JP2603408B2 - Constant temperature and humidity - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant temperature used for performing burn-in processing for reliability evaluation and screening of various semiconductor elements and electronic circuits, and for examining heat resistance and moisture resistance of various articles and materials. Regarding the humidity controller.

[0002]

2. Description of the Related Art As a method for obtaining air of a desired temperature and humidity in a thermo-hygrostat, it is known that saturated air having a predetermined dew point is produced and heated to obtain air of a desired temperature and humidity. I have. As a method for obtaining a saturated gas having such a predetermined dew point temperature, a water called a contact method is used. A method of obtaining saturated air having a predetermined dew point temperature through a through hole has been known for a long time.

However, in this method, water droplets may be mixed in the saturated air, so that when the saturated air is heated,
Since the water droplets evaporate, the desired relative humidity cannot be obtained.
If the purity control of water is insufficient, water-soluble impurities solidify during contact evaporation with air, and the powder of the impurities scatters.
A pump that circulates water, means for miniaturizing water, a motor for driving the water, a saturation tank for bringing micronized water into contact with air, an eliminator for removing excess water droplets, etc. are required. There are drawbacks in that the structure is complicated and large, the cost is high, the power consumption is large, and the number of failures is large.

Therefore, in order to solve such a problem,
By passing air appropriately humidified by the humidifying means through a heat exchanger cooled to a temperature lower than the dew point temperature, excess water is removed (dehumidified) and saturated air having a predetermined dew point temperature is produced. A method of obtaining desired temperature and humidity air is also used. A thermo-hygrostat adopting such a temperature-humidity control system generally includes an air-conditioning room, a test room and air circulation means for circulating air to both the rooms, and the air-conditioning room includes a heat exchanger for generating saturated air. A humidifying unit upstream of the heat exchanger in a flow direction of the circulating air, and a heating unit for heating the saturated air after passing through the heat exchanger.

[0005]

However, this type of thermo-hygrostat has the following problems. If the temperature in the test room is higher than the outside air, the heat in the test room escapes from the heat insulating wall of the test room to the outside, and the temperature accuracy deteriorates. As the heat inside the test room escapes from the heat insulating wall of the test room to the outside, the temperature of the test room wall surface decreases, and it may become lower than the dew point temperature of the test room air. Accuracy deteriorates. Further, the dew condensation water has an adverse effect on articles in a test chamber that dislike water. For example, in order to use a thermo-hygrostat for burn-in processing of a semiconductor element, an electronic circuit, and the like, such an element,
When a connector for electrically connecting a burn-in board equipped with a circuit, a relay board and the like electrically connected to the connector are arranged on a test chamber wall or the like, dew condensation water may be generated on the burn-in board or an article thereon, It flows to connectors, relay boards, etc., causing damage to the articles on the burn-in board, causing electrical insulation failure, short-circuits, etc. at each part.

Therefore, the present invention comprises an air-conditioning room, a test room and air circulation means for circulating air to both the rooms, wherein the air-conditioning room has a heat exchanger for generating saturated air and It is a thermo-hygrostat provided with humidifying means on the upstream side of the heat exchanger and a heating means for heating the saturated air after passing through the heat exchanger, compared with a conventional thermo-hygrostat of the same type. Another object of the present invention is to provide a test chamber capable of improving the accuracy of temperature and humidity of the air in the test chamber and having no risk of dew condensation on the wall surface of the test chamber.

[0007]

According to the present invention, there is provided, in accordance with the above object, an inner wall heating means for heating at least a part of a wall surface of the test chamber in such a thermo-hygrostat, wherein the inner wall heating means is heated by the inner wall heating means. the temperature of the test chamber wall portion the test chamber in circulating air dew point temperature or higher, and comprises means for controlling said internal wall heating means operates to maintain below the circulating air temperature, the control of the inner wall heating unit operation hand
The stage heats the inner wall in synchronization with the operation or stop of the humidifying means.
It is intended to provide a thermo-hygrostat characterized by operating or stopping the means .

