CN104040026B

CN104040026B - Chemical plating copper plating solution without formaldehyde

Info

Publication number: CN104040026B
Application number: CN201280049015.6A
Authority: CN
Inventors: E·施泰因豪泽; S·勒泽勒; S·维泽; T·C·L·阮; L·施坦普
Original assignee: Atotech Deutschland GmbH and Co KG
Current assignee: Atotech Deutschland GmbH and Co KG
Priority date: 2011-10-05
Filing date: 2012-10-01
Publication date: 2019-01-01
Anticipated expiration: 2032-10-01
Also published as: WO2013050332A3; EP2764135A2; TW201323654A; CN104040026A; JP2014528517A; KR20140090145A; JP6180419B2; KR101953940B1; TWI557271B; WO2013050332A8; US20140242264A1; WO2013050332A2

Abstract

The present invention relates to a kind of electroless copper aqueous solutions, it includes copper ion sources, glyoxalic acid source as reducing agent, and the mixture of at least one two succinic acid of poly- amino or at least one poly- amino monobutane diacid or at least one two succinic acid of poly- amino and at least one poly- amino monobutane diacid is used as complexing agent, carries out the purposes of the method and the solution of electroless copper for plated substrate using the solution the invention further relates to a kind of.

Description

Chemical plating copper plating solution without formaldehyde

Technical field

It is used for the present invention relates to a kind of chemical plating copper plating solution, using the method and the solution of solution progress electroless copper The purposes of plated substrate.

Background technique

Chemical plating is the controlled autocatalytic deposition of continuous metal film with the help of no external electrical is supplied.It can pre-process non- Metal surface is so that it has acceptance or catalytic to deposition.The whole or selected portion on surface are preferably preprocessed.Chemical plating The main component of copper bath is mantoquita, complexing agent, reducing agent and alkali and additive as the ingredient optionally selected, such as surely Determine agent.Complexing agent (namely is in hydroxide and the like shape for chelate deposited copper and preventing copper from precipitating from solution Formula).Copper is chelated so that copper can be reduced agent and utilize, which converts metallic forms for copper ion.

Common electroless copper bath uses formaldehyde as reducing agent.Formaldehyde is the most important and public of general chemical copper electroplating method The reducing agent recognized.1987, Environmental Protection Agency USA (U.S.Environmental Protection Agency) divided formaldehyde Class is possible human carcinogen.In June, 2004, international cancer research institution (International Agency for Research on Cancer；IARC formaldehyde) is classified as human carcinogen.Therefore, the chemical plating without formaldehyde has been developed Copper bath requires to meet safety and occupational health.

US4,617,205 disclose a kind of composition of electroless deposition for copper, it includes copper ion, as reduction The glyoxylate and complexing agent of agent, such as EDTA can form with copper and be better than the copper complex formazan complex compound of ethanedioic acid.

US7,220,296 teach a kind of electroless plating bath, and it includes water-soluble copper compound, glyoxalic acid and complexing agents (can be EDTA).

US20020064592 discloses a kind of electroless plating bath, it includes copper ion source, as reducing agent glyoxalic acid or Formaldehyde, and EDTA, tartrate or alkanolamine as complexing agent.

US20080223253 discloses a kind of chemical copper plating solution comprising mantoquita can be selected from formaldehyde, paraformaldehyde, second Aldehydic acid, NaBH₄、KBH₄、NaH₂PO₂, hydrazine, formalin, the reducing agent of polysaccharide (such as glucose) and its mixture and optional From ethylenediamine tetra-acetic acid (EDTA), hydroxyethylethylene diamine tri-acetic acid (HEDTA), cyclohexanediamine tetraacetic acid, diethylenetriamine five The complexing agent of acetic acid and four (2- hydroxypropyl) ethylenediamines (hereinafter also referred to " Quadrol " is the trade mark of BASF AG).

The defect of EDTA, HEDTA, four (2- hydroxypropyl) ethylenediamines and other related complexing agents are to lack biodegrade Property.

The performance of copper plating solution is general unpredictable and mainly regards its component (especially complexing agent and reducing agent) and its group Depending on the molar ratio divided.

Summary of the invention

A target of the invention is to provide the chemical copper plating solution without formaldehyde.

It is another that the goal is to provide have the chemical copper plating solution for improving performance (such as improved copper deposition rate).

Another chemical copper plating solution for aiming at the biodegradable complexing agent using copper of the invention.

It is another to aim at the copper plating solution without formaldehyde and reach the standard of formaldehyde chemistry copper plating solution.It should be suitble to answer For horizontal process and vertical process, wherein final products are for example for high-end technology, such as HDI (high density interconnection) PCB and IC Substrate (IC=integrated circuit, PCB=printed circuit board).The solution should also be suitable for manufacture display.

The present invention provides a kind of chemical copper plating solution, it includes

Copper ion source,

As the glyoxalic acid source of reducing agent, and

At least one poly- two succinic acid of amino or at least one poly- amino monobutane diacid, or at least one poly- two fourth of amino The mixture of diacid and at least one poly- amino monobutane diacid as complexing agent,

Wherein the molar ratio of complexing agent and copper ion is in the range of 1.1:1 to 5:1.

One or more above-mentioned targets pass through chemical copper plating solution as claimed in claim 1 (hereinafter, abbreviated as " solution ") or logical It crosses such as dependent claims and advantageous embodiment described in the specification and completes.

The solution of claim 1 is free of formaldehyde and shows improved copper deposition rate.Can reach 0.15-1.0 μm/ The deposition rate of 10min, 0.15-1.5 μm/10min or even 0.15-2.0 μm/10min.

The advantage that this novel and copper without formaldehyde is bathed is good bath performance, bath stability, good spreadability, height Deposition velocity and low bubbling trend.Crucial bath component formaldehyde is substituted with nontoxic reducing agent.

The molar ratio of poly- two succinic acid of amino of complexing agent or poly- amino monobutane diacid and copper ion leads to the profitability of plating solution Matter, i.e. Kocide SD precipitating are suppressed, bubble formation is suppressed during bath stability and copper facing, and as follows and work is real It is explained further in example.

