JPH052103B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a device that automatically scans and detects flaws on a specimen, and in particular, it relates to a device that automatically scans and detects flaws in a specimen, and in particular,
This invention relates to an automatic flaw detection scanning device suitable for detecting minute internal defects in electronic components such as ICs or LSIs, and various precision mechanical components.

[Background of the invention]

BACKGROUND ART In recent years, a variety of devices have been provided for automatically scanning and detecting flaws on a specimen, and are used to determine the quality of various specimens such as mass-produced parts and important parts. Information for determining the quality of the specimen is obtained by observing the information on the ultrasonic flaw detection results using an automatic flaw detection scanning device.In making this determination, the location, shape, size, and quality of each defect are determined. In addition to knowing the actual situation, knowing the degree of influence that the defective part has on the entire subject, that is, the number of defects and the state of distribution, provides information for accurate judgment. Therefore, the A scope, which is the current main method of displaying ultrasonic flaw detection results,
The graphic displays and records of the B scope and C scope are used differently depending on the purpose of flaw detection, the shape of the object, etc., taking advantage of their characteristics. In other words, A scope is for each defect.
Information about so-called "points" is obtained with the B scope, so-called cross-sectional information under the scanning line of the probe, and with the C scope, information on the planar defect distribution of the object can be obtained.

By the way, various new materials have been developed and used in recent years. Among these, in brittle materials such as ceramics, minute defects in the order of tens of micrometers to several micrometers have a significant impact on the strength and reliability of the material, so it is necessary to detect these minute internal defects. Inspection methods that apply ultrasound have come to be adopted for this purpose. In addition, with the development of the so-called electronic industry in recent years, the ICs and LSIs used there
There are a huge number of them. On the other hand, electronic circuits using ICs, LSIs, etc. usually occupy the most important part of controlling the device or mechanism, and the quality of the device or mechanism depends on the IC, LSI, etc.
It can be said that it depends on the quality of the LSI. For this reason, it is necessary to judge the quality of ICs, LSIs, etc. as strictly as possible, and in addition to electrical and physical tests, ultrasonic flaw detection tests have recently come to be used.

For flaw detection testing of various new materials, electronic components such as IC or LSI, and various precision mechanical parts using ultrasonic waves, it is necessary to obtain defect information over the entire surface of a specific part, so the automatic flaw detection scanning device using the C scope is suitable. An example of a conventional device will be explained with reference to FIG. In the figure, reference numeral 1 denotes an X-direction drive device that holds the probe 4 and moves it on a guide bar in the direction of arrow X-X'. 2 is a Y-direction drive device, and the base 20
It is movable on the top in directions Y and Y', which are perpendicular to the X-X' direction. Reference numeral 3 denotes a Z-direction driving device, which has a guide bar of the X-direction driving device 1, and uses a support 21 provided upright on a base 20 as a guide to drive in the X-X′ direction and Y, Y′ direction. It is movable in the direction of arrow Z-Z' perpendicular to the direction. X, Y and Z
A stepping motor is used to drive each of the drive devices 1, 2, and 3, and a ball screw is used to reduce drive resistance. Reference numeral 5 denotes a water immersion tank containing water 5', in which the probe 4 is immersed, and a subject 6 is placed at the bottom of the tank. P is a probe holding device (hereinafter referred to as a positioner) having the above configuration. 8 is a pulser, a transmission circuit that sends pulses to the probe 4; 9 is a receiver, a circuit that receives the sound pressure signal received by the probe 4 from the subject 6; 10 is a peak detector; An analog voltage proportional to the peak value of the received signal of the receiver 9 is converted to an A/D converter 12.
It is a device that sends 7 is an oscilloscope, into which the output signal of the receiver 9 is input and displayed. 1
A control device 1 is connected to the CPU 13 and sends control signals sent from the CPU 13 to the stepping motors of the X, Y, and Z drive devices 1, 2, and 3. CPU13 is A/D converter 1
2 and sends it to the image processing device 14, and the image processing device 14 sends the pixel memory data to the monitor TV 15 for C-scope display. In the automatic flaw detection scanning device having the above configuration, reception signals for the object 6 are captured at regular time intervals set by the CPU 13.
On the other hand, scanning is performed by a drive device, but the time it takes for the stepping motor of the X-direction drive device 1 to reach a constant speed after it starts, or the time it takes to decelerate and stop, is inevitably A speed change occurs. Therefore, the intervals between the reception signal acquisition positions are not constant, making it impossible to obtain accurate data at equidistant intervals. For this reason, the scanning distance must be extended by the distance range where the speed changes, which requires extra scanning time. Furthermore, if the rotational speed of the stepping motor of each drive device is uneven, data acquisition intervals will not be equidistant, resulting in distortion in the scanned figure. Therefore, there was a problem that accurate information on the flaw detection results could not be obtained.

[Purpose of the invention]

The present invention solves the above-mentioned problems and provides an automatic flaw detection scanning device that makes it possible to capture data at equal distance intervals over the entire surface of the object to be inspected, and that can obtain accurate flaw detection result information in a short time. There is something to do.

