JP7774066B2 - Method for inspecting component mounters and method for manufacturing component mounted boards - Google Patents

Description

The technology disclosed in this specification relates to a method for inspecting a component mounting machine and a method for manufacturing a component mounting board.

The component mounter disclosed in Japanese Patent Application Laid-Open No. 2001-24392 has a conveyor that transports circuit boards and a motor that drives the conveyor. When the motor drives the conveyor with the circuit board placed on it, the conveyor transports the circuit board. After the conveyor transports the circuit board to a predetermined position, components are mounted on the circuit board.

In component mounting machines, the motor that drives the conveyor may break down. If the motor breaks down just before or during product production, the manufacturing efficiency of the product will decrease. This specification proposes technology to detect signs of motor failure in component mounting machines.

This specification discloses an inspection method for a component mounter. The component mounter has a conveyor that transports circuit boards, a motor that drives the conveyor, and a detector that detects an inspection index value, which is the current flowing through the motor or the torque of the motor. The inspection method includes the steps of: executing a detection process to detect the inspection index value using the detector while driving the conveyor by the motor with no circuit boards placed on the conveyor; and executing a determination process to determine whether the inspection index value detected in the detection process satisfies a reference condition.

It is known that before a motor fails, an abnormal value appears in the current flowing through the motor or the motor's torque. In this inspection method, first, in the detection process, the conveyor is driven by the motor with no circuit boards placed on the conveyor. Because there are no circuit boards on the conveyor, the motor can be operated in a constant environment. In the detection process, while the motor is operating in this manner, an inspection index value, which is the current flowing through the motor or the motor's torque, is detected. Because the motor is operated in a constant environment, fluctuations in the inspection index value due to the motor's operating environment are suppressed. Therefore, if the motor is normal, an inspection index value that meets the standard conditions is detected, and if there is an abnormality in the motor, an inspection index value that does not meet the standard conditions is detected. In the judgment process, it is determined whether the detection index value meets the standard conditions, making it possible to detect whether there is an abnormality in the motor. In other words, this inspection method can detect precursors to motor failure.

FIG. 2 is a side view of the component mounter according to the embodiment; FIG. 2 is a plan view of the component mounter according to the embodiment; FIG. 2 is a block diagram showing a control system of a conveyor of the component mounter according to the embodiment.

The main features of the embodiments described below are listed below. Note that the technical elements described below are independent technical elements that demonstrate technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

In one embodiment of the present technology, the component mounter may further include a notification device. The inspection method further includes a step of executing a notification process by the left-standing device to notify a user if the inspection index value does not satisfy the reference condition in the determination process.

This configuration allows the user to be notified when there are signs of an impending motor failure.

In one embodiment of the present technology, the inspection method may further include a step of storing the inspection index value detected in the detection process in a storage device. The reference condition may be defined by the relationship between the inspection index value detected in the detection process and past inspection index values stored in the storage device.

The storage device may be a storage device built into the component mounter, or a storage device installed external to the component mounter. With this configuration, it is possible to determine whether the inspection index value detected in the detection process is normal by comparing it with previously detected inspection index values, thereby more accurately determining whether there is an abnormality in the motor.

As one embodiment of the present technology, a method for manufacturing a component-mounted board is disclosed. This manufacturing method includes any of the inspection methods described above. This manufacturing method further includes, after the detection process, a step of transporting the circuit board by driving the conveyor with the motor and mounting components on the circuit board.

This manufacturing method allows motor inspections to be performed during start-up inspections before production begins.

The component mounting machine 10 of the embodiment shown in Figures 1 and 2 has a conveyor 20, a component feeder 70, and a head 80.

