JPS5989426A - Inspecting device for positional deviation of article - Google Patents

Abstract

PURPOSE:To perform an automatic inspection of the positional deviation of the objective article to be inspected by a method wherein the image of an object is observed through the intermediary of the windows of prescribed shape which are arranged as prescribed within the visual field of an image pickup device. CONSTITUTION:The pattern on the IC substrate OB located on a handling device HL is photographed by an image pickup device 2 through the intermediary of a microscope 1. A judging device 30 observes the image P1 of an object pattern through the intermediary of windows W1-W7 arranged within the visual field P, and the area S1-S7 of the pattern occupied in each window is calculated. As a result, the amount of deviation from the center of picture of the IC substrate is determined using the formulas DELTAy=S1-S2 and DELTAx=S3-S4. The angle of each side of the IC substrate for each side of a visual field P can be calculated using the formula DELTAtheta=S5-S6. Also, if K1<S7<K2 is obtained for the prescribed set values of K1 and K2, a decision is given that the IC substrate is within the visual field P.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is useful in cases where predetermined bonding is performed after relative positioning of an IC or a bonding arm, such as wire bonding work on an IC (integrated circuit) board. The present invention relates to an apparatus for positioning an article such as an IC board, and particularly to an apparatus for inspecting positional displacement of an article used in such an apparatus.

Recently, automation and labor saving of equipment have been actively carried out, but the current situation is that the development of parts that require visual inspection is delayed compared to other parts.

For example, even in the above-mentioned bonding automation apparatus, it is common for a human being to position and bond an IC board while looking at a microscope, etc., and therefore has the drawback that accurate and rapid processing is difficult. However, such work requires precision and is complicated, resulting in significant eye fatigue, resulting in a problem of reduced processing accuracy and speed. Furthermore, after being positioned, the bonding arm is driven according to a certain program.
A predetermined bonding operation is performed.

The present invention has been made in view of the above, and an object of the present invention is to provide an inexpensive and highly reliable inspection device that can accurately and quickly inspect the misalignment of an article.

The feature is that the item is photographed by an imaging device such as an ITV camera (industrial television camera), the image signal (video A signal) is image-processed, and the processed image is given a predetermined shape and arrangement. An image observation window, i.e., a window, is set, and the area value of the object image observed through the window and its correlation are inspected for the deviation of the object from a predetermined reference point or reference line. 5 K L, 〇Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing details of the determination device in FIG. 1, and FIG.
The figure is an explanatory diagram for explaining the determination method according to the present invention and for performing FJJJ. In FIG. 1, 1 is an optical system such as a microscope, 2 is an imaging device such as an ITV camera, and 31j is a calculation/judgment unit 30 consisting of a microprocessor (μm CPU), etc.
, a determination device including a monitor television 31, an input operation section 32, a floppy disk 33, etc.; 4 is a controller;
0Bij IC board, HLFi handling equipment.

That is, what is shown in FIG. 1 is an example in which the present invention is applied to an IC board bonding system.

The pattern on the IC board OB on the handling device HL is displayed on a television (']' V through an optical system 1 such as a microscope.
) Camera 2 takes a picture. Based on the video signal from the TV camera 2, the determination device 3 detects the amount of positional deviation from a reference position, such as the center of the camera, or a separately determined reference line, as will be described later, and outputs the detected amount to the controller 4. The controller 414 gives a command to the handling device HL according to the amount of positional deviation of the IC board OB, and moves it to a predetermined position. In this case, it is possible to appropriately select whether to move the handling device HL or to move the IC board OB. The monitor television 31 is provided to display and monitor the image processed by the determination device 3, and the floppy disk drive 33 generates a window corresponding to the pattern of the IC board OB. The input operation section 3
2 provides the selection designation information and the like to the determination unit 30.

As shown in FIG. 2, the determination device 3 includes not only a determination section 30, a monitor 31, an input operation section 32, and a floppy disk 33 as shown in FIG. It has a circuit 35, a logic circuit 36 including an AND gate, a data memory 37, a read-only memory (ROM) 38, a random access memory (I?, AM) 39, and the like.

