JPH0854430A - Insulation resistance measuring instrument - Google Patents

Abstract

PURPOSE:To provide a stable temperature/humidity environment with consistent reproducibility of measurement data for an insulation resistance measuring instrument when evaluating insulation resistance recovery characteristics by forming dew at normal temperatures after leaving a substrate at a low temperature. CONSTITUTION:A temperature/humidity retainer 2 for housing a sample withdrawn from a constant-temperature/constant-humidity bath 1 is provided in the measurement system and insulation resistance is measured inside. The container 2 is formed from an aluminum material and a bad influence to measurement due to electromagnetic wave is excluded. Humidity from a humidifier 5 is supplied into the container and a specific temperature/humidity environment is achieved by a temperature/humidity controller 6 on the basis of the current temperature/humidity data detected by a temperature/humidity meter 4. The detected insulation resistance data are processed by a scanner 9 and are externally outputted to a personal computer 11 or a printer 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulation resistance measuring apparatus for evaluating insulation resistance recovery characteristics by measuring insulation resistance of a printed circuit board after being left at a low temperature, and particularly to improving reliability of obtained measurement data. The present invention relates to an insulation resistance measuring device capable of

[0002]

2. Description of the Related Art For example, the insulation resistance between conductors or holes such as a copper-clad laminate is one of the basically important characteristics in terms of the quality of the board, but usually, it is more significant.
It is the change in resistance under certain environmental conditions.
That is, the insulation resistance test of this type of sample has the greatest value when it is carried out under the same environmental conditions as when the sample used is actually used.

In this insulation resistance test, after leaving the substrate under a predetermined low temperature condition, it is returned to a constant room temperature environment to cause dew condensation on the sample surface, and the insulation resistance recovery characteristic of the sample at that time is evaluated. .

[0004]

However, in the insulation resistance recovery characteristic test currently performed, the insulation resistance is measured after the sample is taken out in an environment where temperature and humidity are unstable after being left at a low temperature. As a result, there is a problem that the obtained insulation resistance value greatly varies and the reliability of the measurement data is extremely low.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an insulation resistance measuring apparatus capable of measuring the insulation resistance recovery characteristic of a sample in a stable temperature and humidity environment after being left at a low temperature. To aim.

[0006]

In order to achieve the above object, an insulation resistance measuring apparatus according to the present invention comprises a constant temperature and humidity chamber capable of accommodating a sample and forming a low temperature environment, and a sample after being left at a low temperature. A temperature / humidity holding container to be housed, a humidifier that communicates with the temperature / humidity holding container to supply water into the container, and drive-controls the humidifier to hold the temperature / humidity holding container internal space at the constant room temperature environment. It is characterized by comprising a temperature / humidity adjusting means and an insulation resistance meter for measuring the insulation resistance of the sample contained in the temperature / humidity holding container.

According to a preferred embodiment, in the insulation resistance measuring apparatus, the temperature / humidity holding container is placed inside a constant temperature and constant humidity tank.

Further, in another embodiment, the temperature / humidity storage container is placed adjacent to the constant temperature / constant humidity bath outside the container and is formed of an electromagnetic wave barrier material.

Further, more preferably, the temperature and humidity holding container is provided with a heater for raising the temperature inside the container, and the operation is controlled by the temperature and humidity adjusting means.

[0010]

[Function] Instead of taking out the sample to the outside where temperature and humidity are unstable and performing dew condensation / measurement, put the sample in a temperature / humidity holding container isolated from the outside and let the sample surface condense here, so stable measurement is possible. The insulation resistance can be measured under the environment, and the measured insulation resistance values of the same type of sample do not vary, so-called consistent reproducible results can be obtained. At this time, the humidifier and the temperature / humidity adjusting means operate to maintain the humidity inside the temperature / humidity holding container at a predetermined value.

Further, when the temperature and humidity holding container is placed inside the constant temperature and humidity chamber, the influence of electromagnetic waves in the air on the measured insulation resistance value can be reduced, and the reliability of the measurement itself can be improved.

On the contrary, even when the temperature / humidity holding container is placed outside the constant temperature and constant humidity chamber, the container itself is formed of the electromagnetic wave barrier material to prevent the electromagnetic waves from entering the container. Therefore, the adverse effect of electromagnetic waves on the measurement data can be eliminated.

