JPH06160495A - Mechanism for connecting integrated circuit inspection device using electro-optical crystal - Google Patents

Abstract

PURPOSE:To realize a connecting mechanism having a low cost and high reliability in the mechanism for connecting input/output terminals of an integrated circuit to be measured to an electro-optical crystal in an integrated circuit inspection device having the crystal. CONSTITUTION:The connecting mechanism for an integrated circuit inspection device using an electro-optical crystal 4 comprises a spherical elastic conductor 1 brought into pressure contact with an input/output terminal 11 of an integrated circuit and the crystal 4 by pressing the terminal 11 to electrically connect the crystal 4 to the terminal 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection mechanism in an integrated circuit inspection device for inspecting the electrical characteristics of an integrated circuit (IC) assembled to have input / output terminals, and more particularly to a connection mechanism utilizing an electro-optical effect. The present invention relates to a connection mechanism of an integrated circuit inspection device capable of observing a speed electric signal waveform.

[0002]

2. Description of the Related Art It is necessary to confirm that a semiconductor device operates properly in the final step of manufacturing the semiconductor device such as a large scale integrated circuit (LSI) and in the use of the semiconductor device. In order to confirm this, a signal for operating the IC is applied through an input / output terminal of the integrated circuit (IC), and an output signal waveform corresponding to the signal is detected to confirm that normal operation is performed. . The operation of an IC, especially an LSI, is complicated, and it is necessary to change the applied signal as many times as possible to confirm the output signal waveform. An integrated circuit inspection device called an IC tester performs this inspection.

In an integrated circuit inspection device, an IC to be inspected with a main body for generating an applied signal and analyzing the detected signal.
Perform the inspection after electrically connecting the input and output terminals of. Therefore, a contact pin that comes into contact with the input / output terminal of the IC to be tested is provided, and the contact pin and the main body are connected by a cable. However, with the recent increase in the speed of semiconductor elements, the conventional method of connecting with a cable makes it difficult to perform accurate measurement due to a signal delay in the cable. Therefore, efforts are being made to make the cable as short as possible, but the current situation is that it is not enough. Therefore, an optical signal waveform measurement method using the electro-optic effect of the semiconductor element substrate crystal called the Pockels effect has been proposed, and the fact that high-speed signals can be measured (for example, JAValdmanis and G. Mourou, "Subpicosecond e
lectronics sampling: principlesand application "IE
EE JOURNAL OF QUANTUM ELECTRONICS, VOL. QE-22, pp.
69-78).

Further, Japanese Patent Laid-Open No. 1-28566 discloses that
A detection method is disclosed in which a test LSI is mounted on a detection crystal and the waveform of an electric signal is measured. FIG. 4 is a schematic configuration diagram and an overall configuration diagram of the integrated circuit inspection device disclosed in Japanese Patent Laid-Open No. 1-28566. An integrated circuit inspection device having an electro-optic crystal will be briefly described with reference to this drawing.

In FIG. 4, reference numeral 100 is an IC to be inspected, which is brought into contact with the electro-optic crystal 10. Reference numeral 50 denotes a light source unit that generates a light beam such as a semiconductor laser. The light beam passes through the beam splitter 51, is scanned by the light scanning unit 52, and is incident on the electro-optic crystal. Electrodes such as gold mirrors are formed on the surface of the electro-optic crystal 10 in contact with the IC 100 in a form corresponding to the arrangement of the input / output terminals of the IC 100, and the other surface is a transparent electrode. The light incident on the electro-optic crystal 10 passes through the electro-optic crystal 10, is reflected by the gold mirror, is condensed again by the optical scanning unit 52, and is received by the light receiving unit 53 via the beam splitter 51. Since the birefringence changes due to the terminal voltage of the IC 100 inside the electro-optic crystal 10, the polarization state of the light beam traveling back and forth also changes. Therefore, if the change in the polarization state is detected by the polarization filter provided in the light receiving section 53, the terminal voltage of IC 100 can be detected. Reference numeral 54 denotes a control unit that applies an operation signal to the IC 100 via the IC drive circuit 55 in synchronization with the optical scanning unit 52 and the like, and processes the signal detected by the light receiving unit 53 to perform I processing.
Derive the terminal voltage waveform of C 100.

Since the electro-optic crystal 10 is provided very close to the input / output terminals of the IC 100, the signal delay is small and high-speed IC inspection is possible. In order to install the IC in the inspection device, a member called a performance board having holes corresponding to the arrangement of the input / output terminals of the IC is provided on the upper part of the electro-optic crystal, and the IC input / output terminals are provided in the holes of the performance board. Install through. However, if the input / output terminal of the IC is brought into direct contact with the gold mirror that is the electrode of the electro-optical crystal, not only the input / output terminal of the IC, the electrode of the electro-optical crystal, and the electro-optical crystal itself may be damaged. Due to the length error of the input / output terminal of the IC and the error of the tip position of the input / output terminal, there is a problem that the reliability of contact is low and an error occurs in the voltage detected depending on the contact condition. Therefore, the present applicant discloses in Japanese Patent Application Laid-Open No. 4-40381 a connection mechanism using a contact pin having a spring mechanism called a pogo pin in both directions at the contact portion of both the electrode of the electro-optic crystal and the input / output terminal of the IC. ing. FIG. 5 is a diagram showing the overall configuration of this inspection device, FIG. 6 is a diagram showing details of the connecting mechanism, and FIG. 7 is a diagram showing details of a contact pin having spring mechanisms in both directions.

