WO2009110902A1

WO2009110902A1 - Electrically conductive compositions

Info

Publication number: WO2009110902A1
Application number: PCT/US2008/056039
Authority: WO
Inventors: Chih-Min Cheng; Jesse S. Tillotson; Jing Fan; Allison Yue Xiao; Hui Yang; Junbiao Lu; Gunther Dreezen; Gordon Seeley; Judith Earnshaw; Derek A. Graham
Original assignee: Henkel Ag & Co.Kgaa
Priority date: 2008-03-06
Filing date: 2008-03-06
Publication date: 2009-09-11
Also published as: TW200939250A

Abstract

Electrically conductive composition of the invention comprises base metal, a functional additive, and a resin binder. The electrically conductive compositions are particularly useful in packaging consumer products such as electronic devices and electronic components.

Description

3289 EM ELECTRICALLY CONDUCTIVE COMPOSITIONS

Field of the Invention

The present invention relates to electrically conductive compositions.

Background of the Invention

Most commercial electrically conductive compositions use noble metals as filler for conductivity development. Noble metals are resistant to corrosion or oxidation, and the oxides that form on the noble metals are electrically conductive. However, noble metals are high in cost and some, e.g. silver, can lead to migration problems

A need continues to exist in the art for an electrically conductive composition with low cost and no migrations that do not sacrifice electrical conductivity The invention fulfills this need.

Summary of the Invention

The addition of a functional additive to conductive composition containing non-noble metals, specifically base metals, gives improved conductivity over those base metal filled compositions that do not contain a functional additive. The electrically conductive compositions are particularly useful in packaging consumer products such as electronic devices and electronic components.

The addition of some functional additives imparts improved electrical conductivity For other functional additives, the composition may advantageously be formulated to impart improved initial electrical conductivity and maintain stable electrical conductivity over a prolonged aging condition, 85°C and 85% relative humidity in for more than at ieast 400 hours (85°C/85RH) Further, addition of selective combination of functional additives result in synergy where the composition imparts improved initial eSectπcal conductivity and maintains stable electrical conductivity over prolonged aging condition.

One embodiment is directed to an electrically conductive composition comprising base metals, a functional additive, and a resin binder In another embodiment, the composition is directed to an electricaϋy conductive composition that comprises copper, a synergistic combination of functional additives, and a resin binder

Another embodiment of the composition is directed to an electrically conductive composition that comprises copper, a functional additive or a synergistic combination of functional additives, and a resin binder.

In a further embodiment, the functional additive of the electrically conductive composition is selected from the group consisting of reducing sugars, cyclic borane complexes, aromatic sulfonic acids, phosphorus acids, long chain ascorbic acid esters, di-ketones, oximes, monoacids, Schiff bases, and their derivatives; and mixture of phenolic with alcohol, mixture of organic diacids with alcohol, mixture of heterocyclic aromatic organic compounds with alcohol, mixture of acid with alcohol with amino alcohol, and mixtures of di-ketone with oxime to impart improved electrical conductivity

Yet in a further embodiment, the functional additive of the electrically conductive composition is selected from the group consisting of long chain ascorbic acid esters, di-ketones, oximes, monoacids, Schiff bases, phosphorus acids, and their derivatives, and mixture of phenolics with alcohol, mixture of organic diacids with alcohol, mixture of heterocyclic aromatic organic compounds with alcohol, mixture of acid with alcohol with amino alcohol, and mixtures of di-ketone with oxime to impart improved electrical conductivity and maintain stable electrical conductivity over prolonged aging condition

In another embodiment, the electrically conductive composition comprises base metals, a functional additive or a synergistic combination of functional additives, a resin binder and optionally a solvent.

In a further embodiment of the composition is directed to an electrically conductive composition comprising base metals, a functional additive or a synergistic combination of functional additives, a resin binder and optionally a curing agent and/or catalyst

Another embodiment of the composition is directed to electrically conductive composition comprising base metals, a functional additive or a synergistic combination of functional additives, a resin binder and optionally an adhesion improver, coupling agent, and/or a curing accelerator. Yet in another embodiment of the composition, the electrically conductive composition comprises from about 20 to about 95 % by weight of the base metals, from about 0.01 to about 30 % by weight of functional additive or a total combination of functional additives, and from about 5 to about 90 % by weight of resin binder, based on total weight of the composition.

