Aqueous alkaline cleaning solution and method for removing glass filler

Abstract

The present invention relates to an aqueous alkaline detergent solution for glass filler removal, comprising: (a) at least one nonionic surfactant selected from the group consisting of saturated branched or unbranched C5-C12 carboxylic acids or salts thereof, the nonionic surfactant having a concentration of 0.9 to 1.7 g / L; (b) at least one surfactant selected from the group consisting of saturated branched or unbranched C5-C12 alkyls having a negatively charged group selected from sulfates, sulfites, sulfonates, phosphates, phosphites, and carbonates, and saturated C3-C8 alkylaminocarboxylates; (c) at least one compound having at least one hydroxyl group and at least one COC group, selected from the group consisting of alkoxylated C5-C12 alkanols and glycosidic C5-C12 alkanols; and (d) an alkali metal hydroxide having a concentration of 65 to 200 g / L; and a method for use.

Description

Technical Field

[0001] The present invention relates to, for example, a non-conductive layer based on a composite of an organic polymer and a glass filler for use before deposition of a palladium activation layer on a substrate, and a copper layer bonded to the non-conductive layer, and a novel aqueous alkaline cleaning agent solution for removing the glass filler from the substrate, as well as a method and use thereof. In particular, this solution and method are used after a desmear process to further clean a surface having a structure as blind microvias for manufacturing an article, such as a multilayer assembly as a printed circuit board, especially a fine line IC substrate board, and the circuit features as blind microvias can be filled with metal.

Background Art

[0002] Modern electronic device manufacturers are facing the increasing demand for miniaturization and need to pursue the trend of more densely interconnected multilayer printed circuit boards. Epoxy-based composites are the first choice of insulating materials based on their low cost and well-balanced physicochemical and mechanical properties. The latest epoxy build-up laminates have an increasing amount of spherical glass filler required to compensate for the CTE mismatch between the epoxy-based resin matrix and the electroplated copper circuit. Furthermore, their small size on the order of μm enables a smoother surface topography compared to glass fiber bundle reinforced base materials.

[0003] Various recesses, such as traces, blind microvias, or through-holes (THs), are inserted into a resin-based substrate containing glass fillers, for example by drilling. A desmear process is then applied to remove residue from the drilling process. During the industrial desmear process, the adhesion of exposed glass fillers to the substrate surface and recess surfaces may weaken, resulting in loss or damage of their anchoring in the surrounding resin matrix. If these fillers are not removed, the remaining weakly bonded or loose fillers may lead to reduced adhesion of plated copper on the epoxy resin or contamination of copper-to-copper connections in blind microvias or through-holes (THs). This can affect production yield and the reliability of the final product.

[0004] Common approaches to overcome glass filler contamination include fluoride etching solutions described in U.S. Patent Application Publication 2012 / 0298409 and ultrasonic treatment described in U.S. Patent Application Publication 2007 / 0131243. Neither of these strategies is readily applicable to the vertical mode of semi-additive processes (SAP). Serious health concerns associated with fluoride etching solutions immediately disqualify them for most of the industry, while ultrasonic application in vertical mode, even in basket application, is extremely difficult to implement in a homogeneous manner that sufficiently impacts each panel.

[0005] Japanese Patent Publication No. 2010-229536 discloses a pretreatment agent for cleaning the surface of a resin substrate containing a silica-based filler, which is desirable to remove the filler and glass fibers exposed on the substrate surface after a desmear process or the like. The pretreatment agent comprises an alkali, a nonionic ether-based surfactant, and an amine-based complexing agent.

[0006] U.S. Patent Application Publication 2010 / 056416 discloses a cleaning composition having a limited number of natural ingredients, including an anionic surfactant, a hydrophilic compound selected from C6 alkyl polyglucosides, a nonionic surfactant, and a hydrophobic compound such as oleic acid or palmitic acid, wherein the composition has a pH of 7 to 13. The cleaning composition can be used to clean laundry, soft surfaces, and hard surfaces.

[0007] The aforementioned approaches often contain components harmful to health, exhibit high energy consumption, and have strong foaming behavior. Furthermore, the solutions used tend not to adequately remove loose or weakly bound fillers, leading to undesirable foaming. Consequently, subsequent activation of the substrate may result in the formation of an unspecified, inadequately deposited palladium layer on the substrate surface, which can then lead to incomplete copper deposition in subsequent processes. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] U.S. Patent Application Publication No. 2012 / 0298409 [Patent Document 2] U.S. Patent Application Publication No. 2007 / 0131243 [Patent Document 3] Japanese Patent Publication No. 2010-229536 [Patent Document 4] U.S. Patent Application Publication No. 2010 / 056416 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The subject of this invention Therefore, the object of the present invention is to overcome the drawbacks of the prior art and to provide means for improving the removal of loose glass fillers from a wide range of composites having an organic polymer and a glass filler, wherein the filler is exposed on the composite surface after desmear treatment, including recessed structures such as through-holes, traces, or blind microvias, and has low adhesion.

