric field detection. To provide a method. Another object of the present invention is to provide a dip-type circuit test electric field sensor and a method for detecting the electric field thereof, in which the measured area on the measured circuit is not limited. Still another object of the present invention is to provide a dip-type circuit test electric field sensor and a method for detecting the electric field, which can obtain an electric field measurement with high sensitivity.

[0016]

In order to achieve such an object, the electric field sensor for dip type circuit test according to the present invention is provided with a support made of a transparent material and fixed to one end face of the support. It has a polymer layer made of a polymer material in which an organic nonlinear optical material is dispersed or bonded, and the polymer layer is brought close to or in contact with the electric circuit to be measured so as to pick up an electric field from the electric circuit to be measured and supported. The polymer layer is irradiated with light through the body to detect the electric field of the measured electric circuit.

Further, the electric field detecting method according to the present invention is a polymer comprising a support made of a transparent material and a polymer material in which an organic nonlinear optical material fixed to one end face of the support is dispersed or bonded. Using a dip-type circuit test electric field sensor having a layer, the polymer layer is brought close to or in contact with the measured electric circuit to the extent that an electric field from the measured electric circuit is picked up, and light is applied to the polymer layer through the support. Irradiation is performed to detect the electric field of the measured electric circuit.

[0018]

In the electric field sensor for dip-type circuit test according to the present invention, the incident light to the electric field sensor for dip-type circuit test and the light emitted from the electric field sensor for dip-type circuit test are substantially parallel and their distances are Since it is small, a simple optical system using a single objective lens similar to the electric field sensor for circuit test using an inorganic crystal such as gallium arsenide (GaAs) or deuterated potassium dihydrogen phosphate (KD ^* P) is applied. It becomes possible to do.

Therefore, the electric field sensor for dip-type circuit test can measure not only the circuit to be measured but also the circuit to be measured, and the measurement can be performed in the proximity of the circuit to be measured. Further, since the light is incident on the electric field sensor perpendicularly to the optical axis, the above-mentioned astigmatism does not occur, and there is no region where the light cannot be radiated due to the parts or jig of the circuit under test.

Further, since the electric field sensor for dip type circuit test according to the present invention can be moved on the circuit to be measured, the light is always incident on the same position of the electric field sensor for dip type circuit test regardless of the measurement position. Can be measured. By adjusting the incident position of the light on the dip-type circuit test electric field sensor, the reflection position for making the optical path oblique can be made close to the tip of the dip-type circuit test electric field sensor. Light can also be made incident on the peripheral portion of the electric field sensor for pattern circuit test.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings. (Embodiment 1) FIG. 1 is a diagram for explaining the construction of an embodiment of an electric field sensor for dip-type circuit testing according to the present invention. FIG. 1 (a) is a perspective view and FIG. 1 (b) is an electric field sensor tip. A vertical cross-sectional view of each portion is shown, and the same reference numerals are given to the same portions as the above-mentioned drawings. In FIG. 1, a polymer layer 1 made of a polymer material in which an organic nonlinear optical material is dispersed or bonded is, for example, an organic nonlinear optical material such as 2-methyl-4nitroaniline (MNA) and a high molecular weight material such as polymethylmethacrylate (PMMA). It is dispersed or bonded to a molecular material, and is polarized in the same direction so that the electric field in the film thickness direction can be detected. The refractive index of the polymer layer 1 is about 1.5, its shape is a square with one side of about 200 μm, and the film thickness is about 20 μm.

The support 2 which is transparent to light is formed of a glass material such as synthetic quartz or a polymer material such as PMMA having a refractive index similar to that of the polymer layer 1. Further, the support body 2 is formed with a conical side surface 3 which is machined into a conical shape so that its cross section becomes square at an angle of 25 degrees, for example. And one side is 200μ
The polymer layer 1 is fixed to a fixing surface 5 that is a square of m. Further, the other surface parallel to the fixed surface 5 is provided with an antireflection film 4 so as not to cause a loss due to reflection of light, thereby forming a dip-type circuit test electric field sensor 8.

Next, the procedure for detecting an electric field using the dip-type circuit test electric field sensor thus configured will be described. In the above-mentioned electric field sensor 8 for dip-type circuit test, the condensed light beam 7 that is vertically incident on the antireflection film 4 is totally reflected by the conical side surface 3 of the support body 2 and is fixed to the fixed surface 5 of the polymer layer 1. And is incident at an angle of about 50 degrees. This incident light travels at an angle of about 50 degrees even in the polymer layer 1, and the objective lens 6
Is totally reflected at a point on the lower surface of the polymer layer 1 which is determined from the mutual position of the electric field sensor 8 and the electric field sensor 8, and is again totally reflected by the conical side surface 3 and emitted in the incident direction.

In this case, since the incident light and the emitted light are parallel and the distance between them can be reduced to about 300 μm, light can be condensed and collimated by the single objective lens 6. Therefore, the dip-type circuit test electric field sensor 8 is incorporated into an optical system using a single objective lens 6 which is simpler than the conventional optical system shown in FIGS. The electric field of the signal line 9 can be detected by bringing the measured electric field 12 generated from the signal line 9 into close contact with or in contact with the signal line 9 of the circuit under measurement 11 and permeating the polymer layer 1. Further, this dip-type circuit test electric field sensor 8 is made of gallium arsenide (Ga).
As) and deuterated potassium dihydrogen phosphate (KD ^* P).
Such an electric field sensor for circuit test using an inorganic crystal can also be incorporated into a system using the electric field sensor.

Further, since the focused light flux 7 enters and exits perpendicularly to the electric field sensor 8 for dip-type circuit testing, parts with large irregularities are integrated in the circuit under test 11 or the circuit under test 11 is measured. The jig does not limit the area to be measured by forming an area on the circuit to be measured 11 where light cannot be irradiated. Also, this dip-type circuit test electric field sensor 8
Since astigmatism does not occur, a high spatial resolution larger than that of the conventional thin film type circuit test electric field sensor 15 can be obtained, and the angle of the focused light flux 7 in the polymer layer 1 does not become small, so that The sensitivity is increased to about 3 times that of the thin film circuit test electric field sensor 15. Further, since the dip-type circuit test electric field sensor 8 can be moved on the circuit under test 11, the dip-type circuit test electric field sensor 8 can be moved to the same position even at different measurement positions of the circuit under test 11. Light can be incident and measured. Therefore, it is not necessary to correct the sensitivity depending on the measured position.

