Patent Publication Number: US-2023164968-A1

Title: High Density Carrier Tape

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. § 119(a) of European Application No. 21210392.3 filed Nov. 25, 2021, the contents of which are incorporated by reference herein in their entirety. 
     BACKGROUND OF THE DISCLOSURE 
     1 Field of the Disclosure 
     Aspects of the present disclosure relate to a carrier tape holding electrical components and to an assembly comprising a reel and the carrier tape, wherein the carrier tape is wound around the reel. Furthermore, the present disclosure is related to a pick-and-place apparatus for receiving the carrier tape and for picking and placing the electrical components arranged in the carrier tape. 
     2. Description of the Related Art 
     Carrier tapes are known in the art. An example thereof is marketed under the name Surftape®. This known tape comprises an elongated carrier tape body comprising a plurality of cavities that are spaced apart along a longitudinal axis of the carrier tape body. The known tape further comprises an adhesive film covering a first side of the carrier tape body and forming a bottom wall of the cavities, wherein the adhesive film comprises an adhesive configured for attaching an electrical component to the bottom wall of a respective cavity among the plurality of cavities. 
       FIG.  1    illustrates a known pick-and-place apparatus  1000  that is configured for processing this known tape. It comprises a feeding unit  110  for receiving carrier tape  20  and for transporting carrier tape  20 . It further comprises a releasing unit  1200  configured for substantially releasing the attachment of an electrical component  5  in a cavity of carrier tape  20 , and a pick-and-place unit  130  for picking up a released electrical component  5  and for placing the picked electrical component  5  on a further electrical component such as a printed circuit board  140 . 
     In  FIG.  1   , feeding unit  110  comprises a reel holder  111  on which a reel with carrier tape  20  is mounted, and a carrier tape guiding unit  112  configured to guide carrier tape  20  off the reel. 
     Pick-and-place apparatus  1000  further comprises a vision system  150  configured to identify an electrical component  5  in a given cavity of the carrier tape  20 , and a controller  160  configured for controlling pick-and-place unit  130  based on an identified electrical component  5 , and configured for controlling the releasing unit  1200  to release electrical component  5  in the given cavity. 
     Pick-and-place unit  130  comprises a pick-and-place unit controller  132  configured for controlling a robotic arm  131 . Controller  132  is controlled by controller  160 . Robotic arm  131  is provided, at an end thereof, with means for picking an electrical component  5  from a cavity of carrier tape  20 , for example a suction nozzle  133 . 
     Releasing unit  1200  comprises a pen that is brought into and out of engagement with carrier tape  20 . When in engagement, the pen pushes against a backside of carrier tape  20 . This causes carrier tape  20  to bulge as a result of which the electrical component  5  positioned in the cavity above the pen locally detaches from the adhesive film. This allows robotic arm  131  to pick up the electrical component  5  and to place it on printed circuit board  140 . 
     A disadvantage of the known carrier tape is that it offers a relatively low density of electrical components. Here, the density should be construed as the number of electrical components per unit length of the carrier tape. 
     SUMMARY 
     At least some of the embodiments in accordance with a first aspect of the present disclosure provide a carrier tape in which the abovementioned problems do not occur or at least to a lesser extent. 
     According to an aspect of the present disclosure, a carrier tape is provided as defined in claim  1 , wherein the adhesive is configured to substantially release the attachment of the electrical component as a result of heating the adhesive and/or as a result of irradiating the adhesive using light, such as visible light, infrared light, or ultraviolet light, for the purpose of allowing the electrical component to be removed from the cavity using a pick-and-place apparatus. 
     According to an aspect of the present disclosure, the attachment between electrical component and adhesive film is not broken using a needle but by changing the adhesive properties of the adhesive itself. In this way, a needle is no longer needed to partially detach the electrical component. This reduces the risk of damaging the electrical component and allows multiple electrical components to be arranged next to each other inside a single cavity. By using multiple electrical components, the density of electrical components in the carrier tape can be increased. 
