Abstract:
Guide rails for guiding a band-form member such as a film carrier tape in a semiconductor manufacturing apparatus. The guide rails include a pair of rail main bodies with a plurality of guide assemblies provided on the upper surfaces of the rail main bodies so that the guide assemblies partially guide the upper surface of the band-form member.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to guide rails used in a semiconductor manufacturing apparatus for conveying band-form members such as a film carrier tape. 
   2. Prior Art 
   Typical band-form member conveying guide rails used in a semiconductor manufacturing apparatus have a structure as shown in  FIGS. 3(   a ) and  3 ( b ). 
   In this guide rail structure, a pair of guide rails  2 A and  2 B that guide both side portions of a band-form member  1  are installed so as to face each other. The guide rails  2 A and  2 B consist of rail main bodies  3 A and  3 B and vertical-direction guide plates  4 A and  4 B. The vertical-direction guide plates  4 A and  4 B are fastened to the upper surfaces of the rail main bodies  3 A and  3 B so as to form guide grooves  5 A and  5 B between the rail main bodies  3 A and  3 B and vertical-direction guide plates  4 A and  4 B, thus guiding the band-form members  1  in the vertical direction. 
   Guide rails  2 A and  2 B of this type are disclosed in, for instance, Japanese Patent Application Publication (Kokoku) No. H2-54664. In this prior art, a pair of guide rails are provided with upper plates with guide grooves in between. 
   In these conventional band-form member conveying guide rails, the band-form member  1  is conveyed while the entire upper and lower surfaces of both side portions of the band-form member  1  are regulated in the vertical direction by the guide grooves  5 A and  5 B that are formed by the rail main bodies  3 A and  3 B and vertical-direction guide plates  4 A and  4 B. Accordingly, the frictional resistance during the conveyance tends to be large. In particular, when the band-form member  1  is a film carrier tape, the thickness is as thin as 25 to 125 μm, and it is flexible. Thus, undulation and twisting, etc. would occur during the conveying process. As a result of such undulation and twisting, etc., the frictional resistance of the upper and lower surfaces of side portions of the tab tape against the guide grooves  5 A and  5 B increases, and problems such as shape deformation of the tab tape and damage to the tab tape, etc. occur. In cases where the band-form member  1  is a lead frame, undulation and twisting, etc. would not occur; however, when the frictional resistance is high, the motive power of the conveying power supply needs to be increased. 
   Furthermore, when some type of trouble occurs during the conveying of the band-form member  1 , the conveyance must be stopped so as to remove the band-form member  1  from the guide grooves  5 A and  5 B. However, since the guide grooves  5 A and  5 B of the prior art are in a continuous form, it is difficult to remove the band-form member  1  out of these guide grooves  5 A and  5 B. 
   SUMMARY OF THE INVENTION 
   Accordingly, the object of the present invention is to provide band-form member conveying guide rails in which the frictional resistance is reduced, and band-form members can easily be removed from the guide assemblies. 
   The above object is accomplished by a unique structure of a band-form member conveying guide rails that comprise a pair of guide rails disposed facing each other so as to guide both side portions of a band-form member, and each of the guide rails is comprised of a rail main body and a plurality of guide assemblies, in which the guide assemblies are spacedly installed on the upper surface of the rail main body so that they can guide a part of the upper surface of the band-form member. 
   In this structure, each of the guide assemblies are comprised of a width-direction guide element and a vertical-direction guide element; and the width-direction guide element is fastened to the rail main body at fixed intervals in the conveying direction of the band-form member so as to guide the band-form member in the width direction, and the vertical-direction guide element is disposed on the width-direction guide element so as to guide the band-form member in the vertical direction. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1(   a ) is a perspective view of the first embodiment of the band-form member conveying guide rails according to the present invention, and  FIG. 1(   b ) is a view taken from the conveying direction; 
       FIG. 2(   a ) is a perspective view of the second embodiment of the band-form member conveying guide rails according to the present invention, and  FIG. 2(   b ) is a view taken from the conveying direction; and 
       FIG. 3(   a ) is a perspective view of a conventional example of band-form member conveying guide rails, and  FIG. 3(   b ) is a view taken from the conveying direction. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A first embodiment of the present invention will be described with reference to  FIGS. 1(   a ) and  1 ( b ). 
