JPH0780758A - Machined hole discriminating method of camera type standard boring machine - Google Patents

Abstract

PURPOSE:To realize a high accuracy of boring machining by comparing the images before and after the boring machining so as to discriminate the machined hole, after boring machining is carried out at the mark center of a standard mark formed on a base. CONSTITUTION:In this machined hole discriminating method of a camera type standard boring machine the machined hole 3 in a camera view field after a machined hole 3 is formed is extracted and the hole center is calculated, and then the mark center 2a of a standard mark 2 before the boring, and the hole center of the machined hole 3 are compared so as to discriminate the machined hole 3. consequently, a highly accurate discrimination of the process hole can be carried out constantly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for identifying a machined hole in a camera-type reference hole making machine, and more particularly, after making a hole in the center of a reference mark on a substrate and before and after making the hole. The present invention relates to a new improvement for performing high-precision drilling by comparing the images of (1) to identify the processed holes.

[0002]

2. Description of the Related Art Generally, as a method for identifying a processed hole in a camera-type reference hole drilling machine of this type that has been used in the past, when a temperature change occurs, the mounting frame of a CCD type image pickup camera is distorted. As a result, the accuracy of drilling is deteriorated. For example, a temperature drift correction method for a reference drilling machine for a multilayer substrate disclosed in Japanese Patent Laid-Open No. 5-8107 has been proposed. That is, the difference between the image center position of the reference mark before the perforation and the image center position after the perforation is corrected over time.

[0003]

Since the conventional camera-type reference drilling machine is configured as described above, the following problems exist. That is, in the above-described camera-type reference drilling machine, first, the reference mark 2a is obtained from the image before the hole processing to form the hole 3, and then the image after the hole processing is taken in to accurately form the hole 3. I was deciding whether or not. Therefore, 'if there are _two, the pattern S' pattern S which approximates the area and perimeter of the hole 3 in the image after drilling might determine the ₂ and the machining hole, correcting after the center of gravity It was sometimes applied to expressions. Therefore,
When the above-mentioned erroneous correction is performed, it is impossible to maintain the accuracy of drilling, and it is difficult to drill a printed board or the like with high accuracy.

The present invention has been made in order to solve the above problems, and in particular, an image after performing the drilling at the center position of the reference mark on the substrate and before and after the drilling Even if there is an approximate pattern near the reference mark by comparing the processed hole and the processed hole, it is possible to perform high-precision drilling. The purpose is to provide a method.

[0005]

A machined hole identifying method for a camera-type reference hole drilling machine according to the present invention is such that a reference mark formed on a substrate is captured as an image by an imaging camera, and the image is processed to obtain the reference. In the process hole identification method of the camera-based reference hole making machine, which detects the mark center of the mark, forms the processed hole at the center of the mark by the drilling means, and identifies the processed hole. The extraction of the processed hole and the hole center in the camera field of view of the imaging camera are calculated, and the processed hole is compared by comparing the mark center of the reference mark before drilling with the hole center of the processed hole after drilling. Is a method of identifying.

More specifically, the pre-drilling object and the post-drilling object on the substrate are compared with respect to their center of gravity and perimeter, and if the following expressions 1 and 2 are simultaneously satisfied, the above-mentioned processing is performed. The method for identifying a processed hole in a camera-type reference drilling machine according to claim 1, characterized in that it is identified as not a hole. ｜ (Sn's center of gravity)-(Sm ''s center of gravity) | <e _pix ... (1) (1-k) ・ (Sn circumference) <(Sm' circumference) <(1 + k) ・(Sn perimeter) (2) However, n: Identification number of the object before drilling (1 to 3) m: Identification number of the object after drilling (1 to 4) e _pix : Center of gravity Positional error (unit is pixel) k: Perimeter length error coefficient

[0007]

In the machined hole identifying method for the camera-based reference drilling machine according to the present invention, first, the reference mark is captured by the imaging camera, and the obtained image is subjected to labeling processing so that each independent object in the captured image is processed. Find the center of gravity and perimeter. Next, the center position of the reference mark is obtained, and the processed hole is identified by comparing it with the labeling processing result before drilling. That is, FIG. 2 shows an image before drilling and FIG. 3 shows an image after drilling. S ₁ to S ₃ in FIG. 2, the identification number of each object by the labeling process before drilling, S ₁ '~S _4' in FIG. 3 represents an identification number by the labeling processing after drilling. here,
In order to identify the processed holes, the objects S _{1 to} S ₃ before drilling and the objects S ₁ ′ to S ₄ ′ after drilling are compared and determined with respect to the center of gravity and the perimeter. The judgment formula is shown below. │ (Sn's center of gravity)-(Sm ''s center of gravity) | <e _pix・ ・ ・ (1) Equation (1-k) ・ (Sn circumference) <(Sm' circumference) <(1 + k)・ (Sn circumference) ・ ・ ・ (2) Equation n: Identification number of the object before drilling (1 to 3) m: Identification number of the object after drilling (1 to 4) e _pix : Center of gravity Positional error (unit is pixel) k: Peripheral length error coefficient In the above formula, the image processing error e _pix , k is e _pix = 5, k in consideration of variations in image processing before and after drilling. =
0.1 is a reasonable number. Therefore, if the formulas (1) and (2) are satisfied at the same time, it can be identified as not a machined hole. In addition, the identification number S ₁ ′ after drilling is used for the determination of the equations (1) and (2).
As for S ₄ ′, S ₁ ≈ S ₁ ′, S ₂ ≈ S ₂ ′, S ₃ ≈
It becomes S ₃ 'and it can be identified that S ₄ ' is a processed hole. This method can identify the processed hole regardless of how many objects are in the image, and can be executed once for one sheet of the printed circuit board. Furthermore, since the machined hole can be identified with certainty by this method, it can be applied to the inspection of the breakage.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a machined hole identifying method for a camera type reference hole drilling machine according to the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a method for identifying a machined hole in a camera-type reference hole making machine according to the present invention, and is a flow chart showing the operation of machined hole identification. FIG. 2 is an image diagram showing the substrate before drilling holes, and FIG. 3 is an image diagram showing the substrate after drilling holes.

