TW202400981A - Testing device and testing method - Google Patents

Abstract

The purpose of the present invention is to provide a feature in which, in a test of the bending properties of a printed wiring board on which an electronic component is mounted, it is possible to highly accurately detect vibration caused by breakdown of the electronic component. This testing device comprises: a support base (3) for supporting both ends of a mounting surface of a printed wiring board (4) on which an electronic component (5) is mounted; a plunger jig (2) disposed on the surface of the printed wiring board (4) on the opposite side from the mounting surface, the plunger jig (2) applying a load to the electronic component (5) via the printed circuit board (4); a sensor (6) disposed surrounding the electronic component (5) on the mounting surface of the printed wiring board (4), the sensor (6) detecting vibration caused by breakdown of the electronic component (5) and outputting a voltage signal that corresponds to the vibration; a fixing jig (8) for fixing the sensor (6) to the printed wiring board (4); a pressing member for pressing the sensor (6) against the printed wiring board (4); and a measurement unit (10) for measuring the waveform of the voltage signal outputted from the sensor (6).

Description

Test device and test method

This disclosure relates to a testing device and a testing method.

Non-patent document 1 defines a test method for testing printed circuit board bending resistance in a state where electronic components are mounted on a printed circuit board for testing. In this test method, it is judged based on the performance and appearance abnormalities of electronic parts after bending the printed circuit board to the specified size.

In this method, when the electronic component becomes defective, the bending size after damage occurs (hereinafter referred to as the "limit value") is not known. In order to know the limit value, it is not necessary to know how to bend the printed circuit board to a certain size, but it is necessary to know the bending size when the printed circuit board is bent until the electronic component is damaged such as cracks.

For example, Patent Document 1 discloses a device for measuring the flexural strength of a single object to be measured such as electronic components. In a support portion constituting a table on which the object to be measured is placed, there is provided The sound emission sensor (hereinafter referred to as "AE sensor") uses the AE sensor to detect vibrations caused by damage to the measurement object. [Advanced technical documents] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 2010-237197 [Non-patent literature]

[Non-patent document 1] JIS C 5101-22

[Problem to be solved by the invention]

However, the technology described in Patent Document 1 does not assume that the printed circuit board on which the measurement object is mounted is bent, and it does not have a structure for placing the printed circuit board on a table and bending it.

Furthermore, in the technology described in Patent Document 1, even when the printed circuit board is placed in a structure, the entire lower surface of the printed circuit board is in contact with the table, and the vibration caused by the damage of the measurement object is caused by the table. And attenuation, so there is a problem that the detection sensitivity of the AE sensor is reduced.

Here, the purpose of this disclosure is to provide a technology that can detect vibrations caused by damage to electronic components with high accuracy during a bending test of a printed circuit board equipped with electronic components. [Means used to solve problems]

The test device of this disclosure includes: a support base that supports both ends of a mounting surface of a printed circuit board on which electronic components are mounted; and a pusher jig that is disposed on the opposite side of the mounting surface of the printed circuit board. On the surface side, a load is applied to the electronic component through the printed circuit board; the sensor is arranged around the electronic component in the mounting surface of the printed circuit board, and detects damage to the electronic component. The resulting vibration outputs a voltage signal corresponding to the vibration; the fixing fixture secures the sensor to the printed circuit board; the pressing member presses the sensor to the printed circuit board; and the measuring part, Used to measure the waveform of the voltage signal output from the sensor. [Invention effect]

When based on this disclosure, the support base supports both ends of the mounting surface of the printed circuit board. Therefore, the pusher jig applies a load to the electronic component through the printed circuit board, thereby bending the electronic component after it is mounted. Printed circuit board. Furthermore, the sensor is fixed to the printed circuit board by the fixing jig, and is pressed against the printed circuit board by the pressing member. Therefore, the sensor can be stably mounted on the printed circuit board.

In this way, during the bending test of the printed circuit board after mounting the electronic components, the vibration caused by the damage of the electronic components can be detected with high accuracy.

The purpose, characteristics, matters and advantages of this disclosure can be made clearer by the following detailed description and accompanying drawings.

[Form used to implement the invention]

<Embodiment 1> ＜Construction of test equipment＞ Embodiment 1 is explained below using drawings. FIG. 1 is a schematic diagram of the test device of Embodiment 1. FIG. 2 is a schematic diagram of the installation location of the sensor 6 included in the test device of Embodiment 1 viewed from the -Y direction. FIG. 3 is a schematic view of the installation location of the sensor 6 included in the test device of Embodiment 1 viewed from the X direction.

In Figure 1, the X direction, Y direction and Z direction are orthogonal to each other. The X direction, Y direction and Z direction shown in the figure below are also orthogonal to each other. Hereinafter, the X direction and the -X direction, which is the opposite direction to the X direction, will be included, and are also referred to as the "X-axis direction". In addition, below, the direction including the Y direction and the -Y direction which is the opposite direction of the Y direction will also be called the "Y-axis direction". In the following, the direction including the Z direction and the -Z direction which is the opposite direction of the Z direction will also be called the "Z-axis direction".

As shown in Figure 1, the test device includes a pair of support bases 3, a load applying part 1, a sensor 6, a fixing fixture 8, an elastic member 7 as a pressing member, an amplifier 9, and a measuring part 10.

