Component mounting apparatus and component mounting method

Abstract

To provide a component mounting device and a component mounting method capable of appropriately determining a mounting state of a component on a substrate.SOLUTION: When a component is mounted by a nozzle, the thrust of a Z-axis motor for lowering the nozzle and a mounting height which is a difference between the lowest point of the lowered nozzle and a target height are measured. In a case where the measured maximum thrust is equal to or greater than the thrust threshold-value (Yes in ST21), it is determined that the installation state is good (ST22), in a case where the maximum thrust is smaller than the thrust threshold-value (No in ST21) and the installation height is equal to or greater than the height threshold-value (Yes in ST23), it is determined that the installation state is substantially good (ST24), and in a case where the maximum thrust is smaller than the installation threshold-value (No in ST21) and the installation height is lower than the height threshold-value (No in ST23), it is determined that the installation state is bad (ST25).SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a component mounting apparatus and a component mounting method for mounting components on a board. [Background technology]

[0002] In order to mount a component on a board while applying a mounting load, a component mounting device lowers a nozzle holding the component while controlling the lower surface of the component to be mounted so that it is lower than the upper surface of the board. However, when attempting to mount a component on a downwardly recessed board, there is a risk of a missed component mounting attempt, in which the component cannot reach the board (see, for example, Patent Document 1). Patent Document 1 discloses a pressing device that lowers the nozzle while detecting the drive current of a linear motor that lowers the nozzle, and determines that pressing has been successful if the drive current reaches a set value before the nozzle reaches a predetermined height, and determines that pressing has failed (a missed component mounting attempt) if the drive current does not reach the set value even after the nozzle has been lowered to the predetermined height. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-159327 Summary of the Invention [Problem to be solved by the invention]

[0004] However, while the conventional technologies including Patent Document 1 can determine whether a component has been successfully placed on a board or whether it has missed the mark, they cannot determine whether an appropriate placement load has been applied during placement, and there is a problem that there is room for further improvement.

[0005] Therefore, an object of the present disclosure is to provide a component mounting apparatus and a component mounting method that can appropriately determine the mounting state of a component on a board. [Means for solving the problem]

[0006] A component mounting device according to the present disclosure is a component mounting device that picks up a component with a nozzle and mounts the component on a board by lowering the nozzle based on a target height above the board, and includes a thrust measuring unit that measures a thrust of a motor that lowers the nozzle when mounting the component with the nozzle, a mounting height measuring unit that measures a mounting height that is the difference between the lowest point of the lowered nozzle and the target height when mounting the component with the nozzle, and a mounting height measuring unit that measures the base height of the component based on the thrust measured by the thrust measuring unit and the mounting height measured by the mounting height measuring unit. and an attachment state determination unit that determines the attachment state to the board, wherein the attachment state determination unit determines that the attachment state is good when the maximum value of the thrust measured by the thrust measuring unit is equal to or greater than a predetermined thrust threshold, determines that the attachment state is almost good when the maximum value of the measured thrust is smaller than the thrust threshold and the attachment height measured by the attachment height measuring unit is equal to or greater than a predetermined height threshold, and determines that the attachment state is poor when the maximum value of the measured thrust is smaller than the thrust threshold and the measured attachment height is lower than the height threshold.

[0007] The component mounting method disclosed herein is a component mounting method in which a component is picked up by a nozzle and the nozzle is lowered based on a target height above the board to mount the component on the board, and the method measures the thrust of a motor that lowers the nozzle when mounting the component with the nozzle, and measures a mounting height that is the difference between the lowest point of the lowered nozzle and the target height when mounting the component with the nozzle, and determines the mounting condition to be good if the maximum value of the measured thrust is equal to or greater than a predetermined thrust threshold, determines the mounting condition to be almost good if the maximum value of the measured thrust is smaller than the thrust threshold and the measured mounting height is equal to or greater than a predetermined height threshold, and determines the mounting condition to be poor if the maximum value of the measured thrust is smaller than the thrust threshold and the measured mounting height is lower than the height threshold. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to appropriately determine the mounting state of a component on a board. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing a configuration of a main part of a component mounting apparatus according to an embodiment of the present disclosure; [Figure 2] 1 is a cross-sectional view showing a configuration of a main part of a head provided in a component mounting apparatus according to an embodiment of the present disclosure. [Figure 3] 10A and 10B are explanatory diagrams showing the relationship of forces acting on a mounting unit of a head included in a component mounting apparatus according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a block diagram showing the configuration of a control system of the component mounting apparatus according to the embodiment of the present disclosure. [Figure 5] FIG. 2 is a block diagram showing the configuration of a control system for a head attached to a component mounting apparatus according to an embodiment of the present disclosure. [Figure 6] FIG. 10A is an explanatory diagram of the position of the board where the mounting state is judged to be good by a component mounting device according to an embodiment of the present disclosure; FIG. 10B is an explanatory diagram showing the transition of the encoder output; and FIG. 10C is an explanatory diagram showing the transition of the thrust force of the Z-axis motor. [Figure 7] FIG. 10 is an explanatory diagram showing (a) the position of the board when the mounting state is judged to be almost good by a component mounting device according to an embodiment of the present disclosure; (b) an explanatory diagram showing the transition of the encoder output; and (c) an explanatory diagram showing the transition of the thrust force of the Z-axis motor. [Figure 8] FIG. 10A is an explanatory diagram of a board position where a mounting state is determined to be poor by a component mounting device according to an embodiment of the present disclosure; FIG. 10B is an explanatory diagram showing the transition of an encoder output; and FIG. 10C is an explanatory diagram showing the transition of a Z-axis motor thrust. [Figure 9] FIG. 1 is a flow diagram of a component mounting method according to an embodiment of the present disclosure. [Figure 10] 1 is a flow diagram of a method for determining a wearing state according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present disclosure will be described in detail below with reference to the drawings. The configurations, shapes, etc. described below are examples for explanation purposes and can be modified as appropriate depending on the specifications of the component mounting device and head. In the following, corresponding elements in all drawings will be given the same reference numerals, and duplicated explanations will be omitted. In FIG. 1 and in some parts described below, the X-axis (left-right direction in FIG. 1) in the substrate transport direction and the Y-axis (up-down direction in FIG. 1) perpendicular to the substrate transport direction are shown as two axes that are perpendicular to each other in a horizontal plane. In FIG. 2 and in some parts described below, the Z-axis (up-down direction in FIG. 2) is shown as the height direction that is perpendicular to the horizontal plane.

