JPS63217267A - Ultrasonic inspecting device - Google Patents

Abstract

PURPOSE:To suppress vibrations by feeding acceleration which is generated at the time of the movement of a scanning means back to a speed reducing means and generating a driving signal for the scanning means. CONSTITUTION:A control circuit 13 calculates a speed signal for obtaining a speed pattern by a speed signal arithmetic part 13a according to a movement command distance from an input device 12 and outputs information on it to a deviation device 13c. An acceleration detector 14a provided to a scanning device 6, on the other hand, detects the acceleration alpha at the time of the movement of the device 6 and feeds the result back to the deviation device 13c through a gain setter 13 incorporated in the circuit 13. Then the setter 13b multiplies the detected acceleration alpha by a constant K to calculate the speed signal V2=K.alpha and outputs the result to the deviation device 13c. This deviation device 13c calculates the difference (v) between the speed signal V1 calculated and outputted by the arithmetic part 13a and the signal V2 from v=V1-V2 and outputs this difference (v) to a motor 7 as the motor driving signal. Thus, vibrations can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an ultrasonic inspection device for examining internal defects in semiconductors, metal plates, ceramic structures, and the like.

B. Prior Art This type of apparatus is constructed, for example, as shown in FIG. The stage 1 has a pair of fixed guides 2 extending in the Y direction.
a, 2b are provided, and on these fixed guides 2a, 2b,
A movable guide 3 movable in the Y direction, a support body 4 provided at the center of this movable guide 3 movable in the X direction, and a probe movable up and down in the Z direction provided at the lower end of this support body 4. A scanning device 6 consisting of a feeler 5 is provided. The movable guide 3 is movable by a motor 7 provided on one of the fixed guides 2a, and the support body 4 is movable by a motor 8 provided on the movable guide 3. A motor for moving the probe 5 is not shown. Encoders 9 and 1o are connected to these motors 7.8, respectively, and output pulse signals proportional to the rotation of each motor. A water tank 11 filled with water is installed on the stage 1, and the subject TP is immersed in the water tank 11.

When the input device 12 commands the moving direction and distance of the scanning bag @6 in the X and Y directions, the control circuit 13 outputs a motor drive signal with a preset speed pattern as shown in FIG. 3 to the motor 7.8. The motor 7.8 is operated to move the scanning device 6 in the X direction and the Y direction. Motor 7.
In response to the rotation of the scanning device 8, pulse signals are supplied from the encoders 9 and 10 to the control circuit 13, where the moving distance and direction of the scanning device 6 are detected. The control circuit 13 compares the two signals from the encoders 9, 10 and the input device 12, and outputs a motor drive signal to the motor 7.8 until they match. This sets the scanning device 6 at a predetermined x and Y position.

Incidentally, when the motor 7.8 driven by the motor drive signal from the control circuit 13 moves the scanning device 6, an inertial force acts on the scanning device 6 due to acceleration or deceleration. If the scanning device 6 is heavy, its inertial force may cause large vibrations in the scanning device 6. Therefore, a plurality of speed patterns are stored in the control circuit 13, in which the slope of the acceleration/deceleration section is variously set according to the weight of the scanning device 6.
When moving the scanning family @6, the operator must move the scanning device 6.
A speed pattern corresponding to the weight of the scanning device 6 is selected, and a drive signal based on this speed pattern is supplied from the control circuit 13 to the motor 7.8 to gradually accelerate or decelerate the scanning device 6 to suppress vibration.

C0 Problems to be Solved by the Invention However, it becomes necessary to set a plurality of patterns in advance and change the speed pattern each time an inspection is performed due to the weight and weight of the scanning device 6, which makes input operations complicated. Further, when the weight is heavy, if the acceleration or deceleration time is long, vibrations can be suppressed, but there is a problem that it takes time to move the scanning device 6 to the desired x and y positions.

An object of the present invention is to provide an ultrasonic inspection apparatus that solves these problems by feeding back the acceleration acting on the scanning device to the speed control means to form a motor drive signal.

The present invention will be explained based on FIG. 1 showing an embodiment of means for solving problem D6.
The ultrasonic inspection apparatus according to the present invention includes a command means 12 for instructing the ultrasonic probe 5 to move to a predetermined position, and a scanning device capable of moving the ultrasonic probe 5 in at least one direction according to the command. means 6, a driving means 7 for moving the scanning means 6 according to an input drive signal, an acceleration detection means 14a for detecting acceleration when the scanning means 6 moves, and an acceleration detected by the acceleration detection means 14a. The speed control means 13 calculates a drive signal based on the command from the command means 12.

The 89 action acceleration detection means 14a constantly detects the acceleration when the scanning means 6 moves and feeds it back to the speed control means 13. Upon receiving the command from the command means 12, the speed control means 13 calculates a drive signal based on this command and the acceleration fed back from the acceleration detection means 14a, and outputs the result to the drive means 7. The drive means 7 moves the scanning means 6 to a predetermined position based on this drive signal.

F. Example 1 to 4, the present invention will be explained in detail.

Note that the same parts as in Figure 5 in Figures 1 and 2 are
The same reference numerals are given and only the differences will be explained.

In FIG. 2, the support 4 has an X
Acceleration detectors 14a and 14b are provided to detect acceleration in the direction and the Y direction, respectively. Acceleration detectors 14a, 14b
inputs the information to the control circuit 13.

Next, the control circuit 13 will be explained with reference to FIG.