In an embodiment of the invention, the molar ratio of glyoxalic acid and complexing agent is < 4.6:1.It is shown in the present invention, In such as spreadability, backlight and passivation, this molar ratio has Beneficial Effect in the quality on substrate to copper deposition.Glyoxalic acid With the further advantageous molar ratio of complexing agent (specifically EDDS) be≤4.5:1 ,≤4.2:1 ,≤4.0:1 ,≤3.8:1, ≤3.6:1.The preferred lower limit of the molar ratio of glyoxalic acid and complexing agent (specifically EDDS) be 0.45:1 or 0.7:1,1:1 or 2:1.Therefore, the preferred scope of the molar ratio of glyoxalic acid and complexing agent (specifically EDDS) be 0.45:1 to 4.5:1, 0.45:1 is to 4.2:1,0.45:1 to 4.0:1,0.45:1 to 3.8:1 or 0.45:1 to 3.6:1.Other preferred scopes be 1:1 extremely 4.5:1,1:1 are to 4.2:1,1:1 to 4.0:1,1:1 to 3.8:1 or 1:1 to 3.6:1.Glyoxalic acid and complexing agent are (specifically EDDS other preferred scopes of molar ratio) are 2:1 to 4.5:1,2:1 to 4.2:1,2:1 to 4.0:1,2:1 to 3.8:1 or 2:1 To 3.6:1.The ratio is related with the molar concentration amount of complexing agent, if meaning network in this connection using more than one complexing agents The total mol concentration amount of mixture.The molar concentration of glyoxalic acid is preferably at least up to the molar concentration of copper in solution, more preferably It is higher.Therefore, the molar ratio of glyoxalic acid and Cu preferably >=1:1, preferably >=1.5:1, more preferably >=2:1.

Poly- two succinic acid of amino and poly- amino monobutane diacid show fabulous or even high biological degradability.Of the invention Plating solution is without ethylenediamine tetra-acetic acid (EDTA), N'- (2- ethoxy)-ethylenediamine-N, N, N'- triacetic acid (HEDTA) and four (2- hydroxyls Propyl) ethylenediamine.

Solution of the invention and method journey of the invention are preferred for coated printed circuit board, chip carrier (chip Carrier it) and semiconductor wafer or is also used for being coated with any other circuit carrier and interconnection means.The solution specifically for Printed circuit board and chip carrier and semiconductor wafer by surface, groove, Microvia (blind micro vias), lead to Duct (through hole vias) (through-hole) and similar structures copper facing.

Specifically, solution of the invention or method journey of the invention can be used in printed circuit board, chip, carrier, crystalline substance Copper is deposited on the surface of piece and various other interconnection means, in groove, Microvia, through-hole and suitable structure.Such as institute in the present invention With term " through-hole road " or " through-hole " cover the through-hole passage of all kinds and " wear silicon hole including so-called in silicon wafer (through silicon via)”。

It is the metallization of display application to the another application that solution is imagined.In this regard, copper is particularly deposited on glass On glass substrate, especially on surface of plate glass.Wet type compared with the metal sputtering method used so far, on glass substrate Deposition of chemical plating copper is advantageous.It, can be with the benefit that wet chemistry plated deposition is realized in particular, in that glass compared with sputtering process The internal stress of substrate reduces and bending reduction, plant maintenance reduction, effective use of metal, material waste reduction.In addition, with this The solution of invention reaches the high copper deposition rate on glass substrate, especially with the pretreated glass of relatively fewer metal seeds On substrate.

Solution of the invention is aqueous solution.Term " aqueous solution " means main liquid medium (it is the solvent in solution) For water.Other liquid miscible with water, such as alcohol and other polar organic liquids can be added, it is miscible with water.

Solution of the invention can be preferable in water by the way that all components are dissolved in water-based liquid medium to prepare.

The solution contains copper ion source, may be, for example, any water-soluble copper salt.Copper can for example and be not limited to sulfuric acid Copper, copper chloride, copper nitrate, copper acetate, Loprazolam copper ((CH₃O₃S)₂Cu), Kocide SD；Or its hydrate form addition.

Relatively high pH value is preferably used using the electroless copper bath of above-mentioned reducing agent, usually 11 and 14 or 12.5 and 14 Between, preferably between 12.5 and 13.5 or between 12.8 and 13.3.PH value generally passes through potassium hydroxide (KOH), sodium hydroxide (NaOH), lithium hydroxide (LiOH), ammonium hydroxide or tetramethylammonium hydroxide (TMAH) are adjusted.Therefore, solution can contain hydrogen-oxygen Radical ion source, such as and it is not limited to one or more compounds listed above.If if desired solution alkaline pH value and pH value is not yet It is in alkaline range by other components, then for example adds hydroxide source.

Because the dissolubility of ethanedioic acid potassium is higher, potassium hydroxide is especially preferably used.It is used as reduction by oxidation The glyoxalic acid of agent and form ethanedioic acid root anion in the solution.

Glyoxalic acid is the reducing agent for copper ion to be reduced to elemental copper.As used herein, term " glyoxalic acid " includes Glyoxalic acid and acetaldehyde acid ion are not dissociated.In the solution, it may be present and do not dissociate glyoxalic acid and acetaldehyde acid ion.It is existing The definite property of substance (acid or salt) will be depending on solution ph.It is identical to consider to be suitable for other weak acid and weak base.

Term " glyoxalic acid source " covers glyoxalic acid and all compounds that can be converted into glyoxalic acid in aqueous solution.In water In solution, acid and its hydrate equilibrium containing aldehyde.The suitable source of glyoxalic acid is two halogen acetic acids, and such as dichloroacetic acid will be Glyoxylic acid hydrate is hydrolyzed in water-bearing media.The alternative source of glyoxalic acid is bisulfite adduct, for example hydrolyzable Ester or other acid derivatives.Bisulfite adduct may be added to that in composition or be formed on the spot.Bisulfite adduct It can be made by glyoxylate and bisulfites, sulphite or metabisulfite.

It can add one or more other reducing agents when necessary, such as hypophosphoric acid, glycolic or formic acid or above-mentioned acid Salt.However, solution of the invention is free of formaldehyde.Therefore, which is free of formaldehyde.Other reducing agents preferably serve as reducing agent, But it cannot function as the reagent that unique reducing agent uses (referring to the 4th column 20-43 row of US7,220,296 and 54-62 row).Herein In meaning, another reducing agent is also referred to as " reinforcing agent ".