[0011] First, the configuration of component mounting apparatus 1 will be described with reference to Figure 1. Component mounting apparatus 1 has the function of performing a component mounting operation in which components supplied from a component supply unit are mounted on a board to manufacture a mounted board. A board transport mechanism 3 is arranged along the X-axis in the center of base 2. Board transport mechanism 3 transports board B transported from upstream to the mounting operation position, positions it, and holds it. In addition, board transport mechanism 3 transports board B downstream after the component mounting operation has been completed.

[0012] Component supply units 4 are arranged on both sides (front and back directions of the Y axis) of the board transport mechanism 3. Each component supply unit 4 has multiple tape feeders 5 (component supply devices) arranged along the X axis. The tape feeders 5 pitch-feed a carrier tape, on which pockets for storing components D (see FIG. 3) are formed, in a direction (tape feed direction) from the outside of the component supply unit 4 toward the board transport mechanism 3, thereby supplying the components D to a component pick-up position where the components D are picked up by a head 8, which will be described below.

[0013] In FIG. 1, a Y-axis table 6 equipped with a linear drive mechanism is arranged along the Y-axis at both ends of the X-axis on the upper surface of the base 2. A beam 7 similarly equipped with a linear drive mechanism is connected to the Y-axis table 6 so as to be movable along the Y-axis. The beam 7 is arranged along the X-axis. A head 8 is attached to the beam 7 via a plate 7a so as to be movable along the X-axis. The head 8 is detachable from the plate 7a. The head 8 is equipped with a plurality of mounting units 20 (see FIG. 2). A nozzle 29 (see FIG. 2) for suctioning and holding a component D is attached to the lower end of each mounting unit 20.

[0014] The Y-axis table 6 and beam 7 constitute a head moving mechanism 9 that moves the head 8 along the X-axis and Y-axis. The head moving mechanism 9 and head 8 perform a mounting turn in which nozzles 29 attached to the mounting unit 20 pick up and remove components D from tape feeders 5 arranged in the component supply unit 4, and mount them at mounting positions on the board B positioned by the board transport mechanism 3. In this way, multiple nozzles 29 are attached to the head 8, and each nozzle 29 picks up a component D supplied from the component supply unit 4 and mounts it on the board B.

[0015] In Fig. 1, a component recognition camera 10 is disposed between the component supply unit 4 and the board transport mechanism 3. When the head 8, which has picked up a component D from the component supply unit 4, moves above the component recognition camera 10, the component recognition camera 10 captures an image of the component D held by the head 8 and recognizes the holding posture of the component D. A head camera 11 is attached to the plate 7a to which the head 8 is attached. The head camera 11 moves integrally with the head 8.

[0016] As head 8 moves, head camera 11 moves above board B positioned by board transport mechanism 3, and captures an image of a board mark (not shown) provided on board B to recognize the position of board B. When head 8 mounts components on board B, the mounting position is corrected taking into account the recognition result of component D by component recognition camera 10 and the recognition result of the board position by head camera 11.

[0017] 1, a touch panel 12 operated by the worker is installed at the position where the worker works in front of the component mounting device 1. The touch panel 12 displays various information on its display unit, and the worker inputs data and operates the component mounting device 1 using operation buttons and the like displayed on the display unit.

[0018] Next, the configuration of the head 8 will be described with reference to Figure 2. The head 8 has multiple mounting units 20 (four in the X direction in this case) arranged inside a head base 8a. The mounting units 20 are configured such that a shaft 21 extending in the vertical direction (Z axis direction) is raised and lowered by a servo-controlled Z axis motor 22, thereby raising and lowering a nozzle 29.