The conveyor 20 has rails 22, 24, rotating shafts 26, 28, and belts 30, 32. The rails 22, 24 extend parallel to each other with a gap between them. The rotating shafts 26, 28 extend perpendicular to the rails 22, 24. The rotating shafts 26, 28 rotate relative to the rails 22, 24. A gap is provided between the rotating shafts 26, 28. The belts 30, 32 are wound around the rotating shafts 26, 28. Figure 3 shows a control system that controls the conveyor 20. As shown in Figure 3, a motor 40 is connected to the rotating shaft 26. In this embodiment, the motor 40 is a DC motor. The motor 40 rotates the rotating shaft 26. When the rotating shaft 26 rotates, the belts 30, 32 revolve around the rotating shafts 26, 28. As shown by arrow 100 in Figures 2 and 3, the circuit boards 12 are conveyed by an external conveyor onto the conveyor 20 (more specifically, onto the belts 30 and 32). Solder paste, adhesive, etc. are applied to the circuit boards 12 conveyed onto the conveyor 20. The conveyor 20 conveys the circuit boards 12 placed on the belts 30 and 32.

As shown in Figures 1 and 2, the component feeder 70 is disposed to the side of the conveyor 20. The component feeder 70 supplies multiple types of electronic components 72 to a position where they can be picked up by the head 80. The head 80 is configured to move above the conveyor 20 and component feeder 70. The head 80 picks up the electronic components 72 from the component feeder 70 and mounts the picked-up electronic components 72 on the circuit board 12 on the conveyor 20. The head 80 mounts the electronic components 72 on an area on the top surface of the circuit board 12 where solder paste, adhesive, etc. have been applied. The circuit board 12 (i.e., the component-mounted board) on which the electronic components 72 have been mounted by the head 80 is transported by the conveyor 20 to outside the component mounter 10 (e.g., a reflow oven).

As shown in FIG. 3, the component mounter 10 has a motor control board 50, a CPU (Central Processing Unit) 52, and a display screen 54. The motor control board 50 has a motor control IC 50a. The motor control IC 50a is electrically connected to the motor 40. The motor control IC 50a controls the motor 40. The motor control IC 50a can also detect the current flowing through the motor 40. The CPU 52 is electrically connected to the motor control board 50. The CPU 52 issues commands to the motor control IC 50a. The CPU 52 is also electrically connected to and controls the display screen 54. The CPU 52 is also connected to a server 60 external to the component mounter 10 via a communication line.

Next, motor inspection of the component mounter 10 will be described. A user of the component mounter 10 can perform a start-up inspection before starting a process of manufacturing component-mounted boards using the component mounter 10. During the start-up inspection, the user causes the CPU 52 to execute an inspection program with no circuit boards 12 placed on the conveyor 20. When the inspection program is executed, the CPU 52 commands the motor control IC 50a to rotate the motor 40 at a constant speed. As a result, the belts 30 and 32 of the conveyor 20 revolve around the rotation axes 26 and 28 at a constant speed. In other words, the motor 40 drives the conveyor 20. Because no circuit boards 12 are placed on the conveyor 20, the load on the motor 40 is approximately constant while it is rotating at a constant speed. The motor control IC 50a detects the current Im flowing through the motor 40 while it is rotating at a constant speed. The motor control IC 50a detects the current Im multiple times while the motor 40 is rotating at a constant speed, and acquires the waveform of the current Im. The motor control IC 50a sends waveform data of the detected current Im to the CPU 52. The CPU 52 transmits the waveform data of the current Im to the server 60. The server 60 stores the received waveform data of the current Im. Therefore, every time a motor inspection is performed by the component mounter 10, the waveform data of the current Im is stored in the server 60. Therefore, the server 60 accumulates waveform data of the current Im detected in past motor inspections.

