JP2008300409A - Component mounting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a component mounting device in which suitable control of pressing at component loading is possible. <P>SOLUTION: A component mounting device comprising a loading head for sucking a component, pressing the component, and loading the component onto a substrate and a load detector for detecting pressure at component loading comprises a plurality of filters applicable to the output signal of the load detector and means for selecting a filter from the filters. The pressing by the loading head is controlled by applying the plurality of filters (step S42) to the value of the oscillation of the output signal of the load detector (step S40), selecting a filter with which the value of the oscillation of the output signal becomes small (steps S44-S48), and applying the filter to the output signal of the load detector when the loading head is stopped. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a component mounting apparatus, and in particular, to be used for a component mounting apparatus having a mounting head for sucking and mounting a component on a substrate and a load detector for detecting pressure at the time of mounting the component. The present invention relates to a component mounting apparatus that can stably control the pressure applied by the mounting head when mounting components.

  2. Description of the Related Art Conventionally, a component mounting apparatus that controls a pressure contact load when an electronic component is pressed against a board is disclosed in Patent Document 1. First, the configuration will be described.

  As shown in FIG. 13, the conventional component mounting apparatus 1 includes a collet 6 for fixing the electronic component 2 to the substrate 4, a mounting head 10 having the collet 6 and the protruding portion 8, and the protruding portion 8 with a constant pressure. A cylinder 12 that pressurizes the substrate, a load cell 14 that converts a load received from the protrusion 8 into an output signal, a housing 16 that includes the mounting head 10, the cylinder 12, and the load cell 14, and a housing 16 that is fixed to the housing 16. A motor 20 that rotates the ball screw 18, a CPU 22 that controls the motor 20 based on an electric signal from the load cell 14, and a stage 24 that fixes the substrate 4.

  Next, the operation will be described. The motor 20 rotates the ball screw 18 and lowers the housing 16 toward the stage 24. When the electronic component 2 comes into contact with the substrate 4, the load applied to the load cell 14 decreases. Therefore, the CPU 22 can control the motor 20 based on the output signal from the load cell 14 so that a predetermined pressure is applied to the load cell 14. In other words, the pressure contact load applied to the electronic component 2 can be controlled by managing the load on the load cell 14.

JP 2001-127081 A

  However, the conventional component mounting apparatus 1 as shown in Patent Document 1 has a problem that the output signal of the load cell 14 fluctuates due to vibration and electrical noise, and a stable signal cannot be obtained.

  In such a case, even if an output signal is stabilized by applying a low-pass filter, since the type of the low-pass filter is conventionally fixed, it may not be an optimal low-pass filter depending on the environment where the component mounting apparatus 1 is placed. Sex was occurring. That is, if the low-pass filter is not suitable considering the use environment, the frequency of the output signal with respect to the load output from the load cell 14 is different from the frequency characteristic of the low-pass filter, and the variation of the output signal hardly changes. There was a problem that a stable output signal could not be obtained.

  The present invention has been made to solve the above-described conventional problems. A plurality of filters are applied in advance to the fluctuation of the output signal of the load detector, a filter for reducing the fluctuation is selected, and the selected filter is used. It is an object of the present invention to provide a component mounting apparatus that enables appropriate pressure control during component mounting by processing an output signal of a load detector.

  The present invention can be applied to an output signal of the load detector in a component mounting apparatus having a mounting head for sucking and mounting a component on a substrate and a load detector for detecting a pressure when the component is mounted. A plurality of filters, and means for selecting a filter from among the plurality of filters, and applying the plurality of filters to the shake value of the output signal of the load detector when the mounting head is stopped Then, by selecting a filter that reduces the fluctuation value of the output signal and applying it to the output signal of the load detector, the pressure control of the mounting head can be performed, thereby solving the above problem It is.

  According to the present invention, when the mounting head is stopped, a plurality of filters are applied to the electric signal output from the load detector for a certain period of time to determine the vibration, and an appropriate filter suitable for the use environment and situation of the apparatus. Can be selected from the plurality of filters, and by applying the filter to the output signal of the load detector, highly accurate and stable pressure control can be performed.

