阅读说明：本技术 一种键合线制备用铜丝材料的抗氧化处理设备 (Anti-oxidation treatment equipment of copper wire material for bonding wire preparation ) 是由 何孔田 何孔高 张军 于 2020-03-30 设计创作，主要内容包括：本发明提供一种键合线制备用铜丝材料的抗氧化处理设备,包括用于将铜丝镀钯的镀钯箱、用于将铜丝进行清洗的清洗箱、用于将铜丝圈进行松散和控制传输的活动散丝机构、控制铜丝镀钯的镀钯控制机构和机箱,所述镀钯箱的表面与机箱的表面固定连接,镀钯箱的底部和机箱的底部设置有支撑杆,涉及键合线领域。该键合线制备用铜丝材料的抗氧化处理设备根据现有的铜丝作为键合线材料时存在的镀钯和氧化之间的矛盾,设计出特殊的且关联性较高的活动散丝机构和镀钯控制机构,针对圈状包裹的铜丝进行充分的快速的镀钯,解决了一般的圈状包装铜丝在等待镀钯的时候可以减少表面的氧化,但是与镀钯效率又存在极大的矛盾,容易影响到镀钯的效率的问题。(The invention provides an anti-oxidation treatment device for a copper wire material for preparing a bonding wire, which comprises a palladium plating box for plating copper wires with palladium, a cleaning box for cleaning the copper wires, a movable wire loosening mechanism for loosening and controlling transmission of copper wire rings, a palladium plating control mechanism for controlling the copper wires to be plated with palladium and a case, wherein the surface of the palladium plating box is fixedly connected with the surface of the case, and supporting rods are arranged at the bottom of the palladium plating box and the bottom of the case, and the anti-oxidation treatment device relates to the field of bonding wires. According to the contradiction between palladium plating and oxidation existing when the existing copper wire is used as a bonding wire material, the special movable wire scattering mechanism and the palladium plating control mechanism with high relevance are designed, and the copper wire wrapped in a ring shape is subjected to full and rapid palladium plating, so that the problem that the surface oxidation of the common ring-shaped packaging copper wire can be reduced when the copper wire is waited for palladium plating, but the contradiction with the palladium plating efficiency is great, and the palladium plating efficiency is easily influenced is solved.)

1. The utility model provides an anti-oxidation treatment facility of copper wire material for bonding wire preparation which characterized in that: the cleaning device comprises a palladium plating box (1) for plating palladium on a copper wire, a cleaning box (2) for cleaning the copper wire, a movable wire loosening mechanism (3) for loosening and controlling transmission of a copper wire ring, a palladium plating control mechanism (4) for controlling the copper wire to plate palladium and a case (5), wherein the surface of the palladium plating box (1) is fixedly connected with the surface of the case (5), supporting rods (6) are arranged at the bottom of the palladium plating box (1) and the bottom of the case (5), the cleaning box (2) is arranged above the palladium plating box (1) and the case (5), the surface of the cleaning box (2) is fixedly connected with the surface of the case (5), the movable wire loosening mechanism (3) is arranged on the cleaning box (2), and the palladium plating control mechanism (4) is arranged on the palladium plating box (1) and the case (5).

2. The apparatus for oxidation-resistant treatment of copper wire material for bonding wire preparation according to claim 1, wherein: the movable silk dispersing mechanism (3) comprises a motor (31), a plurality of cleaning roller shafts (32), a plurality of movable hollow shafts (33), a first silk dispersing air cushion (34), a second silk dispersing air cushion (35) and a rubber silk guide head (36), wherein two rows of bearings are arranged on the surface of the cleaning box (2), inner rings of the lower rows of bearings are fixedly connected with the surface of the cleaning roller shafts (32), cleaning bristles (37) are fixedly connected to the surface of the cleaning roller shafts (32), movable hollow shafts (33) are fixedly connected with the inner rings of the upper rows of bearings, and insulating rubber is arranged on the surface of the cleaning roller shafts (32), the surface of the movable hollow shafts (33) and the inner wall of the cleaning box (2).