A pair of support bases 3 are composed of cylindrical members extending in the Y-axis direction so as to support both ends (ends in the X-axis direction) of the mounting surface of the printed circuit board 4 arranged parallel to the XY plane. ). The electronic component 5 serving as the object to be measured is mounted in the center of the mounting surface of the printed circuit board 4 .

The load applying part 1 is arranged on the surface side of the printed circuit board 4 opposite to the mounting surface, that is, it is arranged above the printed circuit board 4 (Z direction). The load applying part 1 is provided with a push piece jig 2 protruding downward (-Z direction). The pusher jig 2 is lowered together with the load applying part 1, and a load is applied to the electronic component 5 through the printed circuit board 4.

The sensor 6 is arranged around the electronic component 5 on the mounting surface of the printed circuit board 4 . The sensor 6 is an AE sensor that detects vibration caused by damage to the electronic component 5 and outputs a voltage signal corresponding to the vibration.

As shown in Figures 1 to 3, the elastic member 7, which is an elastic member such as a plate spring, a coil spring, rubber, or foam, is installed in order to press the sensor 6 to the printed circuit board 4. At the lower end of sensor 6 (the end in the -Z direction). The fixing fixture 8 is a fixture used to fix the sensor 6 to the printed circuit board 4 . The fixing fixture 8 is formed in a rectangular frame shape when viewed from the X direction, so that it can press the sensor 6 to the printed circuit board 4 through the elastic member 7 .

The amplifier 9 amplifies the voltage signal output from the sensor 6 and outputs it to the measuring part 10 . The measuring part 10 is a voltage waveform measuring device used to measure the waveform of the amplified voltage signal. Furthermore, the amplifier 9 is not a necessary construction and can be omitted, but the test device preferably includes the amplifier 9 .

＜Test method＞ Next, the test method using the test device is explained. First, the electronic component 5 as the object to be measured is mounted on the mounting surface of the printed circuit board 4 by soldering. The sensor 6 is mounted around the electronic component 5 on the mounting surface of the printed circuit board 4. The fixed fixture 8 is fixed with the elastic member 7 . Moreover, when testing in compliance with the printed circuit board bending resistance requirements of JIS C 5101-22, as the printed circuit board 4, a glass cloth base material epoxy resin with a thickness of 1.6mm±0.2mm or 0.8mm±0.1mm is used Copper-clad laminates for printed circuit boards. In addition, there are regulations that the radius of curvature of a pair of support seats 3 is 5 mm, and the distance between a pair of support seats 3 is 90 mm.

Moreover, the installation position of the elastic member 7 may also be the lower side (-Z direction) of the sensor 6 , as long as it is the installation position where the sensor 6 is pressed by the printed circuit board 4 . For example, the installation position of the elastic member 7 may be on the opposite side to the mounting surface of the printed circuit board 4 , between the fixing jig 8 and the printed circuit board 4 .

Next, the printed circuit board 4 is placed on the pair of supports 3 so that the electronic components 5 are located on the lower side (-Z direction). At this time, the electronic component 5 is in a direction not in direct contact with the pusher jig 2 .

The load applying part 1 is lowered together with the pusher jig 2 so as to contact the surface of the pusher jig 2 opposite to the mounting surface in the printed circuit board 4 . Here, the position of the pusher jig 2 after the pusher jig 2 contacts the printed circuit board 4 is used as the reference position. The load applying part 1 is further lowered together with the pusher jig 2 to apply a further load from the reference position.

The printed circuit board 4 is bent by the load, and when a further load is applied, the electronic component 5 is damaged, and the vibration caused by the damage is generated by the electronic component 5 . This vibration is transmitted to the sensor 6 through the printed circuit board 4 . The vibration caused by the damage of the electronic component 5 is detected by the sensor 6, converted into a voltage signal corresponding to the vibration, and outputted.

This voltage signal is amplified by the amplifier 9 and then input to the measuring part 10 . The signals input to the measuring unit 10 include, in addition to signals caused by damage to the electronic component 5 , noise from the load applying unit 1 and peripheral devices, and self-induction due to vibrations generated in the surroundings. Noise output from detector 6. In order to measure the voltage signal after considering the noise, a threshold value is set for the voltage value between the voltage amplitude of the noise and the voltage amplitude of the voltage signal corresponding to the vibration caused by the damage of the electronic component 5 .

Next, the method of determining the threshold value is explained. After the electronic component 5 is mounted on the printed circuit board, a bending resistance test of the printed circuit board is performed, the sensor 6 is used to detect the vibration caused by the damage of the electronic component 5, and the measuring part 10 is used to measure the voltage signal. amplitude. Moreover, in a state where the electronic component 5 is not mounted on the printed circuit board 4, a printed circuit board bending resistance test is performed, and the amplitude of the voltage signal is measured by the measuring part 10. In the state where the electronic component 5 is not mounted on the printed circuit board 4, the measured voltage signal is noise.

The threshold value is determined by the voltage value between the voltage amplitude of the voltage signal caused by the damage of the electronic component 5 and the voltage amplitude of the noise. Furthermore, when the test device includes the amplifier 9, its amplification part is considered to determine the threshold value.