First, a description will be given with reference to the operation flow of the machining hole identification shown in FIG. First, the reference mark 2 on the substrate 1 shown in FIG. 2 is captured by an imaging camera (not shown) (first step 100), and the obtained image is labeled to obtain
The center of gravity and the perimeter of each of the independent objects S _{1 to} S _n in the captured image are obtained (second step 101). Next, the mark center 2a of the reference mark 2 is obtained, the servo is moved to the center of gravity (mark center) of the reference mark 2, and a drill (not shown) as a drilling means is used for drilling (third step). 102).

An image before drilling is shown in FIG. 2 and an image after drilling is shown in FIG. S ₁ to S ₃ in Figure 2, the identification number of each object by the labeling process before drilling, S ₁ of FIG. 3 'to S
₄ 'represents the identification number by the labeling process after drilling. Here, (the identification number S ₄ machined hole 3 'in Figure 3 shows in) in order to perform the identification of the object S ₁ after AnaAkira and the object S ₁ to S ₃ hole Meizen' to S ₄ ' Of the center of gravity and perimeter of the
A determination is made (fourth and fifth steps 103 and 104). The judgment formula is shown below.

| (Sn's center of gravity)-(Sm ''s center of gravity) | <e _pix (1) Equation (1-k) · (Sn's perimeter) <(Sm''s perimeter) <(1 + k)-(Sn perimeter) ... (2) Equation n: Identification number of the object before drilling (1 to 3) m: Identification number of the object after drilling (1 to 4) e _pix : centroid position tolerance (unit is pixel) k: perimeter tolerance error coefficient Note that the objects S _{1 to} S ₃ and S ₁ ′ to S in FIGS.
'S _1, S ₁ of the' ₄ represents a reference mark 2, S ₄ 'shows the machined hole 3. In the above equation, the allowable error e _pix , k of the image processing is a proper value of e _pix = 5 and k = 0.1 in consideration of the variation in the image processing before and after the drilling. In this case, if the formulas (1) and (2) are satisfied at the same time, it can be identified as not the machined hole 3. Further, if the judgments of the equations (1) and (2) are carried out for the identification numbers S ₁ 'to S ₄ ' after drilling, S ₁ ≈ S ₁ ', S ₂
≅S ₂ ′, S ₃ ≉S ₃ ′, and S ₄ ′ can be identified as the processed hole 3. This method can identify the processed hole 3 regardless of how many objects are in the image, and this identification operation may be performed once for the printed circuit board 1 of one sheet. Furthermore, since the machined hole 3 can be surely identified by this method, it can be applied to an inspection for breaking. That is, when the paulownia is not broken, the image after drilling S _'4 is incorporated. However, if the tung is broken, the image after drilling S _'4 is not incorporated. With this, it can be applied to the inspection for breaking.

[0012]

Since the method for identifying a machined hole in the camera-type reference drilling machine according to the present invention is configured as described above, the following effects can be obtained. That is, since the processed hole is identified by comparing the center of the reference mark before drilling with the center of the processed hole after drilling, high precision is achieved even when multiple objects are formed on the substrate. The machined hole can be identified. Therefore, it is possible to prevent the hole misalignment and prevent the deterioration of the drilling accuracy when the mounting frame of the imaging camera is distorted due to the temperature change, and it is also possible to perform the breakage inspection.

[Brief description of drawings]

FIG. 1 is a flowchart showing a method for identifying a machined hole in a camera-type reference hole making machine according to the present invention.

FIG. 2 is an image showing a substrate before drilling.

FIG. 3 is an image showing a substrate after drilling.

[Explanation of symbols]

1 substrate 2 reference mark 2a mark center 3 processed hole S _{1 to} S ₃ object before drilling S ′ _{1 to} S ′ ₄ object after drilling

Claims (2)

[Claims] 1. A reference mark (2) formed on a substrate (1) is captured as an image by an imaging camera, and the image is subjected to image processing to detect a mark center (2a) of the reference mark (2), In the processing hole identification method of the camera type reference drilling machine, which forms a processing hole (3) at the center of the mark (2a) by a drilling means and identifies this processing hole (3), 3) Calculate the extraction and hole center of the processed hole (3) in the camera field of view of the imaging camera after formation, the mark center (2a) of the reference mark (2) before drilling and the hole after drilling. A machined hole identification method for a camera-based reference hole making machine, characterized in that the machined hole (3) is identified by comparing it with the center of the machined hole (3). 2. An object (S ₁
~ S ₃ ) and the object after drilling (S ₁ 'to S ₄ ') are compared with respect to their center of gravity and perimeter, and if the following formula 1 and formula 2 are satisfied at the same time, the machined hole (3) The method for identifying a processed hole in a camera-type reference drilling machine according to claim 1, characterized in that it is not. ｜ (Sn's center of gravity)-(Sm ''s center of gravity) | <e _pix ... (1) (1-k) ・ (Sn circumference) <(Sm' circumference) <(1 + k) ・(Sn perimeter) (2) However, n: Identification number of the object before drilling (1 to 3) m: Identification number of the object after drilling (1 to 4) e _pix : Center of gravity Positional error (unit is pixel) k: Perimeter length error coefficient