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

  First, a first embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view of an entire component mounting apparatus according to the present embodiment, FIG. 2 is a block diagram of the entire configuration, FIG. 3 is a configuration diagram of a mounting head, FIG. 4 is a load cell layout diagram, and FIG. 5 is a mounting head, load cell, and CPU. FIG. 6 is a circuit diagram of the low-pass filter, FIG. 7 is a frequency characteristic diagram of the low-pass filter, FIG. 8 is a flowchart showing the component crimping mounting, and FIG. 9 is a relationship between mounting head operation and load cell output. FIG. 10 is a configuration diagram of the mounting head of the present embodiment, FIG. 11 is a flowchart of an auto filter search, and FIG. 12 is a diagram showing a component pressurization result based on an actual output value of a load cell.

  The whole component mounting apparatus will be described in detail with reference to FIGS.

  The component mounting apparatus 100 includes a mounting head 110, an X-axis moving mechanism 160 disposed at the front of the component mounting apparatus 100, a Y-axis moving mechanism 170, and a left-right direction slightly behind the center of the component mounting apparatus 100. An extended circuit board conveyance path 180, a component mounting camera 198, a component supply unit 200 that is disposed in the front part (the lower side in the drawing) of the component mounting apparatus 100 and supplies the component 102 mounted on the substrate 104 And a main body 210 storing a controller 212 and the like (FIG. 2).

  The mounting head 110 includes a Z-axis moving mechanism (not shown) that moves the suction nozzle 142 up and down in the vertical direction (Z-axis direction), and rotates the suction nozzle 142 around the nozzle axis (suction axis). A θ-axis moving mechanism (not shown) is provided. The mounting head 110 is mounted with a substrate recognition camera 158 that images a substrate mark formed on the substrate 104. The structure of the mounting head 110 will be described in more detail later.

  The X-axis moving mechanism 160 can move the mounting head 110 in the X-axis direction by an X-axis motor 162 that is a drive source of the X-axis moving mechanism.

  The Y-axis moving mechanism 170 can move the X-axis moving mechanism 160 including the mounting head 110 in the Y-axis direction by a Y-axis motor 172 that is a drive source of the Y-axis moving mechanism.

  The circuit board conveyance path 180 is for receiving and transferring the board 104 from the component mounting apparatuses on both sides when a mounting line is configured with a plurality of component mounting apparatuses. The device 100 can be moved and transported to a predetermined position.

  The component recognition camera 198 (imaging means) is provided in the measuring unit of the component supply unit 200 and is arranged so as to image the component 102 sucked by the suction nozzle 142 from below.

  The main body 210 includes a controller 212, a storage device 214, a display device 216, a keyboard 218, a mouse 220, and an image recognition device 222.

  The controller 212 is, for example, a microcomputer such as a CPU that controls the entire apparatus, and includes a RAM and a ROM. As shown in the block diagram of FIG. 2, the entire component mounting apparatus 100 can be controlled by being connected to each component.

  The storage device 214 is composed of, for example, a flash memory, and can also be used to store component data input by the keyboard 218 and the mouse 220, component data supplied from a host computer (not shown), and the like.

  The display device (monitor) 216 can display, for example, component data, calculation data, and an image of a component captured by the component recognition camera 198 on the display surface.

  The keyboard 218 and the mouse 220 can be used for inputting data such as component data, for example.

  The image recognition device 222 is connected to the component recognition camera 198 and performs image recognition of the component 102 sucked by the suction nozzle 142, and can be composed of an A / D converter 224, a CPU 226, and a memory 228. The analog image signal of the component 102 output from the component recognition camera 198 is converted into a digital signal by the A / D converter 224 and stored in the memory 228, and the CPU 226 uses the image data to absorb the component 102 that has been picked up. Recognize. In other words, the image recognition device 222 can calculate the center and the suction angle of the component 102 and recognize the suction posture of the component 102. The image recognition device 222 also has a function of processing the image data of the board mark imaged by the board recognition camera 158 and calculating the board mark position. It also has a function of processing these two types of image data and transferring both correction data to the controller 212.

  Next, the mounting head 110, the substrate mounting table 184, and the filter, which are each component, will be described.

