Method for mounting a component

A component mounting apparatus including: plural spindles respectively including nozzles, each spindle rotating about a first pivot and each nozzle picking up a component; a head body rotating about a second pivot substantially parallel to a first pivot and rotatably supporting the spindles; and a controller controlling the spindles and the head body to perform: a pickup operation in which the spindle rotates about the first pivot from an initial orientation to a pickup orientation, the nozzle picks up the component, and the spindle rotates from the pickup orientation to the initial orientation so that the component is oriented to a mounting orientation at which the component is to be mounted on a substrate; and a mounting operation in which the picked-up component is transferred to a mounting position of the substrate during which each spindle is retained at the initial orientation.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims priority from Korean Patent Application No. 10-2011-0023822 filed on Mar. 17, 2011 in the Korean Intellectual Property Office and Japanese Patent Application No. 2010-285688 filed on Dec. 22, 2010 in the Japanese Patent Office, the disclosures of which are incorporated herein in their entirety by reference.

BACKGROUND

Apparatuses and methods consistent with exemplary embodiments relate to a rotary mounting head unit and operations of mounting a component, and more particularly, to a rotary mounting head unit and operations of mounting an electronic component on a substrate with less errors.

2. Description of the Related Art

In electronic component mounting apparatuses having a related art rotary head, a plurality of axes are controlled to be synchronized to reduce an operating time of the rotary head. JP 06-77693 discloses technology to reduce an operating time by respectively disposing a plurality of pivot motors in nozzle units, apart from a pivot motor of a rotary head, and by synchronously operating the pivot motors. Also, JP P 2008-227249 discloses technology to reduce an operating time by synchronizing a pivot motor of a rotary head and a lever driving unit for lifting a nozzle.

In the above-described related art electronic component mounting apparatuses, a position where an electronic component is to be mounted is adjusted by synchronously operating a spindle, which includes a nozzle, and a head body rotating in conjunction with the operation of the spindle, and then, performing photographing by using a camera. However, if the rotary head is intermittently operated after performing the photographing, a position of an electronic component may be changed due to a mechanistic error that may occur in spindles, thereby resulting in reduction in precision of a mounting position of the electronic component.

SUMMARY

One or more exemplary embodiments provide a component mounting apparatus that includes a plurality of pivots operating cooperatively and may improve precision of locating a mounting position of the component.

According to an aspect of an exemplary embodiment, there is provided a component mounting apparatus which may include: a plurality of spindles respectively including nozzles, each spindle being configured to rotate about a first pivot and each nozzle being configured to pick up a component; a head body which is configured to rotate about a second pivot substantially parallel to a first pivot, and rotatably support the spindles; and a controller which controls the spindles and the head body to rotate about at least one of the first pivot and the second pivot. The controller may perform: a pickup operation in which the spindle rotates about the first pivot from an initial orientation to a pickup orientation with respect to the head body, the nozzle picks up the component, and then, the spindle rotates from the pickup orientation to the initial orientation so that the component is oriented to a mounting orientation at which the component is to be mounted on a substrate; and a mounting operation in which the picked-up component is transferred to a mounting position of the substrate during which each of the spindles is retained at the initial orientation with respect to the head body.

According to an aspect of another exemplary embodiment, there is provided a mounting head unit which may include: a plurality of spindles respectively comprising nozzles, each nozzle being configured to pick up a component and mount the picked-up component on a substrate, each of the spindles being configured to self-rotate about a first pivot; a head body connected to the spindles and configured to rotate about a second pivot; a power transmitting shaft connected to the spindles through a gear; and a controller which controls the head body to rotate about the second pivot, and controls the power transmitting shaft to rotate the spindles about the first pivot. Here, the controller controls the head body and the power transmitting shaft to perform, a pickup operation in which the spindle rotates about the first pivot from an initial orientation to a pickup orientation with respect to the head body, the nozzle picks up the component, and then, the spindle rotates from the pickup orientation to the initial orientation so that the component is oriented to a mounting orientation at which the component is to be mounted on a substrate; and a mounting operation in which the picked-up component is transferred to a mounting position of the substrate during which each of the spindles is retained at the initial orientation with respect to the head body.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Now, exemplary embodiments according to the inventive concept will be described in detail with reference to the accompanying drawings.

FIG. 1is a perspective view of an electronic component mounting apparatus1, according to an exemplary embodiment.