More preferably, if a heater is provided in the temperature / humidity holding container and the operation of the heater is controlled by the temperature / humidity adjusting means, the temperature at the time of measurement can be held at a constant condition with less variation. The reliability of the measured value can be further improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An insulation resistance measuring apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an insulation resistance measuring apparatus as a first embodiment in which a temperature and humidity holding container is arranged adjacent to a constant temperature and humidity chamber. In FIG. 1, 1 is a constant temperature and humidity chamber for containing a sample to generate a predetermined low temperature environment, 2 is a temperature and humidity holding container for storing a sample after being left at a low temperature, 3 is a constant temperature and humidity chamber 1 and a temperature and humidity holding container 2 is a surface insulation resistance meter that detects the surface resistance of the sample stored in 2. Temperature and humidity holding container 2
Is formed of an electromagnetic wave barrier material such as aluminum,
For example, it is arranged adjacent to the constant temperature and humidity chamber 1 as a housing having dimensions of 300 × 500 × 150 mm. Further, a thermo-hygrometer 4 for detecting the temperature and humidity inside the container is provided inside thereof.

A humidifier 5 is connected to the temperature / humidity holding container 2 to supply water vapor into the container to raise the humidity. The operation of the humidifier 5 is controlled by the temperature / humidity controller 6 based on the in-container temperature data and the humidity data obtained by the temperature / humidity meter 4.

Reference numeral 7 denotes a sample table which is left in a constant temperature and humidity chamber 1 in a low temperature environment and then immediately transferred into the temperature and humidity holding container 2 on which an insulation resistance to be measured is placed. The test piece 8 is arranged. The resistance value data detected by the surface insulation resistance tester 3 is transferred to the scanner 9 as a data processing unit, where predetermined arithmetic processing and the like are performed and output to the CRT 12 of the printer 10 or the personal computer 11. Become. In the present apparatus, the temperature / humidity data in the temperature / humidity holding container 2 controlled by the temperature / humidity controller 6 can also be input to the scanner 9 and externally output.

As described above, the insulation resistance measuring apparatus according to the present embodiment is configured as an insulation resistance measuring system including a plurality of units, and the insulation resistance measurement is performed in the temperature and humidity holding container 2 made of aluminum. The adverse effects of electromagnetic waves and winds and the adverse effects of dust and dirt are eliminated, and such disturbances can be eliminated and pure insulation resistance can be measured. Further, in the present embodiment, a humidifier 5 for supplying humidity to the temperature / humidity holding container 2 is provided, and the temperature / humidity controller 6 controls the humidifier 5 based on the temperature / humidity data from the temperature / humidity meter 4 provided in the holding container 2. Since the operation is controlled appropriately, the measurement environment in the temperature / humidity storage container 2 can be constantly maintained, and the reliability of the obtained data can be improved. As a modification, in addition to the illustrated humidifier 5, a heater (not shown) that raises the temperature in the temperature / humidity holding container 2 is provided, and the operation is entrusted to the temperature / humidity controller 6. good.

FIG. 2 shows an insulation resistance measuring device as a second embodiment of the present invention. In this embodiment, the same components as those in the previous embodiment are designated by the same reference numerals. In the previous embodiment, the temperature and humidity holding container 2 is provided adjacent to the constant temperature and humidity chamber 1.
On the other hand, in the second embodiment, the temperature and humidity holding container 2 is arranged inside the constant temperature and humidity chamber 1.

The temperature / humidity holding container 2 is made of an acrylic material in place of the above aluminum material, and the steam from the humidifier 5 is supplied to the inside thereof as in the first embodiment. There is. A heater 13 is provided at the bottom of the temperature / humidity holding container 2, and its operation is controlled by the temperature / humidity controller 6 like the humidifier 5.

In order to measure the insulation resistance, first, the insulation resistance test piece 8 is left in a constant temperature and humidity chamber 1 in a low temperature environment for a predetermined time, and then a sample table 8 is used by means such as a pusher (not shown).
Is pushed into the temperature and humidity holding container 2 side as it is. Since the temperature / humidity holding container 2 in the present embodiment is provided with the inwardly tilting wing 14 as shown in the drawing, when it is pushed by the sample table 7, the container entrance is automatically opened. Eight inputs are achieved. Along with the setting of the sample table 7 on the fixing member 15 in the container, the wing 14 of the temperature / humidity holding container 2 is closed at about the same time, whereby the space inside the constant temperature and humidity chamber 1 and the temperature / humidity holding container 2 are closed. The internal space is cut off, and a predetermined room temperature environment (measurement condition) is obtained. The operation of the other components shown in the figure is exactly the same as that of the previous embodiment, so the description thereof is omitted here.

