JP2915969B2 - Constant temperature bath for IC testing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial application field" The present invention relates to an IC test thermostat device for placing an IC (semiconductor integrated circuit) in a thermostat at a low temperature and operating the thermostat particularly at a low temperature. The present invention relates to a mechanism for returning a state to a normal temperature.

"Conventional technology" A mechanism for placing an IC in a thermostat and testing it at a low temperature such as -30 ° C is a mechanism for returning the thermostat from a low-temperature operation state to a normal temperature such as 25 ° C. Conventionally, the inside of the constant temperature bath is cooled by a cooling device in the bath such as vaporizing liquid nitrogen and supplied into the constant temperature bath, the outside of the constant temperature bath is heated by the dew condensation prevention heater, and the dehumidified air blowing unit supplies the constant temperature bath to the constant temperature bath. In a low-temperature operation state in which dehumidified air is blown from the outside, the operator first turns off the temperature control on / off switch, thereby stopping the cooling in the constant temperature bath by the cooling device in the bath and stopping the heating of the dew condensation prevention heater. At the same time, the blowing of the dehumidifying air into the constant temperature bath by the dehumidifying air blowing means is stopped, and then the operator switches the control temperature setting switch from the low temperature side to the normal temperature side, so that the control unit is controlled. Temperature information such as 25 ° C. is given, and then the operator turns on the above-mentioned temperature control on / off switch, whereby the inside of the constant temperature bath is heated by the heater for heating the inside of the bath. By monitoring the temperature in the thermostat and turning off the temperature control on / off switch when the temperature in the thermostat reaches a predetermined temperature such as 25 ° C., the heating of the heater in the chamber is stopped. It is configured to be.

[Problem to be Solved by the Invention] However, in the above-mentioned conventional constant temperature chamber for IC testing, in order to return to the normal temperature from the low temperature operation state, the temperature control on / off switch is turned off, and the control temperature setting switch is set to the low temperature side. To a normal temperature side, turn on the temperature control on / off switch, monitor the temperature in the thermostat, and turn off the temperature control on / off switch. When returning to the normal temperature from the state, at the same time as the cooling in the constant temperature bath is stopped, the heating of the dew condensation prevention heater is stopped,
Since the blowing of the dehumidified air to the thermostat is stopped, dew condensation may occur in the thermostat in the process of returning to the normal temperature.

In view of this, the present invention relates to an IC test thermostat device for placing an IC in a thermostat and testing at a low temperature, particularly in a mechanism for returning the thermostat from a low-temperature operation state to a normal temperature, and once turning on a normal-temperature return processing switch. With this simple operation, it is possible to return the temperature from the low-temperature operation state to the normal temperature, and to prevent dew condensation from occurring in the constant temperature bath during the process of returning to the normal temperature.

[Means for Solving the Problems] In the present invention, a constant temperature bath in which an IC to be tested is arranged, a cooling device in a bath for cooling the constant temperature bath, and a heater for heating the inside of the constant temperature bath And a dew condensation preventing heater for heating the outside of the constant temperature bath, a dehumidifying air blowing unit for blowing dehumidified air from the outside to the constant temperature bath, a temperature sensor disposed in the constant temperature bath, and a normal temperature return processing switch,
A display unit and a control unit having the following configuration are provided.

In the low-temperature operation state in which the inside of the constant temperature bath is cooled by the inside cooling unit, the dew condensation prevention heater is heated, and the dehumidifying air is blown onto the constant temperature bath by the dehumidifying air blowing unit, When the normal temperature return processing switch is turned on, the cooling in the constant temperature bath by the cooling device in the bath is stopped, the heater in the bath is heated, and the heater for dew condensation prevention is continued, and the dehumidification is performed. While continuing to blow the dehumidified air to the constant temperature bath by the air blowing means, it is determined whether or not the inside of the constant temperature bath has reached a predetermined temperature from the output of the temperature sensor, and when it is determined that the predetermined temperature has been reached, Controlling the heater for heating the inside of the bath to maintain the inside of the constant temperature bath at a predetermined temperature, and determining whether a predetermined time has elapsed since the inside of the constant temperature bath reached a predetermined temperature, When it is determined that elapsed between the,
Stopping the heating of the in-bath heating heater and the dew condensation preventing heater, stopping the dehumidifying air blowing to the constant temperature bath by the dehumidifying air blowing means, and completing the normal temperature return processing on the display unit. Display configuration.

