JP2006229103A - Defective component detecting method and component mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defective component detecting method and a component mounting method by which a defective component including lead floating can be detected even if a component adsorbing position and a component centroid position are in any positional relation. <P>SOLUTION: A first virtual plane P is specified from a first fundamental triangle, internally including a component adsorbing position S constituted of three lead wires 11 with a great protrusion amount estimated to be in contact with the surface of a circuit board 14 when a component 10 is mounted on the circuit board 14. With this virtual plane P as a reference, it is detected whether or not the height of each of the lead wires 11 is settled within an allowable range. If a centroid position G of the component 10 is not present within the first fundamental triangle, a second virtual plane P2 is specified from a second fundamental triangle, constituted of a side closest to the centroid position G among three sides constituting the first fundamental triangle, and the other lead wire 11 with a great protrusion amount positioned at the opposite side of the first fundamental triangle relative to the relevant side. With this virtual plane as a reference, it is detected whether or not the height of each of the lead wire 11 is settled within the allowable range. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  According to the present invention, in component mounting in which a component having at least a part of a lead wire is taken out from a component supply unit by a suction nozzle and mounted on a mounting position of the circuit board, The present invention relates to a defective component detection method for detecting and eliminating a defective component that may cause a joint failure before mounting, and a component mounting method using the defective component detection method.

  An example of a component mounting apparatus is shown in FIG. In the figure, a component mounting apparatus 1 takes out components from two component supply units 2 (2a and 2b) that supply components to be mounted, and suction nozzles 3 from each component supply unit 2, and mounts them on a circuit board 14. A mounting head 4, a robot 5 that transports the mounting head 4 to a predetermined position, a component recognition device 6 that captures an image of the component held by the suction nozzle 3 and recognizes a deviation in position and angle, and a circuit board 14 And a substrate holding device 7 for holding, and a control unit 9 for controlling the entire operation.

  The component supply unit 2 includes a tray-type component supply unit 2a that supplies components arranged on the tray 8a, and a cassette-type component supply unit 2b that supplies components wound in a tape shape by the parts cassette 8b. It is. Among these, large-sized components such as BGA (Ball Grid Array), QFP (Quad Flat Package), and capacitors are supplied from the tray-type component supply unit 2a, and chip-type components such as chip components are supplied from the cassette-type component supply unit 2b. Small parts are supplied.

  During the operation of the component mounting apparatus 1 configured as described above, the mounting head 4 is moved to a position facing the component supply unit 2 (2a or 2b) by the conveyance of the robot 5, and the component is removed using the suction nozzle 3. Take out. Thereafter, the suction nozzle 3 moves to a position facing the component recognition device 6 by the movement of the mounting head 4, and recognizes the holding state of the component including the position and angle deviation of the sucked component.

  During this time, the circuit board 14 is carried into the component mounting apparatus 1 and is regulated and held at a predetermined mounting position by the board holding apparatus 7. The mounting head 4 holding the components on the suction nozzle 3 moves to a position facing the circuit board 14 by the conveyance of the robot 5. The board recognition device 15 mounted on the mounting head 4 captures an image of the circuit board 14, recognizes a position / angle shift, and transmits the recognition result to the control unit 9. The control unit 9 is loaded with NC data in which the mounting positions of the components mounted on the circuit board 14 are recorded in advance. Based on the state of the component input from the component recognition device 6 and the state of the circuit board 14 input from the substrate recognition device 15, the control unit 9 commands the necessary correction for the position and angle of the suction nozzle 3.

  Each suction nozzle 3 corrects the position and angle of the component based on the command, and mounts the component 10 at a predetermined mounting position on the circuit board 14. The mounting head 4 that has finished mounting the component moves again to a position facing the component supply unit 2 by the conveyance of the robot 5, and repeats the operation so far. The circuit board 14 that has finished mounting all the predetermined components is carried out of the component mounting apparatus 1 by the board holding device 7, and then the next circuit board 14 is carried in and the operation so far is repeated.

  FIG. 8A shows the component 10 sucked and held by the suction nozzle 3. A lead wire 11 extends from the component 10 to the periphery. Some components 10 mounted by the component mounting apparatus 1 do not include such lead wires 11, but in the present invention, as shown in the drawing, a component 10 provided with a plurality of lead wires 11 at least in the periphery is provided. set to target. Or even if it is not the lead wire 11, the component which is provided with the some terminal which should contact the circuit board 14 ahead of a main body at the time of mounting in the side facing the circuit board 14 is made into object. When such a component 10 is implemented on the circuit board 14, the joint position 12 at the tip of each of the lead wires 11 (or the terminals as described above, the same applies hereinafter) is provided on the circuit board 14. Mounted on the corresponding terminal. A paste-like cream solder layer is printed on the terminal on the circuit board 14 side, and the placed component 10 is held at a predetermined position by the viscosity of the cream solder layer.

  The circuit board 14 after mounting the necessary components 10 in this way is later transported to the reflow process, the cream solder layer is melted, and then cooled, whereby each lead wire 11 is soldered to the corresponding terminal. Is done. If even one of the lead wires 11 is not bonded to the corresponding terminal of the circuit board 14, the entire circuit board 14 becomes a defective product. Usually, the large component 10 having such a lead wire 11 is expensive even if it is a single product, and since many other components are already mounted on the circuit substrate 14, the entire circuit substrate 14 is considered defective. Therefore, it is necessary to eliminate the bonding failure of the lead wire 11 as much as possible.

  FIG. 8B shows the plane of the component 10, and FIG. 8C shows the side surface of the component 10. The shape of the component 10 and the number of lead wires 11 are merely examples. When the part 10 has a rectangular shape as shown in the figure, the center of gravity of the part 10 is usually located at or near the intersection C of two diagonal lines shown in FIG. Also, the suction nozzle 3 is normally position-controlled so that the center of the suction nozzle 3 comes near the intersection C. However, depending on the part, the position of the center of gravity does not necessarily overlap the intersection C of the diagonal line, and the part suction position by the suction nozzle 3 does not necessarily coincide with the intersection C exactly as intended. Note that the position of the center of gravity of the component 10 is uniquely determined for each component, and can be input to the control unit 9 as data in advance.

  The lead wire 11 extending from the periphery of the component 10 is made of a thin metal and has a certain rigidity. Due to variations in the manufacturing process of the component 10 or contact with other members in the subsequent transport process, a certain degree of deformation can be applied as shown in FIG. The surface of the circuit board 14 has the above-described cream solder layer, and the bonding position 12 at the tip of the lead wire 11 is captured by the solder layer at the time of mounting. Therefore, even if the lead wire 11 is in a slightly deformed state. In some cases, solder bonding is possible. However, when the lead wires 11 that are extremely deformed as shown in the figure are included, it may be difficult to solder the joining positions 12 of all the lead wires 11 to the respective terminals of the circuit board 14. If mounting is carried out with this being left unattended, the entire circuit board 14 becomes defective as described above. In this specification, the phenomenon that the lead wire 11 is lifted due to such a deformation and is not soldered is referred to as “lead floating”. Even if the lead wire 11 has the shape as designed, other lead wires 11 may project and deform in the direction of the circuit board, resulting in poor bonding. Therefore, the lead floating includes such a case.