[0010] A further object of the present invention is to provide means for improving the removal of glass fillers that have a less foaming tendency.

[0011] Another object of the present invention is to improve adsorption, achieve uniformly dispersed deposition of the palladium catalyst on the substrate surface to impart catalyst, enhance the adhesion of subsequent copper plating, and improve the reliability of copper deposition.

[0012] Another further subject of the present invention is the use of means for manufacturing articles, such as fine-wire HDI boards, MLBs, and multilayer assemblies as IC substrates. [Means for solving the problem]

[0013] These issues are addressed by the present invention.

[0014] In one aspect of the present invention, an aqueous alkaline cleaning agent solution for removing glass filler, (a) A surfactant selected from the group consisting of saturated branched or unbranched C5-C12 carboxylic acids or salts thereof, having a concentration of 0.9-1.7 g / L, (b) at least one surfactant or salt thereof selected from the group consisting of saturated branched or unbranched C5-C12 alkyl groups having a negatively charged group selected from sulfates, sulfites, sulfonates, phosphates, phosphites, and carbonates, and saturated C3-C8 alkylaminocarboxylates, (c) At least one compound selected from the group consisting of alkoxylated C5-C12 alkanols and glycoside C5-C12 alkanols, having at least one hydroxyl group and at least one COC group, (d) Alkali metal hydroxides with a concentration of 65-200 g / L An aqueous alkaline cleaning solution containing [the specified ingredient] is provided.

[0015] In another aspect of the present invention, a method for removing glass filler from a desmeared substrate in the manufacture of an article having an integrated circuit, comprising a nonconductive layer based on a composite of an organic polymer and a glass filler, and a copper layer bonded to the nonconductive layer, wherein the nonconductive layer has at least one blind microvia (BMV) within its surface, the bottom of at least one microvia is constructed of the bonded copper layer, and the surface of the nonconductive layer not bonded to the copper layer and the wall of at least one blind microvia expose the desmeared organic polymer and glass filler, the method comprising the following steps in sequence: (i) Steps to prepare a desmeared substrate, (ii) A step of preparing an aqueous alkaline cleaning agent solution according to the present invention, (iii) A step of treating the substrate with an aqueous alkaline cleaning solution by contacting the substrate with the aqueous alkaline cleaning solution to remove the glass filler from the organic polymer. A method is provided that includes this.

[0016] In yet another aspect of the present invention, there is provided the use of an aqueous alkaline cleaning agent solution for the glass filler removal treatment of a desmear treatment substrate including a non-conductive layer based on a composite of an organic polymer and a glass filler and a copper layer bonded to the non-conductive layer in the manufacture of an article having an integrated circuit, wherein the non-conductive layer has at least one blind microvia within the surface of the non-conductive layer, the bottom of the at least one microvia is constructed by the bonded copper layer, and the surface of the non-conductive layer not bonded to the copper layer and the walls of the at least one blind microvia expose the desmear-treated organic polymer and glass filler.

[0017] In yet another aspect of the present invention, there is provided the use or method of the aqueous alkaline cleaning agent solution according to the present invention above for the manufacture of a multilayer assembly having an alternating layer of a non-conductive layer based on a composite of an organic polymer and a glass filler having a copper-filled recess structure and a copper layer bonded to the non-conductive layer.

[0018] Further aspects of the present invention will be apparent from the dependent claims or from the following description.

[0019] The features will be apparent to those skilled in the art by describing exemplary embodiments in detail with reference to the accompanying drawings.

Brief Description of the Drawings

[0020] [Figure 1] It is a diagram showing an in-house 0 - 5 level scale by SEM for evaluating the glass filler removal performance on the surface of the non-conductive layer of a substrate after applying a test solution. [Figure 2] It is a diagram showing an in-house 0 - 5 level scale by SEM for evaluating the glass filler removal performance on the wall of the BMV of the non-conductive layer of a substrate after applying a test solution. [Figure 3] It is a diagram showing the results of the glass filler removal performance on the surface and within the BMV according to Example 1 of the present invention by SEM. [Figure 4]This figure shows the results of the glass filler removal performance on a surface according to Example 2 of the present invention, as measured by SEM. [Figure 5] This figure shows the results of glass filler removal performance on the surface and within the BMV according to Example 3 of the present invention, as measured by SEM. [Figure 6] This figure shows the results of glass filler removal performance on the surface and within the BMV according to Comparative Example 1, as measured by SEM. [Figure 7] This figure shows the results of glass filler removal performance on the surface and within the BMV according to Comparative Example 2, as measured by SEM. [Figure 8] This figure shows the results of glass filler removal performance on the surface and within the BMV according to Comparative Examples 3, 4, and 5 and Example 1 of the present invention, as measured by SEM. [Modes for carrying out the invention]

[0021] Embodiments are described in detail below, examples of which are shown in the accompanying drawings. The effects and features of exemplary embodiments, as well as methods of implementation thereof, will be described with reference to the accompanying drawings. In the drawings, similar figures indicate similar elements, and redundant descriptions are omitted. Where used herein, the terms "and / or" include any combination of one or more of the related enumerated items. Furthermore, the use of "may be" when describing embodiments of the present invention refers to "one or more embodiments of the present invention."

