JP2005172640A - Mounting inspection apparatus and mounting inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting inspection apparatus and a mounting inspection method capable of satisfactorily determining whether or not a cream solder state or an electronic component mounting state is good even in a narrow adjacent mounting in which adjacent electronic components are closely mounted. provide.
SOLUTION: Using a boundary detection unit 10 that detects a boundary between a land 3 of a printed circuit board 2, a cream solder 4, and an electronic component 5 based on captured image data, and data output from the boundary detection unit 10, Using the position detection unit 11 that detects the position of the cream solder 4 and the position of the electronic component 5, and the data detected by the position detection unit 11, the connection state between the cream solders 4 of the adjacent electronic components 5 and the connection thereof A feature amount extraction unit 12 that extracts a feature amount of the cream solder 4 including the dimension width, and a determination unit 13 that determines the quality of the mounting state based on the position of the cream solder 4 and the feature amount are provided.
[Selection] Figure 1

Description

  The present invention relates to a mounting inspection apparatus and a mounting inspection method for simultaneously inspecting a printed state of cream solder and a mounted state of electronic components on a printed board on which cream solder is printed and electronic components are mounted.

  The manufacturing of a mounting board on which electronic components are mounted executes three processes: a cream solder automatic printing machine that automatically prints cream solder, a component automatic mounting machine that mounts electronic components, and a solder reflow machine that performs reflow soldering. Performed by an automatic machine. In these automatic processes, troubles due to various factors may occur in the cream solder printing process and the parts mounting process, but if soldering is performed by solder reflow with such troubles occurring, reworking The effort is extremely large. Therefore, in order to prevent such a significant increase in labor, it is necessary to inspect the printing state of cream solder and the mounting state of electronic components before performing the reflow soldering operation.

  Relying on this inspection process by visual inspection by an inspection worker cannot completely eliminate the occurrence of mistakes. In addition, with the recent miniaturization of electronic components and the increase in the density of mounting substrates, visual inspection has reached its limit. Considering these points, it is important to perform an automatic inspection. In consideration of various performances such as accuracy, tact, and cost, it is desirable to perform in-line (in the production line) automatic inspection, but this in-line automatic inspection method has a short imaging time and is inexpensive. Inspection with a color camera, which has a large amount of information, is attracting attention.

Hereinafter, the conventional mounting inspection method using a color image will be described with reference to FIG.
As shown in FIG. 8, in the conventional mounting inspection method disclosed in Patent Document 1 or the like, the land 3 on the printed circuit board 2, the cream solder 4 on the land 3, and the electronics illuminated by the illumination 1 Each reflected light from the component 5 is imaged by the color camera 6. An image captured by the color camera 6 is input to the color processing unit 7. The color processing unit 7 converts the RGB color video signal captured by the color camera 6 into lightness, hue, and saturation, and converts it into binary data corresponding to preset colors. Each of the land 3, cream solder 4, and electronic component 5 is extracted by processing with the color extraction table 9. Then, in the boundary detection unit 10 that receives the output from the color processing unit 7, the noise components are smoothed using the extracted data of each color in the land 3, the cream solder 4, and the electronic component 5. The respective contours of the electronic component 5 are traced, and the boundaries between the land 3 and the cream solder 4, the cream solder 4 and the electronic component 5, and the electronic component 5 and the land 3 are detected.

  Next, each position is calculated from the data of each boundary between the land 3 and the cream solder 4, the cream solder 4 and the electronic component 5, and the electronic component 5 and the land 3 detected by the boundary detection unit 10 by the positional deviation calculation unit 81. Then, the amount of positional deviation is calculated, and finally, the determination unit 82 compares the data from the positional deviation calculation unit 81 with the value stored in the allowable value storage unit 14, and the printing state of the solder paste and the electronic components The inspection result storage unit 15 stores the pass / fail determination result.

