WO1996010838A1

WO1996010838A1 - Apparatus and method for bonding tape

Info

Publication number: WO1996010838A1
Application number: PCT/JP1995/001964
Authority: WO
Inventors: Hiroaki Sakai
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 1994-09-30
Filing date: 1995-09-28
Publication date: 1996-04-11
Also published as: KR100285171B1; TW347482B; KR970706601A

Abstract

An apparatus for bonding an anisotropically electroconductive tape (2) onto a substrate (4) includes a tape supply unit (21) for supplying a length of leader tape (1) having a length of anisotropically electroconductive tape (2) bonded to one of opposite surfaces thereof; a tape transport unit (22) for transporting the length of leader tape (1) so supplied in a transport direction (M); a cutting unit (23) for cutting only the length of anisotropically electroconductive tape (2) to provide an anisotropically electroconductive tape segment (107) of a predetermined length; a substrate positioning unit (10) for positioning the substrate (4) to which the anisotropically electroconductive tape segment (107) is to be bonded; and a tape applicator unit (19) for pressing the anisotropically electroconductive tape segment (107) against the substrate (4) to bond the former to the latter. The cutting unit (23) includes two cutter blades (93, 94) for forming respective incisions in the length of anisotropically electroconductive tape (2) and a length of adhesive tape used to remove a piece of anisotropically electroconductive tape (2) bound between the incisions to leave a space of separation (95) dividing the length of anisotropically electroconductive tape (2) into the anisotropically electroconductive tape segment (107) and the remaining anisotropically electroconductive tape.

Description

DESCRIPTION APPARATUS AND METHOD FOR BONDING TAPE Field Of Technology

The present invention relates to an apparatus for bonding an _* anisotropicaily electroconductive tape onto a substrate. Background Art

It is a recent trend to use an anisotropicaily electroconductive tape to secure an electronic component part such as, for example, a TCP (tape carrier package) onto one or more electrodes on a substrate such as, for example, a liquid crystal panel. The anisotropicaily electroconductive tape is generally bonded to one of opposite surfaces of a backing tape (also referred to as a leader tape or a separator tape) and is wound around a supply reel together with the backing tape.

When the electronic component part is to be mounted on the sub¬ strate, the anisotropicaily electroconductive tape together with the backing tape is drawn out from the supply reel towards a work or mounting station where the anisotropicaily electroconductive tape is registered with the substrate so as to assume a position immediately above one or more electrodes on the substrate. After this registration, a pressure applying tool is driven so as to apply a pressure to the other of the opposite surfaces of the backing tape to permit the aniso¬ tropicaily electroconductive tape to be urged and bonded to the electrodes on the substrate.

The above discussed tape bonding method hitherto employed will be discussed in more detail with particular reference to Fig. 36. In Fig. 36, reference numeral 101 represents a positioning table for positioning and registering the substrate, shown in the form of a liquid crystal panel 102, relative to a pressure applying tool 109 movable between elevated and lowered positions along a longi¬ tudinal axis C of a drive shaft rigid with the pressure applying tool 109. A length of anisotropicaily electroconductive tape 105 bonded to a corresponding length of backing tape 104 and wound around a supply reel is drawn out from the supply reel in a direction, indicated by the arrow M, towards a mounting station defined between the pressure applying tool 109, then held at the elevated position, and the positioning table 101 then supporting the liquid crystal panel 102 thereon. The prior art apparatus of a similar kind is so designed that prior to arrival of a leading end of the anisotropicaily electroconductive tape 105 at the mounting station, and at a cutting station preceding the mounting station, generally V-sectioned incisions 105a spaced from each other a distance chosen to be equal to the length L1 to which the anisotropicaily electroconductive tape 105 is desired to be cut can be successively formed in the length of anisotropicaily electroconduc¬ tive tape 105, but not in the length of backing tape 104, to thereby provide a plurality of anisotropicaily electroconductive tape segments remaining bonded in series to the length of backing tape 104. The pressure applying tool 109 is therefore of a generally rectangular configuration having a pressure applying surface of a length equal to the desired cutting length L1 .

With the prior art apparatus, the length of anisotropicaily electro¬ conductive tape 1 05 together with the length of backing tape 104 is transported past the cutting station to the mounting station where the foremost one of the anisotropicaily electroconductive tape segments has its lengthwise intermediate point aligned with the longitudinal axis C of the pressure applying tool 109.

Thereafter, the pressure applying tool is driven towards the lowered position immediately above one or more electrodes of the liquid crystal panel 102 then resting on and properly positioned by the positioning tape 101 , to thereby mount and bond the corresponding anisotropicaily electroconductive tape segment to the electrodes of the liquid crystal panel 102.

In general, most of the substrates such as, for example, liquid crystal panels 102 are of a substantially rectangular shape and electrodes onto which the individual anisotropicaily electroconductive tape segments are bonded by application of a pressure are patterned in a comb-like shape along each of long and short sides of the substrate. Accordingly, depending on which one of the sides of the individual substrate must have the anisotropicaily electroconductive tape segment bonded thereto, a change must be made between the anisotropicaily electroconductive tape segment for mounting on the long side of the substrate must and the anisotropicaily electroconductive tape segment for mounting on the short side of the substrate.

