RU1820372C - Device for environmental testing of electronic engineering items in inert atmosphere - Google Patents

Abstract

The invention relates to test equipment, in particular to devices for climatic testing of housing integrated circuits under conditions of elevated and low temperatures. The device can be used for technological control (probe monitoring) of the electrical parameters of open-frame LSIs (large integrated circuits). The purpose of the invention is to reduce the inert flow rate and increase the reliability of the test results. For this purpose, the test article holders in the device are made in the form of detachable chambers, in which it is possible to separate the movable and stationary Parts both for loading the test product before entering the teloshell enclosure and for conducting tests in the enclosure environment. With the help of spring-loaded shutters installed in the windows of the housing, the device provides the input and output of the chambers from the housing without violating the tightness of the internal environment of the housing. The camera holders have their own heating and cooling elements in the form of TECs (thermoelectric semiconductor converters) and heat-conducting plates, as well as sensors for setting and monitoring temperature, connected to connectors for connecting electrical circuits. The device allows both maintaining and controlling the temperature (± 0.5 ° C) with high accuracy. Test results are highly reliable. The inert flow rate is determined by a one-time filling of the housing. 1 p. Fs, 3 ill. And so on about VI VI

Description

The invention relates to test equipment, namely, devices for climatic testing of electronic products, for example integrated circuits, under conditions of elevated and low temperatures in an inert environment, and can be used for technological probe monitoring of electrical parameters of open large integrated circuits (LSI) in a satellite container.

The purpose of the invention is to improve the operational characteristics of the device by reducing the inert flow rate and increasing the reliability of the test results. .

In FIG. 1 is a cross-sectional view of the construction of a camera holder; in FIG. 2 shows the same camera, right view; in FIG. 3 is a thermally insulated wall of a heat chamber with a window for installing a removable holder. .

The holder is made in the form of a sealed chamber, which consists of two parts - fixed and movable. The movable part 1 allows hermetically closing the test product 2, which is in the contact device (KU). In the movable part 1 there is a temperature control sensor 4 mounted in a heat-conducting (for example, copper) plate 5, which in the closed position of the camera holder is pressed against one of the two planes of the crystal of the tested circuit (open-circuit LSI) 2. Installation and removal of the test articles 2 from KU 3 can be carried out both in open and in closed position using a removable element 6 and screws 7 mounted on the moving part 1. On the fixed part 8 of the camera holder, in addition to the contact device 3 with test B C 2 mounted circuit board 9, which leads from vpaivayuts CG 3 also installed thermally conductive (copper) plate 10, which houses the sensor 11 for specifying and controlling the temperature. Semiconductor thermoelectric converters (TEC) 12 are pressed against the copper plate 10. In a particular embodiment of this device, a cascade-stepped design with the electrically sequential inclusion of three basic elements is used in order to simplify the control system and reduce the number of current sources to one, as well as provide the possibility direct contact of the working surface of the base element with the surface of the LSI crystal.

On the outside of the TEC 12, a finned radiator 13 can be additionally installed to improve heat transfer between the TEC 12 and the test product 2 in the case of testing products with large (more than 2 W) heat.

Connector 14 is designed to supply power to TEC 12 and connect sensors 4 and 11, and connectors 15 serve to establish the electrical mode on the test product 2.

To enable movement of one part of the holder-chamber relative to the other, in the fixed part 8 of the holder there are movable pins 16, which are equipped with levers, (handles) 17, which are located in the grooves. The pins 16 are rigidly connected to the movable part 1. In the heat chamber 18 along the edges of the window 19 whose dimensions correspond to the dimensions of a fixed

parts 8 of the camera holder, grooves 20 are made, along which the pins 21 are moved due to the springs 22. A damper 23 is fixed to the pins 21, which, when the camera holder is removed from the heat chamber 18, will close window 19, because its dimensions exceed the dimensions of the window 19 in the heat chamber 18. The fittings 24 and 25 with check valves allow the inert medium to be replenished, respectively, the internal volume of the holder-chamber (parts 1 and 8) and the volume of the heat chamber 18. Heat-conducting plates 5 are mounted on spring-loaded brackets 26 to provide non-destructive contact with the test product 2.

The device operates as follows. Prior to testing, the test product 2 is loaded into the contact device 3. To do this, the screws 7 are unscrewed and the removable part 6 of the movable part 1 of the holder-chamber is removed, and the product is installed in the control unit 3. Then, the removable part 6 is installed in its original place and tightened with screws 7. B In the case of LSI testing with a small number of leads, loading can also occur at the point of separation of the movable and fixed parts 1 and 8 of the camera holder. To do this, using the pins 16 and the handles 17, the camera parts 1 and 8 are extended. Then both parts of the chamber are moved with the help of handles 17 along the guide pins 16 until the holder of the chamber is completely sealed. The closed chamber (parts 1 and 8) is inserted all the way into the window 19 of the heat chamber 18, after which, by pressing the handles 17, the movable part 1 is moved away from the fixed part 8 by pins 16 to a distance of 30-40 mm. In this case, the shutter 23 together with the pins 21 moving along the grooves 20 is pushed back to 0 by the volume of the heat chamber 18 by the length of the pins 21. Thus, all the camera holders in the windows 19 of the heat chamber 18 are pushed back. All products are blown (washed) with a hot (cold) inert medium, which was previously fed through the nozzle 25 into the volume of the heat chamber 18.

