JP3992094B2 - Component mounting method and component mounting machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a component mounting method and a component mounter for mounting components such as electronic components on a circuit board.
[0002]
[Prior art]
A conventional electronic component mounting machine will be described with reference to FIG. In FIG. 10, reference numeral 1 denotes an XY robot, which is configured to position a head unit 3 including a nozzle 2 at an arbitrary position. The head part 3 is moved, the electronic component 5 to be mounted from the component supply unit 4 is sucked by the nozzle 2, moved to the mounting position on the circuit board 7 fixed to the positioning table 6, and the electronic component sucked by the nozzle 2 5 is mounted on the circuit board 7.
[0003]
The electronic component 5 mounted on the circuit board 7 is required to have a high mounting accuracy with high-density mounting (± 25 μm as an example). For example, recently, there is a microchip component with a length of 0.6 mm and a width of 0.3 mm. In the case of this component, if the mounting position is shifted beyond ± 25 μm, the bonding between the component electrode and the land on the circuit board is not possible. The possibility of becoming stable increases. However, X-axis robots, Y-axis robots, and camera CCDs that are generated due to temperature changes due to environmental temperature changes, heat generated by the drive motor when the machine starts up, heat generated in the sliding part of the X-axis / Y-axis robots, etc. This causes a change in the center position of the machine and the position of each part of the machine frame. For this reason, the preset mounting center point changes due to the influence of environmental temperature changes and the like, resulting in a phenomenon that the mounting accuracy is deteriorated.
[0004]
A specific example of this phenomenon will be described with reference to FIG.
[0005]
As shown in FIG. 11, the X-axis robot 1a drives the head unit 3 in the X-axis direction by the motor 30, and the Y-axis robots 1b-1 and 1b-2 support the X-axis robot 1a at both ends. Drive in the Y direction (direction perpendicular to the paper surface in FIG. 11). Normally, one end of the X-axis robot 1a, for example, the Y-axis robot 1b-1 side is fixed in the X direction, but the other end of the X-axis robot 1a, that is, the Y-axis robot 1b-2 side is X. It is configured to be slidable in the direction.
[0006]
Here, since the X-axis robot 1a moves the head unit 3 in the X direction by the motor 30, the X-axis robot 1a receives heat from the motor 30 and frictional heat due to sliding of the head unit 3. Further, the X-axis robot 1a itself receives frictional heat caused by sliding on the Y-axis robots 1b-1 and 1b-2. When the temperature rises upon receiving these heats, the X-axis robot 1a expands, and particularly in the X direction, it extends by ΔX ₁ toward the Y-axis robot 1b-2. Due to the expansion of the X-axis robot 1a, the head portion 3 is also displaced in the X direction as indicated by a broken line, and as a result, the nozzle 2 is displaced by ΔX _{2 in the} X direction.
[0007]
Although the displacement of the nozzle 2 due to the thermal expansion of the X-axis robot has been described above, the Y-axis robots 1b-1, 1b-2, the frame supporting the Y-axis robot 1b, and the like are also similarly expanded by receiving heat. Of course also join.
[0008]
The displacement of the nozzle 2 is very small, but cannot be ignored if the required mounting accuracy is exceeded.
[0009]
In a conventional electronic component mounting machine, an automatic calibration function is provided in order to eliminate the adverse effect of mounting accuracy due to this temperature change. The automatic calibration function is a function performed in order to maintain the specified mounting accuracy, and automatically performs a calibration operation as necessary based on a preset temperature change value or time elapsed value. The calibration function attaches a jig capable of discriminating the center of the nozzle to the nozzle 2 of the head unit 3, positions the jig at a predetermined position on the camera, and picks up an image with the coordinate value commanded for positioning and the camera. It is a function to calculate the amount of deviation of the coordinate value that recognizes the center of the nozzle and update the offset amount (displacement amount due to temperature change) with respect to the mechanical origin of each machine, and it is configured to automatically do this Has been.
[0010]
[Problems to be solved by the invention]
However, in the above configuration, the offset amount with respect to the mechanical origin of the machine is obtained by the calibration jig, but the offset amount is a temperature change for each unit (head unit 3, XY robot 1, camera unit, etc.). The offset amount is added. The offset amount for each unit varies each time it is measured, and the mechanical variation is added. Therefore, an error in the offset amount of each unit occurs, and even if it is corrected with the offset value obtained by calibration, There was a problem that the mounting accuracy of parts deteriorated.
