KR19980703108A - A method for selectively or partially electrolytic metallizing a substrate surface made of non-conductive material - Google Patents

Abstract

The invention concerns a process for the selective or partial electrolytic metallization of surfaces of substrates made from electrically non-conducting materials which for the purpose of the coating process are secured to plastic-coated holding elements. The proposed process involves the following steps: a) preliminary treatment of the surfaces with an etching solution containing chromium (VI) oxide; followed immediately by b) treatment of the surfaces with a colloidal acidic solution of palladium-/zinc compounds, care being taken to prevent prior contact with adsorption-promoting solutions; c) treatment of the surfaces with a solution containing a soluble metal compound capable of being reduced by zinc (II) compounds, an alkali or alkaline earth metal hydroxide, and a complex forming agent for the metal in a quantity sufficient at least to prevent precipitation of metal hydroxides; d) treatment of the surfaces with an electrolytic metallization solution. By applying this process, it is possible to ensure that only the surfaces of the work piece are coated with metal, not the holding elements or, where applicable, non-conductive plastic layers applied to parts of the work pieces. In addition, the process facilitates direct electrolytic metallization even of large plastic surfaces without prior currentless metallization.

Description

A method for selectively or partially electrolytic metallizing a substrate surface made of non-conductive material

The present invention relates to a method of selectively or partially electrolytic metallizing a substrate surface consisting of an electrically non-conductive material immobilized on a fixed source coated with plastic for subsequent processing.

Various methods of coating non-conductive surfaces are known. In the wet chemical process, the surface to be methylated is suitably pretreated, first catalyzed and then electroless metallized and then electrolytic metallized if necessary or directly electrolytic metallized.

However, the first modified method of electroless metallizing is difficult due to the process control of the electroless metallizing bath, the treatment of wastewater from the bath is complicated and expensive, and the method is difficult due to the low deposition rate of the metallizing bath. It is proven to be disadvantageous because it is time consuming and expensive.

In particular, the electroless metallizing method is problematic in the case of metal coating of, for example, sanitary appliances and plastic parts in the automotive industry, and plastic parts used in cases for electric appliances that screen electromagnetic radiation. In the case of the treatment of such molded parts, a relatively large amount of treatment solution is generally transported from one treatment bath to the next treatment bath, which is shaped in such a way that the treatment solution is transported out of the bath when the part is lifted. Because it has. Electroless baths typically contain significant amounts of toxic formaldehyde and complex formers, which are very difficult to remove, and upon their treatment, large amounts of bath are lost and must be disposed of in a complex manner.

For this reason, a series of metallizing methods have been developed that can directly coat non-conductive surfaces with metals without electroless metallizing. However, this method is particularly for metallizing the walls of boreholes in printed circuit boards. However, in the case of metallization of boreholes, direct electrolytic metallization is considerably simpler than metal sheaths of other plastic parts, for example sanitary appliances, or metal sheaths of certain three-dimensional appearance on the opposite side of the panel. Because less is required. The area of the surface of the non-conductive substrate to be metallized during metallization can be more easily achieved since it is smaller in the case of metallization of boreholes on a printed circuit board.

An electroconductive metallizing method of a nonconductor, covered with a metal chalcogenide, which is to be metallized, is described in EP 0 298 298 A2. Metal chalcogenides are formed by treating the surface with a palladium colloid containing a tin compound that is a protective colloid followed by treatment with a soluble metal chalcogenide compound, preferably metal sulfide.

Similar methods are described in US-A-49 19 768 publication. This method is a method wherein the non-conductive surface is first treated with tin (II) salt, then with dissolved sulfide and then with a solution containing hydrochloric acid and palladium salt. The pre-treated surface is then electrolytic metalized.

EP 0 320 601 A2 describes a nonconductive metallizing method wherein the nonconductive surface is first treated with permanganate to form manganese dioxide on the surface. The manganese dioxide layer is then converted by treatment with a chalcogen compound, preferably a sulfur compound. The metal layer can then be electrolytically deposited.

