JPH06288732A - Position detection of electronic part - Google Patents

Abstract

PURPOSE:To provide a position detection method with high reliability which is not influenced by change of brightness at the boundary of a background and a body as well as a method to detect position regulation information of a part on which electrodes are arranged in a lattice form at high speed and in high precision in image recognition processing at an electronic part mounting facility. CONSTITUTION:Firstly, by picking up an image of an electronic part on which electrodes are arranged in a lattice form, an image pattern 41 is acquired. By finding rough inclination of the image pattern 41 of the electronic part, a processing window 43 to detect positions of the electrodes arranged in the outer periphery is set. From a data on which a difference of the maximum brightness change and average brightness change in the set window 43 is projected or a data on which a finite difference sum of brightness is projected, electrode positions 46 of both ends of an outer peripheral electrode row are detected, and in accordance with them, the electrode positions arranged on the outer periphery are individually detected. From the detected outer peripheral electrode positions 46, position regulation information is computed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image method of a visual recognition device required for mounting electronic parts at high speed and with high precision in an electronic part mounting facility, and an electrode of the electronic parts to be processed. The position is detected more accurately than the image pattern,
The present invention relates to a method of extracting position regulation information.

[0002]

2. Description of the Related Art In recent years, in the field of mounting electronic components, a technique for mounting electronic components on a circuit board at high speed and with high precision is required. Therefore, there is an image recognition technology that processes an image pattern obtained by capturing an image of an electronic component at high speed to detect the position and inclination of the electronic component, and quickly and accurately perform the position regulation information necessary when mounting the component. It tends to be used. In addition, as electronic components are becoming finer, the number of pins of electrodes is increasing. Therefore, regarding an electronic component having a large number of electrodes, it is desired to detect the position of each electrode and calculate optimum position regulation information from them.

Conventionally, as a method of recognizing an electronic component utilizing image recognition technology, there is a transmission recognition method of illuminating a target electronic component from behind and processing a silhouette thereof to detect a center, an inclination, an electrode position, and the like. A reflection recognition method has been proposed in which light is applied from the front and the light reflected from the electrodes is processed to detect the center, inclination, electrode position, and the like.

A conventional component recognition method will be described below with reference to the drawings. FIG. 6 is an example of the transmission recognition method, and shows an example of detecting the tip position of the lead by illuminating the electronic component with lead 61 from behind (hereinafter referred to as transmission illumination 62). Transmitted illumination 6 on electronic component 61 with leads
When 2 is applied and an image is taken by the video camera 63, an image pattern 64 is obtained. The silhouette of the image pattern 65 of the electronic component 61 with leads is displayed by transmitted illumination. When the boundary between the image pattern 65 of the electronic component with leads and the background is detected as shown in FIG. 6C, a position where the trajectory of boundary tracking makes a U-turn is detected as shown by 66. The position of this U-turn is detected as the electrode position to be detected. This transparent recognition method is simple in logic and fast in processing because it processes a silhouette.

However, with the transmission recognition method, it is difficult to detect the electrode position of an electronic component (hereinafter referred to as a J-lead electronic component) in which the electrode is bent inward from the outer shape of the component. Therefore, a reflection recognition method has been proposed that can directly capture the electrodes.

FIG. 7 shows an example of the reflection recognition method, in which the lead position of the J-lead electronic component 71 is detected. Illumination (hereinafter referred to as reflection illumination) 72 is applied from the front of the J-lead electronic component 71, and an image is captured by the video camera 63, and an image pattern 73 is obtained. In the image pattern 74 of the J-lead electronic component 71, since the reflected light of the reflective illumination 72 is projected, the electrode portion is bright. A processing window 75 is provided on the brightly shining electrode portion, and a change in luminance is projected in the v direction to obtain projection data 76. The projection data 76 is first-order differentiated to calculate differential data 77. A position 78 at which the differential data 77 turns from positive to negative is detected, and a processing window 79 having a size enough to cover the electrode is provided at that position. The brightness center of gravity in the processing window 79 is calculated and is set as the electrode position 80. A processing window similar to the processing window 79 is provided on the adjacent electrodes from the given part size and the number of electrodes, and all the electrode positions are sequentially detected.