[0011]
In addition, there are a plurality of types of nozzles 2 in the head unit 3, and there are a plurality of types of camera units for a large field of view and a small field of view. In order to obtain an offset value for each of the plurality of types, the types of nozzles and cameras There is a problem that it is necessary to perform a calibration operation every time, and therefore, the calibration operation takes too much time and productivity is deteriorated.
[0012]
In addition, if the machine is stopped for a long time during the model change, the machine temperature state changes when mounting is resumed, which affects the mounting accuracy. In other words, when production is resumed after the machine has been stopped for a long time, the temperature changes and the temperature changes suddenly. In this state, even if the true offset value is obtained with the conventional calibration function, the temperature continues. Since there is a change, the offset value changes immediately, and the offset value obtained by calibration cannot follow. Therefore, there is a problem that the calibration accuracy cannot be secured unless the offset value of each unit unit is obtained again.
[0013]
In view of the above-described conventional problems, an object of the present invention is to provide an electronic component mounting method and a mounting machine capable of preventing the mounting position shift of an electronic component accompanying a temperature change and improving the productivity.
[0014]
[Means for Solving the Problems]
The present invention includes a component supply unit that supplies a component, a head unit that picks up the component from the component supply unit and mounts the component on a circuit board, and an XY robot that moves and positions the head unit in the X and Y directions. A component mounting method in a component mounter comprising a controller that controls each of the units, and when the controller detects that the circuit board is in a standby state, the reciprocating operation of the movement range set in the XY robot It is determined whether or not an aging operation for performing the above is necessary, and when it is determined to be necessary, the aging operation is performed.
[0015]
The present invention also provides a component supply unit that supplies components, a head unit that sucks components from the component supply unit and mounts the components on a circuit board, and XY that moves and positions the head unit in the X and Y directions. A component mounting machine including a robot and a controller that controls each of the units. When the controller detects that the circuit board is in a standby state, the controller performs a reciprocating operation within a movement range set in the XY robot. It is determined whether or not an aging operation to be performed is necessary, and when it is determined to be necessary, control is performed so as to perform the aging operation.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, each embodiment of the electronic component mounting machine of this invention is described with reference to FIGS.
[0017]
(First embodiment)
First, a first embodiment will be described with reference to FIGS. FIG. 1 shows a configuration of an electronic component mounting machine. In FIG. 1, reference numeral 1 denotes an XY robot, which is configured to position a head unit 3 including a nozzle 2 at an arbitrary position. The XY robot 1 includes an X-axis robot 1a for positioning the head unit 3 in the X direction and a Y-axis robot 1b (1b-1, 1b-2) for positioning the head unit 3 in the Y direction. An H-axis robot (see FIG. 2) that moves up and down in the Z direction is provided. Reference numeral 4 denotes a component supply unit that supplies an electronic component 5 to be mounted. Reference numeral 6 denotes a positioning table, which is configured to position the circuit board 7 at a predetermined position in the Y direction so as to be stationary. 8 is a loader unit that receives the circuit board 7 from the previous process, and 9 is an unloader unit that waits until the circuit board 7 after mounting is moved to the next process. The circuit board 7 is transported by a driven belt. Reference numeral 10 denotes a controller that controls the operation of each of the unit units 1, 3, 4, 6, 8, and 9. Reference numeral 11 denotes an operation unit that inputs an NC program. A component recognition camera unit 12 recognizes the electronic component 5 sucked by the nozzle 2 from the component supply unit 4, and a nozzle station 13 is provided with a replacement nozzle.
[0018]
Next, the control configuration of the electronic component mounting machine will be described with reference to FIG.
[0019]
The controller 10 controls the operation or processing of each unit shown in the figure.
[0020]
Under the control of the controller 10, the X-axis robot 1a moves the head unit 3 in the X direction by rotationally driving a ball screw by a motor. Under the control of the controller 10, the Y-axis robots 1b-1 and 1b-2 move the X-axis robot supporting both ends in the Y direction by rotational driving of the ball screw by the motor. Thereby, the nozzle 2 of the head unit 3 can be moved and positioned on the XY plane. Here, the X-axis robot 1a and the Y-axis robots 1b-1 and 1b-2 may be driven by linear motors.
[0021]
The H-axis robot 31 moves the nozzle 2 up and down in the Z direction under the control of the controller 10. Under the control of the controller 10, the θ-axis robot 32 rotates the nozzle 2 around the axis of the nozzle 2 so as to match the mounting angle of the sucked part.
[0022]
Under the control of the controller 10, the positioning table 6, the loader unit 8, and the unloader unit 9 drive the conveyance belt by the motor and convey the circuit board 7.
[0023]
Under the control of the controller 10, each component supply unit 4 sequentially supplies components by sending a storage tape stored at a constant interval of components by motor driving for each component pitch.
