JPH095357A - Probe contact for signal observation unit in ic tester - Google Patents

Abstract

PURPOSE: To obtain a probe contact for observing an ultrahigh speed signal from above the performance board of IC tester with no error. CONSTITUTION: An SMA connector secured to a probe contact 30 is connected with a coaxial cable which is connected with a signal observation unit. The probe contact 30 is a metal pole wrapping signal wires coaxially wherein a large number of POGO pins 32 for GND contact are arranged, at the forward of the metal pole, such that they can be contained in POGO pins 35, 36 arranged along a circle having center at a POGO pin 31 for signal contact. The POGO pins 35, 36 project several mm to the outside from the forward end of probe contact 30 and touches a metal pad on the performance board of IC tester through a shortest route thus ensuring correct observation of signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe contact for exchanging signals between a performance board of an IC tester and a signal observation device.

[0002]

2. Description of the Related Art An IC tester performs self-diagnosis of the IC tester before performing a DUT or a wafer test. If an abnormality is found in the self-diagnosis, a check such as signal observation is performed to investigate the cause. The check of the IC tester is such that a large number of signal pads and ground pads on the performance board of the IC tester where all the signals necessary for DUT and wafer testing are output are observation points, for example, a sampling oscilloscope and a probe. Observing high frequency signals. Since the clock pulse of the conventional IC tester was 100 Mhz or less, this observation was not difficult, but 100 Mhz
The latest IC testers that exceed z required observation technology to make accurate observations.

The waveforms of the rising and falling edges of the pulse signal must be steep except when specially creating the gentle rising and falling edges of the pulse signal. For example, when the slew rate needs to be 0.4 ns or less, it is not possible to cope with it without special observation technology for pulse signal observation.

As shown in FIG. 3, performance board 1
In the observation of the above pulse signal, the metal pad 2 to be observed is brought into contact with the pins 6 and 7 of the probe contact 10 to take out the signal, and the observation is performed with a sampling oscilloscope or the like. For example, a large number of pads 2 having good conductivity are 0.4 mm on a circular performance board 1 having a diameter of 0.7 m.
It is arranged at intervals. And probe contact 1
The grounding pin 0 (hereinafter referred to as GND) pin 7 contacts the GND pad, and the signal pin 6 of the probe contact 10 contacts the signal pad 2 at the shortest distance to pick up and observe the signal.
In the case of an ultra-high frequency signal, unless the distance between the pad 2 and the probe contact 10 is set to the shortest distance, a phase difference occurs and accurate observation cannot be performed.

An example of the probe contact 15 is shown in FIG. The circumference of the coaxial cable is processed into a metal rod shape and provided as a probe contact 15, the center of the tip of which is a signal pin 16 for observing a pulse signal, and the GND line is GND.
It is connected to the pin 17, and the pin may be a pogo pin. The distance between the signal pin 16 and the GND pin 17 is set to the distance between the putt 21 and the putt 22 in the case of the performance board 20 shown in FIG.

An example of signal observation is shown in FIG. A probe contact 15 is attached to an arm that moves in the XY directions where the pads 21 and 22 are arranged on the performance board 20 like a grid, and a signal is observed by contacting the target pad 21. In the GND pad and the signal pad of the pad 21, since the GND pin 17 and the signal pin 16 of the probe contact 15 are located in the same direction, the distance becomes the shortest and no phase difference occurs. On the other hand, in the pad 22, the GND pad signal pad has the opposite direction of the GND pin 17 and the signal pin 16 of the probe contact 15, so that the GND pin 1 of the probe contact 15 is reversed.
The troublesome thing was to rotate the direction of 7 and the signal pin 16 by 180 °. The other end of the probe contact 15 is, for example, an SMA connector 25, and a coaxial cable 26
Connected to the signal observation equipment.

Further, FIG. 4 shows that the putt on the performance board 1 is composed of a signal pad and a GND pad having a width around the circumference thereof.
Even if the position of the probe contact 10 on the GND side is electrically conducted, the position of the GND pin 7 of the probe contact 10 is not in the shortest distance. Therefore, in the case of an ultra-high frequency signal exceeding 100 Mhz, the observed waveform has a phase difference. Occurs and accurate observation cannot be performed.

Normally, a phase difference occurs unless the signal and GND are equidistant. The measured data will be described with reference to FIG. 2, for example, the rise time of the pulse waveform is 30 ps.
When an input M1 is input and a waveform is observed in the state of the pad 3 in FIG. 4, the output M2 has a phase difference of 16 ps. Practically 10
With recent IC testers exceeding 0 Mhz, signal observation that causes a signal difference of 16 ps only in this portion should not be performed.

[0009]

Generally, a performance board has a circular shape, and a large number of putts exist at regular intervals like a grid pattern. Since the GND of the pad and the pulse signal are not in the same direction, the pin of the probe contact must be constantly rotated and aligned with the GND pad and the signal pad before the signal of the pad can be observed in order to accurately observe the signal. There was a problem. It is an object of the present invention to provide a probe contact that can quickly and correctly observe a large number of pad signals without rotating the probe contact.

