JPH1086322A - Method and apparatus for inspecting cream solder print - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect various print failures by simply and effectively detecting a cream solder printing state with a memory having small capacity. SOLUTION: The method and apparatus for inspecting cream solder print inspect a cream solder print state printed on a circuit pattern of a circuit board 1. The method comprises a first binarizing step of binarizing an image of the board 1 to partition it into a circuit pattern and other portion, and a second binarizing step of binarizing the image to partition it into a circuit pattern and cream solder portion and the other portion, thereby judging defective or non-defective of printing the solder by utilizing the two binarizing steps. To fetch the image, a CCD camera 2 is adopted, and to judge the defective or non-defective of the print, it is executed by an image processor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection of a circuit board used in an electronic device, and more particularly, to a cream solder printing inspection method and apparatus for inspecting a printed state of a circuit board printed with cream solder. .

[0002]

2. Description of the Related Art In recent years, in electronic components such as ICs (hereinafter simply referred to as components), the number of leads and the density of lead arrangement have been remarkably increased, and the mounting position accuracy of an electronic component mounting apparatus using a robot function has been reduced. Severe demands are being made.

[0003] In view of such a background, the following devices have begun to be used for mounting surface mount components. That is, first, a positioning mark or a foot mark (a pattern of a portion to which a lead of a component is soldered) provided in advance on a circuit board such as a printed board, and a component held by a movable member of the robot by suction or the like Is read as image data. After that, based on these data, the position of the circuit board or its circuit pattern and the holding position of the component are corrected to ensure the required mounting positioning accuracy.

By the way, in such an electronic component mounting apparatus for surface mounting components, it is necessary to apply cream solder to a foot mark on a circuit board surface before mounting the component. For this reason, conventionally, in such an electronic component mounting apparatus, a cream solder printing apparatus is installed in a pre-process part.

If there is a deviation between the foot pattern of the circuit board and the printed position of the cream solder, or if the printed amount of the printed cream solder is too small or too small,
After the component mounting process is completed through the reflow process, it appears as defective soldering as a result. When a soldering failure occurs, a problem arises in that a large amount of time and labor is required for repairing the failure, and that the circuit board on which the components are mounted must be discarded.

For this reason, there has been proposed an apparatus for inspecting the printed state of cream solder on a circuit board after the cream solder printing process has been completed. For example, Japanese Patent Application Laid-Open No. Hei 4-279808
The device shown in (1) uses an XY table on which a printed circuit board is placed, and a CCD camera that images the printed circuit board from above, and automatically prints the printing state of cream solder printed on the printed circuit board using a phase shift method. And it inspects at high speed. In the apparatus disclosed in Japanese Patent Application Laid-Open No. 5-113410, the boundary between the solder portion and the printed circuit board portion other than the solder is traced by a line segment. By utilizing the rapid change in the direction change speed, a defect in the printing condition of the cream solder is detected.

In the apparatus disclosed in Japanese Patent Application Laid-Open No. 4-48248, a plurality of pixel data input lines are set for an image of a foot pattern on which cream solder is to be printed. A predetermined criterion level is set for the luminance of the pixel data by these pixel data receiving lines, and cream solder printing is performed based on whether or not a portion exceeding the criterion level appears in the captured pixel data. Is determined.

[0008] Further, although not a cream solder printing state inspection, there is known an inspection method for binarizing an image photographed by a camera in order to narrow an area to be soldered when inspecting a state where parts are soldered. (JP-A-62-123339). In this inspection method, a soldered portion hidden by a component is first removed by binarization. Thereafter, the remaining soldered portions are inspected for defective soldered portions.

[0009]

However, according to the technique disclosed in Japanese Patent Application Laid-Open No. Hei 4-279808, the volume and position of paste solder printed on a printed circuit board are determined from an input image, and ideal shape image information previously captured Is compared with the calculated value, the apparatus becomes large-sized, and is not suitable for simple determination. In addition, standard patterns for all combinations of various shapes and dimensions of printed solder are required, and the number of these standard patterns becomes enormous, requiring a large-capacity memory for storing the standard patterns and processing. There is a problem that large-scale hardware is required to increase the speed.

