JPS59212999A - Measuring apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a measuring device that performs guard-to-guard connection of a plurality of measurement signal cables connecting between a measuring instrument and an element to be measured.

In recent years, with the progress of semiconductor technology, there has been an increasing demand for measuring devices that can measure many parameters at many measurement points down to extremely small precision with high resolution and at high speed. One possible example of such a measuring device is a measuring device that uses a switch matrix and a measurement signal cable to connect a plurality of measuring instruments and a channel section to which an element under test is connected, as shown in FIG. The measuring device shown in FIG. 1 includes an impedance measuring device 10 equipped with a high-frequency voltage source 12 and an ammeter 14, and S M U+ to SM! that function as a power source, an ammeter, and a voltmeter. A DC minute signal measuring instrument 20 equipped with Jn is provided.

In addition, the device under test (hereinafter referred to as DUT) 110° 112 is directly or via an extension cable 120 connected to the channel sections CH1 to C provided in the channel box 80.
Each measuring device 10', 20 and channels CHI to C1-1 are selectively connected by measurement signal cables 30 to 40, 60 to 70 and a switch matrix 50. Inside the switch matrix 50 are measurement signal cables 30 to 40 connected to the measuring instruments 10.20 and channel sections CH to C1-1k.
A large number of switches are installed to selectively connect the measurement signal cables 60 to 70 connected to the 17+) 21 (Jitsukai Sho 57
-131743), the description thereof will be omitted here. In addition, switches 90 to 100 for selectively connecting the channel sections CH, to CHk and the measurement signal cables 60 to 70 are connected to the channel box 80.
Provided inside.

By the way, with the measuring instrument mentioned above, it is possible to measure. The conditions required for this guard vary depending on the measurement item.

For example, the DC minute signal measurement and impedance measurement illustrated above are connected between channels CH and CH2.
When performing this for LI'rllO, the procedure is as follows.

(1) DC minute signal measurement For example, if 5IViUl and SMU2 are used,
Each SMU power supply line (hereinafter, force
e) The voltage detection line (hereinafter referred to as the sense line) F and the voltage detection line (hereinafter referred to as the sense line) S are each shielded by a guard G from the SMU as close to the DLIT as possible to prevent the influence of leakage current. It doesn't seem to be coming out. For this purpose, the force line F1, which is the core line, and the sense line S and each guard G must be at the same α position.

(1) Impedance measurement H of measurement signal cables 30 and 32 connected to high frequency power supply 12°4 ammeter 14 of impedance measuring instrument IO, respectively
The L line and the L line are respectively connected to either the force line F or the sense line S of the measurement signal cables 60 to 66 connected to the channel sections CH, , C) 12. Also guard HG of measurement signal cable 30.32.

It is necessary to electrostatically shield the measurement signal cables 60 to 66 by connecting LG to the guard G of the measurement signal cables 60 to 66. More importantly]) [J.T.
], 10 as close as possible to the measurement signal cable 90.
Guard 0 of 92 and 94.96 must be short-circuited with sufficiently low impedance as shown by broken line 130. The key to this is to secure four return paths in the guard G of each measurement signal cable and perform electromagnetic shielding. As a result, the inductance of the measurement signal cable that enters in series with D[JTll, 0 is reduced, and the mutual inductance between the measurement signal cables is also reduced. It has the effect of preventing fluctuations in results.

Now, in the case of DC minute signal measurement, as mentioned in (1), the guard and the core wire must be at the same potential.
Since the terminals under test of the DU are not necessarily at the same potential,
It is not possible to short-circuit the guards of the measurement signal line near T as in the case of impedance measurement.

