KR102025371B1 - Parts holding head assembly for chip mounting device - Google Patents

Abstract

In the component support head assembly of the component mounter, the touch sensor includes a light emitting unit for emitting light toward the reflective surface of the nozzle, a light receiving unit for receiving the reflected light reflected from the reflective surface, and a sensor unit capable of continuously measuring the received light amount of the reflected light. Thus, a touch detection signal is generated when the light reception amount decreases below the threshold value, and the touch detection sensor sets the threshold value based on the light reception amount after the T-direction rotation operation of the spindle equipped with the nozzle is finished before the touch of the nozzle to be detected. do.

Description

Parts holding head assembly for chip mounting device

Embodiments relate to a component support head assembly of a component mounter, and more particularly, to a component support head assembly having a nozzle for supporting a component of a component mounter for mounting a component (electronic component) such as an IC chip on a substrate. will be.

In general, the component mounter moves the component support head above the component supply section, whereby the nozzle provided in the component support head performs the lowering and raising operation (lifting operation), and vacuum picks up the component at the lower end of the nozzle, and then The component support head is moved above the substrate, whereby the nozzle is further lowered and raised, thereby mounting (mounting) the component at a predetermined coordinate position of the substrate.

As described above, when picking up a component by causing the nozzle to move downward and upward, if the downward stroke of the nozzle is too large, the lower end of the nozzle strongly presses the upper surface of the component to destroy the component. If the down stroke is too small, the nozzle will not contact the top of the part and will not pick up the part. Similarly, in the case where the component is mounted on the substrate, if the downward stroke of the nozzle is too large, the component adsorbed on the lower end of the nozzle is strongly pressed against the substrate and destroyed. If the down stroke is too small, the parts supported by the nozzles cannot contact the upper surface of the substrate and fail to mount the parts. Therefore, the down stroke of the nozzle must be precisely controlled.

As a method for accurately controlling the down stroke of the nozzle, a method using a sensing means (contact sensing sensor) for sensing the contact of the nozzle is proposed in Japanese Patent No. 3553044.

In addition, the present applicant has proposed a method using a reflective optical sensor (optical fiber sensor) as a touch sensing sensor in Japanese Patent Application No. 2013-212220 as a method for accurately controlling the down stroke of the nozzle. The optical fiber sensor has a light emitting portion that emits light toward the reflective surface of the nozzle outer periphery, a light receiving portion that receives the reflected light reflected from the reflective surface, and a sensor portion capable of continuously measuring the received light amount of the reflected light, and the amount of received light has decreased below the threshold. When it is determined that the nozzle is in contact with the part, a touch detection signal is issued. That is, the light generated from the light emitting part of the optical fiber sensor is focused on the reflecting surface when the nozzle is in contact with the part before contact, so that when the nozzle is in contact with the part and its position in the up and down direction changes, The amount of reflected light reflected is reduced and the amount of light received by the light receiving portion of the optical fiber sensor is reduced. Specifically, as shown in FIG. 6 to be described later, the threshold value A is set as a reference, and when the amount of received light decreases below the threshold value A, it is determined that the part is in contact with the nozzle, and the lowering of the nozzle is stopped at that time.

With respect to this threshold A, the inventors set it as a fixed value based on the result of the previous experiment using the optical fiber sensor initially. However, the inventors of the present invention measured the received light amount in the state before the contact where the nozzle did not contact the component, and it was found that the light received amount may fluctuate greatly depending on the individual nozzles even with nozzles of the same type. In addition, it has been found that dirt may adhere to the reflecting surface of the nozzle depending on the use, so that the amount of light received in the state before contacting may fluctuate (decrease) over time even with the same nozzle.

As described above, when the threshold A is set to a fixed value while the amount of light received in the state before contact is changed depending on the nozzle or the passage of time, the following problems occur.

(a) In the case of a nozzle such that the amount of received light in the pre-contact state is below the threshold A, the optical fiber sensor judges that the nozzle has contacted by mistake even though the nozzle does not touch the part. Then, the pick-up (sorption) operation or mounting operation of the component starts before the nozzle actually touches the component, and as a result, a pickup mistake or a mounting mistake occurs. In addition, the nozzle may be in a state where initial contact cannot be detected.