The dip-type circuit test electric field sensor 8 does not need to be adhered to the circuit to be measured 11, is not difficult to handle, and is not susceptible to deformation. Further, this dip-type circuit test electric field sensor 8 adjusts the mutual position of the objective lens 6 and the electric field sensor 8 to totally reflect the incident light on the conical side surface 3 in the immediate vicinity of the fixed surface 5. The area 16 of the end of the electric field sensor 8 for die circuit test which cannot be irradiated with light can be made as small as the thickness of the polymer layer 1.
Therefore, since it is difficult for the dip-type circuit test electric field sensor 8 to approach the circuit under test 11, the dip-type circuit test electric field sensor 8 must be an end portion of the dip-type circuit test electric field sensor 8 and cannot be irradiated with light (for example, near the bonding pad). Such)
Is about 2 from the end of the dip-type circuit test electric field sensor 8.
It becomes as small as about 0 μm.

As one of electro-optical sampling methods, a laser light pulse is divided into two light beams, one of which is made incident on a photoconductive switch as pump light, and the other is made as probe light for electric field detection. A pump-and-probe method is known which measures the response waveform of a conduction switch and the response of a device based on the response waveform. Since the dip-type circuit test electric field sensor 8 does not have a high-reflection film on the lower surface of the polymer layer 1, the light directly incident on the polymer layer 1 vertically passes through the dip-type circuit test electric field sensor 8. The circuit under test 11 can be illuminated. Taking advantage of this feature, pump light may be introduced into the circuit under test 11 through the dip-type circuit test electric field sensor 8 to measure the electric signal in the vicinity of the pump position.

(Embodiment 2) FIG. 2 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the configuration of another embodiment of the electric field sensor for dip-type circuit testing according to the present invention. The same reference numerals are attached. In FIG. 2, the dip-type circuit test electric field sensor 8 is the same as the first embodiment described above.
1 is basically the same as that of FIG. 1, and is different from that of FIG. 1 in that a part of the fixed surface 5 is provided with a high reflection film 17 and light is reciprocated in the polymer layer 1 twice. In this case, when the dip-type circuit test electric field sensor 8 is applied to a measured position such as a transmission line where the interaction length between the electric field and light can be long, it is almost twice as large as that in the first embodiment. The sensitivity of can be obtained. In addition, in the second embodiment, an example in which the light is reciprocated twice is shown, but of course, the number of times of reciprocation can be increased to further improve the sensitivity.

(Embodiment 3) FIG. 3 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the structure of still another embodiment of the electric field sensor for dip-type circuit test according to the present invention. Are given the same reference numerals. In FIG. 3, this dip-type circuit test electric field sensor 8 is basically the same as the above-described first and second embodiments, and
2 is different from FIG. 2 in that the side surface of the polymer layer 1 is processed at the same angle as the conical side surface 3 to form the conical side surface 1a.

In this case, the mutual position of the objective lens 6 and the electric field sensor 8 for dip-type circuit test is adjusted so that the incident light is reflected by the conical side surface 3 in the polymer layer 1 to test the dip-type circuit. The region 16 at the end of the electric field sensor 8 where the light cannot be irradiated is eliminated. Therefore, all the measured circuit 11 can be measured. Further, as in the case of Example 2, a high reflection film may be provided on a part of the fixed surface 5 and light may be reciprocated a plurality of times in the polymer layer 1 in which the organic nonlinear optical material is dispersed or bonded. In this case, the sensitivity can be improved at the measured position where the interaction length between the electric field and the light can be long.

Further, as shown in FIG. 4, the conical side surface 3 of the support 2 and the conical side surface 1a of the polymer layer 1 are side-processed at an angle of 45 degrees, and the conical side surface 1a of the polymer layer 1 is processed. When the light is reflected, the reflected light travels in the polymer layer 1 in parallel to the circuit under measurement 11, and the reflection on the bottom surface of the polymer layer 1 can be prevented.

With such a structure, the angle of light in the polymer layer 1 (angle θ 2 in FIG. 9) is maximized, and the sensitivity is theoretically maximized. When the dip-type circuit test electric field sensor 8 is applied to a measured position such as a transmission line where the interaction length between the electric field and light can be long, the sensitivity can be further increased according to the interaction length. For example, assuming that light and an electric field interact with each other at a distance of about 200 μm in the polymer layer 1 without a problem of phase matching, the sensitivity is about 16 times or more that of the conventional thin film type circuit test electric field sensor 15. It is about 5 times or more that of Example 1 shown in FIG.

Further, as shown in FIG. 5, the side surface of the tip portion of the polymer layer 1 may be cut to such an extent that the optical path in the dip type circuit test electric field sensor 8 is not obstructed. In this case, without adjusting the mutual position of the objective lens 6 and the dip-type circuit test electric field sensor 8, there is no region 16 at the end of the dip-type circuit test electric field sensor 8 which cannot be irradiated with light. Therefore, it is possible to perform measurement on the circuit under test 11.

(Embodiment 4) FIG. 6 is a vertical sectional view of the tip of an electric field sensor for explaining the structure of another embodiment of the electric field sensor for dip-type circuit testing according to the present invention. The same reference numerals are attached. 6, in the electric field sensor 8 for dip-type circuit test according to the present embodiment, the support 2 is not processed into a conical side surface, and the organic nonlinear optical material fixed to the tip of the support 2 is dispersed or combined. Example 1 is that only the polymer layer 1 made of a polymer material is formed to have a conical-shaped side surface 1a that is a conical-shaped side surface.
Is different from

In such a structure, the peripheral light beam 7 that has passed through the support 2 is totally reflected by the conical-shaped conical-shaped side surface 1a of the polymer layer 1, passes through the polymer layer 1, The cone-shaped side surface 1a of the polymer layer 1 that has been processed again into a cone shape is totally reflected, travels through the support 2, and is emitted from the dip-type circuit test electric field sensor 8. In this case, it is not necessary to perform side surface processing on the support body 2.

