WO2004070797A1

WO2004070797A1 - Random-period chip transfer apparatus

Info

Publication number: WO2004070797A1
Application number: PCT/JP2004/001231
Authority: WO
Inventors: Hiroshi Aoyama; Ryoichi Nishigawa
Original assignee: Hallys Corporation
Priority date: 2003-02-07
Filing date: 2004-02-05
Publication date: 2004-08-19
Also published as: US20080005895A1; EP1595278B1; JP3739752B2; US7643904B2; US20040154161A1; KR20050100659A; EP1595278A1; DE602004010071D1; CN100349256C; US7278203B2; JP2004265920A; TWI322647B; DE602004010071T2; CN1748286A; TW200421951A; KR100849934B1

Abstract

A chip transfer apparatus includes a first carrier for feeding chips and a second carrier for carrying works on it. The transfer apparatus also includes a transfer engine including two or more coaxial revolvers, which can revolve coaxially with each other. Each of the coaxial revolvers includes an end-effector for receiving a chip from the first carrier and transferring the received chip onto a work on the second carrier. The end-effectors of the coaxial revolvers are arranged in a circle coaxial with the revolvers. The end-effectors sequentially receive chips from the first carrier at substantially zero speed relative to the first carrier and transfer the received chips onto works on the second carrier at substantially zero speed relative to the second carrier. While the end-effectors are revolving, they undergo periodic speed change control for timing adjustment and speed adjustment for the chip reception and transfer.

Description

DESCRIPTION

RANDOM-PERIOD CHIP TRANSFER APPARATUS Technical Field

The present invention relates to a transfer apparatus for transferring parts onto works with revolving end-effectors.

Background Art

Conventionally, there has been such an electronic parts mounting apparatus available in the field of semiconductor production for receiving chips, transferring the received chips onto works and arranging, sticking or electrically connecting the transferred chips on the works (e.g., Japanese Laid-Open Patent Publication No. HI 0- 145091 ). This apparatus is a rotary type mounting apparatus having multiple transfer heads, which revolve to mount chips on works in sequence. The transfer heads are arranged coaxially around a main shaft and revolve in a circular orbit around the shaft. Operation stages are set at fixed positions on the orbit such as a suction stage where the transfer head sucks a chip from a chip feeder, and a mounting stage where the transfer head mounts the sucked chip on the work. The transfer heads stop at each of the operation stages to transfer chips. In order to keep the main shaft rotating while the transfer heads are stopping, the mounting apparatus is equipped with a fixed cam having a curve to substantially stop the transfer heads by canceling the rotational speed transmitted from the main shaft to the heads. Thus an apparatus is realized which can mount chips while its main shaft is continuously rotating. However such apparatus for mounting electronic parts mentioned above transfers chips by means of transfer heads, the periodic motion is rigid because the motion is generated by mechanical cams. Accordingly, the transfer heads are constrained to move in conjunction with the rotation of the main shaft.

Recently, commodity control by means of disposable type RFID (radio frequency identification) tags is made in several field as a result of advancement of information technology and requirement of the laborsaving for information management. This requires mass production of cheap RFID tags (RF tags or radio tags). The mass production of RF tags may also require following processes or process technologies; feeding electronic parts for RF transmission/reception continuously at a constant interval (pitch) without halting them; receiving the fed parts without halting them; transferring the received parts without halting them onto sheet-type works having an antenna element formed on it while the works are moving continuously and are fed side by side in a constant pitch; arranging, sticking, or electrically connecting the parts onto the work. If the periodic motion of the transfer heads is rigidly fixed, following problems may occur for the mass production mentioned above. That is, it is necessary to replace the cam troublesomely for every products of a different size or pitch. Besides, because the motion of the transfer heads is limited, the heads cannot follow an irregular change of the pitch of fed parts or an irregular change of the pitch of moving works. Those transfer heads cannot respond to random pitch changes or real-time fine adjustment, and consequently, accurate parts positioning is .impossible. Another conventional transfer mechanism is known, which includes a single transfer head and has an electronic cam driven by a single motor with which period can be changed. However, the single transfer head is not adaptable for high-speed mass production even though it may ensure positioning accuracy.