[0022] In the following description of embodiments of the present invention, unless otherwise clearly indicated by the context, singular terms may include plural forms; for example, where “filler” is used below, it includes “plural fillers.”

[0023] The present invention is particularly suitable for use after desmearing of a substrate and before palladium activation, and the composite having an increasing amount of glass filler as spherical glass filler is, for example, part of an SAP-based material. The present invention makes it possible to remove loose or debonded exposed glass filler from the surface and also from the BMV walls during the desmearing process. The present invention provides a cleaned substrate surface and BMV walls for a subsequent metallization process that begins with palladium activation.

[0024] This invention results in higher yield and better reliability of multilayer assemblies manufactured as printed circuit boards, and the adhesion characteristics on industrially relevant IC substrate base materials showed significantly higher peel strength values ​​after processing with the new process.

[0025] In particular, the present invention enables the manufacture of electronic articles, such as multilayer assemblies as HDI and MLB boards and IC substrates having fine feature areas, with line-and-space (L / S) of up to 75 / 75 μm or 25 / 25 μm, and for example, in the case of horizontal application, the aspect ratio of through-holes is about 1:3 to about 1:10, and preferably blind microvias are about 1:1 or 1:1.15 to 1:2.3. In the case of vertical plating application, an aspect ratio of through-holes of about 1:3 to about 1:30 is possible, and preferably blind microvias of about 1:1 or 1:1.15 to 1:2.3 are possible. At the same time, this method provides excellent coating performance while significantly reducing foaming behavior.

[0026] This invention uses components that are less hazardous than those used in the prior art. Furthermore, this invention enables the manufacture of electronic articles under milder conditions in terms of operating temperature and operating time. This results in a significant reduction in energy consumption and improved throughput. Lower temperature schemes also reduce equipment and maintenance costs.

[0027] Beyond reducing foaming behavior, one of the most desirable benefits of cleaning the desmeared substrate surface from loose glass filler is improved adhesion of plated copper to the substrate, such as an epoxy matrix. The obvious reason for this expected improvement in adhesion is the assumption of insufficient bonding of the "loose" glass filler to the substrate. This should be the case for fillers that are less than half embedded in the surrounding epoxy resin after desmearing, or for any re-adsorbed fillers. Copper is then plated around this filler, and when a peeling force is applied, the filler easily lifts away from the substrate.

[0028] The present invention can be used with a wide range of different substrates from different suppliers, the nonconductive layer of the substrate is based on a composite of an organic polymer and a glass filler, and the copper layer is bonded to the nonconductive layer, for example, by lamination.

[0029] This composite is based on a mixture of glass filler and / or silica filler, an organic polymer as a resin and / or plastic, and blends thereof. The resins and plastics include dielectric materials to be metallized, which are typically used in the electronics industry. The resins and plastics are preferably selected from epoxy resins such as epoxy, isocyanate resins, bismaleimidotriazine resins, and phenylene resins; polyesters, such as polyethylene terephthalate (PET), polyimide (PI), polytetrafluoroethylene, acrylonitrile-butadiene-styrene (ABS) copolymer, polyamide (PA), polycarbonate (PC), and mixtures and blends thereof.

[0030] The organic polymer more preferably comprises a polyimide resin or an epoxy resin, and the polyimide resin can be modified by adding polysiloxane, polycarbonate, polyester, etc. The epoxy resin may be a glass filler epoxy board material comprising a combination of epoxy resin and glass filler, or the same as is modified to constitute a high glass transition temperature glass filler epoxy board material having low thermal expansion and a high glass transition temperature.

[0031] Suitable glass fillers are preferably selected from borosilicate glass, quartz glass, silica glass, and fluorinated glass. The sizes of the different fillers range from 0.01 μm to 5 μm in diameter, preferably with an average diameter of 0.5 μm.

[0032] Preferably, the non-conductive layer composite is a build-up film, such as an epoxy-based material. Detailed names are provided as needed. The size of the embedded glass filler is 0.5 μm in diameter on average and 5.0 μm at its maximum.

[0033] The desmear-treated substrate according to the present invention may include a core layer. In this case, the copper layer bonded to the non-conductive layer is further bonded to the core layer. This core layer makes the desmear-treated substrate more flexible and easier to handle, and prevents unwanted twisting of the substrate.