When the cone-shaped conical side surface 1a of the polymer layer 1 has an angle of 45 degrees, the light reflected by the conical-side surface 1a of the polymer layer 1 travels in parallel with the circuit under test 11. Then
It is possible to prevent reflection on the bottom surface of the polymer layer 1. With such a configuration, the angle of light in the polymer layer 1 (angle θ2 in FIG. 9) becomes maximum, and theoretically the sensitivity becomes maximum. When this dip-type circuit test electric field sensor 8 is applied to a measured position such as a transmission line where the interaction length between the electric field and light can be long, the sensitivity can be further increased according to the interaction length. . For example, assuming that light and an electric field interact with each other at a distance of about 200 μm in the polymer layer 1 without a problem of phase matching, the sensitivity is about 16 times or more that of the conventional thin film type circuit test electric field sensor 15. It is about 5 times more than 1.

(Embodiment 5) FIG. 7 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the configuration of another embodiment of the electric field sensor for dip-type circuit testing according to the present invention. The same reference numerals are attached. In FIG. 7, a dip-type circuit test electric field sensor 8 according to the present embodiment is a polymer layer in which only a part of the tip end surface of the conical side surface 3 of the support 2 which is processed into a conical shape is made of an organic nonlinear optical material. The difference from the first embodiment is that it is set to 1. That is, a concave portion such as a groove or a hole is formed on the tip end surface of the conical-shaped conical side surface 3 of the support 2, and the polymer layer 1 is formed in this concave portion.
Are filled and solidified. And this polymer layer 1 is
The conical side surface 3 of the support body 2 that has been processed into a conical shape is polarized in the direction perpendicular to the tip surface.

In such a structure, the condensed light flux 7 which has passed through the support 2 is totally reflected by the conical-shaped conical side surface 3, and is totally reflected by the tip surface of the polymer layer 1 formed in the recess. The light is reflected and again totally reflected by the conical side surface 3 that has been processed into a conical shape, travels through the support 2, and is emitted from the dip-type circuit test electric field sensor 8. At this time, the condensed light flux 7 is first transmitted to the conical side surface 3
It is passed through the polymer layer 1 while being reflected by and then reflected by the conical side surface 3. If the condensed light flux 7 is reflected on the lower surface of the center of the polymer layer 1, the spatial resolution and the sensitivity are maximized. In this case, it is not necessary to carry out side surface processing on the polymer layer 1 and the interaction length between the electric field and the light can be shortened, so that the polymer layer 1 can be applied to the measured position requiring high spatial resolution. .

If the angle of the conical side surface 3 is about 45 degrees, the light reflected by the conical side surface 3 travels in parallel with the circuit to be measured 11 and passes through the polymer layer 1 and then again. The light is reflected by the conical side surface 3 that has been processed into a conical shape at 45 degrees, travels through the support 2, and is detected. With such a configuration, the angle of light in the polymer layer 1 (angle θ2 in FIG. 9) becomes maximum, and theoretically the sensitivity becomes maximum.

Needless to say, the above-described embodiment is merely an example and does not limit the scope of the present invention. For example, light may be reflected by providing a highly reflective film on the conical side surface 3 and the lower surface of the polymer layer 1. In this case, since the total reflection condition is not necessary for the reflection of light in the electric field sensor, the shape of the electric field sensor such as the angle of the conical side surface and the thickness of the support can be designed more freely. That is, when the reflection angle on the lower surface of the polymer layer 1 is designed to be smaller than the total reflection, the distance between the incident light and the emitted light can be reduced, and the dip-type circuit test electric field sensor 8 can be made smaller and more compact. Can be configured to. Further, since the distance between the incident light and the emitted light is small, the single objective lens 6 can further condense light, so that high spatial resolution can be achieved. The lower surface of the polymer layer 1 can also be achieved by using the signal line 9 as a reflector.
In this case, the reflectance is smaller than that of the high reflection film,
There is no need to apply a highly reflective film.

Further, in FIG. 1, the cross-sectional shape of the electric field sensor 8 for dip type circuit test is shown as a square, but
The shape may be a rectangle, another polygon, or a circle depending on the purpose of measurement or convenience in production. For example, in FIG.
An example is shown in which the cross-sectional shape is rectangular in order to allow light to be incident on the entire one-dimensional region and to simultaneously measure the signals in that region. Further, in the electric field sensor for dip-type circuit test shown in the example, the portion which does not become the light reflecting surface is also processed with the cone shape, but the portion which does not become the reflecting surface does not have to be processed into the cone shape. good. Of course, the cross-sectional shapes of the columnar portion and the conical portion may be different.

[0042]

As described above, according to the present invention,
It has a support made of a transparent material and a polymer layer made of a polymer material in which an organic nonlinear optical material fixed to the first end face of the support is dispersed or bonded, and the polymer layer is covered. A conventional thin film is obtained by bringing the polymer layer close to or in contact with the electric circuit to be measured so as to pick up the electric field from the electric circuit to be measured, irradiating the polymer layer with light through the support, and detecting the electric field of the electric circuit to be measured. -Type circuit testing electric field sensor requires two dedicated objective lenses, which does not require a dedicated and complicated optical system, and uses a single objective lens similar to a general circuit testing electric field sensor using an inorganic crystal. It enables measurement with a simple optical system. Therefore, the electric field sensor for circuit test using inorganic crystal is compatible with the optical system, and the limited measurement area on the circuit by circuit parts or jigs with large unevenness or flat plate for supporting the electric field sensor has been a problem in the past. Disappears.

Further, according to the present invention, by increasing the efficiency of converting a change in birefringence into a change in polarization, it is possible to achieve high sensitivity and since there is no astigmatism, a high spatial resolution can be obtained. . In particular, when applied to a position to be measured where a long interaction length between an electric field and light, such as a transmission line, can be obtained, a structure with higher sensitivity can be obtained.

Further, according to the present invention, since there is no handling difficulty associated with bonding and the same part of the electric field sensor for dip type circuit test can always be used, the space of the electric field sensor for dip type circuit test itself can be used. It is possible to obtain an extremely excellent effect such as eliminating the need to correct the specific sensitivity.

[Brief description of drawings]

1A and 1B are views for explaining the configuration of an embodiment of an electric field sensor for dip-type circuit testing according to the present invention, in which FIG. 1A is a perspective view and FIG. 1B is a vertical cross-sectional view of a tip of an electric field sensor.

FIG. 2 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining a configuration of another embodiment of the electric field sensor for dip type circuit test according to the present invention.

FIG. 3 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining a configuration of a dip type circuit test electric field sensor according to another embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining a configuration of another embodiment of the electric field sensor for dip type circuit test according to the present invention.

