Field of Invention

The invention relates to an apparatus and method for filling carrier tapes with electronic components.

Background

In order to transport large quantities of electronic components, it is common practice to package the components onto earner tapes. A carrier tape comprises a flexible support which can be wound onto a reel, and a plurality of longitudinally spaced pockets of a predetermined size, shape and spacing corresponding to the dimensions of electronic components to be placed thereinto. A cover tape is sealed on top of the carrier tape to protect the electric components more securely.

In a conventional system, such as that described in US2011/0231002 components are tested before being deposited onto the carrier tape, to ensure that defective components are not supplied to the customer. The system may include a circular turret around which are located test stations for conducting various mechanical, electrical and/or optical tests on the electronic components. The turret is typically provided with a plurality of component holders such as vacuum nozzles, for picking up, depositing, and moving the components between different test stations.

If a component fails any of the tests as it is shifted around the test stations, the vacuum nozzle typically collects the component and moves it to a reject bin. However, if the component passes all the tests around the turret, it is moved to the station at which a track with the carrier tape is located. The carrier tape is usually provided with sprockets along its longitudinal edges so that the sprocket wheel pulling the tape can precisely align an empty pocket with the vacuum nozzle carrying the component. The vacuum nozzle thus deposits the component into a pocket on the carrier tape, and the carrier tape is shifted by the sprocket wheel to present the next empty pocket to the turret. After the component is loaded onto the carrier tape it may undergo several visual and/or mechanical inspections as a final check before shipping.

For example, a visual inspection device may be positioned downstream of the turret to check the details or orientation of the component (i.e. it is the right way up). If a fault is detected, the carrier tape is reversed and the vacuum nozzle collects the component and may move it via the turret to a reject bin. A disadvantage to this system is that reversing the carrier tape can cause slack. A further disadvantage is that where a cover tape is placed on top of the carrier tape, the cover tape also has to be reversed simultaneously with the carrier tape. These disadvantages make realignment of the pockets to the turret difficult when the process resumes. To minimise this effect the visual inspection device may he located as close as possible to the turret so that the distance of reversal is minimised, but a resultant problem is that the size of the visual inspection device is then limited due to its proximity to the turret.

One or more mechanical inspection devices may also be positioned downstream of the turret, to check for incorrectly placed components such as those which are tilted. As the tilted component reaches the mechanical inspection device, it causes the device to be lifted which triggers the detection mechanism. The electronic component can then be removed as before. However, if a component further downstream on the carrier tape becomes tilted (for example due to an engineer cleaning the track with compressed gas) and hits the back side of the mechanical inspection device as the carrier tape is reversed, the sprockets can be stretched as the back side does not lift, and the whole carrier tape is ruined as it becomes very difficult to realign the pockets precisely.

An aim of the invention therefore is to provide an apparatus and method which overcomes one or more of the above issues. Summary of Invention

In an aspect of the invention, there is provided an apparatus for filling carrier tapes with electronic components comprising:

one or more test stations situated around a circular conveyer;

the circular conveyer including one or more component holders for moving electronic components between the test stations;

a tape filling station for receiving a carrier tape including a plurality of longitudinally spaced pockets; and

at least one inspection system adjacent the tape filling station for detecting faults; characterised in that if a fault is detected, the tape filling station is displaced by a predetermined distance to allow the fault to be corrected.

Advantageously by moving the filling station, rather than reversing the tape as described in the prior art, there is no risk of stretching the sprockets of the tape which may result in misalignment after the defective component is removed and a new component is deposited. In addition, the filling station can be moved very accurately compared to the tape which may be susceptible to stretching or loosening, and as such this also reduces the risk of misalignment for depositing further components. Furthermore the inspection system can be situated further away from the conveyer than conventional systems, allowing the inspection system to be larger and accordingly more accurate.

In one embodiment the faults include visual, electronic and/or positional defects in the electronic components on the carrier tape. Typically the fault is corrected by removing the electronic component corresponding to the detected fault.

In one embodiment at least one optical and/or mechanical inspection system is located adjacent the tape filling station for inspecting the electronic components on the carrier tape

In one embodiment the mechanical inspection system comprises a flipping cover. Typically if a component is tilted or otherwise not correctly seated in a pocket, it lifts the cover as it passes thereunder thereby detecting the positional fault of said component.

In one embodiment the pockets are aligned to the optical axis of the optical inspection system. Typically the optical inspection system comprises a camera.

