JPS58518B2 - Metal wire continuous manufacturing method and cathode used in this method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of metal wires, and more particularly to the continuous formation of infinitely long thin metal wires by electrodeposition.

A conventional technique for producing thin metal wires or strips involves electrodepositing metal on a conductive cathode, peeling it off, and winding it up.

On the other hand, as another conventional method, there is a method for producing ultra-fine wires by drawing, but this method requires a large number of devices for a large number of drawing operations, which is relatively slow and expensive. It is useful for producing ultra-fine wires with cross-sections.

Controlling factors in the electrodepositing process are the configuration and shape of the cathode and the electrodeposition surface associated with the cathode.

Some conventional cathodes have a flat electrodepositing surface on which one or more electrodepositions occur.

The bottom of this miso serves as a conductive electrodeposition surface, and the sides are made of a non-conductive material.

This non-conductive material masks or defines the electrodeposition area, and furthermore, this non-conductive material constitutes a raw material mold that forms the cross section of the wire into a predetermined shape.

A common method for forming these layers is to form an insulating layer on a conductive surface and remove, for example by shaving, the portion of this insulating layer that is intended to form the electrodeposition surface.

However, this type of conventional cathode does not have a continuous electrodeposition surface, but rather has a parallel straight electrodeposition surface or a discontinuous curved electrodeposition surface such as a spiral.

The metal wires produced by such a discontinuous electrodepositing surface are distinct pieces of metal wire, each having a finite length corresponding to the length of the electrodepositing surface on which it is formed.

Such short wire pieces are undesirable, for example, when they are used to make insulated or braided wires.

Another type of conventional cathode is a cylindrical cathode with an electrodeposition surface that is only spiral or circular in shape.

As in the case of cathodes with flat surfaces, the length of metal wires made with cathodes with a spiral groove structure is also finite.

In contrast, techniques employing a circular groove configuration can produce lines of infinite length.

For example, US Pat. No. 1,600,252 discloses a cylindrical cathode with a number of circular grooves formed in the surface of the cylinder parallel to the cylinder.

By immersing a portion of each circle in the electrodeposition liquid and rotating the cylinder, as the electrodeposition liquid drips off, infinitely long lines can be continuously drawn from the circular miso.

However, since the line production rate is dependent on the cathode rotation speed, this production method requires that the relatively short electrodeposition surface be kept in the electrodeposition solution long enough to sufficiently electrodeposit the metal. The downside is that you have to put it down.

Another drawback of conventional cathodes is that they deteriorate with frequent or continuous use.

This is particularly problematic when the masking insulation is in the form of a thin outer layer connected to a planar or cylindrical lower conductive surface.

In this case, the insulating layer tends to separate from the conductive surface with repeated use.

Therefore, during electrodeposition, metal is deposited in these separated areas or cracks, creating bulges or protrusions in the metal that obstruct removal of the wire from the electrodepositing surface, so that the wire is removed as it is removed. It is often cut or modified.

As a result, the lines formed have irregular cross-sections.

Therefore, a first object of the present invention is to provide an electrodeposition forming method that can continuously produce thin metal wires having highly uniform dimensions at high speed.

A second object of the present invention is to provide a method of electrodeposition that minimizes deterioration of the masking insulator and prevents the formation of protruding blemishes in the insulator.

A third object of the present invention is to provide a method of electrodeposition that uses a fixed cathode and improves the adhesion between a conductive part and its insulating part.

A method of continuously producing infinite length metal wire according to the present invention includes providing a cathode including a conductive portion having an electrodeposition surface in the form of a closed loop with a relatively narrow exposed conductive surface. , the electrodeposition surface is removable from the metal, and an insulating material is in continuous contact with the edge of the electrodeposition surface and adhered to the side surface of the conductive portion extending in a direction substantially perpendicular to the electrodeposition surface. and the method further includes electrodepositing the metal on the electrodeposition surface, opening a loop of the continuous metal wire thus obtained, and removing the metal wire from the electrodeposition surface.

The present invention provides a cathode for electrodepositing an infinite length of metal wire, the cathode having a closed loop on one surface and a relatively narrow exposed conductive surface. an electrically conductive base having an electrodeposition surface, the electrodeposition surface being peelable to the metal, and an insulating material in continuous contact with the edges of the electrodeposition surface and in a direction perpendicular to the electrodeposition surface; The conductive portion is bonded to the side surface of the conductive portion.