  First, the mounting head 110 will be described in detail with reference to FIG.

  The mounting head 110 is attached to the head base 112 to move the suction nozzle 142 in the Z axis, the θ rotation mechanism that is also attached to the head base 112 to rotate the suction nozzle 142, and the Z axis movement. And a voice coil motor 150 (hereinafter referred to as VCM) that is attached to a vertical Z drive unit 122 that moves in the Z-axis direction by a mechanism and applies pressure to the component 102.

  In the Z-axis movement mechanism, the head base 112 is a support connected to the X-axis movement mechanism 160 and has an upper stopper 114 described later. The Z-axis motor 116 is a drive source for a Z-axis movement mechanism that raises and lowers the suction nozzle 142, and is attached to the upper portion of the head base 112. The Z-axis motor 116 is connected to the screw portion 120 via the coupling 118. The screw portion 120 is rotatably connected to a ball screw nut 126, and a vertical Z driving portion 122 is fixed to the nut 126. The vertical Z driving unit 122 includes a lower stopper 124 described later, and includes a linear guide 128 between the vertical Z driving unit 122 and the head base 112. Therefore, when the screw portion 120 is rotated by the Z-axis motor 116, the vertical Z drive portion 122 smoothly moves up and down in the Z-axis direction.

  In the θ-axis moving mechanism and the suction nozzle 142, the head base 112 is a drive source for the θ-axis rotation mechanism, and the suction nozzle is rotated around its nozzle central axis (suction axis). A θ-axis motor 130 that rotates the component 102, a belt 132 that transmits the power of the θ-axis motor 130 to the vertical rotation drive shaft 134, a vertical rotation drive shaft 134, a vertical rotation drive unit bearing that includes a spline bearing and a bearing. 136 are attached. The vertical rotation drive shaft 134 is coaxially integrated with the nozzle shaft 138, and the nozzle shaft 138 rotates in conjunction with the vertical rotation drive shaft 134. The nozzle shaft 138 has an upper stopper 146 and a lower stopper 148 which will be described later, and is held by a ball bush 144 provided in the vertical Z drive unit 122. For this reason, the nozzle shaft 138 can operate smoothly in the Z-axis direction and the θ-axis direction. A nozzle chuck mechanism 140 is provided at the lower end of the nozzle shaft 138 so that the suction nozzle 142 can be held and replaced. The suction nozzle 142 can freely hold the component 102 by suction, and the component 102 can be mounted on the substrate 104.

  The VCM 150 is used for pressurizing the component 102 and is attached to the vertical Z driving unit 122. The VCM 150 includes a stator 152 made of a coil fixed to the vertical Z drive unit 122 and a mover 154 made of a permanent magnet attached to the nozzle shaft 138. For this reason, the nozzle shaft 138 can be moved up and down by driving the VCM 150. That is, if the voltage input to the VCM 150 is large, a large force is generated and a long distance movement is realized. If there is no movement, pressurization according to the input voltage can be performed. Here, an upper stopper 146 is mounted on the nozzle shaft 138 between the stator 152 and the head base 112. When the VCM 150 is to be driven largely upward, the upper stopper 146 comes into contact with the upper stopper 114 of the head base 112, and the upward movement stroke of the VCM 150 is restricted to an appropriate range. Similarly, a lower stopper 148 is mounted on the nozzle shaft 138 between the mover 154 and the vertical Z drive unit 122. When the VCM 150 is to be driven largely downward, the lower stopper 148 comes into contact with the lower stopper 124 of the vertical Z drive unit 122, and the downward movement stroke of the VCM 150 is restricted to an appropriate range.

  Next, the substrate mounting table 184 will be described with reference to FIGS. In FIG. 4, the substrate mounting table 184 is made transparent for ease of explanation. The substrate mounting table 184 is fixed to a predetermined position of the substrate 104 by fixing the substrate 104 on the substrate mounting table 184 with the fixed terminal 182 when the substrate 104 is transferred to a predetermined position by the circuit board transfer path 180. Therefore, the component 102 can be mounted accurately and stably. A load detector, for example, a load cell 186 is used in the lower part of the substrate mounting table 184, and is arranged and fixed at four corners of the substrate mounting table 184. A load cell mount 188 is connected to the lower side of the load cell 186. The load cell mount 188 is provided with a load cell stopper 190 for preventing the load cell 186 from being overloaded and being excessively bent and broken. The load cell 186 is connected to a load cell amplifier 192 that amplifies the output signal of the load cell 186.

