Patent Publication Number: US-2007108044-A1

Title: Plating tank

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      The entire disclosure of Japanese Patent Application No. 2005-300255 including specification, claims, drawings and summary are incorporated herein by reference in its entirety.  
     FIELD OF THE INVENTION  
      The present invention relates to the skill which is used for electroplating a platy work, for example printed board etc., by a surface treatment device like an electroplating device.  
     BACKGROUND ART  
      A conventional surface treatment device like an electroplating device treats a platy work which is secured to a rack as to transfer without swinging. However, the surface treatment device of rackless type is suggested, because it is bothering task to mount the platy work in the rack and it is so large load that the device grows in size.  
      As a surface treatment device of rackless type like this, Japanese Laid Open Patent Application No. 2002-363796 (Patent Document 1) is known. Referring to  FIG. 14  and  FIG. 15 , the structure of the surface treatment device will be described as follows.  FIG. 14  shows plane view of the surface treatment device  300  from upside.  FIG. 15  shows side view of the surface treatment device  300  from α-direction.  
      As shown in  FIG. 14  and  FIG. 15 , the surface treatment device  300  is the surface treatment device of so-called pusher type, and has guide rails  10 - 13  for transporting the transport hanger  15  which is holding the platy work such as a printed board. Along with these guide rails  10 - 13 , the surface treatment device  300  has the pre-treatment tank  1  of each type for processing before plating, plating tank  2  for electroplating, recovery tank  3  and water-washing tank  4  for processing after plating, unload section  5  for unloading the platy work, exfoliate tank  6  for separating plating films (hanger restoring process), water-washing tank  7  for water-washing the transport hanger  15  after separating, and load section  8  for loading a board.  
      As rise-and-fall guide rails  10 ,  12  shown in  FIG. 14  falls, the platy work W is dipped into various tanks (e.g., plating tank  2 , exfoliate tank  6 , water-washing tank, and hot water-washing tank, cleaner tank, etc.). Also, when Rise-and-fall guide rails  10 ,  12  are fallen as shown in  FIG. 15 , guide rails  10 - 13  configure one circular guide rail.  
      By falling of rise-and-fall guide rails  10 ,  12  shown in  FIG. 14 , the platy work W is guided into treatment liquids on a dipping position ((x) position of  FIG. 14 ) of the plating tank  2 . The platy work W dipped into treatment liquids is transferred inside the platy tank  2 .  
      The transport hanger  15  used for the surface treatment device  300  of the above-mentioned so-called pusher type, as shown  FIG. 9 , has treating-object holding member  47  with plural clamps  48  for holding the platy work W, slide member  35  which contact slidably with guide rails such as fixed guide rail  11 , and connecting members  44  for connecting such members. The transport hanger  15  holds the upper end of the platy work W by clamp  48 .  
      For the purpose to achieve uniform plating quality or uniform plating film thickness, the surface treatment device  300  of pusher type like the above-mentioned treats the platy work W by spouting jet flow of treatment liquids to the platy work W from spouters arranged both sides of the platy work W inside the platy tank. However, because it doesn&#39;t use the rack, the plating film thickness of platy work W became non-uniform as the platy work W swings when transporting and the distance to electrode is not constant, or the plating film thickness of the edge of the platy work became thicker unusually because current concentration has occurred on the edge of the platy work.  
      Therefore, it is big issue to be solved for the surface treatment device of rackless type to restrict swinging of the platy work and not to occur current concentration on the edge of the platy work W.  
      Consequently, the above-mentioned Patent Document 1 discloses interval between adjacent platy works of back-and-forth is adjusted by fast-forwarding until it becomes predetermined distance (for example, 50 mm) inside the plating tank  2  to prevent from occurring current concentration on the back-and-forth end of the platy work W. Additionally, a linear guide made of Teflon (registered trademark) is attached inside of a surface treatment tank such as a plating tank for preventing the platy work W from swinging, or a shielding plate is attached for preventing from occurring current concentration on the edge of the platy work W (Refer to the Japanese Laid Open Patent Applications No. 2000-178784 (Patent Document 2) and No. 2002-13000 (Patent Document 3)).  
      Moreover, when the printed board (thickness is below 0.1 mm) is used as the platy work (hereinafter referred to as thin plate board), it is suggested that leading guide etc. as shown in  FIG. 16  is arranged inside a tank for the purpose of dipping the platy work W smoothly into each treatment tank (Refer to the Japanese Laid Open Patent Applications No. 2004-346391 (Patent Document 4).  
      The leading guide of Patent Document 4 is comprised of a pair of commutate members  131  (slant down flow boards  131   a,    131   b ) placed at falling position of the thin plate board. As shown in  FIG. 16 , the slant down flow boards  131   a,    131   b  are formed its upper side like as V style. And spouting tubes  132  are arranged along upper end area of the slant down flow boards  131   a,    131   b.  Further, a liquid suction tube  133  is arranged on lower part of the slant down flow boards  131   a,    131   b,  which aspirates plating liquids and spouts it from the spouting tubes  132 . Therefore, it becomes possible to guide the thin plate board promptly with the flow on the lower side spouting from the slant down flow boards  131   a,    131   b.    
      However, the above-mentioned conventional art can&#39;t achieve uniform plating quality by jet flow of plating liquids or uniform plating film thickness by preventing from occurring current concentration on the upper and lower end of the platy work W, though it was possible to prevent current concentration on the back-and-forth end of platy works.  
      For instance, although Patent Documents 2 and 3 discloses that a louver is used for achieving uniform plating quality by commutating the jet flow of plating liquids, the plating efficiency or plating quality may get worse as it may occur excessive current shielding effect in some cases. Also, although shielding plate is arranged on the lower end of the platy work W, enough effect was not attained because currency detouring occurs in some cases. Thus, it is likely to vary plating thickness as occurring current concentration on the upper and lower end of the platy work W.  
      Further, although a linear guide made of Teflon is used for preventing the platy work W from swinging, linear shaped Teflon was easily to break away by touching with platy work W. Therefore, sometimes it is not prevented platy work W from swinging. Further, although it is possible to add metal wire as a core member to the linear guide made of Teflon, when plastic Teflon is broken away and metal wire became exposed, it was caused abrasion on the platy work W by touching with exposed metal wire, and plating quality became worse because the plating adhered to the metal wire is mixed in treatment liquids. Especially, when the thin plate board (thickness is below 0.1 mm) is used, it is subject to swing and twist easily because of plating jet flow. And it is subject to cause abrasion as transporting slidably with platy work W.  