  In order to cope with the lead floating phenomenon, an effort has been made in the past to detect the component 10 including the lead wire 11 having a large deformation amount and discard it without mounting it to avoid the occurrence of a defective circuit board. The deformed lead wire 11 is detected by, for example, irradiating laser light from below the component 10 held by the suction nozzle 3 using a three-dimensional sensor and reflecting the reflected light that is reflected back to the joining position 12 of the lead wire 11. It can be implemented by detecting the amount of deformation.

  9A and 9B show an outline of a three-dimensional sensor used for such a purpose. Both figures are side views of the three-dimensional sensor 20 as viewed from angles different from each other by 90 °. In both figures, the three-dimensional sensor 20 includes a semiconductor laser 21 that emits laser light, a condensing shaping lens 22 that condenses and shapes the laser light, a polygon mirror 23 that scans the laser light using a mechanically rotating mirror, A half mirror 24 that allows part of the laser light to pass and reflects part of the laser light, and a mirror 25 that reflects the laser light are included.

  The three-dimensional sensor 20 further includes an F-θ lens 26 that changes the optical path so that the laser beam mechanically shaken by the polygon mirror 23 is projected onto the component 10 vertically, and the reflection (irregular reflection) of the laser beam that strikes the component 10. And image forming lenses 27a and 27b, and semiconductor position detecting elements 28a and 28b for detecting positions where the reflected light hitting the component 10 is imaged by the image forming lenses 27a and 27b. The position detection elements 28a and 28b have a function of generating an electrical signal having a correlation with the position of the imaged light. Reference numerals 29a and 29b denote output signals output from the position detection elements 28a and 28b.

  The three-dimensional sensor 20 configured as described above operates as follows. Laser light is generated by the semiconductor laser 21, and the laser light is condensed and shaped by the condensing shaping lens 22, and then passes through the half mirror 24, is reflected by the mirror 25, and strikes the polygon mirror 23. The polygon mirror 23 is rotating at a constant speed, and the laser beam hitting the mirror surface is shaken by this. Further, the laser light whose optical path has been changed by the F-θ lens 26 is applied perpendicularly to the component 10, and the reflected light is imaged on the position detection elements 28a and 28b via the imaging lenses 27a and 27b. The position detection elements 28a and 28b generate output signals 29a and 29b that can measure the height of the laser reflecting surface of the component 10 in accordance with the data of the reflected light that has been imaged. The output signals 29a and 29b are transmitted to the control unit 9 (see FIG. 7) and subjected to calculation processing to specify the height of each joint position 12. The optical sensor indicated by reference numeral 31 transmits a rotation amount signal 32 for detecting the rotation speed of the polygon mirror 23.

  FIG. 10A shows a state of the component 10 including the lead wire 11 whose height is measured by the three-dimensional sensor 20 described above. While the component 10 sucked and held by the suction nozzle 3 passes over the three-dimensional sensor 20 (not shown), the height of the joining position 12 of each lead wire 11 is measured, and the height variation r is calculated. . Actually, a least square line is first obtained from the joint position height of each lead wire 11, and the difference in height from the least square line is calculated. This eliminates other factors affecting the height, such as the inclination of the component 10 held by suction. As shown in the figure, even if a deformed lead wire 11a is included, it is determined as non-defective if the variation r is within a predetermined allowable range. When it is out of the allowable range, the suction nozzle 3 discards the component 10 at a predetermined component collection position without mounting the component 10 according to a command from the control unit 9. The discarded part 10 can be recycled by subsequent repairs.

  In the following description, the joint position 12 of the lead wire 11 being “high” means that the joint position 12 of the lead wire 11 extends long downward from the component toward the opposing circuit board 14. “Low” means that the amount of the joint position 12 extending from the component toward the circuit board 14 is short. Further, in the following description, these “high” and “low” are expressions that accurately indicate the height of the joining position 12 of the lead wire 11, but are expressed as the lead wire 11 being high and low for convenience. Sometimes.

  In the lead floating detection method as described above, even if the height variation r of the joint position 12 is within the allowable range, there may be a phenomenon that the joint becomes defective after mounting due to the following factors. When the component 10 as shown in FIG. 10A is placed on the circuit board 14, as shown in FIG. 10B, the joint position 12 a of the high lead wire 11 a protruding downward is first of the circuit board 14. After contacting the surface, the component 10 is placed on the surface of the circuit board 14 while tilting in any direction with the joining position 12a as a fulcrum. For example, if the lead wire 11b located on the right side of the drawing next contacts the circuit board 14, the lead wire 11c located on the opposite left side is separated from the circuit board 14 with the joint position 12a serving as a tilt fulcrum as a center. The circuit board 14 is tilted away from the circuit board 14 by a distance R. This distance R is clearly larger than the variation r shown in FIG. 10A. Therefore, even if the variation r is within the allowable range, it is not possible to detect lead floating in all cases. Although FIG. 10B shows two dimensions, a similar phenomenon can occur in three dimensions.

  In order to avoid the lead floating due to such a phenomenon, in the conventional technique, a virtual plane (assuming a state in which the component 10 is placed on the circuit board 14 instead of the above-described height variation based on the least square line) A technique for measuring the height of each lead wire 11 on the basis of a sheeting plane has been proposed (see, for example, Patent Document 1).

  FIG. 11 shows the contents thereof, and the virtual plane includes three lead wires 11a, 11b, and 11c having a large deformation amount (high) extending toward the side facing the circuit board 14 based on the measurement result by the three-dimensional sensor. Are formed by planes based on triangles indicated by broken lines in the figure connecting the joint positions 12. That is, when the component 10 facing the circuit board 14 is placed on the circuit board 14, it is assumed that these three lead wires 11 a, 11 b, 11 c come into contact with the surface of the circuit board 14.

According to Patent Literature 1, when this virtual plane is assumed, the joint positions 12 of all the lead wires 11 other than the three lead wires 11a, 11b, and 11c are lower than the virtual plane (virtual positions). It is a condition that it exists in a direction closer to the component 10 than the plane. In addition, according to Patent Document 1, the point obtained by projecting the center of gravity G of the component 10 onto the virtual plane is present in the triangle indicated by the broken line, which is the basis of the virtual plane, as shown in FIG. It is a condition. This is presumed that the component 10 can be stably placed on the circuit board 14 only when the center of gravity of the component 10 is included in the triangle that forms the basis of the virtual plane. . It can be inferred from the reason that when a table with four legs of different lengths is placed on a plane, the table stabilizes on a triangular plane composed of three legs including the center of gravity of the table. obtain.
JP-A-10-51195

  However, there is a problem with the above-described method for detecting a defective part including a lead float using a virtual plane including the center of gravity of the part. The position of the center of gravity of the part remains an important element when specifying the virtual plane described above, but the projection point of the center of gravity G of the part 10 does not exist within the triangle that forms the basis of the virtual plane With respect to this solution, the prior art did not present any solution. Further, in the component mounting operation, although the component suction position by the suction nozzle can be another important factor when specifying the virtual plane, the conventional technology has not considered this point. How the component suction position affects the virtual plane will be described with reference to the drawings.

