JPH047549Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a wiring structure in a matrix switch.

In the evaluation of processes in IC manufacturing, various electrical characteristics of a large number of passive elements and active elements on a wafer are measured by sequentially switching over many test terminals. In this case, preparing as many measuring instruments as the number of test terminals requires a great deal of expense, and the configuration of the measuring system also increases, making it difficult to put it to practical use. From this point on, use the matrix switch to
Electrical connection between the measuring instrument and the selected test terminal was achieved through the switch. Such matrix switches include crossbar switches used in communications and semiconductor switch elements used in electronic exchanges, but the former tends to be phased out gradually due to mechanical lifespan, and the latter Since the contact resistance of the switch element is high when it is on (when closed) and the insulation resistance when it is off (when it is open) is low, highly insulated reed relays were generally used.

However, when measuring minute capacitances and minute currents between terminals under test on a wafer, leakage resistance (same meaning as insulation resistance above) and stray capacitance (hereinafter referred to as insulation resistance) and stray capacitance (hereinafter referred to as insulation resistance) between contacts when the matrix switch element is turned off are (referred to as unnecessary components) causes leakage current. Furthermore, if the number of test terminals and measuring devices increases and the scale of the matrix switch increases, the result will be the same as if all of the unnecessary components mentioned above were inserted in parallel between the measuring device terminals, and the minute capacitance and minute current The error increases during measurement.

Therefore, the purpose of this invention is to solve the above matrix.
To provide a wiring structure that can sufficiently exhibit the original performance of a measuring device by reducing the influence of unnecessary components on a switch as much as possible. According to the present invention, a new transfer type switch is connected in series to the switch element connected to the intersection of the measuring instrument drive line and the test terminal drive line. For example, a leakage current generated on the test terminal drive line side is bypassed to the guard line of the drive line via the transfer type switch, and has no effect on the measuring device drive line side.

Next, a description will be given with reference to the drawings.

FIG. 1 is a connection diagram of a matrix switch for explaining the present invention, in which a plurality of switch elements are arranged in rows and columns. That is, the pair of switch elements K ₁₁ , K ₁₁ ′, K ₁₂ , K ₁₂ ′, K ₁₃ , K ₁₃ ′
In the second row, K ₂₁ , K ₂₁ ′, K ₂₂ , K ₂₂ ′, K ₂₃ ,
K ₂₃ ′ and in the third row K ₃₁ , K ₃₁ ′, K ₃₂ , K ₃₂ ′,
K ₃₃ and K ₃₃ ′ are arranged respectively. The switch elements K ₁₁ , K ₁₁ ′, K ₁₂ , K ₁₂ ′, K ₁₃ , K ₁₃ ′ in the first row are connected to the drive line 201 of the measuring instrument terminal 21, and the switch elements K ₂₁ , K ₂₁ ′ in the second row are connected to the drive line 201 of the measuring instrument terminal 21. , K ₂₂ , K ₂₂ ′, K ₂₃ , K ₂₃ ′ are connected to the drive line 202 of the measuring device terminal 22, and K ₃₁ ,
K ₃₁ ′, K ₃₂ , K ₃₂ ′, K ₃₃ , K ₃₃ ′ are voltage source terminals 23
are connected to drive lines 203, respectively. Similarly, the first row switch elements K ₁₁ , K ₁₁ ′, K ₂₁ ,
K ₂₁ ′, K ₃₁ , K ₃₁ ′ are the drive lines 101 of the test terminal 11
In the second column, K ₁₂ , K ₁₂ ′, K ₂₂ , K ₂₂ ′, K ₃₂ ,
K ₃₂ ′ is connected to the drive line 102 of the terminal under test 12, and K ₁₃ , K ₁₃ ′, K ₂₃ , K ₂₃ ′, K ₃₃ , K ₃₃ ′ in the third column is connected to the drive line 103 of the terminal under test 13. Connected. In addition, in the notation of switch elements connected to each intersection above, switch elements with a dart symbol ' are used as guard wire switch elements, and switch elements without a dart symbol are used as core wire switch elements. represent.

In this example, a voltage measuring device V is connected to the row driving line 201, a current measuring device A is connected to the row driving line 202, and a voltage source E is connected to the row driving line 203. When switch elements K ₁₃ , K ₁₃ ′, K ₂₁ , K ₂₁ ′, K ₃₂ , and K ₃₂ ′ are turned on and all other switch elements are turned off, the The output voltage E ₂₀₃ of the voltage source E is applied to the terminal Y to be measured, and the current flowing through the element Y is measured by the current measuring device A.
Furthermore, the voltage between the terminals of the element Y (which is equivalently represented by the potential E ₁₀₃ between the terminal under test 13 and the ground point) is measured by the voltage measuring device V. in this case,
Each drive line consists of a core wire a or b and a guard wire a' or b' as shown in _FIG .
K ₁₁ ′ is inserted between each of the guard lines a′ and b′ in the row and column, which are at the same potential as the core wire. Since each core wire a, b is covered with guard wires a', b' except for the connection part of the core wire switch element _K11 , noise induction from the outside and leakage current can occur except for the switch part. There is no need to consider. However, when the switch element is turned off, a leakage current flows from the core wire B to the side A due to the leakage resistance and stray capacitance generated between the contacts. As the matrix structure becomes larger and the number of switch elements in the OFF state increases, the leakage resistance and stray capacitance of each single switch element will be combined in parallel.

