JPS59128420A - Thermostatic chamber - Google Patents

Abstract

PURPOSE:To enable to measure and monitor the heat distribution of a smaple witout contact, by providing an infrared ray sensor in a thermostatic chamber. CONSTITUTION:Infrared ray emitted from a sample in a thermostatic chamber 1 are detected by an infrared ray sensor 2. The range of heat distribution measurement of a sample 10 is set by a measuring range determining means 5. The heat distribution of the sample, which also corresponds to the state of the inside of the sample, is measured by a heat distribution measuring means 6 without contact, based on the scanning of the sample by the sensor 2. The thermal image of the sample based on the measured heat distribution values is displayed by a CRT9 through an image processing means 8 and monitored. A heater 3 and a cooler 4 are controlled through a thermostatic chamber control means 7, which operates in correspondence with the means 6, and repeated environmental tests under the desired program can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant temperature bath for measuring heat distribution of a sample.

Generally, in order to evaluate the electrical characteristics of a sample, many environmental tests such as high temperature holding using a constant temperature bath and temperature cycling are carried out. During the test, if a defect occurs in the sample and the defect is in a defective location that depends on heat or temperature, the defective location, such as the location of foreign matter, can be determined by measuring the heat distribution of the sample.

Size, shape, etc. can be estimated visually.

For this reason, heat distribution measurement becomes necessary.

This type of conventional heat distribution measurement involves attaching thermistors or thermocouples to multiple locations on a sample in a thermostatic oven, and recording the output of the thermistors or thermocouples on a temperature recording device through an environmental test, based on the recorded results. This was a method for estimating heat distribution.

In the above method, since point measurement is performed by direct contact, only the surface temperature of the sample can be measured, and the internal heat distribution cannot be estimated.

This invention was made to improve the above-mentioned problems, and by installing an infrared sensor in a thermostatic chamber, it is possible to measure and monitor the heat distribution of a sample without contact. It provides a tank.

FIG. 1 is an overall configuration diagram of an embodiment of a constant temperature bath according to the present invention. As is clear from Fig. 1, this embodiment includes an infrared sensor (2) that detects the amount of infrared energy from several samples in a thermostatic oven (1), and a heater that heats the temperature inside the thermostatic oven (1). (3) and a cooler (4) for cooling the temperature, and the measurement range determination means (5) which receives the detection signal of the infrared sensor (2) as input sets the heat distribution measurement range of the sample. Heat distribution measuring means (6) based on its output
Measure the amount of infrared energy of the sample in the tank. The measurement result is level judged and CR is determined by the image processing means (8).
Monitor T f91.

Based on the output of this image processing means (8),
The heater (3), the cooler (4), and the programmed operation are controlled by a constant temperature oven control means (7).

FIG. 2 is a main body view of the thermostatic oven used in the embodiment of FIG. 1. In the figure, the sample is placed in a thermostatic oven +11 together with an infrared sensor (2). αB is a fan that spreads hot and cold air from the heater (3) and cooler (4) to set the temperature inside the thermostatic oven (1); (121 is a control for executing the program of the thermostatic oven itself) The program matching unit 03) is a meter-type temperature indicator, the 0 slope is a power switch for the thermostatic chamber, and 1151 is a pen-recorder type recorder that records the temperature of the thermostatic chamber.

FIG. 3 is a circuit diagram showing the electrical connections of the embodiment of FIG. 1. In the figure, (9) is a CRT, (15) is a microcomputer CPU, αη is an interface for determining signals, and a decoy is a memory for storing data. A timer 09 controls the program operation time of the thermostatic chamber (1), and is connected to the program matching unit α2. @
) is the changeover switch for heater (3).

With the changeover switch of the cooler (4),
Both 1+ and 1+ are connected to the fan circle and are controlled by the program matching unit I- (12+). The connected analog multiplexer is a 4-channel converter that converts its output to digital, and the output is given to c p U (161) through the interface 0η.

(Incorporated) is an operating mechanism for varying the measurement range of a thermal image reproduced on a CRT <91, and this is also controlled to move at regular intervals in the X and Y directions.

