JP4516836B2 - Component mounting equipment - Google Patents

Description

  The present invention relates to a component mounting apparatus, and more particularly to a component mounting apparatus that is suitable for application when preventing a suction error such as an electronic component by a suction nozzle or a mounting error of the suction nozzle itself.

  In an electronic component mounting apparatus for mounting an electronic component on a wiring board, the electronic component is held using a negative pressure generated by vacuum suction with the suction nozzle in contact with the upper surface of the electronic component. It is. At this time, since the vacuum suction state changes depending on various factors, the holding state is not necessarily stable. Therefore, it is important to check whether or not the component has been normally sucked, and an inspection for that is performed. It is.

  As a conventional technique for inspecting a suction mistake by a suction nozzle, a flow sensor is provided in a vacuum passage (pipe) between a suction nozzle for sucking an electronic component and a vacuum generation means, and an output of the flow sensor is set. Japanese Patent Application Laid-Open No. H10-228707 discloses a method for detecting clogging of the suction nozzle holes and erroneous mounting of the nozzles by comparing with a theoretical flow rate value obtained in advance.

  Similarly, a flow rate sensor provided in a vacuum passage between the suction nozzle for sucking electronic components and the vacuum generating means is used, and the output of the sensor is compared with a reference flow rate value stored in advance. Thus, Japanese Patent Application Laid-Open No. 2004-228688 discloses an apparatus that detects the presence or absence of an electronic component or an abnormality in the suction state.

Japanese Patent No. 3269041 Japanese Patent Laid-Open No. 2003-133791

  However, at present, there are many types of electronic components mounted on the wiring board, and the smaller ones range from 400 μm × 200 μm to the larger ones of several tens of square mm.

  In order to cope with such a situation, the current electronic component mounting apparatus is configured to be detachable so that a plurality of types of suction nozzles can be mounted, and in accordance with the size and shape of the mounted electronic components, An optimum nozzle type is selected from a plurality of suction nozzles having different diameters and used for sucking and mounting electronic components.

  However, when using a flow sensor to detect mis-installation of the nozzle, such as the wrong type of suction nozzle being selected, or to detect abnormal suction of electronic components, a nozzle with a small nozzle diameter (for example, φ0.1 [mm] ]), It is in a high negative pressure state that is closer to a vacuum, so it is necessary to detect a very small amount of flow rate change for the above detection, and a highly accurate flow rate sensor with high resolution is required. It is necessary to use it. For this reason, in order to improve detection reliability, for example, a flow rate sensor having a relatively narrow measurement range of 0 to 1 [L / min] or 0 to 3 [L / min] is used, and the resolution of the sensor output is improved. It is necessary to raise.

  On the other hand, when a device having a large hole diameter (for example, φ1 to 2 [mm]) is mounted, it becomes a low negative pressure state closer to atmospheric pressure. In order to detect an oblique standing at the tip of the nozzle, it is necessary to be able to recognize a large flow rate, and it is necessary to use a flow rate sensor having a wide measurement range (for example, 0 to 10 [L / min]).

  Therefore, it is necessary to use a flow sensor with a narrow range when detecting an erroneous mounting of a suction nozzle with a small hole diameter or a suction abnormality of a minute part, and the above detection is impossible with a nozzle with a large hole diameter (the sensor output is saturated). On the other hand, when detecting erroneous mounting of a nozzle with a large hole diameter or abnormal adsorption of a large part, it is necessary to use a flow sensor with a wide range, and the above detection using a nozzle with a small nozzle hole diameter is not possible. There is a problem that the technology disclosed in Patent Documents 1 and 2 cannot be used because it is possible (S / N ratio is low) or the reliability is remarkably lowered.

  The present invention has been made to solve the above-mentioned conventional problems, and when any one of a plurality of types of suction nozzles having different hole diameters is selectively mounted and an arbitrary part from a small part to a large part is mounted. It is an object of the present invention to provide a component mounting apparatus that can easily and reliably detect nozzle mismounting, component adsorption abnormality, and the like.

The present invention comprises a shaft formed with a pipe line connected to a vacuum generating means, and having a suction nozzle attached to a tip part where the pipe line communicates, and the suction nozzle attached to the tip part of the shaft In a component mounting apparatus that mounts on a substrate at a predetermined position after adsorbing the component by making the inside of the pipe line negative pressure while the suction end of the tube is in contact with the component, the tube formed on the shaft A plurality of measuring means capable of measuring the degree of negative pressure or flow rate in the passage in different ranges, and a switching means for switching the measuring means according to the degree of negative pressure or flow rate in the pipe , The above-mentioned problems are solved by the fact that the measuring means is a flow rate sensor for measuring a small flow rate range in the pipeline and a pressure sensor for measuring a low negative pressure range in the pipeline .