Disclosure of Invention

Accordingly, the object of the present invention is to provide a random-period chip transfer apparatus that can realize accurate positioning and high-speed transfer, and that can also respond to changes of the speeds and pitches at which chips and works are fed.

In order to attain the above object, according to the present invention, a chip transfer apparatus for transferring chips onto works, comprises a first carrier for carrying chips thereon; a second carrier for carrying works thereon; a plurality of end-effectors receiving chips from the first carrier and transferring the chips onto the works carried by the second carrier; a plurality of coaxial revolvers, each of which has one end-effector, and can revolve around one common axis independently; and servo drives, each of which drives each of coaxial revolvers to independently and randomly change periodic revolving speed of each coaxial revolver; wherein each of the end-effectors is inseparably mounted on each of the coaxial revolvers and distributed in one common circle around the axis, wherein each of the end-effectors moves sequentially keeping their order by the action of said servo drives, and receives a chip from the first carrier, and transfers the received chip onto the work on the second carrier, and is independently changed its revolving speed during the periodic motion including said receiving and transferring motion.

According to the above constitution, the end-effectors of the coaxial revolvers are arranged in a circle coaxial with the revolvers axis, and are revolved independently in sequence, and sequentially receive chips from the first carrier, and transfer the received chips onto the works on the second carrier while they are revolving with each own periodic speed changed and controlled independently. This can realize high-speed transfer. For example, if the end-effectors are six in number, they can receive chips fed at a speed that is nearly six times the revolving speed. Chips can be fed at a constant pitch sequentially without halting. The end-effectors can receive the fed chips without halting them and transfer the received chips onto works moving at a constant pitch sequentially without halting.

It is possible to transfer chips accurately to predetermined positions on works by accelerating or decelerating the end-effectors in response to pitch variations of works on the second carrier.

Preferably, in the transfer apparatus, each of the end-effectors is synchronized with said first carrier movement to receive a chip from said first carrier at substantially zero speed relative to said first carrier, and is synchronized with said second carrier movement to transfer said received chip onto the work on said second carrier at substantially zero speed relative to the second carrier.

In this case, since a chip is received and transferred at substantially zero speed relative to the carriers, high positioning accuracy and high-speed transfer can be realized in response to changes of the speeds and pitches at which chips and works are fed. Thus, the independent control of the revolution of each end-effector enables free pitch changes and real-time fine adjustments of chips and works, which enable high-speed and accurate transfer. By independently correcting the position of each end-effector, it is possible to achieve tens of microns and some microns in accuracy, thereby improving the productivity and the mounting quality.

Preferably, in the transfer apparatus, each of the coaxial revolvers includes a coaxial bearing arranged in order on the axial direction having an inner race fixed to an outer race of the coaxially adjacent bearing, and having an outer race fixed to an inner race of the coaxially adjacent another bearing; the inner race of the bearing on one end side being fixed to an outer race of an additional bearing which inner race is fixed to one fixed side and the outer race of the bearing on the other end side being fixed to the other fixed side; each of the end-effectors being inseparably fixed to the inner race of the associated bearing, and the outer race of the associated bearing being activated by a rotational driving force of each of the servo drives.

In this case, the coaxial revolvers support each other. If the coaxial revolvers are three in number, they can be driven by three general-purpose servo control system motors positioned at different angles around the axis. This makes it possible to average and distribute the external forces exerted on the bearing axis. Because the coaxial revolvers can revolve independently of each other, the drive wheels made up on each outer race of the associated bearing can be connected to general-purpose servo control system motors so that their revolving speed/phase change control and position correction control can be done. Since a space surrounding each of the outer races of the bearings is wide enough, it is possible to house more accurate direct drive/control in place of the general-purpose servo control system.

Preferably, in the transfer apparatus, each of the coaxial revolvers is individually and independently made its periodic speed change and phase control by the operation of the associated servo drive. In this case, independent control of the revolution of each end-effector enables free pitch changes and real-time fine position adjustment of chips and works. This enables high-speed and accurate transfer.

Preferably, the transfer apparatus further comprising a measuring unit for measuring the speed of the chips carried on the first carrier and/or the speed of the works carried on the second carrier; the servo drives being operated on the basis of the measurement result of the measuring unit. In this case, without using indirect information based on the first carrier and/or the second carrier motion control information, it is possible to use directly obtained speed and/or position data of chips and/or works. Therefore accurate and real-time control of the coaxial revolvers revolution is possible. This enables high-speed and accurate transfer.

