JPS6196437A - Fine leakage position detector - Google Patents

Abstract

PURPOSE:To limit easily a leaked position and to improve detecting accuracy by adhering a rubber ring to the head of a leakage detecting gas blowing gan having coaxial double pipe structure to blow testing gas only upon a fine part of the head part. CONSTITUTION:The leakage detecting gas blowing gan is constituted of an inner pipe 1 made of cupper alloy and connected to a testing gas source through a gas pipe connection terminal 5 formed at its one end and an outer pipe 2 coaxially arranged on the outside of the inner piper 1 and having a branch pipe 3 forming a part of an exhaust pipe on its one side and the rubber ring 4 is adhered to the head part of the gan. When the blowing gan is abutted upon a specimen through the ring 4 and the detecting gas is blown upon the specimen through the inner pipe 1, the gas collides with the outer wall of the speciment, returned by the shielding of the ring 4 and led into the outer pipe 2 and the branch pipe 3. Consequently, the testing position of airtight leakage can be limited.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a micro-leak position detection device whose test specimen is a semiconductor package or the like that requires airtightness.

There are two types of test equipment for detecting airtightness: one for detecting the amount of leakage from the entire hermetically sealed specimen, and the other for detecting the position of leakage in the specimen. For example, the present invention relates to the improvement of a device for accurately detecting the location of a leak, which is the latter vacuum/spraying method using helium gas.

[Conventional technology]

An outline of a conventional micro-leakage test device using helium (He) gas will be explained with reference to a schematic diagram in FIG.

In the schematic diagram, 10 is a helium gun that sprays onto the test object, and 20 is a test object that requires airtightness (for example, a semiconductor package with an appropriate volume).
, 30 is a vacuum pump for evacuating the inside of the package, and 40
is a leak detector.

As is clear from the figure, after the inside of the test object 20 such as a pan cage is evacuated by the pump 30, gas is blown from the outside wall of the pan cage by the gun 20, and the leaking lle gas is detected by the detector 40, and the airtightness is tested. be done.

The helium gun 20 does not move along the surface of the hermetic joint of a semiconductor package, etc., thereby detecting the leak position.

In the figure, reference numeral 50 denotes a standard leak source provided to calibrate the leakage amount of the entire measurement system including the test specimen, and 2 is not necessary when inspecting a test specimen with a limited shape.

The above-mentioned test device has a detection capability with a quantitative leak detection sensitivity of about 1X10" (std-cc/s) using the standard leak source 50. However, the response speed and detection sensitivity vary depending on the size of the test specimen shape ( References, Nondestructive Testing: Part 3
Volume 2, No. 11).

[Problem that the invention seeks to solve]

The leak detection gas spray gun is able to accurately locate leaks because the gas is dispersed in proportion to the distance between the gas-tight joint surface of the test object and the tip of the gun, and widely contacts the gas-tight joint surface of the test object. The disadvantage is that it is difficult to detect.

[Means for solving problems]

The above-mentioned problem is solved by the present invention, which uses a gun with a rubber ring at the tip of a gas spray gun for leak detection and a coaxial double tube configuration in an airtight leak test using a vacuum/spray method. Solved as a position detection device.

[Function] The detection gas spraying gun of the present invention makes it possible to directly contact the tip of the gun to the location where airtight leakage is detected on the test specimen and spray the detection gas only to a minute portion of the tip of the gun that comes into contact. It has a double-tube structure with an inner tube and an outer tube of different types. Of course, the detection gas does not come out in other parts of the specimen that the gun tip does not touch, so the position of the slight leak can be limited (detected).
is easily done.

〔Example〕

FIG. 1 is a sectional view of a gun showing an embodiment of the present invention.

The gas spray gun for leak detection shown in FIG. 1 consists of an inner tube 1 made of, for example, a copper alloy, and an outer tube 2 disposed coaxially outside the inner tube 1. Furthermore, a branch pipe 3 is provided on one side of the outer pipe 2 and communicates with the original pipe to form a part of the exhaust pipe. The open end 7 of the branch pipe 3 is connected to the vacuum pump 30 described in FIG.

The left side of the illustrated gun is the part that comes into contact with the test specimen. A rubber ring 4 is attached to its tip.

On the right side of the gun, the inner tube protrudes from the outer tube 2 and becomes the gas tube connection end 5 to the detection gas source side. In addition, the outer pipe 2 and the branch pipe 3
The connections and the right end 6 of the outer tube 2 are silver-brazed. The operation of the coaxial double tube configuration gun arranged as shown in the figure will be explained with reference to the sectional view of FIG. 2, which shows an enlarged view of the gun tip.

FIG. 2 is a sectional view of the tip of the gun that comes into contact with one side wall of the test piece 20 via the rubber ring 4.

The detection gas 9 press-injected through the inner tube 1 collides with the outer wall of the test specimen 20 where airtight leakage is a problem. However, due to the shielding of the surrounding rubber ring, the colliding gas makes a U-turn and enters the outer tube 2.
and is led out to the branch pipe 3 side, so the test locations for airtight leakage are limited. For example, if the inner diameter 8 of the rubber ring 4 (the inner diameter of the outer tube 2) is approximately 11, a micro-leakage test is performed to check the airtightness within this dimensional plane.

However, if the rubber ring 4 is released from the wall of the specimen.

Needless to say, it is also possible to perform a minute leakage test using a gun with the same configuration as the conventional gun.

〔Effect of the invention〕

According to the gun of the present invention as described above, it is easy to limit the leakage position, especially where airtightness is a problem.

This has the advantage of improving the accuracy of the detection device.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a gun according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view for explaining the previous gun operation. FIG. 3 is a schematic diagram of the entire micro-leakage test device. In the figure, 1 and 2 are the inner and outer tubes of a double tube configuration, respectively. 4 is a rubber ring. 10 is a conventional helium gun. and 20 are test specimens.

Claims (1)

[Claims] A device for detecting the position of minute leaks in an airtight leak test using a vacuum/spraying method, characterized by having a rubber ring at the tip of a gas spray gun for detecting leaks, and the spray gun having a coaxial double tube configuration.