Next, the operation of the above embodiment will be explained with reference to FIGS. 3, 4, and 6. Figure 4 shows flowchart 1 showing the execution program stored in the memory αQ of the microcomputer, and Figure 5 shows the amount of infrared energy emitted from the sample (10) in the thermostatic oven (1) using the infrared sensor (2). FIG. 6 is a diagram illustrating the determination of the temperature level of the output detected by the measurement range determining means (5), heat distribution measuring means (6), thermostat control means (7), image processing means (8), CRT
FIG. 3 is an explanatory diagram of the operation of each star I and timing pulse of FIG.

First, when the program is started, the start pulse Pta of the thermostatic chamber (1) goes to HIGH level (hereinafter referred to as HI) in step (5), and at the same time a timer (1!ll timing pulse Pxl) is sent through the program matching unit (2). becomes HI. Then, in step (26), the timer timing pulse Ptb#''-H is applied until the preset test monitoring start time is reached.
I state is maintained, and the timer timing pulse Pt1) is L.
When the level reaches OW (hereinafter referred to as LOW), it is time to start monitoring the test. In order to repeat the specified temperature cycle, heater start pulse Pz1 and cooler start pulse PH) are generated at the same time, Pza and P2b are synchronized and repeat the HI and LOW states, which causes heater +a+ and cooler (4 ) switches (20), (21
1 0NOFF and repeat the specified cycle time.

Next, in step -, the CRT start pulse Pa2 is set to H.
When it becomes I, the image is adjusted inside the CRT j91.

At the same time as the sample measurement range is set by the CPU 161, the CPU α6 generates a sampling scan pulse P3b.

In step (to), detection of the thermal distribution data level of the sample is performed by the infrared sensor (2). Here, in step (2), heat distribution data obtained by the infrared sensor (2) is monitored by the CRT j9). Next, in order to cause the infrared sensor (2) to scan the infrared sensor (2) at regular intervals in the X and Y directions using the operating mechanism (to) at regular intervals, the sampling scan pulse Pab repeats HI and LOW at regular intervals.

At the same time as this sampling scan pulse Pab, sampling pulse P4B is generated and becomes HI in synchronization.

LOW is repeated until the time when the CRT start pulse Ps3 becomes LOW, and the above heat distribution data is transferred to the CRT (9).
be monitored.

By step Gυ, sampling scan pulse Pab
When the sampling pulse Pa,1 becomes LOW.

Detects the end of sampling. Then, step (3) When the CRT start pulse P3a becomes LOW due to
T j91's monitor turns off. Then step (
Steps (a) to (b) are repeated until the final monitoring time is completed. Then, when the timer timing pulse Plb becomes HI, the final time monitor is detected and Psa+P2a+P2b,
Each pulse of P3aPab and Pia stops, and all operations stop. And prepare for a new start.

Next, Fig. 5 shows the detection of heat distribution data level.

This will be explained using FIGS. 7 and 8. First, Figure 5 (a)
In (to) is a cross section of a cylindrical part 1, for example, a CRT when detecting the level of heat distribution data of a cross section of a fixed resistor.
This is a thermal image monitored by j9). (35) is a waveform corresponding to Dl in FIG. 5(b) at the low temperature section.

The level is output in the L (LOW) range.

It is monitored in light color on CRT 191. (Foundation) is in the middle temperature section.

In FIG. 5(b), the waveform corresponding to D2 is outputted at a level in the range of M (MIDDLE), and is monitored on the CRT 191 in a medium-dark color. (Ma) is the waveform corresponding to Da in Figure 5 (B) at the high temperature section,
The level is output in the H (HI) range, and CR
T! 9) is monitored in deep color. This temperature level L
, M.

By setting the temperature range H, temperature detection signals such as D1 to D3 can be obtained as voltage waveforms within the range.

Next, in Figures 7 and 8, C RT
Changes in the thermal image of sample αα monitored by j91 and abnormal locations will be explained. FIG. 7 is a diagram showing a thermal image at room temperature monitored on the CRT (9).

■ is the molded resin of the fixed resistor, +391
is a cap that connects the resistor (not shown) and the lead wire (back); (411 is a foreign object mixed in the molded resin (381) in the fixed resistor, but it is not clearly visible on the monitor. It has become.

