CN114429443A

CN114429443A - Method for determining polarity of capacitor

Info

Publication number: CN114429443A
Application number: CN202011181852.7A
Authority: CN
Inventors: 范纲伦; 孟宪明; 孙武雄; 廖祝湘; 张基霖; 翁仁龙; 宋柏骏
Original assignee: Giga Byte Technology Co Ltd
Current assignee: Giga Byte Technology Co Ltd
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2022-05-03

Abstract

A method for determining the polarity of a capacitor, comprising: the method includes the steps of obtaining an entity circuit board image, comparing the entity circuit board image with a circuit board design drawing file to obtain an entity capacitor image, obtaining an arch pattern based on a closed pattern in the entity capacitor image, wherein the arch pattern and the closed pattern are at least partially overlapped, and generating and outputting a polarity state of a capacitor related to the closed pattern based on the arch pattern.

Description

Method for determining polarity of capacitor

Technical Field

The present invention relates to a method for determining a polarity state of an electronic device, and more particularly, to a method for determining a polarity state of a capacitor using image recognition.

Background

When manufacturing circuit boards such as computer motherboards and development boards in factories, various electronic components are bonded to a substrate, and there is a possibility that the polarities of the electronic components to be mounted are positive or negative and the pin directions of the electronic components to be mounted are wrong regardless of the manual or automatic mounting of the electronic components. The conventional method for checking the existence of errors is, for example, manual checking, connecting a voltage or current detector to a part of electronic components or a part of area of a circuit board, and measuring whether the measured value thereof meets factory set values. However, the above-described inspection method is too time-consuming and tends to make the entire circuit board manufacturing process inefficient. At present, the image recognition technology can also be used for auxiliary inspection, after the image of the electronic element containing the circuit board is obtained, whether the electronic element has the pin dislocation condition is judged according to the processed image.

However, due to various environmental factors that cannot be precisely controlled, such as the illumination direction, the lens angle of the image capturing device, and the shielding of the neighboring elements, the image containing the electronic element is too distorted or cannot be determined after being pre-processed and converted, or the position of the electronic element to be detected on the circuit board cannot be identified, so that an error detection (undersell) or an over-judgment (over-kill) phenomenon occasionally occurs by using the image identification method, where the error detection means that the pin position of the electronic element is not detected, and the over-judgment means that the pin position of the electronic element is correct and is determined to be reverse.

Disclosure of Invention

In view of the foregoing, the present invention provides a method for determining the polarity of a capacitor, which satisfies the above-mentioned needs, and improves the dilemma of the polarity determination misalignment caused by the poor environment for acquiring the capacitor image.

A method for determining a polarity of a capacitor according to an embodiment of the present invention includes: obtaining a solid circuit board image; comparing the solid circuit board image with a circuit board design drawing file to obtain a solid capacitor image; obtaining an arcuate pattern based on a closed pattern in the physical capacitor image, wherein the arcuate pattern at least partially overlaps the closed pattern; and generating and outputting a polarity state of a capacitor associated with the closed pattern based on the arcuate pattern.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

Fig. 1 is a flow chart of a capacitor polarity method according to an embodiment of the invention.

Fig. 2 is a perspective view of a capacitor suitable for use in the method for determining the polarity state of the capacitor according to an embodiment of the invention.

FIG. 3A is a gray scale diagram of a physical capacitor image according to an embodiment of the invention.

Fig. 3B is a schematic diagram of a rendered solid capacitor image after binarization processing according to an embodiment of the invention.

FIG. 3C is a schematic diagram of a closed pattern according to an embodiment of the invention.

FIG. 4 is a schematic diagram of a circular pattern drawn according to an embodiment of the present invention.

Fig. 5 is a detailed flowchart of a capacitor polarity method according to an embodiment of the invention.