     SUMMARY OF THE INVENTION  
      As to solve the above problems, an object of the present invention is to provide a plating tank used for a surface treatment device such as a electroplating device (especially, for the electroplating device which transports a platy work such as printed board in holding vertically) which can transport platy work such as thin printed board (thickness is below 0.1 mm) securely without causing abrasion, and attain uniform plating quality and uniform plating film thickness.  
      A plural of Independent aspects of the present invention will be indicated as follows.  
      (1) In accordance with characteristics of the present invention, there is provided a plating tank comprising:  
      a treatment tank main body for holding treatment liquids which is arranged as extending in transporting direction of the platy work;  
      a positive electrode;  
      a spouter for spouting the treatment liquids to the said platy work from lateral side of the treatment tank main body;  
      a restrict roller having a plural of rollers, wherein the rollers are attached rotatably from upper part until lower part of the treatment tank main body and arranged consecutively in transporting direction of the platy work as sandwiching both sides of the platy work on moving inside the treatment tank main body;  
      a current shield for preventing from occurring current concentration on the end of the platy work.  
      Therefore, it becomes possible to maintain upright state of the thin plate board W by restrict roller. Also, it doesn&#39;t cause abrasion as roller is used. It becomes possible to treat uniformly.  
      (2) In accordance with characteristics of the present invention, there is provided a plating tank:  
      wherein the said restrict roller is comprised of a plural of roller stand bodies which are having plural rollers vertically, and arranged in transporting direction of the said plating work, and interval on the spouting position of the spouter between adjacent roller stand bodies are wider than the other intervals.  
      Therefore, it becomes possible to provide treatment liquids with platy work (especially, thickness is below 0.1 mm) uniformly by spouter, and it becomes possible to maintain upright state of the thin plate board W by restrict roller. Also, it doesn&#39;t cause abrasion as roller is used. It becomes possible to treat uniformly.  
      (3) In accordance with characteristics of the present invention, there is provided a plating tank:  
      wherein a deviation preventing member is placed at lower end area of the platy work where the spouting position of the spouter is placed as sandwiching both sides of the platy work on moving.  
      Therefore, it becomes possible to prevent from bending on the lower end of platy work (especially, thickness is below 0.1 mm) properly.  
      (4) In accordance with characteristics of the present invention, there is provided a plating tank:  
      wherein the rollers are arranged at least one per predetermined unit area in a region that the restrict rollers are arranged.  
      Therefore, it becomes possible to prevent from swinging or twisting of platy work (especially, thickness is below 0.1 mm) in transporting direction or vertical direction and to maintain intervals between platy work and positive electrode constantly. It becomes possible to attain uniform of plating film thickness.  
      (5) In accordance with characteristics of the present invention, there is provided a plating tank:  
      wherein the said restrict roller is comprised of a plural of roller stand bodies which are having plural rollers vertically, and arranged in transporting direction of the said plating work, and vertical intervals that the rollers of the restrict roller is arranged are range from 50 mm to 100 mm.  
      Therefore, it becomes possible to prevent from swinging or twisting of platy work (especially, thickness is below 0.1 mm) in transporting direction or vertical direction and to maintain upright state. It becomes possible to maintain intervals between platy work and positive electrode constantly and to attain uniform of plating film thickness.  
      (6) In accordance with characteristics of the present invention, there is provided a plating tank:  
      wherein the said restrict roller is comprised of a plural of roller stand bodies which are having plural rollers vertically, and arranged in transporting direction of the said plating work, and the rollers placed over predetermined height differs the vertical position mutually between the roller stand bodies.  
      Therefore, it becomes possible to prevent from causing electrical shielding effect at same height. It becomes possible to prevent from occurring unevenness of plating and to attain uniform plating.  
      (7) In accordance with characteristics of the present invention, there is provided a plating tank:  
      wherein the said current shield is comprised of a upper shielding plate for preventing from occurring current concentration on the upper end of the platy work and/or a lower shielding plate for preventing from occurring current concentration on the lower end of the platy work.  
      Therefore, it becomes possible to prevent current concentration on both upper and lower end of platy work. It becomes possible to attain uniform of plating film thickness.  
      (8) In accordance with characteristics of the present invention, there is provided a plating tank:  
      wherein the said upper shielding plate and/or the lower shielding plate are comprised of plural shielding plates arranged between the said platy work and the said positive electrode, and its overlap with the platy work is the smaller, the closer to the platy work.  
      Therefore, it becomes possible to prevent from detouring of currency by shielding plate. It becomes possible to attain uniform of plating film thickness even if the shielding area of platy work is small. Also, it is possible to enhance productivity as gaining enough current shielding effect without decreasing current value.  
      (9) In accordance with characteristics of the present invention, there is provided a plating tank:  
      wherein the said plurality of shielding plates are formed in a unified manner and able to rise and fall.  
      Therefore, it becomes possible to attain uniform of plating film thickness even if the size of platy work is varied.  
      The other aspects of the present invention will be indicated as follows.  
      (a) In accordance with characteristics of the present invention, there is provided a platy work dipping device, comprising:  
      a treatment tank for dipping a platy work into treatment liquids;  
      a board guide for guiding platy board falling into the treatment tank having a upper guide board and a lower guide board, wherein the lower guide plate is arranged parallel spacing predetermined distance and upper board guide is arranged like taper as widening toward upside vertically and having slit of cutout, and a tip of upper board guide is projecting from fluid level and dipping its slit into plating liquids;  
      a liquid current generator arranged outside the said board guide.  
      Therefore, it becomes possible to guide a platy work smoothly along board guide, as liquid flow from outside of board guide can be led to downward inside the board guide through cutout. Especially, if treatment liquids are acid cleaner including fizzy material like surface-active agent, it is possible to prevent deterioration in plating quality which cause by bubble generated on fluid level and to guide platy board smoothly.  
      (b) In accordance with characteristics of the present invention, there is provided a platy work dipping device:  
      wherein the liquid current generator is sparger for spouting jet flow against the said cutout nearly in a horizontal direction, or air-bubbling tube arranged at nearly middle height inside the treatment tank.  
