DE2153563A1 - Activation solution for electroless metallization, process for its production and application - Google Patents

Description

"Activation solution for electroless plating, process for their production and application ".

The present invention relates to an activation solution for electroless plating of surfaces, i.e. the Metallization by Chemical Reduction «The present invention also relates to a method of manufacture such solutions and their use.

It is already known to activate the surfaces before the metallization without electrical current. At acquaintances Method one uses essentially separate solutions of a tin (II) salt, e.g. tin (II) chloride, and a noble

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LethaliseB »e.g. Jalladium-II'-chloride * The solution of the 2inn-ll * Bälzes - and the solution of precious metal salts are Eehte slogans and the activation thus eats a two-stage igiö Process> that in the application of the solution of the tin-oil seam and the application of the solution of the palladium-II-salt consists, with the two stages by, a flushing process with Water are separated "

For metallization without electrical current, as Activator systems proposed baths, ■ the colloidal tin and contain colloidal silver.

Eventually, combinations of catalytic systems were made colloidal salts of precious metals and tin salts to activate the sub-layers or carrier materials in the Metallization used without electricity *

The colloidal or catalytic activation systems mentioned above are, although they give good results in certain respects, with regard to the stability of the baths, dia contain colloidal catalysts, as well as with regard to the effectiveness of the surface catalysis or the surfaces that are to be metallized without electrical current, in need of improvement «So included the colloidal catalyst or activator systems colloidal catalytic particles of such dimensions that touching and activating certain surfaces that one wishes to metallize without the use of electricity, is made impossible, which is the case, for example, with limited and deep surfaces that are often found in printed Multi-layer circuit cards and surfaces with small holes, such as small blind holes in particular and scratches found in the metallization of other plastic materials.

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U.S. Patent No. 3,011,920 for activation a surface that is to be aietallized without the use of electric current describes liquids, which contain colloidally dispersed particles of the catalytic metal. The sol of the colloidal catalyst is preserved one by making a precious metal salt, a tin salt and a hydrohalic acid mixed. Although the salt of the colloidal catalyst in terms of activation showing satisfactory results, such a colloidal catalyst sol is in terms of application for the activation of the above narrow and deep surfaces due to the dimensions of the particles that make up the Make out Sol, could be improved. The stability of the catalyst or activator composition is also unsatisfactory i.nd to be improved.

The known sols and baths which contain colloidal catalysts are also to be improved with regard to their compatibility with regard to aqueous solutions which contain CrO ~ and HpSO and which are used to prepare the surfaces. The coated plastisols carrier material! En used in Metallisierungseinrichtungen, tend to form cracks after a certain period of use and become porous, whereby a portion of the solution containing CrO ~, and H ₂ SO ₄ containing, in the tears and Pores can be retained and despite rinsing with water after the preparatory stage and before immersion of the objects to be metallized in the activator bath can be dragged into the activator bath. The presence of the preparatory solution, the CrO and H ₂ SO , which has been dragged along. contains, in brines and baths of colloidal catalysts, premature decomposition of the latter can have the consequence that they can no longer be used.

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Furthermore, the use of a sol of a colloidal catalyst according to the U ₀ S. Patent Hr. 3 011 in the metallization cycle, a special treatment of the surface of the catalyzed object with a post-activation solution to remove the protective colloid and / or the agent preventing flocculation from the deposited colloidal particles of the catalytic metal. The post-activation solution used for this particular skin activation treatment can contain perchloric acid and such a Mach activation solution can pose the risk of explosion and fire as the. Perchloric acid can decompose spontaneously and explosively under certain conditions.

The object of the present invention is therefore to provide this Nachaile to overcome and to provide a solution and an activation process that better meet the requirements than the previously known methods and solutions.

The activation method according to the invention for the electroless Metallization of surfaces consists in that the surface (s) of the object with an acidic solution a soluble tin halide / noble metal complex, which has been modified with a Lewis base, brings into contact, until the treated surface is made catalytic, the solution being practically free of colloidal particles Is catalyst metal.

The noble metal of the complex must be used for electroless metallization catalytic for the particular metal selected (or metals in the case of alloy deposition) works. The treatment of the surface with the solution of the complex mentioned is usually carried out by immersing the Surface in the solution, although you can also, if desired

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may use other methods of applying the solution to the surface.

The inventive catalytic activation solution is an acidic solution free of colloidal particles of catalytic metal and containing a soluble tin / precious metal halide complex, which has been modified with a Lewis base contains.

The noble metal of the complex must be used in electroless metallization, i.e. in chemical reduction with respect to the particular metal (or metals, if an alloy is to be deposited) to be deposited, act catalytically. The catalyst solution can be concentrated Solution siin or a concentrated solution that is above for use with an aqueous liquid, usually water, and with a hydrohalic acid such as hydrogen chloride acid, has been diluted.