As described above, according to the second embodiment of the present invention,
By storing the temperature / humidity holding container 2 inside the constant temperature / humidity tank 1 itself, the insulation resistance is measured while the test piece 8 is doubly blocked by the temperature / humidity holding container 2 and the constant temperature / humidity tank 1. Therefore, even if the container 2 for electromagnetic wave shielding is not formed of an aluminum material, a general material such as acrylic can be used to reduce the adverse effects of electromagnetic waves. Further, since it is an internal transfer (slide) type, the operator's hand does not come into contact with the test piece 8, and the resistance fluctuation component due to contamination can be made zero. Naturally, with this double shield, measurement error components due to vibration, wind, dust, dust, etc. can be reduced, and the reliability of measured values can be significantly improved.

(Confirmation Test) In order to confirm the test accuracy of the insulation resistance measuring device configured as described above, the insulation resistance recovery characteristics of the sample after being left at a low temperature were measured using the following equipment and materials.

Insulation resistance meter: Insulation resistance measurement range 10
~ 3 × 106Ω (at measurement voltage 100V) Equipment used: High resistance meter R8340A manufactured by Advantest Co., Ltd. Constant temperature and humidity chamber: ETAC F * 21 manufactured by Kusumoto Kasei Co., Ltd.
0P (with dedicated terminal box) Temperature / humidity range; -20 ° C to 100 ° C, 20% to 98% RH Measurement calculation unit: NEC PC9801FS measurement cable: Low noise double shield type Teflon (trademark) cable Sample: Glass cloth base Material Epoxy resin / copper-clad laminate GE-4F, GE-4 (JIS C 6480) or a comb-shaped electrode substrate using synthetic fiber cloth base material epoxy resin SE-1 as a conductor Conductor width: 0.318 (mm) Conductor spacing : 0.318 (mm) Stacking margin: 15.75 (mm) Cleaning agent: Isopropyl alcohol (JIS K 8
839) Further, the test was conducted in the following procedure.

(1) After cleaning the surface of the substrate with isopropyl alcohol, it is sufficiently dried. (2) After uniformly applying 0.05 ml of flux per substrate, soldering is performed under the following conditions.

Soldering conditions: In accordance with IPC SF-818 Flux: JS-64MSS * (manufactured by Hiroki) Solder composition: 60/40 (Sn / Pb) Solder temperature: 232 ± 6 ° C. Soldering time: 5-10 sec (3 ) After soldering, the insulation resistance value of the board cooled to room temperature is measured under the following measurement conditions, and a board having an insulation resistance value of 1 × 10 ¹³ Ω or more is used as a test piece.

Measurement conditions Measurement voltage: 100 V Measurement environment: Standard test room (23 ° C., 55% RH) Standard test box (temperature and humidity holding container: 23 ° C., 55%)
RH) Indoors when the air conditioner is off (4) Set the temperature and humidity of the constant temperature and humidity chamber to -20 ° C and 0% RH, insert the sample at a temperature of -20 ± 5 ° C, and leave it for 60 ± 5 minutes.

(5) Remove the sample from the constant temperature and humidity chamber,
In each of the following procedures, 10 seconds, 30 seconds, 1 minute to 10 minutes later (every 1 minute during this period), 20 minutes to 60 minutes later (1 hour during this period)
Insulation resistance is measured after 2 hours and 3 hours.

(Test 1) Samples were taken out from the constant temperature and humidity chamber, and among the JS-64MSS * samples, the ones with the highest insulation resistance values were divided into groups of I, II, III, and IV, each of which had a standard value of 6 pieces. The insulation resistance value was manually measured in a test room (23 ° C., 55% RH) and a standard test box (23 ° C., 55% RH). The results are shown in Fig. 3.

The figure shows that there is no noticeable difference between the two, and that values similar to those measured by the standard laboratory are obtained.

