DE2931939A1 - Copper wire with thick tin coating, esp. jumper wire - where intermediate wire drawing is used between two electroplated tin coatings, and wire is then finally drawn and annealed - Google Patents

Abstract

Copper wire is continuously electroplated with min. 7 microns tin (I), and then drawn (II) through a die to compact the tin(I). A second electroplated tin coating (III), min. 7 microns thick, is applied, followed by drawing (IV) to final size. The wire is next fed vertically through a furnace for brief annealing at above 400 deg.C and rapid cooling, to obtain over 3 microns Sn, esp. 7 microns Sn on the finished wire, which is pref. 0.2-1.2 mm dia. Drawing (IV) pref. uses a wire speed of 12-24, esp. 15-20 m/s; and the pref. plant includes two electroplating units sepd. by a drawing machine, and followed by a second drawing machine and a furnace. Esp. used in the inexpensive high-speed mfr. of jumper or hook-up wire.

Description

Method and device for the production of heavily tinned

Copper Wires, Particularly Jumper Wires The invention relates to a process for the production of heavily tinned copper wires, especially jumper wires, according to the preamble of claim 1.

It is particularly used for the efficient production of heavily tinned jumper wires that meet the requirements of DIN 40500, Part 5, V 5 meet, with a particularly strong and diffusion-free tin layer desired whose thickness is not less than 4 μm at any point on the tinned copper wire amounts to. This ensures to a particularly high degree a good and permanent solderability of the jumper wires produced in this way.

From DE-AS 27 30 625 a method for the production of heavily tinned Known copper wires in which a drawn copper wire is galvanically tinned and then annealed or a copper wire galvanically tinned on top is reduced in its cross-section by drawing and then soft-annealed, being a copper wire with a low, below the melting point of tin lying Erwichung Temperatur is used, and the drawn to finished size tinned Copper wire for two to eight hours at a temperature below the melting point of Tin is soft annealed. This known method is because of necessity the use of particularly pure copper with a low heating temperature and the intended, unusually long soft glow time is very costly and involves because of the long annealing times, there is a risk of diffusion and whisker formation, see above that - in order to prevent dentition - it is also provided according to this known method, a nickel layer of less than 2 P on the copper wire prior to electroplating to apply galvanically. This to achieve a product of the necessary high quality The additional process step required in this way increases the cost of those produced in this way Winding wires to a considerable extent.

The same document also describes a method of production of tinned copper wires, which provides for the wire to be galvanically tinned, then to draw to the desired final dimension and in the same operation to glow in a subsequent continuous annealing. However, this is a limiting factor indicated that this known method is used in the manufacture of wires thin tin plating is used, but that as a result of the necessary high throughput speeds temperatures above the melting temperature of the Tin are required. Due to this, however - supposedly - layer thicknesses could be achieved on the order of more than 3 to not be exceeded without it comes to an eccentric tin plating.

The invention is based on the object of an efficient manufacturing process for heavily tinned copper wires with a tinning thickness of more in the final dimension as June 4 and a device suitable for this purpose, to connect heavily tinned copper wires, especially high quality jumper wires of high speed tinning and to produce accordingly increased profitability.

This object is achieved by the invention specified in claim 1. With this solution, the invention sees a substantial improvement on the foregoing described known method, which makes it possible to use heavily tinned copper wires with a circumferentially even tinning thickness of significantly more in the final dimension than 4 am, usually about 7 jun and above, to make which quality wise correspond to the relevant DIN standards.

Further advantageous embodiments of the method according to the invention are given with claims 2 to 4, of which claim 2 is the preparation and claim 4 the dimensions of copper wires to be tinned in this way, and claim 3 measures to be carried out in the course of the heavy tinning process, which are explained in more detail below.

The invention also relates to an apparatus for manufacturing heavily tinned copper wires with a Drawing device and a continuous resistance annealer with contact and deflection rollers as well as a take-off and winding device are arranged, wherein in the direction of movement of the wire before this combined drawing and continuous annealing device at least another drawing device and two electroplating and rinsing basins are arranged. The object of this invention arises from the characterizing features of Claim 5.

Advantageous further developments of the device according to the invention are with claims 6 and 7 indicated, of which claim 6 relates to the arrangement the lower contact roller and the formation of the cooling device relates, on the other hand claim 7 the vertical distance between the upper and the lower contact roller, indicates the design of the same as well as the attached pulleys.

The main advantage of the new method is the increased Quality of the strongly tinned wires produced in this way and the significantly increased ones Economics of manufacturing the same. This arises from the possibility Use common grade copper wires that anneal at relatively high temperatures which exceed the melting temperature of the tin. This is through the vertical wire guidance as well as the high speed with which the wire is passed through the continuous annealer, at least partially a melting of the previously applied tin coating is consciously accepted. However, this is on the one hand by the vertical wire guide and on the other hand due to the special arrangement of the cooling section, namely partly before the lower one Contact annealing, sufficiently mastered to maintain the concentricity of the strong To obtain tin-plating within the specified tolerance values.