Next, a positional deviation calculation method will be briefly described with reference to FIG.
FIG. 9 schematically shows a state in which each boundary of the land 3 </ b> A, land 3 </ b> B, cream solder 4 </ b> A, cream solder 4 </ b> B, and electronic component 5 is detected by the boundary detection unit 10. As shown in FIG. 9, the X direction deviation amount X1A between the land 3A and the cream solder 4A, the Y direction deviation amount Y1A between the land 3A and the cream solder 4A, and the X direction deviation amount between the land 3B and the cream solder 4B. From X1B and the Y-direction shift amount Y1B between the land 3B and the cream solder 4B, the shift amounts X1A, Y1A, X1B, and Y1B between the lands 3A and 3B and the cream solder 4A and 4B are calculated, and the cream solder 4A and the electronic component X-direction misalignment amount X2A between the cream solder 4A and the electronic component 5, Y-direction misalignment amount Y2A, the X-direction misalignment amount X2B between the cream solder 4B and the electronic component 5, the cream solder 4B and the electronic component 5 The amount of deviation X2A, Y2A, X2B, Y2B between the cream solder 4A, 4B and the electronic component 5 is calculated from the Y-direction deviation amount Y2B of the electronic component 5, and further, at the boundary of the outer portion of the electronic component 5 And it calculates the slope of the electronic component 5 in Zui.

Deviation amounts X1A, Y1A, X1B, Y1B between the lands 3A, 3B and the cream solder 4A, 4B, deviation amounts X2A, Y2A, X2B, Y2B between the cream solder 4A, 4B and the electronic component 5, and the electronic component 5 The deviation is determined by comparing the inclination with each allowable value stored in the allowable value storage unit 14.
JP-A-6-160037 (pages 2 to 4 and FIGS. 1 and 2)

  However, in the conventional mounting inspection method, it is possible to determine the quality of the state of the printed cream solder 4 with respect to the land 3 on the printed circuit board 2 and the quality of the mounted electronic component 5. It is no longer possible to cope with higher mounting density.

  That is, as shown in FIG. 10, when the electronic components 5 are mounted close to each other on the printed board 2 at 0.2 mm or less, the interval between the adjacent lands 3 is reduced, and the electronic components 5 are The cream solder 4 that has been separated before mounting may become a state in which the adjacent electronic components 5 are connected to each other after the electronic component 5 is mounted (connection portion E in FIG. 10). It becomes difficult to detect the boundary position of the solder 4. Furthermore, even when the cream solder 4 is connected, the connected portion may be separated by the surface tension in each process of heating and melting and cooling, and normal soldering may be realized. Then, there was a problem that an accurate pass / fail judgment could not be made.

  The present invention solves the above-mentioned problem, and even in the case of narrow adjacent mounting in which adjacent electronic components are mounted close to each other, it is possible to satisfactorily determine whether or not the cream solder state or the electronic component mounting state is good. An object is to provide a mounting inspection apparatus and a mounting inspection method.

  In order to solve the above-described problems, the mounting inspection apparatus of the present invention includes a mounting inspection in which cream solder is printed and a printed circuit board on which electronic components are mounted is imaged by an imaging unit, and the captured image data is processed to perform a mounting inspection. A boundary detection unit for detecting a boundary between a printed circuit board land, cream solder, and an electronic component based on the captured image data, and data output from the boundary detection unit; A feature of cream solder including a position detection unit for detecting a position and a position of an electronic component, and a connection state between cream solders of adjacent electronic components and a connection length thereof using data detected by the position detection unit A solder feature amount extraction unit that extracts a quantity, and a determination unit that determines whether the mounting state is good or not based on the position of the cream solder and the feature amount To.