In a further embodiment, the electrically conductive composition may be in the form of a coating, ink, paste, film, grease, adhesive, tape, encapsulant, and other forms known in the art

Another embodiment provides articles manufactured using the electrically conductive composition of the invention. Encompassed include RFID tags, photovoltaic capacitors, lead-free solder alternatives, printable electronics, thermai interface materials, multilayer ceramic capacitors, piezeoelectronic components, electromagnetic shielding components, and the like

Still another aspect is directed to a process of sealing and/or making or forming an electronic devices and electronic components These processes comprise using the electricaiiy conductive composition of the invention on electronic devices

Detailed Description of the Invention

"Base metals" herein is used to refer to metal that oxidizes or corrodes relatively easily and include copper, iron, nickel, lead, zinc, tin, bismuth and its alloys.

"Noble metals" herein is used to refer to metals that are precious metals that are resistant to corrosion or oxidation and include gold, silver, tantalum, platinum, palladium and rhodium.

"Functional additives" herein is used to refer to additives, reducing agent and/or a complexing agent, that are added to base metals to impart improved electrical conductivity and/or maintain stable electrical conductivity.

Electrically conductive composition of the invention comprises base metals, a functional additive, and a resin binder Any base metal may be used as electrically conductive fillers in the electrically conductive composition. Examples of base metals include copper, iron, nickel, lead, zinc, tin, bismuth, and its alloys. In one embodiment, the base metal is copper. Although copper is highly electrically conductive, copper oxide is not as highly conductive. Copper oxide forms on the surface of copper upon contact with atmosphere and can ultimately prevent electrical conductivity of the composition

The shape of the copper powder is not limited, and the powder may take various forms such as flake, dendrite or spherical. Various copper powder forms may be used alone or in combination as a mixture of two or more different shapes.

The particle size of the copper powder is selected depending upon the particular purpose of the composition, and the upper limit for electrically conductive composition is at about 300 μm. In one embodiment, the copper filler particle size is from about 1 μm to about 100 μm. In another embodiment, the particle size ranges from about 3 μm to about 30 μm.

In one aspect, the total amount of copper in the electricaiiy conductive composition range from about 50% to about 95% by weight of the totai weight of the composition (excluding solvent) In another aspect, the total amount of copper powder is range from about 65% to about 95% of the electrically conductive composition.

It has now been discovered that the addition of a functional additive to conductive compositions containing base metals give improved conductivity over those base metal filled compositions that do not contain a functional additive. It is believed that the functional additives of the invention decrease the resistance by either reducing the oxidized from the base metal or complexing with the base metal to form a soluble complex Three different types of functional additives have been discovered. One, Functional Additive Group I imparts improved initial electrical conductivity. Two, Functional Additive Group Il imparts improved initial electrical conductivity and maintain stable electrical conductivity over the prolonged aging condition (85°C and 85% relative humidity), herein "aging condition". Three, specific mixtures of Functional Additive Group III synergistically imparts improved initial electrical conductivity and maintain stable electrical conductivity over the aging condition. Functional Additive Group I Reducing agents and/or complexing agents of Functional Additive Group I improve the initial electrical conductivity of compositions formulated with base metals. Without the Functional Additive Group I, the compositions with the base metal results in high resistance and cannot be used as electrically conductive composition. Exemplary Functional Additive Group 1 include reducing sugars, cyclic borane complex, aromatic sulfonic acids, phosphorus acids, and their derivatives

In one aspect, the functional additive is a reducing sugar and its derivatives Exemplary reducing sugars include D-glucose, D-ribose, and the like.