[0034] In a further embodiment, two desmeared substrates may be bonded to a core layer. In this case, each copper layer is bonded to a non-conductive layer and the core layer. This makes it possible to process the desmeared substrate having the core layer from both sides and construct a multilayer assembly from both sides of the core layer.

[0035] The aforementioned core layer may be selected from the group consisting of printed circuit board substrates, circuit carrier substrates, interconnect device substrates, and precursors for any of the aforementioned. Such precursors include, among others, FR-1, FR-2, FR-3, FR-4, FR-5, copper clad materials, SAP materials, IC substrates, and laminates thereof, and preferably the core layer is an FR4 material, an SAP material, or an IC substrate.

[0036] The concentration of at least one surfactant (a) in the aqueous alkaline detergent solution is 0.9 to 1.7 g / L, preferably 1.0 to 1.5 g / L, and more preferably 1.2 to 1.4 g / L. If there are two or more surfactants in the solution, the total concentration is also 0.9 to 1.7 g / L, preferably 1.0 to 1.5 g / L, and more preferably 1.2 to 1.4 g / L. It is understood that the surfactants may be added as acids or salts.

[0037] The concentration of at least one surfactant (b) in the aqueous alkaline detergent solution is 0.5 to 10 g / L, preferably 1.5 to 9 g / L, and more preferably 2 to 8 g / L. Another preferred concentration range is 0.5 to 1.2 g / L, preferably 0.7 to 1.1 mg / L, and more preferably 0.75 to 1.0 g / L. If there are two or more surfactants in the solution, the total concentration is also 0.5 to 10 g / L. In a preferred embodiment, the concentration range of at least one surfactant (b) selected from the group consisting of saturated branched or unbranched C5 to C12 alkyl groups having a negatively charged group selected from sulfate, sulfite, sulfonate, phosphate, phosphite, and carbonate is 0.5 to 1.2 g / L, preferably 0.7 to 1.1 mg / L, and more preferably 0.75 to 1.0 g / L. In another preferred embodiment, the concentration range of at least one surfactant (b) selected from the group consisting of saturated C3-C8 alkylaminocarboxylates is 0.5-10 g / L, preferably 1.5-9 g / L, and more preferably 2-8 g / L.

[0038] The concentration of at least one compound (c) having at least one hydroxyl group and at least one COC group in the aqueous alkaline detergent solution is 0.7 to 1.3 g / L, preferably 0.8 to 1.2 g / L, and more preferably 0.9 to 1.1 g / L. If there are two or more alkanols in the solution, the total concentration is also 0.7 to 1.3 g / L, preferably 0.8 to 1.2 g / L, and more preferably 0.9 to 1.1 g / L.

[0039] (d) The concentration of alkali metal hydroxide results in a strongly alkaline pH value, and theoretically has a pH value higher than pH 14. The concentration of (d) alkali metal hydroxide in the aqueous alkaline cleaning agent solution is 65 to 200 g / L, preferably 70 to 100 g / L, and more preferably 75 to 90 g / L.

[0040] Throughout this specification and the claims, it should be noted that the numerical limits of the disclosed ranges and ratios can be combined and are considered to include all intermediate values. Furthermore, all numerical values ​​are considered to be preceded by the modifier "about," whether or not this term is specifically stated.

[0041] At least one surfactant is selected from the group consisting of saturated branched or unbranched C5-C12 carboxylic acids or salts thereof, preferably saturated branched C6-C10 carboxylic acids or salts, more preferably hexanoic acid, octanoic acid, and decanoic acid or salts thereof, most preferably hexanoic acid and octanoic acid or salts thereof. A surfactant selected from the group consisting of saturated unbranched C6-C10 carboxylic acids or salts, more preferably saturated unbranched C6-C8 carboxylic acids or salts, is preferably unsubstituted hexanoic acid and octanoic acid.

[0042] At least one surfactant selected from the group consisting of saturated branched or unbranched C5-C12 alkyl groups having a negatively charged group selected from sulfate, sulfite, sulfonate, phosphate, phosphite, and carbonate is preferably selected from the group consisting of saturated branched or unbranched C5-C8 alkyl groups having a negatively charged group of sulfate, phosphate, and carbonate, more preferably a negatively charged group of sulfate, such as n-pentyl, isopentyl, n-hexyl, 2-ethylhexyl, n-heptyl, or n-octyl, and most preferably the surfactant is sodium 2-ethylhexyl sulfate or sodium isoheptyl sulfate.

[0043] The positive counterion of a saturated branched or unbranched C5-C12 alkyl group having a negative charge is preferably sodium or potassium, more preferably sodium.

[0044] The saturated C3-C8 alkylaminocarboxylate is preferably of formula (III) or (IV):

[0045] [ka]

[0046] [In the formula, R is a branched or unbranched C4-C8 alkyl group, for example, n-pentyl, isopentyl, n-hexyl, 2-ethylhexyl, n-heptyl, or n-octyl.] or

[0047] [ka]

[0048] [In the formula, k is an integer between 3 and 8, preferably between 4 and 6, most preferably 6.] It is a compound of [the compound].

[0049] The surfactant is understood to be added preferably as a salt. The positive counterion of the saturated C3-C8 alkylaminocarboxylate is preferably sodium or potassium, more preferably sodium.

[0050] The alkoxylated C5-C12 alkanol of compound (c) is preferably of formula (I):

[0051] [ka]

[0052] [In the formula, p is an integer between 1 and 2, o is an integer between 4 and 10, m is an integer between 4 and 9, more preferably p is 1, o is between 5 and 7, and m is between 5 and 7] It is a compound of the above. Most preferably, the alkoxylated C5-C12 alkanol is ethoxylated hexanol or ethoxylated octanol in which o is 6.

[0053] The average molecular weight (MW) of the compound of formula (I) is 200 to 15,000 g / mol, preferably 400 to 1,000 g / mol, and most preferably 300 to 600 g / mol.

[0054] The glycoside C5-C12 alkanol of compound (c) is preferably of formula (II):

[0055] [ka]

[0056] [In the formula, n is an integer between 1 and 5, and m is an integer between 4 and 9, preferably between 5 and 7.] The compound is preferably an alkyl polyglucoside (APG) provided under CAS 54549-24-5.

[0057] Preferably, the alkali metal hydroxide is sodium hydroxide or potassium hydroxide, more preferably sodium hydroxide.

[0058] In a preferred embodiment, the aqueous alkaline cleaning agent solution of the present invention comprises (a) at least one surfactant selected from the group consisting of hexanoic acid and octanoic acid or salts thereof; (b) at least one surfactant selected from the group consisting of sodium ethylhexyl sulfate (sodium ethylhexyl sulfate) according to formula (III) [wherein R is 2-ethylhexyl or n-octyl] and formula (IV) [wherein k is 4 to 6], sodium isoheptyl sulfate, and alkylaminocarboxylates; (c) at least one compound selected from the group consisting of alkoxylated C5-C12 alkanols which are compounds of formula (I) [wherein the compound is ethoxylated hexanol, ethoxylated octanol, or ethoxylated decanol, where o is 6] and glycoside C5-C12 alkanols which are compounds of formula (II) [wherein n is an integer from 1 to 5 and m is an integer from 5 to 7]; and (d) sodium hydroxide. In a more preferred embodiment, the aqueous alkaline cleaning agent solution of the present invention further comprises (e) at least one water-soluble alkanolamine.

[0059] In a more preferred embodiment, the aqueous alkaline cleaning agent solution of the present invention comprises the following combinations of (b) sodium ethanol sulfate and (c) ethoxylated hexane-1-ol; (b) 1-aminohexyl carboxylate and (c) ethoxylated decane-1-ol; or (b) APG and (c) 2-ethylhexyl iominodipionate. Preferably, these combinations are used together with (a) hexanoic acid and (d) sodium hydroxide. In a further more preferred embodiment, the aforementioned combinations are used together with monoethanolamine. Most preferably, the aqueous alkaline cleaning agent solution of the present invention consists of the aforementioned combinations.

[0060] Preferably, the aqueous alkaline cleaning agent solution additionally contains (e) at least one water-soluble alkanolamine selected from the group consisting of monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA), preferably 2-aminoethanol. By using a water-soluble alkanolamine, clouding of the solution can be avoided. Our own experiments have shown that cloudy solutions result in undesirable plating results.

[0061] The concentration of at least one water-soluble alkanolamine is 6.5 to 9.0 g / L, preferably 7.5 to 8.5 g / L, and more preferably 7.8 to 8.2 g / L.

[0062] The method of the present invention using the solution of the present invention is preferably used immediately after the desmear process. Optionally, the desmeared substrate is pretreated in step (0) of treating the desmeared substrate with an aqueous solution of a conditioning agent, and then step (i) of providing the desmeared substrate according to the method of the present invention is applied. Step (0) of treating the desmeared substrate with an aqueous solution of a conditioning agent can improve subsequent processing steps using the aqueous alkaline cleaning agent solution of the present invention. The conditioning agent solution preferably comprises an acid such as sulfuric acid or hydrochloric acid, an agent capable of reducing manganese dioxide such as hydroxylammonium sulfate or hydrogen peroxide, and a polymer containing quaternary nitrogen atoms. For example, Securiganth® MV reducing agent, available from Atotech Deutschland GmbH, can be used as the conditioning agent solution. Treatment with the conditioning agent solution may be part of the desmear process.

[0063] This method can be used in vertical and horizontal plating equipment. Preferably, this method is used in vertical plating equipment, where the substrate is transported by a transport device and processed through the processing module of the plating equipment.