(b) In the case of a nozzle in which the amount of received light in the state before the contact greatly exceeds the threshold A, it takes time to reach the threshold A or less even if the nozzle is in contact with the component and the amount of received light decreases. As a result, a long time from the contact of the nozzles to a stop occurs, causing a problem that the nozzles excessively strongly press the parts and break the parts. That is, it is not possible to accurately control the amount of pressurization of the nozzle.

As described above, the touch sensing function by the conventional touch sensing sensor (optical fiber sensor) has insufficient adaptability to the light-receiving amount fluctuation in the pre-contact state due to differences in the properties of the nozzles, that is, robust performance (rugged performance).

Japanese Patent No.3543044 (2004.04.09)

The problem to be solved of the embodiments is to improve the robust performance (rugged performance) of the touch sensing function by the touch sensing sensor in the component support head of the component mounter having the touch sensing sensor sensing the touch of the nozzle.

The component support head assembly of the component mounter according to the embodiment includes a support head, a spindle capable of elevating in the Z direction along the longitudinal direction with respect to the central axis of the support head, a nozzle mounted through an elastic body at the lower end of the spindle, and the spindle. And a lift unit for lifting and lowering in the Z direction, and a touch detection sensor for lifting and lowering in the Z direction by synchronizing with the lift unit and generating a touch detection signal by detecting that the nozzle is in contact with the part or the part supported by the nozzle is in contact with the substrate. A component support head assembly of an equipped component mounter, wherein each of the spindles is rotatable in the circumferential direction (T direction) about the longitudinal direction of the spindle, and the touch sensing sensor emits light toward the reflective surface of the outer circumference of the nozzle. A light-receiving unit, a light-receiving unit for receiving the reflected light reflected from the reflecting surface, and a sensor unit capable of continuously measuring the light-receiving amount of the reflected light, Generating a signal when the touch sensing hayeoteul reduced below the threshold value, the contact detecting sensors, to set the threshold value based on the amount of received light after the T direction of rotation of a spindle equipped with a nozzle of the nozzle before contacting the subject detection end.

Each time the operation of contacting the nozzle is performed, the touch sensor may set a threshold value based on the amount of light received after the T-direction rotation operation of the spindle on which the nozzle is mounted before the nozzle is contacted.

The spindle may be arranged in plural along the circumferential direction of the rotary head rotatably mounted in the R direction (circumferential direction about the center axis of the support head) around the support head, and the touch sensor may be a nozzle to be detected. The threshold value can be set based on the amount of light received after the T-direction and R-direction rotation operation of the spindle on which the nozzle is mounted before contacting.

Each time the operation for contacting the nozzle is made, the touch sensor can set the threshold value based on the amount of light received after the rotation of the T- and R-direction rotations of the spindle on which the nozzle is mounted before contacting the nozzle.

In the description of the embodiments, 'nozzle contact' refers to an operation in which the lower end of the nozzle contacts the upper surface of the component in the pick-up process of the component, and the part supported by the lower end of the nozzle in the mounting process of the component contacts the upper surface of the substrate. The concept includes all of the operations. Therefore, even when only the operation of the nozzle in contact with the component in relation to the 'nozzle contact', it should be understood that the same applies to the operation of the component supported on the nozzle in contact with the substrate. In addition, the 'contacting' of the nozzle may be used in the term 'landing'.

According to the component support head assembly of the component mounter which concerns on the above-mentioned embodiments, the threshold value of the light reception amount which becomes a reference | standard of touch sensing is set based on the measured light reception amount of the state before a contact of the nozzle of a sensing object. In addition, the light reception amount measurement for threshold setting is performed after completion | finish of rotation operation in a T direction and a R direction. That is, since the threshold setting is performed in the state before the contact of the same posture (posture in the rotational direction) as the final posture at the time of the nozzle contact, the optimum threshold value can be set for each nozzle to be detected.

Therefore, the robust performance of the touch sensing function by the touch sensing sensor can be improved. In addition, the falling stroke of the nozzle which supports a component can be controlled more accurately by this.

1 is a perspective view showing an overall configuration of a component support head assembly according to one embodiment.
It is explanatory drawing which shows the mechanism which raises and lowers a spindle (nozzle) in a Z direction in the component support head assembly of FIG.
FIG. 3 is an explanatory diagram showing a configuration around a lift unit for lifting and lowering the spindle (nozzle) in FIG. 2 in the Z direction.
4A and 4B show a state when the spindle (nozzle) is lowered by the lifting unit shown in FIG. 2, FIG. 4A shows a state where the spindle (nozzle) is in the initial position, and FIG. 4B shows the spindle ( The state which lowered the nozzle) is shown.
5 is an enlarged perspective view showing a cross section of a nozzle portion mounted at a lower end of the spindle.
6 is a view schematically showing a change in the amount of received light of the optical fiber sensor when the nozzle is in contact.
7 is a diagram conceptually illustrating a method for setting a threshold in the component support head assembly of FIG. 1.