Further, according to the technique disclosed in Japanese Patent Application Laid-Open No. 5-113410, it is possible to detect whether or not an unnecessary protrusion or chip is present in the printed solder, but it is not possible to detect a printing shift. That is, as the printing failure, the "slight" in which the solder H is printed only on a part of the land L as shown in FIG. 5A, and the land L and the solder H as shown in FIG. 5A. "Slip", no solder H is printed on the land L as shown in FIG. 5C, "unsoldered", and "bridge" connecting the solder H printed on the land L as shown in FIG. 5D. And all of them need to be detected. On the other hand, the technique disclosed in Japanese Patent Laid-Open No. 5-113410 cannot detect the "shift" in FIG. 5B.

On the other hand, in the technique disclosed in Japanese Patent Application Laid-Open No. 4-48248, inspection such as "shift" and "blurring" can be performed. If the accuracy is to be improved, the number of pixel data take-in lines increases, which is equivalent to having standard image data. For this reason, the number of standard patterns becomes enormous in order to increase the accuracy, as in JP-A-4-279808, and a large-capacity memory for storing these is required. This would require extensive hardware.

Further, the technique disclosed in Japanese Patent Application Laid-Open No. 62-123339 is a method in which a captured image is binarized to narrow down the target, which is suitable for inspecting the soldering state of parts. ing. However, when inspecting the state of the cream solder printing, it is necessary to inspect all of "faint", "shift", "unsoldered", "bridge", etc. as shown in FIG. -12333
In the binarization technique shown in No. 9, it is not possible to inspect the printing failure of the cream solder.

An object of the present invention is to provide a cream solder printing inspection method and apparatus capable of easily detecting the state of cream solder printing with a small-capacity memory and detecting various printing defects. With the goal.

[0014]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a cream solder printing inspection method for inspecting a state of cream solder printed on a circuit pattern of a circuit board. A first binarization step of binarizing the image into a circuit pattern and other parts, and a two-step binarizing step to divide the image into a circuit pattern and a cream solder part and other parts. And a second binarizing step of binarizing the two.
The value determination process is used to determine the quality of the cream solder printing.

Further, according to the invention described in claim 2, according to claim 1,
In the cream solder printing inspection method described above, the first 2
In the digitizing step, when the area of the circuit pattern obtained by the binarization is equal to or larger than a predetermined area, it is determined that cream solder printing is defective. In addition, according to the third aspect of the present invention, in the cream solder printing inspection method according to the first or second aspect, in the second binarization step, the area of the circuit pattern stored in advance and
The circuit area obtained by the digitization is compared with the total area of the cream solder portion, and when the difference between the areas is equal to or more than a predetermined value, the cream solder printing is determined to be defective. Furthermore, according to the invention described in claim 4, according to claim 2,
Or in the cream solder printing inspection method according to 3 above,
The image of the circuit board is captured by a monochrome CCD camera, and the area is calculated using the binarized number of white pixels.

According to a fifth aspect of the present invention, there is provided a cream solder printing inspection apparatus for inspecting a state of cream solder printed on a circuit pattern of a circuit board, wherein an image of the circuit board on which the printed cream solder is mounted is provided. , And an image processing unit that binarizes one image captured by the camera unit at least twice, the image processing unit being used for a plurality of binarization processes, and Can be set to different thresholds for pass / fail judgment.

Further, in the invention according to claim 6, in the cream solder printing inspection apparatus according to claim 5, the image processing unit is configured to divide the image of the circuit board into a circuit pattern and other parts. A first threshold for valuation;
It has a second threshold for binarization for dividing the image into a circuit pattern and a cream solder portion, and other portions.

In addition, in the invention according to claim 7, in the cream solder printing inspection apparatus according to claim 6, in the binarization using the first threshold value, the area of the circuit pattern obtained by the binarization is determined. Is larger than a predetermined area, it is determined that the printing of the cream solder is defective. Furthermore, in the invention according to claim 8, in the cream solder printing inspection apparatus according to claim 6, the binarization by the second threshold value includes the area of the circuit pattern stored in advance and the binary value. The total area of the circuit pattern and the cream solder portion obtained by the conversion is compared, and if the difference between the areas is equal to or larger than a predetermined value, it is determined that the cream solder printing is defective. Further, in the ninth aspect of the present invention, in the cream solder printing inspection apparatus according to the seventh or eighth aspect, the camera section is a black-and-white CCD camera, and the area is calculated based on the number of white pixels having been binarized. ing.