  The relationship between the mounting head 110, the load cell 186, and the controller 212 of the component mounting apparatus 100 described above will be described with reference to FIG. The mounting head 110 includes a Z-axis motor 116, a θ-axis motor 130, a VCM 150, drivers 116a, 130a, and 150a, a Z-axis encoder 116b, and a θ-axis encoder 130b. The main body 210 includes a load cell 186, a load cell amplifier 192, and a controller 212 that controls operations. The Z-axis driver 116a and the θ-axis driver 130a are connected to the controller 212. The controller 212 can refer to the output values of the Z-axis encoder 116b and the θ-axis encoder 130b via the Z-axis driver 116a and the θ-axis driver 130a. Based on this command, the Z-axis motor 116 and the θ-axis motor 130 are operated. The load cell amplifier 192 connected to the load cell 186 is connected to the VCM driver 150a. The controller 212 processes the output value of the load cell 186 output from the load cell amplifier 192 via the VCM driver 150a by the controller 212. Based on the processed result, the controller 212 sends a command to the VCM driver 150a to operate the VCM 150.

  Next, a filter that is a characteristic element of the present embodiment will be described in detail. The filter in this embodiment is a low-pass filter 230 shown in FIG. 6 and is realized on the controller 212. In order to remove high frequency components that do not affect the control of component mounting, the low pass filter 230 is calculated from the sampling frequency that captures the output value of the load cell 186 during control. In the present embodiment, since the sampling time for reading the output value of the load cell 186 is 5 msec, the sampling frequency is 200 Hz. Therefore, the cutoff frequency of one low-pass filter 230a can be set to 250 Hz, for example, with a margin. The cut-off frequency of the low-pass filter 230 is preferably as high as possible because the response is lowered when it is lowered. Accordingly, 500 Hz, which is twice the frequency of 250 Hz, is set as the cutoff frequency of the other low-pass filter 230b.

  FIG. 6 shows a circuit diagram of the low-pass filter 230 in the present embodiment. This circuit is a secondary low-pass filter, and has two resistors R1 and R2, two capacitors C1 and C2, and one operational amplifier. By using such a secondary filter, it is possible to cut a sharper high-frequency component than using a primary filter. The operational amplifier constitutes a voltage follower. In the present embodiment, this circuit is realized by software on the controller 212.

  This low-pass filter has the following characteristics.

f0 = 1/2 / π / (C1 * C2 * R1 * R2) ^1/2 (1)
ζ = (1/2) * (C2 / C1) ^1/2 * (R1 + R2) / (R1 * R2) ^1/2 (2)

  Here, f0 is a cut-off frequency (Hz), and ζ is an attenuation constant representing the shoulder characteristic of the low-pass filter at the frequency f0.

  Since R1 = R2 (= R), formulas (1) and (2) become formulas (3) and (4), respectively.

f0 = ^1/2 / π / R / (C1 * C2) ^1/2 (3)
ζ = (C2 / C1) ^1/2 ... (4)

  Since the low-pass filter is a Butterworth type in this embodiment, ζ = 0.707, and C1 and C2 are determined as in Expressions (5) and (6) from Expressions (3) and (4).

C1 = ^{1/2 1/2} / π / R / f0 (5)
C2 = (C1) / 2 (6)

  FIGS. 7A and 7B show schematic frequency characteristics of the low-pass filters 230a and 230b having the two types of cut-off frequencies, respectively.

  As described above, even when two types of filters are applied, since the circuit is realized by software, a plurality of filters can be tried on the controller 212, and the cost for changing the hardware of the component mounting apparatus 100 can be reduced. Development time can be significantly reduced.

  Next, the operation of this embodiment will be described.

  At the time of component mounting, the component mounting apparatus 100 according to the present embodiment performs an operation of sucking the component 102, moving the component 100, and mounting the component 100 by pressure bonding. explain.