Return to the description of the operation of the test device. The threshold value determined in this way is set to the measuring part 10, and the load is applied to the printed circuit board 4 by the load applying part 1 through the pusher jig 2, and the self-sensor 6 is measured by the measuring part 10. Output voltage signal.

When a load is continuously applied to the printed circuit board 4, the electronic components 5 are destroyed. The sensor 6 is used to detect the vibration after the electronic component 5 is damaged. When the waveform of the voltage signal measured by the measuring part 10 exceeds the threshold value, the pushing size of the pusher fixture 2 calculated from the reference position is determined. The limit value of electronic components 5.

Furthermore, the pushing dimension of the pusher jig 2 from the reference position can also be measured in the state after stopping the operation of the load applying part 1 by the trigger signal, or the descending speed of the load applying part 1 can be measured. As a given, it is calculated based on the time required from the time in the reference position to the detection time of the trigger signal. Furthermore, a laser displacement meter or the like can also be used to measure the pushing dimension of the pusher jig 2 from the reference position.

In addition, the sensor 6 may be fixed to the mounting surface of the printed circuit board 4 or any surface on the opposite side. However, it is desirably fixed to the same surface as the electronic component 5 of the printed circuit board 4 . . The reason is that the vibration caused by the damage of the electronic component 5 contains a lot of energy propagated on the mounting surface of the printed circuit board 4. Therefore, the amplitude of the voltage signal output from the sensor 6 becomes larger. The detection sensitivity of vibrations caused by damage is improved.

In this way, since the sensor 6 is fixed around the electronic component 5 in the mounting surface of the printed circuit board 4, the detection sensitivity of the vibration caused by the damage of the electronic component 5 is improved. When the detection sensitivity increases, the voltage signal corresponding to the vibration caused by the damage of the electronic component 5 becomes larger than the noise. The amplitude voltage value of the voltage signal corresponding to the damage of the electronic component 5 is equal to the amplitude voltage value of the noise. The difference becomes larger. As a result, the threshold value set in the measuring part 10 can be set much larger than the amplitude voltage value of the noise, and the false detection rate of vibration caused by damage to the electronic component 5 is reduced.

In addition, in order to further improve the detection sensitivity of the sensor 6, it is desirable to apply a contact medium 11 such as petroleum jelly or grease on the contact surface between the sensor 6 and the printed circuit board 4.

Furthermore, when fixing the sensor 6 to the printed circuit board 4, it is desirable that the pressing force be fixed at a certain pressure or above. FIG. 4 is a schematic diagram showing the state after the vibrator 13 and the sensor 6 are fixed on the printed circuit board 4 included in the test device of the first embodiment. FIG. 5 is a diagram showing the relationship between the pressing force of the sensor 6 on the printed circuit board 4 and the output voltage of the sensor 6 .

As shown in FIG. 4 , before conducting the printed circuit board bending resistance test, the vibrator 13 is fixed around the sensor 6 on the mounting surface of the printed circuit board 4 without the electronic component 5 being mounted. The vibrator 13 is connected with a signal generator 14 . The self-vibrator 13 applies a certain amplitude of vibration to the printed circuit board 4 . FIG. 5 shows the voltage signal output from the sensor 6 after changing the pressing force of the sensor 6 against the printed circuit board 4 .

When the pressing force is reduced, the amplitude of the voltage signal output by the sensor 6 becomes smaller from around 0.4kg/cm ² . Therefore, the pressing force of the sensor 6 against the printed circuit board 4 is made to be above a certain pressure, specifically, above 0.4kg/cm ² , whereby the voltage signal output from the sensor 6 becomes larger. The amplitude difference with the noise becomes larger. When the amplitude difference becomes large, the threshold value set in the measuring part 10 can be set much higher than the amplitude voltage value of the noise, so that the false detection rate of vibration caused by damage to the electronic component 5 is reduced. This can be expected to improve the measurement accuracy of vibration caused by damage to the electronic component 5 .

FIG. 6 is a schematic diagram showing the distance between the sensor 6 and the vibrator 13 . As shown in FIG. 6 , the distance from the sensor 6 to the vibrator 13 is preferably a certain distance or less.

As shown in FIG. 4 , the vibrator 13 is fixed to the position where the electronic component 5 is mounted on the mounting surface of the printed circuit board 4 . Next, the sensor 6 is fixed by the fixing fixture 8 and the elastic member 7 . A signal with a certain vibration amplitude is input from the signal generator 14 to the vibrator 13, thereby causing the printed circuit board 4 to vibrate.

FIG. 7 is a diagram showing the relationship between the distance between the vibrator 13 and the sensor 6 and the output voltage of the sensor 6 after a certain vibration is applied to the printed circuit board 4 in the vibrator 13 . As shown in FIG. 7 , it can be seen that when the distance between the sensor 6 and the vibrator 13 becomes longer, the voltage value output from the sensor 6 decreases.