Preferably, in the transfer apparatus, even if the first and second carriers move at different speeds, each of the end-effectors receives a chip from the first carrier at substantially zero speed relative to the first carrier synchronized with the first carrier movement, and transfers the received chip onto a predetermined position of the work on the second carrier at substantially zero speed relative to the second carrier synchronized with the second carrier movement. This enables high-speed and accurate transfer even in a case where the feeding speed of chips, which depends on the moving speed of the first carrier, is lower than the moving speed of works, which depends on the moving speed of the second carrier. This case may be a case where the end-effectors transfer chips onto works that are larger in size than the chips.

Preferably, in the transfer apparatus, each of the first and second carriers is a rotating cylinder or a conveyor belt. In this case, the end- effectors can receive chips by approaching the chips carried on a rotating cylinder or a running conveyor belt and transfer the received chips onto works by approaching the works carried on a rotating cylinder or a running conveyor belt.

Preferably, in the transfer apparatus, the chips are electronic parts, and the works are IC card parts or RF tag parts in the form of sheets. In this case, it is possible to improve the productivity and quality of IC cards or RF tags by means of the foregoing operation and effect/s of the transfer apparatus.

Brief Description of Drawings

FIG. 1 is a conceptual view of a chip transfer apparatus embodying the present invention.

FIG. 2A is a perspective view of chips and works, showing how the transfer apparatus transfers the chips onto the works.

FIG. 2B is a perspective view of one of the chips and one of the works.

FIG. 3 is a graph of changes in revolving angle with time, showing the revolution of the end-effectors of the transfer apparatus.

FIG. 4A is a schematic diagram of one of the end-effectors, showing how each of them revolves.

FIG. 4B is a graph of a change in revolving angle with time, showing the revolution shown in FIG. 4A.

FIG. 5 is a partial perspective view of the end-effectors.

FIG. 6 A is an end view of a transfer engine of the transfer apparatus.

FIG. 6B is a cross section taken along line A-B-C-O-D in FIG. 6A.

FIG. 7 is an exploded perspective view of a coaxial revolver of the transfer engine.

FIGs. 8A, 8B and 8C are axial sections of the three coaxial revolvers of the transfer engine.

FIG. 9 is a skeleton diagram equivalent to FIG. 6B.

FIG. 10 is a side view of the two transfer engines of the transfer apparatus.

FIG. 11 is a block diagram of the servo drive system of the transfer apparatus.

Best Mode for Carrying Out the Invention

FIG. 1 shows a chip transfer apparatus 1 embodying the present invention. The transfer apparatus 1 includes a first carrier 3 carrying chips 2 on it and feeding the carried chips, a second carrier 5 carrying works 4, onto which chips 2 can be transferred, and two transfer engines 6 (described later in detail). The engines include six coaxial revolvers 10 around one common revolving axis, and each of them has end-effector 71 - 76. Each of the end-effectors 71 - 76 receives a chip 2 from the first carrier 3 and transfers the received chip 2 onto a work 4 on the second carrier 5.

The end-effectors 71 - 76 are arranged at regulated intervals in a circle coaxial with the coaxial revolvers 10 . While the end-effectors 71 - 76 are revolvitig around the common axis, they receive chips 2 in order from the first carrier 3 at a nearly zero speed relative to this carrier synchronously with the rotation of this carrier, and they transfer in order the received chips 2 to predetermined positions on works 4 on the second carrier 5 at a nearly zero speed relative to this carrier synchronously with the movement of this carrier. During the revolution of each of the end-effectors 71 - 76, timing adjustment for the reception and transfer on the revolving orbit, and period change control for the speed adjustment at that time are carried out by each end-effector independently.

In FIG. 1, the end-effector 71 is in the angular position Ql, where it receives a chip 2 from the first carrier 3, the end-effector 72 is in the angular position Q2, where it is moving toward the second carrier 5, the end-effector 73 is in the angular position Q3, where it transfers a chip 2 onto a work 4, and the other end-effectors 74, 75 and 76 are in the angular positions Q4, Q5 and Q6 respectively, where they are moving toward the first carrier 3.