  According to the present invention, the measuring means for measuring the negative pressure or flow rate in the pipe formed in the shaft in a plurality of ranges is provided so that the negative pressure or flow rate in the pipe can be widened. Since it is possible to measure in a range, it is possible to easily and reliably detect suction nozzle mismounting, abnormal suction of parts by nozzles, etc., from small to large nozzle holes mounted on the shaft tip. It becomes possible.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an outline of an electronic component mounting apparatus according to an embodiment of the present invention.

  The electronic component mounting apparatus according to this embodiment includes a base 1, and a transport path 2 is disposed in the center of the base 1 in the X direction. The transport path 2 transports a substrate 3 for mounting components in the X direction, and also serves as a substrate holding unit for holding and positioning the substrate 3 on the transport path 2.

  On both sides of the transport path 2, electronic component supply units 4 are arranged, and a large number (row) of tape-shaped parts feeders 5 are arranged in parallel in each supply unit 4. The parts feeder 5 stores electronic components held on a tape, and sequentially feeds the electronic components by sending the tape in the longitudinal direction of the tape.

  This electronic component mounting apparatus includes an X-axis table 6 and Y-axis tables 8A and 8B as moving means. The X-axis table 6 is provided with an electronic component transfer head 7 whose main part is shown in an enlarged manner in FIG.

  The X-axis table 6 is installed with its both ends supported by a Y-axis table 8A and a guide 8B arranged in parallel to face the Y-axis table 8A. By driving the X-axis table 6 and the Y-axis table 8A, the transfer head 7 moves in the horizontal direction, and an electronic component is picked up from the pickup position of the parts feeder 5 by the suction nozzle 10 mounted on the lower end of the head 7. Is picked up and mounted on the substrate 3.

  A camera 9 is disposed on the moving path of the transfer head 7 between the transport path 2 and the supply unit 4, and the camera 9 can image the transfer head 7 and the suction nozzle 10 from below. Yes. The state in which the transfer head 7 holds the electronic component is imaged by the camera 9, whereby the electronic component is identified and the displacement from the reference position is detected.

  Next, the transfer head 7 provided in the electronic component mounting apparatus according to the present embodiment will be described in detail with reference to FIGS.

  In FIG. 2, a plurality of nozzle shafts 11 are engaged with the θ-axis motor 12 in the transfer head 7, and the nozzle shaft 11 can be driven to rotate in the θ direction independently of each axis. Moreover, the Z-axis motor 13 for raising / lowering each nozzle shaft 11 is provided, respectively, and the nozzle shaft 11 can be raised / lowered independently of each axis. Further, a suction nozzle 10 is detachably attached to the tip of each nozzle shaft 11.

  A suction hole for sucking air is provided at the tip of the suction nozzle 10, and a plurality of types of suction nozzles 10 can be adapted to the respective sizes depending on differences in the size and shape of suction parts. Is prepared. For example, the suction hole of a nozzle for sucking a microchip component or the like is very small as φ0.1 [mm], and the suction hole of a nozzle for sucking a large part such as a tens of [mm] square is φ1 to 2 [ mm] and relatively large. These are accommodated in a nozzle holding part (exchange part) (not shown) provided on the apparatus, and the transfer head 7 moves onto the nozzle holder as needed to freely change the nozzle type. It can be done.

  Next, a chip suction mechanism provided on the transfer head 7 for sucking an electronic component will be described with reference to FIG.

  As shown in this figure, the suction nozzle 10 is provided with a flow rate sensor 15 for measuring the flow rate of the gas flowing in the pipe line via the pipe line 14, and for generating a vacuum by injecting compressed air. It is connected to a vacuum generator 16 made of an ejector. The flow rate sensor 15 has a narrow measurement range such as 0 to 3 [L / min] and is capable of detecting a minute flow rate difference corresponding to the high negative pressure range.

  The vacuum generator 16 is provided with a pressure sensor 17 for measuring the negative pressure in the pipe. The measurement range of the pressure sensor 17 is, for example, -100 to 0 [kPa], A wide range of measurements is possible, including a low negative pressure range from vacuum to atmospheric pressure.

  Next, operation | movement is demonstrated about the electronic component mounting apparatus of this embodiment which consists of the above structure.

