CN106290400A - A hole inspection method and hole inspection equipment applied to boards - Google Patents

Abstract

The present invention discloses a hole detection method and hole detection device applied to a plate, the hole detection method comprising: irradiating N plates placed in parallel horizontally with a backlight source, scanning and obtaining light transmission images of the N plates, N being a positive integer greater than zero; extracting the contour features and hole features of the plate from the obtained image, and splicing the extracted image features based on an image feature splicing method; obtaining hole feature data from the spliced image, and distinguishing each plate body and the hole feature data corresponding to each plate body in combination with the contour features; and distinguishing the N plates respectively according to the standard file and the hole feature data corresponding to each plate body. The hole detection method and hole detection device applied to a plate of the present invention realizes the simultaneous detection of multiple plates based on image feature extraction, feature splicing and image detection, thereby improving the detection efficiency.

Description

A hole inspection method and hole inspection equipment applied to boards

technical field

The invention relates to the technical field of board inspection, in particular to a hole inspection method and hole inspection equipment applied to boards.

Background technique

In recent years, the entire circuit board industry has been in a downturn, the number of orders received has decreased, costs have increased, and production efficiency has decreased. In order to survive the downturn, various circuit board manufacturers have adopted countermeasures, among which controlling personnel costs and improving equipment efficiency have become one of the main countermeasures.

The hole inspection machine is used to check the number of holes and the quality of the holes (defects such as special-shaped holes and plug holes) on the finished printed circuit board or the drilled board, and automatically make an OK/NG judgment. As a sorting instrument, the hole inspection machine, as a professional testing instrument for circuit boards, also faces the requirements of customers for high-efficiency testing.

Therefore, how to improve the detection efficiency of the hole inspection equipment has become a problem to be considered and solved by those skilled in the art.

Contents of the invention

The purpose of the present invention is to provide a hole inspection method and hole inspection equipment applied to boards. Based on image feature extraction, feature splicing and image detection, multiple boards can be inspected at the same time, and the detection efficiency is improved.

To achieve the above object, the present invention provides the following technical solutions:

A hole inspection method applied to a board, comprising:

Illuminate N boards placed side by side with a backlight, and scan to obtain the light-transmitting images of the N boards, where N is a positive integer greater than zero;

Extract the profile features and hole features of the board from the obtained image, and stitch the extracted image features based on the method of image feature stitching;

Acquiring hole feature data from the spliced image, and distinguishing each plate body and hole feature data corresponding to each plate body in combination with contour features;

According to the standard file and the hole feature data corresponding to each board body, the N boards are discriminated respectively.

Optionally, N is 6, and 6 boards are placed side by side horizontally.

Optionally, while the light-transmitting images of the N plates are scanned, contour features and hole features of the N plates are extracted from the obtained images.

Optionally, it also includes: storing and displaying the spliced images.

Optionally, before scanning to obtain the light-transmitting images of the N plates, it also includes:

Load the standard file, and establish the space-time ring data structure according to the standard file;

According to the standard file and the hole feature data corresponding to each plate, the N plates are respectively distinguished, including:

The space-time ring data structure is used to compare and detect the hole feature data of the board, including the registration detection of the board hole and the burr detection of the slot hole, and the board is discriminated according to the detection result.

A hole inspection device applied to boards, comprising:

frame;

N parallel conveyor belts arranged on the frame, N is a positive integer greater than zero;

A scanning mechanism, including a bar-shaped light source arranged below the conveyor belt, and an image sensor arranged above the conveyor belt and opposite to the bar-shaped light source for scanning to obtain light-transmitting images of N plates;

A control host connected to the conveyor belt and the scanning mechanism, the control host includes a processor, and the processor is used to extract the outline features and hole features of the board from the image obtained by scanning, and the method based on image feature stitching will extract The image features are spliced, and the hole feature data is obtained from the spliced image, combined with the contour features to distinguish each plate and the hole feature data corresponding to each plate, and according to the standard file and corresponding to each plate The hole feature data of the N plates are respectively discriminated.

Optionally, it also includes a sorting mechanism arranged at the end of the conveyor belt, the sorting mechanism includes N sets of conveying rollers arranged horizontally, and the N groups of conveying rollers correspond to the N conveyor belts respectively.

Optionally, the sorting mechanism also includes a liftable sorting platform connected to the conveying roller;

The equipment also includes a receiving table connected with the sorting mechanism.

Optionally, it also includes a sensor arranged at the connection between the sorting platform and the conveying roller for sensing whether the conveyed board arrives.

Optionally, double rows of said sensors are included.

