JP2007027247A - Mounting method of electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting method of an electronic component which detects falling of a component sucked by a multiple-nozzle unit during mounting work. <P>SOLUTION: In this mounting method of an electronic component, electronic components are sucked by the multiple-nozzle unit 20 connected to a manifold 30 communicated with vacuum sources 24 and 26, and the individual electronic components are mounted one by one at a plurality of mounting positions while detecting the vacuum pressure inside the manifold 30. The vacuum pressure inside the manifold 30 is detected by a vacuum pressure detection sensor 32 attached to the manifold 30 before and after the multiple-nozzle unit 20 moves to the mounting positions for the electronic components sequentially. When a difference in vacuum pressure before and after the movement is within a predetermined threshold value or less, it is determined that there was no falling of components and the components are mounted. When the difference in vacuum pressure before and after the movement exceeds the threshold value, it is determined that there has been falling of components and the components are not mounted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic component mounting method in which an electronic component of an electronic component supply unit is sucked by a multiple nozzle and mounted on a mounting target such as a substrate.

  In the field of mounting electronic components (hereinafter referred to as “components”), mounting devices are widely used in which components of an electronic component supply unit are adsorbed by a nozzle provided in a transfer head and mounted on a mounting target such as a substrate. Yes. In addition, in order to increase the mounting efficiency of components, there is known one in which a plurality of nozzles (multiple nozzles) are mounted on a transfer head.

  In this type of mounting apparatus, it has become an important issue to prevent the occurrence of a missing part substrate by reliably mounting the components adsorbed by the multiple nozzles on the substrate. For this reason, after the components of the electronic component supply unit are picked up and picked up by the multiple nozzles, a recognition operation is performed to check whether or not the components are picked up by the suction surface of the nozzle by a recognition unit such as a camera.

  However, even in the case of a nozzle that has been confirmed to be picking up a component in this recognition work, the part may fall from the nozzle after the recognition work until the part is mounted on the board. In this case, mounting is performed by a nozzle that does not adsorb components, and there is a possibility that a shortage substrate is generated.

As a means to solve such problems, the vacuum pressure in the multiple nozzles is monitored by a vacuum pressure sensor, and when the difference between the vacuum pressure at the time of component adsorption and the vacuum pressure immediately before mounting is a predetermined threshold or more, the component A mounting method has been proposed for determining that a fall has occurred. Further, in order to reduce the cost merit and the weight of the movable part, it has been proposed to monitor the vacuum pressure with a single vacuum sensor.
JP 2004-71830 A

  However, what is disclosed in the above-mentioned patent document is to detect a drop of a component that may occur when the transfer head moves to the mounting position on the substrate after the recognition work by the camera, and is adsorbed to each of the multiple nozzles. Further, when a plurality of components are sequentially mounted on the substrate, the component drop from the nozzle that sequentially moves to another mounting position on the substrate is not detected.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic component mounting method capable of detecting a drop during the mounting operation of a component adsorbed by a multiple nozzle.

  According to the first aspect of the present invention, each of the electronic components is adsorbed to the multiple nozzles connected to the intake passage communicating with the vacuum generation source, and the electronic components are mounted on the plurality of mounting targets while detecting the vacuum pressure in the intake passage. A method for mounting electronic components to be sequentially mounted at a mounting position, the first moving step of moving the multiple nozzles onto the first mounting position to be mounted, and the vacuum pressure before and after the first moving step If the difference is equal to or smaller than the first threshold value, the first mounting step of mounting the electronic component at the first mounting position, and the second of moving the multiple nozzles onto the next mounting position of the mounting target And a second mounting step of mounting an electronic component at the next mounting position if the difference in vacuum pressure before and after the second moving step is equal to or less than a second threshold. 2. Repeating the moving process 2 and the second mounting process Sequentially mounting electronic components on a plurality of mounting positions of the mounting object.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the difference in vacuum pressure before and after the first moving step exceeds the first threshold value, the first mounting step is interrupted. Do not mount electronic components.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the second mounting step is performed when the difference in vacuum pressure before and after the second moving step exceeds the second threshold value. Stop and do not mount electronic components.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the second threshold value is smaller than the first threshold value.