The heating temperature of the inner wall of the test chamber by the inner wall heating means may be, for example, about 5 ° C. higher than the dew point temperature. In the case of high humidity control, the difference between the test room air temperature and the dew point temperature is small.
It is conceivable to select the heating means capacity so as to maintain a high temperature of about 5 ° C. Dew condensation on the test chamber wall is closely related to the dew point temperature of air circulating in the test chamber,
Since the dew point temperature is proportional to the humidification by the humidifying unit, the control unit for controlling the operation of the inner wall heating unit operates or stops the inner wall heating unit in synchronization with the operation or stoppage of the humidifying unit .

Further, as a specific example of the inner wall heating means,
An air jacket formed along at least a part of the inner wall of the test chamber and a heater for heating air in the air jacket may be provided. In this case, a fan for circulating and / or stirring the air in the air jacket may be provided.

[0010]

According to the constant temperature / humidifier of the present invention, air is circulated to the air conditioning room and the test room by the air circulating means, and the air flowing into the air conditioning room is humidified by the humidifying means as required, and Passing through, the air is dehumidified and becomes saturated air, and the saturated air is reheated by a heating means to obtain a target temperature and humidity, for example, 85 ° C., 85% RH, 40 ° C.,
Air such as 90% RH, 60 ° C., 90% RH is obtained and supplied to the test room.

In the test room, the inner wall heating means is located at the front.
The control means synchronously operates or stops the humidification means.
Operation or stopped Te, the inner wall surface of the test chamber the inner wall of the heating means by more than the dew point temperature of the air circulating in the test chamber, and, because it is heated below the circulating air temperature, condensation on the test chamber wall prevents And the accuracy of the temperature and humidity in the test room is improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. The thermo-hygrostat includes an air-conditioning room 1 and a test room 2, and substantially all of these rooms are surrounded by a heat insulating wall 3. An opening 21 is provided on the front side of the test chamber 2, and the opening 21 is opened and closed by a heat insulating door (not shown). Further, an air duct 4 is formed along the outer wall 11 of the air conditioning room 1.

The air conditioning room 1 and the test room 2 are partitioned by a partition wall 5, and a partition wall 12 is arranged in a part of the air conditioning room 1. An electric heater 6 for heating air is disposed in a ventilation path 13 between the partition wall 12 and the partition wall 5 in the air conditioning room 1, and a ventilation path 14 between the partition wall 12 and the air conditioning room outer wall 11.
Is provided with a heat exchanger 7.

The heat exchanger 7 is formed by fixing a plurality of heat pipes 72 through a plurality of heat exchange fins 71.
The heat pipes are arranged, for example, three vertically and eight horizontally. Each heat pipe is formed by sealing a heat medium (for example, alcohol) in a copper tube. The heat medium evaporation side portion is disposed in the ventilation path 14, and the heat medium condensation side portion is disposed in the duct 4. I have. The heat medium condensing side portion is located higher than the heat medium evaporating side portion.

By adopting the heat exchanger 7 comprising such a heat pipe, the structure of the thermo-hygrostat can be simplified, miniaturized and provided at a low cost, and the power for operation can be saved. The lower ends of the ventilation passages 13 and 14 in the air-conditioning room 1 face a common space 15, which communicates with the test room 2 through an air inlet from the test room 2.

A humidifier 8 is provided below the heat exchanger 7 and contains water W. The water W is heated by an electric heater 81 to evaporate and humidify the incoming air. Above the heat exchanger 7, a temperature detection sensor S1 is arranged in the ventilation path 14, and the sensor detects the temperature of the heat exchanger 7.
The temperature of the air immediately after passing through can be detected. The sensor is not affected by radiant heat from the heater 6 by the partition wall 12.

The upper ends of the ventilation passages 13 and 14 are provided in a common space 1.
6, where a fan F1 for air circulation is provided. The fan F1 is driven by the motor M1. A register (rectifier) R is disposed at an air discharge portion from the fan F1, and a temperature detection sensor S2 is disposed at a position facing the air outlet of the register R. A blower F2 is provided at the lower end of the duct 4 along the air conditioning room to ventilate and cool the heat medium condensing side portion of the heat exchanger heat pipe.
Is provided. The blower F2 is driven by a motor M2.