In FIG. 5, reference numeral 61 is an optical scanning unit, and 6
Reference numeral 2 is a sensor unit including a light source and a light receiving unit, and 63 is a tester head including a detection unit and an IC drive circuit. 64
Is an electro-optic crystal, and a gold vapor deposition mirror corresponding to the input / output terminals of the IC 100 is provided on the upper surface thereof, and a transparent conductive film 66 is provided on the lower surface thereof, as shown in FIG.
67 is for holding crystals with antireflection coating on the lower surface
It is a SiO ₂ plate and is adhered to a transparent conductive film. Reference numeral 80 denotes a connection mechanism, which has contact pins with a spring mechanism in both directions as shown in FIG. Electro-optic crystal 64 and S
The iO ₂ plate 67 and the connection mechanism 80 are attached to the guard ring 69. 70 is a performance board, IC
It has a hole through which 100 input / output terminals pass.

The inspection is carried out with the terminals of the IC 100 to be inspected passed through the holes of the performance board 70.

[0009]

By using a contact pin having a spring mechanism in both directions as described above, the problem of poor contact is alleviated considerably. But I
As the C package is being miniaturized, the distance between pins of the input / output terminals tends to be reduced more and more, and for example, the pitch of the input / output terminals of about 0.4 mm has been used. . The above connection mechanism has a problem in that the cost is high because a large number of contact pins as shown in FIG. 7 need to be arranged at such a pitch, and a large number of small However, there is a problem in that it is not easy from the viewpoint of processing accuracy.

When the processing accuracy is insufficient, the contact pins may come into contact with each other at an angle. In such a case, the metal mirror provided on the crystal surface may be damaged or the oblique force applied to the crystal surface. As a result, the characteristic of the electro-optical effect changes, which causes a problem that a voltage measurement error occurs. The present invention has been made in view of the above problems, and an object thereof is to realize a cheaper and more reliable connection mechanism.

[0011]

The connection mechanism of the present invention comprises an electro-optical crystal whose one surface is electrically connected to the input / output terminal of the integrated circuit under test, and the voltage at the input / output terminal is changed to the electro-optical crystal. A connection mechanism between the surface of an electro-optic crystal and an input / output terminal in an integrated circuit inspection device that can be detected as a change in the polarization state of light reflected and reciprocated in the interior. To achieve the above object, the input / output terminal is pressed. Is provided with a spherical elastic conductor that is pressed between the input / output terminal and the electro-optical crystal to electrically connect the electro-optical crystal and the input / output terminal.

According to another aspect of the present invention, there is provided a guide plate having holes arranged in the same arrangement as the input / output terminals of the integrated circuit under test. The surface of the hole of this guide plate is insulative.

[0013]

[Operation] By using the elastic spherical conductor,
Since the error in the position of the contacting surface is absorbed by the elasticity, the function equivalent to that of the contact pin having the spring mechanism in both directions shown in FIG. 7 can be easily realized. Moreover, since the conductor is spherical, even if an oblique force is applied, the surface is pressed with a uniform force, and therefore the metal mirror of the electro-optic crystal is not damaged.

Further, each spherical conductor needs to be accurately arranged at a position corresponding to the input / output terminal of the integrated circuit to be measured, but since it is spherical, it is possible to simply make a hole in a thin plate and position it. Yes, it is easy to manufacture.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is applied to an integrated circuit inspection device capable of detecting the voltage at the input / output terminal of an IC at high speed by utilizing the electro-optical effect shown in FIGS. Since the portion is only the connecting portion with the electro-optic crystal, only the connecting portion will be described in the following description of the embodiments.

FIG. 1 is a diagram showing the construction of an embodiment of the present invention, (a) is a side sectional view, and (b) is an exploded view of this portion. In FIG. 1, 1 is a sphere made of conductive rubber, 2 is a guide plate for arranging the conductive rubber spheres 1 and made of an electrically insulating material. On the guide plate 2,
The holes are punched in a form corresponding to the arrangement of the input / output terminals of the IC to be inspected, that is, the arrangement of the conducting wires 11 fixed to the performance board 10. The diameter of this hole is 1
The diameter of the conductor rubber ball 1 is slightly larger than the diameter of the conductor rubber ball 1 and is made movable in the vertical direction. Further, the thickness of the guide plate 2 needs to be smaller than the diameter of the conductor rubber ball 1 so as not to prevent the contact with the conductor rubber ball 1. Reference numeral 3 is a guide holder for holding the guide plate 2 at a predetermined position.

Reference numeral 4 denotes an electro-optic crystal, on the upper surface of which a gold mirror having a thickness of about 0.1 μm is vapor-deposited in the same shape as the arrangement of the input / output terminals of the IC, that is, the arrangement of the holes of the guide plate 2. The transparent conductive film 6 is formed on the entire lower surface. 7
Is a transparent quartz glass (SiO ₂ ) plate that protects the transparent conductive film 6, and is bonded to the transparent conductive film 6. A non-reflective coating film 8 is provided on the lower surface of the SiO ₂ plate 7.