It can be seen from the above technical solution that the hole inspection method applied to boards provided by the present invention includes: illuminating N boards placed side by side with a backlight source, and scanning to obtain the light-transmitting images of the N boards, where N is greater than A positive integer of zero; extract the outline features and hole features of the board from the obtained image, and stitch the extracted image features based on the method of image feature stitching; get the hole feature data from the stitched image, and combine the outline features Distinguish each board and the hole characteristic data corresponding to each board; judge the N boards respectively according to the standard file and the hole characteristic data corresponding to each board, and judge whether the holes of each board are qualified , so that multiple boards can be detected at the same time, and the detection efficiency is improved.

The hole inspection equipment applied to boards provided by the present invention includes a frame, N parallel conveyor belts arranged on the frame, a scanning mechanism and a control host; the scanning mechanism includes a strip light source arranged under the conveyor belt , and an image sensor arranged above the conveyor belt for scanning to obtain light-transmitting images of N plates; The feature stitching method stitches the extracted image features, and obtains the hole feature data from the stitched image, and combines the contour features to distinguish each plate and the hole feature data corresponding to each plate, and according to the standard file and Corresponding to the hole feature data of each plate body, the N plates are discriminated respectively. The hole inspection equipment applied to boards provided by the present invention is based on image feature extraction, feature splicing and images, so that multiple boards can be inspected at the same time, and the detection efficiency is improved.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a flow chart of a hole inspection method applied to a plate provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a hole inspection device applied to boards provided by an embodiment of the present invention.

detailed description

In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described The embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

Please refer to Figure 1, which is a flow chart of a hole inspection method applied to a board provided by an embodiment of the present invention. Whether it meets the standard requirements, including whether the hole position and hole quality meet the standard requirements, can be applied to the detection of printed circuit boards, copper clad laminates or drilled boards.

Taking the application to the circuit board as an example, the hole inspection method of the present invention applied to the board is described in detail, including steps:

S10: irradiating N boards placed side by side with a backlight, and scanning to obtain light transmission images of the N boards, where N is a positive integer greater than zero;

Illuminate N circuit boards placed side by side with the backlight. When the light shines on the circuit boards, light will pass through the positions where there are holes on the circuit boards, which can be displayed in the collected light-transmitting images, and the places without holes will appear dark. .

In a specific embodiment of the hole inspection method of the present invention, N can be selected to be 6, and 6 boards to be inspected are placed side by side.

S11: extracting the contour features and hole features of the board from the obtained image, and splicing the extracted image features based on the image feature splicing method;

For the light-transmitting image of the scanned circuit board, it can be binarized first, and then the image features of the circuit board, including contour features and hole features, can be extracted from the image. Then, based on the method of image feature splicing, the image features are spliced.

The stitched images can be stored and displayed. In this embodiment, the extracted image features and the spliced image are stored, which can avoid the storage of images from occupying too much memory space.

In the hole inspection method described in this embodiment, preferably, while scanning the light-transmitting images of the N plates, extract the contour features and hole features of the N plates from the images obtained by scanning, that is, scan the N plates. The light-transmitting image and the image feature extraction of the plate are carried out simultaneously, which can save scanning time and improve detection efficiency.

S12: Obtain hole feature data from the spliced images, and distinguish each plate body and hole feature data corresponding to each plate body in combination with contour features;

The hole feature data is obtained from the spliced images. The hole feature data includes information data such as the center coordinates, aperture, and area of the hole. The holes include slot holes and round holes on the circuit board. According to the contour features of each circuit board, the boundary of each circuit board is distinguished, and the hole feature data corresponding to each circuit board is distinguished according to the boundary of each circuit board.

S13: Discriminate the N plates respectively according to the standard file and the hole characteristic data corresponding to each plate body.

According to the hole feature data of each circuit board, the hole positioning detection of each circuit board is compared with the standard file, and each circuit board is judged separately, including hole position registration, hole size detection, burr detection, porous and few holes Test to determine whether each circuit board is qualified.

It can be seen from the above that this embodiment is applied to the hole inspection method of the board, and the N boards placed side by side are irradiated with the backlight, and the light-transmitting images of the N boards are scanned to obtain the light-transmitting images of the N boards; Contour features and hole features, and based on the image feature splicing method, the extracted image features are spliced; the hole feature data is obtained from the spliced image, and the contour features are used to distinguish each board and the corresponding board. The hole feature data; according to the standard file and the hole feature data corresponding to each plate body, the N plates are respectively discriminated, so that multiple plates can be detected at the same time, and the detection efficiency of the plates is improved.

In the hole inspection method described in this embodiment, before the inspection, before the light-transmitting images of the N boards are obtained by scanning, it further includes: loading a standard file.