The control circuit 13 includes a speed signal calculation unit 13a that calculates a speed signal V based on the moving direction and distance input from the input device 12 and the number of output pulses from the encoder 9, and an acceleration signal output from the acceleration detector 14a. Gain setter 1 that provides a gain for converting α into a speed signal by multiplying it by a constant
3b, and a deviation device 13c which calculates the deviation between the speed signal calculated by the speed signal calculating section 13a and the speed signal converted by the gain setting device 13b and outputs the result to the motor 7 as a motor drive signal. In addition, in this figure, a motor 7 for movement in the X direction, an encoder 9. Although only the acceleration detector 14a and the like are shown, those for moving in the Y direction are also configured in the same manner.

In the above embodiment, movable guide 3. The support 4, the probe 5 serve as a scanning means, the motor 7 serves as a driving means, and the input device 12
is the command means, the speed signal calculation section 13a, the gain setting device 1
3b and the deviation device 13c constitute speed control means, and the acceleration detector 14a constitutes acceleration detection means.

The operation of this embodiment will be explained below.

First, based on the movement command distance from the input device 12, the control circuit 13 calculates a speed signal to obtain a speed pattern as shown in FIG. 3 in the speed signal calculation section 13a, and outputs the information to the deviation device 13c.

The procedure for calculating the speed command signal in the control circuit 13 will be explained with reference to FIG.

First, in step S1, the movement command distance Q from the input device 12 is read, and in step S2, the total number of pulses from the encoder 9 to be output when moving the scanning device 6 by the distance Q by the motor 7 is calculated as P =Q/Q.

Seek more. Here α. is the scanning device 6 per pulse.
is the distance traveled (unit movement distance). Next, the process advances to step S3, and a count value N obtained by counting the pulses output from the encoder 9 by a counter (not shown) is read. In step S4, 2N, which is twice the preset number of pulses N0, is compared with the previously determined total number of pulses P, and if P≧2N0, the process proceeds to step S5. Step S4 is to determine whether the speed pattern described above has three sections, an acceleration section, a steady section, and a deceleration section, as shown in Fig. 3, or only two sections, an acceleration section and a deceleration section. Yes, if P≧2N0, there are 3 sections,
If P<2No, it is determined that there are two sections. Here, No is the number of pulses to be output from the encoder 9 within the acceleration period of the scanning device 6.

In step S5, N and N. and N < N
11, it is determined that the current operation of the scanning device 6 is within the acceleration section in FIG. 3, and the speed signal calculation unit 13a
V engineering which is the addition of ΔV to the speed signal V output from =
V+ΔV is set in step S12. On the other hand, if N≧N0, the process advances to step S6. In step S6, P-
Compare N and No, and if P-N)N, it is determined that the current operation of the scanning device 6 is within the deceleration section in FIG. 3, and v1=v-ΔV is set in step S7. However, if P-N≦N0, the scanning device 6 determines that it is within the steady interval and sets V1=V in step S13.

On the other hand, if P<2N in step S4, control is performed when the speed pattern has only an acceleration section and a deceleration section. In step S9, N and P/2 are compared, and N<P
/2, it is determined that the current operation of the scanning device 6 is within the acceleration section, and V,=V+ΔV is set in step Sll. If N≧P/2, it is determined that the current operation of the scanning device 6 is in the deceleration section, and in step SIO V□
Set =■-ΔV. In step S8, the set V force is outputted as a speed signal V to the deviation device 13c.

On the other hand, the acceleration detector 14a provided in the scanning device 6 is
The acceleration α when the scanning device 6 moves is detected, and the result is fed back to the deviation device 13c via the gain setter 13b built in the control circuit 13. Gain setting device 1
3c, the detected acceleration signal α is multiplied by a constant K to calculate a velocity signal v2=K·α, and the result is output to the deviation device 13c.

In the deviation device 13c, the difference V between the speed signal V□ calculated and outputted by the speed signal calculating section 13a and the speed signal v2 from the gain setting device 13b is expressed as v=V1-V.

and outputs this V to the motor 7 as a motor drive signal.

As in this embodiment, the acceleration acting on the scanning device 6 is detected and fed back to the control circuit 13 to control the motor drive signal, thereby reducing the inertial force that occurs when starting and stopping the scanning device 6, thereby reducing the vibration. suppress. Regarding movement in the Y direction, speed control is performed in the same manner as in the X direction by feeding back the acceleration signal from the acceleration detector 14b for the Y direction.

Although the scanning device 6 is assumed to move in the X direction and the Y direction, it is possible to move only in one direction, in the X direction, the Y direction, and in the Z direction perpendicular to both of these directions, or in the Z direction. The present invention can also be applied to objects that can only be moved. When applied also to the Z direction, a Z direction acceleration detector is provided on a suspension member such as a probe. Further, the configuration of the scanning device is not limited to the embodiment.

G0 Effects of the Invention According to the present invention, the acceleration generated when the scanning means moves is fed back to the speed control means to form a drive signal for the scanning means, so that the inertial force generated in the scanning means can be reduced. Vibration can be suppressed.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, FIG. 1 is a block diagram showing a control system, FIG. 2 is a diagram showing the overall configuration and control system, and FIG. 3 is a speed pattern. Figure 4 showing
The figure is a flowchart showing the flow of processing of the control circuit. FIG. 5 is a diagram showing a conventional example corresponding to FIG. 2. 6: Scanning device 7, 8: Motor 9. 10: Encoder 12: Input device 13: Control circuit

Claims (1)

[Claims] a command means for commanding the ultrasonic probe to move to a predetermined position; a scanning means capable of moving the ultrasound probe in at least one direction according to the command; and a scanning means according to an input drive signal. a driving means for moving the scanning means; an acceleration detecting means for detecting acceleration when the scanning means moves; and calculating the drive signal based on the acceleration detected by the acceleration detecting means and a command from the command means. An ultrasonic inspection device comprising: speed control means.