  First, the mounting head 110 is moved to a predetermined position above the component supply unit 200 by operating the X-axis moving mechanism 160 and the Y-axis moving mechanism 170. Then, the Z-axis motor 112 is driven and the vertical Z drive unit 122 is lowered to bring the suction nozzle 142 closer to the component 102 at a high speed. At this time, a voltage is input to the VCM 150 to move the nozzle shaft 138 downward (the input voltage to the VCM 150 at this time is applied to the negative side), and the lower stopper 148 of the nozzle shaft 138 is moved to the vertical Z drive unit 122. It abuts against the lower stopper 124.

  The vertical Z driving unit 122 continues to descend at high speed, and when the suction nozzle 142 approaches the level of the suction surface of the component 102 mounted, the vertical Z driving unit 122 rapidly stops. At this time, the inertial force works downward due to the weight of the mover 154 and the nozzle shaft 138 and the acceleration at the time of deceleration, but since the position is regulated by the lower stopper 148, it exceeds the force generated in the VCM 150. Even if the inertial force works downward, the position of the tip of the suction nozzle 142 does not change, and the suction nozzle 142 also stops immediately.

  After the suction nozzle 142 is stopped and maintained, the input voltage to the VCM 150 is increased to the + side to generate an upward force on the VCM 150. That is, the output value of the VCM 150 is set so as to reduce the collision load at the time of contact with the component 102 so that no force is applied to the lower stopper 124 of the vertical Z driving unit 122 from the lower stopper 148.

  While maintaining the output value of the VCM 150, the Z-axis motor 116 is driven to lower the vertical Z drive unit 122 at a low speed. At this time, the control of the VCM 150 is different from the pressure mounting of the component 102, and the open loop control is performed.

  The suction nozzle 142 is lowered to the suction surface of the target component 102, and the operation of the Z-axis motor 116 is stopped.

  Thereafter, a solenoid valve (not shown in any figure) of the ejector is turned on, vacuum air for sucking the components is generated in the suction holes of the suction nozzle 142, and the components 102 are sucked.

  Next, the movement operation of the component 102 will be described.

  After the component 102 is sucked, the suction nozzle 142 is lifted by operating the Z-axis motor 116 to lift the vertical Z drive unit 122. Then, the mounting head 110 is moved above the component recognition camera 198 by the X-axis moving mechanism 160 and the Y-axis moving mechanism 170, and the component 102 is imaged by the component recognition camera 198.

  The captured image of the component 102 is subjected to image processing by the image recognition device 222, and the correction data is transferred to the controller 212. The controller 212 reads the board correction data and the component data of the component 102 from the storage device 214. Here, the substrate correction data (Δx, Δy, Δθ) of the substrate 104 based on the substrate mark imaged by the substrate recognition camera 158 is stored in the storage device 214 in advance. Based on the component data and the center of the component 102 and the inclination of the component 102 which are the correction data calculated by the transferred image recognition device 222, the mounting position and the suction posture of the component 102 are recognized. .

  When a positional deviation and an angular deviation are detected between the component mounting position, the center of the component 102, and the suction center, the X-axis motor 162, the Y-axis motor 172, and the θ-axis are corrected so as to correct these deviation amounts. The motor 130 is driven, and the component 102 is moved in a correct posture (reference angle) above a predetermined position of the substrate 104.

  Next, the crimping and mounting operation of the component 102 will be described. Although there is an overlapping part with the suction operation of the component 102, it will be described in detail with reference to FIGS. The Z-axis height of zero means that the lower stopper 148 of the nozzle shaft 138 and the lower stopper 124 of the vertical Z driving unit 122 are in contact with each other without applying a load to the surface of the substrate 104. The height of the vertical Z drive part 122 when mounted is defined. Then, the movement of the vertical Z driving unit 122 with reference to the position is shown in FIG. 9 as the Z-axis height, and will be described below.