In one embodiment the optical axis of the optical inspection system is a preselected distance from the component holder depositing the component in a pocket, said preselected distance being the pitch of the pockets multiplied by an integer. Typically the distance is 48mm and the pitch of the pockets is 2mm, 4mm, 8mm, 12mm, 16mm, or 24mm.

Advantageously the position of the inspection system does not require adjustment as the pitch divides equally into the distance between optical axis and component holder.

In one embodiment the predetermined distance is sufficient to allow a component holder to collect the faulty electronic component from its pocket. This is suitable when a visual or electronic fault is detected. For example if the optical axis of the optical inspection system is 48mm from the component holder, the filling station is displaced 48mm towards the conveyer so that the faulty electronic component is moved underneath the component holder for subsequent removal from the pocket.

In one embodiment the circular conveyer is provided with an axle which is supported from above the conveyer. This allows the tape filling station to be displaced a distance which is equal to substantially the whole diameter of the conveyer (normally it is limited by the central axle thereunder, i.e. a distance equal to about the radius). This is useful for large components where a pocket size of 96mm is used on the carrier tape.

In one embodiment a retest station and/or a reject station is situated next to the circular conveyor, such that a faulty electronic component can be transported and deposited thereinto via a component holder. In one embodiment an electronic component is transported to the retest station the first time a fault is detected, and only moved to the reject station if a fault is detected a second or other predetermined number of times. Advantageously if there is a problem with the setup of one of the inspection systems such that faults are improperly detected, the electronic components can be automatically retested or realigned to increase the chance that they will be considered acceptable.

In one embodiment the tape filling station is configured to move the carrier tape forward successively one pocket at a time, while no faults are detected.

In one embodiment the tape filling station is configured to move the carrier tape forwards or backwards one pocket when a positional fault is detected, and allow' a suction device to remove the faulty electronic component from its pocket. Typically in this embodiment the visual inspection system is shifted to avoid obstructing the suction device. Advantageously because the tape filling station is displaced, the carrier tape only needs to be moved by a distance corresponding to one pocket pitch to be clear of the inspection device which detected the fault, which minimises the risk of damage to the tape. In one embodiment the component holder is a vacuum nozzle capable of vertical movement. This allows the component holder to move down, hold a component via suction, then move up so it can be released elsewhere.

In a further aspect of the invention, there is provided a method for filling carrier tapes with electronic components comprising the following steps:

moving electronic components between test stations situated around a circular conveyer via component holders, electronic components which do not fail any tests being deposited into longitudinally spaced pockets of a carrier tape provided at a tape filling station;

the carrier tape being moved forward and the electronic components thereon being checked for faults by at least one inspection system; characterised in that if a fault is detected, the tape filling station is displaced by a predetermined distance to allow the component in which the fault was detected to be removed. In one embodiment an electronic component may be removed by a component holder or a suction device.

In one embodiment the carrier tape is moved backward or forward by one pocket so the electronic component detected as being faulty is clear of the inspection system.

In one embodiment, the apparatus is configured to stop and/or raise an alarm if a predetermined number of consecutive tests detect faults.

Brief Description of Drawings

It will be convenient to further describe the present invention with respect to the accompanying drawings that illustrate possible arrangements of the invention. Other arrangements of the invention are possible, and consequently the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention.

Figure 1 is a schematic top view of an apparatus for testing electronic components according to an embodiment of the inventi on Figure 2 is a schematic side view of the tape filling station of the embodiment illustrated in Figure 1.

Figure 3 is a schematic side view of the tape filling station, displaced after a defective electronic component is detected.

Figure 4 is a schematic side view of the tape filling station, removing the defective electronic component. Figure 5 is a schematic top view of the apparatus, moving the defective electronic component to a discard station.

Figure 6 is a schematic top view of the apparatus, discarding the defective electronic component.

Figure 7 is a schematic top view of the apparatus, rotating the conveyor to the next electronic component. Figure 8 is a schematic side view of the tape filling station, the next electronic component being delivered.

Figure 9 is a schematic side view of the tape filling station, with the next electronic component being ready for testing.

Figure 10 is a schematic side view of the tape filling station, reverted to its original position.

Figure 11 is a schematic side view of the tape filling station, where the testing procedure continues normal operation.

Figure 12 is a schematic side view of a further embodiment of the tape filling station, where a mechanical inspection system detects a defective component position

Figure 13 is a schematic side view of a further embodiment of the tape filling station, where the carrier tape is reversed by a distance.

Figure 14 is a schematic side view of a further embodiment of the tape filling station in a displaced position.

