JP2010010463A - Electronic component mounting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively and inexpensively find out a sign for a minute defect of a mechanism section for moving a component suction nozzle and a sign for the defect. <P>SOLUTION: When a distal end of the component suction nozzle 2 at a position of height where a light reception window 15b is irradiated with a plurality of parallel laser beams 15c parallel to each other from an opposed light projection window 15a and the sucked electronic component 1 vibrate, a shield portion of the laser beams 15c changes (vibrates) through the vibrations. A laser sensor 35 of a position detector 15 having the light reception window 15b detects the change to perform optical direct detection. Through the detection, abnormality of a device is determined to perform predetermined abnormality handling processing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic component mounting apparatus that picks up a component with a nozzle provided in a head portion, moves the nozzle to a corresponding position on a substrate, and mounts the picked-up component, and in particular, moves the nozzle. The present invention relates to an electronic component mounting apparatus and an abnormality detection method thereof that can effectively find a minute defect of a mechanism part to be caused and a sign of the defect at low cost.

  As a prior art of an abnormality detection method for an electronic component mounting apparatus, there is Patent Literature 1.

  In Patent Document 1, in the control system shown in FIG. 1, a moving unit (head unit 10, suction nozzle 13) is driven by X, Y, Z, and R axes by driving units such as servo motors 2 to 5. Move in each direction. Further, control deviations such as speed deviation and position deviation when the drive unit is normal are stored in the controller 1 as a predetermined value of the control deviation. Then, when performing self-diagnosis of each drive unit, the control deviation at that time is compared with the above-mentioned predetermined value, and abnormality of the drive unit is determined.

  As a result, the settling of the operation deteriorates due to mechanical causes such as assembly failure during manufacture, tension failure due to long-term use of the belt that transmits the driving force of the motor, loose screws, or failure of the motor itself. It is possible to determine abnormalities that adversely affect the mounting accuracy.

Japanese Patent Laying-Open No. 2005-38910 (FIG. 1)

  However, the position detection mechanism for each axis moves the nozzles indirectly by interposing other various mechanisms. In the case of the Z-axis that moves the nozzle up and down, the mechanism unit that performs the operation is usually provided in the head unit. On the other hand, the X-axis and Y-axis operate the entire head unit on which the nozzle is mounted, and the nozzle is moved through a plurality of other mechanism units such as a Z-axis operation mechanism. .

  Further, the position detection means for each axis is also provided on the motor side (rotary encoder) or guide rail side (linear scale), and does not directly detect the position of the nozzle tip.

  Therefore, when moving each axis, a minute position deviation of the nozzle tip itself cannot be detected. For example, the vibration of the nozzle tip due to the vertical movement of the Z axis or the like is difficult to detect from the position detection means of each axis in the configuration as in Patent Document 1. For this reason, a defective mechanism may not be detected and the mounting position may not be stable.

  The present invention is for solving the above-mentioned conventional problems, and is an electronic component that can effectively find a minute defect of a mechanism part for moving a nozzle and a sign of the defect at a low cost. It is an object of the present invention to provide a mounting device abnormality detection method.

  The present invention is an abnormality detection method for an electronic component mounting apparatus in which a component is picked up by a nozzle provided in a head portion, then the nozzle is moved to a corresponding position on a substrate, and the picked-up component is mounted. When stopping the vertical movement of the nozzle in the Z direction, the amplitude of the nozzle vibration in the direction orthogonal to the Z direction is detected, and the maximum amplitude value or vibration convergence time obtained based on the detection is larger than a predetermined threshold value. In the case of the above, the problem is solved by determining that there is an abnormality and performing a predetermined abnormality handling process.

  Here, based on the detection, the maximum amplitude value Amax + of the positive amplitude of the nozzle amplitude, the maximum amplitude value Amax− of the negative amplitude of the nozzle amplitude, and the positive amplitude of the nozzle amplitude are smaller than the predetermined convergence determination value Aacp +. The vibration convergence time T4 and the vibration convergence time T3 in which the negative amplitude of the nozzle amplitude is smaller than a predetermined convergence determination value Aacp− are obtained. The determination can be made based on a comparison of the maximum amplitude value Amax +, the maximum amplitude value Amax−, the vibration convergence time T4, and the vibration convergence time T3 with the corresponding threshold values.

