JPH06102312A - Burn-in method and device - Google Patents

Abstract

PURPOSE:To increase the test efficiency of a burn-in device for conducting operation test under high temperature condition for removing an integrated circuit which causes initialization failure by controlling the power consumption of a device to be tested to a desired constant value to make a burn-in test with high accuracy, supplying devices with high reliability and testing the devices different in types simultaneously. CONSTITUTION:The frequency of pulse supplied from a pulse supply means 21 to a device 6 to be tested is controlled by a pulse supply control means 15 in such a manner that a power supply current Icc flowing into the device 6 to be tested becomes a desired fixed value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burn-in method and apparatus used in a burn-in test performed under high temperature conditions in order to remove an integrated circuit causing an initial failure.

In recent years, integrated circuits have been used in all fields and are required to have high reliability. Therefore, it is necessary to improve the accuracy of the burn-in test for excluding the device that causes the initial failure.

[0003]

2. Description of the Related Art Generally, a burn-in device is a thermostatic chamber, D
A C power supply unit, a power supply circuit for the device under test, a pulse generator for operating the device under test, a driver circuit and the like are provided.

Here, the burn-in test needs to be carried out by defining the junction temperature Tj of the device under test to a constant value. The junction temperature Tj of the device under test is Ta, which is the temperature in the thermostatic chamber. If the thermal resistance of the device under test is Rth and the power consumption of the device under test (power supply voltage x power supply current) is Pc, the temperature T in the constant temperature bath is
a, the thermal resistance Rth of the device under test, and the power consumption Pc of the device under test have a relationship as shown in Equation 1.

[0005]

[Equation 1]

Therefore, in order to maintain the junction temperature Tj of the device under test at a constant value, it is necessary to control the temperature Ta in the constant temperature bath and the power consumption Pc of the device under test to be a constant value.

[0007]

Here, in the conventional burn-in apparatus, the temperature Ta in the constant temperature bath has been controlled to a constant value, but the frequency of the clock for operating the device under test. Was fixed.

Therefore, for example, CMOS or BiCMO
In the device having the S structure, the power supply current does not have a constant value due to variations in type and device characteristics, the power consumption Pc of the device under test varies, and the junction temperature Tj of the device under test is held at a constant value. However, there is a problem in that the burn-in test cannot be performed with high accuracy.

In view of the above points, the present invention makes it possible to supply a highly reliable device by controlling the power consumption Pc of the device under test to a desired constant value and performing a highly accurate burn-in test. At the same time, it is an object of the present invention to provide a burn-in method and an apparatus capable of simultaneously testing devices under test having different model numbers so as to improve the efficiency of the test.

[0010]

The burn-in method of the present invention detects a power supply current flowing into a device under test when a pulse is supplied to the device under test, so that the power supply current has a desired constant value. The frequency of the pulse is controlled.

Further, the burn-in apparatus of the present invention, as shown in the principle diagram of FIG. 1, generates a pulse supply control means 1 and a pulse having a frequency controlled by the pulse supply control means 1, and receives this pulse. A pulse supply means 3 for supplying to the test device 2, a power supply voltage supply means 4 for supplying a power supply voltage Vcc to the device under test 2, and a power supply for detecting a power supply current Icc flowing from the power supply voltage supply means 4 into the device under test 2. And a current detection means 5.

Here, the pulse supply control means 1 controls the pulse supply means 3 so as to supply a pulse having a frequency such that the power supply current Icc detected by the power supply current detection means 5 becomes a desired constant value. Is composed of.

[0013]

According to the burn-in method of the present invention, when the pulse is supplied to the device under test, the power supply current flowing into the device under test is detected, and the frequency of the pulse is adjusted so that the power supply current becomes a desired constant value. Are supposed to control.

As a result, the power consumption of the device under test can be controlled to a desired constant value in the constant temperature bath.
The junction temperature of the device under test can be set to a desired constant value. Therefore, it is possible to perform a highly accurate test and supply a highly reliable device.

According to the burn-in device of the present invention,
The frequency of the pulse supplied from the pulse supply means 3 to the device under test 2 is controlled by the pulse supply control means 1 so that the power supply current Icc flowing into the device under test 2 becomes a desired constant value.

As a result, the power consumption Pc of the device under test 2 can be controlled to a desired constant value in the constant temperature bath, and the junction temperature Tj of the device under test 2 can be set to a desired constant value. Therefore, it is possible to perform a highly accurate test and supply a highly reliable device.

According to the burn-in system of the present invention,
By preparing the circuit shown in FIG. 1 for each device under test having a different type, the junction temperature Tj of each device under test having a different type can be controlled to a desired constant value. Therefore, even devices under test having different types can be tested at the same time, and the efficiency of the test can be improved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first to third embodiments of the burn-in system of the present invention will be described below with reference to FIGS.

First Embodiment FIG. 2 FIG. 2 is a view showing the essential parts of the first embodiment of the present invention. In the figure, 6 is a device under test, 7 is a terminal for power supply voltage Vcc, 8 is a terminal for grounding, and 9 is a terminal for signal input.

