JPS6029632A - Leak inspecting device - Google Patents

Abstract

PURPOSE:To automate an inspecting work by detecting regular reflected light by a leak foam, by two sensor arrays in the X-Y directions, deriving the X-Y coordinates, and displaying a leak position. CONSTITUTION:Plural objects to be inspected 5 are submerged onto the bottom face of a liquid tank 3, and generation of a foam from the object to be inspected of sealing-up failure is quickened by heating the object to be inspected 5 by a heater part 6. When the foam rises and is positioned on a detecting plane A of X and Y sensor arrays 7, 8, light from an illuminating device 1 is regularly reflected by the surface of the foam, and made incident to one sensor of the sensor arrays corresponding to the foam generated position. The sensor arrays 7, 8 are constituted so that parallel lights are made incident into the long cylindrical direction, therefore, the light which is made incident by being regularly reflected by a foam B is irradiated to a photosensor 10 provided on the end of a long cylinder 9 and detected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a leak testing device for completely testing the airtightness of sealed relays, semiconductor devices, and the like.

(Background technology 9 Conventionally, the leak inspection method for inspecting airtightness is as follows: (b) Detect the generation of bubbles in the liquid.

(b) Helium gasket is injected into the object to be inspected, and leaks are detected using a total helium detector.

(c) Detecting the sound or boiling water wave at the time of leakage.

There are other methods such as sealing = a IJ Sire semiconductor deno (
Method (a) is often used for small mass-produced items such as chairs. That is, after placing the entire object to be inspected in a liquid such as fluorocarbon liquid, the generation of bubbles is fully promoted by heating, etc., and the bubbles caused by leakage V? This is a method of visual observation and inspection.

Figure 1 shows an example of a conventional inspection device that has automated the above method. 1 is a lighting device u, 2 is an industrial television camera (iTV camera), 3 is a liquid tank r/i, and 4 is a fluorocarbon liquid. A plurality of inspection liquids such as 5Q and 5Q are arranged next to each other to be inspected, and 6 is a heater section for advancing the bubble generation position. In operation, the iTV camera 2 constantly observes the contents of the test liquid to detect the occurrence of bubbles due to leakage, and image processing is performed to identify all defective test objects.

However, in this kind of method I[! ! I have all the drawbacks that the image processing is complicated and the equipment is very expensive (
−, therefore, there is no need to rely on inexpensive visual methods.
I didn't get it.

(Objective of the Invention) The present invention has been proposed in view of the above two points, and provides a complete set of inexpensive leak inspection devices for automating the leak inspection work for small gifts, which has conventionally relied on visual inspection. The purpose is to do something.

(Disclosure of the Invention) Fig. 2 is a configuration diagram showing an embodiment of the present invention, where ■ is a lighting device provided on the upper blade of the liquid tank 3, 4 is a test liquid such as a fluorocarbon liquid, and 5 is a sealed seal. Objects to be inspected such as type relays, 6
is a heater section, and 7 and 8 are sensor arrays in the X and Y directions, respectively, which are provided on the side surface of the liquid tank 3. For example, as shown in FIG. It is composed of a long cylinder 9 which has been subjected to anti-reflection treatment and a photosensor 10 provided at its end.

In operation, a plurality of five proboscises to be inspected are submerged in the bottom of the liquid tank 3, and the heater section 6 heats the five inspected articles to fully promote the generation of bubbles from the poorly sealed inspected articles. However, the bubbles rise and the X, Y sensor array 7
．． 8, the light beam from the illumination device 1 is specularly reflected on the bubble surface, and the light beam from the illumination device 1 is specularly reflected on the bubble surface, and the light beam from the illumination device 1 is reflected on the detection plane A in the sensor array according to the bubble generation position. or incident on one sensor. As mentioned above, the sensor array 7.8 is configured as shown in Fig. 3 so that parallel light enters in the direction of the long cylinder, so the light that is specularly reflected by the air bubble B and then incident is hits the photosensor 10 provided at the end of the long tube 9 and is detected. It's a trench.
In general, the larger the detection area of a photosensor, the higher the price and the more noise it produces.
It is also possible to make the photo sensor 10 smaller by placing it in front of the photo sensor 10 to collect the reflected light.

