JPS5991361A - Detector for foreign particle in electronic component - Google Patents

Abstract

PURPOSE:To enable quick detection of short-circuiting and release time depending on the presence of foreign particles in a cavity, material and foreign matters by employing a non-distructive method. CONSTITUTION:While a transistor Tr is conductive, a gate of SCR goes down to a ground potential and a lamp L is OFF. Then, a relay 31 to be measured is vibrated with a vibration tester 11 to identify foreign particles in a cavity when an impact sound noise is detected. When the foreign particles causes the internal contact 315 to be short-circuited, the gate voltage of SCR rises up to the power source voltage and when the short-circuiting is held for a longer time than the constant for the rise, the SCR conducts to light the lamp L. The resetting of a detection circuit 32 is done by the operation of a switch S.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention is applicable to, for example, quality control and acceptance inspection of electronic e- and i-products (ICs, l-transistors, relays, etc.) that have cavities (protrusions) inside their packages. The present invention relates to an apparatus for detecting foreign particles in electronic components, which is applied to electronic components.

[Technical background of the invention and its problems]

As is well known, various foreign particles present in the cavities of electronic components can cause various evils to the electronic components. Recently, in order to improve the reliability of electronic components, there has been an increasing demand for detecting foreign particles, especially in the navigation, space, and ship industries.

As an example of this detection method, a PIND test device applies vibration and shock to electronic components, shakes off adhering particles, causes them to collide with the inner wall of the cavity, and detects the sound.
(particle Irrypncl No.1se
A non-destructive test using a device called pefecflon System has been adopted.

FIG. 1 shows the PIND test apparatus tk.

The vibration tester 1 is vibrated by a signal supplied from a vibration source 12.

This vibration wJ source 12 is constructed, for example, from a sine σU oscillator and an amplifier, and is configured to generate a constant imaging signal. Further, an acoustic transducer 14 is provided to the vibration M test tiger 0@11 via an insulating section 13. The number of this sound transducer 14 is, for example, several hundred.
The electronic component 16 to be measured is mounted on the top surface of the transducer 14 using double-sided tape or a water-soluble adhesive 15 that transmits ultrasonic waves. Therefore, this electronic component 16 is vibrated by the vibration tester 1), and this electronic component 1 is
If foreign particles exist in the cavity 6, high-frequency collision acoustic noise is generated by their collision. Is this noise -71 mentioned above? ) The output signal of this transducer 14 is fed to a threshold detector 18 via an ultrasonic amplifier 17. This dark value detector 18 outputs a signal when the input signal exceeds a required level, and this signal is supplied to a lamp 19, which is activated 2' to indicate the presence of foreign particles. Saichi 2L. Also, the front-self threshold detector 18, the ultrasonic amplification 1
The output signal of the oscilloscope 17 is supplied to the oscilloscope 22 together with the output signal of the vibration source 12 and the output signal of the accelerometer 20 provided in the vibration tester 11, which is amplified by the charge amplifier 21 and recorded. be done.

It should be noted that foreign particles existing inside the cavity of the electronic component 16 may become stuck due to static electricity or their internal structure before applying any damage or during vibration, so in order to free these particles during vibration, the vibration test The machine 11 and the vibration source 12 also have the function of generating shock.

In addition, in general, when particles collide with the inner wall of the cavity,
If the coefficient of repulsion is K, then the height of the inner wall of the cavity H(
(inch), amplitude X (inch), and frequency f (Hz): X=IIx(1-K)/yrx(1-K)f=5.52
X (Gx (1+K)/Fix (1-K J l
However, there is a relationship between G: gravitational acceleration, and K is not constant depending on each particle and each package, but assuming K"0, the frequency and acceleration level according to the height of the inner wall of the package are ・R'-> 5ji The mass of the particle can be expressed as the child side.

By the way, if there are conductive foreign particles inside the cavity, the circuit is short! #! 1, but in the case of relays, even non-conductive particles can cause contact failure noise.

In the above test fi:s:, although it is possible to detect the mass of foreign particles present inside electronic components using a non-destructive method, it is not possible to detect the phase quality, size, shape, or adverse effect time of the particles. It has its drawbacks.