     Preferably, a temperature at which the adhesive loses its adhesive properties is less than a melting temperature of the carrier tape body. For example, the temperature at which the adhesive loses its adhesive properties lies in a range between 120 and 170 degrees Celsius. 
     The carrier tape body may consist of one or more materials out of the group consisting of polycarbonate or polystyrene or a mixture thereof. This carrier tape body may have a thickness between 0.2 and 1.0 mm. 
     The adhesive film may comprise an adhesive film carrier on which the adhesive is arranged. Furthermore, the adhesive film carrier can be a continuous film carrier. Alternatively, the adhesive film carrier may comprise a plurality of disjoint patches. In both cases, the adhesive film carrier may consist of one or more materials out of the group consisting of polyolefin, polyvinyl chloride, polyethylene terephthalate, and polyimide. Such adhesive film carrier may have a thickness between 25 and 100 micrometers. 
     The carrier tape may further comprise a plurality of sprocket holes arranged spaced apart along the longitudinal axis of the carrier tape body. These sprocket holes can be engaged by the pick-and-place apparatus for the purpose of guiding and transporting the carrier tape. 
     The carrier tape may further comprise a first covering film arranged on a second side of the carrier tape body opposite to the first side. This first covering film can protect the adhesive film prior to using the carrier tape for holding a plurality of electrical components. Before arranging the electrical components in the cavities of the carrier tape, the first covering film needs to be removed. 
     Alternatively, the carrier tape may further comprise, for each cavity among the plurality of cavities, one or more electrical components arranged in that cavity. In this case, at least one cavity among the plurality of cavities may comprise a plurality of electrical components. This plurality of electrical components in the at least one cavity is preferably arranged in a matrix of rows and columns. The components arranged in the plurality of cavities can be identical. In addition, the same number of electrical components can be arranged in each of the cavities of the carrier tape. Furthermore, the carrier tape may further comprise a second covering layer arranged on a second side of the carrier tape body opposite to the first side, wherein the second covering layer forms a top wall of the cavities. 
     The electrical components arranged in the plurality of cavities can be electrical components out of the group consisting of bare semiconductor dies, packaged electrical components, chip scale packages, chip capacitors, and chip resistors, 
     According to a second aspect of the present disclosure, an assembly is provided that comprises a reel and the abovementioned carrier tape, wherein the carrier tape is wound around the reel. 
     According to a third aspect of the present disclosure, a pick-and-place apparatus is provided of which the releasing unit is configured for substantially releasing the attachment of the electrical component in a cavity of the carrier tape by heating the corresponding adhesive and/or by irradiating the adhesive using light, such as visible light, infrared light, or ultraviolet light. 
     In case the carrier tape comprises the abovementioned second covering layer, the pick-and-place apparatus is configured for removing this covering layer to allow the electrical components arranged in the cavities of the carrier tape to be picked. 
     The releasing unit may comprise a heater and/or an optical light source, such as a laser, wherein the releasing unit is arranged to face the carrier tape from the first side thereof. 
     The pick-and-place apparatus may further comprise a vision system configured to identify one or more electrical components in a given cavity of the carrier tape, and a controller configured for controlling the pick-and-place unit based on the identified one or more electrical components and configured for controlling the releasing unit to release the one or more electrical components in said given cavity. For example, the controller can be configured to control the releasing unit for releasing all electrical components in the given cavity before pick-and-placing these components. Alternatively, the controller can be configured to control the releasing unit for releasing one or some of the electrical components in the given cavity before pick-and-placing this component or these components. In a particular embodiment, an electrical component in a given cavity is first individually released and pick-and-placed, before a next electrical component in the same cavity is released. 
     The feeding unit can be configured for transporting the carrier tape relative to the releasing unit, wherein the controller is configured to control the feeding unit to transport the carrier tape such that alignment between a current cavity of the carrier tape and the releasing unit is broken and such that alignment between a next cavity of the carrier tape and the releasing unit is established after the controller has determined, using the vision system, that no electrical components are present in the current cavity. 
