Abstract:
Apparatus for advancing and processing a flexible panel in a feed path includes a platen located proximate the feed path, the platen defining a platen surface extending in close proximity parallel to the feed path, a linear array of closely spaced fluid ports formed in the platen for receiving a pressurized fluid and directing the fluid toward the feed path in a transversely elongated fluid path, a transversely elongate chamber fixedly connected to the platen for defining a fluid chamber, the fluid ports being fluid-connected to the chamber; first, second, third and fourth roller shafts rotatably supported transversely to the feed path and having a spaced plurality of rollers thereon for contacting the panel, the first and third roller shafts contacting the panel upstream of the fluid port, the second and fourth roller shafts contacting the panel downstream of the fluid port, the rollers of the third and fourth roller shaft being located in offset overlapping relation to the rollers of the first and second roller shafts, respectively, the roller shafts being driven for advancing the panel proximate the platen, the platen having first wing portions extending between adjacent rollers of the first roller shaft for stripping the panel from the rollers of the first roller shaft, and second wing portions extending between adjacent rollers of the second roller shaft for facilitating passage of the sheet member onto the rollers of the second roller shaft, the fluid making area contact and supporting the panel in closely spaced relation to the platen.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 08/478,994, filed Jun. 7, 1995, now U.S. Pat. No. 5,720,813. 
    
    
     BACKGROUND 
     The present invention relates to equipment for handling, processing and cleaning thin panels, including highly flexible sheet members. 
     In the art of conveyorized fluidic processing of extremely thin articles, such as flexible electronic circuits, it is desirable not only to have a machine that both transports the thin articles from conveyor roller to conveyor roller with minimal damage and delivers fluid efficiently and effectively to its surface(s), but also to have such a machine whose parts are easily disassembled for maintenance purposes. This fluidic processing includes, among others, circuit feature etching, photo resist image developing, surface treatments and depositions, rinsing and drying. 
     When the fluid process incorporates delivering the fluid in streams as a sprayed liquid or ducted air over and/or under a conveyorized roller system with the axes of the rollers transverse the direction of desired article travel, it is necessary to mechanically support the thin articles from below and also often from above while attempting to minimize the interference such support tends to impart on the fluid streams. Without sufficient mechanical support, thin articles tend to buckle, wrinkle and/or jam in the conveyor system, causing unwanted machine downtime and loss of product. Towards such minimized interference, narrow rods with wheels are used for mechanical support, rather than solid cylindrical rollers, the spaces between the wheels being intended to allow for more free travel of the sprayed liquid to reach the surface of the article. Often an opposing set of upper rods and wheels are used to keep the articles from lifting and/or buckling. 
     To minimize downtime during maintenance, both rollers and wheeled rods along with fluid delivery devices, have been designed so as to be able to be disengaged and removed easily and individually from the conveyor system. However, in the case of systems for thin articles, to effectively “hand-off” the article from roller to roller so that gravity or the force of the impinging fluid does not cause the thin article to lift or dive between rollers, multiple clip-on guides which attach to conveyor rods or wires are used for mechanical support. The surface of these guides or wires which are nearest to the desired path of article travel approximately form (a) plane(s) above or below the article, above (between) which the article is directed to travel. A disadvantage of such guides or wires is that they tend to interfere with the spray streams, however, and detract from uniformity of processing. Another disadvantage is that such guides or wires need to be individually removed before free access to the wheeled rods can be obtained, such removal being exceptionally tedious where many guides or wires are used. A design that overcomes this impediment to speedy maintenance removal of wheeled rods is to have the wheels of a larger diameter than the center spacing between adjacent rods, or in other words, overlapping wheels. These wheels are effective at guiding the articles and allow for easy removal and installation for maintenance purposes, but still interfere with the delivery of fluid to the article surface. 
     Thus there is a need for apparatus that overcomes the disadvantages of the prior art. 