   A pair of guide rails  10 A and  10 B are installed facing each other so as to guide both sides portions of a band-form member  1 , which is, for instance, a film carrier tape which has some degree of flexibility. The guide rails  10 A and  10 B comprise rail main bodies  11 A and  11 B and a plurality of guide assemblies  12 A and  12 B. 
   The guide assemblies  12 A and  12 B are provided on the upper surfaces of the rail main bodies  11 A and  11 B along the conveying direction of the band-form member  1  indicated by an arrow C or in the length-wise direction of the rail main bodies  11 A and  11 B. The guide assemblies  12 A and  12 B are comprised of shaft members  13 A and  13 B and flange members  14 A and  14 B. The shaft members  13 A and  13 B are provided so as to act as a width-direction guide that guides the band-form member  1  in the direction of width (shown by arrow W); and the flange members  14 A and  14 B are provided so as to act as a vertical-direction guide that guides the band-form members  1  in the vertical direction (shown by arrow V). In this embodiment, the shaft members  13 A and  13 B are cylindrical pillars having heights greater than the thickness of the band-from member  1  to be conveyed, and the flange members  14 A and  14 B are circular plates having a larger diameter than the shaft members  13 A and  13 B and installed on the tops of the shaft members  13 A and  13 B in a coaxial fashion. 
   Accordingly, the band-form member  1  is conveyed while being regulated in the vertical direction by the spaces between the upper surfaces of the rail main bodies  11 A and  11 B and the undersurfaces of the flange members  14 A and  14 B. In this case, the upper surface of the band-form member  1  is partially regulated by the flange members  14 A and  14 B, in other words, the upper surface of the band-form member  1  is regulated only at points where the upper surface of the band-form member  1  is in contact with the flange members  14 A and  1 B; and the portions between the guide assemblies  12 A and  12 B in the conveying direction are not regulated. Accordingly, the frictional resistance during conveying is alleviated, deformation and damage, etc. is less likely occur in the band-form member  1 , and only a small conveying power supply is required. 
   When some type of trouble occurs during the conveying process of the band-form member  1 , it is necessary to stop the conveying and take out the band-form member  1  from the surfaces of the rail main bodies  11 A and  11 B. In this case, according to the present invention, it is only necessary to remove the band-form member  1  from the guide assemblies  12 A and  12 B. Thus, the band-form member  1  can easily be taken out of the rail main bodies  11 A and  11 B. Furthermore, after the band-form member  1  has been removed and the trouble has been taken care of, it is necessary merely to insert the band-form member  1  back into the guide assemblies  12 A and  12 B. Thus, the band-form member  1  can easily be returned to the guide rails  10 A and  10 B. 
     FIG. 2  illustrates a second embodiment of the present invention. 
   In this embodiment, instead of the flange members  14 A and  14 B used in the first embodiment, rollers  21 A and  21 B are employed. More specifically, the guide assemblies  12 A and  12 B are comprised of pin shafts  20 A and  20 B, which are provided on the rail main bodies  11 A and  11 B, and rollers  21 A and  21 B, which are installed on these pin shafts  20 A and  20 B in a rotatable fashion. Like the first embodiment, the pin shafts  20 A and  20 B are cylindrical pillars having heights greater than the thickness of the band-from member  1  to be conveyed, and the rollers  21 A and  21 B are circular in shape with a larger diameter than the pin shafts  20 A and  20 B and installed on tops of the shaft members  13 A and  13 B in a coaxial fashion. 
   Accordingly, in this second embodiment, the spaces between the pin shafts  20 A and  20 B regulate the horizontal movement of the band-form member  1 , and the spaces between the upper surfaces of the rail main bodies  11 A and  11 B and the undersurfaces of the rollers  21 A and  21 B partially regulate the band-form members  1  in the vertical direction, in the same manner as in the first embodiment. In the second embodiment, the rollers  21 A and  21 B can rotate and make rolling contact when the band-form member  1  is conveyed. Accordingly, the frictional resistance is reduced even further than in the first embodiment. Furthermore, the band-form member  1  can easily be removed from the guide rails  10 A and  10 B. 
   As seen from the above, according to the present invention, the frictional resistance during the conveying process of band-form members is alleviated, and also the band-form members can easily be taken out of the guide assembly.