  In FIG. 12A, it is assumed that the suction nozzle 3 is sucking the component 10 at the component suction position S that is away from the center of the component 10. As described above, although the component suction position S is usually aimed at the center position of the component 10 (substantially the position of the center of gravity G), the component suction position S actually varies due to various factors. Alternatively, when the planar shape of the component is a U-shape, the component is not physically present at the position of the center of gravity G. In such a case, the component suction position S is determined at a position close to the center of gravity G. I can't. When the suction nozzle 3 is lowered and the component 10 is brought into contact with the circuit board 14 in the state shown in FIG. 12A, the component 10 is moved away from the center position as shown in FIG. 3 and is placed on the circuit board 14 in an inclined state. Usually, since the suction nozzle 3 is held on the upper side via a spring (not shown), the component 10 is pushed toward the circuit board 14 by the spring force indicated by the arrow 13. This pushing force is usually large enough to push the component 10 beyond the center of gravity G of the component 10 at any position.

  FIG. 12C shows this state in plan view. If the prior art condition that the projection point of the center of gravity G exists in the virtual plane, the triangle serving as the basis of the virtual plane is a triangle indicated by a broken line connecting the joint positions of the lead wires 11a, 11b, and 11c having a large deformation amount. Should be. However, in practice, the component 10 is a plane based on a triangle including the solid line in the figure connecting the three lead wires 11a, 11b, and 11d including the other high lead wire 11d by the pushing action of the suction nozzle 3 described above. It will be placed on the circuit board 14.

  In such a case, as shown in FIG. 12 (c), the component 10 is determined to be a non-defective product as a result of detection of lead floating on a virtual plane based on a broken-line triangle including the projected point of the center of gravity G. However, in actuality, mounting by tilting in the opposite direction increases the distance R (shown in FIG. 12 (b)) between the lead wire 11 and the circuit board 14 shown on the right side of the figure, and leads floating. There is a risk of becoming. In fact, at the manufacturing site, there is often a problem in that a defective joint 10 is found after mounting the component 10 that is made non-defective by the detection method based on the virtual plane including the center of gravity according to the conventional technique.

  As described above, the present invention solves the above-described problems caused by the prior art and takes the component suction position S by the suction nozzle 3 into consideration, and leads regardless of the relationship between the component suction position S and the center of gravity G. A defective component detection method that can detect in advance a defective component including a float and can avoid the occurrence of the circuit board 14 due to a bonding failure of the lead wire 11, and component mounting using the detection method It aims to provide a method.

  The present invention detects lead floating based on a first virtual plane based on a triangle including a component suction position, or in addition to this, based on a triangle including the position of the center of gravity of the component as necessary. The above-described problem is solved by detecting lead floating based on the second virtual plane, and specifically includes the following contents.

  That is, one aspect according to the present invention includes lead floating that causes a bonding failure of lead wires when a component having a plurality of lead wires extending toward the circuit board is mounted on the circuit board by the suction nozzle. In a defective component detection method for finding a defective component before mounting and eliminating the defective component, a bonding position of three lead wires assumed to contact the surface of the circuit board when the component is placed on the circuit board A first virtual plane is identified from a first basic triangle that includes a component suction position of a suction nozzle that sucks and holds the component, and the first virtual plane is The present invention relates to a defective component detection method, wherein the presence or absence of lead floating is determined based on whether or not the height of the bonding position of each lead wire measured with reference is within a predetermined allowable range. The first virtual plane is obtained in consideration of the pushing action by the suction nozzle, and the quality of the part is judged based on this.

  A component placed on the circuit board when the component suction position and any one of the three sides constituting the first basic triangle are close to each other within a predetermined range; However, it may not be stable on the first virtual plane. In such a case, it is another triangle positioned on the opposite side of the first basic triangle with respect to the one side, and contacts the surface of the circuit board when the component swings around the one side as an axis. Then, the second virtual plane is specified from the second basic triangle formed by the joint position of the other one lead wire assumed to be and the one side, and each lead wire measured with reference to the second virtual plane It is preferable to further determine the presence or absence of lead floating based on whether or not the height of the joining position is within a predetermined allowable range.

  If the position of the center of gravity of the component is not included in the first basic triangle, the component placed on the circuit board may still not be stable on the first virtual plane. In such a case, the first swing axis that is the side closest to the center of gravity position among the three sides constituting the first basic triangle is specified, and the first swing axis is determined with respect to the first swing axis. Other triangles located on the opposite side of the first basic triangle, and other parts assumed to contact the surface of the circuit board when the component swings around the first swing axis. A second imaginary plane is identified from a second basic triangle composed of a joint position of one lead wire and the first swing axis, and each lead wire measured with reference to the second imaginary plane is used. It is preferable to further determine whether or not the lead floats based on whether or not the height of the joining position is within a predetermined allowable range.

  Furthermore, even if the position of the center of gravity of the component is included in the first basic triangle, it is closest to the position of the center of gravity among the three sides constituting the first basic triangle. When the first swing axis as a side and the position of the center of gravity are close to each other within a predetermined range, the component may not be stable on the first virtual plane. In such a case, a second basic triangle located on the opposite side of the first basic triangle with respect to the first swing axis is obtained in the same manner as described above, and specified from the second basic triangle. It is preferable to further determine whether or not the lead floats based on whether or not the height of the joining position of each lead wire measured with reference to the second virtual plane is within a predetermined allowable range.

  Similarly, the position of the center of gravity of the part is included in the first basic triangle, and the second closest approach to the position of the center of gravity is included in the three sides constituting the first basic triangle. When the distance between the second side and the position of the center of gravity is close to a predetermined range, the component may not be stable even in the direction of the second side. In such a case, it is another triangle located on the opposite side of the first basic triangle with respect to the second side, and when the component swings around the second side as the axis, A third imaginary plane is identified from a third basic triangle composed of a joining position of another lead wire assumed to contact the surface of the circuit board and the second side, and the third imaginary plane is specified. It is preferable to further determine whether or not the lead floats based on whether or not the height of the joint position of each lead wire measured with respect to the virtual plane is within a predetermined allowable range.

  Furthermore, the position of the center of gravity of the component may not be included in the second basic triangle. In such a case, a second swing axis that is the side closest to the position of the center of gravity among the three sides constituting the second basic triangle is obtained, and the second swing axis is determined with respect to the second swing axis. And another triangle located on the opposite side of the second basic triangle, and is assumed to contact the surface of the circuit board when the component swings about the second swing axis. Each lead measured by using the third virtual plane as a reference by specifying the third virtual plane from the third basic triangle formed by the joining position of the other lead wire and the second swing axis. It is preferable to further determine the presence or absence of lead floating based on whether or not the height of the joining position of the wires is within a predetermined allowable range.