Referring toFIG. 1, a body1aof the electronic component mounting apparatus1includes first rectilinear motion supporting units3disposed at both sides of a table2in a horizontal direction, i.e. an X-axis direction, to extend in a lengthwise direction, i.e. in a Y-axis direction. Each first rectilinear motion supporting unit3includes a first stage4, a servo-motor5, and a ball screw6being rotated by the servo-motor5.

The servo-motor5of the first rectilinear motion supporting unit3disposed on the left is disposed at a front side of the electronic component mounting apparatus1, and the servo-motor5of the first rectilinear motion supporting unit3disposed on the right is disposed at a rear side thereof. Both ends of a second rectilinear motion supporting unit7extending in the X-axis direction are respectively screw-coupled to the ball screws6of the first rectilinear motion supporting units3.

The second rectilinear motion supporting unit7includes a second stage8screw-coupled to the ball screws6of the first rectilinear motion supporting units3, a servo-motor9, and a ball screw10. The second stage8moves in the Y-axis direction by rotation of the ball screws6of the first rectilinear motion supporting units3.

The second rectilinear motion supporting unit7includes the ball screw10driven by the servo-motor9formed on the right side of the electronics component mounting apparatus1. The ball screw10is screw-coupled to a joint block11. An electronic component is attached to the joint block11by air pressure, and the joint block11supports a nozzle head20including eight nozzles18releasing the attached electronic component.

Two openings13are respectively formed in the first rectilinear motion supporting units3in the Y-axis direction, and a substrate transfer device14extending in the X-axis direction is disposed at a front side of the table2to be placed in the openings13.

The substrate transfer device14includes a pair of rails15, and a substrate16on which the electronic component is mounted is transferred on the rails15in the X-axis direction. The electronic component attached to the nozzles18is mounted on a predetermined mounting position of the substrate16disposed on the substrate transfer device14.

InFIG. 1, an electronic component discarding box17into which a discarded element is collected, a nozzle station19for accommodating the nozzles18, and a camera21for photographing the nozzle head20when light is emitted onto the nozzle head20from the bottom, are sequentially disposed at an upper front side of the table2. The camera21photographs the nozzle head20from the bottom to examine a position and an orientation of the electronic component attached to the nozzles18or generation of defects.

InFIG. 1, a plurality of tape feeders22for feeding the electronic component to be mounted on the substrate16are arranged on the right of the camera21in the X-axis direction, but only one pair of tape feeders22are shown inFIG. 1. Each of the tape feeders22supports a tape reel (not shown) and dispose the electronic component (not shown) unreeled from the tape reel in a position where the nozzle head20is approachable.

The electronic component is attached to the nozzles18of the nozzle head20, and is mounted on a position where the electronic component is to be mounted on the substrate16disposed on the substrate transfer device14.

FIG. 2is a cross-sectional view of the nozzle head20of the electronic component mounting apparatus1ofFIG. 1.

Referring toFIG. 2, the nozzle head20rotatably support the spindles36and the nozzles18by an operation of a T-axis motor31in a rotation direction of a first pivot C1passing through a center of each nozzle18extending in a Z-axis direction and rotates the nozzles18by an operation of an R-axis motor32in a rotation direction of a second pivot C2passing through a center of the nozzle head20extending in the Z-axis direction.

By cooperation between the nozzle head20having the above-described structure, the first rectilinear motion supporting units3and the second rectilinear motion supporting unit7, any one of the nozzles18is disposed above the above-described position where the electronic component is attached to the nozzles18or the above-described position where the electronic component is to be mounted, and also the position of each nozzle18is adjusted at an arbitrary angle with respect to a center of the first pivot C1or the second pivot C2.

In the nozzle head20, any one of the nozzles18is disposed above the position where an element is attached, and the nozzle18is lowered by an operation of a lifting member33so that the electronic component is attached to the nozzle18. Then, the nozzle head20raises the nozzle18to which the electronic component has been attached by the operation of the lifting member33, and the nozzle18and the electronic component are disposed above the position where the electronic component is to be mounted. Then, the nozzle head20lowers the nozzle18to which the electronic component has attached by the operation of the lifting member33to mount the electronic component on the substrate16.

The body1aincludes a controller24for controlling the whole operation of the electronic component mounting apparatus1including the first rectilinear motion stages3, the second rectilinear motion stage7, and the nozzle head20, wherein the controller24is disposed at a lower front side of the table2ofFIG. 1. Also, a cart accommodation portion25for accommodating an element supplying cart (not shown) on which the tape feeders22are mounted is disposed on the right of at the lower front side of the table2, wherein the cart accommodation portion25is formed to have a recessed shape.

