JP3269170B2 - Electronic component position detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method for a visual recognition device required for mounting electronic components at high speed and high accuracy in an electronic component mounting facility. Detect the position more accurately from the image pattern,
The present invention relates to a method for extracting positioning information.

[0002]

2. Description of the Related Art In recent years, in the field of electronic component mounting, a technology for mounting electronic components on a circuit board at high speed and with high precision has been required. For this reason, an image recognition technology that processes an image pattern obtained by imaging an electronic component at a high speed, detects the position and inclination of the electronic component, and performs high-speed and accurate positioning information required at the time of mounting the component. Tend to be used. In addition, as electronic components have become finer, the number of pins of electrodes has been increased. Therefore, with respect to an electronic component having a large number of electrodes, it is desired to detect the position of each electrode and calculate optimal positioning information from them.

Conventionally, electronic component recognition methods utilizing image recognition technology include a transmission recognition method of illuminating a target electronic component from behind and processing a silhouette thereof to detect a center, a tilt, an electrode position, and the like. A reflection recognition method has been proposed in which light reflected from an electrode is illuminated from the front, and the center, tilt, electrode position, and the like are detected.

A conventional component recognition method will be described below with reference to the drawings. FIG. 6 shows an example of the transmission recognition method, in which illumination is applied from the rear of the electronic component 61 with leads (hereinafter referred to as transmission illumination 62) to detect the position of the tip of the lead. Transmitted illumination 6 on electronic components 61 with leads
2 and the 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 projected by the transmitted illumination. When the boundary between the image pattern 65 and the background of the electronic component with leads is detected as shown in FIG. 6C, the position where the trajectory of the boundary tracking makes a U-turn is detected as shown at 66. The position where this U-turn is performed is detected as the electrode position to be detected. This transparent recognition method has a simple logic for processing silhouettes and is fast in processing.

However, in the transmission recognition method, it is difficult to detect the electrode position of an electronic component whose electrode is bent inward from the external shape of the component (hereinafter referred to as a J-lead electronic component). Therefore, a reflection recognition method capable of directly capturing the electrodes has been proposed.

FIG. 7 shows an example of a reflection recognition method in which the lead position of a J-lead electronic component 71 is detected. When an 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, an image pattern 73 is obtained. The electrode portion of the image pattern 74 of the J-lead electronic component 71 is bright because the reflected light of the reflected illumination 72 is projected. A processing window 75 is provided in a 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 where the differential data 77 turns from positive to negative is detected, and a processing window 79 large enough to cover the electrode is provided at that position. The luminance centroid in the processing window 79 is calculated and set as the electrode position 80. A processing window similar to the processing window 79 is provided for adjacent electrodes based on a given component size and number of electrodes, and all electrode positions are sequentially detected.

[0007]

With the increase in the number of electrodes, a component (Ball Grid Array) in which the electrodes are arranged in a grid inside the component as shown in FIGS. 8 (a) and 8 (b).
y components, hereafter referred to as BGA components).
In the case of the electrode arrangement shown in (a), the same component information (component size and number of electrodes) as in the case of recognizing the J-lead component is sufficient to detect all electrode positions as in the related art. However, in the case of the electrode arrangement as shown in (c), recognition is impossible without information on the arrangement of each electrode. Since BGA components have various variations in electrode arrangement, it is necessary to preliminarily teach information on individual electrode positions in order to include all of them. For this reason, consistency with the conventional teaching method cannot be obtained, and the processing time and data amount increase considerably.

If the conventional method is applied to the position detection method, data shown in FIG. 8D corresponding to FIG. 7C is obtained, and the differential data 81 is added to the boundary 82 between the background and the body.
Since there is a portion where turns from positive to negative, the true electrode position 83 is not detected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for recognizing parts at a high speed and with high accuracy using the same part information as conventional ones, overcoming the above-mentioned drawbacks of the prior art.

