JP3442818B2 - Environmental testing equipment for electronic components - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component environmental testing apparatus for electronic components.

[0002]

2. Description of the Related Art Precision electronic parts such as semiconductor devices are shipped after undergoing an environmental test to show desired characteristics under a predetermined temperature environment in order to guarantee the temperature. Such an environmental test normally tests whether or not the electronic component exhibits predetermined characteristics at a high temperature of 90 ° C., a room temperature of 25 ° C. and a low temperature of −5 ° C., for example.

Conventionally, the environmental test as described above has been carried out by loading the electronic component D into a constant temperature bath a as shown in FIG. 3, and in order to create a low temperature atmosphere in the constant temperature bath, a liquid is used. A low temperature nitrogen gas obtained by vaporizing nitrogen is introduced. Also,
To create a high temperature atmosphere, a high temperature gas such as heated air is introduced into the constant temperature bath.

[0004]

By the way, when the temperature environment is created in the constant temperature bath to test the electronic parts as described above, there are various problems as follows.

First, there is a problem that a low temperature nitrogen gas is required to create a low temperature atmosphere, which is uneconomical and temperature control is difficult. Second, there is a need for a circuit that circulates nitrogen gas in an airtight manner, and the constant temperature chamber itself must have a certain volume, which inevitably leads to an increase in size and cost of the constant temperature chamber. was there. Thirdly, there is a problem that it takes time to change the temperature because the constant temperature chamber needs to have a certain volume and the temperature is changed by exchanging the gas inside. Fourth, when a large number of electronic components are placed on a tray, etc. and are carried into a constant temperature bath and environmental tests of these many electronic components are collectively performed, it takes more time before the trays reach the environmental temperature. However, there was also a problem that the efficiency of the test was significantly reduced.

The present invention was devised under the circumstances as described above, and solved the problems of the prior art all at once.
It is possible to create a set temperature for environmental testing of electronic parts simply, inexpensively and quickly, and by doing so,
It is an object of the present invention to provide a simpler, faster, and more accurate environmental test for electronic components.

[0007]

In order to solve the above problems, the present invention takes the following technical means.

That is, the environment test apparatus for electronic parts according to claim 1 of the present application comprises a first heat-conductive block located at a higher level, a second heat-conductive block located at a lower level, and and an electronic cooling device is interposed between the first and second heat good conductivity block, above the first heat good conductivity block, electrons contact surface for the electronic component is provided on the protruded the component of the environmental testing device, holes for face the contact surface provided et al is, and the first heat good conductivity
Further equipped with a pallet that does not touch the block ,
It is characterized in that the lower surface of the electronic component placed on the pallet is brought into contact with the contact surface through the hole while the characteristic test of the electronic component is performed.

According to a second aspect of the present invention, there is provided an electronic component environmental testing apparatus comprising: a first thermal conductive block located at a higher level; a second thermal conductive block positioned at a lower level; An electronic cooling device interposed between the second heat conductive block and a control device for controlling the electronic cooling device,
A temperature sensor for detecting the temperature of the first heat conductive block, wherein the first heat conductive block has a protruding contact surface for an electronic component
An environmental testing device with a hole facing the contact surface
And contacting the first heat conductive block
Further comprising a free pallet, the control device, the temperature
Temperature control so that the temperature detected by the
The electronic device is controlled so that the lower surface of the electronic component placed on the pallet is brought into contact with the contact surface through the hole and the characteristic test of the electronic component is performed. Is characterized by.

[0010]

The operation and effect of the present invention is completely different from the conventional method in which a predetermined temperature environment is created in a constant temperature bath to conduct an environmental test of electronic parts. That is, the environmental testing device of the present invention, by directly contacting the electronic component to be tested to the contact surface provided in the first thermal conductive block, by controlling the temperature of the contact surface, of the electronic component, Specifically, the temperature of the internal element is set as desired. In the resin package type electronic component, there is a certain correlation between the thermal energy applied to the surface of the resin package from the contact surface of the first block and the temperature of the internal chip. This correlation means that, for example, when a thermocouple is inserted inside the electronic component and the temperature of the internal chip detected by this thermocouple reaches a desired temperature, the contact surface of the first heat conductive block is It can be known by sampling how much temperature should be at.