  Further, even when the position of the center of gravity of the component is included in the second basic triangle, the first swing axis is excluded from the three sides constituting the second basic triangle. When the second swing axis that is the side closest to the center of gravity position and the center of gravity position are close to each other within a predetermined range, the component is the second virtual plane. It may not be stable on top. Accordingly, even in such a case, a third basic triangle located on the opposite side of the second basic triangle with respect to the second swing axis is obtained in the same manner as described above, and the third basic is determined. The presence or absence of lead floating may be further determined based on whether or not the height of the joint position of each lead wire measured with reference to the third virtual plane specified from the triangle is within a predetermined allowable range. preferable.

  Another aspect according to the present invention is a component mounting method in which a component supplied to a component supply unit is taken out by a suction nozzle, and the component is transported and mounted at a mounting position on a circuit board. The present invention relates to a component mounting method using any one of the above-described defective component detection methods in order to detect a defective component including a lead wire that may possibly occur before mounting. In this case, whether or not the component sucked and held by each suction nozzle is determined by the defective component detection method, and when it is determined that the component is a non-defective product, the suction nozzle mounts the component at a predetermined mounting position on the circuit board, When it is determined that the component is defective, the suction nozzle may include a procedure of discarding the component at a predetermined component collection position without mounting the component on the circuit board.

  By implementing the present invention, it becomes possible to detect and discard components including lead wires that may cause poor connection with the terminal on the circuit board side due to lead floating, and to reduce the quality of defective circuit boards in component mounting and quality Can improve economic efficiency by reducing the number of components and circuit boards to be discarded, and increase the operating rate of the component mounting equipment.

  A defective part detection method according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a side view showing a state in which the component 10 is sucked and held by the suction nozzle 3. In the figure, the suction nozzle 3 sucks the component at a position deviating from the center position of the component 10. Note that when the component 10 is captured in a three-dimensional manner, it is conceivable that the same positional deviation occurs in the direction perpendicular to the drawing, but only the side view will be described for simplification of description. Further, in the following explanation, the component suction position S is targeted for a state deviating from the center position of the component, but the detection method of the present embodiment is the same even when the component suction position is near the center of the component as normal. It can be applied to.

  In FIG. 1 (a), the three-dimensional sensor 20 is opposed to the lower side of the component 10, and the three-dimensional sensor 20 is a reference object as described with reference to FIGS. 9 (a) and 9 (b). The height is measured by detecting the laser light that is reflected back. Thereby, the height of the joining position 12 of each lead wire 11 which becomes a joining point when mounted on the circuit board 14 can be measured. In the measurement, after measuring the height of the joint position 12 of the lead wire 11, a least square line is obtained, and variations in height with respect to the least square line are captured. For this reason, the influence on the height due to the inclination of the component 10 held by the suction nozzle 3 can be easily eliminated, and the following description will be made excluding the factor due to the inclination.

  The height data of each lead wire 11 measured as described above is used, and then the virtual plane P is specified. The virtual plane P is a triangle (hereinafter referred to as a “basic triangle”) that connects the three joint positions of the lead wire 11 that has the largest protrusion amount when the component 10 is placed on the circuit board 14, that is, the high lead wire 11. It is a fixed plane. When there are a large number of support points (joint positions 12 of the lead wires 11 in this case), which three of the points define the basic triangle depends on which part of the component 10 is loaded. In the case of the present embodiment, it is assumed that the pushing force by the suction nozzle 3 is the largest load element with respect to the component 10, and a basic triangle is defined by the three joint positions 12 including the component suction position S therein. Will be. Such a virtual plane P can be obtained as follows, for example.

  When the component 10 held by the suction nozzle 3 in the state shown in FIG. 1A is mounted on the circuit board 14, the component 10 is inclined and placed on the circuit board 14 by the pushing action by the suction nozzle 3 described above. Placed. As shown in FIG. 1B, the virtual plane P when assuming component mounting is a position where the component suction position S by the suction nozzle 3 (correctly, the component suction position S is projected onto the virtual plane P). However, in this specification, it is referred to as a component suction position S for the sake of convenience.) Is included in the basic triangle formed by the joint positions 12 of the three lead wires 11 serving as the basis of the virtual plane P. Must be. At this time, the position of the center of gravity G of the component 10 (specifically, the position projected on the virtual plane P. In the following description, for the sake of convenience, “center of gravity position G” is excluded).

  The component suction position S can be obtained by the component recognition device 6 (see FIG. 7) that recognizes the holding state of the component 10 by the suction nozzle 3. That is, the component recognition device 6 is configured to perform the recognition operation of the component 10 when the suction nozzle 3 that has sucked the component 10 comes to the center position of the visual field. For this reason, it can identify easily by utilizing the relative positional relationship of the center position (namely, the position of the suction nozzle 3) of the imaged image, and the recognized component 10. FIG.

  Next, the three lead wires 11 serving as the basis of the virtual plane P can be specified by the following logic. First, based on the height data of each joint position 12 of the lead wire 11 measured by the above-described method, the lead wires 11 provided on the outer periphery of the component 10 are sequentially compared in a certain direction, and 2 having a large protrusion amount. Find a point. For example, in FIG. 2A, the height of the joining position 12 of each lead wire 11 is compared in the counterclockwise direction indicated by an arrow starting from the lead wire 11 at the position indicated by A. If the component 10 is a polygon such as a rectangle as shown in the figure, first, the highest two lead wires 11a and 11b in the same side are found. Here, “highest” means that none of the other lead wires 11 on the same side is higher than the straight line connecting the two lead wires 11a and 11b.

  Subsequently, proceeding in the same direction (in the case of a polygon, proceeding to the next adjacent side), the joining position 12 of the next lead wire 11 and the joining position 12 of the two found lead wires 11 are connected. A triangle is assumed, and it is verified whether the component suction position S is included in the triangle. If not included, the triangle does not form a virtual plane. Similarly, the joining position 12 of each lead wire 11 is verified in the same direction, and when the lead wire 11 (in the case of 11c shown in FIG. 2A) including the component suction position S is found, A triangle indicated by a broken line in the figure formed between the lead wires 11a and 11b is assumed as a temporary virtual plane p1.

  Next, on the basis of the temporary virtual plane p1, the heights of the joint positions 12 of the lead wires 11 are further compared in the same direction, and the height of the joint positions 12 is higher than that of the temporary virtual plane p1. It is verified whether it is low (that is, it does not protrude in the direction of the circuit board 14). When the high lead wire 11 (for example, 11d shown in FIG. 2B) protruding from the temporary virtual plane p1 is found, the temporary virtual plane p1 so far can no longer be the virtual plane. Next, any two of the three lead wires 11a, 11b, and 11c that include the found high lead wire 11d and that constitute the temporary virtual plane p1 so far are selected, and new A basic triangle indicated by a broken line in FIG. 2B that is the basis of the temporary virtual plane p2 is obtained. At this time, the condition is that the component suction position S is included in the new triangle. In addition, of the lead wires 11a, 11b, and 11c constituting the temporary virtual plane p1, the remaining one point other than the two previously selected points is lower than the virtual plane p2. If this condition is not satisfied, it means that the selection of the previous two points was wrong. In this case, the two points related to other combinations are selected again, and the temporary connection with the lead wire 11d is similarly performed. The virtual plane p2 is obtained, and it is confirmed that the remaining one point is lower than the temporary virtual plane p2.