[0019] Shaft 21 is connected to the lower side of Z-axis motor 22 via output portion 23. The lower end of shaft 21 is inserted into spline guide portion 24, which is rotatable through θ by bearings 24a arranged above and below, and protrudes outward from the lower surface of head base 8a. A nozzle 29 is attached to the lower end of shaft 21 protruding from the lower surface of head base 8a. In this way, nozzle 29 is attached to the lower end of shaft 21, which is raised and lowered by Z-axis motor 22 (motor).

[0020] 2, a return spring 25, which is a compression spring, is attached to the shaft 21 between the output portion 23 and the spline guide portion 24. The return spring 25 exerts an upward repulsive force on the output portion 23. That is, when the nozzle 29 is to be lowered, the Z-axis motor 22 generates a downward thrust, which lowers the shaft 21 against the repulsive force of the return spring 25. When the nozzle 29 is to be raised, the Z-axis motor 22 reduces the thrust it generates, and the return spring 25 raises the output portion 23 with an upward repulsive force, which raises the shaft 21.

[0021] A scale 26 that moves up and down in accordance with the up and down movement of the output unit 23, i.e., the up and down movement of the shaft 21, is provided to protrude upward from the top of the Z-axis motor 22. Also, a position detection sensor 27 that detects the movement of the scale 26 is arranged above the Z-axis motor 22. The position detection sensor 27 outputs encoder pulses that indicate the movement distance and direction of the scale 26 as position signals to the servo control unit 40 (see FIG. 4). The vertical position (height position) of the shaft 21 is detected from the position signal. In other words, the scale 26 and the position detection sensor 27 constitute an encoder 28 that detects the height position of the shaft 21 (or the nozzle 29).

[0022] Next, the relationship between the forces acting on mounting unit 20 will be described with reference to Fig. 3. Thrust Ft is generated by Z-axis motor 22, and acts in a direction that pushes down shaft 21, which is connected via output unit 23. Weight W is the sum of the weights of the hatched parts that indicate the moving parts in the figure, that is, scale 26, output unit 23, shaft 21, nozzle 29, etc., and acts in a direction that pushes down shaft 21, just like thrust Ft.

[0023] The reaction force Fr is the reaction force of the return spring 25, and acts in a direction pushing up the shaft 21 via the output portion 23. The resistance Ff is an external resistive force from the spline guide portion 24 and the like that slidably holds the above-mentioned movable portion, and acts upward on the shaft 21 that is driven in the downward direction. The load Fa represents the load when the nozzle 29 presses the component D held by it against the board B.

[0024] 3 shows a state in which nozzle 29 is pressing component D held by nozzle 29 against board B during component mounting. In this state, load Fa is expressed as Fa = Ft + W - Fr - Ff. When thrust Ft of Z-axis motor 22 is increased while component D is in contact with board B, load Fa increases in proportion to thrust Ft while reaction force Fr of return spring 25 remains constant. Furthermore, load Fa is zero before component D held by nozzle 29 comes into contact with board B, and output section 23 (shaft 21, nozzle 29) descends in proportion to thrust Ft of Z-axis motor 22, increasing reaction force Fr of return spring 25 (Fr = Ft + W - Ff).

[0025] Next, the configuration of the control system of the component mounting apparatus 1 will be described with reference to Fig. 4. The main body control unit 30 provided in the component mounting apparatus 1 is connected to the board transport mechanism 3, tape feeder 5, head 8, head moving mechanism 9, component recognition camera 10, head camera 11, and touch panel 12. Each of the four mounting units 20 provided in the head 8 is equipped with a servo control unit 40. The servo control unit 40 is connected to the Z-axis motor 22 and the position detection sensor 27 of the encoder 28.

[0026] Servo control unit 40 drives Z-axis motor 22 based on the vertical position of shaft 21 (nozzle 29) detected by encoder 28, in accordance with a command from main body control unit 30. Methods for controlling Z-axis motor 22 by servo control unit 40 include position control and torque control. In the case of position control, servo control unit 40 controls Z-axis motor 22 so that the height of nozzle 29 matches the height commanded by main body control unit 30. In the case of torque control, servo control unit 40 controls thrust Ft of Z-axis motor 22 based on a command from main body control unit 30.

[0027] 4, the main body control unit 30 includes a main body storage unit 31, an installation processing unit 32, an installation height measurement processing unit 33, and an installation state determination unit 34. The main body storage unit 31 is a storage device, and stores installation data 31a, threshold data 31b, measured thrust data 31c, measured installation height data 31d, installation state data 31e, and the like.

[0028] The mounting data 31a stores various information for each type of mounting board, such as information identifying the board B (board type number, size, material, thickness, etc.), information on the components D to be mounted on the board B (component name, size, thickness, supply position in the component supply unit 4, etc.), and coordinates of the mounting position on the board B. The mounting data 31a also stores a thrust limit value Ftl (see FIG. 6(c)) of the Z-axis motor 22 during the component mounting operation.