Therefore, the distance between the sensor 6 and the electronic component 5 is set to a certain distance or less. Specifically, the sensor 6 is fixed so that it is 5 mm or less. Thereby, the distance corresponding to the vibration caused by the damage of the electronic component 5 is reduced. The output voltage of the sensor 6 is larger, and the sensitivity becomes higher. By this, the threshold value set in the measuring part 10 can be set much higher than the amplitude voltage of the noise, and the false detection rate of vibration caused by the damage of the electronic component 5 can be reduced, and the measurement accuracy can be expected to be improved. The effect.

＜Effect＞ As described above, the test device of Embodiment 1 includes: the support base 3 that supports both ends of the mounting surface of the printed circuit board 4 on which the electronic component 5 is mounted; and the pusher jig 2 that is arranged on the printed circuit board 4 On the opposite side of the mounting surface, a load is applied to the electronic component 5 through the printed circuit board 4; the sensor 6 is arranged around the electronic component 5 on the mounting surface of the printed circuit board 4. Moreover, the vibration caused by the damage of the electronic component 5 is detected, and a voltage signal corresponding to the vibration is output; the fixture 8 is fixed, and the sensor 6 is fixed on the printed circuit board 4; the pressing member is pressed against the sensor 6 to print The circuit board 4; and the measuring part 10 are used for measuring the waveform of the voltage signal output from the sensor 6. Furthermore, it is better if the test device further includes an amplifier 9 for amplifying the voltage signal output from the sensor 6 . In this case, the measuring part 10 measures the waveform of the voltage signal amplified by the amplifier 9 .

The support base 3 supports both ends of the mounting surface of the printed circuit board 4. Therefore, the pusher jig 2 applies a load to the electronic component 5 through the printed circuit board 4, thereby bending the electronic component 5. Printed circuit board 4. Furthermore, the sensor 6 is fixed to the printed circuit board 4 by the fixing jig 8 and pressed against the printed circuit board 4 by the pressing member. Therefore, the sensor 6 can be stably mounted to the printed circuit board 4 .

Thereby, during the bending test of the printed circuit board 4 after the electronic component 5 is mounted, the vibration caused by the damage of the electronic component 5 can be detected with high accuracy.

Thereby, the safety of the product including the printed circuit board 4 on which the electronic component 5 is mounted can be ensured.

In addition, compared with the method of attaching the sensor 6 to the printed circuit board 4, it can shorten the work time of installing and removing the sensor 6.

In addition, the pressing member includes the elastic member 7. Therefore, by using the elastic member 7 with a known elastic coefficient, the reproducibility of the installation of the sensor 6 becomes higher. By changing the elastic coefficient of the elastic member 7, an appropriate pressing force to the sensor 6 can be easily obtained. As a result, the sensor 6 can be mounted stably with good reproducibility.

In addition, the pressing force between the pressing sensor 6 and the printed circuit board 4 is 0.4 kg/cm ² or more. Therefore, the limit value of the electronic component 5 in the printed circuit board bending resistance test can be detected with good sensitivity.

In addition, the distance from the sensor 6 to the electronic component 5 is 5 mm or less, so the limit value of the electronic component 5 in the printed circuit board bending resistance test can be detected with good sensitivity.

<Embodiment 2> Next, the test device of Embodiment 2 will be described. FIG. 8 is a schematic diagram of the test device of Embodiment 2. FIG. 9 is a schematic view of the installation location of the sensor 6 included in the test device of Embodiment 2 viewed from the X direction. In addition, in Embodiment 2, the same structural elements as those described in Embodiment 1 are assigned the same numbers, and description thereof is omitted.

As shown in FIGS. 8 and 9 , in Embodiment 2, the screw 12 serves as a pressing member. Specifically, in order to fix the sensor 6 to the printed circuit board 4, a fixing fixture 8 and screws 12 are provided.

In this example, the sensor 6 is pressed against the printed circuit board 4 by the screws 12 from the mounting surface side of the printed circuit board 4. However, it can also be fixed by fixing the sensor 6 from the opposite side of the mounting surface of the printed circuit board 4. The fixture 8 is pressed against the printed circuit board 4 by screws 12 . Furthermore, bolts may be used instead of screws 12 .

As described above, in the test device of Embodiment 2, the pressing member includes the bolt or screw 12, so the sensor 6 can be fixed with a stable pressing force without using the elastic member 7.

In addition, by changing the rotation speed of the fixing screw 12, the necessary pressing force of the sensor 6 against the printed circuit board 4 can be more easily adjusted. Therefore, it becomes easier to obtain an appropriate pressing force against the sensor 6. As a result, the vibration caused by the damage of the electronic component 5 can be detected with good sensitivity, thereby achieving the effect of reducing the false detection rate.

In addition, when the elastic member 7 is used to fix the sensor 6, in order to ensure the desired pressing force, the elastic modulus of the elastic member 7 needs to be known. However, the elastic modulus may deteriorate, so the sensor 6. The facial pressure system changes over time. Therefore, in order to obtain a stable pressing force, the elastic modulus of the elastic member 7 must always be managed. However, when the screw 12 is used, the effect of not having to manage the elastic modulus of the elastic member 7 can also be expected. Moreover, compared with the method of attaching the sensor 6 to the printed circuit board 4, it can shorten the working time of installing and removing the sensor 6.

