WO2020120381A2

WO2020120381A2 - Magnetic tape guide

Info

Publication number: WO2020120381A2
Application number: PCT/EP2019/084184
Authority: WO
Inventors: Johan BERGSTRÖM
Original assignee: Mycronic AB
Priority date: 2018-12-12
Filing date: 2019-12-09
Publication date: 2020-06-18
Also published as: WO2020120381A3

Abstract

A component feeder (100) for guiding a component tape (101) towards a picking position (110) of a component mounting machine is provided. The component tape (101) comprises a carrier tape (210), a cover (220) and a plurality of sequentially arranged compartments (231, 232) carrying components (230) to be mounted by the component mounting machine. The exposure of components (230) to the picking position (110) is performed by means of an exposure member (120) configured to separate the cover (220) from the carrier tape (210) such that the components (230) are exposed at the picking position (110). Further, a support mechanism (130) is arranged to guide the component tape (101) between the support (130) and the exposure member (120), and a magnet (140) is arranged to cooperate with the support mechanism (130) to push the component tape (101) against the exposure member (120).

Description

MAGNETIC TAPE GUIDE

Technical field

The present inventive concept generally relates to the field of manufacture and assembly of circuit card assemblies. In particular, the present inventive concept relates to a component feeder for guiding a component tape towards a picking position of a component mounting machine.

Background

Surface Mount Technology (SMT) relates to methods for automated

production of circuit card assemblies. This technology commonly involves a component mounting machine, such as a pick-and-place machine, for placing the electronic components on designated positions on a workpiece, such as a printed circuit board (PCB).

The electronic components may be provided by means of a component tape formed of a lower carrier tape comprising compartments accommodating the electronic components, and an upper, protective cover keeping the electronic components in place. The component tape may be wound on a reel and stored in a magazine configured to be inserted into the component mounting machine.

The free end of the component tape may be introduced into a feeding mechanism, often referred to as a component feeder, configured to guide the component tape to a picking position in which the component is exposed to a picking tool of the component mounting machine. The component is made available for the picking tool by means of an exposure member that removes the cover from the carrier tape as the component tape is fed towards the picking position.

There is a general strive for smaller and faster electronic devices that has increased the demand for efficient handling of smaller components such as 01005 components (0402 in metric code). As a consequence, the handling of smaller components has sharpened the requirements on position stability and reduction of vibrations at the picking position.

Thus, there is a need for improved component feeders for guiding a component tape towards the picking position of a component mounting machine. Summary

It is an objective of the present inventive concept to provide an improved component feeding technology. This and other objectives are achieved by means of a component feeder as defined in the independent claim. Further embodiments of the present disclosure are provided in the dependent claims.

According to a first aspect of the present inventive concept, there is provided a component feeder for guiding a component tape towards a picking position of a component mounting machine. The component tape comprises a cover and a carrier tape having a plurality of sequentially arranged

compartments for carrying components to be mounted by the component mounting machine. The component feeder comprises an exposure member configured to separate the cover from the carrier tape such that the

components are exposed at the picking position, a support mechanism arranged to guide the component tape between the support and the exposure member, and a magnet arranged to cooperate with the support mechanism to push the component tape against the exposure member.

The component feeder may in itself have an active feeding mechanism for transporting the component tape, i.e. the component feeder may be configured for both feeding and guiding a component tape. However, the actual feeding mechanism may be performed by other parts of the component mounting machine, whereas the component feeder may be configured for guiding the component tape that is fed by such other parts to the picking position.

The present inventive concept employs a magnet for improving the guiding of the component tape between the support mechanism and the exposure member. The improved guiding is achieved by means of the attractive magnetic force that causes the support mechanism to be pushed towards the exposure member with the component tape in between, resulting in an increased friction between the component tape and the component feeder that helps preventing the feeder from sliding off the component tape during handling. Further, the improved guiding may help preventing the components from slipping out of their respective compartment as the exposure member separates the cover and the carrier tape. This may be a result of a retaining magnetic attraction of the component, and/or an improved clamping between the component tape and the exposure member. Pushing the support mechanism towards the exposure member may also contribute to the support mechanism being less sensitive to vibrations, which may have a positive impact on the position accuracy of the component tape and its components at the picking position.

The magnet may for example be comprised in, or attached to, the support mechanism and arranged to attract the exposure member (or a structure coupled to the exposure member) such that the support mechanism and the exposure member are forced towards each other. Alternatively, the magnet may be comprised in, or connected to the exposure member in order to exert an attractive magnetic force on the support mechanism. In yet an alternative, the support mechanism may be connected to a first magnet and the exposure member to a further magnet, wherein both magnets may be arranged to utilise a mutual attraction to clamp the component tape between the support mechanism and the exposure member.