This cream solder printing inspection method includes at least two binarization steps for binarizing an image on a circuit board. In the first binarization step, the circuit pattern is separated from other parts. At this time, if the entire circuit pattern is soldered, the area of the circuit pattern portion becomes zero. However, if there is "fading", "shift", "unsoldered" or the like in the printing, a circuit pattern portion is detected. As a result,
Defects such as "unsoldered" can be found. However, a "bridge" in which a solder bridge can be formed between circuit patterns and a "excessive solder" in which solder is excessive cannot be found.

On the other hand, in the second binarization step, the circuit pattern and the cream solder portion are separated from other portions. For this reason, when the solder is finely printed on the circuit pattern, the same area as the area of the circuit pattern stored in advance is calculated, and the circuit pattern is determined to be non-defective. But,
If "displacement", "bridge", "excessive solder" or the like has occurred, the area becomes larger than the area of the circuit pattern stored in advance, and is detected as a defect.

In the cream solder printing inspection apparatus, the image of the circuit board is captured by the camera unit, and the image processing unit binarizes the image. A plurality of thresholds for binarization processing are provided, and each threshold is used for pass / fail determination. The operations corresponding to the above-described first and second binarization steps are performed using the different threshold values. As a result, it is possible to detect many defects such as “faint”, “displacement”, “unsoldered”, “bridge”, and “excessive solder”, which are cream solder printing defects.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cream solder printing inspection apparatus according to the present invention will be described with reference to FIGS. The cream solder printing inspection method will be described together with the description of this apparatus.

This cream solder printing inspection apparatus is shown in FIG.
As shown in FIG. 1, a black-and-white CCD camera 2 serving as a camera unit for capturing an image of a circuit board 1 on which cream solder is printed, an image captured by the CCD camera 2 is binarized and printed. And an image processing unit 3 for determining whether the state is good or bad. This image processing unit 3
Calculates the number of one pixel that has been binarized into black and white from the image signal sent, in this embodiment, the number of white pixels, and outputs it. In addition, this cream solder printing inspection device,
It exchanges data with the image processing unit 3 and stores the data in a personal computer 4.
A monitor unit 5 for monitoring the digitized image is connected.

FIGS. 2 and 3 show a specific configuration of the cream solder printing inspection apparatus having such a system configuration.

In this cream solder printing inspection apparatus,
A conveyor means 11 composed of a belt conveyor for conveying the circuit board 1 is arranged at the center of the apparatus main body, and the circuit board 1 transferred from a conveyor (not shown) arranged on the right side of FIG. It is moved to a conveyor (not shown) to be arranged. Above the vicinity of the center of the conveying means 11, CC
The D camera 2 is movably arranged by the XY robot 12.

The image processing section 3 is incorporated in a lower portion 13 of the apparatus main body below the conveying means 11. The personal computer 4 and the monitor unit 5 are arranged above the apparatus main body. further,
A tower lamp 14 indicating the operation status is provided adjacent to the monitor unit 5, and a control unit 15 in which a control key and the like are arranged is mounted on the lower part 13 of the apparatus main body. Further, drawers 16, 16 for holding tools and the like are provided in the lower portion 13 of the apparatus main body.
Is provided.

As a circuit board which can be inspected by this apparatus,
The size is from 50 × 50 mm to 400 × 500 mm, and the thickness is 0.5 to 2 mm. These values can be changed as appropriate by changing the specifications of the device.

The CCD camera 2 recognizes the difference in the reflectance of the circuit board 1 and is a monochrome camera.
It may be a color camera. However, C for color
When a CD camera is used, it is necessary to extract a specific color from the image of the camera by a color select unit or the like and send it to the image processing unit 3 as a monochrome signal. In the case of a memory having the same capacity, a black-and-white camera can take a larger number of pixels than a color memory. Therefore, a black-and-white camera is preferable in consideration of only cream solder printing inspection. The size of the CCD is 19 mm square, and the number of pixels of the CCD camera 2 is 512 × 480 pixels.