FIG. 5 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the structure of another embodiment of the electric field sensor for dip-type circuit testing according to the present invention.

FIG. 6 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the configuration of another embodiment of the electric field sensor for dip type circuit test according to the present invention.

FIG. 7 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the configuration of another embodiment of the electric field sensor for dip-type circuit testing according to the present invention.

FIG. 8 is a perspective view illustrating a configuration of another embodiment of the electric field sensor for dip type circuit test according to the present invention.

FIG. 9 is a diagram for explaining a state of electric field measurement by a conventional thin film type circuit test electric field sensor, in which (a) is a perspective view;
(B) is a vertical cross-sectional view of the tip of the electric field sensor.

FIG. 10 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining an electric field measurement state by a conventional thin film type circuit test electric field sensor formed on a film.

FIG. 11 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining an electric field measurement state by a conventional thin film circuit test electric field sensor formed on a flat plate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Polymer layer, 1a ... Conical side surface, 2 ... Support body, 3 ... Conical side surface, 4 ... Antireflection film, 5 ... Fixed surface, 6 ... Objective lens,
7 condensed light flux, 8 ... electric field sensor for dip type circuit test, 9
... signal line, 10 ... substrate, 11 ... circuit to be measured, 12 ... electric field to be measured, 13 ... film, 14 ... flat plate, 15 ... thin film type circuit test electric field sensor, 16 ... area where light cannot be irradiated, 1
7 ... Highly reflective film.

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[Procedure amendment]

[Submission date] October 25, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title : Electric field sensor for tip type circuit test and electric field detection method thereof

[Claims]

Detailed Description of the Invention

[0001]

The present invention relates to a tip testing the circuit from the polarization change of light by using a change in birefringence in accordance with the electric field intensity is irradiated to the electro-optical material of the electro-optic material
And electric field detection using the tip-type circuit test electric field sensor for conducting a circuit test using a polymer material in which an organic nonlinear optical material is dispersed or bonded as an electro-optic material It is about the method.

[0002]

2. Description of the Related Art As a means for testing a circuit, a method is known in which an electro-optical material is brought into proximity with or in contact with a circuit to be measured to couple an electric field, and the electric field generated from the circuit to be measured is detected. Since the birefringence of an electro-optical material changes according to an electric field, when the electro-optical material is irradiated with light, the electric field change can be detected as a polarization change, and the polarization can be used to detect a light intensity change. You can In particular, when laser light is used as a light source as a pulse wave and an electric field change is sampled and detected, it is possible to measure an electric signal with a time resolution corresponding to a pulse width, which is called electro-optical sampling.

As an electro-optical material used in such an electric field sensor for circuit testing, a polymer material in which an organic nonlinear material is dispersed or combined has a large electro-optical constant and a quick response as compared with an inorganic crystal material. In addition, because of its small relative permittivity, high sensitivity, high time resolution, and low disturbance are expected.

9A and 9B are views for explaining an example of a conventional electric field sensor for circuit test using an organic nonlinear optical material. FIG. 9A is a perspective view and FIG. 9B is a front view of the electric field sensor. FIG. In FIG. 9, 1 is a polymer layer made of a polymer material in which an organic nonlinear optical material is dispersed or combined,
6 is an objective lens for condensing light, 7 is a condensed light beam, 9
Is a signal line, 10 is a substrate, 11 is a circuit to be measured formed on the substrate 10, and 15 is a thin film type circuit test electric field sensor having the polymer layer 1.

The thin film type circuit test electric field sensor 15 is
The polymer layer 1 is formed by directly applying a polymer material in which an organic nonlinear optical material is dispersed or bonded to the circuit to be measured 11 (film thickness: 10 μm). The thin-film circuit test electric field sensor 15 is usually polarized in the film thickness direction so that the electric field in the film thickness direction of the polymer layer 1 (z-axis direction in FIG. 9) can be detected.

In the method of conducting a circuit test using the thin film type circuit test electric field sensor 15, the condensed light beam 7 is obliquely incident at an incident angle θ1 and reflected at a position where a signal of the circuit under test 11 is desired to be detected. This is done by detecting the electric field from the polarization state of light. The thin-film circuit test electric field sensor 15 of FIG. 9 is formed by directly coating the polymer layer 1 made of a polymer material in which an organic nonlinear optical material is dispersed or bonded onto the circuit to be measured 11. However, in addition to this, for example, as shown in FIG. 10, the polymer layer 1 is formed on the film 13 as a large-area thin film by spin coating to be used as the thin film type circuit test electric field sensor 15, or FIG.
As shown in FIG. 1, a structure in which the polymer layer 1 is formed as a large-area thin film on the transparent flat plate 14 by spin coating and is adhered to the circuit under test 11 to be used as the thin film circuit test electric field sensor 15 is also known.

[0007]

However, such a polymer layer 1 is directly applied to the circuit 11 to be measured, or a structure in which it is fixed to a film 13 or a flat plate 14 which is transparent to light is produced, and When the thin film type circuit test electric field sensor 15 is adhered to the measuring circuit 11 and used as the electric field sensor 15, the following problems occur.

In order to convert the change in the birefringence of the polymer layer 1 according to the electric field generated from the circuit to be measured 11 into the change in polarization, the light is normally projected at an angle of 30 to 50 degrees as shown in FIG. The light is obliquely incident at (θ1). Therefore, the polymer layer 1 is directly applied to the circuit to be measured 11, or a thin film type circuit test electric field sensor 15 formed as a large area thin film by spin coating on the film 13 or the flat plate 14 which is transparent to light. 2 for collecting and collimating light
A dedicated and complicated optical system using one objective lens 6 is required.

In addition, in this optical system, light is obliquely incident from above the circuit under test 11, so that the circuit under test 11 is measured.
If parts having large unevenness are integrated in the area, the parts may interfere with the optical path, or the jig of the circuit under test 11 may interfere with the objective lens 6, resulting in a region where the circuit under test 11 cannot be irradiated with light. Occurrence may occur and the measured area may be limited.

Further, even though the light is incident at an angle of 30 to 50 degrees, the angle of light (θ2) in the polymer layer 1 becomes small due to refraction, which causes a change in birefringence. There is a problem that the efficiency of conversion into polarization change is reduced, and high sensitivity cannot be achieved.

