JPH0815171A - Method and apparatus for inspection soldering - Google Patents

Abstract

PURPOSE:To accurately discriminate the propriety of soldering to the peripheral edge of a soldered part due to the difference of its drape only by inspection information from an imaging camera. CONSTITUTION:A bright-to-dark change point corresponding to the peripheral edge 1c of the soldered part of a soldered object 1 is detected from imaged data imaged at the bright-to-dark change of the soldered part 3 between the conductor part 7 of a base material and the edge 1c of the soldered object 1 in contact with the part 7, and the propriety of the soldering is decided according to the detected result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering inspection method and an apparatus therefor, for example, a conductor land provided on the electronic circuit board with leads of electronic parts for so-called surface mounting on an electronic circuit board as a soldering base material. When soldering the tip peripheral edge of this to the conductor land, the quality of the soldering is inspected by checking whether there is solder on the conductor land and it is well fitted to the tip peripheral edge of the lead. Used for.

[0002]

2. Description of the Related Art Referring to a soldering inspection apparatus to which the present invention shown in FIGS. 1 to 3 is applied, a soldering inspection of an electronic circuit board 2 having a surface mounted electronic component 1 as shown in FIG. 1 is performed. However, the use of the imaging camera 5 has been conventionally performed. The soldering portion 3 of the electronic component 1 mounted on the electronic circuit board 2 as an inspection target as shown in FIGS. 2 and 3 is illuminated by the light projector 4. Parallel light 8 is used for this illumination.

In the soldering portion 3, the tip portion 1b of the lead 1a of the electronic component 1 is applied onto the conductor land 7 provided on the portion of the electronic circuit board 2 where the resist 10 is not present, and the tip portion 1b is soldered. The peripheral edge 1c is soldered to the conductor land 7 with the solder 3a. The imaging camera 5 is aimed at the soldering portion 3 and the soldered portion 3 in the illuminated state is imaged. The image pickup data from the image pickup camera 5 is input to the data processing device 6, and a solder defect is determined by a predetermined data process.

2 and 3 show a lead 1 as an object to be soldered in the soldering portion 3 in which the solder 3a is familiar.
The relationship between the shape of the tip portion 1b of a and the cross-sectional shape and the front shape of the solder 3a is shown. In the figure, the reflected light 9 from the solder 3a is such that the solder 3a is sufficiently familiar to the upper end height position of the soldering portion peripheral edge 1c of the tip end portion 1b of the lead 1a, and the surface of the conductor land 7 turns from this height position to the circumference. Corresponding to the inclination at a certain angle so that
As shown by the broken line in the figure, it is directed obliquely outward and upward. Therefore, the amount of incident light from the solder 3a to the imaging camera 5 per unit area is smaller than that from the horizontal plane. Lead 1
Since the reflected light 9 from the horizontal surface formed by a and the conductor land 7 goes directly upward, the amount of incident light per unit area from the surface of the lead 1a and the conductor land 7 to the imaging camera 5 is from the solder 3a. More than that.

FIGS. 4 to 6 show the luminance distribution state when the image is taken when the familiarity of the solder 3a is good as in the case of FIGS. 2 and 3, and the sectional shape and the front shape of the solder 3a. The relationship is shown. In the luminance distribution state of FIG. 4, the corresponding portions of the solder 3a have low luminance, whereas the corresponding portions of the leads 1a and the conductor lands 7 have high luminance.

FIG. 7 to FIG. 9 show the luminance distribution state when an image is picked up in the case of poor soldering in which no soldering is performed,
The relationship between the sectional shape and the front shape of the solder 3a is shown.

Although the solder 3a is well-known in FIGS. 10 to 12, the solder 3a continues around the periphery 1c of the soldering portion of the tip 1b of the lead 1a in a horizontal state flush with the upper surface of the tip 1b. The relationship between the brightness distribution state when an image is captured and the cross-sectional shape and the front shape of the solder 3a when there is a region to be filled is shown.