In yet another aspect, the functional additive is a cyclic borane complex and its derivatives. The cyclic borane complex include cyclic borane complexes having nitrogen as a ring forming member and cyclic borane complexes having sulfur as a ring forming member In another aspect, the cyclic borane complex is borane-morphαlme, borane-4-methylmorpholιne, boraπe-4-ethylmorpoiine, borane-pyridine, borane-N,N-diethylaniline, borane-1_τ4-oxathιane, borane-piperidine, borane-piperazine, borane 2,6- lutidme complexes, and the like

In a further aspect, the functional additive is an aromatic sulfonic acid and its derivatives, where the sulfonic acid functional group is directly attached to an aromatic ring. In a non-limiting aspect, the aromatic sulfonic acid is 4-dodecylbenzenesulfonιc acid and its derivatives

In another aspect, the functional additive is phosphorus acid and its derivatives Non-limiting examples include phenylphosphonic acid, 1-diphosphoinc acιd, phosphoric acid, short-chain phosphoric acid ester, phosphate monomer w/ hydrophilic extender, 1 -hydroxyethane-1 , and derivatives of this group Functional Additive Group Il

Reducing agents and/or complexing agents of Functional Additive Group Il improve the initial electrical conductivity and maintain stable electrical conductivity for more than 400 hours under the aging condition for composition with base metals. Exemplary Functional Additive Group Il includes long chain ascorbic acid esters, di-ketones, σximes, Schiff bases, phosphorus acid, monoacids, and derivatives of this group In one aspect, the functional additive is a long-chain ascorbic acid ester presented by the general formula.

OR₄ where R₁ is H, saturated or unsaturated C₁ - C₃₀ alkyl group; R₂ ,R₃ and R₄ are H, saturated or unsaturated C-_I - C₃₀ alkyl group or saturated or unsaturated carbonyl group. In a non-limiting aspect, R₂ ,R₃ and R₄ are H in the above formula In another non-limiting aspect, the long-chain ascorbic acid ester is ascorbic acid 6-palmιtate The long-chain ascorbic acid ester is cured and/or dried at temperature above 18O⁰C to activate the redox reaction between the meta! oxide and the additive.

In another aspect, the functional additive is a di-ketone and its derivatives Non-limiting examples of di-ketone based complexing agent include acetyiacetone, ethyl diacetoacetate, 2- thenoyltπfluoroacetone, and the like.

Yet in another aspect, the functional additive is an oxime and its derivatives. An oxime has a general formula of RiR₂-CNOH, where R₁ is saturated or unsaturated C₁ - C₃₀ alkyl group, and R₂ is H, saturated or unsaturated C₁ - C₃₀ alkyl group. Exemplary oxime is dimethoylglyoxime and its derivatives.

In a further aspect, the functional additive is a Schiff base and its derivatives. Non-limiting examples of Schiff base include N,N-bis(salicylidene)-ethylene diamine, N,N-bιs(salicylidene)-1 ,4-butane diamine, and the like.

In another aspect, the functional additive is phosphorus acid and its derivatives. Non-limiting examples include vinyl phosphonic acid, nιtπlotris(methylenephosphonιc acid) water solution, phosphorous acid solution, and derivatives of this group.

Yet in another aspect, the functional additive is a mono-acid and its derivatives. The mono acid derivatives are unsubstituted formamide, substituted formamide, unsubstituted formate, and substituted formate. In a non-limiting aspect, the mono acid is a formic acid and a formate, e g methylformate, ethylformate, butyiformate, ammonium formate, formamide, dimethylformamide, and diethylformamide Functional Additive Group III

The Functional Additives Group III for use in formulating the electrically conductive composition of the invention is synergistic mixtures of functional additives. These specific mixtures synergistically impart improved initial electrical conductivity and maintain stable electrical conductivity under the aging condition for composition with base metals. It has been demonstrated that the specific combinations have improved initial electrical conductivity and stable electrical conductivity under the aging condition over its non- combined additive. Exemplary Functional additive Group III combinations are phenolics with alcohol combination, organic diacids with alcohol combination, heterocyclic aromatic organic compounds with alcohol combination, and acid with alcohol with amino alcohol combination.

In one aspect, the functional additive is a synergistic combination of phenolic with alcohol. The phenolic functional additive is an aromatic material having at [east one hydroxy! group Non-limiting examples of the phenolic group include polyvinyl phenol) and 1 ,4-benzene-dimethanol, which contain the Ar-OH and the Ar-CH₂-OH functionalities present in phenolic resins, respectively. Non-limiting example of alcohol includes glycerol.

In another aspect, the functional additive is a synergistic combination of an organic diacid with alcohol Exemplary organic diacids have low volatility, with a boiling point above about 120^cC, represented by the general formula:

Where n>0 Non-limiting examples of organic diacid include oxaiic acid, succinic acid, and the like. Non-limiting example of alcohol includes glycerol.

In a further aspect, the functional additive is a synergistic combination of heterocyclic aromatic organic compounds with alcohol. Non-limiting example of heterocyclic aromatic organic compound includes 8-hydroxyquinolιne and its derivatives. Non-limiting example of alcohol includes glycerol.

Yet in another aspect, the functional additive is a synergistic combination of an acid, alcohol with amino alcohol Examples of acid include acetic acid Examples of alcohol include glycerol Examples of amino alcohol include tri-ethanolamine.

In genera!, the total amount of functional additives used to prepare the electrically conductive composition ranges from about 0 01 to about 30 % by weight of the total weight of the composition (excluding solvent).

In addition to base metals and functional additives, the electrically conductive composition also comprises a resin. The term resin, as used herein, refers to a polymer that has a binding effect and allows interparticle contact of base metals upon cure/dry of the composition for its end-use application. The end-use application may be in the form of a coating, ink, paste, film, grease, adhesive, tape, encapsulant, and other forms known in the art.

Exemplary resin include epoxy-based, vinyl-based, polyester-based, phenolic-based, or acrylic- based, polyimide-based, polyurethane-based, melamine-based, urea-based, polycarbonate-based, polyallylsulfone-based, amino-based, cellulosic-based, a phenoxy-based, melamine-based, silicone- based resin or mixtures thereof.

In general, the total amount of resin used to prepare the electrically conductive composition ranges from about 5% to about 90% by weight of the total composition (excluding solvent). In one embodiment, the electrically conductive composition contains from about 10% by weight to about 50% of resin, by weight, based on a total weight of the electrically conductive composition.

For the preparation of an electrically conductive composition, above mentioned resin may optionally be used with an organic solvent Non-limiting examples of such solvents include aromatic compound, an ester, an ether, a ketone or an alcohol For example, ethylene glycol or diethylene glycol derivatives such as ethylene glycol monomethyl ether acetate, ethylene glycol moπoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether and the like, esters such as butyl acetate, amyl acetate, cyclohexyl acetate, methyl acetoacetate, ethyl acetoacetate, dimethyl adipate, dimethyl glutarate, dimethyl succinate and the like; ketones such as methylethylketone, cyclohexanone, methylcyclohexanone, diisobutylketone, isophorone and the like. These solvents may be used singly or in combination.

A resin may also be blended with water in an emulsion.

In general, the total amount of solvent and/or water may be up to about 60 %, by weight, of the electrically conductive composition.

In a non-limiting aspect, the electrically conductive composition may further comprise a curing agent and/or catalyst. Non-limiting examples of curing agent and/or catalyst include acid-based, anhydride-based, amine-based (inciuding aliphatic, aromatic, and modified amines), tertiary and secondary amine-based, polyamide-based, imidazole-based, polymercaptan-based, amino-amide-based, boron trifluoπde-amine complex-based, dicyandiamide-based, organic acid hydrazides-based, and derivatives of this group. Suitable curing agent and/or catalyst, in general, will be all those that are known to catalyze or are capable of catalyzing the self-ring opening reaction of an epoxide group

The total amount of curing agent and/or catalyst used to prepare the electrically conductive composition may be up to about 10%, by weight of electrically conductive composition.

The electrically conductive composition may further comprise other optional components as long as they do not impair the properties of the composition Such components may include an adhesion improver, such as a siiicon coupling agent, a titaπate coupling agent, an aluminum coupling agent, and a curing accelerator such as an aliphatic polyamine and an aromatic poiyamine.

The electrically conductive composition is useful to bond components of electronic circuit structures. The electrically conductive composition may be used to bond plurality of electronic circuit components together. The composition of the present invention may be cured or dried to form a shaped article by a conventional method for curing or drying a resin binder.

The temperature for curing or drying the composition varies depending upon the type of the resin binder and additive agents and the intended purpose of the composition, but is usually within a temperature range of from room temperature to 350°C, preferably from room temperature to 250⁰C. For the curing and/or drying of the composition of the present invention, there may be employed a process in which the composition is coated or printed on e.g. a film or sheet of a polyester or polyaliyS sulfone resin, a phenolic resin-laminated board, an epoxy resin-laminated board, or a polyimide film, followed by curing or drying, or a method wherein the composition is poured into a mold and cured therein. The electrically conductive composition may also be pre-applied on a substrate and B-staged to later become reactivated by means of heat or radiation.

The electrically conductive composition may be used in a variety of consumer products such as electronic devices and electronic components Non-limiting examples of such electronic components include RFiD tags, photovoltaic capacitors, lead-free solder alternatives, printable electronics, thermal interface materials, multilayer ceramic capacitors, piezeoelectronic components, electromagnetic shielding components, and the like.

The process of sealing and/or making electronic devices includes applying the electrically conductive composition on the joint interconnection and curing and/or drying the composition A pre- application step is contemplated, where the electrically conductive composition is applied and B-staged to later become re-activated by heat or radiation.

The invention is further illustrated by the following non-limiting examples. Examples The formulations were prepared by first preparing a mixture of resin and solvent Some resins were difficult to disperse in solvent and required some heating. The rest of the components were added and stirred until a homogenous mixture was achieved at room temperature.

Each formulation was then applied onto a substrate with 5-1 Omm x 5cm x 15-200μm (typical thickness after cure/dry 30-50μm) The formulations were then cured and/or dried according to the method of cure/dry. Unless specified otherwise, the cure/dry was performed in air The tract resistance of cured/dried formulation was measured using a Keithley 580 micro-ohm meter. The thickness was measured using a Mitutoyo 0 001 mm digital micrometer The width was measured using a Mitutoyo 0.01 mm digital caliper. The electrical conductivity was then expressed by calculating the electrical volume resistivity (Vr) at room temperature using the following equation¹

Vr = (R x W x T)/L, where

R = track resistance in Ω measured in length, W = width of tack in cm; T = thickness of track after curing/drying in cm, L = length of track in cm

As demonstrated in Table I, the use of Functional Additives Group I resulted in improved initial conductivity over Comparative A formulation Table I. Formulation with Functional Additive Group I

a Cu RD88 available from Ferro Corp, OH b resin: DIACON MG 102 {Lucite International, TN), PKHC (Inchemrez Corporation, SC); A-11 acrylic resin (Rohm & Haas, PA), or VAGH copolymer {DOW Chemical, Ml) c solvent: butyl Cellosolve acetate { Eastman Chemical Company, TN); 2-butoxyethyi acetate {Sigma- Aldrich); or 2-butanone {Sigma-Aldrich) d curing catalyst¹ Cymel 301 (Cytec Industries, NJ) and/or Nacure 5414 (King Industries, CT)

It should be understood that the phosphorus acid functional additives of Group I are not limited to the above examples, if the resultant formulation has a volume resistivity lower than 6.5 x 10-3 Ω-cm. It should also be understood that the phosphorus acid functional additives do not include 1- Hydroxyethylidene-diphosphonic acid, dibutylphosphate, vinyl phosphonic dimethyl ester, triphenylphosphite, triphenylphosphate, phosphate monomers with hydrophobic extender polymer (PAM 200, Rhodia), and phosphate monomers with hydrophobic monomer (PAM 300, Rhodia) since the resultant formulations have volume resistivity greater than 6.5 x 10-3 Ω-cm.