Poly- two succinic acid of amino is the compound with two or more nitrogen-atoms, wherein 2 nitrogen are bonded to fourth two Sour (or salt) group, preferably only two nitrogen-atoms are respectively connected with succinic acid (or salt) group.As used herein, term fourth Diacid includes its salt.The compound has at least two nitrogen-atoms, and due to the commercial availability of amine, preferably has and is no more than About 10 nitrogen-atoms, more preferably no more than about 6 nitrogen-atoms, most preferably 2 nitrogen-atoms.The not connected nitrogen for having succinic acid part is former Son most preferably replaces through hydrogen atom.Succinic acid group is more preferably on terminal nitrogen atom, and most preferably, which respectively also has hydrogen Substituent group.End means first be present in compound or the last one nitrogen-atoms, regardless of other substituent groups why.End Hold another level-one amine nitrogen being defined as before connecting succinic acid part of nitrogen.After connecting succinic acid part, terminal nitrogen turns Move to secondary amine nitrogen.Because of the steric hindrance of two succinic acid groups on a nitrogen, each nitrogen with succinic acid group is preferred Only there is a this group.Remaining key on nitrogen with succinic acid group is preferably by hydrogen or alkyl or alkylidene (straight chain, branch Change or cyclic annular, the cyclic structure of more than one key including engaging more than one nitrogen-atoms or the single nitrogen-atoms of engagement, preferably Straight chain) or with the bonded this group of ether or thioether (preferably there is 1 to 10 carbon atom, 1 to 6 more preferable, most preferably 1 to 3 carbon atom, but most preferably hydrogen) it fills up.Optimizing alkyl is methyl, ethyl and propyl.Nitrogen-atoms is more preferably by alkylidene It is bonded, the alkylidene preferably respectively have 2 to 12 carbon atoms, more preferable 2 to 10 carbon atoms, even more preferably 2 to 8, Most preferably 2 to 6 carbon atoms, also as ethylidene, propylidene, butylidene, pentylidene or hexylidene.Poly- two succinic acid of amino Close object preferably there are at least about 10 carbon atoms and preferably have up to about 50, more preferably up to about 40, most preferably up to About 30 carbon atoms.Term " succinic acid " is herein for acid and its salt；Salt includes metal cation (such as potassium, sodium) and ammonium Or amine salt.

It is to be unsubstituted to replace (preferably) or through inertia suitable for practicing two succinic acid of poly- amino of the invention, Ye Jijing The active group of poly- two succinic acid of amino in selected application will not be undesirably interfered to replace.This inert substituent includes alkane Base (preferably has 1 to 6 carbon atom)；Aryl, including aryl alkyl and alkylaryl (preferably there are 6 to 12 carbon atoms), Wherein alkyl be preferred and alkyl in methyl and ethyl be preferred.

Inert substituent is preferably in any part of molecule, preferably on carbon atom, more preferably in alkylidene (such as in nitrogen Alkylidene between atom or between carboxylic acid group) on, on the alkylidene most preferably between nitrogen groups.

Preferred poly- two succinic acid of amino includes ethylenediamine-N, bis- succinic acid of N'- (EDDS), diethylenetriamines-N, N "- Two succinic acid, trien-N, N " '-two succinic acid, 1,6 bis- succinic acid of hexamethylene diamine N, N'-, tetren-N, - two succinic acid of N " ", bis- succinic acid of 2- hydroxy propylidene -1,3- diamines-N, N'-, 1,2 bis- succinic acid of propane diamine-N, N'-, 1,3- - two succinic acid of propane diamine-N, N ", cis- cyclohexane diamine-N, bis- succinic acid of N'-, bis- fourth two of trans cyclohexane diamines-N, N'- Acid and bis- (2- amino-ethyl the ether)-N of ethylene glycol, bis- succinic acid of N'- (ethylenebis (oxyethylenenitrilo)-N, N'-disuccinic acid).Preferred poly- two succinic acid of amino is ethylenediamine-N, bis- succinic acid of N'-.

This two succinic acid of poly- amino can for example by Kezerian et al. in U.S. patent 3,158,635 (to draw in full Mode is incorporated herein) in disclose process preparation.Kezerian et al. announcement makes maleic anhydride (or ester or salt) It is reacted under alkaline condition with the polyamine for corresponding to required poly- two succinic acid of amino.The reaction obtains many optical isomers, Such as because ethylenediamine is reacted with maleic anhydride there are two asymmetric carbon atoms in ethylenediamine disuccinic acid To the mixture of three kinds of optical isomer [R, R], [S, S] and [S, R] ethylenediamine disuccinic acids (EDDS).These mixtures are with mixed Solvate form uses, or is separated by the method in currently available technology to obtain required isomers.Alternatively, [S, S] isomery Body is reacted by the acid of such as L-Aspartic acid and the compound of such as 1,2- Bromofume to prepare, such as Neal and Rose, “Stereospecific Ligands and Their Complexes of Ethylenediaminedisuccinic Acid ", Inorganic Chemistry, volume 7, (1968), described in the 2405-2412 pages.

Poly- amino monobutane diacid is at least two nitrogen-atoms and succinic acid (or salt) is partially attached to a nitrogen-atoms Compound.The compound preferably has at least two nitrogen-atoms and the commercial availability due to amine, preferably has no more than about 10 nitrogen-atoms, more preferably no more than about 6, most preferably 2 nitrogen-atoms.Remaining nitrogen-atoms is (i.e. not connected to have succinic acid part Atom) preferably replace through hydrogen atom.Although succinic acid part may connect to any amine, Dante diacid group is preferably attached to end Hold nitrogen-atoms.End means first or the last one amine present in compound, regardless of other substituent groups how.Terminal nitrogen It is another be defined as level-one amine nitrogen, then connect succinic acid part.After connecting succinic acid part, terminal nitrogen is transferred to second level The nitrogen of amine.Remaining key on nitrogen with succinic acid group is preferably by hydrogen or alkyl or alkylidene (straight chain, branching or ring-type, packet Include the cyclic structure for engaging more than one key of more than one nitrogen-atoms or the single nitrogen-atoms of engagement, preferably straight chain) or have Ether or the bonded this group of thioether (preferably have 1 to 10 carbon atom, 1 to 6 more preferable, most preferably 1 to 3 carbon original Son, but most preferably hydrogen) filling.Optimizing alkyl is methyl, ethyl and propyl.Nitrogen-atoms is generally bonded by alkylidene, this Asia Alkyl respectively has 2 to 12 carbon atoms, preferably 2 to 10 carbon atoms, more preferable 2 to 8 and most preferably 2 to 6 carbon atoms, It also is ethylidene, propylidene, butylidene, pentylidene or hexylidene.Poly- amino monobutane diacid compound preferably has at least about 6 A carbon atom and preferably have up to about 50, more preferably up to about 40 and most preferably at most about 30 carbon atoms.It is suitable for Practicing poly- amino monobutane diacid of the invention is to be unsubstituted (preferably) or such as above for poly- two succinic acid compound of amino It is described to replace through inertia.