      Therefore, it becomes possible to guide a platy work smoothly along board guide, as liquid flow from sparger can be led to downward inside the board guide through cutout without occurring bubble on fluid level inside the board guide.  
      (c) In accordance with characteristics of the present invention, there is provided a platy work dipping device:  
      wherein the liquid current generator is sparger for spouting jet flow toward upper part than the said cutout in upper direction against a horizontal direction.  
      Therefore, it becomes possible to guide a platy work smoothly along board guide, as liquid flow from sparger toward upper part in upper direction against a horizontal direction can be led to downward inside the board guide through cutout without occurring bubble on fluid level inside the board guide.  
      (d) In accordance with characteristics of the present invention, there is provided a platy work dipping device:  
      wherein liquid current generator is air-bubbling tube discharging air upwards.  
      Therefore, it becomes possible to guide a platy work smoothly along board guide by simple structure, as liquid flow from air-bubbling tube which discharging air upwards can be led to downward inside the board guide through cutout without occurring bubble on fluid level inside the board guide.  
      (e) In accordance with characteristics of the present invention, there is provided a platy work dipping method for guiding a platy work falling into the treatment body by using a board guide:  
      projecting a tip of upper board guide from fluid level and dipping its slit into plating liquids;  
      generating by liquid current generator arranged outside the said board guide and under fluid level;  
      falling and dipping a platy work into treatment liquids.  
      Therefore, it becomes possible to guide a platy work smoothly along board guide, as liquid flow from outside of board guide can be led to downward inside the board guide through cutout. Especially, if treatment liquids are plating liquids, it is possible to prevent deterioration in plating quality which cause by bubble generated on fluid level and to guide platy board smoothly.  
      The characteristics of the present invention are broadly indicated as noted above, but structure, contents, object, and features will be clear though reference to the figures and according to the following disclosure. 
    
    
     BRIEF DESCRITION OF THE DRAWINGS  
       FIG. 1  shows α-α cross-section of plating tank  2  ( FIG. 14 ).  
       FIG. 2  shows the structure of inside plating tank  2  from β-direction of  FIG. 1 .  
       FIG. 3  shows plane view of plating tank  2  from γ-direction of  FIG. 1 .  
       FIG. 4  shows detail structure of roller stand body from β-direction of  FIG. 1 .  
       FIG. 5  shows detail structure of deviation preventing member  122  ( 122   a,    122   b ).  
       FIG. 6  shows detail structure of board dipping device  600 .  
       FIG. 7  shows perspective view of board guide  62 .  
       FIG. 8  shows detail structure of jet nozzle  64 .  
       FIG. 9  shows detail structure of the transport hanger  15 .  
       FIG. 10  shows cross-section near the center of the transport hanger  15 .  
       FIG. 11  shows plane view of intermittent transporter  17  on the rise-and-fall guide rail  10 .  
       FIG. 12  shows the structure of positioning transporter  18 .  
       FIG. 13  shows the structure of board dipping device.  
       FIG. 14  shows plane view of surface treatment device  300  from upside.  
       FIG. 15  shows side view of surface treatment device  300  from α-direction.  
       FIG. 16  shows the structure of conventional leading guide.  
       FIG. 17  shows the structure of spouter  302 .  
       FIG. 18  shows the structure of shields (shielding means)  303 .  
       FIG. 19  shows view of support connecting member  216  from thin plate board W&#39;s side.  
       FIG. 20  shows the structure of positive electrode  102 .  
       FIG. 21  shows overlapping range of thin plate board W and shielding plate.  
       FIG. 22  shows the structure of roller stand body  120 &#39;s lower part.  
       FIG. 23  shows the view of swinging board W from transporting direction.  
       FIG. 24  shows the view of swinging board W from upside of plating tank.  
       FIG. 25  shows the structure of roller stand body  120 &#39;s upper end.  
       FIG. 26  shows relationship between number of roller  116  and predetermined area of thin plate board W to be transported. 
    
    
     DETAILED DESCRIPTION OF DESIRED EMBODIMENTS  
      1. Plating Tank  
      The basic structure of the surface treatment device is the same as shown in  FIG. 14  and  FIG. 15 .  FIG. 14  shows plane view of surface treatment device  300  from upside.  FIG. 15  shows side view of surface treatment device  300  from α-direction.  
      As shown in  FIG. 14  and  FIG. 15 , the surface treatment device  300  is the surface treatment device of so-called pusher type, and having guide rails  10 - 13  for transporting the transport hanger  15  which is holding the platy work such as a printed board, and arranged such that along these guide rails  10 - 13 , the pre-treatment tank  1  of each type for processing before plating, plating tank  2  for electroplating, recovery tank  3  and water-washing tank  4  for processing after plating, unload section  5  for unloading the platy work, exfoliate tank  6  for separating plating films (hanger restoring process), water-washing tank  7  for water-washing the transport hanger  15  after separating, and load section  8  for loading a board.  
      As rise-and-fall guide rails  10 ,  12  shown in  FIG. 14  falls, the platy work W is dipped into various tanks (e.g., pre-treatment tank  1 , plating tank  2 , recovery tank  3  and water-washing tank  4 , and exfoliate tank  6 ). Also, when Rise-and-fall guide rails  10 ,  12  has fallen as shown in  FIG. 15 , guide rails  10 - 13  configure one circular guide rail.  
       FIG. 1  shows α-α cross-section of plating tank  2  ( FIG. 14 ) as one embodiment of the present invention. A treatment tank main body  100  (including after-mentioned overflow tank  202 , drain  200 ) is holding treatment liquids. The thin plate board W (platy work), which is to be treated in the treatment tank main body  100  filled with treatment liquids, is held and hung by clamping of the transport hanger  15  on its upper end. By transferring the transport hanger  15 , the thin plate board W also moves inside the treatment tank main body  100 .  
      The treatment tank main body  100  is comprised of positive electrode  301  for supplying metal ion of electroplating, spouter  302  for spouting treatment liquids toward the thin plate board W, shielding means  303  for shielding currency not to occur current concentration on the edge of the thin plate board W, restrict roller  304  arranged as sandwiching the thin plate board W for keeping the thin plate board W on standing state when moving in the treatment tank main body  100 . Furthermore, the concrete structure of the positive electrode  301 , the spouter  302 , the shielding means  303 , the restrict roller  304  will be described as follows.  