Methods for analyzing the material, size, and shape of foreign particles have also been studied in glazes.In the case of package-type parts, the general method is to file a part of the package surface with a file, etc., and then remove the inside of the cavity. Make a hole with something like a needle to prevent particles from entering from the outside. Apply adhesive tape to the hole,
Perform the PIND test again. This test is repeated until foreign particles adhere to the tape and no detection signal is generated.

After that, the tape is removed and the particles are observed under a microscope to identify their size and shape, and then the material of the particles is identified by X-ray photography.

By such a method, the size, shape, and
Materials can be analyzed. However, this analysis requires the complete destruction of a portion of the package, which requires special skills.

In addition, testing and analysis require a long period of time, laborious equipment is required, and there is a large amount of volume and liquid.

This has become an obstacle for quality control and acceptance inspection of child parts. In particular, electronic components where it is important to determine the temporal influence of foreign particles (e.g. contact components such as relays and switches)
In many cases, it is basically impossible to investigate the cause using the above-mentioned destructive tests, and other detection means are desired.

[Purpose of the invention]

This invention has been made based on the above-mentioned circumstances, and its purpose is to use a non-destructive method to detect the presence of foreign particles in electronic component cavities and to prevent short circuits due to the material and foreign particles. Or open time ff+
′μ, which can be detected in a short time with a unique configuration
Child part 1 saw foreign particle detection 44 jig, '! [Summary of the Invention] This invention vibrates an electronic component using a PIND test device, determines the presence of foreign particles based on the presence or absence of collision acoustic noise, and detects the external connection terminal of the electronic component. By detecting conduction or non-conduction using the first to third switching means, time constant circuit, and display means, it is possible to determine the material of foreign particles present inside the cavity of the electronic component and the short or complete open time. This makes it possible to judge.

[Embodiments of the invention]

The following is a poem about the dormitory embodiment of this invention with reference to the drawings.
I will clarify.

In FIG. 2, numeral 3 indicates an electronic component to be measured, such as a relay, and this relay 31 is installed as an electronic component to be measured in the vibration tester 1 of the above-mentioned PINJ test equipment. 32 is an external terminal 31. of the relay 3. ~314 is shown as a detection circuit connected to the detection circuit 32.
The internal contacts 31m+ 316 of the relay 31 are short-circuited (or closed) for a predetermined period of time or more due to internal foreign particles.
If it is, this f'L'fI: is to be displayed.

That is, the base and emitter of the first switching means, for example, the transistor Tr in the detection circuit 32 are the external terminals of the relay 31, for example tf J I tr J
1, the emitter of this transistor 'fr is grounded, the collector is grounded via a capacitor C, and is connected to the gate of a second switching means, for example a SIRISC SCR. The cathode of this thyristor SCH is grounded, and the anode is a display means,
For example, it is connected to one fixed contact of a third switching means, for example a normally closed switch S, via a lamp L''ft-.
(!QDC't- is connected to the ground. Also, one fixed contact of the switch S is connected to the collector of the transistor 1t through a resistor R1v and a variable resistor R,'i in series, and is connected to the collector of the transistor 1t through a resistor Rsk. It is connected to the base of the transistor Tr.The ML capacitor C and the resistor R are connected to the base of the transistor Tr.
1%1] The variable resistor R1 constitutes a time constant circuit.

In the above configuration, the transistor litr is normally turned on, and in this state, the gate of the thyristor SCR is brought to approximately ground potential due to the low output impedance of the transistor Tr. Therefore, the signal SCR is in a non-conducting state and the lamp L is turned off.

In this state, the relay 31 is
The collision acoustic noise is detected by means similar to the conventional method, and it is determined that foreign particles are present in the cavity. Furthermore, this foreign particle causes relay 3
1 internal contact 31. When the transistor Tr is short-circuited, the base of the transistor Tr is grounded, and the transistor Tr is in an off state. Therefore, the gate voltage of the SIRISK SCH connected to the collector of the transistor Tr is increased to the power supply voltage. The rate of this increase is the capacitor C
and the time constant determined by the resistor Rl + R*, for example rfc20,001μF', R1+Rz
” 1000 = 15000 is number 10 p see
It is. Therefore, if the short-circuit state is maintained longer than this time constant, the thyristor SCR becomes conductive and the n1 lamp L is lit. Therefore, it is determined that the internal contact 31m of the relay 31 is short-circuited.