Hereinafter, with reference to the embodiments of the accompanying drawings, the configuration and operation of the component support head assembly of the component mounter according to the embodiments will be described in detail.

1 is a perspective view showing an overall configuration of a component support head assembly according to one embodiment.

The component support head assembly 10 of the component mounter according to the embodiment shown in FIG. 1 is a rotary head type component support head, and the rotary head 30 is centered on the head body 20 fixedly disposed. It is mounted rotatably in the R direction about the axis. The rotary head 30 is provided with a plurality of spindles 31 at equal intervals along the circumferential direction thereof, and a nozzle 32 for adsorbing and supporting a part at the lower end of each spindle 31 is mounted.

The rotary head 30 is rotated in the R direction by the driving of the R servo motor 21 provided in the head main body 20. Moreover, each spindle 31 rotates in the T direction around the axis line by the drive of the T-servo motor 22 provided in the head main body 20. As shown in FIG. In addition, the head main body 20 is arranged with a Z servo motor 23 for raising and lowering the spindle 31a at a specific position in the Z direction along the longitudinal direction of the spindle. The mechanism for rotating the rotary head 30 in the R direction by the driving of the R servo motor 21 and the mechanism for rotating each spindle 31 in the T direction by the driving of the T servo motor 22 are well known. Description is omitted. The mechanism for lowering the spindle 31a by the drive of the Z servo motor 23 will be described below.

It is explanatory drawing which shows the mechanism which raises and lowers a spindle (nozzle) in a Z direction in the component support head assembly of FIG.

FIG. 2: is explanatory drawing which shows the mechanism which raises and lowers the spindle 31a to Z direction in the component support head assembly 10 of FIG. The motor shaft of the Z servo motor 23 arranged in the head main body 20 is connected to the screw shaft 24a of the ball screw mechanism 24, and the nut 24b is attached to this screw shaft 24a. And the lifting part 25 is connected to this nut 24b. Therefore, the lift part 25 moves in the Z direction with the nut 24b by the drive of the Z servo motor 23.

Only one lifting part 25 is provided on the head main body 20 side. When lowering the spindle 31, the spindle 31 (the spindle 31a at the specific position) that is lowered by moving the spindle 31 relative to the lifter 25 is selected, and the lifter 25 ), The spindle 31a is lowered by lowering.

FIG. 3 is an explanatory diagram showing a configuration around a lift unit for lifting and lowering the spindle (nozzle) in FIG. 2 in the Z direction.

In this embodiment, as shown in Fig. 3, the rotary head 30 is rotated in the R direction to move the spindle 31 with respect to the elevating portion 25, and the spindle just below the elevating portion 25. Lower (31a). However, the structure which selects and lowers the spindle 31a in a specific position is not limited to this, You may make it select the spindle which moves and raises and lowers a lifting part. In addition, two or more specific positions may be provided.

2, the optical fiber sensor is connected to the nut 24b to which the elevating portion 25 is connected through a spline nut 28 mounted on a spline shaft 27 fixedly provided at the connecting bar 26 and the head main body 20. 40 is connected. That is, the optical fiber sensor 40 is provided integrally with the lifting part 25. Therefore, when the lifting unit 25 moves in the Z direction by the driving of the Z servo motor 23, the optical fiber sensor 40 moves in the Z direction in synchronization with it. "Moving in sync" means moving together in a mechanically integrated state, and moving by different driving means but moving together at the same speed. The state is shown to FIG. 4A and 4B.

4A and 4B show a state when the spindle (nozzle) is lowered by the lifting unit shown in FIG. 2, FIG. 4A shows a state where the spindle 31a is in the initial position, and FIG. 4B is shown in FIG. The state in which the spindle 31a is lowered by the elevated lifting section 25 is shown. Moreover, the spindle 31 is always biased toward the initial position upwards by the elastic body 33 (refer FIG. 2) which consists of two coil springs.

