JP2898281B2 - Strip material plating apparatus and strip material transport method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for plating or cleaning a strip material such as a strip-shaped IC lead frame.
The present invention relates to a transport device and a method for passing strip materials into a tank.

[0002]

2. Description of the Related Art In general, plating of an IC lead frame is performed by continuously passing a hoop material wound on a reel through a plurality of lead frames connected in a strip shape to a plating tank. Conventionally, lead frames have generally been manufactured by press punching, but in recent years, the market for lead frames formed by an etching method has been increasing with the trend of increasing the number of pins and reducing the number of different types. A lead frame formed by an etching method is manufactured as a strip-shaped member in which several lead frames are connected due to its manufacturing method. Therefore, it is necessary to separately put such strip-shaped members in a plating tank to perform plating.

As shown in FIG. 4, the simplest method for plating substantially the entire surface of such a strip material is to grip the upper end of the strip material 31 with a clip 32, and
Is suspended in the plating tank 33. Strip material 31
Is applied through a metallic clip 32 and a wire 34 supporting the clip. A pair of anode electrodes 35 including a plating metal are arranged in the plating tank 33 so as to face both sides of the strip material 31.
Is applied with a positive voltage.

However, in this method, no plating is applied to the strip material portion gripped by the clip 32. Conversely, plating is applied to the clip 32, causing loss of plated metal, and the clip 32 needs to be replaced frequently. In order to automate the equipment, a complicated mechanism for automatically holding or releasing the strip material 31 by the clip 32 is required.

As another method, as shown in FIG. 5, while transporting the strip material 41 in the longitudinal direction by roller transport,
There is a method of passing through a plating tank 42 shorter than the length of the strip material 41. The negative potential applied to the strip material 41 is provided via a metal power supply roller 43. However, one of the drawbacks of this method is that plating is applied to the power supply roller 43 by the plating solution leaking from the plating tank 42, and it is necessary to frequently perform maintenance for removing the plating or replacing the power supply roller 43. . Another disadvantage is that it is difficult to replenish the lower anode electrode 44 of the pair of upper and lower anode electrodes 44 disposed in the plating tank 42 so as to face both sides of the strip 41 with plating metal.

Another method is disclosed in Japanese Patent Application Laid-Open No. 7-9708.
No. 8 discloses a method. in this way,
The strip material is passed through the plating tank by simultaneously moving the two wires in the longitudinal direction while holding the strip material between the two wires stretched so as to pass through the plating tank. The negative potential applied to the strip is provided via a metal wire.

[0007]

However, in the method described in the above-mentioned publication, in which the strip is gripped and transported between the two wires, the strip is gripped using the above-described clip. However, it is impossible to solve the problem that plating is not applied to a part of the strip material.

For example, in the case of a strip material in which a plurality of lead frames are connected, an additional portion for connection which is finally cut and discarded is provided at an end in the width direction, and this portion is narrowed between two wires. If it does, there is no functional problem even if this part is not plated. However, the appearance problem as a finished plating product remains. In addition, when stored for a long period of time, there is a possibility that corrosion will proceed from a portion that has not been plated. Further, it is difficult to perform a loading operation for holding the end portion of the strip material between the two wires and an unloading operation for removing the strip material that has been twisted after the processing from the wires. Requires a special mechanism for that, and the device becomes complicated. Further, when performing the loading operation and the unloading operation, the strip material is likely to drop, and the equipment is frequently stopped.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is intended to pass a strip material through a plating tank or the like when it is necessary to plate the entire strip material. It is an object of the present invention to provide a plating apparatus and a transport method having a reasonable transport apparatus for causing the plating apparatus.

[0010]

SUMMARY OF THE INVENTION A strip plating apparatus according to the present invention is a plating apparatus for performing electrolytic plating on substantially the entire surface of a strip by passing the strip through a plating tank. The two wires stretched in a substantially horizontal direction so as to pass through the inside of the wire are in contact with each other in the horizontal direction, and the lower side of the strip is placed in a valley formed above the contact portion of the two wires. By moving the two wires simultaneously in the longitudinal direction while holding the strip material in a substantially vertical position by means for preventing the strip material from falling down, the strip material is passed through the inside of the plating tank. .