FIG. 8 is a thermal image when the sample was heated during an environmental test.

(381 is the part of the mold resin that is at a low temperature and is monitored in light color.

(39) is the part of the cap that is at medium temperature and is monitored in medium dark color.

(40) is a portion of the lead wire that has reached a high temperature due to heating and is monitored in a dark color.

(41) is a foreign substance mixed in the mold resin (38), and its existence was not well known before the temperature was applied. In this way, when the foreign matter (41) reacts to heat and is monitored by the CRT (9), the location, size, and shape of the foreign matter can be clearly seen. In this way, the thermal images at room temperature and during the heating test change. Furthermore, by applying the rated power to the sample (10) with one circuit (42), heat can be applied from the inside by the electric current, which leads to the effect of further speeding up the discovery of the foreign object (41).

Although the above embodiment was limited to fixed resistors, it can be used for other parts as well, such as patterns on printed circuit boards, through-holes, and other abnormal locations.

Discovery of short circuits, pattern breaks, foreign matter contamination, etc., measurement of welding temperature during relay operation tests, confirmation of whether or not disconnection occurs at the specified temperature as part of temperature fuse evaluation tests, and mounting units, etc. Confirmation of thermal design, measurement of changes over time, etc. can be done in the same way as described above.

As described above, according to the present invention, a means is provided to automatically measure the amount of infrared energy of a sample in a thermostatic chamber using an infrared sensor, and the measurement results are monitored on a CRT. Environmental tests can be carried out by non-contact, while avoiding inconveniences such as human error on all surfaces and internal parts, determining the state of heat distribution based on the level of the detection signal, and monitoring the results on a CRT using color shading. In addition, visual confirmation can be made when a defect occurs on the spot.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of a thermostatic chamber according to the present invention, FIG. 2 is a configuration diagram of the thermostatic chamber main body, FIG. 3 is a circuit diagram showing the electrical connections of FIG. Flowchart 1/Figure 5 shows the operation shown in Figures 4 and 6. Figure 5 is a diagram explaining the relationship between the level of the waveform of the detection signal obtained in Figures 4 and 6 and the shade of color, and its measurement range. 4 is a diagram explaining the pulse operation of FIGS. 3 and 4. FIG. FIGS. 7 and 8 are diagrams for explaining changes in thermal images and discovery of abnormal locations. In the figure, (1) is a constant temperature bath, (2) is an infrared sensor, and (3)
is a heater, (4) is a cooler, (5) is a measurement range determining means, (6) is a heat distribution measuring means, (7) is a constant temperature oven determining means,
(8) is the image processing means, (9) is the CRT, α0 is the sample, α2 is the program matching unit I-, (16) is the CPU of the microcomputer, (l is the interface, (1B+ is the memory. Timer, (a) is the heater switch, (2υ is the cooler switch, (22) is the analog multiplexer, '(231 is the converter, (goods) is the operating mechanism, (
38) is mold resin. (39) is the resistor cap, (40) is the resistor lead wire. (41) is a foreign substance. Note that the same reference numerals in Figure 9 indicate the same or equivalent parts. Agent Shin Kuzuno - Figure 1 2] Futagami. 2 73 74 ~ 15 Figure 4 Start 25 people Dirt NO monitor 1r time ES CRT image adjustment "-" 2. ! ? Level detection 0 shakucho monitor set\Nosa VV-7 Ushitori\no No. 7 Figure 8

Claims (1)

[Claims] attached to the inner wall of the thermostatic chamber in which a sample is mounted and the heat distribution of the sample is measured;
an infrared sensor that detects the overall amount of infrared energy emitted by the sample; a measurement range determining means that receives the detection signal of the infrared sensor as an input and determines the detection range of the infrared sensor; and scans the infrared sensor over the sample. and a heat distribution measuring means for measuring the amount of infrared energy of the sample in the thermostatic chamber based on the output of the predetermined range determining means; a thermostat control means for detecting switching of the device and the start or end of the measurement time; an image processing means for performing image processing on the detection signal of the amount of infrared energy measured by the heat distribution measuring means and reproducing it into a thermal image; and a display device that displays the heat distribution of the sample as a thermal image based on the output of the means.