3. The apparatus for oxidation-resistant treatment of copper wire material for bonding wire preparation according to claim 2, wherein: the surface of the movable hollow shaft (33) is fixedly connected with a first silk dispersing air cushion (34), the surface of the movable hollow shaft (33) is fixedly connected with a second air cushion (35) for dispersing the filaments, the surfaces of the first silk dispersing air cushion (34) and the second silk dispersing air cushion (35) are in a spiral shape, the surface of the first silk dispersing air cushion (34) and the interior of the second silk dispersing air cushion (35) are communicated with the interior of the movable hollow shaft (33), one end of the movable hollow shaft (33) is fixedly provided with an electromagnetic air inlet valve (38), the surface of the first silk dispersing air cushion (34) is fixedly connected with a rubber silk guide head (36), the inner part of the rubber thread guide head (36) is hollow, the surface of the rubber thread guide head (36) is in the shape of a circular truncated cone, the surface of the first silk dispersing air cushion (34) and the surface of the second silk dispersing air cushion (35) are provided with corrugated grooves (39) with opposite inclination directions.

4. The apparatus for oxidation-resistant treatment of copper wire material for bonding wire preparation according to claim 1, wherein: the fixed surface of machine case (5) is connected with extension board (310), the fixed surface of extension board (310) is connected with motor (31), the output shaft of motor (31) passes through the fixed surface of shaft coupling and a washing roller axle (32) and is connected, a plurality of same driving belt (311) has been cup jointed on the surface of washing roller axle (32), the surface of washing roller axle (32) and the surface of activity hollow shaft (33) all are provided with gear (312), gear (312) intermeshing on adjacent washing roller axle (32) and the activity hollow shaft (33) from top to bottom.

5. The apparatus for oxidation-resistant treatment of copper wire material for bonding wire preparation according to claim 1, wherein: the palladium plating control mechanism (4) comprises an air pump (41), a storage battery (42), a plurality of outer circular pipes (43) which correspond to the rubber wire guides (36) one by one, an inner ring pad (44), a ring piece (45), a first conducting strip (46), a second conducting strip (47), a palladium metal rod (48), an arc-shaped top plate (49) and an inclined sliding rod (410), wherein the surface of the outer circular pipe (43) is fixedly connected with the inner wall of the palladium plating box (1), the inner ring pad (44) is positioned inside the outer circular pipe (43), the inner wall of the inner ring pad (44) is fixedly connected with the second conducting strip (47), the surface of the outer circular pipe (43) is fixedly connected with the first conducting strip (46), the palladium metal rod (48) is inserted on the inner ring pad (44) and is contacted with the second conducting strip (47), the ring piece (45) is arranged between the outer circular pipe (43) and the inner ring pad (44), the surface of the ring piece (45) is provided with a plurality of air holes (411).

6. The apparatus for oxidation-resistant treatment of copper wire material for bonding wire preparation according to claim 5, wherein: the storage battery (42) and the air pump (41) are both arranged inside the case (5), the positive electrode of the storage battery (42) is electrically connected with the first conducting strip (46), the negative electrode of the storage battery (42) is electrically connected with the second conducting strip (47), the air outlet end of the air pump (41) is sleeved with the air outlet pipe (412), and the air outlet end of the air outlet pipe (412) is sleeved with the bottom end of the outer ring pipe (43).

7. The apparatus for oxidation-resistant treatment of copper wire material for bonding wire preparation according to claim 5, wherein: the surface of the arc-shaped top plate (49) is fixedly connected with a plurality of inclined sliding rods (410) which are circumferentially distributed by taking the center of the arc-shaped top plate (49) as a circle center, the surface of each inclined sliding rod (410) is provided with a spiral groove (413), one end, far away from the arc-shaped top plate (49), of each inclined sliding rod (410) is connected with the surface of the outer ring pipe (43) in an inserting mode, the arc-shaped top plate (49) is located above the outer ring pipe (43), the diameter of the arc-shaped top plate (49) is smaller than the inner diameter of the outer ring pipe (43), and the diameter of the arc-shaped top plate (49) is larger than.

Technical Field

The invention relates to the technical field of bonding wires, in particular to an anti-oxidation treatment device for a copper wire material for preparing a bonding wire.