  According to the present invention, it is possible to detect a drop of a component during a mounting operation by a multiple nozzle, and it is possible to prevent the occurrence of a missing substrate.

  An embodiment of the present invention will be described with reference to the drawings. 1 is a perspective view of an electronic component mounting apparatus according to an embodiment of the present invention, FIG. 2 is a side view of a multiple nozzle according to an embodiment of the present invention, and FIG. FIG. 4 is a schematic diagram of an exhaust system, FIG. 4 is a piping diagram of an intake system according to an embodiment of the present invention, FIG. 5 is a configuration diagram of a control system of an electronic component mounting apparatus according to an embodiment of the present invention, and FIG. 7 is a flowchart showing the mounting operation of the electronic component in one embodiment of the invention, FIG. 7 is a graph showing the fluctuation of the absolute vacuum pressure in the intake passage in one embodiment of the invention, and FIGS. FIG. 10 is a side view of a multiple nozzle according to another embodiment of the present invention, and FIG. 10 is a graph showing fluctuations in the relative vacuum pressure in the intake passage in the embodiment.

  First, an electronic component mounting apparatus will be described with reference to FIGS. In FIG. 1, a conveyance path 2 extending in the X direction is disposed at a substantially center on a base 1. The conveyance path 2 conveys the substrate 3 as a mounting target and positions it at a predetermined position. In the present invention, the substrate transport direction is the X direction, and the direction perpendicular to the substrate in the horizontal plane is the Y direction. An electronic component supply unit 4 is disposed on both sides of the transport path 2 in the Y direction, and a plurality of tape feeders 5 are detachably arranged in parallel. A number of parts are stored in the tape feeder 5.

  A pair of Y tables 6 are disposed at both ends of the base 1 in the X direction. An X table 7 is installed on these Y tables 6 and moves in the Y direction by driving the Y table 6. A transfer head 8 is disposed on the side of the X table 7 and moves in the X direction by driving the X table 7. As shown in FIG. 2, the transfer head 8 is provided with a plurality of nozzles 20 (10 nozzles in the present embodiment) as multiple nozzles for sucking parts in a line in the X direction. The Y table 6 and the X table 7 are horizontal moving means for moving the nozzle 20 horizontally on the base 1.

  In FIG. 1, a line camera 9 as a component recognition unit is disposed between the conveyance path 2 and the electronic component supply unit 4, and picks up and picks up a component picked up by the nozzle 21 of the transfer head 8 from below. Then, the presence / absence of a component, the suction posture, etc. are recognized (see FIG. 2).

  Next, the structure of the intake / exhaust system in the transfer head 8 will be described with reference to FIGS. FIG. 3 is a piping diagram of the intake / exhaust structure, and FIG. 4 is a piping diagram of the intake system.

In FIG. 3, an intake pipe 21 and an exhaust pipe 22 are connected to each nozzle 20, and the intake pipe 21 and the exhaust pipe 22 are connected to an air pressure source 24 via an air pressure adjusting unit 23. Each nozzle 20 is connected to an intake pipe 21 via an intake valve 25, and the adsorption / non-adsorption of components at any nozzle 20 can be selectively controlled by opening / closing the intake valve 25. An ejector 26 and a regulator 27 are provided in series in the intake pipe 21. When a compressed air flow is sent from the air pressure source 24 to the ejector 26, the intake pipe 21 is sucked with a negative pressure. The air pressure source 24 and the ejector 26 serve as a vacuum generation source that causes the nozzle 20 to attract components.

  In addition, each nozzle 20 is connected to the exhaust pipe 22 via an exhaust valve 28, and the suction and breakage of components at any nozzle 20 can be selectively controlled by opening and closing the exhaust valve 28. A regulator 29 is interposed in the exhaust pipe 22.

