CA2068992C

CA2068992C - Complex compounds of an oligomeric or polymeric nature

Info

Publication number: CA2068992C
Application number: CA002068992A
Authority: CA
Inventors: Lutz Stamp; Elisabeth Zettelmeyer-Decker; Heinrich Meyer; Gonzalo Urrutia Desmaison
Original assignee: Atotech Deutschland GmbH and Co KG
Current assignee: Atotech Deutschland GmbH and Co KG
Priority date: 1989-11-17
Filing date: 1990-11-06
Publication date: 1997-08-19
Anticipated expiration: 2010-11-06
Also published as: EP0500616B1; WO1991007522A1; DE3938710C2; DE59010794D1; DE3938710A1; KR927003872A; ATE161899T1; KR100212370B1; ES2111541T3; JP3093259B2; JPH05501572A; EP0500616A1

Abstract

The invention concerns complexes of a metal of group 8 to 11 of the periodic table with at least one organic ligand,characterized by the fact that the complex is in oligomeric to polymeric multi-nucleus form and the organic ligand contains at least an N, O, or P atom or a multiple bond, or more than one of these elements.

Description

2~9~2 COMPLEX COMPOUNDS OF AN OLIGOMERIC OR POLYMERIC NATURE
The invention concerns new, complex compounds, solutions of which can be utilized to generate metal seeds (after appropriate reduction), particularly on non-metallic surfaces. This seed formation on su~strate surfaces frequently serves as preparation for subsequent chemical metallization (if necessary, with galvanic reinforcement) of nonconductors. This processing step is of great importance, especially in the manufacture of printed circuits for the electronics industrv.
Other areas of application include decorative and functional metallization, as in the automobile and fixtures industries, as well as the manufacture of chip carriers, hybrid circuits, optical data media, and shielding for cases and components in the electronics industry.
Two fundamentally different processes are known for seed formation on nonconductive substrates. One process starts with a solution cont~in;ng colloidal metal particles, and deposits these particles as seeds directly on the substrate surface.
The other process contains the metal in the form of a soluble compound, and the metal is first deposited onto the surface in this form. The deposited metal c. _und is then reduced in a separate reduction step, and the metal seeds are formed directly on the surface.
one disadvantage of the known methods, however, is that with a two-stage process using a compound such as palladium chloride as the precious metal salt and zinc (II) chloride, for instance, as the reducing agent, one can only activate unlaminated (i.e. free of copper metal) substrate material;
otherwise, the precious metal will precipitate on (bec cemented to) the copper laminate.
Simple metal salts and monomeric metal complexes also do not adsorb particularly well on many materials; or they adsorb sufficiently well only in solutions with high ' ~.
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concentrations of the metal compound. Yet adsorbates applied to a surface in this way desorb very easily (e.g. in rinsing operations) and so do not adhere very strongly to surfaces.
Activation solutions which contain both the precious metal salt and the reducing agent (so-called colloidal activators), however, are highly sensitive to foreign ions and other contaminants, which leads to irreversible coagulation of the precious metal. Moreover, such activation solutions in which zinc (II) compounds act as both reducing agent and protective colloid are unstable in comparison to oxidation by means of atmospheric oxygen, and require a continual, measured addition of the reducing agent.
These activation solutions also have the disadvantage of working at strongly acidic pH values. In the case of multiple layers, this frequently results in damage to the black/brown oxide layer in the area of the boreholes, and thus to the so-called red ring phPn~ ~non.
All activator solutions used up to now in industrial applications share the disadvantage of working only in a rather small pH range; therefore, they require expensive controls and monitoring.
The object of the invention is to identify substances for a stable activation solution which does not damage the substrate material to be metallized, and in particular does not damage the material's bonding sites; which is easy to apply; and which exhibits a high degree of adsorption for all non-metallic, substrate materials.
In accordance with the invention, this objective is attained through use of complex compounds as characterized in the descriptive part of patent claim 1.
Advantageous embodiments are described in the subclaims.
Monomeric complexes of palladium and other metals which .

