SU1201356A1 - Method of preparing permalloy surface to application of copper coatings - Google Patents

Abstract

A METHOD FOR PREPARATION OF A PERMALLY SURFACE BEFORE DRAWING COPPER COATINGS, including electrochemical etching in an alkaline electrolyte and washing, characterized in that, in order to improve the adhesion of copper to permalloy and to reduce the cost of the process, after the washing, an additional electrochemical etching was applied to the process, after the washing, 4), in the case, 10%, 4), 4), in the case of washing, 10), 4), 4), in the case of cleaning, 10), 4) should be additionally etched; hydrochloric acid solution at a cathode current density of 3-10 A / dm, followed by electrochemical deposition of a copper sublayer at a cathode current density of 5-10 A / dm from a solution containing; Dichloride 3-10 copper, about in Sol on acid, 35–13.06 ta, M Water, l To 1.

Description

The invention relates to electroplating, in particular, to the preparation of the surface of permallo before the electrodeposition of thick (up to 300 microns) copper coatings. The purpose of the invention is to improve the adhesion of copper to permalloy and to improve the process. A positive effect is achieved with the fact that, after washing, an additional electrochemical etching is carried out in 4.35-13.06 M hydrochloric acid solution at a cathode current density of 3-10 A / dm, followed by electrochemical deposition of a copper sublayer at a cathodic current density of 5- 10 A / dm in a hydrochloric acid solution with the addition of copper dichloride. Etching in hydrochloric acid provides surface activation, which leads to good adhesion of the permallo to the copper layer. Cathodic etching treatment is carried out to clean the permallo from dissolution products formed on the surface evolved by hydrogen. Using a concentration of hydrochloric acid below 1.31 M does not provide satisfactory adhesion. A decrease in the cathode current density below 3.0 A / dm does not provide cleaning and surface activation, as a result of which the copper layer is peeled off. With an increase in current density of 10 A / dm, deep etching occurs, as a result of which the applied metal is peeled off. After washing and activating, a 0.62.2 μm thick layer of copper is applied from a concentrated hydrochloric acid solution (13.14 M. Then dichloride is added to the solution at a concentration of 1-10 g / l. An intermediate layer is necessary to prevent the formation of oxide layer on the permallo surface. The maximum limiting concentration of hydrochloric acid is chosen to reduce the evolution of hydrogen during the electrodeposition of copper from the chloride solution. Increasing the concentration of copper dichloride to 10 g / l 56 will increase the speed deposition of high-quality copper precipitation. Further increase in the concentration of copper dichloride is impractical because it increases the cost of the process. Reducing the concentration of copper dichloride below 1 g / l is impractical because of frequent adjustment of the solution and increasing the precipitation time, copper is deposited at a current density of 2 , 5-10 A / dm 0.52 min. Lowering the current density does not provide the maximum speed of the process, increasing the current density above 10 leads to the deposition of poor-quality precipitation. The choice of electrolysis time is determined by the fact that the thickness of the copper sublayer (0.6-2.2 µm) ensures the adhesion of the copper layer to the thick copper layer (up to 300 µm). The deposition of a copper layer with a thickness of 300 µm is carried out from sulfuric acid electrolyte containing g / l: copper sulphate 200; sulfuric acid 50, the proposed method ensures the build-up of a copper layer with a thickness of up to 300 microns. Coating is carried out on samples of alloys 80НХС and 81НМА, Example 1. Copper coatings are applied in the following sequence. Electrochemical degreasing in solution, in g / l: caustic sodium (potassium) 10-20; sodium carbonate 20-30; trisodium phosphate 30-50; liquid sodium glass 3-5, Solution temperature 70-90 ° C, current density 10 A / dm - at a cathode 3 min at the cathode and at the anode 2 min. Washing in cold running water: Electrochemical etching in hydrochloric acid solution (1.3113, 14 M) at a current density of 3-10 A / dm one minute. The electrodeposition of copper (0.62, 2 μm) from a concentrated hydrochloric acid solution containing copper chloride (1-10 g / l). The process is carried out at a current density of 2.5-10 0.5-2-2 minutes. Rinse in running cold water,

Electrodeposition of copper (up to 300 microns) from standard copper sulfate electrolyte in g / l: copper sulfate 200; sulfuric acid 50. The process is conducted at a current density of 3-5 A / dm 4-5 hours

Conducted tests on the adhesion of the copper coating according to the bending method to the fracture of the sample show that the copper coatings (up to 300 microns) obtained by the proposed method have good adhesion

12013564

with permalloy, since the flaking of the coating does not occur when the sample is broken.

The table shows the data illustrating the proposed method.

As can be seen from the table, the proposed treatment method leads to the subsequent coating with 10 good adhesion and allows replacing the deficient nickel chloride with copper chloride.

Claims (2)

METHOD FOR PREPARING THE PERMALLO SURFACE BEFORE THE APPLICATION OF COPPER COATINGS, including electrochemical etching in an alkaline electrolyte and washing, characterized in that, in order to improve the adhesion of copper to permalloy and to reduce the cost of the process, an additional electrochemical etching 5 is carried out after washing, 5,3,3 in 4 06 M hydrochloric acid solution at cathodic current density 3-10 A / dm ¹ followed by electrochemical deposition of a copper sublayer at a cathodic current density of 5-10 A / dm ¹ from a solution containing: Copper dichloride, g 3-10 Hydrochloric acid, M 4.35-13.06 Water, l To 1. >