[0029] 4, threshold data 31b stores a thrust threshold Ftt (see FIG. 6(c)), which is a threshold for the thrust Ft of Z-axis motor 22, and a height threshold Hbt (see FIG. 6(b)), which is a threshold for the mounting height Hm, used by mounting state determination unit 34, which will be described later, when determining the mounting state of component D. Measured thrust data 31c stores transition data of thrust Ft of Z-axis motor 22 during component mounting work measured by thrust measurement unit 42, which will be described later, or a maximum thrust Ftm (FIG. 6(c)), which is the maximum value of thrust Ft.

[0030] Measured mounting height data 31d stores mounting height Hm, which is the difference between the height of the lowest point of nozzle 29 during component mounting work measured by mounting height measurement unit 35 (described later) and target height Hg (see FIG. 6(b)) (see FIG. 6(a)). Mounting state data 31e stores the mounting state of component D determined by mounting state determination unit 34 in association with information specifying board B (mounted board) on which component D is mounted and information specifying the mounting position. Mounting state data 31e is used as tracing information for the purpose of quality control of board B (mounted board) on which component D is mounted.

[0031] Here, the control system of the head 8 will be described in detail with reference to FIG. 5. The head 8 in this example is equipped with four mounting units 20(#1) to (#4). Each mounting unit 20(#1) to (#4) is equipped with a Z-axis motor 22(#1) to (#4), an encoder 28(#1) to (#4), and a servo control unit 40(#1) to (#4). The four mounting units 20(#1) to (#4) have the same configuration, and the following description will be given using mounting unit 20(#1) as an example. Furthermore, the symbols (#1) to (#4) that identify the mounting units 20, etc. will be omitted as appropriate.

[0032] 5, servo control unit 40 includes motor driver 41, thrust measurement unit 42, thrust limiting unit 43, position detection unit 44, and contact detection unit 45. Motor driver 41 is a drive control device for Z-axis motor 22, which is a servo motor, and supplies current to Z-axis motor 22 (arrow a) based on a preset operation pattern to drive Z-axis motor 22. Motor driver 41 then detects deviations from the target height and target elevation speed determined by the operation pattern using pulse signals sent from encoder 28 (arrow b), and drives Z-axis motor 22 using servo control that feeds back the detected deviations.

[0033] The thrust force measuring unit 42 has a function of measuring the thrust force Ft of the Z-axis motor 22. That is, the thrust force Ft generated by the Z-axis motor 22 is measured based on the current (arrow a) supplied to the Z-axis motor 22 from the motor driver 41 or the current value (arrow c) notified from the motor driver 41. The thrust force Ft measured during the component placement operation is transmitted to the main body control unit 30 and stored as measured thrust force data 31c. The servo control unit 40 transmits time transition data of the thrust force Ft as well as the maximum thrust force Ftm measured during the component placement operation. In this way, the thrust force measuring unit 42 measures the thrust force Ft of the Z-axis motor 22 that lowers the nozzle 29 when the nozzle 29 places the component D.

[0034] 5, thrust limiting unit 43 sets thrust limit value Ftl instructed by main body control unit 30 to motor driver 41 (arrow d). In this embodiment, thrust Ft of Z-axis motor 22 during component placement work is limited based on thrust limit value Ftl. That is, when nozzle 29 places component D, thrust limiting unit 43 limits thrust Ft of Z-axis motor 22, which lowers nozzle 29, to a predetermined value (thrust limit value Ftl).

[0035] The contact detection unit 45 calculates the rate of change ΔFt of thrust from the thrust Ft measured by the thrust measurement unit 42. Furthermore, when the calculated rate of change ΔFt of thrust exceeds a predetermined contact determination value, the contact detection unit 45 determines that the component D picked up by the nozzle 29 has come into contact with the board B.

[0036] 5, position detection unit 44 counts encoder pulses (arrow e) from encoder 28 of Z-axis motor 22. This count value becomes position information indicating the height position of nozzle 29 (hereinafter referred to as "nozzle height H"). That is, position detection unit 44 detects nozzle height H of nozzle 29 based on the position signal from Z-axis motor 22. The nozzle height H of the lowest point of nozzle 29 measured during component mounting work is transmitted to main body control unit 30.

[0037] In FIG. 4, the mounting processing unit 32 controls each part of the component mounting apparatus 1 to perform the component mounting work based on the component name, mounting position, target height Hg, thrust limit value Ftl, etc. of the component D to be mounted on the board B contained in the mounting data 31a.

[0038] When nozzle 29 places component D at a placement position on board B during component placement work, placement height measurement processor 33 calculates placement height Hm, which is the difference between nozzle height H of the lowest point of nozzle 29 transmitted from servo controller 40 and target height Hg to which nozzle 29 is lowered, and stores this as measured placement height data 31d in main body storage unit 31. In other words, mounting unit 20 of head 8 and placement height measurement processor 33 constitute placement height measurement unit 35 that measures placement height Hm, which is the difference between the lowest point of lowered nozzle 29 and target height Hg, when nozzle 29 places component D.

