Abstract:
The invention relates to a packaging system having a tool for inserting electronic components into a carrier tape, which has passage openings. The tool has a pick-up device to pick up the components from a carrier film and position them in the passage openings by means of a lifting movement. The packaging system has a guide plate for the linear sliding conveyance of the carrier tape populated with electronic components, and in each case devices for applying upper and lower cover films to the carrier tape. The invention additionally relates to a method of populating the carrier tape with electronic components.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This Utility Patent Application claims the benefit of the filing date of German Application No. DE 102 17 792.9, filed Apr. 20, 2002, and International application Ser. No. PCT/DE03/01278, filed Apr. 16, 2003, both of which are herein incoirorated by reference. 
   BACKGROUND 
   The invention relates to a packaging system with a tool for enclosing electronic components in a carrier tape, and a method of populating the carrier tape. 
   For the purpose of transport and delivery to an automatic placement machine, electronic components are often enclosed in what are known as carrying or transport tapes, which can be stored and transported in the rolled-up state. Transport tapes of this type have preformed tape pockets, in which electronic components can be arranged and transported in an accurate position, and can be removed from the transport tapes in an accurate position. For the purpose of transport, the tape pockets of a transport tapes are covered with the aid of a covering tape, so that the electronic components cannot fall out of the tape pockets and cannot change their position in relation to the three spatial axes until they are removed from the transport tapes. 
   During the introduction and positioning, in particular of small and/or lightweight electronic components and/or semiconductor chips, such as are needed in great numbers for integrated circuit technology, illumination and laser engineering and the like, rapid placement with a high throughput rate is associated with the risk that the components will jump out of the tape pockets and therefore hamper the placement operation of an automatic placement machine for transport tapes considerably. Not only does the placement have to be interrupted, but in principle the automatic machine has to look for the electronic components that have jumped out and the placement position of the automatic machine has to be redefined and readjusted. 
   A further problem in the placement of transport tapes with small and/or lightweight electronic components in the millmeter range is to be seen in the fact that the precision requirements both on the shaping of the tape pockets and on the automatic placement machines require continually increasing investment and development costs, in order to position the electronic components precisely and in an accurate position in the tape pockets, and in order to meet these precision requirements. 
   Electronic components are inserted into the pockets of the transport tape by means of a rotary cross or a pivoting arm. The electronic components are at this time already separated on the wafer or on the blank to such an extent that they can be separated from a carrier film and picked up by the pivoting arm. All the methods described need a relatively great deal of handling and are therefore associated with certain minimum cycle times. 
   Pick-up devices for handling and positioning semiconductor chips at their envisaged installation location are disclosed by JP 100 84 005 A, by JP 100 84 006 A and by JP 100 84 032 A. A device for positioning semiconductor chips is also disclosed by JP 061 51 483 A. 
   SUMMARY 
   One embodiment of the invention provides a device and a method for populating transport tapes with electronic components or semiconductor chips with which rapid, reliable and precise population with electronic components from transport tapes such as paper tapes with a double-sided film cover or blister tapes with a single-sided film cover is possible. 
   According to one embodiment of the invention, a packaging system is provided with a guide plate for the linear guidance of a carrier tape that can be populated with electronic components or with semiconductor chips. The guidance can be carried out horizontally in a sliding manner. The guide plate has a passage opening. 
   The packaging system has a carrier-tape populating tool, which has a vacuum pipette and a lifting needle, which can also generally be constructed as a lifting device. In this case, the vacuum pipette is designed in such a way that it can pick up an electronic component in each case or a semiconductor chip in each case from above. The lifting needle can be constructed in such a way that it guides the electronic component or the semiconductor chip from below. 
   The vacuum pipette and the lifting needle are intended to pick up vertically in each case an electronic component or semiconductor chip provided on a carrier film or carrier plate and to position the electronic component or semiconductor chip picked up in each case in a cavity or a passage opening in each case on a carrier tape. In this case, the vacuum pipette and/or the lifting needle can in each case carry out a lifting movement and move in and/or through the passage opening in the guide plate. 
   The components are wiped off the vacuum pipette, specifically in particular by the movement of the carrier tape in the transport direction. 
   The packaging system further comprises at least one upper cover film device for applying an upper cover film and/or a lower cover film device for applying a lower cover film to the carrier tape. 
   According to another embodiment of the invention, the packaging system according to the invention comprises a tool for inserting electronic components into a carrier tape, which has passage openings to hold individual electronic components. The tool has a pick-up device with a vacuum pipette and a lifting needle to pick up the electronic components vertically from a carrier film or carrier plate and to position the components in the passage openings by means of a lifting movement of the vacuum forceps. The carrier tape is guided in the horizontal transport direction in such a way that it wipes the components off the vacuum pipette in the transport direction. The packaging system also has a guide plate for the linear, sliding horizontal conveyance of the carrier tape populated with electronic components, and in each case devices for applying an upper and a lower cover film to the carrier tape. 