With the prior art apparatus, such change is accomplished by a selective use of one of pressure applying tools 109 having different lengths to suit to the respective anisotropicaily electroconductive tape segments for mounting on the long and short sides of the substrate. The prior art apparatus does therefore require complicated and time-consuming procedures to exercise a positioning of the selected pressure applying tool and/or an adjustment in parallelism of the pressure applying surface. Disclosure Of The Invention

Accordingly, the present invention is intended to provide an improved tape bonding apparatus which does not require a replacement of the pressure applying tool even though a change occurs in length of the side onto which the anisotropicaily electroconductive tape segment is desired to be bonded.

In order to accomplish the foregoing object, the present invention provides an apparatus for bonding an anisotropicaily electroconductive tape onto a substrate, which comprises a positioning table for positioning the substrate, a leader tape drawing mechanism for drawing a length of leader tape having one surface to which a length of anisotropicaily electroconductive tape is bonded, in a direction of transport, a cutter operable to cut only the length of anisotropicaily electroconductive tape, having been drawn together with the length of leader tape, to provide an anisotropicaily electroconductive tape segment of a required length, a pressure applying tool for pressing through the leader tape the anisotropicaily electroconductive tape segment to bond the latter to the substrate, a leader tape peeling mechanism for peeling a portion of the leader tape off from the aniso¬ tropicaily electroconductive tape segment, and a leader tap feed mechanism for feeding that portion of the leader tape peeled off from the anisotropicaily electroconductive tape segment in the transport direction. This apparatus of the present invention is so operable that one end of the pressure applying tool upstream of the transport direction is aligned with a trailing end of the anisotropicaily electroconductive tape segment with respect to the transport direction before such anisotropicaily electroconductive tape segment is pressed to bond to the substrate. According to the present invention, in the event that the desired cutting length to which the length of anisotropicaily electroconductive tape is desired to be cut is changed, the pressure applying tool need not be changed for a different size of the pressure applying tool. Specifically, since regardless of the size of the pressure applying tool, the upstream end of the pressure applying tool with respect to the transport direction is at all times aligned with the trailing end of the anisotropicaily electroconductive tape cut from the remaining length of anisotropicaily electroconductive tape and, therefore, there is no possibility that the leading end of the remaining length of anisotropicaily electroconductive tape following the anisotropicaily electroconductive tape segment may be erroneously bonded to the substrate. Accordingly, even though the desired cutting length to which the length of anisotropicaily electroconductive tape is desired to be cut is varied, no replacement of the pressure applying tool with a different size of a similar pressure applying tool is needed, making it possible to increase the tape bonding efficiency. Brief Description Of The Drawings

This and other objects and features of the present invention will become clear from the following description taken in conjunction with a preferred embodiment thereof with reference to the accompanying drawings, in which like parts are designated by like reference numerals and in which:

Fig. 1 is a schematic perspective view of a tape bonding apparatus according to the present invention;

Fig. 2 is a schematic perspective view, on an enlarged scale, of a substrate positioning unit and a tape applicator unit both employed in the tape bonding apparatus;

Fig. 3 is a schematic side view of the substrate positioning unit and the tape applicator unit shown in Fig. 2;

Fig. 4 is a schematic perspective view, on an enlarged scale, of a chuck employed in the tape bonding apparatus;

Figs. 5 to 8 are schematic front elevational views of the chuck in different operative positions, respectively;

Fig. 9 is a schematic front elevational view of the tape bonding apparatus of the present invention;

Fig. 10 is a schematic sectional view of a leader tape take-up unit employed in the tape bonding apparatus of the present invention;

Fig. 1 1 is a schematic front elevational view, on an enlarged scale, of a tape cutting unit employed in the tape bonding apparatus of the present invention;

Figs. 12 to 17 are schematic sectional view of a suction block shown in relation to the tape cutting unit, showing the sequence of cutting operation with the tape cutting unit held at different operative positions, respectively;

Fig. 18 illustrates a block diagram of a control system employed in the tape bonding apparatus of the present invention;

Figs. 19 to 35 are schematic diagrams showing the sequence of operation of the tape bonding apparatus of the present invention with the various component parts held at different operative positions, respectively; and Fig. 36 is a schematic diagram showing a pressure applying tool employed in the prior art apparatus. Best Mode For Carrying Out The Invention

Referring first to Figs. 1 to 4, the tape bonding apparatus shown therein comprises a machine bench 9 including a substrate positioning unit 10 mounted thereon for positioning a substrate 4. The substrate positioning unit 1 0 includes an X-table 1 1 adapted to be driven by an X-motor 12 in a direction shown by the arrow X, a Y-table 1 3 mounted above the X-table 1 1 and adapted to be driven by a Y-motor 14 in a direction shown by the arrow Y and at right angles to the direction X, and a θ-table 1 5 mounted above the Y-table 1 3 for turning the substrate 4 in a horizontal plane. The machine bench 9 carries handlers 1 6 and 1 7 positioned on respective sides of the substrate positioning unit 10 and has an upright support bed 9a rigidly mounted thereon so as to extend substantially parallel to the direction M of transport of a length of anisotropicaily electroconductive tape 2 as will subsequently be described. The machine bench 9 also includes a top carrier plate 1 8 mounted thereon by means of a plurality of columns or any suitable support legs so as to overlay the substrate positioning unit 10. A tape applicator unit 1 9 as will be described later is supported immediately above the substrate positioning unit 10 by means of a frame 20 secured from below to the top carrier plate 1 8..