      The positive electrode  301  is comprised of a pair of positive electrodes  102 ,  104  which is arranged plenty with keeping a predetermined interval along transporting direction of the thin plate board W, and power supply rail  224  which is arranged in the treatment tank main body  100  along transporting direction of the thin plate board W for suspending and energizing positive electrodes  102 ,  104  shown in  FIG. 1 .  
      The spouter  302  is comprised of eductor box  204  for equalizing pressure of plating liquids, a pair of spargers  106  for spouting plating liquids from both sides of the thin plate board W at nearer position to the thin plate board W than positive electrodes  102 ,  104 , pipe  210 , and circulation pump  208  for returning plating liquids through the pipe  210  to the eductor box  204  after filtering discharged through drain  200  or overflow tank  202  by barrier filter shown in  FIG. 1 .  
      The shielding means  303  is comprised of following four shielding plates shown in  FIG. 1 . The lower board shielding plates  108  are arranged with facing at lower end of the thin plate board W close to the thin plate board W along transporting direction of the thin plate board W. On the other hand, the upper board shielding plates  109  are arranged with facing at upper end of the thin plate board W close to the thin plate board W along transporting direction of the thin plate board W as well. Also, between positive electrode  102 ,  104  and sparger  106 , the lower electrode shielding plate  112  is arranged around lower end area of positive electrode  102 ,  104  and the upper electrode shielding plate  113  is arranged around upper end area of positive electrode  102 ,  104  close to positive electrode  102 ,  104  along transporting direction of the thin plate board W respectively. Also, the shielding means  303  has a height adjuster  220  for adjusting height of lower board shielding plates  108  and lower electrode shielding plate  112  based on size of the thin plate board W. Left side of  FIG. 1  indicates lowered condition corresponding to large sized thin plate board W and right side of  FIG. 1  indicates heightened condition corresponding to small sized thin plate board W.  
      The restrict roller  304  is comprised of the roller stand body  120  which reaches until nearly upper end area&#39;s height of thin plate board and stood on upper face of the lower shielding plates  108 , and the work-end deviation preventing member  122 . The restrict roller  304  is possible to adjust a height based on size of the thin plate board W with lower board shielding plates  108  and lower electrode shielding plate  112  by the above-mentioned height adjuster  220 .  
      The roller stand body  120  is comprised of shaft  114  which stands on the lower board shielding plate, and roller  116  which is attached vertically on the shaft  114  and rotatably. Also, it is possible to secure the roller  116  to shaft  114  and to rotate itself the shaft  114 .  
      Concretely, as shown in  FIG. 4  that shows detail structure of roller stand body from β-direction of  FIG. 1 , the roller stand body  120  has the roller  116  formed by PP (Polypropylene) resin, and adjusting member  116   e  which adjust each distance between upper and lower rollers by putting shaft  114  to each insert hole and intermediating between upper and lower rollers. Further, securing member  116   g  is attached around upper end area of the shaft  114  for the roller  116  and the adjusting member  116   e  not to be tripped.  
      As shown in  FIG. 25 , the securing member  116   g  is attached as spacing clearance (L 70 ) from upper end of top roller  116 . Therefore, as the roller  116  can float in plating liquids, it will be prevented from rotating improperly based on scratching between each roller  116  and adjusting member  116   e,  and further be prevented from causing abrasion based on contact between the thin plate board W and roller  116 .  
       FIG. 2  shows the structure of inside plating tank  2  from β-direction of  FIG. 1 . It is indicated that a number of the roller stand body  120  is arranged toward transporting C-direction of the thin plate board W.  
       FIG. 3  shows plane view of plating tank  2  from γ-direction of  FIG. 1 . The thin plate board W is transported between facing roller stand bodies  120 . Thus, the thin plate board W is transported with right state (maintaining upright state) because the roller  116  of roller stand body  120  restricts the thin plate board W. By the way, the restrict roller  304  has roller stand body  120  and roller  116  for maintaining upright state (right state) as shown below.  
      First, the arrangement of the roller stand body  120  will be described. As shown in  FIG. 22 , facing roller stand bodies  120  are arranged as the distance L 40  between roller  116  and thin plate board W becomes from 1 mm to 5 mm (e.g., this case is 4 mm). If the distance is below 1 mm, it may cause abrasion on surface of the thin plate board W as the roller  116  contacts with thin plate board W. Also, if the distance is over 5 mm, it may cause non-uniform of plating film thickness as the thin plate board W is distorted vertically.  
      Also, intervals L 3  between roller stand body  120  are wider than the other intervals L 2  at the position where sparger  106  is placed (indicated as N in  FIG. 4 ) in this embodiment. Interval L 3  is lager than diameter of the roller  116  at the position N where the sparger  106  is placed in this embodiment. Interval L 2  is smaller than diameter of the roller  116  at the other position. Therefore, it is possible to spread jet flow of plating liquids on the thin plate board W effectively as the roller stand body  120  doesn&#39;t interfere with jet flow of plating liquids which is discharged by the sparger  106 .  
      However, because of the said large intervals L 3 , it may be caused bending of the thin plate board W at the position based on jet flow of the sparger  106 , or incomplete transporting as bent part intrudes between the roller stand bodies  120 . Therefore, deviation preventing member  122   a  is placed at lower part of the roller stand body  120 , and deviation preventing member  122   b  is placed at middle height of the roller stand body  120  in this embodiment. Especially, it is important that the deviation preventing member  122   a,  which is for preventing lower end of the thin plate board W from bending, is placed at lower end part.  
       FIG. 5  shows detail structure of deviation preventing member  122  ( 122   a,    122   b ).  FIG. 5A  shows plane view, and  FIG. 5B  shows side view. As shown in  FIG. 5 , deviation preventing member  122   a  is obviously secured to lower part of shaft  114  (0-50 mm from top face of the lower board shielding plate  108 , especially in the range of 0-20 mm: 5 mm, in this case). While the roller  116  is attached rotatably, the deviation preventing member  122   a  doesn&#39;t rotate. Also, as shown in  FIG. 5A , transporting space  124  of the thin plate board W is formed between facing deviation preventing members  122   a.  In this way, it is prevented from that bent part intrudes between the roller stand bodies  120 , or that deviates from lower board shielding plate  108 . Furthermore, the structure of deviation preventing members  122   b  is same as deviation preventing members  122   a.    