   The packaging system according to this embodiment of the invention has only minimal handling movement to pick up and transfer electronic components located on a blank into a carrier tape. The components merely have to be pushed upwards by means of a linear lifting movement, so that no kind of complicated handling steps or method steps of the vacuum pipette are necessary. In addition, no additional tools or aids are required in order to remove the electronic components from a vacuum pipette, since this task is performed by the carrier tape to be populated. Wiping the electronic component of the vacuum pipette by means of the carrier tape is a procedure which treats the electronic component gently. By using a vacuum pipette which has a central capillary that is evacuated during the lifting operation and during the wiping operation, the component and in particular the upper side of the component are treated gently. To this end, the vacuum pipette has at its tip a highly polished minimum contact surface, onto which the upper side of the component is pressed. This contact surface can belong to a Teflon tip, which is correspondingly compliant, and does not damage the upper side of the component. In the case of metallic vacuum pipettes, the contact surface can additionally be hardened, in order to achieve long service lives. Hardening of this type can be carried out by means of diffusion hardening, which means that no additional surface layer is built up. In the case of what is known as “Kolsterising”, hardnesses from about 1200 to 1300 Vickers are achieved without additional material being applied. 
   A further advantage of the vacuum pipette with its highly polished minimum contact surface is that a small amount of vacuum power is sufficient to hold the component with the evacuated capillary. Furthermore, adjustment and adaptation of the vacuum pipette both to the thickness of the components and to the thickness of the carrier tapes are possible with simple means. 
   According to one embodiment of the invention, the pick-up device is a vacuum pipette, which permits gentle and secure handling of the electronic components. According to a further embodiment of the invention, the vacuum pipette has a lifting direction at right angles to the conveying direction of the carrier tape and through the passage openings in the latter. Just like the vacuum pipette, the lifting needle in one embodiment also has a lifting direction at right angles to the conveying direction of the carrier tape and as far as the lower edge of the passage openings in the latter. The only minimal lifting movements of the vacuum pipette and of the lifting needle ensure exact positioning and deposition of the electronic components in the carrier tape. According to one embodiment of the invention, the lifting movements of the lifting needle are synchronised with the lifting movements of the vacuum pipette, and the vacuum is maintained until the transport tape moving forward has wiped the electronic component off the mouthpiece of the vacuum pipette. 
   An alternative embodiment of the invention provides for at least the vacuum pipette to have a horizontal movement component in the same direction as the conveying direction of the carrier tape as it inserts an electronic component into a passage opening. This horizontal movement component of the vacuum pipette reliably prevents the electronic components falling out downwards after the vacuum has been removed. 
   The electronic components can be picked up and deposited in the carrier tape particularly simply if they are applied to a component carrier or a blank in rows and/or columns and are held together by a carrier film. 
   The component carrier or the blank with the carrier film, according to a further embodiment of the invention, is applied to a support table that can be displaced horizontally, which makes rapid and accurate displacement and positioning of the electronic components underneath the carrier tape easier. In one embodiment, the support table can be displaced in a first horizontal direction parallel to the conveying direction of the carrier tape and in a second horizontal direction at right angles thereto. 
   In order to separate the electronic components from the blank or the carrier foil without difficulty, the support table has a second opening of larger diameter than the lifting needle, which can in each case be moved into a position located vertically underneath a passage opening in the carrying tape. The lifting needle can be pushed through this opening and, together with the vacuum pipette, can convey the respective electronic component into the carrier tape. 
   In one embodiment, the guide plate has a first opening of larger diameter than an outline of an electronic component, through which opening the linear lifting axes of the vacuum pipette and of the lifting needle extend centrally. Located directly above this first opening is the passage opening in the carrier tape, into which an electronic component is deposited in each case. 
   According to a further embodiment of the invention, downstream of the pick-up device in the conveying direction of the carrier tape, the packaging system has feed devices for the lower cover film and for the upper cover film. The latter are pressed onto the underside and upper side of the tape by means of deflection rollers and by a pressing device in each case, and are connected to the said tape. This can be carried out, for example, by means of a heating device or else by adhesive bonding. The feed device for the upper cover film is arranged downstream, in the conveying direction of the carrier tape, of the feed device for the lower cover film. 
   In order that the electronic components cannot fall through their feed slot in the guide plate when the lower cover film is being applied, a vacuum suction device is provided above the feed device for the lower cover film, by means of which the electronic components are held in the passage opening. 