The first carrier 3 is a cylindrical or columnar rotor and receives a chip 2 at a point P0 from the adjacent chip feeder 30 and transfers the received chip 2 at a point PI to one of the coaxial revolvers 10. Normally, the first carrier 3 rotates at a constant speed and carries chips 2 at regular intervals on its cylindrical wall. The cylindrical wall may be formed with holes, through which air can be sucked to hold chips 2 on the wall. The held chips 2 are released by stopping the suction or applying positive pressure at a predetermined rotary position. As shown in FIG. 1, the chip feeder 30 takes the form of a roller, around which a tape may temporarily retain chips 2 ^;on it until they are fed. Alternatively, a continuous material might be fed and cut into chips, which might then be fed to the chip feeder 30.

The second carrier 5 may include a belt, which can be moved by four rollers 51 - 54. The start end of the belt is fed as shown by arrow 55 from a roll (not shown), and the other end is taken up as shown by arrow 56 by another roll (not shown).

Each of the two carriers 3 and 5 is so adjusted by drives (not shown) and a drive control system (not shown) as to operate at a constant speed. Before chips 2 are transferred onto works 4, the conditions of the chips 2 and works 4 are photographed by three measuring units 103, 106 and 105, which may be cameras. The image processing of the photographs makes it possible to detect irregular pitches, abnormal positions, foreign substances and other abnormalities. Before chips 2 are transferred onto works 4, the moving speeds of the chips 2 and works 4 are measured by the measuring units 103, 106 and 105 so that the revolution of the coaxial revolvers 10 can be controlled.'

For the production of RF tags, as shown in FIGs. 2A and 2B, the transfer apparatus 1 transfer chips 2 that are electronic parts for RF reception and transmission onto works 4 each of which is a RF tag part having an antenna 41. The works 4 may be carried on the second carrier 5 in the form of a belt. Alternatively, the works 4 may be printed, photographically formed or otherwise integrally formed on a flexible substrate in the form of a tape as the second carrier 5. Both terminals 42 of the antenna 41 on each work 4 may be coated in advance with conductive resin for electric connection. Each chip 2 is mounted between the antenna terminals 42 on one of the works 4. The RF tags are so small as to be called sesame chips. The RF tags need to be tens of microns or some microns in accuracy for the positioning accuracy of the chips 2. This can be realized by the transfer apparatus 1. For mass production of cheap RF tags, the chips 2 can be mounted as stated above while the works 4 are conveyed in series without halting. The transfer apparatus 1 can be used not only to produce RF tags, but also to transfer and mount electronic parts onto IC card parts etc.

The foregoing high-speed and accurate transfer can be realized by the revolution of the end-effectors. The end-effector revolution will be described below with reference to FIG. 3, which shows changes with time in the revolving angles θ of the end-effectors. The curves CI - C6 represent the movement of the end-effectors 71 - 76 in FIG. 1 respectively. The points ql - q6 on the curves at a time tl correspond to the angular positions Ql - Q6 (FIG. 1) respectively. The starting point of the revolving angles θ (θ = 0) is defined as the point where an end-effectors is on a line which connects each revolving center of the first carrier 3 and the coaxial revolvers 10, and the rotational direction is defined as counterclockwise as shown in FIG. 1. With reference to FIG. 3, a period Tl is the period (the chip feeding interval) at which the end-effectors 71 - 76 receive chips 2 from the first carrier 3, and Tl is determined by the rotational speed of the first carrier 3 and the intervals at which chips 2 are carried on this carrier. The period T2 is the time interval at which all six end-effectors 71 - 76 receive chips 2, and transfer the received chips one time respectively. The period T2 measured for a small number of cycles is about six times Tl (T2 nearly equal 6 x Tl).^* The average period T2 for a large number of cycles is six times Tl (T2 = 6 x Tl). The revolution of each of the six end-effectors is independently controlled so that chips can be fed and transferred at a speed of about six times the revolving speed of the end-effectors.

