JPH0774730B2 - Appearance inspection method for soldered parts - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a method of inspecting the appearance of a soldered component for visually inspecting the soldering state of a component mounted on a printed wiring board by soldering.

[Prior art]

Conventionally, as a method of inspecting the soldering state of components mounted by soldering on a printed wiring board, a light source that irradiates the soldered components is provided and the reflected light from the soldered components is
A method is known in which the appearance of soldered parts is inspected by detecting with a V camera to judge the quality of the soldered state (JP-A-61-235067, JP-A-62-123794, etc.). reference). In this inspection method, the amount of reflected light from the soldered portion of the mounted component is measured, the end of the component is determined, and then the quality of the soldered state or the mounted state of the component is determined.

[Problems to be Solved by the Invention]

According to the above method, since the amount of reflected light and the direction of reflection change depending on the soldering state, it is not possible to accurately determine the position of the end portion of the component, and there is a problem that subsequent quality determination becomes inaccurate. An object of the present invention is to solve the above-mentioned problems, and by determining the end of the component based on the three-dimensional measurement value of the component mounted by soldering on the printed wiring board, it is possible to determine the quality. It is intended to provide a method for inspecting the appearance of a soldered component, which can accurately perform the above.

[Means for Solving the Problems]

In order to achieve the above object, in the method of claim 1, a component mounted by soldering on a printed wiring board is three-dimensionally measured, and a side edge is formed in a direction along a side edge adjacent to a soldered portion in the component. Search lines are set near the inside and outside of the part respectively, and the height difference from the surface of the printed wiring board is calculated at predetermined intervals on each search line, and the position where the absolute value of the difference is greater than or equal to the predetermined value is set. After detecting as the edge of the part, set the inspection window of the specified size including the soldered portion based on the obtained edge, and determine the shape of the soldered portion obtained from the height of each part in the inspection window. The quality of the soldered state is determined based on the amount of solder. According to the method of claim 2, the component mounted by soldering on the printed wiring board is three-dimensionally measured, and a plurality of search lines in the direction intersecting with the side edge adjacent to the soldered portion of the component are set. , The height difference from the surface of the printed wiring board is obtained at predetermined intervals on each search line, and the difference between the difference on the search line passing through the part and the difference on the search line passing through the soldering part is used. After finding the search line that is closest to the edge of the part among the search lines that pass over the part, set the specified size of the inspection window including the soldered part based on the found search line, The quality of the soldering state is determined based on the shape of the soldered portion and the amount of solder obtained from the height of each portion. Further, according to the method of claim 3, the component mounted by soldering on the printed wiring board is three-dimensionally measured, and the search line is set from the center of the component in the direction along the side edge adjacent to the soldered portion of the component. , After classifying the shape of the soldering portion based on the height from the surface of the printed wiring board on the search line and the rate of change of the height, the quality of the soldering state is determined for each classified shape. . According to the method of claim 4, the leaded component, which is surface-mounted by soldering on the printed wiring board, is three-dimensionally measured, and the height is set on the first search line which is set in the direction intersecting with the protruding direction of the lead. After the position of the lead is detected by binarizing the lead with a predetermined threshold value, a second search line is set on the detected lead in the protruding direction of the lead, and a predetermined interval is set on the second search line. Obtain the difference in height from the surface of the printed wiring board for each
The quality of the soldering state is determined based on the calculated change tendency of the difference.

[Action]