For example, 10 row drive lines are connected to measuring instruments, etc.
If a matrix is constructed with 60 column drive lines connected to the main and test terminals, the number of core wire switch elements inserted at each intersection (considering only the core wires) will be 600.

Therefore, assume that only two switch elements are turned on to activate two drive lines for each row and column, and all the other 598 switch elements are turned off. Now, if the stray capacitance between the contacts of a single switch element when it is off is 1 PF, and its insulation resistance is 1×10 ¹² Ω, the stray capacitance between the activated row drive lines increases to about 35 PF. Also, its insulation resistance value is approximately
The leakage current is significantly reduced to 1.4×10 ¹⁰ Ω, and therefore, if a voltage of 100 V is applied between the row drive lines, a leakage current of about 7×10 ⁻⁹ A will flow between the lines.

The present invention was devised to eliminate the above-mentioned drawbacks, and all the leakage current that occurs when the switch element is turned off is bypassed to the guard wire. value is
2PF, and the leakage current can be reduced to almost 1/35 respectively. That is, as shown in FIG. 3A, a transfer type switch element _K10 is added in series with a switch element, for example _K11 , connected to the intersection of the core line a of the row drive line and the column drive line b, and The lead of K10 is arranged in such a structure that when the switch element _K11 for guard line and the switch element _K11 ' for guard line are off, the lead of _K10 is connected to guard line a'. According to the matrix switch with such a configuration, the stray capacitance becomes zero, and the leakage current i from the column drive line b side via the core wire switch element _K11 is transferred to the core wire switch element _K11 and the transfer type switch K. Even if the flow flows into the conductor between _K10 (the part shown by the thick line between these switch elements in FIG. 3A) as shown _by the arrow, all of the guard wire a is ’, so
This effect does not appear on the row drive line a side at all.

In addition, FIG. 3B shows a switch element K ₁₀ ' of the same type added in series in addition to the transfer type switch element K _10. In this case, the leakage current due to the switch element K ₁₁ when turned off is It does not affect either row or column drive lines. That is, in FIG. 3B, in addition to providing a row side transfer type switch element K ₁₀ between the pair of core wire element K ₁₁ and guard wire switch element K ₁₁ ′ and the row drive lines a, a′. Here, a column-side transfer type switch element K ₁₀ ' is further provided between the pair of K ₁₁ and K ₁₁ ' and the column drive lines b, b'. This results in
When the pair of switch elements K ₁₁ and K ₁₁ ′ is open, that is, turned off, the row conductor and core wire between the core switch switch K ₁₁ and the row transfer type switch element K ₁₀ As can be seen from FIG. 3B, the column side conductors between the transfer type switch element K ₁₁ and the column side transfer type switch element K ₁₀ ′ are connected to the guard line a′ on the row side and the guard line b′ on the column side, respectively. connected to become part of the With such a connection, the tip of the core wire a on the row side and the tip of the core wire b on the column side are
guarded by a row-side conductor and a column-side conductor, respectively;
Even if a leakage current flows from the opposite drive line through the core wire switch element _K11 , it is diverted to the respective guard wires a' and b' by these conductors.

Therefore, the present invention exhibits remarkable effects when using a matrix switch to measure the electrical characteristics of a selected element from a large number of test terminals, particularly minute currents and minute capacitances.

[Brief explanation of the drawing]

Fig. 1 is a connection diagram of a matrix switch for explaining the present invention, Fig. 2 is a schematic illustration of a switch element inserted at the intersection of row and column drive lines, and Figs. 3A and B are 1 is a partial connection structure diagram of a matrix switch according to an embodiment of the present invention; FIG. 201, 202, 203...Row drive line, 10
1, 102, 103... Column drive line, E... Voltage source, A... Current measuring device, V... Voltage measuring device, Y...
... Test element, K ₁₁ , K ₁₁ ′ ... K ₃₃ , K ₃₃ ′ ... Switch element, K ₁₀ , K ₁₀ ′ ... Transfer type switch element, a, b ... Core wire, a', b' ...Guard line.

Claims (1)

[Claims for Utility Model Registration] Each of the plurality of row drive lines and column drive lines consists of a core wire covered with a guard wire, and is connected to the intersection of each of the row and column drive lines so that the core wires of the drive lines are connected to each other. In a matrix switch equipped with a switch for connecting and connecting guard wires to each other, each of the switches connected to the intersection has a row conductor and a column conductor between the row drive line and the column drive line to be connected. The row side conductor is connected to the core wire of the row drive line when the connection between the row drive line and the column drive line is on, and when the connection between the column drive line and the row drive line is off. a row side transfer type switch element connected to a guard line of the row drive line; a core wire switch element that connects the row side conductor and the column side conductor when the line is on and disconnects it when the line is off; and the line drive line. a guard wire switch element that connects the line and the guard wires of the column drive line when on and disconnects them when off, and connects the column side conductor to the core wire of the column drive line when on; By having a column side transfer type switch element connected to the guard line of the column drive line when off, the core wires of the row drive line and the column drive line are connected to the row side conductor and the column side conductor when on. and connect the row drive line and the guard line of the column drive line, and in the off state, the row side conductor is a part of the guard line of the row drive line, and the column side conductor is connected to the column drive line. A matrix switch characterized in that it is a part of a guard line of a column drive line.