JPH04144248A - Testing method of semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To notably cut down the thermal delay time conventionally impossible to be tested until the IC temperature declines to the value within the range of set up temperature by a method wherein, in order to test a semiconductor integrated circuit by absorbing the generated heat thereof using a semiconductor element having the Peltier effect, the semiconductor integrated circuit is precooled down before the power supply voltage thereof is turned ON. CONSTITUTION:A temperature sensor 5 is buried in the position near the IC chip 7 in a metallic block 4 to measure the temperature of the IC chip being tested so that the measured value may be converted into specific output by a thermostat 2 while controlling the output from a Peltier element 3 to maintain the temperature of the IC chip 7 being tested at a specific value. On the other hand, the thermostat 2 is impressed with the signal to control the Peltier element 3 from an IC tester 1 before turning-ON the power supply voltage of IC according to the data collected from the thermal response characteristics of a substrate using a tester signal wire 9. Through these procedures, this signal can be controlled by a test program using the tester pin of the IC tester 1 so as to be freely controlled by the outputs from respective ICs 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for testing the electrical characteristics of a semiconductor integrated circuit, and particularly to a test method for cooling a high-power semiconductor integrated circuit.

[Conventional technology]

Conventionally, high power and T A B (Tape Out
The self-heating of semiconductor integrated circuits (hereinafter referred to as ICs) that are shipped in a bonded state is reduced by a semiconductor element having a Peltier effect (hereinafter referred to as a Peltier element).
When testing the IC by absorbing it, the self-heating of the IC is detected by an external temperature sensor, the temperature of the Peltier element is controlled based on this detection point, and the IC is tested in an appropriate test environment.

FIG. 3 shows a schematic block diagram of an example of a test device that cools an IC using a Peltier element and tests electrical characteristics.

The Peltier element 3 is adhered onto a metal block with excellent thermal conductivity, and the IC chip 7 in the IC 6 to be tested is brought into close contact with the lower side of the metal block. A temperature sensor 5 is embedded in the metal block at a position closer to the IC chip, measures the temperature of the IC chip 7 under test, converts the measured value into a specified output in the temperature control section 2, and outputs the Peltier element 3. and tries to keep the temperature of the IC chip 7 constant.

However, the heat generation of the IC chip 7 increases rapidly when the IC power supply voltage is applied, but the Peltier element 3
Since the function starts to lower the temperature detected by the temperature sensor 5 in the metal block 4 to the set temperature only when the temperature of the metal block 4 rises due to the heat generated by the IC chip 7, a delay time occurs.

Furthermore, even after the Peltier element 3 starts outputting to lower the temperature to the set temperature, there is a time period for heat transfer in the metal block 4 between the Peltier element 3 and the IC chip 7, as shown in the thermal response characteristics in Figure 4. As such, a certain amount of time is required for the IC chip to reach the set temperature.

[Problem to be solved by the invention]

Therefore, in the conventional electrical characteristic testing method for semiconductor integrated circuits described above, in order to test each guaranteed specification (performance) within a certain temperature range, after the IC is powered on,
There was a restriction that the test could not be started until the temperature was within the set temperature range.

Another drawback is that even if the test is started outside the set temperature range of the IC, it cannot be guaranteed that the test will continue until the temperature microscopically falls within the set temperature range.

[Means to solve the problem]

The test method for semiconductor integrated circuits according to the present invention is based on the time from when an IC is energized and starts generating heat until a temperature sensor detects a change in temperature of the IC, and the time when a Peltier element lowers the temperature to a set temperature in response to this. The device has means for shortening the delay time from when the IC starts outputting until the IC is cooled to within a set temperature range by applying in advance a signal from the IC tester to control the temperature of the Peltier element.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic block diagram of a test device for explaining a first embodiment of the present invention.

A Peltier element is bonded onto a metal block with excellent thermal conductivity, and the IC chip 7 in the IC to be tested is brought into close contact with the underside of the metal block.

A temperature sensor 5 is embedded in the metal block at a position closer to the IC chip 7, the temperature of the IC chip 7 under test is measured, and the measured value is converted into a specified output by the temperature control unit 2,
Controls the output of Peltier element 3 and controls the IC under test.
Keep the temperature of chip 7 constant.

On the tester signal line 9, a signal for controlling the Peltier element 3 is applied from the IC tester 1 to the temperature control section 2 before the power supply voltage ○N of the IC is applied based on data obtained from known thermal response characteristics.

This signal can be controlled by a test program using the tester bin of the IC tester 1, and can be freely controlled by the output of each IC 6.

The output signal of the tester 1 is interrupted at the time when the heat generation of the IC 6 reaches a certain level after the P OWE RON of the IC 6, that is, at the time A in FIG. The Peltier element 3 is controlled by.

FIG. 3 is a schematic block diagram of a test device for explaining a second embodiment of the present invention.

In the first embodiment, the temperature control signal from the IC tester 1 was directly applied to the detection signal of the temperature sensor 5, and the test program was used for control.
The temperature control signal from the C tester 1 and the detection signal of the temperature sensor 5 are connected by the input signal changeover switch 10.
This input signal changeover switch is controlled by a timer 11.

That is, the test program controls only the input timing of the temperature control signal, and the switching with the detection signal of the temperature sensor 5 is forcibly executed at the time set by the timer 11.

〔Effect of the invention〕

As explained above, the present invention is capable of absorbing the self-heating of the semiconductor integrated circuit generated during the test by using a semiconductor element having a Peltier effect during the electrical characteristic test of a semiconductor integrated circuit that requires high power. By pre-cooling the semiconductor integrated circuit before turning on the power supply voltage, it is possible to significantly shorten the thermal delay time, which was conventionally not tested until the IC temperature fell within the set temperature range. Become.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of a test device for explaining a first embodiment of the present invention, and FIG. 2 is a schematic block diagram of a test device for explaining a second embodiment of the present invention. Figure 3 is a schematic block diagram of a test device for explaining an example of a conventional semiconductor integrated circuit testing method, and Figure 4 shows the thermal response of the temperature detected by the temperature sensor when cooling an IC using a Peltier element. It is a characteristic diagram. DESCRIPTION OF SYMBOLS 1... IC tester, 2... Temperature control part, 3... Peltier element, 4... Metal block, 5... Temperature sensor, 6... IC17... IC chip, 8...・Connector, 9...Tester signal line, 10...Input signal selection switch, 1]...Timer.

Claims (1)

[Claims] In a test method for a semiconductor integrated circuit in which self-heating of a semiconductor integrated circuit generated during the test is absorbed by a semiconductor element having a Peltier effect and tested by an IC tester, the semiconductor integrated circuit is tested after the semiconductor integrated circuit starts generating heat. The time it takes for the temperature sensor to detect a temperature change in the circuit,
In response to this, the IC tester controls the temperature of the Peltier element by controlling the delay time from when the Peltier element starts outputting to lower the temperature to the set temperature until the semiconductor integrated circuit is cooled to within the set temperature range. A test method for semiconductor integrated circuits that has a means of shortening the time by applying a signal in advance.