Figure 15 is a schematic side view of a further embodiment of the tape filling station where the optical inspection system is shifted. Figure 16 is a schematic side view of a further embodiment of the tape filling station where a vacuum system removes the defective electronic component. Figure 17 is a schematic side view of a further embodiment of the tape filling station reverted to its original position.

Figure 18 is a schematic side view of a further embodiment of the tape filling station with a replacement electronic component.

Figure 19 is a schematic side view of a further embodiment of the tape filling station where the testing procedure continues normal operation.

Figure 20 is a schematic side view of a further embodiment of the tape filling station, where a further mechanical inspection system detects a defective component position.

Figure 21 is a schematic side view of a further embodiment of the tape filling station, where the carrier tape is reversed by a distance. Figure 22 is a schematic side view of a further embodiment of the tape filling station where the optical inspection system is shifted.

Figure 23 is a schematic side view of a further embodiment of the tape filling station where a vacuum system removes the defective electronic component.

Figure 24 is a schematic side view of a further embodiment of the tape filling station in a displaced position.

Figure 25 is a schematic side view of a further embodiment of the tape filling station with a replacement electronic component.

Figure 26 is a schematic side view of a further embodiment of the tape filling station reverted to its original position. Figure 27 is a schematic side view of a further embodiment of the tape filling station where the testing procedure continues normal operation.

Figure 1 illustrates a schematic top view of an apparatus for testing electronic components, comprising a circular conveyer 1 with a plurality of working stations 2 of various types and sizes articulated around the circular conveyer 1.

The circular conveyer 1 is equipped on its periphery with a plurality of component- holders 1 1 , for example aspiration nozzles, allowing electronic components to be collected by vacuum and transported from one working station 2 to the next of the processing line. The successive working stations perform various successive operations on the electronic components, such as tests, marking, conditioning, sorting, etc.

Components to be tested are fed to the circular conveyer 1 by a feeding station (which may be any of the working station 2) After the tests, defect-free components are unloaded from the circular conveyer, and deposited into pockets of a carrier tape at a tape filling station 3.

Figure 2 illustrates a schematic side view of the tape filling station 3, comprising a carrier tape 31 with a plurality of regularly spaced pockets 31 1 for lodging electronic components 312 after the test on the circular conveyer 1. The electronic components are delivered into the tape 31 when the vacuum of a component holder 11 of the circular conveyer 1 is released, so that the electronic component 312 held by this holder is dropped into the pocket 311 of the carrier tape 31 below the nozzle.

The carrier tape 31 is continually moved forward in the direction of the arrow 35 by a wheel 32. Electronic component 313 dropped at the filling station 3 thus reaches an inspection position at a distance 34 where it is inspected by an inspection system 4. The inspection system may be a vision system comprising a camera lens 42 as well as illuminating device 41. Prisms and/or mirrors for redirecting the image of the component toward the camera 42 may be used. The electronic component 313 is usually aligned to the optical axis of the optical inspection system 4.

Other inspection systems may be used, such as a thru-beam sensor for testing the presence of component in a pocket. The inspection system allows an automatic verification of the components, and automatic detection of defective components 313, for example components which are mismarked, misaligned, flipped, tilted or deviated. In addition, further tests and inspections may be performed on the components 312, 313 within the pockets.

In the illustrated example, the inspection system 4 inspects the component which is 48mm ahead of the component holder 11 depositing the component. The 48mm distance 34 is selected based on the pitch of the pockets of the tape i.e the distance between the centres of adjacent pockets, which is preferably a multiple of the distance between inspection system 4 and component holder 11.

Advantageously the distance 34 of 48mm eliminates (or at least minimises) the need to adjust the position of inspection system 4 in order to align it to the pockets of components under test when filling tapes with various pitches (corresponding to different sizes of electronic components). Thus carrier tape pockets with pitches 2mm, 4mm, 8mm, 12mm, 16mm, and 24mm will all have pockets positioned without offset under the inspection system, as these pitches divide into 48mm wholly (without remainder). A 24mm distance will allow ^? carrier tapes with pocket pitches of 2mm, 4mm, 8mm, and 12mm to achieve the same result. However, a distance of 48mm is preferred as it allows a larger illuminating device to be used, for achieving higher image quality in the vision inspection, without interfering with the component holder 11. With further reference to Figure 3, electronic component 313 is detected as being defective by the vision inspection system which triggers automatic displacement of filling station 3 by actuator 33, as indicated by arrow 331. By moving the whole conveyor, the defective component 313 is delivered back to the filling position, below an aspiration nozzle 11. The displacement 331 corresponds to the distance between the inspection station 4 that detected the defective component and the filling station.