  The mounting inspection method of the present invention includes a step of imaging a printed circuit board on which cream solder is printed and an electronic component is mounted, and the land of the printed circuit board, the cream solder, and the electronic component based on the captured image data. Using a boundary detection step for detecting a boundary, data output from the boundary detection unit, a position detection step for detecting the position of the cream solder and the position of the electronic component, and data detected by the position detection unit Based on information including the extraction process of extracting the connection state of cream solders of adjacent electronic components and the connection length of the connected parts, and the connection state of the cream solders and the connection dimensions of the connected parts And a determination step for determining whether the mounting state is good or bad.

  According to this configuration and method, it is possible to know the connection state between cream solders of adjacent electronic components and the connection dimensions of the connected portions and to detect the boundary position of the cream solder. It is possible to determine whether the cream solder state is good or not after mounting the solder, and to ensure the mounting quality after solder reflow.

  As described above, according to the present invention, since the connection state between cream solders of adjacent electronic parts and the connection dimension of the connected parts can be known, the cream solders in a state where the electronic parts are mounted on the cream solder. Whether the cream solder state including the connected state is good or bad can be determined well, and the mounting quality after solder reflow can be improved. In addition, it is possible to accurately cope with the recent increase in mounting density.

  In addition to detecting the connection state between cream solders of adjacent electronic parts, it is also possible to detect the connection dimension of the connected parts, so even if the cream solder is connected, the connection dimension is small Thus, it is possible to accurately determine that the connected parts are separated in the subsequent solder reflow process and that there is a high possibility that normal soldering can be realized. Therefore, even in such a case, a solder reflow can be performed after that to achieve normal soldering, and a method in which subsequent solder reflow is not performed when cream solders of adjacent electronic components are connected at the time of inspection is adopted. Compared to the case, the yield can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
1 is a diagram showing a configuration of a mounting inspection apparatus according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the mounting inspection apparatus includes a white illumination 1 as illumination means for irradiating a printed board 2 as an inspection target on which cream solder 4 is printed and an electronic component 5 is mounted, and the inspection target. A color camera 6 serving as an image pickup unit that picks up an image and outputs image data, and a color video signal output from the color camera 6 is input to input the color of the electronic component 5, the color of the land 3 of the printed circuit board 2, and the cream solder 4. The color processing unit 7 that extracts and outputs each color data, and detects the boundary between the land 3, the cream solder 4, and the electronic component 5 of the printed circuit board 2 based on the signal output from the color processing unit 7. Features of the boundary detection unit 10, the position detection unit 11 that detects the position of the cream solder 4 and the electronic component 5 using the data output from the boundary detection unit 10, and the cream solder 4 The solder feature amount extraction unit 12 for calculating the position of the cream solder 4 and the electronic component 5 and the feature amount of the cream solder are compared with allowable values stored in advance in the allowable value storage unit 14 to determine whether the mounting state is good or bad. And a test result storage unit 15 for storing a determination result of the test. The color processing unit 7 includes a color conversion unit 8 that converts RGB color video signals into lightness, hue, and saturation, and a color extraction table 9 that converts binarized data corresponding to preset colors. It is comprised by.

Using this mounting inspection apparatus, a mounting inspection method is performed as follows.
First, the land 3 on the printed circuit board 2, the cream solder 4 on the land 3, and the electronic component 5 are illuminated by the white illumination 1 and imaged by the color camera 6.

  The color processing unit 7 converts the RGB color video signal of the image captured by the color camera 6 into lightness, hue, and saturation by the color conversion unit 8, and further converts the color image signal into a preset color by the color extraction table 9. Correspondingly, it is converted into binary data and output, and in the color extraction table 9, it is converted into data obtained by extracting the cream solder 4 portion. The output data converted into lightness, hue, and saturation by the color conversion unit 8 is output not only to the color extraction table 9 but also to the boundary detection unit 10, the position detection unit 11, and the solder feature amount extraction unit 12. .