In this method, a sufficiently high chalcogenide layer can be formed by special pre-treatment for subsequent metallization of the borehole in the printed circuit board. However, the conductivity of such layers is insufficient to metallize a large area of the non-conductive substrate, because too large non-conductive paths must be bridged from the contacts of the current source. Upon metallization, the chalcogenide layer breaks in close proximity to the contact.

US-A-39 84 290 describes a method for treating a borehole wall in a printed circuit board with a solution containing a metal that is more precious than copper first to form a metal coating on the copper surface or non-conductive surface on the printed circuit board. It is. The metal coating is then removed from the copper surface again and then the metal coating on the non-conductive surface and the copper surface is electrolytic metallized.

Another direct electrolytic metallization method is described in DE 33 23 476 C2. The non-electrolyte product to be metallized is first treated with a palladium activator stabilized by a noble metal-containing solution such as a tin compound and then electrolytically coated in a metallization bath. The metallizing bath contains a suitable organic additive, whereby the desired metal precipitation is promoted on the metal coating on the nonconductive area, formed in the preceding process step.

DE 37 41 459 C1 publication discloses organic compounds containing nitrogen prior to electrolytic metallizing, for example polyvinyl pyrrolidone, 2,2,6,6-tetramethyl-4-piperidone, pyridinium propyl sulfide. Described is a method of making an injection contact printed circuit board by direct electrolytic metal deposition on a catalytically activated surface of a base material pretreated with a solution containing at least one of pobetaine or polymerizable polyquaternary ammonium chloride. .

EP 0 456 982 A1 discloses that the substrate is first catalyzed in a solution containing a palladium colloidal solution, for example stabilized with a tin compound, and then the tin compound is removed from the surface of the substrate by known methods (more than tin for this purpose). A method of electrolytic metallizing of substrates which electrolytic metallizes the surface after further containing a precious metal compound) is described.

Although the conductive layer of the formed layer is insufficient for metallizing a wide non-conductive surface, the method can also metallize the borehole walls in a printed circuit board.

WO 89/08375 A1 describes completely different methods. The method is likewise used for the manufacture of injection contact printed circuit boards. However, the first conductive layer is formed by subsequent treatment of the conductive polymer, which firstly treats the nonconductive surface with a permanganate solution to precipitate manganese dioxide on the treated area, and then flushes the excess treatment solution with the printed circuit board. Is immersed in a solution containing one monomer of a pyrrole, furan or thiophene group, and then contacting the substrate with an acidic solution to form a conductive polymer layer from the liquid film containing the monomer on the borehole. It can then be electrolytically metallized directly.

German published document 30 07 789 A1 describes a method for depositing a conductive layer on a non-conductive surface, in which a conductive base layer formed by electroless chemical polymerization of one or more conductive polymers on the surface is formed on the surface. Subsequently produced, further conductive layers, such as conductive polymer layers or metal layers, are deposited. If the process of the method is repeated several times, the method can also directly electrometallize a substrate having a wide non-conductive surface. However, this is not practical because it requires an abnormally long process.

In addition, the conductive polymer layer formed on the surface has sufficiently high conductivity only for a short time after its preparation. After this, it decreases rapidly, so metallizing of a large area is still impossible.

EP 0 616 053 A1 describes a direct metallization method of a non-conductive surface, in which the surface is first treated with a detergent / regulator solution, followed by an activator solution stabilized with a tin compound, for example palladium chloride solution. The treatment is followed by a solution containing alkali hydrooxides and complex formers as well as metal compounds that are more precious than tin. The surface can then be treated with a solution containing a reducing agent and finally electrolytic metallized.

According to the known method, it is usually only possible to direct electrolytic metallization of narrow surfaces, for example the borehole walls of an phospho circuit board; Metallizing of large plastic surfaces fails in most cases due to the lack of metallizing ability of the layers formed on the nonconductive surface.