  The present invention also provides an electronic component mounting apparatus that picks up a component with a nozzle provided in the head portion, then moves the nozzle to a corresponding position on the substrate, and mounts the picked-up component. When the vertical movement of the optical sensor provided in the head unit and the nozzle in the Z direction is stopped, the nozzle vibration in the direction orthogonal to the Z direction is detected by the optical sensor when detecting the positional deviation of the components being detected. A control means for obtaining a maximum amplitude value or a vibration convergence time based on the amplitude of the current and determining that there is an abnormality when the maximum amplitude value or the vibration convergence time is greater than a predetermined threshold and performing a predetermined abnormality handling process This solves the problem.

  According to the present invention, it is possible to grasp the state of the nozzle tip with higher accuracy by directly grasping the vibration at the tip of the nozzle picking up the component by some detection means, and it is possible to detect a mechanism failure and a state change. In addition, it is possible to prevent the mounting position from shifting.

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

  FIG. 1 is a perspective view of an electronic component mounting apparatus according to an embodiment to which the present invention is applied as viewed obliquely from above.

  The electronic component mounting machine sucks the electronic component 1 supplied from the parts feeder F by the component suction nozzle 2 and carries it to a board (not shown) located at an adjacent position. Here, the electronic component 1 is mounted on the substrate by releasing the negative pressure. The component suction nozzle 2 is fitted into or removed from the lower end (tip) of the nozzle shaft 3 by a load greater than a certain value in the axial direction.

  The nozzle shaft 3 is supported in the vertical direction by a slide bracket 4 and is moved up and down in accordance with the vertical movement of the slide bracket 4. The slide bracket 4 is supported so as to be movable in the vertical direction with respect to the frame 5 via a linear guide 6, and is driven up and down by a Z-axis motor 7 via a ball screw 8, and a nozzle shaft. 3 is also driven in the vertical direction.

  Further, the nozzle shaft 3 is configured to be rotated around its axis via a timing belt 10 by a θ-axis motor 9 while being supported by a slide bracket 4. Further, a negative pressure passage (not shown) is formed in the nozzle shaft 3 so as to transmit the negative pressure to the tip of the mounted component suction nozzle 2.

  The nozzle shaft 3 to the timing belt 10 constitute one component suction unit 11 as a set, and the plurality of component suction units 11 constitute a head portion 12.

  Such a head portion 12 is supported by an XY robot device 14 (not shown in the whole, an X-axis rail is shown in FIG. 1) via an interface member 13, and the axial direction (vertical direction) of the nozzle shaft 3. Is the Z axis, it can be freely moved in the XY direction within a horizontal plane.

  Here, reference numeral 15 in FIG. 1 is attached to the above-described frame 5, and a position detector 16 for detecting the position of the electronic component 1 sucked by the component suction nozzle 2 is attached to the frame 5. A camera for recognizing the mark on the circuit board, the position when the electronic component 1 is picked up, and the position of the electronic component 1 mounted on the circuit board are shown.

  The electronic component 1 is different in size and shape depending on the type of resistor, capacitor, IC, etc., and the component suction nozzle 2 is replaced with a different type depending on the electronic component 1 to be sucked. Is.

  FIG. 2 is a block diagram showing the configuration of the main part of the control system centering on the shaft motor in the electronic component mounting apparatus of the present embodiment.

  The head unit 12 is equipped with a Z-axis motor 7, a θ-axis motor 9, and a laser sensor 35 built in the position detector 15. The head unit 12 is moved in the X axis direction or the Y axis direction by the driving force of the X axis motor 31 or the Y axis motor 32.

  These motors 7, 9, 31, 32 and the laser sensor 35 are connected to the CPU 51 via corresponding drivers 41 to 45. The CPU 51 is connected to a memory 52 that records various programs, data, and the like. The control device 37 mainly includes such drivers 41 to 45, a CPU 51, and a memory 52.

  The motors 7, 9, 31, and 32 have, for example, built-in rotary encoders and perform closed-loop position control and speed control with the control device 37 as the center.

  In addition, a program for performing processing to which the abnormality detection method for an electronic component mounting apparatus according to the present invention is applied is recorded in the memory 52 in the control device 37 and executed by the CPU 51. For example, a flowchart of FIG. The processing as shown in FIG. Various set values of this process are recorded and stored in the memory 52 as data. Thus, the control device 37 corresponds to the control means of the present invention.

  FIG. 3 is a perspective view showing the operation of the optical position detector 15 that performs vibration detection to which the present invention is applied in the present embodiment.