According to the above configuration, plating can be applied to almost the entire surface of the strip material. Further, since the strip material is passed through the plating tank while being held substantially vertically, for example, the two wires and the anode electrode are arranged so that the strip material passes substantially between the pair of anode electrodes arranged in the plating tank. By arranging them, it becomes easy to apply a plating having a uniform thickness to both sides of the strip material. It is also easy to replenish the pair of anode electrodes with plating metal.

The negative voltage applied to the strip material to be plated can be easily applied via the conductive wire if at least one of the two wires is a conductive wire, for example, a metal wire.

Preferably, the two wires are wound around a bobbin outside the plating tank, so that the two wires move inside the plating tank in the longitudinal direction. As another method, for example, each wire may be configured in an endless loop, but the method of winding around a bobbin is excellent because there is no seam and the wire can be stably fed by further absorbing the elongation of the wire. I have.

As a member constituting a means for preventing the strip from falling down, a pair of guide rods erected so as to sandwich the two wires are provided at regular intervals along the longitudinal direction of the two wires. Is preferred. In order to reduce the contact friction with the transported strip material, it is preferable that the guide rod be rotatable. The guide rod may simply be configured to be freely rotatable around its axis, but it is more preferable that the guide rod be rotationally driven by the driving means at a rotational speed corresponding to the moving speed of the wire.

As a specific structure for simply realizing the above-mentioned rotational driving, a wire pulley is fixed to a lower portion of a pair of guide rods, and a contact state of the two wires is sandwiched between the pair of wire pulleys. Is maintained, and when the two wires move in the longitudinal direction, the guide rod is preferably rotated via a pair of wire pulleys.

As a means for preventing the use of the guide rod in combination with the above-mentioned guide rod or as an alternative thereto, a nozzle for injecting a plating solution having a width wider than the width of the strip from the upper side of the strip to the lower side has a length of two wires. Preferably, they are provided at regular intervals along the direction. Injecting the plating solution into the plating tank is desirable for stirring the plating solution to obtain uniform plating, but by performing this injection from above the strip material to below, the lifting of the strip material is prevented. The lower side is pressed against the wire. In addition, by spraying the plating solution downward in a width wider than the thickness of the strip, an effect of preventing the strip from falling down can be obtained.

That is, when the strip is in a substantially vertical position, the strip is positioned substantially at the center of the plating jet and substantially parallel to the jet flow direction, so that a pressure substantially equal to both sides of the strip is applied from the plating jet. Can be However, when the strip is slightly inclined in the jet, the jet changes, and as a result, pressure in the direction to correct the inclination is applied to the strip from the plating jet. This prevents the strip from falling down.

As described above, the method of transporting the strip material while holding it vertically is not limited to the plating apparatus, but can be applied to other apparatuses.

That is, the method for transporting strips according to the present invention is a method for transporting strips through a tank such as a plating tank or a washing tank, and is substantially horizontal so as to pass through the tank. Means for contacting two wires stretched in the horizontal direction with each other, placing the lower side of the strip in a valley formed above the contact portion of the two wires, and preventing the strip from falling down By moving the two wires simultaneously in the longitudinal direction while holding the strip material in a substantially vertical posture,
It is characterized in that the strip material is passed through the tank.

[0020]

FIG. 1 shows a schematic configuration of a plating apparatus according to an embodiment of the present invention. This plating apparatus is an apparatus for passing a strip material such as a member to which a plurality of IC lead frames are connected into the inside of a plating tank 1 and performing a plating process on the entire surface thereof. Longitudinal slots are formed on opposing wall surfaces of the plating tank 1, and strips held in a substantially vertical posture enter the plating tank 1 from one slot 2 and exit from the other slot 3.

As means for transporting the strip material, two metal wires 4 are stretched almost horizontally and pass through the slots 2 and 3 of the plating tank 1. FIG. 2 shows a cross section of a main part of the apparatus viewed from the traveling direction of the strip material. As can be seen from FIG. 2, the two wires are in contact with each other in the horizontal direction, and the lower side of the strip 5 is placed in a valley formed above the contact portion. The diameter of the wire 4 needs to be at least larger than the thickness of the strip material, and is preferably as large as possible for stable conveyance. In one embodiment, a thickness of 0.1
3mm diameter C to transport ~ 0.4mm strips
u wire was used. Other metal wires such as Fe may be used.