  In FIG. 4, the intake pipe 21 communicates with a manifold 30, and ten nozzles 20 are attached to the manifold 30 in a line at equal intervals. Each nozzle 20 communicates with the manifold 30 through a ventilation path 31, and the intake valve 25 is interposed in the ventilation path 31. A vacuum pressure sensor 32 is attached substantially at the center of the manifold 30 to detect the vacuum pressure in the intake system from the intake pipe 21 to each nozzle 20. The manifold 30 serves as an intake passage for communicating each nozzle 20 with a vacuum generation source including an air pressure source 24 and an ejector 26.

  Since the intake / exhaust system in the transfer head 8 is configured as described above, when a vacuum generation source malfunctions or air leaks, or when about half of the nozzles 20 of the multi-nozzle nozzles 20 do not adsorb components. A large amount of air leak occurs in the intake system, and the vacuum pressure in the manifold 30 decreases to such a degree that it is difficult to stably adsorb components in the other nozzles 20. Therefore, by setting the threshold value as an absolute vacuum pressure value in advance, when the vacuum pressure in the manifold 30 is equal to or lower than the set threshold value, the component can be stably adsorbed due to the above factors. It can be determined that the situation is difficult.

  In addition, after the component is sucked to the nozzle 20 and the component is dropped when the transfer head 8 is moved for mounting on the substrate 3, an air leak occurs in the intake system, and the vacuum pressure in the manifold 30 decreases. . Therefore, by setting the threshold value in advance as a relative vacuum pressure value, when the difference in vacuum pressure in the manifold 30 before and after the transfer head 8 moves exceeds the preset threshold value, It can be determined that the component has fallen and the component is not attracted to any nozzle 20.

  Next, the configuration of the control system of the electronic component mounting apparatus will be described with reference to FIG. The control unit 50 includes a transport path 2, a tape feeder 5, a Y table 6, an X table 7, a transfer head 8, a line camera 9, an intake valve 25, an exhaust valve 28, a vacuum pressure sensor 32, an air pressure adjusting unit 23, an air pressure source. 24 is electrically connected. Further, the control unit 50 is connected to the database unit 43, the operation input unit 44, and the display unit 45 through a bus 51. The database unit 43 stores component data 43a, control parameters 43b, board data 43c, nozzle data 43d, and threshold data 43e.

  The electronic component mounting apparatus receives a control command from the control unit 50, adsorbs the electronic components to the multiple nozzles connected to the intake passage communicating with the vacuum generation source, and detects the vacuum pressure in the intake passage. The operation of sequentially mounting electronic components at a plurality of mounting positions to be mounted is performed.

The electronic component mounting apparatus is configured as described above. Next, the electronic component mounting operation will be described with reference to FIG. FIG. 6 is a flowchart showing the mounting operation of the electronic component. First, the driving of the mounting apparatus is started, the transfer head 8 is moved to the pickup position on the tape feeder 5 and the air pressure source 24 is driven to adsorb predetermined components to the nozzle 20 (
ST1). After the components are sucked, the vacuum pressure in the manifold 30 is detected by the vacuum pressure sensor 32 and compared with a preset third threshold value TH3. Whether the vacuum pressure in the manifold 30 is equal to or higher than the third threshold value TH3. It is determined whether or not (ST2). The third threshold value TH3 is set as an absolute vacuum pressure value, for example, 40 kPa. When the vacuum pressure in the manifold 30 is 40 kPa or less, failure of the vacuum generation source, air leak, and the multiple nozzles If non-adsorption of components occurs in about half of the nozzles 20 among the nozzles 20, it is determined that a large amount of air leak occurs in the intake system, making it difficult to keep the components stably adsorbed.

  FIG. 7 shows an example of fluctuations in the vacuum pressure in the manifold 30 in the operation (ST1) of picking up parts from the tape feeder 5 and sucking them onto the nozzles 20. From the start of the suction until the time t1, the parts are sucked smoothly and a constant vacuum pressure P0 is maintained. The suction of the component is performed by bringing the lower end of the nozzle 20 into contact with the upper surface of the component and then opening the intake valve 25 of the nozzle 20 (the intake valves 25 of the other nozzles 20 are closed). Therefore, if the suction of the parts is successful, the vacuum pressure in the manifold 30 hardly fluctuates and a substantially constant vacuum pressure state is maintained. At time t1, any one of the nozzles 20 fails to adsorb the component, causing an air leak, and the vacuum pressure is reduced from P0 to P1. At time t2, another nozzle 20 fails to adsorb the component, drops to the vacuum pressure P2, and falls below the third threshold value TH3.