  In this way, the provisional virtual plane p2 is specified, and in the same manner, based on the provisional virtual plane p2, the joint positions of the lead wires 11 are successively compared in the same direction. Is lower than the provisional virtual plane p2. When a lead wire 11 higher than the temporary virtual plane p2 (11e shown in FIG. 2B) is found, the basis of the new virtual virtual plane p3 including the higher lead wire 11e is the same as before. Find the basic triangle (shown by the dashed line in the figure). In this way, the joint position heights of all the lead wires 11 are checked around the part 10, the original point A is returned, and the second round check is performed in the same direction. This is because when the lead wire 11 (for example, 11e shown in the figure) having a particularly high protruding amount is found during the first round, the component 10 is largely inclined while being placed on the circuit board 14, so that This is because even if the lead wire 11 is considered to be low (for example, 11f shown in FIG. 2C), there is a possibility of forming a basic triangle of a virtual plane. Thereafter, the height confirmation is sequentially advanced in the same manner, and when the new lead wire 11 protruding from the temporary virtual plane pn after one round of the confirmation is not found, the temporary virtual plane pn is changed to the final virtual plane. P can be specified (indicated by a solid line in FIG. 2C).

  That is, the finally specified virtual plane P includes the component suction position S, and is composed of the joint positions of the three lead wires 11 (11b, 11e, 11f) that protrude highest toward the circuit board 14. This means that the height of the joint position of all the other lead wires 11 does not protrude from the virtual plane P and extend to the circuit board 14 side. When mounting the component 10, when the component 10 is pushed toward the circuit board 14 at the component suction position S by the suction nozzle 3, it can be assumed that the virtual plane P coincides with the surface of the circuit board 14. Again, this virtual plane P is not related to the center of gravity position G of the part, and the center of gravity position G is out of consideration.

  The virtual plane P specified as described above is used as a reference plane, and then the lead floating of each lead wire 11 is confirmed. As shown in FIG. 1B, the height R of the joint position 12 of each lead wire 11 from the virtual plane P is obtained from the previous measurement data, and it is verified whether these are within a predetermined allowable range. . If even one lead wire 11 that falls outside the allowable range is found, it is determined that the component 10 includes a factor that causes a bonding failure with the circuit board 14 and is eliminated in advance without being mounted. Specifically, the control unit 9 (see FIG. 7) stops the mounting operation of the component 10 with respect to the suction nozzle 3 that sucks the component 10, and reaches the component collection position separately provided in the component mounting apparatus 1. Issue a directive to transport and discard. If the heights of the joining positions 12 from the virtual plane P are all within the allowable range, a mounting operation command can be given to the suction nozzle 3 that sucks the component 10.

  As described above, when the component 10 is actually mounted on the circuit board 14, the virtual plane P corresponding to the mounting plane is determined by the pushing action of the suction nozzle 3 instead of the gravity center position G of the component 10. In the prior art, since there was no idea of obtaining the virtual plane P based on the component suction position S, a defective circuit board is found after the mounting of all the parts to be mounted on the circuit board 14 is completed. There was a problem. By implementing the present invention, it is possible to eliminate such a problem.

  Next, a method for detecting a defective part including a lead float according to the second embodiment of the present invention will be described with reference to the drawings. As described in the first embodiment, the component 10 is based on a triangle connecting three joint positions 12 including the component suction position S by the pushing action by the suction nozzle 3 regardless of the center of gravity position G. It can be assumed that the virtual plane P is a mounting plane when components are mounted. Since a paste-like cream solder layer is provided on the surface of the circuit board 14, the component 10 is usually transported to the next reflow process while being mounted by the adhesive force of the cream solder layer. The lead wires 11 are soldered together.

  However, as shown in FIG. 3A, after the suction nozzle 3 that has finished the mounting operation is lifted away from the component 10, the component 10 is held on the virtual plane P (the surface of the circuit board 14 in the figure). The restraining force from the outside to keep is lost, and the component 10 can be in an unstable state. For example, when the circuit board 14 after component mounting is suddenly accelerated in the direction shown by the arrow 17 for conveyance, or when some factor such as vibration of the apparatus or wind pressure acts, the force due to this external factor is increased. If the adhesive strength of the ream solder that holds the component 10 in the state indicated by the broken line of FIG. 10 is exceeded, the component 10 supports the joint position 12a of the lead wire 11a that is the basis of the virtual plane P as indicated by the solid line in the figure. As a result, the situation of tilting in the opposite direction can occur. In this case, if the center-of-gravity position G of the component 10 is on the right side of the bonding position 12a, the component 10 can be stabilized on the circuit board 14 in this reversely inclined state. When such a situation occurs, the lead wire 11b located on the left side of the drawing is separated from the circuit board 14, and this may cause a new lead floating.

  FIG. 3B shows the component 10 at this time as viewed from above. Since the center of gravity G of the component 10 is located outside the triangle connecting the three lead wires 11a, 11b, 11c including the component suction position S that is the basis of the virtual plane P1, the component suction position S The pressed part 10 was originally in an unstable state. When the external force as described above is applied, if the restraining force from above by the suction nozzle 3 at the component suction position S is lost, one side connecting the lead wires 11a and 11c in the basic triangle that is the basis of the virtual plane P1. The component 10 can be inclined to the opposite side with V as an axis (hereinafter, this axis is referred to as “oscillation axis V”). In this case, the component 10 is located between the joint position 12 of the other lead wire 11d having a large protruding amount on the right side of the drawing and the joint positions 12 of the two lead wires 11a and 11c forming the swing shaft V. It becomes stable on the plane P2 corresponding to the new basic triangle indicated by the solid line.

  Alternatively, as shown in FIG. 3C, when the center of gravity G of the component 10 is on the rocking axis V of the basic triangle that is the basis of the virtual plane P1, or even if it is within the basic triangle. However, if the swing axis V is too close, the component 10 may be inclined in the opposite direction around the swing axis V due to the action of a rotational moment caused by the rapid acceleration of the circuit board 14. How close the swing axis V and the center of gravity G are to each other depends on the viscosity and amount of cream solder used, the acceleration / deceleration speed of the circuit board 14, and so on. Absent.

  Assuming the above situation, a virtual plane based on a triangle including the component suction position S shown in the first embodiment (hereinafter referred to as “first virtual plane P1”) is added. Assuming another virtual plane (hereinafter referred to as “second virtual plane P2”) located on the opposite side of the first virtual plane P1 with respect to the swing axis V, each lead wire 11 is assumed. It is preferable to verify whether the height of the bonding position 12 is within a predetermined allowable range in order to avoid the occurrence of defective substrates. In this case, the “oscillation axis” is the side closest to the center of gravity G of the component 10 among the three sides constituting the basic triangle that is the basis of the first virtual plane P1 (FIG. 3B, (Side connecting the lead wires 11a and 11c) in (c).

