TWI658281B - Device and method for drilling detection of printed circuit board - Google Patents

Abstract

The invention provides a drilling detection device and method for a printed circuit board. The drilling detection method includes: scanning an image of a test board to obtain the test information of the drilled holes on the test board; calculating the test information and A deviation information of a standard information is used to generate a deviation information. It is characterized in that the acquisition of the standard information includes the following steps: a drilling feature learning step that enables a detection device to use any of a plurality of holes on the same plate The image is used as a learning object, and the template is an actual printed circuit board finished product. The standard information establishment step enables the detection device to obtain the positions of a plurality of drilled holes on the template based on the drilling feature learning step, and uses the The image features of a drill hole on the template establish standard information.

Description

Device and method for drilling detection of printed circuit board

The invention relates to a drilling detection device and method, in particular to a drilling detection device and method for performing quality detection on a plurality of holes on a printed circuit board.

In the manufacturing process of printed circuit boards, they are roughly divided into main stations such as inner layer stations, crimping stations, drilling stations, and inspection stations in order. First, the printed circuit boards are completed with development and etching processes at the inner layer stations. Enter the crimping station for blackening / browning, and press the printed circuit board for multiple laminations at the crimping station. The laminated printed circuit board then goes to the drilling station for through-hole or blind hole drilling. After the drilling is completed, the printed circuit board is washed, and finally the printed circuit board is sent to an inspection station for optical drilling inspection.

In the quality inspection part of the inspection station, different information can be obtained according to the type of drilling. In the through-hole inspection part, the patent No. 488165 "A method for analyzing the accuracy of drilling of printed circuit boards" has disclosed an inspection Station drilling analysis method, which first enters printed circuit board drilling measurement data and theoretical data, and uses the measurement data and theoretical data to calculate the average value, deviation, standard deviation, process accuracy, and process precision And related statistical data such as process capability index; in terms of presentation, according to the selection of drilling tool diameter and regional selection items, select the statistical data of the range, and according to the selected statistical data, use the vector map, distribution map and arrow target map The image is displayed, so as to provide a clear analysis chart to effectively present the drilling distribution on the printed circuit board and its corresponding deviation amount and deviation direction. In the blind hole detection section, the patent No. CN1278100C "printed circuit board" "A blind hole quality analysis method" has disclosed a blind hole quality analysis method at an inspection station, which is first input to a laser on a printed circuit board. Design of processing blind holes Data and actual measurement data, and use the design data and measurement data to calculate various deviation statistics. The deviation statistics are expressed in the form of target map, hole offset distribution map, vector map, pad area ratio distribution map and residual Distribution map of the area ratio of the glue. Use these charts to display copper window information, pad information, or relative information between the copper window and the pad. Finally, the information can clearly show the manufacturing quality of the laser blind holes on the printed circuit board.

However, the printed circuit board needs to be cleaned after drilling and the residual glue and blackening / browning layer can be inspected before optical drilling quality inspection. It cannot be inspected directly after drilling, which is extremely inconvenient in use.

That is, the purpose of the present invention is to provide a drilling inspection device and method for a printed circuit board which is convenient to use.

A drilling inspection method for a printed circuit board according to the purpose of the present invention includes: scanning an image of a test board to obtain test information of the drilled holes on the test board; calculating deviation statistics of the test information and a standard information The measurement is to generate a deviation information; it is characterized in that the acquisition of the standard information includes the following steps: a drilling feature learning step, so that a detection device uses any hole image in a plurality of holes of the same plate as a learning object, The template is an actual printed circuit board finished product; the standard information establishing step enables the detection device to obtain a plurality of drilled holes on the template based on the drilling feature learning step, and uses one drilled hole on the template. Standard information for image characteristics.

The drilling inspection device for a printed circuit board according to the present invention is used to execute the drilling inspection method for a printed circuit board, and the drilling inspection device includes a detection device capable of performing image scanning and calculating deviation statistics.

The drilling detection method for a printed circuit board in the embodiment of the present invention adopts an actual finished printed circuit board as a template, and uses the drilling characteristics on the template as standard information to overcome the design. The difference between the data and the finished product, the detection and analysis results will be closer to the actual results after the printed circuit board is pressed and drilled; and because the standard information and the information to be tested are obtained from the finished printed circuit board, it does not matter whether it is before or after cleaning. The finished printed circuit boards can be inspected directly, which improves the convenience for operators.

S1‧‧‧Steps of establishing optical positioning point

S2‧‧‧Drilling feature learning steps

S3‧‧‧Standard information creation steps

S4‧‧‧Statistical operation steps

S5‧‧‧Result display steps

6, 6’‧‧‧ printed circuit board

a, b, c‧‧‧ model

a01‧‧‧Drilling

a11‧‧‧Bronze window

a12‧‧‧pad

a13‧‧‧residue

a14‧‧‧perforation

A1‧‧‧Bronze window radius

A2‧‧‧pad radius

C1‧‧‧Bronze Window Center

C2‧‧‧ land center

FIG. 1 is a flowchart of an embodiment of a drilling inspection method for a printed circuit board according to the present invention.

