Abstract:
Equipment for the automated affixation of contacts and contact housings to segments of flexible printed circuits includes a holding device which holds the segment and raises the segment up from a starting position in the plane of the flexible printed circuit. The segment is firmly retained during processing when a contact is applied and a housing mounted. After processing, the segment is returned to approximately its starting position. Detectors may be used to position the holding device as appropriate to process a desired segment which may be rotated upwardly along a circular guide into the processing position.

Description:
[0001]    The invention relates to equipment for fitting out a flexible printed circuit with at least one segment comprising at least one conductor end, wherein the segment is part of the flexible printed circuit and can be raised up for processing.  
         BACKGROUND OF THE INVENTION  
         [0002]    Flexible printed circuits (FPCs) consist of at least one layer of electrically insulating material and at least one layer of electrically conductive material. Copper, which is mounted on a base film, is usually used as the electrically conductive material. The production of conductor tracks or paths is usually carried out by means of a chemical process. The copper surface required for the conductor tracks is covered. The unprotected copper surface is subsequently removed, for example, by means of an etching process. Complex conductor track arrangements and minimal conductor track spacings can be made by this production technique. Connection with the conductor tracks is made by means of, for example, a soldering technique or a crimping technique. In the case of a soldered connection, solder with a low melting point connects, under the action of heat, the copper of the conductor track with, for example, a contact leg of a plug. In the case of a crimp connection, the contacts are mechanically connected with the conductor track.  
           [0003]    At the end of at least one conductor track the flexible printed circuit may be slit or slotted at the sides and at the end of the conductor track or tracks (the loose part with the conductor track ends is termed a “segment”). A contact is connected with the conductor track by means of a crimping process at the now freely movable conductor track end. In that case claws of the contact pierce the flexible printed circuit in a piercing process and are bent over on the rear side of the flexible printed circuit in a crimping process. The contact is fixedly connected with the flexible printed circuit by the plastic deformation of the claws, whereby the electrical transfer between conductor track and contact is guaranteed. After application of the contact or contacts to the freely movable conductor track ends or segments the contact or contacts are plugged or inserted into a housing.  
           [0004]    Semi-automatic equipment which apply the contacts to the conductor tracks and fit the contacts with housings are known from the state of the art. The flexible printed circuits bearing the conductor tracks are fed individually or from rolls, wherein the segments are previously slotted. The segments are manually raised up and fed to the crimping process. After processing, the segment is brought back approximately into the original position.  
           [0005]    The productivity of the entire installation is limited by the manual feed of the segments.  
           [0006]    The present invention has an object of avoiding the disadvantages of the known equipment and of creating equipment by means of which the processing of flexible printed circuits can be undertaken more efficiently, avoiding manual positioning of segments to be fitted with contacts.  
         BRIEF DESCRIPTION OF THE INVENTION  
         [0007]    In accordance with the invention, a device for processing flexible printed circuits having at least one segment includes a holding device which raises the segment, firmly holds the segment for processing, and returns the segment to the starting position after processing.  
           [0008]    The advantages achieved by the invention are essentially to be seen in that productivity can be increased and printed circuit quality can be improved. The device according to the invention is arranged above a support carrying the flexible conductor track and necessary for the transport of the conductor track. Passages in the support are not necessary for the handling of the flexible printed circuits. Due to the smooth support free of passages, neither scratches nor damage to the flexible printed circuit can arise during transport.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The present invention is explained in more detail in the following description and accompanying figures, in which:  
         [0010]    [0010]FIG. 1 is a perspective view of a detail of a flexible printed circuit with segments;  
         [0011]    [0011]FIG. 2 is a perspective view of equipped segments of the printed circuit;  
         [0012]    [0012]FIG. 3 is a detail perspective view of a segment rear side with equipped contacts;  
         [0013]    [0013]FIG. 4 is a detail perspective view of a segment conductor side with equipped contacts;  
         [0014]    [0014]FIG. 4 a  is a detail perspective view of strip-connected contacts before the installation;  
         [0015]    [0015]FIG. 5 is a plan view of equipment in according with the invention for fitting out a flexible printed circuit with segments;  
         [0016]    [0016]FIG. 6 is a perspective view of a crimping press for equipping a segment with contacts;  
         [0017]    [0017]FIG. 7 is an elevation view of a housing equipping means for fitting the contacts with a housing and a holding device for holding the segment to be equipped;  
         [0018]    [0018]FIG. 8 shows a variant of arrangement of the holding device;  
         [0019]    [0019]FIG. 9 is a plan view of the holding device before the raising-up of a segment; and  
         [0020]    [0020]FIG. 10 is an elevation view of the holding device when holding the segment during the equipping process. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]    [0021]FIG. 1 shows a detail of a flexible printed circuit  1  with electrical conductor tracks  2 . At the end of at least one conductor track  2  the flexible printed circuit  1  is slit or slotted laterally and at the end of the conductor track  2 . The freely movable part with the conductor track ends, also termed a segment, is denoted by  3 .  