The electrodepositing method according to the invention uses a cathode having a closed loop conductive portion forming an electrodepositing surface exposed to an electrode solution.

An insulating portion is adhered to the conductive portion in a plane substantially perpendicular to the electrodeposition surface and is in continuous contact with the edge of the electrodeposition surface.

The resulting closed loop layer of metal (typically copper) is electrodeposited from an electrodeposition liquid onto the electrodeposition surface.

When the electrodeposited metal has reached a predetermined thickness, the layer is cut and one end of the cut layer is removed from the electrodeposition surface toward a winder.

By controlling the extraction speed and the electrodeposition speed, a continuous metal wire having a predetermined cross-sectional dimension can be obtained.

By using a cathode with a double spiral electrodeposition surface, the production rate is particularly high since the cathode area can be used effectively.

The present invention will now be described with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, a metal wire 12 is formed on a cathode 14, which is in an electrolyte 18 in an electrodeposition tank 16.

Once the metal wire is formed, it is placed on the electrodeposition surface 20 of the cathode 14.
It is peeled off and sent to the take-up spool 22.

A power supply 24 and a rectifier 26 provide direct current to the cathode 14 and anode 28.

The cathode 14 has a closed-loop strip 30 made of an electrically conductive material, which is inert to the electrodeposited metal, ie, has the property of being peeled off by the metal.

A layer 32 of insulating material is adhered to the strip 30a;
The end surface of the strip 30 is exposed to serve as the plated side surface 20.

In the cathode shown in FIGS. 1 and 2, the strip 30 is a strip of conductive material, the ends of which are welded or otherwise connected to each other to form a closed loop. There is.

The material forming the band must be capable of being peeled off from the electrodeposited metal.

A "peelable substance" is a substance that does not have a negative effect on the electrodeposition surface 20 and the electrodeposited metal, and also reacts strongly during electrodeposition to form a strong adhesion to the plating side surface and prevent the wire 12 from being peeled off. It must not be a substance that makes it impossible.

For example, when forming a copper wire by electrodeposition, stainless steel, chromium, titanium, rhenium, and molybdenum are suitable as materials to be peeled off, and stainless steel is particularly preferred because it is inexpensive and easily available.

As shown in FIG. 2, the cross section of the strip 30 is rectangular, and one end surface thereof is a surface for electrodeposition.

The overall shape of this band-shaped body 20 is circular, but it can also be oval.
Kidney shapes and other rotating shapes are equally useful as long as they have a closed or continuous loop.

Furthermore, the cross section may be transformed into a trapezoid, a triangle, etc.
Rolled materials with rectangular cross sections are easily available;
Moreover, a rectangular cross section is advantageous since its end face 20 is highly uniform and is therefore particularly suitable for producing a uniform metal wire 12.

Any material may be used for the insulating layer 32 as long as it has the required insulation, adhesiveness, and durability.

"Adhesiveness" includes elasticity, temperature properties, or both, and means the ability to maintain adhesion over a temperature range, and "durability" refers to the ability to withstand the environment of a plating bath. Say the characteristics.

Suitable materials for such an insulating layer include epoxy resins such as those commercially available under the trade name Lucite or Bakelite, ceramics, plastics, and the like.

The insulating layer 32 is adhered to the wide side surface 30a of the strip-shaped body 30, leaving only the electrodeposition surface 20 exposed.

It is advantageous to form an oxide layer on the side surface 30a before this adhesion because both insulation and adhesion are strengthened.

For example, if it is stainless steel, it can be oxidized to produce molybdenum,
If it is rhenium or other metal, it can be coated with an oxide such as alumina.

A metallurgical press can be used for the actual bonding.

When bonding, the opposing ends of the insulating layer protruding from the strip 30 are brought together to form an insulating end 34, and one or both of these insulating ends are ground to form the electrodeposition surface 20 on the end. expose.

That is, insulating layer 32 is used to mask and define electrodeposition surface 20.

A feature of the present invention is that the insulating layer and the adhesive surface are substantially perpendicular to the electrodeposition surface 20.

