JPS61241673A - Ic testing device - Google Patents

Abstract

PURPOSE:To make light IC test possible besides ordinary IC without submodule by providing an electricity-light converter, a light-electricity converter and a change-over switch of an IC to be tested and a light IC to be tested. CONSTITUTION:Information such as a specified pattern and timing etc. is input ted from a waveform controlling section 5 to a test head section 80 through the input terminal of a light IC to be tested 70 designated by a test program. Mode changing switches 87, 80' are switched to light mode side. An electric signal from a driver 10 is converted to laser light by an electricity-light con verter 81 and supplied to a specified input terminal of the IC 70 through a light guide 83, a switch 85 etc. as a light signal having pattern of '1' and '0' and timing. Output light of the IC 70 is transmitted to a light-electricity con verter 82 through a light guide 86, a switch 85 and a light guide 84 and referred to an expected value by a CPU through comparators 11a, 11b and a controlling section 5 as an electric signal, and test is performed. In the case where the object of test is an ordinary IC 7, test is performed switching to electric mode side by switches 87, 80'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC testing device that is also capable of testing optical ICs whose input and output are performed using optical signals.

[Conventional technology]

Fig. 2 is a block diagram showing a conventional IC test equipment, in which 1 is a central processing unit, 2 is a timing generator, 3 is a pattern generator, 4 is a fail memory, 5 is a waveform control unit, and 6 is a DC parameter measurement unit. 7, the IC under test 58 is a test head section, 9 is a data bus, 1o is a driver, 11 is a comparator, and 200 is the entire IC testing apparatus.

The operation of this IC testing device will be explained below.

A test program for testing the IC 7 under test is created externally and is transferred to the central processing unit 1 via magnetic tape or the like.
is memorized. The test program stored in the central processing unit 1 is sent out from the data bus 9 according to the program steps, and is sent to the timing generator 2. After being converted into a required waveform by the pattern generator 3, it is sent to the test head section 8, and the driver 10 converts it into a required voltage or current value and applies it to a predetermined terminal (pin) of the IC under test 7. The output from the IC7 under test is
The "H" level and "L" level are taken in through the comparator 11, and the fail memory 4 is taken in through the waveform control section 5.
is stored in the Go
/No GO is determined, and the test of the IC 7 to be tested is executed. In addition to the function test, DC parameters such as current and voltage can also be measured by accessing the DC parameter measuring section 6 via the switch matrix.

FIG. 3 is a block diagram showing details of the test head section 8 of the above-mentioned IC testing apparatus 200, with the DC parameter measuring section 6 omitted for clarity. In FIG. 3, the same symbols as in FIG. 2 indicate the same parts, 11a, 11
b is a comparator.

12 is a voltage bus, 13.14 is a level setter, 15.1
6 is a reference voltage generator for the comparators 11a and 11b, 17 is an input/output changeover switch, and 18 and 19 are switches.

In the test head section 8 shown in FIG.

The input waveform supplied from the waveform control section 5 is applied to the driver 10, the voltage value is determined by the level setter 13.14 connected to the voltage bus 12, and the input/output changeover switch 17. The voltage is applied to a predetermined pin of the IC under test 7 via the switch 18 .

Further, the output from the IC under test 7 is input to the waveform control unit 5 via a switch 19 and comparators 11a and 11b whose other inputs are determined by a reference voltage generator 15 and 16.

As described above, the conventional IC test apparatus 200
A test head section 8 is configured to correspond to each of the 7 pins, and interfaces with the IC under test 7 through an electrical signal system.

However, in recent years, optical ICs in which input or output is an optical signal, or both input and output are optical signals, have come into practical use.

Figure 4 shows the configuration of an optical IC that uses optical signals for both input and output. 7o indicates the entire optical IC under test, and 71 indicates an optical signal.
An electric conversion element, 72 is an arithmetic function circuit, 73 is an output amplification circuit, 74 is an electric-optical conversion element, 75.76 is an optical waveguide,
77 is a light input, and 78 is a light output.

In this optical IC 70 to be tested, the pre-input cuff 7 transmitted from the optical waveguide 75 is converted into electricity by an optical-to-electrical conversion element 71 such as a photodiode, and is transmitted to the arithmetic function circuit 72 . Here, calculations such as waveform shaping and amplification are executed, and after being amplified in an output amplification circuit 73, an electric-to-optical conversion element 74 consisting of a photodiode or a laser diode is used.
The signal is output from the first cuff 8 and transmitted by the optical waveguide 76.

In addition, FIG. 5 shows the general optical IC 70 to be tested as described above.
The same reference numerals as in FIG. 4 indicate the same parts, and 79 is a bonding pad for electrical connection such as power supply.

In order to test such an optical IC 70 under test using the conventional IC test equipment 200, a submodule is added to the probe portion that contacts the optical IC 70 under test.
It carried out optical conversion and photo-electrical conversion.

[Problem that the invention seeks to solve]

In the conventional IC test apparatus 2oO as described above, in order to test the optical IC 70 under test, a submodule is provided in the probe portion that contacts the optical IC 70 under test, and the electrical
Since optical conversion and optical-to-electrical conversion must be performed externally, the pin electronics function to correspond to any terminal of the light weight C70 under test cannot be used.
There was a problem in that the test speed was slowed down by the additional capacity of the external module.

This invention was made in order to solve this problem.
The purpose of the present invention is to obtain an IC testing device capable of performing the following tests.

[Means for solving problems]

The IC testing device according to the present invention includes a mode changeover switch for switching tests between an electric-to-optical converter, an optical-to-electrical converter, an IC under test, and an optical IC under test, inside the IC test device. We have established the following.

[Effect]

In this invention, for example, when testing an optical IC under test, the mode selector switch is changed, an electrical signal is applied as an optical signal to the optical IC under test using an electrical-to-optical converter, and the optical IC under test outputs the signal. An optical-to-electrical converter converts the optical signal into an electrical signal.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of a test head section 80 which is a main part of an IC testing apparatus 100 of the present invention. The same reference numerals as in FIG.
Optical converter, 82 is an optical-to-electrical converter, 83 is an output optical waveguide, 84 is an input optical waveguide, 85 is an input/output switch, 86 is an input/output optical waveguide, 87.88 is a mode switch. Shows a switch.

The operation will be explained below.

Optical IC70 under test specified by test program
Information such as a required pattern, timing, etc. is input from the waveform control section 5 to the test head section 80 in response to the input terminal. Here, in the case of Fig. 3, the test object is a normal IC7 to be tested, but in Fig. 1, the test object is an optical IC7 to be tested.
0, the input/output is switched to the optical mode side by the mode changeover switches 87 and 88. Therefore, the electrical signal output from the driver 10 is transmitted to the electrical-optical converter 8.
1, it is converted into laser light etc., and “l 11 , 1
It becomes an optical signal having a pattern and timing of 1 Q II, and is sent to an optical waveguide 83 for output and an input/output switch 85.
, are supplied to a predetermined input terminal of the optical IC under test 70 via an input/output optical waveguide 86.

This input/output changeover switch 85 is a changeover switch that allows one optical waveguide to handle both input and output, and uses a GaAs optical switch, etc., and increases the S/N ratio as necessary. Microlenses etc. are used for this purpose.

On the other hand, the output light from the optical IC under test 70 is transmitted to the optical-to-electrical converter 82 via an input/output optical waveguide 86, an input/output switch 85, and an input optical waveguide 84, and is converted into an electrical signal. The signal is then input to the comparators 11a and Ilb, and further input to the fail memory 4 shown in FIG. 2 via the waveform control section 5. Then, Go/NOGo is determined by referring to the expected value of the test program.

Further, when the test object is the IC 7 to be tested, the test is performed by switching the input/output to the electric mode side using the mode changeover switches 87 and 88.

Note that since the number of input/output terminals of the optical IC 70 under test is generally not as large as that of the normal IC 7 under test, only a part of the test head section 8 of the conventional IC test apparatus 200 is used as the test head section 80 of the present invention. It is also possible to reduce costs by adopting this configuration.

Further, in the above embodiment, the test of the optical IC 7Q under test where both input and output are optical signals has been described, but when testing an optical IC where only one of the input and output is an optical signal, mode changeover switch 87.88 The test may be performed by appropriately controlling the switching of.

〔Effect of the invention〕

As explained above, this invention includes an electric-to-optical converter, an optical-to-electrical converter, and a mode changeover switch inside the IC testing device, so that it can be used not only for normal IC testing but also for normal IC testing.
Optical ICs also have the advantage of being able to be tested very easily and with high reliability, just by operating a mode changeover switch, no different from conventional testing methods.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the test head section which is the main part of the IC testing device of the present invention, FIG. 2 is a block diagram showing a conventional IC testing device, and FIG. 3 is a conventional IC testing device. Block diagram showing details of the test head section of
The figure is a block diagram showing the functional configuration of an optical IC, and FIG. 5 is an external perspective view of a general optical IC. In the figure, 1 is a central processing unit, 2 is a timing generator,
3 is a pattern generator, 4 is a fail memory, 5 is a waveform control section, 6 is a DC parameter measurement section, 7 is an IC under test 19
is a data bus, 10 is a driver, 11a, 11b are comparators, 12 is a voltage bus, 13.14 is a level setter, 15° 16 is a reference voltage generator, 17 is an input/output changeover switch, 18.19 is a switch, 7o is the optical IC18 under test.
0 is a test head section, 81 is an electrical-optical converter, 82 is an optical-electrical converter, 83 is an optical waveguide for output, 84 is an optical waveguide for input, 85 is an input/output switch, and 86 is for input/output. optical waveguide, 87° 88 is a mode selection switch, 10
0 is an IC test device.

Claims (1)

[Claims] A required electrical signal is applied to a predetermined pin of the IC under test via the test head, and an electrical signal output from the IC under test is input to the central processing unit via the test head. An IC testing device that performs a test by comparing the electrical signal with a pattern obtained by the test includes an electrical-to-optical converter that applies the electrical signal as an optical signal to the optical IC under test, and an electrical signal that converts the optical signal output from the optical IC under test into an electrical signal. an optical-to-electrical converter for inputting data to the central processing unit; and a mode changeover switch for switching between the IC under test and the optical IC under test.
C test equipment.