WO1993012267A1 - Polymeric resin, in particular for depositing metal on a substrate, and use thereof - Google Patents

Abstract

A polymeric resin, in particular for depositing metal on a substrate, including a combination of a complex compound chosen from the group which includes palladium acetate, copper acetate, nickel acetate, copper formiate, nickel formiate, hydrates thereof and mixtures thereof; and cyanoethylcellulose dissolved in dimethylformamide or hydroxypropylmethylcellulose dissolved in water, the palladium acetate being unsuitable in the latter case; and uses thereof.

Description

 "Polymeric resin. In particular for the deposition of metal on a substrate and its use".

The present invention relates to a polymeric resin, used in particular for the deposition of metal on substrates, and its use.

The first detailed experiments of direct deposition (direct writing) of traces of metallic palladium on substrate were carried out by Gross et al., See in particular on this subject Appl. Phys. Lett. 46, 1184 (1985). To do this, they used an ionized argon laser to decompose palladium acetate films, spread by the so-called spin-coating technique from a solution of this compound in chloroform. H. Esrom et al., Mat. Res. Nice. Proc. 131, 581 (1989) carried out the same experiments in projection, using an exciter laser. The techniques proposed by these authors, however, have many drawbacks and prove to be limited in certain applications. In fact, the solutions of palladium acetate in chloroform are unstable and can only be stored for 48 hours; after this period, the formation of metallic palladium in the solution is observed. In addition, during their decomposition under laser radiation, these formulations using chloroform give rise to periodic structures, that is to say to a succession of metallic waves. They also have the drawback of not decomposing under low power ultraviolet radiation (ultraviolet lamps) and once spread, they decompose quickly into metallic palladium. Since these chloroform solutions are also very low in viscosity, the spreading methods used are limited to the technique of coating by rotation. These solutions also pose major cleaning problems during the after-treatment of the substrates.

Mention will also be made of patent US-A-4,927,897 as well as patent applications EP-A- 0 092 601 and 0 243 794. Patent US-A-4,927,897 relates to catalytic solutions of polymeric compounds particular composition completely different from that of the polymer resins of the invention and covers the unique aspect of catalyst for non-electrolytic baths, giving non-selective metallic deposits and only after thermal decomposition. Patent application EP-A-0 092 601 relates to catalytic solutions or suspensions of compounds of coordination with palladium and in particular of palladium acetate. For this, in addition to the coordination compounds, organic solvents are used in combination with vehicles, such as, in particular, cellulose derivatives. Neither dimethylformamide as organic solvent nor lacyanoethylcellulose and 1-hydroxypropylmethylcellulose as cellulose derivatives are mentioned. Patent application EP-A-0 243 794 relates to polymer solutions of coordination compounds but without also mentioning cyanoethylcellulose and hydroxypropylme¬ thylcellulose as cellulose derivatives. In addition, these two EP patent applications cover, like the aforementioned American patent, the unique aspect of catalyst for non-electrolytic baths, the disadvantage of which is to give rise to non-selective metallic deposits and only after thermal decomposition. . One of the essential aims of the present invention therefore consists in remedying the disadvantages mentioned above and to present a polymeric resin, in particular for the deposition of metal on a substrate, extremely stable, which can be used under infrared, visible and ultraviolet radiation even of low power and which, once spread on the subs¬ trat, does not decompose spontaneously. In addition, this resin during its decomposition under laser radiation, does not give rise, like formulations using chloroform, to periodic structures, that is to say to a succession of metallic waves but indeed to traces straight and homogeneous metal and, given its adjustable viscosity, its method of spreading on the substrate is not limited to the coating technique by rotation. The metallic deposition can be carried out selectively and directly, without having to resort to the use of catalytic or non-electrolytic baths.

To this end, according to the invention, the polyene resin comprises, in combination, a coordination compound chosen from the group comprising palladium acetate, copper acetate, nickel acetate, copper formate, nickel formate, their hydrates and their mixtures, and cyanoethylcellulose, dissolved in dimethylformamide. If water is used as solvent, the polymeric resin will comprise, in combination, a coordination compound chosen from the group comprising copper acetate, nickel acetate, copper formate, nickel formate, their hydrates and mixtures thereof, and hydroxypropyl methylcellulose.

According to an advantageous embodiment of the invention, the concentrations of coordinating compound and of cyanoethylcellulose are respectively from 1.10 ^" to 6.10 ^" mol and from 5 to 50 g per liter of dimethylformamide, the concentration of compound coordination, per liter of dimethylformamide, when the compound of coordination is hydrated copper acetate, being 2.5.10 "'to 6.10 ^" ' mole and, when it is nickel acetate, its concentration is 3.3.10 "'mole.

According to a particularly advantageous embodiment of the invention, the concentrations of coordination compound and of cyanoethylcellulose, per liter of dimethylformamide, when the coordination compound is palladium acetate, are respectively 1.10 ^"3 at 3.10 "'mole, advantageously 9.10 ^{' 2} mole and from 5 to 50 g, advantageously 10 g for the deposition of catalytic palladium, and from 8.10 ^{" 2} to 3.1Ô ^"1 mole, advantageously 9.10 ^{" 2} mole and 20 at 50 g, advantageously 30 g for the deposition of conductive palladium. According to another advantageous embodiment of the invention, the concentrations of coordination compound and of hydroxypropyl methylcellulose are respectively from 1.10 ^"3 to 6.10 ^" mol and from 1 to 50 g per liter of water, these concentrations, when the coordination compound is hydrated copper acetate, being respectively 4.10 ^"1 mole and 8 g per liter of water, and when the coordination compound is of copper formate, said concentrations are respectively 5.5 × 10 ^* 'mole and 4 g per liter of water.

The present invention also relates to the use of the palladium polymer resin, and more particularly to a process for depositing palladium on the surface of a substrate. This process is characterized in that it consists in applying a thin layer of the aforementioned resin containing the palladium to be deposited on the surface of the substrate, in irradiating the surface of this substrate covered with this thin layer of resin by means of- a source of visible, ultraviolet or infrared light so as to cause a deposit of palladium on the surface of the substrate at the location of the irra- and remove the remaining layer of unirradiated resin.

According to another embodiment of the invention, after having applied the thin layer of resin containing palladium to the surface of the substrate, the surface of this substrate covered with this thin layer of resin is treated by a thermal source so to cause a deposit of palladium on the surface of the substrate. According to an advantageous embodiment of the invention, when a visible light source is used, this is constituted by an ionized argon laser adjusted in the visible and, when an ultraviolet light source is used, this is this is made up of a pulsed excimer laser, an ultraviolet lamp or an ionized argon laser set in ultraviolet.

The invention also provides a method of depositing copper or nickel on the surface of a substrate. This process is characterized in that it consists in applying a thin layer of the polymeric resin containing copper or nickel to be deposited on the surface of the substrate, in irradiating the surface of this subs¬ trat covered with this thin layer of resin in by means of a visible, ultraviolet or infrared laser source so as to cause a deposit of copper or nickel on the surface of the substrate at the location of the irradiated areas and to remove the remaining layer of non-irradiated resin. Advantageously, an ionized argon laser adjusted in the visible range is used as visible laser source and as an ultraviolet laser source a pulsed excimer laser or an ionized argon laser adjusted in the ultraviolet. According to a particularly advantageous embodiment of the invention, the layer of unirradiated resin remaining by soaking in acetonitrile and rinsing with water, deionized or not and, in the case where the substrate is a ceramic material, this layer of resin is removed by immersing the substrate for a period of approximately 30 seconds to one minute in a 2% solution of hydrofluoric acid and 10% sodium chloride, rinsing it with deionized water, immersing it for about 5 minutes in an ultrasonic acetonitrile bath and rinsing again with deionized water.

According to a preferred embodiment of the invention, the surface of the substrate is cleaned before applying the resin layer thereto and, in the case where the substrate is a ceramic material, the surface of the latter is cleaned by immersing it for about 10 minutes in a 2% solution of hydrofluoric acid and 10% sodium chloride and then rinsing it with deionized water.

Finally, in the case of palladium resin, the invention also relates to a method of metallization of the surface of the substrate to be treated, according to which, after the removal of the possible remaining layer of non-irradiated resin (in the case use of a light source), the substrate covered with the palladium deposit is immersed in a catalytic bath to allow the deposition of a metallization layer on this palladium deposit.

The invention also provides, in the case of palladium resin, a process for direct metallization of the substrate, according to which, after having applied the thin layer of resin containing palladium on the surface of said substrate, the latter is dried and directly immerses the substrate covered with this resin in a catalytic bath to allow the deposition of a layer of metal on said substrate. Other details and particularities of the invention will emerge from the description below, by way of nonlimiting example, of polymeric resins according to the invention, and of their applications for the deposition of palladium, copper and / or nickel on the surface of substrates and, in some cases, for the metallization of these surfaces.

dans laquelle n représente le degré de polymérisation. En fait, la cyanoéthylcellu- lose est une cellulose sur laquelle sont greffés des groupements cyanoéthyle. La nature polymérique du matériel de base, c'est-à-dire de la cellulose ne change pas, le degré de polymérisation de la cellulose n'étant pas modifié. D'excellents résultats ont été obtenus avec une cyanoethylcellulose d'un degré de substitution (nombre moyen de groupements cyanoéthyle venant se greffer sur la cellulose) de 2,5 à 3,0 et d'un degré de polymérisation (n) variant de 600 à 3000. Comme on vient de la préciser, le solvant, c'est-à-dire le dimethylformamide ou l'eau sera choisi en fonction du composé de coordination et de la matière cellulosique utilisés. C'est ainsi que dans le cas où la résine polymérique contient de la cyanoethylcellulose, le solvant sera le dimethylformamide, la cyanoethylcel¬ lulose étant en effet insoluble dans l'eau, et le composé de coordination sera l'acétate de palladium, l'acétate de cuivre, l'acétate de nickel, le formiate de cuivre, le formiate de nickel, un de leurs hydrates ou un mélange de deux ou plusieurs de ces composés, et dans le cas où la résine polymérique contient de l'hydroxy¬ propylmethylcellulose, le solvant sera l'eau et le composé de coordination l'acétate de cuivre, l'acétate de nickel, le formiate de cuivre, le formiate de nickel, un de leurs hydrates ou encore un mélange d'au moins deux de ces composés. Le fait que la qualité des dépôts métalliques sur le substrat n'est pas altérée tenterait à prouver que le solvant joue un rôle actif dans la composition de la résine. En ce qui concerne les concentrations en soluté, c'est-à-dire en composé de coordination et en cyanoethylcellulose ou hydroxypropylméthylcellulose de la résine polymérique, celles-ci dépendent bien entendu de la nature de ces composants et du solvant utilisé. Toutefois, on utilisera d'une manière générale, suivant l'invention, le composé de coordination et la cyano- éthylcellulose en des concentrations allant respective¬ ment de 1.10^"3 à 6.10^"' mole et de 5 à 50 g par litre de dimethylformamide. C'est ainsi que, par exemple, lorsque le composé de coordination est l'acétate de cuivre hydraté [Cu(Ac)₂.H₂0] , sa concentration, par litre de dimethylformamide, sera de 2,5.10^"' à 6.10^"' mole, et de préférence de 2.10^'1 mole. Lorsqu'on combine de l'acétate de nickel à la cyanoethylcellulose, leurs concentrations respectives seront d'environ 3,3.10^'' mole et de 5 à 50 g par litre de dimethylformamide.As already stated above, the purpose of the polymer resins of the invention is to replace the chloroform solutions of palladium acetate known hitherto, the use of which is limited and the major drawback of which is their low stability during storage (around 2 days maximum). For this, polymeric resins have been developed comprising a coordination compound combined with cyanoethylcellulose or hydroxypro¬ pylmethylcellulose, in solution in a solvent, the solvent used being either dimethylformamide when the resin contains cyanoethylcellulose, or l water when the resin contains hydroxypropylmethylcel¬ lulose. These polymeric resins have the advantage of decomposing under infrared and visible radiation as well as under low power ultraviolet radiation and of being extremely stable in storage, for minimum periods of two months and up to up to 'at one year. The coordination compounds are chosen from palladium acetate, copper acetate, nickel acetate, copper formate, nickel formate, their hydra and mixtures of at least two or more of these compounds, palladium acetate and its hydrates, however, not being used when the polymeric resin contains hydroxypropylmethylcellulose and water as a solvent. Cyanoethylcellulose is a polymer of general formula

in which n represents the degree of polymerization. In fact, cyanoethylcellu- lose is a cellulose on which cyanoethyl groups are grafted. The polymeric nature of the basic material, that is to say cellulose, does not change, the degree of polymerization of the cellulose being unchanged. Excellent results have been obtained with a cyanoethylcellulose with a degree of substitution (average number of cyanoethyl groups grafted onto the cellulose) from 2.5 to 3.0 and with a degree of polymerization (n) varying from 600 at 3000. As we have just specified, the solvent, that is to say dimethylformamide or water, will be chosen according to the coordination compound and the cellulosic material used. Thus, in the case where the polymeric resin contains cyanoethylcellulose, the solvent will be dimethylformamide, cyanoethylcel¬ lulose being in fact insoluble in water, and the coordinating compound will be palladium acetate, copper acetate, nickel acetate, copper formate, nickel formate, one of their hydrates or a mixture of two or more of these compounds, and in the case where the polymeric resin contains hydroxypropylmethylcellulose , the solvent will be water and the coordination compound copper acetate, nickel acetate, copper formate, nickel formate, one of their hydrates or a mixture of at least two of these compounds . The fact that the quality of the metal deposits on the substrate is not impaired would try to prove that the solvent plays an active role in the composition of the resin. As regards the concentrations of solute, that is to say of coordination compound and of cyanoethylcellulose or hydroxypropylmethylcellulose of the polymeric resin, these naturally depend on the nature of these components and on the solvent used. However, in general, according to the invention, the coordination compound and the cyano- ethylcellulose in concentrations ranging respectively from 1.10 ^"3 to 6.10 ^" 'mole and from 5 to 50 g per liter of dimethylformamide. Thus, for example, when the coordinating compound is hydrated copper acetate [Cu (Ac) ₂ .H ₂ 0], its concentration, per liter of dimethylformamide, will be 2.5.10 ^" 'to 6.10 ^" 'mole, and preferably 2.10 ^{' 1} mole. When combining nickel acetate with cyanoethylcellulose, their respective concentrations will be approximately 3.3.10 ^' ' mole and 5 to 50 g per liter of dimethylformamide.

In certain cases, the type of metalli¬ deposit, that is to say catalytic or conductive, will depend on the concentration of coordination compound of the resin. Thus, in the case of palladium, when it is desired to obtain a deposit of conductive palladium, the concentration of palladium acetate [Pd (Ac) ₂ ] could be different from that used when it is desired to obtain a deposit of catalytic palladium. The table below gives the extended and preferred concentration ranges of Pd acetate and cyanoethylcellulose per liter of dimethylformamide, depending on whether one wishes to obtain a deposit of catalytic or conductive palladium on a ceramic substrate.

Board

Concentration ranges of Pd acetate and cyanoethylcellulose in DMF

En fait, la résine de l'invention, de par sa nature polymérique, n'est pas un simple mélange mais bien une combinaison ou, plus particulièrement, un complexe des composants mis en présence. Des études de spectroscopie par infrarouge et de photoélectrons ont permis de prouver que l'on obtient une nouvelle molécu¬ le : en fait, lorsque l'on utilise les trois composants du Tableau précité, on obtient une nouvelle molécule par complexation du palladium avec le dimethylformamide et/ou la cyanoethylcellulose.

In fact, the resin of the invention, by its polymeric nature, is not a simple mixture but a combination or, more particularly, a complex of the components brought into contact. Infrared spectroscopy and photoelectron studies have shown that a new molecule is obtained: in fact, when the three components of the above table are used, a new molecule is obtained by complexation of palladium with the dimethylformamide and / or cyanoethylcellulose.

As regards the polymeric resins containing, in combination, a coordination compound and hydroxypropylmethylcellulose, the concentrations of these respective constituents are respectively from 1.10 ^"3 to 6.10"'mole and from 1 to 50 g per liter of water . When the coordinating compound is copper acetate hydrate, the concentrations of hydrated copper acetate and hydroxypropylmethylcellulose are preferably respectively 4.10 ^"! Mol and 8 g per liter of water, and when the coordination compound is formate copper, copper formate and hydroxypropyl methylcellulose concentrationsrespectively advantageously 5.5.10 ^" 'mole and 4 g per liter of water.

According to the invention, as already specified above, to deposit the palladium, copper or nickel on the surface of a substrate, a thin layer of the polymeric resin of the invention containing the metal in question is applied to the surface of the subs¬ trat, the surface of this substrate covered with this fine resin layer is irradiated by means of a visible, ultraviolet or infrared light source in the case of palladium, or by means of a visible, ultraviolet or infrared laser source in the case of copper and nickel, so as to cause a deposition of palladium, copper or nickel depending on the source used, on the surface of the substrate at the location of the irradiated areas and removing the remaining unirradiated resin layer. Preferably, the so-called spin-coating technique is used to apply the layer of polymeric resin to the surface of the substrate or support. This coating technique, well known to specialists, consists in depositing the substrate or support on a spinner by maintaining it thereon by suction, for example by means of a vacuum pump, to cover it with the necessary volume of resin for obtain total coverage and then rotate the spinner while controlling its acceleration, i.e. the number of revolutions per minute and per second to reach the chosen speed, its rotation speed and the rotation time (time delay ). For this, advantageously use accelerations of 400 to 200 revolutions / minute / second, rotation speeds of 200 to 1000 revolutions / minute and rotation times ranging from 60 to 99 seconds. It would of course be possible to use other coating methods, such as, for example, coating with a brush or roller or immersion. The resin, spread in a thin layer on the substrate will then be exposed to the radiation of a visible, ultraviolet or infrared light source. This irradiation will cause the deposition of metal on the substrate. As already specified above, the nature of the polymeric resin of the invention, unlike chloroform solutions of palladium acetate, will make it possible to use a wide variety of sources emitting in the visible , ultraviolet or infrared. As an example of a visible source, mention will be made of the ionized argon laser set in the visible range, with a wavelength from 454.5 nm to 528.7 nm, with a power of 0.100 to 10 W and a speed d '' writing from 30 to 4000 μm / sec. and examples of ultraviolet sources are the pulsed excimer laser, with a wavelength of 248 nm, with an energy of 150 to 750 mJ / cm ² , with a number of pulses from 3 to 70 and a frequency from 10 to 50 Hz, ultraviolet lamps with a wavelength of 254 nm and a power of 5 to 100 W (irradiation duration of 2 hours to 48 hours) (only for palladium deposition) and the ionized argon laser set in the ultraviolet.

If it is desired, according to the invention, to obtain a metallic deposit of a particular design or pattern on the surface of a substrate, irradiation will generally be carried out through a mask containing the design or pattern produced. In the case of an ultraviolet lamp, such as that represented by the reference numeral 1 (FIG. 1), the mask 2 containing the design or pattern produced, subjected to UV radiation 3 will be in contact with the substrate 4 (distance from lamp to support / mask: 0.5 to 1 cm). In the case of a pulsed excimer laser, such as that represented by the reference numeral 5 (FIG. 2), the writing scheme will in fact be done by projection by means of a telescope, constituted by a set of lenses 6 and 7 arranged between the laser 5 and the mask 2, which makes it possible to obtain a parallel beam 8 depending on the choice of these lenses 6 and 7. 6 is a concave plane lens, with a focal length of 100 mm and 7 a plane lens convex 200 mm focal length. By adjusting the distance between the lenses 6 and 7, it is possible to obtain an enlargement of the beam 8 over a range going from x 1.5 to x 5. The mask 2 consists of the drawing of the circuit to be drawn on the substrate 4 and is projected onto the latter. The lens 9, arranged between the mask 2 and the substrate 4, allows the projection of the mask pattern on the substrate. The masks used within the framework of the arrangements of these FIGS. 1 and 2 are based on chromium on quartz and are in fact made up of a quartz blade on which a thin layer of chromium has been vaporized. Masks, such as pierced aluminum can also be used. Technology masking used in this regard is in fact the same as that used in the manufacture of integrated circuits or VLSI (Very Large Scale Integration, manufacture of integrated circuits). For direct writing, it is preferable to use an ionized argon laser adjusted in the visible, such as for example that represented by the reference numeral 10 in FIG. 3. In this case, the laser beam 11 will be focused on the substrate. 4, thanks to the presence of a projection lens 12. The desired design or pattern is then obtained by moving the sample 4 by a table or a system of X-Y tables (not shown) controlled by computer. In the above figures, identical or similar elements have been designated by the same references. It is of course possible to use other laser sources than that mentioned above, such as laser diodes or even YAG lasers. In fact, the type of laser used does not depend on the nature of the substrate but rather on the nature of the application. This is how, for example, to deposit catalytic palladium on large surfaces without specific drawing (from 60 μm ² to 2 mm ² ) (writing by projection, see FIG. 2) the excimer laser seems the most suitable. On the other hand, to deposit conductive catalytic palladium on small surfaces and according to a specific design (traces of 5 μm wide), the direct writing of the metal by the ionized argon laser is better (see Figure 3). Ultraviolet lamps, for their part, give a resolution of a few square millimeters or make it possible to cover large areas from cm ² to m ² (see figure

1).

According to a variant of the invention, it is also possible, in the case of the deposition of palladium, after the application of the thin layer of palladium polymeric resin on the surface of the substrate, treating it by a thermal source to cause a non-selective deposition of palladium on the surface of the substrate.

In fact if we compare the different sources that can be used in the context of the invention, the laser sources are preferable in a large number of cases because the advantages conferred by the use of the laser beams are the speed of the process (from 1 to 2 minutes), the selectivity of the deposit (any type of drawing can be considered) and a high resolution.

The invention also provides a method of metallizing the surface of the substrate thus treated, that is to say by means of a light or thermal source, according to which, after the removal of the layer of polymeric resin to the non-irradiated palladium remaining in the case of the use of a light source, the substrate covered with the palladium deposit is immersed in a catalytic bath to allow the deposition of a metallization layer on this palladium deposit. It would also be possible to carry out a direct, non-specific metallization of the surface of the substrate to be treated, according to which, after the application of the thin layer of palladium polymer resin on this surface, the thin layer of resin is dried, preferably at a temperature not exceeding 80 ° C, advantageously between 60 and 70 ° C and the substrate is immersed directly in a catalytic bath only to allow the deposition of a layer of metal on the substrate. The catalytic or "electroless" baths and their operating modes have been the subject of patents in the name of Shipley and of a certain number of publications; see in particular in this regard P. Binda, J. Tweedie, J. Electroche. Soc. 130 (5), 1112 (1983) and M. Paunovic, Plating Surf. Finish. 17 (1983). Metals which can be deposited via these catalytic baths to form the metallization layer are in particular copper and / or nickel. Substrates which can be used in the context of the invention are ceramic materials, in particular those used for microelectronics, polymeric substrates, such as epoxides, glass, silica, quartz, fabrics and certain semi-materials -conductors. In fact, given the great diversity of usable energy sources,. there is practically no limitation as to the nature of the supports. Each of these requires appropriate pre- and post-treatment. In general, the pretreatment consists of cleaning the surface of the substrate before applying the resin layer, with deionized water and technical acetone and the post-treatment consists in removing the non-irradiated resin. by soaking in acetonitrile and rinsing with water, deionized or not. The ceramic supports and the epoxy supports are the only ones to require a more specific treatment, and in particular, as will be seen in the application examples given below concerning the ceramic supports, the use of a ultrasonic acetonitrile bath.

EXAMPLES

Example l

Application of catalytic palladium deposition on a ceramic support using a resin based on palladium acetate, cyanoethylcellulose and dimethylformamide as solvent

Three examples of catalytic palladium deposition on ceramic support are given below, the first by projection of UV radiation from an excimer laser, the second by projection of UV radiation from a UV lamp. and the third by direct writing using an ionized argon laser. Except for the irradiation conditions, the products, their quantities and all the other processing conditions are identical in the three examples. Preparation of the polymeric resin:

Mix 9.10 ^"2 mole of palladium acetate with 7.5 to 10 g of cyanoethylcellulose, and dissolve in 1 liter of dimethylformamide. Pretreatment of the supports:

Immerse them for 10 minutes in a 2% solution of hydrofluoric acid and 10% sodium chloride. Rinse with deionized water. Spreading the resin: Place the support on the spinner, cover the latter with the necessary volume of resin to obtain total coverage. Rotate with an acceleration of 400 rpm / second, a speed of 900 rpm for 60 seconds. Dry in an oven to obtain a dry film. Irradiation condition:

Excimer laser (optical assembly according to figure 2): Wavelength: 248 nm Energy: 450 mJ / cm ² Number of pulses: 70

Frequency: 10 Hz.

UV lamp (optical assembly according to figure 1): Wavelength: 254 nm Power: 100 W Duration of irradiation: 2 h 00

Ionized argon laser (optical assembly according to figure

3):

Wavelength: 514 nm Power: 0.100 W Writing speed: 4000 μm / sec. Sub-treatment of the supports:

Immerse them for one minute in a solution

2% hydrofluoric acid and 10% sodium chloride, rinse with deionized water, wash in an ultrasonic bath filled with acetonitrile for 5 minutes, rinse with deionized water. These supports are then immersed in catalytic baths (electrolesε) with copper or nickel to deposit and grow on the traces of palladium, respectively copper or a nickel-based alloy.

These catalytic baths meet the following characteristics: Catalytic baths with copper

Bath temperature: between 45 and 50 ° C. - source of copper ions: copper sulphate or related salt; 3 to 5 g / 1 reducing agent: formaldehyde; 0.7 to 7 g / 1 complexing agent: EDTA, gluconic acid, gluconate, etc. ; 20 to 30 g / 1 (excess) - pH control agent: NaOH; pH = 10 to 13 additives: stabilizer, wetting agents; 0.02 to 0.3 g / 1. Nickel catalytic baths

The baths used are baths which catalyze nickel. The nickel ions in aqueous solution are reduced by hypophosphite, which produces not a nickel deposit but an Ni-P alloy containing 12 to 13% of phosphorus depending on the pH of the bath. - Bath temperature: between 90 and 100 ° C source of nickel ions: nickel sulfate in aqueous solution; 7.82 g / 1 nickel sulfate reducing agent: sodium hypophosphite; 8.5 to 7.2 g / 1 - complexing agent: glycolic acid; 20 to 30 g / 1 pH control agent: 4.7-5.1; H ₂ S0 ₄ diluted additives: stabilizers, wetting agents, fluorinated compounds; 0.02 to 0.3 g / 1. Example 2

Application of copper deposition on various supports using aqueous resins based on hydrated copper acetate or copper formate and hydroxypropylmethylcellulose. a) Copper resin composed of hydrated copper acetate [Cu (C0 ₂ CH ₃ ) ₂ .H ₂ 0; 4.10 ^" 'mole] and of hydroxy¬ propylmethylcellulose (8 g / liter) with water as solvent. Direct writing tests (optical assembly of FIG. 3 of the attached drawing) are carried out on coated glass of a thin layer of this resin. The best results are obtained with the Spectra-Physics laser, model 2045, at a wavelength of 457.9 nm (aperture of the output diaphragm of 12) with a focusing objective of 18 μm opening. On the glass, at a writing speed of 3500 μm / s and an irradiation power of 150 mW, resistances of the order of a few tens of kΩ are obtained after cleaning the resin not irradiated These traces are always conductive after treatment with HCl, treatment which aims to remove any oxides b) Aqueous resin consisting of copper formate [Cu (HC0 ₂ ) ₂ ] 0.55 molar etd hydroxypropyl methylcellululose at 4 g / l. Good results are obtained with the Spectra-Physics laser, mo dele 2016, at 488 nm and with a focusing objective of 18 μm aperture. On the epoxy as support, a writing speed of 3000 to 4000 μm / s and a power of 50 mW, give resistances of a few tens of kΩ. On the polyide, the first optimization of the results under the aforementioned conditions leads to a scanning speed of 1500 μm / s and a laser power of 50 mW. The measurement of the resistance before and after cleaning the resin is of the same order of magnitude (kΩ), which suggests very good adhesion.

These new resins are prepared by mixing as indicated in Example 1 and are spread as explained in the same Example 1.

Comparative example

Use of a resin based on palladium acetate, ethylcellulose and dimethylformamide

A resin identical to that of Example 1 is prepared, but replacing the cyanoethylcellulose by ethylcellulose. It is spread by rotation on pre-treated ceramic as in Example 1. Direct metallization of the surface of the ceramic substrate to be treated, after drying of the resin layer at a temperature of 65 ° C and direct soaking of the ceramic substrate in a catalytic bath, cannot be obtained, the resin dispersing in the catalytic bath which is thus irreparably polluted. The substrate is not metallized. In addition, this resin can only be used for 24 hours, because after this time a precipitate of metallic palladium is observed on the walls of the container.

It will therefore be concluded that the choice of the cellulose derivative of the polymeric resin is extremely important according to the results obtained, and that one cannot replace cyanoethylcellulose for resins having dimethylformamide as solvent and hydroxypropylmethylcellulose for resins having water as solvent, by other cellulose derivatives, such as, for example, ethylcellulose.

Example 3 Direct metallization of ceramic substrates and epoxides a) Direct metallization of ceramics: The resin used in this case is identical to that used in Example 1, as is the pretreatment of the supports and spreading of the resin. One ceramic thus treated is immersed in a copper catalytic bath and another in a nickel catalytic bath. After 5 minutes, the substrates covered with copper or nickel (2 μm) are removed from the baths, rinsed with water and dried (paper towel). The metallic deposits obtained are conductive and adherent (30 N / cm). b) Direct metallization of epoxides: The resin used in this case is also identical to that of Example 1, the pretreatment of the epoxy supports being carried out according to the procedure proposed by Shipley, this method consisting in passing the supports through four baths different pretreatment, with abundant rinsing with water between each bath. These baths are made up of packaging and / or cleaning solutions well known to specialists, the second bath being in particular made up of KMn0 ₄ at 60 g / liter. The purpose of this pretreatment is to clean and strip the surface of the epoxy in order to adhere the metallic layers of copper and nickel. The spreading of the resin is also done as indicated in the context of Example 1. An epoxy substrate thus treated is immersed in a catalytic bath with copper and another in a catalytic bath with nickel. After 5 minutes, the substrates covered with copper or nickel (2 μl) are removed from the baths, rinsed with water and dried (paper towel). The metallic deposits obtained are conductive and adherent (30 N / cm).

Following the spectroscopic studies which have been carried out, it appears that the polymeric resins of the invention are new complexes. In the more specific case of solutions of palladium acetate and cyanoethylcellulose, the latter not only improves the quality of the deposits and the selectivity of these may give rise to a modular viscosity, forming a polymeric film after the step of coating by rotation or "spin-coating". The cyanoethylcellulose added to the solutions of palladium acetate must not absorb the incident radiation (that is to say, it must be transparent to UV). On the other hand, it must be soluble in solvents of palladium acetate. This is the case with other solvents, such as chloroform. However, the organometallic palladium resin is only stable in dimethylformamide. On the other hand, in chloroform, after several hours, there is precipitation of a mirror of metallic palladium. When the resin consists of ethylcellulose (rather than cyanoethylcellulose), the same type of deposit of a metallic palladium mirror was observed after 24 hours. On the other hand, with PVC as a polymer, no metallic deposit could be observed after irradiation under UV lamps. Consequently, the results obtained with cyanoethylcellulose show that this polymer does not play a simple role of agent regulating the viscosity. It would also be involved in the photochemical decomposition of palladium acetate on the one hand and the stability of the resin on the other hand. In addition, in addition to the fact that the resins of the invention make it possible to carry out selective metalli¬ cial deposits, they do not require prior heat treatment, unlike the polymer solutions or suspensions of the above-mentioned patent documents. Furthermore, the catalytic bath stage is not compulsory.

It should be understood that the present invention is in no way limited to the forms of embodiment described above and that many modifications can be made without departing from the scope of this patent.

Claims

1. Polymeric resin, in particular for depositing metal on a substrate, characterized in that it comprises, in combination, a coordinating compound chosen from the group comprising palladium acetate, copper acetate, nickel acetate, copper formate, nickel formate, their hydra¬ and their mixtures, and cyanoethylcellulose, dissolved in dimethylformamide. 2. Polymeric resin, in particular for depositing metal on a substrate, characterized in that it comprises, in combination, a coordinating compound chosen from the group comprising copper acetate, nickel acetate, copper formate, nickel formate, their hydrates and mixtures, and hydroxypropylmethylcellulose, in solution in water. 3. Resin according to claim 1, characterized in that the cyanoethylcellulose corresponds to the general formula (C _t5 H ₁₉ 0 ₅ Ν ₃ ) .., in which n represents the degree of polymerization and varies from 600 to 3000. 4. Resin according to either of claims 1 and 3, characterized in that the concentrations of coordination compound and of cyanoethylcellulose are respectively from 1.10 ^"3 to 6.10 ^' ' mole and from 5 to 50 g per liter of dimethylformamide. 5. Resin according to claim 4, characterized in that the coordinating compound is hydrated copper acetate and its concentration is 2.5.10 "to 6.10" 'mole per liter of dimethylformamide. 6. Resin according to claim 4, characterized in that the coordinating compound is nickel acetate and its concentration is 3.3.10 ^" 'mole per liter of dimethylformamide. 7. Resin according to either of Claims 1 and 3, for the deposition of palladium catalytic, characterized in that -The coordinating compound is palladium acetate and its concentration, per liter of dimethylformamide, is 1.10 ^"3 to 3.10 ^' ' mole and preferably 9.10" ² mole. 8. Resin according to claim 7, characterized in that the concentration of cyanoethyl¬ cellulose, per liter of dimethylformamide, is from 5 to 50 g and preferably from 10 g. 9. Resin according to either of Claims 1 and 3, for the deposition of conductive palladium, characterized in that the coordi¬ nation compound is palladium acetate and its concentration, per liter of dimethylformamide, is from 8.10 ^"2 to 3.10 ^" 'mole and preferably from 9.10 ^{' 2} mole. 10. Resin according to claim 9, characterized in that the concentration of cyanoethyl¬ cellulose, per liter of dimethylformamide, is from 20 to 50 g and preferably from 30 g. 11. Resin according to claim 2, characterized in that the concentrations of coordination compound and of hydroxypropyl methylcellulose are respectively from 1.10 ^" to 6.10 ^" mole and from 1 to 50 g per liter of water. 12. Resin according to claim 11, characterized in that the coordinating compound is hydrated copper acetate and the concentrations of hydrated copper acetate and hydroxypropyl methylcellu¬ lose are respectively 4.10 ^" mol and 8 g per liter of water . 13. Resin according to claim 11, characterized in that the coordination compound is copper formate and the concentrations of copper formate and hydroxypropylmethylcellulose are respectively 5.5.10 ^" mole and 4 g per liter of water . 14. A method of depositing palladium on the surface of a substrate, characterized in that it consists applying a thin layer of the resin containing the palladium according to any one of claims 1, 3, 4 and 7 to 10, on the surface of said substrate, irradiating the surface of this substrate covered with this thin layer of resin by means of a visible, ultraviolet or infrared light source so as to cause a deposit of palladium on the surface of the substrate at the location of the irradiated areas and to remove the remaining layer of non-irradiated resin. 15. A method of metallizing the surface of the substrate according to claim 14, characterized in that after the removal of the remaining layer of non-irradiated resin, the substrate covered with the palladium deposit is immersed in a catalytic bath to allow depositing a metallization layer on this palladium deposit. 16. A method of depositing palladium on the surface of a substrate, characterized in that it consists in applying a thin layer of the resin containing the palladium according to any one of claims 1, 3, 4 and 7 to 10 , on the surface of said substrate and to treat the surface of this substrate covered with this thin layer of resin by a thermal source so as to cause a deposit of palladium on the surface of the substrate. 17. A method of metallizing the surface of the substrate according to claim 16, characterized in that the substrate covered with the palladium deposit is immersed in a catalytic bath to allow the deposition of a metallization layer on this palladium deposit. 18. A method of metallizing the surface of a substrate, characterized in that it consists in applying a thin layer of the resin containing palladium according to any one of claims 1, 3, 4 and 7 to 10, on the surface of said substrate, to be dried the thin layer of resin applied and immersing the substrate covered with this resin in a catalytic bath to allow the deposition of a layer of metal on said substrate. 19. The method of claim 18, characterized in that the thin layer of resin is dried at a temperature not exceeding 80 ° C, preferably between 60 and 70 ° C. 20. Method according to any one of claims 15 and 17 to 19, characterized in that the metallization layer is formed of copper and / or nickel. 21. Method according to any one of claims 14 to 20, characterized in that the resin used is formed from palladium acetate and cyanoe¬ thylcellulose in solution in dimethylformamide. 22. The method of claim 21, characterized in that the concentrations of palladium acetate and cyanoethylcellulose are respectively of the order of 9.10 ^'2 mole and 7.5 to 10 g per liter of dimethylformamide. 23. A method of depositing copper on the surface of a substrate, characterized in that it consists in applying a thin layer of the resin containing the copper according to any one of claims 1 to 5, 11 and 12, on the surface of said substrate, to irradiate the surface of this substrate covered with this thin layer of resin by means of a visible, ultraviolet or infrared laser source so as to cause a deposit of copper on the surface of the substrate at the location of the irradiated areas and removing the remaining unirradiated resin layer. 24. A method of depositing nickel on the surface of a substrate, characterized in that it consists in applying a thin layer of the resin containing the nickel according to any one of claims l to 4, 6, 11 and 13, on the surface of said substrate, to irradiate the surface of this substrate covered with this thin layer of resin by means of a visible laser source, ultraviolet or infrared so as to cause a deposit of nickel on the surface of the substrate. at the location of the irradiated areas and to remove the remaining non-irradiated resin layer. 25. A method according to any one of claims 14 to 24, characterized in that the resin layer is applied to the surface of the substrate by the so-called rotational coating technique. 26. A method according to any one of claims 14, 15 and 20 to 24, characterized in that one uses as a light source or laser an ionized argon laser adjusted in the visible. 27. Method according to any one of claims 14, 15 and 20 to 24, characterized in that a pulsed excimer laser or an ionized argon laser adjusted in the ultraviolet is used as the light source or ultraviolet laser. 28. Method according to any one of claims 14, 15 and 20 to 22, characterized in that an ultraviolet lamp is used as the ultraviolet light source. 29. Method according to either of claims 27 and 28, characterized in that the irradiation is carried out through a mask to obtain a deposit of metal of a particular design or pattern on the surface of the substrate. 30. Method according to any one of claims 14 to 29, characterized in that the substrate is a ceramic material, a polymeric material such as an epoxide, glass, silica, quartz, a fabric or a semiconductor material. 31. Method according to any one of claims 14 to 30, characterized in that it cleans the surface of the substrate before applying the resin layer. 32. Process according to claim 31, characterized in that the substrate is a ceramic material and in that the surface of the latter is cleaned by immersing it for approximately 10 minutes in a 2% solution of hydrofluoric acid and 10 % sodium chloride and then rinsing it with deionized water. 33. Process according to any one of claims 14, 15 and 20 to 32, characterized in that the remaining layer of non-irradiated resin is removed by soaking in acetone and rinsing with water, deionized or not. 34. Method according to any one of claims 14, 15 and 20 to 32, characterized in that the substrate is a ceramic material and in that the remaining layer of unirradiated resin is removed by immersing said substrate for a period of 1'order from 30 seconds to 1 minute in a solution of 2% hydrofluoric acid and 10% sodium chloride, rinsing it with deionized water, immersing it for about 5 minutes in an acetonitrile bath at ultrasound and rinsing it again with deionized water.