Reference numerals

1: capacitor with a capacitor element

11: solid pattern

31: pattern image

32: closed pattern

4: circular pattern

41: first arcuate pattern

42: second arcuate pattern

S1-S4, S41-S46: step (ii) of

Detailed Description

The invention will be described in detail with reference to the following drawings, which are provided for illustration purposes and the like:

referring to fig. 1, a flow chart of a first embodiment of a method for determining a polarity state of a capacitor according to the present invention is shown, which includes the following steps: step S1, obtaining an image of a solid circuit board; step S2, comparing the solid circuit board image with the circuit board design drawing file to obtain a solid capacitor image; step S3, obtaining an arch pattern based on the closed pattern in the solid capacitor image, wherein the arch pattern and the closed pattern at least partially overlap; and step S4, generating and outputting a polarity status of a capacitor associated with the closed pattern based on the arcuate pattern.

Please refer to fig. 1 and fig. 2 together to describe the first embodiment of the present invention in more detail, wherein fig. 2 is a perspective view of the capacitor 1. The upper surface of the capacitor 1 has a solid pattern 11, the solid pattern 11 is used to represent the polarity direction of the capacitor 1, usually the solid pattern 11 is in the shape of an arc, and the orientation of the arc relative to the chord thereof represents the orientation of the cathode relative to the anode of the capacitor 1. That is, if the arc of the arcuate solid pattern 11 is located on the right side of the chord thereof, the negative electrode of the capacitor 1 is located on the right side of the positive electrode of the capacitor 1. In an embodiment of the present invention, an image of a physical circuit board is obtained in step S1. In practice, an image may be obtained by taking a picture of the circuit board, shooting the picture by the image capturing device, and the like, and the obtained picture is used as an image of the solid circuit board, wherein the circuit board at least includes a capacitor, that is, the image of the solid circuit board obtained by the image capturing device at least includes the capacitor. In addition, in order to reduce the calculation amount of the electronic device for determining the polarity state of the capacitor or eliminate unnecessary noise in the image, in step S1, in addition to obtaining an image (defined as an initial circuit board image) by means of photographing, recording, etc. the image may be further subjected to image preprocessing, such as binarization (binarization), and morphological image processing, such as erosion (erosion) and/or dilation (dilation), etc., to form the solid circuit board image, so as to remove unnecessary noise or enhance the image, etc., and achieve the purpose of improving the image quality and facilitating subsequent determination.

Step S2 compares the physical circuit board image with a circuit board design file to obtain a physical capacitor image. In particular, the circuit board design file is a design file of this circuit board, in particular a design electronic file. The circuit board design file represents a plurality of electronic components of the circuit board, such as various capacitors, resistors, microchips, processing chips …, etc., and preferably includes a plurality of predetermined coordinates, wherein each predetermined coordinate corresponds to an electronic component. In the following description about the first embodiment of the capacitor polarity state determination method of the present invention, only the preset capacitor coordinates among the preset coordinates will be explained as an example. In this embodiment, a transformation matrix between the physical circuit board image and the circuit board design drawing file can be obtained by presetting a plurality of reference points on the circuit board and the circuit board design drawing file, and the transformation matrix transforms the preset capacitor coordinates into physical capacitor coordinates on the physical circuit board image, so as to obtain the physical capacitor image covered in the physical circuit board image. In detail, the embodiment of obtaining the physical capacitor image based on the physical capacitor coordinates may be: the image capture range is formed by extending outward around the coordinates of the solid capacitor, wherein the outward extending manner is to extend a predetermined length around the coordinates of the solid capacitor along two opposite directions of a plurality of axes (e.g., a vertical axis and a horizontal axis) of the image of the solid capacitor, so that the image capture range includes the capacitor. It should be noted that the above manner of obtaining the physical capacitor image is merely illustrative of one embodiment, and the present invention is not limited thereto.