The air inflow portion at the upper end portion and the air outflow portion at the lower end portion of the test chamber 2 are used for adjusting the air flow, preventing insertion of an operator's hand or arm, and preventing articles from falling. A plate 22 made of a perforated plate, a steel plate, a lattice plate, or the like is provided. An air jacket 24 is formed along substantially the entire inner wall 23 of the test chamber 2 on the outside thereof, and an electric heater 25 for heating the air in the jacket and a fan for stirring and circulating the air in the jacket are partially provided in the jacket. F3
Is provided. The fan F3 is driven by a motor M3.

The temperature detected by the temperature sensor S1 is inputted to a dew point temperature controller 91. Also,
In the controller 91, a saturated air having a dew point temperature required for obtaining a desired temperature and humidity air can be generated.
The dew point temperature for that can be set. The controller 91 further compares the temperature detected by the sensor S1 with the set dew point temperature, and when the detected temperature becomes lower than the set dew point temperature, the blower F
While the second motor M2 is stopped, the humidifier heater 81 is energized, and when the detected temperature becomes higher than the set dew point temperature, an instruction is given to rotate the blower F2 while energizing the humidifier heater 81 is stopped. It has become.

The heater 25 in the air jacket 24 of the test chamber 2 is turned on and off in synchronization with turning on and off the humidifier heater 81. This is to prevent dew condensation on the test chamber wall 23 and to keep the temperature in the test chamber. The dew condensation on the inner wall 23 is closely related to the dew point temperature of the air circulating in the test chamber, and the dew point temperature is proportional to the energization ratio to the humidifier heater 81. Therefore, they are turned on and off synchronously in this manner. Further, the heaters 81 and 25 are provided so that the purpose of preventing dew condensation on the wall 23 of the test chamber and keeping the temperature in the test chamber can be achieved, and the humidifier 8 can perform necessary humidification.
Has been selected.

The temperature detected by the temperature detection sensor S2 is input to an air temperature controller 92.
In the temperature controller 92, a target air temperature can be set. The controller 92 further includes a sensor S2
Is compared with a set temperature, and based on the difference, the heater 6 is turned on and off so as to obtain a target air temperature.

The fan motors M1 and M3 are constantly operated. In the figure, PW is a power source, I is an inverter, T1, T
2. T3 is a thyristor. In addition to the thyristor, a solid state relay or the like can be used. According to the constant temperature and humidity chamber described above, the air is circulated to the air conditioning room 1 and the test room 2 by the operation of the fan F1.

The air flowing from the test room 2 into the air-conditioning room 1 is divided into two flows passing through the ventilation paths 13 and 14, and the air passing through the ventilation path 13 is heated by the heater 6. The heater 6 is turned on and off based on an instruction from the temperature controller 92. More specifically, the input from the sensor S2 is compared with the set air temperature in the controller 92, and the energization is controlled in proportion to the deviation of the temperature detected by the sensor S2 from the set temperature.

On the other hand, the air passing through the ventilation passage 14 passes through the humidifier 8 at the preceding stage, is appropriately humidified, and then passes through the heat exchanger 7, where it is cooled and dehumidified and becomes saturated air. . Since the heat exchanger 7 includes the heat pipe 72, the temperature of the air that has passed through the heat exchanger 7 is substantially uniform in each part. Therefore, the air temperature detected by one sensor S1 indicates the average temperature of the whole air that has passed through the heat exchanger 7.

The temperature detected by the sensor S1 is controlled by the dew point temperature controller 9
1 and the detected temperature is compared with the set dew point temperature. If the detected temperature is higher than the set dew point temperature,
While the power supply to the humidifier heater 81 is stopped, the blower F2
Is operated, thus cooling the heat medium condensing side portion of the heat exchanger heat pipe 72 by ventilation, thereby increasing the cooling capacity of the heat exchanger 7 and consequently the dew point of the saturated air passing through the heat exchanger 7 The temperature drops.

When the detected temperature becomes lower than the set temperature, the humidifier heater 81 is energized while the blower F2 is stopped, and thus the dew point of the saturated air passing through the heat exchanger 7 increases. In addition, each energization control of the heater 81 and the blower F2 is performed in proportion to the deviation of the detected temperature from the set temperature.