The soluble complex according to the invention is obtained by an acidic soluble salt of the noble metal, a soluble tin (II) halide, a Lewis base and a hydrohalic acid mixed and the reaction mixture obtained in this way kept long enough for the complex to form Has. The formation of the complex is indicated by the fact that the acidic solution formed as the product of the reaction is catalytically active has become effective. The term "catalytically active" means that the acidic solution is as it is or after dilution is able to have a normally non-catalytic ^ or practically non-catalytic ^ surface to activate or to make catalytic. On such an activated surface it forms when it is in a bath for electroless metallization, e.g. a copper plating or nickel plating bath is immersed by chemical reduction, a satisfactory deposit,

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The storage time of the reaction mixture for preparation of the soluble complex in question is long, usually several days. The Lewis base is at least in an amount sufficient to form the soluble complex is present in the mixture and the stannous chloride is in an amount in excess of that required to convert the precious metal salt into a precious metal of the valence ITuIl ' to reduce, present. '

In the reaction mixture, the tin (II) halide reduces the Precious metal ions to a metal with the valence ITuIl. It will take place thus several reactions between the noble metal r> .3i Valence zero, the tin (II) halide and the Lewis base, which are, for example, an alkanol with 1 to 3 carbon atoms is formed. It is assumed (although this mechanism is not known with certainty) that 6as alkanol forms a complex or a coordination compound with the noble metal and the tin (II) halide, after which a mol- Cellular rearrangement or ligand transfer, which is inhibited by the alkanol, occurs. It is believed, that the Lewis base, like the alkanol with 1 to 3 carbon atoms, causes the growth of the molecule of the complex blocking end groups disrupts or terminates, creating a soluble molecule of relatively low molecular weight forms in a non-colloidal size.

The solution of the soluble complex thus obtained is used as it is as an activator for catalyzing the surface of the used electrolessly to be metallized object. For economic reasons it is advisable to do so acidic solution, which is a concentrated solution, to be diluted before use, this diluting thereby takes place, for example, that one volume part of such a concentrated solution with a volume part 3? Hydrogen chloride acid (analytically pure) and five volumes of de-ionized or distilled water mixed.

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The presence of the Lewis base is responsible for the formation of the one in question soluble complex is essential. In the absence of the Lewis base, e.g. methanol, no soluble base is obtained Complex, but insoluble particles of a colloidal catalyst and a colloidal sol are formed.

The absence of colloidal particles in the invention Catalyst or activator solution is determined by a classic optical method.

The advantages of the method according to the invention over the known / experienced are in particular the following:

(1) There is better penetration not only into narrow areas to be activated, in particular with the Manufacture of printed circuit boards with multiple layers but also better penetration in small holes, especially in blind holes and in gaps in the metallization of other plastic materials, which is due to the small dimensions of the molecule of the invention used Complex results and what results from a considerably larger number of nucleation sites or catalytic sites, which are arranged on the surface to be metallized, manifested.

(2) Due to the greater penetration into these cavities and thus due to the larger number of nucleation sites, a complete and continuous covering of narrow cavities, cracks and small holes by the electroless metal deposition is possible than was possible with previously known methods, since these depositions are frequent are incomplete or non-uniform due to poor penetration of the colloidal catalyst particles due to their significantly larger dimensions. .'.-.,. ,.

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BATH ORIGINAL

(3) The activation solutions according to the invention have a significantly improved stability.

(4) The compatibility with regard to the introduction of aqueous preparation solutions containing CrO ~ and HoSO-, becomes considerable in comparison to the poor compatibility of the previously known activation baths improved.

(5) It becomes possible to use a specialist activation solution run without the risk of explosion as this solution is an aqueous dilute hydrochloric acid solution that is normally used in one of the plating cycles previous stage is used and is therefore easily available.

The stability of the activation solutions according to the invention is such that about 56.8 liters of such a solution 6 months of storage in a container to no formation of a deposit on the container wall. still to skin formation on the top surface of the solution or elsewhere. In contrast, one observes at a colloidal sol that has been kept in a container for about 2 months, the formation of a considerable Deposition on the container walls and the formation of a surface skin on the upper surface of the sol.

Although no limitation is intended to be introduced by theoretical considerations, it is assumed that the at Formation of the soluble tin / noble metal / halogenide complex modified with the aid of a Lewis base Mechanism first / an acid catalyzed reduction of the noble metal ions through the tin (II) halide up to to a skill zero. The Lewis base, like a

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Alkanol with 1 to 3 carbon atoms, such as methanol, then forms a complex or a coordination compound with the noble metal and the tin (II) halide. Afterward there is a molecular conversion or a ligand transfer, which is inhibited by the Lewis base possibly for mechanical reasons of steric hindrance, as illustrated by the following scheme.

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egg

Cl

HIGH

Pd

Cl

HIGH

CH ₃ OH

H OH

Cl i Cl

Cl

Pd

Cl

H CH,

V ³

Cl

Cl

Pd

0-H CH,

Cl and many other combinations of

Reduction SnCIo

Cl

H CH,

Pd ^v

H CH, ^ ₀ / ϊ

egg

.Sn
Cl Cl

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where η is an integer of at least 1 and usually greater than 1. The soluble complex molecule formed is ionic and especially anionic.

The soluble stannous halide used as the reagent to form the soluble complex is generally a Halide which corresponds to the formula SnXp in which X is a halogen atom with an atomic number between 17 and 35 inclusive represents. Such tin (II) halides are tin (II) chloride and tin-II bromide. The tin (II) halide molecule may contain water of hydration or water of crystallization,

Any Lewis base can be used as the Lewis base to prepare the soluble complex. The term "Lewis base" as used herein includes any atomic ion or molecule other than water that can provide a pair of electrons to form a covalent bond with a Lewis acid. It will be understood, however, that the Lewis base must be compatible with the soluble complex in question. The term "compatible" as used herein _? means that a Lewis base of the type indicated above exerts the desired effect in the preparation of the soluble complex by on the one hand the formation of an insoluble complex with a relatively high molecular weight and on the other hand preventing the precipitation of the noble metal of valence zero and thereby in the solution of the complex or the catalyst does not introduce any molecules, atoms or ions which noticeably impair the activation solution or the ability of this solution to effectively catalyze a surface to be electrolessly metallized. The term "Lewis acid" embraces any atom, ion or molecule that is capable of accepting a pair of electrons from a Lewis base. Examples of according to the invention

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Setting Lewis bases are alkanols with 1 to 5 carbon atoms, such as methanol, ethanol, n-propanol and isopropanol also mixtures of an alkanol having 1 to 3 carbon atoms with an alkali metal propionate, such as sodium propionate or potassium propionate.

Furthermore, any soluble noble metal salt can be used will. Examples of noble metal salts which can be used according to the invention are salts of the metals of the platinum group, such as palladium chloride, palladium bromide, palladium sulfate, Palladium nitrate, diammine palladium hydroxide, platinum

. chloride Iiatinbromidy platinum sulfate and gold-I-chloride.

* Other salts of metals of the platinum group that can be used according to the invention are the salts of rhodium, ruthenium, osmium and iridium, for example iridium dichloride, osmium trichloride, iJiodium trichloride, rhodium sulfate and ruthenium tetrachloride. Silver salts, such as silver nitrate, can also be used in accordance with the invention

The reaction temperatures for the production of the soluble complex of the invention may extend between room temperature and elevated temperatures of about 65-66 ⁰ C.

) The relative amounts of reactants can vary considerably, provided that the Lewis base is present in the reaction mixture in at least an amount sufficient to produce the soluble complex; the tin (II) halide is present in an excess, typically in a large excess of 600 % or more, based on the theoretically required amount, in order to reduce the total amount of the noble metal salt to a noble metal of valence zero; while the pH of the reaction mixture by adding a hydrohalic acid, such as

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-. 13 -

Hydrochloric acid, acidic, i.e. generally at one Value is kept below about 1.

The Lewis base should be between. the tin (II) halide and the noble metal salt in the reaction mixture exist to form an insoluble colloidal system of relatively high molecular weight and to prevent the precipitation of the precious metal with a value of zero.

The concentrated activator solutions and the diluted concentrated ones Solutions probably have a pH value below 1.

In the following, particularly preferred embodiments according to the invention are to be explained.

The Lewis base, e.g., an alkanol having 1 to 3 carbon atoms such as methanol, is preferred in the manufacture added to the reaction mixture before the addition of the noble metal salt. When the Lewis base does not start the redox reaction Is present between the tin (II) halide and the noble metal salt, this redox reaction can take place quickly occurs, lead to the fact that the noble metal formed in the redox reaction with a valence zero is a colloidal one insoluble system with a relatively high molecular weight forms and / or fails from this system.

The soluble tin (II) halide is preferably added to the reaction mixture in small proportions, with between these additions homogenizes the resulting mixture. The tin (II) halide is preferably in the form of an aqueous one Solution, a hydrohalic acid, where the anion of hydrohalic acid is preferably identical to that Anion of the tin (II) halide is. The hydrohalic acid

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ORiGlMAL BATHROOM

-H -

usually corresponds to the IOrmel HX, where X is a halogen atom means having an atomic number of 17 to 35 inclusive, which definition includes HCl and HBr. In the The first partial addition is preferably effected in an excess of tin (II) halide over that for reducing the total noble metal salt stoichiometric amount required for a valence of zero. The size of the other added Tin (II) halide quantities and the number of these partial additions are not particularly critical. It is sufficient to add a sufficient amount of tin (II) halide to the reaction mixture that is sufficient to show a slow growth promote the molecular size of the complex, to a point as this complex is able to stimulate the stro ^ - · to catalyze loose deposition of at least one metal by chemical reduction. The temperatuc of the reaction mi- ' Observation in the homogenization between the Tc-ilzi »gifts of the tin (II) halide is preferably between about 32% and about 57 ° C, and especially between about 38 and about 49 ° Co The reaction temperature can be specified within this range Temperature ranges, if necessary, maintained either by supplying external V / arms and / or by cooling will.

The Lewis base, e.g. an alkanol with 1 to 3 carbon atoms such as methanol, is preferably added before the addition of the Noble metal salt, as already stated above, added to the reaction mixture and is in a sufficient Amount added to allow the formation of an insoluble colloidal catalyst system with a relatively high molecular weight and the precipitation of the precious metal with the valence zero to prevent from such a system. The Lewis base additions are then made in small proportions, preferably by placing the resulting reaction size between such additions homogenized. The amount added with each addition

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The amount of Lewis base carried and the number of these individual additions are not particularly critical, provided that the The amount of the total lewis base added to the reaction mixture is sufficient for the dimension of the complex molecule in the Maintain a range of dimensions corresponding to a soluble, non-colloidal complex of relatively low molecular weight.

At least one partial addition of the alkanol is preferably carried out simultaneously with the partial addition of 1 to 3 alkanol Carbon atoms, together with the tin-II-lialogenide in the same solution is added which also contains a hydrogen halide contains acid.

Preferably an alkali stannate such as sodium stannate is used or potassium stannate before adding stannous chloride to the Facilitation of the reaction added to the reaction mixture.

The preferred noble metal salt is palladium chloride. That as The preferred reagent tin (II) halide is tin (II) chloride.

The reaction temperature in the preparation of the soluble complex according to the invention is preferably between about 32 and 54 ^° C. and most preferably between about 38 and 49 ^° C.

The preferred Lewis bases for forming such a complex are alkanols having 1 to 3 carbon atoms, where Methanol is the preferred alkanol.

A particularly preferred procedure for preparing the soluble complex is that one hydrogen halide acid, water and an alkanol in a reaction vessel or introduced into a reaction zone by adding a solution of a noble metal salt in a hydrohalic acid and the liquid thus obtained for a time that is im

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-.16 -

is generally between 1 and 2 hours, C, and preferably homogenized at a temperature! between about 32 and about 54 ⁰ between 38 and '49 ⁰ C or stirred. Then, an acidic solution containing hydrohalic acid, ■ is tin II halide and containing alkanol is added to the thus obtained liquid reaction mixture. the resulting mixture is then preferably during a time which is generally between about 2 and 3 hours at a temperature between about 32 ⁰ C and about 54 ⁰ C and in particular between about 38 ° C and about 49 ⁰ C is homogenized. to the resulting reaction mixture is preferably added, and in separated form a sar.re stannous halide acid into a hydrogen halide is dissolved and a Alkalimetallpropionatlösung in an alkanol having 1 to 3 carbon atoms. the liquid mixture thus obtained is preferably for a time which is usually between about 3 and 4 hours, at a temperature between about 32 ⁰ C and about 54 ⁰ C ■ and in particular between about 38 ⁰ C and about 49 ° C, stirred or homogenized. An aqueous solution of an alkali metal propionate, hydrohalic acid and tin (II) halide is preferably added to the resulting liquid mixture in separate form. The liquid mixture thus obtained is then stored for a period of at least 5 to 6 days sufficient to obtain the desired soluble complex. The reaction takes place for a considerable part, in particular during the total time of this storage time, with the formation of a soluble functional complex. The last-mentioned storage step is preferably carried out with the reaction mixture at room temperature without stirring. Although this last retention step is preferably carried out in the reaction vessel, the reaction mixture before this storage step in which provided for the sale container can such be ₀ B. keg transferred, so that the storage stage is carried out in these vessels. In the-

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sea lall it is important to have the container with a facility through which excess gas pressure can escape »In addition you can use a vent hole or a hole in the upper part of the wall of the Pierce the lid. If the retention level is in the If the container intended for sale is made, the container in question should not be used before the above-mentioned period of time has elapsed Unless the customer has been advised that the catalyst solution will not be available until after it has expired the specified period of time can be used.

The homogenization or agitation during the above preparation can be carried out with any suitable agitation means take place.

The object (or the substrate surface (i)) that is metallizing should be, if it has not already been cleaned, e.g. * by immersion in a classic hot one, will not pickling solution containing silicate, cleaned * Other suitable methods can also be used to finish the To clean the surface, such as mechanical cleaning by treating with a sandblasting blower or by sanding. The surface is then rinsed with water. After rinsing, it can be placed in a dilute acidic solution, For example, immersed in an aqueous 20% hydrochloric acid solution in order to neutralize any remaining alkaline materials, after which the surface treated in this way rinse again with water.

The substrate surface treated in this way is then through Immersion in the activating solution according to the invention, e.g. in that obtained according to Example 2, for a period of time which is sufficient to make the surface catalytically active, which generally takes place in the course of 1 minute or more, made catalytically or activated. In a less advantageous

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such a solution can adhere to one embodiment soluble complex can be sprayed onto the surface to be activated * Me activated surface obtained in this way is removed from the activating solution or the catalyst and rinsed with water.

The catalytically-made surface is then (typically by immersion) contacted with a Nachaktivierungfslösung into contact, preferably made of a '- "- dilute HCl solution (Höl concentration from 10 to 25 #) Loading ^r, where the contact time, which is usually is at least 1 minute, must be sufficient to achieve a release of the catalytic noble metal on the surface, after which a rinse with water is effected.

Any solution that is capable of a release of the catalytic Securing precious metal on the surface to be metallized can be used as a post-activation solution can be used, a dilute HCl solution being preferred. Although not a limitation by theoretical considerations is to be induced, it is believed that the treatment with a skin activation solution is used to activate materials, such as. remove excess tin from the treated surface and expose the catalytic precious metal. Another explanation is that treatment with a Bach activating solution leads to materials other than the catalytic noble metal are prevented from affecting the catalytic activity of the latter to affect,

The catalytic surface is then electrolessly metallized, by looking at the activated surface in general

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by immersion »with a solution for metallization chemical reduction: to form a desired metal layer, e.g. with a copper plating solution, a nickel plating solution, a cobalt / nickel alloy deposition through chemical reduction, brings into contact. The duration of contact with the plating solution by chemical reduction is such that a metal layer of the desired thickness is deposited on the surface. The surface metallized in this way is then rinsed with water.

Non-limiting examples of aqueous baths for formation of copper-nickel-cobalt and cobalt / mckel alloy deposits by chemical reduction, the baths are of the following compositions:

Bath for copper plating by chemical reduction

g / ltr. Copper sulfate 29 Sodium carbonate '25. Seignette salt 140 "Versene T" 17th Sodium Hydroxide 40 Formaldehyde (37% solution) 166

("Versene T" is a brand name for a commercially available one Substance containing ethylenediaminetetraacetic acid (EDTA) and Contains triethanolamine).

This bath is used at a temperature of 21 ⁰ C and at a / pH prior to metallization von.11,5 ·: ,, ^■;

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Bath for nickel plating by chemical reduction

g / ltr.

Nickel chloride '30

Sodium citrate 20

• Amm on ium chi or id 50

Sodium hypophosphite 10

Ammonium hydroxide 30

The bath is poured in to a pH of 8 to 10 with EELOH

v / ends.

and is served at a temperature of 21 to 43 ° C

Bath for coating with cobalt by chemical reduction

g / ltr.

Cobalt chloride 30

I Sodium Citrate 35

Ammonium chloride. 50

Sodium hypophosphite 20

The pH of the bath is adjusted to a value of with ammonia

set to 10 and the bath is used at a temperature between 90 and 96 ⁰ C.

Bath for the deposition of cobalt / nickel alloys by chemical reduction

fi / ltr.

Cobalt chloride 30

Nickelchlorld 30

Seignette salt 200

Ammonium chloride 50

Sodium hypophosphite 20

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The pH of the bath is adjusted to a value of 8 to 10 with ammonia and this bath is used at a temperature between 90 and 96 ^° C.

After the metallization, the substrate surface is usually electroplated with a desired metal. A typical bath for the galvanic deposition of a metal such as copper consists of an aqueous acidic sulphate bath containing 200 to 300 g of OuSO ₄ ⁹ SH ₂ O and 15 to 40 g of free HoSO (sulfuric acid concentration 66 ° Baume) per liter. G-o if desired. For example, a further metal can be applied electrolytically on such a first electrodeposited layer.

I've the following examples to illustrate the present invention Explain much more without limiting them.

Example 1 .

First, a soluble complex according to the invention is prepared.

520 ml of HCl (analytically pure) with a concentration of 37 ^a / ° HCl, 165 ml of distilled water, 6.60 g of sodium stannate and 13 ml of anhydrous methanol are placed in a reaction vessel. Then 1.65 g of palladium chloride dissolved in 4.4 ml of 37% HCl (analytically pure) are added to the contents of the reaction vessel. The mixture in the reaction vessel is stirred and ^{the reaction temperature is brought to a value of 38 to 49 °} C. by exothermic reaction and by supplying external heat and this temperature is maintained during the reaction. After mixing the reactants for 1 hour at a

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At a temperature between 38 and 49 ^° C., a solution of 26.2 ml of 37% HCl (analytically pure), 16.5 g of anhydrous tin (II) chloride and 7.3 ml of anhydrous methanol is added to the reaction mixture. The resulting liquid mass is stirred in the reaction vessel for 2 hours at a temperature between 38 and 49 ⁰ C, whereupon in separate additions to the resulting mixture:

(1) a solution of 14.9 g of anhydrous tin (II) chloride in 24.8 ml of 37% HCl (analytically pure) and ^: ' ^:

(2) 3.45 ml of a solution of 24 g of sodium propionate in i; d, pser-free Adding methanol. ■ .......:.

The liquid mass obtained in this way is for 3 hours a temperature between 38 and 49 ° C stirred, whereupon to the liquid mixture thus obtained in separate additions 2.3 ml of a solution of 24 g of sodium propionate in water, 117 ml of 37% HCl (reagent grade) and 190 g of anhydrous Adding tin-IT-chloride. The liquid mixture thus obtained is then stored in the reaction vessel for 6 days, after which the soluble tin / palladium chloride complex modified by methanol for activation or catalyzing the surface of an object to be metallized can be used.

Although the liquid solution thus obtained can be used as it is as an activator, it is preferably before use typically by mixing the solution (or concentrate) thus obtained with HCl and purified water in a ratio of 1 liter. HCl (37 % analytically pure) and 5 liters of deionized or distilled water per liter of the liquid concentrated solution thus obtained. Such a dilute activation solution results in the catalyzing of the surface

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Chen of objects to be metallized without current at room temperature excellent results taking the treatment done by immersion for 5 minutes.

The reaction of methanol with palladium and / or tin (II) chloride is caused by the evolution of gas from the reaction mixture after each partial addition of methanol and by the Formation of an insoluble colloidal sol when the methanol is not used as a reagent is indicated.

Example

The procedure given in Example 1 is used here, but tin (II) bromide and HBr instead of Tin-II chloride and HCl was used. You get one soluble tin / palladium bromide complex modified by methanol, which is dissolved in the aqueous acidic liquid reaction medium

example

The procedure of Example 1 is repeated, but instead of the palladium chloride used in Example 1 is used Platinum chloride (PtCIp) used. So you get a soluble one with methanol modified tin / platinum chloride complex, which is in solution in the aqueous acidic liquid Reaction medium is present.

example

The procedure of Example 1 is repeated, but using platinum bromide (PtBr ₂ ) instead of the palladium chloride used in Example 1. So you get one with.

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nol modified soluble tin / platinum bromide complex, the is in solution in the aqueous acidic liquid reaction medium.

example

The procedure used in Example 1 is repeated, however, using gold I chloride (AuCl) instead of the palladium chloride used in Example 1. In this way, a soluble one modified with methanol. adorned tin / gold chloride complex that dissolved in the "- aqueous acidic liquid reaction medium is present.

example

The procedure of Example 1 but is repeated using ethanol in place of methanol, which in examples, game It was used 1 _o obtained in this manner with ethanol a modified soluble tin / Palladdum chloride complex, in solution in the liquid aqueous acidic reaction medium is present.

example

The procedure given in Example 1 is repeated, but using ethanol and platinum chloride (PtCl ₂ ) instead of the methanol and palladium chloride used in Example 1, respectively. A soluble tin / platinum chloride complex modified by ethanol is obtained in this y / eise, the. dissolved in the aqueous acidic liquid reaction medium.

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At s ρ i e 1 8

The procedure of Example T is repeated but using of ethanol, tin-II-bromide and HBr instead of ' Methanol, tin (II) chloride or HCl, in this way a soluble tin / palladium bromide complex modified with ethanol is obtained, der.gelöst is present in the liquid acidic aqueous reaction medium.

example

The procedure of Example 1 is repeated but with partial application of propanol instead of methanol · In this way, a soluble one modified with propanol is obtained Tin / palladium chloride complex that is dissolved in the liquid acidic aqueous reaction medium is present.

Be-Is ρ i el 1Ό

The procedure of Example 1 is repeated but using of propanol and platinum chloride (PtClp) instead of methanol and palladium chloride. In this way one obtains a soluble tin / platinum chloride complex modified with propanol, which is dissolved in the liquid acidic aqueous reaction medium.

Example 11

Multiple '! G-10 "and fiberglass epoxy cards that come with are provided with a copper layer, are electrolessly copper-plated and then galvanically with a copper deposition as follows Mistake:

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1. Immersion in a hot alkaline pickling solution for 3 to 5 minutes at 60 to 71 ^° C

2. Rinse with water. - ^; ■■ "■ -"'"■"■>

3. Immersion in one at room temperature for 3 minutes solution containing 120 g of ammonium persulphate per liter.

4. Rinse with, water.

5. Immersion at room temperature for 1 to 3 minutes in a 15% sulfuric acid solution.

6. Rinse with water.

7. Immersion at room temperature for 1 to 2 minutes in a 10 to 25% hydrochloric acid solution.

Rinse with water.

9. Immersion at room temperature for 3 to 5 minutes in an activation solution according to the invention which contains a tin / palladium chloride complex modified with methanol contains. Such an activation solution is obtained by mixing 1 volume of HCl (37 #ig analytically pure) and 1 volume of deionized water with T part by volume of a concentrated solution prepared according to Example 1, the tin / palladium chloride complex modified with methanol contains.

10. Rinse with water.

11. Immersion at room temperature for 3 to 5 minutes in a 10 to 20% hydrochloric acid solution.

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12. Rinse with water.

13. Electroless copper plating at room temperature for 8 to 12 hours and

14. Electrolytic copper plating.

The copper plating of the surface of all holes drilled through the plates is complete without any defects in the Let the deposition be determined.

Example 12

Various salt shaker lids made of acrylonitrile / butadiene / ötyrol-misehpolymerisat, d, h. ei ^ ieia ABS copolymer with a classic electroless nickel-plating bath at room temperature and then electrolytically like follows copper-plated:

1. Immersion for 5 minutes at 60 to 710 in a warm one alkaline mordant.

2. Rinse with water.

3. Chemical treatment of the plastic material by immersion in a classic aqueous solution of CrO * and H ₂ SO ₄ . '^;

4. Rinse with water.

5. Immerse in a 10-20 sequence hydrochloric acid solution for 1 minute at room temperature.

6. Rinse with water «

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7, immersion in a for 1 minute at room temperature According to the invention activator solution which contains a tin / palladium chloride complex modified with methanol and which was obtained according to the manner described in Example 11, step 9),

8, rinse with water,

9, immersion for 3 minutes at room temperature in a 10 to 20% hydrochloric acid solution.

10, rinse with water,

11, nickel-plating with electric current for 10 minutes at;, room temperature,

12, electrolytic or galvanic copper plating,

The metal deposited on the cover adheres very well, the deposition is complete and there are no flaws discover.

example

Various buttons for dishwashers made of ABS mixed polymer and various door handles made of ABS mixed poly. merisat will be in the same. Way under the same conditions and using the same metallization compositions, as described in Example 11, metallized. The activation solution used is one according to the invention Activation solution and contains a tin / palladium chloride complex modified with methanol, which is prepared in accordance with the in Example 11, step 9) described manner would be obtained. the formed metal deposit on the surfaces of the buttons

209819/1093

and the handle adheres well and completely and a flaw can be found.

B e i s ρ i e 1 14

Investigations are being made to determine the stability of the catalyst solution according to the invention, which corresponds to that with methanol contains modified tin / palladium chloride complex and which is free of colloidal particles with the colloidal baths, the colloidal particles of metallic palladium

_to compare,
In the preparation of the non-colloidal catalyst solution and the colloidal baths for these investigations, 1 volume of the concentrated catalyst was mixed with 5 volumes of deionized water and 1 volume of 37% hydrochloric acid (analytically pure) in each case. The catalyst concentrate used to produce the> non-colloidal catalyst solution according to the invention is also a real solution which is free from colloidal particles and which was produced according to the manner indicated in Example 1.

A portion of each catalytic composition is placed in suitable separated containers, which are subsequently while another portion of each catalytic composition is placed in suitable containers which are left open. The containers have the same dimensions, the same capacity and have a large diameter, so that a high ratio of the free surface to the total volume each catalytic composition is adjusted in each examination. The liquid compositions are observed in the open and covered containers until each of these compositions has decomposed, which results from the complete loss of the characteristics

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BATH QRiGINAi

seeing deep color of the liquid and showing the inability of the liquid to act as a catalyst. The time required for such a composition to occur is determined for each composition and is given in Table I below:

TlBEEEB I

Catalytic ^ composition

Solution containing the tin / palladium chloride coraplex, modified with a Lewis base contains and is free from colloidal, particles and according to those given in Example 1 Way was made

Bath # 1, which contains colloidal metallic palladium

Bath # 2, which contains colloidal metallic palladium

Bad Mr. 3> the colloidal metallic Palladium contains times to decompose

Catalyst Catalyst uncovered covered (days) (days)

35-38

11 - H.

7-8

18-19

26-27

10-11

5-6

15-18

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From the above Table I shows the first and The smaller number of days, which is given in the column "Times to decomposition", indicates the time after which one is first a loss of the intense dark color of the catalytic composition or an uneven defective one Metallization notes the electrolessly metallized surfaces, while the second and greater number of Days indicates the time after which there is a complete loss of the intense deep coloration of the catalytic Composition and the almost complete absence of electroless metal deposition * call the one to be metallized treated surface determines. So shows the first line of the numbers given in Table I the number 35 as the first smaller number of days and 28 as the second larger Zalil before «. Number of days in the Column "uncovered catalyst" during the first number of days 26 and the second number 27 in the column "covered Catalyst "reads, whereby this indication of the numbers is continued similarly in the further table. The bath No. 1 in the present example, the colloidal iretallisc ^ es Containing palladium and also that given in the following example 15 were carried out in a manner analogous to that in example 1 specified method, with the difference that no Lewis base was used in the manufacture. The baths Mr. 2 and 3i used in the present example and also the bath used in Example 15 containing colloidal metallic palladium catalytic baths that are commercially available.

, Stability of The significant improvement of the / real solution of the invention In comparison with the catalyst, the stability of colloidal baths is clear from those given in Table I. The results of the examination can be seen.

2 09819/10 93

BATH ORIGINAL

Example 15

In this example, tests were carried out to determine the compatibility of the activator solution according to the invention, which contains the tin / palladium chloride complex modified with a Lewis base and is free of colloidal particles, with respect to small amounts of a solution containing chromic acid or sulfuric acid, compared to Compatibility of baths containing colloidal metallic palladium with these solutions. Such a solution, which contains chromic acid and sulfuric acid, can be dragged into the activator solution through cracks, crevices and pores of the metallization support containers covered with plastisol or through the cracks, pores, holes etc. of the objects to be metallized, especially if these metallization supports have been used for a long time . A true inventive catalyst solution and colloidal catalyst bath are prepared according to the manner described in Example H above. Two additional colloidal catalyst baths, which are commercially available, were also used in these studies. A preparatory aqueous solution containing CrO ^ and H ₂ S (K is added to each catalytic composition in an amount of $ 0.75 by volume (calculated based on the volume for each catalytic composition). which contains CrO, and H ₂ SO., contains 27.5% by weight of CrO ₅ and 27.0% by weight of H ₂ SO ,. The catalytic compositions are then stored in containers until they are no longer used as catalysts can be used for electroless copper plating, as evidenced by the loss of the strong dark characteristic color of the liquid and the inability of this liquid composition to act as a catalyst. The time taken for this decomposition to occur is as follows for each catalytic composition Table II given.

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TABLE II

.Eatalytic composition

Solution containing the tin / palladium chloride complex modified with a Lewis base contains and is free of. colloidal particles prepared according to the manner described in Example 14

Bath number 1, the colloidal metallic Contains palladium

Bad ETr. 2, the colloidal metallic Contains palladium

Bath Fr. 3, the colloidal metallic Contains palladium

Time in days until the composition no longer acts as a catalyst

45 - 52

7 -

1 ■ -

22 -

14th

25th

In Table II given above, the first smaller number of days given in the second column means the Period of time after which for the first time there is a loss of the intense dark coloration of the catalytic composition · or a faulty metallization of the electrolessly metallized Surfaces, while the second number of days equals the length of time after one full. constant loss of the intense dark coloration of the catalytic Composition and a practical.complete Inability to electroless a metallic deposit on the

209819/1093

to cause surfaces to be metallized, ascertains. The results given in Table II show the considerable improvement in the compatibility of the catalytic solution according to the invention, which contains the tin / palladium chloride complex modified with a Lewis base and which is free of colloidal particles, compared with the presence of a small amount an aqueous solution containing CrO ₀ and HpSO 2, compared to the compatibility of colloidal baths with such a solution.

^{At 3} P ^{le: L}

In this example, an investigation of the non-colloidal activator solution according to the invention, the tin / palladium-chloro-Trl-E-Jmplex modified with a Lewis base, which was prepared according to the manner indicated in Example 1, with regard to the. Activation of printed circuit boards made of epoxy resin ¹¹ G-IO "and glass fibers, which were pierced with holes and provided with a copper deposit, was carried out, whereby it was found that excellent adhesion of the electrolessly deposited copper on the copper layer is regularly achieved good adhesion is achieved without the need to carry out a special post-activation treatment of the plates in special laehaktivierungslösung except in dilute HCl, which is a relatively harmless solution compared to perchloric acid solutions, which bring explosion and fire hazards.

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Claims (11)

PATENT CLAIMS Catalytic activation solution for surfaces to be metallized without current, characterized in that it comprises an acidic liquid catalyst solution practically free of colloidal metallic particles which has a soluble tin halide / Edelie · all complex modified with a Lewis base and contains a hydrohalic acid. 2. Solution according to claim 1, characterized in that it has a pH value below about 1. 3. Solution according to claim 2, characterized in that the Lewis base is an alkanol having 1 to 3 carbon atoms, in particular methanol is that the noble metal Is palladium, platinum, gold or silver and that the hydrohalic acid is hydrochloric acid. 4ο solution according to one of claims 1 and 2, characterized characterized in that the Lewis base is a mixture of methanol with an alkali propionate, in particular sodium propionate is. 5. Process for the production of one of colloidal metallic particles practically free, for the electroless one Me i-alliüierung of surfaces suitable catalytic activation solution, characterized in that a soluble salt of a noble metal, a Lewis base, a soluble 209819/1093 Tin (II) halide and a hydrohalic acid mixed and the reaction mixture thus obtained is kept for a sufficiently long period of time until one with the Lewis base modified soluble tin / noble metal halide complex obtained, the tin (II) halide in excess about the amount required to reduce the precious metal salt to a precious metal of valence lull and the Lewis base are present in an amount sufficient to obtain the soluble complex. 6. The method according to claim 5, characterized in that the Lewis base is added in the course of the preparation of the reaction mixture before the addition of the noble metal salt "and one at a reaction ^{temperature between about 32 0} C and about 54 ⁰ C, preferably between sth . \ 3.8 ⁿ C and works about 4-9 ⁰ O. ■ 7 ο method of making one of colloidal metallic particles practically free catalytic suitable for electroless metallization of surfaces Activation solution, characterized in that a hydrohalic acid, water and an alkanol with 1 to Introducing carbon atoms into a reaction zone, a solution of a noble metal salt in a hydrogen halide acid is introduced into the reaction zone, the mixture thus obtained in the reaction zone at a temperature between about 32 C and about 54 0, one to the mixture thus obtained is a solution containing a hydrohalic acid and a tin (II) halide and the mixture is maintained for a period of at least about 3 Days to a time sufficient for the soluble complex to form, stored with the tin (II) halide is added in excess of the amount required 209819/1093 is to make the precious metal salt a precious metal of valence Hull to reduce and the Lewis base is added in a sufficient amount so that one is soluble Complex receives. 8. The method according to claim 7, characterized in that before storage for at least about 3 days, the liquid mixture containing the hydrohalic acid and the tin (II) halide and also an alkanol having 1 to 3 carbon atoms, for about 2 to 3 ^v hours, egg a temperature between about 32 ⁰ C and about 54 ⁰ C, preferably between about 38 ⁰ C and homogenized for about 49 ° C, after which separately to the resulting mixture, a solution of a soluble stannous halide in a P ' äure and a further solution of a Alkalimetallpropionats in an alkanol with 1 added to 3 carbon atoms, the mixture thus obtained for from about 3 to 4 hours at a temperature between etwa.32 ⁰ C and about 54 ⁰ C, preferably between about 38 ⁰ C and 49 ^° C. and an aqueous solution of an alkali metal propionate, a hydrohalic acid and a tin (II) halide is added to the resulting mixture in separate form. 9. The method according to any one of claims 5 to 8, characterized in that the Lewis base is an alkanol With 1 to 3 carbon atoms, especially methanol, as tin (II) halide tin (II) chloride, as noble metal salt Palladium chloride, platinum chloride, gold chloride or silver chloride and, as hydrohalic acid, hydrochloric acid used. 209819/1093 10. Use of the catalytic activation solutions according to claims 1 to 4 for activating a surface of an object to be electrolessly metallized. 11. Use according to claim 10, characterized in that the activated surface before the electroless Metallization is immersed in a Mach activation treatment solution. 12. Use according to claim 11, characterized in that An aqueous solution of HCl is used as the post-activation solution. 13 * Use according to claim 11, characterized in that it is carried out at a reaction temperature between about 38 ⁰ C and about 49 ° C. 209819/1093