CN114945804A

CN114945804A - Ink-jet printing circuit board

Info

Publication number: CN114945804A
Application number: CN202080092845.1A
Authority: CN
Inventors: 茱莉亚·库申; 埃琳娜·希娜; 特雷沙·拉莫斯
Original assignee: Kateeva Inc
Current assignee: Kateeva Inc
Priority date: 2020-01-13
Filing date: 2020-12-21
Publication date: 2022-08-26
Also published as: EP4090914A1; WO2021146061A1; EP4090914A4; KR20220127272A; TW202136909A; JP2023512445A

Abstract

Described herein are methods of treating a substrate comprising depositing an electrically conductive material on a substrate, applying a primer material soluble in water or an acidic aqueous solution onto the electrically conductive material, inkjet printing an acid-resistant patterning material reactive with the primer material according to a pattern onto the primer material to form an acid-resistant mask; and exposing the substrate to an acid to etch the exposed portion of the conductive material.

Description

Ink-jet printing circuit board

Technical Field

Embodiments herein generally relate to manufacturing circuit boards using an inkjet printing process. The present application describes new methods and inks for ink jet printing circuit boards.

Background

Printed Circuit Boards (PCBs) are typically made by the following method: a conductive sheet (e.g., copper metal) is formed on a non-conductive substrate, portions of the conductive sheet are masked, and unmasked portions are etched to leave a pattern of conductive traces on the non-conductive substrate. An acid-resistant resin material is generally used for masking. Copper is typically etched using an acid solution. The mask material protects the copper underneath from acid attack. In one commonly used process, a mask material is printed onto the conductive sheet using an ink jet printing process. PCB products may include one substrate with circuitry printed on one or both sides, or may include multiple substrates with multiple circuits laminated in a composite device.

In an ink jet process for forming a negative image of a circuit pattern on a PCB device, a primer material is first applied to a substrate, and then a material reacting with the primer is applied to the primer in the form of a pattern by ink jet printing. The reactive material reacts with the primer and is frozen by the reaction. The primer is typically a polycationic material such as polyethyleneimine, a divalent salt matrix, or a vinylpyrrolidone polymer. The patterning material is an acid-resistant material that reacts with the polycationic material. Examples of such materials include acrylic resins and styrene-acrylic resins. The primer is typically applied to the metal surface and dried. The pattern material is then applied in the pattern to react with the primer and to be frozen. The pattern material is typically applied in an alkaline form, pH >7.0 to react with the primer. An acid, such as HCl, may be added to the primer to enhance the reaction.

In many cases, the base contained in the pattern material is volatile. For example, ammonia is used in some cases. The volatility of the base in the pattern material complicates the use of the material as an inkjet material, since as the volatile material ages, the composition and properties of the inkjet material change and the application of the material by inkjet printing becomes unreliable. The viscosity of the material changes, resulting in an inaccurate application of the material to the substrate. As a result, the patterns formed in the conductive material are typically out of tolerance. In the field of ink jet printed PCBs, new methods and materials are needed to reliably pattern conductive coatings.

Disclosure of Invention

Embodiments described herein provide a method comprising depositing an electrically conductive material on a substrate, applying a primer material soluble in water or an aqueous acidic solution onto the electrically conductive material, inkjet printing an acid-resistant patterning material reactive with the primer material according to a pattern onto the primer material to form an acid-resistant mask, and exposing the substrate to an acid to etch exposed portions of the electrically conductive material.

Other embodiments described herein provide a method comprising depositing an electrically conductive material on a substrate, inkjet printing a blanket layer of an acid soluble primer material comprising a polycationic material onto regions of the electrically conductive material, inkjet printing an acid resistant patterning material comprising a polyanionic material onto the primer material according to a pattern to form an acid resistant mask, and exposing the substrate to an acid to remove portions of the electrically conductive material according to the pattern.

Other embodiments described herein provide a method comprising depositing an electrically conductive material on a substrate, inkjet printing a blanket of an acid-soluble primer material comprising a polycationic material and a solvent onto regions of the electrically conductive material, removing the solvent to cure the primer material, inkjet printing an acid-resistant patterned material comprising a polyanionic material onto the cured primer material according to a pattern to form an acid-resistant mask, and exposing the substrate to an acid to remove portions of the electrically conductive material according to the pattern.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 is a flow diagram of a method summarized according to one embodiment.