[0010]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an image inputting step of obtaining an image pattern of a component in which electrodes are arranged in a grid inside a component body, and an image inputting step of obtaining an image pattern. A coarse inclination detection step for detecting the inclination of the component, a coarse outer electrode detection step for detecting a rough position of an electrode array arranged on the outer periphery in the electrode group arranged in a grid, and an electrode arranged on the outer periphery The outer electrode precision detection step of detecting the individual electrode positions of the electrode array originally arranged on the outer periphery with the rough position of the array, and the position adjustment information necessary for mounting components from the individual electrode positions arranged on the outer periphery Is calculated.

The method of detecting a rough position includes a processing range setting step of setting a processing window orthogonal to the electrode row, and a maximum brightness projecting step of projecting a maximum brightness in a direction parallel to the electrode row within the processing window. And an average luminance projecting step of projecting an average luminance in a direction parallel to the electrode row within the processing window; a difference data extracting step of detecting a difference between the maximum luminance projection data and the average luminance projection data; And a position detecting step of detecting an electrode position from the data of the above.

As another method of detecting a rough position, a processing range setting step of setting a processing window orthogonal to the electrode row, and a luminance difference projecting a sum of differences in a direction parallel to the electrode row in the processing window. It comprises a sum projection step and a position detection step of detecting an electrode position from the projection data of the obtained difference sum.

[0013]

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

As a method for roughly detecting the specific electrode position, first, a processing window orthogonal to the electrode row is set. The maximum luminance and the average luminance within the set processing window are projected in a direction parallel to the electrode rows. By taking the difference between the two projection data, data is obtained in which the portion where the luminance change is small in the direction parallel to the electrode row is deleted. By detecting the first peak of the obtained data, the electrode position can be accurately detected without detecting noise.

As another method of roughly detecting the specific electrode position, a processing window is first set in the same manner, and the sum of the differences in the parallel direction is projected on the electrode row of the luminance within the set processing window. And data indicating the magnitude of the change in the direction parallel to the electrode row. By detecting the first peak of the obtained data, the electrode position can be detected without detecting noise.

[0016]

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

In FIG. 1, a first step is an image pattern input step 11, in which a video signal is obtained by capturing an image of a BGA component to be recognized by an imaging means such as a video camera. The obtained imaging signal is digitized to be an image pattern.

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

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

The fourth step is an outer electrode precision detection step 14,
The electrode position is estimated from both end positions of the outer peripheral electrode row and the number of electrodes obtained in the third step, and an electrode detection processing window 47 covering the electrodes is set. An electrode position 48 is obtained by detecting the luminance center of gravity within the set processing window. Perform the same processing 4
This is performed on the side, and all electrode positions arranged on the outer periphery are detected.

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

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

In FIG. 2, reference numeral 21 denotes a processing range setting step. The electrode detection processing window 51 orthogonal to the electrode row is based on the rough inclination of the BGA component detected in advance.
Set.

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

Reference numeral 23 denotes an average luminance projection step. When the projection is performed with the average luminance on a line parallel to the electrode row in the processing window set in the processing range setting step, average luminance projection data 53 is obtained. As in the case of the maximum luminance projection data, the projection data becomes large at the position corresponding to the electrode position, but is smaller than the maximum luminance projection data because it is averaged with the body part.

Numeral 24 denotes a difference data extracting step, in which difference data 54 is obtained by calculating the difference between the maximum luminance projection data obtained in the maximum luminance projection step and the average luminance projection data obtained in the average luminance projection step. At the position corresponding to the body part, the maximum luminance projection data and the average luminance projection data are almost the same size, but at the position corresponding to the electrode position, the average luminance projection data is smaller, so the difference data corresponds to the electrode part. Only the position to do remains.

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

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

In FIG. 3, reference numeral 31 denotes a processing range setting step.
An electrode detection processing window 56 orthogonal to the electrode rows is set based on the rough inclination of the BGA component detected in advance.