The detection circuit 32 is reset by operating the switch S. If the lamp L goes out (by operating the switch S), it is determined that the short-circuited state of the internal contact 315 in the relay 31 has been released.
, if the lamp L is not turned off, it is determined that the short-circuit condition continues.

According to the above configuration, during or after the PIND test, the external connection terminal 311* of the electronic component to be measured, for example, the relay 31
By detecting the conductivity and non-conductivity of 31 N and displaying it using 2 amplifiers L, it is possible to determine the conductivity and non-conductivity of the foreign particle and also determine the short-circuit time of the foreign particle. Therefore, it is extremely convenient because all necessary tests can be performed without completely destroying electronic components. In addition, since the configuration is simple and the time required for testing is short, it is suitable for quality lateral distortion of a large number of parts.

Note that the detection circuit 32 is not limited to one circuit;
If necessary, multiple circuits can be used to simultaneously test the states of multiple internal circuits of the electronic component to be measured.

In addition, in the above embodiment, the circuit configuration was such that all states in which the internal contacts, which should normally be open circuits, were short-circuited (closed) due to foreign particles were detected, but with the circuit configuration shown in FIG. It is also possible to detect that a previously closed circuit has become open due to particle collisions. In FIG. 3, the same parts as in FIG. 2 are given the same reference numerals.

That is, in FIG. 3, both ends of the resistor R4 are connected to external connection terminals of the electronic component to be measured.

One end of this resistor R4 is connected to one fixed contact of the switch S through a resistor Rs'c, and the other end is grounded and connected to the other fixed contact of the switch S through a DC power supply DC' (r). The connection point of the resistors R41R5 is connected to the transistor T through the resistor R1 and the variable resistor R2k in series.
The collector of the transistor Tr is connected to one fixed contact of the switch S via a resistor R6.
1 emitter is connected to the gate of thyristor SCH.

The cathode of this thyristor SCR is grounded, and the anode is connected to one fixed contact of the switch S via a rung L'lt.

With such a configuration, the open state of the closed circuit can be detected in the same manner as in the above implementation.

Furthermore, depending on the electronic component, it is also possible to use a combination of the detection circuits shown in FIGS. 2 and 3.

Furthermore, in both of the above embodiments, the first. The second and third switching means are not limited to transistors, thyristors, and mechanical normally closed switches.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

〔Effect of the invention〕

As detailed above, the present invention uses a non-destructive method to detect the presence or absence of foreign particles in the cavity of an electronic component, the material, and the short circuit or open time caused by the foreign particles in a short time using a simple configuration. It is possible to provide an electronic particle detection device capable of detecting foreign particles within a city.

[Brief explanation of drawings]

FIG. 1 is a diagram shown to explain the configuration of a conventional PIND test device and a PIND test device applied to the present invention, and FIG. 2 is a circuit configuration showing an embodiment of a foreign particle detection device in an electronic section according to the present invention. 3 are circuit configuration diagrams showing other embodiments of the present invention. 11... Vibration tester, 12... Vibration source, 31...
Relay, 31. ~314...External connection terminal, 316°316...Internal contact, Tr...Transistor, SC
R...Thyristor, S...Switch %R1...Resistor, R2...Variable resistor, C...Cono differential length. Applicant's representative Patent attorney Takeshi Suzue Examination Figure 1 Figure 3

Claims (1)

[Claims] means for applying vibration and impact to the electronic component to be measured; and a first switching means connected to the external connection terminal of the electronic component and controlled to turn on and off depending on whether the internal circuit of the electronic component is conductive or non-conductive. , a time constant circuit provided at the output end of the switching means of this silk 1, and on/off control by the output signal of this time constant circuit 1. a second switching means controlled by the second switching means; a display means controlled by the second switching means; and a third switching means for controlling the power supplied to the second switching means.