Preferred poly- amino monobutane diacid includes ethylenediamine monobutane diacid, diethylenetriamines monobutane diacid, triethylene Tetramine monobutane diacid, 1,6- hexamethylene diamine monobutane diacid, tetren monobutane diacid, 2- hydroxy propylidene -1,3- diamines list Succinic acid, 1,2- propane diamine monobutane diacid, 1,3- propane diamine monobutane diacid, cis- cyclohexane diamine monobutane diacid, trans cvclohexvl Alkane diamines monobutane diacid and bis- (the 2- amino-ethyl ether) monobutane diacids of ethylene glycol.Preferred poly- amino monobutane diacid is ethylenediamine list Succinic acid.

This poly- amino monobutane diacid can for example by Bersworth et al. in U.S. patent 2,761,874 (its disclose in Appearance be incorporated herein by reference) in and the method as disclosed in Jpn.Kokai Tokkyo Koho JP57,116,031 To prepare.In general, Bersworth et al. disclose make Alkylenediamine in a mild condition and two alkylene triamines with Under temperate condition (in alcohol) in maleate reaction, obtain the amido derivative of the alkyl-substituted aspartic acid of N-.It should Reaction obtains the mixture of R isomers Yu S isomers.

In one embodiment, when solution contains the mixture of poly- two succinic acid of amino and poly- amino monobutane diacid, Poly- two succinic acid of amino is preferably identical as the poly- amino-substituent of poly- amino monobutane diacid.Therefore for example, if poly- amino two Succinic acid is ethylenediamine-N, and bis- succinic acid of N'-, then polyamine monobutane diacid is ethylenediamine monobutane diacid.

In a preferred embodiment, by ethylenediamine-N, bis- succinic acid of N'- (EDDS) is used as complexing agent.EDDS is because of it High biological degradability and be preferred complexing agent.Other electroless coppers bath of complexing agent containing biodegradable (such as tartrate) is usual Metallic nickel is total to using toxicity.It has been found that toxicity can be avoided to be total to metal in the present invention.Therefore, solution of the invention is total without toxicity Metal.Solution of the invention is preferably without nickel.

Present inventor have found that obtaining the copper significantly improved in the solution of the present invention comprising glyoxalic acid and EDDS Deposition rate.Because when by formaldehyde-EDDS combination compared with formaldehyde-EDTA, copper deposition is not in the comparative example using formaldehyde Improve or only slightly improve, institute is as unpredictable consequence.

Term " EDDS " includes racemic EDDS or its all optically active isomer, such as (S, S)-EDDS and its salt And derivative.The term preferably means (S, S)-EDDS or its salt.EDDS can be prepared by the method for PCT/GB94/02397. In the solution, depending on solution ph, ethylenediamine disuccinic acid and ethylenediamine disuccinic acid radical ion may be present.

In one embodiment, solution of the invention contains the copper ion of following concentration, complexing agent (preferably EDDS) And glyoxalic acid:

Cu ion: 1-5 g/l corresponds to 0.016-0.079mol/l

Complexing agent: 5-50g/l corresponds to 0.034-0.171mol/l

Glyoxalic acid: 2-20g/l corresponds to 0.027-0.270mol/l

Copper ion, complexing agent (preferably EDDS) and the glyoxalic acid of the further preferably following concentration of solution of the invention:

Cu ion: 2-3g/l corresponds to 0.031-0.047mol/l

Complexing agent: 20-40g/l corresponds to 0.068-0.137mol/l

Glyoxalic acid: 2-20g/l corresponds to 0.027-0.270mol/l

In the present invention, complexing agent (means complexing agent total amount in this connection, also even uses more than one complexing agents, then For the sum of the molal quantity of all complexing agents) with the molar ratio of copper ion it is in 1.1:1 to 5:1, the model of more preferable 1.5:1 to 5:1 In enclosing.It has been displayed when using this molar ratio, namely when complexing agent (specifically EDDS) is relative to excessive mole of copper Concentration is in use, solution of the invention has better performance.In the present invention, when glyoxalic acid is used as reducing agent, display Complexing agent (specifically EDDS) and the copper at least molar ratio of 1.1:1 are required for complex copper ion out.Molar ratio < 1:1 draws It plays Kocide SD precipitating and copper facing may not occur.On the other hand, > 5:1 molar ratio can cause bath unstable during copper facing Qualitative and high bubble formation on the surface of the substrate.

In another embodiment, the molar ratio of complexing agent (meaning complexing agent total amount in this connection) and copper ion is 2:1 To 5:1, more preferably 3:1 to 5:1.If stirring copper bath during deposition, air agitation is preferably used, and ought also make in addition to glyoxalic acid When with another reducing agent (also referred to as " reinforcing agent "), wherein another reducing agent is preferably selected from glycolic, hypophosphoric acid or formic acid, Most preferably glycolic, then this example is especially advantageous.

Solution of the invention may include and not necessarily comprising other component, such as stabilizer, surfactant, additive (as rate control additive), crystal grain macro additive, pH buffer, pH adjusting agent and reinforcing agent.This other groups Divide and be for example described in following documents (being incorporated in entirety by reference): (specifically the 6th column the 17th US4,617,205 Row to the 25th row of the 7th column disclosure), US7,220,296 (specifically the 63rd row of the 4th column to the 26th row of the 6th column), US2008/0223253 (specifically referring to paragraph 0033 and 0038).

Stabilizer is the chemical combination for keeping chemical plating solution stable for outer plating (outplating) undesirable in bulk solution Object.Term " outer plating " means nonspecific and/or uncontrolled copper deposition.The reduction of copper (II) should be only on required substrate surface Occur rather than is not specific in entire bath.Stabilisation function can for example by serve as catalyst poison substance (such as containing Have the compound of sulphur or other chalkogenides) or by forming copper (I) complex compound, thus inhibiting to form the chemical combination of copper oxide (I) Object is realized.

Suitable stabilizer is (being not limited to) bipyridyl (2,2'- bipyridyl, 4,4' bipyridyl), phenanthroline, sulfydryl-benzo Thiazole, thiocarbamide or derivatives thereof (such as diethyl thiourea), cyanide (such as NaCN, KCN, K₄[Fe(CN)₆]), rhodanate, iodate Object, ethanol amine, sulfydryl-benzotriazole, Na₂S₂O₃, polymer (such as polyacrylamide, polyacrylate, polyethylene glycols Or polypropylene glycols and its copolymer), wherein 2,2'- bipyridyls (being abbreviated as " DP "), diethyl-thiocarbamide, K₄[Fe(CN)₆]、 NaCN and Mercapto-benzothiazole are to be especially suitable for.