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

Reference numeral 33 denotes a position detecting step. Since the luminance difference sum projection data obtained in the luminance difference sum projection process is data only at the position corresponding to the electrode portion, the electrode position is detected by detecting the first peak position exceeding the threshold value 58, and the processing is performed. finish.

[0032]

As described above, according to the present invention, even if the component information given in advance is the same as the conventional one, it is necessary to perform the same processing for the components in which the electrodes are arranged in a grid pattern of any pattern, and the positioning is required in the same process. It is possible to extract information at high speed and with high accuracy. Also, in the position detection, there is no influence from a remarkable change in luminance other than the position of the electrode.
Therefore, more reliable position detection can be realized.

[Brief description of the drawings]

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

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

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

FIG. 4A is an explanatory view of an image pattern input step and a coarse tilt detection step in the same position detection method. FIG. 4B is an explanatory view of a rough outer electrode detection step in the same position detection method. Explanatory drawing of the fine detection process

FIG. 5 (a) is an explanatory view of a processing method in an outer peripheral electrode coarse detection step of the same position detection method. (B) An explanatory view of another processing method in an outer peripheral electrode coarse detection step of the same position detection method.

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

8A is a plan view of a BGA component, FIG. 8B is a side view of the BGA component, FIG. 8C is a plan view of another type of BGA component, and FIG.

[Explanation of symbols]

 41 Image pattern of BGA part 42 Rough inclination of BGA part 43 Processing window for electrode row detection 44 Electrode row position 45 Processing window for both electrode position detection 46 Both electrode position 47 Electrode detection processing window 48 Electrode position 51 Electrode detection processing Window 52 Maximum luminance projection data 53 Average luminance projection data 54 Difference data 55 Threshold value 56 Processing window for electrode detection 57 Luminance difference sum projection data 58 Threshold value 61 Electronic component with lead 62 Transmission illumination 63 Video camera 64 Image pattern 65 Lead Image pattern 66 corresponding to electronic component with electrode 66 Electrode position 71 J-lead electronic component 72 Reflective illumination 73 Image pattern 74 Image pattern corresponding 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

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Emile Bozuma 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Masamichi Morimoto 1006 Odaka Kadoma Kadoma, Osaka Pref. In-company (56) References JP-A-6-209200 (JP, A) JP-A-5-313518 (JP, A) JP-A-5-296724 (JP, A) (58) Fields investigated (Int. . ^7, DB name) G01B 11/24 H05K 13/04

Claims (3)

(57) [Claims] 1. A first step in which an electronic component whose electrodes are arranged in a grid inside a component body is a recognition target, and a first step of capturing an image of the recognition target to obtain an image pattern, and an outer shape of the component 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 a row of electrodes arranged on the outer periphery in the electrode group arranged in a grid, A fourth step of detecting the individual positions of the electrodes arranged on the outer periphery based on the rough positions detected in the three steps, and individual positions of the electrodes arranged on the outer periphery detected in the fourth step A method for detecting the position of an electronic component having electrodes arranged in a grid, comprising a fifth step of calculating positioning information necessary for mounting the component from the electronic component. A third step of setting a processing window orthogonal to an electrode array arranged on the outer periphery of the image pattern obtained in the first step of the position detection method in the third step;
A second step of projecting a maximum luminance on a line parallel to the electrode row in the processing window, an eighth step of projecting an 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 maximum luminance projection data obtained and the average luminance projection data obtained in the eighth step, and a tenth step of detecting an electrode position from the difference data obtained in the ninth step. Item 1
The method for detecting the position of an electronic component described in the above. 3. An eleventh step of setting a processing window orthogonal to an electrode array arranged on the outer periphery of the component with respect to the image pattern obtained in the first step of the position detection method; A twelfth step of projecting a sum of differences on a line parallel to the electrode row in the first step, and a first step of detecting an electrode position from projection data of the sum of differences obtained in the twelfth step.
2. The position detecting method according to claim 1, comprising three steps.