     The feeding unit may comprise a reel holder on which a reel with the carrier tape as described above can be arranged, and a carrier tape guiding unit configured to guide the carrier tape off the reel. 
     The pick-and-place unit may comprise a robotic arm, and a pick-and-place unit controller configured for controller the robotic arm and configured to be controlled by the controller. The robotic arm can be provided, at an end thereof, with means for picking an electrical component from a cavity of the carrier tape, for example a suction nozzle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the features of the present disclosure can be understood in detail, a more particular description is made with reference to embodiments, some of which are illustrated in the appended figures. It is to be noted, however, that the appended figures illustrate only typical embodiments and are therefore not to be considered limiting of its scope. The figures are for facilitating an understanding of the disclosure and thus are not necessarily drawn to scale. Advantages of the subject matter claimed will become apparent to those skilled in the art upon reading this description in conjunction with the accompanying figures, in which like reference numerals have been used to designate like elements, and in which: 
         FIG.  1    illustrates a known pick-and-place apparatus handling a known carrier tape. 
         FIGS.  2 A and  2 B  illustrate an embodiment of a carrier tape in accordance with an aspect of the present disclosure and a reel on which this carrier tape is wound. 
         FIGS.  3 A and  3 B  illustrate cross-sectional views of the carrier tape of  FIG.  2 A  at two different positions. 
         FIG.  4    illustrates an embodiment of a pick-and-place apparatus configured for handling the carrier tape of  FIG.  2 A . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  2 A and  2 B  illustrate an embodiment of a carrier tape  1  in accordance with an aspect of the present disclosure and a reel  10  on which carrier tape  1  is wound, respectively.  FIGS.  3 A and  3 B  illustrate cross-sectional views of the carrier tape of  FIG.  2 A  at two different positions. The position corresponding to  FIG.  3 A  is indicated by line IIIA, and the position corresponding to  FIG.  3 B  is indicated by line IIIB. 
     Now referring to  FIGS.  3 A and  3 B , carrier tape  1  comprises a polycarbonate or polystyrene carrier tape body  2  having a thickness between 0.2 and 1.0 mm in which a plurality of cavities  3  is provided. An adhesive film  4  covers a first side of carrier tape body  2  and forms a bottom wall  3 A of cavities  3 . Adhesive film  4  comprises an adhesive film carrier  4 B on which an adhesive  4 A is arranged. Adhesive film carrier  4 B may comprise polyolefin, polyvinyl chloride, polyethylene terephthalate, polyimide or a mixture thereof. Adhesive film carrier  4 B generally has a thickness between 25 and 100 micrometer and can be a continuous film carrier or it may comprise a plurality of disjoint patches. 
     Adhesive  4 A is configured for attaching an electrical component  5  to the bottom wall  3 A of a respective cavity  3  among the plurality of cavities  3 . Furthermore, adhesive  4 A is configured to substantially release the attachment of an electrical component  5  as a result of heating the adhesive  4 A and/or as a result of irradiating the adhesive  4 A using light, such as visible light, infrared light, or ultraviolet light. This allows electrical component  5  to be removed from cavity  3  using a pick-and-place apparatus  100  as will be described in conjunction with  FIG.  4   . 
     A temperature at which adhesive  4 A loses its adhesive properties is less than a melting temperature of carrier tape body  2 . For example, the temperature at which adhesive  4 A loses its adhesive properties lies in a range between 120 and 170 degrees Celsius. 
     Carrier tape  1  comprises a plurality of sprocket holes  7  arranged spaced apart along the longitudinal axis of carrier tape body  2 . 
     In  FIG.  3 A  it is shown that carrier tape  1  may comprise a second covering layer  7  arranged on a second side of carrier tape body  2  opposite to the first side. Second covering layer  7  forms a top wall  3 B of cavities  3 . 