In one embodiment, mainly due to environment and occupational health reason, stabilizer is selected from the stabilization of cyanide-free Agent.Therefore, the preferred cyanide-free of solution of the invention.In this connection, 2,2'- bipyridyl is preferred stabilizer.Bipyridyl is excellent Choosing is added with the amount of 1-10mg/l.

European application EP1876262 discloses a kind of electroless copper bath, and containing the conduct of one or more thiocarboxylic acids must group Point.The thio-compounds referred in EP1876262 includes the compound with formula HS- (CX1) r- (CHX2) s-COOH, wherein X1 For-H or-COOH；X2 is-H or-SH；R and s is positive integer, and wherein r is 0 to 2 or 0 or 1；And s is 1 or 2.In EP1876262 The particular instance of the thio-compounds referred to is thioglycolic acid, propane thioic acid, thiomalic acid and two thio-2 succinates.Root According to EP1876262, this thiocarboxylic acid is compatible with glyoxalic acid and its salt and makes chemical plating by preventing from forming copper oxide Copper composition stability.According to EP1876262, thio-compounds must minimum be 0.01ppm.In the present invention, it shows Out when the thiocarboxylic acid component generally and specifically referred in EP1876262 is from using or at least below in EP1876262 When the limit referred to, the better performances of electroless copper bath.May be present trace as generally and specifically referred in EP1876262 Thiocarboxylic acid, premise be the amount be lower than 0.01ppm.It is preferable, however, that thiocarboxylic acid is not added in solution of the invention, I.e. the bath is without containing any thiocarboxylic acid generally and specifically referred in EP1876262.

In another aspect, the present invention relates to a kind of electroless copper plating method, this method includes to make substrate and as described above Chemical copper plating solution contact.

For example, substrate can be impregnated or is immersed in solution of the invention.It in the method, can be by the whole table of substrate Face or only selected portion copper facing.

It is preferred that stirring solution during use.Specifically, work agitation and/or agitation can be used.It is preferred that stirring Type is the air agitation of solution.Air agitation can be realized by being bubbled air by the solution in use.

This method will carry out one section of grace time to obtain the deposit of required thickness, and required thickness will regard specific application again Depending on.

A contemplated of the invention application would be particularly applicable to prepare printed circuit board.Copper according to the method for the present invention The electroless deposition hole, surface, groove, the blind microchannel that are used especially in printed circuit board wear plating (through- plating).Bilateral or multi-layer board (rigid or flexibility) can carry out plating by means of the present invention.

Method journey of the invention is applicable to provide thickness in the range of 0.1 μm to 25 μm, preferably in 0.25 μm and 3 μm Between chemical plating copper deposit.

The substrate for being generally used for printed circuit board manufacture is most frequently epoxy resin or epoxy-glass composite.But it can be used Other materials, specifically for phenolic resin, polytetrafluoroethylene (PTFE) (PTFE), polyimides, polyphenylene oxide, double maleic acids triazine-tree Rouge (bismaleintriazine-resins, BT resin), cyanate and polysulfones.

In addition to applying this method in printed circuit board manufactures, it is also seen that this method applies in general to plate non-conductive base Plate, including plastics, such as acronitrile-butadiene-styrene (ABS) and polycarbonate；Ceramics and glass.

In an embodiment of the method for the present invention, this method is in 20-60 DEG C, preferably 20-55 DEG C, more preferable 20-50 DEG C, carry out at a temperature in the range of even more preferably 20-45 DEG C and most preferably 20-40 DEG C.Because using current technology based on The solution of formaldehyde, for efficiency is well electroplated, particularly with enough copper deposition rates, it is necessary to have higher temperature, so this is implemented Mode is extremely advantageous.

It is intended to surface namely the substrate surface of copper-plated substrate, especially nonmetallic surface, it can be by within the scope of this field Method pre-processes (such as US4, described in 617,205 the 8th columns) so that its for copper deposition have it is higher acceptable or from Catalytic.The whole or selected portion on surface can be preprocessed.However, not must pre-process in each case and regard base Depending on the type on plate and surface.In pretreatment, substrate can be made to be sensitized, then deposition chemical plating copper on it.This measure can pass through It is adsorbed in catalytic metal (such as noble metal, such as palladium) on substrate surface to realize.

Preprocessing process is mainly depending on parameter (such as required property of substrate, required application and copper surface).

It can particularly for the illustrative and non-limiting preprocessing process of the laminated object of printed circuit board and other suitable substrates It comprises the steps of:

A) contact substrate with activator solution, which contains colloidal state or ionic catalytic metal, and such as noble metal is excellent It is selected as palladium, so that substrate surface becomes have catalytic,

And optionally, if especially activator contains ionic catalysis metal,

B) contact substrate with reducing agent, wherein the metal ion of ion activation agent is reduced to metal element,

Alternatively, if activator contains colloidal state catalytic metal,

C) contact substrate with accelerator, wherein by the component self-catalysis metal removal of colloid (such as protective colloid).

It is preferred that the other steps that can be optionally executed before above-mentioned steps a) with any combination are as follows:

I. substrate is cleaned and adjusts to increase absorption.Organic matter and other residues are removed with detergent.Detergent can also Containing preparing surface for activation step, namely enhancing Catalyst Adsorption and the other materials for generating activating surface more evenly (regulator).

Ii. the substrate is etched to remove oxide from copper surface, especially from the internal layer in hole.This can be by being based on persulfate Or the etch system of peroxide carries out.

It contacts substrate with prepreg solution (such as hydrochloric acid solution or sulfuric acid solution), regards feelings in the prepreg solution Condition contains alkali metal salt (such as sodium chloride).Pre-preg liquid is to protect activator from bringing (drag-in) into and polluting.

In the preprocessing process of another type, using permanganate etch step.It describes in accompanying example using high The so-called decontamination process (Desmear process) of manganate etching step.Decontamination process can be combined with above-mentioned steps.It is specific and Speech, decontamination process can before the step a) of above-mentioned preprocessing process, or execute step i)-iii) in one or more steps feelings In above-mentioned steps i)-iii under condition) it executes before.Also decontamination process can be performed and carry out alternative steps i) and ii).

In the preprocessing process of the metallization of the metallization and glass substrate particularly suitable for display application, only make surface It contacts with prepreg solution and activator solution, is then contacted with solution of the invention.Before pre-soak step with cleaning solution And adhesiving reinforcing agent contact is the step of optionally selecting, and can be carried out in advance.