[Operation] In the thermostatic bath apparatus for IC testing of the present invention configured as described above, if the operator first turns on the normal-temperature return processing switch, a series of operations are automatically performed by the control unit. The constant-temperature bath can be returned from the low-temperature operation state to the normal temperature by a simple operation of turning on the normal-temperature return processing switch once. Also, even if the normal temperature return processing switch is turned on, heating of the dew condensation prevention heater does not stop until a predetermined time elapses after the inside of the constant temperature bath reaches a predetermined temperature due to heating of the heater in the bath, and the constant temperature bath does not stop. Since the blowing of dehumidified air to the air does not stop, no dew condensation occurs in the constant temperature bath during the process of returning to normal temperature.

Example FIG. 1 shows an example of an IC test thermostat apparatus of the present invention.

An IC placement unit 11 is provided in the thermostat 10, and an IC to be tested is placed in the IC placement unit 11 (not shown). The in-bath cooling means 20 is provided for the incubator 10 to vaporize, for example, liquid nitrogen and supply it to the in-bath 10 to cool the in-bath 10 to a low temperature such as −30 ° C. In the thermostat 10,
A heater 30 for heating the inside of the constant temperature bath 10 is provided. Outside the constant temperature bath 10, a dew condensation preventing heater 40 for heating the outside of the constant temperature bath 10 is provided. Outside the thermostat 10, a dehumidifying air blowing means 50 for blowing dehumidified air into the thermostat 10 is provided. As an example, dehumidifying air blowing means 50
The compressed air from the compressed air source 51 is supplied to the air dryer 53 through the valve 52 to be dehumidified, the dehumidified air from the air dryer 53 is blown from the nozzle 54 to the thermostat 10, and is heated by the air heating heater 55, The heated dehumidified air is blown from the nozzle 56 to the thermostat 10.

A temperature sensor 60 is provided in the thermostat 10. Outside the thermostat 10, an operation panel 70 on which a normal-temperature return processing switch 71 and a light-emitting diode 72 are mounted, and a display unit 80 are provided. The display unit 80 is, for example,
A signal tower 81 having a blue lamp 81B, a yellow lamp 81Y, and a red lamp 81R, a chime 82, and a plasma display 83 are provided. A control unit 90 for executing a control operation program shown in FIG. 2 and described below is provided.

That is, in the low temperature operation state of the constant temperature bath 10, the inside of the constant temperature bath 10 is cooled to a low temperature such as −30 ° C. by the cooling unit 20 in the bath, the heater 40 for preventing dew condensation is heated, and the dehumidifying air blowing unit 50 is heated. The valve 52 is opened, the air dryer 53 is driven, and the heater 55 for air heating is heated, so that the unheated dehumidified air and the heated dehumidified air are blown to the thermostat 10, but in this low-temperature operation state, The control unit 90 first determines whether or not the normal temperature return processing switch 71 is turned on in the decision 91.

Then, when the worker turns on the normal temperature return processing switch 71, and when the decision 91 determines that the normal temperature return processing switch 71 is turned on, the control unit 90 proceeds to the process 92, and the control unit 90 proceeds to the process 92. By thermostat
The cooling inside the tank 10 is stopped, the heater 30 in the tank is heated, the heater 40 for preventing dew condensation is continued to be heated, and the valve 52 of the dehumidifying air blowing means 50 is kept open.
By keeping the driving of the air heater 53 and the heating of the air heater 55, the blowing of the unheated dehumidified air and the heated dehumidified air to the thermostat 10 is continued.