When the temperature of the contact surface on the first heat conductive block necessary for obtaining the desired chip temperature of the electronic component is determined, the electronic cooling device is controlled so that this temperature is achieved. Of.

The electronic cooling device is a semiconductor device having a solid-state heat pump function by the so-called Peltier effect. Depending on the magnitude of the electric current passed through the electronic cooling device, the first heat-conductive block and the second heat-conductive block are provided. It is possible to easily control the magnitude of heat transfer between the two blocks, and it is also possible to easily reverse the direction of heat transfer between the blocks by changing the direction of the direct current. Further, the time for obtaining the desired temperature from energization is relatively short, and therefore, even when changing the temperature, this can be achieved quickly.

In the electronic cooling device, the temperature of the contact surface provided on the first heat-conductive block is increased by transferring heat from the first heat-conductive block to the second heat-conductive block. Can be kept at a low temperature such as −5 ° C., on the other hand, conversely, the heat transfer from the second good thermal conductivity block to the first good thermal conductivity block can be achieved by changing the conduction polarity. The temperature of the contact surface provided on this first heat conductive block,
For example, a high temperature such as 90 ° C. can be used. Of course, it is also easy to set and maintain the temperature of the contact surface of the first heat conductive block at room temperature of 25 ° C., for example, by setting the magnitude and direction of the current to predetermined values.

As is apparent from the above description, in the present invention, the contact surface provided on the first heat conductive block is brought into direct contact with the electronic component to be tested to bring it to a desired temperature. The temperature is set and then a substantial environmental test is conducted. Moreover, the temperature change between low temperature, room temperature, and high temperature can be performed very easily and quickly. Also,
The set temperature is maintained stably. Furthermore, even when a large number of electronic components are collectively subjected to an environmental test,
Since it is possible to set the temperature of the electronic components via the contact surface that directly contacts these electronic components, unnecessary members such as trays can be set compared to the conventional environmental test method using a high temperature tank for setting the ambient temperature. It is not necessary to heat up or cool down even more, which greatly increases the speed of temperature change.

As a result of the above, according to the present invention, the environmental test of the electronic component can be carried out easily, quickly and accurately, and as a whole, the efficiency of the environmental test of the electronic component is remarkably higher than the conventional one. Increase.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below.
A specific description will be given with reference to the drawings.

FIG. 1 schematically shows the configuration of an example of an electronic component environmental testing device 2 of the present invention. Reference numeral 3 indicates a first heat conductive block made of a heat conductive metal such as stainless steel or aluminum, and its upper portion is in contact with the lower surface of the package portion of the resin package type electronic component D. The contact surface 4 is formed to project. An electric heating means such as a sheath heater 5 is also incorporated inside the first heat conductive block 3. Further, a temperature sensor 6 such as a thermocouple is attached for detecting the temperature of the first heat conductive block 3, and thus the surface temperature of the contact surface 4.

In FIG. 1, reference numeral 7 indicates a second thermal conductive block made of a thermal conductive metal such as stainless steel or aluminum, like the first thermal conductive block 3.

An electronic cooling device 8 is interposed between the lower surface of the first thermal conductive block 3 and the upper surface of the second thermal conductive block 7. As shown in FIG. 1, the electronic cooling device 8 includes a P-type thermal semiconductor element 9 and an N-type thermal semiconductor element 10, and metal electrodes 11 and 12.
Has a structure in which π type is alternately connected in series.
Of course, each metal electrode 1 forming the upper surface of the electronic cooling device 8
1 and the lower surface of the first thermal conductive block 3 and between the metal electrodes 12 forming the lower surface of the electronic cooling device 8 and the upper surface of the second thermal conductive block 7. An insulator 13 such as a thin alumina ceramic plate is interposed.

Between both ends of the electronic cooling device 8, a DC power supply device 14 capable of changing the magnitude and direction of the current is connected.