     SUMMARY 
     The present invention meets this need by providing an apparatus having a plenum for delivering fluid through one or more orifices or a sieve that is aligned transverse to an article transport path. Wings extend upstream and/or downstream of the plenum and integrate with wheeled rod(s) immediately adjacent thereto. In one aspect of the invention, the apparatus includes a platen member located proximate the feed path, parallel thereto; at least one fluid port formed in the platen member for receiving a pressurized fluid and directing the fluid toward the feed path in a transversely elongated ejecting strip of fluid; a first roller shaft rotatably supported transversely to the feed path and having a spaced plurality of rollers thereon for contacting the panel upstream of the fluid port; a second roller shaft rotatably supported transversely to the feed path and having one or more rollers thereon for contacting the panel downstream of the fluid port; means for driving the first and second roller shafts for advancing the panel proximate the platen member; and the platen member having first wing portions extending between adjacent rollers of the first roller shaft for stripping the panel from the rollers of the first roller shaft, the ejecting strip of fluid making unimpeded contact along the full transverse width of the panel as the panel is advanced. 
     The platen member can define a main platen surface extending in close proximity to the feed path, end extremities of the first wing portions defining spaced segments of a first transition surface that extends between the rollers of the first roller shaft not closer to the feed path than the nip of the rollers of the first roller shaft, the first transition surface smoothly joining the main platen surface for facilitating passage of the sheet member over the platen member. The platen member can further include second wing portions extending between adjacent rollers of the second roller shaft. End extremities of the second wing portions can define spaced segments of a second transition surface that extends between the rollers of the second roller shaft not closer to the feed path than the nip of the rollers of the second roller shaft for facilitating passage of the sheet member onto the rollers of the second roller shaft. The main platen surface can be substantially planar and horizontal. 
     An exit extremity of the fluid port can be elongated in a direction transverse to the feed path. Preferably the apparatus has a linear array of closely spaced fluid ports for producing the elongated ejecting strip of fluid. The apparatus can further include a transversely elongate chamber member fixedly connected to the platen member for defining a fluid chamber, the fluid ports being fluid-connected to the chamber. The chamber member can be integrally formed with the platen member. The apparatus can further include a pair of releasable mounts, each of the releasable mounts being fixably connected proximate a respective end extremity of the chamber member for releasably supporting the platen member and the chamber member relative to the feed path. The fluid ports can extend substantially a full width of the feed path. 
     The apparatus can further include a third roller shaft rotatably supported transversely to the feed path and rotationally coupled to the means for driving, the third roller shaft having a spaced plurality of rollers thereon for contacting the panel upstream of the rollers of the first roller shaft, the rollers of the third roller shaft being located in offset overlapping relation to the rollers of the first roller shaft. The apparatus can further include a fourth roller shaft rotatably supported transversely to the feed path and rotationally coupled to the means for driving, the fourth roller shaft having a spaced plurality of rollers thereon for contacting the panel downstream of the rollers of the second roller shaft, the rollers of the fourth roller shaft being located in offset overlapping relation to the rollers of the second roller shaft. 
     The means for driving can include a powered drive shaft rotatably supported and oriented parallel to the feed path, the drive shaft being coupled in geared relation to each of the roller shafts. The apparatus can further include at least one auxiliary roller shaft rotatably supported transverse to the feed path and having a plurality of rollers thereon for contacting the panel on a side thereof opposite the first and second roller shafts. 
     In another aspect of the invention, an apparatus for guiding and processing a flexible panel in a feed path in association with a first and second roller shafts, each roller shaft having a spaced plurality of rollers thereon for contacting and advancing the panel, includes the platen member defining a main platen surface; means for supporting the platen member with the main platen surface proximate the feed path at a location intermediate the first and second roller shafts; the at least one fluid port formed in the platen member; and the platen member having the first wing portions. 