[0024]
Under the control of the controller 10, the component recognition camera unit 12 images the suction position and posture of the component moved by the head unit 3 on the component recognition camera unit 12 by the nozzle 2. The captured image is input to the component recognition processing unit 35. The component recognition processing unit 35 processes the input image and detects a shift between the component center and the nozzle center and a rotation shift of the component. The controller 10 sends a command to the X-axis robot 1a, Y-axis robots 1b-1, 1b-2, and θ-axis robot 32 so as to be mounted on the circuit board at a position / angle corrected for the detected deviation amount.
[0025]
An outline of the operation of the electronic component mounting machine having the above configuration will be described. When mounting the electronic component 5 on the circuit board 7 in the electronic component mounting machine, the circuit board 7 is carried from the loader unit 8 onto the positioning table 6 and positioned and fixed at a predetermined position. 3, the electronic component 5 to be mounted from the component supply unit 4 is sucked by the nozzle 2, moved to the mounting position on the circuit board 7 fixed on the positioning table 6, and the electronic component 5 sucked by the nozzle 2. Is mounted on the circuit board 7. The circuit board 7 after the electronic component 5 is mounted is carried out for the next process by the unloader unit 9. The operation of actually mounting components on the circuit board as described above is controlled by the actual operation unit 40 in the controller 10.
[0026]
In the electronic component mounting machine described above, the temperature of each unit rises from the start of operation. As the temperature rises, thermal expansion or deflection associated with expansion occurs in each unit, and the position of the nozzle 2 is displaced. The situation is shown in FIG. FIG. 5 shows how the temperature of the XY robot 1 changes with the passage of time from the start of operation, and the X-axis robot 1a, Y-axis robot 1b, and component recognition camera 12 are shifted in the X and Y directions, respectively. It shows how the amount (displacement) changes. As shown in FIG. 5, the temperature of the XY robot 1 rises from the start of operation, and accordingly, the deviation amount of the Y-axis robot 1b also increases. However, when a predetermined time elapses, both the temperature and the deviation amount are in a steady state.
[0027]
Therefore, if the rise time from the start of operation to this steady state is shortened and the steady state is always maintained during operation, the offset amount (displacement amount due to temperature fluctuation) of the nozzle 2 can be maintained in a steady state. And high mounting accuracy can be secured.
[0028]
Next, the operation of the electronic component mounting machine for maintaining the steady state as described above will be described.
[0029]
As shown by the arrow in FIG. 3, when the next circuit board 7 is not waiting on the loader unit 8 and while the next circuit board 7 waiting on the loader unit 8 is loaded onto the positioning table 6. The X-axis robot 1a, the Y-axis robot 1b of the XY robot 1 and the H-axis robot that moves the nozzle 2 in the Z direction in the head unit 3 reciprocate within the maximum movement amount or an appropriately set movement range from the mechanical origin. Aging operation is automatically performed. By this aging operation, the temperature and deviation amount of each unit can be maintained in a steady state during operation, and highly accurate positioning can be ensured. Such an aging operation is controlled by an aging unit 41 in the controller 10.
[0030]
Next, a control procedure for performing this aging operation will be described with reference to FIG. As shown in FIG. 4, when the controller 10 (aging unit 41) detects that the circuit board 7 is in a standby state (step # 1), the elapsed time from the last mounting on the circuit board or each unit part ( It is determined whether aging is necessary based on the temperature of the head unit 3, the XY robot 1, the component recognition camera unit 12, etc. (step # 2). If it is determined that aging is necessary, an aging operation command is output, As described above, an aging operation is performed on the X axis and Y axis of the XY robot 1 and the H axis of the head unit 3. When it is determined that aging is unnecessary, the control is switched to the control by the actual operation unit, and the process waits without performing aging until the circuit board 7 is carried in. If the circuit board 7 is subsequently carried onto the positioning table 6 during the aging operation, the aging operation is stopped (step # 3), and then the actual operation for mounting the electronic component 5 is started as described above. (Switch to control by the actual operation unit 40) (Step # 5). By performing the ace operation in this way, a decrease in mechanical position accuracy due to a temperature change of each unit portion is prevented.
[0031]
The aging operation can be performed while an aging operation command is output from the controller 10 based on a standby time, a temperature change, or the like.
[0032]
In step # 4, when the circuit board 7 is loaded, if the controller 10 determines that the temperature and the offset amount of the nozzle 2 have not recovered to the steady state due to aging, priority is given to maintaining the mounting accuracy. Then, the aging operation can be continued until the circuit board 7 is stopped from being loaded and is restored to a steady state. It can be set in advance in the controller 10 from the operation unit 11 which of the maintenance of the mounting accuracy and the maintenance of the production operation rate is prioritized.