Background

The bonding lead is used for connecting a silicon chip electrode with an external leading-out terminal of a lead frame, transmitting a chip electrical signal and dissipating heat generated in the chip, and is a key material for packaging an integrated circuit, the main materials of bonding wires in China at present are gold and aluminum, but the chip is higher in density, stronger in function, lower in price and lower in power consumption along with the requirement of electronic packaging, so that the packaging is developed towards the direction of fine spacing, multiple pins, small bonding pads and small bonding points, under the development trend of the electronic packaging technology, copper wire bonding can better meet the packaging requirement, compared with the gold and aluminum bonding wires which are commonly used at present, the copper bonding wire is low in price, the cost can be saved under the same condition, the thermal conductivity and the electric conductivity are larger than those of gold wires, and under the condition that the diameters of the two wires are the same, a copper wire can conduct more current and more heat in unit time, the mechanical property of the copper wire is superior to that of the gold wire, the copper wire has stronger supporting force and toughness than the gold wire under the same condition, the properties are favorable for forming a large-span wire drawing and a smaller-distance flat cable in bonding, the future development requirement is met, after the bonding is finished, an intermetallic compound formed by the copper wire and an aluminum layer electrode of a chip has stable performance and slower growth speed, so that the contact resistance is reduced, the generated heat is less, the bonding strength can be improved, the welding reliability and the device performance are finally improved, the service life of the chip is prolonged, but the chemical stability of the copper is poor, the surface is easy to be oxidized to form an oxide film, the strength of a dry joint is low, a phenomenon of virtual dryness can be generated in a small amount, the contact area between the copper and air can be reduced to the greatest extent in order to avoid the oxidation of the copper surface, and the oxidation degree of the surface of the copper wire can also, the prior art can also avoid oxygen rapid copper oxidation under a high temperature state by inputting a certain flow of rare gas during welding, wherein in the process of palladium plating, two methods are adopted at present, one method is to put the whole copper wire into a plating tank, which is densely stacked with the copper wire and has a large surface area and shields each other, which can affect the uniformity of palladium plating, the other method is to transmit the copper wire separately, so that the copper wire is fully contacted with electroplating solution, but the method needs to disperse the copper wire, the copper wire needing to be electroplated can not be tightly wound before transmission, especially can not be in a ring shape, otherwise, the copper wire can be tightened, staggered and entangled when pulled, the pulling force can cause the copper wire to be broken, even if a certain buffer structure is adopted, the copper wire can not be broken, the ring-shaped copper wires can be mutually stacked, the contact time with air and the contact surface area are reduced, and the packaging is convenient, the oxidation is conveniently avoided, the oxidation of the surface of a common ring-shaped packaging copper wire can be reduced when the copper wire is waited for being plated with palladium, but the efficiency of the copper wire is greatly contradicted with the efficiency of the palladium plating, and the efficiency of the palladium plating is easily influenced, so that the oxidation resistance treatment equipment of the copper wire material for preparing the bonding wire is needed.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides an anti-oxidation treatment device for a copper wire material for preparing a bonding wire, which solves the problems that the oxidation of the surface of a common ring-shaped packaging copper wire can be reduced when the copper wire is waited for palladium plating, but the efficiency of palladium plating is greatly contradicted with the efficiency of palladium plating, and the efficiency of palladium plating is easily influenced.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: the anti-oxidation treatment equipment for the copper wire material for preparing the bonding wire comprises a palladium plating box for plating palladium on a copper wire, a cleaning box for cleaning the copper wire, a movable wire scattering mechanism for loosening and controlling transmission of a copper wire ring, a palladium plating control mechanism for controlling the copper wire to plate palladium and a case, wherein the surface of the palladium plating box is fixedly connected with the surface of the case, supporting rods are arranged at the bottom of the palladium plating box and the bottom of the case, the cleaning box is arranged above the palladium plating box and the case, the surface of the cleaning box is fixedly connected with the surface of the case, the movable wire scattering mechanism is arranged on the cleaning box, and the palladium plating control mechanism is arranged on the palladium plating box and the case.

