Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
  • G01N29/02—Analysing fluids
  • G01N29/032—Analysing fluids by measuring attenuation of acoustic waves
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
  • C23C18/1601—Process or apparatus
  • C23C18/1633—Process of electroless plating
  • C23C18/1675—Process conditions
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
  • C23C18/1601—Process or apparatus
  • C23C18/1633—Process of electroless plating
  • C23C18/1675—Process conditions
  • C23C18/1683—Control of electrolyte composition, e.g. measurement, adjustment
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D21/00—Processes for servicing or operating cells for electrolytic coating
  • C25D21/12—Process control or regulation
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2291/00—Indexing codes associated with group G01N29/00
  • G01N2291/01—Indexing codes associated with the measuring variable
  • G01N2291/011—Velocity or travel time
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2291/00—Indexing codes associated with group G01N29/00
  • G01N2291/01—Indexing codes associated with the measuring variable
  • G01N2291/018—Impedance
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2291/00—Indexing codes associated with group G01N29/00
  • G01N2291/02—Indexing codes associated with the analysed material
  • G01N2291/028—Material parameters
  • G01N2291/02818—Density, viscosity

Definitions

• Control parameters that are developed from the bulk phase of the electrolyte have so far been preferred for monitoring galvanic and electroless metal deposition baths. This means the tracking of process-relevant bath parameters via wet chemical, instrumental-analytical and physical measurement methods. On the basis of these measurement data, the dosages required for process control are carried out.
• a monitoring method for galvanic baths is known from DE-OS 30 43 066, in which the concentration of a bath substance is determined continuously or intermittently by measuring the electrical conductivity, the density or the refractive index.
• Cyclic voltammetry can be used to check the content of organic additives in galvanic baths; please refer .
• DAHMS continuous monitoring of acidic copper electrolytes by cyclic voltammetry, Metall Chemistry 43, 345 (1989).
• impedance and mixed potential measurements have been successfully used to control copper baths without external current. These methods are electrochemical test methods and contain in-situ information about the surface process.
• independent variables such as mass, charge, impedance, elastic coating properties and viscosity of the liquid phase (electrolyte) by means of in-situ measurements using a detector (oscillating quartz crystal), and in particular in the case of continuous registration of mass changes to determine at least one or more of the quantities mentioned and to use the information obtained in this way about layer properties and the electrolyte to control the metallization process.
• quartz crystal surface which is in contact with the electrolyte, is also the working electrode of the electrolytic cell, and in addition to changes in mass, other electrochemical in-situ variables such as charge flow and impedance can also be measured.
• this methodological approach is also suitable for tracking the elastic surface properties of the deposited coatings or the viscosity of the electrolyte.
• the (texture-dependent) surface tension or expressed as a synonym, the elastic coating properties as a function of the layer thickness, K.E. HEUSLER et al. , Ber. Bunsenges. Phys. Chem. 92, (1988), 1218 and H. SP ⁇ HN, Metall Chemistry, 16, (1962), 109.
• the metal film can be removed either chemically or in-situ by applying a suitable potential.
• pulse technology can also be used as a measurement variant, i.e. H. the periodic switching on and off of the measuring probe.
• the measuring probe is an electrochemical cell with a classic three-electrode arrangement, see Figure 1.
• the control takes place via a potentiostat and a function generator.
• the working electrode of this system is the side of the quartz crystal facing the electrolyte. A change in mass at this electrode leads to a detuning of the resonance frequency of the quartz oscillator, which is measured via a frequency counter and fed to the small computer for processing.
• the charge is measured in the circuit between the counter electrode (CE) and working electrode (WE) using a coulometer.
• a voltage pulse is impressed on the measuring probe and evaluated together with the current response as a Fourier transformation.
• Elastic coating properties correlate with frequency detuning which result from the tension effects of these layers; the measurement is carried out by pressure compensation on the quartz crystal side facing away from the electrolyte. The surface tension can be calculated from these measurement data.
• the frequency detuning which results only from the electrolyte contact, is measured.
• the metallization process is carried out by appropriate
• the new control method is used for example at
• Frequency detuning is carried out as a function of the foreign mass assignment.
• the mass can optionally be registered with the other sizes mentioned.
• the measurement takes place with oscillating, mass sensitive
• Quartz crystals which can be coated on both sides with metal films and usually only one side of the
• Liquid contact will increase the sensitivity of the detection
• the process is based on the periodically repeated deposition and dissolution of the nickel / phosphor layers.
• the electroless (chemically reductive) deposition of nickel-phosphorus films takes place on the surface of the quartz crystal that is in contact with the electrolyte. From the detuning of the resonance frequency of the quartz crystal, the foreign mass assignment and thus the layer thickness and deposition speed can be directly determined. derive; G. SAUERBREY, Z. Phys. , 155, (1955), 206. - 6 -
• the coated side of the quartz crystal is switched as a working electrode in the three-electrode arrangement.
• the anodic dissolution takes place by means of a potential that is constant over time or a potential ramp.
• the chemical composition of the nickel-phosphorus layer can be determined by simultaneously registering the electrical charge converted during this process and the change in mass. The following reaction is used:
• the chemical composition of the layer can be inferred from the ratio of charge to mass change ( ⁇ Q. / ⁇ m).
• step two of the method possible either in the deposition electrolyte or in any other, for example indifferent, electrolyte.
• an electrolyte becomes the composition
• a nickel-phosphorus layer is also deposited from a bath of the composition mentioned in Example 1 at temperatures between 86-90 ° C. at a pH of 4.8 after the addition of 5 ⁇ 10 mol / 1 thiourea.
• the current-voltage curves of the anodic dissolution show a strong change compared to the layers that were deposited from a bath without addition ( Figure 5).
• the current-voltage curves can be correlated with data on corrosion resistance, which are obtained from independent tests (such as salt spray test, "Kesternich test"). It is shown that the nickel-phosphorus alloys which are deposited from baths with additions of thiourea or other sulfur homologues have significantly poorer corrosion resistance.
• compositions of chemical-reductive nickel baths which can be monitored and controlled using the described method are listed in Examples 3-6.

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• 1990
  • 1990-04-17 DE DE19904012556 patent/DE4012556C1/de not_active Expired - Lifetime
• 1991
  • 1991-04-12 WO PCT/DE1991/000312 patent/WO1991016472A1/de not_active Ceased

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