The apparatus also comprises, in the order from an upstream side towards a downstream side with respect to the direction of transport of the length of anisotropicaily electroconductive tape 2, a tape supply unit 21 from which a length of leader tape 1 having the anisotropicaily electroconductive tape 2 bonded thereto is supplied; a tape cutting unit 23 for successively forming transverse spaces of separation, as will be described later, in the length of anisotropicaily electroconductive tape 2 to thereby provide anisotropicaily electroconductive tape segments; a tape end detecting sensor 26 in the form of a height measuring sensor for detecting one end of the anisotropicaily electroconductive tape segment as will be described later; a tape transport unit 22 for transporting the leader tape 1 in the direction M of transport along a predetermined transport path; and a leader tape take-up unit 24 for taking up the length of leader tape 1 into a leader tape recovery box 25.

As best shown in Figs. 2 and 3, the frame 20 is of a shape similar to the shape of an inverted figure of "L", including a horizontal wall rigidly secured from below to the top carrier plate 18 and also including a vertical wall. Guide rails 32 and 33 are secured the vertical wall of the frame 20 so as to extend at right angles to the direction M of transport and spaced a distance from each other in a direction conforming to the transport direction M. A generally U-shaped slide plate 34 carrying a pressure applying tool 35 secured to a horizontal portion thereof is mounted on the guide rails 32 and 33 for sliding motion therealong so that the pressure applying tool 35 can be selectively lowered and lifted. A pressure applying cylinder 36 including a downwardly oriented piston rod 37 is secured to the vertical wall of the frame 20 at a location intermediate between the guide rails 32 and 33 with a free end of said piston rod 37 connected to the slide plate 34. Thus, it will readily be seen that, when the piston rod 37 is projected or retracted relative to the pressure applying cylinder 36, the pressure applying tool 35 can be lowered or lifted, respectively.

As shown in Figs. 2, 3 and 9, a plurality of, for example, two, drive cylinders 28 each having a piston rod 28a are mounted atop the machine bench 9 and below the tape applicator unit 19 with a norizontal support plate 27 mounted on respective free ends of the piston rods 28a. The tape supply unit 21 , the tape end detecting sensor 26, the leader tape take-up unit 24 and the leader tape recovery box 25, all referred to above, are mounted on this horizontal support plate 27 for simultaneous movement up and down together with the horizontal support plate 27. The tape supply unit 21 includes a cassette mounting plate 29 on which a tape supply cassette 30 accommodating therein a leader tape supply reel 57 around which the length of leader tape 1 is wound and from which the leader tape 1 is drawn outwardly is detachably mounted. This tape supply unit 21 also . includes a tape suction block 31 disposed at a location spaced a certain distance downstream from the tape supply cassette 30 on the cassette mounting plate 29 with respect to the transport direction M. This tape suction block 31 has a perforated undersurface adapted to suck the leader tape 1 to keep the latter so as to extend horizontally and, for this purpose, the suction block 31 has a suction passage 31 a (Figs. 12 to 17) of a generally comb-like configuration defined therein which opens outwardly through a plurality of suction ports opening at the undersurface thereof.

The tape transport unit 22 positioned below the substrate positioning unit 10 includes a chuck drive table 39 extending a distance in a direction along the transport direction M and a chuck 38 mounted on the chuck drive table 39 for movement along the chuck drive table 39 in the direction X when a chuck drive motor 40 is driven. The substrate positioning unit 10 includes, as best shown in Fig. 2, a suction retainer 41 mounted on the 0-table 1 5, adapted to be driven by a θ-table 42, for sucking a central portion of the undersurface of the substrate 4 to support the latter in position.

The details of each of the chuck 38 and the chuck drive table 39 will now be described with particular reference to Fig. 4. As shown therein, the chuck drive table 39 is comprised of a generally elongated cover 39 of a generally square cross-section having a slid defined in a top wall thereof so as to extend lengthwise thereof, a guide rail 44 positioned inside the elongated cover 39 and fixedly mounted on a bottom wall thereof so as to extend lengthwise thereof, a slider 45 positioned inside the elongated cover 39 and slidably mounted on the guide rail 44, a carrier block 46 fixedly mounted on the slider 45 and having a through-hole defined therein so as to extend in a direction parallel to the direction X, and a ball nut 47 secured to the carrier block 46 in alignment with the through-hole defined in such carrier block 46. A bearing 49 forming a part of the chuck 38 is fixedly mounted on the carrier block 46 and positioned outside the elongated cover 43.

The bearing 49 has a chuck cylinder 51 and a lock cylinder 52 carried thereby so as to protrude therefrom towards the tape transport path immediately above the upright support bed 9a. The chuck cylinder 51 includes drive pieces 51 a and 51 b movable in a direction close to and away from each other and nipping rollers 53 and 54 carried respectively by the drive pieces 51 a and 51 b for movement together therewith in a manner as will be described later. These nipping rollers 53 and 54 cooperate with each other to nip a portion of the length of leader tape 1 therebetween as shown in Fig. 4 when the drive pieces 51 a and 51b are driven in a direction close to each other.