  Thus, when the vacuum pressure in the manifold 30 is lower than the third threshold value TH3, the operation of the mounting apparatus is stopped (ST3). On the other hand, when the vacuum pressure in the manifold 30 at the end of the suction is equal to or higher than the third threshold value TH3, the transfer head 8 is moved above the line camera 9 to scan the part sucked by the nozzle 20 from below. (ST4). The posture of the component sucked by the nozzle 20 by scanning is recognized and the presence / absence of the component is confirmed (ST5), and the component mounting operation is not performed for the non-sucking nozzle 20 (ST6). As a result, empty mounting of components is prevented in advance, and occurrence of a missing substrate is avoided.

  Conventionally, when the presence of the non-adsorbing nozzle 20 is confirmed, the suction valve 25 of the nozzle 20 is closed to recover the vacuum pressure. However, when there is an input error in the recognition parameter of the line camera 9 or the like. In this case, the nozzle 20 that sucks the component is erroneously determined to be a non-suction nozzle, and the intake valve is closed and the component is dropped, so the intake valve 25 is not closed to prevent this. I am doing so.

  When the scanning is completed, the vacuum pressure in the manifold 30 is reset to zero (ST7). The amount of decrease in vacuum pressure due to component drop after zero reset is managed as a difference in vacuum pressure as a relative value.

  Next, the transfer head 8 is moved onto the substrate 3, and the nozzle 20 that sucks the component to be mounted first is moved to the first mounting position on the substrate 3 (ST8). The operation of ST8 is the first movement process.

  After the first moving step (ST8), the vacuum pressure in the manifold 30 when moving to the first mounting position is detected and compared with a preset first threshold th1, and the difference in vacuum pressure is determined. It is determined whether it is equal to or less than the first threshold th1 (ST9). When the difference in vacuum pressure exceeds the first threshold th1, it is determined that the component has dropped from any of the nozzles 20 while the transfer head 8 is moving to the first mounting position on the substrate 3. .

If the first threshold th1 is too large, the amount of decrease in the vacuum pressure does not reach the first threshold th1 due to the drop of the component, and it is erroneously determined that the component is attracted and held despite the component falling. There is a risk. On the other hand, if it is too small, air leakage may occur depending on the suction posture even if parts are not picked up or picked up by other nozzles. Therefore, the amount of decrease in the vacuum pressure reaches the first threshold th1. There is a risk of misrecognizing that the component has fallen despite the fact that the component is adsorbed. Therefore, in the present embodiment, the first threshold th1 is set to 8 kPa, which is a value that is approximately half of the difference in vacuum pressure in the manifold 30 from the case where no component is adsorbed to a certain nozzle 20. In order to prevent misrecognition.

  FIG. 8 shows an example of fluctuations in the vacuum pressure in the manifold 30 at ST8. From time zero reset (ST7) to time t1, the parts are stably adsorbed and the relative vacuum pressure 0 is maintained. At time t1, a component falls from one of the nozzles 20 to cause an air leak, and the relative vacuum pressure is reduced to p1.

  In this way, when the vacuum pressure difference p1 exceeds the first threshold th1, the operation of the mounting apparatus is stopped (ST10). As a result, empty mounting of components is prevented in advance, and occurrence of a missing substrate is avoided. On the other hand, if it is equal to or less than the first threshold th1, it is determined that the component has not dropped, and the component is mounted (ST11). The operations of ST9 and ST11 are the first mounting process.

  Next, the vacuum pressure in the manifold 30 at the end of the first mounting process (ST9, ST11) is reset again to zero (ST12). Next, the transfer head 8 is moved on the substrate 3, and the nozzle 20 that sucks the component to be mounted next is moved to the next mounting position on the substrate 3 (ST13). The operation of ST13 is a second moving process.