A support frame 6 having an H-shaped cross section is provided inside the plating tank 1. The support frame 6 is also formed in a box shape, and a vertically elongated slot 6 is formed in a wall portion through which the wire 4 and the strip material 5 pass.
a and 6b are formed. That is, it has a double tank structure in which an inner tank with the support frame 6 is formed inside the plating tank 1.
A pair of guide rods 7 are erected at predetermined intervals along the wire 4 on the horizontal surface (bottom surface) of the support frame 6 so as to sandwich the two wires. This pair of guide rods 7
This is for preventing the strip material 5 in the vertical posture placed on the wire 4 from falling down. Therefore, it is necessary to erect at least an interval shorter than the length of the strip 5 along the wire, and it is preferable to erect at an interval about half the length of the strip 5.

As shown in FIG. 2, the shaft 7 of the guide rod 7
aThe lower end is fixed to the support frame 6 via a bearing 8,
It is freely rotatable. Further, a wire pulley 9 is fixed to a lower portion of the guide rod 7. A pair of wire pulleys 9
By sandwiching the pair of wires 4 therebetween, the contact state of the pair of wires 4 is maintained and the position of the wires in the vertical direction is also regulated. Further, as the wire 4 moves, the pair of guide rods 7 are driven to rotate via the pair of wire pulleys 9. As the guide rod 7 rotates,
The contact friction between the transported strip 5 and the guide rod 7 is reduced. In the present embodiment, the guide rod 7 and the wire pulley 9 except the shaft 7a are made of polyethylene, and the shaft 7a
Was made of titanium. Note that the guide rod 7 and the wire pulley 9 may be integrally formed.

The two wires 4 are simultaneously wound around a bobbin (not shown) provided outside the plating tank 1. As a result, the two wires 4 and the strip material 5 placed thereon move in the plating tank 1 at a constant speed. If the winding is performed intermittently, it is possible to intermittently convey the strip material by the wire. When the winding on one bobbin is completed, the apparatus is temporarily stopped, and the wire is rewound on the other bobbin. Alternatively, the bobbin on which the wire is wound and the empty bobbin are exchanged. After that, the wire transport and the plating process are restarted.

The work of inserting the strip material held in a vertical position between the guide rods from above and placing it on the two wires in front of the plating tank may be performed by hand, An automatic transfer device using various mechanisms may be provided. The same applies to the operation of taking out the strip material after the plating treatment that has passed through the plating tank. However, when another tank is connected for the steps before and after the plating step, the above-described wire transfer can be performed over a plurality of tanks. For example, pre-treatment steps for plating include chemical polishing and cleaning, and post-treatment steps include neutralization, cleaning, and drying. A plurality of plating processes (for example, base nickel plating, palladium plating, and ultra-thin gold plating) may be performed in a plurality of plating tanks.

FIG. 3 is a schematic diagram showing the overall configuration of an example of a plating automation apparatus including the plating apparatus of the present invention.

The strip material 5 is placed on the two wires 4 and transported in the processing tank 20 in the direction of the arrow 23. In the apparatus shown in FIG. 3, the processing tank 20 is divided into three tanks 21a, 21b, 21c by partition plates 22a, 22b. In the pretreatment tank 21a, plating pretreatment such as chemical polishing and cleaning of the strip material 5 is performed. The plating layer 21b is further subdivided into a plurality of tanks (not shown), and for example, Ni, Pd, and Au are sequentially plated. In the post-treatment tank 21c, neutralization, washing, drying and the like are performed.

The feeding of the two wires is performed at a constant speed or intermittently by a wire feeding device 27 having two bobbins 26a and 26b driven by a motor.
The placement of the strip material 5 on the wire is automatically performed by a loading device 24 installed in front of the processing tank 20. The loading device 24 holds the strips one by one with a chucking device (not shown) and places them on the grooves of the two wires 4.

Removal of the strip 5 from the processing tank 20 is automatically performed by the unloading device 25. The unloading device 25 removes the processed strip material 5 by one.
The sheets are gripped by a chucking device (not shown) one by one, picked up from the wire 4, and stored in a predetermined place. The winding of the two wires is performed by two motor-driven bobbins 28a, 2a.
8b.

