JPS61186866A - Vibration testing device - Google Patents

Abstract

PURPOSE:To improve the extraction ratio of a loose contact by providing two vibration generating devices which have different natural vibration frequencies, generating a complicate random waveform, and testing an object body on vibration condition close to actual environmental vibration. CONSTITUTION:A support part 18 which supports a printed board 2 is fitted onto a base plate 17 across vibration isolating rubber 19 and vibration generat ing devices 20 and 21 which generate different natural vibrations and are con trolled by a vibration generating device control part 26 are provided at both sides of the support part 18. Then, one of the vibration generating devices 20 and 21 is so constituted as to generate fast vibration and the other is so constituted as to generate slow vibration, thereby generating complicate random vibration. The support part 18 supports the printed board 2, which is operated by a printed board control part 7 while vibrated at random to detect malfunc tion. Consequently, the test is taken on condition close to the actual condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration testing device for electronic devices such as printed circuit boards on which circuit components are mounted.

In recent years, the demand for quality assurance of electronic devices has increased more and more.
For example, emphasis has been placed on vibration tests to identify latent defects such as poor soldering on printed circuit boards, adhesion of solder debris, and poor tightening of component mounting screws, as well as other initial defects.

Particularly in soldering, loose contact (unreliable contact) between circuit components and circuit patterns due to defects etc. is a problem, and in order to reliably remove this, the printed board under test is put into an operating state and vibrated, and the circuit is operated. It is carried out to determine whether the quality of the product is good or bad.

The vibration itself is also changed from a fixed frequency sine wave to a sine wave based on a sweep program, but this test differs from random vibration in an actual environment.

For this reason, future vibration tests will be conducted using random waves, and there is a need for a vibration testing device that can perform random vibrations.

[Conventional technology]

The conventional technology will be explained below with reference to FIGS. 5 and 6.

FIG. 5 is a perspective view showing a conventional method for testing loose contacts on a printed board, and FIG. 6 is a side view showing a method for testing loose contacts using a vibration tester.

In the loose contact test, first, the printed circuit board 2 is mounted on the housing 1 as shown in FIG.

Next, a printed board drive circuit 3 that drives the printed board 2,
The connector is connected to a printed board control section 7 which includes a printed board detection circuit 4 that detects the operating state of the printed board 2, a malfunction detection circuit 5 that detects a malfunction of the printed board 2, and a display section 6 that displays the details of the malfunction. 8 and 9, and in the operating state, hit the top surface of the printed board 2 as shown by arrow A or the side part as shown by arrow B with a hammer (not shown) to perform a so-called loose contact hammer test. .

Data during such testing is detected by the operation detection circuit 4, and the data is fed back to the printed board drive circuit 3 and sent to the malfunction detection circuit 5.

When the malfunction detection circuit 5 detects a malfunction, it displays the details of the error on the display section 6 and at the same time outputs the occurrence of the error to the printed board drive circuit 3.

In addition to the loose contact hammer test described above, a method using a vibration tester as shown in FIG. 6 is also frequently used.

That is, the magnet 14 provided on the base 11 is connected to the AC power source 15.
A vibration testing machine 10 that vibrates a vibration table 13 supported by a spring component 12 on a base 11 in the direction of arrow C-D.
is used.

In such a test, first, the printed board 2 is fixed to the vibration table 13 using a jig 16.

Thereafter, the magnet 14 is excited with alternating current to generate a desired vibration in the vertical direction (arrow C-D), thereby vibrating the printed board 2.

Along with the above vibration, the printed board 2 is operated by the printed board control section 7 to perform a predetermined test in the same manner as described with reference to FIG.

[Problem that the invention seeks to solve]

In the test method explained above, in the case of Figure 5, the printed board is hit with a hammer, so the strength changes depending on how hard you hit it.
In addition, there is a problem that continuous vibration cannot be obtained due to instantaneous vibration, and in the case of Fig. 6, the vibration generated by the vibration tester is a sine wave, which is different from the random wave in the actual environment. has a different problem.

Furthermore, the circuit components mounted on the printed board often operate in pulses, and the probability that the timing of the peak vibration and the timing of the electrical operation coincide is small, resulting in an extremely low extraction rate of loose contacts.