  After the second moving step (ST13), the vacuum pressure value at the time of moving to the second mounting position is detected and compared with a preset second threshold th2, and the difference in vacuum pressure is the second difference. It is determined whether or not it is equal to or less than the threshold th2 (ST14). The second threshold th2 is set to approximately half of the first threshold th1, and when the difference in vacuum pressure exceeds the second threshold th2, the transfer head 8 is positioned on the substrate 3 at the first mounting position. It is determined that the component has fallen from any of the nozzles 20 while moving from the position to the second mounting position.

  The reason why the second threshold th2 is set to a value approximately half of the first threshold th1 is due to the difference in the movement distance of the nozzle 20. In other words, the distance from the first mounting position on the board to the next mounting position is shorter than the distance (about 1 mm in the case of micro components) that moves to the first mounting position on the board after the scanning is completed, and is required for movement. There is little time. Therefore, the response delay of the change in the vacuum pressure in the manifold 30 due to the drop of the component affects the detection value in the vacuum pressure sensor 32, and the vacuum pressure is detected before the amount of decrease in the vacuum pressure reaches the first threshold th1. Sometimes. In this case, there is a possibility that a part may be mistakenly recognized as having not fallen despite being dropped. For this reason, the second threshold th2 smaller than the first threshold th1 is set for the drop of the component from the nozzle 20 that moves on the substrate with a short span so that the above-described erroneous recognition does not occur.

  FIG. 9 shows an example of the fluctuation of the vacuum pressure in the manifold 30 at ST13. At time t1, the vacuum pressure value in the manifold 30 at the end of the first mounting process (ST9, ST11) is reset again to zero (ST12). After the zero reset, the component is stably adsorbed and maintained at a relative vacuum pressure of 0 until time t2. At time t2, a component falls from one of the nozzles 20 to cause an air leak, and the relative vacuum pressure is reduced to p2.

As described above, when the vacuum pressure difference p2 exceeds the second threshold th2, the operation of the mounting apparatus is stopped (ST15). As a result, empty mounting of components is prevented in advance, and occurrence of a missing substrate is avoided. On the other hand, if it is equal to or smaller than the second threshold th2, it is determined that the component has not dropped, and the component is mounted (ST16). The operations of ST14 and ST16 are the second mounting process.

  Thereafter, by repeatedly performing the second moving step (ST13) and the second mounting step (ST14, ST16), the transfer head 8 is further moved to the next mounting position, and the component adsorbed by the nozzle 20 is placed on the substrate. 3 are sequentially mounted at a plurality of mounting positions. At this time, if the difference in vacuum pressure before and after the movement of the transfer head 8 exceeds the second threshold th2, the mounting operation is stopped to prevent the component from being empty-mounted and the occurrence of a missing substrate. To avoid.

  As described above, according to the present invention, it is possible to determine the fall of the component from the multiple nozzles during the mounting operation by detecting the vacuum pressure in the intake passage that communicates the multiple nozzles with the vacuum generation source. Therefore, it is suitable for a mounting device consisting of one vacuum pressure sensor and multiple nozzles configured to be able to control suction / non-suction of components individually. It is possible to realize an electronic component mounting apparatus that can avoid the above-described problem.

  Note that the above-described zero reset (ST7, ST12) of the vacuum pressure value in the manifold 30 is not an essential operation in the present invention. The fall of the component can also be determined by comparing the difference between the vacuum pressure after the component scanning (ST5) and the vacuum pressure after the first moving step (ST8) with the first threshold th1. it can. Also, by comparing the difference between the vacuum pressure after mounting the component at the first mounting position (ST11) and the vacuum pressure after the second moving step (ST13) with the second threshold th2, Can determine fall.

  The threshold values th1, th2, and TH3 are set in advance in consideration of the air pressure sent from the air pressure source 24, the form of piping such as the intake pipe 21, the type and number of nozzles 20, and the like. The value can be set according to various conditions of the mounting apparatus to be applied.