   The method according to one embodiment of the invention for populating a carrier tape with electronic components has the following steps. A carrier tape is provided with passage openings for a packaging system for populating with electronic components. By means of a vacuum pipette, individual electronic components are picked up from a support table arranged underneath the conveying plate of the packaging system. In each case an electronic component is introduced into each passage opening in the carrier tape by means of a vertical lifting movement of the vacuum pipette that lifts the electronic component. The electronic component is then wiped off the vacuum pipette with the aid of the carrier tape. An upper side of a tape is closed by applying an upper cover film. In the same way, an underside of a tape is closed by applying a lower cover film. 
   With this method, the electronic component is transferred extremely gently into the passage openings or cavities in the carrier tape, since the contact surface of the vacuum pipette is extremely small and wiping the electronic component off in the horizontal direction from this contact surface does not represent any loading on the electronic component. 
   A configuration of the method according to one embodiment of the invention provides for the electronic components to be picked up from above by a vacuum pipette and from below by a lifting needle, which permits exact deposition of the components in the carrier tape. In one embodiment, the vacuum pipette and the lifting needle carry out a vertical lifting movement through a first opening in the guide plate, while the transport tape is moved transversely thereto and wipes the electronic component off the vacuum pipette in the transport direction. 
   An alternative embodiment of the method according to the invention provides for at least the vacuum pipette to carry out a horizontal movement with the conveying direction of the carrier tape as it inserts the electronic component into a passage opening in the latter, as a result of which the electronic components are reliably prevented from falling out downwards through the first opening after the vacuum to the vacuum pipette has been switched off. 
   The lower cover film is applied to the carrier tape from below through a feed slot in the guide plate. In order that the electronic components cannot fall down through this feed slot, a vacuum suction device is provided above the feed device for the lower cover film. 
   The upper and lower cover film in each case be applied in an adhesive manner by means of a heating device to the upper side and lower side of the tape. Alternatively, the cover films can also be adhesively bonded to the carrier tape. In one embodiment, the carrier tape used is a paper tape. The cover films are in one embodiment made of thermoplastic or likewise of paper. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles of the invention. Other embodiments of the present invention and many of the intended advantages of the present invention will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. 
       FIG. 1  illustrates a schematic illustration of a packaging system according to the invention having a tool for inserting electronic components into a carrier tape. 
       FIG. 2  illustrates a detailed extract from the packaging system corresponding to  FIG. 1 . 
       FIG. 3  illustrates a basic sketch of the pick-up device of a further embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. 
     FIG. 1  illustrates a schematic cross-section of a packaging system  2  according to the invention having a tool  4  for inserting electronic components  10  into a carrier tape  6 . The tool  4  comprises a pick-up device  41  for picking up and transferring electronic components  10  which are in groups on a blank  8 . By means of the pick-up device  41 , which substantially comprises a vacuum pipette  42  and a lifting needle  43 , individual electronic components  10  are separated from a carrier film  81  belonging to the blank  8  and placed in passage openings  63  in the carrier tape  6 . 
   The carrier tape  6  in one embodiment consists of paper and is conveyed in a sliding manner on a guide plate  21 . The guide plate  21  extends over a sufficient length such that, in the conveying direction C behind the tool  4 , sufficient space remains to apply an upper cover film  64  to an upper side  61  of the tape and a lower cover film  65  to an underside  62  of the tape. For this purpose, the feed device  26  for the lower cover film  65  is provided on the underside of the guide plate  21 , by means of which the lower cover film  65  is led up to the underside  62  of the tape over a plurality of deflection rollers (conveying direction E). 
   Above the feed device  26  for the lower cover film  65  there is provided a vacuum suction device  27 , by means of which the electronic components  10  lying in the passage openings  63  in the carrier tape  6  and pushed along on the guide plate  21  by the latter are sucked upwards to a guide covering  29  of the guide plate  21  and are prevented from falling out downwards from a feed slot  32  for the lower cover film  65 . 
   Behind the feed device  26  for the lower cover film  65 , in the conveying direction C of the carrier tape  6 , there is arranged a feed device  25  for an upper cover film  64 , by means of which the upper cover film  64  is led up to the upper side  61  of the tape over a plurality of deflection rollers (conveying direction D). By means of heating devices  28 , the upper and lower cover films  64 ,  65  are firmly connected in adhesive manner to the carrier tape  6 . By means of the cover films  64 ,  65  the electronic components  10  are prevented from falling out of the passage openings  63  in the carrier tape  6 . The cover films  64 ,  65  in one embodiment consist of a thermoplastic and are melted point by point by means of the heating devices  28  and connected to the paper carrier tape  6 . Alternatively, instead of the heating devices  28 , provision can also be made for possible ways of connecting the cover films  64 ,  65  to the carrier tape  6  by means of adhesive bonds. 
   The carrier tape  6 , after being populated with the electronic components  10 , can be wound up onto a roll, which means it is suitable to be transported and delivered to an assembly line. 
