Semiconductor test apparatus

• US 20020043987A1
• Filed: 07/23/2001
• Published: 04/18/2002
• Est. Priority Date: 07/26/2000
• Status: Active Grant

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Ando Electric Co., Ltd. (Yokogawa Electric Corporation)
• Inventors: Takeuchi, Nobuaki
• Granted Patent: US 6,614,252 B2
• Time in Patent Office: Days
• US Class Current: 324/765
• CPC Class Codes: G01R 31/2822 of microwave or radiofrequency circuits of attenuation, gain, e.g. using network analyzers G01R27/28
• CPC Class Codes: G01R 31/2851 Testing of integrated circuits [IC] G01R31/317 takes precedence; testing individual devices G01R31/26; testing printed circuits G01R31/2801
• CPC Class Codes: G01R 31/31721 Power aspects, e.g. power supplies for test circuits, power saving during test for scan test G01R31/318575

Abstract

The present invention allows reducing the power consumption, reducing the amount of heat generation, improving the frequency characteristics, and reducing noise superposition. A control circuit 25 supplies to a control circuit 5 a control signal CS 1 that indicates the setting voltage of a DUT 9 as a control signal CS 8. In addition, the control circuit 25 controls switching power sources 21 and 22 and the polarity control circuits 23 and 24 depending on control signals CS 4 to CS 7 such that the voltage drop amount of the control elements 6 and 7 becomes a value sufficient to operate the control elements 6 and 7 based on a control signal CS 1 and a detected signal DS2 that is fed back from the DUT 9. The control circuit 5 controls the control elements 6 and 7 depending on the control signal CS 8. The control elements 6 and 7 generate a voltage that is to be output to the DUT 9 from the output voltage generated by the switching power sources 21 and 22 and whose polarity is controlled by the polarity control circuits 23 and 24.

Claims

1. A semiconductor test apparatus that applies a variable voltage to a measured device to test the measured device, providing:

constant voltage generating devices that generate a plurality of variable voltages;

voltage polarity control devices that control the polarity of the plurality of variable voltages generated by said constant voltage generating device;

control elements that generate an applied variable voltage applied to said measured device from the plurality of variable voltages whose parity is controlled by said voltage polarity control devices;

a first control device that controls the generation operation of the applied variable voltage in said control elements based on the fixed applied voltage that is applied to said measured device and the terminal voltage of said measured device fed back from said measured device; and

a second control device that controls the variable voltage value controlled by said constant voltage generating device and the polarity control controlled by said voltage polarity control device based on the fixed applied voltage that is applied to said measured device and the terminal voltage of said measured device fed back from said measured device.

2. A semiconductor test apparatus according to claim 1 wherein said second control device links the voltage drop amount of said control element to the fixed applied voltage that is applied to said measured device so that the value thereof becomes sufficient for the operation of the control elements, and controls the variable voltage value controlled by said constant voltage generating device and the polarity control controlled by said voltage polarity control device.

3. A semiconductor test apparatus according to claim 1 wherein:

said control elements and said first control device are provided on the test head on which said measured device is mounted;

said constant voltage generating device, said voltage polarity control device, and said second control device are provided on the control unit disposed separated from said test head; and

a digital signal is used in signal propagation between said test head and said control unit.

6. A semiconductor test apparatus according to claim 2 wherein said second control device:

A;

in the case that the fixed applied voltage that is applied to said measured device is positive,

the voltage output of said first switching constant voltage generating device is output as is in the case that the output voltage of the first switching constant voltage generating device can be set to a voltage equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element to operate stably;

the minimum output voltage of said first switching constant voltage generating device is output in the case that a voltage equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element to operate stably is lower than the minimum output voltage of said first switching constant voltage generating device;

the output voltage of said second switching voltage generating device is output as is in the case that the output voltage of said second switching constant voltage generating device can be set to a voltage equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element to operate stably;

the output of said second switching constant voltage generating device is shorted by said voltage polarity control device in the case that a voltage equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element to operate stably is positive, and this voltage is smaller than the minimum output voltage of said second switching constant voltage generating device;

the minimum output voltage of said second switching constant voltage generating device is output and the output of said voltage polarity control device located at the output side of said second switching constant voltage generating device is reversed in the case that a voltage equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element to operate stably is negative, and this voltage is smaller than the minimum output voltage of said second switching constant voltage generating device;

the variable voltage value controlled by said constant voltage generating device and the polarity control controlled by said voltage polarity control device are controlled such that the absolute value of the output voltage from said second switching constant voltage generating device is output and the output of said voltage polarity control device that is located at the output side of said second switching constant voltage generating device is reversed in the case that a voltage equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element to operate stably is negative and larger than the minimum output voltage of said second switching voltage generating device; and

B;

in the case that the target voltage applied to said measured device is negative;

the output voltage of the second switching constant voltage generating device is output and the output of said voltage polarity control device, which is located at the output side of said second switching constant voltage generating device, is reversed in the case that the output voltage of said second switching constant voltage generating device can be set to the absolute value of a voltage equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element to operate stably;

the minimum output voltage of said second switching constant voltage generating device is output and the output of said voltage polarity control device, which is located at the output side of said second switching constant voltage generating device is reversed in the case that the absolute value of the a voltage equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element to operate stably is lower than the minimum output voltage of said second switching constant voltage generating device;

the output voltage of said first switching constant voltage generating device is output and the output of said voltage polarity control device, which is located at the output side of said second switching constant voltage generating device, is reversed in the case that the output voltage of said first switching constant voltage generating device can be set to the absolute value of a voltage equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element to operate stably;

the output of said voltage polarity control device, which is located at the output side of said first switching constant voltage generating device, is shorted in the case that a voltage equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element to operate stably is negative and smaller than the value produced by multiplying the minimum output voltage of said first switching constant voltage generating device by −

1;

the minimum output voltage of said first switching constant voltage generating device is output in the case that a voltage equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element to operate stably is positive and smaller than the minimum output voltage of said first switching constant voltage generating device; and

the variable voltage value controlled by said constant voltage generating device and the polarity control controlled by said voltage polarity control device are controlled such that the output voltage of said first switching constant voltage generating device is output as is in the case that a voltage equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element to operate stably is positive and larger than the minimum output voltage of said first switching constant voltage generating device.

7. A semiconductor test apparatus according to claim 1 wherein said control elements and said first control device form one group, said groups are provided in plurality in parallel, and the plurality of applied variable voltages generated by each of the groups is applied to said measured device.

4. A semiconductor test apparatus according to claim I wherein said constant voltage generating device provides:

a first switching constant voltage generating device that generates an output voltage that is larger than the fixed applied voltage that is applied to said measured device; and

a second switching constant voltage generating device that generates an output voltage that is smaller than the fixed applied voltage that is applied to said measured device.

5. A semiconductor test apparatus according to claim I wherein said voltage polarity control device can reverse or not reverse the polarity of the plurality of variable voltages generated by said constant voltage generating device or short said plurality of variable voltages based on the control of said second control device.