According to the method of claim 1, the component mounted by soldering on the printed wiring board is three-dimensionally measured, and the edge of the component is determined based on the three-dimensional measurement value. The attached portion can be identified, and the mounting state and soldering state of the component can be accurately inspected.
In addition, search lines are set on the inside and outside of the component in the vicinity of the side edge in the direction along the side edge adjacent to the soldered part of the component, and the height from the surface of the printed wiring board on each search line is set. Since the edge of the component is detected based on the change, the edge of the component can be detected even when the soldered portion is wider or narrower than the width of the component. The method of claim 1 is particularly effective when the soldered portion is wider than the width of the component, the reason for which will be described below. That is, when the soldered portion is wider than the width of the component and a large amount of solder is used (as shown in FIG. 7 described later), in the plane along the surface of the printed wiring board, near the edge of the component. A large bulge occurs and the edge of the part cannot be determined using only the change in height above the search line through the part. Therefore, in the method of claim 1, the search line is set on the inside and the outside of the part so that the edge of the part can be determined on either of the search lines. As described above, by using the two search lines having different setting conditions for the component, the probability that the edge of the component can be accurately determined becomes high. According to the method of claim 2, a plurality of search lines are set in a direction intersecting with a side edge of the component adjacent to the soldering portion,
Since the position of the edge of the component is detected based on the difference in height between the search line passing through the part and the search line passing through the soldering part, no matter what shape the soldering part has, The edge of the part can be accurately detected. According to the method of claim 3, the search line is set from the center of the component in the direction along the side edge adjacent to the soldered portion of the component, and the height from the surface of the printed wiring board on the search line and the rate of change in height are set. After classifying the shape of the soldering part based on, the quality of the soldering state is judged for each classified shape, so the shape of the soldering part that can be regarded as a good product is classified in advance and within this range The quality of the soldered state is determined, and the inspection can be performed quickly and accurately. According to the method of claim 4, the leaded component mounted on the printed wiring board by soldering is three-dimensionally measured, and the height of the component is increased above the first search line set in the direction intersecting the lead protruding direction. After detecting the position of the lead by binarizing the height with a predetermined threshold value, the printed wiring board of the printed wiring board is arranged on the detected lead at a predetermined interval on the second search line set in the protruding direction of the lead. Since the difference in height from the surface is obtained and the quality of the soldering state is judged based on the changing tendency of the obtained difference, it is possible to inspect the soldering state for each lead with respect to the part with the lead, which is complicated. The inspection can be automated.