[0010]

In order to achieve the above object, in the signal transmitting / receiving means for a signal observing device of an IC tester of the present invention, one pin of the GND pin of the probe contact that contacts the pad of the performance board is used. To a large number of pins and attached so as to correspond to the direction of 360 °.

The probe contact was a cylindrical tube made of metal to be attached to an arm that moves in the XY directions. Since it is a metal cylindrical tube, it is convenient to determine the point of the pad except for electromagnetic interference.

The GND contact pins of the probe contact are mounted in a coaxial structure with a large number of GND pins arranged around the signal pin as a center pin. Since a large number of GND pins are arranged in a circle, the distance between the signal observation pad and the pin is minimized, and the phase difference can be prevented.

[0013]

[Function] The probe contact has a coaxial structure, and since the outer circumference is a cylindrical tube using metal, it also has an electromagnetic shielding effect. For the probe contact, a metal cylindrical tube is attached to the arm that moves in the XY directions, and a large number of GND pins are attached, so it is easy to aim at the point of the putt at the shortest distance, which greatly contributes to the prevention of phase difference.

Signal pin of probe contact and GN
Since the D pin uses a pogo pin, the contact point can be prevented without damaging the pad point.

[0015]

EXAMPLE An example will be described with reference to FIG.
In FIG. 1, the SM is provided at the base of the probe contact 30.
The A connector is attached and fixed, and is connected to the coaxial cable and connected to the signal observation device. The probe contact 30 has a coaxial structure. At the tip of a cylindrical metal that wraps the probe contact 30, the center signal is arranged in a set of a pogo pin 31, a pogo pin socket 35, and a plurality of GND pogo pins 32 on the circumference, and a pogo pin socket 36. did.

For example, the size of the probe contact 30 is about 10 mm in diameter, and the total length is SMA connector 70 m.
m. Signal pogo pin 31 and GN in the center of the circle
The probe contact 30 has a coaxial structure in which eight GND pogo pins 32 are provided with the distance between the D pogo pins 32 being 3.8 mm. The length of the pogo pins 31 and 32 is about 12 mm, and the pogo pin socket 35 of the probe contact 30 is
36 from the tip of the probe contact 30.
It hits the target signal observation point with a configuration protruding outside by about 5 mm. Pogo pin 3 of probe contact 30
The periphery of the pogo pin sockets 35 and 36 for 1, 32 is fixed with, for example, Teflon as a filler, and the pogo pins 31, 33 are used.
The characteristic impedance of was set to 51Ω.

[0017]

Since the present invention is configured as described above, it has the following effects.

It has become possible for an engineer who does not have a signal observation technique to perform accurate observation even when using the probe contact of the present invention.

Since the tip of the probe contact was made of pogo pin, wear of the pad was reduced and contact failure was eliminated.

The number of GND side pogo pins at the tip of the probe contact can be adjusted by pulling out from the pogo pin socket as needed.

Since many pogo pins are provided at the tip of the probe contact, if one signal point is held down, it becomes GND.
Since the direction of can be contacted by 360 °, it is not necessary to rotate the probe contact for signal observation, which enables signal observation at the shortest distance.

In the probe contact, a metal cylindrical tube is attached to an arm that moves in the XY directions, and a large number of GND pins are attached, so that it is easy to aim at the point of the putt at the shortest distance, which greatly contributes to the prevention of phase difference.

[Brief description of drawings]

FIG. 1 shows a side view and a bottom view of a probe contact according to one embodiment of the present invention.

FIG. 2 shows an input M1-output M in one embodiment according to the prior art.
2 shows a passage characteristic diagram of No. 2.

FIG. 3 is a signal observation diagram in which a phase difference does not occur in an example according to the related art.

FIG. 4 is a signal observation diagram in which a phase difference occurs in one example according to the related art.

FIG. 5 is a signal observation diagram of an XY arm according to an embodiment of the related art.

FIG. 6 shows a side view and a bottom view of a probe contact in one example according to the prior art.

[Explanation of symbols]

 1,20 Performance board 2,3,21,22 Pat 6,7,16,17 pin 10,15,30 Probe contact 25 SMA connector 26 Coaxial cable 31,32 Pogo pin 35,36 Pogo pin socket

Claims (2)

[Claims] 1. A signal pin (31), a plurality of GND pins (32) coaxially arranged around the signal pin (31), and the signal pin (31) and the GND pin. The circumference of the metal that fixes and incorporates (32) and a medium that keeps the specific impedance of the signal pin (31) constant is filled between the signal pin (31) and the plurality of GND pins (32). A probe contact for a signal observation device of an IC tester, comprising: a filler; and a connector connected to the signal pin (31) and GND pin (32) side and the base of the other end. 2. The probe contact for a signal observation device of an IC tester according to claim 1, wherein the signal pin (31) and the plurality of GND pins (32) are made of pogo pins.