  The Z-axis motor 116 is driven from the Z-axis height (Z3) after the XY movement, and the vertical Z drive unit 122 is lowered to bring the suction nozzle 142 that sucks the component 102 closer to a predetermined place on the substrate 104 at high speed. (Step S2 in FIG. 8). At this time, as shown in the first VCM output value of T1 in FIG. 9, a voltage is input to the VCM 150 to move the nozzle shaft 138 downward (at this time, the input voltage to the VCM 150 is applied to the negative side. The output value V2 is obtained to obtain a predetermined pressure at the time of component mounting), and the lower stopper 148 of the nozzle shaft 138 is abutted against the lower stopper 124 of the vertical Z drive unit 122. FIG. 10 shows the mounting head 110 in this state.

  The vertical Z drive unit 122 continues to descend at a high speed (step S4 in FIG. 8), and the component 102 to be mounted immediately moves the vertical Z drive unit 122 immediately before the mounting surface height (Z-axis height at this time is Z1). Stop and maintain (step S6 in FIG. 8). At this time, the inertial force works downward due to the weight of the mover 154 and the nozzle shaft 138 and the acceleration at the time of deceleration, but since the position is regulated by the lower stopper 148, it exceeds the force generated in the VCM 150. Even if the inertial force works downward, the position of the tip of the suction nozzle 142 does not change, and the suction nozzle 142 also stops immediately.

  After the suction nozzle 142 is stopped and maintained, the input voltage of the VCM 150 is increased to the + side to increase the output value of the VCM 150 (step S8 in FIG. 8). When the input voltage to the VCM 150 is zero, that is, when the output value of the VCM 150 becomes zero (step S10 in FIG. 8), the Z-axis motor 116 is turned on as shown in T2 first Z-axis height in FIG. The vertical Z driving unit 122 is driven to descend from Z1 at a lower speed than the rate of decrease at T1 (step S12 in FIG. 8).

  When the output value of the VCM 150 increases and an upward force is generated in the VCM 150, that is, no force is applied from the lower stopper 148 to the lower stopper 124 of the vertical Z drive unit 122. At that time, the output value of the VCM 150 (referred to as V1) is maintained (step S14). When the output value is V1, the collision load at the time of contact between the component 102 and the substrate 104 can be reduced.

  When the component 102 sucked by the suction nozzle 142 comes into contact with the substrate 104, pressure is generated on the substrate mounting table 184 that supports the substrate 104. Then, the force is transmitted to the load cell 186, a signal is output from the load cell amplifier 192, and the contact timing T0 of the component 102 with zero Z-axis height is detected (step 16 in FIG. 8). At this contact timing T0, the input voltage to the VCM 150 is increased to the minus side, that is, the output value of the VCM 150 is decreased (step S18 in FIG. 8), and the output value of the VCM 150 is switched from upward to downward. Pressure is applied to the component 102 from the nozzle 142. Then, the vertical Z driving unit 122 descends to a height (Z2) lower than the Z-axis height zero that is a preset Z-axis height, for example, a height of 0.2 mm below, and stops its operation ( Steps S20 and S22 in FIG. 8).

  On the other hand, the input voltage to the VCM 150 increases to the minus side, and when the output value of the VCM 150 reaches the target value V2, the output value V2 is maintained (steps S24 and S26 in FIG. 8). Since the VCM 150 determines whether the output value of the load cell 186 is the target load by forming a closed loop control, when the output value V2 is obtained, the load cell 186 obtains a predetermined output L1 corresponding to the target load. It is done. At the end of T2 in FIG. 9, the Z-axis height and the VCM output value are simultaneously the target values Z2 and V2, respectively. This is the timing when the Z-axis height becomes Z2, and the VCM output value is the target value. This is a result of adapting the reduction ratio of the input voltage to the VCM 150 so as to be the value V2.

  As shown at the beginning of T3 in FIG. 9, the Z-axis height Z2 and the VCM output value V2 are maintained for a predetermined time T3 in response to the Z-axis height and the VCM output value being both target values. (Step S28 in FIG. 8) is pressurized. During this time, V2 is maintained so that the output L1 of the load cell 186 is constant. After T3 elapses, the vacuum air is stopped, the Z-axis motor 116 is operated, and the vertical Z drive unit 122 is raised (step S30 in FIG. 8). Then, the mounting head 110 is moved to the suction position of the next component 102 by the X-axis moving mechanism 160 and the Y-axis moving mechanism 170.