FIGS. 13 to 15 show the brightness distribution imaged when the solder 3a is not completely fitted to the soldering portion peripheral edge 1c of the tip 1b of the lead 1a, and when the fitting is poor, the sectional shape and the front shape of the solder 3a. Shows the relationship with.

By the way, in the conventional data processing for soldering inspection, noise is removed by binarizing the electric signal corresponding to each pixel taken in the image pickup camera 5 to remove noise. From the imaged data corresponding to each pixel in the three inspection areas 11, 12 and 13 as shown in FIG. 13, respectively, the number of pixels having a certain brightness level or higher in each of the inspection areas 11 to 13 (high brightness area) Also, the quality of soldering is determined by the number of pixels (low brightness area) below a certain brightness level.

For example, depending on the image data of each pixel in the inspection area 11, the majority of the pixels are below a certain level as shown in FIG. 4, and it is determined that the solder familiarity is good. As shown in FIG. 4, the imaging data of the pixels in the regions 12 and 13 indicates that the number of pixels equal to or higher than a certain luminance level and the number of pixels equal to or less than the certain luminance level are substantially equal to each other, or are equal to each other. It is also determined to be good on the basis of the condition that there is a pixel having a luminance level equal to or above.

Therefore, in the inspection state shown in FIGS. 7 to 9, unlike the cases of FIGS. 4 to 6, since the inspection area 11 includes only pixels having a certain luminance level or higher, it can be determined that the solder familiarity is defective. However, even in the inspection areas 12 and 13, only pixels having a certain luminance level or higher can be determined to be defective.

However, in the inspection state shown in FIGS. 10 to 12, the solder 3a is slightly raised and the solder familiarity is better than in the case of the non-defective product shown in FIGS. If all the pixels have a certain luminance level or higher, it is determined that the solder familiarity is poor. This means that the number of pixels above a certain luminance level and the number of pixels below a certain luminance level in the other inspection areas 12 and 13 are substantially the same as in the good cases shown in FIGS. , Or that there are pixels with a certain brightness level or higher,
There is a problem if the inspection result in the inspection area 11 is overturned and the judgment is made good only by the normal condition.

For example, in the unfamiliarity of soldering, FIG.
As shown in FIGS. 3 to 15, there are relatively many soldering failures in which the height of the solder 3a to the tip edge 1c of the soldering portion is not sufficient. In order to discriminate this, in the inspection areas 12 and 13, the number of pixels above a certain luminance level and the number of pixels below a certain luminance level are substantially equal to each other, or above a certain luminance level, as in the good case of FIG. Even if the normal condition is satisfied, the inspection area 11 has a constant brightness level as compared with a pixel having a constant brightness level or less due to a thin shadow portion along the tip of the lead 1a. Since the above-mentioned number of pixels is overwhelmingly large, it is determined to be defective.

Therefore, when the inspection state shown in FIGS. 10 to 12 is obtained, it cannot be judged as a non-defective product in distinction from the cases shown in FIGS. 13 to 15.

Therefore, conventionally, by installing a three-dimensional height measuring device separately from the image pickup camera 5 and measuring the height H of the solder 3a, the good condition shown in FIGS. 10 to 12 and the condition shown in FIGS.
5 is determined as a defective state.

[0016]

However, as in the prior art, if the number of pixels above or below a certain luminance level in a specific inspection region is used, it is possible to judge whether the soldering is good or bad depending on the familiarity of the solder. However, the inspection accuracy is low, and a three-dimensional measuring instrument is required to obtain sufficient inspection accuracy, which is expensive. Moreover, the operation of the data processing circuit connected to the imaging camera 5 and the operation of the three-dimensional measuring device are required, which is troublesome. In addition, since the shape of the soldering part that is familiar to the solder is various depending on the relationship between the shape of the periphery of the soldering part and the position where the soldering is performed, it is necessary to judge whether the soldering is good or bad. Skill and know-how are required to set the inspection area and the judgment conditions in each, and the setting work is not easy and takes a long time.