The electronic cooling device 8 transfers heat between its upper and lower surfaces by the Peltier effect as described below. At the π-type connection where a current flows from the N-type element to the P-type element, electrons move from a low energy level to a high energy level, so that the vibration energy of the surrounding crystal lattice is absorbed, and as a result, the temperature decreases. . On the contrary, in the π-type connection part where the current flows from the P-type element to the N-type element, the electrons move from the state of high energy level to the state of low energy level, so that surplus energy is given to the surrounding crystal lattice to The vibration energy increases, which results in an increase in temperature. When this is applied to the configuration of FIG. 1, when the direct current flows in the direction of arrow A, the temperature lowers on the upper surface of the electronic cooling device 8 and the temperature rises on the lower surface. That is, the heat of the first heat conductive block 3 is absorbed and the heat is released to the second heat conductive block 7. In other words, heat transfer from the first heat-conductive block 3 to the second heat-conductive block 7 occurs,
As a result, the temperature of the first heat conductive block 3 decreases,
The temperature of the second heat conductive block 7 rises.

On the contrary, when the direction of the direct current is changed so that the current flows in the direction of arrow B in FIG.
As a result of heat transfer from the first thermal conductive block 3 to the first thermal conductive block 3, the temperature of the second thermal conductive block 7 decreases and the temperature of the first thermal conductive block 3 increases.

The degree of heat transfer as described above can be easily changed by changing the magnitude of the electric current to be passed through the electronic cooling device 8.

From the above, the temperature of the contact surface 4 provided on the first heat conductive block 3 can be freely changed from low temperature to high temperature, and the temperature after the change can be maintained. In this embodiment, the heater 5 is incorporated in the first heat conductive block 3, and the heater 5 assists the heating of the first heat conductive block 3 by the action of the electronic cooling device 8. The contact surface 4 can be set at a high temperature more quickly.

The current control for the electronic cooling device 8 and the current control for the heater 5 can be performed by the control device 15 which is composed of a microcomputer or the like. The power supply device 14 of the electronic cooling device 8 is controlled by the control device 15. The power supply device 16 for the heater 5 is also controlled by the control device 15. As control input signals, temperature information from the temperature sensor 6 such as the thermocouple is input to the control device 15.

As shown in FIG. 1, in the environment test apparatus 2 of the present invention, a tray or pallet 17 for mounting the electronic component D is provided above the first heat conductive block 3. Is located in. The pallet 17 is provided with a hole 18 for exposing the contact surface 4 provided in a protruding shape on the first heat conductive block 3.
Only the lower surface of the electronic component D placed on the pallet 17,
The contact surface 4 can be contacted. The external lead L extending from the electronic component D placed on the pallet 17 is pressed onto the pallet by the pressing member 19 which also serves as a measurement terminal. In this state, when the electronic component D reaches a predetermined temperature, Characteristic tests are conducted. Needless to say, the configuration of the pallet 17 can be variously changed according to the form of the electronic component D to be tested. Also, when performing such an environmental test on an electronic component that has been subjected to lead forming by bending the external leads downward, it is possible to use a measurement socket (not shown) into which the external leads can be inserted, instead of the pallet 17 described above. Is.

In the above structure, the temperature of the electronic component D to be tested is set, for example, as follows. As mentioned above, environmental tests typically involve, for example, -5.
At low temperatures of 0 ° C, room temperature of 25 ° C, and high temperatures of 90 ° C, it is tested whether it exhibits the desired properties. Of course, this temperature should be a temperature at which the internal chip is applied in the case of the resin package type electronic component, and for that purpose, the following temperature control method is adopted.

First, prior to the test, a thermocouple is inserted into an electronic component of the same type as the electronic component to be tested so as to reach the internal chip, and the temperature detected by the thermocouple becomes predetermined. As described above, the electronic cooling device 8 and / or
Alternatively, the heater 5 is driven. From this, it becomes clear what temperature the temperature sensor 6 inserted in the first heat-conductive block should show in order for the chip temperature of the electronic component D to become predetermined. Therefore, in subsequent tests,
The electronic cooling device 8 and / or the heater 5 are arranged so that the temperature of the first heat conductive block 3 detected by the temperature sensor 6 becomes the temperature found by the preliminary temperature sampling as described above. It should be controlled.