  The boundary detection unit 10 uses the cream solder color extraction data, smoothes the noise component, tracks the contour of the cream solder 4 and detects the boundary, and the position detection unit 11 reads the saturation data from the color processing unit 7. And the boundary data of the cream solder 4 detected by the boundary detection unit 10, the position of the electronic component 5 is obtained, the amount of deviation from the ideal position of the electronic component 5, the outer position of the electronic component 5, and the electronic component 5 Calculate the slope.

  The solder feature amount extraction unit 12 extracts the feature amount of the cream solder 4 from the boundary data of the cream solder 4 and the position of the electronic component 5 by a method described later, and the determination unit 13 extracts the position detection unit 11 and the solder feature amount. The data from the unit 12 is compared with the value stored in the tolerance storage unit 14 to determine whether the printing state of the cream solder 4 and the mounting state of the electronic component 5 are good or bad, and the determination result in the inspection result storage unit 15 Save. Then, reflow soldering is performed with a solder reflow machine only when the mounting state is determined to be good.

  Next, a more detailed operation in the mounting inspection method will be described. It should be noted that since the data captured by the color camera 6 is the same as the conventional mounting inspection method until the operation of extracting the color data using the color extraction table 9, the description thereof will be omitted, and the description after the boundary detection unit 10 will be omitted. The operation will be described.

  As shown in FIG. 2, the image captured by the color camera 6 is obtained by the boundary detection unit 10, the position of the electronic component 5 based on the preset design data of the printed circuit board 2 and the fixed position of the printed circuit board 2. Is cut out by a cutout rectangle K having a constant magnification of the design dimension of the electronic component 5 with the ideal position of the electronic component 5 as the center. In the case shown in FIG. 2, the electronic component 5 is cut out with double dimensions of the long side and the short side, but the magnification is variable. The boundary of the cream solder 4 is detected within the cutout rectangle K.

  In the case shown in FIG. 2, the cream solder 4A provided at the position shown above in FIG. 2 in the electronic component 5A to be inspected, and the position shown above in FIG. 2 in the electronic component 5C adjacent to the electronic component 5A. The cream solder 4 </ b> C provided in FIG. 4 is physically connected. However, by cutting out with the cutout rectangle K, a part of these cream solders 4A and 4C is divided, and the cream solder boundary H1 which is a closed space is extracted. Further, the cream solder 4B provided at the position shown below in FIG. 2 in the electronic component 5A to be inspected, and the position shown below in FIG. 2 in the electronic component 5C adjacent to the electronic component 5A. The cream solder 4D indicates a case where the cream solder 4D is not physically connected. In this case, a plurality of cream solder boundaries H2 and H3 by the cream solder 4B and the cream solder 4D may be detected. The area within each cream solder boundary H2 and H3 is calculated, the area is more than a certain value, and the average position of the boundary position in the XY direction and the center of the land 3 based on the design data of the printed circuit board 2 are calculated. The distance is calculated and one (cream solder boundary H2) having the smallest distance value is selected.

  Further, the method for extracting the boundary of the cream solder 4 may be created from the extracted data extracted by color extraction, but is not limited thereto. For example, as shown in FIG. 3, when the resolution of the color camera 6 is increased, each of the particles 4r of the cream solder 4 becomes a separate image, and the printed board 2 and the cream solder 4 are further separated. In the case of the printed circuit board 2 in which it is difficult to extract the color of the particles 4r, it is difficult to extract the boundary point based only on the color extraction data of the cream solder 4 portion. Therefore, model template matching based on the data of one cream solder particle 4r using all image data of lightness, hue, saturation, or single or combined image data output from the color processing unit 7. Alternatively, matching is performed based on an actually captured image, the position of each cream solder particle 4r is measured, and the theoretical diameter value of each cream solder particle 4r1 is known. A method may be used in which a circle having a theoretical diameter of the cream solder particles 4r is drawn at the position of, and the boundary of the cream solder 4 is extracted from the boundary point of the aggregate of the circles. This method is also effective.