The revolving motion of one end-effector will be described with reference to FIGs. 4A and 4B, which show the revolving angle change with time for the end-effector 71 during its orbiting. The end-effector 71 receives (at point e on the curve of FIG. 4B) a chip 2 at revolving angle 0 (zero), time tl, and revolving speed VI, and then transfers (at point f) the received chip 2 onto a work at revolving angle θ 1 , time t2, andrevolving speed V2, and finaly returns (at a point g) to the initial position at revolving angle 2π, at a time t3 (= tl + T2). Time period al , a3, or a5 are the periods where the revolving speeds are kept constant in order to receive or to transfer a chip2 at nearly zero relative speed to the chip on the first carrier 3 or to the work on the second carrier. Time periods a2 or a4 are the periods where the end-effector 71 accelerates or decelerates while it is revolving in the orbit.

Not only speed adjustment but also time adjustment are made during the time periods a2 and a4. For example, with reference to FIGs. 1 , a pitch variation of works 4 on the second carrier 5 measured by the camera 105 may require the end-effector 71 to transfer the chip 2 on it onto one of the works a time Δt earlier. In this case, the end-effector 71 can be so accelerated as to make the curve of FIG. 4B to pass through a point fl in place of a point f (i.e. changed from solid line to broken line), and this makes it possible to transfer the chip 2 accurately to the predetermined position on the work 4. Thus, by independently controlling the revolution of each of the end-effectors 71 - 76, it is possible to transfer chips 2 onto works 4 accurately at high speed.

The structure of the coaxial revolvers 10 and transfer engines 6 will be described below with reference to FIGs. 5 - 10. FIG. 5 shows the end portions of the end-effectors, FIGs. 6A and 6B show the transfer engine, FIGs. 7 and 8 show the coaxial revolvers, FIG. 9 shows the skeleton of the engine, and FIG. 10 shows the side view of the transfer engines. Each of the end-effectors 71 - 76 is fitted with a suction pad 70 near its one end (FIG. 5), which has a hole formed through it for pneumatic control, and with which the end-effector receives a chip by means of suction through the pad hole and transfers the received chip by making the pressure normal or positive. The suction pad 70 revolves together with the end-effector. As shown in FIG. 5, the three end-effectors 71, 73 and 75 make one set, and the other three end-effectors 72, 74 and 76 make another set. Each of the sets is bulid in each transfer engine. The three end-effectors of one of the sets are positioned alternately with those of the other set in the same circle. As shown in FIG. 10, two transfer engines 6 are positioned coaxially with and opposite each other.

With reference to FIGs. 6A, 6B, 7, and 8 A - 8C, one of the two transfer engines 6 having three end-effectors 71, 73 and 75 is descrived. As shown in FIG. 6A and 6B, the transfer engine 6 includes three fixed frames 60a, 60b and 60c, four large-diameter coaxial bearings positioned between the fixed frames 60a and 60c, a hollow shaft 60 fixed to the fixed frame 60a and three small-diameter coaxial bearings 61, 63 and 65 fixed to the hollow shaft 60. The end-effectors 71, 73 and 75 take the form of bars extending eccentrically from and in parallel with the center axis CL. The end- effectors 71, 73 and 75 are supported by the large-diameter and small- diameter bearings in such a manner that each end-effector can revolve around one common center axis CL as one united body forming a coaxial revolver 10. Each of end-effectors is included with a coaxial revolvers 10, and one transfer engine 6 has three end-effectors, so one transfer engine 6 has three coaxial revolvers 10.

The revolving mechanisms of the coaxial revolvers 10 having end- effector 71 will be described below. The end-effector 71 is supported at its one end portion (near the suction pad 70) by the small-diameter bearing 61 on the hollow shaft 60, and the other end portion is fixed through a connector ring 90 to the inner race 81 of the large-diameter bearings. The inner race 81 is supported by an outer race 80 of the large-diameter bearing fixed to the fixed frame 60c. The inner race 81 is fixed to the outer race 82 of the axially adjacent large-diameter bearing through an annular connector 91. The outer periphery of the annular connector 91 is surrounded by and fixed to a drive wheel 92. The drive wheel 92 has teeth (a precision gear or the like) formed on its outer periphery, which may be driven by a timing belt. The outer race 82 is supported by an inner race 83 of the large diameter bearing (FIG. 6B and 8B). A circumferentially adjacent another end- effector 73 is fixed to the inner race 83 by a connector ring 90 (FIG. 8B). The coaxial revolvers 10 including the end-effectors 73 and 75 are constructed similarly to the above-mentioned coaxial revolver 10 including the end-effector 71 (FIG. 6B, 7 and 8A - 8C). Specifically, end-effectors 73 has a pair of inner race 83 and outer race 84 supported by a connector ring 90 and an annular connectors 93, and end-effectors 75 has a pair of inner race 85 and outer race 86 supported by a connector ring 90 and an annular connectors 95. Drive wheels 94 and 96 are provided corresponding to the end-effectors 73 and 75. The inner race 81 and outer race 86 is respectively supported by an outer race 80 and inner race 88 fixed to the fixed frames 60c and 60a.