The tin-plating according to the invention has a final dimension of considerably more than 3 pun, preferably about 7 µm, layer thickness. Because the tin with a Application thickness of at least 7 in each case galvanically in two separate stages applied to the copper wire and this in between to a corresponding calibration dimension drawn, with the layer of the first application of tin being compacted, results one that adheres firmly to the wire surface and is dense over the entire layer thickness Tinning. This changes its substantially uniform consistency and thickness hardly even in the subsequent annealing process, although this is brief Reached temperatures which are above the melting temperature of the tin.

To ensure this, the tinned copper wire is after second application of tin drawn to the desired final dimensions, then on a uniform Annealing and cooling section guided its length vertically, it in one Passage briefly heated to more than 400 ° C and in immediate consequence abruptly to room temperature is cooled.

Before the first tinning, the copper wire is drawn to a nominal size and annealed so that it can easily be tinned between the two plating can be drawn on the calibration measure, regardless of the quality of the selected Copper.

After the second tinning, the copper wire is drawn off with a take-off speed between 12 and 24 m / s, preferably between 15 and 20 m / s drawn to the final dimension and annealed, whereby the temperature is more than 500 oC, in immediate succession cooled abruptly, peeled off and finally wound up. The withdrawal speeds are chosen so high that the tin hardly melts at the high annealing temperature starts moving, but rather as a result of the vertical wire guidance of the wire surface adheres to the circumference essentially concentrically until it is in fractions of a second - before the downstream lower contact roller - immersed in the cooling liquid and is thereby immediately solidified again sufficiently. For this purpose, the mechanical tensioned annealing length of the tinned drawn wire at least 100 cm, preferably more than 150 cm, including the first one in front of the lower contact roller Cooling section in which an intensive one immediately after or during the annealing process The annealed wire is cooled at about 30 ° C. The will be concentric melted tinning of the same within a fraction of the annealing length like this solidified that the deflection of the wire over the lower contact roller within the coolant is possible without changing the tinning coating.

After all, the wire after it is deflected in the one behind this After-cooling section arranged on the control roller aftergbkdhlt to room temperature.

The annealing temperature and the current intensity required to reach it are usually based on the wire diameter at a given voltage, the quality of the copper wire used and the withdrawal speed.

The process is for strong tinning of wires with a diameter between 0.2 and 1.2 mm well suited, with a tinning thickness of about 7, nn is reached. To achieve the high annealing temperature of around 500 OC or more can with a constant set tension between the two contact rollers, E.g. 38 y, a current corresponding to the tinned copper wire drawn to size Strength to be put. The annealed wire is then suddenly under this tension immersed in a cooling liquid and at least in the surface area to below the melting temperature of the tin cooled.

Because in this process the melting temperature of the tin is far exceeded and the annealing times are in the millisecond range, there is a risk of whisker formation avoided, and due to the short glow times, the risk of formation is more pronounced Diffusion layers between the copper and the tin suppressed. But this brings the further great advantage that additional in the process according to the invention Measures to prevent the formation of diffusion, such as the known pre-coating the surface of a wire to be heavily tinned with a thin nickel coating or other known measures of this kind are unnecessary.

The invention is set out below with further details and Advantages of the same on the basis of an exemplary embodiment illustrated in the drawing explained in more detail.

In the drawing: FIG. 1 shows a schematic representation Combined electroplating, tin plating, drawing and resistance continuous annealing device and Fig. 2 also schematically in an enlarged representation Continuous annealing and the immediately adjoining part of the drawing device.

The manufacturing arrangement shown in Fig. 1 for heavily tinned Copper wires includes a drain 23, two combined pretreatment electroplating and sink 24, with a calibration pulling device 5 arranged therebetween Gauging device 2 and a continuous resistance annealer 3 as well as intermediate take-off devices 25, deflection rollers 26 and one arranged within the housing 7 of the pulling device 2 Spooling device 10 for receiving a heavily tinned copper wire manufactured in this way 30. These devices can, as shown, on a common base plate 1 with an upright support frame 6 one behind the other in the corresponding order arranged, or - depending on the space - combined into separate units, such as one of the combined pre-treatment, electroplating and rinsing basins 24 with the associated outlet 23, the calibration pulling device 5 and one of the intermediate suction devices 25. In any case, the gauge block pulling device 2 is with continuous resistance annealing 3 to a mechanically firmly connected and functionally cooperating unit summarized.