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contain ligands other than those specified in the invention, such as solvent molecules or ions derived therefrom by processes such as protonation or deprotonation, surprisingly can be converted to stable solutions of oligomeric metal complexes through establishment of bonds between these molecules or ions derived therefrom. The individual metal seeds are connected by individual molecules or ions coordinated with them as bridging ligands. Therefore, these complexes are fundamentally different, in terms of their chemical structure and properties, from complexes in which metal atoms are bonded to oligomeric/polymeric organic molecules, as is described, for instance, in EP 82438.
The oligomeric metal complexes of the invention exhibit an extraordinary capacity to adsorb on nearly n~-metallic materials, including materials that are important in the manufacture of printed circuit boards, such as epoxy resin, polyimide and glass, as well as other synthetics such as acrylonitrile-butadiene-styrol copolymerisates (ABS), polyamide, polycarbonate, polyphenyleneoxide, polyethersulfone, polyetherimide, and on ceramics such as aluminum oxide and aluminum nitride, and on mixtures of these materials. Even diluted solutions yield ltn~cnAlly strong and adhesive coatings on the surfaces of non-metals.
On metallic surfaces such as copper, however, there is hardly any adsorption; in particular, cementation does not occur with metal deposition. For this reason, the complexes of the invention are outstA~ing when used in processes for the metallization of non-metal/metal composite materials.
Thus the activator used according to the invention has none of the disadvantages that are necessarily associated with the traditional systems. By virtue of its oligomeric structure, it exhibits great affinity to diverse, substrate materials; and the precious metal seeds that are formed are very active, so that extremely thick metal coats can be achieved with this type of activation. This is extremely ..

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~a S~n2 important in the most diverse applications. In the metallization of any given plastic parts which have heterogenous surfaces - because of different processing conditions, for instance - or which have different surface morphologies from part to part, an extremely thick and active activation coating is important, and can be achieved with the complexes of the invention. In electronic applications, the reliability of electrical circuits which have a dense and adhesive metal deposit on through-plated boreholes, is determined by the peculiar chemical composition of the synthetic substrate, which varies from case to case; here too, a high degree of activity and a high coating density of the metal particles of the activator system are required, such as are generated by the metal complexes of the invention in the manner described. This is especially true for the diverse materials in these composite substrates, such as those which are used for the highly complicated, multi-layer circuits for the electronics 20 industry. ~ -Such activators do not attack either substrate materials or, in particular, their bonds, since they are manufactured without halogen and can be operated in a wide pH range from alkaline to weakly acidic.
25The solutions of such activators are very stable.
Shelf lives of several years are possible before a new mixture becomes necessary. The lack of susceptibility to oxidation by atmospheric oxygen deserves special emphasis;
this characteristic has become much more important of late, and will become increasingly important since in modern production lines the treatment solutions are applied with surge or spray nozzles.
In this way, the activation solution comes into very close contact with atmospheric oxygen. Solutions, such as activation solutions containing zinc (II) compounds, which are oxidized under these conditions and thus are unstable, , . . - ~ .

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cannot be used in such modern plants. The activator of the invention, however, which is fully inert to oxidation by atmospheric oxygen, is very well suited to use with surge or spray techniques.
This property constitutes a clear advantage over other known processes including the traditional immersion technique. No chemicals need be added because they are not consumed throu~h atmospheric oxidation.
Solutions of such oligomeric metal complexes are therefore especially well suited to activation of substrate materials for making conductor pathways and for activation of boreholes for the purpose of establishing through-connections in the manufacture of printed circuits.
The application of solutions of oligomeric~polymeric metal complexes is usually preceded by pretreatment of the materials/objects to be seeded. This serves to clean the surfaces and/or to help prepare the surface for adsorption through ?ch~nical or chemical means. The materials/objects to be seeded are then treated with a solution of the oligomeric/polymeric metal complexes of the invention in the actual activation stage. This can be accomplished by immersion, but also by spraying, surge or other te~hniques.
The reaction time of the solution on the surface ranges from 10 seconds to 30 minutes. This process results in strong adsorption of the metal complex on the surface. Surplus solution is then removed in a rinsing step (for example, in a standing rinse, circulation rinse or spray rinse). ;
The adsorbed metal complex remains firmly fixed to the surface of the substrate which is to undergo activation.
30 Next, the substrate is treated with a solution of a reducing ;
agent (approximately 10 seCOn~c to 30 minutes). This can be accomplished by immersion, rinsing, surge or other techniques. In this process, the adsorbed complex is destroyed by reduction, and highly active metal seeds are formed which remain firmly fixed to the substrate surface.