  Next, the position detection unit 11 uses the model template matching based on the theoretical shape and dimensions of the electronic component 5 while using the saturation image data output from the color processing unit 7, and the image center of the electronic component 5. The amount of misalignment is extracted. As shown in FIG. 4, in the model template, a plurality of rectangular operators (detection portions) 16 are arranged in a portion having the characteristics of the electronic component 5, and the operator 16 performs the processing for the saturation image data. Matching calculation is performed in the major axis direction, and the position of the portion 17 (the detection point) having the highest evaluation value is detected. This process is performed for all the operators 16, and the center of gravity position O of the electronic component 5 is calculated from the average value of the positions of the detection points 17 in all the operators 16. Further, regarding the detection of the tilt angle of the electronic component 5, the angle formed by the straight line connecting the detection point 17L1 and the detection point 17Ln of the operator 16 set in the major axis direction of the electronic component 5, and the detection point 17M1 and the detection point 17Mn Detection is performed using an average value of angles formed. Further, the distance between the detection point 17L of the operator 16 and the detection point 17M of the operator 16 is averaged from 1 to n of each of the detection point 17L and the detection point 17M, and the dimension in the minor axis direction of the electronic component 5 is obtained. Similarly, the dimension in the major axis direction of the electronic component 5 is measured from the average from 1 to m of the detection point 17J of the operator 16 and the detection point 17K of the operator 16.

  Note that here, the case where the matching operation is performed using the saturation data is described, but the present invention is not limited to this, and all the data of brightness, hue, saturation, or data of single or combination Thus, a method of performing calculation to measure the position, angle and dimension of the electronic component 5 may be used, and such a method is also effective.

Further, in the matching calculation, not the model template matching but the matching calculation using an actual image is also effective.
Next, a solder feature amount extraction method performed by the solder feature amount extraction unit 12 will be described with reference to FIG. First, in the boundary extraction position of the cream solder 4 obtained by the method already described with reference to FIG. 2, a portion that overlaps the outer position of the electronic component 5 or has a gap is aligned with the outer position of the electronic component 5. Then, a cream solder boundary H is created. Next, the maximum width position and the minimum width position of each of the cream solder boundary H in the X direction and the Y direction are calculated, and a circumscribed rectangle Q circumscribing the cream solder boundary H is detected, and the dimension in the X direction or the Y direction is determined. When the land size corresponding to the corresponding electronic component 5 is equal to or greater than a predetermined magnification, it is determined that the cream solder 4 is connected. When it is determined that the cream solder 4 is not connected, the average position of the maximum width position and the minimum width position of the cream solder boundary H is regarded as the cream solder center position o.

  Further, a vertical protrusion amount U1 (see FIG. 5C), which is the distance in the Y direction of the cream solder boundary H, is calculated from the position corresponding to the center in the minor axis direction in the outer portion of the electronic component 5. Similarly, on the other side of the electronic component 5, the vertical protrusion amount U <b> 2 (see FIG. 5A) that is the distance in the Y direction of the cream solder boundary H is calculated from the position corresponding to the center in the short axis direction. Further, a lateral protrusion amount V1 (see FIG. 5C), which is a distance in the X direction of the cream solder boundary H, is calculated from a position corresponding to the center in the major axis direction of the outer portion of the electronic component 5. Similarly, the lateral protrusion amount V2 is calculated from the X-direction distance between the X position of the corner portion on the opposite side of the minor axis in the outer portion of the electronic component 5 and the cream solder boundary H. Further, in the same manner, the lateral protrusion amount V3 and the lateral protrusion amount V4 are calculated for the other electronic component 5 as well. Thus, the numerical values of the vertical protrusion amounts U1, U2 and the horizontal protrusion amounts V1, V2, V3, V4 are calculated.