Among them, loading the standard file can use the original file as the standard file by calling the original file used by the produced board; or, you can choose a board as the standard version and scan the standard board to make the standard file and store the data. If it is applied to circuit board inspection, the original file used in the production of circuit boards can be called, and its original file can be used as a standard file, or a circuit board can be selected as a standard version to make a standard file for use.

Further preferably, the space-time ring data structure can be established according to the standard file, specifically: the first coordinate information is established based on the standard object in the standard file, and the space-time ring data structure is established according to the first coordinate information, and the space-time ring data structure includes a plurality of A point set of standard points, the plurality of standard points all have corresponding first distances and first angles, so that when the application of the space-time ring data structure detects the collected images, the preset detection step is performed based on the Comparison of the first distance and the first angle; wherein, the first distance is the distance from the origin of the first coordinate information, and the first angle is the distance from the standard point to the first coordinate information A two-dimensional angle formed between the distance segment between the origins and the positive X coordinate axis of the first coordinate information.

In the detection applied to the circuit board, the standard points contained in the established space-time loop data correspond to the holes on the circuit board.

Correspondingly, in step S13: according to the standard file and the hole feature data corresponding to each plate body, the N plates are respectively discriminated, specifically including:

The space-time ring data structure is used to compare and detect the hole feature data of the board, including the registration detection of the board hole and the burr detection of the slot hole, and the board is discriminated according to the detection result.

In the hole inspection method of this embodiment, the space-time ring data structure is established according to the standard file, and the space-time ring data structure is applied to the detection of hole features in the circuit board image. When the detection accuracy is high or the detection image resolution is high When the requirements are high, this method can reduce the amount of calculation, reduce time-consuming, and improve detection efficiency.

Correspondingly, the embodiment of the present invention also provides a hole inspection device applied to boards, please refer to Figure 2, the hole inspection device includes:

Rack 1;

N parallel conveyor belts 2 arranged on the rack, where N is a positive integer greater than zero;

The scanning mechanism 3 includes a bar-shaped light source arranged below the conveyor belt, and an image sensor 30 arranged above the conveyor belt and opposite to the bar-shaped light source for scanning to obtain light-transmitting images of N plates;

A control host connected to the conveyor belt 2 and the scanning mechanism 3, the control host includes a processor, and the processor is used to extract the contour features and hole features of the board from the image obtained by scanning, and the method based on image feature splicing The extracted image features are spliced, and the hole feature data are obtained from the spliced images, and each board and the hole feature data corresponding to each board are distinguished by combining the contour features, and according to the standard file and corresponding to each The hole feature data of the plate body is used to distinguish the N plates respectively.

This embodiment is applied to board hole inspection equipment, and is used to detect boards with holes to check whether the holes of the board meet the standard requirements, including whether the hole position and the quality of the holes meet the standard requirements. It can be applied to printed circuit boards, cladding Inspection of copper plate or drilled plate, etc.

The hole inspection equipment in this embodiment includes a frame 1, N parallel conveyor belts 2 arranged on the frame, a scanning mechanism and a control host. The hole inspection equipment can detect N boards at the same time, and transport the N boards to the scanning mechanism through the conveyor belt, and the bar-shaped light source irradiates light to the parallel N boards, and the image sensor scans to obtain the light-transmitting images of the N boards; the control The host computer includes a processor, which is used to extract the profile features and hole features of the board from the images obtained by scanning. The extracted image features are stitched based on the method of image feature stitching, and the hole feature data is obtained from the stitched images. Combined The outline feature distinguishes each board and the hole feature data corresponding to each board, and the N boards are respectively distinguished according to the standard file and the hole feature data corresponding to each board. Therefore, this embodiment is applied to a hole inspection device for boards. Based on image feature extraction, feature splicing and image detection, multiple boards can be inspected at the same time, so that the detection efficiency is improved.

In this embodiment, the bar-shaped light source is an LED bar-shaped light source, and the LED light source has a long service life and ensures the stability of detection. A power control board is arranged in the lower chassis of the equipment, which is connected to the control host, and the LED strip light source is adjustable and controlled by the control host.

The image sensor 30 is arranged opposite to the bar-shaped light source. The image sensor may be a contact image sensor, and the image sensor 30 is provided with a focus motor for adjusting the measurement focal length of the image sensor. The image sensor 30 may be a high-resolution contact image sensor.

N parallel conveyor belts 2 are arranged on the frame, and in a specific embodiment, 6 parallel conveyor belts can be arranged to detect 6 boards at the same time. The hole inspection equipment also includes a drive motor connected to the conveyor belt 2 for driving the conveyor belt to convey.

The hole inspection equipment also includes a sorting mechanism 4 arranged at the end of the conveyor belt 2, the sorting mechanism includes N groups of conveying rollers 40 arranged horizontally, and the N groups of conveying rollers 40 are respectively connected to the N described Conveyor belt 2 corresponds.