In a preferred example, the magnet is a permanent magnet. However, the magnet may also be an electromagnet arranged for pushing the component tape against the exposure member.

The support mechanism may be understood as a structure on which the component tape may slide as it is fed towards the picking position. The support mechanism may for example be arranged to support the underside of the component tape, i.e. , the carrier tape comprising the component compartments. The support mechanism may be configured to support the component tape in a vertical direction, i.e., the direction in which the picking tool may move when picking the component, and/or in a lateral direction, i.e., a sideway direction with reference to the feeding direction of the component tape.

Thus, by feeding direction is meant the direction in which the component tape is fed towards the picking position, whereas lateral direction refers to a width direction of the component tape. Further, the cover may be considered as arranged above or on the carrier tape. Consequently, the carrier tape may be considered as arranged below or under the cover.

The carrier tape comprises a plurality of compartments, which also may be referred to as pockets for accommodating components. The compartments may be distributed along the component tape, and thus the feeding direction, in an equidistant sequence.

The exposure member may be arranged above the component tape, such that it can engage and at least partly remove the cover from the carrier tape before the tape reaches the picking position. The exposure member may hence be arranged upstream the picking position, as seen in the feeding direction.

According to an embodiment, the magnet may be arranged at a position that is separated from the picking position in the feeding direction. The magnet may hence be arranged to push the component tape against the exposure member before the component tape reaches the picking position.

By having the magnet positioned separately from the picking position and pushing the component tape against the exposure member, a proper exposure of the component located in the compartment of the carrier tape may be provided.

According to an embodiment, the magnet may be comprised in the support mechanism. Integrating the magnet in the support mechanism’s structure is advantageous in that no additional space is needed for accommodating the magnet. An integrated magnet may also allow for reduction of the component feeder size by compensating the reduction of strength of a smaller support mechanism.

According to an embodiment, the support mechanism may further comprise a spring configured to push the support mechanism towards the exposure member. The spring may for example be formed as a flat spring, and may further be configured to be releasably attached to the feeder. The releasable attachment of the flat spring support mechanism allows for the spring to be removed and replaced with another spring, having a different spring constant. This may for example be utilised for adapting the feeder to a thinner component tape, which may require a support mechanism that generates a higher spring force than what is required for thicker component tapes.

According to an embodiment, the support mechanism may be formed by a first section and a second section that are movable relative to each other. The first and second section may for example be articulately coupled to each other. The movable sections allow for different parts of the support mechanism to perform different functions, such as applying different forces to different portions of the component tape. The sections may hence define different lengths of the support mechanism, as seen in the feeding direction.

According to an embodiment, the first section may be configured to support the component tape at the picking position, and the second section may be configured to push the component tape against the exposure member. The force applied by the first section to the carrier tape at the picking position may be selected to allow for enable a stable and fixed positioning of components and hence a greater accuracy of the component picking, thereby reducing the risks of poor performance in terms of e.g.

incomplete picks and missed picks. The force applied by the second section to the component tape under the exposure member may be selected to reduce to a minimum the gap between the exposure member and the component tape, thereby allowing for the component tape cover to be properly removed from the carrier tape. Further, a proper clamping of the component tape may prevent the feeder from sliding off the component tape during handling. In one example, the different forces applied by the flat spring support mechanism at the first and second section may be selected to allow the support mechanism to be slightly flexible at the first section (under/at the picking position) and straight and stiff at the second section (under/at the exposure member).

According to an embodiment, the second section of the support mechanism may comprise the magnet. The magnet may be attached to the second section or comprised in the second section (e.g. as integral part of the second section of the support mechanism), and may extend along the entire length of the second section or only a part of the length of the second section be defined by a certain length along the length of the support mechanism. Preferably, the feeder comprises a magnetic exposure member arranged to be attracted by the magnet.

According to an embodiment, the first section of the support

mechanism may comprise a further magnet configured to exert a retaining force on the exposed component. The magnet may be a low force magnet allowing components to remain steady at the bottom of their compartments on the component tape so as to reduce the risk for picking malfunctions while still allowing for the component to be removed by the picking tool. The holding effect of the force exerted from the magnet to the components may also allow for the reduction of vibrations generated by the feeding mechanism. In one example, the magnet of the first section may be arranged similarly as the one in the second section i.e. attached to the first section or comprised in the first section (e.g. as integral part of the first section of the support mechanism) and may be extend along the entire length of the first section or along a part of the first section, as seen in the feeding direction. The length of the magnet of the first section may for example be long enough to extend beyond the length of a compartment of the component tape to allow at least one component to be attracted by the magnet while being at the picking position.