For industrial bristles of direct electrolytic metallization of dense structural plastic parts, such as combs or products designed to be significantly stretched in three dimensions (eg coffee pots, telephone handsets, water pipe fittings), Since it interferes with manufacturing, the product during the manufacturing process must be fixed on a support frame that cannot be coated during the metallizing process. Otherwise, the metal layer must be raised from the support frame after the product in the manufacturing process has been coated. This requires additional costs for the removal of the coating along with the consumption of the compound. Moreover, in this case the productivity of the metallizing equipment is lower because the coated metal of the frame must first be stripped off before refilling the product during the manufacturing process.

Therefore, the problem of the present invention is to selectively or partially replace the surface of a substrate made of a non-conductive material immobilized on a fixed source, for example a support frame coated with plastic, while avoiding the disadvantages of the prior art. There is a need to find a method for electrolytic metallization.

This problem is solved by claims 1, 7 and 8. Preferred aspects of the invention are indicated in claim 2.

The process according to the invention comprises the following process steps:

a) pre-treatment with a corrosion solution containing chromium (VI) oxide,

b) treating the substrate surface with a colloidal acid solution of palladium / tin compound, avoiding precontact with the adsorption-promoting solution,

c) the surface of the substrate with a solution containing a soluble metal compound, an alkali metal hydroxide or an alkaline earth metal hydroxide that can be reduced by a tin (II) compound, and at least a complex forming agent for metals that prevents precipitation of the metal hydroxide Processing step,

d) treating the surface of the substrate with a solution for electrolytic metallization.

The substrate surface may be washed at some or all stages of the process.

According to the prior art, in particular, in the production of printed circuit boards, so-called conditioning solutions are used as absorption-promoting solutions. These are especially common in aqueous solutions containing a polymer electrolyte having a molecular weight of at least 10,000 g / Mol, for example a polymer cationic polymer. Treatment of the non-conductive surface with the control solution not only coats the plastic substrate to be metallized with the metal as desired, but also unnecessarily also the fixed source with plastic covering the outside.

On the other hand, according to the method according to the present invention, since the substrate is not in contact with the control solution, it is not necessary to remove the metal from the fixed source again after use. Rather, after metallization of the substrate surface and removal of the metallized substrate, the stationary circle is returned directly to the production line without further processing to load another non-conductive substrate to be directly metallized. If metals are deposited on the contacts / metal points during metallization, they should be removed from time to time to avoid contact problems and impurities in the bath.

No further cleaning and corrosion steps are needed to strip the coated metal of the frame portion below the contacts. In this case, the cost of waste disposal is also reduced. In addition, little compound is consumed. Since a large number of substrates can be metallized with a certain number of existing stationary sources, the productivity of metallizing equipment is also increased.

However, prior to treating the substrate with an activator, a prerequisite is that the substrate should not be in contact with an agent that promotes the adsorption of colloidal particles in any case.

In addition to solutions known to those skilled in the art, particular attention should be paid to the removal of contaminated wash water, especially when circulating water is used in the plant.

Carry-over of the circulating water from a controlled bath of parallel manufacturing equipment should be avoided because preparations which can act in the same way as adsorption-promoting polymer electrolytes can be introduced. Therefore, it is not meaningful to use parallel frames for the manufacture of printed circuit boards and for the purposes of the invention.

The advantage of the method lies in the fact that the surface of the substrate to be metallized is partially metallized so that a portion of the substrate can be covered with a suitable material. In addition, since the material is not coated during the process according to the invention, it is subsequently applied without damaging the metal coating on the metallized substrate even during the treatment necessary for the selective removal of the metal deposited therein. It is very easy to remove material.

The invention particularly relates to a packaging surface, ie a non-conductive molded part of a three-dimensional structure, for example a plastic part for a sanitary part, an automobile assembly or a housing to be electrically screened, wherein the narrowest packing area of the object is substantially smaller than its surface. This is suitable because the disadvantage in transporting the treatment solution from the bath can only be avoided to the extent that it is actually unsatisfactory. When electrolytic metallization is carried out directly by the method according to the invention without prior electroless metallizing, toxic wastewater containing less complexing agent is produced than by conventional plastic metallization.