That is, the object image u1'V passing through the optical system 1 is sequentially converted into an electric signal by the camera 2, and is binarized at a predetermined threshold level in the binarization/double-sided division circuit 34, and then a predetermined signal is generated. The signal is quantized or pixelated. The window generation circuit 35 is provided to generate a window for observing only a predetermined area within the imaged screen imaged by the TV camera 2, that is, a window, and therefore the logic circuit 36 outputs pixelated data within the window. only is taken out and stored in data memory 37. To generate a window, open or close the window horizontally when scanning with the TV right camera,
All you need to know is the vertical coordinate position, and the method is as follows:
These horizontal and vertical position coordinates are stored in a fixed memory (for example, the floppy disk device 33 in FIG. 1 or the ROM 3 in FIG. 2).
8), and by using an input device and a monitor device each time, representative position information regarding the window is given, and during that time, interpolation calculation processing is performed and stored in the memory (for example, RAM 39 in Fig. 2). ), but in any case, it is desirable that a plurality of windows of arbitrary shapes can be generated at desired positions. Regarding this point, the present applicant has already proposed, so if necessary, for example,
Please refer to No. 71496 etc. Although circuits for synchronizing the subject image and the TV camera 2 are omitted in FIG. 2, they are provided as appropriate.

Based on the data stored in the memory 37 in this manner, the operation determination unit (μm CPU) 30 performs the following operation 9 determination.

Figure 3 shows the subject (
It shows a monitor image of an IC board), a pFi imaging screen, r'1tj: subject image, and W1 to W7 are windows as described above. That is, the portions of windows W1 to W7 that overlap with the subject image are each shaded, and in the μ-CPU 30, the area values of the shaded portions are 81 to S.
7 respectively. This is because, as explained in Fig. 2, the subject image is divided into pixels of a predetermined size.
Since the area of the pixel is known in advance, the area can be easily determined by counting the number of pixels and multiplying by the unit area. Note that the shapes of windows Wl and W2 and W3 and W4 are congruent with each other, and they are arranged at symmetrical positions across a predetermined axis passing through the center of screen P, and the same holds true for windows W5 and W6. It is. Note that the window W7 has a different function from these, and the area of the pattern existing therein is divided into S7 and 1. 2 as a predetermined setting value, if the condition Kl < 87 < K2 is satisfied, it is determined that the IC board is present, or based on this result, the following deviations from the reference point or reference axis are determined. This is used as a signal to start the operation of determining the

For the above area values 81 to S4, calculations as shown in the following equation are first performed.

S 1-82-Δy S3- S4-ΔX Here, Δx-0. If Δy==Q, the center of the IC board coincides with the center of the screen. The tabs, ΔX, and Δy represent the amount of deviation of the IC board from the center of the screen. Next, in the same manner as above, the calculation 55-86=Δθ is performed for the windows W5°W6K. This view Δθ is proportional to the amount of inclination of each side of the IC board, and if Δθ - 0, each side of the IC board can be said to be parallel to the corresponding side of the imaging screen P4.
Note that window W5. W6iJ-Window W1.
It can also be set at a position symmetrical to W3 or W4. In other words, the shape and arrangement of the window can be changed depending on the shape and size of the IC board, but this window information can be stored in the floppy disk device 33 in FIG. 1 or in the ROM 38°I (, AM39' If you store it in *, you can easily deal with it just by giving instructions from the input device.

Note that before calculating the difference between the area values within a pair of windows, a rough determination can be made by comparing the area values of each window with respective predetermined standard values.

As described above, according to the present invention, a window of a predetermined shape is arranged in a predetermined manner within the field of view of an imaging device, and the area value (τ and correlation thereof) of a subject image observed through the window is inspected. Since the positional shift of the target article can be inspected, it has the advantage that bonding automation of IC parts can be realized simply and inexpensively, and reliability can be improved.

The present invention is applicable not only to the above-mentioned IC board bonding work, but also to a wide range of applications such as positioning and handling of various articles.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing details of the determination device in FIG. 1, and FIG.
The figure is an explanatory diagram for explaining the determination method according to the present invention. Code explanation 1...Microscope, 2...TV camera,
3. Hitting/determination device, 4...--controller, 3o
....determination section, 31 ....monitor, 32.
... Input operation section, 33 ... Floppy disk, 34 ... Binarization/screen division circuit, 35
...Window generation circuit, 36...Logic circuit, 37...-Data memory, 3rd...
・Read-only memory (ROM), 39...
Random access memory (RAM), W1 to W7...
...Window Agent Patent Attorney Akio Namiki Agent Patent Attorney Kiyoshi Matsuzaki Figure 1L Figure 2, Figure 3

Claims (1)

[Claims] The object image of the object to be inspected observed through a predetermined optical means is captured by a horizontal and vertical sequential scanning imaging device, and the captured image signal is digitized and processed to produce images from a predetermined position or coordinate axis of the object. A first window having a size congruent with each other at symmetrical positions across a horizontal axis and a vertical axis including the center of an imaging field of view of the imaging device; window generating means for generating second windows that are congruent with each other in symmetrical positions with at least one of the windows as an axis; calculation means for calculating a correlation area value between a pair of windows; 1. An apparatus for inspecting positional deviations of articles, which mainly inspects deviations from predetermined axes.