FIG. 2 is a machine vision image of a blackened / brownized / uncleaned printed circuit board according to an embodiment of the present invention.

FIG. 3 is a machine vision image diagram of a printed circuit board after cleaning and removing glue in an embodiment of the present invention.

FIG. 4 is a machine vision image diagram of a drill hole of a template in the embodiment of the present invention.

5 is a machine vision image diagram showing a state of missing holes in an embodiment of the present invention.

FIG. 6 is a machine vision image diagram showing a padless state of a drilled hole in an embodiment of the present invention.

FIG. 7 is a machine vision image diagram showing an excessively large state of a drilled copper window in an embodiment of the present invention.

8 is a machine vision image diagram showing a state where a drilled copper window is too small in an embodiment of the present invention.

FIG. 9 is a machine vision image diagram showing a state in which a drilled pad is too small in an embodiment of the present invention.

FIG. 10 is a machine vision image diagram showing a deviation state of a hole in a drill according to an embodiment of the present invention.

FIG. 11 is a machine vision image diagram showing a state of residual glue in a drill hole according to an embodiment of the present invention.

FIG. 12 is a machine vision image diagram showing a breakdown state of a drill hole in an embodiment of the present invention.

FIG. 13 is a defect distribution chart shown in the embodiment of the present invention.

FIG. 14 is a scatter diagram of deviation amounts of the entire boreholes of the test plate and the template in the embodiment of the present invention.

FIG. 15 is a matching schematic diagram of matching template a, template b and template c to obtain matching information according to an embodiment of the present invention.

As shown in Figs. 1 and 4, the embodiment of the drilling detection method for a printed circuit board drilling inspection device of the present invention for detecting a hole a01 of a printed circuit board uses an actual printed circuit board as a template to detect Analyze the drilling of other printed circuit boards with the same process. The printed circuit board can be the blackened / brown / unwashed and debonded printed circuit board 6 shown in FIG. 2, or the cleaned and removed board shown in FIG. 3. The glued printed circuit board 6 'is not limited in implementation. For the convenience of description, in the following embodiment, the printed circuit board 6 'after cleaning and de-gluing as shown in FIG. 3 is taken as an example for description. The method for drilling detection includes the following steps: establishing an optical positioning point step S1: taking A printed circuit board is used as a template a, and the detection device performs image scanning on the template a to record the hole position coordinates of a plurality of holes on the template a to establish a plurality of optical positioning points (not shown). The optical positioning points can be used to quickly find the corresponding optical positioning points on other templates and the board under test, and can be used to locate other templates and the board to be tested. The holes can be mechanical or laser drilling .

Drilling feature learning step S2: causing the detection device to scan the image of the template a obtained from the step S1 of establishing an optical positioning point, and select any one of the multiple holes a01 on the template a as a learning object, Record the gray scale, diameter, and center information of a copper window a11 and a pad a12 of the drilled hole a01, where the drilled hole a01 can be located in the blackened / brown / uncleaned printed circuit shown in Figure 2 On the board 6, or the printed circuit board 6 'after cleaning and de-gluing as shown in FIG. 3, the drilled hole a01 has a copper window a11 and a pad a12; the standard information establishing step S3: the detection device is placed in the drilled hole. Based on the hole feature learning step S2, determine and obtain the hole positions of a plurality of holes a01 on the template a and record their center coordinates, and use the features of the image of at least one hole a01 on the template a (Figure 4) to establish Contains standard information of the radius A1 of the copper window a11, the center C1 of the copper window a11, the radius A2 of the pad a12, and the center C2 of the pad a12; Statistical operation step S4: After the detection device completes the standard information establishment step S3, the image scanning is performed on a test board having the same process as the template a, and the test method is obtained according to the method described in step S1 of establishing an optical positioning point. A plurality of optical positioning points of the test board are used to locate the test board, and according to the method described in step S3 of the standard information establishment, the test information of a plurality of holes a01 on the test board is obtained, and then the test information and the The deviation statistics of the standard information are used to generate deviation information. Among them, the board to be tested with the same process refers to if the template a is a blackened / brown / uncleaned printed circuit board, then the board to be tested is also Blackening / browning / uncleaning the degreased printed circuit board. If the template a is the cleaned and degreased printed circuit board, the board under test is also the cleaned and degreased printed circuit board; the result shows step S5: After the deviation statistics of the statistical operation step S4 are calculated by the detection device, the deviation information is displayed in an image or chart such as a machine vision image diagram, a defect distribution chart, a hole target map, and a process capability index (CPK) data; the machine See The image map includes the missing image (Figure 5), no pad pattern (Figure 6), oversized copper window (Figure 7), undersized copper window (Figure 8), undersized pad (Figure 9), and hole deviation ( (Fig. 10), adhesive map with adhesive a13 (Fig. 11), breakdown chart with perforation a14 (Fig. 12); the aforementioned defect distribution chart (Fig. 13) shows the above-mentioned various types of defects (Fig. 5 to 12) Distribution position on the tested printed circuit board; Figure 14 is a scatter diagram of the deviation of the entire drilling a01 of the test board and the template a. The X-axis and Y-axis in the figure represent the test information and standard information, respectively. The two deviations in the vertical direction show the dispersion of the deviations of the entire bore a01.