First Embodiment As shown in FIG. 1, basically, a sensor unit 11 that obtains three-dimensional data, and coordinate calculation that calculates three-dimensional coordinates based on the data obtained by the sensor unit 11. The unit 12, the storage unit 13 that stores the three-dimensional coordinates obtained by the coordinate calculation unit 12 together with other data, and the mounting on the printed wiring board 1 by soldering based on the obtained three-dimensional coordinates An inspection processing unit 10 for inspecting a soldered portion of the component 2 is provided. The inspection processing unit 10 determines the edge of the component 2 soldered on the printed wiring board 1 on the basis of the three-dimensional coordinates and the position of the edge of the component 2. It is composed of a mounting state inspection unit 15 that determines the quality of the mounting state and a soldering state inspection unit 16 that determines whether the soldering state of the soldered portion detected based on the edge of the component 2 is good or bad. The sensor unit 11 is a so-called three-dimensional scanner. For example, the sensor unit 11 scans the surface of the inspection object with a light beam and
A device in which three-dimensional data is obtained by using a triangulation method using a position detection element such as D is used. Next, the inspection method will be described. First, the printed wiring board 1 on which the component 2 is mounted by soldering is set at a predetermined position on the measurement stage, and the three-dimensional measurement is performed as described above. Three
When the dimension measurement is performed, it is assumed that the center position of the component 2, the dimensions (length × width × height) of the component 2, and the direction of the component 2 after mounting are known. The measurement information obtained by the three-dimensional measurement is stored in the storage unit 13. Hereinafter, the minimum unit stored in the storage unit 13 will be referred to as a pixel due to similarity to image processing. The component end determination unit 14 of the inspection processing unit 10 determines the position of the edge of the component 2 using the three-dimensional measurement values stored in the storage unit 13 according to the procedure shown in FIG. Performs mounting state inspection and soldering state inspection. First, the edge of the component 2 is searched for on the search line l ₁ set in the direction connecting the both ends of the soldered component 2 (hereinafter referred to as the longitudinal direction), starting from the center point C of the component 2. . Since there are two end edges of the part 2, the search is performed on the search line l ₁ from the center point C in both directions. Here, in the first step, it is determined whether or not the soldering is performed in the state shown in FIG. here,
3 to 9, (a) is a top view and (b) is a cross section. In the soldering state as shown in FIG. 3, the height changes abruptly at the edge of the component 2 as shown in FIG. 3 (b). Then, when the difference becomes a negative value from 0 and the absolute value becomes equal to or larger than the predetermined value, it is determined that the edge of the component 2 has been reached. In this case, both ends of the component 2 can be detected. On the other hand, if soldering is performed in the state shown in FIGS. 4 and 5, only one end of the component 2 can be detected by the above method based on the difference in height. Therefore,
In the second step, the position of the other edge is obtained from one of the detected edges and the known dimension of the component 2. That is, only one edge is obtained by actual measurement, and the other edge is obtained by calculation. Further, if soldering is performed in the state as shown in FIG. 6, neither edge of the component 2 can be detected by the height difference. In this case, it can be seen that the soldering portion 3 is convex from the upper surface of the component 2 when the height difference changes from 0 to a positive value. Therefore, the rising point u ₁ of the soldering portion 3 Find u ₂ and find the distance between both points u ₁ and u ₂ . Further, the difference d between the distance thus obtained and the dimension of the component is obtained, and the position separated from both points u ₁ and u ₂ by a dimension half the difference d on the search line l ₁ is defined as the edge position. Consider it. Although the soldered state as shown in FIGS. 7 and 8 can be regarded as a good product, the position of the edge of the component 2 cannot be determined in the above-described three stages. Therefore, in the above three steps, the component 2
If the position of the edge of is not determined, use the following procedure. That is, this time, the search line is moved from the center point C of the component 2 in the direction orthogonal to the longitudinal direction (hereinafter referred to as the width direction).
Set l ₂ and search for the position of one side edge that has not been soldered. This position can be easily searched based on the difference in height. A pair of search lines running in the longitudinal direction of the component 2 are separated from the position of the side edge of the component 2 detected in this way by a predetermined distance to the outside and the inside of the component 2, respectively.
Set l and m. Here, the length of each search line l, m is
And the size of the land on the printed wiring board 1 are set in advance. In the soldering state as shown in FIG. 7, since the soldering portion 3 exists on the search line 1 outside the component 2,
As shown in FIG. 6C, a change in height on the search line 1 is detected, and a point rising from 0 to positive is regarded as an edge of the component 2. In this case, even if the height change on the search line m inside the component 2 is observed, the edge of the component 2 cannot be identified as shown in FIG. 7 (d). In the soldering state as shown in FIG. 8, above the search line 1 outside the component 2, there is no change in height as shown in FIG. above m
As shown in FIG. 3D, there is a portion where the height changes abruptly. Therefore, if the difference in height is calculated and a point where the difference is negative and the absolute value is equal to or larger than a predetermined value is obtained, one edge of the component 2 is detected. The other edge can be determined based on the dimensions of the component 2 as in the second step. Even at this stage, the edge of the component 2 cannot be determined in the soldering state as shown in FIG. 9, so in this case,
Determine as follows. That is, FIG. 9 (a)
As shown in (b), search lines l _{3 to} l ₆ running in the width direction at predetermined intervals in the longitudinal direction of the component 2 are set. Each search line
Since the height above l _{3 to} l ₆ changes as shown in FIGS. 10A to 10D, if the height difference dh is taken for each predetermined number of pixels,
The maximum value of the difference dh on each of the search lines l _{3 to} l ₆ is equal to or higher than the height h ₀ of the part 2 at the part corresponding to the part 2 (dh ≧ h ₀ ),
At the soldered portion 3, the height is smaller than the height h _{0 of the} component 2 (dh <h ₀ ). Therefore, on each search line l _{3 to} l ₆ , the part 2
The maximum value of the height difference is sequentially obtained from the inside of, and when the condition of dh <h ₀ is satisfied, the position of the search line that satisfies dh ≧ h ₀ immediately before is regarded as the edge of the component 2. All you have to do is do it. The component 2 and the soldered portion 3 are distinguished by the maximum value of the height difference. In addition, the height difference of the upper surface of the component 2 is almost 0, whereas the height of the soldered portion 3 is almost zero. The difference may be positive or negative to be used for identification. Further, the surface of the printed wiring board 1 may be used as a reference plane for identification by utilizing the difference between the cross-sectional area of the component 2 and the cross-sectional area of the soldered portion 3. By sequentially performing the above determination, the edge of the soldered component 2 can be determined. Next, the quality of the mounting state is determined by comparing the obtained edge position of the component 2 with the edge position preset as the range of non-defective products. Further, the inspection window W having a size set in advance is set with reference to the obtained position of the edge of the component 2.
They are arranged as shown in the figure, and the quality of the soldering state is determined based on the added value and the difference value of the height in the inspection window W. This processing procedure is shown in FIG. That is, the inspection window W has a rectangular shape, and as shown in FIG. 13, the height H of the midpoint p of the side ab near the edge of the component 2 is obtained.
On the line connecting the midpoint p and the midpoint of the side cd,
The height difference dh is sequentially obtained from the midpoint p. This difference dh is
If it is negative and the absolute value is greater than or equal to the prescribed value M ₁ (dh ≤ −M ₁ ), then if positive and the absolute value exceeds the prescribed value M ₂ (dh>
M ₂ ), it is considered that the soldering condition is bad, such as insufficient wetting of the solder or holes, so it is judged as defective and the process ends. Also, set a predetermined reference value −m ₁ , m ₂ for the difference dh, and d
Classify according to which of the three conditions of h <-m ₁ , -m ₁ ≤ dh ≤ m ₂ , and dh> m ₂ is satisfied, and after calculating the appearance frequency of each condition, according to the condition that the appearance frequency is the maximum. Then, the soldering state is classified into three types. That is, the above conditions correspond to the case where the soldered portion 3 has the shape shown in FIGS. 14 (a) to 14 (c). Further, a point at which the height from the substrate surface becomes 0 on the way from the midpoint p to the midpoint of the side cd is q, and this point q is the end of the soldered portion 3. Therefore, the length L of the soldered portion 3 can be obtained as the distance between the midpoint p and the point q in the longitudinal direction of the component 2. As described above, the three parameters of the wetting height H of the soldering portion 3, the length L of the soldering portion 3 and the soldering state P are determined. Therefore, if the lower limit H ₀ of the wetting height and the lower limit L _{0 of the} length are set in advance in consideration of the strength of soldering, the soldering condition can be regarded as a good product. It is the case where any one of the conditions of the types is satisfied and H ≧ H ₀ and L ≧ L ₀ are satisfied. In this way, since the quality of the soldered portion 3 is determined based on the shape and the characteristic amount of the soldered portion, the quality determination can be performed accurately.

Second Embodiment In the present embodiment, as shown in FIG.
Based on the component edge determination unit 14 that determines the edge of the component 2 soldered on the printed wiring board 1 based on the three-dimensional coordinates stored in the storage unit 13, and the position of the edge of the component 2. The soldering area determining unit 17 that determines the inspection window corresponding to the area of the soldering portion 3, the inspection point setting unit 18 that sets a large number of inspection points in the inspection window, and the height of each inspection point that has been set. And a quality determination unit 19 for determining the quality of the soldering state based on. The quality determination unit 19 determines the quality of the soldered state according to the procedure disclosed in Japanese Patent Application No. 63-158817, and the value corresponding to the cross-sectional area of the soldered portion 3 based on the height of each inspection point. Then, the quality of the soldering state is determined based on the change in the cross-sectional area and the change in the difference in the cross-sectional area. The In determining the edges of the component 2 in the component end determining unit 14 first sets the search lines l ₁ running through the center point C of the part 2 in the longitudinal direction of the street part 2, on the search line l ₁ 1 The height difference dh is calculated for each pixel or for each pixel (see FIG. 3). Since the soldered state can be regarded as a good product in any of the three types shown in Fig. 16, in order to judge these shapes, positive and negative reference values for the height difference dh -m ₁ , m ₂
Is set to determine the edge of the component 2. That is, in the shape of FIG. 16A, the point where dh <−m ₁ is set as the edge of the component 2. Further, in the shape of FIG. 16 (b), the point where dh = 0 after dh> m ₂ is defined as the edge of the component 2. In the shape of FIG. 16 (c), since the edge of the component 2 cannot be determined by the reference values −m ₁ and m ₂ , the point that is lower than the known height H of the component 2 by the predetermined value δ is The edge of the component 2. When the edge of the component 2 is determined as described above, the inspection window W is set based on this position. After that, inspection points are set in a grid pattern in the inspection window W, and the quality of the soldering state is determined based on the height of each inspection point.

Third Embodiment In the present embodiment, the shape of the soldered portion 3 is classified by obtaining the height difference dh similarly to the second embodiment, and at this time point, the primary judgment of the quality of the soldering state is made first. I am trying. That is, the basic configuration is the same as that of the first embodiment, and the processing procedure in the inspection processing unit 10 is changed. First, the search line l ₁ is set in the longitudinal direction of the part 2 from the center point C of the part 2 and
The height difference dh is calculated for each pixel based on the height above l ₁ (see FIG. 3). If the difference dh is obtained, the second embodiment
Similarly, by setting the positive and negative reference values −m ₁ and m ₂ for the difference dh, the soldering state that can be regarded as a good product is 3
It can be classified into types. That is, the shape that can be regarded as a good soldered state is the 16th
There are three types of shapes shown in the figure, and the height difference dh is the 16th
The shape of FIG. 16 (a) becomes negative, the shape of FIG. 16 (b) becomes positive and then becomes negative, and the shape of FIG. 16 (c) is negative, but the maximum absolute value is It will be smaller than Fig. 16 (a). Therefore, if the reference values −m ₁ and m ₂ are set appropriately,
6 (a) to 6 (c) can be identified under the following conditions. FIG. 16 (a): First, dh <−m ₁ is satisfied, and then dh> m ₂ is not satisfied. FIG. 16 (b): First, dh> m ₂ is satisfied, and then dh <−m Figure 16 comprising the ₁ (c): - when m becomes ₁ ≦ dh ≦ m ₂ do not meet these conditions may be defective. In this way, by classifying the shape of the soldered portion 3, it is possible to make a primary determination of a defective product. Next, as shown in FIG. 18, the inspection window W corresponding to the soldering portion 3 is set, and the secondary determination of the unnecessary product is performed based on the shape of the soldering portion 3 and the solder amount. Here, the inspection window W is set in advance. That is, the reason why the shape of the soldered portion 3 is considered to be a defective product is that it has insufficient wetting as shown in FIG. 17 (a) or has a pinhole as shown in FIG. 17 (b). Another search line is set in the inspection window W in parallel with the search line l _1, and the height difference is obtained on the newly set search line to detect whether or not these shapes occur. If the shape of the soldering part 3 can be regarded as a good product,
After the difference becomes negative, it approaches 0 and reaches the end point of the search line, but in the case of a defective product, as shown in FIG. 17, it tends to become positive after the difference becomes negative. Therefore,
The quality of the shape of the soldered portion 3 can be determined by determining whether or not the difference shows such a change. Such quality determination is common to the three types of classified shapes. Next, the quality of the solder amount is also determined. To determine the amount of solder, it is desirable to distinguish between the component 2 and the soldered portion 3. However, in the shape of FIGS. 16 (b) and (c), the edge of the component 2 cannot be determined. The amount of solder is determined based on the height of each point. Further, the quality of the solder is judged by comparing the amount of solder with a non-defective product standard range preset for each shape. That is, in the shape of FIG. 16 (a), the point where the height difference dh becomes negative on the search line l ₁ can be regarded as the end edge of the component 2, so the component 2 and the soldered portion 3 Can be identified, and the amount of solder can be accurately determined. On the other hand, in the shape of FIG. 16 (b), the position where the height difference dh rises positively is used as the reference point, and the search line l ₁ passes through this reference point.
The total volume is obtained in the range from the line orthogonal to the tip of the soldered portion 3 and is regarded as the amount corresponding to the amount of solder. Further, in the shape of FIG. 16 (c), the total volume in the inspection window W is obtained and regarded as the amount corresponding to the solder amount, and compared with the non-defective product standard range. In this case, the height reference when determining the volume is that the inspection window W formed in a rectangular shape is the average value of the heights of the vertices. Although Example 1 was mainly a method for a leadless package (a leaded package can be applied other than the determination of the edge of the component 2), Example 2 and Example 3 are Either a leaded package or a leadless package can be applied as long as it is a mounting type package.

Fourth Embodiment In this embodiment, an example in which the soldering component is a flat package with leads is shown. In a leaded flat package, the quality of the soldered state of each lead is determined, so it is necessary to first determine the position of the lead.
Therefore, as shown in FIG. 19, the position of the lead 4 is detected within the preset lead search window W ₁ . In obtaining the position of the lead 4, first, the height of each point in the lead inspection window W ₁ is set to the above with reference to the average height of the vertices of the lead inspection window W ₁ set in a rectangular shape. It is binarized by a predetermined threshold value obtained based on the standard. That is, the threshold value is set at a position higher than the reference value, and 1 is set when the threshold value is exceeded, and 0 is set when the threshold value is lower than the threshold value, and the height of each point in the lead inspection window W ₁ is binarized. Here, the threshold value is set to a value smaller than the thickness of the lead 4. Next, on the search line lc set as the center line in the lead inspection window W ₁ parallel to the edge where the lead 4 projects in the component 2, for the binarized height, a continuous length of 1 The positions of the start point and the end point of the section where 1 is continuous are obtained, and the number of appearances of the section where 1 is continuous is obtained. As described above,
The width of the lead 4 is determined by the continuous length of 1, and the number of the leads 4 can be determined by the position of the lead 4 and the number of appearances of the interval in which 1 is continuous based on the positions of the start point and the end point of the continuous 1 section. As described above, since the start point and the end point of each lead 4 on the search line lc are obtained, it is orthogonal to the search line lc inside the lead 4 at a position slightly apart from the start point and the end point. Each search line is set, and the height difference is obtained on each search line. When the difference becomes negative and the absolute value exceeds the predetermined value, it is the case of a good product in Fig. 20 (a) or Fig. 20 (b).
If the absolute value of the difference is not less than or equal to the predetermined value, the soldering part 3 is
Any shape shown in FIG. 21 (a) or FIG. 21 (b) can be regarded as a non-defective product. Therefore, when the difference becomes negative and the absolute value becomes equal to or larger than the predetermined value, the position is set as the tip of the lead 4 and the inspection window W is set based on the width of the lead 4 as shown in FIG. After that, the sum of the heights of the respective points in the inspection window W with respect to the height standard set based on the lead inspection window W ₁ is obtained. This total sum corresponds to the amount of solder. Therefore, the quality based on the amount of solder is determined by comparison with a predetermined reference amount of solder. Further, a search line extending from the base of the lead 4 to the tip is set in the inspection window W, and the height difference is obtained on this search line, and as shown in FIG. 20 (b), it becomes negative once. When it becomes positive later, it is determined that there is insufficient solder wetting or there is a hole, and it is determined that the product is defective.

【The invention's effect】

According to the method of claim 1, the component mounted by soldering on the printed wiring board is three-dimensionally measured, and the edge of the component is determined based on the three-dimensional measurement value. The attached portion can be identified, and the mounting state and soldering state of the component can be accurately inspected.
In addition, search lines are set on the inside and outside of the component in the vicinity of the side edge in the direction along the side edge adjacent to the soldered part of the component, and the height from the surface of the printed wiring board on each search line is set. Since the edge of the component is detected based on the change, there is an advantage that the edge of the component can be detected even when the soldered portion is wider or narrower than the width of the component. The method according to claim 1 is particularly effective when the soldering portion is wider than the width of the component, and when the soldering portion is wider than the width of the component and a large amount of solder is used, the method of the printed wiring board is improved. A large bulge occurs in the vicinity of the edge of the part in the plane along the surface, and it is impossible to determine the edge of the part using only the change in height on the search line passing through the part, According to the method of claim 1, since the search lines are set on the inside and the outside of the part, the edge of the part can be determined on either of the search lines, and the probability that the edge of the part can be accurately determined. Has the advantage that According to the method of claim 2, a plurality of search lines are set in a direction intersecting with a side edge of the component adjacent to the soldering portion,
Since the position of the edge of the component is detected based on the difference in height between the search line passing through the part and the search line passing through the soldering part, no matter what shape the soldering part has, There is an effect that the edge of the component can be accurately detected. In the method of claim 3, the search line is set from the center of the component in the direction along the side edge adjacent to the soldered portion of the component,
After classifying the shape of the soldering part based on the height from the surface of the printed wiring board on the search line and the rate of change in height, the quality of the soldering state is judged for each classified shape. The shape of the soldered portion that can be regarded as a non-defective product is classified in advance, and the quality of the soldered state is determined within the range, which has the effect of enabling quick and accurate inspection. According to the method of claim 4, the leaded component surface-mounted on the printed wiring board by soldering is three-dimensionally measured,
After detecting the position of the lead by binarizing the height with a predetermined threshold value on the first search line set in the direction intersecting the protruding direction of the lead, the protruding direction of the lead is detected on the detected lead. Since the height difference from the surface of the printed wiring board is obtained at predetermined intervals on the second search line set to, the quality of the soldering state is determined based on the changing tendency of the obtained difference. There is an advantage that a leaded component can be inspected for the soldering state for each lead and a complicated inspection can be automated.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, FIGS. 2 to 14 are operation explanatory diagrams of the same, FIG. 15 is a schematic configuration diagram showing a second embodiment of the present invention, and FIG. Same operation explanation diagram,
17 and 18 are operation explanatory views showing the third embodiment of the present invention, and FIGS. 19 to 22 are operation explanatory views showing the fourth embodiment of the present invention. 1 ... Printed wiring board, 2 ... Component, 3 ... Soldering part,
4 ... Lead, W ... Inspection window.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 61-293658 (JP, A) JP-A 62-55502 (JP, A) JP-A 63-229311 (JP, A) JP-A 60- 127404 (JP, A)

Claims (4)

[Claims] 1. A component mounted on a printed wiring board by soldering is three-dimensionally measured, and in the direction along the side edge adjacent to the soldered portion of the component, in the vicinity of the side edge, inside and outside the component, respectively. Set the search line, calculate the height difference from the surface of the printed wiring board at each predetermined interval on each search line, and after detecting the position where the absolute value of the difference is a predetermined value or more as the edge of the component, then calculate The inspection window of the specified size including the soldered part is set with the edge as the reference, and the quality of the soldering state is determined based on the shape of the soldered part and the amount of solder obtained from the height of each part in the inspection window. A method for inspecting the appearance of a soldered component, which comprises determining 2. A component mounted by soldering on a printed wiring board is three-dimensionally measured, a plurality of search lines in a direction intersecting with a side edge of the component adjacent to the soldered portion are set, and each search line is set. The height difference from the surface of the printed wiring board is obtained at predetermined intervals on the above, and the difference on the search line passing through the part and the difference on the search line passing through the soldered part are used After finding the search line that is closest to the edge of the component among the passing search lines, set the inspection window of the specified size including the soldered part based on the obtained search line, and set the height of each part in the inspection window. A method for inspecting the appearance of a soldered component, characterized in that the quality of the soldered state is determined based on the shape of the soldered portion and the amount of solder obtained from the above. 3. A component mounted by soldering on a printed wiring board is three-dimensionally measured, and a search line is set from the center of the component in a direction along a side edge adjacent to the soldered portion of the component,
The feature is that after classifying the shape of the soldered part based on the height from the surface of the printed wiring board on the search line and the rate of change of the height, the quality of the soldering state is judged for each classified shape. Appearance inspection method for soldered parts. 4. A component with a lead, which is surface-mounted by soldering on a printed wiring board, is three-dimensionally measured, and a predetermined height is set on a first search line set in a direction intersecting the protruding direction of the lead. After detecting the position of the lead by binarizing with the threshold value of, a second search line is set on the detected lead in the protruding direction of the lead, and the second search line is set at predetermined intervals on the second search line. A visual inspection method for a soldered component, characterized in that a difference in height from the surface of a printed wiring board is obtained, and the quality of the soldering state is judged based on the changing tendency of the obtained difference.