＜Embodiment 3＞ Next, the test device of Embodiment 3 will be described. Fig. 10 is a schematic diagram of the test device of Embodiment 3. Furthermore, in Embodiment 3, the same structural elements as those described in Embodiments 1 and 2 are assigned the same numbers, and description thereof is omitted.

As shown in FIG. 10 , in Embodiment 3, in addition to the structure of Embodiment 1, a frequency band elimination filter 15 that attenuates voltage signals in a specific frequency band is provided between the sensor 6 and the measurement unit 10 . Furthermore, in addition to the structure of Embodiment 2, a frequency band elimination filter 15 may be provided.

As mentioned above, the output signal of the sensor 6 includes, in addition to the signal caused by the damage of the electronic component 5 , noise from the load applying part 1 and peripheral equipment, and vibration generated in the surroundings. , the noise output from the sensor 6. Originally, it was necessary to detect the signal caused by the vibration caused by the damage of the electronic component 5. However, when it was misled by the noise and mistakenly detected as the vibration caused by the damage of the electronic component 5, the printed circuit board bending resistance test was produced. The limit value of the electronic component 5 is mistakenly determined to be a value different from the original limit value. Therefore, by arranging the frequency band cancellation filter 15 between the sensor 6 and the measurement part 10 , it is possible to suppress false detection of noise as vibration caused by damage of the electronic component 5 .

For example, when the electronic component 5 is a ceramic multilayer capacitor, after the sensor 6 detects the vibration when it is damaged, the signal is detected in a larger frequency range. Even if the voltage signal in a specific frequency band is attenuated by the frequency band cancellation filter 15, the voltage signals in other frequency bands pass through the frequency band cancellation filter 15 with almost no attenuation. For example, when the frequency of noise is 400kHz, select filter 15 to attenuate the frequency band near 400kHz. When the frequency of the vibration caused by the damage of the electronic part 5 is between 100kHz and below 600kHz, together with the noise of 400kHz, the voltage signal of 400kHz caused by the vibration after the damage of the electronic part 5 is also attenuated.

However, signals in other frequency bands pass through the frequency band elimination filter 15 with almost no attenuation. As a result, the frequency band elimination filter 15 is disposed between the sensor 6 and the measurement unit 10, thereby eliminating the voltage signal detected by the sensor 6 due to the vibration of the ceramic multilayer capacitor as the electronic component 5. The voltage difference with noise becomes larger.

For reference, FIG. 11 shows the output signal waveform measured by the sensor 6 for the vibration caused by the destruction of the ceramic multilayer capacitor after reaching the limit value. In addition, FIG. 12 is a histogram showing each frequency of the vibration caused by the destruction of the ceramic multilayer capacitor after reaching the limit value.

As mentioned above, the test device of Embodiment 3 further includes the frequency band elimination filter 15 arranged between the sensor 6 and the measurement unit 10 . Therefore, the frequency band cancellation filter 15 can be used to attenuate the noise until it is set below the threshold of the measurement unit 10 . Thereby, the false detection rate of the limit value of the electronic component 5, which is mainly caused by noise, is reduced, and an effect of improving the detection accuracy can be expected.

<Embodiment 4> Next, the test device of Embodiment 4 will be described. FIG. 13 is a schematic diagram of the installation location of the sensor 6 included in the test device of Embodiment 4 viewed from the -Y direction. 14(a) and (b) are enlarged views showing the portion 8a of the outer peripheral surface of the fixed jig 8 included in the test device of Embodiment 4 that faces the pusher jig 2. In addition, in Embodiment 4, the same structural elements as those described in Embodiments 1 to 3 are assigned the same numbers, and description thereof is omitted.

As shown in FIG. 13 , in the fourth embodiment, the shape of the outer peripheral surface of the fixing jig 8 is different from the structure of the first embodiment. Next, the fixing jig 8 will be described. As in the case of Embodiment 1, the fixing jig 8 is formed in a rectangular frame shape surrounding the printed circuit board 4 and the elastic member 7 serving as the pressing member when viewed from the X direction. Here, in Embodiment 4 and later, the case where the pressing member includes the elastic member 7 will be described. However, the pressing member may include the screw 12 or the bolt. The inner peripheral surface of the fixed jig 8 contacts the surface of the printed circuit board 4 on the opposite side to the mounting surface and the portion of the elastic member 7 on the opposite side of the printed circuit board 4 . As shown in FIG. 14(a) , in Embodiment 4, the portion 8a of the outer peripheral surface of the fixed jig 8 that faces the pusher jig 2 is formed in an arc shape.

In order to improve the vibration detection sensitivity, the sensor 6 must be fixed around the electronic component 5. When approaching the fixed fixture 8 to the electronic component 5, the fixed fixture 8 contacts the pusher fixture 2. When the two are in contact, during the bending test, the pusher fixture 2 and the fixed fixture 8 are rubbed and vibrate. Because this vibration generates noise, the false detection rate increases. The tip of the pusher jig 2 is specified as R=5 in the JIS printed circuit board bending resistance test, and has its limit in shortening the distance between the sensor 6 and the electronic component 5 . Here, the portion 8a of the outer peripheral surface of the fixed jig 8 that faces the pusher jig 2 is made into an arc shape. This makes it harder for the two to come into contact and allows the sensor 6 to be closer. Electronic parts 5. As a result, the detection sensitivity of the vibration caused by the damage of the electronic component 5 is improved.