Furthermore, if the insulating layer 32 were to separate from the strip 30, the gold layer electrodeposited in this separated area would automatically line up in the direction in which the metal wire 12 would peel off from the plating side surface 20.

Therefore, it is possible to prevent the metal wire from being cut or deformed when the metal wire is taken out, and furthermore, the masking edge 36 of the insulating layer is prevented from deteriorating due to abrasion caused when the metal wire is taken out.

Forming the electrode with the above structure does not require a method of forming grooves in the surface of the outer insulating layer adhered to the electrodeposition surface.

FIG. 1 schematically shows an embodiment of an apparatus for continuously producing extremely long thin metal wires according to the present invention, and its operation will be explained assuming that it produces copper wires.

An insulated lead wire 38 passing through the insulating layer 32 electrically connects the AC power source 24 and the negative terminal of the rectifier 26 to the strip 30 and the electrodeposition surface 20.

The other insulated lead 40 connects the positive terminal of the rectifier 26 to the anode 28.
is connected to.

The anode 28 is a platinum wire cage with a relatively low quality copper piece placed inside.

The cathode 14 and the anode 28 are submerged in an electrodepositing electrolyte of a conventional composition and spaced apart from each other.

A suitable test solution contained 240 grams of hydrated copper sulfate per 11 and 39 cubic centimeters of sulfuric acid per 11 at room temperature.

With the above configuration, the copper layer is electrodeposited on the electrodeposition surface 20, but the speed of this electrodeposition is determined by the area of the surface for plating and
It depends on the current density and the density of the electrodeposition solution.

If the current density at the cathode is constant, the amount of electrodeposition is directly proportional to the elapsed time.

The electrodeposition takes the form of a continuous closed loop electrodepositing surface 20 whose edges are defined by the edges of the surface 20 and the edges of the insulating layer to provide uniform, parallel edges.

The production process begins as follows. That is, the metal is allowed to electrodeposit on the surface 20 for a sufficient period of time to form a layer of desired thickness, and then the electrodeposited metal layer is cut.

One end of the cut metal layer is pulled off the electrodeposition surface and guided through the idler wheel 42 to the winder 22, which continuously winds up the copper wire from the surface 20.

If the copper wire 12 is wound on the winder 22 at a constant speed and the changing parameters such as the current density are kept constant, the first part taken out from the cathode, that is, the electrodepositing surface 20, is
A copper wire is obtained whose cross section has a uniform area except for the portion corresponding to the circumferential length.

This first section has a higher electrodepositing surface 20 than the following sections.
It is generally thicker because it remains on top longer (the time to form the first loop plus the time to remove this loop).

However, all of the parts except the first part remain on the electrodeposition surface for the same period of time determined by the winding speed of the winder (which is set constant) and the length of the loop for one revolution of the electrodeposition surface.

The production rate and the cross-sectional dimensions of the metal wire and the metal wire are interrelated, depending on the same parameters.

These parameters include the width and length of the electrodepositing surface.

The width of the electrodepositing surface controls the metal wire 120 width.

Other factors being constant, widening the electrodepositing surface increases the time required to electrodeposit a layer of a given thickness.

The length of the electrodeposition surface affects the electrodeposition rate and, along with the winding speed, determines the amount of time that a section of metal wire 12 is on the electrodeposition surface.

Another variable parameter, the winding speed, corresponds directly to the production speed.

Assuming other factors remain constant, increasing the winding speed will produce the metal wire faster, but the thickness of the metal wire will decrease because the metal wire spends less time on the electrodepositing surface. do.

A longer electrodeposition surface is advantageous.

The reason for this is that if the surface for electrodeposition is long, it is possible to increase the winding speed while taking enough time to make the metal wire a sufficient length.

Other parameters that influence the production rate and metal wire dimensions are those that control the rate of electrodeposition and include the current density of the cathode, the composition, density, temperature of the electrolyte, and the condition of the electrodepositing surface. .

For example, a circular loop cathode with a loop length of 200 cm and a width of 1 cm and a surface for electrodeposition of 0.01 cm is placed in the electrolyte described above, the current is maintained at 120 mA/cm2, and the first metal wire electrodeposition is performed for 2 hours. In this case, a metal wire with a cross-sectional area of 120 m112 can be continuously removed from the electrodepositing surface at a speed of 105 cm/hour.