To assemble this part, the protective SiO ₂ plate 7, the electro-optic crystal 4, the guide holder 3, and the guide plate 2 are inserted into the guard ring 9 in this order, and then the conductive rubber ball 1 is mounted. The above is positioned by the guard ring 9. The conductive rubber ball 1 is fixed in position by the guide plate 2 and pressed from both sides by the input / output terminals of the electro-optical crystal 4 and the IC, so that further fixing processing (adhesion or the like) is unnecessary. On the other hand, by aligning the input / output terminal 11 of the IC and the guard ring 9 with the positioning pin 12 provided on the performance board 10, all the elements can be aligned.

At the time of inspection, the input / output terminal (pin) of the IC to be inspected is inserted into the hole of the performance board 10 and the conductive rubber ball 1 is pressed at the tip thereof to bring the pin into contact with the gold mirror 5 of the electro-optic crystal 4. It As a method of processing the conductive rubber sphere, a method of injecting the heated and melted raw material through a fine and pointed injection hole and cooling it slowly than the speed at which it becomes spherical due to surface tension is considered.

Further, since it is not necessary that the whole is made of a conductive material, as shown in FIG. 2, it is possible to use one in which the central portion is made of ordinary rubber or plastic and the periphery is covered with conductive rubber. Further, in this embodiment, the guide plate 2 is made of an insulating material, but the thickness of the guide plate cannot be made so thick that it may be difficult to perform accurate machining inexpensively with a material such as ceramics. In that case, as shown in FIG. 3, after accurately processing a metal plate such as stainless steel,
You may make it coat an insulating material. In FIG. 3, 32 is a metal material such as stainless steel or tungsten, and 31 is a coated insulating material.

As described above, by making the shape of the conductive elastic material spherical, it is possible to realize a connection mechanism which is easy to manufacture and low in cost.

[0022]

As described above, the present invention provides a rubber ball,
It can be configured with low-cost components such as guide plates,
Further, in order to deal with different kinds of LSIs, it is only necessary to prepare a guide plate adapted to the terminal arrangement, so that it is possible to deal with a wide variety of products at low cost. Also, the force exerted by rubber is almost perpendicular to the electro-optic crystal, and the crystal surface (metal mirror)
Since there is no fear of damage to the device, it is possible to avoid a cause of voltage measurement error.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing another embodiment of the spherical elastic conductor.

FIG. 3 is a diagram showing another embodiment showing a conductive sphere.

FIG. 4 is a diagram showing a schematic configuration of an integrated circuit inspection device having an electro-optic crystal.

FIG. 5 is a diagram showing an overall configuration of an integrated circuit device.

FIG. 6 is a view showing a conventional electro-optic crystal connection part.

FIG. 7 is a view showing the structure of a contact pin used in the conventional example of FIG. 6 and having a spring mechanism in both directions.

[Explanation of symbols]

 1 ... Spherical elastic conductor 2 ... Guide plate 3 ... Guide holder 4 ... Electro-optic crystal 5 ... Gold mirror electrode 6 ... Transparent conductive film 9 ... Guard ring 10 ... Performance board 11 ... IC input / output terminal (pin)

Claims (7)

[Claims] 1. An electro-optical crystal (4), one surface of which is electrically connected to an input / output terminal (11) of an integrated circuit to be measured, wherein a voltage of the input / output terminal (11) is applied to the electro-optical crystal (4). A connection mechanism for connecting to the input / output terminal (11) of the electro-optic crystal (4) in an integrated circuit inspection device capable of being detected as a change in the polarization state of light reflected and reciprocated in the crystal (4). By pressing the output terminal (11), it is pressed between the input / output terminal (11) and the electro-optical crystal (4), and the electro-optical crystal (4) and the input / output terminal (1) are connected.
1. A connection mechanism in an integrated circuit inspection device having an electro-optic crystal, comprising a spherical elastic conductor (1) for electrically connecting 1). 2. The connection mechanism according to claim 1, wherein the spherical elastic conductor (1) is made of conductive rubber. 3. The connection mechanism according to claim 1, wherein the spherical elastic conductor (1) is formed by forming a conductive rubber film on an insulating rubber ball. 4. A positioning guide plate (2) for the spherical elastic conductor (1), which has holes arranged in the same arrangement as the input / output terminals of the integrated circuit to be measured, and at least the surface of the holes is insulating. The connection mechanism according to claim 1, wherein: 5. The connection mechanism according to claim 1, wherein the hole of the guide plate (2) has a diameter equal to or larger than a diameter of the spherical elastic conductor (1). 6. The connection mechanism according to claim 4, wherein the guide plate (2) is an insulating plate that is sufficiently thinner than the diameter of the spherical elastic conductor (1). 7. The guide plate (2) is a plate sufficiently thinner than the diameter of the spherical elastic conductor (1) in which an insulating material is formed on the surface of a metal plate. The connection mechanism according to any one.