Semiconductor test apparatus with reduced power consumption and heat generation
First Claim
1. A semiconductor test apparatus that applies a variable voltage to a measured device to test the measured device, comprising:
- a constant voltage generating device for generating a plurality of variable voltages;
a plurality of voltage polarity control devices each for controlling the polarity of a respective one of said plurality of variable voltages generated by said constant voltage generating device;
a plurality of control elements each for applying a variable voltage whose polarity is controlled by the respective voltage polarity control device to said measured device;
a first control device that controls the application operation of the applied variable voltage by each of said control elements based on a fixed applied voltage that is applied to said measured device and a terminal voltage of said measured device fed back from said measured device; and
a second control device that controls the value of each of the variable voltages generated by said constant voltage generating devices and the polarity control controlled by each of said plurality of voltage polarity control devices based on the voltages applied to said measured device by said plurality of control elements and the terminal voltage of said measured device fed back from said measured device.
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Accused Products
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.
5 Citations
7 Claims
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1. A semiconductor test apparatus that applies a variable voltage to a measured device to test the measured device, comprising:
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a constant voltage generating device for generating a plurality of variable voltages;
a plurality of voltage polarity control devices each for controlling the polarity of a respective one of said plurality of variable voltages generated by said constant voltage generating device;
a plurality of control elements each for applying a variable voltage whose polarity is controlled by the respective voltage polarity control device to said measured device;
a first control device that controls the application operation of the applied variable voltage by each of said control elements based on a fixed applied voltage that is applied to said measured device and a terminal voltage of said measured device fed back from said measured device; and
a second control device that controls the value of each of the variable voltages generated by said constant voltage generating devices and the polarity control controlled by each of said plurality of voltage polarity control devices based on the voltages applied to said measured device by said plurality of control elements and the terminal voltage of said measured device fed back from said measured device. - View Dependent Claims (2, 3, 4, 5, 6, 7)
said plurality of control elements and said first control device are provided on a test head on which said measured device is mounted;
said constant voltage generating device, said plurality of voltage polarity control devices, and said second control device are provided on a control unit disposed separated from said test head; and
a digital signal is used in signal propagation between said test head and a control unit.
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4. A semiconductor test apparatus according to claim 1 wherein said constant voltage generating devices comprise:
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a first switching constant voltage generating device that generates an output voltage that is larger than the fixed 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 voltage that is applied to said measured device.
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5. A semiconductor test apparatus according to claim 1 wherein each said voltage polarity control device can reverse or not reverse the polarity of the respective variable voltage generated by said constant voltage generating device that it controls or short circuit the said respective variable voltage based on the control of said second control device.
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6. A semiconductor test apparatus according to claim 4 wherein said second control device:
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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 level equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control elements supplied with voltage by said first switching device to operate stably;
the minimum output voltage of said first switching constant voltage generating device is output in the case that a voltage of a level equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element supplied with voltage by said first switching device 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 of a level equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element supplied with voltage by said first switching device to operate stably;
the output of said second switching constant voltage generating device is shorted the associated voltage polarity control device in the case that a voltage of a level equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element supplied with voltage by said second switching device 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 of a level equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element supplied with voltage by said second switching device to operate stably is negative, and this voltage is smaller than the minimum output voltage of said second switching constant voltage generating device;
the values of the variable voltages controlled by said constant voltage generating device and the polarity control the respective controlled by each 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 of a level equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element supplied with voltage by said second switching device 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 a 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 of a level equivalent to said fixed applied voltage having subtracted therefrom the amount of voltage drop necessary for allowing the control element supplied with voltage by said second switching device 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 the associated 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 of a level equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element supplied with voltage by said first switching device to operate stably;
the output of said voltage polarity control device, located at the output side of said first switching constant voltage generating device, is shorted in the case that a voltage of a level equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element supplied with voltage by said first switching device to operate stably is negative and smaller than the value produced by multiplying the minimum output voltage of said 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 of a level equivalent to said fixed applied voltage having added thereto the amount of voltage drop necessary for allowing the control element supplied with voltage by said first switching device to operate stably is positive and smaller than the minimum output voltage of said first switching constant voltage generating device; and
the variable voltage values controlled by said constant voltage generating device and the polarity control controlled by said voltage polarity control devices 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 supplied with voltage by said first switching device to operate stably is positive and larger than the minimum output voltage of said first switching constant voltage generating device.
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7. A semiconductor test apparatus according to claim 1 wherein said control elements and said first control device form one group, and further comprising a plurality of said groups provided in parallel, and the plurality of applied variable voltages generated by each of said groups is applied to said measured device.
Specification