Thus, the method according to the invention is much more cost effective, less complex and more environmentally friendly than methods known in the art.

Under the circumstances known to the person skilled in the art, depending on the substrate to be metallized, the substrate may first be subjected to, for example, diethylene glycol or an ethylene glycol derivative, or an organic solvent such as dimethylformamide, or the like before starting the process according to the invention. It is necessary to expand the substrate in polar or nonpolar solvents. These solvents may also be used in admixture with water. Particularly preferred treatment agents are further added alkalizing agents, for example alkali hydroxides or tetraalkyl ammonium hydroxides. Depending on the type of substrate to be treated, the solution may be used at or above ambient temperature.

According to the invention, in the process of step a), the surface to be metallized is pre-treated in a corrosion solution. This typically includes a solution containing chromic acid, which solution may also further contain sulfuric acid. A preferred solution is one containing 360 g of chromium (VI) oxide and 360 g of concentrated sulfuric acid in 1 liter of water. The solution is heated to treat, for example, at a temperature of 60 ° C. Depending on the nonconductive substrate to be metallized, the processing time is between 2 and 16 minutes.

For certain substrate materials, it is possible to use permanganate solutions, for example solutions containing from 100 g / l to 150 g / l sodium hydroxide and 30 g / l to 60 g / l sodium hydroxide in aqueous solutions, instead of solutions containing chromic acid solutions. .

After washing with water, the chromium (VI) compound attached to the surface of the substrate is reduced to the chromium (III) compound. During permanganate treatment, manganese oxide precipitates are likewise reduced and removed. For this purpose, for example, an acidic aqueous solution of sodium hydrogen sulfate can be used. However, other reducing agents such as hydroxylamine are also suitable.

After another washing operation, the substrate is treated in a solution containing concentrated hydrochloric acid or other inorganic acid, for example, 300 m / l concentrated sulfuric acid. Such treatment is useful to avoid continuous dilution by washing with an activator solution to treat the substrate. Since the activating agent may also contain tin compounds in addition to the palladium compounds, the inorganic acid treatment solution may further contain the tin compounds as well. In this case the carry-over loss is partially compensated. The treatment time in the preliminary immersion solution can vary widely. The only important factor is that the surface of the substrate is completely wet. Any bath temperature can be selected.

The success of this method is probably based on the fact that adsorption of palladium particles from colloidal solutions is used to coat non-conductive surfaces with numerous palladium particles. Since palladium originates from a colloidal solution, after adsorption they are surrounded by a protective colloid envelope which prevents electrical conduction of the deposited palladium layer.

The activator typically consists of an aqueous solution of hydrogen chloride of an inorganic acid, preferably palladium colloid. The palladium content in the solution may be formulated in the range of about 50 mg / l to 500 mg / l solution, in particular about 150 mg / l to 250 mg / l solution. Palladium salts can be used to produce colloids. Further tin (II) salts are added to the solution and partially oxidized to tin (IV) compounds during the reaction of the palladium salt with tin (II). The tin content in the solution can be adjusted within the range of 2 g / l to 50 g / l solution, preferably 10 g / l to 25 g / l solution. Colloidal solutions can be prepared according to the methods described in US-A-30 11 920 and US-A-36 82 671.

When hydrochloric acid is used as the inorganic acid, the concentration range of hydrochloric acid is within 2% to 30% by weight, preferably 5% to 15% by weight in water. Electroplating experiments show that the activator must be concentrated hydrogen chloride. With a hydrochloric acid content of less than 0.5 Mol / l solution, palladium from the activator is no longer sufficiently adsorbed on the surface to achieve rapid metal growth during metallization.

After activator treatment, the substrate is washed again.

In this process, the reducing ability of the tin (II) compound from a solution containing a metal, preferably copper ions, reduces the ions to a metal, preferably metal copper and in this way a metal, for example copper, palladium Used to deposit between particles. In addition, the broken tin (II) / tin (IV) layer is removed by this method.