Metal wire produced to this size generally has a rounded rectangular formation with a trapezoidal cross section.

In many cases, it is desirable that the cross section of the metal wire be circular, and it has a wide range of applicability.

Conventional drawing or swaging techniques may be used to obtain such a round cross-section metal wire.

In particular, if one or more drawing dies or tension capstans are placed in front of the winder, the shape of the wound metal wire can be achieved as desired.

Since the initial cross-section of the metal wire is relatively small, the possibility of the metal wire shearing, deforming, or straining is extremely small.

FIG. 3 shows a preferred embodiment of a cathode suitable for producing infinitely long metal wires according to the invention.

The shape of the electrodepositing surface shown is in the form of an opposite spiral or double spiral.

In this shape, the terminal portions form loops 44 and 46 on two adjacent sides.
It is made by winding a long continuous band in a spiral shape.

Configuring the cathode in this way has the following advantages.

(1) One complete loop obtained along the electrodepositing surface is relatively long, thus increasing production speed.

(2) The production amount of metal wire per unit area of the cathode increases.

(3) Since there are no sharp bending points, there is no problem when taking out the metal wire.

FIG. 4 schematically illustrates a method of forming a double spiral cathode of the form shown in FIG.

A strip 48 of a suitable electrodeposition surface material, for example stainless steel, and two spacer strips 50, 51 are placed on a supply roll 48a.
, 48b, 50a, and 51a and wind them around the cathode hub 52 at the same time.

Each end of the strip 48 is connected to a separate supply roll 48a or 48b.
The inner terminal loop 44 is wound around the supply roller 4.
It is formed in a portion of the strip 48 located between 8a and 48b.

Inner terminal loop 44 is formed by slot 54 and is supported within central opening 52a of hub 52.

To form the other loop 46 to create a closed loop electrodeposition strip, the outer ends of the strip 48 are butt welded and precisely ground until the thickness of the weld is equal to the thickness of the strip. The method is appropriate.

The edge of the loop thus obtained becomes the electrodepositing surface 20.

In FIGS. 3 to 5, the stripes 50 and 51 are narrower than the strip 48 in the direction perpendicular to the electrodeposition surface 20, and can be used for electrodeposition on one or both sides of the cathode. Accordingly, it is positioned in the winding process so as to be evenly spaced from one edge or from two edges of the strip 48.

In the embodiment of FIG. 5, the spacer strips 50, 51 are spaced only from the surface on which the electrodeposited wire 12 will be formed, so that miso is formed between the spiral layers of the electrodeposited surface 20.

Alternatively, the width of the strips used for spacing may be set equal to the width of the strips 50, and this may be etched to form the miso paste.

This etching process is advantageous if the spacer strips are of copper or a material with similar etching properties.

The use of electrically conductive metal as the spacer strips is advantageous as it increases the overall electrical conductivity of the cathode body.

A copper backing layer 55 is provided to electrically contact all the loops of the strips 48, 50, 51 (the fifth
), this further increases the conductivity of the cathode.

The grooves formed as described above are filled with an insulating material 56, and the electrodepositing surface 2 is applied as in the case of the layer 32 of FIGS. 1 and 2.
0 is masked and isolated from other conductive surfaces of the cathode.

Since the insulating material 56 is used in a viscous state, it can easily flow into the miso and fill it.

The viscosity required for this is basically determined by considering the size of the miso.

Typical wire dimensions for producing 34AWG wire are:
Typical groove dimensions for a 24 AWG fabric are 20 mils wide by 100 mils deep with a 4 mils thick electrodeposition surface, 50 mils wide by 100 mils deep and 13 mils thick. The surface for electrodeposition is covered with a thin layer.

In addition to the viscosity conditions mentioned above, the properties required for insulation materials are:
These include adhesion, thermal responsiveness, elasticity, and durability in the electrodeposition environment described above for layer 32.

A preferred insulation material is a low viscosity filled resin obtained by
It is a low viscosity filled resin manufactured by Emerson & Cumming Company.

To apply this resin insulating material 56, it is sufficient to place a wound cathode in a closed mold and add resin to completely cover the cathode.