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2 Ij ~ ' 9 v 2 Surplus reducing agent can then be rinsed off.
Reducing agents well suited to this task are, for example, borohydrides such as NaBH4, or borane-amine complexes, especially dimethylaminoborane, phosphinic acid or their salts, formaldehyde, hydrazine or others, and mixtures of these reducing agents. In selecting the appropriate complex ligands, the reducing agent of the currentless electrolyte used in the subsequent step can also be utilized for the reduction. The complex disintegrates in the process to soluble components and highly active metal particles.
The degree of oligomerization of the relevant metal complex exerts considerable influence on the activity of the metal particles that are generated because this factor partially determines the size and morphology of the metal particles formed in the reduction. The degree of oligomerization of the complex compounds lies between 3 and 10,000 monomeric units; complex ~^ _unds with 5 to 500 monomeric units are especially suitable.
The oligomeric character of the formed molecules can be demonstrated with techniques such as light scattering measurements. This method can also be used to ascertain the average degree of oligomerization. The size of the oligomeric molecules can be regulated through adjustment of the reaction conditions under which they form bonds (time, temperature, concentration, pH), and by the nature of the precious metal ions and their ligands that are used. The desired molecular weight can be attained through an appropriate combination of parameters.
The activation baths that are produced with these oligomeric complexes can then be utilized under extremely diverse conditions to satisfy the relevant requirements.
Their mode of action is effective over a broad range of working conditions (especially pH value). The oL~ nature of the baths used with the activators of the invention means .
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reduced expenditures for control, and so lower costs, with no loss of quality in production. The activation of non-metallic substrates achieved with the activators that are generated from the complex compounds of the invention can be utilized for currentless metallization with diverse metal coatings, which in turn can be metallized using either galvanic techniques or without foreign current. Metals which can be deposited on substrates using the activation technique of the invention include copper, nickel, gold, palladium, silver, cobalt, zinc or alloys of these metals, or alloys with elements such as phosphorous or boron, as with the Ni/P and Ni/B systems.
Furthermore, it was demonstrated that other substances added for technical reasons in the preparation of solutions of oligomeric/polymeric complex compounds can have a positive or negative influence on the capacity of these solutions to activate non-metallic substrates. Noteworthy in this regard are substances for buffering the system at certain pH values, such as borates, carbonates, phosphates and acetates. The type of acid used in the preparation of solutions te.g. hydrochloric acid, sulfuric acid, acetic acid) can also be important. Thus in Example l tsee below), the boric acid added during preparation improved the efficacy of the activator solution thereby obtained in comparison to a solution without this additive, or compared with a solution in which phosphate, for instance, was used as a buffer. Positive and negative effects, however, are difficult to predict, and must be determined in each case.
It is especially advantageous to produce the oligomeric metal complexes of the invention in the solvent (or in one of the solvent components) that is later used in the application of the solution for the activation. In this case, it is not necessary to isolate (intermediate) products, which makes the preparation of activator solutions extremely simple. Below we describe one example of a - :- : .
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' ' , .~ ' .-~6~9~2 preparation procedure by which the oligomeric metalcomplexes of the invention can, in principle, be produced (other preparation methods are also possible). The calculated quantity of the ligand is added to a salt or an appropriate starting complex compound of the relevant metal in suitable solvents such as water, or organic solvents such as aliphatic alcohols, alcohol ethers such as ethylene glycol monoethers, or ethers such as ethylene glycol diethers, or mixtures thereof.
In many cases, the desired complex formation occurs spontaneously; in other cases, the solution is brought to the temperature required to start a reaction. After the reaction is completed, the monomeric complex can be isolated by techniques such as evaporation of the solvent. In order to prepare a solution of the corresponding oligomeric complex, one dissolves the monomeric complex in the desired solvent, sets the requisite reaction parameters, especially the pH value, to the values required for the relevant product, and heats the solution until equilibrium is attained (normally several hours) at approximately 50 to 70$ C. As a rule, it is not possible to separate the oligomeric/polymeric complex thereby generated from the solution. The conditions needed to isolate the complexes in solid form normally lead to changes in the size and chemical structure of the molecules. Therefore, characterization of the complexes depends exclusively on spectroscopic or other in situ methods in th~ solution. The structure of the oligomeric compounds thereby generated is most probably characterized by the ligands and/or solvent molecules or solvent ions which bridge between the metal atoms, resulting in a long string. In any case, knowledge of the exact structure is not critical for the mode of action of the complexes as activators, and thus is not an object of the patent. The possible metals are Cu, Ag, Au, Ni, Pd, Pt, Ru, Rh, Os and Ir. The metals themselves, their salts, or other .
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complex compounds of the relevant elements can be utilized as the starting complex compound for preparation of the complex compounds of the invention. Compounds which typically form monomeric complexes with metal ions are used as ligands in the preparation of the complex compounds of the invention. Compounds with one or several N, O, S or P
atoms, or one or several multiple bonds, or several of these elements at the same time, are preferred. Particularly suitable in this regard are compounds of the nitrogen-heterocycle group, such as pyridines, pyridazines, pyrimidines, pyrazines, quinolines, cinnolines or phthalazines.
For use as activators, the complexes of the invention are dissolved in the solvent at concentrations of 1 to 10,000 mg/l, preferably at concentrations between 20 and 500 mg/l. Determining factors for the optimal concentration are dependent on the specific application; the choice of procedural parameters, such as temperature, treatment time, etc., ty~e of substrate, type of complex and adequate absorption of the complex on the substrate that will undergo activation.
In principle, any solvent or solvent mixture which can solubilize the oligomeric/polymeric metal complexes of the invention sufficiently well for generation of the effect can be utilized for application of said complexes. It is much more preferable to use the same solvent as that used for the preparation; that is, a solvent of the group of alcohols, glycols, alcohol ethers or ethers, but especially water.
The pH value of the solutions utilized for activation can lie between 1 and 14, preferably between 5 and 12. It can be adjusted to the desired value through addition of acids, such as sulfuric acid, hydrochloric acid, nitric acid, phosphoricacid or acetic acid; or, dep~n~ing on the desired pH value, through addition of lyes such as soda lye, potash lye or ammonia.