As a result of various experiments and studies conducted by the inventors of the present invention with respect to imaging data in the case of poor soldering, the results shown in FIG.
In the case of poor soldering in which the solder is not sufficiently familiar with the soldering part periphery as in the case of FIG. 15, a bright / dark change point in the luminance distribution corresponding to the soldering part periphery can be formed between the soldering part periphery and the solder. I thought about paying attention to.

An object of the present invention is to solve the conventional problem on the basis of such an attention, and it is possible to accurately judge the quality by the difference in the familiarity of the solder to the periphery of the soldering portion only by the inspection information from the image pickup means. The main object of the present invention is to provide a soldering inspection method and an apparatus for the same.

[0019]

In order to achieve the above-mentioned object, the soldering inspection method according to the present invention is designed to provide a space between the conductor portion of the base material and the periphery of the soldering object applied to the conductor portion. The main feature is to detect a bright-dark change point corresponding to the peripheral shape of the soldering portion of the object to be soldered from imaging data obtained by imaging the soldering portion, and determine the quality of soldering based on the detection result.

In this case, the direction of the solder flow direction is determined from the imaged data, the soldering failure candidate is determined based on the direction of the solder flow direction, and only the soldering portion of the soldering failure candidate is described in claim 1. It is preferable to judge whether the soldering is good or bad.

In order to achieve the above-mentioned object, the soldering inspection apparatus of the present invention straddles in the width direction on the soldering failure determination line corresponding to the peripheral shape of the soldering portion of the soldering object, and extends in the length direction. Image pickup data for a defect inspection area having a predetermined length along the line, image pickup means for giving image pickup data for a defect candidate detection area corresponding to the solder flow range, and storage means for storing each image pickup data from the image pickup means And a determination unit that determines the direction of the solder flow direction from the imaged data corresponding to the defect candidate detection area stored in the storage unit, and determines the soldering defect candidate by the direction of the solder flow direction, With respect to only the soldering portion of the soldering failure candidate, a bright / dark change point corresponding to the soldering failure determination line is detected from the imaged data corresponding to the inspection area, and the soldering is detected from the detection result. And further comprising a judging means for judging whether.

[0022]

In the above-mentioned structure which is the main feature of the soldering inspection method of the present invention, from the imaging data obtained by imaging the soldering portion between the conductor portion of the base material and the periphery of the soldering object applied to it, The bright and dark change points corresponding to the peripheral shape of the soldering part of the object to be soldered are detected. This is based on the image data of the soldering part and the conductor of the base material and the soldering part applied to it. The bright and dark change points in the luminance distribution corresponding to the soldering state with the peripheral edge of the object to be soldered are not sufficiently familiar with the peripheral edge of the soldered object It is coded that the soldering peripheral edge shape is presented according to the shape of the soldering peripheral edge, and that the soldering edge peripheral shape is not present when the familiar height of the solder is sufficient. Detection of light-dark change points corresponding to Since determining the quality of soldering by result, it is possible to determine soldering acceptability by solder familiar state to the soldering portion periphery, the only accurate information from the imaging means.

By the way, if there is a flow direction in the solder around the periphery of the soldering portion of the object to be soldered and the soldering is good due to the familiarity of the solder with the periphery of the soldering portion, this is not always the case, but it is a defect. If there is a certain direction, there is always a direction, and the solder flow direction can be grasped in the image data as a state in which pixels with almost the same brightness line up in the direction corresponding to the peaks of the solder peaks. Judge the direction of the solder flow direction from the direction of the line-up direction,
When a soldering defect candidate is determined by the direction of the solder flow direction, it is possible to first roughly detect a soldering defect candidate having a high probability of soldering defect from a large number of soldering parts. By determining the quality of soldering only for the candidates,
It is possible to reduce the waste of determining whether the soldering is good or bad for all the soldering portions.