[0064] The method of the present invention is preferably used when (iii) the treatment is carried out at 55-65°C for 3-7 minutes. Low temperatures reduce energy consumption and also reduce equipment costs for using higher temperatures. In addition, evaporation of low-boiling point components can be prevented and strong suction can be avoided.

[0065] The method of the present invention is preferably used before the activation of the non-conductive layer surface of a desmeared substrate, for example, palladium activation, for subsequent metallization of substrates for manufacturing integrated circuits, such as articles having multilayer assemblies, as fine-wire HDI boards, MLBs, and IC substrate articles.

[0066] Therefore, this method may, in non-limiting examples, preferably further include the following steps when manufacturing an article:

[0067] (iv) For subsequent metallization, the step of treating the substrate of step (iii) with an activating solution on the surface of the nonconductive layer of the substrate treated in step (iii), preferably the step of treating the substrate of step (iii) with a palladium activating solution, thereby depositing a palladium ion layer on the surface of the nonconductive layer of the substrate treated in step (iii). Other useful activating solutions known in the art may include carbon, conductive polymers, or metal colloids including copper, palladium, palladium-tin, etc., for subsequent direct electrolytic metallization.

[0068] The palladium-activated solution contains at least one palladium ion source. Additionally, the solution may contain other metal ion sources as mixtures thereof, including ruthenium ion sources, rhodium ion sources, palladium ion sources, osmium ion sources, iridium ion sources, platinum ion sources, copper ion sources, silver ion sources, nickel ion sources, cobalt ion sources, gold ion sources, and copper ion sources, silver ion sources, and nickel ion sources, cobalt ion sources, and gold ion sources. The palladium ions and the additional metal ions are adsorbed on the surface of the substrate.

[0069] (v) A step of processing the substrate of step (iv) using a palladium activating solution together with a palladium reducing solution, wherein the deposited palladium ion layer of step (iv) is converted into a metallic palladium layer.

[0070] The surface of a substrate containing at least palladium ions is treated using a solution containing at least one reducing agent selected from the group consisting of boron-based reducing agents, hypophosphate ion sources, hydrazine and hydrazine derivatives, ascorbic acid, isoascorbic acid, formaldehyde sources, glyoxylic acid, glyoxylic acid sources, glycolic acid, formic acid, sugars, and salts of the aforementioned acids, which is suitable for reducing metal ions (at least palladium ions) adsorbed on the surface of the substrate to a metallic state.

[0071] (vi) A step of treating the substrate from step (v) with an electroless copper plating bath to obtain a copper layer on the layer from step (v).

[0072] An electroless copper plating bath will most effectively form a metal or metal alloy layer on the surface obtained in step (v). Generally, the plating bath comprises a solvent, typically water, and at least one source of metal ions to be deposited. Further optional components are complexing agents (or chelating agents) for the metal ions (e.g., those described below), reducing agents, stabilizers, cosolvents, wetting agents, and functional additives such as brighteners, accelerators, inhibitors, and anti-tarnish agents. Such baths and components are known in the art. An electroless copper plating bath may further comprise a nickel ion source, a cobalt ion source, and mixtures thereof.

[0073] (vii) A step in which, when a layer of carbon or conductive polymer is deposited on the substrate, the substrate from step (vi) or step (iv) is treated with an electrolytic copper or nickel plating bath to obtain a copper or nickel layer on the surface while filling the BMV with copper or nickel. The copper or nickel layer may be a copper alloy or nickel alloy containing alloying metals such as tungsten or silver.

[0074] In a preferred embodiment of the present invention, the electroplating bath in step (vii) is an electroplating copper bath for obtaining a copper layer. The substrate obtained in step (vii) can be used to construct a multilayer assembly by using the following steps.

[0075] In one embodiment, the copper layer of step (vii) can be structured by a process step (viia) known in the art to obtain a conductive structure.

[0076] (viii) A step of laminating the copper layer of the substrate from step (vii) or the structured copper layer from step (via) with a further non-conductive layer based on a composite of an organic polymer and a glass filler.

[0077] (ix) A step of processing the non-conductive layer of the substrate from step (viii) by laser drilling to create a recessed structure as a BMV within the non-conductive layer, wherein the bottom of the BMV is formed by the surface of the copper layer (the BMV is drilled to the surface of the copper layer).

[0078] (x) A process of treating the substrate of process (ix) with the desmear process of the drilled substrate of process (ix), which includes, for example, the following subsequent steps: treatment with a swelling agent, treatment with a permanganate, and treatment with a reducing agent, or optionally treatment with an aqueous solution of a adjusting agent.

[0079] If more alternating layers are required, the substrate from process (x) can be processed again in processes (iii) to (vii), or other processes can be repeated.