As demonstrated in Table Ii, the use of the Group Ii functional additives imparted improved initial conductivity and stable conductivity under aging condition over the Comparative A formulation Table Il Formulation with Functional Additive Group Il

Formulation Functional Additive (g) Other Method Initial Vr Aged Vr component (g) of (Ω cm) (Ωcm)/hr cure/dry

9 2 69 67.15^a 180C/ 8.64 x 10-4 2.75 x 10-3

Ascorbic acid 6- 14 48^b 15min /600hr paimitate¹ 13 73°

1.95^d 10 3.31 69.6a RT 2.4 x 10-4 7 8 x 10-4

Acetylacetone¹ 9.01 ^b overnight /500hr

18 08^c

11 3.53 74.93^a RT 8.2 x 10-4 2.2 x 10-2

Ethyl diacetoacetate¹ 9.67^b overnight /500hr

11.87 ^C

12 3.3 69. T RT 3.7 x 10-4 3.0 x 10-2

2- 9.0^b overnight /500hr thenoyltrifluoroacetone¹ 18.0^c

13 3.3 69.7^a RT 3.6 x 10-4 6 2 x 10-4 dimethoylglyoxime¹ 9.0^b overnight /400hr

18.0^c

14 3 53 67.40^a RT for 2.6 x 10-4 1 20 x 10-3

N,N-bιs(salicylidene)- 8 74^b overnight /500hr ethylene diamine¹ 20 33°

15 3.17 60.10^a RT for 5.10 x 10-4 1.9O x 10-2

N,N-bιs(salicylidene)- 7.78^b overnight /500hr

1 ,4-phenylene diamine¹ 28 95^C

16 2.83 69 70^a 180C/ 3.0 x 10-4 4.4 x 10-4

Vinyl phosphonic acid⁵ 9.02^b 30mιn /500hr

18 45^C

17 6 34 67.44^a RT for 2.4 x 10-4 5.1 x 10-4

50% H2O 8.73^b overnight /600hr

Nitnlotris 17.49^C

(methylenephosphonic acid) water solution¹

18 3.25 69.80^a RT for 4.7 x 10-4 7.1 x 10-4

50% H2O 9.00^b overnight /400 hr

Hypophosphorous acid 17.95^C water solution¹

19 11.99 Formic acid¹ 78.40^a IR Cure 4.8x 10-5 1 5 x 10-4

4.80^b in N2 for /1000hr

4.81° 30min/

180C

1 Sigma-Aldrich

5 BASF a Cu RD88 available from Ferro Corp, OH b resin DIACON MG 102 (Lucite International, TN); PKHC (Inchemrez Corporation, SC); A-11 acrylic resin (Rohm & Haas, PA); or VAGH copolymer (DOW Chemical, Ml) c solvent butyl Cellosolve acetate ( Eastman Chemical Company, TN); 2-butoxyethyl acetate (Sigma-

Aldrich); or 2-butanone (Sigma-Aldrich) d curing catalyst¹ Cymel 301 {Cytec Industries, NJ) and/or Nacure 5414 (King Industries, CT)

It should be understood that the di-ketone functional additives of Group Il are not limited to the above examples, if the resultant formulation has volume resistivity lower than 6.3 x 10-3 Ω-cm and maintains stable conductivity under the aging condition. It should also be understood that the di-ketone additives of Group Il do not include hexafluoroacetylacetone, D-tartaric acid, 2-thenoyltrifluoroacetone, iminodiacetic acid, 1 ,4-butanediol bis (3-amιnocrotonate), dimethylacetoacetamide water solution, phenylmalonic acid, ninhydrin, 4-hydroxy-4-meihyl-2-pentaone, allyl acetoacetate, deprotonated allyl acetoacetate, 2-methacrloyloxy ethyl acetoacetate, N,N'-{1 ,4-pheπylene) bιs(acetoacetamide), 1 ,4- butanediol diacetoacetate,1 ,5-diphenyl-13,5-pentanetrιone, and 2,2,6,6-tetrametyl,3-5-heptanedιone since the resultant formulations do not have stable conductivity under the aging condition.