In the above-mentioned structure of the soldering inspection apparatus of the present invention, the image pickup means extends over the width of the soldering defect determination line corresponding to the peripheral shape of the soldering portion of the object to be soldered in the width direction and has a predetermined length along the length direction. Image data for the inspection area and the image data for the defect candidate detection area corresponding to the solder flow range, and solder the image data for each of the limited defect candidate detection area and the defect inspection area. Arrangement of pixels with almost the same brightness corresponding to the direction of the solder flow direction caused by the direction of the solder flow direction with a high probability of failure, and the familiarity of the solder to the periphery of the soldering part of the soldering object Each of the bright and dark change points corresponding to the peripheral shape of the soldering part, which is caused by the lack of the, is surely reflected, and this is passed through the storage state in the storage means. By providing the defect candidate soldering part by another means and the defect determining operation for the defect candidate soldering part by the determining means, only the defect candidate soldering part having a high probability of the defect detected in advance is acceptable or not. It is possible to achieve a highly efficient and highly accurate inspection for making the above determination from the limited imaging data more efficiently.

[0025]

EXAMPLES The soldering inspection method and apparatus according to the present invention will be specifically described below with reference to some examples.

FIG. 1 shows a soldering inspection apparatus as a first embodiment of the present invention. The apparatus according to the present embodiment includes a conductor land 7 which is a conductor portion of the electronic circuit board 2 which is a base material, and a tip portion which is a soldering portion of the lead 1a of the electronic component 1 which is a soldering target and is applied to the conductor land 7. From the imaging data of the soldering portion 3 between the soldering portion peripheral edge 1c of 1b,
An inspection method is adopted in which the presence or absence of the arrangement state of the bright and dark change points corresponding to the shape of the soldering portion peripheral edge 1c is detected, and the quality of the soldering is determined based on the detection result.

FIGS. 16 and 19 show such an inspection method.
In the case where the image pickup camera 5 has sufficient solder familiarity as shown in FIG. 10 and good soldering, and as shown in FIG. 13 which has insufficient solder familiarity and poor soldering, each soldering portion FIG. 17 and FIG. 18 show the luminance distribution state when the image of No. 3 is picked up, and FIG. 17 and FIG. The relationship is shown in FIG.
1 is a soldering portion 3 corresponding to the defective soldering state of FIG.
The relationship between the cross-sectional shape and the front shape of the soldering part peripheral edge 1c and the solder 3a is shown.

Comparing the case of good soldering shown in FIGS. 16 to 18 with the case of bad soldering shown in FIGS. 19 to 21, the good soldering shown in FIGS. The familiar height of the solder 3a with respect to the soldering portion peripheral edge 1c is not sufficient, so that a step S is formed between the soldering portion peripheral edge 1c and the solder 3a, and the soldering portion peripheral edge is illuminated by the illumination at the time of imaging. A shadow is formed along 1c, and an array L is formed along the shape of the soldering portion peripheral edge 1c at a bright / dark change point in the luminance distribution shown in FIG. 19 corresponding to the soldering state obtained from the imaging data. However, in FIG.
~ In the good soldering state shown in FIG.
Since the familiar height of the solder 3a with respect to c is proper and the step S is not formed between the two, the line L along the shape of the soldering part peripheral edge 1c cannot be formed at the light / dark change point in the luminance distribution shown in FIG. .

In the above inspection method, the conductor lands 7 of the electronic circuit board 2 and the tips 1b of the leads 1a applied to the conductor lands 7 are used.
Of the soldering part 3 between the soldering part 1c and the soldering part 1c, the bright and dark change point corresponding to the shape of the soldering part 1c is detected, specifically, The presence / absence of the arrangement state L of the light-dark change points is detected. This is done only in the case of poor soldering in which the familiar height of the solder 3a to the soldering portion peripheral edge 1c is not sufficient and a step S is formed as described above. Arrangement state L according to the shape of the attachment portion peripheral edge 1c
And that when the familiar height of the solder 3a is appropriate and there is no step S, the alignment state L does not exist, and whether the soldering is good or bad depends on the presence or absence of the alignment state L of the light-dark change point. Since the judgment is made, the quality of soldering due to the familiar height of the solder to the periphery of the soldering part can be judged with high accuracy only by the information from the imaging camera, and the three-dimensional measuring device is not necessary. Combined with the processing device 6,
It is possible to save the labor and time required to operate the three-dimensional measuring device.