FIG. 2 is a flow chart of a method outlined in accordance with another embodiment.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be incorporated directly into other embodiments without further recitation.

Detailed Description

The PCB fabrication process described herein uses an inkjet process to apply a patterned mask material onto a substrate. The mask material is a bi-component material formed from stable precursors, at least one of which is printed in a pattern using an ink jet process. The two-component material is a stable acid-resistant material that defines the circuit pattern to be resolved in the conductive coating on the PCB.

FIG. 1 is a flow diagram summarizing a method 100 according to one embodiment. At 102, a primer is formed on a conductive material layer of a substrate. The substrate may be any material that provides a basis for the layer of conductive material. For example, the substrate may be a conventional circuit board blank made of resin, optionally impregnated with polymer fibers. The substrate may also be a piece of glass, a polymer film, or any other material on which circuits or microcircuits are to be formed. The layer of conductive material is typically a metal or any acid-soluble conductive material. Copper is an example and is very common.

Primers are ionic materials that can be applied as a liquid and cured into a layer. The primer material may be a polymer precursor or a polymer material dissolved in a solvent. The primer polymer is typically a polycationic polymer (i.e., a polybase), which is a polymer that can accept one or more protons to become cationic. The polycationic polymer has multiple positions and can accept protons from a proton donor to form ionic bonds or catalyze the formation of covalent or covalent-like bonds. Examples of polymeric materials that can be used in the primer material include polyethylene imine, polypemimine, polyputrescine (polytetramethylene amine) and other related polyamine polymers, which can be substantially linear or crosslinked polyamidoamines, polyvinylpyrrolidone, polydiallyldimethylammonium chloride, polylysine, polytriazine, polyacetamide and polythioaminal, as well as natural and semi-synthetic polycationic materials such as chitosan, gelatin, cellulose, and starch derivatives such as dextran and dextrin, pectin, polypeptides and alginates. These may be used as homopolymers, copolymers or multimers and may be interpolymerized, crosslinked or dendrimerically copolymerized with other monomers and polymers such as vinylic species (i.e., polyaminodiacrylate co-esters), epoxy species, polyurethane species. Where polymerizable species such as vinyl and epoxy species are included in the primer precursor, activators such as free radical activators, co-activators (e.g., two monomers of a co-polymerization system, such as epoxy, urethane, etc.), and the like may be included. The polymeric primer material is typically acid soluble so that the primer material that does not react with the patterning material can be subsequently removed to expose the conductive material for etching.

The polymeric primer material is applied with an aqueous precursor containing a polymeric primer material applied as a first component of a two-component system to the electrically conductive material of the substrate for securing the patterned acid-resistant mask to the electrically conductive material. The liquid medium used for applying the primer material typically comprises water and an organic, water-miscible co-solvent, such as monoethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, glycerol, fatty and aromatic amides, carboxylic acids, ethers, esters, alcohols, organosulfides, sulfones, such as sulfolane, carbitol, butyl carbitol, cellosolve, amino alcohols (i.e. aminomethylpropanol), ketones, N-methylpyrrolidone, cyclohexylpyrrolidone, hydroxy ethers, lactones, imidazoles and mixtures thereof. The non-aqueous component is typically present in an amount of 0 wt% to about 50 wt%, which aids in dissolving any other additives that may be used, such as colorants (i.e., Bayscript blue dye), salts, chelating agents (i.e., Trilon B), and the like. Wetting agents such as BYK-345, BYK-307, BYK-306, BYK-308, BYK-333, BYK-341, and the like, available from BYK Chemie; fluorad FC-120 or other fluorosurfactants; MASURF FS-1620, available from Mason chemical; surfinol 104PG and Dynol 604 available from air products; and Silwet L77 available from Witco chemicals; TEGO Wet 270 available from Evonik; and Triton X-100, FS-30, FS-34, FS-35, and FS3100 available from Chemours, Inc. The wetting agent may be present in an amount up to about 20 weight percent of the total mixture.

