SU953012A1 - Copper-plating electrolyte - Google Patents

Description

The invention relates to the deposition of electroplating, in particular copper, and can be used in mechanical engineering and instrument making.

 A known copper electrolyte containing copper sulphate, aluminum sulphate, ammonium nitrate and aqueous ammonia l.

The disadvantage of this electrolyte is that hydrogenation of the steel base is observed during the electroplating process, while the quality of the copper coatings decreases.

The closest to the invention to the technical essence and the achieved result is a copper-plating electrolyte containing copper sulphate, nickel sulphate, sodium sulphate, ammonium sulphate, aqueous ammonia solution, a nitrogen-containing organic additive, for example, a quinone derivative, and water 2.

The disadvantages of the famous ele ktro; Litas are the deflagration of the steel base, which manifests itself in a drop in the ductility of wire samples by 7-11% with Dk 2-10 A / dm% low current efficiency (62-77%), significant porosity (from 2.2 to by 1 cm).

The aim of the invention is to reduce the hydrogen absorption of the steel base and reduce the porosity of the coating.

This goal is achieved. We find that the copper electrolyte containing copper sulphate, nickel sulphate, sodium sulphate, ammonium sulphate, aqueous ammonia, and nitrogen-containing organic additives.

10 and water, as a nitrogen-containing organic additive, contains N-allyl diethylene glycine hydrochloric acid or N-vinyl diethylenetriamine hydrochloric acid. with the following ratio of components:

80-100

Sulfate copper, g

Sulphate ni10-30 cell, g

Sulphate

20

30-50

sodium, g

Sulphate

70-90

AMG, g

Aqueous solution am170-190 miak (25%), ml

25

N-allyl diethylenetriamine hydrochloride

or N-vinyl diethylenetriamine hydrochloride, ad0.001-0.002

thirty

Water ldo 1

The deposition is carried out at a pH of 9.5-10.0, the temperature of the electrolyte 18-25C and cathode current density of 2-10 L / dm.

N-Allyl diethylenetriamine hydrochloride is obtained according to the equation: l) NH7-C2H4NH-C2H4NHrj + CH2 CH-CHjCg- - NH2-C2H4NH-C2H4NHCH2-CHH, 2 more than 2) Hj ; - - H2NC2H4NHC2H NH-CH CH HC. .

In a three-neck flask with a capacity of 500 ml with a stirrer, an addition funnel and a calcium chloride tube, 103 g of diethylenetriamine and 100 m of dry carbon tetrachloride are placed. 76.5 g of allyl chloride is added dropwise to the solution at-5 ° C and the slushy liquid is stirred for 1 hour at room temperature. The white or yellowish precipitate formed is filtered and dried under vacuum. The second compound N-vinyl diethylenetriamine hydrochloride is prepared in a similar way.

Sugar-free unsaturated amines are crystalline, colorless compounds, well soluble in water.

To obtain the proposed electrolyte, three mixtures of components were prepared.

For determination, electrolytes were prepared according to Table 1.

Electrolytes are prepared as follows.

Calculated amounts of salts are consistent. dissolved in distilled water heated to 50 ° C; 0 ° C; the solution is filtered and aqueous ammonia is added. In order to remove impurities, the electrolyte is processed for 6 hours and an organic additive is added.

Example 1. At the electrodeposition of copper from the electrolyte of composition 1 (Tables 2 and 3) at bk 2 A / dm, crystalline brilliant copper deposits with good adhesion are formed. The ductility of wire samples is 96 ,, 2-100%. The current output is 97%, and blzsk 70 relative units Scattering power 50%. The coating is equal, with no pitting and filamentous dendrites. Electrolyte coating capacity is 100%. The stability of the electrolyte is maintained for a long time, the correction for all components is carried out 1 time per two months, for ammonia 1 time per week. The deposition rate is 0.53 µm / min.

Example2. From the electrolyte from Stage 2 (Tables 2 and 3) with Dk 4 A / d, quantitative precipitates with good adhesion are obtained, a high current output (CTA 92%), brilliant (76 relative units), almost porous ( the pore number per cm is 2-0.5). The ductility of the steel base is 95.9-98%, dissipative-ability - 63%. The deposition rate is 1.4 µm / min.