Further, the thin film type circuit test electric field sensor 15
When the thin film type circuit test electric field sensor 15 has a spatial non-uniformity in sensitivity because it is applied to or bonded to the circuit under test 11, a signal having the same intensity is measured depending on the measurement position of the circuit under test 11. May be detected as signals of different intensities. However, it is difficult to evaluate and correct the spatial nonuniformity of the sensitivity of the thin-film circuit test electric field sensor 15 that has been applied or adhered once.

Particularly, in the case of the thin film type circuit test electric field sensor 15 formed on the film 13 as shown in FIG. 10, when the thin film type circuit test electric field sensor 15 is bonded to the circuit under test 11, it is difficult to handle. However, there is a problem that the thin-film circuit test electric field sensor 15 itself is deformed to cause spatial nonuniformity of sensitivity.

On the other hand, in the case of the thin film type circuit test electric field sensor 15 formed on the flat plate 14 as shown in FIG. 11, the polymer layer 1 and the film 13 are solved although the above-mentioned problems are solved.
The condensing light beam 7 is transmitted through a flat plate 14 (thickness of about 200 μm or more) that is thicker than the optical axis, and as a result, astigmatism makes it difficult to condense and the spatial resolution deteriorates. There is.

Further, there is a problem that a region 16 which can not irradiated with light at the end of the thin-film circuit test field sensor 15 for the optical path of the oblique in the flat plate 14 occurs. Therefore, when the thin-film circuit test electric field sensor 15 is adhered, it becomes impossible to measure the portion to be measured that must be the end of the thin-film circuit test electric field sensor 15, for example, the vicinity of the bonding pad. The area 16 that cannot be irradiated with light is 8 times the thickness of the flat plate 14 when the angle θ1 is 50 degrees.
It will be about 0% (about 160 μm).

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a tip type circuit test electric field sensor capable of measuring an electric field by a simple optical system and its electric field detection. To provide a method. Another object of the present invention is to provide a tip type circuit test electric field sensor and a method of detecting the electric field thereof, in which the measured head area on the circuit to be measured is not limited. Still another object of the present invention is to provide a tip type circuit test electric field sensor and a method for detecting the electric field, which can obtain an electric field measurement with high sensitivity.

[0016]

In order to achieve such an object, a tip type circuit test electric field sensor according to the present invention is provided with a support made of a transparent material and fixed to one end surface of the support. It has a polymer layer made of a polymer material in which an organic nonlinear optical material is dispersed or bonded, and the polymer layer is brought close to or in contact with the electric circuit to be measured so as to pick up an electric field from the electric circuit to be measured and supported. The polymer layer is irradiated with light through the body to detect the electric field of the measured electric circuit.

Further, the electric field detecting method according to the present invention is a polymer comprising a support made of a transparent material and a polymer material in which an organic nonlinear optical material fixed to one end face of the support is dispersed or bonded. Using a tip-type circuit test electric field sensor having a layer, the polymer layer is brought close to or in contact with the measured electric circuit to the extent that an electric field from the measured electric circuit is picked up, and light is applied to the polymer layer through the support. Irradiation is performed to detect the electric field of the measured electric circuit.

[0018]

The electric field sensor tip type circuit test in the present invention, the incident light to the tip type circuit test field sensor, is substantially parallel to and a distance thereof and emitted light from the tip type circuit test field sensor Since it is small, a simple optical system using a single objective lens similar to the electric field sensor for circuit test using an inorganic crystal such as gallium arsenide (GaAs) or potassium dihydrogen phosphate deuteride (KD ^* P) is applied. It becomes possible to do.

Therefore, the electric field sensor for tip type circuit test can perform not only the contact with the circuit to be measured but also the proximity to the circuit to be measured, and the adhesion is unnecessary. Further, since the light is incident on the electric field sensor perpendicularly to the optical axis, the above-mentioned astigmatism does not occur, and there is no region where the light cannot be radiated due to the parts or jig of the circuit under test.

Further, since the tip type circuit test electric field sensor of the present invention can be moved on the circuit to be measured, the light is always incident on the same position of the tip type circuit test electric field sensor regardless of the measurement position. Can be measured. Further, the light, by adjusting the incident position of the tip type circuit test electric field sensor, it is possible to a reflecting position for the optical path at an angle to the tip nearest tip type circuit test field sensor, tip Light can also be made incident on the peripheral portion of the electric field sensor for pattern circuit test.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings. (Embodiment 1) FIG. 1 is a diagram for explaining the construction of an embodiment of a tip type circuit test electric field sensor according to the present invention. FIG. 1 (a) is a perspective view and FIG. 1 (b) is an electric field sensor tip. A vertical cross-sectional view of each portion is shown, and the same reference numerals are given to the same portions as the above-mentioned drawings. In FIG. 1, a polymer layer 1 made of a polymer material in which an organic nonlinear optical material is dispersed or bonded is, for example, an organic nonlinear optical material such as 2-methyl-4nitroaniline (MNA) and a high molecular weight material such as polymethylmethacrylate (PMMA). It is dispersed or bonded to a molecular material, and is polarized in the same direction so that the electric field in the film thickness direction can be detected. The refractive index of the polymer layer 1 is about 1.5, its shape is a square with one side of about 200 μm, and the film thickness is about 20 μm.

The support 2 which is transparent to light is formed of a glass material such as synthetic quartz or a polymer material such as PMMA having a refractive index similar to that of the polymer layer 1. Further, the support body 2 is formed with a conical side surface 3 which is machined into a conical shape so that its cross section becomes square at an angle of 25 degrees, for example. And one side is 200μ
The polymer layer 1 is fixed to a fixing surface 5 that is a square of m. Further, the other surface parallel to the fixed surface 5 is provided with an antireflection film 4 so as not to cause a loss due to reflection of light, thereby forming a tip type circuit test electric field sensor 8.

Next, a procedure for detecting an electric field using the tip type circuit test electric field sensor configured as described above will be described. In the tip-type circuit test electric field sensor 8 described above, the condensed light flux 7 that is vertically incident on the antireflection film 4 is totally reflected by the conical side surface 3 of the support body 2 and with respect to the fixed surface 5 of the polymer layer 1. And is incident at an angle of about 50 degrees. This incident light travels at an angle of about 50 degrees even in the polymer layer 1, and the objective lens 6
Is totally reflected at a point on the lower surface of the polymer layer 1 which is determined from the mutual position of the electric field sensor 8 and the electric field sensor 8, and is again totally reflected by the conical side surface 3 and emitted in the incident direction.