[0007]

With the increase in the number of pins of electrodes, as shown in FIGS. 8 (a) and 8 (b), parts in which electrodes are arranged in a grid pattern (Ball Grid Arra) are provided.
y parts, hereinafter referred to as BGA parts) have appeared.
In the case of the electrode arrangement as shown in (a), in order to detect all the electrode positions as in the conventional case, the same component information (component size / number of electrodes) as when recognizing the J lead component is sufficient. However, in the case of the electrode arrangement as shown in (c), the recognition is impossible without the information about the arrangement of each electrode. Since there are various variations in the electrode arrangement of BGA parts, it is necessary to teach the information of the individual electrode positions in advance in order to include all of them. Therefore, the consistency with the conventional teaching method cannot be obtained, and the processing time and the data amount increase considerably.

When the conventional method is applied to the position detecting method, the data shown in FIG. 8 (d) corresponding to FIG. 7 (c) is obtained, and the differential data 81 is generated at the boundary portion 82 between the background and the body.
The true electrode position 83 is not detected because there is a portion in which is changed from positive to negative.

An object of the present invention is to overcome the above-mentioned drawbacks of the prior art and to provide a high-speed and high-accuracy component recognition method with component information equivalent to the conventional one.

[0010]

In order to solve the above-mentioned problems, the present invention provides an image input step of obtaining an image pattern of a component in which electrodes are arranged in a grid pattern inside a component body, and a rough outline from the component outline. Inclination coarse detection step for detecting the inclination of the component, outer peripheral electrode coarse detection step for detecting the rough position of the electrode array arranged on the outer periphery of the electrode group arranged in a grid pattern, and electrode arranged on the outer periphery Peripheral electrode precision detection process that detects the individual electrode positions of the electrode row that is arranged on the outer circumference at the rough position of the row, and position adjustment information necessary for mounting components from the individual electrode positions that are arranged on the outer circumference The position regulation information calculation step of calculating

Further, a method for detecting a rough position is a processing range setting step of setting a processing window orthogonal to an electrode array and a maximum brightness projection step of projecting maximum brightness in a direction parallel to the electrode array in the processing window. And an average luminance projection step of projecting average luminance in a direction parallel to the electrode row within the processing window, a difference data extraction step of detecting a difference between the maximum luminance projection data and the average luminance projection data, and the obtained difference The position detecting step of detecting the electrode position from the data of 1.

As another method for detecting a rough position, a process range setting step of setting a process window orthogonal to the electrode array and a brightness difference projecting a sum of differences in a direction parallel to the electrode array within the process window. It comprises a sum projection step and a position detection step of detecting the electrode position from the projection data of the obtained difference sum.

[0013]

According to the present invention, by the above means, the target electronic component is first imaged to obtain an image pattern, and the conventional technique is applied to the image pattern to detect the rough inclination of the component. The electrode positions at both ends of the electrode row located on the outer periphery of the electrode group arranged in a grid are detected using the dimensions of the electronic component and the detected inclination, which are the same information as the prior art given in advance. . Next, based on the electrode positions at both ends of the obtained electrode array and the inter-electrode dimensions and the number of electrodes, which is the same information as the prior art given in advance, within the electrode group arranged in a grid pattern. The positions of the electrodes located on the outer circumference are individually detected. Information necessary for position regulation is calculated from the detected electrode position.

As a method of roughly detecting the specific electrode position, first, a processing window orthogonal to the electrode array is set. The maximum brightness and the average brightness within the set processing window are projected in a direction parallel to the electrode array. By taking the difference between the two projection data, data is obtained in which a portion with little change in luminance is deleted in the direction parallel to the electrode array. The electrode position can be accurately detected without detecting noise by detecting the peak that appears at the beginning of the obtained data.

As another method of roughly detecting the specific electrode position, first, a processing window is set in the same manner, and the sum of differences in the parallel direction is projected on the electrode array of the brightness in the set processing window. , Obtain data showing the magnitude of change in the direction parallel to the electrode array. The electrode position can be detected without detecting noise by detecting the peak that appears first in the obtained data.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a method for detecting the electrode position of a BGA part will be described with reference to FIGS.

In FIG. 1, a first step is an image pattern input step 11, in which a BGA part which is an object to be recognized is imaged by an image pickup means such as a video camera to obtain a video signal. The obtained image pickup signal is digitized to form an image pattern.