Figure 5 schematically shows the range of bubbles that can be detected by one sensor. This is a diagram observed from above, and bubbles B are assumed to be moving 171J in a direction perpendicular to the plane of the paper. Here, the artificial width (s1) of the long tube 9 and the length of the light introduction part of the long tube 9 - aWt.

If the distance between the inlet tip of the long cylinder and the bubble B is 'tL (maximum value is the length of one side of the liquid tank), the width of the area overlapping with the adjacent sensor is h-L@tanθ=L-D/l- ---+1), and when h is large, the separation from the neighboring sensor becomes worse, and the accuracy of position detection decreases.VC.

Therefore, as a countermeasure to this problem, a light shielding plate 12 is used as shown in Figure 6.
It is effective to provide several of them in parallel to the light introducing section.

That is, by adjusting the arrangement interval of the light shielding plates 12, D of the tIJ formula can be significantly reduced, and the overlapping detection area with adjacent sensors can be reduced, thereby improving the detection accuracy to the full width.

FIG. 7 shows an example of the coordinate assignment of the detection plane A in FIG. 2, where X, ~Xn, Y+ ~Yn indicate the coordinates of the individual sensors. Note that although the figure shows a case 7 in which the number of divisions is nXn, there is no problem if the number of divisions is nxm (n'=m).

FIG. 8 is a block diagram showing the circuit configuration for processing the signals obtained from the sensor array described above, and the output of the sensor array 7.
The analog light reception signals are input to the conno rake 15° 1G through each of them, and the analog light reception signals are compared at a certain threshold level and converted into a binary signal indicating the presence or absence of bubbles. Then,
The determination processing circuit 17 is configured to obtain the coordinates from one of the X and Y directions when all bubbles are detected, and operate the defect display circuit 18 to display the position of the object to be inspected where the leak has occurred.

Next, FIG. io shows another embodiment of the present invention, in which a convex cylindrical lens is used as the lens to greatly improve detection sensitivity. In other words, the configuration of the sensor described above is shown in Fig. 9 (a), but in this case, the period for which the specularly reflected light from bubble B is incident is short, and the relationship between the light receiving sensitivity and the response speed of the circuit, etc. As shown in FIG. 1IjJ (0), there may be a case where the detection signal of the sensor does not reach the comparator level Vth. As a countermeasure to this problem, it is possible to increase the detection sensitivity by increasing the amplification factor by t, but in this case, the S/
This is not preferable because the N ratio deteriorates.

-+: In addition, if the field of view in the vertical direction V in which the bubble moves is widened, a large and expensive photosensor will be required, and furthermore, in this case, there will be a problem if noise increases.

Therefore, even with this actual 1rli 9IJ sensor 10, the S/N ratio is low. This makes it possible to obtain sufficient detection sensitivity without deterioration. FIG. 11 shows the detection signal when this practical example is adopted, and the detection sensitivity is improved and the period t during which the bubble B exists within the visual field. , the detection probability can be greatly improved.
Even small air bubbles with a small amount of reflected light can be sufficiently detected.

Next, FIGS. 12 and 13 show all other embodiments of the present invention, in which improvements have been made to the lighting device R1 and the liquid tank. In other words, in the embodiment shown in FIG. 2 described above, the liquid 4 was illuminated by the illumination device 1 installed on the upper blade of the liquid tank 3, and the specular reflection from the air bubbles was detected by the entire sensor array. , the specularly reflected light is limited to a very small portion of the entire surface of bubble B, as shown in FIG.
The bright area of the bubble B seen from the sensor is as shown by the shaded area in Fig. 15 (A). Therefore, there is a limit to the light receiving sensitivity, and from 1 to f (, received light k) Accuracy was also extremely poor when it came to determining the size of all bubbles and determining leak status. In addition to the above, in the configuration shown in FIG. 2, the illumination device 1 is located directly above the liquid tank 3, which has the disadvantage that it obstructs work such as taking in and out small objects to be examined.