         [0022]    [0022]FIG. 2 shows equipped segments  3  of the flexible printed circuit  1 . Electrical contacts  4  are connected by means of a crimping process with the conductor tracks  2  at the freely movable conductor track ends, wherein the contacts  4  are fitted into housings  5 .  
         [0023]    [0023]FIG. 3 shows a segment rear side with fitted contacts  4 , wherein each contact  4  is provided with claws  6 . The claws  6  of the contact  4  pierce in a piercing process the flexible printed circuit  1  and are, as shown in FIG. 4, bent over on the conductor side of the flexible printed circuit  1  in a crimping process. The claws  6  pierce the flexible printed circuit  1  near the conductor tracks  2  and are bent over onto the conductor tracks  2 . Contacts can also be provided, the claws of which pierce the conductor tracks. By virtue of the plastic deformation of the claws  6  the contact  4  is fixedly connected with the flexible printed circuit  1 , whereby the electrical transfer between conductor track  2  and contact  4  is guaranteed.  
         [0024]    [0024]FIG. 4 a  shows a belt product or strip-connected contacts  4  before the fitting. The strip-connected contacts  4  are available for the crimping process from rolls and are separated from the tape portion  4 . 1  before crimping.  
         [0025]    [0025]FIG. 5 shows a plan view of equipment for fitting out a flexible printed circuit  1  having segments  3 . The flexible printed circuit  1  is fed in the arrow direction P 1  in an inlet station  7  from a roll  7 . 1  by means of draw-off rollers  7 . 2  to a draw-off station  8 , which has a cutting device  8 . 1  at its entrance. The cutting device  8 . 1  cuts the flexible printed circuit  1  to the desired length or to the desired panel.  
         [0026]    The panel is transported in the arrow direction P 1 . 1  to a first processing station  11  by means of holding grippers  9 , which serve as a guide and holder, and transport grippers  10 , which serve as advancing means. As shown in FIG. 5, holding grippers  9  and transport grippers  10  are arranged on both sides of the panel to be transported. Holding grippers  9  and transport grippers  10  can also be arranged on only one side of the panel. In the first processing station  11  the segments  3  are raised up and provided with contacts  4 , which are plugged into a housing  5  per segment  3 . A crimping press  14  and a housing equipping means  15  are arranged at a first platform  13  movable in the arrow direction P 2  along first linear axles  12 . The drive for the first platform  13  is not illustrated. A holding device  16  arranged below the first platform  13  raises the segments  3  up from the flexible printed circuit  1 , firmly holds the segments  3  during the processing and thereafter brings the segments  3  back into their original position. The crimping press  14  is supplied with contacts  4 , which are available in strip-connected form from rolls  18 . A housing bin  19  keeps a supply of the housings  5  ready for the housing equipping means  15 .  
         [0027]    In a further processing station  17 , segments  3  may be fitted with contacts different from the contacts  4  of the first processing station  11 . A further processing station is provided for each kind of contact or orientation of the segment to be equipped, wherein the processing stations are comparable in construction. The housing equipping means  15  of the further processing station  17  similarly receives housings  5  from the corresponding housing bin  19 . After the last processing station, there is provided an outlet station which stacks and delivers the fitted-out panels.  
         [0028]    [0028]FIG. 6 shows schematically the crimping press  14  for equipping a segment  3  with contacts  4 . The contacts  4  are fed in strip-connected form to a first feeder  20  which separates the contacts  4  by means of a knife  21 . An upper crimping die  22  picks up the contacts  4  individually and equips the segment  3  held by means of the holding device  16 , wherein the claws  6  pierce the segment  3  and are bent over onto the conductor track  2 , as shown in FIG. 4, by means of a lower crimping die  23 . Before the equipping, the first platform  13  has been positioned on the segment  3  by means of a first detector scanning the edge of the segment  3 . A second detector  24  scans at least the first conductor track  4  of the segment  3  and positions the upper crimping die  22  and the lower crimping die  23  on the conductor track  2  to be equipped. A first drive  25  is provided for crimping movement of the upper crimping die  22 . A second drive  26  positions the upper crimping die  22  and the third drive  27  positions the lower crimping die  23  on the conductor track  2  to be equipped.  