  Next, when the cream solder 4 is connected, first, the soldering length b in the Y direction is sequentially measured from the outer position a of the electronic component 5 to the position c of the cut out circumscribed square Q. The data string of the connection length b with respect to the measurement position is created, and the connection length is extremely long depending on the range not exceeding the narrow adjacent distance (distance between the adjacent electronic components 5) or the position of the adjacent electronic component 5. The position where the connection length b is the shortest in the data string up to the short range is the cream solder connection point P, and the connection length bP is detected as the cream solder connection length. However, depending on the amount of cream solder 4 applied or printed, when the difference between the maximum value and the minimum value of the connection length row is very small, or as the distance from the length of the electronic component outer position is closer to the adjacent electronic component 5 Sometimes it gets bigger. Therefore, in the above-described two types, the connection length b, which is the length in the Y direction of the cream solder boundary H at the intermediate position between the land 3 and the land 3 calculated at the design position, is measured. The connection point is regarded as the intermediate point. Similarly, in the vertical direction, the solder connection length d in the X direction is sequentially measured to create a data string of the connection length d, and the cream solder connection point Q and the cream solder connection length dQ are detected.

  Further, up to cream solder connection point P or point Q, the cream solder boundary H is calculated again, the maximum and minimum positions of the cream solder boundary H at that position are calculated, and the same as when the cream solder 3 is not connected. The numerical values of the vertical protrusion amounts U1, U2 and the horizontal protrusion amounts V1, V2, V3, V4 are calculated by the method.

  Further, in the determination unit 13, the vertical protrusion amounts U1, U2 and the horizontal protrusion amounts V1, V2, V3, V4, cream solder, which are the position information and inclination information of the electronic component 5 and the information of the cream solder state, measured previously. Numerical values stored in the allowable value storage unit 14 using all of the information alone or selected state quantities depending on the positions of the connection points P and Q and the cream solder connection lengths bP and dQ. By the comparison determination process, the component state and the solder state are inspected, and the quality determination as the state before joining is performed.

  According to such a configuration, even when the cream solders 4 of the adjacent electronic components 5 are connected to each other, the position of the cream solder 4 corresponding to the electronic components 5 and the extent of the spread can be accurately determined. And the printed state of the cream solder 4 under the mounted electronic component 5, including the connection state between the cream solders, can be simultaneously and satisfactorily inspected. It is possible to improve and improve the subsequent mounting quality such as solder reflow. In addition, it is possible to accurately cope with the recent increase in mounting density.

  Furthermore, since not only the connection state between the cream solders 4 of the adjacent electronic components 5 can be detected, but also the connection dimension of the connected parts can be detected, even when the cream solders 4 are connected to each other, the connection dimension is small. In this case, it is possible to accurately determine that the connected parts are separated in the subsequent solder reflow process and that there is a high possibility that normal soldering can be realized. Therefore, even in such a case, the solder reflow can be performed after that to achieve normal soldering, and when the cream solders 4 of the adjacent electronic components are connected to each other at the time of inspection, a method in which the subsequent solder reflow is not performed. Compared with the case where it employ | adopts, a yield can be improved.

  Further, since the feature amount extraction unit 12 extracts the amount of protrusion of the cream solder 4 with respect to the electronic component 5 as a feature amount and makes a determination based on the data including the amount of protrusion, the reliability at the time of determination is improved. .

  In addition, as the illumination 1 in the said embodiment, the thing of the structure which can change an incident light quantity and an incident direction according to the mounting state of the electronic component 5 in the printed circuit board 2 as a test object is desirable. A suitable image can be obtained and the reliability in determination is further improved.

  Further, in addition to the above configuration, the result after reflow soldering can be input, and depending on the result information and information such as the connection length stored in the inspection result storage unit 15, the allowable value The permissible value stored in the storage unit 14 may be configured to be correctable. According to this, the permissible value is adapted to the actual situation, and the reliability can be further improved.