Such a determination can be achieved without being limited to the case where the soldering portion peripheral edge 1c is a straight line, and when soldering is performed at several points on the soldering portion peripheral edge 1c, each of these soldering portions 3 By making the same determination for each, it can be applied to various soldering inspections.

As shown in FIG. 22, the data processing device 6 of the present embodiment solders the image pickup camera 5 to the soldering portion 3 of the soldering target which is the electronic component 1 surface-mounted on the electronic circuit board 2. In order to detect the presence or absence of the arrangement state L of the light-dark change points corresponding to the shape of the peripheral edge 1c, the soldering failure determination line 1 set so as to follow the arrangement state L extends over the width B direction. A storage unit 22 for storing image pickup data from the image pickup camera 5 which is the image pickup unit, and an image pickup unit that can give image pickup data for the defect inspection area 21 (FIG. 16) having a predetermined length Le along the direction. Computation means 23 for computing the presence / absence of the arrangement state L of the light / dark change points corresponding to the soldering failure determination line from the imaged data corresponding to the defect inspection area 21 stored in FIG.
And a judging means 24 for judging whether the soldering is good or not based on the presence or absence of the alignment state L detected by the computing means 23. The defect inspection area 21 can be appropriately set by the inspection area setting means 25, and this setting is made. Defect inspection area 21
Or only the image data corresponding to the defect inspection area 21 out of the image data in the entire image pickup area of the image pickup camera 5 is picked up. Input to the storage means 22. Alternatively, after inputting the image data in the entire image pickup area of the image pickup camera 5 into the storage means 22, the image data corresponding to the defect inspection area 21 is extracted and the calculation means 23 is extracted.
You can also type in.

In the configuration of the image data processing device 6 as described above, the image pickup camera 5 allows the soldering failure determination line 1 corresponding to the shape of the soldering portion peripheral edge 1c of the electronic component 1 which is the soldering target to be in the width B direction. The imaging data for the defect inspection area 21 of a predetermined length Le along the lengthwise direction is provided, and the imaging data in the limited defect inspection area 21 is given as
It is possible to reliably reflect the arrangement state L of the light-dark change points corresponding to the shape of the soldering portion peripheral edge 1c, which is caused by the lack of the familiar height of the solder 3a to the soldering portion peripheral edge 1c. It is possible to judge the quality of soldering from the presence or absence of the arrangement state L of the light-dark change points corresponding to the soldering failure judgment line 1 by simply processing the data in the storage means 22, the calculation means 23 and the judgment means 24. Therefore, the quality of soldering can be inspected efficiently and highly accurately from a small amount of image data.

In the defect inspection area 21, for example, the presence or absence of the alignment state L is detected from the imaged data by calculation,
In accordance with the luminance distribution state in the good soldering state of FIG. 23 and the bad soldering state of FIG. 24, the required number of the inspection lines 21a in the width B direction are set in the length Le direction as shown by the broken line. . In this case, the inspection width 21a1 of each inspection line 21a shown in FIG. 25A and the corresponding brightness distribution projection processing width 21a2 can be set appropriately. This is convenient because it is possible to deal with different types of inspection targets and types of inspection. 21a3 is each inspection line 2
The inspection length in 1a is shown.

The brightness level detected per pixel of each inspection line 21a is indicated by, for example, a shown in FIG.
1 to a9, projection values A to C are obtained from these as A = a1 + a2 + a3 B = a4 + a5 + a6 C = a7 + a8 + a9.

