CN101142343A - Selective catalytic activation of non-conductive substrates - Google Patents

Abstract

A process of providing a pattern of a metal on a non-conductive substrate to create loop antennae for wireless articles, for creating circuitry for smart cards, such as phone cards, and for providing electromagnetic shielding of electronic devices is provided. The method comprises the steps of catalyzing the non-conductive substrate by applying a catalytic ink, reducing a source of catalytic metal ions in the catalytic ink to its associated metal, depositing electroless metal on the pattern of catalytic ink on the surface of the substrate; and plating electrolytic metal on the electroless metal layer to produce the desired pattern of metal on the non-conductive substrate. The catalytic ink typically comprises one or more solvents, a source of catalytic metal ions, a crosslinking agent, one or more copolymers, a polyurethane polymer, and, optionally, one or more fillers.

Description

The selective catalytic activation of non-conductive substrate

The cross reference of related application

The application is to be that the sequence number in April 30 in 2004 is the part continuation application of 10/837, No. 109 application (being similarly pending application) applying date, and the subject content of this application all is incorporated into this by reference.

Technical field

The present invention relates to make the modification method of non-conductive substrate patterning with electrolytic metal.Patterned substrate of the present invention is used to make the tours antenna that wireless articles is used, and is used to make the circuit of phonecard, also is used to electronics that the electromagnetic interference (EMI) shielding is provided.

Background technology

Many appliance and electronics need the pattern metallization of non-conductive substrate for the interconnection of electric room.The example of this type of application comprises high density packing (multi-chip module), antenna, flexible circuit, printed-wiring board (PWB) and flat-panel monitor.

RF identification (RFID) is a type of automatic recognition system.The purpose of rfid system is that data can be transmitted by a kind of handheld device that is called label (tag), and it reads by a kind of RFID reader, and is handled according to the needs of special applications.Basic rfid system is made of three parts:

Antenna or coil

Transceiver (having decoder)

Transponder (RF label), its information with uniqueness carry out the electronic program design

Comprise the mode that the wireless articles of label, identification plate, smart card etc. communicates to connect by a kind of radio frequency (RF), carry out radio communication with base station unit or reader.These article can be used to electronic recognition and follow the trail of article, personnel and transaction.Can receive by the antenna on the wireless articles by the RF signal that base station unit transmitted, perhaps can receive by base station unit with the RF signal that antenna transmitted on it, perhaps can receive by the opposing party in them by the RF signal that each transmitted in wireless articles and the base station unit by wireless articles.

The RFID label can classify as active or passive two kinds.Active RFID tag is driven by the battery of inside, generally carries out read/write operation, that is to say that the data of label can be rewritten and/or revise.The demand of the visual purposes of storage capacity of active label and changing.Passive RFID tags does not pass through independently external power source when operation, but obtains the electrical power for operation by the reader generation.

The significant advantage of all types rfid system is the noncontact that this technology had, the essence of non-direct-view.Label can see through multiple material, for example snow, mist, ice, paint, old dust and dirt and other visually with environment on disadvantageous situation and being read, and barcode or other optically read technology can't play a role in these cases.

Under each situation, all be to receive or transmit by the antenna on the wireless articles by the RF signal that wireless articles received or transmitted.Owing to wish that usually the size of wireless articles can be less, thus the antenna on it size is less too.The electrically-conductive coil pattern of RF antenna can make antenna receive in radio-frequency region and quantity of radiant energy.Antenna transmits the amplitude of RF signal for the sensitivity of little amplitude RF signal and by antenna, all is the positive function of area that tours antenna surrounded and the conductor institute pitch of the laps number that forms this ring.For compact tag or identification plate, its size has limited the area that tours antenna can surround, and has therefore also just limited the RF performance of antenna.Usually, antenna is optimised as it can be transmitted and received energy in the narrower frequency range of radio-frequency region.Radio-frequency antenna is connected with unicircuit usually.This unicircuit receives the energy from detecting unit, modulates this energy with the identification icon that is stored in the unicircuit, and then the energy that will modulate is sent to detecting unit.The RF identification tag is operated in 3GHz or higher range of frequency at 100KHz usually.

The method of having described the method for multiple assembling wireless articles in the prior art and on these type of article, having formed RF antenna and circuit.

Authorize the 6th, 333, No. 721 patents of the U.S. of Altwassen, its subject content all is incorporated into this by reference, thereby has described a kind of method that impresses out electrically-conductive coil formation RF antenna by the outside at tinsel.The shortcoming of this method is can produce a large amount of metallic scrap when making wire coil.In addition, low by tinsel by the snappiness of the RF antenna made of mode of the impression snappiness more required than many purposes.

The another kind of method that is used for forming the RF antenna of being advised is to utilize normally used peeling off (strip-back) technology when making printed circuit board (PCB).When making printed circuit board (PCB), on substrate, form layer of conductive material (being metal), and will it goes without doing the zone of antenna peel off.When making the very waste that just seems when making radio-frequency antenna in this way because a radio-frequency coil antenna covered substrate surface-area about 10%.By contrast, the area of the required covering of enforcement of general printed circuit board (PCB) is approximately 70～80%.

Another method that forms the RF antenna on non-conductive substrate is described in the U.S. the 6th that authorizes people such as Brady, 662, No. 430 patents, its subject content all is incorporated into this by reference, wherein circuit is connected with the antenna made from matrix material, and is connected for point between this matrix material and the circuit.Antenna is by the formed thickener of metal-powder, polymeric material and solvent is made by a wire mesh screens to the mode on the substrate.When thickener is still moist, contact with moist slurry by the electrical contact that makes circuit, thereby circuit and material are combined, then remove solvent again and/or polymer matrix material is solidified.

At RCD Technology, among the WO 01/69717 that Inc. proposed, its subject content all is incorporated into this by reference, has described a kind of method of utilizing conductive ink to form the RF antenna.Conductive ink is imprinted on the substrate according to the pattern of RF aerial coil, and then solidifies.But this printed antenna former state is used, or electrode can be connected with the conductive ink pattern, and then electroplates layer of metal on the conductive ink pattern.

The basic problem of RF label and identification equipment is: the cost of tag/card sheet must be reduced to littler than the cost of the product of attachment labels, could use a large amount of labels then, and mass production could further reduce cost like this.The cost of label is semi-conductor chip, antenna, carries the cost of the substrate of holding antenna and chip and attach cost.Because this kind equipment is used more and more widely, when reducing production costs, there remains a need in the art for the efficient that reaches higher in the processing procedure.

The present inventor finds, can be by using a kind of catalytic ink composite that is used to form antenna and circuit of novelty, plate one deck electroless plating composition then, then plate one deck electrolysis plating coating composition again, thereby advantageously produce antenna and circuit.The contriver also is surprised to find, and the catalytic ink prescription of novelty of the present invention can be advantageously used in provides the electromagnetic interference (EMI) shielding on electronics, and then plates no electric metal plating coating composition.

Being used for the method for EMI shielding is provided on electronics is known in the art.Authorize the 6th, 697, No. 248 patents of the U.S. of Luch, its subject content is incorporated into this by reference fully, has listed the common method of several EMI of being used for shieldings, and the problem that some occurred in these methods.

The common method that is used for shielded electronic equipment comprises that the electroconductibility barrier with reflection and/or absorbing radiation comes around electronic component.The simplest method is to select metal housing or shell to be used for shielding in theory.The sheet metal lining can be used in combination with the plastics outside surface, also must be attached on the plastic housing but trend towards costliness, and this makes assembling procedure become complicated and longer.

Developed a lot of methods and provide shielding, comprised and use conductive coating paint (it can apply by the apparatus that sprays paint of routine) and vacuum metallization processes (it comprises the electric conduction of heating metal and makes its evaporation, so that metal is condensed on the frosting) for plastic components.

The another kind of method that makes plastics have the EMI shielding comprises uses electroless deposition process to come non-conductive surface such as plastic chemistry ground coating one deck continuous metal film.Use comprises that a series of chemical steps of etching reagent and catalyzer prepare non-conductive plastic base, to accept to make metal chemical reduction and sedimentary metal level from solution.This method generally includes the copper of the highly conductive of deposition skim, is the nickel external coating (EC) then, and its protection copper internal layer is avoided oxidation and corrosion.Because electroless deposition process is a kind of dipping method, thus technology that can dependence operator within reason and on random appearance almost the uniform coating of coating, no matter its size or complicacy are how.Electroless deposition process also provides the pure metal surface of highly conductive, and it can obtain good relatively shield effectiveness.In addition, next the part of electroless plating can be electroplated, although do not use plating usually, unless part also has certain ornamental or functional demand.

But this method has comprised too many step, and is very easy to be used to make the influence of the process variables of plastic base.In addition, selective metallization, the particularly selective metallization on complicated shape be difficulty very, and this is because electroless plating tends to be coated with any surface of exposing to the open air, unless overall process is controlled meticulously.Though carried out the process that multiple trial is reduced at plating on the plastic base, this area still needs the plating plastic base so that EMI to be provided the modification method of shielding.

Though extensively disclose catalytic ink composite and plating coating catalyst in the prior art, this area still needs to can be used for to form RF antenna, phonecard circuit and provides EMI the improvement catalytic ink composite of shielding for electronics.

In the 3rd, 414, No. 427 patents of the U.S. that authorizes Levy, its subject content all is incorporated into this by reference, has described a kind of method of coming catalysis material surface to be plated by chemical reduction plating method.This method is used a kind of catalyzer, and it comprises the palladium chloride complex that is dissolved in organic solvent (being acetone).Yet this catalyzer is not very effective when catalysis non-conductive (plastics) substrate.

In the 4th, 368, No. 281 patents of the U.S. that authorizes people such as Brummett, its subject content all is incorporated into this by reference, has described a kind of method of making flexible print wiring on flexible substrate.People such as Brummett have described a kind of printing ink composite, and it comprises a kind of suitable palladium co-ordination complex.This complex compound is by chemical formula L _mPdX _nExpression, wherein L is ligand or unsaturated organic group, and Pd is the metallic palladium base of complex compound, and X is halogenide, alkyl or bidentate ligands, and m and n be integer, and wherein m is 1 to 4, and n is 0 to 3.Yet, do not point out that the described catalytic ink composites of people such as Brummett can be used to form the RF antenna and the circuit of wireless articles.

The U.S. the 5th that is authorizing Portner, 288, in No. 313 patents, its subject content all is incorporated into this by reference, a kind of plating coating catalyst has been described, it comprises a kind of catalytic particulate mixture that is scattered in the liquid coating composition, and can be used for forming the metallic coating of selective deposition.This catalytic particle is formed by the reductive metal-salt, and this metal-salt is the electroless plating catalyzer that is coated on the inert particulate carrier.This inventive method can be carried out plating with good plating speed, and forms a kind of settling, and it still can keep strong adhering to the substrate of its below under long-time situation about using.Yet this catalyzer must use with the form of thickener, and before coating catalyst, this method also needs to make the step of non-conductive substrate solvation (promptly softening).

In the 5th, 378, No. 268 patents of the U.S. that authorizes people such as Wolf, its subject content all is incorporated into this by reference, has described a kind of paint base composition, is used for the chemical metallization of substrate surface, and need not to carry out etching with oxygenant as before.This paint base composition comprises a) membrane-forming agent based on polyurethane system; B) has particular surface tensile additive; C) ionic state and/or colloidal state precious metal or its organo-metallic covalent compound; D) filler; And e) solvent.Yet, do not point out that the described paint base compositions of people such as Wolf can optionally be applied to make RF antenna or smart card circuitry.

In the 6th, 461, No. 678 patents of the U.S. that authorizes people such as Chen, its subject content all is incorporated into this by reference, has also described a kind ofly will contain the method that solvent, carrier and metal catalyst ionic catalyst solution are coated on substrate surface.But the whole surface of this catalyst solution covered substrate, or optionally only be coated on the part surface of substrate.Solvent strength in the catalyst solution layer on substrate surface can be reduced by heated substrates.By further heated substrates, can in residual catalyst layer, form metal cluster.Mode that then can electroless plating scribbles the part metal refining of catalyst solution on the surface of substrate.Then, scribble the extra metal of part deposition of catalyst solution on the surface of substrate again in the mode of electrolysis plating.Yet people such as Chen do not point out that in the summary of the invention of its description its catalyzer can be used for making the method for RF antenna or smart card circuitry yet.

Therefore, in the art, still need to overcome the improvement catalytic ink composition of many shortcomings in the prior art, and use this catalytic ink composition to make the RF antenna that wireless articles uses and the modification method of circuit, and the improvement EMI shielding of electronics need be provided.

Summary of the invention

The present invention comprises a kind of method that metal pattern is provided prevailingly on non-conductive substrate, comprise the steps:

A) by a kind of catalytic ink that comprises source of catalytic metal ions is coated on the surface of non-conductive substrate according to required pattern, come the catalysis non-conductive substrate;

B) source of catalytic metal ions in the catalytic ink is reduced to original metal;

C) the no electric metal of deposition on the catalytic ink pattern of substrate surface; And

D) on no electric metal layer the plating electrolytic metal to desired thickness, thereby on non-conductive substrate, form required metal pattern.

In a preferred embodiment, the catalytic metal ion comprises palladium ion, and it can be reduced to palladium.The catalytic metal ion that other can be reduced into original metal comprises gold, platinum, silver and copper, all can be used for the present invention.Perhaps, catalytic metal itself can directly be included among the catalytic ink.

In one embodiment, catalytic ink becomes required pattern by silk screen printing, i.e. the pattern of antenna, and be dried.Other mode of printing comprises intaglio printing, lithography and flexographic printing, also can be used to make catalytic ink to be printed as required pattern.In another embodiment, catalytic ink is printed as required pattern EMI is provided shielding.

Catalytic ink of the present invention comprises prevailingly:

A) one or more solvents;

B) source of catalytic metal ions, for example palladium, gold, platinum, silver, copper etc.;

C) linking agent;

D) one or more multipolymers;

E) polyether polyols with reduced unsaturation; And

F) one or more fillers of non-imposed selection.

Perhaps, the metal pattern on the non-conductive substrate can utilize the method that may further comprise the steps to provide:

A) by a kind of catalytic ink that comprises source of catalytic metal ions is coated on the surface of non-conductive substrate according to the profile of the required pattern form with solid pattern, come the catalysis non-conductive substrate;

B) source of catalytic metal ions in the catalytic ink is reduced to original metal;

C) the no electric metal of deposition on the catalytic ink pattern of substrate surface;

D) on no electric metal layer the plating electrolytic metal to desired thickness, thereby on non-conductive substrate, form required metal pattern;

E) according to required pattern printing UV resist; And

F) coating metal between the resist is etched away, to define required circuit.

In a preferred embodiment, the catalytic metal ion comprises palladium ion, and it can be reduced to metallic palladium.The catalytic metal ion that other can be reduced into original metal comprises gold, platinum, silver and copper, all can be used for the present invention.Perhaps, catalytic metal itself can directly be included among the catalytic ink.

Catalytic ink composite of the present invention also can be used to plating circuit on phonecard, and need not to use traditional palladium activated bath.

In this embodiment, phonecard is made according to following steps:

A) catalytic ink that will comprise source of catalytic metal ions is coated on the non-conductive substrate, and with this catalytic ink drying;

B) as previously mentioned, the source metal in the printing ink (being palladium) being reduced to valence state is zero metal (being metallic palladium);

C) resist is imprinted on the phonecard between " safety fuse " circuit, to produce circuit with gap;

D) (uncovered area of catalytic ink) goes up the deposition electroless nickel plating in the zone of exposing to the open air; And

E) plating electrolytic tin/lead on electroless nickel plating.

Description of drawings

RF antenna on the non-conductive substrate that Fig. 1 has described to be made by the inventive method.

The different views of the RF antenna on the non-conductive substrate that Fig. 2 has described to be made by the inventive method.

Fig. 3 has described the phonecard made by the inventive method.

Fig. 4 has described the position of carrying out the copper deposit thickness measurement on six positions of RF antenna.

Embodiment

The present invention relates on non-conductive substrate, provide the whole bag of tricks of metal pattern.The present invention can be used to produce the tours antenna that wireless articles is used, and is used for forming the circuit of smart card such as phonecard, and is used for providing on electronics EMI shielding.

In the first embodiment, this method comprises the steps:

A) by a kind of catalytic ink that comprises source of catalytic metal ions is coated on the surface of non-conductive substrate according to required pattern, come the catalysis non-conductive substrate;

B) source of catalytic metal ions in the catalytic ink is reduced to original metal;

C) the no electric metal of deposition on the catalytic ink pattern of substrate surface; And

D) on no electric metal layer the plating electrolytic metal to desired thickness, thereby on non-conductive substrate, form required metal pattern.

Catalytic ink preferably comprises palladium ion, and it can be reduced to metallic palladium.The catalytic metal ion that other can be reduced into original metal comprises gold, platinum, silver and copper, all can be used for the present invention.Perhaps, catalytic metal itself can directly be included among the catalytic ink.

In a preferred embodiment, catalytic ink becomes required pattern by silk screen printing, i.e. the pattern of antenna, and be dried.Other mode of printing comprises intaglio printing, lithography and flexographic printing, also can be used to catalytic ink is printed as required pattern.In another preferred embodiment, catalytic ink is printed according to required pattern, so that EMI to be provided on the electronics substrate shielding.

The representative formula of catalytic ink is as follows:

A) one or more solvents;

B) source of catalytic metal ions, for example palladium, gold, platinum, silver, copper etc.;

C) linking agent;

D) one or more multipolymers;

E) polyether polyols with reduced unsaturation; And

F) one or more fillers of non-imposed selection.

The various compositions of printing ink composite will be described in a more detailed discussion below.

After catalytic ink is printed as required pattern, the mode of the source of catalytic metal ions in the printing ink (being palladium) by being contacted with a kind of suitable reductive agent by catalytic substrate, and be reduced to metal (being that valence state is zero palladium).Though multiple reductive agent is arranged applicable to enforcement of the present invention, reductive agent preferably includes sodium borohydride, dimethylamine borane or hydrazine.

Then, with electroless metal deposition on the catalytic ink pattern on the substrate.No electric metal generally is selected from electroless nickel plating and electroless copper, though other no electric metal prescription is also applicable to enforcement of the present invention.To those skilled in the art, suitable electroless plating bath prescription is known.

At last, electrolytic metal by plating on the electroless metal deposition thing.Can be used for suitable electrolysis plating bath of the present invention is the tart electroless copper bath.Copper (or other metals) is plating to the antenna thickness of about 0.5～0.7mil usually, and selects its resistance value less than about 3.0ohm.Perhaps, electroless deposition process can be used to set up all required thickness.

When with electrolytic mode plating tours antenna, owing to will obtain quite difficulty of the uniform copper of thickness, the present invention also comprises second embodiment that can avoid this type of problem.

In this second embodiment, this method comprises the steps:

A) by a kind of catalytic ink that comprises source of catalytic metal ions is coated on the surface of non-conductive substrate according to the profile of the required pattern form with solid pattern, come the catalysis non-conductive substrate;

B) source of catalytic metal ions in the catalytic ink is reduced to original metal;

C) the no electric metal of deposition on the catalytic ink pattern of substrate surface;

D) on no electric metal layer the plating electrolytic metal to desired thickness, thereby on non-conductive substrate, form required metal pattern;

E) according to required pattern printing UV resist; And

F) coating metal between the resist is etched away, to define required circuit.

The catalytic metal ion preferably comprises palladium ion, and it can be reduced to metallic palladium.The catalytic metal ion that other can be reduced into original metal comprises gold, platinum, silver and copper, all can be used among the present invention.Perhaps, catalytic metal itself can directly be included among the catalytic ink.

Identical with first embodiment is, catalytic ink becomes required pattern by silk screen printing, i.e. the pattern of antenna, and be dried.Other mode of printing comprises intaglio printing, lithography or flexographic printing, also can be used to make catalytic ink to be printed as required pattern.In a preferred embodiment, catalytic ink becomes to have the solid striped of day line profile by silk screen printing, and is dried.

After catalytic ink was printed as required pattern, the source of catalytic metal ions in printing ink (being palladium) was reduced to metal (being that valence state is zero palladium), and, as previously mentioned, with electroless metal deposition on catalytic ink.

Acid copper with electrolysis mode by plating on no electric metal, make the thickness of solid antenna striped reach about 0.5 to about 0.7mil.Then, a kind of UV resist is preferably applied in the mode of silk screen printing according to antenna pattern, employed suitable UV resist can comprise, for example, but the UV resist of wire mark, dry film photoresist or other UV resists.At last, the plating coating copper between the resist is etched away, to define the circuit of antenna.

Catalytic ink composite of the present invention also can be used to plating circuit on phonecard, and need not to use traditional palladium activated bath.In a preferred embodiment, the phonecard substrate comprises polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene (ABS) (ABS) or polyvinylidene dichloride (PVC).

In a preferred embodiment, the PET phonecard is made according to following steps:

A) catalytic ink that will comprise source of catalytic metal ions is coated on the pet substrate, and dry this catalytic ink;

B) as previously mentioned, the source metal in the printing ink (being palladium) is reduced to original metal (being metallic palladium);

C) resist is imprinted on the phonecard between " safety fuse " circuit, to produce circuit with gap;

D) (uncovered area of catalytic ink) goes up the deposition electroless nickel plating in the zone of exposing to the open air; And

E) plating electrolytic tin/lead on electroless nickel plating.

This catalytic ink can or well known to a person skilled in the art that additive method applies by blank silk screen print method.

Each step of the present invention will be described in more detail hereinafter.

Discuss as the front, the typical composite of the catalytic ink of this novelty of the present invention comprises:

A) one or more solvents;

B) source of catalytic metal ions is selected from the group that combination constituted by palladium, gold, platinum, silver, copper and aforementioned metal;

C) linking agent;

D) one or more multipolymers;

E) polyether polyols with reduced unsaturation or tackiness agent; And

F) one or more fillers of non-imposed selection.

Employed solvent a kind of solvent of rapid evaporation normally in the catalytic ink composite of the present invention.Usually, the group that ester constituted of the optional free aromatic hydrocarbon of the solvent of catalytic ink and aliphatic hydrocarbon, glycerine, ketone, ester, glycol ethers and glycol ethers.More specifically, this solvent can comprise toluene, dimethylbenzene, glycerine, acetone, methyl ethyl ketone, pimelinketone, isophorone, butylacetate, dioctyl phthalate (DOP), butyl glycolate, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, ethylene glycol ethyl ethers acid esters, propylene glycol methyl ether acetate, methyl propyl ketone, Methyl amyl ketone and/or Pyranton.Other can not produce reaction with the composition that constitutes the printing ink composite, and the meeting rapid evaporation, and promptly boiling point is lower than about 90 ℃ suitable solvent, also is known for a person skilled in the art.The also mixture that can use multiple solvent to constitute.In a preferred embodiment, solvent is a pimelinketone.The usage quantity of solvent is generally about 50 to about 80 weight % of catalytic ink composition, and preferred about 55 to about 75 weight %.The consumption of solvent is decided on desired method of cooling.

In an alternative embodiment, do not use the catalytic metal ion, but catalytic metal particles itself is contained in the printing ink, thereby need not carry out follow-up reduction reaction.Yet, use metallic particles will make accurate printing-ink become more difficult.

In a preferred embodiment, the catalytic metal ion comprises palladium, and the palladium source in the catalytic ink composition of the present invention generally is to be selected from Palladous chloride, acid chloride and palladous sulfate.In one embodiment, the palladium source is Palladous chloride formed solution in having the water of hydrochloric acid of about 10% to about 20%.In an alternative embodiment, the palladium source is about 0.1% to about 2% the solution of acid chloride in pimelinketone.Though the palladium source is described to Palladous chloride or acid chloride, the present invention is not limited to these compounds.The contriver also considers gold, platinum, silver and copper compound, and they are normally known to those skilled in the art.These examples for compounds can be in people's such as the 5th, 855, No. 959 patents of the U.S. of people such as Boecker, Ferrier the U.S. the 5th, people's such as 518, No. 760 patents and Tisdale the U.S. the 5th, 443, find in No. 865 patents, its subject content all is incorporated into this by reference.The consumption in the source of palladium or other catalytic metals is generally about 1 to about 2 weight % of catalytic ink composite.

The linking agent of catalytic ink composite generally includes polymeric polyisocyanate.Other linking agents that also are suitable among the present invention comprise superoxide, for example benzoyl peroxide, methylethyl ketone peroxide etc.As for the example of isocyanate crosslinking, following several isocyanic ester are typical: various isomeric tolylene diisocyanates and its mixture; The hexamethyl vulcabond; Diphenylmethanediisocyanate; The affixture of TriMethylolPropane(TMP) and tolylene diisocyanate etc.The consumption of linking agent is generally about 1 to about 3 weight %.

When isocyanate-crosslinked, crosslinked action is undertaken by the end-OH base of printing ink polyester portion, and small portion is undertaken by the hydroxyl on substrate-OH part and other components.Because isocyanic ester can be a kind of multi-functional isocyanic ester with 2 to 4 or more a plurality of isocyanate groups, reaction can produce a kind of full cross-linked printing ink, and it can fully be attached to general substrate, for example Mylar ^(can available from the pet film of DuPont company).

The optional free acrylic copolymer of multipolymer, by ethylene copolymer, the chlorination of vinylchlorid or the group that non-fluorinated copolymers and other similar compounds constituted that acrylate or vinyl-acetic ester form, it can be used singly or in combination.In a preferred embodiment, multipolymer comprises vinylchlorid and Propylene glycol monoacrylate.Multipolymer accounts for about 3 to about 10 weight % of catalytic ink composite usually.

The catalytic ink composite also comprises a kind of polyether polyols with reduced unsaturation.The solvent that polyether polyols with reduced unsaturation is dissolved in the catalytic ink composite usually is in the pimelinketone.The content of this urethane/solvent mixture is generally about 3 to about 10 weight % of catalytic ink composite.

Catalytic ink composition of the present invention also contains one or more fillers, its optional free talcum, the oxide compound of manganese, titanium, magnesium, aluminium, bismuth, copper, nickel, tin, zinc and silicon, silicate, wilkinite, chalk, electrical conductivity Carbon black, and the group that mixture constituted of aforementioned substances.In a preferred embodiment, these one or more fillers comprise talcum and pyrolytic silicon dioxide.Filler accounts for about 10 to about 30 weight % of catalytic ink composite usually.In catalytic ink composite of the present invention, preferably use about 15 to arrive the talcum of about 25 weight % and about 0 to about 5 weight % pyrolytic silicon dioxide.

The catalytic ink composite can be coated on the substrate in several ways, for example well known to a person skilled in the art dipping, spraying, (slide) coating of sliding, slit (slot) coating, roller coat, Meyer rod (Meyer-rod) coating, intaglio plate is coated with and the method for blade coating, can be used for the whole surface of coated substrates.Coating can be so that the substrate surface complete metalization fully.Patterned if desired metallization can be used to well known to a person skilled in the art that engraving method removes the selection area of complete coating layer.Perhaps, utilize method, catalyst solution only is coated in the selected zone of substrate surface as silk screen printing, flexographic printing, drawing, ink jet printing and intaglio printing.Substrate surface has only the place that has applied catalyst solution to be metallized.Therefore, the substrate metalization of the patterning of catalyst solution coating can formation patterning.

The viscosity of (thixotropy) of the present invention catalytic ink composite is preferably about 1000 in the scope of about 8000cp, and more preferably from about 3000 to about 6000cp (in shearing rate is 200 seconds ^-1Condition under record), so that printing ink can be imprinted on the substrate by the mode of silk screen printing.If use other modes as intaglio printing, lithography or flexographic printing that the catalytic ink composite is printed on the substrate, then the viscosity of catalytic ink composite will be adjusted according to selected printing process.

Non-conductive substrate can be by polymer formation, as polyimide, polyethylene terephthalate (PET), Mylar ^, polyester, polycarbonate, ABS, PVC, paper or White Board and other are at similar substrate known in the art.Preferred use a kind of resilient material, make system's deflection.In a preferred embodiment, non-conductive substrate is a polyethylene terephthalate.The thickness of substrate is generally about 0.75mm (about 0.03 inch), but can 0.05 to 1.0mm (about 0.002 to 0.040 inch, promptly in 2～40mil) the scope.Other spendable baseplate materials comprise polyimide, polyimide-acid amides, polyparabanic acid, polycarbonate, polysulfones, polyamine, cellulose triacetate etc.For EMI is provided the situation of shielding, the substrate of electronics is made up of PET or polyimide usually.

Then, utilize a kind of suitable reduction/activator, make the source of catalytic metal ions in the catalytic ink composite be reduced into original metal (or title " activation ").The reductive agent preferred package contains sodium borohydride.Other can be used for hydrazine vitriol and two hydrazine vitriol that reductive agent of the present invention comprises hydrazine, hydrazine hydrate, sodium hydroxide.

Activation can be finished multinomial important task:

1) by the catalytic metal ion being reduced into original metal and making metal diffusing form the mode of cluster, produced catalytic metal (being palladium) cluster by nucleation and growth;

2) make the polymeric carrier polymerization in the catalyst ink or make its curing, to promote that solidified carries intravital cohesive strength; And

3) promote molecule phase mutual diffusion between substrate and the polymeric carrier, caused the sticking power between substrate and the solidified polymeric carrier to promote.

After the activation, can utilize electroless deposition process to make metal deposition on catalysis and activatory substrate.To those skilled in the art, electroless deposition process is normally known.Plating is selected from the group that is made of electroless copper, electroless nickel plating and its combination usually in the no electric metal of catalytic ink.The bath composition that is used for electroless copper for example is disclosed in the 4th, 368, No. 281 patents of the U.S. of authorizing people such as Brummett, and its subject content all is incorporated into this by reference.Other metal bath compositions that can be used for electroless deposition comprise gold and silver and palladium, all are disclosed in the prior art, for example authorize the 3rd, 937, No. 857 patents of the U.S. of people such as Brummett, and its subject content all is incorporated into this by reference.

Then utilize the electrolysis plating on formed foundation metal layer, to deposit extra metal, make it reach required thickness with electroless deposition process.The electrolysis plating has more efficient (the electrolysis plating has higher plating speed) than electroless plating.The electrolysis method for plating comprises by anode and applies electric current, reduces the required electronics of chemical reaction to be provided at negative electrode, and this method is known to those skilled in the art.

Electrolytic metal generally is to utilize the tart electroless copper bath to come plating.Perhaps, the electroless deposition thing of further plating palladium or gold on copper deposit.The electrolysis plating bath that is fit to also is disclosed in the 4th, 368, No. 381 patents of the U.S. of authorizing people such as Brummett, and its subject content all is incorporated into this by reference.

Usually, with the resistance value of the metal deposit of electrolysis mode plating less than about 3.0ohm.

Fig. 1-Fig. 3 has described to utilize the RF antenna that method of the present invention produces and the various views of circuit on non-conductive substrate.Fig. 1 and Fig. 2 have proposed the example of two kinds of RF antennas making according to the inventive method.For each RF antenna, on six positions of RF antenna, measure the thickness (these six location marks are in Fig. 4) of copper deposit.These measuring results are listed in table 1 and the table 2.

Table 1: obtained reading on the RF antenna depicted in figure 1

Reading	mil Cu
		1	1.321
2	0.963
		3	0.469
4	0.261
		5	0.193
6	0.183

Table 2: obtained reading on the RF antenna depicted in figure 2

Reading	mil Cu
		1	0.522
2	0.503
		3	0.812
4	0.911
		5	0.832
6	0.659

What Fig. 3 described is the circuit of actual phonecard.Thickness at five position measurement electrolytic tin/lead deposit things of phonecard circuit the results are shown in table 3.

Table 3: obtained reading on the phonecard circuit depicted in figure 3

Reading	mil SnPb	％Sn	％Pb
				1	0.413	79.600	20.402
2	0.424	78.763	21.242
				3	0.426	78.374	21.631
4	0.431	78.324	21.682
				5	0.434	79.071	20.935
On average	0.426	78.826	21.178

In the specific embodiments that the EMI shielding is provided for non-conductive substrate, catalytic ink of the present invention preferably is coated on the non-conductive substrate by the mode of silk screen printing, on selected zone, to provide catalytic ink.As needs, can use other printing process, as intaglio printing, lithography and flexographic printing, replace silk screen printing.Then with the catalytic ink drying, and be reduced into catalytic metal as mentioned above.To not have the pattern of electric metal according to catalytic ink then, with about 0.5～2.0 micron, the thickness of preferred about 1 micron (40 microinch) is deposited on the non-conductive substrate.No electric metal also can be deposited on the catalytic ink with other thickness.In addition, as needs, but the deposit multilayer catalytic ink.Those skilled in the art select metal and required thickness according to its general knowledge according to concrete should being used for.In a preferred embodiment, no electric metal is an electroless copper.

As needs, can carry out the test of cross score adhesive tape adhesive power to estimate the adhesive power of coating on the non-conductive substrate.The test of adhesive tape adhesive power can be carried out according to ASTM D-3359.

For make a kind of preservation period limit for length's catalytic ink composition, this catalytic ink can be used as two-component system and uses, wherein reactant is preserved with different separately composite forms, just only mixed before using.Then spontaneously produce reaction, or come accelerated reaction by heat and/or suitable catalyzer.

Claims (21)

1. the method for a plating on non-conductive substrate, this method comprises the steps:

A) a kind of catalytic ink is coated on the part surface at least of non-conductive substrate, wherein this catalytic ink comprises:

I) solvent;

Ii) source of catalytic metal ions;

Iii) linking agent;

Iv) multipolymer; With

V) polyether polyols with reduced unsaturation;

B) with suitable reductive agent this source of catalytic metal ions is reduced to original metal; And

C) coating metal on the catalytic ink that is coated on the part surface of non-conductive substrate.

2. the method for claim 1, wherein this catalytic ink applies by the mode with silk screen printing, intaglio printing, lithography or flexographic printing.

3. the method for claim 1, wherein this solvent is selected from the group that ester constituted by aromatic hydrocarbon and aliphatic hydrocarbon, glycerine, ketone, ester, glycol ethers and glycol ethers.

4. method as claimed in claim 3, wherein this solvent is selected from the group that combination constituted by toluene, dimethylbenzene, glycerine, methyl ethyl ketone, pimelinketone, butylacetate, dioctyl phthalate (DOP), butyl glycolate, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, ethylene glycol ethyl ethers acid esters, propylene glycol methyl ether acetate, acetone, isophorone, methyl propyl ketone, Methyl amyl ketone, Pyranton and above-mentioned substance.

5. method as claimed in claim 4, wherein this solvent is a pimelinketone.

6. the method for claim 1, wherein this catalytic metal ion is selected from the group that combination constituted by palladium, gold and silver, platinum, copper and above-mentioned substance.

7. method as claimed in claim 6, wherein this catalytic metal ion comprises palladium.

8. method as claimed in claim 7, wherein the palladium source is selected from the group that is made of palladium chloride and acid chloride.

9. method as claimed in claim 8, wherein the palladium source is palladium chloride formed solution in having the water of hydrochloric acid of about 10% to about 20%.

10. method as claimed in claim 8, wherein the palladium source is about 0.1% to about 2% the solution of acid chloride in pimelinketone.

11. the method for claim 1, wherein this linking agent is a polymeric polyisocyanate.

12. the method for claim 1, wherein this multipolymer comprises vinylchlorid and Propylene glycol monoacrylate.

13. the method for claim 1, wherein this catalytic ink comprises one or more fillers, and this filler is selected from by talcum, the oxide compound of manganese, titanium, magnesium, aluminium, bismuth, copper, nickel, tin, zinc and silicon, silicate, wilkinite, chalk, carbon black, and the group that combination constituted of aforementioned substances.

14. method as claimed in claim 13, wherein these one or more fillers comprise talcum and pyrolytic silicon dioxide.

15. the method for claim 1, wherein this non-conductive substrate is selected from the group that is made of polyimide and polyethylene terephthalate.

16. the method for claim 1, wherein this source of catalytic metal ions is reduced into original metal by a kind of reductive agent of selecting from the group that is made of sodium borohydride, hydrazine, hydrazine hydrate, hydrazine vitriol and two hydrazine vitriol.

17. method as claimed in claim 16, wherein this reductive agent is a sodium borohydride.

18. the method for claim 1, wherein this metal is selected from the group that is made of electroless copper, electroless nickel plating and its combination.

19. method as claimed in claim 18, wherein this metal is an electroless copper.

20. the method for claim 1, wherein this metal is plating to about 0.5～1.5 micron thickness.

21. electromagnetic interference coated substrates of making by the described method of claim 1.

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