Also can use the combined pre-treatment electroplating and sink 24 divided into appropriately arranged sections one behind the other or these be arranged one above the other on different levels, which is known and not The subject of the invention is.

The calibration drawing device 5 is with mutually coordinated drawing dies 14 and a lined-up trigger device 25, and can if necessary one also behind the second electroplating basin 24, possibly below Interposition of pulleys 26 may be arranged.

The gauge block pulling device 2 has a plurality of terms drawing dies 14 that are matched to one another in their tapering passage opening equipped with intermediate rollers 15 and a double take-off 4, which acts as an insulating body, preferably formed with a correspondingly profiled ceramic or plastic shell is. The double trigger for this purpose one of its profile sections for pulling out the wire 30 from the drawing device 2 and for its supply to the continuous annealing 3 and with its second profile section for pulling the wire 30 out of the latter. At the same time, the wire 30 is also fed via a dancer roller 27 and a laying device 11 to the winding device arranged on the bottom of the housing 7 10.

All these facilities are just like those of the continuous annealing 3 upstream or downstream deflection rollers 12, 13 as insulating bodies, e.g. made of plastic, formed or mounted on insulating axles or quills 28. Likewise is also the arm 29 of the laying device 11 made of an insulating material of sufficient strength and dimensional stability. These measures ensure the specified current flow, about the in the contact continuous annealing 3 between the upper contact roller 8 and the lower contact roller 9 tautly guided annealing section of the wire 30 with sufficient Amperage with a correspondingly set voltage of the glow current.

The continuous annealing 3 is above the base plate on the upright frame 6 and essentially comprises the two contact rollers 8, 9 and those thereof Deflection pulleys attached at a distance, electrically insulating or with insulating bearings 12, 13. The lower contact roller 9 can be rotated in a stationary manner in a cooling liquid 16 stored and the upper contact roller 8 at a vertical distance over the The lower contact roller 9 immersed in the cooling liquid 16 is rotatable and vertical adjustable arranged.

The upper contact roller 8 is connected to a power supply line, while the lower contact roller 9 is connected to the neutral conductor via a current-carrying line a three-phase system is connected. On the other hand - as already mentioned - the Spooling device 10 and the associated laying device 11 together with the other wire-guiding devices Facilities arranged isolated from earth.

In the embodiment of this device shown in FIG the lower contact roller 9 is arranged in a cooling element 17, the boundary walls of which are dimensioned with a greater height than width, and on which a circulation pipe system 20 for the cooling liquid 16 with a pump 21 and a cooling device 22 connected. This can be used as a separate dry cooler or - as shown - in Be designed in the form of a laid in the cooler 17 cooling coil. Essential is that the cooling box 17 and the circulation pipe system 20 with a cooling liquid 16, preferably water, are filled, the level of which - according to the respective Wire diameter - is kept essentially constant. This can be done through appropriate Adjustment of the drainage system, e.g. by precise setting of the Pump 21 delivered delivery rate or the pressure of the liquid coolant 16 take place.

Preferably, the wire 30 is on its vertical annealing path in Guide and cooling tubes 18, 19 out, each of which in the direction of movement is arranged in front of and behind the lower pulley 9 so that it is with its lower dipped open end as far as possible in the cooling liquid 16. If now that Circulating pipe system 20 for the cooling liquid 16 into the lower contact roller 9 Lined up cooling tube 19 opens, the delivery rate of the pump 21 can be so set that in this for the heavily tinned and annealed Wire 30 an after-cooling section forming tube 19 a corresponding to the desired cooling Column of water is created, which drains into the cooling box 17 and there the desired mirror height the coolant 16 holds the same time from the lower portion of the cooling box 17 is pumped out. The end section of the In front of the lower contact roller 9 arranged tube 18 thus forms a comparison to the tensioned annealing length of the wire, a very short pre-cooling section, the length of which is longer can be determined very precisely in the manner described above. The relationship Annealing line to pre-cooling line is essential for the quality of the Tinning of the heavily tinned wire produced in this way and the evenness the tin layer thickness.

In a preferred embodiment, the upper contact roller 8 is at a distance arranged vertically adjustable by more than 150 cm above the lower contact roller 9. This enables an exact adjustment of the relationship described above from annealing length to pre-cooling distance of the tinned wire 30, on the one hand by setting the height of the coolant level and, on the other hand, by determining the length the annealing section by vertically moving the upper contact roller 8 to one further or smaller distance from the lower contact roller 9.

The two contact rollers 8, 9 are circumferentially profiled and with a Edged with nickel band. The deflection rollers 12, 13 arranged to the side thereof are as ceramic or plastic or the like. Discs formed or in plastic bushings or mounted on plastic axles in an insulating manner.