Also, 1) Do not connect the UT directly to the channel section (
, a test fixture or a probe for fixing the DUT or contacting the point to be measured with a probe or the like to obtain an electrical connection.
It is common practice to connect a measuring jig, such as a jig, to the end of the channel part, but in this case there is the following order of connection. In other words, considering the above 1) and ++), it is desirable to provide a guard as close as possible to D U 'r, so when using a glover etc. As shown, an extension cable 120 with a guard extends the guard close to the internal DUT, such as a prober. Ideally, short-circuiting between the guards should be done at the tip of the extension cable, but due to the mechanism and operation of the prober, etc., it is necessary to keep the tip of the extension cable as light as possible. Also, due to the nature of this measuring device, the channel section can be provided as a standard configuration, but the prober and test fixture that can be attached to the end of the channel section can be of various shapes depending on the user's needs. It is thought that there are many cases. In this case, it is undesirable to burden the user with short-circuiting between the guards, and this may not be possible depending on the structure of the glover or test fixture.

It is an object of the present invention to solve the above-described problems and to improve measurement accuracy, resolution, and stability by performing appropriate guard-to-guard processing according to measurement items.

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 2 is a diagram showing the configuration of a measuring device according to a first embodiment in which the present invention is applied to the measuring device shown in FIG. 1, and elements common to those in FIG. 1 are given the same reference symbols. It is. In this embodiment, an inter-guard connection line 150 for connecting the guards, and an inter-guard connection line 150 provided corresponding to the channel portions CH, to CHk, respectively, are provided.
Switches 140 to 144 are provided in the channel box 80 to selectively connect the channels. Switches 140-144 (also switches 90-100 and switch matrix 50) are connected to the automatic measurement controller (
(not shown). Here, a case will be described in which the impedance of the DUTllo connected between the channel sections CH and CH2 is measured by the impedance measuring device 10. First, switch matrix 50
Connect the H line and L line from the impedance measuring device 10 to the force line F (of course, sense m S (Itll is also fine) of the measurement signal cable 60 and 64, respectively, and also connect the guards HG and LG to the corresponding guard G, respectively. Connecting.

Then, by closing the switches 90 and 94, the impedance measuring device 10 is connected to the channel sections CH, , CH2.

Further, by closing the guard switches 140 and 142, the guards of the measurement signal cables 60 and 64 are short-circuited via the guard connection line 150, and the return current I
Electromagnetic shielding is performed by flowing R through the guard. Also, leave the switches not mentioned above open. On the other hand, when performing DC minute signal measurement, the connection of the switch matrix 50 is changed and the switch 90 is
, 92, 94. Close 96. Also guard switch 1
40.142 is in the open state and the connection between the guards is cut off (.By adopting this configuration, it is possible to freely short and open the guards corresponding to any channel parts, so the measurement items Appropriate guard-to-guard short-circuit processing can be performed between the pressure channel portions according to the situation.

In this embodiment, only one path can be taken to short-circuit between the guards due to the configuration of the guard switches 140 to 144 and the guard connection line 150, but a plurality of independent paths may be provided. For this purpose, for example, multiple guard connection lines and guard switches may be provided, or instead of providing a common connection line such as the guard connection line 150 in FIG. 2, a guard switch may be provided for each pair of channel sections. Various modifications are possible, such as performing short-circuit processing between guards.

Now, as explained in relation to Fig. 1, a prober and a test fixture are further attached to the end of the channel section l) U
When measuring T, consideration must be given to the extension cable extending from the channel section. A second embodiment of the present invention in this case will be described below with reference to FIGS. 3 to 6.

FIG. 3 is a diagram showing the configuration of a measuring device according to an embodiment in which the present invention is applied to the measuring device shown in FIG. 1, in which a prober is connected to the channel portion of the measuring device via an extension cable. The same reference symbols are used for the elements. In the measuring device shown in FIG. 3, channel sections CH1 to CHk
and the glover 160 are connected by extension cables 116 to 120, respectively. Additionally, a UT 114 is placed within the prober 160. In order to keep the tips of the extension cables as light as possible, the guards at the tips of the extension cables 116 to 120 are connected to channel portions CH1 to CH4 by guard lead-out lines 170 to 174, respectively.
A guard connecting line 200 and guard switches 190 to 194 are provided there, and short-circuiting between the guards is performed in the same manner as in the first embodiment shown in FIG. Here, the guard lead lines 170 to 174 have distributed inductances L1 to L31, distributed resistance R,
to R3, the impedance that enters in series with the return current path formed by the guard may have an undesirable effect on the measurement. In that case, capacitors 180 to 184 having capacitances that resonate in series with the distributed inductances L1 to L3 at the impedance measurement frequency may be inserted in series into the guard drawers 170 to 174, respectively, as shown in FIG.

