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Timing calibration apparatus and method in a semiconductor integrated circuit tester

Imported: 23 Feb '17 | Published: 22 Oct '02

Toshiyuki Okayasu

USPTO - Utility Patents

Abstract

There are provided a timing calibration apparatus and a timing calibration method capable of carrying out the calibration of timing on an IC tester with high accuracy. There is provided a probe to be sequentially contacted with pins of an IC socket on which an IC under test is to be mounted, and a calibration pulse supplied to the IC socket from the IC tester is taken in the probe. The calibration pulse is compared with the reference timing, thereby to calibrate the timing on a driver included signal path. In the probe a calibration pulse is generated, which is sequentially supplied to the pins of the IC socket, thereby to calibrate the timing on a comparator included signal path in each of channels. There are provided in the probe an optical modulator for converting an electric signal into an optical signal and an optically driven type driver. An optical cable couples between a calibration controller provided in the IC tester and the probe.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing, in outline, the construction of a first embodiment of the timing calibration apparatus according to the present invention;

FIG. 2 is a block diagram showing a specific example of the calibration controller and the probe shown in FIG. 1;

FIG. 3 is a plan view showing an example of the structure of the photoconductive element shown in FIG. 2;

FIG. 4 shows a waveform illustrating an output waveform from the optically driven type driver shown in FIG. 2;

FIG. 5 is a plan view showing a specific example of the optical modulator shown in FIG. 2;

FIGS. 6A-6B shows waveforms for explaining the operation of the optical modulator shown in FIG. 5;

FIG. 7 is a block diagram showing, in outline, the construction of a second embodiment of the timing calibration apparatus according to the present invention;

FIG. 8 is a block diagram showing, in outline, the construction of on example of the known IC testers;

FIG. 9 is a block diagram for explaining the principle constructions and the operations of the timing generator and the waveform formatter used in the IC tester shown in FIG. 8;

FIGS. 10A-10E are timing charts for explaining the operations of the timing generator and the waveform formatter shown in FIG. 9;

FIGS. 11A-11E are timing charts for explaining an example of the timing measuring function that the IC tester shown in FIG. 8 is provided with; and

FIGS. 12A-12E are timing charts for explaining another example of the timing measuring function that the IC tester shown in FIG. 8 is provided with.

Claims

1. A timing calibration apparatus in an IC tester, said IC tester comprising:

2. A timing calibration apparatus in an IC tester, said IC tester comprising:

3. A timing calibration apparatus in an IC tester, said IC tester comprising:

4. The timing calibration apparatus as set forth in claim 1 or 3, wherein said optically driven type driver comprises: a plurality of photoconductive elements, each coming to electrically conductive state by applying light thereon; and a plurality of voltage supplies selected by said plurality of the photoconductive elements respectively, and for generating voltages corresponding to a logical signal.

5. The timing calibration apparatus as set forth in claim 2 or 3, wherein said optical modulator has such a structure that an electric field formed by the voltage of the calibration pulse is applied to either one of branched two optical waveguides, the direction of said electric field being orthogonal to the travelling direction of light, and said optical modulator is one of the type which modulates light by utilizing a delay of light caused by application of the electric field to light and varying the quantity of light of an interference light obtained by that the branched two lights have been unified.

6. The timing calibration apparatus as set forth in claim 1 or 3, wherein said optically driven type driver is coupled to said optical drive signal supply means by an optical cable.

7. The timing calibration apparatus as set forth in claim 2 or 3, wherein said optical modulator is coupled to said photoelectric converter by an optical cable.

8. A timing calibration method in an IC tester, said IC tester comprising:

9. A timing calibration method in an IC tester, said IC tester comprising: