DE19830037C2 - Process for pretreating copper surfaces - Google Patents

Description

The invention relates to a method for pretreating copper surfaces for subsequent formation of an adherent bond between the reserved finished copper surfaces and plastic substrates. The solution is preferred wise for pretreating copper layers having printed circuit boards for the purpose of the subsequent formation of an adhesive bond between the PCB inner layers and printed circuit board resin inner layers and for pretreating printed circuit boards having copper layers adherent bonding of the copper layers with plastics Resists.

In the production of printed circuit boards, various sub-processes go through performed in which copper surfaces adherent to an organic substrate ge need to be tied. In some cases, the required adhesion of the Ensured compounds formed over a very long period of time his. In other cases, a strong bond must be only temporarily, For example, if the organic substrate only during the manufacturing process ses the circuit board remains on the copper surfaces. For example, must the adherent bond of dry film resists used to structure the Conductor tracks on printed circuit boards are used, with the copper surfaces only during the Be guaranteed PCB manufacturing process. After the formation of the ladder The resists can be removed again.

The easiest way to increase the adhesive strength is to use the Etch copper surfaces before forming the compound while doing so roughen. For this purpose, microetching solutions, for example sulfuric acid Lö solutions of hydrogen peroxide or sodium peroxodisulfate.  

Another method is described in US-A-3,645,772. After that, a Pretreatment solution used for the copper surfaces, for example Contains 5-aminotetrazole.

A long-term stability is especially in the laminating process for Mehrlagenlei terplatten required. For these purposes are other pretreatment methods required for the copper surfaces.

In the manufacture of multilayer printed circuit boards, several printed circuit boards are used layers together with insulating synthetic resin layers (so-called prepregs: fiberglass reinforced epoxy resin films). The inner co The content of a laminate must be constant throughout the life of the conductor stay upright. For this the auflie on the inner layers must ing copper layers, preferably the Leiterzugstrukturen, superficially be treated. To solve this problem, various procedures have been adopted developed.

The one commonly used for pretreatment before lamination Method is to form an oxide layer on the copper surfaces. In this process known as black or brown oxide process set very aggressive reaction conditions for oxide formation. A disadvantage of the method is that ver the adhesion to the resin layer average oxide layer only a low resistance to acid, insbesonde hydrochloric acid, has treatment solutions, so that they can be used in subsequent processes sen for metallizing the through holes attacked in printed circuit boards and the bond to form delaminations of the attacked Positions are lifted again (pink ring phenomenon: visible from the outside Attack of the black oxide layer in the immediate vicinity of a hole in Circuit boards by discoloration of the originally black oxide layer, in the the pink copper layer of the inner layer can be recognized as an annular defect becomes; wedge void phenomenon: in a through a treated hole in ladder plates made cross section recognizable defect in the form of a gap between a copper inner layer and the adjacent circuit board resin  by the attack of acidic treatment solutions on the black oxide layer).

One solution to the problem described above is to use the oxide layer before the lamination process superficially reduce. The reduced Black oxide has opposite to that at the via of the passage holes used a higher stability than normal Black oxide. However, by the additional reduction step are erhebli costs. In addition, they are used for the reduction treatment baren chemicals against oxidation by air little resistant, so that the Service life of the baths and the durability of the additives chemicals limited are. This problem is to be solved according to JP-A-08097559 in that then the reduced copper oxide layers ver with a protective layer by treating them with an aqueous solution, in an aminothiazole and / or aminobenzothiazole compound is contained. However, on the one hand the cost problem of expensive reduction chemicals and their lack of oxidation resistance and on the other Also, the acid instability of the layer can not be completely eliminated.

Another possibility for adhesion mediation is the Kupferoberflä with an aqueous or alcoholic solution of an azole compound to treat. Such a method is for example from WO 96/19097 A1 known. Thereafter, the copper surfaces are treated with a solution, in the 0.1 to 20 wt .-% hydrogen peroxide, an inorganic acid, for example sulfuric acid, an organic corrosion inhibitor, for example Ben zotriazole, and a wetting agent are included. Due to the corrosive action of water peroxide, the copper surfaces are etched, so that mikrorauhe Ober surfaces arise.

Also, from US-A-4,917,758 etching solutions are known, but for Abdün serve copper cladding on the PCB materials. In the Solutions are also hydrogen peroxide, sulfuric acid and a Nitrogen-containing compound, preferably aminobenzoic acid, aminote trazol or phenylurea.  

Further etching solutions are given in US-A-4,158,593 and US-A-4,140,646. These solutions for etching copper on printed circuit boards contain sulfur acid and hydrogen peroxide and inorganic compounds of selenium in the oxidation state + IV, preferably selenium dioxide, selenious acid or their Salts.

In US-A-3,770,530 etching solutions for copper, especially for use in Circuit board production, described the peroxodisulfate and additives to Increase the etching rate included. As additives are 1,2,3-triazoles, 1,2,4-tri azoles and tetrazoles proposed.

In Patent Abstract of Japan, C-1209, 1994, Vol. 296, JP 6-57 453 A are Etching solutions for copper described with which an etching process for the production PCBs without significant lateral attack of the copper surfaces possible is. The etching solutions contain cupric chloride, hydrochloric acid and 2-amino benzothiazole or its derivatives.

The present invention is therefore based on the problem, the Nachtei To avoid le of the prior art and in particular a pre-treatment to find a method of joining with copper surfaces Plastic surfaces produced with excellent adhesion of the composite can be. The procedure should be simple, safe to handle and cheap his. In addition, no precipitations should be present in the treatment solutions form. It is also important that by treatment with the solution also a Material connection is available, which in subsequent processes in the manufacture of printed circuit boards, for example in the metallization of Durchgangsbohrun in printed circuit board material, does not cause problems (pink ring, wedge void Education). Preferably, therefore, the pretreatment solutions used should be used for the application in printed circuit board manufacturing process.

This problem is solved by the method according to claim 1.

The inventive method is used for pretreatment of copper surfaces for subsequent formation of an adhesive bond with plastic substrates. For this purpose, the copper surfaces having substrates, for example, copper foils or coated with copper foils resin laminates, brought into contact with a first solution containing the following components:

• a) hydrogen peroxide,
• b) at least one acid and
• c) at least one nitrogen-containing, five-membered heterocycli a compound which does not contain sulfur, selenium or tellurium in the Has heterocycle.

Thereafter, the substrates having the copper surfaces are contacted with a second solution containing at least one adhesion promoting compound from the group consisting of sulfinic acids, selenic acids, tellurin acids, heterocyclic compounds containing at least one sulfur, selenium and / or tellurium atom in the heterocycle, as well as sulfonium, Selenonium- and telluronium salts, wherein the sulfonium, Selenonium- and Telluro niumsalze are compounds having the general formula A.

where A = S, Se or Te,
R ₁ , R ₂ and R ₃ = alkyl, substituted alkyl, alkenyl, phenyl, substituted phenyl, benzyl, cycloalkyl, substituted cycloalkyl wherein R ₁ , R ₂ and R _{3 are the} same or different, and
X ^- = anion of an inorganic or organic acid or hydroxide.

It should be selected adhesion-promoting compounds that are in the acidic, preferably sulfuric acid, solution has sufficient solubility sen.

The problem underlying the invention is particularly by the applications of the method according to claims 18 and 19 solved. Thereafter, the inventive method is preferably for Vor treat PCB layers having copper layers for Forming an adhesive bond between the PCB inner layers and Synthetic resin layers and for pretreatment of copper layers having Printed circuit boards for forming an adhesive bond between the copper layers and plastic resists.

Preferred embodiments of the invention are in the subclaims specified.

Preferred sulfinic acids in the second solution are adhesion-promoting compounds having the chemical formula B

with R ₄ , R ₅ and R ₆ = hydrogen, alkyl, phenyl, substituted phenyl or R ₇ - (CO) - with R ₇ = hydrogen, alkyl, phenyl, substituted phenyl, wherein R ₄ , R ₅ and R _{6 are the} same or are different,
and aromatic sulfinic acids.

Preferably, formamidinesulfinic acid is an adhesion-promoting compound in the second solution included. As aromatic sulfinic acids may be preferred Benzenesulfinic acid, toluenesulfinic acid, chlorobenzenesulfinic acids, nitrobenzenesul fic acids and Carboxybenzolsulfinsäuren be used.

As adhesion-promoting heterocyclic compounds are preferably thio phenes, thiazoles, isothiazoles, thiadiazoles and thiatriazoles used.

Suitable thiophenes are compounds having the chemical formula C.

with R ₈ , R ₉ , R ₁₀ , R ₁₁ = hydrogen, alkyl, substituted alkyl, phenyl, substituted phenyl, halogen, amino, alkylamino, dialkylamino, hydroxy, alkoxy, carboxy, carboxyalkyl, alkoxycarbonyl, aminocarbonyl, R ₁₂ - CONH- with R ₁₂ = hydrogen, alkyl, phenyl or substituted phenyl, wherein R ₈ , R ₉ , R ₁₀ and R _{11 may be the} same or different and may be part of condensed on the thiophene ring homo or heterocyclic rings.

Particularly preferred thiophenes are aminothiophenecarboxylic acids, their Esters and amides. For example, 3-aminothiophene-2-carboxylic acid methyl be used advantageously ester.

Suitable thiazoles are compounds having the chemical formula D:

with R ₁₃ , R ₁₄ , R ₁₅ = hydrogen, alkyl, substituted alkyl, phenyl, substituted phenyl, halogen, amino, alkylamino, Dial kylamino, hydroxy, alkoxy, carboxy, carboxyalkyl, alkoxycarbonyl, aminocarbonyl, R ₁₆ -CONH- with R ₁₆ = hydrogen, alkyl, phenyl or substituted phenyl, wherein R ₁₃ , R ₁₄ and R _{15 may be the} same or different and R ₁₄ and R _{15 may be} part of a ring fused to the thiazole homo- or heterocyclic ring.

Particularly suitable thiazoles are aminothiazole and substituted aminothia Zole. Furthermore, preferred thiadiazoles are adhesion-promoting compounds the group consisting of aminothiadiazole and substituted aminothiadiazole len.

Further, as sulfonium salts, preferably trimethylsulfonium, Triphenylsulfonium, Methioninalkylsulfonium- and Methioninbenzylsulfonium salts as adhesion-promoting compounds contained in the second solution are used.

In addition to the aforementioned compounds, in the second solution, white contain tere ingredients. Preferably, the second solution contains as well like the first solution also an acid, preferably an inorganic acid and particularly preferably sulfuric acid. In addition, in the second  Solution copper ions may be included, for example, by dissolution arise from copper on the treated copper surfaces.

In the first solution are in addition to hydrogen peroxide and an acid in addition Containing nitrogen-containing five-membered heterocyclic compounds, which contain no sulfur, selenium or tellurium atom in the heterocycle. It can monocyclic and polycyclic fused ring systems as hetero cyclic compounds are used. For example, the verbin containing fused benzene, naphthalene or pyrimidine rings. For the Selection of these compounds should be noted that these are in the acidic solution should have sufficient solubility. Preferably, triazoles, Tetrazoles, imidazoles, pyrazoles and purines or their derivatives in the solution contain.

In particular, the first solution contains triazoles having the chemical formula E1 as heterocyclic compounds

with R ₁₇ , R ₁₈ = hydrogen, alkyl, amino, phenyl, substituted phenyl, carboxyalkyl, wherein R ₁₇ and R _{18 may be the} same or different and part of a condensed to the triazole ring homo- or heterocyclic ring.

Particularly preferred heterocyclic compounds in the first solution are Benzotriazole, methylbenzotriazole, ethylbenzotriazole and dimethylbenzotriazole.

In addition, the first solution may contain tetrazoles having the chemical formula E2 as adhesion-promoting compounds

where R _{19 is} hydrogen, alkyl, haloalkyl, amino, phenyl, substituted phenyl, benzyl, carboxy, carboxyalkyl, alkoxycarbonyl, aminocarbonyl or R ₂₀ -CONH where R _{20 is} hydrogen, alkyl, phenyl or substituted phenyl.

As a preferred tetrazole compound, 5-aminotetrazole and 5-phenyltetra used. Benzimidazole will be used as the preferred imidazole compound det. 5-aminotetrazole, 5-phenyltetrazole, benzotriazole, methylbenzotriazole and Ethylbenzotriazole are in the first because of their good solubility Pretreatment solution and preferred availability due to its ready availability bonds.

Preferred combinations are benzotriazole, methylbenzotriazole, ethylbenzene zotriazole, 5-aminotetrazole and 5-phenyltetrazole as nitrogen-containing, five hetero-cyclic compounds in the first solution with aminothio phencarboxylic acids, their esters and amides, aminothiazole and substituted Aminothiazoles as heterocyclic compounds in the second solution.

In addition, the first solution generally contains copper ions extending through Formations of the copper surfaces form and accumulate in the solution.

The inventive method provides an extremely simple Vorbe Treatment of copper surfaces for the subsequent adherent connection with Plastics safe. Essentially, there are only two process steps necessary, namely the treatment of the copper surfaces with the two inventions solutions according to the invention for the subsequent formation of a composite with organic substrates. The adhesive strength does not decrease even after a long time.  

In the first solution, the nitrogen-containing heterocyclic compounds or in the second solution the adhesion-promoting Ver bonds can not contain nearly as high adhesion of the Be achieved. In addition, the long-term stability of the composite after pretreatment with solutions which provide adhesion according to the invention not contain the compounds, much worse than after use solutions containing the adhesion-promoting compounds.

In addition, those related to the metallization of Through holes in PCB problems, namely the Bil Formation of pink ring and wedge voids, through the use of these additional Compounds avoided in the pretreatment solutions, as with the he An adhesion-promoting layers produced according to the invention drawn acid resistance, while black oxide (black oxide) and reduced black oxide layers against hydrochloric acid solutions have some sensitivity. It has even been shown that the Adhesive strength of a composite with organic substrates in certain cases len further improve when the copper surfaces after Be act with the inventive method and before producing the Compound be treated with dilute acid. Preferably, this can be done Hydrochloric acid are used. In addition, the process is largely stable dig against precipitation.

The advantageous effect of the method according to the invention was surprising as well as a sole use of adhesion-promoting compounds in one the pretreatment solutions without application of the nitrogen-containing, five-membered heterocyclic compounds in the other solution not the desired high long-term adhesive strength results. By applying both the Nitrogen-containing, five-membered heterocyclic compounds as well the adhesion-promoting compounds discolor the copper surfaces and lead to the desired properties. Furthermore, in Vergleichversu Chen found that especially difficult to oxidize sulfinic, selenin and Tellu rinsäuren are particularly well suited as adhesion-promoting compounds.  

For safe pretreatment, the copper surfaces are usually first cleaned. All conventional cleaning solutions can be used for this purpose become. Usually wetting agents and optionally complexing agents, For example, triethanolamine containing aqueous solutions used.

After rinsing the cleaned copper surfaces, these are in the first Solution treated. Thereafter, the substrates can be rinsed to adhere to remove liquid from the substrate surface. Then follows the Treatment in the second solution. However, the copper surfaces can also immediately after treatment with the first solution without further rinsing step directly into contact with the second solution.

In this treatment, the copper surfaces discolour to form a adhesion-promoting layer from pink to a shade of brown, depending on the nature of used combination of nitrogen-containing, five-membered heterocyclic in the first solution and adhesion-promoting compounds in the second solution.

Due to the micro-etching effect of the hydrogen peroxide in conjunction with the Säu In the first solution, micro-rough copper surfaces are obtained because of the surface enlargement an increase of the adhesive strength of the Subsequently formed composite between the copper surfaces and the Plastic substrate allows. It is also believed that the adhesion speed of the subsequently formed composite in addition to these surfaces enlarged by the formation of a copper-organic compound improved which is probably made of copper, the nitrogen-containing verbin formation and the adhesion-promoting connection on the copper surface.

As the acid in the first solution is preferably inorganic acid, FITS preferably sulfuric acid. Basically, there are others Acids can be used.  

To stabilize hydrogen peroxide against decay, the first Solution additional additional compounds, for example p-phenolsulfonic acid, contain.

Both solvents can be water and additionally organic solvents Solvents, such as alcohols, for example, the solubility of the contained therein, in particular the nitrogen-containing, five limy heterocyclic compounds or the adhesion-promoting verbin increases.

In addition, other inorganic and organic compounds in be included in the solutions, such as wetting agents. Copper sulfate can also be contained in the second solution.

The treatment with both solutions is preferably at a temperature from 20 to 60 ° C performed. The treatment time is preferably 10 to 600 seconds. The higher the temperature is set, the faster it works the solution. Therefore, if necessary, much shorter treatment be chosen. In practical terms, however, will preferably an average temperature selected, for example from 25 to 40 ° C to better control the reaction. Medium treatment times are 20 to 90 seconds. In addition, because of possible incom patibilities of certain components of the solution at elevated temperature, at For example, because at elevated temperature poorly soluble wetting agent, the Requirement to maintain an upper temperature limit.

The concentration ranges preferably set in the solutions are:

First solution

Sulfuric acid, conc. 10 to 250 g / l Hydrogen peroxide, 30% by weight 1 to 100 g / l five-membered nitrogen-containing heterocyclic compound 0.5 to 50 g / l

Second solution

Sulfuric acid, conc. 10 to 250 g / l Adhesion-promoting compounds: sulphinic, seleninic and / or telluric acid 0.05 to 10 g / l adhesion-promoting heterocyclic compound 0.5 to 25 g / l Sulfonium, selenonium and / or telluronium salt 0.01 to 10 g / l

The optimum concentrations of the aforementioned bath components depend on the type of nitrogen-containing, heterocyclic Verbindun conditions and adhesion-promoting connections.

After treatment with the method according to the invention, the Kup Rinse surfaces again, preferably with warm, deionized What ser. They are then dried, for example with hot air.

Optionally, the copper surfaces after rinsing with dilute Acid, preferably with 10 wt .-% hydrochloric acid or 10% by weight of sulfuric acid. Treatment times from 5 seconds to 300 seconds Customers are useful. After the acid treatment, the Kup Rewind surfaces rinsed again, preferably with deionized water.

To increase the durability of the solutions according to the invention, it is advantageous the ready - to - use treatment solutions shortly before the implementation of the Procedure to set. For example, to approach the first solution Hydrogen peroxide containing a sulfuric acid solution of nitrogen the heterocyclic compound are mixed or shortly before the Ge need an already prepared solution be supplemented to the desired Adjust concentrations of the individual components.

The treatment of the workpieces having the copper surfaces can be done in usual diving systems are performed. In the treatment of ladder plates, it has proven to be particularly favorable, so-called passage systems in which the printed circuit boards on a horizontal transport path  guided through the plant and thereby with the treatment solutions via suitable nozzles, such as spray or splash nozzles, in contact to be brought. The PCBs can do this horizontally or vertically or be held in any other orientation.

The following examples serve to further illustrate the invention:

example 1

There were a first and a second aqueous solution by Zusammenmi made of the following constituents:

First solution

Sulfuric acid, 96% by weight 50 ml Hydrogen peroxide, 30% by weight in water 40 ml benzotriazole 10 g Copper (II) sulfate pentahydrate 62 g Make up to 1 liter with deionized water

Second solution

Sulfuric acid, 96% by weight 50 ml 2-aminothiazol 8.0 g Copper (II) sulfate pentahydrate 62 g Make up to 1 liter with deionized water

Both solutions were heated to 40 ° C. A copper foil (PCB quality thickness, about 25 microns) was first in the first solution for 60 seconds and then immersed in the second solution for 60 seconds without intermediate rinsing. Thereafter, the film was rinsed with warm deionized water (50 ° C) and dried with warm air.

The copper foil had a light brown color after treatment.  

The copper foil was then laminated to a prepreg (glass fiber reinforced epoxy resin film (FR4 resin), Type 2125 MT, Thickness 0.1, from Dielektra, DE) by heating the copper and prepreg sheets at a temperature of 175 ° C a pressure of 2.5. 10 ⁶ Pa (25 bar) were pressed together.

The peel strength of the copper foil on the prepreg sheet was measured. It Peel strengths of 10.7 to 11.0 N / cm were determined.

Example 2

Again a first and a second aqueous solution were prepared by co prepared from the following constituents:

First solution

Sulfuric acid, 96% by weight 50 ml Hydrogen peroxide, 30% by weight in water 40 ml benzotriazole 10 g Copper (II) sulfate pentahydrate 62 g Make up to 1 liter with deionized water

Second solution

Sulfuric acid, 96% by weight 50 ml 2-aminothiazol 8.0 g benzotriazole 10 g Copper (II) sulfate pentahydrate 12 g Make up to 1 liter with deionized water

Both solutions were heated to 40 ° C. A copper foil (PCB quality thickness, about 25 μm) was first introduced into the first solution for 60 seconds dipped, then rinsed with deionized water and then in 60 seconds immersed the second solution. Thereafter, the film was deionized with warm rinsed in water (50 ° C) and dried with warm air.

The copper foil had a light brown color after treatment.  

Thereafter, the film was pressed with a prepreg (conditions as in Example 1) and the peel strength of the composite measured. There were detention strength values of 9.8 to 10.1 N / cm.

Claims (19)

A method of pretreating copper surfaces for subsequent formation of an adherent bond between the copper surfaces and plastic substrates by contacting the copper surfaces with a first solution containing

• a) hydrogen peroxide,
• b) at least one acid and
• c) at least one nitrogen-containing, five-membered heterocyclic compound which has no sulfur, selenium or tellurium atom in the heterocycle,

