Winding type flexible printed circuit board tape transferring system

Information

  • Patent Grant
  • 6592065
  • Patent Number
    6,592,065
  • Date Filed
    Thursday, October 11, 2001
    23 years ago
  • Date Issued
    Tuesday, July 15, 2003
    21 years ago
Abstract
A winding type flexible printed circuit board tape transferring system includes tape let-off wheel unit, a tape take-up wheel unit, two idle wheel units adapted to guide movement of the flexible printed circuit board tape from the tape let-off wheel unit to the tape take-up wheel unit, a tension control wheel unit adapted to control the tension of the flexible printed circuit board tape being transferred from the tape let-off wheel unit to the tape take-up wheel unit, and at least one work wheel unit adapted to rotate a respective rotary encoder upon movement of the flexible printed circuit board tape, enabling the rotary encoder to output a signal to a control unit indicative of the position of the flexible printed circuit board tape.
Description




BACKGROUND AND SUMMARY OF THE INVENTION




The present invention relates to a printed circuit board tape transferring system, and more specifically, to winding type flexible printed circuit board tape transferring system, which is practical to transfer flexible printed circuit board of different types and widths.




Following fast development of telecommunication industry, semiconductor industry, and planer display industry, different thin-film tapes such as tape carried package, tape ball grid array, and chip on film are intensively used as tapes for printed circuit board. These flexible film tapes commonly have sprocket holes symmetrically arranged along the two opposite lateral sides for positioning in a transferring system. The thickness of these flexible film tapes is about 0.025˜0.125 mm. The width of these flexible film tapes ranges from minimum 35 mm to maximum over 200 mm. When employing these flexible film tapes to the fabrication of flexible printed circuit board, several problems may be encountered as outlined hereinafter.




1. It is difficult to keep the coplanarity of the flexible film tape without any contacts at the region of circuits during the manufacturing process.




2. When transferring the flexible film tape, an improper control of the transmission mechanism may cause the transmission mechanism to damage or deform the sprocket holes of the flexible film tape.




3. A flexible film tape without sprocket holes is not transferable.




4. When running an examination operation, the transferring system must be break off, and then the examination apparatus is operated to examine one segment of the flexible film tape, and then the flexible film tape is carried forwards, and then the examination apparatus is returned to its former position for examining a next segment of the flexible film tape. This repeated transferring and examining procedure wastes much time.




The present invention has been accomplished to provide a winding type flexible printed circuit board tape transferring system, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide a winding type flexible printed circuit board tape transferring system, which is practical to transfer flexible printed circuit board tapes of different widths. It is another object of the present invention to provide a winding type flexible printed circuit board tape transferring system, which is practical to transfer flexible printed circuit board tape having sprocket holes as well as flexible printed circuit board tapes without sprocket holes. It is still another object of the present invention to provide a winding type flexible printed circuit board tape transferring system, which keeps the flexible printed circuit board tape flattened transversely extended out when transferring it, preventing the flexible printed circuit board tape from wrinkling. According to one aspect of the present invention, the winding type flexible printed circuit board tape transferring system includes a tape let-off wheel unit controlled to let off a flexible printed circuit board tape for processing, a tape take-up wheel unit controlled to take up the flexible printed circuit board tape from the tape let-off wheel unit, two idle wheel units adapted to guide movement of the flexible printed circuit board tape from the tape let-off wheel unit to the tape take-up wheel unit, a tension control wheel unit adapted to control the tension of the flexible printed circuit board tape being transferred from the tape let-off wheel unit to the tape take-up wheel unit, and at least one work wheel unit adapted to rotate a respective rotary encoder upon movement of the flexible printed circuit board tape, enabling the rotary encoder to output a signal to a control unit indicative of the position of the flexible printed circuit board tape. According to another aspect of the present invention, the wheels of the tension control wheel unit, idle wheel units, and at least one work wheel unit each comprise a wheel axle, a fixed wheel blade fixedly fastened to the wheel axle, an adjustment wheel blade slidably mounted on the wheel axle in parallel to the fixed wheel blade and fixed in the desired position subject to the width of the flexible printed circuit board tape by a holding down screw. The fixed wheel blade and the adjustment wheel blade each have a shoulder adapted to support the flexible printed circuit board tape being transferred from the tape let-off wheel to the take-up wheel.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of a winding type flexible printed circuit board tape transferring system according to the present invention.





FIG. 2

is an exploded view in an enlarged scale of a part of the present invention, showing the arrangement of the tape let-off wheel unit and the tape take-up wheel unit on the rack.





FIG. 3

is an exploded view in an enlarged scale of a part of the present invention, showing the arrangement of the tension control wheel unit on the rack.