  The logic for specifying the basic triangle that is the basis of the second virtual plane P2 is as follows. In FIG. 3C, two of the joining positions 12 of the lead wires 11 constituting the basic triangle have already been specified by the lead wires 11 a and 11 c constituting the swing axis V. For the lead wires 11 having one remaining joint position, the lead wires 11 positioned on the right side with respect to the swing axis V are sequentially selected one by one in one direction (for example, starting from the lead wire 11x adjacent to the lead wire 11a). The two lead wires 11a and 11b constituting the swing axis V and the lead wire 11 are connected to form a triangle, and a temporary virtual plane Px (not shown) based on the triangle. ) First. Next, it is verified whether or not the subsequent bonding position 12 of each lead wire 11 does not protrude toward the circuit board 14 beyond the temporary virtual plane Px. If a protruding lead wire 11y (not shown) is found, a triangle connecting the joint position of the protruding lead wire 11y and the two lead wires 11a and 11c constituting the previous swing axis V will be described hereinafter. Is replaced with a provisional virtual plane Py (not shown), and the same procedure is repeated. All the lead wires 11 positioned on the right side of the swing axis V are confirmed in the same manner, and the provisional virtual plane when the joining position of the lead wires 11 protruding further is not found is “the second virtual plane P2. Is identified.

  Next, with respect to the second virtual plane P2 specified as described above, the heights of the joint positions 12 of all the lead wires 11 are measured with reference to the second virtual plane P2, and each height is determined in advance. Verify whether it is within the specified tolerance. This height measurement is the same as the height measurement for the first virtual plane P1 in the previous embodiment. In the unlikely event that even one lead wire 11 deviating from the allowable range is found, the component 10 including the deviated lead wire 11 may float on the lead when tilted in the reverse direction described above. It means that it is discarded as a defective product in advance. Reworking of the part 10 after disposal is possible as well.

  That is, in this embodiment, in addition to the verification of the joint position height of each lead wire 11 from the first virtual plane P1 based on the component suction position S by the suction nozzle 3 shown in the first embodiment, By also verifying the joint position height of each lead wire 11 from the second virtual plane P2 located on the opposite side across the swing axis V, the occurrence of a defective circuit board can be prevented with higher accuracy. It is supposed to be. Whether or not the verification of the height with respect to the second virtual plane P2 as a reference is added to the defective component detection procedure, first, the center-of-gravity position G of the component 10 in the triangle that forms the basis of the first virtual plane P1. Is the first criterion, and even if it is included, the second criterion is whether or not the center of gravity position G and the swing axis V are close to each other. . As described above, how close the center of gravity G and the swing axis V are to be added to the target of the defective part determination is not unconditionally determined by various factors, but is individually determined by the state of occurrence of defective lead floating. It is preferable. As an example, for example, if the circuit board 14 is rectangular, the length of the side including the lead wire 11 constituting the swing axis V is 1/5 to 1/10, and if it is circular, the diameter is 1/5 to 1 It can be a temporary measure whether or not the distance is within 10/10.

  When the component suction position S by the suction nozzle 3 is close to the swing axis V within a predetermined range (including the case where the component suction position S is on the swing axis V), the gravity center position G Regardless of which side of the oscillating shaft V is located, it is possible that the component 10 once mounted by some external force may be inclined to the opposite side around the oscillating shaft V described above. Accordingly, even in such a case, it is preferable to verify the lead float on the basis of the first and second virtual planes P1 and P2 on both sides of the swing axis V as a boundary.

  FIG. 4 shows another aspect of the present embodiment. In the figure, the solid line indicates a basic triangle that is the basis of the first virtual plane P1 constituted by the lead wires 11a, 11b, and 11c. In the example shown in the figure, both the component suction position S and the gravity center position G of the component 10 are included in this basic triangle. However, the two sides of the triangle are both close to the center of gravity G, and after the component 10 is mounted on the circuit board 14, it is inclined in either of the following directions due to equipment vibration, acceleration / deceleration of the circuit board 14, etc. It is in an unstable state that cannot be judged.

  In such a case, both the first side connecting the triangular lead wires 11a and 11b and the second side connecting the lead wires 11a and 11c, which are the basis of the first virtual plane P1, are swing axes. It is preferable to assume that there are two second virtual planes P2 located on opposite sides of the first virtual plane P1 with respect to the respective swing axes V. That is, in addition to verifying the height of the joint position 12 of each lead wire 11 with respect to the first virtual plane P1, the height of each joint position 12 with respect to the two second virtual planes P2 is determined. It is assumed that it is verified to determine whether the component 10 should be mounted or discarded. Identification of the lead wires 11 (11d and 11e in FIG. 4) constituting the basic triangle that is the basis of each second virtual plane P2, and the height of the joining position of each lead wire 11 from the second virtual plane P2 The measurement procedure is the same as described above. The degree to which the component suction position S, the center of gravity position G, and the side serving as the swing axis V are close to each other is determined in a manner similar to that described above. In other words, the determination is made according to the situation of the occurrence of the malfunction.

  Next, a method for detecting a defective part including a lead float according to a third embodiment of the present invention will be described with reference to the drawings. In FIG. 5, a basic triangle serving as a basis of the first virtual plane P1 indicated by a broken line in the drawing in consideration of the component suction position S is specified by connecting the lead wires 11a, 11b, and 11c. In the case where the center of gravity G is not included in the basic triangle, next, on the opposite side of the previous basic triangle with respect to the swing axis V connecting the lead wires 11a and 11b which are sides closest to the center of gravity G. A basic triangle that is the basis of the second virtual plane P2 that is positioned is specified by connecting the swing axis V and another high lead wire 11d as indicated by a solid line. And the height of the joining position of each lead wire 11 is verified on the basis of the respective virtual planes P1, P2, and the quality of the component is verified. The procedure so far is the same as that of the second embodiment.

  However, in this case, as shown in FIG. 5, there is a possibility that the gravity center position G does not exist in the basic triangle indicated by the solid line that is the basis of the second virtual plane P2. Alternatively, even if the center of gravity position G is included in the basic triangle, in the case where the center of gravity position G is close to one side other than the side constituting the swing surface V, as shown in FIG. In addition, it is not closest to the swing axis V (hereinafter referred to as “first swing axis V1”) that defines the first and second virtual planes P1 and P2, but is closest to the gravity center position G. The component 10 is defined by the first and second imaginary planes P1 and P2 around a swing shaft (hereinafter referred to as “second swing shaft V2”) connecting the lead wires 11a and 11d as sides. Further tilting in the opposite direction can occur.

  When such a phenomenon occurs, the determination of the joining position height of the lead wire 11 with reference to the first and second virtual planes P1 and P2 is insufficient, and the determination becomes insufficient with respect to the second swing axis V2. Assuming a third virtual plane P3 based on a triangle including the one-dot chain line in the figure located on the opposite side of the second virtual plane P2, each lead wire is based on the third virtual plane P3. It is preferable to verify the height of the bonding position 11 in order to prevent the occurrence of defective circuit boards. The present embodiment is directed to a detection method including such a procedure.