[0080] If necessary, additional steps may be performed between the preceding steps, such as rinsing with DI water or an acidic or alkaline aqueous solution; etching cleaning agent step; pre-immersion step; and / or drying step.

[0081] Except for the solution of the present invention in the preceding step, the bath compositions and solutions used are well known in the art. Suitable solutions for the desmear process, palladium activating solutions, palladium reducing solutions, electroless and electrolytic copper solutions are known and can be purchased, for example, from Atotech Deutschland GmbH as Securiganth® MV, Neoganth® MV activator, Neoganth® MV reducing agent, Printoganth® MV, and Cupracid® AC.

[0082] The present invention will now be described with reference to the following figures and non-limiting examples. [Examples]

[0083] The relative ratios of the compounds used in the present invention in the examples have been found to be preferred and useful, but are not considered limiting.

[0084] I. Evaluation of glass filler removal performance I.1 Procedure All tested substrates contained a nonconductive layer based on a composite of organic polymer and glass filler (layer thickness ranged from 35 μm to 40 μm, with glass filler content varying between 42 and 74 mass%; the size of the embedded glass filler averaged 0.5 μm in diameter and maximum 5.0 μm), and a copper layer (Cu-clad FR4 core) bonded to the nonconductive layer. The nonconductive layer was laser-drilled to obtain BMVs of approximately 40 μm in diameter (arranged in a grid of 10 × 10 BMVs and 500 μm edge lengths), and the substrates were desmeared before application of test solutions of the aqueous alkaline cleaning agent solution of the present invention and other solutions not according to the present invention.

[0085] Glass filler removal performance was evaluated by microscopic imaging using SEM. The coupon size was reduced as needed, and iridium was sputtered for 60 seconds on a tilted stage (30°) to ensure sufficient conductivity on the walls of the blind microvias (BMVs). SEM measurements were also performed on a stage tilted at 30°, ensuring the tilt was in the same direction as during sputtering. Imaging was performed using a secondary electron (SE) detector at magnifications from 1k to 5k.

[0086] Glass filler removal performance is judged using an internal 0-5 level scale (0 = no loose glass filler (meaning all loose glass fillers are removed); 5 = maximum loose glass filler (meaning very little glass filler is removed)), and is described for each SEM image. According to this 6-level scale, up to 3 is still acceptable, but 4 and 5 are unacceptable and result in undesirable plating results.

[0087] As an example for evaluation, Figure 1 shows an in-house 0-5 level scale, measured by SEM, for evaluating the glass filler removal performance on the surface of the non-conductive layer of a substrate after coating with the test solution.

[0088] As an example for evaluation, Figure 2 shows an in-house 0-5 level scale, measured by SEM, for evaluating the glass filler removal performance on the BMV walls of the non-conductive layer of the substrate after coating with the test solution.

[0089] Test Examples (Examples and Comparative Examples of the Invention) After the desmear process, the substrate was treated with the aqueous alkaline cleaning agent solution of the present invention, having a solution temperature of 60°C and a residence time of 5 minutes. All components of the test solution were diluted with DI (DI-deionized water). Subsequently, the substrate was prepared as described above for each SEM image analysis, and the glass filler removal performance was evaluated.

[0090] Example 1 of the present invention (I1) concentration in solution: Hexanoic acid 1.4 g / L Sodium ethanol sulfate 0.8g / L Ethoxylated hexane-1-ol (Cas 31726-34-8) 1.1 g / L Sodium hydroxide (NaOH) 84g / L MEA-Monoethanolamine (over 98%) 6.5g / L

[0091] In Figure 3, the glass filler removal performance shown by SEM imaging (magnification = 5kx) on the surface was 0.5 (left side: surface area between BMVs), and 1 in the BMV (right side: side wall of BMV, edge of capture pad visible).

[0092] Example 2 of the present invention (I2) concentration in solution: Hexanoic acid 1.4 g / L 1-aminohexylcarboxylate 8g / L Ethoxylated decane-1-ol (CAS 26183-52-8) 1.0 g / L NaOH 84g / L

[0093] In Figure 4, the glass filler removal performance shown on the surface by SEM imaging (magnification = 5kx) was 1.

[0094] Example 3 of the present invention (I3) concentration in solution: Hexanoic acid 1.4 g / L APG (CAS 54549-24-5) 0.75 g / L 2-Ethylhexyliminodipropionate 2g / L NaOH 84g / L

[0095] In Figure 5, the glass filler removal performance shown by SEM imaging (magnification = 5kx) on the surface was 3 (left: surface area between BMVs), and it was 3 in the BMV (right: side wall of BMV, edge of capture pad visible).

[0096] Comparative Example 1 (C1) concentration in solution: NaOH 84g / L

[0097] In Figure 6, the glass filler removal performance shown by SEM imaging (magnification = 5kx) on the surface was 4.5 (left: surface area between BMVs), and 4.5 in the BMV (right: side wall of BMV, edge of capture pad visible).