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3~2 The following examples describe the preparation of some solutions containing oligomeric/polymeric metal complexes of the invention for activation of non-metallic surfaces. In addition, we report the characteristic bands of the W and visible spectra of these solutions (wavelength of the absorption maximum in nm, s = shoulder).

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sulfuric acid (0.95 g PdSO4 = 4.7 mM) and 0.54 g (5 mM) 2-amino-6-methylpyridine are added to 400 ml water and agitated until a homogeneous orange-colored solution has formed. Then, 8.4 g (0.15 mole) potassium hydroxide are slowly added while stirring, and the solution turns a brownish-red. It is stirred until the potassium hydroxide is completely dissolved. The potassium hydroxide must be added slowly enough to permit control of the evolution of heat. Next, 5 g (0.98 mole) boric acid are added, and stirred until complete dissolution. The pH value of this solution is then adjusted to 10 by addition of soda lye or sulfuric acid, and the volume adjusted to 0.5 1. The solution thereby obtained is heated for approximately 6 hours to 50 to 60$ C. The hue of the solution will become darker and change to a reddish-brown, yet remain clear.
This change and deep~ning of color is the visual sign that the oligomerization/polymerization process is taking place.
After dilution with water to 2.5 - 5 liters (corr~sponAing to a palladium concentration of 100 - 200 mg/l), the solution is ready for activation of substrates in the manufacture of printed circuit boards for the electronics industry. Soda lye or sulfuric acid is used to readjust the pH value should the dilution result in a pH value which deviates from the desired one. W : (250 s, 305 s, 420 s).
Example 2 10 ml of a solution of palladium sulfate in sulfuric acid (0.95 g PdSO4 = 4.7 mM) and 0.54 g (5 mM) 2-amino-3-methylpyridine are added to 2 liters water and stirred until the solution bec_ es clear and homogeneous.
The solution is adjusted to pH 11 with soda lye and heated for 6 hours to 60$ C. After a possible dilution to achieve the desired palladium concentration, the pH is adjusted to the desired value with soda lye or sulfuric acid. W: (250 - - : .................... : ....... ~ ... -.
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2~i~JI~3~2 5, 305 s, 410 s).
Example 3 10 ml of a solution of palladium sulfate in sulfuric acid (0.95 g PdSO4 = 4.7 mM) are added to 400 ml water in which 0.54 g (5 mM) 3-ethylpyridine has been dissolved. One gram boric acid is added while stirring, and the solution is stirred until complete dissolution. The pH value of the solution is adjusted to 11 with soda lye, and then the volume is adjusted to 500 ml with water. The oligomeric complex has formed after 24 hours at 60$ C, and the solution can be diluted to a palladium concentration of approximately 150 mg/l. UV: (265, 295 s).
Example 4 0.5 g (4.7 mM) of palladium dust is mixed with 3 ml concentrated nitric acid; the solution is heated to approximately 90S C until the palladium has dissolved completely. This solution is added to a solution of 0.65 g (5 mM) phthalazine in 4 liters water and mixed. Next, 10 g (0.17 mole) acetic acid is added and mixed. The pH value is then adjusted to 5 with soda lye. The solution is ready for use after 12 hours of heating to 50$ C. W: (235, 255, 315, 325).
Example 5 1.3 g (4.9 mM) PdBr2 are dissolved in 10 ml 10%
hydrochloric acid while heating and stirring. 0.43 g (5 mM) piperazine is added and stirred until dissolution. After dilution to 2.5 liters, 4.2 g (0.07 mole) acetic acid is added and dissolved by stirring. The pH is adjusted to 12 with soda lye. The solution is ready for use after 6 hours of heating to 60s C. W: (300 s).
Example 6 0.42 g (2.4 mM) PdC12 is dissolved in a mixture of 1 ml conc~ntrated hydrochloric acid and 4 ml water while heating, and then diluted to 2 liters; 0.27 g (2.5 mM) 3-hydroxymethylpyridine is then added and mixed. Next, 10 . , ..... . . . . . .
. ~ .. ' ' '9S'2 g (0.16 mole) boric acid are added and stirred until complete dissolution. The pH value is adjusted to 9.5 with potash lye, and the oligomerization is carried out by heating to 45~ C for 36 hours. W: (260, 320 s).
Example 1 -10 ml of a solution of palladium sulfate in sulfuric -acid (0.95 g PdSO4 = 4.7 mM) and 0.67 g (4 mM) cinnoline hydrochloride are added to 3 liters water and stirred until complete dissolution. After 5 g (0.08 mole) boric acid have been dissolved, the pH value is adjusted to 10.5 with soda lye; the solution is then heated for 6 hours to 60$ C. If necessary, the solution is then diluted to the desired bath concentration. W: (225, 315 s, 440 s). ~ ;
Example 8 A solution of 1.05 g t4.7 mM) palladium acetate in 10 ml 10% hydrochloric acid is diluted to 2 liters with water, mixed with 0.75 g (5 mM) N-acetyl-6-methyl-2-aminopyridine and agitated. Five grams (0.042 mole) sodium dihydrogen phosphAte are added and stirred until dissolved. Soda lye is added to attain a pH value of 7. The solution is ready for use after 5 hours at 60$ C. W: (275, 390 s).
Example 9 10 ml of a solution of palladium sulfate in 35%
sulfuric acid (0.95 g PdS04 = 4.7 mM) and 0.78 g (5 mM) 2,2-dipyridyl are added to 200 ml water and stirred until a homogeneous solution has formed. This solution is poured -slowly into asolution of 20 g sodium hydroxide in 5 liters water while stirring vigorously. The pH value is then adjusted to 12, if necessary. The solution is ready to use after 5 hours at 70$ C. W: (250, 303 s, 310).
Example 10 A solution as per Example 9 is prepared, but with 0.63 g (5 mM) 2-amino-4-hydroxy-6-methylpyrimidine substituted for the dipyridyl.
W : (260 s, 305 s, 410 s).

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Example 11 10 ml of a solution of palladium sulfate in 35%
sulfuric acid (0.95 g PdS04 = 4.7 mM) and 0.40 g (5 mM) pyridazine are added to 4 liters water and stirred. 5 g (0.08 mole) boric acid are added and stirred until completely dissolved. The pH value of the solution thus obtained is then adjusted to 11 with soda lye. It is heated for 6 hours to 605 C. Subsequently, the solution is diluted to the desired palladium concentration. W: (240 s, 275, 350 s).
Example 12 A solution as per Example 11 is prepared, but with 0.56 g (5 mM) 5-amino-3,4-dimethylisoxazole (W: 240 s, 280 s, 440 s) or 0.45 g (5 mM) DL-alanine (UV: 300 s) used in place of the pyridazine.
Example 13 10 ml of a solution of palladium sulfate in dilute sulfuric acid (0.95 g PdSO4 = 4.7 mM) and 0.61 g (5 mM) 2-amino-4,6-dimethylpyridine are added to 2.5 liters water.
After a homogeneous, yellow solution has formed, soda lye is used to adjust the pH value to 11. Next, the solution is heated to 60$ for 12 hours. After cooling, the solution is diluted to 5 liters with isopropanol. W: (260 s, 420 s).
The following example is for purposes of comparison.
It describes the preparation of a solution of a monomeric complex.
Example 14 A solution of 1.08 g (lO mM) 2-amino-4-methylpyridine in 10 ml water is mixed with a solution of 0.84 g (4.7 mM) PdCl2 in 10 ml 10% hydrochloric acid. Monomeric dichloro-bis(2-amino-4-methylpyridine) palladium (II) is generated in a form that can be filtered out.
A solution of 0.65 g (1.7 mM) [(CH3C5H3NNH2)2 CL2 Pd]
in 1 liter of water shows the typically poor adsorption characteristics of monomeric complexes, and yields 95~ .~ ..