That is, the light / dark change point of the imaged data is determined as to whether or not the difference in the brightness level of each pixel on each inspection line 21a is equal to or greater than a predetermined value, and is detected as a boundary portion at which this determination is reversed. You can However, in the pixel unit, since the shape of the solder 3a is indefinite, there are minute light and dark change points in the solder 3a, and therefore there is a possibility of identifying other than the light and dark change points that are originally desired.

Therefore, as shown in FIGS. 24 (a) and 24 (b), by performing a projection process in which pixels are added in the inspection width 21a1 direction of the inspection line 21, it is possible to remove minute light-dark change points, Arrangement state L along the shape of the soldering portion peripheral edge 1c
Can be accurately detected. As a result, in the imaging data A to C shown in FIG. 24B, the inspection length 21a3
When the difference between the image pickup data A and B in the direction and the difference between B and C exceed a predetermined value, it can be detected as a light-dark change point X shown in FIG. 27 corresponding to a defective soldering state, and exceeds the predetermined value. If not, the bright-dark change point X is not detected as shown in FIG. 26 corresponding to the good soldering state. In addition, the defective soldering state shown in FIG. 27 corresponds to FIGS. 19 and 24, and the arrangement state L of the light-dark change points X is formed. This is not the case in FIG. Therefore, in FIG.
It is possible to determine that there is a soldering failure due to unfamiliar soldering in the cases of FIG. 9, FIG. 24, and FIG. 27, and these image data processings can be performed by the calculation processing of the calculation means 23 and the judgment operation of the judgment means 24.

These arithmetic processing and determination operation can be easily performed by utilizing the internal function of the microcomputer.

There is unevenness on the surface of the solder 3a of the soldering section 3, and the brightness distribution when the image is taken includes the low brightness section 31 corresponding to the unevenness as shown in FIG. 28. It is mixed with the arrangement state L of light-dark change points corresponding to the shape of the peripheral edge 1c.

Therefore, when the light-dark change point X is calculated by the arithmetic processing based on the imaged data at this time, as shown in FIG. 29, in addition to the light-dark change point X along the alignment state L, the low-luminance portion 31 due to the unevenness is formed. The corresponding light / dark change point X1 is also detected.

Therefore, it is impossible to properly detect the light-dark change point X1 as noise with respect to the necessary light-dark change point X1 by only the above-described arithmetic processing for detecting the light-dark change point.

Therefore, in such a case, as shown in FIG. 30, the detected light / dark change points X and X1 are coordinated corresponding to the position of the detected pixel in the inspection line direction 21a2, and the horizontal axis is the detected number. The vertical axis represents the histogram, and the presence or absence of the alignment state L is determined based on the number of light-dark change points at the position corresponding to the soldering failure determination line 1.

FIGS. 31 to 36 show a second embodiment of the present invention. When performing the soldering inspection as in the first embodiment, a specific example corresponding to the flow direction of the solder 3a of the image data is carried out. A high-luminance pixel in a certain level range (which can be made into a low-luminance pixel in a certain level range by lighting, data processing, or the like) obtained as a state is indicated by an arrow 41 in FIGS. 31 and 34.
The direction of the flow direction of the solder 3a is determined depending on which direction the continuous direction is, and the soldering failure candidate of the soldering portion 3 is determined based on the direction of the flow direction of the solder. The quality of soldering as in the first embodiment is determined only for the soldering portion 3 which is a soldering failure candidate.

On the solder 3a around the periphery 1c of the soldering portion of the lead of the electronic component to be soldered, the arrow 4
There is a flow direction as shown by 1, and the soldering part peripheral edge 1
The present inventors have also found that when soldering is good due to the familiar height of the solder 3a with respect to c, this is not always the case, but in the case of poor soldering, there is always such an orientation as shown in FIG. are doing.