  First, the substrate 3 is transported and positioned on the transport path 2. Next, the transfer head 7 moves onto the supply unit 4 to pick up electronic components. At this time, an arbitrary suction nozzle 10 is attached to the tip of the nozzle shaft 11.

  While the transfer head 7 is moving, in the state where the suction nozzle 10 is not sucking the electronic component, the inside of the pipe line 14 is set to a negative pressure by the vacuum generator 16 provided in the transfer head, and the tip of the suction nozzle 10 Air is sucked from the hole.

  At this time, if the suction nozzle 10 attached to the nozzle shaft 11 is for a large part, the flow rate flowing through the conduit 14 is large because the nozzle diameter is large, which is the measurement range of the flow sensor 15. 3 [L / min] is exceeded and the sensor output is saturated (for example, if the voltage output range is 1 to 5 [V], the output voltage is 5 [V]). In this way, it is recognized whether or not the output of the flow rate sensor 15 in a state where no component is adsorbed, and is stored in a flash memory (primary storage device) of the apparatus main body (not shown).

  Further, at this stage, it is determined whether or not the attached suction nozzle is the correct type, that is, whether or not it is erroneously mounted, by a nozzle type detection method described later.

  Next, the transfer head 7 is moved to the component suction position, and after the position is accurately determined, the nozzle shaft 11 is lowered by driving the Z-axis motor 13. Immediately before the suction nozzle 10 attached to the tip of the nozzle shaft 11 descends to the component suction height and comes into contact with the electronic component housed in the parts feeder 5, the vacuum generator 16 is operated to pipe the nozzle shaft 11. By setting the inside of the passage 14 to a negative pressure, the electronic component that is in contact with the suction nozzle tip is sucked (pickup). The nozzle 10 that has attracted the electronic component is raised to a height at which the transfer head 7 can be moved by driving the Z-axis motor 13.

  At this time, information indicating whether or not the output of the flow sensor 15 at the time of non-adsorption is already stored in the flash memory is read out. Based on this information, if not saturated, the output of the flow sensor 15 is used to detect an abnormal suction of the component by the nozzle 10. On the other hand, if it is saturated, the suction of the component by the nozzle is similarly detected using the output of the pressure sensor 17.

  Next, the detection method will be described in detail (the detection principle is basically the same for both the flow sensor and the pressure sensor).

  Since the suction hole area (blocking condition) varies depending on the type (hole diameter) of the suction nozzle 10 and the suction state of the components as shown in FIG. The flow rate and pressure in the passage 14 change. That is, the flow rate is large and the decreasing pressure is small (low negative pressure is low) at the time of non-adsorption as shown in FIG. It becomes higher and becomes an intermediate value in the case of abnormal suction such as oblique standing of parts shown in FIG.

  For this reason, the threshold value determined from the actual measurement result of the sensor output under each condition is stored in a memory (storage device) of the apparatus main body (not shown), and the nozzle output is compared with the sensor output value. It is possible to recognize whether the type of suction nozzle mounted on the shaft 11 is correct or not, and whether the electronic component is abnormally sucked.

Here, detection of the nozzle type, that is, detection of whether or not the type of the suction nozzle mounted is correct (whether or not it is mounted incorrectly) will be described in detail with reference to the flowchart of FIG. In this example, it is assumed that the hole diameters of the nozzles A to D are larger in the order of A, B, C, and D, the nozzles A and B can be detected by the flow sensor 15, and the nozzles C and D cannot be detected. . Further, the output value of the flow rate sensor _F S, the output value _P S of the pressure sensor, the output value at each nozzle mounted _{S A,} S _B, S _C, S D, the intermediate of the output value of _{S A} and _{S B Are} respectively denoted as S _AB .

As described above, the vacuum generator 16 is operated with an arbitrary nozzle mounted on the shaft and is detected by the flow sensor 15. If the flow sensor output _PS is not saturated (detectable) in Step 1, it is compared with the intermediate value _F S _AB (threshold) between the nozzles A and B determined in advance (Step 2), and the sensor output Is smaller than Nozzle A, and vice versa.

When the output of the flow sensor 15 is saturated (undetectable) in step 1, switching to the detection by the pressure sensor 16 by a control device (not shown) (switching means), a value of the sensor output _{P S,} a nozzle C which are calculated in advance An intermediate output value _P S _CD (threshold value) of D is compared (step 3), and it is similarly determined whether the nozzle is C or D.

  As a result of the above determination, if the nozzle type is different from the type assumed in advance in the production program, it is determined that the current nozzle is erroneously mounted.