Preferably, the movable silk scattering mechanism comprises a motor, a plurality of cleaning roll shafts, a plurality of movable hollow shafts, a first silk scattering air cushion, a second silk scattering air cushion and a rubber silk guide head, two rows of bearings are arranged on the surface of the cleaning box, inner rings of the lower row of bearings are fixedly connected with the surface of the cleaning roll shafts, cleaning bristles are fixedly connected with the surface of the cleaning roll shafts, movable hollow shafts are fixedly connected with the inner rings of the upper row of bearings, and insulating rubber is arranged on the surface of the cleaning roll shafts, the surface of the movable hollow shafts and the inner wall of the cleaning box.

Preferably, the fixed surface of activity hollow shaft is connected with first scattered silk air cushion, the fixed surface of activity hollow shaft is connected with the scattered silk air cushion of second, the surface of first scattered silk air cushion and surface and the scattered silk air cushion of second is the heliciform, the surface of first scattered silk air cushion and the inside of the scattered silk air cushion of second all communicate with the inside of activity hollow shaft, the one end fixed mounting of activity hollow shaft has electromagnetic air inlet valve, the fixed surface of first scattered silk air cushion is connected with rubber thread guide head, the inside of rubber thread guide head is hollow form, the surface of rubber thread guide head is the round platform shape, the surface of first scattered silk air cushion and the surface of the scattered silk air cushion of second are provided with the opposite ripple groove of direction of slope.

Preferably, the fixed surface of machine case is connected with the extension board, the fixed surface of extension board is connected with the motor, the output shaft of motor passes through the fixed surface of shaft coupling and a cleaning roller axle and is connected, a plurality of same driving belt has been cup jointed on the surface of cleaning roller axle, the surface of cleaning roller axle and the surface of activity hollow shaft all are provided with the gear, and adjacent cleaning roller axle and the gear intermeshing on the activity hollow shaft from top to bottom.

Preferably, the palladium plating control mechanism comprises an air pump, a storage battery, a plurality of outer circular tubes, inner circular pads, circular sheets, a first conducting sheet, a second conducting sheet, palladium metal rods, an arc-shaped top plate and inclined sliding rods, wherein the outer circular tubes correspond to the rubber wire guides one by one, the surface of each outer circular tube is fixedly connected with the inner wall of the palladium plating box, the inner circular pads are located inside the outer circular tubes, the inner walls of the inner circular pads are fixedly connected with the second conducting sheets, the surface of each outer circular tube is fixedly connected with the first conducting sheet, the palladium metal rods are inserted into the inner circular pads and are in contact with the second conducting sheets, the circular sheets are arranged between the outer circular tubes and the inner circular pads, and a plurality of air holes are formed in the surfaces of the circular.

Preferably, the storage battery and the air pump are both arranged inside the case, the anode of the storage battery is electrically connected with the first conducting strip, the cathode of the storage battery is electrically connected with the second conducting strip, the air outlet end of the air pump is sleeved with the air outlet pipe, and the air outlet end of the air outlet pipe is sleeved with the bottom end of the outer ring pipe.

Preferably, the surface of the arc-shaped top plate is fixedly connected with a plurality of inclined slide bars which are circumferentially distributed by taking the center of the arc-shaped top plate as a circle center, the surface of each inclined slide bar is provided with a spiral groove, one end, far away from the arc-shaped top plate, of each inclined slide bar is connected with the surface of the outer ring pipe in an inserting mode, the arc-shaped top plate is located above the outer ring pipe, the diameter of the arc-shaped top plate is smaller than the inner diameter of the outer ring pipe, and the diameter of the arc-shaped top.

(III) advantageous effects

(1) According to the invention, by arranging the movable wire scattering mechanism, the looped copper wire can be repeatedly and regularly poked left and right, the copper wire loop is continuously loosened, the copper wire is fully cleaned by a scrubbing structure, and meanwhile, the subsequent palladium plating process is facilitated.

(2) According to the invention, by arranging the palladium plating control mechanism, the copper wire is pulled into a state of large diameter at the bottom ring and small diameter at the top ring by virtue of certain elasticity and ring shape of the copper wire after being scattered in a ring shape, the scattered copper wire can continuously and elastically shake and sequentially pile into a ring shape of large diameter at the bottom and small diameter at the upper part when contacting with the electroplating solution in the state, the movable loosening mechanism continuously shakes the separated copper wire in the electroplating solution, the electroplating efficiency of the copper wire is obviously improved, and the gas output by the air pump can continuously and upwards shake the copper wire which is piled into a ring shape again and has an inclined surface, so that the electroplating solution can be mixed, and the full electroplating of the copper wire which is coiled again can be promoted.