The image processing unit 3 performs a black and white binarization process on the image input by the CCD camera 2 and calculates the number of pixels in a white portion. Four values can be set as threshold values for the binarization. Further, 256 grayscale levels are possible as black and white grayscale levels. Also, one within one screen
6 windows W can be set, while 16 screens are possible as the number of screens.
Inspection at a total of 256 (16 × 16) points is possible. However, the number of screens can be increased by controlling the personal computer 4.

Here, the image processing speed from image capture to binarization processing is extremely high, about 0.08 seconds per screen. On the other hand, the mechanical measurement time is about 0.5 seconds for one screen, and the measurement time for about 40 screens is about 20 seconds.

The image processing unit 3 also determines whether or not the printing condition of the cream solder is good. For this reason, the image processing unit 3
Stores the area (= number of pixels) of the circuit pattern on which the cream solder is printed. At this time, the inspection points are manually instructed to this apparatus, and the number of pixels of the circuit pattern at each inspection point is stored. Further, the image processing unit 3 sets standard values (upper and lower limits) for making a pass / fail judgment, performs an operation for making the judgment, and makes a judgment on the standard value. Further, the position of the inspection point can be corrected by software.

Various data generated by the image processing unit 3 are sent to the personal computer 4. On the other hand, control data for causing the image processing unit 3 to perform various operations is sent from the personal computer 4. The data sent to the personal computer 4 and the result processed by the personal computer 4 are stored in a hard disk in the personal computer 4 or a floppy disk or a memory card via the personal computer 4.

Next, the operation of the cream solder print inspection apparatus and the cream solder print inspection method using this apparatus will be described. Note that this description will be made with reference to the flowchart of FIG. 4 and various printing states of FIG.

First, the circuit board 1 on which cream solder is printed on a circuit pattern of copper foil is transferred to the transport means 11 by an adjacent conveyor. The transport means 11 on which the circuit board 1 is placed is moved when the circuit board 1 is substantially at the center.
Stop once. Then, the pins for positioning and mounting rise from below the circuit board 1 and hold the circuit board 1. Thereafter or simultaneously, the CCD camera 2 is driven in the XY directions by the XY robot 12, and captures a predetermined image (step S1 in FIG. 4). 1

The image processing section 3 cuts the captured image at the set window W, and binarizes the window W in a first binarization step (step S2).
Then, the number of white pixels in the window W is calculated (step S3). The black and white binarization level, that is, the threshold value, can be set for each window W, and the binarization level can be set in four stages.

In the first binarization step, a binarization process is performed in which the circuit pattern is white and the ground portion of the cream solder or the circuit board 1 is black. Specifically, of the 256 gradations, a portion from the 136th gradation to the 256th gradation is set to white, and a color below the 135th gradation is set to black. For this reason, FIG.
In the case of a perfect non-defective product, the number of white pixels is zero. However, a value that passes as a non-defective product is a value of 0 or more, for example, less than 50 pixels in this embodiment. It is preferable that the pass line be represented by the absolute value of the number of pixels rather than the original ratio of the copper foil to the area of the circuit pattern from the viewpoint of reducing component adhesion failure.

The image processing section 3 detects whether or not the number of white pixels is larger than a passing criterion (step S4). If the number of pixels is equal to or more than 50 pixels, it is rejected and removed from the line by a robot (not shown) or manually. This allows
Failures such as “faint” shown in FIG. 5A, “displacement” shown in FIG. 5B, and “unsoldered” shown in FIG. 5C are detected, and the circuit board 1 having such a failure is detected. Will be removed. In the first binarization step, FIG.
The “bridge” shown in (D) indicates that the number of white pixels is 0 or 0.
And it is considered a good product.

On the other hand, if it is less than 50 pixels, step S
Proceeding to 5, the image in the window W is binarized at another binarization level by the second binarization step. This second
In the binarization process, the circuit pattern of the copper foil and the cream solder portion are white, and the ground portion of the circuit board 1 is black.
Perform a value conversion process. Specifically, the 100th out of 256 gradations
The portion from the gradation to the 256th gradation is white, and the color below the 99th gradation is black. Then, the number of white pixels is calculated (step S6). Here, in the case of a perfect non-defective product shown in FIG. 5E, the number of white pixels is equal to the number of pixels in the copper foil circuit pattern. Therefore, the number obtained by subtracting the number of pixels in the circuit pattern stored in advance from the obtained number of pixels is 0. However, the values that pass as good products are
Each of plus and minus is less than 50 pixels.