  The light projection window 15a of the position detector 15 that irradiates a plurality of parallel laser beams 15c and the light receiving window 15b of the position detector 15 to which these laser beams 15c are guided are mutually connected via the tip of the component suction nozzle 2. It arrange | positions so that it may oppose. In this figure, the respective beams (light beams) of the laser beams 15c parallel to each other are indicated by broken-line arrows.

  The position detector 15 measures the suction position of the electronic component 1 sucked by the component suction nozzle 2 (centering: position measurement of the electronic component 1 with reference to the tip of the component suction nozzle 2). .

  The component suction nozzle 2 is driven in the vertical direction by the Z-axis motor 7 and moved. As shown in this figure, the sucked electronic component 1 is placed on the path of the laser beam 15c irradiated from the projection window 15a. After being positioned, the electronic component 1 sucked by the component suction nozzle 2 is rotated by the θ-axis motor 9. Then, according to the external shape of the rotating electronic component 1, the parallel shielding portions of the plurality of laser beams 15c change. By detecting the change by the laser sensor 35 of the position detector 15 having the light receiving window 15b, it is possible to measure the suction position of the electronic component 1 sucked by the component suction nozzle 2.

  In the present embodiment, the vibration of the component suction nozzle 2 and the vibration of the electronic component 1 sucked by the component suction nozzle 2 by the position detector 15 originally provided for the measurement of the suction position as described above are as follows. Optical detection is performed directly. That is, when the tip of the component suction nozzle 2 at the height irradiated with a plurality of parallel laser beams 15c or the sucked electronic component 1 vibrates, the shielding portion of the laser beam 15c is accompanied by the vibration. Changes (vibrates). Therefore, the change (vibration) of the shielding portion is optically directly detected by the laser sensor 35, and the control device 37 detects the abnormality of the mechanical mechanism included in the electronic component mounting apparatus based on the detection result. .

  FIG. 4 is a graph showing the lateral vibration of the suction component immediately after stopping the vertical movement operation by the Z-axis motor in the present embodiment.

  In FIG. 4, the horizontal axis is the time axis, and the vertical axis indicates the amplitude of vibration at the tip of the component suction nozzle 2 in the horizontal direction orthogonal to the Z-axis direction. Or a vertical axis | shaft shows the amplitude of the vibration in the electronic component 1 attracted | sucked to the front-end | tip of the component suction nozzle 2 of the horizontal direction similarly. The amplitude of this vibration is detected by the laser sensor 35, and is therefore a direction perpendicular to the optical axis of the laser light 15c and in which the optical axes of the plurality of laser lights 15c are arranged.

  The component suction nozzle 2 is driven in the vertical direction by the Z-axis motor 7, and as shown in FIG. 3, the tip of the component suction nozzle 2 is sucked on the path of the laser beam 15c irradiated from the projection window 15a. This vertical movement is stopped so that the electronic component 1 is positioned. Then, as shown in FIG. 4, the tip of the component suction nozzle 2 and the electronic component 1 for suction vibrate immediately after the stop due to the impact of the stop, and then the vibration gradually attenuates.

  The magnitude (amplitude) of the vibration accompanying the stop impact and the damping time of the vibration depend on the mechanical state around the head unit 12 including the component suction nozzle 2. For example, an increase in backlash of the linear guide 6 or the ball screw 8 can be detected as an increase in the magnitude of such vibration or an extension of the attenuation of the vibration. Therefore, in the present embodiment, the abnormality detection of the electronic component mounting apparatus is performed based on the magnitude of the vibration and the decay time.

  In this embodiment, after the time T0 when the movement operation in the Z-axis direction (vertical direction) is stopped, the maximum amplitude Amax + in the specific direction in the horizontal direction and the maximum amplitude Amax− in the direction opposite to the direction are It is made to obtain | require by the control apparatus 37. FIG. Note that the time from time T0 when the maximum amplitude Amax + is reached is the maximum plus amplitude time T1. Further, the time from the time T0 when the maximum amplitude Amax- is reached is set as the maximum minus amplitude time T2.

  Furthermore, when the amplitude (absolute value) in the plus direction becomes smaller than the convergence determination value Aacp + and the amplitude (absolute value) in the plus direction does not become larger than the convergence determination value Aacp + thereafter, the amplitude finally increases. The time when the convergence determination value Aacp + is reached is set as T4. Then, the control device 37 obtains the time from time T0 to time T4, that is, the vibration convergence time ΔT4.