In certain embodiments, copper compounds are used in the solution as metal compounds. However, silver, gold, palladium and other precious metals are also suitable, for example. All compounds which are particularly soluble in aqueous media, for example salts such as copper sulfate and copper acetate, are considered as copper compounds. The concentration of the metal is adjusted within the range of 0.1 g / l to 50 g / l aqueous solution, preferably 0.5 g / l to 15 g / l solution.

Solutions containing metal ions are preferably alkaline. The solution contains alkali or alkaline earth metal hydroxides and further complex formers for metals. It has been proved that lithium hydroxide is particularly preferred as alkali metal hydroxide. Basically, however, other hydroxides such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide or barium hydroxide are also suitable. Their concentration is in the range of 0.1Mol / l to 3Mol / l aqueous solution, preferably 0.5Mol / l to 1.5Mol / l aqueous solution.

In addition, the contained complex former serves to keep the metal dissolved in the alkaline solution constant. The complex former should therefore have a sufficiently large complex formation constant for the metal and be present at least in an amount sufficient to prevent precipitation of the metal hydroxide. In particular complexes such as ethanolamine, ethylene diamine and salts thereof, tartaric acid and salts thereof, citric acid and salts thereof and compounds such as N, N, N ', N'-tetrakis- (2-hydroxypropyl) -ethylene diamine It has proved to be particularly suitable as an agent.

The working temperature of the solution containing the metal ions can be adjusted within all practicable ranges, but preferably within the range of 30 ° C. to 65 ° C., and in preferred embodiments within the range of 50 ° C. to 60 ° C.

After treating with a solution containing metal ions, the substrate is washed again.

The first reduction of metal ions can be enhanced with an additional reduction step. For this purpose the substrate is contacted with another solution containing a reducing agent. Basically, all reducing agents can be considered. However, boron / hydrogen compounds have proven to be most preferred. For example, sodium borohydride in alkaline solution or dimethylaminoborane in alkali or weakly acidic solution is particularly suitable for improving the conductivity of the resulting metal layer, thus making it particularly easy to metal It can rise.

The substrate is washed again to completely remove the residue of the reducing agent from the substrate surface.

After this treatment, the extremely thin layer has a sufficiently high electrical conductivity for subsequent electrolytic metallization. All electrolytically depositable metals can be deposited directly on the pre-treated substrate surface according to the method without further electroless metallizing. Copper, nickel, palladium and other precious metals are suitable for this purpose, for example. Another metal may be deposited on the metal. In addition, the first metal layer may be partially covered with a dielectric layer for functional effects or functionality.

In addition, such a dielectric layer may be applied to the surface of the substrate prior to each processing step described above to inhibit metallization at this point.

The body of the substrate, in particular the acrylonitrile / butadiene / styrol copolymer or mixture of these and other nonconductive materials, can be metallized. In particular, substrates comprising polyvinyl collide are hardly eroded by the pre-treatment solution containing chromium (VI) ions. Thus, for example, by coating a fixed source such as a support frame with the material during the electrolytic metallization of plastics, their metallizing during the electrolytic treatment can be avoided.

The substrate is contacted with the treatment solution by dipping, spraying, scattering or jetting.

The following examples serve to illustrate the invention:

Example 1

A suitable metal frame is covered with polyvinyl-based plastic (Tegumit, product of Atotech Deutsche GmbH, Berlin, Berlin). After the metal contacts of the previously insulated frame are stripped off by the coating process, the molded parts (passive shower heads) of the plastic acrylonitrile / butadiene / styrene- (ABS) -copolymer to be metallized are fixed to this point. The array is subsequently treated with the following solution:

1. The parts are immersed in a bath heated to 65 ° C. containing 360 g / l of chromium (VI) oxide and 360 g / l of concentrated sulfuric acid in aqueous solution for initial corrosion.

2. After 6 minutes, the excess acid is washed off the surface of the molded part and treated with sodium hydrogen sulfate to reduce all chromium (VI) ions still attached to the surface of the molded part.