In the example of FIG. 14(a) , the portion 8a of the outer peripheral surface of the fixed jig 8 that faces the pusher jig 2 is formed in an arc shape. However, it is not limited to this. The shape of the contact with the push piece fixture 2 is sufficient. For example, as shown in FIG. 14(b) , the portion 8a of the outer peripheral surface of the fixed jig 8 that faces the pusher jig 2 may also be formed in an inclined shape.

As described above, in the test device of Embodiment 5, the fixed jig 8 is formed into a frame shape surrounding the printed circuit board 4 and the pressing member, and the inner peripheral surface of the fixed jig 8 is in contact with the printed circuit board 4 The surface on the opposite side of the mounting surface and the part on the opposite side of the printed circuit board 4 in the pressing member are formed in the portion 8a of the outer peripheral surface of the fixed jig 8 that faces the pusher jig 2. It is arc-shaped or inclined.

Therefore, the sensor 6 can be arranged closer to the electronic component 5 than in the first embodiment. As a result, the vibration caused by the damage of the electronic component 5 can be detected with better sensitivity, thereby achieving the effect of further reducing the false detection rate.

＜Embodiment 5＞ Next, the test device of Embodiment 5 will be described. FIG. 15 is a schematic diagram of the installation location of the sensor 6 included in the test device of Embodiment 5 viewed from the X direction. 16(a) and (b) are enlarged views showing the portion 8b in contact with the printed circuit board 4 among the inner peripheral surfaces of the fixing jig 8 included in the test device according to the fifth embodiment. 16(c) and (d) show the portion 8b in contact with the printed circuit board 4 among the inner peripheral surface of the fixed jig 8 included in the test device according to the fifth embodiment, and the outer peripheral surface of the fixed jig 8. , an enlarged view of the part 8a facing the pusher fixture 2. In addition, in Embodiment 5, the same structural elements as those described in Embodiments 1 to 4 are assigned the same numbers, and description thereof is omitted.

As shown in FIGS. 15 and 16(a) , in Embodiment 5, compared to Embodiment 4, the shape of the inner peripheral surface of the fixed jig 8 is different. Among the inner peripheral surfaces of the fixed jig 8, The portion 8b in contact with the printed circuit board 4 is formed in an arc shape.

When the load is continuously applied to the printed circuit board 4 by the pusher jig 2, the printed circuit board 4 is deformed into an arc shape (see FIG. 13), and tensile stress is applied to the electronic component 5. As the deformation of the printed circuit board 4 increases, the stress on the electronic components 5 also increases, and finally reaches a limit value, and the electronic components 5 are destroyed. Therefore, the limit value of the electronic component 5 affects the deformed shape of the printed circuit board 4 . Ideally, the printed circuit board 4 is expected to be deformed into the same shape as when the fixing jig 8 is not installed. The smaller the area of the portion 8b of the fixing fixture 8 that is in contact with the printed circuit board 4, the smaller the influence on the deformed shape of the printed circuit board 4. As a result, there is no difference in the magnitude of the tensile stress acting on the electronic component 5 between the state where the fixing jig 8 is mounted on the printed circuit board 4 and the state where it is not mounted, so that high-precision testing is possible.

In the example of FIG. 16(a) , the portion 8b of the inner circumferential surface of the fixed jig 8 that is in contact with the printed circuit board 4 is formed into an arc shape. However, it is not limited to this. As long as the fixed jig 8 The area of the part 8b of the tool 8 that is in contact with the printed circuit board 4 only needs to be smaller. For example, as shown in FIG. 16( b ), the portion 8 b of the inner peripheral surface of the fixed jig 8 that is in contact with the printed circuit board 4 may be formed in an inclined shape. Furthermore, as shown in FIGS. 16(c) and (d) , the inner peripheral surface shape of the fixed jig 8 of the fifth embodiment and the outer peripheral surface shape of the fixed jig 8 of the fourth embodiment may be combined.

As described above, in the test device of Embodiment 5, the fixed jig 8 is formed in a frame shape surrounding the printed circuit board 4 and the pressing member, and the inner peripheral surface of the fixed jig 8 is in contact with the printed circuit board 4 The surface on the opposite side of the mounting surface and the part of the pressing member on the opposite side to the printed circuit board 4, and the part 8b of the inner peripheral surface of the fixing jig 8 that is in contact with the printed circuit board 4 are formed as Arc-shaped or inclined.

Therefore, there is no difference in the magnitude of the tensile stress acting on the electronic component 5 between the state where the printed circuit board 4 is mounted with the fixing jig 8 and the state where it is not mounted, thereby achieving the effect of enabling high-precision testing.

<Embodiment 6> Next, the positioning jig 16 of Embodiment 6 will be described. FIG. 17 is a schematic diagram of the positioning jig 16 of Embodiment 6 viewed from the Z direction. FIG. 18 is a schematic diagram of the positioning jig 16 of Embodiment 6 viewed from the -Y direction. FIG. 19 is a schematic diagram of the state after installing the sensor 6 using the positioning jig 16 of Embodiment 6, viewed from the Z direction. FIG. 20 is a schematic diagram of the state after the sensor 6 is installed using the positioning jig 16 of Embodiment 6, viewed from the -Y direction. Furthermore, in Embodiment 6, the same structural elements as those described in Embodiments 1 to 5 are assigned the same numbers, and description thereof is omitted.