[0033]
Further, the moving range and moving speed of the reciprocating operation regarding the aging operation can be determined by looking at the degree to which the temperature of each unit has decreased from the steady state and the time until the next operation start. For example, the moving range and moving speed of the reciprocating operation are determined and set so that the temperature can be restored to a steady state within the time until the next operation start. As the moving range of the reciprocating operation is increased and the moving speed is increased, the recovery to the steady state is accelerated.
[0034]
Further, any method may be used for detecting the temperature of each unit section or its configuration as long as the temperature of each unit section can be detected. Instead of detecting the temperature, the offset variation of the nozzle 2 may be monitored and detected. A specific configuration example for detecting the temperature will be described in a subsequent embodiment.
[0035]
(Second Embodiment)
Next, a description will be given of a second embodiment in which an aging operation is performed when the machine is stopped for model switching or the like.
[0036]
When the machine is initially set, the aging mode is set to be valid at the time of model switching, so that the aging operation is executed when the machine is switched. At this time, the aging operation is executed when the machine is stopped for a certain time or a certain temperature change is caused by time management or temperature management by the controller 10.
[0037]
According to the present embodiment, it is possible to prevent the offset amount with respect to the mechanical origin of the machine from changing even when the machine is stopped.
[0038]
Further, instead of the automatic aging described above, the aging operation can be configured to be turned on / off by turning on / off a switch for a predetermined aging operation of the operation unit 11, whereby the switch The aging function can be easily executed by operation.
[0039]
Further, switching between manual operation of aging by the above switch operation or automatic operation of aging by the determination of the controller 10 can be performed by setting a predetermined switch in advance.
[0040]
(Third embodiment)
Next, a third embodiment in which activation control of the aging operation is automatically performed based on the relationship between the passage of time after the start of the machine operation and changes in the temperature state and the accuracy state will be described with reference to FIGS.
[0041]
In the start-up state of the machine, the temperature of the apparatus starts to rise as shown in FIG. This temperature rise causes mechanical fluctuations, the center coordinates of each unit portion with respect to the mechanical origin change, and a mounting position shift amount occurs.
[0042]
In FIG. 5, the temperature rise starts from the start of the machine, the temperature rise is saturated after 2 hours, and the displacement of the mounting position similarly enters the stable region after 2 hours. Therefore, as shown in FIG. 6, for example, when the required mounting accuracy is ± 25 μm, if the allowable temperature fluctuation range A including the saturation state of the corresponding temperature is set, the temperature within the allowable temperature fluctuation range A can be set. Since there is no problem with the mounting accuracy, the mounting accuracy can be ensured by ending the aging and entering the actual production when the temperature enters the allowable temperature fluctuation range A by the aging operation.
[0043]
Next, when the machine in the temperature saturation state is stopped due to the substrate waiting state or the state of changeover at the time of model change, the controller 10 correlates the time for aging from the database stored in advance and the temperature rise. The relationship is estimated, and it is determined whether to perform the aging operation with reference to the allowable temperature fluctuation range A and the current temperature.
[0044]
Thus, the aging operation can be activated in the optimum state by obtaining the correlation between the temperature and the mounting accuracy and controlling the aging operation.
[0045]
In the above description, when the controller 10 determines that it has entered the allowable range A while measuring the aging operation time or measuring the temperature of each unit part due to aging, the aging is stopped. Thus, aging can be performed efficiently.
[0046]
(Fourth embodiment)
Next, referring to FIGS. 7 and 8, a temperature sensor is mounted on a required unit portion of the machine, and the temperature state of each unit portion is confirmed to appropriately determine the start of the aging operation. explain.
[0047]
As shown in FIG. 7, a temperature sensor 14 is attached to each unit such as the X-axis robot 1 a, Y-axis robot 1 b, head unit 3, and component recognition camera unit 12 of the XY robot unit 1. From the operation screen, the temperature that affects the mounting accuracy, which is a reference when starting the aging operation for each unit as shown in FIG. 8, is set in advance. And when the detected temperature in each unit part becomes a temperature state lower than this preset precision influence temperature, it is comprised so that the automatic aging operation | movement may be started in the controller 10. FIG. In FIG. 7, 12a is a support for the component recognition camera unit 12, and 13 is a nozzle station.
[0048]
Thus, for example, when the accuracy influence temperature of the component recognition camera unit 12 is set to 25 ° C., the installation accuracy is ensured by automatically entering the aging operation when the temperature sensor 14 detects a temperature lower than that temperature. An aging operation is automatically performed.