In the present invention, the strip material 5 is placed on the two wires 4 and conveyed. Therefore, unlike the case where the strip material 5 is conveyed while being held between the two wires, the loading device 24 forms the strip material. It is easy to automate the placing operation and the operation of picking up the strips by the unloading device 25, and the occurrence of troubles such as dropping the strips in these operations can be extremely reduced. In FIG. 3,
In order to simplify the drawing, detailed configurations such as guide rods in the processing tank 20 are omitted.

As shown in FIG. 2, a pair of anode electrodes 10 are arranged at predetermined intervals so as to face both surfaces of the strip material 5 to be conveyed. The anode electrode 10 is one in which a plating metal is placed in a metal basket that is insoluble in a plating solution. The anode electrode 10 is fixed to the left and right inner walls of the support frame 6 via a support fitting 11, a metal bar 12, and an L-shaped member 13. In FIG. 1, one anode electrode 10 and its mounting member 11,
Only 12 and 13 are depicted.

As shown in FIG. 1, the anode electrode 10 is connected to the positive electrode side of the DC power supply 14. On the other hand, the negative electrode side of the DC power supply 14 is electrically connected to the wire 4 via a wire bobbin not shown. Therefore, a negative voltage is applied to the strip material 5 placed on the wire 4 via the wire 4.

Further, above the strip material 5, the wire 4
A plating solution supply pipe 15 is provided along the longitudinal direction of the wire. On the lower surface of the pipe, nozzles 16 for injecting the plating solution at a predetermined width downward are provided at predetermined intervals along the longitudinal direction of the wire. I have. Separate nozzle 16 to pipe 15
The nozzle 16 may be integrally formed on the lower surface of the pipe 15. The interval at which the nozzles 16 are provided is preferably as short as possible, and is at least shorter than the length of the strip material 5 in the direction along the wire 4.

The nozzle 16 has a function of supplying a plating solution to the inner space of the support frame 6 in the plating tank 1 and stirring the plating solution to obtain uniform plating. Further, by injecting the plating solution from above the strip material 5 downward, the lifting of the strip material 5 is prevented, and the lower side thereof is pressed against the wire 4. In addition, strip material 5
It also has the function of preventing falling.

That is, when the strip material 5 is in a substantially vertical position, the strip material 5 is located substantially at the center of the plating jet and almost parallel to the jet direction, so that substantially equal pressure is applied to both sides of the strip material 5. Added from the jet. However, when the strip 5 is slightly inclined in the jet, the jet changes, and as a result, pressure in the direction to correct the inclination is applied to the strip 5 from the plating jet. This prevents the strip material 5 from falling down.

The plating solution supplied into the support frame 6 leaks from the slots 6a and 6b of the support frame 6. Furthermore, it leaks outside from the slots 2 and 3 of the plating tank 1.
The leaked plating solution is collected in a management tank (not shown), and is again supplied to the plating solution supply pipe 15 by the pump. By circulating the plating solution in this way,
The strip material 5 and the anode electrode 10 are always kept in the plating solution. When a DC voltage is applied between the anode electrode 10 and the strip 5 in this state, ions of the plating metal dissolved in the plating solution precipitate on the surface of the strip 5,
The desired electrolytic plating is performed. Since the plating metal of the anode electrode 10 decreases as it melts into the plating solution, the plating metal is replenished into the basket of the anode electrode 10 as necessary.

In the above-described embodiment, the wire pulley fixed to the lower portion of the pair of guide rods and supporting the two wires so as to sandwich the two wires is preferably made of a somewhat elastic resin. It is possible to always apply a biasing force to the wire from the pulley so as to be in close contact with each other. Alternatively, a mechanism that applies a biasing force using a spring or the like in a direction to reduce the interval between the pair of guide rods and the wire pulley may be employed.

When the wire is wound around the bobbin, a wire driving mechanism using a pinch roller may be separately provided in order to easily control the constant speed running of the wire. That is, a pinch roller that rotates at a constant speed across the wire is provided after the plating tank, and the bobbin simply winds up the wire with a relatively weak torque so that the wire does not loosen. In another embodiment, instead of winding the wire around a bobbin,
The wire may pass through the outside of the plating bath to form an endless loop that returns from the back of the plating bath to the front.