(3) According to the invention, a special movable wire scattering mechanism and a palladium plating control mechanism with high relevance are designed according to the contradiction between palladium plating and oxidation existing when the existing copper wire is used as a bonding wire material, and the copper wire wrapped in a ring shape is subjected to full and rapid palladium plating, so that the problem that the surface oxidation of a common ring-shaped packaging copper wire can be reduced when the copper wire is subjected to palladium plating, but the efficiency of palladium plating is greatly contradicted with the efficiency of palladium plating, and the efficiency of palladium plating is easily influenced is solved.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is an enlarged view of the structure of FIG. 1 at A according to the present invention;

FIG. 3 is a front view of a second wire air mattress structure according to the present invention;

FIG. 4 is a side view of a second wire air mattress structure according to the present invention.

The automatic cleaning device comprises a palladium plating box 1, a cleaning box 2, a movable silk scattering mechanism 3, a motor 31, a cleaning roller shaft 32, a movable hollow shaft 33, a first silk scattering air cushion 34, a second silk scattering air cushion 35, a rubber silk guide head 36, cleaning bristles 37, an electromagnetic air inlet valve 38, a corrugated groove 39, an extension plate 310, a transmission belt 311, a gear 312, a palladium plating control mechanism 4, an air pump 41, a storage battery 42, an outer annular pipe 43, an inner annular cushion 44, an annular sheet 45, a first conductive sheet 46, a second conductive sheet 47, a palladium metal rod 48, an arc-shaped top plate 49, an inclined slide rod 410, an air hole 411, an air outlet pipe 412, a spiral groove 413, a chassis 5 and a support rod 6.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 4, an embodiment of the present invention provides an antioxidant treatment device for a copper wire material for bonding wire preparation, including a palladium plating tank 1 for plating palladium on a copper wire, a cleaning tank 2 for cleaning the copper wire, a movable wire scattering mechanism 3 for loosening and controlled transmission of a copper wire loop, a palladium plating control mechanism 4 for controlling the palladium plating on the copper wire, and a case 5, wherein the surface of the palladium plating tank 1 is fixedly connected with the surface of the case 5, support rods 6 are disposed at the bottom of the palladium plating tank 1 and the bottom of the case 5, the cleaning tank 2 is disposed above the palladium plating tank 1 and the case 5, the surface of the cleaning tank 2 is fixedly connected with the surface of the case 5, the movable wire scattering mechanism 3 is disposed on the cleaning tank 2, and the palladium plating control mechanism 4 is disposed on the palladium plating tank 1 and the case 5.

The movable silk dispersing mechanism 3 comprises a motor 31, a plurality of cleaning roller shafts 32, a plurality of movable hollow shafts 33, a first silk dispersing air cushion 34, a second silk dispersing air cushion 35 and a rubber silk guide head 36, wherein two rows of bearings are arranged on the surface of the cleaning box 2, the inner rings of the lower rows of bearings are fixedly connected with the surface of the cleaning roller shaft 32, the surface of the cleaning roller shaft 32 is fixedly connected with cleaning bristles 37, the inner rings of the upper rows of bearings are fixedly connected with the movable hollow shafts 33, insulating rubber is arranged on the surface of the cleaning roller shaft 32, the surface of the movable hollow shafts 33 and the inner wall of the cleaning box 2, the surface of the movable hollow shafts 33 is fixedly connected with the first silk dispersing air cushion 34, the surface of the movable hollow shafts 33 is fixedly connected with the second silk dispersing air cushion 35, the surfaces of the first silk dispersing air cushion 34 and the surfaces of the second silk dispersing air cushion 35 are in a spiral shape, and the surfaces of the first silk dispersing, an electromagnetic air inlet valve 38 is fixedly installed at one end of the movable hollow shaft 33, a rubber yarn guide head 36 is fixedly connected to the surface of the first yarn dispersing air cushion 34, the interior of the rubber yarn guide head 36 is hollow, the surface of the rubber yarn guide head 36 is in a circular truncated cone shape, corrugated grooves 39 with opposite inclination directions are formed in the surface of the first yarn dispersing air cushion 34 and the surface of the second yarn dispersing air cushion 35, an extension plate 310 is fixedly connected to the surface of the case 5, a motor 31 is fixedly connected to the surface of the extension plate 310, an output shaft of the motor 31 is fixedly connected to the surface of one cleaning roller shaft 32 through a coupler, the same transmission belt 311 is sleeved on the surfaces of the plurality of cleaning roller shafts 32, gears 312 are arranged on the surfaces of the cleaning roller shafts 32 and the movable hollow shaft 33, and the cleaning roller shafts 32 which are adjacent up and down.