[0039] 4, mounting state determination unit 34 determines the mounting state of component D on board B based on thrust Ft (measured thrust data 31c) measured by thrust measurement unit 42 and mounting height Hm (measured mounting height data 31d) measured by mounting height measurement unit 35. Note that although the above description is of a configuration in which component mounting apparatus 1 is equipped with mounting state determination unit 34, a configuration in which a management computer connected to component mounting apparatus 1 is equipped with mounting state determination unit 34 may also be used. In this case, measured thrust data 31c and measured mounting height data 31d are transmitted to the management computer, and mounting state determination unit 34 of the management computer determines the mounting state of component D.

[0040] Here, with reference to Figures 6 to 8, the details of the determination of the mounting state by the mounting state determiner 34 will be described. Figure 6 shows a state in which the mounting state is determined to be "good," Figure 7 shows a state in which the mounting state is determined to be "almost good," and Figure 8 shows a state in which the mounting state is determined to be "bad." In Figures 6 to 8, the servo control unit 40 controls the Z-axis motor 22 according to the same command. Figure 6(a) shows the position of the board B in which the mounting state is determined to be "good." Figure 6(b) shows the time progression of the output of the encoder 28 in which the mounting state is determined to be "good." Figure 6(c) shows the time progression of the thrust Ft of the Z-axis motor 22 in which the mounting state is determined to be "good."

[0041] 6(a) shows a state in which, during a component mounting operation, nozzle 29, which has picked up component D1, is moved above the mounting position and then lowered toward target height Hg. Target height Hg is set to a height at which component D1 picked up by nozzle 29 lands on unwarped board B, and nozzle 29 then descends to apply an appropriate load Fa to component D. In this example, board B is unwarped, and the height of the top surface of board B (board height Hb1) is higher than target height Hg, so component D1 picked up by nozzle 29 comes into contact with (lands on) the top surface of board B before nozzle 29 reaches target height Hg.

[0042] In Figure 6(b), commands sent from the main body control unit 30 are indicated by dotted lines. The servo control unit 40 controls the Z-axis motor 22 so that the nozzle height H of the nozzle 29 rises or falls in accordance with the commands. In this example, the nozzle 29 is controlled to descend so as to reach the target height Hg at time T2, and to maintain the nozzle height H at the target height Hg for a preset mounting retention time from time T2. The nozzle 29 is then controlled to rise from time T3, when the mounting retention time has elapsed since time T2. Note that during the mounting retention time from time T2 to time T3, the nozzle 29 is released from suction of the component D1.

[0043] 6(b), the output of encoder 28 when controlled according to the command is shown by a solid line. The output of encoder 28 on the vertical axis indicates nozzle height H of nozzle 29. In this example, component D picked up by nozzle 29 lands on board B at time T1, which is earlier than time T2, and the descent of nozzle 29 stops. Then, nozzle 29 begins to rise at time T4, which is later than time T3. In this example, the height of the lowest point of nozzle 29 is board height Hb1, and placement height measurement unit 35 measures the difference between board height Hb1 and target height Hg as placement height Hm1 (=Hb1-Hg).

[0044] 6(c), when component D1 lands on board B at time T1, thrust Ft of Z-axis motor 22 increases rapidly. Then, when thrust Ft reaches thrust limit value Ftl, thrust Ft is controlled so as not to exceed thrust limit value Ftl, thereby maintaining thrust Ft at thrust limit value Ftl. Note that thrust limit value Ftl is set to a value greater than thrust threshold value Ftt. Thereafter, from time T3, nozzle 29 is controlled to rise, thereby causing thrust Ft to decrease rapidly. In this example, thrust measurement unit 42 measures the maximum value of thrust Ft of Z-axis motor 22 (maximum thrust Ftm1) as thrust limit value Ftl, which is greater than thrust threshold value Ftt.

[0045] The load Fa1 applied to the component D1 is the maximum value of the increase in thrust Ft from the thrust Ft of the Z-axis motor 22 at time T1 when the component D1 lands on the board B. The mounting state determination unit 34 determines that the mounting state is "good" when the maximum value of the thrust Ft measured by the thrust measurement unit 42 (maximum thrust Ftm1) is equal to or greater than a predetermined thrust threshold Ftt. In other words, a component D1 with a "good" mounting state is a component D1 to which an appropriate load Fa1 has been applied after landing on the board B.

[0046] 7(a) shows an example in which board B is warped downward at the mounting position, and the height of the top surface of board B (board height Hb2) is higher than target height Hg but lower than board height Hb1 in the state without warp shown in Fig. 6(a). In this case as well, nozzle 29 descends, causing component D2 picked up by nozzle 29 to come into contact (land) on the top surface of board B before nozzle 29 reaches target height Hg.

[0047] 7(b), in this example, component D2 picked up by nozzle 29 lands on board B at time T5, which is earlier than time T2, and the descent of nozzle 29 stops. Then, nozzle 29 begins to rise at time T6, which is later than time T3, when the placement holding time has elapsed. In this example, the lowest point of nozzle 29 is board height Hb2, and placement height measurement unit 35 measures the difference between board height Hb2 and target height Hg as placement height Hm2 (=Hb2-Hg). Placement height Hm2 is greater than height threshold Hbt.