The above composition is generally applied to the conductive material of the substrate using a method that can obtain a thin and uniform coating of the primer material on the conductive material. One such method is ink jet printing. Other methods include spray coating, band coating, slot coating, die coating, and gravure coating. The composition is adjusted for such methods, for example by adjusting the viscosity to obtain optimal coating. For example, the above polymers can be adjusted by adjusting the type of monomer and catalyst or activator content or activity according to molecular weight and crosslinking to provide optimal loading of the primer material at the target viscosity required for the application method. The precursor is typically applied to a thickness of 2-50 μm so as to directly contact the conductive material of the substrate, thereby covering at least a portion of the conductive material to be processed for patterning into a circuit.

After the precursor material is applied, the precursor material is cured to form a primer material. The substrate may be subjected to a drying process, which may include elevated temperatures up to about 150 ℃ (e.g., about 80 ℃) and/or reduced pressures (e.g., a negative pressure up to about 250 torr). Where polymerizable components are included that require activation, the substrate may be exposed to ultraviolet light to activate polymerization of these components. The obtained primer is a solid coating on the conductive material of the substrate which reacts with the second component of the two-component system to be coated in a pattern to form a patterned mask.

In 104, an optional transition material is applied to the primer material. The transition material prepares the surface of the primer for acceptance and adhesion in an optimum manner to the patterned material to be subsequently applied. For example, a solvent removal material may be applied to the primer material to speed up the removal of the slowly evaporating solvent species by dissolving the solvent species in the more volatile material. As another example, an adhesion promoter may be applied. The adhesion promoter may include a function capable of combining with the primer material and the patterning material. Examples of adhesion promoters that may be used include peptides and silane coupling agents having acid and base reactive functional groups. Functionally, the transition material may be similar to the primer material, but the two differ in composition, physical properties, or chemical properties. For example, a second polymeric primer material of the same composition but differing in molecular weight or reactive site density may be applied. Alternatively, the second polymeric primer material may be a different polymer than the underlying polymeric primer material. An optional transition material is optionally used to enhance the adhesion between the patterned material and the primer material. The transition material may also be used to adjust for any thickness, density, or surface height non-uniformity in the primer material.

In 106, the patterning material is applied to the transition material, or directly to the primer to react with the primer. The patterned material is applied in a pattern to form a patterned acid-resistant mask material that covers portions of the conductive material while leaving other portions uncovered. The patterning material is applied as a liquid using a patterned coating process such as printing, e.g., ink jet printing or other liquid printing processes. The patterning material contains a material that reacts with the polycationic material of the primer to form an acid-resistant polymer. Thus, the material is the second component of a two-component system comprising a primer material and a primer reactive material. The primer reactive material is an anionic or polyanionic material (i.e., a polyacid), such as polyacrylic acid or polymethacrylic acid, and the like. It is also possible to use mixed polyalkylacrylic acids as copolymers or polymers or as homopolymers and/or mixtures of copolymers and polymers. Other suitable polyanionic materials include polyanionic cellulose (i.e., ANTISOL polyanionic cellulose from the Dow chemical company) and polystyrene sulfonate. The polyanionic material is used in an aqueous solution, and may further contain a wetting agent, a coloring agent, and the like as described above.

A base that is at least slightly soluble or miscible in water is added to the patterned material to activate the polyanionic material in the patterned material. The strong base increases the reactivity of the patterning material with the primer material or the primer plus transition material. It is believed that the strong base can remove protons from the polyanionic material to produce anions that are more reactive with the primer material or the primer plus transition material.

The base should have a pH of 7.2 to 12 and a relatively low volatility so thatThe ink does not change composition significantly during application to the substrate. Low toxicity is also an advantage. Suitable materials for use as strong bases include alkylamine NR ¹ R ² R ³ Wherein R is ¹ 、R ² And R ³ Is composed of carbon and hydrogen, and R ¹ 、R ² And R ³ May be independently hydrogen, having the formula C _x H _y N _z Wherein x is 3-6 (i.e., an alkylamine having 3-6 carbon atoms), z is 1 or 2, and y is 2x +2+ z; alkanolamine NR ⁴ R ⁵ R ⁶ Wherein R is ⁴ 、R ⁵ And R ⁶ At least one of (A) is hydroxyalkyl C _a H _2a OH, wherein R ⁴ 、R ⁵ And R ⁶ May be hydrogen and R alone ⁴ 、R ⁵ And R ⁶ One or more of (A) may be an alkyl group C _a H _2a+1 (ii) a And organic cyclic amines such as pyrrole, pyrrolidine, piperidine, imidazole, pyrazole, pyridine, purine, diazine, triazine, and the like. Exemplary materials are isopropyl methylamine, butylamine, 3-dimethylamino-2-propanol and triethanolamine. Small amounts of ammonia, such as up to about 10% ammonia by weight of the entire composition, may be included with the above-described material stabilizer in amounts such that the loss of ammonia by evaporation does not significantly alter the properties of the patterned material. The carbon containing base has a reduced volatility, which contributes to the thermal stability of the patterned material. A lower molecular weight base may be used at a lower temperature to minimize base volatility and compositional variations in the patterned material. When higher temperatures are encountered, a strong base of greater molecular weight may be used.

The patterned material is applied in a precision patterned deposition process such as inkjet printing. In inkjet printing, the patterned material is applied in individual droplets to form uniformly sized features down to 10 μm. Accordingly, a mask pattern may be formed on the conductive material of the substrate. The precise patterned deposition of the liquid may be performed using an ink jet printer available from Kateeva corporation of newark, california or using a system available from other manufacturers.

The patterning material is frozen by a substantially instantaneous reaction with the primer, thereby forming rigid or semi-rigid polymeric features in the pattern. Since the polymer features formed by the reaction of the patterning material with the primer material are acid resistant, the polymer features can be used as a mask in an acid treatment to remove unreacted primer material and exposed conductive material. If any of the components can be activated by radiation, the patterned material can be selectively exposed to UV radiation to enhance hardness or rigidity. For example, after depositing the patterned material on the primer material, the substrate may be irradiated with 395nm light for 30 seconds to increase the hardness of the patterned polymer material. Increasing the hardness may increase the acid resistance of the patterned polymer material.

In 108, the substrate is treated with an acid to remove the primer material and expose a portion of the underlying conductive material. Aqueous solutions of weak acids, such as acetic acid or citric acid, and the like, may be used. Strong acids such as HCl, optionally including salts such as ferric chloride and cupric chloride, acetic acid, nitric acid, chloric acid, perchloric acid, iodic acid, bromic acid and sulfuric acid, optionally including suitable salts (i.e., iron or copper salts) or strong acids, may also be used. Suitable acids have a pH of 1.75 or higher in water. The conductive material not covered by the patterned polymeric material is exposed while the conductive material covered by the patterned polymeric material remains covered because the patterned polymeric material is acid resistant. The substrate may be immersed in a solution of the acid, or the acid or a solution thereof may be sprayed onto the surface of the substrate bearing the primer material. The solution may be concentrated to 1M, but lower concentrations may be used. In some cases, an electrical potential may be applied to enhance the etch rate. For example, electrodes may be attached to opposite edges of the conductive material and a DC or AC electric field applied to enhance the reaction of the metal with ions in the etchant solution. In some cases, the treatment of 108 may partially remove the primer material, leaving a thin coating to protect the conductive material from environmental factors, such as where the substrate is not immediately further processed. When using particularly strong acids, care should be taken not to damage the acid-resistant pattern or to etch the conductive material unevenly.

The acid treatment process may be done in one coating or optionally in two coatings. For example, the first acid coating may be performed with a weak acid, and the second acid coating may be performed with a strong acid. In another example, the primer material may be removed using water treatment without using acid, and then etched using acid coating. In another example, a strong acid may be applied followed by a weak acid or water. In this case, the strong acid forms a pattern and etches the exposed conductive material, and the application of the weak acid or water removes etch byproducts and may also remove remaining pattern material.

At 110, the etching is stopped and the substrate is rinsed with water to remove the etchant from the substrate. Alcohols, such as isopropyl alcohol and the like, may be included in the aqueous solution as a rinsing solution. In some cases, the patterned polymer may remain on the PCB or may be removed upon rinsing with water, which may be accelerated by increasing the temperature and/or pH. Protic cosolvents, such as alcohols and ammonia, may also accelerate dissolution. The primer material is also typically water soluble, but removal can be facilitated by the use of high temperature and/or polar aprotic solvents, such as pyridine and N-methylpyrrolidone.

The resulting PCB is a substrate with a conductive microcircuit pattern thereon. These microcircuits can now be packaged. Alternatively, the second resin substrate may be laminated on the first substrate with a microcircuit, so that a three-dimensional circuit structure may be constructed.

FIG. 2 is a flowchart outlining a method 200 in accordance with another embodiment. Method 200 is a method of forming a patterned ink for fabricating microcircuits on a PCB. At 202, a water-miscible base is added to a volume of water to form a base mixture. The base is an alkylamine, alkanolamine or organic heterocyclic amine. Bases generally have low volatility, e.g., boiling points between room temperature and about 180 ℃, pH values in water of 7.5-12, and low or no toxicity are advantageous, but not required.

Suitable alkylamines have the structure NR ¹ R ² R ³ Wherein R is ¹ 、R ² And R ³ At least one of carbon and hydrogen, R ¹ 、R ² And R ³ May be independently hydrogen, having the formula C _x H _y N _z Where x is 3 to 6 (i.e., an alkylamine having 3 to 6 carbon atoms), z is 1 or 2 (a monoamine and a diamine), and y is 2x +2+ z. Examples of the alkylamine include isopropyl methylamine, diethylamine, triethylamine and trimethylamine. Suitable alkanolamines have the general structure NR ⁴ R ⁵ R ⁶ Wherein R is ⁴ 、R ⁵ And R ⁶ At least one of (A) is hydroxyalkyl C _a H _2a OH, wherein R ⁴ 、R ⁵ And R ⁶ Can be hydrogen alone, and R ⁴ 、R ⁵ And R ⁶ One or more of which may be an alkyl group C _a H _2a+1 . Examples of alkanolamines include triethanolamine and 3-dimethylamino-2-propanol. Suitable organic cyclic amines include pyrrole, pyrrolidine, piperidine, imidazole, pyrazole, pyridine, purine, diazine and triazine. Mixtures of any of these compounds may be used, and small amounts of ammonia may be included in the mixture. The base mixture is generally prepared to a pH of 7.5-12.

At 204, the polyanionic material is added to the base mixture. A polyanionic material is a polymer having a plurality of mobile proton sites. The polyanionic material may be one or more of polyacrylic acid, polymethacrylic acid, mixed polyalkylacrylic acids, as a copolymer or a multimer, or as a homopolymer and/or a mixture of a copolymer and a multimer, a polyanionic cellulose (i.e., ANTISOL polyanionic cellulose from the Dow Chemicals company). Typically, the polyanionic material is added as a solid or as an aqueous dispersion.

At 206, the polyanionic material is dissolved in the base mixture. The base mixture is mixed with the added polyanionic material for a period of time, such as 2-24 hours. The mixture may be heated to a temperature 10-20 deg.C above ambient temperature.

At 208, other solvents, surfactants, or cosolvents may optionally be added to adjust the viscosity, pH, surface tension, or other properties desired for the treatment. Water may be used with other solvents, for example alcohols such as ethylene glycol. It should be noted that any suitable solvent may be used to prepare the mixture according to the concepts described herein. The base and the solvent are selected to dissolve the polyanionic material based on the deprotonation strength of the base in the solvent.

An exemplary formulation prepared according to method 200 is shown below. The example formulations are numbered at the top of the table with the components numbered down one side of the table. The components are as follows:

component 1-Joncryl 8085 (ammonium hydroxide solution of polyacrylic acid); component 2-Joncryl 682 (polyacrylic acid); the component 3-propylene glycol; component 4 (base) -aminomethylpropanol; component 5 (base) -isopropylmethylamine; component 6 (base) -ethanolamine; component 7 (base) -isobutylamine; component 8 (base) -1-amino-2-propanol; component 9 (base) -sec-butylamine; component 10 (base) -3-dimethylamino-2-propanol; component 11-ethylenediaminetetraacetic acid (EDTA); the component 12-Bayscript Cyan; component 13-BayDescript Blue; component 14-TEGO Wet 500; component 15-deionized water.