By evacuating the mold or heating it to a moderate level, the miso can be completely filled with resin, and the resin can be degassed.

Once the miso is filled with resin, the resin is cured, and the electrodeposition surface 20 of the cathode is ground and polished to expose the electrodeposition surface 20.

If cracks or other imperfections occur in the resin coating, they can be easily corrected by adding more resin to these areas.

If portions of the copper spacer strips 50 or 51 are still exposed during grinding, these strips may be etched and dug out and filled with resin.

Another method of making a double spiral cathode is to machine or photoetch the desired material onto a metal substrate, and a photoetched cathode is shown in FIG.

A substrate 58, preferably formed from stainless steel 316, is used and a photoresistive material is applied to one surface (or surfaces) thereof forming the electrodepositing surface 20.

A slightly rough surface is advantageous for adhering the photoresistive material.

Grooves 60 are formed by exposing and etching the desired double spiral pattern of known dimensions onto the applied photoresistant material.

A metal layer suitable for stripping the metal wire from the electrodeposition surface, such as a loam, is then plated or applied to the protrusions to form the electrodeposition surface 20.

Fill in the insulation as before.

In the embodiments shown in FIGS. 5 and 6, in which an insulated lead wire is connected to the cathode in the same manner as before to make the current density on the electrodeposition surface uniform, the insulated lead wire is connected to the copper layer through the adjacent insulating layer 56a. 55°58.

The above is a method and apparatus for producing metal wires of extremely long and uniform dimensions by electrodeposition at high speed, which comprises a continuous closed-loop electrodeposition surface and an insulating layer for a mask almost perpendicular to this surface. A method using a fixed cathode was described.

Although the present invention has been described with reference to a cathode having a substantially circular electrodeposition surface, it is clear that other cathode shapes may be used as long as the exposed electrodeposition surface forms a closed loop.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of a processing apparatus constructed according to the present invention, FIG. 2 is a cross-sectional view of the cathode shown in FIG. 1 taken along line 2-2, and FIG. 4 is a schematic diagram illustrating one method of forming the cathode shown in FIG. 3, and FIG. 5 is a plan view of the cathode shown in FIG. 3 formed by the method shown in FIG. 4. 6 is a cross-sectional view corresponding to FIG. 5 of a double spiral cathode formed by another method according to the present invention. 12... Metal wire, 16... Tank for electrodeposition, 18... Electrolyte, 2
0... Surface for electrodeposition, 22... Winder, 24... Power supply, 26...
Rectifier, 28... Anode, 29... Copper piece, 30... Band-shaped body forming a closed loop, 30a... Side wall surface, 32... Insulating layer, 34... Insulating end, 36... Masking edge, 38, 40... Insulated lead wire, 42 ...Idle wheel, 44.46...Terminal loop, 48...Strip of surface material for electrodeposition, 50, 51...Spacer strip, 48
a. 48b, 50a, sob...supply roller, 52...cathode hub, 52a...center opening, 54...slot, 55...backing layer, 56...insulating material, 56a...insulating layer, 58...copper layer, 60...
Groove.

Claims (1)

[Claims] 1. Providing a cathode having an exposed conductive electrodepositing surface, electrodepositing a metal on the electrodepositing surface, and removing the metal wire thus formed from the electrodepositing surface. In a method for serially producing metal wires of indeterminate lengths, including:
The cathode has an electrodepositing surface in the form of a closed loop with a relatively narrow exposed conductive surface, the electrodepositing surface being substantially peelable to the metal, and an insulating material extending along the edges of the electrodepositing surface. A method for continuously manufacturing a metal wire, characterized in that the metal wire is adhered to a side surface of the conductive portion that is in continuous contact with the electrodeposition surface and extends in a direction perpendicular to the electrodeposition surface. 2 conductive base 30.48.58 has on one side an electrodeposition surface 20 in the form of a relatively narrow exposed conductive surface in the form of a closed loop.
wherein the electrodeposition surface is substantially peelable from the metal, and the insulating material 32.56 is in continuous contact with the edges of the electrodeposition surface and extends in a direction generally perpendicular to the electrodeposition surface 20. A cathode used in a continuous metal wire manufacturing method, characterized in that the cathode is bonded to the side surface 30a of the conductive portion.