The image processing section 3 detects whether or not the difference in the number of white pixels is larger than the acceptance criterion (step S7). And
If the difference is not less than 50 pixels, it is rejected and removed from the line by a robot (not shown) or manually.
As a result, in FIG.
The "bridge" shown in (D) is detected as a defective product and removed. In addition to the “bridge”, “excessive solder” or the like with too much solder is also detected.

In one window W, binarization processing having different levels is performed twice, and after the inspection, if the binarization processing is passed, the same inspection is performed in the next setting window W. Therefore, the image processing unit 3 determines in step S8 whether or not another window W has been set, and if there is a setting, in step S9, the setting binarization level for the window W is set in the other setting window W. Performs binarization processing. And
Returning to step 3, the same operation is repeated. When the same cream solder is printed on the same copper foil circuit pattern, the binarization levels (= thresholds) are set to the same value.

If another window W has not been set, it is checked whether or not another image W has been set (step S10). If there is a setting, step S1
And the same operation is repeated again from the image capturing.
When the setting for taking in another image has not been made, the circuit board 1 is returned to the transporting means 11 and is transported to an adjacent conveyor (not shown) by the transporting means 11 to execute the next surface mounting step.

On the other hand, the image processing section 3 determines whether or not the next circuit board 1 is held on the pins for positioning and placing (step S11). Then, when the next circuit board 1 is prepared, the process returns to step S1 to capture an image. If there is no next circuit board 1, the image processing unit 3 ends its operation and processing.

The image processing performed by the image processing unit 3 is as follows.
It can be monitored by the monitor 5. Further, the data captured by the image processing unit 3, the result of the arithmetic processing, the result of the pass / fail judgment, and the like are captured by the personal computer 4 into the personal computer 4. Then, the data and the processed data are stored in a hard disk in the personal computer 4, an inserted floppy disk, or the like.

It should be noted that, depending on the circuit board 1, the cream solder portion may appear white in the first binarization step, and may be rejected although it is a non-defective product. In such a case, it is possible to perform processing for removing a portion where such an abnormality occurs from the window W in advance. Further, in this embodiment, the binarization level can be set to four levels, but other levels other than the two levels described above may be such that solder plating is recognized as white, The level at which a circuit pattern portion formed of a material other than the foil is recognized as white can be set.

In this embodiment, since the image is captured using the CCD camera 2, it is possible to set a window W in the image and detect the pixels in the window W. Therefore, even for the large circuit board 1, only the points to be inspected can be inspected efficiently. Moreover, since the binarization level can be set for each window W, the efficiency and inspection accuracy are further improved.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. is there. For example, the binarization level may be set not in four stages but in two stages or in other stages. That is, if there are two or more stages, various stages can be appropriately adopted. Also,
The number of times of the binarization processing within the same window W may be three or more, instead of two. Furthermore, although the number of white pixels in the binarization is calculated, the number of black pixels in the remaining portion may be calculated, or the level may be inverted to calculate the number of black pixels.

In the setting of the binarization level, it is also possible to set the intermediate gray scale to white or black and to set the gray scales on both sides other than the middle black or white. Further, when an image is captured by a CCD camera, the image may be captured while the circuit board 1 is transported without being temporarily stopped. Also, CCD
When a color camera is used as the camera 2, the same camera may be used to inspect the component mounting state and the soldering state, in addition to the inspection of the cream solder printing state. In addition, other image capturing means such as a line sensor may be used instead of the CCD camera 2.

[0048]

As described above, in the cream solder printing inspection method according to the first aspect, the captured image is binarized at least twice at different binarization levels (thresholds). Moreover, in the first binarization step, the circuit pattern is binarized so as to be separated from the other parts, and in the second binarization step, the circuit pattern and the cream solder part are binarized so as to be separated from the other parts. Valued. For this reason, cream solder printing "faint", "shift", "not solder",
Almost all defects such as "bridge" can be easily detected.

According to the second and seventh aspects of the present invention,
When a circuit pattern having a predetermined area or more is detected, it is determined that printing is defective, so that the defective rate when components are mounted can be significantly reduced.