On the other hand, the lock cylinder 52 includes drive pieces 52a and 52b movable in a direction close to and away from each other and lock fingers 55 and 56 carried respectively by the drive pieces 52a and 52b for movement together therewith in a manner as will be similarly described later. Each of the lock fingers 55 and 56 is of a shape having one end secured to the associated drive piece 52a or 52b and the opposite end terminating above or below the nipping roller 53 or 54, a generally intermediate portion thereof having been bent perpendicularly. The lock fingers 55 and 56 cooperate with each other in such a manner that, when the drive pieces 52a and 52b are driven close to each other, the lock fingers 55 and 56 clamp therebetween the nipping rollers 53 and 54 then held in position to nip that portion of the length of leader tape 1. When the nipping rollers 53 and 54 are so clamped by the lock fingers 55 and 56, the nipping rollers 53 and 54 are unable to rotate freely and, therefore, the length of leader tape 1 is constrained as nipped by and between the nipping rollers 53 and 54. It is to be noted that the bearing 49 supports the chuck cylinder 51 and the lock cylinder 52 so as to permit the chuck and lock cylinders 51 and 52 to be turned about an axis coaxial with the longitudinal axis of the nipping roller 53 then moved close to the nipping roller 54. A chuck rotating cylinder 50 in the form , of a rotary cylinder is utilized to turn the chuck and lock cylinders 51 and 52 simultaneously about the axis coaxial with the longitudinal axis of the nipping roller 53 then moved close to the nipping roller 54.

The operation of the chuck 38 will now be described with reference to Figs. 5 to 8. It is to be noted that a condition of Fig. 5 in which both of the chuck and lock cylinders 51 and 52 are held at an "open" position with the nipping rollers 53 and 54 separated away from each other and the lock fingers 55 and 56 similarly separated away from each other is referred to as the chuck 38 being held at a release position and that a condition of Fig. 6 in which both of the chuck and lock cylinders 51 and 52 are held at a "closed" position with the nipping rollers 53 and 54 moved close to each other and also with the lock fingers 55 and 56 moved similarly close to each other is referred to as the chuck 38 being held at a clamp position. So long as the chuck 38 is in the release position as shown in Fig. 5, the nipping rollers 53 and 53 are separated away from each other and hence away from the length of leader tape 1 and, therefore, the chuck 38 is free to move relative to the length of leader tape 1 .

However, when the chuck 38 is brought into the clamp position as shown in Fig. 6, the nipping rollers 53 and 54 are brought close to each other with that portion of the length of leader tape 1 nipped therebetween and retained in position by the lock fingers 55 and 56 then driven close to each other and, therefore, the length of leader tape 1 is constrained in position without being moved lengthwise thereof. Subsequent movement of the chuck 38 in the transport direction M results in pull of the length of leader tape 1 in such transport direction M. When the leader tape 1 is desired to be peeled off from the length of anisotropicaily electroconductive tape 2, the chuck rotating cylinder 50 is driven to turn the chuck and lock cylinders 51 and 52 90° counterclockwise about the axis coaxial with the longitudinal axis of the nipping roller 53, allowing that portion of the length of leader tape 1 to be bent to assume a shape substantially similar to the shape of a figure ^HS" as shown in Fig. 7. Thereafter, the lock cylinder 52 is brought into the open position while the chuck cylinder 51 remains held in the closed position, and starting from the condition shown in Fig. 7, the chuck 38 is moved in a direction counter to the transport direction M. By so doing, a portion of the leader tape 1 which extends downstream of the nipping roller 54 with respect to the transport direction M can be upwardly shifted relative to another portion of the leader tape 1 which extends upstream of the nipping roller 53 with respect to the transport direction M. Starting from the condition shown in Fig. 7 and when the chuck 38 is subsequently brought to a position adjacent the substrate 4 resting on the suction retainer 41 , that portion of the leader tape 1 extending downstream of the nipping roller 54 with respect to the transport direction M is shifted upwardly relative to the length of anisotropicaily electroconductive tape 2 and, therefore, the leader tape 4 can be peeled off from the anisotropicaily electroconductive tape segment then bonded to the substrate 4.

With particular reference to Fig . 10, the details of the leader tape take- up unit 24 will now be described. The leader tape take-up unit 24 comprises a housing 60 enclosing various component parts of the leader tape take-up unit 24 as will be subsequently described. The housing 60 has a front upright wall provided with dual bearings 63. The leader tape take-up unit 24 also comprises feed rollers 58 and 59 rigidly mounted on horizontally extending shafts 61 and 62 for rotation together therewith, respectively, and cooperable with each other to feed the length of leader tape 1 while nipping it therebetween. The shafts 61 and 62 rotatably extend through and are in turn supported by the bearings 63, and drums 64 and 65 are mounted on respective ends of the shafts 61 and 62 remote from the associated feed rollers 58 and 59 for rotation together therewith. A feed motor 66 housed within the housing 60 and installed on the bottom thereof is drivingly coupled with the shaft 62 through an endless drive belt 68 drivingly trained between a drive pulley 67 on a motor shaft of the feed motor 66 and a driven pulley 69 that is coupled with the shaft 62 through a friction clutch 70. The friction clutch 70 is so designed that only a predetermined quantity of torques can be transmitted from the feed motor 66 to the shaft 62. Within the housing 60, a lock cylinder 71 is installed at the bottom thereof, having a piston rod 72 oriented upwardly. This piston rod 72 has upper and lower friction pads 73 and 74 secured thereto so as to protrude transverse therefrom with the friction pad 73 positioned between the drums 64 and 65 and with the friction pad 74 positioned immediately below the drum 65. When the friction pads 73 and 74 are brought into contact with the drums 64 and 65, respectively, the shafts 61 and 62 then rotating can be brought to a halt and, consequently, feed of the length of leader tape 1 by rotation of the feed rollers 58 and 59 in respective directions counter to each other can be interrupted.