Furthermore, upon receiving waveform data of the current Im from the motor control IC 50a, the CPU 52 reads past data of the current Im from the server 60. Hereinafter, the current Im detected in the current motor inspection is referred to as current Im1, and the current Im read from the server 60 (i.e., the current Im detected in a previous motor inspection) is referred to as current Im2. Current Im2 may be a current obtained from waveform data of the current Im detected in the previous motor inspection (e.g., the average value of the current Im detected in the previous motor inspection), or may be a value obtained from waveform data of multiple current Ims stored in the server 60 (e.g., the average value of the current Ims detected in multiple previous motor inspections). The CPU 52 compares the waveform data of current Im1 with current Im2 and determines whether the waveform data of current Im1 is within the normal range. That is, the CPU 52 determines whether the waveform data of current Im1 is within the normal range based on the relative relationship between the waveform data of current Im1 and current Im2. For example, the CPU 52 can calculate an upper limit by multiplying the current Im2 by a constant (e.g., 1.1), and set the range below the upper limit as the normal range and the range above the upper limit as the abnormal range. After setting the normal range and the abnormal range, the CPU 52 determines whether the waveform data of the current Im1 is within the normal range. The CPU 52 determines that the motor 40 is normal if the entire waveform data of the current Im1 is within the normal range, and determines that there is an abnormality in the motor 40 if part or all of the waveform data of the current Im1 is within the abnormal range.

When the CPU 52 determines whether the waveform data of current Im1 is within the normal range, it displays the determination result on the display screen 54. In this way, the CPU 52 displays the determination result on the display screen 54, allowing the user to know whether the motor 40 is normal or not during the start-up inspection.

After the start-up inspection is completed (i.e., after the motor inspection is completed), the user begins the component mounting board manufacturing process using the component mounter 10. The component mounting board manufacturing process can be initiated not only when the waveform data of current Im1 during motor inspection is within the normal range, but also when the waveform data of current Im1 during motor inspection is within the abnormal range. The fact that the waveform data of current Im1 is within the abnormal range does not mean that the motor 40 will immediately become inoperable, but rather that the motor 40 may become inoperable in the near future. Therefore, even when the waveform data of current Im1 is within the abnormal range, the motor 40 can still be used. Therefore, the component mounting board manufacturing process can be initiated even when the waveform data of current Im1 is within the abnormal range. In the component mounting board manufacturing process, as shown by arrow 100, an external conveyor transports the circuit board 12 onto the conveyor 20. The conveyor 20 transports the circuit board 12 to a predetermined position and stops. The head 80 mounts electronic components 72 on the circuit board 12 on the conveyor 20. The circuit board 12 (i.e., component-mounted board) on which the mounting of electronic components 72 has been completed is carried out of the component mounter 10 by the conveyor 20. In this manner, the component-mounted board is manufactured.

As described above, in the motor inspection of this embodiment, the conveyor 20 is driven by the motor 40 without the circuit board 12 placed on the conveyor 20, and the current Im flowing through the motor 40 is detected in this state. Because the circuit board 12 is not placed on the conveyor 20, when the motor inspection is repeatedly performed, the load on the motor 40 is approximately the same in each motor inspection. Therefore, the motor 40 can be operated in approximately the same environment in each motor inspection. Therefore, if the motor 40 is not abnormal, the waveform data of the current Im flowing through the motor 40 in each motor inspection will be approximately the same. Therefore, in the motor inspection, it is possible to accurately determine whether or not there is an abnormality in the motor 40 based on the waveform data of current Im1. In particular, if the waveform data of current Im1 is significantly larger than the previous current Im2, there is a high possibility that there is some kind of abnormality in the motor 40. Therefore, by comparing the waveform data of current Im1 with the previously detected current Im2, it is possible to more accurately determine whether or not there is an abnormality in the motor 40.

Furthermore, in the motor inspection of this embodiment, the CPU 52 displays the inspection results on the display screen 54. This allows the user to know that there are signs of a malfunction in the motor 40 before the motor 40 becomes inoperable. This allows the user to repair or replace the motor 40 while the component mounter 10 is stopped. This prevents the production of component mounting boards from being stopped due to a malfunction of the motor 40, allowing for efficient production of component mounting boards.

Motor inspection in this embodiment is also performed during start-up inspection. Typically, during start-up inspection, the conveyor 20 is driven for a certain period of time without a circuit board 12 placed on it to prepare it for operation (so-called warm-up operation). By performing motor inspection during start-up inspection, the motor inspection can be performed in conjunction with the warm-up operation. This allows the component mounter 10 to operate efficiently.

In the above-described embodiment, the previously detected current Im2 is stored in a server external to the component mounter 10. However, the component mounter 10 may have a storage device, and the current Im2 may be stored in that storage device.

