JPH075426Y2 - Temperature characteristic test tank - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention tests the temperature characteristics, high temperature resistance, and low temperature resistance of electronic devices, especially printed wiring boards, circuit boards, etc. on which electrical / electronic components and elements are mounted. However, the present invention relates to a temperature characteristic test tank for testing, investigating, or confirming the quality of the characteristic.

(Prior Art) Electronic equipment, in particular, a main part thereof, and of course, a printed circuit board on which an integrated circuit and other elements are mounted realizes proper operations and functions. In fact, it is necessary to maintain the correct function without any abnormality over the years. Therefore, if some means to detect the malfunction of this kind of device is not taken in advance, the reliability of the product should be improved. I can't.

And, such means for improving the reliability are not limited to being adopted only at the stage of the first trial manufacture of the device and its first mass production, and thereafter, for the purpose of improving this electronic device and reducing the cost. In many cases, since design changes are made to circuits and the like, these means are also adopted in this case.

At the time of circuit energization, the important means for new production and subsequent improvement and modification of electric and electronic circuits as described above, that is, means for improving or maintaining reliability, is carried out on such circuit boards. Alternatively, it is a temperature characteristic test during operation.

Conventionally, the temperature characteristic of the mounted circuit, that is, the test method of high temperature characteristic, low temperature characteristic is to place the circuit part in a constant temperature bath, but these constant temperature baths are, of course, originally intended to be thermally isolated from the outside. Since it has a closed structure with a door, it was very difficult to test the temperature of the circuit part when energized.

It is necessary to supply an electric current from the outside for the temperature characteristic test at the time of energization of a circuit part such as a printed circuit board on which the above-mentioned electronic elements and electric parts are mounted, but the conducting wire for this supply is the constant temperature chamber. It prevented the doors from being completely closed, so that their isothermal state was not assured to a great extent and it was therefore difficult to test the exact temperature characteristics of these circuits. Particularly in recent electronic circuits or information circuits, since many signal lines, address buses, data buses, etc. are included in addition to the power supply system conducting wires, it is more difficult to carry out an accurate temperature characteristic test. Was becoming.

(Problems to be solved by the invention) Therefore, a thermostatic chamber with an air curtain having an opening on the front surface is being developed. However, if wind blows on the air curtain and the flow thereof is disturbed, the constant temperature (especially low temperature) performance is remarkably deteriorated, so that more energy than necessary to maintain the constant temperature must be supplied.

The present invention solves the above problems and provides a temperature characteristic test tank in which a constant temperature state is completely maintained even when a large number of wirings for external or other parts are present in the circuit part which is the DUT. To do.

(Means for Solving Problems) The temperature characteristic test tank of the present invention is a temperature characteristic test apparatus for electronic devices and the like, and includes a small and movable housing, and a temperature test chamber having an upper opening portion and a side opening portion. A first air curtain formed by the forced ventilation means and the temperature elevating means and traversing at least the inside of the upper opening portion of the temperature test chamber, and a first air curtain formed by the forced ventilation means and traversing at least the outside of the upper opening portion of the temperature test chamber. It is characterized in that it includes a second air curtain and a side door that opens and closes the side opening.

(Operation) The device of the present invention is moved to a place convenient for the test. After placing the DUT in the temperature test chamber, the conductors or the like for transmitting power and control signals to the DUT can be pulled out of the tank from the upper opening where the double air curtain is formed.
The power supply connected to the conductors and even the measuring instrument do not have to be housed in the test tank, and unnecessary life shortening can be prevented, and the temperature inside the tank is kept constant by the air curtain.

Further, since the air curtain is formed so as to cover the upper part, the influence of cross wind that is usually generated is small. In addition, particularly in the low temperature test, the test can be efficiently performed without letting out the cool air in the test tank.

Further, since the side doors can be opened, the DUT can be easily stored, and even a large number of DUTs can be packed closely. In addition, the test can be performed with the side door open, and the door can be used as a workbench.

(Example) Hereinafter, a temperature characteristic test tank of the present invention will be described in detail with reference to the drawings showing an example thereof.

FIG. 1 is a schematic sectional view of a temperature characteristic test tank of the present invention, FIG. 2 is a schematic plan view thereof, and FIG. 3 is a block diagram of its configuration.

In FIG. 1, reference numeral 1 denotes a housing having a temperature test chamber 2 capable of accommodating a printed circuit board on which electronic elements such as integrated circuits and electronic parts such as capacitors are mounted, and an upper opening 3 thereof. The first and second air curtains 4, 5
The side opening 7 is provided with a side door 7,
A caster 8 is provided at the lower part so that it can be moved. A temperature control operation section 10 and a temperature display section 11 are provided on the appropriate surface section 9.