The nozzle head20illustrated inFIG. 2has a cylindrical shape in a Z-axis direction and includes a head body34, which has a cylindrical shape and is supported by the joint block11in a direction of the second pivot C2to be capable of rotating, and a plurality of nozzles18disposed at equal intervals in a circumferential direction centering around the second pivot C2. A plurality of spindles36are disposed on a lower outer circumference of the head body34to extend in the Z-axis direction, wherein the spindle36has a rod shape. The head body34rotatably supports the spindles36about the first pivot C1. Each of the nozzles18is disposed at a lower end portion of each of the spindles36.

A body tube35, which is hollow, is disposed on a lower outer circumference of the head body34to be capable of rotating integrally with the head body34. Upper and lower portions of each spindle36are respectively supported by upper and lower walls of the body tube35to be capable of rotating in a rotation direction of the first pivot C1and to be lifted along the first pivot C1.

Also, the nozzle head20includes a power transmission shaft37penetrating the head body34, an input gear38disposed to be capable of rotating integrally with an upper end of the power transmission shaft37, an output gear39disposed to be capable of rotating integrally with a lower end of the power transmission shaft37and rotating coaxially with the power transmission shaft37, and the T-axis and R-axis motors31and32that respectively have driving center axes CT and CR extending in the Z-axis direction and are disposed at an upper portion of the joint block11.

The T-axis and R-axis motors31and32are disposed in such a way that their respective drive axes31aand32aprotrude downward. A pinion gear31cis disposed on an outer circumference of the drive axis31ato be capable of rotating integrally with the drive axis31aand to be engaged with the input gear38having a relatively large diameter. A drive force of the T-axis motor31is transmitted to the power transmission shaft37through a first reduction gear pair including the pinion gear31cand the input gear38. The drive force is transmitted to each spindle36through a second reduction gear pair including the output gear39and a nozzle drive gear41which will be described later. The spindle36rotates about the first pivot C1.

A relay axis32bis disposed coaxially with the drive axis32aunder the drive axis32aof the R-axis motor32and is engaged with the drive axis32ato be capable of rotating integrally with the drive axis32a. The pinion gear32cis disposed on an outer circumference of the relay axis32bto be capable of rotating integrally and coaxially with the relay axis32b. Also, the pinion gear32cis engaged with a head drive gear42having a relatively large diameter and disposed on an upper outer circumference of the head body34to be capable of rotating integrally and coaxially with the head body34. A drive force of the R-axis motor32is transmitted to the head body34through a third reduction gear pair including the pinion gear32cand the head drive gear42. The head body34rotates about the second pivot C2.

Reference numeral32ddenotes a ball bearing unit supporting a contact portion between the drive axis32aand the relay axis32b, wherein the ball bearing unit may include a plurality of rows of balls (not shown).

FIG. 3Ais a cross-sectional view of the nozzle head20in an axial direction when only the T-axis motor31is driven in the electronic component mounting apparatus ofFIG. 1.

The nozzle drive gears41are respectively disposed at lower portions of the spindles36to be capable of rotating integrally and coaxially with the spindles36, and the nozzle drive gears41are engaged with the output gear39. Thus, if the R-axis motor32stops and only the T-axis motor31is driven, the spindles36and the nozzles18rotate about the respective first pivots C1.

FIG. 3Bis a cross-sectional view of the nozzle head20in an axial direction when only the R-axis motor32is driven in the electronic component mounting apparatus ofFIG. 1.

If the T-axis motor31stops and only the R-axis motor32is driven, the output gear39stops, the head body34and the body tube35rotate about the second pivot C2, the spindles36and the nozzles18rotate about the second pivot C2, and the nozzle drive gears41rotate along an outer circumference of the output gear39to transmit power, and thus, the spindles36and the nozzles18rotate about the respective first pivots C1.

FIG. 3Cis a cross-sectional view of the nozzle head20in an axial direction when the T-axis motor31and the R-axis motor32are driven in the electronic component mounting apparatus ofFIG. 1.