  The basic triangle on which the third virtual plane P3 is based is specified on the right side of the drawing with respect to the two lead wires 11a and 11d constituting the second swing axis V2 and the second swing axis V2. First, a temporary virtual plane Px (not shown) constituted by the bonding position 12 of any one of the lead wires 11 is assumed, and the other lead wires 11 cross the temporary virtual plane Px and the circuit board 14. It can be done by sequentially verifying whether or not it protrudes in the direction of. This procedure is the same as the procedure for specifying the basic triangle that is the basis of the second virtual plane P2 described above.

  If the lead wires 11a, 11d, and 11e constituting the basic triangle that is the basis of the third virtual plane P3 are specified by the above logic, then all the lead wires 11 from the third virtual plane P3 are joined. The position height is measured, and it is verified whether or not each height is within a predetermined allowable range. The procedure at this time is the same as in the previous embodiment. In the unlikely event that even one lead wire 11 that is out of the allowable range is found, the lead wire 11 that has come off is inclined so that the component 10 is along the third virtual plane 3 on the circuit board 14. May lead to floating and will be discarded to avoid mounting.

  That is, in this embodiment, the verification of the joint position height of each lead wire 11 with reference to the first virtual plane P1 shown in the first embodiment and the second shown in the second embodiment. In addition to the verification of the joint position height of each lead wire 11 with respect to the virtual plane P2, from the third virtual plane P3 located on the opposite side of the second swing axis V2 with respect to the second virtual plane P2. By also verifying the joint position height of each of the lead wires 11, it is possible to prevent the occurrence of a defective circuit board with higher accuracy. Whether or not to add the third virtual plane P3 to the defective component detection procedure is determined by first including the center-of-gravity position G of the component 10 in the basic triangle that is the basis of the first and second virtual planes P1 and P2. Whether or not the second center of gravity position G is close to the second swing axis V2 even if it is included. The standard. It is the same as described in the second embodiment that it is not possible to determine how close they are to be included in the procedure for determining a defective part.

  Here, it is assumed that the gravity center position G is included in any of the first to third virtual planes P1, P2, and P3, but it is not included in these, and the fourth, fifth,... It may theoretically be necessary to assume a virtual plane Pn. The procedure in this case is the same as the procedure for specifying the third virtual plane P3, and this procedure may be repeated until the gravity center position G is included in any one of the virtual planes.

  The embodiments of the defective part detection method according to the present invention have been described above. FIG. 6 shows a flowchart summarizing these procedures. The procedure of the defective part detection method according to the present invention will be described again with reference to the drawings. First, the part 10 is sucked by the suction nozzle 3 in step # 1, and the part by the suction nozzle 3 is used by using the part recognition device 6 in step # 2. The suction position S is detected. Next, in step # 3, the joint position height of each lead wire 11 of the component 10 is measured using the three-dimensional sensor 20. Based on the measurement result, a basic triangle for obtaining a virtual plane is specified in step # 4, and in step # 5, a (first) virtual plane P1 is specified based on the basic triangle.

  In step # 6, the joint position height of all the lead wires 11 is measured with reference to the virtual plane P1, and it is verified in step # 7 whether this result is within a predetermined allowable range. If it is not within the allowable range (No), it is determined in step # 9 that it is a defective part that causes the lead to float, and the part 10 is discarded without being mounted.

  If it is determined in step # 7 that it is within the allowable range (Yes), then, in step # 8, is the gravity center position G of the component 10 included in the basic triangle that is the basis of the virtual plane P1? Whether or not is verified. If it is included, the process proceeds to step # 10, and the component is sent to the component mounting as being non-defective. Here, even if the center of gravity position G is included in the basic triangle, if the center of gravity position G is close to any one side of the basic triangle, step # 12 and the following will be described. It may be an option to proceed to this procedure. Or conversely, even if the gravity center position G is not included in the basic triangle in step # 8, it can be an option to treat it as a non-defective product only by the determination in step # 7. The above is the procedure targeted in the first embodiment.

  Next, when the gravity center position G is not included in the basic triangle in step # 8, the process proceeds to step # 12, and the side closest to the gravity center position G is swung among the sides of the basic triangle. Next, in step # 14, the joint position 12 of the lead wire 11 having a large protruding amount that contacts when the component 10 is inclined to the opposite side around the swing axis V, and the swing axis V are identified. To identify the basic triangle. Based on the basic triangle, the second virtual plane P2 is specified in step # 15, and in step # 16, the joint position height of each lead wire 11 is measured with reference to the second virtual plane P2.

  In step # 17, it is determined whether or not the height of all the lead wires 11 is within the allowable range. If the height is out of the range (No), it is determined as a defective part in step # 9. At 18, it is verified whether or not the center of gravity position G of the part is included in the basic triangle of the second virtual plane P2. If the center-of-gravity position G is included in the basic triangle (Yes), the part is determined to be a non-defective product in Step # 10. If not included (No), the process can proceed to a further step (not shown). . Alternatively, it may be an option to treat the part as a non-defective product when it is determined in step # 17 that it is within the allowable range without proceeding to the next step. Alternatively, even if the center of gravity position G is included in the basic triangle in step # 18, if the center of gravity position G is close to any one side of the basic triangle, the following procedure is further performed. Proceeding can also be an option. The above is the procedure targeted in the second embodiment.

  Although omitted in FIG. 6, when the gravity center position G is not included in the basic triangle in Step # 18 (No), the subsequent procedure is a repetition of the procedure from Step # 12 to Step # 18. As a result, the third, fourth,... Virtual planes are obtained, and the quality of the component is determined based on whether or not the heights of all the lead wires are within the allowable range with reference to each virtual plane. This is the procedure targeted in the third embodiment.

  The defective part detection method of each embodiment according to the present invention has been described above. However, the application of the present invention is not limited to that displayed in each of the embodiments described so far. For example, the planar shape of a part is not limited to a rectangle or a polygon, but can be handled in the same manner even if it is a circle, an ellipse, or other irregular shapes. In the case of a circle or ellipse, it can be considered that one pitch of adjacent lead wires constitutes one side of a polygon.

  In the example shown in the drawing, the lead wire extends to the entire circumference of the outer peripheral portion of the component. However, the component does not necessarily extend to the entire circumference, and the component is mounted on the circuit board only by the lead wire. It is sufficient that the lead wire extends to a position where it can be placed. For example, in the case of a rectangular shape, a total of three or more lead wires extend from at least two sides, and in the case of a circular shape, a total of three or more lead wires need only extend from at least three places with appropriate intervals.

  Further, in the above-described example, the lead wire extends from the component and extends, but this is not always necessary, and a plurality of terminals provided on the bottom surface (surface on the mounting side) of each component are connected to the circuit board side. Even if it is a case where it joins to this terminal, it is possible to apply the defective component detection method of this invention similarly. Accordingly, the lead wire referred to in this specification includes a terminal of such a type that directly extends from the surface of the component. However, even in this case, each terminal protrudes downward from the bottom surface of the component, that is, when the component is placed on the circuit board, other elements are first placed on the surface of the circuit board. It is a premise that the configuration is such that it does not contact.