Further, many semiconductor devices can measure a forward voltage value (so-called VF value), which indicates that the voltage changes with temperature when a constant current is passed.
Since this forward voltage value has a 1: 1 correspondence with the chip temperature, the internal chip temperature can be known by measuring this forward voltage value. Therefore, prior to the environmental test, for the electronic components of the same type, in order for the forward voltage value to represent a predetermined temperature, which temperature the first thermal conductive block 3 should exhibit, in other words, the temperature sensor described above. The temperature from which the output from 6 should indicate is measured, and in the subsequent tests, as indicated by the signal from the sensor 6, the electronic cooling device 8
And / or the heater 5 may be controlled.

As described above, according to the electronic component environmental testing apparatus of the present invention, the electronic component environmental testing can be performed with a simple and compact structure.

FIG. 2 shows an example of the structure of the pallet 17 when a large number of electronic components D are collectively subjected to an environmental test. In this case, as in the case shown in FIG. 1, the pallet 17 is formed with holes 18 for exposing the lower surface of the mounted electronic component D downward. A plurality of contact surfaces 4 are formed on the upper surface of the first heat conductive block 3 in a protruding shape. As can be seen from this figure, the pallet 17 is used to measure a large number of electronic components D.
However, the contact surface 4 provided on the first heat conductive block 3 for applying heat or cold to the electronic component D does not contact the pallet 17 and It makes contact with the bottom surface only. Therefore, it is possible to quickly set only the electronic component D to the predetermined temperature and perform the test without waiting for the pallet 17 to be heated or cooled, and the temperature can be changed extremely quickly. This also significantly improves the efficiency of the environmental test, as compared with the conventional method in which a constant temperature bath is used. Moreover, since the entire pallet 17 is not heated and cooled to a high temperature, this pallet 1
The life of 7 is also extended.

Of course, the scope of the present invention is not limited to the above embodiments. In the embodiment, the heater is incorporated in the first heat conductive block, but whether or not to incorporate such a heater is a matter of choice.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing another embodiment of the present invention.

FIG. 3 is a conventional explanatory diagram.

[Explanation of symbols]

1 Environmental test temperature setting device 2 Environmental test equipment 3 First heat conductive block 4 contact surface 5 heater 6 Temperature sensor 7 Second heat conductive block 8 Electronic cooling device 15 Control device

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Claims (2)

(57) [Claims] 1. A first heat-conductive block located at a higher level, a second heat-conductive block located at a lower level, and a heat-conductive block interposed between the first and second heat-conductive blocks. With the electronic cooling device, the first heat conductive block,
Electronic contact surface for the electronic component is provided on the protruded
The component of the environmental testing device, holes for face the contact surface provided et al is, and the first
A pallet that does not come into contact with the first heat conductive block is further provided, and a characteristic test of the electronic component is performed while the lower surface of the electronic component placed on the pallet is brought into contact with the contact surface through the hole. An environment testing device for electronic parts, characterized in that it is configured to perform. 2. A first heat-conductive block located at a higher level, a second heat-conductive block located at a lower level, and a heat-conductive block interposed between the first and second heat-conductive blocks. An electronic cooling device, and a control device for controlling the electronic cooling device,
A temperature sensor for detecting the temperature of the first heat conductive block, wherein the first heat conductive block has a protruding contact surface for an electronic component
An environmental testing device, wherein a hole facing the contact surface is provided, and the first heat
More pallets that don't touch the conductive blocks
Provided, the control device detects the temperature from the temperature sensor is predetermined
To control the electronic cooling device so that
The electronic component environment is characterized in that the lower surface of the electronic component placed on the pallet is brought into contact with the contact surface through the hole while performing a characteristic test of the electronic component. Test equipment.