(Test 2) 25 ° C., 75% in constant temperature and humidity chamber
Use a measurement system that is controlled by a personal computer so that the temperature drops from RH to -20 ° C and 0% RH.
After achieving 0 ° C. and 0% RH, the sample was then taken out, put in a standard test box (23 ° C., 55% RH) to cause dew condensation on the sample surface, and thereafter the insulation resistance recovery characteristics were measured. FIG. 4 shows the results. The explanation of the arrow in the parentheses in the figure indicates that the sample was taken out from the environment of −20 ° C., 0% RH to 23 ° C., 55% RH at that time to condense the substrate. The same applies to the subsequent graphs. As the sample flux, JS-64MSS * and JS80MS are used.
Almost the same value was obtained in three measurements.

(Test 3) As in Test 2, after controlling the personal computer to achieve -10 ° C. and 0% RH in about 2 hours, the sample was taken out and the standard test box (25 ° C., 75%) was used.
RH) to cause dew condensation on the surface of the sample, and thereafter the insulation resistance recovery characteristic was measured. Results are shown in FIG. As the flux of the sample, JS-64MSS * and A90 were used, and almost the same value was obtained in three measurements.

(Test 4) As in Test 2, after controlling -20 ° C. and 0% RH in about 2 hours by controlling a personal computer, the standard test box (23 ° C.) in the constant temperature and humidity chamber was kept without taking out the sample. , 55% RH) to cause dew condensation on the sample surface, and thereafter the insulation resistance recovery characteristics were measured. The result is shown in Fig. 6.
Shown in Sample flux is JS-64MSS * and JS
80MS was used and three measurements gave almost the same values. The test conditions and temperature conditions of the tests 1 to 4 are summarized in the table below.

[0033]

[Table 1]

In order to confirm the effect of the insulation resistance measuring apparatus of the present invention, various insulation resistance recovery characteristic evaluation tests which have been conventionally performed as comparative examples were conducted in the following manner.

(Comparative Test 1) Samples were taken out from the constant temperature and humidity chamber, and among the JS-64MSS samples, the ones each having a higher insulation resistance value were divided into I, II, and III groups of 6 sheets each, and the air conditioner was turned off. The insulation resistance value was manually measured in the room. FIG. 7 shows the results. The figure shows I, II, II
Although the difference is recognized between the groups of I, it shows that the values greatly vary within each group.

(Comparative Test 2) The inside of the constant temperature and humidity chamber was 25 ° C. and 7
Using a measuring system that is controlled by a personal computer so that the temperature drops from 5% RH to -20 ° C and 0% RH, it will be -2 in about 2 hours.
After achieving 0 ° C. and 0% RH, the sample was then taken out, and the surface of the sample was condensed in the air conditioner inoperative state without using the standard test box, and then the insulation resistance recovery characteristics were measured. The results are shown in Fig. 8. The figure shows that the results of three measurements greatly vary under the influence of electromagnetic waves in the air.

(Comparative Test 3) The inside of the constant temperature and humidity chamber was 25 ° C. and 7
Using a measuring system that is controlled by a personal computer so that the temperature drops from 5% RH to -20 ° C and 0% RH, it will be -2 in about 2 hours.
After achieving 0 ° C. and 0% RH, the sample was then taken out, and the sample surface was condensed with dust scattered in the air, and then the insulation resistance recovery characteristics were measured. The results are shown in Fig. 9.
The figure shows that, similarly to the comparative test 2, the measurement results of three times greatly vary.

(Comparative Test 4) Similar to Comparative Test 2, the sample was taken out and the insulation resistance recovery characteristic was evaluated. However, the air conditioner is turned on during the measurement and the measurement environment is 14 ° C and 55% RH.
Changed to. The results are shown in Fig. 10. The figure shows that the measurement results of three times greatly vary with changes in temperature and humidity.

(Comparative Test 5) Similar to Comparative Test 2, the sample was taken out and the insulation resistance recovery characteristic was evaluated. However, vibration and wind were applied to the sample during the measurement. The results are shown in Fig. 11. The figure shows that the results of three measurements vary greatly. The test conditions and temperature conditions of each of the comparative tests 1 to 5 are summarized in the table below.

[0040]

[Table 2]

From the above measurements, it was confirmed that in Tests 1 to 4 using the standard test box, the obtained insulation resistance recovery characteristics were also almost constant and stable between repeated tests. On the other hand, in Comparative Tests 1 to 5 that do not use the standard test box, the obtained insulation resistance recovery characteristics also vary widely between repeated tests, and even if the average value represents the recovery characteristics, the reliability of the data itself is reduced. This proves that the sex is extremely low.