     The present invention allows for continuous conveyorized processing of thin, discrete articles, is easily removed for maintenance purposes, and delivers fluid directly to the article surface with flow that is unimpeded over a continuous line transverse to the direction of article travel. The device slips easily in and out of the conveyor as one complete unit, simplifying removal for maintenance purposes. 
    
    
     DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where: 
     FIG. 1 is a generalized depiction of a conveyorized processing machine incorporating apparatus according to the present invention for delivering one or more fluids to a flexible panel as it travels along a predetermined feed path; 
     FIG. 2 is an exploded view of the apparatus and a portion of the machine in FIG. 1; 
     FIG. 3 is a cross-sectional front view of the apparatus of FIG. 1; and 
     FIG. 4 is a top view of a lower portion of the apparatus of FIG.  1 . 
    
    
     DESCRIPTION 
     The present invention is directed to apparatus that is particularly useful for advancing, guiding, and processing highly flexible sheet members. With reference to FIGS.  1 - 4  of the drawings, FIG. 1 depicts a general representation of a conveyorized processing machine  10 , with an input module  12 , a first processing module  14 , a second processing module  16 , a drying module  18  and an output module  20 . A flexible panel  22  is transported along a feed path  24  on a conveyor  91 . Each of the modules  12  through  20  serve to transport the flexible panel  22 , while the modules  14  through  18  additionally deliver at least one processing fluid (liquid or gaseous) to at least one surface of the flexible panel  22 , and are separable from each other for addition or subtraction of processes to the machine  10 . The processing fluids which are applied can include, but are not limited to, processes such as photo resist developing, etching, through-hole treatment, plating, rinsing, surface treatment, anti-tarnish, drying and the like. 
     The flexible panel  22  can be a flexible circuit member, such as plated and/or etched copper lines on polyamide, epoxy-glass laminate or kapton, but might also be other thin, flexible articles which are to be processed, such as shadow masks, photographic films, thin glass sheets, or etc. Fluid delivery is achieved by the means of pumps, blowers, and the like (not shown), and in the case of liquid process fluids, is usually recirculated from a tank or sump within each module. The materials of construction for each of the modules in the machine  10  are compatible with their respective processing fluids and can include for example, polyvinyl chloride (PVC), chloro-polyvinyl chloride (CPVC), titanium, stainless steel, kynar, polypropylene, polycarbonate (Lexan) and/or tempered glass. 
     According to the present invention, the machine  10  is provided with one or more processing apparatus  30 , one such apparatus  30  being located in the second processing module  16 . It is contemplated that counterparts of the apparatus  30  may be utilized in the first processing module  14  and the drying module  18 . With particular reference to FIG. 2, the apparatus  30  is shown in relation to the conveyor  91  internal to a fluid process module in the processing machine  10 , looking from the back side of the view shown in FIG. 1. A pair of conveyor rails  38  for the preferred embodiment provide rotational support for both a drive shaft  42  (supported by one of the rails  38  only, by means of a plurality of drive shaft bearing blocks  46 ), and also for a plurality of lower roller shafts  90  (by means of a plurality of roller shaft bearing blocks  36 ). One or more drive motors (not shown) rotate(s) the drive shaft  42  and a plurality of drive shaft gears  44  extending along the drive shaft  42 , which engagingly turn a plurality of roller shaft gears  34 , the lower roller shafts  90  each with a plurality of lower rollers  80 , which engage the flexible panel  22  for transport along the feed path  24 . In the preferred embodiment, the rails  38  are machined from ½″ thick PVC, CPVC or polypropylene plastic. 