Each of three coaxial revolvers 10 includes one end-effector, one large-diameter bearing, one annular connector, one drive wheel. The annular connector fixes the inner race and the outer race of the axially adjacent two large-diameter bearings each of which is of one of the circumferentially adjacent two end-effectors. The outer race and inner race at both ends of the connected four large-diameter bearings are fixed to fixed frames. Thus the large-diameter (three plus one additional) four bearings are connected by so-called cascade connection. The transfer engine 6 is structured so that three coaxial revolvers 10 support each other.

FIG. 11 shows the servo drive system of the transfer apparatus. This drive system includes a CPU 100 for the servo control of the drive of the coaxial revolvers 10. The CPU 100 makes independent servo control of six motors M, each of which drives one of the coaxial revolvers 10. Because each coaxial revolver 10 revolves independently, each drive wheel 92, 94 or 96 is connected to a general-purpose servo control system motor so that revolving speed/phase change control and position correction control can be made. It is possible to disperse or cancel the external pressure exerted on the revolving axis through the drive wheels 92, 94 and 96, by positioning the three motors M for each drive wheel at different angles around this axis. The outer peripheries of the drive wheels 92, 94 and 96 are surrounded by an open space, where various mechanisms can be fitted. This makes it possible to replace the general-purpose servo control system motors with direct drive mechanisms for more accurate control.

The suction and release of chips by the end-effectors 71 - 76 will be described below with reference to FIG. 6B. The hollow shaft 60 of each transfer engine 6 has three holes 70a formed through its cylindrical wall and a center hole 70b formed through its end wall adjacent to the frame 60a. Negative pressure for the chip suction is applied through the communicating path made of the holes of the suction pads 70; the spaces in the end- effectors; holes and slits of the small-diameter bearings 61, 63 and 65; and the shaft holes 70a and 70b; by a pneumatic controller (not shown), which is fitted to the transfer apparatus. The small-diameter bearings 61, 83 and 65 are formed with pressure control holes (not shown). While the small- diameter bearings 61, 83 and 65 are rotating with the end-effectors 71 - 76, the pressure control holes can be connected to a pipe line (not shown) for release so that chips can be released from the suction pads 70.

The present invention is not limited to the preferred embodiment, which may be modified into various forms. For example, a continuous material might be cut into chips, which might then be fed at a constant pitch onto the first carrier 3. In this case, the transfer apparatus might be fitted with means of alignment for pitch-stabilizing correction and position correction. The transfer apparatus might also be fitted with a non-halt phase synchronizer for making the work intervals on the second carrier 5 constant without halting the works being fed. This could make the transfer apparatus more efficient. The transfer apparatus can also be used as a converting machine, a printer, a labeler, a semiconductor producing apparatus or the like for transfer-printing of coating liquid on continuous or separated sheets, and an apparatus for transfer, relocation, lamination or arrangement of small chips or labels.

In the above described embodiment, the transfer apparatus 1 has two opposite transfer engines, and each transfer engine has three coaxial revolvers and three end-effectors (FIG. 10), however, the constitution of the present invention is not limited to this. The number of the end-effectors is determined depending on the size or shape of the chips to be transferred or on the production volume. For example, for labeling to articles of clothing, one transfer engine having two end-effectors and two coaxial revolvers can be employed. In this manner, a transfer engine having at least more than two end-effectors and two coaxial revolvers is effectively used as the transfer apparatus of the present invention in which each end-effector is independently drove to adjust its revolving speed during one orbiting movement to receive a chip and to transfer the chip.