(Embodiment 2)
FIG. 6 is a diagram showing the configuration of the mounting inspection apparatus according to Embodiment 2 of the present invention. In FIG. 6, the same components as those in FIGS. 1 to 5 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 6, in this mounting inspection apparatus, a laser as an imaging unit that receives light from a laser light source 21 as an illuminating unit and the laser light source 21 that has been reflected by the land 3, cream solder 4, and electronic component 5. A detector 22, a height processing unit 23 for detecting the height of the land 3, the cream solder 4, the electronic component 5, etc. on the printed circuit board 2 based on the data obtained by the laser detector 22, and the height processing unit The boundary detection unit 24 that detects the boundary between the land 3 of the printed circuit board 2, the cream solder 4, and the electronic component 5 based on the signal output from the circuit board 23, and the data output from the boundary detection unit 24, A position detection unit 25 that detects the positions of the solder 4 and the electronic component 5, a solder feature amount extraction unit 26 that calculates a feature amount of the cream solder, the cream solder 4, and the electronic component The position and the feature amount of the solder cream are compared with a tolerance value stored in the tolerance value storage unit 28 in advance, and a determination unit 27 that determines the quality of the mounting state, and an inspection result memory that stores a determination result of the inspection Part 29. The mounting inspection apparatus shown in the first embodiment is also provided separately, and includes a boundary detection unit 24, a position detection unit 25, a solder feature amount extraction unit 26, a determination unit 27, an allowable value storage unit 28, and an inspection result storage unit. 29 and the like have the same functions as the boundary detection unit 10, the position detection unit 11, the solder feature amount extraction unit 12, the determination unit 13, the allowable value storage unit 14, and the inspection result storage unit 15 described in the first embodiment. Although not shown, the position detection unit 25 is also configured to input the position and inclination data of the electronic component 5 and the boundary position of the cream solder 4 as described in the first embodiment.

  In such a configuration, the light from the laser light source 21 is irradiated to the land 3, the cream solder 4, and the electronic component 5, and the reflected light is received by the laser detector 22. The laser detector 22 outputs data such as the barycentric position data of the light corresponding to the received light information, and the height processing unit 23 calculates the barycentric position of the object at each XY position by the triangulation method. The data is output to the boundary detection unit 24. The boundary detection unit 24 extracts the boundary position between the cream solder 4 and the electronic component 5 from the height data and outputs it to the position detection unit 25. The position detection unit 25 extracts the position and inclination of the electronic component 5. The solder feature amount detection unit 26 extracts the feature amount of the cream solder 4 from the position and inclination data of the electronic component 5, the boundary position of the cream solder 4, and the height information at each part of the cream solder 4. In the determination unit 27, the data from the position detection unit 25 and the solder feature amount extraction unit 26 are compared with the values stored in the allowable value storage unit 28, and the printing state of the cream solder 4 and the mounting state of the electronic component 5 are compared. The inspection result storage unit 29 is configured to store the result.

  In the above-described configuration, the vertical protrusion amounts U1 and U2 and the horizontal protrusion amounts V1, V2, V3 and V4, cream solder connection points P and Q, and the cream solder connection length, which are characteristic amounts of the cream solder 4 of the first embodiment. In addition to the depths bP and dQ, the cream solder height T shown in FIG. 7 is measured, and all of the information is stored in the allowable value storage unit 28 using a single or selected state quantity. Through the comparison determination process with the numerical values, the mounting state of the electronic component 5 and the printing state of the cream solder 4 are inspected, and quality determination as a state before joining is performed.

According to the second embodiment, since the determination is made including information on the cream solder height T, the reliability is further improved.
In this embodiment, the triangulation method is used as the height measurement method, but an optical interference method (phase shift method, white light interference method), confocal method, stereo stereoscopic method, and X-ray measurement method are used. Also good.

  The present invention can be applied to a mounting inspection apparatus and a mounting inspection method for simultaneously inspecting a printed state of cream solder and a mounted state of electronic components on a printed circuit board on which cream solder is printed and electronic components are mounted. Although it is suitable for the inspection before melting the solder, it can also be used as an inspection after melting the cream solder.