By the way, mutual inductance exists between the guard lead-out lines 170 to 174, and these mutual inductances vary greatly depending on the arrangement of the guard lead-out lines 170 to 174. Therefore, it is desirable to construct a transmission line transformer by twisting the guard lead-out wires oppositely, as shown in FIG. 4, which shows the processing of the guard lead-out wires. Fifth
The figure is an explanatory diagram of the effect of the above-mentioned twisting when measuring impedance, and FIG. 6 is a diagram showing an equivalent circuit from guard lead-out lines 170 to 172 (distributed resistance components are omitted). In FIGS. 5 and 6, MB2 is the mutual inductance between the guard lead wires 170 and 172 in the transmission line transformer configured by twisting. As shown in FIG. 5, the return current iR passes through the transmission line transformer in normal mode. Therefore, the inductances entering in series with the guard wires 170 and 172 are Ll-M, 2, and L2M, respectively, as shown in FIG.
+2, which is extremely small (in the ideal state, Ll==L
2 == MB2, and the series inductance becomes 0). Therefore, when the angular frequency of the high frequency for impedance measurement is ω, CIT for series resonance]2l/ω2(Lm
-M+2) (m=1.2) By twisting the guard lead wires together in this way, the inductance that enters the return current in series becomes extremely small and does not depend on the arrangement of the button and the guard lead wire. Furthermore, since an electromagnetic shielding effect is provided, K is less susceptible to disturbances. Furthermore, if the above-mentioned inductance is made sufficiently small by the twisting, the series resonance capacitors 180 and 182 are completely unnecessary.

Note that the present invention is of course not limited to a measuring device using a switch matrix as shown in FIG.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an example of a measuring device to which the present invention is applied;
FIG. 2 is a configuration diagram of a measuring device according to a first embodiment of the present invention, FIG. 3 is a configuration diagram of a measuring device according to a second embodiment of the present invention, and FIG.
The figure shows the processing of the guard lead-out line of the measuring device in Fig. 3, the figure 5 shows the effect of the guard lead-out line processing in Fig. 4, and the figure 6 shows the guard lead-out line in Fig. 5. It is an isometric circuit diagram of the part. 10 Ni impedance measuring device, 2o: DC minute signal measuring device, 30 to 40.60 to 7o: measurement signal cable,
11 (l to 114: DUT, 116 to 1
20: Extension cable, 140 to 1114.190 to 194: Guard switch, 150.200: Guard connection line, 170 to 174: Guard lead-out line, 180
to 184: capacitor, CH, to CHk: channel section, G, HG, LG: guard. Yokogawa Shoney V) Packard Corporation Agent Patent Attorney Hase Yotsugi O 4 Figure 75 Decoy on the 6th

Claims (1)

[Claims] (1) A plurality of channel sections connected to the device under test, a plurality of measurement signal cables connecting the channel sections to the measuring instrument, each having a guard, and a device under test between the guards. and selectively connecting switch means. (2. In the measuring device according to claim 1, an extension cable each having a guard is provided for connection from the channel portion to the device under test, and
(3) The measuring device according to claim 2, wherein the switch means is disposed near the channel t-comb, and a guard at the tip of each extension cable is electrically connected to the switch means, A measuring device characterized in that electrical connection between the guard at the tip end of each of the extension cables and the switch means is made through a container.