FIG. 5 is a perspective view showing an enlarged cross section of a nozzle portion mounted at a lower end of the spindle, and FIG. 6 is a diagram schematically illustrating a change in the received light amount of the optical fiber sensor when the nozzle is in contact.

The optical fiber sensor 40 is a light-emitting unit and a light-receiving unit assembled on the same axis together with an optical fiber or a lens, and its configuration is well known. In this embodiment, the optical fiber sensor 40 is disposed above the inclination of the nozzle 32 mounted through the coil spring 34 (elastic member) at the lower end of the spindle 31 as shown in FIG. . The light emitting portion of the optical fiber sensor 40 emits light P in an inclined downward direction toward the reflecting surface 32a of the outer circumferential upper surface of the nozzle 32 shown in FIG. 5. The light P is received as reflected light at the light receiving portion of the optical fiber sensor 40.

Here, the nozzle 32 is mounted to the lower end of the spindle 31 via the coil spring 34 as described above. Therefore, when the nozzle 32 of the lower end contacts by the lowering of the spindle 31, the coil spring 34 is compressed and the vertical position of the nozzle 32 with respect to the spindle 31 changes. Specifically, the nozzle 32 moves relatively toward the lower end side of the spindle 31.

On the other hand, the light P generated from the light emitting portion of the optical fiber sensor 40 is reflected on the reflecting surface 32a when the nozzle 32 is not in contact with the lens 40a shown in FIG. 2. Focus is on. Therefore, when the nozzle 32 contacts and the vertical position changes, the amount of reflected light reflected by the reflecting surface 32a decreases, and the amount of received light received by the light receiving portion of the optical fiber sensor 40 decreases (see FIG. 6). . In this embodiment, the decrease in the amount of received light is sensed by the sensor portion 40b of the optical fiber sensor 40. The sensor unit 40b judges that the nozzle 32 has contacted when the amount of received light decreases by a predetermined amount, specifically, for example, when it is equal to or less than the threshold A shown in FIG. 6, and issues a touch detection signal.

7 is a diagram conceptually illustrating a method for setting a threshold in the component support head assembly of FIG. 1.

Hereinafter, a method of setting the threshold A in the component support head assembly according to the embodiment will be described with reference to FIG. 7. In addition, although FIG. 7 shows the mounting process of mounting the component 60 on the board | substrate 70, the setting method of the threshold value A is the same also in the pick-up process of components.

In Fig. 7, the Z-direction lowering operation (Z-axis lowering) of the nozzle 32 is started at the point A. In the initial stage of the Z-axis descending, the nozzle 32 descends while simultaneously performing the T-direction rotation operation (T-axis rotation) and the R-direction rotation operation (R-axis rotation) described in FIG. Thereafter, the sensor portion 40b of the optical fiber sensor 40 has a measured light reception amount after the T-axis rotation and the R-axis rotation are completed (B point in FIG. 7) before the contact of the nozzle 32 to be sensed. A threshold A is automatically set immediately based on this, and it judges whether the nozzle 32 has contacted based on this threshold A. In the example of FIG. 7, since the light reception amount became below the threshold value A at time C, it is judged that the nozzle 32 contacted at this time. This threshold setting is repeated for each mounting (pickup) operation of the component by the nozzle 32, and the threshold A is updated each time.

In addition, the timing of the end of the T-axis rotation and the R-axis rotation, which are the timings of the setting of the threshold A, can be grasped by the control program of the component support head. It can determine based on the encoder value of the Z servo motor 23 to elevate.

In this way, by setting the threshold A based on the measured amount of received light after the completion of the T-axis rotation and the R-axis rotation, the optimum threshold A can be set for each nozzle 32 to be detected. That is, when T-axis rotation and R-axis rotation are complete | finished, the attitude | position of the rotation direction of the nozzle 32 becomes the same as the final attitude | position at the time of a contact. Therefore, the threshold value A set on the basis of the light reception amount in the pre-contact state equal to this final posture is optimal as a determination reference value of touch detection by the reduction in light reception amount. By determining whether the nozzle 32 is in contact using the threshold value A set for each nozzle 32 in this manner, the amount of received light in the pre-contact state changes in each nozzle 32 according to the difference in the properties of the nozzle 32. Even if it is, the threshold value A is set accordingly, and the robust performance of the touch sensing function by the optical fiber sensor 32 is improved. In addition, even if the amount of light received in the state before the contact of the nozzle 32 decreases with time due to the dirt of the nozzle 32 or the like, each time the nozzle 32 is used, an accurate threshold A corresponding to the amount of light received at that time is set. Also in this respect, the robust performance can be improved and the usable period of the nozzle 32 can be extended. If the threshold value A is a fixed value, the above-mentioned problem occurs when the amount of received light in the state before the contact of the nozzle 32 decreases, so it is necessary to replace it with a new nozzle early.