The sorting mechanism also includes a liftable sorting platform 41 connected to the conveying roller 40, and the hole inspection equipment also includes a receiving platform 5 connected to the sorting mechanism.

In this embodiment of the hole inspection equipment, the control host is arranged in the chassis of frame 1. The control host includes a processor, a motion control card and a drive motor. The driving motor controls the actions of the conveying rollers and the sorting table of the sorting mechanism to sort the conveyed boards.

The boards to be sorted are placed side by side on the conveyor belt 2, and are transported to the scanning structure 3 by the conveyor belt 2. The image sensor 30 collects the transmitted image of the board, and the processor processes the image and judges each board separately to determine whether each board is If it is qualified, an OK/NG judgment is made. The boards are conveyed to the sorting mechanism by the conveyor belt, and the control host controls the action of the sorting mechanism according to the judgment result, sorts each board, and transports the sorted boards to the receiving station for corresponding receiving.

The hole inspection equipment also includes a sensor arranged at the connection between the sorting platform 41 and the conveying rollers for sensing whether the conveyed board has arrived. When the conveyed board reaches the conveying roller, it will be sent to the sorting platform after being sorted, and the up and down of the sorting platform is controlled by the sensor sensing whether the board arrives.

Preferably, it includes double rows of sensors, so that when one row of sensors fails, the other row of sensors can normally sense whether the board has arrived, so as to control the sorting platform up and down normally.

The hole inspection equipment also includes a display 6 connected to the control host, and a display stand for placing the display. The monitor can be placed above the rack, and the operator can observe the images of each board through the monitor for corresponding control.

The hole detection equipment applied to boards described in this embodiment realizes a multi-channel detection process as a whole, can detect multiple boards at the same time, improves the detection efficiency, and can meet the high-efficiency detection of small boards, and the equipment adopts a modular numerical control system, which can Realize various special functions to meet different user needs.

A hole inspection method and hole inspection equipment applied to boards provided by the present invention have been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention, and the descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (10)

1. A hole inspection method applied to a plate, characterized in that, comprising: Illuminate N boards placed side by side with a backlight, and scan to obtain the light-transmitting images of the N boards, where N is a positive integer greater than zero; Extract the profile features and hole features of the board from the obtained image, and stitch the extracted image features based on the method of image feature stitching; Acquiring hole feature data from the spliced image, and distinguishing each plate body and hole feature data corresponding to each plate body in combination with contour features; According to the standard file and the hole feature data corresponding to each board body, the N boards are discriminated respectively. 2. The method according to claim 1, wherein N is 6, and 6 boards are placed side by side side by side. 3. The method according to claim 1, characterized in that, while scanning the light-transmitting images of the N plates, the profile features and hole features of the N plates are extracted from the obtained images. 4. The method according to claim 3, further comprising: storing and displaying the spliced images. 5. The method according to claim 1, further comprising: before scanning to obtain the light transmission images of the N plates: Load the standard file, and establish the space-time ring data structure according to the standard file; According to the standard file and the hole feature data corresponding to each plate, the N plates are respectively distinguished, including: The space-time ring data structure is used to compare and detect the hole feature data of the board, including the registration detection of the board hole and the burr detection of the slot hole, and the board is discriminated according to the detection result. 6. A hole inspection device applied to boards, characterized in that it comprises: frame; N parallel conveyor belts arranged on the frame, N is a positive integer greater than zero; A scanning mechanism, including a bar-shaped light source arranged below the conveyor belt, and an image sensor arranged above the conveyor belt and opposite to the bar-shaped light source for scanning to obtain light-transmitting images of N plates; A control host connected to the conveyor belt and the scanning mechanism, the control host includes a processor, and the processor is used to extract the outline features and hole features of the board from the image obtained by scanning, and the method based on image feature stitching will extract The image features are spliced, and the hole feature data is obtained from the spliced image, combined with the contour features to distinguish each plate and the hole feature data corresponding to each plate, and according to the standard file and corresponding to each plate The hole feature data of the N plates are respectively discriminated. 7. The equipment according to claim 1, further comprising a sorting mechanism arranged at the end of the conveyor belt, the sorting mechanism comprising N groups of horizontally arranged conveying rollers, and N groups of conveying rollers Corresponding to the N conveyor belts respectively. 8. The device according to claim 7, wherein the sorting mechanism further comprises a liftable sorting platform connected to the conveying roller; The equipment also includes a receiving table connected with the sorting mechanism. 9 . The device according to claim 8 , further comprising a sensor for sensing whether the conveyed board arrives, which is arranged at the connection between the sorting platform and the conveying roller. 10 . 10. The apparatus of claim 9, comprising a double row of said inductors.