The palladium plating control mechanism 4 comprises an air pump 41, a storage battery 42, a plurality of outer ring tubes 43 corresponding to the rubber wire guides 36 one by one, an inner ring pad 44, a ring sheet 45, a first conducting sheet 46, a second conducting sheet 47, a palladium metal rod 48, an arc-shaped top plate 49 and an inclined slide rod 410, wherein the surface of the outer ring tube 43 is fixedly connected with the inner wall of the palladium plating box 1, the inner ring pad 44 is positioned inside the outer ring tube 43, the inner wall of the inner ring pad 44 is fixedly connected with the second conducting sheet 47, the surface of the outer ring tube 43 is fixedly connected with the first conducting sheet 46, the palladium metal rod 48 is inserted on the inner ring pad 44 and is contacted with the second conducting sheet 47, the ring sheet 45 is arranged between the outer ring tube 43 and the inner ring pad 44, the surface of the ring sheet 45 is provided with a plurality of air holes 411, the storage battery 42 and the air pump 41 are both arranged inside the case 5, the anode of the storage battery 42 is electrically connected with, the air outlet 412 is sleeved at the air outlet end of the air pump 41, the air outlet end of the air outlet 412 is sleeved with the bottom end of the outer ring pipe 43, the surface of the arc-shaped top plate 49 is fixedly connected with a plurality of inclined slide rods 410 which are circumferentially distributed by taking the center of the arc-shaped top plate 49 as a circle center, a spiral groove 413 is formed in the surface of each inclined slide rod 410, one end, away from the arc-shaped top plate 49, of each inclined slide rod 410 is connected with the surface of the outer ring pipe 43 in an inserting mode, the arc-shaped top plate 49 is located above the outer ring pipe 43, the diameter of the arc-shaped top plate 49 is smaller.

When the cleaning brush is used, a power supply is connected, a ring-shaped copper wire is sleeved on the first loose wire air cushion 34 and the second loose wire air cushion 35 on each movable hollow shaft 33, then a certain amount of gas is input into the first loose wire air cushion 34 and the second loose wire air cushion 35 through the electromagnetic air inlet valve 38 until the first loose wire air cushion 34 and the second loose wire air cushion 35 expand, then the motor 31 is started, the motor 31 drives each cleaning roller shaft 32 to rotate through the driving belt 311, the cleaning roller shaft 32 drives the movable hollow shaft 33 to rotate through the gear 312, the movable hollow shaft 33 drives the first loose wire air cushion 34 and the second loose wire air cushion 35 to rotate, the copper wire ring continuously moves left and right on the first loose wire air cushion 34 and the second loose wire air cushion 35 and is loosened and pushed to two sides by the cleaning brush bristles 37 which reversely rotate, the copper wires moving to the left end parts of the first wire dispersing air cushion 34 and the second wire dispersing air cushion 35 gradually contact the rubber wire guides 36 and fall into the palladium plating box 1 through the rubber wire guides 36, the copper wires are continuously shaken and sleeved on the inclined slide rods 410 under the action of gravity and in a self-ring shape and an elastic state, under the action of the inclined slide rods 410, the copper wire rings are in a ring shape with a thick bottom and a thin upper part, the copper wires contact the first conducting strips 46, the palladium metal rods 48 contact the second conducting strips 47, gas output by the air pump 41 is blown to the electroplating solution and the copper wire rings through the air outlet pipe 412 and the air holes 411, the copper wires which are formed into the ring shape again are continuously turned over and fully contact with the electroplating solution which is stirred uniformly until electroplating is completed.