In this case, since the incident light and the emitted light are parallel and the distance between them can be reduced to about 300 μm, light can be condensed and collimated by the single objective lens 6. Accordingly incorporated into an optical system using a single objective lens 6 of simpler conventional optical system shown in FIGS. 9 to 11 the tip type circuit test field sensor 8, the tip-type circuit test field sensor 8 The electric field of the signal line 9 can be detected by bringing the measured electric field 12 generated from the signal line 9 into close contact with or in contact with the signal line 9 of the circuit under measurement 11 and permeating the polymer layer 1. Also, this tee
The up-type circuit test electric field sensor 8 is made of gallium arsenide (Ga).
As) and deuterated potassium dihydrogen phosphate (KD ^* P)
Such an electric field sensor for circuit test using an inorganic crystal can also be incorporated into a system using the electric field sensor.

Further, since the focused light flux 7 enters and exits perpendicularly to the electric field sensor 8 for tip type circuit test, parts with large irregularities are integrated in the circuit under test 11, or the circuit under test 11 is measured. The jig does not limit the head region to be measured because a region where the light cannot be irradiated is generated on the circuit to be measured 11. Further, this tip type circuit test electric field sensor 8
Since astigmatism does not occur, a high spatial resolution larger than that of the conventional thin film type circuit test electric field sensor 15 can be obtained, and the angle of the focused light flux 7 in the polymer layer 1 does not become small, so that The sensitivity is increased to about 3 times that of the thin film circuit test electric field sensor 15. Further, since the tip-type circuit test electric field sensor 8 can be moved on the circuit under test 11, even at different measurement positions of the circuit under test 11, the tip-type circuit test electric field sensor 8 is located at the same position. Light can be incident and measured. Therefore, it is not necessary to correct the sensitivity depending on the measured position.

The tip type circuit test electric field sensor 8 does not need to be adhered to the circuit to be measured 11 and is not difficult to handle and is not susceptible to deformation. The tip type circuit test electric field sensor 8 adjusts the mutual position of the objective lens 6 and the electric field sensor 8 so that the incident light is totally reflected by the conical side surface 3 in the immediate vicinity of the fixed surface 5. more, the region 16 can not be irradiated with light of the end of the tip type circuit test field sensor 8 can be reduced to the same extent as the thickness of the polymer layer 1.
Therefore, it is difficult to approach the tip-type circuit test electric field sensor 8 on the circuit to be measured 11, so that the tip-type circuit test electric field sensor 8 must be an end portion of the tip-type circuit test electric field sensor 8 and light cannot be irradiated (for example, in the vicinity of the bonding pad). Such)
Is about 2 from the end of the electric field sensor 8 for tip type circuit test.
It becomes as small as about 0 μm.

As one of electro-optical sampling methods, a laser light pulse is divided into two light beams, one of which is made incident on a photoconductive switch as pump light, and the other is made as probe light for electric field detection. A pump-and-probe method is known which measures the response waveform of a conduction switch and the response of a device based on the response waveform. Since the tip-type circuit test electric field sensor 8 does not have a high reflection film on the lower surface of the polymer layer 1, the light directly and vertically incident on the polymer layer 1 is used for the tip-type circuit test. It is possible to pass through the electric field sensor 8 and illuminate the circuit under test 11. Utilizing this feature, the tip-type circuit test electric field sensor 8 may be passed through to introduce the pump light into the circuit under test 11, and the electrical signal may be measured in the vicinity of the pump position.

(Embodiment 2) FIG. 2 shows a tip according to the present invention.
FIG. 9 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the configuration of another embodiment of the electric circuit sensor for testing a loop type circuit, in which the same parts as those in the above-mentioned figures are designated by the same reference numerals. 2, Te
The electric field sensor 8 for the ip type circuit test is the same as that of the first embodiment described above.
1 is basically the same as that of FIG. 1, and is different from that of FIG. In this case, when the tip type circuit test electric field sensor 8 is applied to a measured position such as a transmission line where the interaction length between the electric field and the light can be long, the tip type circuit test electric field sensor 8 is almost doubled as compared with the first embodiment. The sensitivity of can be obtained. In addition, in the second embodiment, an example in which the light is reciprocated twice is shown, but of course, the number of times of reciprocation can be increased to further improve the sensitivity.

(Embodiment 3) FIG. 3 shows a tip according to the present invention.
Is a longitudinal sectional view of the electric field sensor tip for explaining the configuration according to another embodiment of the electric field sensor flop type circuit test, it is denoted by the same reference numerals in FIG same parts described above. In FIG. 3, the tip-type circuit test electric field sensor 8 is basically the same as in the above-described first and second embodiments.
2 is different from FIG. 2 in that the side surface of the polymer layer 1 is processed at the same angle as the conical side surface 3 to form the conical side surface 1a.

[0030] In this case, by adjusting the mutual position of the objective lens 6 and the tip type circuit test field sensor 8, by causing the incident light is reflected by the conical side surface 3 in the polymer layer 1, Tea
The region 16 of the end portion of the up- type circuit test electric field sensor 8 where the light cannot be irradiated is eliminated. Therefore, all the measured circuit 11 can be measured. Further, as in the case of Example 2, a high reflection film may be provided on a part of the fixed surface 5 and light may be reciprocated a plurality of times in the polymer layer 1 in which the organic nonlinear optical material is dispersed or bonded. In this case, the sensitivity can be improved at the measured position where the interaction length between the electric field and the light can be long.

Further, as shown in FIG. 4, the conical side surface 3 of the support 2 and the conical side surface 1a of the polymer layer 1 are side-processed at an angle of 45 degrees, and the conical side surface 1a of the polymer layer 1 is processed. When the light is reflected, the reflected light travels in the polymer layer 1 in parallel to the circuit under measurement 11, and the reflection on the bottom surface of the polymer layer 1 can be prevented.

With this structure, the angle of light in the polymer layer 1 (angle θ2 in FIG. 9) is maximized, and the sensitivity is theoretically maximized. When the tip type circuit test electric field sensor 8 is applied to a measured position such as a transmission line where the interaction length between the electric field and the light can be long, the sensitivity can be further increased according to the interaction length. For example, assuming that light and an electric field interact with each other at a distance of about 200 μm in the polymer layer 1 without a problem of phase matching, the sensitivity is about 16 times or more that of the conventional thin film type circuit test electric field sensor 15. It is about 5 times or more that of Example 1 shown in FIG.