In the implementation of the embodiment of the present invention, after the operator interprets the image or chart displaying the deviation information, if the drilling quality between the test board and the template a is significantly different, this situation is roughly divided into two cases. First, the quality of the drilled hole a01 on the board to be tested is indeed defective due to process problems, and the second is that the template a itself has defects and generates wrong standard information, so the operator can create step S3 in the standard information. In addition, multiple sample templates (two or more) are added in the test device, and the detection device takes the average value of the characteristics of multiple sample templates as the standard information for re-inspection, or when the test device performs the standard information establishment step S3 for the first time , Then take the feature average of a plurality of templates The value is used as standard information. Taking Figure 15 as an example, although the template a lacks a hole position of a hole a01, the detection device finds that the template b and the template c match the hole position information of a template b and a template c. The template c has a drill hole b01 and c01 at the same position respectively, it can be determined that the template a lacks a drill hole a01, and the detection device uses the matching information as standard information.

The drilling inspection method for a printed circuit board in the embodiment of the present invention uses an actual printed circuit board finished product as a template, which overcomes the gap between the design data and the actual finished product, so that the detection analysis result can be closer to the printed circuit board pressing and bonding. The actual results after drilling; and because the standard information and the information to be tested are obtained from the finished printed circuit board, the finished printed circuit board can be directly inspected whether it is before or after cleaning, which improves the operator's use of Convenience.

In the implementation, it is possible to further improve the accuracy of the standard information by matching the drilling characteristics of the plurality of templates and taking the average value of the drilling characteristics of the plurality of templates as the standard information, so that the detection and analysis results are more accurate. accurate.

In addition, in implementation, in another embodiment of the present invention, the step S1 of establishing an optical positioning point is not necessary, and the action of the detection device scanning to obtain the image of the template a may be changed to the drilling feature learning step S2 and executed. .

However, the above are only the preferred embodiments of the present invention. When the scope of implementation of the present invention cannot be limited by this, any simple equivalent changes and modifications made in accordance with the scope of the patent application and the description of the invention for the present invention are all Still within the scope of the invention patent.

Claims (11)

A drilling inspection method for a printed circuit board includes: scanning an image of a test board to obtain test information of the holes drilled on the test board; calculating deviation statistics between the test information and a standard information to generate a The deviation information is characterized in that the acquisition of the standard information includes the following steps: a drilling feature learning step, so that a detection device uses any drilling image in a plurality of holes of the same plate as a learning object, and the template is a The actual printed circuit board finished product; standard information establishing steps to enable the detection device to obtain the positions of a plurality of drilled holes on the template based on the drilling feature learning step, and use the image features of one drilled hole on the template Create standard information. The drilling inspection method for a printed circuit board according to claim 1, wherein the standard information is at least one printed circuit board that has undergone blackening / browning treatment, or a printed circuit board that has not been cleaned or removed Made after the printed circuit board. The drilling inspection method for a printed circuit board according to claim 1, wherein the standard information includes a copper window diameter, a copper window center, a pad diameter, and a pad center. The drilling inspection method for a printed circuit board according to claim 1, wherein the information to be measured is at least one printed circuit board that has undergone blackening / browning treatment, or a printed circuit board that has not been cleaned and removed, or Obtained after cleaning and removing the printed circuit board. According to the drilling inspection method for a printed circuit board according to claim 1, the drilling feature learning step includes recording the gray scale, diameter, and center information of the drilled copper windows and pads. The drilling inspection method for a printed circuit board according to claim 1, further comprising a step of establishing an optical positioning point before the step of learning the characteristics of the drilling hole. The step of establishing an optical positioning point scans and records a plurality of holes on the template. To establish the optical positioning point, and obtain the optical positioning points of the board under test according to the method described in the step of establishing the optical positioning point to locate the board under test. According to the drilling inspection method for a printed circuit board according to claim 1, the standard information establishing step is to match the drilling characteristics of a plurality of sample templates, and take the average of the drilling characteristics of the plurality of sample templates as the standard. Information. The drilling inspection method for a printed circuit board according to claim 1, wherein the deviation information is displayed as an image or a chart, and the image or chart includes, but is not limited to, a machine vision image, a defect distribution chart, and a hole target map. And process capability indicators. According to the drilling inspection method for a printed circuit board according to claim 8, the machine vision image map includes but is not limited to a missing map, a no-pad map, a copper window too large, a copper window too small, a pad too small, Hole deviation map, adhesive map and breakdown map. According to the drilling inspection method for a printed circuit board according to claim 8, the defect distribution chart shows missing defects, no pad defects, oversized copper windows, undersized copper windows, underpad defects, hole deviation The distribution position of at least one of the defect, the adhesive defect and the breakdown defect on the printed circuit board. A drilling inspection device for a printed circuit board is used to perform the drilling inspection method for a printed circuit board according to any one of claims 1 to 10. The drilling inspection device includes: image scanning and calculation Detection device for deviation statistics.