Another process for being frequently used for glass substrate can be carried out with the following steps before copper facing: the glass surface exhibition to be plated Now as the metallic of crystal seed.Metallic can be brought by sputtering process to surface.Illustrative crystal seed is to be made of following Particle: or mixtures thereof copper, titanium, molybdenum, zirconium, aluminium, chromium, tungsten, niobium, tantalum or alloy.Another crystal seed can be metal oxide, or mixed Close metal oxide, such as tin indium oxide.This process can also be used for plastic base, such as is made by polyethylene terephthalate Substrate.

Make the pretreated glass surface and contains the activator of ionic catalysis metal (such as noble metal, preferably palladium) Solution contact, so that surface becomes have catalytic.Make the reduction of ionic catalysis metal on surface by seed metal.In this process In, another reducing agent of addition can be omitted.This process is particularly in the copper facing for the glass substrate of display application.

Illustrative preprocessing process or its single step are combined into alternative preprocessing process when necessary.

In another aspect, the present invention relates to the purposes that chemical copper plating solution as described above is used for the following object of plating: Printed circuit board, chip, ic substrate, MID (mold interconnecting device, molded interconnect device) group Part, display (such as liquid crystal display, TFT display, plasma scope, electroluminescent display (ELD) and chrome aobvious Show device (ECD), specifically for the display of following object: electronic device or TV, display component, flat panel sensor, such as X Ray imaging device) or plastic part, such as plastic part for functional or decorative purpose.

Now by following instance, the present invention will be described in more detail.Illustrate that this example to illustrate the present invention, but is not construed as The limitation present invention.

Detailed description of the invention

Fig. 1 is used for the step of decontamination multilevel process of clean surface.

Fig. 2 is used for the step of through-hole plating (through hole) process of activation.

Fig. 3 is directed to the reference sample of backlight measurement, shows the result of D1 to D10.

Copper thickness when Fig. 4 uses the bath with different complexing agents on glass substrate.

Example

Method

Backlight approach:

Industrial standard backlight test (Backlight Test) can be used for the copper-plated spreadability of chemical plating in through-holes Assessment, wherein the test piece of chemical plating is cut, so that the region of all standing endless when inspecting through intense light source is detected as bright spot [US2008/0038450A1]。

The quality of copper deposit is measured by the light quantity observed under conventional light microscope.

The result of backlight measurement is provided with D1 to D10 scale, and wherein D1 means worst result and D10 means best choosing knot Fruit.Fig. 3 shows the reference sample of display D1 to D10 result.

1. example

Bath composition

Constitute table

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	2-3g
Biodegradable complexing agent (EDDS)	20-25g
		Alkali (KOH)	20-40g
Stabilizer (bipyridyl)	0.001-0.005g
		Reducing agent (glyoxalic acid)	6.4-24g

Operation temperature: 38-50 DEG C

Deposition rate: about 0.6 μm/10min.

Job description

In this example, test sample is handled in common decontamination process to clean hole wall surface and internal layer copper surface.Separately Outside, make resin surface rough to reach good copper adhesiveness.

Decontamination process is multilevel process, and step is showed in Fig. 1.

Swelling agent is made of ORGANIC SOLVENT MIXTURES.During this step, it is stain (drill smear) and other to remove brill Impurity.60-80 DEG C of high temperature promotes swelling agent infiltration, to generate the surface of expansion.Therefore, the permanganate then applied is molten Liquid can produce compared with vigorous erosion.Later, reducing solution (reaction control agent) generates during permanganate step from surface removal Manganese dioxide.

During PTH (plated-through-hole, plating through hole), electrically non-conductive material is prepared for copper deposition. The activation step of Fig. 2 displaying PTH process.

Detergent is to remove organic matter and adjust surface for subsequent activation step.

Etch cleaned agent removes oxide from the surface of Kong Zhongtong internal layer.Substance as etch cleaned agent be selected from sulfuric acid with The mixture of hydrogen peroxide, or selected from peracetic dithionite or it is selected from permonosulphuric acid salt.Etch cleaned liquid, which removes, contains etch composition Additive and/or stabilizer can also be contained outside.

Panel is activated with palladium and hole surface is to contain colloidal state or ionic catalytic metal (such as noble metal, preferably palladium) Activator in carry out so that surface become have catalytic.In a possible configuration, activator contains by organic ligand The palladium ion of complexing.There is the pre-preg liquid (Predip) of prefix that should protect activator in order to avoid bringing into and polluting.

The final step of activation process is reducing agent (Reducer).Here, palladium ion is reduced to that there is high catalysis to live The element palladium of property.After reducing agent step, deposition of chemical plating copper is carried out with solution of the invention.Reducing agent and ionic metal It closes object combination and is used as activator.Its use as hypophosphites, boron hydride, amido borohydrides reducing agent.

For deposition of chemical plating copper, it is added in suitable quantity of water by the way that component will be bathed with the sequence summarized in table 1 and generates bath It constitutes.Use air agitation.Operation temperature changes between 38-50 DEG C.Moreover, sedimentation time be set to 10-60 minutes with Reach required copper thickness.

Bathe feature

Deposition velocity (measured to FR4 material (such as Matsushita MC100EX)): about 0.6 μm/10min.

Bubbling trend (test material: the ABF GX-92 from Ajinomoto): low or nothing

Spreadability (FR4 and GX-92): good

Color (FR4 and GX-92): orange red

There is the FR4 of through-hole to test backlight covering copper.

Plating example

Test panel is set to undergo entire decontamination process (following table).

Decontamination process

Decontamination step	Immersion time [minute]
		Swelling agent	5
Permanganate	10
		Restore regulator	5

Activation process based on ion activation agent system:

Activation process

Activator step	Immersion time [minute]
		Detergent	4
Etch cleaned agent	1
		Pre-preg liquid	1
Activator	4
		Reducing agent	3

The composition example of copper bath is described in following table.

Bathe the example constituted

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	3g(0.047mol)
Biodegradable complexing agent: (S, S)-EDDS	25g(0.085mol)
		Alkali: KOH	23g
Stabilizer: 2,2'- bipyridyl	0.003g
		Reducing agent: glyoxalic acid	10g(0.135mol)

Operation temperature: 38 DEG C

Deposition rate: 0.6 μm/10min.

Bubbling trend: nothing

Spreadability: good

Backlight D8

Color: orange red

2. comparative example: glyoxalic acid and HEDTA or glyoxalic acid and several biodegradable complexing agent comparative example 2.1:HEDTA (N'- (2- ethoxy)-ethylenediamine-N, N, N'- triacetic acid)

Bath composition

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	2g
Complexing agent: HEDTA	15g
		Alkali: KOH	11.2g
Stabilizer: 2,2'- bipyridyl	0.006g
		Reducing agent: glyoxalic acid	7.4g

Operation temperature: 45 DEG C

Deposition rate: 0.5 μm/10min

Backlight: D7

Bath stability: good

Spreadability: good

Color: orange red

Disadvantage: the complexing agent of nonbiodegradable

Comparative example 2.2: biodegradable D-sorbite

Bath composition

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	3g
Biodegradable complexing agent: D-sorbite	25g
		Alkali: KOH	11.2g
Stabilizer: 2,2'- bipyridyl	0.004g
		Reducing agent: glyoxalic acid	6.7g

Operation temperature: 60 DEG C

Deposition rate: 0.3 μm/10min

Backlight: D8

Bath stability: low

Spreadability: good

Color: orange red

Disadvantage: low deposition rate

Comparative example 2.3: biodegradable sodium potassium tartrate tetrahydrate

Bath composition

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	2.5g
Biodegradable complexing agent: sodium potassium tartrate tetrahydrate	90g
		Alkali: KOH	6g
Stabilizer: 2,2'- bipyridyl	0.004g
		Reducing agent: glyoxalic acid	5g

Operation temperature: 38 DEG C

Deposition rate: 0.3 μm/10min

Backlight: D8-D9

Bath stability: low

Bubbling trend: low

Spreadability: good

Color: orange red

Disadvantage: needing high complexing agent concentration and deposition rate is low

Comparative example 2.4: biodegradable gluconic acid

Bath composition

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	1.5g
Biodegradable complexing agent: gluconic acid	18g
		Alkali: KOH	16g
Stabilizer: 2,2'- bipyridyl	0.008g
		Reducing agent: glyoxalic acid	7.4g

Operation temperature: 50 DEG C

Deposition rate: 0.4 μm/10min

Backlight: D4-D5

Bath stability: extremely low

Spreadability: bad

Color: micro- depth is orange red

Disadvantage: undesirable copper deposition and extremely low bath activity

It summarizes:

When glyoxalic acid is used as reducing agent, common biodegradable complexing agent (such as tartrate) cannot meet bath again It is required that.The comparative biodegradable complexing agent containing glyoxalic acid tested above shows low deposition rate and/or needs high complexing Agent concentration.The other biodegradable complexing agents tested do not show copper deposition or at all about spreadability, deposition velocity and drums Bubble trend shows bad result.On the contrary, bis- succinic acid of (S, S)-ethylenediamine-N, N'- ((S, S)-EDDS) is biodegradable And the requirement that meets electroplating industry.Solution of the present invention containing EDDS be characterized in that its good bath efficiency, good spreadability, High deposition velocity and low bubbling trend.Due to the strong complexation property of EDDS, the other biologies of stability ratio of copper bath of the invention Degradable complexing agent is much better.

3. example: EDDS is compared with EDTA is containing different reducing agents

3.1 example containing glyoxalic acid as reducing agent

3.1.1 composition 1: the solution of the present invention containing glyoxalic acid/EDDS is bathed

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	3g
Complexing agent: EDDS	30g
		Alkali: KOH	7.2g
Stabilizer: 2,2'- bipyridyl	0.003g
		Reducing agent: glyoxalic acid	8g (about 0.1mol/l)

Operation temperature: 38 DEG C

Deposition rate: 0.8 μm/10min

Backlight: D6

Bath stability: good

Spreadability: good

Color: orange red

It is bubbled: bubble-free

3.1.2 composition 2: the comparative example containing glyoxalic acid/EDTA is bathed

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	3g
Complexing agent: EDTA	20g
		Alkali: KOH	7.2g
Stabilizer: 2,2'- bipyridyl	0.003g
		Reducing agent: glyoxalic acid	8g (about 0.1mol/l)

Operation temperature: 38 DEG C

Deposition rate: 0.4 μm/10min

Backlight: D4

Bath stability: good

Spreadability: it is bad, it can be observed to be passivated

Color: micro- depth is orange red

It is bubbled: nothing

As a result:

As comparative example 3.1.1 and 3.1.2, about the copper deposition rate under identical plating conditions, contain EDDS's Twice faster than the bath containing EDTA of copper plating solution.In addition, reaching preferred spreadability with EDDS.

3.2 comparative example using formaldehyde as reducing agent

3.2.1 composition 3: the comparative example containing formaldehyde/EDDS is bathed

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	3g
Complexing agent: EDDS	30g
		Alkali: KOH	7.2g
Stabilizer: 2,2'- bipyridyl	0.003g
		Reducing agent: formaldehyde	5g (about 0.1mol/l)

Operation temperature: 38 DEG C

Deposition rate: 1.1 μm/10min

Backlight: D7

Bath stability: good

Spreadability: good

Color: orange red

It is bubbled: bubble-free

3.2.2 composition 4: the comparative example containing formaldehyde/EDTA is bathed

Bathe component	The concentration of every 1l
		Copper ion (Cu²⁺)	3g
Complexing agent: EDTA	20g
		Alkali: KOH	7.2g
Stabilizer: 2,2'- bipyridyl	0.003g
		Reducing agent: formaldehyde	5g (about 0.1mol/l)

Operation temperature: 38 DEG C

Deposition rate: 0.9 μm/10min

Backlight: D6

Bath stability: low

Spreadability: bad, slight deactivation

Color: micro- depth is orange red

It is bubbled: being

As a result:

The bath of the formaldehyde containing EDDS/ shows the deposition rate more slightly higher than the bath of the formaldehyde containing EDTA/.But when EDTA is replaced by EDDS For when (referring to example 3.1.1 and 3.1.2), the increase of deposition rate is more much lower than with glyoxalic acid.Therefore, in the bath containing formaldehyde In, EDDS can be equivalent to or slightly better than EDTA.However, using glyoxalic acid as reducing agent, EDDS shows more much better than EDTA As a result (deposition rate increases about 100%), this can not be predicted in view of background technique.

4. example: using the complexing agent EDDS of various concentration and the experiment of copper

The variation of molar ratio EDDS:Cu

Test result

Deposition rate: 0.6 μm/10min

At least must 1.1:1 molar ratio EDDS:Cu the copper ion in alkaline solution is complexed.Molar ratio < 1.1:1 causes Kocide SD precipitating.Accordingly, it is possible to without copper facing.

Molar ratio > 5:1 causes to bathe the high bubbling trend on unstability and PCB material.Deposited colors be it is deep orange red and Backlight is under the desirable value of D7.

Uncontrolled copper deposition on beaker can be found after with bath 6 (EDDS:Cu that molar ratio is 6:1) electroless copper. Bath stability is inadequate.