Hereinafter, the details of the tape cutting unit 23 will be described with particular reference to Fig. 1 1 . A plurality of sleeve-like guide legs, two of which are shown by 76 in Fig. 1 1 , are fixedly mounted atop the machine bench 9 at a location adjacent to and downstream of the tape supply unit 21 . The guide legs 76 slidably receive therein corresponding rods 77 rigidly secured to and extending downwardly from an upright frame 78 to permit the latter to be movable up and down. This vertical movement of the upright frame 78 with the rods 77 guided within the corresponding guide legs 76 is effected by a tape cutting cylinder 75 including a cylinder body fixedly mounted atop the machine bench 9 and a piston rod coupled with the upright frame 78. The tape cutting unit 23 comprises an adhesive tape supply reel 80 mounted on the upright frame 78 for rotation about an axis perpendicular to the upright frame 78, and an adhesive tape take-up reel 81 mounted on the upright frame 78 for rotation about an axis parallel to the axis of rotation of the adhesive tape supply reel 80. A length of adhesive tape 79 having adhesive-coated and non- coated surfaces opposite to each other extends from the adhesive tape supply reel 80 to the adhesive tape take-up reel 81 by way of guide rollers 82, 83 and 84 all rotatably mounted on the upright frame 78, said guide rollers 83 and 84 being disposed on the upright frame so that a portion of the length of adhesive tape 79 extending between those guide rollers 83 and 84 may extend substantially horizon¬ tally below the tape suction block 31 and across a cutting station. It is to be noted that the length of adhesive tape 79 has its adhesive-coated surface oriented upwardly towards the tape suction block 31 as it travels across the cutting station by the reason which will be described later.

The adhesive tape take-up reel 81 is drivingly coupled with a tape take-up motor 86 by means of a substantially endless belt 87 so that the length of adhesive tape 79 can travel from the supply reel 80 towards the take-up reel 81 by way of the guide rollers 82, 83 and 84 across the cutting station. Extending immediately below that portion of the length of adhesive tape 79 extending between the guide rollers 83 and 84 is a back-up guide plate 85 secured to an upper portion of the upright frame 78 for the support from below of that portion of the length of adhesive tape 79 with the adhesive-coated surface thereof oriented upwardly, i.e., in a direction counter to the back-up guide plate 85.

A slider 89 having a bracket 90 secured thereto is slidably engaged on a vertical guide 88 which is secured to the upright frame 78 at a location below the back-up guide plate 85 so as to extend perpendicular thereto . The bracket 90 carries a cutter fixture 91 mounted atop the bracket 90 and is normally urged upwardly by a spring 92 interposed between the bracket 90 and the upright frame 78. A pair of cutter blades 93 and 94 each having a width substantially equal to or slightly greater than the width of the length of anisotropicaily electroconductive tape 2 are fixedly mounted on the cutter fixture 91 so as to extend upwardly one on each side of that portion of the length of adhesive tape 79 extending between the guide rollers 83 and 84. Each of the cutter blades 93 and 94 is of a type having a free end remote from the cutter fixture 91 which is sharpened over the entire width thereof conforming to the widthwise direction of the length of anisotropicaily electroconductive tape 2.

The tape cutting unit 23 of the above described structure operates in the following manner which will now be described with reference to Figs. 1 2 to 1 7.

Prior to an actual cutting operation taking place, the suction passage 31 a in the tape suction block 31 is evacuated by a suction device 104 (Fig . 1 8) so that a portion of the length of anisotropicaily electroconductive tape 2 together with a corresponding portion of the leader tape 1 which extends immediately below the tape suction block 31 can be sucked onto the perforated undersurface of such tape suction block 31 to keep such portion of the anisotropicaily electroconductive tape 2 horizontally as shown in Fig. 1 2.

After that portion of the anisotropicaily electroconductive tape 2 has been retained by the tape suction block 31 together with that corresponding portion of the leader tape 1 , and as shown in Fig. 1 3, the tape cutting cylinder 75 is driven to elevate the upright frame 78, causing the spaced cutter blades 83 and 84 to plunge into that portion of the anisotropicaily electroconductive tape 2, but not into that portion of the leader tape 1 . While the cutter blades 83 and 84 having plunged into that portion of the anisotropicaily electroconductive tape 2 in the manner described above, the upright frame 79 is further elevated. However, since the cutter blades 93 and 94 are normally biased upwardly by the spring 92 together with the bracket 90 as hereinbefore described, further elevation of the upright frame 78 takes place independently of the cutter blades 93 and 93, allowing the latter to remain in position having plunged into that portion of the anisotropicaily electroconductive tape 2 while the spring 92 is pulled axially outwardly.