In addition, in the above-described embodiment, an upper limit value is set for the current Im1, but a lower limit value may also be set for the current Im1. In other words, the range between the upper limit value and the lower limit value may be set as the normal range for the current Im1.

In addition, in the above-described embodiment, whether current Im1 is normal or not is determined by comparing current Im1 with previously detected current Im2. However, whether current Im1 is normal or not may also be determined without comparing it with current Im2. For example, current Im1 may be determined to be normal if it is equal to or less than an upper limit value set as a fixed value, and may be determined to be abnormal if current Im1 is higher than the upper limit value set as a fixed value. Furthermore, the determination reference value for current Im1 (e.g., upper limit value or lower limit value) may be varied depending on various conditions.

In addition, in the above-described embodiment, waveform data of current Im1 was obtained by detecting current Im1 multiple times during motor testing. However, current Im may be detected only once during motor testing. It is possible to determine whether the motor is normal or abnormal based on data from a single current Im.

In addition, in the above-described embodiment, the motor control IC 50a detects the current Im flowing through the motor 40, but the current Im may also be detected by a current sensor or the like. Furthermore, the torque of the motor 40 may be detected instead of the current Im. The torque of the motor 40 may be calculated by the motor control IC 50a based on the current Im. Furthermore, the torque of the motor 40 may be detected by a torque sensor. Detecting the torque of the motor 40 can also detect the presence or absence of an abnormality in the motor 40. In particular, in a DC motor, the torque of the motor 40 is approximately proportional to the current Im flowing through the motor 40, so detecting the torque of the motor 40 can also detect the presence or absence of an abnormality in the motor 40, as in the above-described embodiment.

In addition, in the above-described embodiment, the motor 40 was rotated at a constant speed during motor inspection, but the rotation speed of the motor 40 may also be changed in a predetermined pattern.

In addition, in the above-described embodiment, when the current Im1 is within the normal range, the display screen 54 displays that the motor 40 is normal, and when the current Im1 is within the abnormal range, the display screen 54 displays that the motor 40 is abnormal. However, when the current Im1 is within the normal range, it is not necessary for the display screen 54 to display that the motor 40 is normal. In other words, the determination result may be displayed on the display screen 54 only when there is an abnormality in the motor 40.

In addition, in the above-described embodiment, the judgment result of the motor inspection was notified to the user by displaying on the display screen 54, but the judgment result may also be notified to the user by lighting up a warning lamp or by sounding from a speaker, etc.

The technical elements described in this specification or drawings may exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings simultaneously achieve multiple objectives, and achieving any one of those objectives is itself technically useful.

Claims (3)

A component mounter inspection method, comprising:
The component mounter,
a conveyor for transporting the circuit board;
a motor that drives the conveyor;
a detector for detecting an inspection index value which is a current flowing through the motor or a torque of the motor;
and
The inspection method comprises:
a step of performing a detection process during a start-up inspection, in which the detection process detects the inspection index value by the detector while the conveyor is driven by the motor with the circuit board not being placed on the conveyor;
a step of executing a determination process during the start-up inspection to determine whether the inspection index value detected in the detection process satisfies a reference condition;
An inspection method comprising:
the inspection method further includes a step of storing the inspection index value detected in the detection process in a storage device during the start-up inspection,
the reference condition is defined by a relative relationship between the inspection indicator value detected in the detection process and a plurality of past inspection indicator values stored in the storage device,
An inspection method in which the relationship is set as an upper limit or lower limit for the inspection index value detected in the detection process, based on a value obtained from an average value of a plurality of past inspection index values . the component mounter further includes an alarm device,
The inspection method further includes a step of executing, during the start-of-work inspection , a notification process of notifying a user by the notification device when the inspection index value does not satisfy the reference condition in the determination process.
The inspection method according to claim 1 . A method for manufacturing a component mounting substrate,
The inspection method according to claim 1 or 2 ,
a step of, after the detection process, driving the conveyor by the motor to transport the circuit board and mounting components on the circuit board;
A manufacturing method comprising the steps of: