Method and composition for producing etch-resistant patterns on metal surfaces

Abstract

A method and composition set for forming an etch-resistant mask on a metal surface is provided. The method may include applying a composition comprising a first reactive component to a metal surface to form a primer layer; and printing another composition comprising a second reactive component in an image manner on the primer layer by a non-impact printing process to produce an etch-resistant mask, wherein when a droplet of the second composition contacts the primer layer, the reactive component undergoes a chemical reaction, thereby immobilizing the droplet. The set may include a first liquid composition comprising a fixed reactive component and a second liquid composition comprising an etch-resistant reactive component, wherein the fixed reactive component and the etch-resistant reactive component are capable of undergoing a chemical reaction to form a two-component material that is insoluble in water and insoluble in an acidic etching solution.

Description

Field of the Invention

[0001] Embodiments of the present invention are directed to fabricating conductive patterns on metal surfaces, such as printed circuit boards (PCBs), by applying an etch-resistant mask directly on the metal layer.

[0002] background

[0003] Printed circuit boards (PCBs) are widely used in most electronic products. The manufacture of PCBs is considered to be cheaper, faster and more accurate than using other wiring methods such as point-to-point construction. However, there is a continuous search for simpler and more cost-effective manufacturing processes that will maintain high quality and will be able to produce PCBs according to specific requirements, including cost-effective manufacturing of smaller batches, manufacturing of larger batches with high production volume, manufacturing of boards on demand, manufacturing of boards with denser wiring, manufacturing of boards with thinner lines, and others.

[0004] The wiring pattern in PCB manufacturing is usually completed by a subtractive method, which includes removing copper from a copper layer laminated to an insulating material board, leaving only the required copper wire (also known as a pattern or image) as a conductive path. The process includes applying an etch-resist mask on the copper layer and removing the exposed copper portion by an etching process. The current commonly used method for preparing an etch-resist mask includes coating the copper layer with a photosensitive etch-resist substance (generally a UV photosensitive substance); preparing a photomask using, for example, a photo plotter or a laser plotter; exposing the layer to UV radiation to cure and fix the exposed area to a pattern on the copper layer; and removing the unexposed etch-resist substance by chemical development. Until then, the wiring pattern can be produced by etching the unmasked copper portion, followed by a stripping process for removing the etch-resist mask. The wiring pattern covers about 25% of the surface of the circuit board. However, during production, the entire board is coated with a photosensitive etch-resist substance, and then the wiring pattern is exposed to UV radiation or other radiation to form an etch-resist mask. The remaining photosensitive resist is washed away.

[0005] The etch-resistant pattern can also be applied to the copper layer by an additive method, for example, by non-impact printing (e.g., inkjet printing). Conventional inkjet materials have relatively low viscosities, and therefore when ink droplets will hit non-absorbent surfaces such as copper surfaces, uncontrolled diffusion of droplets and other phenomena such as aggregation, coalescence, and extensive dot gain usually occur. Therefore, the printed pattern may exhibit reduced resolution, insufficient detail, inconsistent line widths of the patterned parts, poor line edge smoothness, short circuits between adjacent conductors, and disconnection of patterned lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. Figure 1 The invention, both as to its organization and method of operation, together with its objects, features, and advantages may be best understood by reference to the following detailed description when read in conjunction with the accompanying drawings:

[0007] Figure 1 is a flow chart of a method for producing an etch-resistant mask according to some embodiments of the present invention; and

[0008] Figure 2 is a diagram to assist in understanding a method for producing an etch-resistant mask according to an embodiment of the present invention.

[0009] It will be understood that, for simplicity and clarity of illustration, the elements shown in the drawings are not necessarily drawn to scale. For example, for clarity, the size of some of the elements may be enlarged relative to other elements. In addition, reference numerals may be repeated in the drawings to indicate corresponding or similar elements where deemed appropriate.

[0010] Overview

[0011] Embodiments of the present invention relate to a method for forming or applying an anti-etching mask on a metal layer by non-impact printing. The method may include: applying a first liquid composition comprising a first reactive component to a metal surface to form a primer layer; and printing a second liquid composition comprising a second reactive component on the primer layer in an image manner by a non-impact printing process to produce an anti-etching mask according to a predetermined pattern, wherein when a droplet of the second liquid composition contacts the primer layer, the second reactive component undergoes a chemical reaction with the first reactive component, thereby fixing the droplet.

[0012] Embodiments of the present invention are directed to a two-part ink composition set for applying an etch-resistant mask on a metal layer. The set may include a first liquid composition comprising a fixing reactive component and a second liquid composition comprising an etch-resistant reactive component, wherein the fixing reactive component and the etch-resistant reactive component are capable of undergoing a chemical reaction to form a two-component material that is insoluble in water and insoluble in an acidic etching solution. Detailed Description

[0013] In the following detailed description, a large number of specific details are set forth in order to provide a complete understanding of the present invention. However, it will be appreciated by those skilled in the art that the present invention can be practiced without these specific details. In other examples, well-known methods, procedures and components are not described in detail in order not to obscure the present invention.

[0014] Embodiments of the present invention relate to a method for forming or applying an etch-resistant mask on a metal layer by non-impact printing, for example, by inkjet printing. Embodiments of the method may be applicable to, for example, the manufacture of a printed circuit board (PCB). The method for applying an etch-resistant mask on a metal surface according to an embodiment of the present invention may include: applying a first liquid composition comprising a first reactive component to the surface to form a primer layer, and then printing a second liquid composition comprising a second reactive component on the primer layer to produce an etch-resistant mask according to a predetermined pattern. According to an embodiment of the present invention, the second reactive component undergoes a chemical reaction with the first reactive component to produce a two-component material that is insoluble in water and insoluble in an etching solution. The two-component material has an increased viscosity relative to a separate component, and the reaction causes the fixation of a droplet of the second composition when impacting the primer layer.

[0015] The metal layer can be a copper layer laminated to an insulating non-conductive substrate. For ease of explanation, the following description relates to a copper surface. It should be appreciated that other metal surfaces, such as aluminum surfaces, stainless steel surfaces, gold surfaces, and other surfaces are also equally applicable to embodiments of the present invention.

[0016] According to an embodiment of the present invention, an etch-resistant mask can be formed by continuously applying two liquid compositions to a metal layer, each liquid composition comprising a reactive component that can undergo a chemical reaction with another reactive component contained in another composition. The product of the chemical reaction is referred to as a two-component material. Each of the compositions is water-soluble, and the two-component reaction product material is insoluble in water and insoluble in an etching solution. In other words, the two-component reaction product material is neither water-soluble nor soluble in an etching solution for etching a metal layer. According to some embodiments, the etching solution can be an acidic etching solution, such as a mixture of, for example, cupric chloride and hydrogen peroxide.

[0017] According to some embodiments, at least one of the compositions may include more than one reactive component, which may undergo chemical reactions with one or more reactive components in another composition. According to embodiments of the present invention, one of the compositions may include multivalent groups and / or polycationic groups and / or polyvalent inorganic cations, and may be used as a fixed composition. Another composition may include polyanionic groups and may be used as an etch-resistant composition. In some embodiments, it may not be necessary to remove the layer containing the fixed composition before the etching process, and the layer is removed during the etching process.

[0018] For example, a non-limiting list of fixed reactive components can include polyethylene imine, divalent salts, heteropolymers of vinyl pyrrolidone, and others.

[0019] According to an embodiment of the present invention, the first composition can be applied to the copper surface as a uniform layer or in an image form by inkjet printing or any other printing or coating method. The second composition is printed using a non-impact printing method, such as by inkjet printing, to form a desired wiring pattern. When the droplet of the second composition hits the primer layer on the metal surface, the chemical reaction (i.e., multivalent and / or polycationic groups or multivalent cations react with polyanions) experienced between the two reactive components causes a momentary relative increase in the viscosity of the second composition, which prevents the uncontrolled diffusion of the droplet. The droplet is fixed or solidified without spreading on the surface. According to an embodiment of the present invention, the reactive component of the first composition can be a fixed component, which chemically fixes the printed pattern to the substrate when reacting with the second component of the second composition. The reactive component of the second composition can be an etch-resistant component. Such a component can include, for example, an acidic etch-resistant substance that prevents acid etching. In some embodiments, the fixed component may be able to adhere to the metal layer to ensure that the etch-resistant mask will remain attached to the metal layer during the etching process. According to other embodiments, the reactive component of the first composition can be an etch-resistant component and the reactive component of the second composition can be an immobilization component.

[0020] The composition comprising the fixing component can be applied to the metal surface as a primer layer using non-impact printing or any other known coating method to form a uniform or patterned layer. The composition comprising the anti-etching component can then be applied imagewise by non-impact printing to form an anti-etching mask. In some embodiments, an acid solution can be added to the first composition to activate the fixing material.

[0021] Alternatively, according to some embodiments of the present invention, non-impact printing or any other known method can be used to apply the composition comprising the anti-etching component on the metal surface as a primer layer, to form a uniform or patterned layer.Then the composition comprising the fixed component can be applied imagewise to form an anti-etching mask by non-impact printing.For ease of explanation, the following description mainly relates to an embodiment in which the fixed composition is directly applied on the metal surface and the anti-etching composition is deposited on the formed fixed layer. However, it should be understood that the following description also relates to an embodiment in which the order of the deposited composition is reversed.

[0022] Some embodiments of the present invention may be directed to a two-part ink composition set for applying an etch-resistant mask on a metal surface. The set may include two solutions, each solution stored in a different container (e.g., two aqueous solutions), the first solution may include a fixed component, and the second solution may include an etch-resistant component. The fixed component in the first solution and the etch-resistant component in the second solution may react with each other to form an etch-resistant insoluble composition that is neither soluble in water nor in an etching solution and has good adhesion to metals such as copper.

[0023] Reference Figure 1 , Figure 1 is a flow chart of a method for producing a conductive pattern according to some embodiments of the present invention, and refers to Figure 2 , Figure 2 Pictured Figure 1 According to embodiments of the present invention, as illustrated in block 110, in some embodiments, the method may include forming a primer layer on the metal surface. The primer layer (e.g., Figure 2 The layer 230) can be laminated to an electrically insulating substrate (e.g. Figure 2 The metal surface of the substrate 210 (eg, Figure 2 The reactive component of the first composition can be a water-soluble fixed component and can include a reactive cationic group, such as a polycation or a multivalent cation. The cationic reactive component may be able to adhere to a metal surface, such as a copper surface. In some embodiments, applying the first liquid composition can be performed by any industrial coating method.

[0024] The limiting examples of cationic reactive components can include polyamides such as polyethyleneimine, polyquaternary amines, long-chain quaternary amines, polytertiary amines, and polyvalent inorganic cations such as magnesium cations, zinc cations, calcium cations, copper cations, iron cations and ferrous cations at various pH levels. The polymer component can be incorporated into the preparation as a soluble component or in the form of an emulsion. Primer layer can be applied to the metal surface using any suitable printing or coating methods including but not limited to inkjet printing, spraying, metering rod coating, roller coating, dip coating and other. Primer layer can be uniform or patterned.

[0025] In some embodiments, the primer layer can be a continuous layer that substantially covers the entire metal surface. Alternatively, the primer layer can be printed in an image manner according to the desired pattern. The pattern can be applied by non-impact printing, for example, by inkjet printing. The desired pattern can be, for example, the copper wiring of a PCB.

[0026] As illustrated in frame 120, in some embodiments, the method may include printing a second liquid composition containing a second reactive component on the primer layer by a non-impact printing process. Printing is performed in an image manner using, for example, an inkjet printer to form an anti-etching mask according to a predetermined pattern onto the metal surface. During the printing process of the second liquid, the metal surface may be heated to a high temperature to further improve the printing quality. Typical surface temperatures may be in the range of 25°C and up to 80°C. The second liquid composition includes a second reactive component, which may undergo a chemical reaction with the first reactive component contained in the primer layer to fix the droplets of the second composition when contacting or impacting the primer layer. The product of the chemical reaction is a material having a substantially higher viscosity than each of the first and second compositions and being insoluble in water and etching solutions. The insoluble anti-etching pattern may have a dry layer thickness of at least 0.01 microns. In some embodiments, the thickness of the printed pattern may be up to 12 microns.

[0027] In some embodiments, the reactive component of the second composition can be water-soluble and can include reactive anionic groups. Non-limiting examples of anionic reactive components can include at least one anionic polymer (in base form) having a pH higher than 7.0. Anionic polymers can be selected from acrylic resins and styrene acrylic resins in the form of their dissolved salts. Anionic polymers can be selected from sulfonic acid resins in the form of neutralization of their dissolved salts such as sodium, ammonium or amine and in the form of polymer emulsions or dispersions. The polymer component can be introduced into the formulation as a soluble component or in the form of an emulsion. Alternatively, in some embodiments, the method can include applying an anti-etching composition to form a primer layer, and the second layer can be formed by using a non-impact printing method to print a fixed composition in an image-like pattern.

[0028] As illustrated in block 130, in some embodiments, the method may include removing exposed or unmasked portions of the primer layer, which may be a fixed layer containing a cationic component, or alternatively an etch-resistant layer containing a polyanionic reactive component in other embodiments. If the first layer is a fixed layer, then in some embodiments, the fixed composition may be washed away during the etching process. The exposed portion of the first layer may consist primarily of reactive components and may be easily washed away simply by immersing the plate in water, while the etch-resistant mask formed by the chemical reaction of the first reactive material and the second reactive material is insoluble and remains attached to the metal surface.

[0029] As illustrated in block 140, embodiments of the method may include etching the metal surface. For example, the masked copper plate may be etched by a copper etching (e.g., acid copper etching) solution to remove the unmasked copper portion. As illustrated in block 150, the anti-etching mask is then removed. For example, in PCB manufacturing, when the anti-etching mask is removed, a predetermined wiring pattern of conductive copper wires attached to the surface of the insulating plate 210 may be exposed. Example

[0030] Using Epson stylus 4900 inkjet printer, exemplary anti-etching composition (second composition as described herein) is printed on the FR4 copper-clad board with a thickness of 1 / 2Oz, 1 / 3Oz and 1Oz. In some cases, first use Epson stylus 4900 inkjet printer, with fixed composition (first composition as described herein) coating copper, form fixed layer, on this fixed layer, selectively print anti-etching composition according to predetermined pattern. In the following description, % (w / w) is the measurement of the concentration of the material by weight percentage relative to the composition weight. Use the etchant bath of the ferric chloride etchant solution that comprises the concentration (strength) provided by Amza [pernix 166] to etch away the copper that is not protected by the area of ​​exposed resist. Etching is carried out at a temperature of 35 ℃ for 3 minutes in the Spray Developer S31 provided by Walter Lemmen GMBH. The anti-etching mask was stripped by immersing the etched board in a 1% (w / w) NaOH aqueous solution at a temperature of 25° C., and then washing the FR4 copper board with water and drying by air at 25° C. In some experiments, industrial etching units including advanced etching units and super etching units (manufactured by Universal or Shmidth, which contain a cupric chloride solution for etching unprotected copper) were also used to etch the copper board.

[0031] Embodiment 1-on the anti-etching composition (comparative data) printed on the top of uncoated copper FR4 board.Anti-etching composition (second composition) is prepared with 10% propylene glycol and 1% (w / w) 2-amino-2-methyl propanol, 0.3% (w / w) BYK 348 and 2% (w / w) Bayscript BA Cyan provided by BYK.These materials are dissolved in the water containing 24% Joncryl 8085 styrene acrylic resin solution as anionic reactive component.Use Epson stylus 4900 inkjet printer, the anti-etching composition is printed on the FR4 copper-clad board with a thickness of 1 / 2Oz to produce an anti-etching mask.The thickness of the dry anti-etching mask is 5 microns.

[0032] The resist mask was visually inspected and the printed pattern showed very poor printing quality with extremely poor edge definition, line breaks, and severe shorts between lines.

[0033] Example 2 - Anti-etching compositions were prepared as detailed in Example 1. A primer or fixing composition was prepared as an aqueous solution of a mixture of 10% (w / w) LUPASOL PR8515 (polyethyleneimine as the cationically reactive component) supplied by BASF, 10% (w / w) propylene glycol, 10% n-propanol and 0.3% (w / w) TEGO 500 (substrate wetting additive to suppress foaming) supplied by Evonik Industries.

[0034] FR4 copper plate is coated using Epson stylus 4900 inkjet printer. The coated plate is placed dry at room temperature to obtain a completely transparent uniform coating covering the entire surface without any crystal-formed dry layer with a thickness of 0.3 μm. Using Epson stylus 4900 inkjet printer, the anti-etching composition is printed on the coated copper plate and dried at 80°C to produce a two-component anti-etching mask. Visual inspection of the anti-etching mask shows a better print quality than Example 1, but still shows a relatively poor print quality, with widened lines, and short circuits between lines. Etching unmasked copper and removing the anti-etching mask are carried out as described in detail above. The wiring pattern produced after the etching process has the same image as the anti-etching mask, with the same widened lines, and short circuits between lines. It should be noted that for some applications, the print quality as shown by Example 2 may be sufficient.

[0035] Example 3 - An anti-etching composition was prepared as detailed in Example 1. A fixing composition was prepared as detailed in Example 2 except that 0.3% (w / w) TEGO 500 was replaced with 0.3% (w / w) TEGO 500 containing 13% (w / w) concentrated HCl.

[0036] As described in detail in Example 2, FR4 copper plates were coated with a fixing composition using an Epson stylus 4900 inkjet printer, and a coating as described in detail in Example 2 was formed after drying. Similar to Example 2, the anti-etching composition was inkjet printed on the coated copper plate and dried at 80°C to produce a two-component anti-etching mask. The anti-etching pattern showed high print quality, with a thickness of clear fine lines as low as 2 mm, with sharp edges and no line breakage. Etching unmasked copper and removing the anti-etching mask were performed as described in detail above. The wiring pattern produced by etching and stripping processes showed a clear pattern, with a width of fine lines as low as 15 microns, with sharp edges and no line breakage.

[0037] Example 4 - Two-component reaction, etch-resistant composition printed on a copper surface coated with a reactive cationic composition containing hydrochloric acid (HCl). The etch-resistant composition was prepared as detailed in Example 1. The fixing composition was prepared as an aqueous solution of a mixture of 10% (w / w) Styleze W-20 (supplied by ISP as a 20% polymer solution in water), 0.1% BYK 348, and 13% (w / w) concentrated HCl.

[0038] A FR4 copper plate was covered with the fixing composition using a Mayer rod to produce a dry layer with a thickness of 0.4 μm. The coated plate was left to dry to obtain a completely transparent coating without crystal formation over the entire copper surface. Similar to Example 2, the anti-etching composition was inkjet printed on the coated copper plate and dried at 80° C. to produce a two-component anti-etching mask.

[0039] The anti-etching pattern exhibits clear high print quality and thin lines down to 2 mm, which contain sharp edges and no line breaks. The residue of the fixing layer not covered by the anti-etching composition is washed by soaking the board in water at a temperature of 25°C for 2 minutes and dried at 80°C. Etching of the exposed copper and removal of the anti-etching mask are carried out as described in detail above. The wiring pattern on the board exhibits clear thin lines with a width down to 2 mm, which contain sharp edges and no line breaks.

[0040] Example 5 - Two-component reaction, etch-resistant composition printed on a copper surface coated with a reactive cationic composition containing hydrochloric acid (HCl). The etch-resistant composition was prepared as detailed in Example 1. The fixing composition was prepared as an aqueous solution of a mixture of 10% (w / w) Lupasol HF (supplied by BASF as a 56% polymer solution in water), 0.1% BYK 348 containing 13% (w / w) concentrated HCl.

[0041] A Mayer rod was used to cover a FR4 copper plate with the fixing composition to produce a dry layer with a thickness of 1 μm. The coated plate was left to dry to obtain a completely transparent coating without crystal formation over the entire copper surface. Similar to Example 2, the anti-etching composition was inkjet printed on the coated copper plate and dried at 80° C. to produce a two-component anti-etching mask.

[0042] The anti-etching pattern exhibits clear high print quality, and thin lines as low as 2 mm, which contain sharp edges and no line breaks. The residue of the fixing layer not covered by the anti-etching composition is washed by soaking the board in water at a temperature of 25°C for 3 minutes and dried at 80°C. Etching the exposed copper and removing the anti-etching mask are carried out as detailed above. The wiring pattern on the board exhibits clear thin lines with a width as low as 2 mm, which contain sharp edges and no line breaks.

[0043] Example 6 - Two-component reaction: Anti-etching composition printed on a copper surface coated with a reactive cationic composition containing hydrochloric acid (HCl). The anti-etching composition was prepared as detailed in Example 1. The fixing composition was prepared as an aqueous solution of a mixture of 10% (w / w) Lupasol PN50 (supplied by BASF as a 49% polymer solution in water), 0.1% BYK 348 containing 13% (w / w) concentrated HCl.

[0044] A Mayer rod was used to cover a FR4 copper plate with the fixing composition to produce a dry layer with a thickness of 1 μm. The coated plate was left to dry to obtain a completely transparent coating without crystal formation over the entire copper surface. Similar to Example 2, the anti-etching composition was inkjet printed on the coated copper plate and dried at 80° C. to produce a two-component anti-etching mask.

[0045] The etch-resistant pattern shows clear high print quality, and thin lines as low as 2 mm, which contain sharp edges and no line breaks. The residue of the fixed layer is processed as described in detail in Example 5. Etching exposed copper and removing the etch-resistant mask are carried out as described in detail above. The wiring pattern on the board shows clear thin lines, which have a width as low as 2 mm, contain sharp edges and no line breaks.

[0046] Example 7 - Two-component reaction, etch-resistant composition printed on a copper surface coated with a reactive composition containing citric acid. The etch-resistant composition was prepared as detailed in Example 1. The fixing composition was prepared as an aqueous solution of a mixture of 10% (w / w) citric acid, 25% (w / w) propylene glycol, 0.3% (w / w) TEGO 500 (substrate wetting additive to suppress foaming) supplied by Evonik Industries.

[0047] Using an Epson stylus 4900 inkjet printer, a FR4 copper plate was coated with the fixing composition. The coated plate was left to dry at room temperature to obtain a completely transparent uniform coating with a dry layer thickness of 0.3 μm covering the entire surface without crystal formation. Similar to Example 2, the anti-etching composition was inkjet printed on the coated copper plate and dried at 80° C. to produce a two-component anti-etching mask.

[0048] The resist pattern exhibits clear high print quality, and thin lines down to 2 mm, which contain sharp edges and no line breaks. Etching the exposed copper and removing the resist mask are performed as detailed above. The wiring pattern on the board exhibits clear thin lines with a width down to 2 mm, which contain sharp edges and no line breaks.

[0049] Example 8 - Two-component reaction, coating composition comprising an etch-resistant composition The composition was prepared as detailed in Example 1. The fixing composition was prepared as an aqueous solution of a mixture of 2.5% (w / w) Zn(NO3)2, 3.75% (w / w) calcium acetate, 0.2% (w / w) Capstone 51, 5% (w / w) n-propanol and 5% (w / w) Lupasol FG (supplied by BASF).

[0050] A Mayer rod was used to cover a FR4 copper plate with the fixing composition to produce a dry layer with a thickness of 0.5 μm. The coated plate was left to dry to obtain a completely transparent coating without crystal formation over the entire copper surface. Similar to Example 2, the anti-etching composition was inkjet printed on the coated copper plate and dried at 80° C. to produce a two-component anti-etching mask.

[0051] The etch-resistant pattern shows clear high print quality, and thin lines as low as 2 mm, which contain sharp edges and no line breaks. Etching exposed copper and removing the etch-resistant mask are carried out as described in detail above. The wiring pattern on the board shows clear thin lines, which have a width as low as 2 mm, contain sharp edges and no line breaks.

[0052] Example 9 - An etch-resistant composition was prepared as an aqueous solution of a mixture of 8% (w / w) PVA, 24% Joncryl 8085 styrene acrylic resin solution (supplied as a 42% aqueous polymer solution), and 1.5% 2-amino-2-methylpropanol.

[0053] The fixing composition was prepared as follows: 2% (w / w) Basacid Red 495, 10% (w / w) propylene glycol, 10% n-propanol, 0.3% (w / w) TEGO 500, 10% (w / w) Lupasol G20 (provided by BASF) containing 12% (w / w) concentrated HCl. A FR4 copper plate was covered with the anti-etching composition using a Mayer rod to produce a dry layer with a thickness of 2.4 μm. The coated plate was left to dry to obtain a completely transparent coating without crystal formation on the entire copper surface. The fixing composition was inkjet printed on the coated copper plate and dried at 80° C. to produce a two-component anti-etching mask.

[0054] The anti-etching pattern shows clear high print quality, and thin lines as low as 2 mm, which contain sharp edges and no line breaks. The residue of the coating not covered by the anti-etching ink is washed by immersing the board in an aqueous solution of 1% (w / w) NaHCO3 for 30 seconds at a temperature of 25°C and dried at 80°C. Etching the exposed copper and removing the anti-etching mask are carried out as described in detail above. The wiring pattern on the board shows clear thin lines with a width as low as 2 mm, which contain sharp edges and no line breaks.

[0055] Cationic composition (fixed reactive component)

[0056] Non-limiting examples of cationic reactive components (fixed reactive components) can include polyamides such as polyethylene imine, divalent metal salts, organic or inorganic acids, heteropolymers of vinyl pyrrolidone, dimethylaminopropyl methacrylamide; methacryloylaminopropyl lauryl dimethyl ammonium chloride, polyquaternary amines, and polyamines in natural form or as ammonium salts.

[0057] The thickness of the dried immobilizing layer may be as thin as about 0.01 microns. Typical desired thicknesses of the dried layer may vary between 0.025 microns and 5 microns.

[0058] The cationic composition (first composition) may include additional components suitable for adapting the application method and the desired width of the dry layer. The composition may have a viscosity suitable for spraying or inkjet printing, for example, a viscosity of less than 60 centipoise or between 3-20 cP (centipoise) at ambient temperature, respectively. In the case of applying a different coating method, the composition may have a higher viscosity.

[0059] In some embodiments, an acidic solution may be added to the first solution to increase the reactivity of the first layer to the copper layer 320 and its reactivity against the etching layer or the fixing layer. In some embodiments, the first layer may be further developed, for example, by water, before the copper etching process. In some embodiments, the applied first layer may be dried before the second layer is applied. The layer so dried may contain primarily the first reactive material. The first layer may be dried using any known drying method.

[0060] Table 1 lists some non-limiting examples of first reactive components (eg, fixing components) and first compositions (eg, fixing compositions, cationic compositions).

[0061] Table 1

[0062]

[0063]

[0064] Anionic composition (etching-resistant polymer component)

[0065] In some embodiments, the second reactive component (e.g., a polymer component) can be an anti-etching component (resistant to metal etching solutions). The second reactive component can include polyanion active groups, such as: acrylates, styrene acrylates; phosphates and sulfonates. Due to the chemical reaction between the first reactive material (which includes a polycation) and the second reactive material (which includes a polyanion), a droplet of the anti-etching ink applied on the first (e.g., fixed) layer can be immobilized and fixed to the copper surface. Since the fixation is very rapid (in the microsecond range), the size of the printed pattern is similar to the size of the desired pattern. The compound formed by the reaction of the first reactive material and the second reactive material (both of which are soluble in water) should be insoluble in the copper etching solution.

[0066] The second composition can have a viscosity of less than 60cP, for example 3-20cP, at a jetting temperature suitable for inkjet printing. In the case of applying different coating methods, the composition may have a higher viscosity. In some embodiments, the second composition may include a reactive component no more than 20% (w / w) to maintain the required viscosity. In some embodiments, when dissolved in the composition, the polyanion reactive component (etching resistant polymer) can have a maximum value of 5000 mol weight (for example, polymer can have a relatively short chain). In some embodiments, the etching resistant polymer can have a higher molar weight, resulting in a composition in the form of a polymer emulsion or dispersion. The second reactive component can have a high acid value, for example, every gram of polymer has more than 100 reactive anionic groups. For example, the etching resistant polymer according to an embodiment of the present invention can have more than 200, 240, 300 or more reactive anionic groups in each chain.

[0067] Some non-limiting examples of the second reactive component (anti-etching component) and the second composition (anti-etching composition, anionic composition) are listed in Table 2.

[0068] Table 2

[0069]

[0070] In some embodiments, the fixing composition listed in Table 1 and the anti-etching composition listed in Table 2 may be included in a kit for forming an anti-etching mask according to some embodiments of the present invention.

[0071] Although certain features of the present invention have been illustrated and described herein, many modifications, substitutions, variations and equivalents will now occur to those of ordinary skill in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and variations when such modifications and variations fall within the true spirit of the present invention.

Claims

1. A method for producing an anti-etching pattern, comprising: applying a first liquid composition comprising a first reactive polymer component to the metal surface; as well as printing a second liquid composition comprising a second reactive polymer component by a non-impact printing process to produce a patterned etch-resistant mask, wherein when the second liquid composition contacts the first liquid composition, the second reactive polymer component undergoes a chemical reaction with the first reactive polymer component, thereby forming an etch-resistant mask, and Applying the first liquid composition is accomplished by non-impact printing.

2. The method of producing an etch-resistant pattern according to claim 1, wherein the first reactive polymer component and the second reactive polymer component are water-soluble, and the chemical reaction produces a two-component material that is insoluble in water and insoluble in an acidic etching solution.

3. The method for producing an anti-etching pattern according to claim 1, further comprising: removing a portion of the first liquid composition that does not participate in the chemical reaction; and An etching process is performed using a metal etching solution to remove exposed metal portions not covered by the anti-etching mask.

4. The method for producing an etching resist pattern according to claim 3, wherein removing the portion of the first liquid composition and performing the etching process are performed simultaneously.

5. The method for producing an etch-resistant pattern according to claim 1, wherein one of the first reactive polymer component and the second reactive polymer component comprises at least one of the following: polyethyleneimine, a divalent metal salt, an acid, a heteropolymer of vinylpyrrolidone, dimethylaminopropylmethacrylamide, methacryloylaminopropyllauryldimethylammonium chloride, polyquaternary amines, polyamines in natural form or as ammonium salts, or any mixture thereof. 6 . The method for producing an etch-resistant pattern according to claim 1 , wherein one of the first reactive polymer component and the second reactive polymer component comprises at least one of acrylate, styrene acrylate, phosphate, sulfonate, and any mixture thereof.

7. A two-part ink composition set for applying an anti-etching mask obtained by the method for producing an anti-etching pattern according to claim 1 on a metal layer, comprising: a first liquid composition comprising a water-soluble first reactive polymer component; and a second liquid composition comprising a water-soluble second reactive polymer component, Wherein the first reactive polymer component and the second reactive polymer component are capable of undergoing a chemical reaction to form a two-component material that is insoluble in water and insoluble in an acidic etching solution.

8. The two-part ink composition set according to claim 7, wherein the first reactive polymer component comprises at least one of the following: polyethylene imine, a divalent metal salt, an acid, a heteropolymer of vinyl pyrrolidone, dimethylaminopropyl methacrylamide, methacryloylaminopropyl lauryl dimethyl ammonium chloride, a polyquaternary amine, a polyamine in natural form or as an ammonium salt, or any mixture thereof.

9. The two-part ink composition set according to claim 7, wherein the second reactive polymer component comprises at least one of the following: acrylates, styrene acrylates, phosphates, sulfonates, and any mixtures thereof.

10. A method for producing an anti-etching pattern, comprising: depositing a first aqueous composition comprising a first reactive component onto the metal layer of the substrate; depositing a second aqueous composition comprising a second reactive component on selected portions of the deposited first aqueous composition to form a two-component material mask in a pattern to protect selected areas of the metal layer through a chemical reaction between the first reactive component and the second reactive component; depositing an etching solution to remove the metal layer in areas not protected by the two-component material mask; and After deposition of the etching solution, the two-component material mask is removed. 11 . The method for producing an anti-etching pattern according to claim 10 , wherein one of the first reactive component and the second reactive component comprises a cationic component, and the other of the first reactive component and the second reactive component comprises an anionic component.

12. The method for producing an anti-etching pattern according to claim 11, wherein: The cationic component includes polyethyleneimine, polyquaternary amines, long-chain quaternary amines, or polytertiary amines, and the anionic component includes acrylates, styrene acrylates, phosphates, or sulfonates. 13 . The method for producing an anti-etching pattern according to claim 11 , wherein at least one of the cationic component and the anionic component comprises a polymer.

14. The method for producing an anti-etching pattern according to claim 10, wherein the two-component material mask is insoluble in at least one of water and the etching solution.

15. A method for producing an anti-etching pattern, comprising: depositing a first aqueous composition comprising a first reactive component onto the metal layer of the substrate; drying the first aqueous composition; depositing a second aqueous composition comprising a second reactive component on selected portions of the dried first aqueous composition to form a two-component material mask in a pattern to protect selected areas of the metal layer through a chemical reaction between the first reactive component and the second reactive component; and An etching solution is deposited to remove the metal layer in areas not protected by the dual component material mask.

16. The method for producing an etch-resistant pattern according to claim 15, further comprising removing one or more additional components of the first aqueous composition deposited on the metal layer that are not subjected to the chemical reaction.

17. A method for producing an anti-etching pattern, comprising: depositing a first aqueous composition comprising a first reactive component onto the metal layer of the substrate; depositing a second aqueous composition comprising a second reactive component on selected portions of the deposited first aqueous composition to form a two-component material mask in a pattern to protect selected areas of the metal layer through a chemical reaction between the first reactive component and the second reactive component; and An etching solution is deposited to remove the metal layer in areas not protected by the two-component material mask and to remove one or more additional components of the first aqueous composition deposited on the metal layer that did not undergo a chemical reaction.

18. The method for producing an anti-etching pattern according to claim 17, further comprising removing the dual-component material mask after depositing the etching solution.

19. The method for producing an anti-etching pattern according to claim 17, wherein depositing one or both of the first aqueous composition and the second aqueous composition comprises non-impact printing.

20. The method for producing an anti-etching pattern according to claim 17, wherein depositing one or both of the first aqueous composition and the second aqueous composition comprises inkjet printing.

21. The method for producing an anti-etching pattern according to claim 17, wherein: The metal layer includes copper.

22. The method for producing an anti-etching pattern according to claim 17, wherein the second aqueous composition further comprises a dye.

23. The method for producing an anti-etching pattern according to claim 17, wherein: The first reactive component comprises a first reactive polymer and the second reactive component comprises a second reactive polymer; One of the first and second reactive polymers comprises a cationic component; The other of the first and second reactive polymers comprises an anionic component; and a chemical reaction occurs between the cationic and anionic components.

24. A method for producing an anti-etching pattern, comprising: depositing a first aqueous composition comprising a first reactive component onto the metal layer of the substrate; depositing a second aqueous composition comprising a second reactive component on selected portions of the deposited first aqueous composition to form a two-component material mask in a pattern to protect selected areas of the metal layer through a chemical reaction between the first reactive component and the second reactive component; and Depositing an etching solution to remove the metal layer in areas not protected by the dual component material, wherein: The first reactive component comprises a first reactive polymer and the second reactive component comprises a second reactive polymer; One of the first and second reactive polymers comprises a cationic component; the other of the first and second reactive polymers comprises an anionic component; and a chemical reaction occurs between the cationic and anionic components, and The first reactive polymer includes one or more of polyethylene imine, a heteropolymer of vinyl pyrrolidone, a polyquaternary amine, and a polyamine in native form or in ammonium salt form. 25 . The method for producing an anti-etching pattern according to claim 24 , wherein the second reactive polymer comprises one or both of acrylate and styrene acrylate.

26. The method for producing an etch-resistant pattern according to claim 24, wherein depositing the first aqueous composition comprises depositing the first aqueous composition as a continuous coating on the metal layer.

27. The method for producing an anti-etching pattern according to claim 24, wherein in a dry state, the thickness of the two-component material mask ranges from 0.01 μm to 12 μm.

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