Numeral 10 is a power supply voltage source forming a power supply voltage supply means for supplying a power supply voltage Vcc to the device under test 6.
Reference numeral 1 is an electrolytic capacitor for smoothing the power supply voltage Vcc to remove noise.

Further, 12 is a power supply current detecting means for detecting the power supply current Icc as a voltage magnitude, 13 is a resistor for detecting the power supply current, and 14 is an amplifier for amplifying a voltage difference between both ends of the resistor 13. .

Numeral 15 is a pulse supply control means,
Reference numeral 16 is a comparator, 17 is a reference voltage source for outputting a reference voltage Vref for determining the power supply current Icc, and 18 is an integrating circuit forming a low-pass filter. In addition, 19 is a resistor and 20 is a capacitor.

Here, the pulse supply control means 15 is
A pulse supply means described later so that the output voltage of the amplifier 14 supplied to the comparator 16 and the reference voltage Vref match, that is, output a pulse of a frequency such that the power supply current Icc becomes a desired constant value. It controls the voltage controlled oscillator.

Reference numeral 21 is a pulse supply means for generating a pulse for operating the device under test 6 and supplying the pulse to the device under test 6, and 22 is a voltage controlled oscillator (VCO) which is a variable frequency oscillator. , 23 are driver circuits for supplying the pulse output from the voltage controlled oscillator 22 to the device under test 6.

In the first embodiment, the power supply voltage Vcc is supplied from the power supply voltage source 10 to the device under test 6. In this case, the device under test 6 is placed between both ends of the resistor 13.
A voltage difference corresponding to the magnitude of the power supply current Icc flowing into

This voltage difference is amplified by the amplifier 14 and compared with the reference voltage Vref by the comparator 16,
A voltage corresponding to the difference voltage is output and supplied to the voltage controlled oscillator 22 via the integrating circuit 18.

Here, the voltage control oscillator 22 is controlled by the pulse supply control means 15 as described above.
Since the power supply current Icc determined by ref is controlled so as to output a pulse having a frequency such that it has a desired constant value, the power consumption Pc of the device under test 6 is controlled to a desired constant value in the constant temperature bath. can do.

Therefore, according to the first embodiment, the junction temperature Tj of the device under test 6 can be controlled to a desired constant value, a highly accurate burn-in test can be performed, and a highly reliable device can be supplied. .

Further, according to the first embodiment, by preparing the circuit shown in FIG. 2 for each device under test having a different type, a desired junction temperature Tj can be obtained for each device under test having a different type. Since it can be controlled to a constant value, devices under test having different model numbers can be tested at the same time, and the efficiency of the test can be improved.

Second Embodiment FIG. 3 FIG. 3 is a view showing the essential parts of the second embodiment of the present invention. In the figure, 24 is a device under test, and 25 is a power supply voltage Vcc.
Terminals, 26 is a ground terminal, and 27 and 28 are signal input terminals.

Further, 29 is a power supply voltage supply means for supplying a power supply voltage Vcc to the device under test 24, 30 is a power supply voltage source, and 31 is an operational amplifier which constitutes a constant voltage circuit. Reference numeral 32 is an electrolytic capacitor for smoothing the power supply voltage Vcc to remove noise.

Further, 33 is a power supply current detecting means for detecting the power supply current Icc as the magnitude of voltage, 34 is a resistor for detecting the power supply current, and 35 is a digital value A of the voltage difference between both ends of the resistor 34. / D converter.

Reference numeral 36 is a digital signal of the pulse supply means described later so that the digital value output from the A / D converter 35 has a desired constant value, that is, the power supply current Icc has a desired constant value. It is a microcomputer that controls the control oscillator.

Further, 37 generates a pulse for operating the device under test 24 and outputs this pulse to the device under test 2
4 is a pulse supply means, 38 is a digital control oscillator which is a variable frequency oscillator, 39 is a pattern generator which outputs a pulse group of a predetermined pattern based on the output of the digital control oscillator 38, 4
Reference numerals 0 and 41 are driver circuits for supplying the pulse output from the pattern generator 39 to the device under test 24.

In the second embodiment, the power supply voltage Vcc is supplied from the power supply voltage supply means 29 to the device under test 24. In this case, a voltage difference corresponding to the magnitude of the power supply current Icc flowing into the device under test 24 occurs between both ends of the resistor 34. This voltage difference is generated by the A / D converter 3
5, digitized into a microcomputer 3
6 is supplied.

Here, the microcomputer 36 is
Since the digital control oscillator 38 is controlled so that the digital value output from the / D converter 35 has a desired constant value, that is, the power supply current Icc has a desired constant value, the device under test is kept in the thermostatic chamber. The power consumption Pc of 24 can be controlled to a desired constant value.

Therefore, according to this second embodiment as well,
It is possible to control the junction temperature Tj of the device under test 24 to a desired constant value, perform a highly accurate burn-in test, and supply a highly reliable device.

According to the second embodiment, by preparing the circuit shown in FIG. 3 for each device under test having a different type, the junction temperature of the device under test having a different type can be set to a desired constant value. Since the values can be controlled, the devices under test having different types can be tested at the same time, and the efficiency of the test can be improved.

