Defect detecting of PCB using Image processing in this it included the basic principal that enhancing the image quality through the image processing technique and this compare with the original image and ideal image and defect detect through the subtraction method

1. APPLICATION OF IMAGE PROCESSING IN THE DETECTION
OF PRINTED CIRCUIT BOARD
Presented by:
Jeevan B M
4KV11EC032
VIII SEM E&C
KVGCE
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2. CONTENTS
• Introduction
• Image Acquisition System
• Image Enhancement
• Edge Detection
• Image Binarization
• Defect Detection Of Subtraction Method
• Conclusions
• References
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3. INTRODUCTION
• Electronic equipments quality and performance depends on
quality of printed circuit board[PCB].
• Defections appear in PCB
o Solder mark is unevenness
o Lines and pads damages productions in PCB
So detection is a necessary to ensure the quality of PCB
• defections appear in PCB due to
o Bad welding points
o Short circuit
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4. •Image processing has two purposes
oImages suitable for human observation and
detection
oRecognize and understand images automatically
•The system includes
oImage acquisition system
oImage enhancement
oEdge detection
oDefect detection
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Continue..

5. Image Acquisition system:
Figure: Acquisition system
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6. •System is composed of light source, conveyor belt, controlling
board, circuit board and CCD camera.
•Light sources that improve the capabilities of vision systems.
•Conveyor belt is used to automatically transmit detected circuit
boards.
•According to the requirements, we fix the CCD camera on the
position is fixed.
•The speed of the belt should match the CCD acquisition rate.
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7. •The hole procedure consists of 3 steps
1) Detected board should be placed.
2) Setting the CCD camera resolution and exposure time.
3) The circuit board images collected by CCD are saved to
PC.
• Then image processing and feature extraction is going to be
undertaken.
Continue..
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8. Image Enhancement
•Image gray transformation and image smoothing are the two
methods of image enhancement.
•Image smoothing also called blurring of an image and image
smoothing is mainly used to reduce the noise.
•Gray scale image refereed as monochrome or one color image
contains only brightness information no color information.
•Gray level correction is a simple and effective way to enhance
image in spatial domain.
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9. Continue..
• In this paper two dimensional gray equalization is
achieved
• Gray transformation increase the dynamic range,
expand the image contrast and make the image
clearer.
a) Original Image b) Enhancement Image
Figure. Gray Enhancement Image
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10. Edge Detection
•In this edge of the object is reflected by the discontinuity of
gray level.
•It can be divided into step edges and roof edges according
to the characteristics.
•the purpose of edge detection is to obtain external contour
features of the image.
•Edge detection is the name for which identifying points in a
digital image.
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11. Image binariztion
•Binary image is a simplest type of image can take on two
values typically black or white and 0 or 1.
•It is a important technology to get the image contour.
•Mathematical morphological opening operation can be used
to eliminate small objects, separating objects, smooth larger
object boundaries without obvious area changes.
•Morphological opening operation is firstly proposed to the
original image in solder joint
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12. a) Background image b) Image Enhancement
Figure .Morphological image enhancement
Figure . Binarization of solder joints
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13. Defect detection of subtraction method
•Background subtraction can provide the difference between
images.
•And can be used to
oGuide the dynamic monitoring
o Moving target detection and tracking
o Image background elimination and image recognition .
•In this process difference corresponding to missing
components in a target PCB is identified.
• In the processing noise will be extracted and leaving only
defect characteristics .
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14. a) Detect Image b)Template image (c)Defect detection
Figure . Image detection of Subtraction Method
Figure shows is the defect detection image by subtraction
method, and
a) is the board image to be detected.
b) is the template image.
c) is the defect detection image by subtraction.
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15. CONCLUSION
•This paper analysis the Binarization and defects detecting
system of the printed circuit board based on image
processing technology.
•The system is composed of image acquisition, image
enacement, edge détection , image binariztion and defects
detection by subtraction method.
•This method can perform high effective, fast speed and
accurate measurement by the powerful digital image
processing ability
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16. REFERENCES
[1] Xiong Zhenjiao. Research on the Detection Method Based
on Image for Defect in Circuit Board. [Mj. School of
Information Engineering Nanchang Hangkong University,
2012.
[2] N.G.Shankar, Z.W. Zhong. Defect detection on
semiconductor
wafersurfaces[I].Microelectronic Engineering , 2005: 337-
346.
[3] JIANG Ke-wan, WU Qi. Application of Image Recognition
Technology in PCB Precision.
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17. • Xiong Bangshu, Xiong Zhenjiao, Mo Van. Detection Method of
Printed Circuit Board Defect
•S-J Ko, Lee Y H. Center Weighted Median Filter and their
Application to Image Enhancement
•Liu He. Digital image processing and application [ Mj. China
Electric Power Press, 2005
• Zhao Chunhui. Modern Image Processing Technology and
Matlab Realization[M]. Beijing People' Posts And
Telecommunications press, 200 I.
•K.RCastleman. Digital Image Processing. Newyork Prentice
Hall,1998.
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18. •Bin He. Digital Image Processing [Mj. Beijing People' Posts
And Telecommunications Press, 2001
• Zhou Iinping.MATLAB6.5 Image Processing and Application
Examples[Mj. Beijing: Science
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