In various embodiments, the base is added to the water to form a base mixture, and then the polyacrylic acid component is added to the base mixture to form a dispersion mixture. The dispersion mixture is stirred for a period of time to dissolve the polyanionic material. Thereafter, the other ingredients are added in no particular order. The example formulations are as follows:

	1	2	3	4	5	6	7	8	9	10	11
												1				30
2	12.9	12.9	12.9		12.9	12.9	12.9	12.9	12.9	12.9	12.9
												3	15.0	15.0	15.0	15.0	15.0	15.0	15.0	15.0	15.0	15.0	15.0
4				0.5	6.4
												5						5.25
6							4.39
												7								5.25
8									5.4
												9											5.25
10	17.6	8.8	5.4							7.5
												11	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01
12				3.0	3.0	3.0	3.0	3.0	3.0	3.0	3.0
												13	3.0	3.0	3.0
14	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3
												15	51.19	59.99	63.39	51.19	62.39	63.54	64.4	64.54	63.39	61.29	63.54

the ink made by the method 200 of fig. 2 may be used as a patterned material for use in the method 100 of fig. 1. Such inks may be prepared prior to use in forming circuit patterns, and may be stored or used for periods of up to one month. The inks may be mixed continuously at the time of use to form the patterned material, or may be mixed intermittently during use.

The amount of base required depends on the dissociation constant of the base, the relative acid strength of the conjugated anion, and the polyanionic material. Stronger bases will produce more anions with lower acid strength. The higher molecular weight polyanions require more and/or stronger anions to solubilize them. For convenience, a base with low toxicity may be selected, but any suitable base may be selected according to its ionic properties. The base is generally selected according to its solubility in the solvent or solvent mixture for the ink and its ability to attract protons from the polyanionic material. The amount of base required depends on the concentration of acid groups on the polyanionic material and the dissociation constant of the base. Ideally, the base also does not substantially react with the polycationic material used as the primer, or the amount of base used is such that little excess base remains after interaction with the polyanionic material.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

The claims (modification according to treaty clause 19)

1. A method, comprising:

depositing a conductive material on a substrate;

applying a primer material soluble in water or an acidic aqueous solution onto the conductive material;

ink-jet printing an acid-resistant patterning material reactive with the primer material according to a pattern onto the primer material to form an acid-resistant mask, the patterning material comprising an alkali solution of a polyanionic materialA liquid wherein the base is of the structure NR ¹ R ² R ³ In which R is ¹ 、R ² And R ³ Is carbon and hydrogen, or has the general structure NR ⁴ R ⁵ R ⁶ Wherein R is ⁴ 、R ⁵ And R ⁶ At least one of (A) is hydroxyalkyl C _a H _2a OH or an organic cyclic amine; and

exposing the substrate to an acid to etch the exposed portion of the conductive material.

2. The method of claim 1, wherein the primer material is applied by inkjet printing.

3. The method of claim 2, wherein the patterning material comprises a polyacrylic acid or a polyanionic cellulose.

4. The method of claim 3, wherein the primer material comprises a polycationic polymer.

5. The method of claim 4, wherein exposing the substrate to an acid comprises applying a first acid to the substrate and then applying a second acid to the substrate.

6. The method of claim 1, wherein the primer material comprises a polycationic material.

7. A method, comprising:

depositing a conductive material on a substrate;

ink-jet printing a blanket (blanket) of an acid-soluble primer material onto the region of conductive material, the primer material comprising a polycationic material;

ink-jet printing an acid-resistant patterning material onto the primer material according to a pattern to form an acid-resistant mask, the acid-resistant patterning material comprising a polyanionic material and a base, wherein the base is of structure NR ¹ R ² R ³ Of an alkylamine of (i), wherein R ¹ 、R ² And R ³ Is carbon and hydrogen, or has the general structure NR ⁴ R ⁵ R ⁶ Wherein R is ⁴ 、R ⁵ And R ⁶ At least one of (A) is hydroxyalkyl C _a H _2a OH or an organic cyclic amine; and

exposing the substrate to an acid to remove portions of the conductive material according to the pattern.