During the further upward movement of the upright frame 78, that portion of the adhesive tape 79 backed up by the back-up guide plate 85 rigid with the upright frame 70 is shifted upwardly together with the upright frame 78 until the adhesive-coated surface of that portion of the adhesive tape 79 is brought into contact with a piece of anisotropicaily electroconductive tape 2 delimited between the cutter blades 93 and 94 then plunged into that portion of the anisotropicaily electroconductive tape 2 retained by the suction block 31 as shown in Fig. 14.

Thereafter, the tape cutting cylinder 75 is driven to lower the upright frame 78 accompanied by a corresponding downward shift of that portion of the adhesive tape 79 backed up by the back-up guide plate 85, the piece of anisotro¬ picaily electroconductive tape 2 having been cut by the cutting blades 93 and 94 and sticking to the adhesive-coated surface of the adhesive tape 79 is removed from the leader tape 1 as shown in Fig. 15, leaving in the length of anisotropicaily electroconductive tape 2 a space of separation 95 corresponding in length to the spacing between the cutter blades 93 and 94. Further lowering of the upright frame 78 results in a corresponding downward shift of the cutter blades 93 and 94 away from the suction block 31 as shown in Fig. 16 in readiness for feed of the length of anisotropicaily electroconductive tape 2 together with the corresponding length of leader tape 1 in the transport direction M, thereby completing one cycle of tape cutting.

As shown in Fig. 17, once the length of anisotropicaily electro¬ conductive tape is fed in the transport direction M a distance away from the cutting station, but before the separation space 95 formed in the length of anisotropicaily electroconductive tape 2 leaves completely away from the suction block 31 , the tape end detecting sensor 26 detects passage of the separation space 95 to measure the position of leading and trailing ends of the separation space 95 with respect to the transport direction M.

Thus, it will readily be understand that in the practice of the present invention no heating means is employed to cut the length of anisotropicaily electroconductive tape, but the separation space 95 is formed therein by means of the cutter blades 93 and 94. Accordingly, the trailing end of the segment of anisotropicaily electroconductive tape 2 that has been separated from the remaining length of anisotropicaily electroconductive tape 2 by the cutter blades 93 and 94 and the leading end of the segment of anisotropicaily electroconductive tape 2 which would be subsequently formed during the next succeeding cutting cycle represent a beautifully cut edge. This is in contrast to a burn-out technique in which the heating means is used to burn a portion of the length of anisotropicaily electroconductive tape to provide a similar separation space and which is apt to result not only in the separation space of an irregular shape, but in modification in quality of at least cut regions of the anisotropicaily electroconductive tape.

Fig. 18 illustrates a block diagram of a Control system employed in the tape bonding apparatus of the present invention. In Fig. 18, reference numeral 96 represents a heater built in the pressure applying tool 35 for heating the latter; reference numeral 97 represents a heater drive circuit for energizing the heater 96; reference numeral 98 represents a cylinder drive unit for driving various cylinders such as the lock cylinder 52 and so on; reference numeral 99 represents an axle control unit for driving various motors such as the chuck drive motor 40 and so on; reference numeral 100 represents a main control unit such as, for example, a central processing unit (CPU); reference numeral 101 represents a storage unit comprised of various memories for the storage of data to be referred to by the main control unit 100, particularly those including the desired cutting length L1 , dis¬ tances D1 , D2 and D3 as will be discussed later, and the spacing C between the cutter blades 93 and 94; reference numeral 102 represents a height calculating unit 102 for processing an output from the tape end detecting sensor 26 and for outputting height information descriptive of the presence or absence of the anisotropicaily electroconductive tape 2; reference numeral 103 represents an input/output control unit for controlling inputs and/or outputs; reference numeral 105 represents a tape supply control unit for controlling the tape supply unit 21 ; and reference numeral 106 represents a handler control unit for controlling the operation of the handlers 1 6 and 17.

With the tape bonding apparatus constructed as hereinbefore described, it operates in the following manner which will now be described with reference to Figs. 1 9 to 35. In describing the operation of the tape bonding apparatus of the present invention, it is assumed that the length of anisotropicaily electroconductive tape 2 is desired to be cut to provide a segment of anisotropicaily electroconductive tape, identified by 107, of a length equal to the desired cutting length L1 for bonding on the substrate 4.

Referring first to Fig. 1 9, there is shown an initial condition of the tape bonding apparatus. The tape bonding apparatus has all fixed in position a cutting position P3 at which the cutter blade 94 is positioned; a sensing position PO spaced a distance D3 from the cutting position P3 in a downstream direction with respect to the transport direction M and where the tape end detecting sensor 26 detects passage of an end of the length of anisotropicaily electroconductive tape; a tape end position P1 spaced a distance D1 from the sensing position PO from the sensing position PO in a downstream direction with respect to the transport direction M and where an upstream end of the anisotropicaily electroconductive segment 107 with respect to the transport direction M should assume when such anisotropicaily electroconductive segment 107 is to be pressed by the pressure applying tool 35 onto the substrate 4; and a chuck retracted position P2 spaced a distance D2 from the sensing position PO in a downstream direction with respect to the transport direction M and defined at a location downstream of the pressure applying tool 35 with respect to the transport direction M.

During the initial condition shown in Fig. 19, a leading portion of the leader tape 1 is drawn to the leader tape take-up unit 24, it being however to be noted that no anisotropicaily electroconductive tape is bonded to that leading portion of the leader tape 1 . Also, the nipping rollers 53 and 54 of the chuck 38 are then held at the chuck retracted position P2.