Also, if the T-axis motor31and the R-axis motor32are synchronously-driven so that both the head body34(the head drive gear42) and the power transmission shaft37(the input gear38) rotate at the same speed about the second pivot C2, the nozzle drive gears41do not rotate along an outer circumference of the output gear39due to the rotation movement of the output gear39(that is, the spindles36and the nozzles18do not rotate about the respective first pivots C1), and the spindles36and the nozzles18rotate about the second pivot C2at the same speed as the head body34and the body tube35.

An upper portion of each spindle36is supported by an upper wall of the body tube35through a radial ball bearing43(roughly shown inFIG. 2), and a lower portion of each spindle36is supported by a lower wall of the body tube35through a radial ball bearing44(roughly shown inFIG. 2).

Also, an upper portion of the power transmission shaft37is supported by an upper inner circumference of the head body34through a heat upper radial ball bearing45(roughly shown inFIG. 2), and a lower portion of the power transmission shaft37is supported by a lower inner circumference of the head body34through a head lower radial ball bearing46(roughly shown inFIG. 2).

FIG. 4Ais a cross-sectional view of the nozzles18to which electronic component E is attached when the T-axis motor31and the R-axis motor32are synchronously-driven in the nozzle head20as illustrated inFIG. 3C.FIG. 4Bis a cross-sectional view of the nozzles18to which the electronic components E are attached when the T-axis motor31and the R-axis motor32are synchronously-driven in the nozzle head20as illustrated inFIG. 3C.

InFIG. 4A, the nozzles18and the head body34are synchronously-rotating when rotating angles of the head body34with respect to the nozzles18are equal, and thus, the electronic component E is attached to the nozzles18in an element attachment position A1. InFIG. 4A, respective positions of the electronic component Es attached to the nozzles18are the same with respect to the nozzles18supporting the electronic components E.

FIG. 4Cis a cross-sectional view of the nozzles18and the electronic components E which are rotated by driving only the T-axis motor31after the electronic components E are attached to the nozzles18.

The camera21captures images of the nozzle head20in which the electronic component E is attached to the nozzles18below the nozzle head20. Examination for the positions of the electronic component E attached to the nozzles18is performed by using information regarding the imaging performed by the camera21. After the examination is performed, the electronic component E attached to the nozzles18is mounted on the substrate16in an element mounting position A2.

When an orientation of the electronic component E attached to the nozzles18is different from an orientation by which the electronic component E is to be mounted, the orientation of the electronic component E needs to be adjusted by performing an imaging examination by using the camera21and then differentially driving the T-axis motor31and the R-axis motor32to rotate the nozzles18about the second pivot C2.

However, if the imaging examination is performed by using the camera21and then rotating the nozzles18, an error may occur in the position of the electronic component E due to a mechanistic error that may occur with respect to the nozzles18. The mechanistic error includes a shaking error due to rotation of the spindle26, a shaking error occurring in a bearing, and the like.

FIG. 5Ais a cross-sectional view of the nozzles18which are rotated by driving only the T-axis motor31in a reverse direction and the electronic component E is attached to a first nozzle in the nozzle head20as illustrated inFIG. 3A.

FIG. 5Bis a cross-sectional view of the nozzles18which are rotated by driving only the T-axis motor31in a normal direction after the electronic component E is attached to the first nozzle in the nozzle head20as illustrated inFIG. 3A.

The current embodiment can prepare for a case where a mounting orientation of the electronic component E at which the electronic component E is mounted on a substrate is different from an pickup orientation of the electronic component E at which the electronic component E is picked up by the nozzles18. For this purpose, the nozzles18are rotated at a predetermined angle in a reverse direction to pickup orientations from their initial orientations with respective to the head body34by considering the mounting orientation of the electronic component E. Then the nozzle picks up the electronic component E (refer toFIG. 5A). After picking up the electronic component E, the nozzles18are rotated in a forward direction to be returned to their initial orientations from the pickup orientations with respective to the head body34(refer toFIG. 5B). Hereinafter, a series of operations of the nozzles18picking up the electronic component E are referred to as a pickup operation.

FIG. 5Cis a cross-sectional view of the nozzles18which are rotated by synchronously-driving motors after attachment of the electronic components E is completed by repeating the operations illustrated inFIGS. 5A and 5B. The pickup operation is performed sequentially for each of the nozzles18.

The electronic component E is sequentially attached to the nozzles18with the mounting orientation at which the electronic component E is mounted on a substrate, by repeating the series of operations of the above-described pickup operation with respect to the nozzles18(refer toFIG. 5C).