[0048] 7(c), when component D2 lands on board B at time T5, the thrust Ft of Z-axis motor 22 rises sharply, but the maximum thrust Ftm2 does not reach the thrust limit value Ftl. Furthermore, the maximum thrust Ftm2 is smaller than the thrust threshold value Ftt. The load Fa2 applied to component D2 that has landed on board B is smaller than the load Fa1 applied to component D1 in good condition.

[0049] The mounting state determination unit 34 determines the mounting state to be "almost good" if the maximum value of the thrust Ft (maximum thrust Ftm2) measured by the thrust measurement unit 42 is smaller than the thrust threshold Ftt and the mounting height Hm2 measured by the mounting height measurement unit 35 is equal to or greater than the predetermined height threshold Hbt. That is, a component D2 in an "almost good" mounting state is a component D2 that has not been subjected to the appropriate load Fa1 but has been mounted on the board B by applying a load Fa2 after landing on the board B. The component D2 that has been mounted on the board B in an almost good mounting state is then soldered to the board B by reflow soldering.

[0050] 8(a) shows an example in which board B is tilted significantly downward at the mounting position, and the height of the top surface of board B (board height Hb3) is lower than target height Hg. In this case, nozzle 29 reaches target height Hg before component D3 being sucked onto the descending nozzle 29 reaches (lands on) the top surface of board B.

[0051] 8(b), in this example, the nozzle 29 reaches the target height Hg at time T7, which is later than time T2, and the descent of the nozzle 29 stops. Then, the nozzle 29 starts to rise at time T8, which is later than time T3, when the placement holding time has elapsed. In this example, the lowest point of the nozzle 29 is the target height Hg, component D3 is not placed on board B, and the placement height measurement unit 35 measures the placement height Hm3 as 0 (zero). In other words, the placement height Hm3 is lower than the height threshold Hbt.

[0052] 8(c), during the mounting retention time when the nozzle 29 is at its lowest point (between time T7 and time T8), the load Fa3 applied to the component D3 is 0 (zero) because the component D3 picked up by the nozzle 29 is not in contact with the upper surface of the board B. Furthermore, the maximum thrust Ftm3 of the Z-axis motor 22 during the mounting retention time is smaller than the thrust threshold Ftt.

[0053] The wearing condition determination unit 34 determines that the wearing condition is "poor" if the maximum value of the thrust Ft (maximum thrust Ftm3) measured by the thrust measurement unit 42 is smaller than the thrust threshold Ftt and the wearing height Hm3 measured by the wearing height measurement unit 35 is lower than the height threshold Hbt.

[0054] In this way, the placement state determination unit 34 compares the maximum thrusts Ftm1-Ftm3 measured by the thrust measurement unit 42 with the thrust threshold Ftt, and compares the placement heights Hm1-Hm3 measured by the placement height measurement unit 35 with the height threshold Hbt, thereby determining whether the placement state of the components D1-D3 is "good," "almost good," or "poor." This allows for an appropriate determination of the placement state of the components D1-D3 on the board B. The thrust threshold Ftt and the height threshold Hbt are determined based on experiments and past experience when placing the components D1-D3 on the board B.

[0055] In the above description, the placement state determination unit 34 determines the placement state of the components D1-D3 based on the thrust Ft of the Z-axis motor 22. However, the placement state may be determined based on the current supplied to the Z-axis motor 22 in addition to the thrust Ft of the Z-axis motor 22. In this case, the placement state determination unit 34 compares the maximum current supplied to the Z-axis motor 22 from the motor driver 41 with a current threshold, and compares the placement heights Hm1-Hm3 measured by the placement height measurement unit 35 with a height threshold Hbt, thereby determining whether the placement state of the components D1-D3 is "good," "almost good," or "poor." Furthermore, when the nozzle 29 places the components D1-D3, the current of the Z-axis motor 22, which lowers the nozzle 29, is limited to a predetermined value (current limit value).

[0056] 9 and 10, and with reference to FIGS. 6 to 8, a component mounting method will be described in which components D1 to D3 are picked up by nozzle 29 and then lowered based on a target height Hg above board B to mount components D1 to D3 on board B. Here, one mounting turn in which nozzle 29 holds components D1 to D3 and mounts them at mounting positions on board B will be described.

[0057] 9, first, mounting processing unit 32 causes nozzle 29 to pick up components D1 to D3 from tape feeder 5 (ST1) and moves nozzle 29 to above the mounting position (ST2). Next, servo control unit 40 operates Z-axis motor 22 by position control to start descending nozzle 29 (shaft 21) (ST3: descent start step). As a result, nozzle 29 holding component D starts descending toward the mounting position on board B. Note that the descent start step (ST3) may be executed before nozzle 29 arrives above the mounting position (before ST2 is completed).