As shown in Fig. 20, the nipping rollers 53 and 53 of the chuck 38 are brought to a position below the pressure applying tool 35 and are reciprocatingly moved, while the chuck 38 are repeatedly brought into the release position as shown in Fig. 5 and the clamp position as shown in Fig. 6 one at a time, to thereby pull the length of leader tape 1 in the transport direction until the tape end detecting sensor 26 detects passage of the leading end of the length of anisotro¬ picaily electroconductive tape 4. During this time, the leader tape take-up unit 24 performs a feeding operation in synchronism with a tape drawing operation performed by the chuck 38 in the manner described above.

Then, as shown in Fig. 21 , when the tape end detecting sensor 26 detects the passage of the end of the length of anisotropicaily electroconductive tape 2, the chuck 38 is brought into the release position with the nipping rollers 53 and 54 separated away from each other and is then moved to a predetermined position E, spaced a distance DE1 ( = D2 - D1 - LI ) from the sensing position PO as shown in Fig. 22, where the chuck 38 is brought into the clamp position with the nipping rollers 53 and 54 closed with each other to nip- the leader tape 1 .

Thereafter, starting the condition shown in Fig. 22, the chuck 38 nipping the leader tape 1 pulls the latter a distance A1 ( = L1 - D3) as the chuck 38 is moved in a downstream direction with respect to the transport direction M until a cutting edge of the cutting blade 94 aligns with a portion of the length of anisotropicaily electroconductive tape 2 spaced a distance equal to the desired cutting length LI inwardly from the leading end of the length of anisotropicaily electroconductive tape 2 as shown in Fig. 23.

Thereafter, the tape cutting operation which has been described in detail with reference to Figs. 12 to 16 is carried out. As a result of the tape cutting operation, the separation space 95 is formed in the length of anisotropicaily electroconductive tape 2 to provide the anisotropicaily electroconductive tape segment 107 on a downstream side of the cutting blade 94 with respect to the transport direction M. As discussed with reference to Figs. 12 to 16, the trailing end of the anisotropicaily electroconductive tape segment 107 that has been separated from the remaining length of anisotropicaily electroconductive tape 2 and the leading end of the remaining length of anisotropicaily electroconductive tape 2 will not be deformed irregularly.

After the tape cutting operation, and as shown in Fig. 26, the leader tape 1 is again fed by the chuck 38 including the nipping rollers 53 and 54 and the leader tape take-up unit 24 in a manner similar to that described hereinabove until the tape end detecting sensor 26 detects passage of the separation space 95, specifically arrival of the leading end of the remaining length of anisotropicaily electroconductive tape 2 separated from the anisotropicaily electroconductive tape segment 107 at the sensing position. Upon detection of the arrival of the leading end of the remaining length of anisotropicaily electroconductive tape 2 at the sensing position, information on the distance x, shown in Fig. 26, over which the leading end of the remaining length of anisotropicaily electroconductive tape 2 has been moved in the transport direction M from a position aligned with the cutting blade 93 is stored in the storage unit 101.

The length of leader tape 1 carrying the length of anisotropicaily electroconductive tape 2 including the anisotropicaily electroconductive tape segment 107 is further moved downstream by movement of the chuck 38 in the transport direction until the trailing end of the anisotropicaily electroconductive tape segment 107, spaced by the separation space 95 from the remaining length of anisotropicaily electroconductive tape 2, is brought into alignment with the tape end position P1 as shown in Fig. 27. After this alignment, and as shown in Fig.

28, the cylinders 28 are driven to lower the horizontal support plate 27 togethe. with those component parts (the tape supply unit 21 , the tape end detecting sensor

26, the leader tape take-up unit 24 and the leader tape recovery box 25 enclosed by the single-dotted lines, causing the anisotropicaily electroconductive tape segment 107 to be seated onto the substrate 4.

After the anisotropicaily electroconductive tape segment 1 7 has been seated onto the substrate 4 in the manner described above, and as shown in Fig.

29, the pressure applying cylinder 36 is driven to lower the pressure applying tool 35 to apply a pressure through the leader tape 1 to the anisotropicaily electro¬ conductive tape segment 107 to cause the latter to be bonded to the substrate 4. At this time, in view of the presence of the separation space 95 between the anisotropicaily electroconductive tape segment 107, then bonded to the substrate

4, and the remaining length of anisotropicaily electroconductive tape 2, there is no possibility that at least the leading end of the remaining length of anisotropicaily electroconductive tape 2 may be erroneously bonded to the substrate 4 even though the accuracy of feed of the leader tape 1 and the positioning accuracy of the pressure applying tool 35 are low to some extent.

Thereafter, the pressure applying tool 35 is elevated by driving the pressure applying cylinder 36 and the chuck 38 is rotated counterclockwise about the longitudinal axis of the nipping roller 53 by driving the chuck rotating cylinder 50, thereby bringing the chuck 38 in a condition ready to peel the leader tape 1 away from the anisotropicaily electroconductive tape segment 107 as shown in

Figs. 7 and 30. While the chuck 38 is retained in that ready-to-peel condition, the chuck 38 is moved upstream with respect to the transport direction as shown in Fig. 31 , thereby peeling the length of leader tape 1 completely away from the anisotropicaily electroconductive tape segment 107. At this time, rotation of the feed rollers 58 and 59 of the leader tape take-up unit 24 are inhibited to thereby avoid any possible withdrawal of that portion of the length of leader tape 25 which has been recovered into the leader tape recovery box 25.