  Further, by setting the second threshold th2 to a value smaller than the first threshold th1, it is possible to more accurately determine whether or not a component has dropped from the nozzle 20 that moves on the substrate 3 to be mounted. In particular, when the component to be mounted is a minute chip component and the adjacent components are close to each other at about 1 mm, the moving time from the mounting position to the next mounting position is extremely short. The response delay of the change in the vacuum pressure affects the detection value of the vacuum pressure sensor 32, and the vacuum pressure may be detected before the amount of decrease in the vacuum pressure reaches the first threshold th1. In this case, it is erroneously recognized that the part has not been dropped although it has been dropped. Therefore, in the detection of the vacuum pressure during movement on the substrate, a second threshold value th2 smaller than the first threshold value th1 is provided to make a more accurate determination of component dropping to prevent the occurrence of a missing substrate.

  Further, the line camera 9 as the component recognition means is not necessarily provided on the base 1. For example, as shown in FIG. 10, the line camera 60 can be directly attached to the moving head 8. A line camera 60 attached via a bracket 62 to a beam 61 extending in the X direction on the moving head 8 sequentially moves below each nozzle 20, and picks up and positions the components at each nozzle 20. Recognize the presence or absence of parts. This enables efficient recognition work by a so-called on-the-fly method of recognizing a component at an arbitrary position without performing an operation of moving the moving head 8 above the fixed line camera 9.

  According to the electronic component mounting method of the present invention, it is possible to detect the falling of the component during the mounting work by the multiple nozzles, and it is possible to prevent the occurrence of a missing part substrate. This is useful in the field of mounting electronic components that adsorb some electronic components and mount them on a mounting target such as a substrate.

The perspective view of the mounting device of the electronic component in one embodiment of this invention The side view of the multiple nozzle in one embodiment of the present invention Structure diagram of intake and exhaust system in one embodiment of the present invention Intake system piping diagram in one embodiment of the present invention 1 is a configuration diagram of a control system of an electronic component mounting apparatus according to an embodiment of the present invention. The flowchart which showed the mounting operation | movement of the electronic component in one embodiment of this invention The graph which showed the fluctuation | variation of the absolute vacuum pressure in the intake passage in one embodiment of this invention The graph which showed the fluctuation | variation of the relative vacuum pressure in the intake passage in one embodiment of this invention The graph which showed the fluctuation | variation of the relative vacuum pressure in the intake passage in one embodiment of this invention Side view of multiple nozzles in another embodiment of the present invention

Explanation of symbols

3 Substrate 20 Nozzle 24 Air Pressure Source 26 Ejector 30 Manifold th1 First Threshold th2 Second Threshold TH3 Third Threshold

Claims (4)

An electronic component that adsorbs electronic components to multiple nozzles connected to an intake passage communicating with a vacuum generation source, and sequentially mounts the electronic components at a plurality of mounting positions to be mounted while detecting the vacuum pressure in the intake passage. Implementation method,
A first moving step of moving the multiple nozzles onto an initial mounting position of the mounting target;
If the difference in vacuum pressure before and after the first moving step is equal to or less than a first threshold, a first mounting step for mounting an electronic component at the first mounting position;
A second moving step of moving the multiple nozzles onto the next mounting position of the mounting target;
If the difference in vacuum pressure before and after the second moving step is equal to or less than a second threshold, a second mounting step of mounting an electronic component at the next mounting position;
Including
An electronic component mounting method, wherein the second moving step and the second mounting step are repeatedly performed to sequentially mount electronic components at a plurality of mounting positions to be mounted.   The electronic component is not mounted by interrupting the first mounting step when the difference in vacuum pressure before and after the first moving step exceeds the first threshold value. The electronic component mounting method described.   2. The electronic component is not mounted by interrupting the second mounting step when the difference in vacuum pressure before and after the second moving step exceeds the second threshold value. Or the mounting method of the electronic component of 2. 4. The component mounting method according to claim 1, wherein the second threshold value is smaller than the first threshold value.

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