Thus, the temperature of the saturated air that has passed through the heat exchanger 7 is controlled to the set dew point temperature for obtaining air having the desired temperature and humidity. As described above, as a result of controlling the cooling capacity of the heat exchanger 7, the amount of heat exchange in the heat exchanger 7 becomes minimum or close to a necessary minimum, and therefore, the heat exchange surface temperature and the heat exchange amount have passed through the heat exchanger 7. The difference from the air temperature is reduced, and the temperature of the passing air is made uniform in each part, which contributes to more accurate dew point temperature control.

Thus, the heated air flowing out of the air passage 13 and the saturated air flowing out of the air passage 14 are mixed and stirred by the fan F1 to obtain the desired temperature,
The air is supplied to the test chamber 2 as air having a relative humidity, and an article (not shown) arranged in the test chamber 2 is subjected to a burn-in process or the like. Further, the ventilation path 13 is provided in the air-conditioning chamber 1 so that the heat in the test chamber can flow into the test chamber and be used for reheating the saturated air. The permissible heat value of the inner article can be increased.

In the test chamber 2, the heater 25 of the air jacket 24 is turned on and off in synchronization with the turning on and off of the humidifier heater 81, so that even when the dew point temperature is changed, the air temperature in the jacket, and hence the air temperature in the jacket, is changed. , Test chamber wall 23
Is slightly higher than the dew point temperature of the test chamber air (5 ° C in this example).
高温 15 ° C.).
Of the heat from the outside, the dew condensation on the inner surface of the test chamber wall 23 is prevented, and thus the temperature and humidity accuracy of the test chamber air is improved. Further, since the occurrence of dew condensation is prevented, the problem that occurs when dew condensation occurs is also solved.

The air blown out to the test room 2 is circulated again to the air-conditioning room 1, but the test room 2 is surrounded by the heat insulation jacket 24 as described above, and the inner wall 23 is kept at a temperature higher than the dew point temperature. No loss of water vapor due to water, has the same absolute humidity as air in the dew point state, and changes the absolute humidity after mixing even if the air obtained by the heater 6 is combined with the saturated air obtained by the heat exchanger 7 side There is no.

[0031]

As described above, according to the present invention, an air-conditioning room, a test room, and an air circulating means for circulating air to both the rooms are provided, and the air-conditioning room has a heat exchanger for generating saturated air, A constant-temperature and constant-humidity device provided with humidifying means upstream of the heat exchanger in the flow direction of the circulating air, and heating means for heating saturated air after passing through the heat exchanger, wherein the same type as in the related art Compared to the constant temperature and humidity chamber, the temperature and humidity accuracy of the test room air can be improved, and a device free from dew condensation on the wall surface of the test room can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air-conditioning room 11 Outside wall of an air-conditioning room 12 Partition wall of an air-conditioning room 13, 14 Airway 15 Common space below an airway 16 Common space above an airway 2 Test room 21 Test room opening 22 Plate body for rectification etc. 23 Test room Wall 24 Air jacket 25 Inner jacket heater 3 Insulation wall 4 Air duct 5 Partition wall 6 Air heater 7 Heat exchanger 71 Fin 72 Heat pipe 8 Humidifier 81 Humidifier heater 91 Dew point temperature controller 92 Air temperature controller F1 Air circulation Fan F2 Blower F3 Fan S1, S2 Temperature detection sensor

Claims (2)

(57) [Claims] An air circulating means for circulating air to an air-conditioning room, a test room, and both the rooms, wherein the air-conditioning room has a heat exchanger for generating saturated air and the heat exchanger in a flow direction of the circulating air. In a thermo-hygrostat provided with humidifying means on the more upstream side and heating means for heating saturated air after passing through the heat exchanger, inner wall heating for heating at least a part of the test chamber wall surface. Means for controlling the operation of the inner wall heating means so as to maintain the temperature of the wall surface of the test chamber heated by the inner wall heating means at the dew point temperature of the air circulating in the test chamber and at the circulating air temperature or lower. Means for controlling the operation of the inner wall heating means,
Operating or heating the inner wall heating means in synchronization with the operation or stoppage of the stage;
A thermo-hygrostat characterized by being stopped . 2. The method according to claim 2, wherein the inner wall heating means is provided on the inner wall of the test chamber.
An air jacket formed at least partially along
It has a heater to heat the air in the air jacket.
A thermo-hygrostat according to claim 1 .