As shown in FIG. 3, the first air curtain 4 is an air flow close to the temperature of the temperature test chamber 2, and the second air curtain 5
Has an air flow close to the outside temperature.

Next, the first air curtain 4 and the second air curtain 5 will be described in more detail including heating and cooling means for the air flow. In FIG. 3, 13 and 14 are first and second air nozzles, for example. It has a honeycomb structure.
Reference numerals 15 and 16 are first and second air sinks, and first and second air curtains 4 and 5 are formed between the first and second air nozzles 13 and 14 and the first and second air sinks 15 and 16. Further, the temperature detector 17 is installed in this portion.

Air is blown out or sucked into the first and second air nozzles 13 and 14 and the first and second air sinks 15 and 16 by forced ventilation means 18 and 19, and thus the discharged or sucked air flow is the first air. In the case of a loop which communicates with the curtain 4, it then contacts the internal coil 21 of the temperature elevating means 20 and exchanges heat with each other to reach the first air nozzle 13. The loop communicating with the second air curtain 5 does not particularly come into contact with the temperature elevating means,
Reach the air nozzle 14. Although the air curtain has two layers in this embodiment, it may have three or more layers.

Next, the temperature elevating means 20 described above will be further described. In FIG. 3, the left side of the chain double-dashed line is provided on the inner side of the housing 1, and the right side thereof is provided on the outer side. Are first and second expansion valves, which regulate the pressure of refrigerant such as CFCs, and 24 and 25 are check valves, which form a bypass. An external coil 26 has a function similar to that of the internal coil 21 and operates as an evaporator or a capacitor. Reference numeral 27 denotes a compressor, which compresses the vaporized refrigerant entering from the inner coil 21 or the outer coil 26. Reference numeral 28 denotes a direction switching device that switches the direction of the flow of the refrigerant. 29 is a solenoid valve that changes the flow rate of the refrigerant.

The direction switching device 28 and the solenoid valve 29 are controlled by a command from the temperature control operating section 10, for example.

Next, a method of using the temperature characteristic test tank of the present invention will be described. The pair to be tested, such as a printed circuit board on which integrated circuit elements and other electric and electronic elements are mounted, opens the side door 7 of the upper opening 3 or the side opening 6 and opens the temperature test chamber 2 from there. To store. In this case, even if the device under test and its peripheral devices, power supply, etc. are connected by a large number of conductors, the device under test may be inserted as it is in a state where the conductors cross the air curtain.

The operation of the temperature elevating / lowering means 20 will be described first during the cooling test in the above-mentioned manner. In this case, the temperature control operation part 10 is arranged so that the refrigerant flows through the direction switching device 28 from left to right in FIG. Set via.

In this mode, the refrigerant is the first check valve 24 and the second expansion valve.
Through 23, the internal coil 21 functions as an evaporator and the external coil 26 functions as a capacitor. In this case, the first
The air flow sent by the forced ventilation means 18 is cooled by the internal coil 21 which is an evaporator.
The refrigerant that has undergone heat exchange in the internal coil 21 and is vaporized is the compressor
It is compressed at 27 and then the external coil 26 raises the temperature.

(Effect of the Invention) As described above, the temperature characteristic test tank of the present invention can perform the temperature characteristic test without trouble even if the device under test is connected to the external power source / measuring device through the lead wire.

In addition, since it is portable, it can be moved to a place where there is as little wind as possible that affects the air curtain, and because of its structure, it is not easily affected by the side wind that normally occurs, and extra energy is required to maintain a constant temperature. You don't need it.

Further, since the side doors can be opened, even a large number of DUTs can be densely packed and easily stored, which is a remarkable industrial effect.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a schematic sectional view thereof, FIG. 2 is a schematic plan view thereof, and FIG. In the figure, 2: temperature test chamber, 4: first air curtain, 5: second air curtain, 13: first air nozzle, 14: second air nozzle, 15: first air sink, 16: second air sink .

Claims (1)

[Scope of utility model registration request] 1. A temperature characteristic test apparatus for electronic equipment,
A small and movable housing, a temperature test chamber having an upper opening and side openings, a first air formed by forced ventilation means and temperature elevating means and traversing at least the inside of the upper opening of the temperature test chamber. A temperature including a curtain, a second air curtain formed by forced ventilation means and crossing at least the outside of the upper opening of the temperature test chamber, and a side door opening and closing the side opening. Characteristic test tank.