     A lower fluid delivery device  50  with an integral fluid chamber  52 , an integral lower platen member  54  having a platen surface  55 , and a pair of lower mounting blocks  56  (on both ends). The platen member  54  has a plurality of fluid ports  74  formed therein for directing pressurized fluid to at least a lower surface  23  of the flexible panel  22 . In the preferred embodiment, these fluid ports are a row of drilled holes about 0.063 in. in diameter which are substantially normal to the surface  55  of the lower platen member  54  and spaced on 0.250 in. centers in a line transverse to the feed path  24 . Other embodiments can be envisioned, such as a single, continuous elongated slot, a series of slanted slots, or arrays of ports of any of a number of shapes, and/or ports drilled at angles varying from normal to nearly tangential to the surface  55  of the platen member  54 , without departing from the intent of the present invention, which is to provide at least one surface of the flexible panel  22  with processing fluid across an elongate area, which elongate area is to be simultaneously unimpeded with any substantial mechanical fluid flow blockage between the surface  55  of the platen member  54  and the flexible panel surface  23 , this unimpeded region being continuous in a strip across the transverse width of the flexible panel  22 . Although this preferred embodiment delivers processing fluid in jets which impinge on the surface of the panel  22 , the fluid may be applied relatively quiescently for processes sensitive to high flow rates as well. Additionally, the aforementioned conveyor  91  and the lower fluid delivery device  50  may transport and process the panel  22  in a vertical, rather than horizontal, configuration. 
     An optional upper fluid delivery device  60  with an integral upper fluid chamber  62 , an upper platen member  64  (having a platen surface  65 ) and upper mounting blocks  66  has counterparts of the fluid ports  74  (hidden from view in FIG. 2) for directing pressurized fluid to at least an upper surface  25  of the flexible panel  22 . Both of the fluid delivery devices  50  and  60  have at least one inlet  70  (shown only for the upper device  60 ) attached by a plumbing union  72  for receiving processing fluid from the aforementioned pumps or blowers. The fluid ports  74 , the union  72 , and the inlet  70  are not necessarily identical for the devices  50  and  60 , nor are the ports  74  necessarily identical within the devices  50  or  60 . 
     The conveyor  91  consists of a plurality of roller assemblies  81  which each consist of one of the roller shafts  90 , two of the roller shaft bearing blocks  36 , one of the roller shaft gears  34 , and one or more of the lower rollers  80 . The preferred embodiment optionally allows for an upper roller shaft  190  (each with a plurality of upper rollers  180 ) which can slide into grooves (not shown) in the roller shaft bearing blocks  36 , in order to maintain the flexible panel  22  within the desired feed path. The upper roller shafts  190  and their rollers  180  can slide freely up and down in the grooves in the roller bearing blocks  36  during operation and for removal, and each assembly  81  can be removed as a unit. Also in the preferred embodiment, the lower rollers  80  are 2.25 inches in diameter and approximately ⅛ in. thick, and the roller assemblies  81  are spaced on a two-inch longitudinal pitch along the conveyor  91 . Alternatively, the lower rollers  80  can be much thicker, and can comprise a substantial portion of the width of the conveyor. As will be further discussed with FIGS. 3 and 4, such an arrangement of pitch distance being less than roller diameter allows for overlapping of the rollers  80  along the feed path  24 . 