The figure which shows the structure of the mounting inspection apparatus which concerns on Embodiment 1 of this invention. Schematic plan view for explaining a boundary detection process of cream solder in the mounting inspection method according to the first embodiment of the present invention. (A) The other schematic enlarged plan view which demonstrates the boundary detection process of the cream solder in the mounting inspection method, (b) is a figure which shows the particle | grains of cream solder notionally The figure explaining the position detection process of the electronic component in the mounting inspection method (A)-(c) is a figure explaining the feature-value detection process of the cream solder in the same mounting inspection method, respectively. The figure which shows the structure of the mounting inspection apparatus which concerns on Embodiment 2 of this invention. Schematic side view for explaining the characteristic amount detection step of cream solder in the mounting inspection method according to Embodiment 2 of the present invention The figure which shows the structure of the conventional mounting inspection apparatus Schematic plan view for explaining a cream solder misalignment detection step in a conventional mounting inspection method Schematic plan view showing the state of cream solder

Explanation of symbols

1 Illumination (illumination means)
2 Printed circuit board (inspection target)
3 Land 4, 4A-4D Cream solder 5, 5A, 5C Electronic component 6 Color camera (imaging means)
7 Color processing unit 8 Color conversion unit 9 Color extraction table 10, 24 Boundary detection unit 11, 25 Position detection unit 12, 26 Solder feature extraction unit 13, 27 Judgment unit 14, 28 Allowable value storage unit 15, 29 Test result storage Part 21 Laser light source (illumination means)
22 Laser detector (imaging means)
23 Height processing section

Claims (8)

A mounting inspection apparatus that performs imaging inspection by imaging a printed circuit board on which a solder paste is printed and an electronic component is mounted, and processing the captured image data.
A boundary detection unit for detecting a boundary between the land of the printed circuit board, the cream solder, and the electronic component based on the captured image data;
Using the data output from the boundary detection unit, a position detection unit that detects the position of the cream solder and the position of the electronic component,
Using the data detected by the position detection unit, the solder feature amount extraction unit that extracts the cream solder feature amount including the connection state of the cream solder of the adjacent electronic components and the connection length thereof,
The mounting inspection apparatus provided with the determination part which determines the quality of a mounting state based on the position of the said cream solder, and the said feature-value.   The mounting inspection apparatus according to claim 1, wherein the determination unit determines whether or not the mounting state is good by comparing with a preset allowable value.   The mounting inspection apparatus according to claim 1, wherein the solder feature amount extraction unit extracts an amount of cream solder protruding from the electronic component as a feature amount.   The mounting inspection apparatus according to claim 1, wherein the solder feature amount extraction unit extracts the height of the cream solder as the feature amount.   The mounting inspection apparatus of any one of Claims 1-4 provided with the illumination means which can change an incident light quantity and an incident direction according to the mounting state of the electronic component in the printed circuit board as a test object. A step of imaging a printed circuit board on which cream solder is printed and electronic components are mounted;
A boundary detection step for detecting a boundary between the land of the printed circuit board, the cream solder, and the electronic component based on the imaged image data;
Using the data output from the boundary detection unit, a position detection step of detecting the position of the cream solder and the position of the electronic component,
Using the data detected by the position detection unit, an extraction step of extracting the connection state between cream solders of adjacent electronic components and the connection length of the connected parts;
A mounting inspection method comprising: a determination step of determining whether or not the mounting state is good based on information including a connection state between the cream solders and a connection dimension of connected portions.   The mounting inspection method according to claim 6, wherein, in the determination step, the quality of the mounting state is determined by comparing with a preset allowable value.   The mounting inspection method according to claim 6 or 7, wherein the quality determination of the mounting state in the determination step is performed before the solder reflow operation.

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