Therefore, in this embodiment, the illumination device was installed on the side of the liquid tank, and mirrors were placed on the inside of the liquid tank to greatly increase the amount of specularly reflected light from the bubbles, thereby improving detection sensitivity. , it is possible to easily determine the bubble size at 1'41.

In FIGS. 12 and 13, reference numeral 20 indicates an illumination device, which is provided on the upper blades of the sensor arrays 7 and 8 in a row. In addition, a υ absorber 22 is disposed in the field of view of the surface facing the sensor arrays 7 and 8, and the entrance portions of the sensor arrays 7 and 8 and the illumination device 20 are removed (, (
The surface ycItj of lJ, t+'-trowel where mirrors 21 are all arranged, absorber 22 is provided on a part of the surface facing sensor arrays 7 and 8,'C is directly from the inner surface of the liquid tank. This is to prevent reflected light from entering the sensor.

Therefore, )t
: Illumination with light rays from all directions! 1-Totona/
! ,).

In the past, during a leak test, the entire surface of bubble B became a bright area and was observed and measured by illuminating one bubble in all directions. I can't do what I want to do.

Therefore, the amount of received light is significantly increased by V, and detection sensitivity can be improved, and the size of the bubble can also be determined from the received light 1^.

(Effects of the Invention) As described above, in the present invention, in the apparatus for inserting the object to be inspected into a V tube in the seven liquid tanks and discharging the C relief into the air bubbles generated from the object to be inspected, A lighting device is placed above the object to be inspected, and the specularly reflected light from the IJ bubbles is detected by two sets of sensor arrays in the X and Y directions installed on the sides of the liquid tank, and from the output signals of these sensor arrays. Determine the X-Y coordinates and display the leak position/) J: So, (a) I did not use the traditional <4 TV camera, but instead used all the expensive photosensors, and performed the leak inspection with a cylinder configuration. I can do it.

(b) Complex processing is not necessary and high-speed processing is required.

(c) Since the coordinate output can be obtained with high precision, it is possible to efficiently handle multiple objects at the same time, and it is also possible to obtain a defect selection output.

VR4 has remarkable effects such as

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a conventional inspection device, Fig. 2 is a configuration diagram showing one embodiment of the present invention, Figs. 3 to 6 are configuration diagrams of individual sensors constituting the sensor array, and Fig.
FIG. 8 is a block diagram showing an uninvented circuit configuration, FIGS. 9 to 11 are explanatory diagrams of other embodiments, and FIGS. 12 to 15 are further diagrams of other embodiments. It is an explanatory diagram concerning an example of. ■, 20...Lighting device, 3...Liquid tank, 4...
... Test liquid, 5 ... Test object, 6 ...
・Heater part, 7゜8... Sensor array, 9...
Long tube, to...F 1st sensor, 11...
...Convex lens, 12... Light shielding plate, 13゜14-
・-Amplification circuit, 15, 16... Comparator,
17... Judgment processing circuit, 18... Defective display circuit, 19... Cylindrical lens, 21...
...Mirror, 22... Absorber Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Q1 (A) (B) Figure 10 Figure 11 Figure 12 Figure 1 Figure 14\ Figure 15 (A) (B) □

Claims (3)

[Claims] (1) In a device for inspecting leak sound by immersing an object to be inspected in a liquid tank and using air bubbles generated from the object to be inspected, an IJJ device is placed above the object to be inspected, and the specular reflection caused by the leak bubbles. The light is detected by two sets of sensor arrays in the X-Y direction provided on the sides of the liquid tank, and the X-Y coordinates are determined from the output signals of the sensor arrays and the leak positions are indicated. Inspection equipment. (2) Each sensor of the sensor array has a long cylindrical light introduction part, a cylindrical lens whose vertical direction is 1 to 100 m long, and is arranged at the focal position of this cylindrical lens.
The leak testing device according to claim 1, which comprises a c-photosensor. (3) The leak inspection device according to claim 1, wherein a mirror is disposed on the inner surface of the liquid tank except for a portion that falls into the field of view of the sensor array.