[Means for solving problems]

The above-mentioned problems are solved by the vibration testing apparatus of the present invention, in which at least two vibration generators having different natural frequencies are provided to generate random vibrations and test a test object such as a printed circuit board. Ru.

[Effect]

That is, by providing, for example, two vibration generators with different natural frequencies, a plurality of vibrating bodies interfere with each other and generate complex random waveforms, and the test object is placed under vibration conditions close to actual environmental vibrations. It becomes possible to test with

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Fig. 1 is a perspective view of a vibration testing device according to the present invention, Fig. 2 is a side half-sectional view showing an example of a vibration generator, and Fig. 3 (al.
- (C) are side half-sectional views sequentially explaining the operation of the vibration generator, and Fig. 4 (al) - (C) are diagrams showing vibration waveforms.

In the figure, 17 is a base, 18 is a support part, 19 is a vibration-proof rubber, 20.21 is a vibration generator, 22 is a compressor,
23 is a regulator, 24 is an operation switch, 25 is a solenoid valve, 26 is a vibration generator control unit, 27 is a piston type vibrator, 28 is a cylinder, 29a, 29b are air chambers, 30 is an air supply hole, 31a, 31b are narrow The holes 32 are exhaust holes, and 33 are blind holes. Identical parts are designated by the same reference numerals throughout the figures.

As shown in FIG. 1, the vibration generator of the present invention has a support part 18 for supporting a printed board 2 mounted on a base 17 using anti-vibration components such as anti-vibration rubber 19. It is equipped with vibration generators 20 and 21.

The vibration generators 20 and 21 generate different unique vibrations, for example, 20 generates low-speed vibrations of 80 Hz, and 21 generates high-speed vibrations of 110 Hz.

The vibration generator 20.21 is driven by using compressed air as a power source, for example, and is composed of a compressor 22, a regulator 23, an operation switch 24, and a solenoid valve 25, as shown in FIG. It is controlled by the device control section.

That is, the air compressed by the compressor 22 is sent to the vibration generator 20.21 via the regulator 23 that maintains the air pressure at a constant value and the solenoid valve 25 that opens and closes the air passage using the operation switch 24. .

The vibration generator 20.21 includes a piston type vibrating body 27 and a cylinder 2 into which the piston type vibrating body 27 is inserted, as shown in the figure.
8, and the piston-type vibrating body 27 has different areas of the pressing portions 27a and 27b in the front-rear direction.

Further, the sliding part of the cylinder 28 is a sliding part 28 with a step.
a and 28b.

Air chambers 29a and 29b are provided in the portion of the cylinder 28 that corresponds to the pressing portions 27a and 27b, and an air supply hole 30 is provided in the air chamber 27a.

A blind hole 33 from the pressing portion 27b having a large area is provided at the axis of the piston-type vibrating body 27, and a blind hole 33 is provided from the pressing portion 27b having a large area.
8b has a small hole 31a that opens into the air chamber 29a through the blind hole 33, and when the small hole 31a opens into the air chamber 29a, the piston-type vibrating body 27 is located on the sliding surface of the cylinder 28, and the piston-type vibrating body 27 is The pore 31a moves in the E direction and the air chamber 2
A narrow hole 31b is provided from a blind hole 33 so as to open into an exhaust hole 32 provided in the sliding portion of the cylinder 28 when the cylinder 28 is removed from the cylinder 9a and becomes closed.

The pore 31b is closed on the sliding surface of the cylinder 28 when the pore 31a opens into the air chamber 29a.

The operation will be explained with reference to FIGS. 3(a) to 3(C).

As shown in FIG. 3 (al), when the piston-type vibrating body 27 is moving to the left of the cylinder 28, the pore 31a is closed, and therefore four people are placed in the air chamber 29a through the air supply hole 30. The compressed air presses the pressing part 27a of the piston-type vibrating body 27 according to its pressure and moves it to the right (in the direction of arrow F), as shown in the figure (bl).

In the state shown in the figure ('b), the pores 31a are
9a, so compressed air flows through the pore 31a and the blind hole 3.
3 into the air chamber 29b, and the piston-type vibrating body 2
7. Press the pressing portion 27b.