      Next, the arrangement of the rollers will be described. As shown in  FIG. 26  in the region that 10-12 units of roller stand bodies  120  are arranged, there is at least one roller per predetermined unit area (e.g. 100 mm×100 mm). The region that the roller stand bodies  120  are arranged means region viewed where the roller stand bodies  120  are arranged in a transporting direction of the thin plate board W from a direction perpendicular to the transporting direction on as shown in  FIG. 26 . On the region, it is possible to reduce swinging of the thin plate board W effectively, by arranging at least one the rollers  116  for restricting swing per predetermined unit area against the thin plate board W in the region. The reason why based on this per predetermined unit area for arranging roller is to restrict both swings toward transporting direction and vertical direction. Furthermore, predetermined unit area is desirable up to 100 mm×100 mm.  
      Therefore, it becomes possible to prevent non-uniform plating film thickness occurring from that the thin plate board W loses erectness by jet flow of plating liquids and a distance from positive electrode  102 ,  104  changes as shown in  FIG. 23  and  24 . And, it becomes possible to prevent incomplete transport occurring from that the tip of thin plate board W swings and intrudes between the roller stand bodies  120 . Furthermore,  FIG. 24  shows the view of swinging board W from upside of plating tank.  
      Vertical intervals between adjacent rollers  116  of the roller stand bodies  120  are 50-100 mm. The vertical Intervals mean the intervals of circular plates of rollers  116  (L 30  shown in  FIG. 4 ). If it is below 20 mm, the rollers  116  cause electrical shielding effect against the thin plate board W, and it may be caused non-uniform plating film thickness. On the other hand, if it is over 100 mm, thin plate board W is bent between rollers  116  and lose erectness, and it may be caused non-uniform plating film thickness by varying a distance of the thin plate board W to the positive electrode  102 ,  104  vertically and locally as shown in  FIG. 23 . Furthermore,  FIG. 23  shows the view of swinging board W from transporting direction.  
      Further,  FIG. 4  shows arranging condition of the roller stand body  120 . In the arrangement of plural roller stand bodies  120 , the roller stand bodies  120  of 10-12 numbers arranged in transport direction of thin plate board W are forming one unit, and the height of each roller  116  is different from the others. For example, there is no roller which is same height H as roller  116   a  of center area (at predetermined height: for example, at higher position over 50 mm from lower end of the platy work). There is no roller which is some height as the others. This is for the reason that linear unevenness of plating is not to be formed on thin plate board W by contacting with roller  116  at same height, and the plating film thickness on the surface of thin plate board W is not to be getting thinner by forming electrical shadows of the roller  116  at same height part.  
      However, the rollers on lower part of the roller stand bodies  120 , below 50 mm from top face of lower board shielding plate  108 , are allowed to be positioned at same height. The bottom roller  116   b  of the roller stand bodies  120  is arranged at below 50 mm, especially below 20, from top face of lower board shielding plate  108 . This is for the reason that, the lower end of thin plate board W is raised, if the thin plate board W loses erectness by jet flow of plating liquids as shown in  FIG. 23 . As the bottom roller is arranged as closer as possible to the lower end of the thin plate board W, it is prevented that the lower end of the thin plate board W deviates from clearance formed by lower board shielding plate  108 .  
      As mentioned previously, the roller stand body  120  is formed standing on the lower board shielding plate  108 , and moves up and down with the lower board shielding plate  108  integrally. Therefore, the positional relationship between lower board shielding plate  108  and bottom roller  116   b  of roller stand body  120 , or deviation preventing member  122   a  doesn&#39;t change if the height is adjusted based on size of the thin plate board W. The simple structure makes it possible to be operated against various sized thin plate board W in the same way.  
      Thus, the restrict roller  304  in this embodiment regulates five elements to improve quality of electroplating, and the arrangement of roller  116  is determined. That is, the arrangement of roller  116  is determined for (i) keeping upright condition of the thin plate board W, (ii) reducing current shield effect by roller  116 , iii), keeping effect of plating jet flow by spouter iv) preventing incomplete transport occurring from that the thin plate board W intrude between roller stand body  120 , v) preventing from causing abrasion by roller  116 .  
      Concretely, to establish the above (i) the roller  116  is arranged at least one per predetermined unit area (e.g. 100 mm×100 mm) basically. Further, a distance between roller  116  and thin plate board W is determined as range 1-5 mm (below 5 mm) and a interval between vertical rollers  116  is determined as range 50-100 mm (below 100 mm) to restrict vertical deflection of the thin plate board W more effectively. To establish the above (ii), a interval between vertical rollers  116  is determined as range 50-100 mm (over 50 mm), and the rollers  116  placed over predetermined height differs the vertical position mutually between the roller stand bodies  120  of 10-12 numbers. To establish the above (iii), intervals L 3  between roller stand body  120  are wider than the other intervals at the position where sparger  106  is placed. To establish the above (iv), the rollers on lower part of the roller stand bodies  120  are allowed to be positioned at same height, and deviation preventing member  122   a  is placed where the roller stand bodies  120  are arranged spacing the above intervals L 3 , and the roller stand body  120  where sparger  106  is not placed is spaced Interval L 2  which is smaller than diameter of the roller  116 . Lastly, to establish the above (iv), the securing member  116   g  secures as spacing clearance from upper end of top roller  116  and thin plate board W is determined as range 1-5 mm (over 1 mm).  
      Although each combination of them can be selected accordingly, it is desirable to be provided entirely.  
       FIG. 17  shows the structure of spouter  302  excluding positive electrode  301 , restrict roller  304  and shielding means  303 . As shown in  FIG. 17 , spouter  302  spouts treatment liquids by sparger  106  toward the thin plate board W.  
      Plating liquids spouted from sparger  106 , is discharged from the treatment tank main body  100  through drain  200  or overflow tank  202 , and returns to eductor box  204  by circulation pump  208  through the pipe  210  after filtering by barrier filter  209 , and returns to sparger  106  again as circulating after equalizing pressure of plating liquids in eductor box  204 .  
      Plural eductor boxes  204  are arranged on the bottom of the treatment tank main body  100  along transporting direction of the thin plate board W. As shown in  FIG. 17 , eductor boxes  204  are bolted on the bottom plate of the treatment tank main body  100  as height adjustable. On the side plate of eductor box  204 , connecting hole is formed and pipe  210  is connected for transferring liquids. Also, support member  204   a  is attached to the eductor box  204 , which prevents that it becomes impossible to equalize pressure of plating liquids by changing shape based on pressure of plating liquids transferred from circulation pump  208 .  