During its passage through the manufacturing arrangement described above the copper wire is removed from the outlet 23, degreased, rinsed, pickled, tin-plated and finally rinsed, which process after a calibration train that compacts the tinning applied in this way is repeated. In this way in two layers with a 10 to 14 jun thick layer of tin provided copper wire 30 is then the pulling device 2 optionally via a Intermediate take-off device 25 supplied directly or with intermediate rewinding. In the pulling device 2 we the so tinned wire down to the desired target size drawn, then passed vertically through the contact annealing 3 in one pass, in the process annealed and immediately afterwards in the area of the lower contact roller 9 same pre-cooled. If desired, it can also be used in the lower contact roller 9 upstream guide and cooling tube 18 of the mechanically stretched through Wire can be kept under steam or under an inert gas.

The cooling of the wire 30 is also behind the lower contact roller 9 continued to about room temperature, preferably in an after-cooling tube 19. The cooled and dried wire is finally over a dancer roller 27 and the second section of the double take-off 4 of the isolated winding device 10 supplied, on which it is finally wound up as a finished jumper wire. This type of production is simple and extremely efficient. She can be done after Adjustment of the current strength and the level of the cooling liquid 16 without special Carry out maintenance continuously for a long time, with only the filled ones Coils of the winding device 10 need to be replaced.

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Claims (7)

Claims: 1. Process for the production of heavily tinned copper wires, especially jumper wires, with a tin-plated copper wire continuously drawn to the final dimension and in immediate succession at a temperature which is above the melting temperature of tin, soft-annealed by means of electrical heat and then is cooled, peeled off and wound up so that it is possible to use it e t that the tinning with a final dimension of significantly more than 3 pm is preferred about 7ffli layer thickness in two separate stages with an application thickness of each at least 7 pin galvanically applied to the copper wire, and this in between drawn to a corresponding calibration dimension, the layer of the first tin application is compacted, and that after the second application of tin, the tinned copper wire drawn to the desired final dimensions, then on a uniform annealing and The length of the cooling section is guided vertically, briefly in one pass heated to more than 400 OC and in immediate consequence abruptly to room temperature is cooled. 2. The method according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that the copper wire is drawn to a full size before the first tinning is soft annealed. 3. The method according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t that the copper wire after the second tinning with a withdrawal speed between 12 and 24 m / s, preferably between 15 and 20 m / s, drawn to the final dimension, annealed, cooled, peeled off and wound up, the annealing temperature being more than 500 OC, with a mechanically tensioned annealing length of the tinned drawn Wire of at least 100 cm, preferably more than 150 cm, and then more intense Cooling of the annealed wire at about 30 0C, whereby the concentrically melted Tinning of the same is solidified within a fraction of the annealing length. 4. The method according to any one of claims 1 to 3, d a d u r c h g e k It is noted that wires with a diameter between 0.2 and 1.2 mm with the strong concentric tin-plating of at least 4 eLm layer thickness in the final dimension be provided. 5. Device for performing the method according to one of the claims 1 to 4, in which a pulling device and on a common base plate a continuous resistance annealer with contact and deflection rollers as well as a take-off and winding means are arranged, wherein in the direction of movement of the wire in front of this combined drawing and continuous annealing device, at least one more Drawing device and two electroplating and rinsing basins are arranged, d a d u r c h g e k e n n -z e i c h n e t that the continuous annealing (3) on an upright Frame (6) is arranged and two contact rollers (8, 9) and at least two electrically insulating pulleys (12, 13) attached at a distance comprises, wherein a lower contact roller (9) stationary in a cooling liquid (16) rotatably mounted, and an upper contact roller (8) at a vertical distance above the lower contact roller (9) immersed in the cooling liquid (16) rotatable and arranged vertically adjustable and connected to a power supply line is, and the lower contact roller (9) via a current-carrying line with the neutral conductor a three-phase system is connected, wherein the winding device (10) and the associated Laying device (11) are arranged isolated from earth. 6. Apparatus according to claim 5, d a d u r c h g e k e n n z e i c h n e tf that the lower contact roller (9) is arranged in a cooling box (17), whose boundary walls are dimensioned with a greater height than width, and on a circulation pipe system (20) for the cooling liquid (16) with a pump (21) and a recooling device (22) is attached, wherein the cooling box (17) and the circulation system (20) are preferably filled with water, the level of which is correspondingly the respective wire diameter is kept essentially constant. 7. Apparatus according to claim 5 or 6, d a d u r c h g e k e n n z e i c h n e t that the upper contact roller (8) at a distance of more than 150 cm above the lower contact roller (9) is arranged vertically adjustable, the two Contact rollers (8, 9) are circumferentially profiled and bordered with a nickel band and the pulleys (17, 13) arranged to the side thereof as ceramic or the like. Discs formed or in plastic bushings or on plastic axis carriers are stored insulated.