     FIG. 2  illustrates, in a schematic cross-section, a detailed extract from the packaging system  2  corresponding to  FIG. 1 . In this case, the actions of picking up and transferring the electronic components  10  from the blank  8  into the carrier tape  6  are illustrated. 
   The blank  8  comprises a carrier film  81 , on which the electronic components  10  are fitted in an adhesive manner in rows and columns. The carrier film  81  rests with its underside on a support table  22 , which can be displaced in the horizontal direction. In one embodiment, the support table  22  can be displaced in the conveying direction C of the carrier tape  6  and at right angles thereto. Provided centrally in the support table  22 , what is known as the vacuum mushroom, a second passage opening  24  is provided, through which a lifting needle  43  can be moved vertically upwards (lifting direction B). While the component is being lifted, vacuum is applied to the vacuum mushroom in order to hold the adhesive film  81  on the vacuum mushroom. 
   The support table  22  is located immediately underneath the guide plate  21 , so that an electronic component  10  can be conveyed directly from the blank  81  into a passage opening  63  in the carrier tape  6  by means of the pick-up device  41  of the tool  4  and can be deposited there. For this purpose, the vacuum pipette  42  can be moved through a first opening  23  in the guide plate  21 , downwards through the latter, in the direction opposite to the lifting direction A, and placed on an upper side of an electronic component  10 . At the same time, the lifting needle  43  is pressed against the carrier film  81  from below. By means of a simultaneous lifting movement of the lifting needle  43  and of the vacuum pipette (lifting directions A, B), the electronic component  10  is lifted off the carrier film  81  of the blank  8 , the lifting needle  43  piercing the carrier film  81 . 
   The pick-up device  41  is moved vertically upwards until the electronic component  10  is positioned in the passage opening  63  in the carrier tape  6 . The carrier tape  6  is displaced to the right on the guide plate  21 , in the conveying direction C, the electronic components  10  located in the respective passage openings  63  being displaced on the guide plate  21  at the same time. Provided above the guide plate  21  and at a distance from the latter is a guide covering  29 . The carrier tape  61  is pulled along between the latter and the guide plate  21 . 
   In order to prevent the electronic component  10  falling downwards through the first opening  23  in the guide plate  21  after the lifting needle  43  has been set down, the vacuum pipette  42  holds the electronic component  10  until the lifting needle  43  has moved back and the component has been wiped off the vacuum pipette by the tape advance. In order to provide further increased safety against such falling out, provision can be made, in one variant, for the vacuum pipette  42  to carry out not only a vertical lifting movement in the lifting direction A but also a slight horizontal movement in the conveying direction C of the carrier tape  6 , until the electronic component  10  is resting safely on the guide plate  21  and slides along on the latter. 
     FIG. 3  illustrates a basic sketch of the pick-up device  41  of a further embodiment of the invention. The components with the same functions as in the preceding figures are identified by the same reference symbols. 
   The carrier tape  6  is arranged with its passage openings  63  or cavities between an upper guide  31  and a lower guide  32 . A film with electronic components  10  is fitted underneath the lower guide. This film is pierced by the lifting needle  43  in order to lift a component  10  and transfer it to a vacuum pipette  42 . 
   In this case, the lower opening of the vacuum pipette  42  is covered by the component  10 . An airstream produced by a vacuum pump, not shown in this view, is interrupted and a vacuum is produced in the inner channel in the vacuum pipette  42 . As a result of the pressure difference built up in the process between the inner channel in the vacuum pipette  42  and the outer side of the vacuum pipette  42 , the component  10  is pressed against the vacuum pipette  42 . In this case, a pressure sensor, not shown in this view, is provided on the inner channel in the vacuum pipette  42 , by means of which a controller, not shown in this view, is informed as to whether there is a component  10  on the upper opening of the vacuum pipette  42  or not. In addition to the pressure sensor or alternatively thereto, an airflow sensor can be provided, which detects whether more than a minimum quantity of air is flowing through the inner channel in the vacuum pipette  42 . If this is the case, there is no component on the lower opening of the vacuum pipette  42 . 
   The vacuum in the inner channel in the vacuum pipette  42  is set to be just so high that the component  10  is held on the lower opening of the vacuum pipette  42  and does not fall off it. 
   The vacuum pipette  42  lifts the electronic component  10  into the cavity or passage opening  63  in the carrier tape  6 . As the tape  6  is pulled horizontally between the upper guide  31  and the lower guide  32 , one edge  66  of the tape carries the electronic component with it and wipes it gently off the vacuum pipette. Because of the lower holding force of the minimized vacuum in the vacuum pipette  42 , only a little friction has to be overcome in the process. In this case, the electronic component  10  is held by the tip of the vacuum pipette in the direction of arrow F by means of vacuum suction until the lower opening of the vacuum pipette  42  partly releases it. At this moment, it is picked up and carried by the guides  31  and  32 . 
   Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.