  Further, when the amplitude (absolute value) in the negative direction becomes smaller than the convergence determination value Aacp− and the amplitude (absolute value) in the negative direction does not become larger than the convergence determination value Aacp− after this, finally, The time when the amplitude becomes the convergence determination value Aacp + is defined as T3. Then, the control device 37 obtains the time from time T0 to time T3, that is, the vibration convergence time ΔT3.

  The control device 37 detects an abnormality of the electronic component mounting apparatus based on the maximum amplitude Amax +, the maximum amplitude Amax−, the vibration convergence time ΔT4, and the vibration convergence time ΔT3.

  Specifically, in the following cases, the electronic component mounting apparatus determines that there is some abnormality.

(Abnormality determination 1): When the absolute value of the maximum amplitude Amax + or the absolute value of the maximum amplitude Amax− is larger than the preset amplitude allowable maximum value Alim (a positive integer value), it is determined that there is some abnormality. To do.
(Abnormality determination 2): When the vibration convergence time ΔT4 or the vibration convergence time ΔT3 is longer than the preset maximum time Tlim, it is determined that there is some abnormality.

  FIG. 5 is a flowchart showing an abnormality detection process of the electronic component mounting apparatus according to this embodiment.

  The abnormality detection process is mainly performed by the control device 37.

  First, in the abnormality detection process (abnormality detection method) of the present embodiment, in step S101, various settings are performed prior to the Z-axis operation.

  That is, in this step S101, first, the Z-axis movement distance Zd, the speed Zs, and the acceleration Za are set. In addition, an allowable amplitude maximum value Alim when the Z-axis operation is stopped, a value Aacp for determining that the amplitude has converged, and an allowable maximum time Tlim until convergence are set. Further, the number of times of measurement Cn, the nozzle mass Nw, the component mass Cw, the component shape Cs, etc. may be set.

  For example, an abnormality that cannot be found in one abnormality detection process may be found by performing the abnormality detection process several times, and the number of processes is set as the number of measurement Cn.

  Furthermore, in this step S101, when performing the θ rotation operation simultaneously with the Z-axis vertical movement, in addition to these settings, the rotation amount θdiv, the rotation speed θω, and the rotation acceleration θβ are set.

  Subsequently, in step S102, the Z-axis operation is started. When the θ-axis operation is performed together with the Z-axis operation, the θ-axis operation is started in this step S102. At the start of such an operation, the start of the operation is expected so that the timing at which the Z-axis operation is completed is the timing at which the XY-axis operation stops or does not swing during the constant speed operation.

  In step S103, it is determined whether the starting Z-axis operation has been stopped, and the above-described time T0 is detected.

  If it is determined that the Z-axis operation is stopped, in step S104, the maximum amplitude Amax +, the maximum amplitude Amax−, the maximum positive amplitude time ΔT1, and the maximum negative amplitude time ΔT2 are determined based on the signal captured from the laser sensor 35. The vibration convergence time ΔT4 and the vibration convergence time ΔT3 are obtained.

  In step S105, an abnormality determination of the electronic component mounting apparatus is performed based on the above-described abnormality determination 1 and abnormality determination 2.

  If it is determined that there is an abnormality, the process proceeds to step S106, and as the abnormality process, the content of the determined abnormality is displayed, recorded, and an abnormality handling process corresponding to the content is performed. For example, depending on the content of the determined abnormality, the operator is urgently notified by a warning sound or warning light, or the operation of the electronic component mounting apparatus is stopped to suppress the expansion of the apparatus failure and the occurrence of defective products. Or you may.

  If it is determined that there is no abnormality, the process proceeds to step S107, and a repeated determination process is performed. This repeat determination process repeats the number of times of measurement Cn and performs the processes from step S102 to step S105. In step S107, it is determined whether or not the measurement has been repeated for the number of times Cn. If it is still determined that the number of measurements is less than Cn, the process branches to the front of step S102. Alternatively, if it is determined that the number of measurements Cn has been reached, the process proceeds to step S108.

  In step S108, the maximum amplitude Amax +, the maximum amplitude Amax−, the maximum positive amplitude time ΔT1, the maximum negative amplitude time ΔT2, the vibration convergence time ΔT4, and the vibration convergence time ΔT3 obtained in step S104 are recorded and stored. To do. The data thus recorded and stored can be used for subsequent maintenance and the like. For example, the mechanism state of the electronic component mounting apparatus can be observed by the change of the value.