Then, since the area of the pressing part 27b is larger than that of 27a, the piston-type vibrating body 27 moves to the left (in the direction of arrow E) as shown in FIG.

In the state shown in FIG. 3(C), the pore 31a is in a closed state,
The pore 31b is open to the exhaust hole 32.

Therefore, the compressed air in the air chamber 29b is supplied to the blind hole 33 and the fine hole 31.
The air is discharged to the exhaust hole 32 through the air chamber 29b, and the pressing force of the air chamber 29b becomes zero.

When the pressing force of the air chamber 29b becomes zero, the piston-type vibrating body 27 moves rightward again (in the direction of arrow F) due to the pressing force of the compressed air in the air chamber 29a, as shown in FIG.

Vibration occurs due to the above-mentioned reciprocating motion being repeatedly and continuously performed.

The vibration generators 20 and 21 having such a structure are provided on the left and right sides of the support part 18 as shown in FIG.
By driving the first part 26, vibrations having a waveform as shown in FIG. 4 can be obtained.

That is, the vibration generators 20 and 21 are each equipped with piston-type vibrators having different masses, one of which has a small mass and generates high-speed vibration, and the other has a large mass and is configured to generate low-speed vibration. are doing.

The waveform in the high-speed vibration generating section is, for example, as shown in FIG. 4 (al), and the waveform in the low-speed vibration generating section is, for example, as shown in FIG. 4 (bl).

When both vibration systems are integrated by the support part 18,
The vibrations become a composite wave with a random waveform as shown in FIG. 3(C).

This random vibration is caused by the mass and natural frequency of the vibrating body,
The pneumatic pressure of the compressed air, the natural frequencies of the cylinder and the support part 18, and other complicated factors are intertwined and result in unpredictable results.

The vibration waveform synthesized in this manner is an extremely complex random waveform, and can be considered to be closer to the real environment than a conventional sine wave.

Therefore, while the printed board 2 is supported on the support part 18 as shown in FIG. 1 and the random vibration is applied,
By operating the printed board 2 using the printed board control section 7 and detecting malfunctions in the same manner as explained in the figure, the test can be performed more closely to the actual environment.

〔Effect of the invention〕

As explained above, by using the vibration testing device of the present invention for vibration testing of electronic devices such as printed boards, it becomes possible to test the test object with random vibration, and it is possible to perform tests that are close to the actual environment. Since continuous impact can be applied to the test object, the extraction rate of loose contacts, for example, can be greatly improved, and together with the streamlining of work, the quality assurance level can be improved. is now possible.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a vibration testing device according to the present invention, FIG. 2 is a side half-sectional view showing an example of a vibration generator, and FIG. Side half-sectional view, Figure 4 (al~ (C1 is a diagram showing vibration waveforms. Figure 5 is a perspective view showing a conventional test method for loose contacts of printed circuit boards, Figure 6 is a vibration tester. 2 is a side view showing a loose contact testing method according to the present invention. In the figure, 2 is a printed board, 3 is a printed board drive circuit, 4 is an operation detection circuit, 5 is a malfunction detection circuit, 6 is a display section,
7 is a printed board control unit, 8.9 is a connector,
10 is a vibration tester, 15 is an AC power supply, 16
is a jig, 17 is a base, 18 is a support part, 19
is vibration-proof rubber, 20.21 is vibration generator, 22
2 is a compressor, 23 is a regulator, 24 is an operation switch, 25 is a solenoid valve, 26 is a vibration generator control unit, 27 is a piston type vibrator, 2 is a cylinder, 29a, 2
9b is an air chamber, 30 is an air supply hole, 31a and 31b are pores, 32 is an exhaust hole, and 33 is a blind hole. Sorry 2 Figure (d) □E (Su -F Akira 3 Figure Akira S Figure 6

Claims (1)

[Claims] It consists of a support section that supports an electronic device, a vibration generator provided on the support section, and a test device that operates the electronic device supported on the support section and detects its operating state. A vibration test device for detecting the operating state of the supported electronic device while applying vibration to it, the device comprising at least two vibration generators having different natural frequencies. Device.