      As shown in  FIG. 17 , spargers  106  is formed by attaching plural jet nozzles  106   a  for spraying plating liquids to nozzle tube  106   b  with spacing predetermined intervals. The nozzle tube  106   b  is stood on eductor box  204 , and eductor box  204  and lower end of nozzle tube  106   b  are connected through connecting hole for transferring liquids. On the other hand, upper end of the sparger  106  is fit in hole formed on the nozzle fixing member which is attached along transporting direction of the thin plate board W. Therefore, jet flow of plating liquids against the thin plate board W is constant, as the sparger  106  is prevented from leaning (tumbling) to the opposite side of the thin plate board W or from vibrating by spouting pressure when spouting plating liquids.  
      As shown in  FIG. 17 , jet nozzle  106   a  of spargers  106  are arranged at alternate height between right side and left side of the thin plate board W. This is to make difference in jet pressure of plating liquids on the thin plate board W and to realize flow transferring inside thorough-hole formed on the thin plate board W.  
       FIG. 18  shows the structure of shielding means  303  excluding positive electrode  301  and a portion of spouter  302 . As shown in  FIG. 18 , shielding means  303  is comprised of upper board shielding plates  109 , upper electrode shielding plate  113 , lower board shielding plates  108 , and lower electrode shielding plate  112  having a rolling mechanism, plate  110  and support connecting member  216  for connecting lower board shielding plates  108  and lower electrode shielding plate  112  integrally, height adjuster  220  for elevating lower board shielding plates  108  and lower electrode shielding plate  112  integrally, and guide table  214  for guiding lower electrode shielding plate  112  when adjusting height, and pole  155 .  
      As shown in  FIG. 18 , upper board shielding plates  109  and upper electrode shielding plate  113  are attached to nozzle fixing member  212 . The upper board shielding plates  109  and the upper electrode shielding plate  113  are height adjustable up and down in drawing respectively, because of having long hole of up and down direction in drawing and bolting on nozzle fixing member  212  through the long hole.  
      In this way, upper board shielding plates  109  and upper electrode shielding plate  113  are used at the same time, because it is desirable to shield currency effectively at minute area such as 1-5 mm from edge of the thin plate board W. By using upper board shielding plates  109 , current concentration on upper end of the thin plate board W is controlled locally. The upper electrode shielding plate  113  controls currency, that upper board shielding plates  109  couldn&#39;t control adequately, not to detour around upper end of the thin plate board W.  
      Also, as shown in  FIG. 18 , shielding plate of the thin plate board W&#39;s lower end having the lower board shielding plates  108  and the lower electrode shielding plate  112  to prevent from current concentration on the thin plate board W&#39;s lower end in this embodiment. The reason using lower board shielding plates  108  and lower electrode shielding plate  112  at the same time is same as the above-mentioned reason of upper board shielding plates  109  and upper electrode shielding plate  113 .  
      The overlap L 60  of shielding plates  108 ,  109 ,  112 ,  113  from edge of the thin plate board W (overlapping length between thin plate board W and shielding plate shown in  FIG. 21 : hereinafter referred to as overlap level) is set the smaller, the closer to the thin plate board W. For instance, lower board shielding plate  108 , which is more closer to the thin plate board W, is set overlap level smaller than lower electrode shielding.  
      It is desirable that distance L 50  ( FIG. 22 ) of board shielding plates  108 ,  109  from the thin plate board W is range 1-50 mm. Therefore, it is possible to prevent from occurring current concentration on the edge of the platy work W effectively without reducing amount of energization required in plating (without reducing plating effectiveness).  
      Concretely, the upper board shielding plates  109  is overlapped 1-15 mm (10 mm in this embodiment) against upper end of the thin plate board W. The upper electrode shielding plate  113  is overlapped 10-60 mm (50 mm in this embodiment) against upper end of the thin plate board W. Also, the upper board shielding plates  109  (tip of L shaped bottom) is arranged 25 mm distance from the thin plate board W.  
      On the other hand, the lower board shielding plates  108  is overlapped 1-10 mm (5 mm in this embodiment) against lower end of the thin plate board W. The lower electrode shielding plate  112  is overlapped 50-75 mm (65 mm in this embodiment) against lower end of the thin plate board W. Also, the lower board shielding plates  108  is arranged 4 mm distance from the thin plate board W.  
      By the way, the effect of shield currency changes, if the setting of overlapping level between board shielding plate and electrode shielding plate has changed. Therefore, as the above-mentioned, lower board shielding plates  108  and lower electrode shielding plate  112  are adjustable of height by height adjuster  220  integrally not to change the overlap level between board shielding plate and electrode shielding plate, even if the size of the thin plate board W has changed.  
      In  FIG. 18 , lower board shielding plates  108  is attached on the plate  110 , and the plate  110  is connected to the lower electrode shielding plate  112  through support connecting member  216 , and lower board shielding plates  108  and lower electrode shielding plate  112  are formed integrally. Furthermore, the support connecting member  216  is also fixed on upper face of the lower board shielding plates  108  for preventing deflection of plate  110 .  
      As shown in  FIG. 18 , guide table  214  for guiding lower electrode shielding plate  112  is attached on the bottom plate of the treatment tank main body  100  as housing the above eductor box  204  on its downward. Poll  155  is stood upside of guide table  214 , and its upper end is bolted on nozzle fixing member  212 . The lower electrode shielding plate  112  is bolted (not illustrated) movably up and down through vertical long hole against guide table  214 , and rolling mechanism  150  arranged on lower electrode shielding plate  112  fits in pole  155  movably up and down through roller  150   a.  In this way, as the lower electrode shielding plate  112  is guided by guide table  214  and poll  155 , lower board shielding plates  108  and lower electrode shielding plate  112  and roller stand body  120  are guided integrally when adjusting height by height adjuster  220 .  
      In  FIG. 18 , height adjuster  220  is comprised of driving motor  220   a,  pulley  220   b,  connecting wire  220   c,  driving belt  220   d,  and one end of the connecting wire  220   c  is fixed to pulley  220   b  and other end is connected to support connecting member. As wire  220   c  is rolled up by pulley  220   b  based on driving of driving motor  220   a,  lower board shielding plates  108  and lower electrode shielding plate  112  and roller stand body  120  are rises integrally.  