Third Embodiment ... FIG. 4 and FIG. 5 FIG. 4 is a view showing the essential parts of a third embodiment of the present invention. The third embodiment is an improvement of the first embodiment shown in FIG. 2, and is provided with a timer circuit 42 and an AND circuit 43, and is otherwise configured similarly to the first embodiment.

In the third embodiment, the timer circuit 4
When the output of 2 is always at the high level, all the pulses output from the voltage controlled oscillator 22 are output to the driver circuit 23.
The burn-in test can be performed as in the first embodiment.

On the other hand, in the case where the voltage controlled oscillator 22 outputs a pulse as shown in FIG. 5A, as shown in FIG. 5B, a pulse having a frequency lower than that of the pulse output from the voltage controlled oscillator 22. Timer circuit 4
In the case of outputting from 2, the intermittent (intermittent) pulse as shown in FIG. 5C can be obtained at the output side of the AND circuit 43, and this is supplied to the device under test 6 via the driver circuit 23. be able to.

Therefore, according to the third embodiment, it is possible to obtain the same effects as those of the first embodiment, and
A temperature cycle test can be performed by applying a temperature cycle to the device under test 6. In addition, the second embodiment can be similarly improved.

[0043]

As described above, according to the present invention, the temperature of the pulse supplied to the device under test is controlled so that the power supply current flowing into the device under test has a desired constant value. It is possible to control the power consumption of the device under test to a desired constant value and to set the junction temperature of the device under test to a desired constant value, so perform highly accurate testing and supply a highly reliable device. be able to.

Further, according to the present invention, by preparing the circuit shown in FIG. 1 for each device under test having a different model, the junction temperature of each device under test having a different model can be controlled to a desired constant value. Therefore, even devices under test having different types can be tested at the same time, and the efficiency of the test can be improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of a burn-in device according to the present invention.

FIG. 2 is a diagram showing a main part of the first embodiment of the present invention.

FIG. 3 is a diagram showing a main part of a second embodiment of the present invention.

FIG. 4 is a diagram showing a main part of a third embodiment of the present invention.

FIG. 5 is a waveform diagram for explaining the operation of the third embodiment of the present invention.

[Explanation of symbols]

 1 pulse supply control means 2 device under test 3 pulse supply means 4 power supply voltage supply means 5 power supply current detection means Vcc power supply voltage Icc power supply current

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Togashi 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (6)

[Claims] 1. A power supply current flowing into the device under test when a pulse is supplied to the device under test is detected, and the frequency of the pulse is controlled so that the power supply current has a desired constant value. And burn-in method. 2. A pulse supply control means (1) and a pulse supply means (3) for generating a pulse having a frequency controlled by the pulse supply control means (1) and supplying the pulse to a device under test (2). ) And a power supply voltage supply means (4) for supplying a power supply voltage (Vcc) to the device under test (2),
A power supply current detection means (5) for detecting a power supply current (Icc) flowing from the power supply voltage supply means (4) into the device under test (2), and the pulse supply control means (1) detects the power supply current. The pulse supply means (3) is controlled so as to supply a pulse having a frequency such that the power supply current (Icc) detected by the means (5) has a desired constant value. And burn-in equipment. 3. The power supply current detection means (5) is connected in series to a line connecting the power supply voltage supply means (4) and the device under test (2), and is connected to the device under test (2). A resistor that detects the flowing power supply current (Icc),
The pulse supply control means (1) comprises a comparator for comparing the output voltage of the amplifier with a reference voltage, and an output side of the comparator. The pulse supply means (3) is provided with a connected integration circuit, and the pulse supply means (3) outputs a voltage-controlled oscillator whose output pulse frequency is controlled by the pulse supply control means (1) and the voltage-controlled oscillator. The burn-in apparatus according to claim 2, further comprising a driver circuit that supplies a pulse to the device under test (2). 4. The power supply current detection means (5) is connected in series to a line connecting the power supply voltage supply means (4) and the device under test (2), and is connected to the device under test (2). A resistor that detects the flowing power supply current (Icc),
And an A / D converter for converting the voltage difference between both ends of the resistor into a digital value. The pulse supply control means (1) is configured so that the digital value output from the A / D converter is a desired constant value. The pulse supply means (3) comprises a microcomputer for controlling the frequency of the pulse output from the pulse supply means (3).
Is a digital control oscillator whose output pulse frequency is controlled by the microcomputer, a pattern generator which outputs a pulse group of a predetermined pattern based on the output of the digital control oscillator, and a pulse which is output from the pattern generator. 3. The burn-in apparatus according to claim 2, further comprising a driver circuit which supplies the device under test (2). 5. The pulse supplying means (3) includes a control circuit for intermittently supplying a pulse to the device under test (2). The burn-in device according to 3 or 4. 6. The power supply voltage supply means (4) is configured to include a constant voltage circuit for converting a power supply voltage (Vcc) into a constant voltage, as set forth in claim 2, 3, 4 or 5. Burn-in equipment.