     Materials of construction for the rollers  80  and  180  can include EPDM, polypropylene, or other material which is resistant to decomposition under the desired operating conditions. The preferred embodiment also includes perforations (not shown) within each of the rollers  80  and  180  to allow lighter weight and/or to minimize the blockage of fluid flow in a transverse direction. The roller shafts  90  and  190  for the preferred embodiment are constructed of epoxy-coated 0.375 inch diameter fiberglass rods, and the bearing blocks  36  and  46 , along with the gears  34  and  44 , are molded polypropylene. For most uses of the fluid delivery devices  50  and  60 , a preferred material is extruded PVC. The fluid delivery device  50  is extruded in one piece along with a lower forward wing portion  100  and a lower rearward wing portion  104  (both attached to the lower device  50 ). Similarly, the fluid delivery device  60  is extruded in one piece along with an upper forward wing portion  200  and an upper rearward wing portion  204  (both attached to the upper device  60 ), which wing portions  100 ,  104 ,  200  and  204  are then subsequently machined to create a plurality on each wing of spaced segments  101 ,  105 ,  201  and  205 , respectively. Dispersion plates (not shown) may be included within the chambers  52  and/or  62  to help uniformly distribute the fluid pressure among the fluid ports  74 . End plugs which include the respective mounting blocks  56  and  66  are glued in to seal the ends of fluid chambers  52  and  62 , respectively. In the preferred embodiment, the fluid chambers  52  and  62  are approximately 1⅝ in. wide by 1⅞ in. tall, with the winged portions  100 ,  104 ,  200  and  204  extending approximately 2 in. out from the sides of fluid chambers  52  or  62 . The thickness of the winged portions  100 ,  104 ,  200  and  204  and of the walls of the fluid chambers  52  and  62  is approximately 0.25 in. The spaced segments  101 ,  105 ,  201  and  205  are all approximately of equal rectangular dimensions (though not necessarily so) and are about 1.625 (in the direction parallel to feed path  24 ) in. by 0.875 in. (in the transverse direction) with spaces between them (in the transverse direction) of about 0.375 in. It is noted here that other dimensions and spacings may be used, the main purpose being to support the flexible panel  22  sufficiently while not interfering with the rotation of the rollers  80  or  180 . 
     With further reference to FIG. 2, access to areas above or below the conveyor  91  for maintenance purposes is facilitated by sliding the roller assemblies  81  out of one of a plurality of conveyor rail slots  40  in the conveyor rails  38 . Similarly, one or both of the fluid delivery devices  50  and  60  may be removed by sliding the respective mounting blocks  56  and  66  out of the conveyor rail slots  40  and by undoing the plumbing unions  72 . This aspect of simple removal of the fluid delivery devices  50  and/or  60  is one of the useful advantages of the inventive apparatus, while still maintaining support of the flexible panels  22  as they are being transported during operation, as further described below. Although just one configuration of simple, independent removal of the fluid delivery devices  50  and  60  has been disclosed in detail, other configurations can be used (such as using flexible hoses with hose clamps in place of rigid plumbing with the plumbing unions  72  or releasable clamps and brackets in place of slidable roller shaft bearing blocks  36 ) to allow for the desired removability, and need not be exhaustively described. 
     With reference to FIGS. 3 and 4, the working relationship of the rollers  80  and  180  and the fluid delivery devices  50  and  60  can be seen. The rollers  80  as they relate to the fluid devices  50  consist of a first lower roller set  82  immediately forward of the lower device  50 , a second lower roller set  84  immediately to the rear of the lower device  50 , a third lower roller set  86  forward of the first lower roller set  82 , and a fourth lower roller set  88  immediately to the rear of the second lower roller set  84 . Immediately above the lower sets  82 ,  84 ,  86  and  88  are a first upper roller set  182 , a second upper roller set  184 , a third upper roller set  186 , and a fourth upper roller set  188 , respectively. Corresponding to roller sets  82  through  88  and  182  through  188  are first through fourth lower roller shafts  92 ,  94 ,  96  and  98  and first through fourth upper roller shafts  192 ,  194 ,  196  and  198 , respectively. The lower roller sets  82  through  88  are all driven in a clockwise direction as indicated by a lower direction arrow  89 , by means of the respective roller shafts  92 - 98 , which are all engaged with the drive shaft  42  in the manner described for FIG.  2 . Likewise, the upper roller sets  182  through  188  are all rotated in a counter clockwise direction as indicated by a upper direction arrow  189 . Note that in FIG. 3 the upper rollers  180  and the upper roller shafts  190  are depicted (for ease of numbering) at an exaggerated vertical spacing from the lower rollers, while in actual operation the upper rollers  180  will actually contact the corresponding lower rollers  80  when there is no panel between them. The upper rollers  180  are idler rollers, and are driven in a counterclockwise direction by the rotation of the lower rollers  80  and/or the passage of the flexible panel  22  beneath them. One or more of the upper roller shafts  190  and upper rollers  180  may optionally be driven as well. 