Further, according to the third and eighth aspects of the present invention, when the difference from the original area is equal to or larger than the predetermined area difference, it is determined that a failure occurs, so that the failure rate when a component is mounted can be reduced. In addition, when combined with the invention of claim 2, it is possible to significantly reduce the defect rate after mounting components.

In addition, in the inventions according to the fourth and ninth aspects, since a monochrome CCD camera is used, the memory for image processing can be reduced. Therefore, the processing circuit can be simplified.

Further, in the cream solder printing inspection apparatus according to the fifth aspect, at least one captured image is
Is binarized twice. In addition, since the threshold value for each binarization process is used for judging pass / fail, it is possible to reliably and efficiently inspect cream solder printing with a simple mechanism.

Further, in the invention according to claim 6, the first threshold value is binarized so as to separate the circuit pattern from other portions, and the second threshold value is a circuit pattern and a cream solder portion. Is binarized so as to be distinguished from other parts. For this reason, "smear" of cream solder printing,
Almost all defects, such as "displacement", "unsoldered", and "bridge" can be easily detected.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a system of a cream solder print inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a front view of a cream solder print inspection apparatus that embodies the system of FIG. 1;

FIG. 3 is a right side view of FIG. 2;

FIG. 4 is a flowchart of image processing in the image processing unit shown in FIG. 1;

FIGS. 5A and 5B are diagrams showing various defective states of cream solder printing, in which FIG. 5A shows “blurring”, FIG.
(C) “Unsoldered”, (D) “Bridge”,
(E) shows good products.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit board 2 CCD camera (camera part) 3 Image processing part 4 Personal computer 5 Monitor part 11 Transport means 12 XY robot 13 Lower part of apparatus main body

Claims (9)

[Claims] 1. A cream solder printing inspection method for inspecting the state of cream solder printed on a circuit pattern of a circuit board, wherein the image of the circuit board is divided into the circuit pattern and other parts. First to value
And a second binarizing step of binarizing the image in order to divide the image into the circuit pattern and the cream solder portion and other portions. A cream solder printing inspection method, characterized in that the quality of the cream solder printing is determined by using a value process. 2. In the first binarization step,
2. The cream solder printing inspection method according to claim 1, wherein when the area of the circuit pattern obtained by the quantification is equal to or larger than a predetermined area, the cream solder printing is determined to be defective. 3. In the second binarization step, the area of the circuit pattern stored in advance is compared with the total area of the circuit pattern and the cream solder portion obtained by the binarization. 3. The cream solder printing inspection method according to claim 1, wherein when the difference between the areas is equal to or greater than a predetermined value, the printing of the cream solder is determined to be defective. 4. The image processing apparatus according to claim 2, wherein the image of the circuit board is captured by a monochrome CCD camera, and the area is calculated by the number of binarized white pixels.
Inspection method for cream solder printing as described. 5. A cream solder printing inspection device for inspecting a state of cream solder printed on a circuit pattern of a circuit board, a camera section for capturing an image of the circuit board on which the printed cream solder is placed, At least two images captured by this camera unit
An image processing unit for performing the binarization process twice, wherein the image processing unit can set different threshold values for performing the binarization process a plurality of times and for each of the pass / fail determination. Characteristic cream solder printing inspection device. 6. The image processing unit, wherein a first threshold value for binarization for dividing an image of the circuit board into the circuit pattern and other parts, and the image, 6. The cream solder printing inspection apparatus according to claim 5, further comprising a second threshold for binarization for dividing the circuit pattern and the cream solder portion from the other portions. . 7. In the binarization based on the first threshold value, when the area of the circuit pattern obtained by the binarization is equal to or larger than a predetermined area, it is determined that cream solder printing is defective. The cream solder printing inspection device according to claim 6, wherein: 8. The binarization based on the second threshold value, the area of the circuit pattern stored in advance, and the total area of the circuit pattern and the cream solder portion obtained by the binarization. 8. The cream solder print inspection device according to claim 6, wherein the cream solder printing is determined to be defective if the difference between the areas is equal to or greater than a predetermined value. 9. The cream solder printing inspection according to claim 7, wherein the camera section is a monochrome CCD camera, and the area is calculated by the binarized number of white pixels. apparatus.