Since the flow direction of the solder 3a corresponds to the peak portion of the solder 3a, the high-brightness pixel 42 on the image data.
Can be regarded as the arrangement state HL of the solder 3a.
The direction of the flow direction 41 of the
When the soldering failure candidate of the soldering portion 3 is determined by calculation depending on the direction of the flow direction 41 of a, the soldering failure candidate having a high probability of soldering failure is first roughly detected from a large number of soldering portions. Every time, by determining the soldering quality of only the soldering portion 3 of the soldering failure candidate, it is possible to reduce waste of performing the soldering quality determination on all the soldering portions 3. And the inspection efficiency is improved. 40 is the flow direction 4 of the solder 3a
1 and the minimum required defect candidate detection area set to detect the direction of the defect candidate. Therefore, similarly to the case of determining whether the soldering is good or bad, the detection of the defective soldering candidate can be achieved by the small amount of the imaging data. The inspection apparatus is different from the first inspection apparatus except that the type of image data to be handled and the processing are different.
The same configuration as that of the embodiment may be used, and the description thereof will be omitted.

Note that the determination of the direction of the flow direction 41 of the solder 3a can also take into consideration the difference in the area where the high brightness pixels 42 are arranged.

[0046]

According to the main feature of the soldering inspection method of the present invention, the brightness in the brightness distribution corresponding to the soldering state between the conductor of the base material and the periphery of the soldering portion applied to the conductor. Change point, in the case of poor soldering in which the familiarity of the solder to the soldering part periphery of the soldering target is not sufficient, by utilizing the state according to the soldering part periphery shape of the soldering target, The bright and dark change points corresponding to the peripheral shape of the soldering portion are detected from the imaged data, and the quality of the soldering is accurately determined only by the information from the imaging means. The quality of soldering can be inspected inexpensively, efficiently, and highly accurately without the need for a conventional three-dimensional measuring device and its operation.

In this case, since the direction of the flow direction of the solder corresponds to the defect candidate of the soldering portion, the direction of the flow direction of the solder is determined from the image pickup data, and the soldering is performed according to the direction of the flow direction of the solder. According to the configuration in which the defect candidate is determined and the quality of the soldering is determined for the soldering part of the soldering defect candidate only, the soldering is performed only for the previously detected soldering defect candidate. Since the quality of the soldering is determined and the waste of determining the quality of the soldering for all the soldering portions is reduced, the inspection efficiency is correspondingly improved.

According to the soldering inspection apparatus of the present invention, the image pickup means provides the image pickup data for the limited defect candidate detection area corresponding to the solder flow direction and the limited defect inspection area corresponding to the soldering failure determination line. Determining defect candidates and defects only with the image pickup data of minutes, and performing a determination operation, an efficient and highly accurate inspection that determines the quality of only the soldering portions of the defect candidates with a high probability of previously detected defects,
It can be achieved more efficiently from the limited imaging data.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a soldering inspection apparatus to which the present invention is applied.

FIG. 2 is a side view of a soldering part showing an inspection state in the apparatus of FIG.

FIG. 3 is a front view of the soldering portion of FIG.

FIG. 4 is a plan view showing an example when soldering is a non-defective product.

5 is a side view showing a non-defective soldering portion in FIG. 4. FIG.

6 is a front view showing a non-defective soldering portion of FIG. 4. FIG.

FIG. 7 is a plan view showing a soldering portion of a defective product.

8 is a side view showing a soldering portion of the defective product of FIG. 7. FIG.

9 is a front view showing a soldering portion of the defective product of FIG. 7. FIG.

FIG. 10 is a plan view showing another example when the soldering is non-defective.

11 is a side view showing a non-defective soldering portion of FIG. 10. FIG.

FIG. 12 is a front view showing a non-defective soldering portion of FIG.

FIG. 13 is a plan view showing another example when soldering is a defective product.

14 is a side view of a defective soldering portion of FIG. 13. FIG.

FIG. 15 is a front view of the defective soldering portion of FIG.

16 is an explanatory diagram showing a luminance distribution state of an imaging visual field in the case of a non-defective product by the apparatus of FIG.

FIG. 17 is a side view showing a non-defective soldering portion of FIG. 16;

FIG. 18 is a front view showing a non-defective soldering portion of FIG. 16;

19 is an explanatory diagram showing a luminance distribution state of an imaging visual field in the case of a defective product by the device of FIG.