Next, detection of the component suction state will be described in detail with reference to the flowchart of FIG. The symbols of the flow sensor output value and the pressure sensor output value are the same, and the sensor output values at the time of component adsorption and non-adsorption are expressed as S _ON and S _OFF , respectively.

If the flow sensor output read from the flash memory is not saturated in step 11, the electronic component is mounted with the mounted nozzle (step 12), and the output _F S of the flow sensor detected in that state is set. Then, _F S _ON and _F S _OFF obtained in advance are compared (step 13), and it is determined whether the normal adsorption, the adsorption error, or the abnormal absorption in between.

On the other hand, the flow rate sensor output is read, in case of saturation in step 11, switching the output of the pressure sensor by the control device, as well as electronic components adsorbed in step 14, performs a comparison of the pressure sensor output _{P S} Then, it is judged whether the suction state is good or bad.

  When it is detected by the method described above in detail that the suction of the component by the suction nozzle 10 is normal, the recognition camera 9 provided in the apparatus main body is used to recognize the suction position and angle of the component. Move up to recognize the position of the suction component. Based on the result of this position recognition, the transfer head 7 moves to a predetermined position on the substrate 3 that is positioned and fixed on the transport path 2, and the electronic component is mounted on the substrate by driving the θ-axis motor 12 and the Z-axis motor 13. 3 and the nozzle 10 is raised by releasing the vacuum.

  After mounting the part, information on whether or not the output of the flow sensor at the time of non-adsorption stored in the flash memory is saturated is read. Based on this information, if it is not saturated, the output of the flow sensor 15 is used and the vacuum generator 16 is actuated again. In the case where the component remains, and if it is saturated, the same inspection is performed using the output of the pressure sensor 17.

  According to the embodiment described above in detail, in order to mount electronic components of various sizes and shapes, in the electronic component mounting apparatus using a plurality of nozzles having different diameters, no matter which nozzle is used, Since it becomes possible to reliably detect mismounting of nozzles, abnormal suction of electronic components, take-out, and the like, it is possible to improve the reliability of mounting quality.

  In addition, since a sensor with a narrow measurement range can be used, the sensor size can be reduced, and the sensor can be mounted in the vicinity of the nozzle mounting portion, so that the stability is increased and the weight is reduced. Therefore, there is an advantage that an increase in the load on the drive mechanism portion of the head can be prevented even if it is mounted on the head.

  In the above-described embodiment, the case where the flow rate sensor 15 and the pressure sensor 17 are used in combination as one negative shaft as the negative pressure measuring means has been described. A wide range of flow rate sensors may be used together to support measurement in a high negative pressure (small flow) range and a low negative pressure (large flow) range.

  Also, when the sensor output is saturated, the gain of the sensor amplifier is automatically switched to enable measurement over a wide range, and the high negative pressure (small flow) range and low negative pressure (large (Flow rate) range may be supported.

The perspective view which shows the outline | summary of the electronic component mounting apparatus of one Embodiment which concerns on this invention The perspective view which expands and shows the transfer head with which the said electronic component mounting apparatus is provided. The schematic perspective view which shows the relationship between the suction nozzle with which the shaft with which the said transfer head is equipped, the flow sensor, and the pressure sensor is shown. The perspective view explaining the adsorption state by an adsorption nozzle Flow chart showing the procedure for detecting the type of suction nozzle Flow chart showing the procedure for detecting the suction state of a component

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Board | substrate 5 ... Parts feeder 7 ... Transfer head 10 ... Adsorption nozzle 11 ... Nozzle shaft 12 ... (theta) axis motor 13 ... Z-axis motor 14 ... Pipe line 15 ... Flow rate sensor 16 ... Vacuum generator 17 ... Pressure sensor

Claims (1)

A pipe line connected to the vacuum generating means is formed, and a shaft to which the suction nozzle can be attached is provided at a tip portion where the pipe line communicates,
Component mounting that is mounted on a substrate at a predetermined position after suctioning the component by applying a negative pressure in the pipe line with the suction end of the suction nozzle attached to the tip of the shaft in contact with the component In the device
A plurality of measuring means capable of measuring the degree of negative pressure or flow rate in the pipe formed in the shaft in different ranges;
A switching means for switching the measuring means according to the degree of negative pressure or flow rate in the pipe ,
The component mounting apparatus , wherein the measuring means is a flow sensor for measuring a small flow rate range in the pipe and a pressure sensor for measuring a low negative pressure range in the pipe .

Images