  Next, a characteristic auto filter search of the present embodiment performed by the component mounting apparatus 100 according to the present embodiment when the mounting head 110 is stopped, for example, before component mounting will be described below with reference to FIGS. 11 and 12. Will be described in detail. The low-pass filter 230 applied in the present embodiment is a Butterworth type second-order low-pass filter 230 as shown in FIG. In this embodiment, since the low-pass filter 230 is realized by software, software including the entire auto filter search is read from the storage device 214 in advance to the controller 212 and executed.

  First, the output value of the load cell 186 can be captured for a certain period of time, for example, 3 seconds in a state where the mounting head 110 is stopped before the mounting of the component without the movement of the XYZθ axis of the component mounting apparatus 100 (step of FIG. 11). S40).

  For example, two types of low-pass filter processing are performed on each value acquired for a certain period of time (step S42 in FIG. 11). The frequency of the low-pass filter is calculated from a sampling frequency that takes in the output value of the load cell at the time of control, and an object is to filter a high frequency component that does not affect the control. Here, two types of low-pass filters having different cutoff frequencies are applied to the output value for 3 seconds.

  Next, the standard deviation 3σ indicating the fluctuation of the output value of the load cell 186 is obtained for each of the low-pass filters 230a and 230b with respect to the result data to which the two types of low-pass filters 230a and 230b of 250 Hz and 500 Hz are applied (FIG. 11). Step S44). The obtained results are, for example, 15 g for the 250 Hz low-pass filter 230 a and 40 g for the 500 Hz low-pass filter 230 b.

  In consideration of the comparison of the above results with the use environment and parts used (step S46 in FIG. 11), in the present embodiment, the filter in which the low-pass filter 230a having the smallest standard deviation 3σ and the cutoff frequency of 250 Hz is selected. (Step S48 in FIG. 11).

  Therefore, when the output value of the load cell amplifier 192 is input to the controller 212 at the time of component mounting, 250 Hz low-pass filter processing is performed in the controller 212. The processed data is regarded as an output value of the load cell 186 for load control, and the controller 212 controls the output value of the VCM 150 based on the output value to adjust the load. Specifically, the above-described control can be easily executed by writing the filter constant determined by the auto filter search into a program activated at the time of component mounting. In this embodiment, the software itself that runs on the controller 212 functions as a filter selection unit.

  FIG. 12B shows the result when the component is pressurized by applying the low-pass filter 230a having a cutoff frequency of 250 Hz in the present embodiment. FIG. 12A shows the result when pressure is applied in the same part and under the same pressure condition but without the low-pass filter 230a. In any case, load pressing from 150 g to 200 g was performed on the component for about 0.6 seconds, but in this embodiment, the pressing accuracy is not impaired, that is, highly accurate and stable pressing is performed. ing.

  Therefore, by applying a plurality of low-pass filters 230 to the output value of the load cell 186 before mounting the component on which the XYZθ axis is stopped, the standard deviation 3σ is obtained for the result data, and the comparison is examined. It is possible to obtain the low pass filter 230 suitable for the usage environment of 100. Therefore, it is possible to perform highly accurate and stable pressure control by the mounting head 110 using a low-pass filter that is optimal for the usage environment of the component mounting apparatus 100.

  Since the standard deviation 3σ of the output value of the load cell 186 can be measured without applying the low-pass filter 230, it is possible to determine whether the environment of the component mounting apparatus 100 is suitable for installation. .

  In addition, the standard deviation 3σ is calculated for the output value of the load cell 186 that has been captured for a certain time, and if it is greater than a certain value, for example, if the output value of the load cell 186 is 3σ = 300 g or more, an error signal is output. It is also possible to use this as an installation environment diagnostic mode informing the operator that the environment in which the apparatus is installed is an environment in which the mounting accuracy of the component mounting apparatus 100 cannot be ensured.