20 is a side view showing a soldering portion of the defective product of FIG. 19. FIG.

21 is a front view showing a soldering portion of the defective product of FIG. 19. FIG.

22 is a block diagram showing a specific example of the image data processing device in FIG. 1. FIG.

23 is a plan view showing the relationship between the inspection line array and the luminance distribution state of the imaging visual field in the inspection area of FIG.

24 is a plan view showing the relationship between the inspection line array and the luminance distribution state of the imaging visual field in the inspection area of FIG. 20.

FIG. 25 is a diagram showing a specific example of inspection line columns in FIGS. 23 and 24, and pixels and projection value extraction in each column.

FIG. 26 is a diagram showing a presence / absence detection state of a bright / dark change point arrangement state in the inspection line sequence in the inspection area of FIG. 17;

27 is a diagram showing a presence / absence detection state of a state of arrangement of bright / dark change points in the inspection line array in the inspection area of FIG. 20;

28 is a plan view showing a state in which the inspection line array and the light-dark change points corresponding to the unevenness of the solder in the inspection region of FIG. 20 are mixed with the arrangement state of the light-dark points.

29 is a diagram showing an inspection line sequence and detection states of light-dark change points in the inspection region of FIG. 20;

30 is a histogram for a calculation for detecting a predetermined arrangement state of light-dark change points from the light-dark change point detection state of FIG.

FIG. 31 is a plan view showing a case of a non-defective product having a detection area for detecting a soldering failure determination line and a detection area for detecting a solder flow direction according to the second embodiment of the present invention.

32 is a side view showing the state of the solder portion of FIG. 31. FIG.

33 is a front view showing the state of the solder portion of FIG. 31. FIG.

FIG. 34 is a plan view showing a case of a defective product having a detection area for detecting a soldering failure determination line and a detection area for detecting a solder flow direction according to the second embodiment of the present invention.

FIG. 35 is a side view showing a state of the solder portion of FIG. 34.

FIG. 36 is a front view showing the state of the solder portion of FIG. 34.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 electronic component 1a lead 1b tip part 1c soldering part periphery 2 electronic circuit board 3 soldering part 3a solder 4 light projector 5 imaging camera 6 image data processing device 7 conductor land 21 defect inspection area 21a inspection line 22 storage means 23 computing means 24 Judgment means 40 Defect candidate detection area 41 Solder flow direction 42 High brightness pixel L Bright / dark change point arrangement state l Soldering failure judgment line HL High brightness pixel arrangement state X Bright / dark change point

Claims (3)

[Claims] 1. From the image data obtained by imaging the soldering portion between the conductor portion of the base material and the periphery of the soldering object applied to the conductor portion, the shape of the periphery of the soldering portion of the soldering object is determined. A soldering inspection method, characterized in that a light / dark change point is detected, and the quality of soldering is determined based on the detection result. 2. The method according to claim 1, wherein the direction of the solder flow direction is determined from the imaged data, the soldering failure candidate is determined based on the direction of the solder flow direction, and only the soldering portion of the soldering failure candidate is determined. A soldering inspection method for determining the quality of soldering. 3. Imaging data for a soldering failure inspection area of a predetermined length that extends across the width direction on a soldering failure determination line corresponding to the peripheral shape of the soldering portion of a soldering target, and solder. Image pickup means capable of giving image pickup data for the defect candidate detection area corresponding to the flow range, storage means for storing the respective image pickup data from the image pickup means, and the defect candidate detection area for storage in the storage means. The defect inspection area for only the soldering portion of the soldering defect candidate and the determining means for determining the direction of the soldering flow direction from the corresponding imaging data and determining the soldering defect candidate based on the direction of the solder flow direction. Detects a light-dark change point corresponding to the soldering failure determination line from the imaging data corresponding to
A soldering inspection apparatus comprising: a determination unit that determines the quality of soldering based on the result of this detection.