5. example: having different glyoxalic acid: the coating solution of EDDS molar ratio

The different mol ratio for testing EDDS and glyoxalic acid in electroless copper bath, as shown in following table.

Bath is constituted:

The molar concentration and quality of Cu, complexing agent and reducing agent

Test panel undergoes entire decontamination process (table 2) and the activation process (table based on ion activation agent system

3), as described in example 1.

Following parameter is applied to the chemical plating in electroless copper bath:

-T=38℃

Illusory plating (Dummy plating): 10-15 minutes

Exposure time: 10 minutes

Test material: in addition to outside the GX-92 (short decontamination: 2', 4', 4') and FR4 that have been described in example 1, also use by with Test panel made of lower material.

ABS (short decontamination: 2', 4', 2') is used for test coverage and passivation；

R1755C (decontamination: 5', 10', 5') is tested for backlight.

In the following table, the result of deposition test is shown.

Bath number	A	B	C	D
					Bath stability (continues one)	Stablize	Stablize	Stablize	Stablize
Spreadability	100%	50%	0%	0%
					Backlight	D7-D8	D8-D9	n/a	n/a
Passivation	It is no	Slightly	By force	By force

In all baths, bath stability is reduced after one day.Next day, Kocide SD precipitating occur.Stablize to improve bath Property, recommend at least EDDS of 1.1:1: copper ratio.But experiment of the invention shows glyoxalic acid: EDDS molar ratio is to the copper on substrate The influence of deposition quality.

Test shows that copper deposition quality is reduced as acetaldehyde acid concentration improves.Acetaldehyde acid concentration in electroless copper bath When higher, copper-acetaldehyde acid complex may be competed with Cu-EDDS complex compound to be formed and glyoxalic acid also functions to complexing agent and it is non-reduced The effect of agent.

Although acetaldehyde acid concentration is sufficiently high so that playing the role of two kinds (complexing agent and reducing agents), with copper-glyoxalic acid network The reduction process for closing object seems to be restricted.Forming copper-acetaldehyde acid complex can cause to bathe unstability and copper plated material Passivation.Herein, passivation means that copper surface becomes inactive to electroless copper process；Electroless copper process is whole on passivated surface Only.When glyoxalic acid: when the molar ratio of EDDS is 4.6:1 or 4.6:1 or more, copper deposition quality is reduced.Initial reactivity, copper covering Property and passivation depending on glyoxalic acid: depending on the molar ratio of EDDS.

Complexing agent plays an important role during electroless copper.Not each complexing agent is used equally for reduction process.Network Mixture EDDS and copper form the complex compound that can be reduced easily.In the glyoxalic acid for being lower than 4.6:1: under EDDS ratio, specifically In 3.6:1 or lower than under 3.6:1, deposition quality (spreadability, backlight) is fabulous.

6. example: using the experiment of thiocarboxylic acid

Containing/EDTA of thiocarboxylic acid is free of compared with EDDS

Thioglycolic acid is used as thiocarboxylic acid in an experiment.

The test inventory constituted using different baths

Operation temperature: 55 DEG C

Test result

Thioglycolic acid causes the dark color of deposition of chemical plating copper.Deposition rate is because using thioglycolic in electroless copper bath Acid and reduce.

7. example: copper deposition sample when being bathed using the copper containing different complexing agents on glass substrate: sputter has Ti/Cu crystal seed Glass

Pretreatment:

Fig. 4 shows the result for being directed to different complexing agents copper thickness obtained.

Claims

1. a kind of electroless copper aqueous solution, it includes

Copper ion source,

As the glyoxalic acid source of reducing agent, and

It is poly- as poly- two succinic acid of amino of at least one of complexing agent or at least one poly- amino monobutane diacid or at least one The mixture of two succinic acid of amino and at least one poly- amino monobutane diacid,

Wherein the molar ratio of the complexing agent and copper ion is in the range of 1.1:1 to 5:1, and wherein glyoxalic acid and complexing agent rub You are than being 2:1 to 3.6:1, and wherein copper ion concentration is 0.031-0.047mol/l, and acetaldehyde acid concentration is 0.027-0.270mol/ L, complexing agent concentration 0.034-0.171mol/l,

The electroless copper aqueous solution does not contain thiocarboxylic acid.

2. electroless copper aqueous solution as claimed in claim 1, wherein the molar ratio of the complexing agent and copper ion is in 1.5:1 to 5:1 In the range of.

3. electroless copper aqueous solution as claimed in claim 1, wherein the complexing agent is at least one poly- two succinic acid of amino.

4. electroless copper aqueous solution as claimed in claim 1, wherein the complexing agent is ethylenediamine-N, bis- succinic acid of N'- (EDDS).

5. electroless copper aqueous solution as claimed in claim 1, wherein the solution further includes one or more stabilizers.

6. electroless copper aqueous solution as claimed in claim 5, wherein the stabilizer is selected from bipyridyl, phenanthroline, sulfydryl-benzo thiophene Azoles, thiocarbamide or derivatives thereof, cyanide, rhodanate, iodide, ethanol amine, sulfydryl-benzotriazole, Na₂S₂O₃, polymer poly Acrylic amide, polyacrylate, polyethylene glycols or polypropylene glycols.

7. electroless copper aqueous solution as claimed in claim 5, wherein the stabilizer is selected from copolymer, the polypropylene of polyacrylamide The copolymer of the copolymer of esters of gallic acid, the copolymer of polyethylene glycols or polypropylene glycols.

8. electroless copper aqueous solution as claimed in claim 1, wherein the solution further includes hydroxide ion source.

9. electroless copper aqueous solution as claimed in claim 1, wherein the solution also includes the second reducing agent in addition to containing glyoxalic acid.

10. electroless copper aqueous solution as claimed in claim 9, wherein second reducing agent be selected from hypophosphoric acid, glycolic, formic acid and The salt of these acid.

11. a kind of method for electroless copper, this method includes the chemistry for making substrate with such as any one of claims 1 to 10 Plate copper liquor contact.

12. as claim 11 method, be in the range of 20-60 DEG C at a temperature of carry out.

13. a kind of purposes of such as electroless copper aqueous solution of any one of claims 1 to 10, is used for printed circuit board, collection At the plating of circuit substrate, chip, mold interconnecting device, display or plastic part.

14. a kind of purposes of such as electroless copper aqueous solution of any one of claims 1 to 10, is used for the plating of glass substrate It covers.

15. being used for the plating of the glass substrate of display such as the purposes of claim 14.