The second step is the coarse inclination detecting step 12, in which the image pattern 41 is scanned as shown by S in FIG. 4A to detect the edge of the component body portion. The approximate inclination 42 of the BGA component is detected by linearly approximating the detected edge group.

The third step is the outer peripheral electrode rough detection step 13,
An electrode array detection processing window 43 is provided on the basis of the rough inclination detected in the second step, the brightness change in the processing window is projected in the v direction, and the projection data is analyzed to obtain the position 44 of the electrode array. Next, a processing window 45 for detecting electrode positions at both ends is set based on the obtained electrode position 44, the change in brightness in the set processing window 45 is projected in the u direction, the projection data is analyzed, and both ends of the electrode array are analyzed. The electrode position of is detected.

The fourth step is the outer peripheral electrode precision detection step 14,
The electrode position is estimated from both end positions and the number of electrodes of the outer peripheral electrode array obtained in the third step, and the electrode detection processing window 47 covering the electrode is set. The center of brightness in the set processing window is detected to obtain the electrode position 48. Similar processing 4
This is performed for the sides and all the electrode positions arranged on the outer circumference are detected.

The fifth step is the position regulation information calculation step 35.
Then, from the electrode positions arranged on the outer periphery obtained in the fourth step, B
The center position / inclination of the GA part is calculated, and the processing ends as position regulation information.

Next, a method of detecting the electrode position of the BGA component in the outer peripheral electrode rough detecting step in the above-described embodiment of the present invention will be described with reference to FIGS.

In FIG. 2, reference numeral 21 is a processing range setting step. An electrode detection processing window 51 that is orthogonal to the electrode array based on the roughly detected inclination of the BGA part.
To set.

Reference numeral 22 denotes a maximum brightness projection step, which obtains maximum brightness projection data 52 by projecting the maximum brightness on a line parallel to the electrode array within the processing window set in the processing range setting step. Since the electrode portion has the highest brightness, the projection data becomes large at the position corresponding to the electrode portion.

Reference numeral 23 is an average luminance projection step, which obtains average luminance projection data 53 by projecting the average luminance on a line parallel to the electrode array within the processing window set in the processing range setting step. Similar to the maximum brightness projection data, the projection data is large at the position corresponding to the electrode position, but is smaller than the maximum brightness projection data because it is averaged with the body portion.

A difference data extraction step 24 obtains difference data 54 by calculating the difference between the maximum brightness projection data obtained in the maximum brightness projection step and the average brightness projection data obtained in the average brightness projection step. At the position corresponding to the body part, the maximum brightness projection data and the average brightness projection data are about the same size, but at the position corresponding to the electrode position, the average brightness projection data is smaller, so the difference data corresponds to the electrode part. Only the position to do remains.

25 is a position detecting step. Since the difference data obtained in the difference data extracting step is only the data corresponding to the position corresponding to the electrode portion, the electrode position is detected and the process is terminated by detecting the first peak position exceeding the threshold value 55.

Next, another method for detecting the electrode position of the BGA part in the outer peripheral electrode rough detection step in the above-described embodiment of the present invention will be described with reference to FIGS.

In FIG. 3, 31 is a process range setting step,
An electrode detection processing window 56 orthogonal to the electrode array is set based on the roughly detected inclination of the BGA part.

Reference numeral 32 denotes a luminance difference sum projection process, which projects the luminance difference sum projection data 57 by projecting a value obtained by accumulating the luminance differences on the lines parallel to the electrode rows within the processing window set in the processing range setting step. obtain. Since there is not much brightness difference except for the electrode part, the brightness difference sum projection data has a high value only at the position corresponding to the electrode part.

33 is a position detecting step. Since the brightness difference sum projection data obtained in the brightness difference sum projection step is data only at the position corresponding to the electrode portion, the electrode position is detected and processed by detecting the first peak position exceeding the threshold value 58. finish.

[0032]

EFFECTS OF THE INVENTION The present invention has the above-described structure, and even if the component information given in advance is the same as the conventional one, the components having the electrodes arranged in a grid pattern of all patterns are subjected to the same processing to perform the positional regulation necessary for mounting. It becomes possible to extract information at high speed and with high accuracy. Further, the position detection is not affected by a significant change in brightness other than the electrode position.
Therefore, more reliable position detection can be realized.