  It should be noted that the determination value in the above-described step S105 can be adjusted by a predetermined constant of Nw, Cw, Cs. For example, the determination value may be used for actual determination after being multiplied by these Nw, Cw, and Cs constants.

  In the present embodiment, the position detector 15 provided with the laser sensor 35 is used. However, the means for detecting the vibration of the component suction nozzle 2 and the vibration of the electronic component 1 sucked by the component suction nozzle 2 are the same. It is not limited to such a thing. For example, a camera may be used.

  In the present embodiment, the position detector 15 provided in the head unit 12 is used as the vibration detecting means of the present invention. However, other parts, for example, other than the head unit 12, such as X-axis movement and Y-axis You may install in a place without movement. However, in this case, it is necessary to move the head unit 12 to the installation position when vibration is detected.

  Furthermore, the electronic component mounting apparatus according to the present embodiment picks up a component with a nozzle provided in the head unit, and then moves the nozzle to a corresponding position on the substrate to mount the sucked component. However, another form of electronic component mounting apparatus may be used. As long as the head unit including the nozzle is moved in some form, the present invention can be similarly applied to the abnormality detection of the moving mechanism. For example, the pick-up of the component by the nozzle is not limited to the suction by the negative pressure air pressure, and may be one in which the component is held by an actuator that performs a mechanical operation.

The perspective view which looked at the electronic component mounting apparatus of embodiment with which this invention was applied from diagonally upward The block diagram which shows the structure of the control system principal part centering on the shaft motor in the said embodiment. The perspective view which shows operation | movement of the optical position detector 15 which performs the vibration detection to which this invention is applied in the said embodiment. In the said embodiment, the graph which shows the horizontal vibration of the adsorption | suction component immediately after the operation | movement stop of an up-down movement by a Z-axis motor stops The flowchart which shows the abnormality detection process of the electronic component mounting apparatus in the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electronic component 2 ... Component adsorption nozzle 3 ... Nozzle shaft 7 ... Z-axis motor 9 ... (theta) axis motor 12 ... Head part 15 ... Position detector 15a ... Light projection window 15b ... Light receiving window 15c ... Laser beam 31 ... X-axis motor 32 ... Y-axis motor 35 ... Laser sensor 37 ... Control device 51 ... CPU
52 ... Memory

Claims (3)

After picking up a component with a nozzle provided in the head part, the nozzle is moved to a corresponding position on the substrate, and the abnormality detection method of the electronic component mounting apparatus that mounts the picked-up component,
When stopping the vertical movement of the nozzle in the Z direction, the amplitude of the nozzle vibration in the direction perpendicular to the Z direction is detected,
When the maximum amplitude value or vibration convergence time obtained based on the detection is greater than a predetermined threshold, it is determined that there is an abnormality, and a predetermined abnormality handling process is performed. Abnormality detection method for component mounting equipment.   Based on the detection, the maximum amplitude value Amax + of the positive amplitude of the nozzle amplitude, the maximum amplitude value Amax− of the negative amplitude of the nozzle amplitude, and the vibration convergence time in which the positive amplitude of the nozzle amplitude is smaller than a predetermined convergence determination value Aacp + The vibration convergence time T3 in which the negative amplitude of T4 and the nozzle amplitude is smaller than a predetermined convergence determination value Aacp− is obtained, and the maximum amplitude value Amax +, the maximum amplitude value Amax−, the vibration convergence time T4, and the vibration The abnormality detection method for an electronic component mounting apparatus according to claim 1, wherein the determination is performed based on a comparison between a convergence time T3 and a corresponding threshold value. In an electronic component mounting apparatus that picks up a component with a nozzle provided in the head portion, moves the nozzle to a corresponding position on the substrate, and mounts the picked-up component,
An optical sensor provided in the head unit for detecting a positional shift of a component picked up by the nozzle;
When stopping the vertical movement of the nozzle in the Z direction, the maximum amplitude value or vibration convergence time is obtained based on the amplitude of the nozzle vibration detected by the optical sensor in the direction orthogonal to the Z direction, and a predetermined threshold value is obtained. If it is larger, it is determined that there is an abnormality, and a control unit that performs a predetermined abnormality handling process;
An electronic component mounting apparatus comprising:

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