       FIG. 19  shows view of support connecting member  216  from thin plate board W&#39;s side. As shown in  FIG. 19 , connecting wire  220   c  is connected on the support connecting member through wire joint  218 .  
       FIG. 20  shows the structure of positive electrode  102 . Furthermore,  100   c  is a cap for dropping hole  100   b.  Positive electrode  102  comprising  301  has an anode case  102   a  for housing plating metallic material like copper ball, and grip  102   d  is formed on side face of the anode case  102   a,  and hook  102   e  is formed on lower part of the grip  102   a  for attaching anode case  102   a  to power supply rail  224  shown in  FIG. 1 . The upper end of the grip  102   d  reaches almost height of opening area  102   b.  Also, four guide bars  102   c  are attached at even intervals on the opening area  102   b  (two bars are impossible to see because of overlapping in the back direction of drawing). The upper end of guide bars  102   c  are extended until dropping hole  100   b  for dropping metallic material which is formed on the floor  100   a  of the treatment tank main body  100 .  
      It is needed to supply the anode case  102   a  with metallic material when keeping on plating task. It is prevented that metallic material drops into the treatment tank main body  100  without housing in anode case  102   a  for existing of guide bar  102   c  when dropping in dropping hole  100   b.    
      Also, it is needed to maintain by taking up the anode case  102   a  when keeping on plating task. By the way, as metallic material is often supplied excessively to avoid lacking of metallic material (dropping metallic material as brimming from dropping hole  100   b ), metallic material is prevented from dropping into the treatment tank main body  100  by fitting guide tube in dropping hole  100   b  formerly. However, it was difficult to get rid of metallic material supplied excessively when using guide tube, and it takes a lot of trouble to remove the anode case  102   a  in maintenance. It becomes easy to remove the anode case  102   a  in maintenance, as metallic material supplied excessively from dropping hole  100   b  is removed easily by using guide bars  102   c.    
      2. Board Dipping Device  
      The plating tank  2  in the embodiment described above has the board dipping device for dipping the thin plate board W at dipping spot  2   a  ( FIG. 15 ). Referring to  FIG. 13 , the structure of board dipping device will be described as follows. Furthermore,  FIG. 13A  shows cross-section of board dipping device  600  indicating a condition when a board has fallen at (x)-position shown in  FIG. 14 .  FIG. 13B  shows plane view of the board dipping device  600  shown in  FIG. 13A  from upside.  
      As shown in  FIG. 13A , the board dipping device  600  is comprised of treatment tank main body  60  which holds plating liquids for dipping the thin plate board W, board guide  62  for guiding the thin plate board W when falling into the treatment tank main body  60 , and air-bubbling tube  68  which is generator of liquid current arranged outside the said board guide  62 .  
      As shown in  FIG. 13A , the board guide  62  is comprised of lower guide plate  62   a  arranged parallel spacing predetermined distance t, upper guide plate  62   b  which is arranged like taper as widening toward upside vertically and having slit  62   c  of cutout, and current plate  62   d  for preventing liquid current which is occurred by air-bubbling from spreading and weakening. Also, the board guide  62 , as shown in  FIG. 13A , is arranged as projecting the tip  62   e  of upper board guide  62   b  from fluid level and dipping the said slit  62   c  into plating liquids.  FIG. 7  shows perspective view of board guide  62 .  
      The air-bubbling tube  68 , which is generator of liquid current, discharges air upward based on air supply though pipe  66  shown in  FIG. 13A . Therefore, upward flow occurs as circumjacent plating liquids of uprising air uprises and the plating liquids sectioned by current plate  62   d  flows from downside of current plate  62   d.  Further, the uprisen plating liquids run through slit  62   c,  and forms down flow between lower guide plates  62   a.  Thus, it becomes possible to guide and dip the thin plate board W along the board guide  62  smoothly. Further, as an experimental result, it was more effective to guide smoothly when arranging air-bubbling tube  68  at middle depth area in the treatment tank main body  60  than arranging at same height as slit  62   c  or at lower area of current plate  62   d.  Also, as an experimental result, it was more effective to guide the thin plate board W smoothly when forming slit  62   c  on upper guide  62   b  than forming it on lower guide  62   a.    
      The structure as the above-mentioned makes it easy to guide the thin plate board W smoothly because of generated liquid flow by generator arranged outside the board guide  62 , as the board guide  62  is projecting the tip  62   e  of upper board guide  62   b  from fluid level and dipping the said slit  62   c  into plating liquids.  
      Further, as shown in  FIG. 13 , the board dipping device is placed at dipping spot of board in the plating tank  2 , and the air-bubbling tube  68  is used as a generator of liquid current. However, it is possible to use jet nozzle  64  as a generator of liquid current as shown in  FIG. 6A  when it is desirable to enhance treatment effectiveness on though-hole of the thin plate board W and inside via hole, and when an acid-wash clean treatment is performed in pre-treatment tank  1  where bubbling should be avoided. In this case, jet flow is discharged nearly in a horizontal direction toward slit  62   c  from jet nozzle  64 . Therefore, it becomes possible to guide and dip the thin plate board W along the board guide  62  smoothly, as flow is generated which passes through slit  62   c  and directs downward between lower guides  62   b.    
      As an experimental result, it was more effective to guide the thin plate board W smoothly when discharging a jet flow toward upper part R of slit as shown in  FIG. 8  than discharging directly toward the slit. In  FIG. 8 , the jet flow is discharged upwardly to the level plane.  
      As shown in  FIG. 6B , jet nozzle  64  is arranged at even intervals in a transporting direction of the transport hanger  15  (E-direction). As shown in  FIG. 6A , it is arranged fixedly at same height as cutout  62   c  of the board guide  62 .  
      Also, on the fluid level, it is possible to blow off by setting an air blower arranged outside the board guide  62 , before discharged air through air-bubbling tube  68  forms bubbles on the fluid level. It is realized by arranging the air blower as its air discharge direction faces in a direction opposite to board guide. Therefore, it becomes possible to achieve a enough effect based on treatment liquids by preventing the thin plate board W from acquiring bubbles on the surface.  