As shown in FIGS. 17 to 20 , in Embodiment 6, the positioning jig 16 is used to position the sensor 6 .

First, the structure of the positioning jig 16 will be described. As shown in Figures 17 and 18, the positioning fixture 16 includes a plate-shaped base 16a, two guide pins 17, two fixing plungers 18, a sensor positioning plate 19, and a micrometer head. 20.

The base 16a is formed in a rectangular shape as viewed from the Z direction. In the base 16a, which is closer to the -X direction than the central part in the The concave portion 21 is depressed in the -Z direction.

Two guide pins 17 respectively clamp the recesses 21 in the base 16a and are arranged on both sides in the X-axis direction to position the printed circuit board 4 in the Y-axis direction. The two fixing plungers 18 are respectively located at positions facing the two guide pins 17 of the base 16a, and push the two guide pins 17 of the printed circuit board 4.

The sensor positioning plate 19 is provided at the peripheral edge of the recess 21 in the base 16 a in the X direction. In order to position the sensor 6 , it has a semicircular notch 19 a matching the cross-sectional size of the sensor 6 . The micrometer head 20 is provided at the X-direction end of the main body 6 a to position the printed circuit board 4 in the X-axis direction.

Next, the positioning method of the sensor 6 using the positioning jig 16 will be described using FIGS. 19 and 20 . First, the fixing jig 8 is arranged in the recess 21 of the positioning jig 16 . Thereafter, the printed circuit board 4 on which the electronic component 5 is assembled is placed through the opening on the inner peripheral side of the fixing jig 8 formed in the positioning jig 16 . At this time, the recess 21 has a structure that can be arranged horizontally (parallel to the XY plane) with respect to the base 16 a of the positioning jig 16 without contacting the printed circuit board 4 and the fixing jig 8 .

The position of the printed circuit board 4 in the Y-axis direction is determined along the guide pin 17 and the fixing plunger 18 of the positioning jig 16 . The position adjustment in the X-axis direction is carried out when the printed circuit board 4 moves until it touches the micrometer head 20 . Furthermore, the position of the micrometer head 20 in the positioning jig 16 is adjusted in advance to a position where the distance between the electronic component 5 and the sensor 6 becomes the desired distance. In this state, the sensor 6 is pushed to the semicircular notch 19a of the sensor positioning plate 19 to position the sensor 6, and the sensor 6 is fixed with an elastic member. Thereafter, the printed circuit board 4 is moved in the −X direction, and the printed circuit board 4 is removed from the positioning jig 16 , thereby completing the positioning and fixing of the sensor 6 .

As shown in FIG. 7 , when the distance between the sensor 6 and the vibrator 13 becomes longer, the voltage value output from the sensor 6 decreases. Therefore, the sensor 6 is fixed so that the distance between the sensor 6 and the electronic component 5 is 5 mm or less. However, if the sensor 6 is brought close to the electronic component 5, the fixed jig 8 contacts the pusher jig 2 during the bending test.

However, as shown in Figures 13 and 14 (a) and (b), the portion 8a of the outer peripheral surface of the fixed jig 8 that faces the pusher jig 2 is arc-shaped or inclined, thereby The fixed fixture 8 can be closer to the push fixture 2 . However, as mentioned above, the sensor 6 must be positioned with good accuracy.

As described above, in the test method of Embodiment 6, the sensor 6 is fixed to the mounting surface of the printed circuit board 4 by the fixing jig 8 and the pressing member on the mounting surface of the printed circuit board 4 on which the electronic component 5 is mounted. In the process surrounding the electronic component 5 , a positioning jig 16 is used to position the sensor 6 to the printed circuit board 4 .

Therefore, the sensor 6 can be fixed to the periphery of the electronic component 5 with high accuracy, and the output voltage of the sensor 6 corresponding to the vibration caused by the damage of the electronic component 5 is large, so the detection sensitivity of the vibration is improved. system improved.

Although this teaching has been explained in detail, the above explanation is based on the overall situation and is an illustration and not a limitation. It can be understood that numerous modifications not illustrated can be assumed.

Furthermore, each embodiment can be freely combined, and each embodiment can be appropriately modified or omitted.