In the above embodiment, a metal wire rope is used as a wire. However, the wire is not necessarily made of metal, and any wire having appropriate conductivity can be connected to a strip material through this wire. A voltage can be applied. Further, in the present invention, the term “wire” means not only a so-called wire rope in which a plurality of strands are twisted but also a wide range of wires. Furthermore, to reduce the loss of plated metal and minimize the need for maintenance such as wire replacement,
It is preferable to use a wire made of a material that is difficult to be plated. In addition, when a Ni wire is used for the Cu wire, the Cu material can be prevented from being eluted into the plating solution,
Maintenance requirements can be minimized.

The strip material transported by the transport method of the present invention is not limited to the etching lead frame in which a plurality of lead frames are connected as described in the description of the prior art. The present invention can be applied not only to the transfer method of the present invention when plating a hoop material cut into strips by pressing, but also to transfer various strip materials other than a lead frame. Can be.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a strip plating apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the plating apparatus of FIG.

FIG. 3 is a schematic diagram showing a schematic configuration of a plating automation apparatus according to an embodiment of the present invention.

FIG. 4 is a perspective view showing an example of a conventional strip plating apparatus.

FIG. 5 is a perspective view showing another example of a conventional strip plating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plating tank 2, 3 Slot 4 Wire 5 Strip material 6 Support frame 7 Guide rod 9 Wire pulley 10 Anode electrode 14 DC power supply 15 Plating solution supply pipe 16 Plating solution spray nozzle

Claims (10)

(57) [Claims] 1. A plating apparatus for performing electrolytic plating on substantially the entire surface of a strip material by passing the strip material inside a plating tank, wherein the plating apparatus is stretched in a substantially horizontal direction so as to pass through the inside of the plating tank. The two wires contact each other horizontally, and
The lower side of the strip is placed in a valley formed above the contact portion of the wire, and the two strips are held in a substantially vertical position by means for preventing the strip from falling down. By simultaneously moving the wires in the longitudinal direction,
A strip material plating apparatus, wherein the strip material is passed through the inside of the plating tank. 2. The plating apparatus according to claim 1, wherein at least one of said two wires is a conductive wire, and a negative potential is applied to said strip material via said conductive wire. 3. The plating according to claim 1, wherein the two wires are wound around a bobbin outside the plating tank, so that the two wires move inside the plating tank in a longitudinal direction. apparatus. 4. A pair of guide rods standing so as to sandwich the two wires are fixed along the longitudinal direction of the two wires as a member constituting a means for preventing the strip material from falling down. The plating apparatus according to claim 1, wherein the plating apparatus is provided at intervals. 5. The plating apparatus according to claim 4, wherein said guide rod is rotatable. 6. A wire pulley is fixed to a lower portion of the pair of guide rods, and the two wires are sandwiched between the pair of wire pulleys to maintain a contact state of the two wires, and 6. The plating apparatus according to claim 5, wherein when the two wires move in the longitudinal direction, the guide rod rotates via a pair of wire pulleys. 7. As means for preventing the strip material from falling, a nozzle for spraying a plating solution having a width wider than the thickness of the strip material from above to below the strip material is provided in a longitudinal direction of the two wires. The plating apparatus according to any one of claims 1 to 6, wherein the plating apparatus is provided at regular intervals along the distance. 8. A method of transporting a strip material through a tank such as a plating tank or a washing tank, wherein the two wires are stretched in a substantially horizontal direction so as to pass through the tank. Are horizontally contacted with each other, the lower side of the strip is placed in a valley formed above the contact portion of the two wires, and the strip is substantially prevented by means for preventing the strip from falling down. A method of transporting a strip material, wherein the strip material is passed through the tank by simultaneously moving the two wires in a longitudinal direction while maintaining the vertical position. 9. A means for preventing the strip material from falling down, wherein a pair of guide rods erected at regular intervals along the longitudinal direction of the wires so as to sandwich the two wires are used. The transport method described. 10. Injecting a liquid such as a plating solution or a cleaning solution from an upper nozzle provided at regular intervals along a longitudinal direction of the two wires in a width wider than the thickness of the strip material. 10. The transport method according to claim 8, wherein the strip material is prevented from falling down.