0 r and me r 3. From the electrolysis of composition 3 (Tables 2 and 3), with A / d, cathode deposits are obtained with a high scattering power (), brilliant (2 77 Rel. Units) with good adhesion. The high ductility of steel cathodes (N 9496, 4%) virtually eliminates hydrogen absorption of steel, which is especially important for modern electroplating. The precipitates are practically porous with a fine-crystalline structure.

The starting material for the formation of the ammonia complex is copper sulfate, and ammonium (25% solution) was used as an additive, which was introduced to increase the stability of the CH (NH) 4 complex. To increase the electrolyte conductivity, sodium sulfate and sulfuric acid were added to the bath. .71 is ammonium, and to improve the structure of the precipitate, nickel sulphate. Electrolysis was carried out at 18-25 C at pH 9.5-10, a cathode current density of 210 A / dm and mechanical stirring. The properties of copper coatings obtained from the proposed electrolyte are presented in Tables 2 and 3.

The submergence of the base metal during the electrodeposition of copper was studied by changing the ductility of the steel spring wire from carbon steel U8A 0 1 mm, measured by the number of revolutions until fracture on twisting on the K-5 machine.

Inhibiting anti-inflammatory effect (N) was determined by the formula

N - -100%,

Eo

where a and a J, is the number of revolutions before the destruction of the wire, the sample before and after copper plating, respectively.

The working length of the specimen is 100 mm, and the tensile load is 1.2 kg. Wire samples were made of spring high-strength steel composition,%: C 0.8; Si 0,2 ;; Mp Q, 22; P 0.018; S 0.02; Cr 0.15; N1 0.12. The test samples were mounted in five pieces in a special device at a par 1 distance from the anode. Sample preparation consisted of polishing with micron sandpaper and obeshirivanii Vienna lime. This type of degreasing does not affect the mechanical properties of the steel, is accompanied by the removal of the surface layer of oxides and eliminates hydrogenation of the steel during surface preparation. When studying the physicomechanical properties of electroplating, a 300 ml rectangular bath was used. A 50x22 2 mm plate made of steel 10 served as the cathode. The appearance of the copper coatings was examined using a microscope. The microhardness of copper deposits was measured on a pmt-3 device by the method of static indentation of a diamond pyramid under a load of 20 g. Microhardos was calculated using the formula 1854 p kg / mm. d where p is the load, 20 g; d - the print diagonal. The brightness of the electrolytic copper coatings was measured on a photoelectric brightness meter PB-2 in relative units relative to video glass, the brightness of which is 65 relative units. The range of values 1-10 corresponds to a matte surface, 10-50 to a semi-glossy, 50-90 shiny, 90-100 to a mirror-shiny surface. The precipitation copper porosity was determined according to GOST 3247-46. The current efficiency was determined using a copper coulometer. Determine the scattering ability according to the method of Hering-Blum and calculate the distance from the anode to the far cathode using the formula i d kp n 0; -fi is the distance from the anode to the near cathode; the mass of the actually released metal on the cathodes. The coating ability of an electrolyte was determined by the method of the angular cathode, the clutch was considered satisfactory if no swelling or cracking of the coating was observed during polishing of the galvanic upset to the steel base, and the edges of the polished circle were equal and globally.-The use of organic additives of hydrochloric acid unsaturated amines in the proposed Copper electrolyte can significantly reduce the deposition of the steel base, improve the quality of copper coatings, and improve the electrolyte dissipation capacity. The high inhibitory hydrogen living effect of unsaturated amines {N 90.0-100% can be accounted for at the expense of three centers of adsorption — three nitrogen atoms — contributes to better adsorbability of these compounds on the cathode surface. The inhibitory activity of organic compounds is determined by the electron density at the adsorption center of the molecule. The higher the electron density, the stronger the adsorption of the organic compound, which is due to the donor – acceptor interaction of a lonely pair of electrons of the nitrogen atom with incomplete d orbitals of iron. The addition of N-allydiethylenetriamine hydrochloride has a more effective effect (the ductility of steel is 93-100%) than the addition of N-vinyl diethylenetriamine hydrochloride (N 90-99.6%), which can be explained by the difference in the length of the hydrocarbon chain. substitute During the electrodeposition of copper from the ammonia electrolyte, the surface of the copper electrode is negatively charged, since .0-0.06 V, -0.320 V, o,. -0.500 V, cplVu --- -0.710 B, -0.760 V, Ya-ol / Am -0.800 V. Consequently, the most likely inhibitors should be cationic and molecular additives. The potential of the cathode in the presence of the additives studied is shifted to the negative side. Such a character of changes in the cathode potential in the presence of organic substances indicates that the cathodic reduction process of divalent copper and hydrogen ions is complicated by the adsorption layers of organic molecules formed on the cathode surface. Additives introduced into the copper electrolyte displace the cathode potential to 740 Bi at DK 2 A / dm, and at Dk 10 A / dm, the potential reaches a value of -1.3 V. At the same time, cathode deposits are pore-free, brilliant, fine-crystalline, evenly distributed over the surface, with good adhesion. There is a correlation between the effect of the studied additives on cathodic polarization and the properties of cathode deposits. In the presence of the studied additives, high-quality electroplating copper coatings are obtained, the brightness of which is 58., 5-80 rel. Units — The main brightening agent in ammonia electrolyte is finely dispersed sol consisting of monovalent copper complex ions with ammonia. Particles of this ash, settling on the surface of the cathode, apparently form an adsorption film, which is continuously destroyed and renewed in the process of electrolysis. The action of organic additives is likely to manifest itself in stabilizing this evil.

in a highly dispersed state and the formation of adsorption layers on the faces of growing crystals.

In the presence of organic additives, microextraction is in the range of 220-270 kg / mm. Adsorbing to the faces of growing crystals, organic substances change the degree of dispersion of the structure, the internal stresses in the grain.

The presence of additives of hydrochloric unsaturated amines in the electrolyte contributes to the formation of nonporous copper coatings. There is a correlation between the effect of the investigated additives on the porosity of the coating and the hydrogenation of the metal during copper plating. The resulting hydrogen atoms are molarized and do not adsorb on the surface of the steel; therefore, the hydrogen absorption slows down more strongly than the organic matter adsorbing film.

The addition of organic substances to the ammonia electrolyte increases the cathodic current efficiency, which is equal to 68-98%, which is associated with the inclusion of these additives in the growing sediment. The dispersing ability of the ammonia electrolyte is much higher than the PC of sulfate, pyrophosphate and ethylenediamine electrolytes and is 44-82% with Dk 2-10 A / dm

As a result of the tests carried out, it was found that the use of the ammonia electrolyte proposed provides the following advantages in comparison with the well-known: obtaining steel parts with a minimum hydrogen absorption of the steel base, which is especially important in mechanical engineering, instrument-making, where it is necessary to prevent metal embrittlement; obtaining high-quality copper deposits with a fine-crystalline structure, smooth, shiny, with good adhesion, almost porous; a significant increase in dissipative capacity, which is especially important in obtaining uniform copper coatings; an increase in cathode current yield; the deposition is carried out directly on the steel without an intermediate sublayer, which is especially important in practical galvanostrate; the stability of the electrolyte is maintained for a long period, the covering power is 100%.

Table 1

Copper sulfate, g Nickel sulphate, g Sodium sulphate, g Ammonium sulphate, g

Aqueous solution of ammonia 25%, ml

Solvent Acid Amines, Moles

Water l

90 20 40 80

80 10 30 70

180

170

0,0015

0.001 To 1 To 1

GOI

CO

ON

At VO (

About t

r

ON

1L

vo

3

och

VC 0

S

Oh oh

U1

on VO

CM VO (N

(X)

g

HF1

CM

about oo

oo

Vd

r

VO

00

CM CT

in

CO

a

VO

in a

T c

(U1

00

1L

VO ON

0

but

VO

oo cr

oh oh

CTl

about ns n

sh

with

S (U

Claims (2)

The inventive electrolyte containing copper sulphate, nickel sulphate, sodium sulphate, ammonium sulphate, aqueous ammonia aetocontaining / organic additive and water, characterized in that, in order to reduce the carbonization of the steel base and reduce the porosity of the coating, As a nitrogen-containing organic additive, it contains N-allyl diethylene triamine hydrochloride or N-BINILDI ethylene triamine hydrochloride with the following ratio of components: sulfuric acid copper, r80-100 nickel sulphate, r10-30 Ser sodium sulfate, g 30-50 20 Ammonium sulphate, g Aqueous solution of ammonia (25%), 170-190 ml N-Allyldiene tylenetriamine hydrochloride or N-vinyldiethylenetriamine, 0.001-0.002 mol Water, l To 1 Information sources , ntye in view of the examination 1.Av-torskoe certificate of the USSR 608854, cl. C .25 D 3/38, 1976. 2. USSR author's certificate for application 2486461, c. 25 D 3/38, 7.