8. The method of claim 7, wherein said polyanionic material is a polyacrylic acid or a polyanionic cellulose.

9. The method of claim 7, wherein the primer material comprises a polycationic polymer.

10. The method of claim 9, wherein the primer material comprises a co-solvent.

11. The method of claim 9, wherein the patterning material further comprises ammonia.

12. A method of forming a printed circuit board, the method comprising:

depositing a conductive material on a substrate;

ink-jet printing an overlayer of an acid-soluble primer material onto the region of conductive material, the primer material comprising a polycationic material and a solvent;

removing the solvent to cure the primer material;

ink-jet printing an acid-resistant patterning material onto the cured primer material according to a pattern to form an acid-resistant mask, the acid-resistant patterning material comprising a polyanionic material and a base, wherein the base is of structure NR ¹ R ² R ³ In which R is ¹ 、R ² And R ³ Is carbon and hydrogen, or has the general structure NR ⁴ R ⁵ R ⁶ Wherein R is ⁴ 、R ⁵ And R ⁶ At least one of (A) is hydroxyalkyl C _a H _2a OH or an organic cyclic amine; and

13. The method of claim 12, wherein exposing the substrate to an acid comprises exposing the substrate to a weak acid followed by a strong acid.

14. The method of claim 12, further comprising: treating the substrate with water to expose a portion of the conductive material prior to exposing the substrate to the acid.

15. The method of claim 12, further comprising: after exposing the substrate to the acid, rinsing the substrate with an alcohol solution.

Claims

1. A method, comprising:

depositing a conductive material on a substrate;

applying a primer material soluble in water or an acidic aqueous solution to the conductive material;

ink-jet printing an acid-resistant patterning material that reacts with the primer material onto the primer material according to a pattern to form an acid-resistant mask; and

2. The method of claim 1, wherein the patterning material comprises a polyanionic material.

3. The method of claim 2, wherein the patterning material is a basic solution of a polyanionic material and the base is a strong base comprising carbon.

4. The method of claim 3, wherein the base is an amine.

5. The method of claim 4, wherein the primer material is applied by inkjet printing.

6. The method of claim 5, wherein the patterning material comprises a polyacrylic acid or a polyanionic cellulose.

7. The method of claim 6, wherein the primer material comprises a polycationic polymer.

8. The method of claim 7, wherein exposing the substrate to an acid comprises applying a first acid to the substrate and then applying a second acid to the substrate.

9. The method of claim 1, wherein the primer material comprises a polycationic material and the patterning material comprises a polyanionic material dissolved in a basic solution comprising a strong base comprising carbon.

10. A method, comprising:

depositing a conductive material on a substrate;

ink-jet printing an acid-resistant patterning material onto the primer material according to a pattern to form an acid-resistant mask, the acid-resistant patterning material comprising a polyanionic material; and

11. The method of claim 1, wherein the polyanionic material is a polyacrylic acid or a polyanionic cellulose and the base is of structure NR ¹ R ² R ³ Of an alkylamine of (i), wherein R ¹ 、R ² And R ³ Is carbon and hydrogen, or has the general structure NR ⁴ R ⁵ R ⁶ Wherein R is an alkanolamine ⁴ 、R ⁵ And R ⁶ At least one of (A) is hydroxyalkyl C _a H _2a OH or an organic cyclic amine.

12. The method of claim 11, wherein the primer material comprises a polycationic polymer.

13. The method of claim 12, wherein said polyanionic material is dissolved in an aqueous solution.

14. The method of claim 12, wherein the primer material comprises a co-solvent.

15. The method of claim 12, wherein the patterning material further comprises ammonia.

16. The method of claim 13, wherein the aqueous solution consists of the base dissolved in water.

17. A method of forming a printed circuit board, the method comprising:

depositing a conductive material on a substrate;

removing the solvent to cure the primer material;

inkjet printing an acid-resistant patterning material onto the cured primer material according to a pattern to form an acid-resistant mask, the acid-resistant patterning material comprising a polyanionic material; and

18. The method of claim 17, wherein exposing the substrate to an acid comprises exposing the substrate to a weak acid followed by a strong acid.

19. The method of claim 17, further comprising: treating the substrate with water to expose a portion of the conductive material prior to exposing the substrate to the acid.

20. The method of claim 17, further comprising: after exposing the substrate to the acid, rinsing the substrate with an alcohol solution.