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unsatisfactory metallization when used under conditionscomparable to those of oligomeric/polymeric complexes.
The following example describes a possible sequence of operations for metallization of nonconductive materials that utilizes solutions of the oligomeric/polymeric metal complexes of the invention.
Example 15 Desmear/de-etching process optional -Cleaner I
10 Rinse Cleaner II optional Rinse Caustic cleaner 15 Rinse Pre-immersion solution Activator solution Rinse Reducing agent 20 Rinse after post-immersion solution Chemical copper Rinse Galvanic copper optional With this procedure, the solutions of examples 1 to 13 yield good to excellent coating of the non-metallic substrate with metal (transillumination test). In contrast, the solution of a monomeric complex as per Example 14 yields a very poor coating.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Complex compounds of a metal of the 8th to 11th group of the periodic table of elements with at least one organic ligand, characterized by a complex in an oligomeric to polymeric, polynuclear form, and an organic ligand which contains at least one N, O, S or P atom, or a multiple bond, or several of these elements.

2. Complex compounds as per Claim 1, characterized by a degree of oligomerization or polymerization lying between 3 and 10,000, preferably between 5 and 500.

3. Complex compounds as per Claims 1 and 2, wherein the organic ligand contains a trivalent nitrogen atom.

4. Complex compounds as per Claim 3, wherein the organic ligand is a nitrogen-heterocycle, preferably of the class of pyridines, pyridazines, pyrimidines, pyrazines, quinolines, cinnolines or phthalazines.

5. Complex compounds as per Claims 1 to 4, characterized by the participation of solvent molecules or ions derived therefrom (e.g. H20, OH-, 0-2) in the structure of the complex.

6. Complex compounds as per Claim 5, wherein solvent molecules or ions derived therefrom are the bridging ligands.

7. Complex compounds as per Claims 1 to 6, wherein the organic ligand has both the functional group(s) required for bonding to the metal, and an additional, polar functional group for adherence to the substrate.

8. Complex compounds as per Claims 1 to 7, wherein the metal is Cu, Ru, Rh, Pd, Ag, Pt or Au.

9. Complex compounds as per Claims 1 to 7, wherein the metal is Ru, Rh, Pd or Ag.

10. Complex compounds as per Claims 1 to 7, wherein the metal is Pd.

11. Complex compounds as per Claims 1 to 7, wherein the oligomeric complex contains at least two different metals.

12. Complex compounds as per Claims 1 to 11, wherein the ratio of metal to ligand is 5 : 1 to 1 : 8, preferably 2 : 1 to 1 : 2.

13. Activator solution for activation of non-metallic substrates for subsequent currentless metallization, wherein the activator solution contains a complex compound as per Claims 1 to 12 dissolved in water or a solvent.

14. Process for generation of metal seeds, whereby solutions of complexes as per Claims 1 to 12 in water, organic solvents, or mixtures thereof are utilized, and the substrate to be seeded is first treated with these solutions, followed by treatment with a solution of a reducing agent.

15. Process for generation of metal seeds as per Claim 14, whereby solutions are used which contain the metal at concentrations of 1 to 10,000 mg/l, preferably 20 to 500 mg/l.

16. Application of the process as per Claims 14 and 15 for activation of non-metallic substrates for the purpose of subsequent chemical (without foreign current) metallization, if necessary with subsequent galvanic reinforcement.

17. Application of the process as per Claims 14 to 16 for the manufacture of printed circuits.