EP3252187A1 - Slipring with reduced contact noise - Google Patents

Abstract

A method for producing a gold-plated slip ring contact comprising the following method steps: providing an electrically conductive substrate; electroplating a copper layer (12) on the substrate; electroplating a nickel and / or nickel-phosphor layer (14) on the copper layer (12); and electroplating a gold layer (16) on the nickel and / or nickel phosphor layer (14). Here, during the galvanic application of the copper layer (12) to the substrate in the electroplating bath used, at least one scum pattern is not used, which in the list of scraps consisting of 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, cationic polymers with urea groups , 1- (3-sulfopropyl) -pyridinium betaine, 1- (2-hydroxy-3-sulfopropyl) -pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allyl sulfonate, N, N-dimethyl N- (3-cocoamidopropyl) -N- (2-hydroxy-3-sulfopropyl) ammonium betaine, polyamines, 1H-imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, 1-benzyl 3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium selenocyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate and carbon disulfide.

Description

Technical area

The invention relates to a method for producing a gold-plated slip ring contact, a sliding contact and a galvanic bath.

State of the art

US 4,398,113 discloses a slip ring assembly having a conventional slip ring contact.

In the prior art, it is known to produce slip ring contacts as follows. A copper layer (from 0.1 .mu.m up to 4 .mu.m layer thickness) is successively applied to a mechanically processed copper-containing substrate material as activation layer, if required a nickel and / or nickel-phosphor layer (in each case from 1 .mu.m to 10 .mu.m layer thickness) as diffusion barrier. , Support and corrosion protection layer and a hard gold layer (from 1 micron up to 15 microns) applied as a contact material.

Presentation of the invention

The invention has for its object to improve the electrical behavior, in particular the noise behavior of the sliding contact.

This object is achieved by the method according to claim 1, a sliding contact according to claim 8 and a galvanic bath for depositing copper according to claim 10. Advantageous embodiments of the invention are specified in the subclaims.

The method for producing a gold-plated slip ring contact comprises the following method steps: provision of an electrically conductive substrate, electrodeposition of a copper layer on the substrate, electroplating of a nickel and / or nickel phosphor layer on the copper layer, and electroplating of a gold layer on the nickel layer. and / or nickel-phosphorus layer. In this case, during the galvanic application of the copper layer to the substrate in the electroplating bath used, at least one brightener from a list of brighteners is not used. This list of brighteners consists of 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, cationic polymers with urea groups, 1- (3-sulfopropyl) -pyridinium betaine, 1- (2-hydroxy-3-sulfopropyl) -pyridinium Betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allylsulfonate, N, N-dimethyl-N- (3-cocoamidopropyl) -N- (2-hydroxy-3-sulfopropyl) ammonium betaine, polyamines, 1H Imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, 1-benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tartarite, potassium selenocyanate, alkali antimonyl tartrate , Sodium selenite, thallium sulfate and carbon disulfide. In the galvanic application of the copper layer to the substrate in the electroplating bath used, at least two brighteners of the abovementioned list are preferably not used. More preferably, the galvanic application of the copper layer to the substrate in the electroplating bath used no brightener is used at all.

Such sliding contacts make an electrical connection between moving parts. In this case, such a sliding contact can be used either as a fixed part or as a moving part. Of course, such a sliding contact can also be used both as a stationary part and as a moving part of an abrasive module. For example, Such a sliding contact can also be used as a brush or as a sliding track.

The absence of said brighteners ensures that the copper layer deposited on the preferably brass-containing substrate has a higher roughness than in the prior art. To characterize the coating roughness, Sa or Sq values according to EN ISO 25178 can be used. Here, the Sq value is the RMS or the square average of the profile height of the surface. The Sa value is an average of the absolute values of the profile height of the surface. Typical Sa or Sq values are on the order of 10 to 50 nm for prior art copper baths. Using the baths described in the invention, the layer roughness of the deposited copper layer becomes Sq or Sq values of 200 nm to 1 increased. In the further deposition, depending on the used intermediate layer and final layer, a certain leveling done. However, the Sa and Sq values of the final layer according to the invention are higher by a factor of typically 5 to 20 and thus rougher compared to conventional final layers.

The following table values were determined as mean values of one sample series (10 replicate tests).

Typical Sa and Sq values for standard copper layers and inventive copper layers as well as standard final layers and end layers according to the invention (Example Copper; Nickel and / or nickel phosphorous; Gold systems): layer Sa (nm) Increase Sa (x-factor) Sq (nm) Increase Sq (x-factor) Copper (technical standard) 23 28 Copper (invention) 320 14 432 16 Final layer (technical standard) 23 28 Final layer (invention) 380 17 497 18

This increased roughness of the copper layer leads to the subsequent galvanic deposition of a nickel and / or nickel-phosphorus layer on the copper layer and a gold layer on the nickel and / or nickel-phosphor layer to increased roughness of the gold layer, which is crucial for the electrical behavior , The roughness of the layer applied to the substrate, in this case the copper layer, is decisive for the roughness of the uppermost layer. It can also be said that the roughness of the copper layer continues with several electroplated layers down to the last galvanic layer.

A gold layer produced in this way has improved electrical properties, in particular reduced contact noise, in contrast to conventional sliding contacts. Thus, a sliding contact also has these improved electrical properties, in particular reduced contact noise. This has been demonstrated by the applicant conducted spring wire tests. In this case, such a layer structure with a rough uppermost gold layer can be used either on the brush or on the brush wires or on the slideway or both on the brush or on the brush wires and on the slideway. In a typical test setup, electrical noise values, e.g. measured as the 90% percentile of the peak-to-peak noise over 5 revolutions over the lifetime, typically at least a factor of 2.

When plating the copper layer on the substrate, a pure copper cyanide solution is preferably used as the electroplating bath. Alternatively, copper sulfate (copper vitriol), sodium copper cyanide or potassium copper cyanide may be used.

The copper layer is preferably applied to the substrate with a layer thickness of up to 4 μm. In a particularly advantageous embodiment, it is a copper layer with a layer thickness of up to 10 microns.

In the case of the galvanic application of the nickel and / or nickel-phosphorus layer to the copper layer, the nickel and / or nickel-phosphorus layer is preferably applied with a layer thickness between 5 and 10 μm.

In the case of the galvanic application of the gold layer to the nickel and / or nickel phosphor layer, the gold layer is preferably applied with a layer thickness of between 3 and 9 μm, more preferably 6 μm.

With the method for producing a gold-plated slip ring contact, a slip ring contact is produced, which has the following layer sequence: an electrically conductive substrate, a copper layer on the substrate, a nickel and / or nickel-phosphorus layer on the copper layer, and a gold layer on the nickel and / or nickel-phosphorus layer. The substrate preferably has brass. It is further preferred that the substrate is made of brass.

This slip ring contact, which e.g. can be mounted on a brush or on a sliding track, characterized as already described above by improved electrical properties.

In the electrodeposition of copper of the above method, a plating bath is used for the deposition of copper, wherein in the plating bath at least one scum from the list of scraps, consisting of 3-carboxy-1 (phenylmethyl) pyridinium chloride sodium salt, cationic polymers with urea groups, 1- (3-sulfopropyl) -pyridinium betaine, 1- (2-hydroxy-3-sulfopropyl) -pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allyl sulfonate, N, N-Dimethyl-N- (3-cocoamidopropyl) -N- (2-hydroxy-3-sulfopropyl) ammonium betaine, polyamine, 1H-imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt , 1-benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium selenocyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate, carbon disulfide. Preferably, no brightener from the list mentioned is used in the galvanic bath.

Description of the drawings

• Figur 1 zeigt den ersten Schritt des erfindungsgemäßen Verfahrens zur Herstellung eines vergoldeten Schleifringkontaktes. Hierbei wird ein bevorzugt aus Messing oder einer anderen kupferbasierten Legierung hergestelltes Substrat 10 bereitgestellt.
• Figur 2 zeigt den zweiten Schritt des erfindungsgemäßen Verfahrens zur Herstellung eines vergoldeten Schleifringkontaktes. Hierbei wird eine Kupferschicht 12 auf das Substrat 10 galvanisch aufgetragen.
  Hierbei wird beim galvanischen Auftragen der Kupferschicht 12 auf das Substrat 10 als Galvanikbad bevorzugt ein Elektrolyt auf Basis von Kalium-Kupfercyanid verwendet.
  Die Kupferschicht 12 wird bevorzugt auf das Substrat mit einer Schichtdicke von bis zu 4 µm aufgetragen. In einer besonders vorteilhaften Ausführungsform handelt es sich bei Kupferschicht 12 um eine Kupferschicht mit Schichtdicke von bis zu 10 µm.
• Figur 3 zeigt den dritten Schritt des erfindungsgemäßen Verfahrens zur Herstellung eines vergoldeten Schleifringkontaktes. Hierbei wird eine Nickel- und / oder Nickel-Phosphorschicht 14 auf die Kupferschicht 12 galvanisch aufgetragen. Die Nickel- und / oder Nickel-Phosphorschicht 14 wird bevorzugt mit einer Schichtdicke zwischen 5 und 10 µm aufgetragen.
• Figur 4 zeigt den vierten und letzten Schritt des erfindungsgemäßen Verfahrens zur Herstellung eines vergoldeten Schleifringkontaktes. Hierbei wird eine Goldschicht 16 auf die Nickel- und / oder Nickel-Phosphorschicht 14 galvanisch aufgetragen. Die Goldschicht 16 wird bevorzugt mit einer Schichtdicke zwischen 3 und 9 µm, besonders bevorzugt 6 µm, aufgetragen.
• Figur 4 zeigt somit ebenfalls einen erfindungsgemäßen Schleifkontakt mit der oben beschriebenen Schichtabfolge auf dem Substrat 10. Wie ebenfalls oben beschrieben weist der Schleifkontakt eine rauere Oberfläche als Schleifkontakte aus dem Stand der Technik auf.

The invention will now be described by way of example without limitation of the general inventive idea by means of embodiments with reference to the drawings.

• FIG. 1 shows the first step of the process according to the invention for producing a gold-plated slip ring contact. Here, a substrate 10 preferably made of brass or other copper-based alloy is provided.
• FIG. 2 shows the second step of the process according to the invention for producing a gold-plated slip ring contact. In this case, a copper layer 12 is applied galvanically to the substrate 10.
  In this case, an electrolyte based on potassium copper cyanide is preferably used in the galvanic application of the copper layer 12 to the substrate 10 as a galvanic bath.
  The copper layer 12 is preferably applied to the substrate with a layer thickness of up to 4 μm. In a particularly advantageous embodiment, copper layer 12 is a copper layer with a layer thickness of up to 10 μm.
• FIG. 3 shows the third step of the process according to the invention for producing a gold-plated slip ring contact. In this case, a nickel and / or nickel-phosphor layer 14 is applied galvanically to the copper layer 12. The nickel and / or nickel-phosphor layer 14 is preferably applied with a layer thickness between 5 and 10 μm.
• FIG. 4 shows the fourth and final step of the process according to the invention for producing a gold-plated slip ring contact. In this case, a gold layer 16 is applied galvanically to the nickel and / or nickel-phosphor layer 14. The gold layer 16 is preferably applied with a layer thickness of between 3 and 9 .mu.m, more preferably 6 .mu.m.
• FIG. 4 Thus, also shows a sliding contact according to the invention with the layer sequence described above on the substrate 10. As also described above, the sliding contact on a rougher surface than sliding contacts from the prior art.

LIST OF REFERENCE NUMBERS

10

substratum

12

copper layer

14

Nickel and / or nickel-phosphorus layer

16

gold layer

Claims (11)

Method for producing a gold-plated slip ring contact with the following method steps: - Providing an electrically conductive substrate (10); - electroplating a copper layer (12) on the substrate (10); - Electroplating a nickel and / or nickel-phosphorus layer (14) on the copper layer (12); and - electroplating a gold layer (16) on the nickel and / or nickel-phosphorus layer (14); characterized in that
during the galvanic application of the copper layer (12) on the substrate (10) in the electroplating bath used at least one scum image is not used, which in the list of gloss images, which consists of 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, cationic polymers Urea groups, 1- (3-sulfopropyl) -pyridinium betaine, 1- (2-hydroxy-3-sulfopropyl) -pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allyl sulfonate, N, N-dimethyl N- (3-cocoamidopropyl) -N- (2-hydroxy-3-sulfopropyl) ammonium betaine, polyamines, 1H-imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, 1- Benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium selenocyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate and carbon disulfide. Method according to claim 1,
characterized in that
when electroplating the copper layer (12) onto the substrate (10) in the electroplating bath used no brightener in the list of brighteners 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, cationic polymers with urea groups, 1- (3-sulfopropyl) - Pyridinium betaine, 1- (2-hydroxy-3-sulfopropyl) -pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allyl sulfonate, N, N-dimethyl-N- (3-cocoamidopropyl) -N - (2-hydroxy-3-sulfopropyl) ammonium betaine, polyamines, 1H-imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, 1-benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide , Potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium selenocyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate and carbon disulfide. Method according to claim 1 or 2,
characterized in that
when galvanic application of the copper layer (12) on the substrate (10) as a galvanic bath, a pure copper cyanide solution is used. Method according to one of the preceding claims,
characterized in that
during galvanic application of the copper layer (12) to the substrate (10), the copper layer (12) is applied with a layer thickness of up to 4 μm. Method according to one of the preceding claims,
characterized in that
during galvanic application of the copper layer (12) to the substrate (10), the copper layer (12) is applied with a layer thickness of up to 10 μm. Method according to one of the preceding claims,
characterized in that
during galvanic application of the nickel and / or nickel-phosphorus layer (14) to the copper layer (12), the nickel and / or nickel-phosphor layer (14) is applied with a layer thickness of between 5 and 10 μm. Method according to one of the preceding claims,
characterized in that
during electroplating of the gold layer (16) on the nickel-phosphor layer (14), the gold layer (16) with a layer thickness between 3 and 9 .mu.m, preferably 6 .mu.m, is applied. Slip contact comprising: an electrically conductive substrate (10); a copper layer (12) on the substrate (10); a nickel-phosphor layer (14) on the copper layer (12); and a gold layer (16) on the nickel-phosphorus layer (14); characterized in that
during the galvanic application of the copper layer (12) on the substrate (10) in the electroplating bath used at least one scum image is not used, which in the list of brighteners consisting of 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, cationic polymers Urea groups, 1- (3-sulfopropyl) -pyridinium betaine, 1- (2-hydroxy-3-sulfopropyl) -pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allyl sulfonate, N, N-dimethyl N- (3-cocoamidopropyl) -N- (2-hydroxy-3-sulfopropyl) ammonium betaine, polyamines, 1H-imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, 1- Benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium selenocyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate and carbon disulfide. Sliding contact according to claim 8,
characterized in that
during the galvanic application of the copper layer (12) to the substrate (10) in the electroplating bath used, no gloss images of the list of luster patterns 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, cationic polymers with urea groups, 1- (3-sulfopropyl) Pyridinium betaine, 1- (2-hydroxy-3-sulfopropyl) -pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allyl sulfonate, N, N-dimethyl-N- (3-cocoamidopropyl) -N - (2-hydroxy-3-sulfopropyl) ammonium betaine, polyamines, 1H-imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, 1-benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide , Potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium selenocyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate and carbon disulfide. Galvanic bath for the deposition of copper,
characterized in that
in the plating bath at least one scum from the list of scraps consisting of 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, cationic polymers with urea groups, 1- (3-sulfopropyl) -pyridinium betaine, 1- (2-hydroxy 3-sulfopropyl) -pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allyl sulfonate, N, N-dimethyl-N- (3-cocoamidopropyl) -N- (2-hydroxy-3-sulfopropyl ) Ammonium betaine, polyamines, 1H-imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, 1-benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, Alkali arsenite, potassium tellerite, potassium selenocyanate, Alkaliantimonyltartrat, sodium selenite, thallium sulfate and carbon disulfide, is not included. Galvanic bath for the deposition of copper,
characterized in that
no brightener in the galvanic bath from the list of brighteners 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, cationic polymers with urea groups, 1- (3-sulfopropyl) -pyridinium betaine, 1- (2-hydroxy-3-sulfopropyl ) -Pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allylsulfonate, N, N-dimethyl-N- (3-cocoamidopropyl) -N- (2-hydroxy-3-sulfopropyl) ammonium betaine, Polyamines, 1H-imidazole polymer with (chloromethyl) oxirane, 3-carboxy-1- (phenylmethyl) pyridinium chloride sodium salt, 1-benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tartarite, Potassium selenocyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate and carbon disulfide.

Images