Advantageously by moving the filling station, rather than reversing the tape as described in the prior art, there is no risk of stretching the sprockets of the tape which may result in misalignment after the defective component is removed and a new component is deposited. In addition, the filling station can be moved very accurately compared to the tape which may be susceptible to stretching or loosening, and as such this also reduces the risk of misalignment for depositing further components

With regard to Figure 4, the circular conveyer 1 is indexed backward presenting the nearest empty nozzle 1 1 above the defective component 313. The nozzle then moves down to collect and remove the component from the pocket with subsequent upward movement.

With respect to Figures 5-6, the circular conveyer 1 then rotates in direction 112 to deliver the defective component 312 to a station T equipped with tubes or bins or any other storage means for segregation according to a predetermined defects category. The next electronic component 1 1 1 can then be delivered as a replacement to the empty space on the carrier tape 31.

With regard to Figures 7-9, the circular conveyer l is indexed onward presenting the next electronic component 111 above the empty pocket 31 1 from which the defective component 313 was removed, whereupon the replacement component is then delivered into this pocket.

As illustrated in Figures 10-11, the filling station then reverts to its earlier position, the actuator 33 reversing by distance 332, until the replacement electronic component 111 reaches the inspection station 4 that detected the defective component. The replacement component is then verified, and the processing continues as before.

In another embodiment of the invention, case A as illustrated by Figures 12-19, the system comprises a mechanical inspection system 6 which is arranged a few millimetres ahead of the filling station pocket, and an optical inspection system 4 which is placed after the mechanical inspection system.

With regard to Figure 12, electronic components 312 dropped at the filling station 3 reach the mechanical inspection station 6, which may comprise a flipping cover just above the tape, arranged so as to be displaced each time a tilted or turned component protrudes out of the pocket. This displacement is detected by a sensor A spring or gravity returns the cover back to its initial position after it has been moved. As illustrated in Figure 13, defectively placed component 314 triggers automatic inversion of carrier tape 31 by wheel 32 by a short distance, so that it is clear of the mechanical inspection system 6.

With respect to Figure 14, the filling station is then displaced a distance 332 by actuator 33 away from the filling position.

As illustrated in Figures 15-16, the inspection device 41 is shifted upwards to allow a vacuum device 5 to gain free access to the pocket to remove the defective component 314. The vacuum system 5 is used when the condition of the component does not favour the use of component holder 11 for said purpose, for example substantially tilted.

With respect to Figure 17, filling station 3 is then returned 332 to its previous position by actuator 33, while at the same time the circular conveyer is rotated onward bringing next component 111 above the pocket from where defective component 314 was removed.

With regard to Figures 18-19, the pocket is filled with replacement component 111 and carrier tape 31 is moved forward one pocket delivering the replacement component for testing by mechanical inspection system 6

In a further embodiment of the invention, case B as illustrated by Figures 20-27, the system comprises a first mechanical inspection system 6, a vision inspection system 4, and a second mechanical inspection system 7. The second inspection system 7 is arranged a few millimetres ahead of the pocket under the optic monitoring system 4.

With regard to Figures 20-21 a defectively placed component 315 as detected by mechanical test system 7, which triggers carrier tape 31 to be reversed one pocket by wheel 32 so that it is clear of the mechanical inspection system 7, and the visual inspection system to be shifted upwards.

With respect to Figures 22-23, this allows vacuum system 5 access to the pocket without obstruction, where it can remove the defective component 315 and deposit the same into a bin (not shown). It will be appreciated that other systems may be used for removing defective components from pockets.

With regard to Figures 24-25, the filling station 3 is then displaced 331 by actuator 33 to bring the emptied pocket to the filling position under nozzle 11, and a replacement component 111 is then delivered into the empty pocket by the component holder 11.

As illustrated in Figures 26-27, filling station 3 is then returned to its previous position so that testing may resume.

It will be appreciated that the aforementioned embodiments allow the apparatus to continue the tape filling process without stopping for human intervention. Nevertheless the apparatus may be configured to stop if a predetermined number of consecutive tests fail (typically between 1 and 10), so that a check can be made for any anomalies, which can then be corrected. For example repeated rejections with the same pocket may be caused by an anomalous carrier tape condition or problematic mechanism.

It will be appreciated by persons skilled in the art that the present invention may also include further additional modifications made to the apparatus which does not affect the overall functioning of the apparatus.