[0042]

As described above, the insulation resistance measuring device according to the present invention is capable of accommodating a sample after being left at a low temperature and measuring the insulation resistance of the sample in addition to the conventional constant temperature and humidity chamber. Since the temperature and humidity holding container is provided, the insulation resistance can be measured by dew condensation on the sample surface under a constant environmental condition where the contact with the outside is cut off, and the reliability of the measurement data can be improved. In addition, since the sample is stored in a temperature and humidity holding container, the influence of electromagnetic waves, vibrations and wind on the measurement data can be eliminated, and the adhesion of dust and dirt to the sample can be eliminated. Can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an insulation resistance measuring device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an insulation resistance measuring device according to a second embodiment of the present invention.

FIG. 3 is a temperature and humidity holding container of the present invention (standard test box)
And test 1 using a standard laboratory (manual measurement)
FIG. 5 is a diagram showing the results of the above and showing the recovery characteristics of surface insulation resistance.

FIG. 4 is a container for holding temperature and humidity of the present invention (standard test box)
It is a figure which shows the result of the test 2 (automatic measurement) which used the above, and shows the recovery characteristic of insulation resistance.

FIG. 5: Temperature and humidity storage container of the present invention (standard test box)
It is a figure which shows the result of the test 3 (automatic measurement) which used the above, and shows the recovery characteristic of insulation resistance.

FIG. 6 is a container for holding temperature and humidity of the present invention (standard test box)
It is a figure which shows the result of the test 4 (automatic measurement) which used the above, and shows the recovery characteristic of insulation resistance.

FIG. 7 is a diagram showing an insulation resistance recovery characteristic of a comparative test 1 measured manually in a room when the air conditioner is off.

FIG. 8 is a diagram showing insulation resistance recovery characteristics of comparative test 2 automatically measured in a room when the air conditioner is off.

FIG. 9 is a comparative test 3 in which the surface of the sample is condensed in a state where dust is scattered in the air, and the insulation resistance value at that time is automatically measured.
It is a figure which shows the result of.

FIG. 10 is a diagram showing the result of a comparative test 4 in which the sample is taken out and the insulation resistance value is automatically measured when the air conditioner is turned on during the measurement as in the comparative test 2.

FIG. 11 is a diagram showing a result of a comparative test 5 in which the sample is taken out like the comparative test 2 and the insulation resistance value when the vibration and the wind are applied during the measurement is automatically measured.

[Explanation of symbols]

 1 Constant Temperature and Humidity Tank 2 Temperature and Humidity Storage Container 3 Surface Insulation Resistance Meter 4 Temperature and Humidity Meter 5 Humidifier 6 Temperature and Humidity Controller 7 Sample Stand 8 Insulation Resistance Test Piece 9 Scanner 10 Printer 11 Personal Computer 12 CRT 13 Heater

Claims (4)

[Claims] 1. An insulation resistance measurement in which a sample is left in a predetermined low temperature environment, then returned to a constant room temperature environment to cause dew condensation on the surface of the sample, and the insulation resistance of the sample is measured to evaluate insulation resistance recovery characteristics. A device, which is a thermo-hygrostat capable of accommodating the sample to form the low temperature environment, a temperature / humidity holding container for accommodating the sample after being left at a low temperature, and a container communicating with the temperature / humidity holding container. A humidifier for supplying water to the inside, a temperature and humidity adjusting means for driving and controlling the humidifier to hold the temperature and humidity holding container inner space in the constant room temperature environment, an insulation resistance meter for measuring the insulation resistance of the sample, An insulation resistance measuring device comprising: 2. The insulation resistance measuring device according to claim 1, wherein the temperature and humidity holding container is placed inside the constant temperature and constant humidity chamber. 3. The insulation resistance measuring device according to claim 1, wherein the temperature / humidity storage container is placed adjacent to the constant temperature and constant humidity chamber and is formed of an electromagnetic wave barrier material. 4. The insulation according to claim 1, wherein the temperature / humidity holding container includes a heater for raising the temperature inside the container, and the temperature / humidity adjusting means also controls the operation of the heater. Resistance measuring device.