[0058] Next, the thrust measuring unit 42 measures the thrust Ft of the Z-axis motor 22 (ST4: thrust measurement step). Next, the servo control unit 40 determines whether the thrust Ft of the Z-axis motor 22 exceeds the thrust limit value Ftl (ST5: thrust determination step). If the thrust Ft does not exceed the thrust limit value Ftl (No in ST5), the servo control unit 40 determines whether the commanded attachment maintenance time (or descent time) has been exceeded (ST6: time determination step). If the descent time has not been exceeded (No in ST6), the servo control unit 40 determines whether the nozzle height H of the nozzle 29 has exceeded the target height Hg (whether the nozzle height H is lower than the target height Hg) (ST7: height determination step).

[0059] 9, if the nozzle height H is not lower than the target height Hg (No in ST7), the process returns to the thrust measurement step (ST4) and the nozzle 29 continues to descend. If the thrust Ft exceeds the thrust limit value Ftl (Yes in ST5), or if the descending time has elapsed (Yes in ST6), or if the nozzle height H is lower than the target height Hg (Yes in ST7), the servo control unit 40 stops the descending of the nozzle 29 (shaft 21) (ST8: descending stop step). Next, the mounting height measurement unit 35 measures the mounting heights Hm1 to Hm3 (ST9: mounting height measurement step).

[0060] Next, when the placement hold time has elapsed, servo control unit 40 raises nozzle 29 (shaft 21) to the standby position (ST10: raising step). In this way, when nozzle 29 places components D1-D3, thrust Ft of Z-axis motor 22 that lowers nozzle 29 is measured (ST4), and placement heights Hm1-Hm3, which are the differences between the lowest point of lowered nozzle 29 and the target height Hg, are measured (ST9). Next, placement state determination unit 34 determines the placement state of components D1-D3 based on thrust Ft of Z-axis motor 22 measured in the thrust force measurement step (ST4) and placement heights Hm1-Hm3 measured in the placement height measurement step (ST9) (ST11: placement state determination step).

[0061] 10, in the wearing state determination step (ST11) (wearing state determination method), the wearing state determination unit 34 determines whether the maximum thrusts Ftm1 to Ftm3 of the Z-axis motor 22 are equal to or greater than the thrust threshold Ftt (ST21: maximum thrust determination step). If the maximum thrusts Ftm1 to Ftm3 are equal to or greater than the thrust threshold Ftt (Yes in ST21), the wearing state determination unit 34 determines that the wearing state is "good" (ST22: good determination step). If the maximum thrusts Ftm1 to Ftm3 are smaller than the thrust threshold Ftt (No in ST21), the wearing state determination unit 34 determines whether the wearing heights Hm1 to Hm3 are equal to or greater than the height threshold Hbt (ST23: wearing height determination step).

[0062] If the wearing heights Hm1 to Hm3 are equal to or greater than the height threshold Hbt (Yes in ST23), the wearing state determination unit 34 determines that the wearing state is "almost good" (ST24: almost good determination step). If the wearing heights Hm1 to Hm3 are smaller than the height threshold Hbt (No in ST23), the wearing state determination unit 34 determines that the wearing state is "poor" (ST25: poor determination step).

[0063] In this way, when the maximum value of the measured thrust force Ft (maximum thrust forces Ftm1 to Ftm3) is equal to or greater than the predetermined thrust force threshold Ftt (Yes in ST21), the wearing state determination unit 34 determines the wearing state to be "good" (ST22) (see FIG. 6). Also, when the maximum value of the measured thrust force Ft (maximum thrust forces Ftm1 to Ftm3) is smaller than the thrust force threshold Ftt (No in ST21) and the measured wearing heights Hm1 to Hm3 are equal to or greater than the predetermined height threshold Hbt (Yes in ST23), the wearing state determination unit 34 determines the wearing state to be "almost good" (ST24) (see FIG. 7).

[0064] Furthermore, if the maximum value of the measured thrust Ft (maximum thrusts Ftm1 to Ftm3) is smaller than the thrust threshold Ftt (No in ST21) and the measured mounting heights Hm1 to Hm3 are lower than the height threshold Hbt (No in ST23), the mounting state determiner 34 determines the mounting state to be "bad" (ST25) (see FIG. 8). This allows the mounting state of the components D1 to D3 on the board B to be properly determined.

[0065] As described above, the present disclosure discloses the following technical ideas.

[0066] (Technology 1) A component mounting apparatus (1) that picks up a component (D) with a nozzle (29) and mounts the component (D) on a board (B) by lowering the nozzle (29) based on a target height (Hg) above the board (B), a thrust force measuring unit 42 that measures a thrust force Ft of a motor (Z-axis motor 22) that lowers the nozzle 29 when the nozzle 29 places the component D; a mounting height measuring unit 35 that measures a mounting height Hm, which is the difference between the lowest point of the lowered nozzle 29 and a target height Hg, when the nozzle 29 is used to mount a component D; a mounting state determination unit (34) that determines the mounting state of the component (D) on the board (B) based on the thrust (Ft) measured by the thrust measurement unit (42) and the mounting height (Hm) measured by the mounting height measurement unit (35); The wearing state determination unit 34 If the maximum value of the thrust Ft (maximum thrust Ftm) measured by the thrust measuring unit 42 is equal to or greater than a predetermined thrust threshold Ftt, the wearing state is determined to be "good", When the maximum value of the measured thrust Ft is smaller than the thrust threshold Ftt and the attachment height Hm measured by the attachment height measurement unit 35 is equal to or greater than the predetermined height threshold Hbt, the attachment state is determined to be "almost good", The component mounting device 1 determines the mounting state as "bad" when the maximum value of the measured thrust force Ft is smaller than the thrust threshold Ftt and the measured mounting height Hm is lower than the height threshold Hbt.