Upon complete removal of that portion of the leader tape 1 from the anisotropicaily electroconductive tape segment 107, and as shown in Fig. 32, the cylinders 28 are driven to elevate the horizontal support plate 27 together with the component parts enclosed by the single-dotted chain line and the chuck 38 is returned to the initial position with the nipping rollers 58 and 59 positioned one above the other. Thereafter, as shown in Fig. 33, the chuck 38 is brought into the release position and is subsequently moved to the predetermined position E2, spaced a distance DE2 from the sensing position PO downstream of the transport direction, to chuck the length of leader tape 1 for the next succeeding cycle. It is to be noted that the distance DE2 is equal to D2 + D3 - LI - x. Thereafter, as shown in Fig. 35, the length of leader tape 1 is again drawn in the transport direction by the chuck 38 in the clamp position until the leading end of the remaining length of anisotropicaily electroconductive tape 2 is brought to a position spaced a length L3 from the tape cutting position P3, with the tape bonding apparatus subsequently repeating the foregoing cycle. Industrial Applicability

Thus, rom the foregoing description, it has now become clear that the tape bonding apparatus of the present invention comprises a tape supply unit for supplying in one transport direction a length of leader tape having one surface to which a length of anisotropicaily electroconductive tape is bonded; a tape transport unit for transporting the length of leader tape, supplied from the leader tape supply unit, in the transport direction; a tape cutting unit for cutting only the length of anisotropicaily electroconductive tape to provide an anisotropicaily electrocon¬ ductive tape segment of a predetermined length with respect to the transport direction; a substrate positioning unit for positioning a substrate to which the anisotropicaily electroconductive tape segment is bonded; and a tape pressing unit for pressing the anisotropicaily electroconductive tape segment to bond the latter to the substrate. The tape cutting unit employed in the tape bonding apparatus in accordance with the present invention comprises an incision forming member forming two incisions in the length of anisotropicaily electroconductive tape which are spaced a predetermined distance from each other in a direction lengthwise of the anisotropicaily electroconductive tape, and a removal means for removing a piece of anisotropicaily electroconductive tape, bound between the spaced incisions, from the length of leader tape. This cutting unit is so designed as to provide a space of separation in the length of anisotropicaily electroconductive tape that divides it into the anisotropicaily electroconductive tape segment and the remaining length of anisotropicaily electroconductive tape. Accordingly, even though the feed accuracy with which the length of leader tape is fed is not high to some extent, there is no possibility that a portion of the remaining length of anisotropicaily electroconductive tape which should not be bonded to the substrate may be erroneously bonded to the substrate, thereby facilitating an accurate and reliable bonding operation. In addition, since no length of anisotropicaily electroconductive tape is heat-treated in the practice of the present invention, it is possible to avoid an undesirable deformation or modification in quality of ends of the length of anisotropicaily electroconductive tape.

Claims

1. An apparatus for bonding an anisotropicaily electroconductive tape onto a substrate, which comprises a positioning table for positioning the substrate; a leader tape supply mechanism for supplying a length of leader tape having a length of anisotropicaily electroconductive tape bonded to one of opposite surfaces thereof; a cutter for cutting only the length of anisotropicaily electroconductive tape, having been supplied from the leader tape supply unit, to provide an anisotropicaily electroconductive tape segment of a predetermined length; a pressure applying tool for pressing through the length of leader tape the anisotropicaily electroconductive tape segment to bond the latter to the substrate; a pressing mechanism for pressing the pressure applying tool against the substrate; a leader tape peeling mechanism for peeling a portion of the length of leader tape off from the anisotropicaily electroconductive tape segment; and a leader tape feed mechanism, characterized in that before such anisotropicaily electroconductive tape segment is pressed to bond to the substrate, one end of the pressure applying tool upstream of the transport direction is aligned with a trailing end of the anisotropicaily electroconductive tape segment with respect to the transport direction.

2. The apparatus as defined in Claim 1 , characterized in that said end of the pressure applying tool upstream of the transport direction and said trailing end of the anisotropicaily electroconductive tape segment are aligned with each other by eeding the length of leader tape in the transport direction by means of the leader tape feed mechanism.

3 A method of pressing an anisotropicaily electroconductive tape, bonded to one of opposite surfaces of a length of leader tape, to bond it to a substrate, which method comprises the steps of: drawing the length of leader tape from a leader tape supply mechanism in a predetermined transport direction; cutting the anisotropicaily electroconductive tape, bonded to the length of leader tape so drawn from the leader tape supply mechanism, to provide an anisotropicaily electroconductive tape segment of a predetermined length; transporting the length of leader tape in a direction from one end to the _t opposite end of a pressure applying tool having a pressure applying surface of a length greater than the length of the anisotropicaily electroconductive tape segment, and aligning a trailing end of the anisotropicaily electroconductive tape segment with respect to the transport direction with said one end of the pressure applying tool; pressing through the length of leader tape the anisotropicaily electro¬ conductive tape segment against the substrate by means of the pressure applying surface to bond said anisotropicaily electroconductive tape segment to the substrate; and peeling the length of leader tape off from the anisotropicaily electro¬ conductive tape segment then bonded onto the substrate.