  As described above, in this embodiment, the output value of the load cell 186 includes two types of Butterworth types with different cutoff frequencies (even if some delay occurs, the attenuation rate of the frequency larger than the cutoff frequency is large, the filter characteristics are steep and stable) Applying low-pass filter 230 (excellent), but applying Bessel type (slightly slow filter characteristics, low delay and excellent high-speed), different cutoff frequencies, and applying Butterworth and Bessel type filters Even if compared, it is included in the present invention. Further, the low pass filter 230 may employ not only the second order but also the first order, the third order, the fourth order, and the like. Alternatively, the output value of the load cell 186 may be subjected to FFT conversion to obtain a frequency component, and a more effective low-pass filter 230 may be applied to the calculated peak value of the frequency component. Further, not only the low-pass filter 230 but also a filter that attenuates only a specific frequency such as a notch filter may be used.

  In this embodiment, the load cell 186 is used as a load detector. However, the load detector is not limited to the load cell 186 as long as it is a sensor that detects a load.

  Further, the auto filter search is not limited to before the component mounting, and if the mounting head 110 is stopped, it is also included in the present invention that it is periodically performed during the component mounting.

  Further, only in the auto filter search stage, the filter is realized as software, and a plurality of or one constant variable hardware is provided between the VCM 150 and the load cell amplifier 192 shown in FIG. It goes without saying that the present invention also includes that the controller 212 functions as a filter selection means and supplies a signal that selects a constant and a filter to a filter configured by hardware.

  In this embodiment, the low-pass filter 230 that minimizes the fluctuation with respect to the output value of the load cell 186 is determined. However, the present invention is not limited to this. For example, if the mounting component is not likely to cause mounting failure, for example, if it is only the type of mounting component such as a chip resistor or capacitor, the filter can be selected to minimize the delay caused by the filter, so speed, stability, etc. It is clear that the present invention includes that the filter is determined in a comprehensive comparison.

  In this embodiment, the controller 212 processes the output value of the load cell 186, but the present invention is not limited to this. Based on the result processed by the load cell amplifier 192, the controller 212 instructs the load cell amplifier 192 on the processing method, and instructs the VCM driver to operate the VCM 150 based on the result output based on the processing method. Needless to say, the present invention includes a case of sending or operating the VCM 150 by processing the output of the load cell 186 by the VCM driver 150a based on an instruction from the controller 212.

The perspective view of the whole component mounting apparatus which concerns on 1st Embodiment of this invention. Block diagram of the entire configuration Configuration diagram of the same mounting head Similarly load cell layout Similarly, a block diagram showing the relationship between the mounting head, load cell and CPU Similarly, low-pass filter circuit diagram Similarly, frequency characteristics of low-pass filter Flow chart showing the same component mounting Similarly, a timing chart showing the relationship between mounted head operation and load cell output Configuration diagram of the same mounting head Same auto filter search flowchart Similarly, the figure showing the part pressurization based on the output value of the actual load cell Schematic diagram of conventional component mounting equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 ... Component mounting apparatus 2, 102 ... Component 4, 104 ... Board | substrate 14, 186 ... Load cell 16 ... Case
20 ... Motor
22 ... CPU
24 ... Stage 110 ... Mounted head 112 ... Head base 114, 146 ... Upper stopper 116 ... Z-axis motor 122 ... Vertical Z drive unit 124, 148 ... Lower stopper 130 ... θ-axis motor 138 ... Nozzle shaft 142 ... Suction nozzle 150 ... VCM
158 ... Board recognition camera 160 ... X axis movement mechanism 162 ... X axis motor 170 ... Y axis movement mechanism 172 ... Y axis motor 180 ... Board transport path 184 ... Board mounting table 192 ... Load cell amplifier 198 ... Parts recognition camera 200 ... Parts supply Unit 210 ... Main body 212 ... Controller 214 ... Storage device 222 ... Image recognition device 230, 230a, 230b ... Low pass filter

Claims (1)

In a component mounting apparatus having a mounting head for sucking and mounting a component on a substrate and a load detector for detecting a pressure at the time of mounting the component,
A plurality of filters applicable to the output signal of the load detector;
Means for selecting a filter from among the plurality of filters,
When the mounting head is stopped, the plurality of filters are applied to the shake value of the output signal of the load detector, and a filter that reduces the shake value of the output signal is selected. By applying to the above, the component mounting apparatus is characterized in that pressure control of the mounting head is performed.

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