According to an embodiment, the exposure member may comprise a separating portion for separating and lifting a side of the cover from the carrier tape, wherein the magnet may be arranged to exert a force on the separating portion so as to push the component tape against the exposure member. The separating portion may have e.g. a cutting edge allowing the cover to be detached from at least one side of the carrier tape. The exposure member may have a progressively larger width (i.e. thickness in the lateral direction) along the feeding direction so as to allow for the cover tape to be lifted from the carrier tape when detached from the at least one side. In this way, the compartments and their components may be exposed at the picking position that follows the exposure member downstream of the feeder when looking in the feeding direction.

According to an embodiment, the exposure member may be laterally displaceable in relation to the feeding direction of the component tape. The lateral movement of the exposure member allows for the feeder to be adapted to different widths of carrier tape and to different configurations and

dimensions of the compartments.

According to an embodiment, the exposure member may be angularly displaceable in relation to a feeding direction of the component tape. The angular displacement of the exposure member may allow for the separating portion to be adaptable for different width of carrier tapes (e.g shorter width requires a smaller angle of the exposure member with the feeding direction). Another example may be that the angular displacement of the exposure member allows for different types of carrier tapes to be used with the feeder e.g. carrier tapes with cover tapes glued at different positions on their width.

Brief description of the drawings

The above, as well as additional objects, features and advantages of the present inventive concept, will be better understood through the following illustrative and non-limiting detailed description detailed description of embodiments of the present invention. Reference will be made to the appended drawings, on which:

figure 1 illustrates a cross-sectional side view of a component feeder; figure 2 illustrates a closer view of the exposure member and the position of the magnet in the second section of the support mechanism; figure 3 shows a portion of a cross section of the component feeder, illustrating the sections of the support mechanism;

figure 4 illustrates a top view of the component feeder, showing possible angular displacement of the exposure member.

figure 5 illustrates a component tape mounted in a component feeder.

As illustrated in the figures, the sizes of the elements, features and other structures may be exaggerated or not depicted proportionally for illustrative purposes. Thus, the figures are provided to illustrate the general elements of the embodiments.

Detailed description of embodiments

Figure 1 illustrates cross section of a side view of a component feeder 100 according to an embodiment. The component feeder 100 handles a portion of a component tape 101 by feeding it to a picking position 110 of the

component mounting machine (not shown). The picking position 110 defines the location where the components of the component tape 101 may be picked by the picking tool of the component mounting machine. The component feeder of figure 1 further comprises an exposure member 120 positioned upstream of the picking position 110 when looking in the feeding direction, represented by the x-axis (horizontal axis) in figure 1. The component feeder

100 illustrated in figure 1 also comprises a support mechanism 130 positioned at under a portion of the component tape 101 , the picking position 110 and the exposure member 120. The support mechanism 130 may comprise a magnet 140 arranged in the structure of the support mechanism 130 or attached to the support mechanism 130. The magnet 140 may be positioned so that it aligns with the exposure member 120. The support mechanism 130 may be of a flat spring design, and may be provided with hooks 150 at its ends, allowing the support mechanism 130 to be releasably attached to the component feeder 100.

During operation, the component tape 101 may be moved along the feeding direction (x-axis in figure 1 ), passing the exposure member 120 which allows components of the component tape 101 to be ready for picking at the picking position 110. The spring, the support mechanism 130 and the magnet 140 may exert vertical forces (i.e. along the y-axis) on the component tape

101 so as to improve the positioning accuracy at the picking position 110 and reduce the risk of the exposure member 120 sliding off the component tape 101.

With reference to figure 2, a perspective view 200 of a portion of a component feeder 100, exposure member 120 and picking position 110 is shown. As mentioned above, the exposure member 120 may be located upstream from the picking position 110 when looking in the feeding direction. The exposure member 120 comprises a separating portion 240 which may have an edge 250 for pushing aside the tape cover 220 from the carrier tape 210. The exposure member 120 may further comprise a gradually increasing vertical thickness in the feeding direction, which allows the detached side of the cover tape to be lifted from the carrier tape 210. The thicker end of the exposure member 120 may be wide enough to allow the cover tape 220 to be completely lifted from sequentially arranged compartments (231 , 232) of the carrier tape 210, and the components 230 comprised therein, at the picking position 110. The exposure member 120 may separate and lift the tape cover 220 from the carrier tape 210 in such a way that the tape cover 220 forms at least a perpendicular angle with the carrier tape 210 to ensure that the pickable surface of the components 230 is completely free of any tape cover obstruction at the picking position 110, thus allowing for the risks of picking malfunctions to be reduced.