In the above configuration, the component mounter having the component support head assembly 10 sucks and picks up a component from the component supply portion by a nozzle 32 mounted at the lower end of the spindle 31, transfers the component onto the printed circuit board, and prints the printed circuit board. It is mounted at a predetermined position on the image. At the time of adsorption and mounting of this component, the sensor unit 40b of the optical fiber sensor 40 judges whether the nozzle 32 has contacted based on the threshold A set for each nozzle 32 according to the above-described method, and detects the contact. When a touch detection signal is issued. This touch detection signal is transmitted to the control part (control means) 50 shown in FIG. The control unit 50 stops the Z servo motor 23 that lowers the lift unit 25 when receiving the touch detection signal. As a result, the lowering stroke of the nozzle 32 is precisely controlled so that the nozzle 32 contacts accurately.

Although the sensor part 40b of the optical fiber sensor 40 was provided separately from the control part 50 in the above embodiment, the function of the sensor part 40b can also be assembled to the control part 50. FIG. As the touch sensor, a reflection type optical sensor other than the optical fiber sensor 40 may be used. The present embodiment is also applicable to component support heads other than the rotary head type, that is, component support heads that do not involve the R-direction rotational operation. In this case, the threshold A is set after the end of the T-axis rotation.

The configuration and effects of the above-described embodiments are merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the invention should be defined by the appended claims.

10: part support head assembly 30: rotary head
20: head body 31, 31a: spindle
21: R Servo Motor 32: Nozzle
22: T Servo Motor 32a: Reflective Surface
23: Z servo motor 33: elastic body
24: ball screw mechanism 34: coil spring
24a: screw shaft 40: optical fiber sensor
24b: nut 40a: lens
25: lifting portion 40b: sensor portion
26: connection bar 50: control unit
27: spline shaft 60: parts
28: spline nut 70: substrate

Claims (4)

A support head, a spindle capable of elevating in a Z direction along a longitudinal direction with respect to a central axis of the support head, a nozzle mounted through an elastic body at a lower end of the spindle, an elevating portion for elevating the spindle in a Z direction, and The component support head of the component mounter having a touch detection sensor which moves in the Z direction in synchronism with the lifting portion and detects that the nozzle is in contact with the component or that the component supported by the nozzle is in contact with the substrate and generates a touch detection signal. As an assembly,
Each of the spindles is rotatable in a circumferential direction about the longitudinal direction of the spindle,
The touch sensor includes a light emitting part that emits light toward a reflective surface of the outer circumference of the nozzle, a light receiving part that receives reflected light reflected from the reflective surface, and a sensor part that can continuously measure the received light amount of the reflected light, Generating the touch detection signal when the amount of received light decreases below a threshold,
The touch sensor is a component mounter that sets the threshold value based on the amount of light received after the rotational movement in the circumferential direction around the longitudinal direction of the spindle on which the nozzle is mounted before contacting the nozzle as a sensing target. Support head assembly. The method of claim 1,
Each time the operation of contacting the nozzle is made, the touch sensor is based on the light receiving amount after the end of the circumferential rotational operation about the longitudinal direction of the spindle on which the nozzle is mounted before the nozzle is contacted. Part support head assembly of the part mounter that sets the value. The method according to claim 1 or 2,
The spindle is arranged in plurality in the circumferential direction of the rotary head rotatably mounted in the circumferential direction about the central axis of the support head,
The touch sensor may be configured to have a circumferential direction about the longitudinal direction of the spindle on which the nozzle is mounted and a circumferential rotation about the central axis of the support head before the contact of the nozzle to be sensed. A component support head assembly of a component mounter for setting the threshold based on the amount of received light. The method of claim 3,
Each time the operation of contacting the nozzle is made, the touch sensor is arranged in the circumferential direction about the longitudinal direction of the spindle on which the nozzle is mounted before the contact of the nozzle and in the circumferential direction about the central axis of the support head. The component support head assembly of the component mounter which sets the said threshold value based on the light reception amount after completion | finish of the rotation operation of this.

Images