  In the above description, the defective component detection method has been described. However, the present invention also includes a component mounting method in which components including lead floating are excluded in advance using the defective component detection method.

  The defective component detection method and component mounting method according to the present invention can be widely used in the industrial field of component mounting in which components such as electronic components are mounted on a circuit board.

It is explanatory drawing which shows the aspect of the virtual plane in the defective component detection method of embodiment concerning this invention. It is explanatory drawing which shows the procedure which pinpoints the virtual plane shown in FIG. It is explanatory drawing which shows the aspect of the virtual plane in the defective component detection method of other embodiment concerning this invention. It is explanatory drawing which shows the other aspect of the virtual plane shown in FIG. It is explanatory drawing which shows the aspect of the virtual plane in the defective component detection method of further another embodiment concerning this invention. It is a flowchart which shows the procedure of the defective component detection method concerning this invention. It is a perspective view which shows the component mounting apparatus which can apply the defective component detection method concerning this invention. It is explanatory drawing which shows the condition where the lead wire extended around a component becomes a malfunction of lead floating. It is a side block diagram which shows the internal structure of the three-dimensional sensor which measures the joining position height of the lead wire shown in FIG. It is explanatory drawing which shows the condition where the lead wire extended around the component with which the circuit board was mounted | worn becomes a malfunction of a lead floating. It is explanatory drawing which shows the detection method for detecting the lead floating defect disclosed by the prior art. It is explanatory drawing which shows the problem of the detection method shown in FIG.

Explanation of symbols

1. 1. component mounting device; Component supply unit, 2a. Tray-type component supply unit, 2b. 2. Cassette-type component supply unit Suction nozzle, 6. Component recognition device, 8a. Tray, 9. Control unit, 10. Parts, 11. 11. Lead wire Bonding position, 14. Circuit board, 20. 3D sensor,
C. The center of the part (intersection of the part diagonal); The center of gravity (position of the center of gravity) of the part; Virtual plane; Part suction position, V. Oscillating shaft.

Claims (10)

When mounting a component with multiple lead wires that extend toward the circuit board on the circuit board using a suction nozzle, a defective component that includes a lead float that causes a lead wire joint failure is found and eliminated. In the defective part detection method for
A component suction of a suction nozzle that is formed by a joining position of three lead wires that are assumed to come into contact with the surface of the circuit board when the component is placed on the circuit board, and sucks and holds the component. Identifying a first imaginary plane from a first basic triangle containing a position therein;
A defective part characterized in that the presence or absence of lead floating is determined based on whether or not the height of the joining position of each lead wire measured with respect to the first virtual plane is within a predetermined allowable range. Detection method. When the part suction position and any one of the three sides constituting the first basic triangle are close to each other within a predetermined range, the first basic triangle with respect to the one side Other one of the triangles located on the opposite side of the one side, and when the component swings around the one side as an axis, the joining position of the other one lead wire assumed to contact the surface of the circuit board and the one side A second virtual plane is identified from a second basic triangle formed by
The presence or absence of lead floating is further determined based on whether or not the height of the joining position of each lead wire measured with respect to the second virtual plane is within a predetermined allowable range. The defective part detection method according to claim 1. If the center of gravity of the component is not included in the first basic triangle, the first of the three sides constituting the first basic triangle is the side closest to the center of gravity. Identify the swing axis,
The circuit board when another component is located on the opposite side of the first basic triangle with respect to the first oscillation axis, and the component swings about the first oscillation axis. A second imaginary plane is identified from a second basic triangle formed by the joining position of another lead wire assumed to contact the surface of the first surface and the first swing axis,
The presence or absence of lead floating is further determined based on whether or not the height of the joining position of each lead wire measured with respect to the second virtual plane is within a predetermined allowable range. The defective part detection method according to claim 1. It is a case where the centroid position of the part is included in the first basic triangle, and is the side closest to the centroid position among the three sides constituting the first basic triangle When the distance between the first swing axis and the position of the center of gravity is close to a predetermined range, the other is located on the opposite side of the first basic triangle with respect to the first swing axis. A position of another lead wire assumed to come into contact with the surface of the circuit board when the component swings around the first swing axis, and the first swing. A second virtual plane is identified from a second basic triangle composed of a moving axis;
The presence or absence of lead floating is further determined based on whether or not the height of the joining position of each lead wire measured with respect to the second virtual plane is within a predetermined allowable range. The defective part detection method according to claim 1. Of the three sides constituting the first basic triangle, when the second side that is second closest to the center of gravity position and the center of gravity is within a predetermined range, Another triangle located on the opposite side of the first basic triangle with respect to the second side, and when the component swings around the second side as an axis, A third imaginary plane is identified from a third basic triangle constituted by the joining position of another lead wire assumed to be in contact with the second side;
The presence or absence of lead floating is further determined based on whether or not the height of the joint position of each lead wire measured with respect to the third virtual plane is within a predetermined allowable range. The defective part detection method according to claim 4. If the centroid position of the component is not included in the second basic triangle, the second position which is the side closest to the centroid position among the three sides constituting the second basic triangle Find the swing axis,
The circuit board when another component is located on the opposite side of the second base triangle with respect to the second swing axis, and the component swings about the second swing axis. A third imaginary plane is identified from a third basic triangle composed of the joining position of another lead wire assumed to be in contact with the surface of the first and the second swing axis,
The presence or absence of lead floating is further determined based on whether or not the height of the joint position of each lead wire measured with respect to the third virtual plane is within a predetermined allowable range. The defective part detection method according to claim 3. The position of the center of gravity of the component is included in the second basic triangle, and the center of gravity excluding the first oscillation axis among the three sides constituting the second basic triangle When the distance between the second swing axis that is the side closest to the position and the position of the center of gravity approaches within a predetermined range, the second swing axis is Yet another triangle that is located on the opposite side of the basic triangle of the circuit board and that is assumed to contact the surface of the circuit board when the component swings about the second swing axis. A third imaginary plane is identified from a third basic triangle formed by the joining position of the lead wire and the second swing axis;
The presence or absence of lead floating is further determined based on whether or not the height of the joint position of each lead wire measured with respect to the third virtual plane is within a predetermined allowable range. The defective part detection method according to claim 3.   The defective part detection method according to any one of claims 1 to 7, wherein the part is any one of a capacitor, a QFP (Quad Flat Package), and a BGA (Ball Grid Array). In the component mounting method of taking out the component supplied to the component supply unit by the suction nozzle, transporting the component and mounting it on the mounting position of the circuit board,
The defective part detection method according to any one of claims 1 to 8, wherein a defective part including a lead wire that may cause a bonding failure due to lead floating is detected before mounting. Component mounting method. Judge the quality of the parts sucked and held by each suction nozzle by the defective part detection method,
When it is determined that the product is a non-defective product, the suction nozzle mounts the component at a predetermined mounting position on the circuit board,
The component mounting according to claim 9, further comprising a procedure for discarding the suction nozzle at a predetermined component recovery position without mounting the component on the circuit board when the suction nozzle is determined to be a defective component. Method.

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