Then, after examination with respect to the electronic component E is performed by capturing images of the nozzle head20by using the camera21, the nozzle head20is moved to the component mounting position A2to be mounted on a substrate (not shown). Hereinafter, a series of operations for mounting the electronic component E are referred to as a mounting operation. When the mounting operation is performed, an orientation of the electronic component E supported by the nozzles18of the nozzle head20which are retained at their initial orientations, i.e. an orientation of the electronic component E at which the nozzles18holds the electronic component E is the same as the mounting orientation by which the electronic component E is to be mounted on a substrate, and thus, the electronic component E may be mounted by lowering the nozzles18with respect to the substrate without rotating the nozzles18.

The nozzles18do not need to rotate to be adjusted to be in the mounting orientation by which the electronic component E is mounted on the substrate (not shown) after performing the imaging examination, and thus, precision of a position where the electronic component E is mounted is prevented from deteriorating due to, for example, a mechanistic error occurring in the nozzles18, thereby minimizing a change in a relative position of the electronic component E from when imaging the electronic component E to when mounting the electronic component E that may occur due to the nozzles18rotating in a reverse direction.

According to the current embodiment, the nozzles18may be rotated in conjunction with the head body34by synchronously-driving driving units, and thus, the electronic component E may be mounted in an component mounting position without rotating the spindles36after performing the imaging examination by using the camera21, thereby improving precision of a position where the electronic component E is mounted because an error due to, for example, a mechanistic error, does not occur in the spindles36after performing an imaging examination by using the camera21.

As described above, the pickup operation is performed when the nozzles18are rotated at a predetermined angle by considering an orientation by which the electronic component E is to be mounted in the element mounting position A2, and thus, an orientation of the electronic component E attached to the nozzles18is already the same as an orientation by which the electronic component E is to be mounted in the element mounting position A2when performing a mounting operation of the electronic component E. At this time, an operation for performing the mounting operation of the electronic component E without rotating the nozzles18is performed, which is referred to as a “precision preferred mode”.

FIG. 6is a view of the nozzle head20to which the electronic component E is attached in the electronic component mounting apparatus ofFIG. 1when seen from the camera21.

As described above, in the precision preferred mode in which precision of a mounting position of the electronic component E is preferred, when driving units are synchronously-driven in order to rotate the nozzles18, unnecessary parts may be easily generated in an imaging field of view B of the camera21, thereby reducing a size of the electronic component E capable of being imaged at a time by using the imaging field of view B of the camera21.

In order to effectively utilize the limited imaging field of view of the camera21, the nozzle head20may be rotated to maintain an orientation in which the electronic component E is attached to be in a particular orientation. The maintaining of the orientation in which the electronic component E is attached to be in the particular orientation means that an orientation of the nozzles18when the electronic component E is attached to the nozzles18is set to rotate the nozzles18within a range of predetermined angles or that the nozzles18are not rotated from their initial orientations so that the electronic component E attached to the nozzles18is included in the imaging field of view B of the camera21.

As such, a function of preferentially controlling a function of securing the imaging field of view B of the camera21prior to a function of securing precision of a position where the electronic component E is mounted is referred to as an “imaging preferred mode”. In the imaging preferred mode, a rotation movement about the first pivot C1with respect to a rotation movement about the second pivot C2is adjusted by synchronously-driving the first pivot C1and the second pivot C2so that an image of the electronic component E is exactly included in the imaging field of view B.

For example, in a square electronic component E illustrated inFIG. 6, a size of the electronic component E may be imaged up to √{square root over (2)} times at a time. That is, imaging may be effectively performed by effectively utilizing the limited imaging field of view B of the camera21. The electronic component mounting apparatus1may selectively perform any one of a precision preferred mode in which precision of a position where the electronic component E is mounted in the nozzle head20is preferentially secured and an imaging preferred mode in which the imaging field of view B of the camera21is preferentially secured in order to effectively recognize the electronic component E.

According to a rotary mounting head unit and a method and apparatus for mounting an electronic component, nozzles may be optimally rotated in conjunction with a head body by synchronously-driving driving units. For example, the electronic component may be mounted in an element mounting position without rotating spindles after performing imaging examination of the electronic component supported by the nozzles, thereby improving precision of a position where the electronic component is mounted because a change in a position due to, for example, a mechanistic error, does not occur in the spindles after performing an imaging examination. Also, an image may be effectively obtained by rotating the spindles in order to effectively utilize an imaging field of view during the imaging examination.