FIG. 4

is an exploded view in an enlarged scale of a part of the present invention, showing the arrangement of the work wheel unit on the rack.





FIG. 5

is an exploded view in an enlarged scale of a part of the present invention, showing the arrangement of the idle wheel unit on the rack.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to

FIG. 1

, a winding type flexible printed circuit board tape transferring system in accordance with the present invention is shown comprised of a tape let-off unit


1


, two idle wheel units


5


, a tension control wheel unit


3


, at least one, for example, two work wheel unit


4


, a tape take-up wheel unit


2


, and a rack


6


.




Referring to FIG.


5


and

FIG. 1

again, the idle wheel units


5


are mounted on the rack


6


near two opposite lateral sides and adapted to guide the flexible film tape


7


from the let-off wheel


10


to the take-up wheel


20


, each comprised of an axle bearing


53


, a wheel axle


54


, and an idle wheel


50


. The axle bearing


53


is fixedly fastened to the rack


6


by fastening elements, for example, screws


52


, having one side


531


extended through the rack


6


. The wheel axle


54


is supported in the corresponding axle bearing


53


, having one side


542


coupled to the corresponding idle wheel


50


.




Referring to FIG.


2


and

FIG. 1

again, the tape let-off unit


1


comprises a motor


11


, a coupling


12


, an axle bearing


13


, a wheel axle


14


, and a let-off wheel


10


. The motor


11


has an output shaft


111


adapted to rotate the wheel axle


14


and the let-off wheel


10


, causing the let-off wheel


10


to let off the flexible film tape


7


, and a power line


112


connected to the frequency transformer of the control unit (not shown), which controls the speed of the motor


11


. The axle bearing


13


is fixedly fastened to the rack


6


by fastening elements, for example, screws


15


. The wheel axle


14


has one end


141


inserted through the axle bearing


13


and then coupled to the output shaft


111


of the motor


11


by the coupling


12


, and the other end


142


fastened to the let-off wheel


10


.




Referring to FIG.


3


and

FIG. 1

again, the tension control wheel unit


3


comprises a linear motor


31


, a vertical track


32


, an axle bearing


33


, a wheel axle


34


, and a tension wheel


30


. The linear motor


31


is adapted to move the axle bearing


33


and the wheel axle


34


along the vertical track


32


to the desired elevation, causing the tension wheel


30


to control the tension of the flexible film tape


7


being delivered from the let-off wheel


10


to the take-up wheel


20


. The position signal of the linear motor


31


is provided to the control unit for reference, enabling the control unit to control the speed of the tape let-off unit


1


and the tape take-up unit


2


properly. The linear motor


31


is fixedly fastened to the rack


6


by fastening elements, for example, screws


35


. The vertical track


32


comprises two parallel rails


321


fixedly fastened to the rack


6


along two long sides of the longitudinal sliding slot


61


in the rack


6


by fastening elements, for example, screws


36


, and two slides


322


respectively slidably coupled to the rails


321


. The axle bearing


33


is fixedly fastened to the slides


322


by fastening elements, for example, screws


37


, having a rear side


331


inserted through the longitudinal sliding slot


61


of the rack


6


and coupled to the reciprocating shaft


311


of the linear motor


31


. The wheel axle


34


has one end


342


coupled to the axle bearing


33


, and the other end


341


coupled to the tension wheel


30


. When starting the motor


31


to move the reciprocating shaft


311


forwards (upwards) or backwards (downwards), the axle bearing


33


is moved with the reciprocating shaft


311


upwards or downwards along the longitudinal sliding slot


61


, and therefore the tension wheel


30


and the wheel axle


34


are moved with the axle bearing


33


to adjust the tension of the flexible film tape


7


.




Referring to FIG.


4


and

FIG. 1

again, each work wheel unit


4


comprises a work wheel


40


, a coupling


42


, an axle bearing


43


, a wheel axle


44


, and a rotary encoder


41


. The flexible film tape


7


is extended from the let-off wheel


10


through the idle wheel


50


of one idle wheel unit


5


, the tension wheel


30


, the work wheel


40


of each work wheel unit


4


, and the idle wheel


50


of the other idle wheel unit


5


to the take-up wheel


20


. During forward movement of the flexible film tape


7


, the friction force between the flexible film tape


7


and the work wheel


40


forces the work wheel


40


to rotate, thereby causing the rotary encoder


41


to rotate with the work wheel


40


. The rotary encoder


41


detects the position of the flexible film tape


7


, and provides a corresponding signal to the control unit for further examination and circuit exposure control. The axle bearing


43


is fixedly fastened to the rack


6


by fastening means, for example, screws


45


. The wheel axle


44


has one end


441


inserted through the axle bearing


43


and coupled to the wheel shaft


411


of the rotary encoder


41


by the coupling


42


, and the other end


442


fastened to the work wheel


40


. The wheel shaft


411


of the rotary encoder


41


is inserted through an opening


471


of a bracket


47


at the rack


6


, and coupled to the wheel axle


44


by the coupling


42


.