Further, as shown in FIG. 5, the side surface of the tip portion of the polymer layer 1 may be cut to such an extent that the optical path in the tip-type circuit test electric field sensor 8 is not obstructed. In this case, without adjusting the mutual position of the objective lens 6 and the tip-type circuit test electric field sensor 8, there is no region 16 at the end of the tip-type circuit test electric field sensor 8 which cannot be irradiated with light. Therefore, it is possible to perform measurement on the circuit under test 11.

(Embodiment 4) FIG. 6 shows a tip according to the present invention.
FIG. 9 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the configuration of another embodiment of the electric circuit sensor for testing a loop type circuit, in which the same parts as those in the above-mentioned figures are designated by the same reference numerals. Referring to FIG. 6, in the tip-type circuit test electric field sensor 8 according to the present embodiment, the support 2 is not processed into a conical side surface, and the organic nonlinear optical material fixed to the tip of the support 2 is dispersed or bonded. Example 1 is that only the polymer layer 1 made of a polymer material is formed to have a conical-shaped side surface 1a that is a conical-shaped side surface.
Is different from

In such a structure, the condensed light flux 7 that has passed through the support 2 is totally reflected by the conical-shaped conical-shaped side surface 1a of the polymer layer 1, passes through the polymer layer 1, The cone-shaped side surface 1a of the polymer layer 1 processed again into the cone shape is totally reflected, travels through the support 2, and is emitted from the tip type circuit test electric field sensor 8. In this case, it is not necessary to perform side surface processing on the support body 2.

When the cone-shaped conical side surface 1a of the polymer layer 1 has an angle of 45 degrees, the light reflected by the conical-side surface 1a of the polymer layer 1 travels in parallel with the circuit under test 11. Then
It is possible to prevent reflection on the bottom surface of the polymer layer 1. With such a configuration, the angle of light in the polymer layer 1 (angle θ2 in FIG. 9) becomes maximum, and theoretically the sensitivity becomes maximum. When the tip type circuit test electric field sensor 8 is applied to a measured position such as a transmission line where the interaction length between the electric field and the light can be long, the sensitivity can be further increased according to the interaction length. . For example, assuming that light and an electric field interact with each other at a distance of about 200 μm in the polymer layer 1 without a problem of phase matching, the sensitivity is about 16 times or more that of the conventional thin film type circuit test electric field sensor 15. It is about 5 times more than 1.

(Embodiment 5) FIG. 7 shows a tip according to the present invention.
FIG. 9 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the configuration of another embodiment of the electric circuit sensor for testing a loop type circuit, in which the same parts as those in the above-mentioned figures are designated by the same reference numerals. In FIG. 7, a tip-type circuit test electric field sensor 8 according to the present embodiment is a polymer layer in which only a part of the tip end surface of the conical side surface 3 of the support 2 which is processed into a conical shape is made of an organic nonlinear optical material. The difference from the first embodiment is that it is set to 1. That is, a concave portion such as a groove or a hole is formed on the tip end surface of the conical-shaped conical side surface 3 of the support 2, and the polymer layer 1 is formed in this concave portion.
Are filled and solidified. And this polymer layer 1 is
The conical side surface 3 of the support body 2 that has been processed into a conical shape is polarized in the direction perpendicular to the tip surface.

In such a structure, the condensed light flux 7 which has passed through the support 2 is totally reflected by the conical-shaped conical side surface 3, and is totally reflected by the tip surface of the polymer layer 1 formed in the recess. The light is reflected and then totally reflected by the conical side surface 3 which has been processed into a conical shape, travels through the support 2, and is emitted from the tip type circuit test electric field sensor 8. At this time, the condensed light flux 7 is first transmitted to the conical side surface 3
It is passed through the polymer layer 1 while being reflected by and then reflected by the conical side surface 3. If the condensed light flux 7 is reflected on the lower surface of the center of the polymer layer 1, the spatial resolution and the sensitivity are maximized. In this case, it is not necessary to carry out side surface processing on the polymer layer 1 and the interaction length between the electric field and the light can be shortened, so that the polymer layer 1 can be applied to the measured position requiring high spatial resolution. .

If the angle of the conical side surface 3 is about 45 degrees, the light reflected by the conical side surface 3 travels in parallel with the circuit to be measured 11 and passes through the polymer layer 1 and then again. The light is reflected by the conical side surface 3 that has been processed into a conical shape at 45 degrees, travels through the support 2, and is detected. With such a configuration, the angle of light in the polymer layer 1 (angle θ2 in FIG. 9) becomes maximum, and theoretically the sensitivity becomes maximum.

Needless to say, the above-described embodiment is merely an example and does not limit the scope of the present invention. For example, light may be reflected by providing a highly reflective film on the conical side surface 3 and the lower surface of the polymer layer 1. In this case, since the total reflection condition is not necessary for the reflection of light in the electric field sensor, the shape of the electric field sensor such as the angle of the conical side surface and the thickness of the support can be designed more freely. That is, when the reflection angle on the lower surface of the polymer layer 1 is designed to be smaller than the total reflection, the distance between the incident light and the emitted light can be reduced, and the tip type circuit test electric field sensor 8 can be made smaller and more compact. Can be configured to. Further, since the distance between the incident light and the emitted light is small, the single objective lens 6 can further condense light, so that high spatial resolution can be achieved. The lower surface of the polymer layer 1 can also be achieved by using the signal line 9 as a reflector.
In this case, the reflectance is smaller than that of the high reflection film,
There is no need to apply a highly reflective film.

Further, in FIG. 1, the cross-sectional shape of the electric field sensor 8 for tip type circuit test is shown as a square, but
The shape may be a rectangle, another polygon or a circle depending on the purpose of measurement and the convenience of production. For example, in FIG.
An example is shown in which the cross-sectional shape is rectangular in order to allow light to be incident on the entire one-dimensional region and to simultaneously measure the signals in that region. Further, in the tip type circuit test electric field sensor shown in the embodiment, the conical shape is also applied to the part which does not become the light reflecting surface, but the part which does not become the reflecting surface does not have to be processed into the conical shape. good. Of course, the cross-sectional shapes of the columnar portion and the conical portion may be different.