         [0029]    [0029]FIG. 7 shows the housing equipping means  15  for fitting at least one contact  4  with a housing  5  and the holding device  16  for holding the segment  3  to be equipped. The housing equipping means  15  is arranged at the first platform  13 , which is movable along the first linear axles  12  transversely to the transport direction of the flexible printed circuit  1 . The linear axles  12  are supported on a fixed support  40  and at least one linear axle  12  is provided with a linear drive, which is not illustrated. The housings  5  are stored in a first housing tube or shaft  28 , wherein the housings  5  are dispensed from the housing bin  19 . The contacts  4  arranged in the raised-up segment  3  are aligned and held by means of a positioning plate  31 . 1 , wherein an adjustable double-sided comb embraces the contacts. A first ram  30  driven by means of a first cylinder  29  pushes a housing  5 , which is stored in a second housing shaft  31 , over the contacts of the segment  3  held by means of the holding device  16 . Thereafter a second ram  33  driven by means of a second cylinder  32  closes the housing  5 . After retraction of the rams  30 ,  33  the second housing shaft  31  is free for reception of a further housing  5 , which is transported into the housing shaft  31  by means of a second feeder  34 .  
         [0030]    Carriers  35 , which carry a second platform  36 , are arranged at the first platform  13 . The platform  36  is mounted to be displaceable along second linear axles  37 , wherein a second linear drive  38  moves the second platform  36 . The second platform  36 , movable transversely to the direction of transport of the flexible printed circuit  1 , serves as a carrier for the holding device  16 , which is arranged above a support  39  carrying the flexible printed circuit  1 . During the equipping process the second platform  36  executes a counter-movement relative to the movement of the first platform  13 , wherein the holding device  16  remains stationary relative to the flexible printed circuit  1 . When the first platform  13  moves for driving the crimping press  14  or the housing equipping means  14  up to the segment  3  to be equipped, the holding device  16  remains stationary.  
         [0031]    [0031]FIGS. 8, 9 and  10  show a variant arrangement of the holding device  16 . The second platform  36  is not, as shown above, connected with the first platform  13 . The carriers  35  of the second platform  36  are supported on the fixed support  40 . The second platform  36  together with the holding device  16  is positioned on the segment  3  to be equipped and then remains stationary during the equipping process.  
         [0032]    [0032]FIG. 8 and FIG. 9 show the holding device  16  before the raising-up of a segment  3 . A third detector  41  scans the end edge of the segment  3  and stops the advance of the flexible printed circuit  1 . A fourth detector  51  scans the side edge of the segment  3  and positions the holding device  16  in the transverse direction relative to the flexible printed circuit  1  on the segment  3  to be equipped. A vacuum gripper  43  arranged at a slide  42  grips the segment  3  as vacuum is applied to the vacuum gripper  43 . A third cylinder  44  executes, by its piston rod  45 , a movement in the arrow direction P 3 , rotating the slide  42  along a circular guide  50  through 90° up to abutment  46 , whereby the segment  3  is raised up. A piston rod  47  of a fourth cylinder  48  is then driven out, whereby the piston rod  47  presses a die  49  onto the rear side of the segment  3  against the vacuum gripper  43 . The segment  3  is now, as shown in FIG. 10, firmly held between vacuum gripper  43  and die  49  until the equipping process is concluded. Thereafter the die  49  is retracted, the slide  42  rotated back through 90° by means of the third cylinder  44  and the vacuum gripper  43  detached as pressure is applied to the vacuum gripper  43 . The equipped segment  3  is then again in the approximate starting position.  
         [0033]    The two lefthand segments  3  of the printed circuit  1  shown in FIG. 1 can be raised up by the orientation of the holding device  16  shown in FIGS.  7  to  10 . The raising up takes place in the anticlockwise sense. The remaining segments  3  of the printed circuit  1  shown in FIG. 1 have to be raised up in clockwise sense. For that purpose the holding device  16  is so oriented in the respective processing station that the slide  42  executes a movement in the clockwise sense.  
         [0034]    The above-explained processing of the segment  3  comprises the equipping of the segments  3  with contacts  4  and the fitting of the contacts  4  with housings  5 . The holding device  16  for raising up the segments  3  can also be used for other operations, such as, for example, cleaning the conductor tracks, preparing the conductor tracks for the soldering process, producing soldered connections or application of bores or punchings to the segments  3  and/or to the conductor tracks  2  of the segments  3 .