The transfer apparatus of the present invention can achieve tens of microns and some microns in accuracy of the transfer position by independently correcting the movement and position of each end-effector, however, present invention can also be used as a transfer apparatus which is required rather moderate condition for transfer positioning or chip handling. For example, there are cases that the required accuracy for the transfer position is several millimeters, or the relative speed between a work and a chip to be transferred is acceptable even if not substantially zero. In these cases, by using the transfer apparatus of present invention the productivity rate can be improved.

More than two chips can be also transferred on to one work in a cycle. In this case, coaxial revolvers each of which is equipped with a plurality of end-effectors, or with an one-to-one end-effector can be used. The plurality of chips can be arranged in the moving direction or perpendicular direction to the moving direction of the work carried on the second carrier.

In the above described embodiment, the suction pads 70 are fitted so that chips are hold within a plane perpendicular to the radial direction of the coaxial revolvers (FIG. 5), however, the direction holding chips in the present invention is not limited to this. For example, chips can be hold within a plane parallel to the rotation plane of end-effectors (a plane perpendicular to the common axis). In this case, the common revolving axis of the transfer engine(s), accordingly of the coaxial revolvers and end- effectors, is set in vertical direction, and chips are received and transferred within a substantially same horizontal plane. Therefore, each end-effector revolves in a horizontal plane, and receives a chip from the first carrier on the revolving orbit in the horizontal plane, and after adjustment of revolving speed and timing, transfers the chip onto the work on the second carrier moving in the horizontal plane.

Claims

1. A chip transfer apparatus for transferring chips onto works, the apparatus comprising: a first carrier for carrying chips thereon; a second carrier for carrying works thereon; a plurality of end-effectors receiving chips from said first carrier and transferring the chips onto the works carried by the second carrier; a plurality of coaxial revolvers, each of which has said one end- effector, and can revolve around one common axis independently; and servo drives, each of which drives each of said coaxial revolvers to independently and randomly change periodic revolving speed of each coaxial revolver; wherein each of said end-effectors is inseparably mounted on each of said coaxial revolvers and distributed in one common circle around said axis, wherein each of said end-effectors moves sequentially keeping their order by the action of said servo drives, and receives a chip from said first carrier, and transfers said received chip onto the work on said second carrier, and is independently changed its revolving speed during the periodic motion including said receiving and transferring motion.

2. The transfer apparatus according to claim 1 wherein each of the end-effectors is synchronized with said first carrier movement to receive a chip from said first carrier at substantially zero speed relative to said first carrier, and is synchronized with said second carrier movement to transfer said received chip onto the work on said second carrier at substantially zero speed relative to the second carrier.

3. The transfer apparatus according to claim 2 wherein each of said coaxial revolvers includes a coaxial bearing arranged in order in the axial direction having an inner race fixed to an outer race of the coaxially adjacent bearing, and having an outer race fixed to an inner race of the coaxially adjacent another bearing; the inner race of the bearing on one end side being fixed to an outer race of an additional bearing which inner race is fixed to one fixed side and the outer race of the bearing on the other end side being fixed to the other fixed side; each of said end-effectors being inseparably fixed to the inner race of the associated bearing, and the outer race of the associated bearing being activated by a rotational driving force of each of said servo drives.

4. The transfer apparatus of claim 2 wherein each of the coaxial revolvers is individually and independently made its periodic speed change and phase control by the operation of the associated servo drive.

5. The transfer apparatus according to claim 4 further comprising: a measuring unit for measuring the speed of the chip carried on the first carrier and/or the speed of the work carried on the second carrier; the servo drives being operated on the basis of the measurement result of the measuring unit.

6. The transfer apparatus according to claim 4 wherein, even if the first and second carriers move at different speeds, each of the end-effectors receives a chip from the first carrier at substantially zero speed relative to the first carrier synchronized with the first carrier movement, and transfers the received chip onto a predetermined position of the work on the second carrier at substantially zero speed relative to the second carrier synchronized with the second carrier movement.

7. The transfer apparatus according to claim 6 wherein each of the first and second carriers is a rotating cylinder or a conveyor belt.

8. The transfer apparatus according to claim 2 wherein the chips are electronic parts, and wherein the works are IC card parts or RF tag parts in the form of sheets.