[0049]
Further, in the above embodiment, the example in which the unit portion is within the allowable temperature fluctuation range A during the mounting operation by performing aging when the temperature of each unit portion is reduced has been described. A sensor and heater mechanism can be installed so that the required unit temperature is automatically held constant by the heater mechanism when the mounting operation stops, so that the effect of mounting accuracy due to temperature changes can be eliminated. .
[0050]
Further, as shown in FIG. 9A, the detected temperature transition can be displayed on the operation screen of the operation unit 11 or the monitor-dedicated screen. In this case, it is possible to display and monitor at a glance whether the temperature of each unit is within the allowable range A in the steady state at each time. If the temperature falls below the allowable range A as shown in FIG. 9B, a warning can be displayed on the screen to prompt the operator to perform an aging operation.
[0051]
By monitoring in this way, the operator can accurately determine the necessity / unnecessity of aging.
[0052]
Of course, the controller 10 can also determine whether aging is necessary / unnecessary even if monitoring is possible on the monitoring screen as described above.
[0053]
In addition, if such temperature transition is stored and accumulated, it can be used when analyzing the cause of the reduced mounting accuracy.
[0054]
【The invention's effect】
According to the component mounting method and the component mounter of the present invention, when the circuit board is in a standby state, it is determined whether or not an aging operation for causing the XY robot to perform a reciprocating operation within a moving range is necessary. Since the aging operation is performed only when it is performed , the calibration operation can be reduced to improve the productivity and improve the mounting accuracy.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic configuration of a component mounter according to a first embodiment of the present invention.
FIG. 2 is a control block diagram in the same embodiment.
FIG. 3 is an explanatory diagram of an aging operation in the same embodiment.
FIG. 4 is an aging operation flowchart in the same embodiment;
FIG. 5 is a diagram showing a relationship between a lapse of time after the machine is started, a change in apparatus temperature, and a change in shift amount of each unit unit.
FIG. 6 is an explanatory diagram of aging operation control according to a third embodiment of the present invention.
FIG. 7 is an explanatory diagram of an arrangement state of a temperature sensor according to a fourth embodiment of the present invention.
FIG. 8 is an explanatory diagram of a temperature setting screen by an operation screen in the embodiment.
FIG. 9 is an explanatory diagram of aging operation control according to another embodiment of the present invention.
FIG. 10 is a perspective view showing a schematic configuration of a conventional component mounter.
FIG. 11 is an explanatory diagram showing displacement due to a temperature change of a conventional head unit and an XY robot.
[Explanation of symbols]
1 XY robot (unit part)
3 Head (unit)
5 Electronic Component 6 Positioning Table 7 Circuit Board 10 Controller 11 Operation Unit 12 Component Recognition Camera Unit (Unit Unit)
14 Temperature sensor 40 Actual operation part 41 Aging part

Claims (6)

A component supply unit that supplies components, a head unit that picks up components from the component supply unit and mounts the components on a circuit board, an XY robot that moves and positions the head unit in the X and Y directions, and the units A component mounting method in a component mounter comprising a controller for controlling,
When the controller detects that the circuit board is in a standby state, it is determined whether or not an aging operation for causing the XY robot to perform a reciprocating operation within a set movement range is necessary.
A component mounting method comprising performing the aging operation when it is determined to be necessary. In determining whether an aging operation is necessary,
2. The component mounting method according to claim 1, wherein whether or not an aging operation is necessary is determined based on an elapsed time since the previous mounting on the circuit board or a temperature of each part.   The component mounting method according to claim 1, wherein in determining whether or not an aging operation is necessary, the determination is made by determining whether maintenance of mounting accuracy is given priority or maintenance of production operation rate is given priority.   When the circuit board is carried in, if the controller determines that the temperature has not recovered to a steady state by the aging operation, the circuit board is stopped and the aging operation is performed until the circuit board is restored to the steady state. The component mounting method according to claim 1, further comprising:   2. The moving range or moving speed of the reciprocating motion of the XY robot with respect to the aging operation is determined based on a degree that the temperature of each part has decreased from a steady state or a time until the next operation start. Component mounting method. A component supply unit that supplies components, a head unit that picks up components from the component supply unit and mounts the components on a circuit board, an XY robot that moves and positions the head unit in the X and Y directions, and the units A component mounter equipped with a controller for controlling,
When the controller detects that the circuit board is in a standby state, the controller determines whether or not an aging operation for causing the XY robot to perform a reciprocating operation within the set movement range is necessary. A component mounter that performs control so as to perform the aging operation.

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