[0042]

As described above, according to the present invention,
It has a support made of a transparent material and a polymer layer made of a polymer material in which an organic nonlinear optical material fixed to the first end face of the support is dispersed or bonded, and the polymer layer is covered. A conventional thin film is obtained by bringing the polymer layer close to or in contact with the electric circuit to be measured so as to pick up the electric field from the electric circuit to be measured, irradiating the polymer layer with light through the support, and detecting the electric field of the electric circuit to be measured. -Type circuit test electric field sensor requires two dedicated objective lenses, which does not require a dedicated and complicated optical system, and uses a single objective lens similar to general inorganic crystal circuit test electric field sensors. It enables measurement with a simple optical system. Therefore, the electric field sensor for circuit test using the inorganic crystal is compatible with the optical system, and the limited measurement area on the circuit by circuit parts or jigs with large unevenness or flat plate for supporting the electric field sensor has been a problem. Disappears.

Further, according to the present invention, by increasing the efficiency of converting a change in birefringence into a change in polarization, it is possible to achieve high sensitivity and since there is no astigmatism, a high spatial resolution can be obtained. . In particular, when applied to a position to be measured where a long interaction length between an electric field and light, such as a transmission line, can be obtained, a structure with higher sensitivity can be obtained.

[0044] Further according to the present invention, tip in order to be able to difficulties in handling due to adhesion without always use the same part of the field sensor tip type circuit testing
It is possible to obtain an extremely excellent effect such as the need to correct the spatial sensitivity of the electric field sensor for die circuit test itself.

[Brief description of drawings]

1A and 1B are diagrams illustrating a configuration according to an embodiment of a tip-type circuit test electric field sensor according to the present invention, in which FIG. 1A is a perspective view and FIG. 1B is a vertical cross-sectional view of a tip portion of an electric field sensor.

FIG. 2 is a vertical cross-sectional view of the tip portion of the electric field sensor for explaining the configuration of another embodiment of the electric field sensor for tip type circuit test according to the present invention.

FIG. 3 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining a configuration of a tip type circuit test electric field sensor according to still another embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining the configuration of another embodiment of the electric field sensor for tip type circuit test according to the present invention.

FIG. 5 is a vertical cross-sectional view of the tip portion of the electric field sensor for explaining the configuration of another embodiment of the tip type circuit test electric field sensor according to the present invention.

FIG. 6 is a vertical cross-sectional view of the tip portion of the electric field sensor for explaining the configuration of the tip type circuit test electric field sensor according to another embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view of the tip of an electric field sensor for explaining the configuration of another embodiment of the electric field sensor for tip type circuit test according to the present invention.

FIG. 8 is a perspective view illustrating a configuration of another embodiment of the tip type circuit test electric field sensor according to the present invention.

FIG. 9 is a diagram for explaining a state of electric field measurement by a conventional thin film type circuit test electric field sensor, in which (a) is a perspective view;
(B) is a vertical cross-sectional view of the tip of the electric field sensor.

FIG. 10 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining an electric field measurement state by a conventional thin film type circuit test electric field sensor formed on a film.

FIG. 11 is a vertical cross-sectional view of a tip portion of an electric field sensor for explaining an electric field measurement state by a conventional thin film circuit test electric field sensor formed on a flat plate.

[Explanation of Codes] 1 ... Polymer layer, 1a ... Cone-shaped side surface, 2 ... Support, 3 ... Cone-shaped side surface, 4 ... Antireflection film, 5 ... Fixed surface, 6 ... Objective lens,
7 condensed light flux, 8 ... electric field sensor for tip type circuit test, 9
... signal line, 10 ... substrate, 11 ... circuit to be measured, 12 ... electric field to be measured, 13 ... film, 14 ... flat plate, 15 ... thin film type circuit test electric field sensor, 16 ...
7 ... Highly reflective film.

Front page continuation (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/66 C 7514-4M D 7514-4M

Claims (9)

[Claims] 1. A support comprising a transparent material, and a polymer layer comprising a polymer material in which an organic nonlinear optical material fixed to the first end surface of the support is dispersed or bonded, The polymer layer is brought close to or in contact with the measured electric circuit to such an extent that an electric field from the measured electric circuit is picked up, and the polymer layer is irradiated with light through the support to change the electric field of the measured electric circuit. An electric field sensor for dip-type circuit testing characterized by detecting. 2. The polymer layer according to claim 1, wherein the polymer layer is fixed on the entire surface of the first end surface, and the side surface of the polymer layer has a conical side surface processed into a conical shape. Characteristic DIP type electric field sensor for circuit test. 3. The support according to claim 1 or 2, wherein the support has a conical side surface that is processed into a conical shape so that the first end surface is a minute region. Electric field sensor for dip type circuit test. 4. The dip-type circuit test electric field sensor according to claim 1, wherein a part of the first end face has a reflection region that reflects light. 5. A support, which is made of a transparent material, has a concave portion formed on a first end surface thereof, and has a conical side surface processed so that the first end surface is a minute region, and is fixed in the concave portion. And a polymer layer made of a polymer material in which the organic non-linear optical material is dispersed or bonded, and the polymer layer is close to or in contact with the measured electric circuit to the extent that an electric field from the measured electric circuit is picked up. The dip-type circuit test electric field sensor, wherein the polymer layer is irradiated with light through the support to detect the electric field of the electric circuit to be measured. 6. The dip-type circuit test according to claim 3, wherein a conical pyramidal side surface of the support has a reflecting film that reflects light. Electric field sensor. 7. The electric field sensor for dip-type circuit test according to claim 1, wherein the support and the polymer layer have substantially the same refractive index. 8. The dip according to any one of claims 1 to 7, wherein an antireflection film is formed on a second end surface of the support, which is opposed to the first end surface. Electric field sensor for type circuit test. 9. A dip-type circuit having a support made of a transparent material and a polymer layer made of a polymer material in which an organic nonlinear optical material fixed or fixed to the first end surface of the support is dispersed or bonded. Using a test electric field sensor, the polymer layer is brought into proximity or contact with the measured electric circuit to the extent that an electric field from the measured electric circuit is picked up, and the polymer layer is irradiated with light through the support, An electric field detecting method comprising detecting an electric field of the measured electric circuit.