JPS637628B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screening device for semiconductor devices, particularly semiconductor ICs.

As semiconductor ICs advance in manufacturing technology, they are becoming more highly integrated and faster, which generally leads to an increase in IC power consumption.

Such ICs undergo a screening test to accelerate the destruction of fragile products and remove initial defects by leaving them in a constant temperature environment for a certain period of time while applying a bias voltage or performing a specified operation. Implemented.

To create a test environment, it is common to use a constant temperature chamber, and the temperature environment inside the chamber is thermally isolated from the outside.

When screening ICs that consume large amounts of power in such an environment, the heat generated by the ICs may make it impossible to control the temperature inside the tank, resulting in thermal runaway, which may lead to product destruction and significant losses. In-tank IC
In order to reduce the total heat generation amount, it is necessary to reduce the number of ICs mounted or use a large constant temperature oven.

The purpose of the present invention is to provide a device that eliminates such problems and reduces the waiting time for the next operation by automatically cutting off the heater in the tank after the screening time is completed and by accelerating air cooling of the heated IC. This is what we provide.

A feature of the present invention is that, for example, the heat-resistant isolating material has air intake,
An exhaust hole is provided, and a servo mechanism opens and closes the hole in an analog manner to prevent the temperature inside the tank from overheating.A timer that can be preset detects the completion of the screening time and automatically lowers the temperature inside the tank. The point is that it is equipped with the means.

Next, the functions of the device will be explained with reference to the figures. 1st
The figure shows a conventional constant temperature bath. Reference numeral 1 denotes a stirring fan, which uses motor power to stir the air inside the tank in order to make the temperature distribution in the tank uniform. 2 is made of a material that is heat resistant and has low thermal conductivity to block the outside air. 3 is a heater for increasing the temperature inside the tank, and its power is controlled by a temperature controller to maintain a prescribed temperature. 5 is a thermocouple for detecting the temperature inside the tank. 12 is a hole for releasing heat inside the tank;
If the amount of heat released and the amount of heat generated by the IC in the tank exceed the amount of heat released by these holes, temperature control becomes impossible.
Also, if the hole is made unnecessarily large, it will result in energy loss, so it has to be kept to an appropriate size.

FIG. 2 shows an apparatus according to an embodiment of the present invention, and 7 is a thermocouple for detecting a temperature that cannot be controlled by the temperature controller 4. In FIG. This thermoelectromotive force becomes a drive signal for the servo motor control section 8, and the intake and exhaust amounts are controlled by operating the servo motor and moving the intake and exhaust sliders from side to side. Of course, the efficiency can be enhanced by adding an intake fan and an exhaust fan. It is clear that this suction/exhaust mechanism allows the temperature inside the chamber to be controlled within the expected control range even when the heat generation inside the chamber is relatively large, and it is possible to mount several times as many ICs as in Figure 1. be. Reference numeral 11 is a preset timer, and if the screening time is set, the heater power of the temperature controller 4 is set to zero at the same time as the screening is completed by counting the time from the start, and
This actuates as a drive signal to the servo motor control unit, fully opening the intake and exhaust holes, and rapidly lowering the temperature inside the tank.

As described above, the screening device according to the present invention can increase the number of ICs to be screened, and can quickly carry out the work of unloading products after screening is completed, and is expected to have a significant effect on improving productivity.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a thermostatic chamber main body of a conventional screening apparatus, and FIG. 2 is a schematic diagram of a thermostatic chamber according to an embodiment of the present invention. In addition, in the figure, 1...A stirring fan in the tank, 2
...Heat-resistant isolation material, 3...Heater block, 4...
Temperature controller, 5... thermocouple, 6... stirring motor, 7... suction/exhaust temperature detection thermocouple, 8... servo motor control section, 9... servo motor, 10...
Intake and exhaust slide lids, 11...timer,
12...Exhaust hole.

Claims (1)

[Claims] 1. A means for providing an intake/exhaust hole in a constant temperature chamber and opening and closing the hole diameter in an analog manner to maintain the temperature inside the chamber at a predetermined value;
1. A screening device for semiconductor devices, comprising a function of operating forced air cooling using a time meter.