In another embodiment, in order to reduce the amount of computation of the personal electronic device or eliminate unnecessary noise, image preprocessing (such as the aforementioned image processing of binarization, erosion and/or dilation) may be performed on the image in the image capturing range, and then the content of the image preprocessing may be used as the aforementioned solid capacitor image. In practice, since only the real capacitor image with a smaller range is needed than the initial board image with a larger range, the amount of computation can be greatly reduced when the image preprocessing is performed in step S2 instead of step S1. As shown in fig. 3A to 3C, the solid capacitor image is obtained by binarizing the image (shown in fig. 3A) in the image capturing range (shown in fig. 3B) and then performing morphological image processing such as erosion or dilation (shown in fig. 3C). As can be seen from fig. 3A and 3C, fig. 3A includes a pattern image 31, and the pattern image 31 is an image of the solid pattern 11, such as the capacitor 1, appearing in the solid circuit board image, and the closed pattern 32 shown in fig. 3C corresponds to the pattern image 31. Due to various environmental factors such as the illumination direction, the lens angle of the image capturing device, and the shielding of the neighboring elements, some unnecessary data of the image after image preprocessing is not effectively removed, or some necessary data is accidentally removed, and the like, the closed pattern 32 may be inconsistent with the pattern image 31.

Please refer to fig. 4 at the same time. Next, in step S3, an arch pattern (a first arch pattern 41) is obtained based on the closed pattern 32 in the physical capacitor image, wherein the first arch pattern 41 at least partially overlaps the closed pattern 32. Preferably, the first arcuate pattern 41 is the smallest arc encompassing this closed pattern 32, and the bow of the first arcuate pattern 41 is to the left or right of its chord (e.g., the bow of the first arcuate pattern depicted in FIG. 4 is to the right of its chord).

Please refer to fig. 2 and fig. 4. Following step S3, step S4 generates and outputs a polarity status of a capacitor associated with the closed pattern 32 based on the bow pattern, that is, the polarity status can be obtained according to the orientation relationship of the bow and the chord of the first bow pattern 41, wherein the polarity status can be "the negative electrode of the capacitor is located on the left side of the positive electrode of the capacitor" or "the negative electrode of the capacitor is located on the right side of the positive electrode of the capacitor", but the invention is not limited thereto. In detail, referring to fig. 5, step S4 according to an embodiment of the present invention may include sub-steps S41 to S46. In the sub-step S41, the circular pattern 4 is generated according to the first arcuate pattern 41, and in detail, the circle center of the circular pattern 4 and the semicircular position thereof can be found by iterating each coordinate point on the contour of the first arcuate pattern 41 by using bisection methods (bisectors), so as to generate the circular pattern 4, wherein the arc of the first arcuate pattern 41 at least partially overlaps the outer periphery of the circular pattern 4, and the portion of the outer periphery that is not overlapped by the arc forms the second arcuate pattern 42 with the chord of the first arcuate pattern 41, for example, the circular pattern 4 can be divided into two arcuate patterns (i.e. the first arcuate pattern 41 and the second arcuate pattern 42) by the chord of the first arcuate pattern 41. In sub-step S42, a first characteristic value of the first bow-shaped pattern 41 and a second characteristic value of the second bow-shaped pattern 42 are compared. In the present embodiment, the first characteristic value and the second characteristic value are the same type of physical quantity of each of the arcuate patterns, and are used to show the difference between the first arcuate pattern 41 and the second arcuate pattern 42. For example, the first and second characteristic values may be the areas of the first and second

arcuate patterns

41 and 42, respectively, or the arc lengths of the first and second

arcuate patterns

41 and 42, respectively, although the invention is not limited by the above physical quantities.

Please continue to refer to fig. 4 and 5. In sub-step S43, it is determined whether the first characteristic value is smaller than the second characteristic value, and if yes, step S44 is performed, and if no, step S45 is performed. In detail, the first characteristic value and the second characteristic value may represent a magnitude relationship between the first arcuate pattern 41 and the second arcuate pattern 42. Referring to fig. 2, since the circular pattern 4 may correspond to the circular periphery of the capacitor 1, one of the first and second

arcuate patterns

41 and 42 having a smaller characteristic value may correspond to the solid pattern 11, and one of the first and second

arcuate patterns

41 and 42 having a larger characteristic value may correspond to a portion of the circular periphery of the capacitor 1 not including the solid pattern 11, the polarity state may be determined by obtaining a magnitude relationship between the first and second characteristic values.