characterized in that the copper surfaces thereafter with a second solution containing at least one adhesion-promoting compound selected from the group consisting of sulfinic acids, selenic acids, tellurinic acids, heterocyclic compounds containing at least one sulfur, selenium and / or tellurium in the heterocycle, and sulfonium -, selenonium and telluronium salts, are brought into contact, wherein the sulfonium, selenonium and telluronium salts are compounds having the general formula A.
where A = S, Se or Te,
R ₁ , R ₂ and R ₃ = alkyl, substituted alkyl, alkenyl, phenyl, substituted phenyl, benzyl, cycloalkyl, substituted cycloalkyl wherein R ₁ , R ₂ and R _{3 are the} same or different, and
X ^- = anion of an inorganic or organic acid or hydroxide. 2. The method according to claim 1, characterized in that sulfinic acids from the group consisting of compounds having the chemical formula B
with R ₄ , R ₅ and R ₆ = hydrogen, alkyl, phenyl, substituted phenyl, R ₇ - (CO) - with R ₇ = hydrogen, alkyl, phenyl or substituted phenyl, wherein R ₄ , R ₅ and R _{6 is the} same or are different,
and aromatic sulfinic acids are selected as adhesion-promoting compounds. 3. The method according to any one of the preceding claims, characterized net that Formamidinsulfinsäure selected as an adhesion-promoting compound becomes. 4. The method according to any one of claims 1 and 2, characterized in that aromatic sulfinic acids from the group consisting of benzenesulfinic acid, Toluenesulfinic acid, chlorobenzenesulfinic acids, nitrobenzenesulfinic acids and carb oxybenzenesulfinic acids are selected as adhesion-promoting compounds. 5. The method according to any one of the preceding claims, characterized net, that at least one heterocyclic compound from the group, best from thiophenes, thiazoles, isothiazoles, thiadiazoles and thiatriazoles, is selected as an adhesion-promoting compound. 6. The method according to claim 5, characterized in that at least one thiophene from the group consisting of compounds having the chemical formula C.
with R ₈ , R ₉ , R ₁₀ , R ₁₁ = hydrogen, alkyl, substituted alkyl, phenyl, substituted phenyl, halogen, amino, alkylamino, dialkylamino, hydroxy, alkoxy, carboxy, carboxyalkyl, alkoxycarbonyl, aminocarbonyl, R ₁₂ - CONH- with R ₁₂ = hydrogen, alkyl, phenyl or substituted phenyl, wherein R ₈ , R ₉ , R ₁₀ and R _{11 may be the} same or different and part of condensed on the thiophene ring homo or heterocyclic rings,
is selected as an adhesion-promoting compound. 7. The method according to any one of claims 5 and 6, characterized in that at least one thiophene from the group consisting of aminothiophencar Bonsäuren, their esters and their amides, as an adhesion-promoting compound is selected. 8. The method according to any one of claims 5 to 7, characterized in that at least one thiazole from the group consisting of compounds having the chemical formula D.
with R ₁₃ , R ₁₄ , R ₁₅ = hydrogen, alkyl, substituted alkyl, phenyl, substituted phenyl, halogen, amino, alkylamino, Dial kylamino, hydroxy, alkoxy, carboxy, carboxyalkyl, alkoxycarbonyl, aminocarbonyl, R ₁₆ -CONH- with R ₁₆ = hydrogen, alkyl, phenyl or substituted phenyl, where R ₁₃ , R ₁₄ and R _{15 may be} identical or different and R ₁₄ and R _{15 may be} part of a ring fused to the thiazole ring homo- or heterocyclic ring,
is selected as an adhesion-promoting compound. 9. The method according to any one of claims 5 to 8, characterized in that at least one thiazole from the group consisting of aminothiazole and sub substituted aminothiazoles, is selected as an adhesion-promoting compound. 10. The method according to any one of claims 5 to 9, characterized in that at least one thiadiazole from the group consisting of aminothiadiazole and substituted aminothiadiazoles, selected as an adhesion-promoting compound becomes. 11. The method according to any one of the preceding claims, characterized net, that at least one sulfonium salt from the group consisting of trimers ethylsulfonium salts, triphenylsulfonium salts, methionine alkylsulfonium salts and Methioninbenzylsulfoniumsalzen, as an adhesion-promoting compound is chosen. 12. The method according to any one of the preceding claims, characterized net, that at least one compound from the group consisting of Triazo len, tetrazoles, imidazoles, pyrazoles and purines, as nitrogen-containing, five-membered heterocyclic compound is selected. 13. The method according to claim 12, characterized in that at least one triazole having the chemical formula E1
with R ₁₇ , R ₁₈ = hydrogen, alkyl, amino, phenyl, substituted phenyl, carboxyalkyl, where R ₁₇ and R _{18 may be} identical or different and part of a homo- or heterocyclic ring fused to the triazole ring,
is selected as a nitrogen-containing, five-membered heterocyclic compound. 14. The method according to any one of claims 12 and 13, characterized in that at least one triazole is selected from the group consisting of benzotriazole, Me thylbenzotriazole, ethylbenzotriazole and dimethylbenzotriazole, as nitrogen ent retaining five-membered heterocyclic compound is selected. 15. The method according to any one of claims 12 to 14, characterized in that at least one tetrazole having the chemical formula E2
where R _{19 is} hydrogen, alkyl, haloalkyl, amino, phenyl, substituted phenyl, benzyl, carboxy, carboxyalkyl, alkoxycarbonyl, aminocarbonyl or R ₂₀ -CONH where R _{20 is} hydrogen, alkyl, phenyl or substituted phenyl
is selected as a nitrogen-containing, five-membered heterocyclic compound. 16. The method according to any one of claims 12 to 15, characterized in that at least one tetrazole is selected from the group consisting of 5-aminotetrazole and 5-phenyltetrazole, as a nitrogen-containing, five-membered heterocyclic Connection is selected. 17. The method according to any one of the preceding claims, characterized net, that for component b. in the first solution sulfuric acid as acid is selected.   18. The method according to any one of the preceding claims, characterized net, that copper layers having printed circuit board inner layers for forming ei An adhesive bond between the PCB inner layers and art pretreated resin. 19. The method according to any one of the preceding claims, characterized net, that has copper layers having printed circuit boards for forming an adherent Composite between the copper layers and made of plastics Resists are pretreated.