Figure 3 illustrates side view of a portion of the component feeder 100 of figure 2, in which the flat spring design of the support mechanism 130 is shown. The support mechanism 130 is located under the component tape 101 and may be divided into a first section 350 and a second section 360. The first and second sections 350, 360 may be articulately coupled, for example at the centre 340 of the support mechanism 130. The first section 350 is configured to support the component tape 101 at the picking position 110 and the second section 360 is configured to push the component tape 101 against the exposure member 120. A further magnet 310 may be located in or attached to the first section 350 of the support mechanism 130 and be aligned under the picking position 110. The articulate coupling allows for the first and second section (350, 360) to move vertically relative to each other. In the second section 360, the magnet 140 may exert a first force 322 pushing the component tape 101 towards the separation portion 240 of the exposure member 120 and opposing the exposure member’s force 321 applied on the component tape 101. These opposing forces (321 , 322) may allow for any gap between the component tape 101 and the exposure member 120 to be reduced. The further magnet 310 may be located under the picking position in such a way that it exerts a second force 330 allowing for the exposed components 230 to be attracted towards the support mechanism 130 and remain stable in their sequentially arranged compartments (231 , 232) until they are picked by the picking tool. This may reduce the risk of erroneous picking. The further magnet 310 may be configured to provide a weaker magnetic force than the magnet in the second section 360 to allow the first section 350 of the support mechanism 130 to be more flexible than the second section 360. The different behaviour of the first and second sections (350, 360) of the support mechanism 130 may allow for an accurate adaptation of the component feeder 100 to different thickness of component tapes 101.

In relation to figure 4, a top view 400 of a portion of a component feeder 100 according to an embodiment is disclosed. The present component feeder 100 may be similarly configured as the embodiments described with reference to any of the previous figures. The exposure member 120 may be laterally and/or angularly displaceable in relation to the feeding direction of the component tape 101. The exposure member 120 may be displaced along the feeding direction 420, transverse to the feeding direction 420 and/or rotated 410 with respect to the feeding direction 420 so as to ensure a correct exposure of the components at the picking position 110.

With reference to figure 5, an example of the component tape 101 , stored on a component tape reel 510 and mounted in a component feeder 100, is disclosed. The component tape may be inserted into the component feeder 100 in the feeding direction. During use, the cover tape 220 may be lifted by the exposure member 120 as component tape 101 is fed forward in the feeding direction by means of a feeding mechanism (not shown in figure 5).

In the above the inventive concept has mainly been described with reference to a limited number of examples. However, as is readily

appreciated by a person skilled in the art, other examples than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.

Claims

1. A component feeder (100) for guiding a component tape (101 ) towards a picking position (110) of a component mounting machine, the component tape (101 ) comprising a carrier tape (210) and a cover (220), and the carrier tape (210) comprising a plurality of sequentially arranged compartments (231 , 232) carrying components (230) to be mounted by the component mounting machine, wherein the component feeder (100) comprises:

an exposure member (120) configured to separate the cover (220) from the carrier tape (210) such that the components (230) are exposed at the picking position (110);

a support mechanism (130) arranged to guide the component tape (101 ) between the support (130) and the exposure member (120); and

a magnet (140) arranged to cooperate with the support mechanism (130) to push the component tape (101 ) against the exposure member (120).

2. The component feeder (100) according to claim 1 , wherein the magnet (140) is arranged at a position that is separated from the picking position (110) along a feeding direction of the component tape (101 ).

3. The component feeder (100) according to claim 1 or 2, wherein the magnet (140) is comprised in the support mechanism (130).

4. The component feeder (100) according to any one of the preceding claims, wherein the support mechanism (130) further comprises a spring configured to push the support mechanism (130) towards the exposure member (120).

5. The component feeder (100) according to claim 4, wherein the spring is a flat spring configured to be releasably attached to the feeder (100).

6. The component feeder (100) according to any one of the preceding claims, wherein the support mechanism (130) is formed by a first section (350) and a second section (360), the first section (350) and the second section (360) being movable relative to each other.

7. The component feeder (100) according to claim 6, wherein the first section (350) and the second section (360) are articulately coupled to each other.

8. The component feeder (100) according to claim 6 or 7, wherein the first section (350) is configured to support the component tape (101 ) at the picking position (110), and wherein the second section (360) is configured to push the component tape (101 ) against the exposure member (120).

9. The component feeder (100) according to claims 6 to 8, wherein the first section (350) is arranged at the picking position (110), and wherein the second section (360) comprises the magnet (140).

10. The component feeder (100) according to claim 9, wherein the first section (350) comprises a further magnet (310) configured to exert a retaining force (330) on the exposed component (230).

11. The component feeder (100) according to any one of the preceding claims, wherein the exposure member (120) comprises a separating portion (240) for separating and lifting a side of the cover (220) from the carrier tape (210), and wherein the magnet (140) is arranged to exert a force (321 ) on the separating portion (240).

12. The component feeder (100) according to any one of the preceding claims, wherein the exposure member (120) is laterally displaceable in relation to a feeding direction of the component tape (101 ).

13. The component feeder (100) according to any one of the preceding claims, wherein the exposure member (120) is angularly displaceable in relation to a feeding direction of the component tape (101 ).