     In operation, as the flexible panel  22  travels across the rollers  80  past respective roller nips  99  and corresponding nips  199  on the rollers  180 . As used herein “nip” refers to a tangential point on a roller nearest the intended feed path  24 . Regarding the rollers  180  of the upper fluid delivery device  60 , both gravity and fluid flow would tend to combine to pull the leading edge of flexible panel  22  downward away from the intended feed path  24 , which ultimately could lead to the panel straying from the feed path  24  and/or jamming in the conveyor  91  or surrounding apparatuses, both of which would lend to undesirable loss of production time, materials and/or labor. To avoid this difficulty, the present invention provides that after the flexible panel  22  has passed the nip  99  of the first lower roller set  82 , the extremities of the forward wing portion  100  and the surface  55  of the platen member  54  extends out from the fluid chamber  52  and divides into the segments  101  which overlap into the spaces between the rollers  82  and which provide a lower transition surface  102 , elevated slightly below the nip  99  of the lower set  82 , for guiding and/or supporting the flexible panel  22  so that it travels across lower platen member  54  and is brought in contact with a transversely elongate ejecting strip of fluid  76 . 
     The vertical position of the fluid delivery devices  50  and  60  relative to the feed path  24  can be adjusted by using set screws (not shown) in a lower set-screw hole  58  and an upper set-screw hole  68 , and is preferably set so that the surfaces  55  and  65  of the platens  54  and  64  are 0.150 in. further from feed path  24  than the nips  99  and  199  of the rollers  80  and  180 , respectively. The set screws for the lower device  50  adjust height off of the bottom of the rail slots  40  (see FIG.  2 ), and the set-screws for upper device  60  adjusts height off of the top of the lower mounting block  56 . Note that use of these set screws allows for adjustability while not interfering with the relatively easy removal of the devices  50  and  60  from the conveyor rails  38 . In the preferred embodiment, the set screws are #1/4-20 by 1 in. long and are made of either stainless steel or titanium metal. 
     As the flexible panel  22  passes proximate the ejecting strip of fluid  76 , the strip of fluid may additionally provide a fluid bearing between the lower surface  23  of flexible panel  22  and the upper surface  55  of the platen member  54 , significantly reducing the friction therebetween and further easing its transport. In this way, both the objectives of maintaining the desired transport direction of the panel and of delivering processing fluid to at least the lower surface  23  in the transverse elongate area in the vicinity of the ejecting strip of fluid  76  without mechanical impediments to flow, are achieved. 
     Similarly for FIGS. 3 and 4, on the downstream side of the lower fluid delivery device  50 , the lower rearward wing portion  102  can also be extended outwards from the fluid chamber  52  and can be divided into the lower rearward segments  105  which overlap into the spaces between the rollers  80  of the second lower roller set  84 . This aids in smoothly guiding flexible panel  22  onto second lower roller set  84 . Likewise, although not shown in FIG. 4, the optional upper fluid delivery device  60  can be used with the upper forward and rearward wing portions  200  and  204  with the upper segments  201  and  205  that overlap the spaces between upper rollers  180  of upper roller sets  182  and  184 , respectively. These upper forward and rearward wing portions  200  and  204  provide transition surfaces  202  and  206  for preventing flexible panel  22  from diverting upward away from the intended feed path  24  due to either surface tension effects or fluid flow or pressures. 
     Also depicted in FIGS. 3 and 4 is the overlapping between adjacent lower roller sets  82  and  86  as well as the sets  84  and  88 . Without such overlap, the flexible panel  22  might tend to fall between these roller pairs and would become diverted away from being adequately or completely processed along the feed path  24 , or would become jammed in the conveyor  91 , either of which can detract from processing yields and/or quality. Similarly, the preferred embodiment optionally includes overlapping between pairs of upper roller sets  182  and  186  and between sets  184  and  188 . 
     Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not necessarily be limited to the description of the preferred versions contained herein.