After the test items are held in the volume of the heat chamber 18 at specified intervals, the holders with the test items are removed to measure the parameters. For this, the camera holders by the handles 17 are removed from the windows 19 outside the heat chamber 18. As the valve 23 is extended, the springs 22 approach the cockpit 19 in the heat chamber 18 and close it until the holder of the camera completely exits the heat chamber 18. Thus, sealing and isolating the internal volume of the heat chamber 18 from the external environment.

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Then, the camera holder with connectors 15 is mounted on the head of the measuring device (not shown in the drawing). To maintain the temperature, while measuring the parameters of the test product 2, a cable from the temperature controller (not shown) is connected to connector 14. Through internal installation, connector 14 is connected to the TEC 12, which transmit the set temperature (heat-cold) through the heat-conducting (copper) plate 10 to the test product 2. Sensors 4 and 10 control the temperature and from them a control signal is sent to the controller to maintain the set temperature. The controller reverses the temperature from (+) to. (-) and, accordingly, the temperature is reversed on the working surface of TEP 12, because The physics of TEC is based on the Peltier effect.

If it is necessary to replenish the holder of the chamber with an inert medium from the central line and the nozzle 24, the inert medium is fed into the internal volume of the holder of the chamber. The radiator serves to remove heat from the outer surface of the TEC 12 in order to stabilize its temperature relative to the ambient temperature.

Thus, in this design, the movable part of the holder inside the heat chamber moves away, and when removed, the holder tightly closes with the fixed part. In the open position of the holder of the chamber, the test article inside the heat chamber is blown with an inert medium, and when the parts of the holder of the chamber are closed, the inert medium is captured in a microvolume and held for subsequent measurement. Consequently, in the measurement, the test product is in the same environment as in the test.

Due to the fact that the holder-chamber has its own heating and cooling elements in the form of TECs, temperature sensors, and the test inert medium is kept in a small volume, the parameters of the test products can be measured indefinitely under temperature conditions (heat or cold). The camera holders can be taken out of the device and installed into it in turn or in any arbitrary order without violating the test regime of the remaining products,

This device allows, under conditions when there are dozens of products in the chamber, to provide a long-term test mode, for example, failure-free operation (500 hours or more), and since after the test the products are measured in the same real test conditions, a reliable estimate of the parameters and their departure in time under the influence of electric and temperature factors is achieved. As a result of this, the device allows 5 to give a reliable estimate of the potential reliability of each tested product. The high reliability of the measured information allows you to more carefully reject products according to their capabilities.

0 Important for extra-large, single-chip circuits that are expensive in manufacturing technology and require ideal environmental conditions. The measurement time for such circuits is ten minutes. This is important for

5 microcircuits with high heat dissipation (tens of watts), when each product requires high accuracy both to maintain and control the temperature. Tests using the proposed

0 devices are quite simple, technologically advanced in production conditions and allow promptly carry out a reliable assessment of the reliability of products.

Regarding the inert flow rate,

5 then in this device only one-time filling of the chamber with an inert medium is required and only if additional recharge is necessary.

It should also be noted that the device

0 allows, in the case of using TECs of small geometric dimensions, to test devices at high and ultrahigh frequencies (over 10 MHz).

Claims (1)

5 Claims A device for climatic testing of electronic products in an inert environment, containing a heat chamber, in the through windows of the thermally insulated walls of which are removable holders, the fixed parts of which are provided with contacts for connection with the test products installed on these parts, and mounted on the moving parts 5 heat-conducting plates with integrated temperature sensors, and the movable parts of the removable holders are made with the possibility of pressing the heat-conducting plates to the test products, and 0 shutters for closing through-windows when removable holders are removed, characterized in that, in order to improve the operational characteristics of the device by reducing the inert medium flow rate and increasing the reliability of the test results, the movable and fixed parts of the removable holders in closed position form a sealed chamber, moreover, on the stationary parts additional heat conducting plates with additional temperature sensors built into them, while additional heat-conducting plates are in contact with the test products and semiconductor thermoelectronic converters, and the shutters are placed inside the heat chamber on spring-loaded pins mounted with the possibility of longitudinal movement in the grooves of the heat-insulated walls of the heat chamber. 7 8 16 3 Yu to Vud / J / 7 i I AM  I G i and FIG. g / 23 21 & N Figz