It should be understood that the Schiff base functionai additives of Group Il are not limited to the above examples, if the resultant formulation has volume resistivity lower than 6.5 x 10-3 Ω-cm and maintains stable conductivity under the aging condition It should also be understood that that the Schiff base of Group Il do not include N,N-bis(salicylιdene)-ethylenediamine, N,N-bιs(salicylidene)-1 ,2- phenyleπediamine, and N,N-bis(sa!icylιdene)-1 ,4-butanediamιne since the resultant formulations do not have stable conductivity under the aging condition.

It should be understood that the phosphorus acid functional additives of Group Il are not limited to the above examples, if the resultant formuiation has volume resistivity lower than 6.5 x 10-3 Ω cm and maintains stable conductivity under the aging condition It should also be understood that the phosphorus acid functionai additives of Group I! do not include 1-hydroxyethylidene-diphosphonic acid, dibutylphosphate, vinyl phosphonic dimethyl ester, tπphenylphosphite, triphenylphosphate, phosphate monomers with hydrophobic extender polymer (PAM 200, Rhodia), and phosphate monomers with hydrophobic monomer (PAM 300, Rhodia) since the resultant formulations do not have stable conductivity under the aging condition

The use of specific combinations of Group III functional additives resulted in improved initial conductivity and stable conductivity under aging condition over the comparative examples. The synergy is shown over the uncombined, separate functionai additives in Table III (Comparative B-i) Table III Formulation with Functional Additive Group III

Comparative C 5.2 glycerol' 59 0^a 200C/30min 4 00 x 10-3 Non-

6.0^b conductive

27. T

2 1 ^d

Comparative D 5 Polyviπylphenol' 58^a 30-220C Non- Non-

27^b @ 5C/mιn conductive conductive

10^c

Comparative E 5 58^a 30-220C Non- Non-

1 ,4-beπzene- 27^b @ 5C/mιn conductive conductive dimethaπol¹ 10^c

Comparative F 4 0 Oxalic acid ' 56.6^a 30-220C Non- Non-

12.6^b @ 5C/min coπductive conductive

26 8° in N2

Comparative G 9.2 59 0^a 200C/30min 8 79 x 10+2 Non-

8-hydroxyquιnoline¹ 6.0^b conductive

23 T

2.1^d

Comparative H 2.68 Acetic acid¹ 67.20^a 150C/30min Non- Non-

9.92^b conductive conductive

20.20^c

Comparative I 2.68 67.20^a 150C/30min Non- Non- tri-ethanolamiπe¹ 9 92^b conductive conductive

20.20^C

20 4.56 54.69^a 30-220C 2.55 x 10-4 9 6 x 10-2 pojyvinylphenol¹ 8.21^b @ 5C/mιn /1200hr

6.46 glycerol¹ 26.08^c

21 5 09 55.27^a 30-220C 3.15 x 10-4 3 4 x 10-3

1,4-benzene- 10.68^b @ 5C/mιn /1008hr dimethanol¹ 22.71^C

6 25 glycerol¹

22 5 17 Oxalic acid ' 54.85^a 30-220C 2.0O x 10-4 6.5 x 10-4

5 95 glycerol¹ 10.89^b @ 5C/min /1056hr

23 14^C

23 2.3 59 0^a 200C/30min 4.48 x 10-4 9.1 x 10-4

8-hydroxyquιnoline¹ 6.0^b /1000hr

6.9 glycerol¹ 23.7^C

2.1^d

24 6.15 Acetic acid' 61 40^a 150C/10min 1.3 x 10-4 2.4 x 10-4

2.46 glycerol¹ 9 06^b /400hr

2.46 18 47^C tri-ethanolamine¹

1 Sigma-Aldπch a Cu RD88 available from Ferro Corp, OH b resin: DIACON MG 102 (Lucite International, TN), PKHC (Inchemre∑ Corporation, SC), A-11 acrylic resin (Rohm & Haas, PA); or VAGH copolymer (DOW Chemical, Ml) c solvent: butyl Cellosolve acetate (Eastman Chemical Company, TN), 2-butoxyethyl acetate (Sigma-

Aldrich); or 2-butanone (Sigma-AIdrich) d curing catalyst: Cymel 301 (Cytec industries, NJ) and/or Nacure 5414 (King Industries, CT)

Claims

1. An electrically conductive composition comprising"

(a) a base metal,

(b) a functional additive, and

(c) a resin; wherein the composition has an initial volume resistivity of less than 6.5 x 10-3 Ω-cm.

2. The electrically conductive composition of claim 1 , wherein the base metal is copper, iron, nickel, lead, tin, zinc, and alloys thereof.

3. The electrically conductive composition of claim 2, wherein the base metal is copper.

4. The electrically conductive composition of claim 1 , wherein the functional additive is selected from the group consisting of reducing sugars, cyclic borane complex, aromatic sulfonic acids, phosphorus acid, long chain ascorbic acid esters, di-ketone, oxime, monoacids, Schiff base, mixture of phenol-type functionality with alcohol, mixture of carbinol-type functionality with alcohol, mixture of organic diacids with alcohol, mixture of heterocyclic aromatic organic compounds with alcohol, mixture of acid with alcohol with amino alcohol, mixtures of dι-ketone with oxime, and derivatives thereof

5. The electrically conductive composition of claim 1 , wherein the resin is selected from the group consisting of epoxy-based, vinyl-based, polyester-based, phenolic-based, or acrylic-based, polyimide-based, polyurethane-based, melamine-based, urea-based, polycarbonate-baseci , polyallylsulfone-based, amino-based, cellulosic-based, a phenoxy-based, melamine-based, silicone-based resin and mixtures thereof.

6. The electrically conductive composition of claim 1 , further comprising a solvent.

7. The electrically conductive composition of claim 1 , further comprising a curing agent and/or catalyst.

8. The electrically conductive composition of claim 1 , further comprising an adhesion improver, a coupling agent, and/or a curing accelerator.

9. An electrically conductive composition comprising {a} a base metal;

(b) a functional additive; and

(c) a resin; wherein the composition has an initial volume resistivity and maintains a volume resistivity of less than 6 5 x 10-3 Ω cm under 85X/85%RH for at least 400 hours.

10. The electrically conductive composition of claim 9, wherein the base metal is copper, iron, nickel, lead and zinc.

11. The electrically conductive composition of claim 9, wherein the base metal is copper

12 The electrically conductive composition of claim 9, wherein the functional additive is selected from the group consisting of long chain ascorbic acid esters, di-ketones, oximes, monoacids, Schiff base, phosphorus acid, mixture of phenolics with alcohol, mixture of organic diacids with alcohol, mixture of heterocyclic aromatic organic compounds with alcohol, mixture of acid with alcohol with amino alcohol, mixtures of dι-ketone and oxime, and derivatives thereof.

13. The electrically conductive composition of claim 9, wherein the resin is selected from the group consisting wherein the resin is selected from the group consisting of epoxy-based, vinyl-based, polyester-based, phenolic-based, or acrylic-based, polyimide-based, polyurethane-based, melamine-based, urea-based, polycarbonate-based , polyallylsulfone-based, amino-based, cellulosic-based, a phenoxy-based, melamine-based, silicone-based resin, and mixtures thereof.

14 The electrically conductive composition of claim 9, further comprising a solvent.

15. The electrically conductive composition of claim 9, further comprising a curing agent and/or catalyst.

16 The electrically conductive composition of claim 9, further comprising an adhesion improver, a coupling agent, and/or a curing accelerator.

17 An electronic device comprising the electrically conductive composition of claim 1.

18. An electronic device comprising the electrically conductive composition of claim 9.

19. A process of sealing and/or making or forming an electronic devices and electronic components comprising applying the electrically conductive composition of claim 1 on the joint interconnection and curing and/or drying said composition