[Brief description of drawings]

FIG. 1 is a flowchart of a method for detecting a position of an electronic component according to an embodiment of the present invention.

FIG. 2 is a flowchart of a processing method in an outer peripheral electrode rough detection step of the same position detection method.

FIG. 3 is a flowchart of another processing method in the outer peripheral electrode rough detection step of the same position detection method.

FIG. 4A is an explanatory diagram of an image pattern input step and a coarse inclination detection step in the same position detection method. FIG. 4B is an explanatory diagram of an outer peripheral electrode rough detection step in the same position detection method. Illustration of the precision detection process

5A is an explanatory view of a processing method in a peripheral electrode rough detection step of the same position detection method. FIG. 5B is an explanatory view of another processing method in a peripheral electrode rough detection step of the same position detection method.

6A is an explanatory diagram showing a configuration of a transmission recognition method, FIG. 6B is an explanatory diagram of an image pattern in the method, and FIG. 6C is an explanatory diagram of a conventional position detecting method of an electronic component by the method.

FIG. 7A is an explanatory diagram showing a configuration of a reflection recognition method. FIG. 7B is an explanatory diagram of an image pattern in the method. FIG. 7C is an explanatory diagram of a conventional position detecting method of an electronic component by the method.

8A is a plan view of a BGA part, FIG. 8B is a side view of a BGA part, FIG. 8C is a plan view of another type of BGA part, and FIG. 8D is an explanatory diagram of application of a conventional electronic part position detection method to a BGA part.

[Explanation of symbols]

 41 Image pattern of BGA part 42 Rough inclination of BGA part 43 Processing window for electrode array detection 44 Electrode array position 45 Processing window for detecting both ends electrode position 46 Both ends electrode position 47 Processing window for electrode detection 48 Electrode position 51 Processing for electrode detection Window 52 Maximum brightness projection data 53 Average brightness projection data 54 Difference data 55 Threshold value 56 Electrode detection processing window 57 Brightness difference sum projection data 58 Threshold value 61 Leaded electronic components 62 Transmitted illumination 63 Video camera 64 Image pattern 65 leads Image pattern equivalent to electronic component with 66 Electrode position 71 J lead electronic component 72 Reflective illumination 73 Image pattern 74 Image pattern equivalent to J lead electronic component 75 Processing window 76 Brightness change projection data 77 Differential data 78 Zero Ross point 79 processing window 80 electrode position 81 derivative data

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Emile Bosma 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masamichi Morimoto, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A first step of obtaining an image pattern by picking up an image of a recognition target object by using an electronic part, in which electrodes are arranged in a grid shape inside a component body, as a recognition target object, and an outer shape of the part body in the image pattern. A second step of detecting a rough inclination of the component from the shape; a third step of detecting a rough position of the electrode from the row of electrodes arranged on the outer periphery of the electrode group arranged in a grid pattern; A fourth step of detecting individual positions of the electrodes arranged on the outer circumference based on the rough positions detected by the three steps, and individual positions of the electrodes arranged on the outer circumference detected by the fourth step. A method for detecting the position of an electronic component in which electrodes are arranged in a grid pattern, the method including a fifth step of calculating positional regulation information required for mounting the component from the above. 2. A sixth step in which the third step sets a processing window orthogonal to the electrode array arranged on the outer periphery of the component with respect to the image pattern obtained in the first step of the same position detecting method,
Obtained from the second step of projecting maximum luminance on a line parallel to the electrode row in the processing window, the eighth step of projecting average luminance on a line parallel to the electrode row in the processing window, and the seventh step. A ninth step of calculating a difference between the projection data of the maximum brightness obtained and the projection data of the average brightness obtained from the eighth step, and a tenth step of detecting the electrode position from the difference data obtained from the ninth step. Item 1
A method for detecting the position of the described electronic component. 3. The eleventh step of setting a processing window orthogonal to the electrode array arranged on the outer periphery of the component with respect to the image pattern obtained in the first step of the same position detection method, and the processing window In the twelfth step of projecting the difference sum on a line parallel to the electrode row in the first step, and the first step of detecting the electrode position from the projection data of the difference sum obtained in the twelfth step.
The position detecting method according to claim 1, comprising three steps.