      Although, it is applied to plating tank in the embodiment described above, it is possible to apply to the other treatment tank like washing.  
      3. The Structure of the Surface Treatment Device and the Transport Hanger  
      As shown in  FIG. 14  and  FIG. 15 , the surface treatment device  300  is the surface treatment device of so-called pusher type, and having guide rails  10 - 13  for transporting the transport hanger  15  which is holding the platy work such as a printed board, and arranged such that along these guide rails  10 - 13 , the pre-treatment tank  1  of each type for processing before plating, plating tank  2  for electroplating, recovery tank  3  and water-washing tank  4  for processing after plating, unload section  5  for unloading the platy work, exfoliate tank  6  for separating plating films (hanger restoring process), water-washing tank  7  for water-washing the transport hanger  15  after separating, and load section  8  for loading a board.  
      Rise-and-fall guide rails  10 ,  12  shown in  FIG. 15  are guide rails which rise and fall when loading or unloading the board W (such as printed board), and when dipping the board W into various type of tanks (e.g., plating tank  2 , recovery tank  3  and water-washing tank  4 , etc.). Fixed guide rails  11 ,  13  are guide rails fixed respectively for transporting the transport hanger  15  which has fallen into plating tank  2 , exfoliate tank  6 .  
      Referring to  FIG. 9 , the structure of the transport hanger  15  will be described.  
      As shown in  FIG. 9 , the transport hanger  15  has treating-object holding member  47  with plural clamps  48  for holding the treating-object W, slide member  35  which contact slidably with guide rails such as fixed guide rail  11 , and connecting members  44  for connecting such members. Copper and brass are used for the material of the slide member  35  and connecting members  44 .  
      The width L 0  of treating-object holding member  47  is calculated based on the width W 0  of platy work W and clamping margin W 1 . For example, if clamping margin W 1  exists on both sides of platy work W (width W 0 ) as shown in  FIG. 9 , the width L 0  of treating-object holding member  47  is calculated by formula: L 0 =W 0 −2×W 1 .  
      As shown in  FIG. 10 , a bearing  36  which has the gear  40  adjusting together with chain belt  39  (comprising the fixed guide rail transporter  19  in  FIG. 7 ) of one-way clutch type is fixed on the slide member  35 . Therefore, the gear  40  which adjusts together with chain belt  39  on the fixed guide rail  11 ,  13  can rotate only in B-direction shown in  FIG. 9  when feeding forward.  
      The pusher contacting face  37  shown in  FIG. 9  is a part contacted by the pusher  16 ,  21  ( FIG. 11 ) of intermittent transporter  17 ,  22  which is transport means of the transport hanger  15   
      The nail-hooking part  32  of  FIG. 10  is a part contacted by the transport nail  30  ( FIG. 12 ) of positioning transporter  18  for transporting the transport hanger  15 . These transporters of the transport hanger  15  will be described as follows.  
      4. Each Transporter for the Transport Hanger  
      The transport hanger  15  shown in  FIG. 9  is transferred by intermittent transporter  17 ,  22 , positioning transporter  18 ,  23 , fixed guide rail transporter  19 ,  24 , and letting-off transporter  20 ,  25  in the surface treatment device  300  as follows.  
      First, intermittent transporter  17 ,  22  which is attached on top of the rise-and-fall guide rails  10 ,  12  transport the transport hanger  15  pitch by pitch that is respectively placed at (c)-(f),(h)-(k) intermittently by using the pusher  16   a - d,    21   a - d  ( FIG. 11 ).  FIG. 11  shows plane view of intermittent transporter  17  on the rise-and-fall guide rail  10 .  
      The positioning transporter  18  shown in  FIG. 15  is arranged along the fixed guide rail  11 . And the transport hanger  15  ( FIG. 15 ), which has fallen into dipping spot  2   a  (board dipping position) at (x)-position where is upside of the plating tank  2 , is transferred to the fixed guide rail  11  and fed forward until (b)-position. And, the distance between platy work W (thin plate board W) and the fore one placed at (a)-position (left side in  FIG. 15 ) in the plating tank  2  is adjusted to predetermined width L 1  (e.g. L 1 =5 mm).  
       FIG. 12  shows the structure of positioning transporter  18 . The positioning transporter  18  shown in  FIG. 12  is movable back and forth in X, Y-direction along rail which is arranged separately from the fixed guide rail  11 , and having a transport nail  30  biased in Z-direction by spring in the condition shown  FIG. 12A . Therefore, when transporting the transport hanger  15 , firstly pass through the nail-hooking part shown in  FIG. 10  by shrinking the spring (condition shown in  FIG. 12B ). After that, the transport hanger  15  is transferred to C-direction shown in  FIG. 14 , as the positioning transporter  18  moves in the opposite direction (Y-direction of  FIG. 12C ) and the transport nail  30  hooks the nail-hooking part  32  of transport hanger  15 . At this time, the moving speed of the positioning transporter  18  is needed to be faster than moving speed of the fixed guide rail transporter  19  (i.e. the moving speed of the chain belt  39 ) as to catch up a foregoing transport hanger  15  that the fixed guide rail transporter  19  is transporting. Also, the structure and the movement of positioning transporter  23  of exfoliate tank  6 &#39;s side are same as positioning transporter  18  of plating tank  2 &#39;s side shown in  FIG. 12 .  
      The fixed guide rail transporter  19 ,  24  transports the transport hanger  15  to C-direction of  FIG. 14  which is fed forward by the positioning transporter  18 ,  23 , with keeping predetermined distance (L 1  of  FIG. 15 ).  
      The letting-off transporters  20 ,  25  transfer the transport hanger  15 , which is transported by the fixed guide rail transporter  19 ,  24  until (g), (o), to (h), (f) position of the rise-and-fall guide rails  10 ,  12  respectively ( FIG. 14 ). Also, the structure and the movement of letting-off transporter  20 ,  25  are same as positioning transporter  18  shown in  FIG. 12 .  
      5. The Other Embodiment  
      Also, in the embodiment described above, although the upper (lower) board shielding plate and the upper (lower) electrode shielding plate are used as two shielding plates against the thin plate board W, it is possible to add a further shielding plate between board shielding plate and electrode shielding plate.  
      Also, in the embodiment described above, although the upper board shielding plate and the upper electrode shielding plate move up and down independently, it is possible to let them move up and down integrally.