3. After another washing step, the molded part is briefly immersed in a bath containing 300 ml of concentrated hydrochloric acid per liter of aqueous solution,

4. Immerse in an activator containing 300 ml of concentrated hydrochloric acid per liter of aqueous solution, 250 mg of palladium (used as palladium (II) chloride) and 17 g of tin (II) chloride for 1 minute.

5. After washing the surfaces of the molded parts one by one, they were treated for 1 minute in a 60 ° C solution containing 25 g of lithium hydroxide, 20 g of sodium hydroxide, 4 g of copper sulfate, and 15 g of tartaric acid per liter of aqueous solution. In this case, the tin compound adsorbed on the surface will probably be exchanged for copper.

6. The molded parts together with the frame are then immersed in a commercially available copper sulphate metallizing bath for metallization.

Within one hour at a current density of 2 A / dm ² , a homogeneous polished copper layer will be deposited entirely on the ABS molded part. No copper deposits are found on the support frame coated with polyvinyl chloride. In the peel test according to the German standard DIN, the metal layer has an adhesion greater than 1 N / mm.

Example 2

The method described in Example 1 is repeated except that a nickel bath (Watts type) is used instead of the copper sulfate bath in the step 6 process. The same result is achieved in view of the selectivity of the method and the adhesion of the deposited metal layer.

Example 3

The ABS sample is partially covered with a polyester layer and then treated as described in Example 1.

The polyester layer is not metallized.

Example 4

2-in part of the so-called injection molding process, in part from plastics containing ABS (Cycoloy C1100, Firm General Electric Plastics, Russelsheim, Germany) and in part from polyamides (Noryl GTX924, Firm General Electric Plastics). The molded part (telephone case) manufactured by the shot method is processed as described in Example 1. Only plastics containing ABS are covered with metal, while there is no metal at all on the polyamide surface.

Example 5

Similar to Example 1, before the treatment according to the method of step 3 (pre-immersion) to compare the frame and the ABS molded parts fixed thereto, the polymer Luresin KNU per liter of aqueous solution was prepared to control the ABS surface. 1 g of Firm BASF) is immersed in a solution heated to 45 ° C. for 2 minutes.

After the treatment step, both the ABS surface and the Tegumit surface of the frame are metallized.

Example 6

Molded parts of polycarbonate (Lexon BE from Firm General Electric Plastics) (automobile radiator grille)

1. Soak for 5 minutes in a solution at ambient temperature containing 700 g of diethylene glycol ethyl ether acetate per liter of water for expansion.

2. The solution is then treated for 6 minutes in a solution at 70 ° C. containing 380 g CrO _3, 380 g concentrated sulfuric acid, 20 g Cr ₂ O ₃ , and 0.1 g fluorotenside (FC 95, 3M Corp., USA) for initial corrosion.

3. After washing the excess corrosion solution, remove the still attached chromium (VI) from the solution containing 40 g of sodium disulfide per liter of aqueous solution.

4. The molded part is activated for 3 min in a 35 ° C. solution containing 150 ml of concentrated sulfuric acid, 220 g of palladium collide and 30 g of tin (II) chloride per liter of aqueous solution.

5. After washing with water, it is treated for 1 minute in a 60 ° C solution containing 4 g of copper sulfate, 150 g of tartaric acid, 20 g of sodium hydroxide, and 20 g of lithium hydroxide hydrate per liter of aqueous solution.

6. After washing, the molded part is decoratively coated with a commercially available copper metallizing electrolyte (Cupracid HT, Firm Atotech Deutschland GmbH). After 7 minutes, the molded part is completely covered with copper. After the test, the copper layer was further treated in the same bath for 45 minutes to deposit a 25 μm thick layer.

Example 7

The ABS molded part is treated similarly to the experiment described in Example 1.

The surface conductivity of the formed layer is measured before metallizing. After the treated molded part is washed with water and dried, resistance measurement is performed with two measuring electrodes pressed onto the surface of the treated molded part at a surface spacing of 1 cm.