[0067] As a result, the component mounting device 1 can determine the mounting status of the component D mounted on the board B as "good", "bad", or "almost good", and can appropriately determine the mounting status of the component D on the board B.

[0068] (Technology 2) The component mounting device 1 according to technique 1 limits the thrust Ft of the motor (Z-axis motor 22) that lowers the nozzle 29 to a predetermined value (thrust limit value Ftl) when the nozzle 29 mounts the component D.

[0069] This allows the component mounting apparatus 1 to prevent the component D from being damaged or from having reliability problems due to an excessive load Fa being applied to the component D by the descending nozzle 29.

[0070] (Technology 3) A component mounting method in which a component D is picked up by a nozzle 29, and the nozzle 29 is lowered based on a target height Hg above the substrate B, thereby mounting the component D on the substrate B, When component D is placed by nozzle 29, the thrust Ft of the motor (Z-axis motor 22) that lowers nozzle 29 is measured (ST4). When component D is placed by nozzle 29, the placement height Hm, which is the difference between the lowest point of the lowered nozzle 29 and the target height Hg, is measured (ST9). If the maximum value of the measured thrust Ft (maximum thrust Ftm) is equal to or greater than the predetermined thrust threshold Ftt (Yes in ST21), the attachment state is determined to be good (ST22). If the maximum value of the measured thrust Ft is smaller than the thrust threshold Ftt (No in ST21) and the measured attachment height Hm is equal to or greater than the predetermined height threshold Hbt (Yes in ST23), the attachment state is determined to be almost good (ST24). If the maximum value of the measured thrust force Ft is smaller than the thrust threshold value Ftt (No in ST21) and the measured mounting height Hm is lower than the height threshold value Hbt (No in ST23), the mounting condition is determined to be poor (ST25).

[0071] As a result, the component mounting device 1 can determine the mounting status of the component D mounted on the board B as "good", "bad", or "almost good", and can appropriately determine the mounting status of the component D on the board B. [Industrial Applicability]

[0072] The component mounting device and component mounting method of the present disclosure have the effect of being able to appropriately determine the mounting state of a component on a board, and are useful in fields where components are mounted on boards. [Explanation of symbols]

[0073] 1. Component mounting equipment 22 Z-axis motor (motor) 29 nozzles 35 Mounting height measurement unit B board D, D1~D3 parts Ft Thrust Ftl Thrust limit value (predetermined value) Ftm, Ftm1 to Ftm3 Maximum thrust (maximum thrust value) Ftt Thrust Threshold Hbt ​​height threshold Hg target height Hm, Hm1~Hm3 Mounting height

Claims

1. A component mounting apparatus that picks up a component with a nozzle and mounts the component on a board by lowering the nozzle based on a target height above the board, a thrust measuring unit that measures a thrust of a motor that lowers the nozzle when the nozzle is used to place the component; a mounting height measuring unit that measures a mounting height, which is the difference between the lowest point of the lowered nozzle and the target height, when the nozzle is used to mount the component; a mounting state determination unit that determines a mounting state of the component on the board based on the thrust measured by the thrust measurement unit and the mounting height measured by the mounting height measurement unit, The wearing state determination unit When the maximum value of the thrust measured by the thrust measuring unit is equal to or greater than a predetermined thrust threshold value, the wearing state is determined to be good; determining that the wearing state is substantially good when the maximum value of the measured thrust is smaller than the thrust threshold value and the wearing height measured by the wearing height measuring unit is equal to or greater than a predetermined height threshold value; The component mounting device determines that the mounting state is defective when the measured maximum value of the thrust force is smaller than the thrust threshold value and the measured mounting height is lower than the height threshold value.

2. 2. The component mounting device according to claim 1, wherein the thrust of the motor that lowers the nozzle is limited to a predetermined value when the component is mounted by the nozzle.

3. A component mounting method in which a component is picked up by a nozzle and the nozzle is lowered based on a target height above a board to mount the component on the board, measuring a thrust of a motor that lowers the nozzle when the component is placed by the nozzle; When placing the component with the nozzle, a placement height is measured, which is the difference between the lowest point of the lowered nozzle and the target height; If the measured maximum value of the thrust is equal to or greater than a predetermined thrust threshold, the mounting state is determined to be good; determining that the mounting state is substantially good when the measured maximum value of the thrust force is smaller than the thrust threshold value and the measured mounting height is equal to or greater than a predetermined height threshold value; a component mounting method, wherein the mounting state is determined to be defective if the measured maximum value of the thrust force is smaller than the thrust threshold value and the measured mounting height is lower than the height threshold value;

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