Next, proceeding to Decision 93, it is determined from the output of the temperature sensor 60 whether or not the temperature in the thermostat 10 has reached 25 ° C.
When it is determined that the temperature has reached, the process proceeds to process 94 to control the heater 30 in the bath to maintain the inside of the constant temperature bath 10 at 25 ° C.

Next, proceed to Decision 95, and the inside of the
It is determined whether or not 5 minutes have elapsed since the temperature reached, and when it is determined that 5 minutes have elapsed, the process proceeds to process 96, in which heating of the in-tank heater 30 and the dew condensation prevention heater 40 is stopped, and dehumidification is performed. By closing the valve 52 of the air blowing means 50, stopping the driving of the air dryer 53, and stopping the heating of the heater 55 for air heating, the blowing of the unheated dehumidified air and the heated dehumidified air to the thermostat 10 is stopped. Then, the process proceeds to the process 97, where the signal tower 81 of the display unit 80 is displayed.
Blinks the yellow lamp 81Y, sounds the chime 82, displays a message on the plasma display 83 indicating that the normal-temperature return processing has been completed, and turns on the light-emitting diode 72 on the operation panel 70.

As described above, in the constant temperature chamber device for IC testing of the present invention, when the worker first turns on the normal temperature return processing switch 71, a series of operations are automatically performed by the control unit 90, and the normal temperature return processing is performed. The simple operation of turning on the switch 71 once can return the thermostat 10 from the low-temperature operation state to the normal temperature. Also, the normal temperature return processing switch 71
Even if is turned on, the heating of the dew condensation prevention heater 40 is not stopped until a predetermined time elapses after the inside of the constant temperature bath 10 reaches a predetermined temperature due to the heating of the heater 30 in the bath,
Since the blowing of the dehumidified air to the thermostat 10 does not stop, no dew condensation occurs in the thermostat 10 in the process of returning to the normal temperature.

[Effects of the Invention] As described above, according to the present invention, it is possible to return the constant-temperature bath from the low-temperature operation state to the normal temperature by a simple operation of turning on the normal-temperature return processing switch once, and to return to the normal temperature. During the process, no condensation occurs in the thermostat.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a constant temperature chamber device for IC testing according to the present invention, and FIG. 2 is a flowchart showing an example of a control operation program executed by a control unit thereof.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁶ , DB name) G01R 31/26 B01L 11/00 G01N 35/00-37/00 G01N 27/28

Claims (1)

(57) [Claims] 1. A constant temperature bath in which an IC to be tested is arranged, a cooling unit in the bath for cooling the inside of the constant temperature bath, a heater for heating the inside of the constant temperature bath, and a heater for heating the outside of the constant temperature bath A dew condensation prevention heater, dehumidifying air blowing means for blowing dehumidified air from the outside to the constant temperature bath, a temperature sensor disposed in the constant temperature bath, a normal temperature return processing switch, a display unit,
A control unit, wherein the control unit cools the inside of the constant temperature bath by the inside cooling unit, heats the dew condensation prevention heater, and blows dehumidified air onto the constant temperature bath by the dehumidified air blowing unit. In the low-temperature operation state, when the normal-temperature return processing switch is turned on, the cooling in the constant-temperature bath by the cooling device in the bath is stopped, the heater in the bath is heated, and the heater for preventing condensation is heated. While continuing to blow the dehumidified air to the constant temperature bath by the dehumidifying air blowing means, it is determined from the output of the temperature sensor whether or not the inside of the constant temperature bath has reached a predetermined temperature, to the predetermined temperature When it is determined that the temperature has reached, the inside-bath heating heater is controlled to maintain the inside of the constant-temperature bath at a predetermined temperature, and whether a predetermined time has elapsed after the inside of the constant-temperature bath has reached a predetermined temperature. When it is determined that the predetermined time has elapsed, the heating of the heater for heating in the tank and the heater for preventing dew condensation are stopped, and the blowing of dehumidified air to the constant temperature bath by the dehumidified air blowing means is stopped. In addition, the constant temperature bath device for IC test, wherein the display unit indicates that the normal temperature return process has been completed.