2: Push piece fixture 3: Support base 4: Printed circuit board 5: Electronic parts 6: Sensor 7: Elastic component 8: Fixed fixture 9: Amplifier 10:Measurement Department 12:Screws 15: Band elimination filter 16: Positioning fixture

FIG. 1 is a schematic diagram of the test device of Embodiment 1. FIG. 2 is a schematic view of the installation location of the sensor included in the test device of Embodiment 1 viewed from the -Y direction. 3 is a schematic view of the installation location of the sensor included in the test device of Embodiment 1 viewed from the X direction. 4 is a schematic diagram showing a state after the vibrator sensor is fixed on the printed circuit board included in the test device of Embodiment 1. FIG. 5 is a graph showing the relationship between the pressing force of the sensor on the printed circuit board and the output voltage of the sensor. Figure 6 is a schematic diagram showing the distance between the sensor and the vibrator. Figure 7 is a diagram showing the relationship between the distance between the vibrator and the sensor and the output voltage of the sensor after applying a certain vibration to the printed circuit board in the vibrator. FIG. 8 is a schematic diagram of the test device of Embodiment 2. 9 is a schematic view of the installation location of the sensor included in the test device of Embodiment 2 viewed from the X direction. Fig. 10 is a schematic diagram of the test device of Embodiment 3. Figure 11 is a diagram showing the output signal waveform detected by the sensor in response to the vibration that causes damage after the ceramic multilayer capacitor reaches the limit value. FIG. 12 is a histogram showing the frequencies involved in the vibration that causes damage to the ceramic multilayer capacitor after it reaches the limit value. 13 is a schematic view of the installation location of the sensor included in the test device of Embodiment 4 viewed from the -Y direction. FIG. 14 is an enlarged view showing the portion of the outer peripheral surface of the fixed jig included in the test device of Embodiment 4 that faces the pusher jig. FIG. 15 is a schematic view of the installation location of the sensor included in the test device of Embodiment 5 viewed from the X direction. 16 shows a portion of the inner circumferential surface of the fixed jig included in the test device of Embodiment 5 that is in contact with the printed circuit board, and a portion of the outer circumferential surface of the fixed jig that faces the pusher jig. Enlarge image. FIG. 17 is a schematic diagram of the positioning jig of Embodiment 6 viewed from the Z direction. FIG. 18 is a schematic diagram of the positioning jig of Embodiment 6 viewed from the -Y direction. FIG. 19 is a schematic diagram of the positioning jig of Embodiment 6 and the state after the sensor is installed, viewed from the Z direction. 20 is a schematic diagram of the positioning jig of Embodiment 6 and the state after the sensor is installed, viewed from the -Y direction.

1:Load application part

2: Push piece fixture

3: Support base

4: Printed circuit board

5: Electronic parts

6: Sensor

7: Elastic component

8: Fixed fixture

9: Amplifier

10:Measurement Department

11: Contact with media

Claims (11)

A test device including: A support base supports both ends of the mounting surface of a printed circuit board on which electronic components are mounted; The pusher jig is disposed on the opposite side of the mounting surface of the printed circuit board, and applies a load to the electronic component through the printed circuit board; The sensor is arranged around the electronic component in the mounting surface of the printed circuit board, and detects vibration caused by damage to the electronic component, and outputs a voltage signal corresponding to the vibration; Fixing fixture to fix the sensor on the printed circuit board; a pressing member that presses the sensor to the printed circuit board; and The measuring part is used to measure the waveform of the voltage signal output from the sensor. The test device of claim 1, further comprising an amplifier for amplifying the voltage signal output from the sensor, The measuring part measures the waveform of the voltage signal amplified by the amplifier. The test device of claim 1 or claim 2, wherein the pressing member includes an elastic member. The test device of claim 1 or claim 2, wherein the pressing member includes bolts or screws. The test device of claim 1 or claim 2 further includes a frequency band elimination filter disposed between the sensor and the measurement part. Such as the test device of claim 1 or claim 2, wherein the pressing force from the sensor to the printed circuit board is more than 0.4kg/cm ² . For example, the test device of claim 1 or claim 2, wherein the distance from the sensor to the electronic component is less than 5 mm. The test device of claim 1 or claim 2, wherein the fixing fixture is formed into a frame shape surrounding the printed circuit board and the pressing member, The inner peripheral surface of the fixing jig contacts the surface of the printed circuit board on the opposite side to the mounting surface and the portion of the pressing member on the opposite side of the printed circuit board, The portion of the outer peripheral surface of the fixed fixture that faces the pusher fixture is formed into an arc shape or an inclined shape. The test device of claim 1 or claim 2, wherein the fixing fixture is formed into a frame shape surrounding the printed circuit board and the pressing member, The inner peripheral surface of the fixing jig contacts the surface of the printed circuit board on the opposite side to the mounting surface and the portion of the pressing member on the opposite side of the printed circuit board, The portion of the inner peripheral surface of the fixed fixture that contacts the printed circuit board is formed into an arc shape or an inclined shape. A test method using the test device of claim 1 or claim 2, characterized by: (a) Mount the electronic component to the mounting surface of the printed circuit board, and fix the sensor to the periphery of the electronic component in the mounting surface of the printed circuit board through the fixing fixture and the pressing member. process; (b) The process of placing the printed circuit board on the support base so that the electronic component is located on the lower side; (c) The process of lowering the pusher fixture to contact the surface of the printed circuit board opposite to the mounting surface; (d) The process of further lowering the pusher jig and applying a load to the printed circuit board from the reference position where the pusher jig contacts the upper surface of the printed circuit board; (e) When the printed circuit board is bent and the electronic component is damaged, when the waveform of the voltage signal measured by the measuring part exceeds the preset threshold, the value will be calculated from the reference position. The push-in size of the push piece fixture is used as the limit value of the electronic component. The test method of claim 10, wherein in the process (a), a positioning jig is used to position the sensor on the printed circuit board.

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