     Prior to filling cavities  3  with components  5 , carrier tape  1  may comprise a first covering film  6  arranged on a second side of carrier tape body  2  opposite to the first side. First covering film  6  protects adhesive film  4  prior to using carrier tape  1 . After removing first covering film  6 , components  5  can be arranged inside cavities  3 . After arranging components  5 , second covering layer  7  may be arranged to close off cavities  3 . First covering film  6  and/or second covering film  7  generally do not cover sprocket holes  8 . 
     According to the present disclosure, each cavity  3  can be filled with a plurality of electrical components  5 , which can be arranged in a matrix of rows and columns. Moreover, the components can be identical. 
     Electrical components  5  can be components out of the group consisting of bare semiconductor dies, packaged electrical components, chip scale packages, chip capacitors, and chip resistors. 
       FIG.  4    illustrates a pick-and-place apparatus  100  configured for handling carrier tape  1  of  FIG.  2 A . Several components of pick-and-place apparatus  100  are similar or identical to the components of pick-and-place apparatus  1000  shown in  FIG.  1   . These components are referred to using the same reference signs. 
     Releasing unit  120  of pick-and-place apparatus  100  is configured for substantially releasing the attachment of the electrical component  5  in a cavity  3  of carrier tape  1  by heating the corresponding adhesive  4 A and/or by irradiating adhesive  4 A using light, such as visible light, infrared light, or ultraviolet light. For example, as shown in  FIG.  4   , releasing unit  120  comprises an optical light source, such as a laser  121 . Moreover, releasing unit  120  is arranged to face carrier tape  1  from the first side thereof. 
     Pick-and-place apparatus  100  further comprises a vision system  150  configured to identify one or more electrical components  5  in a given cavity  3  of carrier tape  1 . Controller  160  is configured for controlling pick-and-place unit  130  based on the identified one or more electrical components  5  and configured for controlling releasing unit  120  to release the one or more electrical components  5  in said given cavity  3 . In an embodiment, controller  160  is configured to control releasing unit  120  for releasing all electrical components  5  in said given cavity  3  before pick-and-placing these components  5 . In another embodiment, controller  160  is configured to control releasing unit  120  for releasing one or some of the electrical components  5  in said given cavity  3  before pick-and-placing this component  5  or these components  5 . In particular embodiment, a single component  5  is released each time, which is subsequently pick and placed before releasing a next component  5 . 
     For releasing components  5 , light from laser  121  may be directed to those components  5 . For example, releasing unit  120  may comprise a mirror, such as a MEMS mirror, for directing laser light from laser  121  towards the position of a component to be released next. This position can be determined using image data collected by vision system/camera  150 . This same camera can be used to verify that a given component has been picked, and/or to determine that no more components  5  are present in a cavity  3 . After controller  160  has determined that this latter case applies, it will control carrier tape guiding unit  121  to transport carrier tape  1  to move to a next cavity  3 . More in particular, a next cavity  3  will be brought into alignment with releasing unit  120  and pick-and-place unit  130 . 
     It should be noted that the present application does not exclude other means to bring carrier tape  1  and releasing unit  120  in alignment. For example, laser  121  can be configured to move as a whole instead of or in addition to using a mirror to direct the laser light. 
     In the above, the present disclosure has been described using detailed embodiments thereof. However, the present disclosure is not limited to these embodiments. Instead, various modifications are possible without departing from the scope of the present disclosure which is defined by the appended claims and their equivalents. 
     Particular and preferred aspects of the disclosure are set out in the accompanying independent claims. Combinations of features from the dependent and/or independent claims may be combined as appropriate and not merely as set out in the claims. 
     The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalization thereof irrespective of whether or not it relates to the claimed disclosure or mitigate against any or all of the problems addressed by the present disclosure. The applicant hereby gives notice that new claims may be formulated to such features during prosecution of this application or of any such further application derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in specific combinations enumerated in the claims. 
     Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub combination. 
     The term “comprising” does not exclude other elements or steps, the term “a” or “an” does not exclude a plurality. Reference signs in the claims shall not be construed as limiting the scope of the claims.