[Summary of the invention]

The present invention includes a probe holding device in which a probe is held so as to be scannable in the X, Y, and Z directions with respect to a subject by each drive device, and a probe holding device that is connected to a CPU and that drives each positioner. a control device that transmits a control signal to control the scanning position of the probe; a device that transmits a voltage pulse signal to the probe and receives the signal that the probe receives from the subject; The output signal is sent to the CPU via an A/D converter.
In an automatic flaw detection scanning device, the control device is connected between the control device and the A/D converter, and a display device automatically records and displays the contents of the C scan input to the computer and processed via the CPU. A frequency dividing circuit is provided to divide the control signal transmitted from the device to each driving device of the probe holding device, and the output signal of the frequency dividing circuit is set as the A/D start signal of the A/D converter. C-scan the entire surface of the object to be scanned.
This allows accurate flaw detection result information to be obtained in a short time.

[Embodiments of the invention]

An embodiment of the present invention will be explained with reference to FIG.
In the figure, the same reference numerals as in FIG. 2 indicate the same thing. The figure shows the conventional example shown in FIG. 2 with a frequency dividing circuit 16 added thereto. The frequency dividing circuit 16 is provided between the control device 11 and the A/D converter 12, and divides the frequency of the control signal sent from the control device 11 to the stepping motors of each drive device 1, 2, and 3 of the positioner P.
The output signal of the frequency dividing circuit 16 is input as an A/D start signal to the A/D converter 12.

Since each of the stepping motors rotates in accordance with the number of pulses transmitted from the control device 11, each drive device, for example, the X-direction drive device 1, is displaced in the X-X' direction in accordance with the number of pulses. That is, from the rotation angle of the stepping motor per pulse and the pitch of the ball screw of the X-direction drive device 1, the
The amount of displacement Δx in the X′ direction is determined. In the present invention, the pulses sent from the control device 11 to the stepping motor of the X-direction drive device 1 are branched and input to the frequency dividing circuit 16, so the pulses sent from the control device 11 are frequency-divided. A/D converter 12
is output to. For example, if the frequency division number of the frequency dividing circuit 16 is N, a pulse will be outputted from the frequency dividing circuit 16 every N times the displacement amount Δx of the X-direction drive device 1. The pulse from the frequency dividing circuit 16 is an A/D
Since it is input to the converter 12 as an A/D start signal, the A/D converter 12 receives a received signal every N times Δx corresponding to the displacement Δx of the X-direction drive device 1. Become. Therefore, by arbitrarily changing the frequency division number N of the frequency dividing circuit 16,
It becomes possible to capture a received signal corresponding to an arbitrary amount of displacement of the X-direction drive device 1. The above description is the same for each of the Y and Z drive devices.
By providing the frequency dividing circuit 16, the conventional CPU
It is no longer necessary to output the signal for receiving the received signal of the A/D converter 12, which was output from the A/D converter 13, and therefore the calculation time in the CPU 13 is omitted, and the scanning speed becomes faster.

〔Effect of the invention〕

As explained above, the present invention is an automatic flaw detection scanning device that uses C scan to detect minute internal defects in various new materials such as ceramics, electronic components such as IC or LSI, and various precision mechanical components. A frequency divider circuit was provided to divide the control signal sent to each drive device of the positioner, and the output signal of the frequency divider circuit was used as the A/D start signal of the A/D converter. Accurate flaw detection result information can be obtained even during deceleration, and scanning time can be shortened because the conventional method of scanning an extra distance during acceleration and deceleration can be omitted.
In addition, even if the rotational speed of the motor of each drive device is uneven, it will not be affected and data can always be captured at equal distance intervals, so there will be no distortion in the obtained figure and it will be more accurate. You can obtain accurate flaw detection result information.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment of the present invention, and FIG. 2 is an explanatory diagram of a conventional example. P...Positioner, 1...X direction drive device, 2...
Y direction drive device, 3... Z direction drive device, 4... Probe, 5... Water immersion tank, 6... Subject, 11... Control device, 12... A/D converter, 13... CPU, 16...
Frequency divider circuit.

Claims (1)

[Claims] 1 A probe holding device in which the probe is held so as to be scannable in the X, Y, and Z directions by each drive device relative to the subject, and a probe holding device connected to a CPU and each driving device of the probe holding device a control device for transmitting a control signal for controlling a scanning position of the device; and a control device for transmitting a control signal to the probe;
A device that transmits voltage pulse signals and receives signals received by the probe from the subject, and an output signal from the device is input to the CPU via an A/D converter and processed via the CPU. In the automatic flaw detection scanning device, the control device and the A/D
A frequency dividing circuit for frequency dividing the control signal transmitted from the control device to each driving device of the probe holding device is provided between the converter and the output signal of the frequency dividing circuit to the A/D converter. An automatic flaw detection scanning device characterized in that the A/D start signal is an A/D start signal.