In sub-step S44, when the first characteristic value is smaller than the second characteristic value, it is determined that the polarity state is such that the orientation of the first arcuate pattern 41 with respect to the second arcuate pattern 42 is the orientation of the negative electrode of the capacitor with respect to the positive electrode of the capacitor. Conversely, in the sub-step S45, when the first characteristic value is greater than the second characteristic value, it is determined that the polarity state is such that the orientation of the first arcuate pattern 41 with respect to the second arcuate pattern 42 is the orientation of the positive electrode of the capacitor with respect to the negative electrode of the capacitor.

Finally, in the present embodiment, the sub-step S46 outputs the polarity state of the sub-step S44 or the sub-step S45. In addition, in the actual production line quality control program, in addition to the above method for determining the polarity state of the capacitor, the correlation between the polarity state and a preset state in the circuit board design drawing file can be further confirmed, so as to perform corresponding additional actions in due time when there is an abnormality. In detail, in an embodiment of the present invention, the circuit board design file may further have a plurality of predetermined states respectively associated with the plurality of electronic components, and after the polarity state of the capacitor is determined in the sub-steps S44 and S45, it is further determined whether the polarity state is the same as the corresponding predetermined state. If the polarity state is the same as the preset polarity state, outputting the polarity state; if the polarity state is different from the preset polarity state, the polarity state is not only output, but also an alarm signal can be generated or the method can be executed again to avoid the error that the different judgment is only accidental.

By the method for determining the polarity state of the capacitor provided by the invention, even if the environment for obtaining the image of the capacitor is not good, the orientation of the solid pattern 11 can be confirmed by the obtained bow pattern, and the polarity state of the capacitor can be accurately determined.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for determining a polarity of a capacitor, comprising:

obtaining a solid circuit board image;

comparing the solid circuit board image with a circuit board design drawing file to obtain a solid capacitor image;

obtaining an arcuate pattern based on a closed pattern in the physical capacitor image, wherein the arcuate pattern at least partially overlaps the closed pattern; and

a polarity state of a capacitor associated with the closed pattern is generated and output based on the arcuate pattern.

2. The method of claim 1, wherein the bow pattern is defined as a first bow pattern, and generating and outputting the polarity status of the capacitor associated with the closed pattern based on the first bow pattern comprises:

generating a circular pattern according to the first arch pattern, wherein the arc of the first arch pattern at least partially overlaps the outer periphery of the circular pattern, and the part of the outer periphery which is not overlapped with the arc and the chord of the first arch pattern form a second arch pattern;

comparing a first characteristic value of the first bow-shaped pattern with a second characteristic value of the second bow-shaped pattern;

when the first characteristic value is smaller than the second characteristic value, judging that the polarity state is that the orientation of the first arch pattern relative to the second arch pattern is the orientation of the cathode of the capacitor relative to the anode of the capacitor;

when the first characteristic value is larger than the second characteristic value, judging that the polarity state is that the orientation of the first bow-shaped pattern relative to the second bow-shaped pattern is the orientation of the anode of the capacitor relative to the cathode of the capacitor; and

the polarity state is output.

3. The method of claim 2, wherein the first characteristic value and the second characteristic value are areas of the first bow pattern and the second bow pattern, respectively.

4. The method of claim 2, wherein the first characteristic value and the second characteristic value are arc lengths of the first arc pattern and the second arc pattern, respectively.

5. The method of claim 1, wherein obtaining the image of the physical circuit board comprises:

shooting a circuit board by an image taking device to obtain an initial circuit board image; and

and performing at least one of binarization, erosion and expansion on the initial circuit board image to form the solid circuit board image.

6. The method of claim 1, wherein comparing the physical circuit board image with the circuit board design file to obtain the physical capacitor image comprises:

an image capturing range is formed by outwards expanding a frame by taking a physical capacitor coordinate as a center;

and performing at least one of binarization, erosion and expansion on the image capturing range to obtain the solid capacitor image.