Referring to

FIGS. 1 and 2

, the tape take-up wheel unit


2


comprises a motor


21


, a coupling


22


, an axle bearing


23


, a wheel axle


24


, and a take-up wheel


20


. The motor


21


has an output shaft


211


adapted to rotate the wheel axle


24


and the take-up wheel


20


, causing the take-up wheel


20


to take up the flexible film tape


7


from the let-off wheel


10


and a power line


212


connected to the frequency transformer of the control unit, which controls the speed of the motor


21


subject to the speed of the motor


11


of the tape let-off unit


1


. The axle bearing


23


is fixedly fastened to the rack


6


by fastening elements, for example, screws


25


. The wheel axle


24


has one end


241


inserted through the axle bearing


23


and then coupled to the output shaft


211


of the motor


21


by the coupling


22


, and the other end


242


fastened to the take-up wheel


20


.




During operation, the idle wheel


50


of each idle wheel unit s guides the flexible film tape


7


from the let-off wheel


10


to the take-up wheel


20


, and the tension wheel


30


controls the tension of the flexible film tape


7


. When the flexible film tape


7


passing over the shoulder


401


of the work wheel


40


of each work wheel unit


4


, the work wheel


40


is forced to rotate, thereby causing the corresponding rotary encoder


41


to rotate synchronously, so that the rotary encoder


41


accurately detect the amount of movement of the flexible film tape


7


and provides a signal indicative of the position of the flexible film tape


7


to the control unit for further examining, scanning, and circuit exposure controls. Further, the shoulder


401


of the work wheel


40


of each work wheel unit


4


forces the flexible film tape


7


to extend out in transverse direction, preventing the flexible film tape


7


from wrinkling.




Further, the idle wheel


50


of each idle wheel unit


5


, the tension wheel


30


of the tension control wheel unit


3


, and the work wheel


40


of each work wheel unit


4


are respectively comprised of a fixed wheel blade


502


,


302


or


402


and an adjustment wheel blade


503


,


303


or


403


. The fixed wheel blade


502


,


302


or


402


and the adjustment wheel blade


503


,


303


or


403


each have a wheel shoulder


501


,


301


or


401


and a wheel hub


500


,


300


or


400


. The wheel shoulders


501


,


301


or


401


support the flexible film tape


7


, keeping the middle part of the flexible film tape


7


suspended above the wheel hubs


500


,


300


or


400


. Therefore, the wheels


50


,


30


, and


40


do not touch the circuit area


71


of the flexible film tape


7


during movement of the flexible film tape


7


from the let-off wheel


10


to the take-up wheel


20


. The fixed wheel blade


502


,


302


or


402


is fixedly fastened to the respective wheel axle


54


,


34


, or


44


. The adjustment wheel blade


503


,


303


or


403


is mounted on the respective wheel axle


54


,


34


, or


44


and fixed in position by a tightening up screw


505


,


305


, or


405


. When loosened the tightening up screw


505


,


305


, or


405


, the adjustment wheel blade


503


,


303


or


403


can be moved axially along the respective wheel axle


54


,


34


, or


44


to adjust the pitch between the fixed wheel blade


502


,


302


or


402


and the adjustment wheel blade


503


,


303


or


403


subject to the width of the flexible film tape


7


to be delivered.




As indicated above, the invention achieves the following advantages:




1. When delivering the flexible film tape


7


from the let-off wheel


10


to the take-up wheel


20


, the shoulders


501


,


301


, and


401


of the wheels


50


,


30


, and


40


force the flexible film tape


7


to extend out in transverse direction, preventing the flexible film tape


7


from wrinkling.




2. The transferring system is practical to transfer a flexible film tape, which is partially wrinkled or deformed.




3. The wheels


3


,


4


, and


5


are so designed that the pitch between the respective fixed wheel blade


302


,


402


or


502


and the adjustment wheel blade


303


,


403


, and


503


is adjustable subject to the width of the flexible film tape to be transferred.




4. The transferring system is practical to transfer flexible film tapes having sprocket holes as well as flexible film tapes without sprocket holes.




A prototype of winding type flexible printed circuit board tape transferring system has been constructed with the features of FIGS.


1


˜


5


. The winding type flexible printed circuit board tape transferring system functions smoothly to provide all of the features discussed earlier.




Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.



Claims
  • 1. A winding type flexible printed circuit board tape transferring system comprising:a rack; a tape let-off wheel unit mounted on said rack, said tape let-off wheel unit comprising a let-off wheel controlled to let off a flexible printed circuit board tape; a tape take-up wheel unit mounted on said rack, said tape take-up wheel unit comprising a take-up wheel controlled to take up the flexible printed circuit board tape from said tape let-off wheel unit; two idle wheel units respectively mounted on said rack, said idle wheel units each comprising an idle wheel adapted to guide movement of the flexible printed circuit board tape from said tape let-off wheel unit toward said tape take-up wheel unit; a tension control wheel unit mounted on said rack and arranged between said idle wheel units, said tension control wheel unit comprising a tension wheel- moved to control the tension of the flexible printed circuit board tape being transferred from said tape let-off wheel unit toward said tape take-up wheel unit; and at least one work wheel unit mounted on said rack and arranged between said idle wheel units, said at least one work wheel unit each comprising a work wheel disposed in contact with the flexible printed circuit board tape being transferred from said tape let-off wheel unit toward said tape take-up wheel unit and forced to rotate upon movement of the flexible printed circuit board tape, and a rotary encoder coupled to said work wheel for synchronous rotation with said work wheel to detect the position of the flexible printed circuit board tape being transferred from said tape let-off wheel unit toward said tape take-up wheel unit and to output a signal to a control unit indicative of the position of the flexible printed circuit board tape.
  • 2. The winding type flexible printed circuit board tape transferring system as claimed in claim 1 wherein the idle wheel, tension wheel, and work wheel of each of said idle wheel units, said tension control wheel unit, and each of said at least one work wheel unit each comprise a wheel axle, a fixed wheel blade fixedly fastened to said wheel axle, an adjustment wheel blade mounted on said wheel axle and axially slidably arranged on said wheel axle in parallel to said fixed wheel blade, and a holding down screw adapted to fix said adjustment wheel blade to said wheel axle to fix the pitch between said fixed wheel blade and said adjustment wheel blade, said fixed wheel blade and said adjustment wheel blade each having a shoulder adapted to support the flexible printed circuit board tape being transferred from said let-off wheel to said take-up wheel.
  • 3. The winding type flexible printed circuit board tape transferring system as claimed in claim 2 wherein:said tape let-off wheel unit further comprises a motor fixedly mounted on said rack and controlled to rotate said let-off wheel, the motor of said tape let-off wheel unit comprising an output shaft, a wheel axle fixedly fastened to said let off wheel, an axle bearing fixedly mounted on said rack and adapted to support the wheel axle being fixedly fastened to said let-off wheel, and a coupling, which couples the wheel axle at said let-off wheel to the output shaft of the motor of said tape let-off wheel unit for enabling motor of said tape let-off wheel unit to rotate said let-off wheel; said tape take-up wheel unit further comprises a motor fixedly mounted on said rack and controlled to rotate said take-up wheel, the motor of said tape take-up wheel unit comprising an output shaft, a wheel axle fixedly fastened to said take-up wheel, an axle bearing fixedly mounted on said rack and adapted to support the wheel axle being fixedly fastened to said take-up wheel, and a coupling, which couples the wheel axle at said take-up wheel to the output shaft of the motor of said tape take-up wheel unit for enabling motor of said tape take-up wheel unit to rotate said take-up wheel; said idle wheel units each further comprise an axle bearing fixedly mounted on said rack and adapted to support the wheel axle of the respective idle wheel unit for enabling the idle wheel of the respective idle wheel unit to be rotated upon movement of the flexible printed circuit board tape from said let-off wheel toward said take-up wheel; said tension control wheel unit further comprises a linear motor fixedly mounted on said rack and adapted to move said tension wheel vertically, said linear motor comprising a vertically extended reciprocating shaft, a vertical track fixedly mounted on said rack, and an axle bearing supporting the wheel axle of said tension wheel on said track and moved with said reciprocating shaft along said vertical track to control the elevational position of said tension wheel; said at least one work wheel unit each further comprises an axle bearing fixedly mounted on said rack and adapted to support the wheel axle of the work wheel of the respective work wheel unit, and a coupling, which couples the axle wheel of the work wheel of the respective work wheel unit to the rotary encoder of the respective work wheel unit for enabling the work wheel of the respective work wheel unit to rotate the rotary encoder of the respective work wheel unit upon movement of the flexible printed circuit board tape from said let-off wheel toward said take-up wheel.
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Number Name Date Kind
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2958477 James et al. Nov 1960 A
2985396 Johnson May 1961 A
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