The side course image of the copper layer is also measured.

A surface conductivity of about 50 μSiemens (μS) is measured. A metallized surface is formed on the molded part, wherein the metalizing advance point is moved by 9 cm within 1.5 minutes from the contact of the molded part.

FIG. 1 shows the growth (cm) of the conductivity (μS) according to the hydrochloric acid concentration (Mol / l) in the activator (method step 4) and the metal forward point (cm) after 1.5 minutes of metallization (process step 6) time. The experimental values showed that the conductivity increased almost linearly with increasing acid concentration, while the metal deposition rate did not increase in proportion to the concentration after a sharp rise above the minimum concentration.

Example 8

Example 7 is repeated to examine the sample for various variables.

The growth of the metal forward point on the substrate surface, which proceeds from the cathode, is measured. The results are shown in the table below and graphically shown in the figures. A 15 cm long and 6 cm wide ABS panel as a sample is treated according to the invention, which is then contacted on a narrow side and plated with copper.

Table 1 shows the development of the metal advance points of the two samples for metal plating times of 2.5 minutes or less at an electroplating voltage of 0.6 volts.

Table 2 shows the growth rates (cm / min) calculated from a number of samples metallized with various electroplating voltages at various time points after the start of metallization.

Note that the maximum growth rate is reached after about 2 minutes of coating initiation and then remains approximately constant. These table values were replaced with FIG. 2.

Tables 3 and 2 show that the growth rate is dependent on the bath temperature during the treatment according to step c) of claim 1 or step 5 of Examples 1 and 8.

During the holding time of 1 to 10 minutes in the bath (Cu-LINK) at temperatures of 27 ° C., 45 ° C. and 60 ° C., different metallization durations were made in the electrolytic copper bath for the samples used, 15 × 6 cm in size. . During low and low or short durations, low conductivity is given to the substrate, so a corresponding long metallizing time is required.

On the other hand, it was recognized that there was almost no difference in coating duration and average growth rate at bath temperatures of 45 ° C. to 60 ° C. at the same duration. On the other hand, when the duration in the Cu-LINK bath is extended, the duration in the metalizing bath may be increased, or the duration at that point may be shortened.

TABLE 1

TABLE 2

TABLE 3

Claims (10)

a) pre-treating the surface of the substrate made of an electrically nonconductive material with a corrosion solution containing chromium (VI) oxide, b) treating the substrate surface with a colloidal acid solution of palladium / tin compound, avoiding precontact with the adsorption-promoting solution, c) the surface of the substrate with a solution containing a soluble metal compound, an alkali metal hydroxide or an alkaline earth metal hydroxide that can be reduced by a tin (II) compound, and at least a complex forming agent for metals that prevents precipitation of the metal hydroxide Processing step, d) electrolytic metallizing of the surface of the substrate made of an electrically nonconductive material immobilized on a fixed source coated with plastic for subsequent processing, comprising electrolytic metallizing the surface of the substrate. The method of claim 1, wherein the surface is washed at some or every step of the method. The method according to claim 1 or 2, wherein the soluble metal compound is a copper compound. The method according to any one of claims 1 to 3, wherein the alkali hydroxide is lithium hydroxide. The method of claim 1, wherein the complex former is tartaric acid and / or tartrate. The method of claim 1, wherein the surface of the substrate made of acrylonitrile / butadiene / styrol copolymer or a mixture of these and other nonconductive materials or of a substrate made of polycarbonate Characterized in that the method. A plastic part having a three-dimensional structure, wherein the packaging surface is substantially smaller than the metallized surface by the method according to any one of claims 1 to 6. A case for a sanitary part, a molded part for the automotive industry, or an electrical appliance shielded from electromagnetic radiation, metalized by the method according to any one of claims 1 to 6. A method for electrolytic metallizing a non-conductive surface, characterized by each or all new or combinations of the described properties. An electrolytic metallized product characterized by each or all new or combinations of the described properties.