[0098] Comparative Example 2 (C2) and Example 1 (I1) of the present invention Concentration of C2 in solution: MEA (over 98%) 12.37g / L Polyethylene glycol-(4-tert-octylphenyl)-ether (CAS 9002-93-1) 4.12 g / L 2-Propanol 1.03 g / L Guanidinium chloride 96% or more, 1.65 g / L

[0099] The desmeared substrate was pre-treated in a conditioning step (0) in which the desmeared substrate was treated with an aqueous conditioning solution, and then the solutions of C2 and I1 were applied onto the pre-treated desmeared substrate. The conditioning step (0) was carried out using Securiganth® MV reducing agent, which is available from Atotech Deutschland GmbH.

[0100] In Figure 7, the glass filler removal performance shown on the surface by SEM imaging (magnification = 5kx) was 5 for C2 (left side: surface area between BMVs) and 3 for I1 (right side: surface area between BMVs).

[0101] Comparative Examples C3, C4, and C5 were prepared as follows and carried out in parallel with the composition of Example I1 of the present invention (see above).

[0102] Comparative Example 3 (C3) according to Japanese Patent Publication No. 2010-229536 (paragraph [0015, 10 minutes, 80℃]) Particle in C3 solution: MEA 5.00g / L EDA 5.00g / L Polyoxyethylene β-naphthyl ether (CAS number 35545-57-4) 10.00 g / L Potassium hydroxide 50.00 g / L

[0103] Comparative Example 4 (C4) using the surfactant described in Japanese Patent Publication No. 2010-229536 (5 minutes, 60°C) Concentration of C4 in solution: MEA 6.50g / L Polyoxyethylene β-naphthyl ether (CAS number 35545-57-4) 10.00 g / L NaOH 84.00g / L

[0104] Comparative Example 5 (C5) using the surfactant described in Japanese Patent Publication No. 2010-229536 (5 minutes, 60°C) Concentration of C5 in solution: MEA 6.50g / L Polyoxyethylene β-naphthyl ether (CAS number 35545-57-4) 1.00 g / L NaOH 84.00g / L

[0105] The desmeared substrate was pretreated in a conditioning step (0) in which the desmeared substrate was treated with an aqueous conditioning solution, and then solutions of C3, C4, C5, and I1 were applied onto the pretreated desmeared substrate. The conditioning step (0) was carried out using Securiganth® MV reducing agent, available from Atotech Deutschland GmbH.

[0106] As shown in Figure 8, the glass filler removal performance on the substrate surface and the BMV surface region, as measured by SEM imaging (magnification = 5kx), was 2-2.5 for C3, C4, and C5, and 1-1.5 for I1.

[0107] Not only was the glass filler removal performance of Comparative Examples C3, C4, and C5 not as good as that of Example I1 of the present invention, but significant problems were also observed in terms of peel strength (see below). Furthermore, the turbidity at the working temperature was strong, in contrast to the completely transparent working solution of Example I1 of the present invention, and similarly, stronger foaming behavior was observed.

[0108] II. Evaluation of foaming properties of aqueous alkaline cleaning agent solutions To evaluate the foaming behavior, a 100 ml graduated cylinder was used. The cylinder was filled with 50 ml of the test solution and sealed. After starting a stopwatch, the cylinder was shaken for 10 seconds, and most of the test solution was converted into foam. As shaking ended, the foam began to disappear and the test solution would gradually return to a foam-free state. After a total of 60 seconds, the volume of remaining foam in the test solution was determined. A faster disappearance of foam is considered better.

[0109] Table I shows the foaming behavior of the aqueous alkaline cleaning agent solution of the present invention according to Example I1 and Comparative Example C2. Example I1 of the present invention shows significantly less foam and faster foam disappearance than Comparative Example C2, thereby demonstrating the significantly improved foaming characteristics of Example I1 of the present invention.

[0110] [Table 1]

[0111] III. Investigation of adhesion Following the desmear process, two desmeared substrates were subjected to additional experiments using the aqueous alkaline cleaning agent solution of the present invention according to Example I1 of the present invention, and the solutions according to Comparative Examples C2, C3, C4, and C5.

[0112] Next, the two substrates were treated as follows: Palladium activating solution, palladium reducing solution, and electroless copper solution are known and can be purchased, for example, from Atotech Deutschland GmbH as Securiganth® MV, Neoganth® MV activator, Neoganth® MV reducing agent, and Printoganth® MV.

[0113] [Table 2]

[0114] In peel strength experiments, it was found that the adhesion between copper and resin improved, and that using aqueous alkaline cleaning agent solution I1 resulted in significantly higher adhesion values ​​compared to using solution C2 (Tab. II (Table 3)) or solutions C3, C4, and C5 (Tab. III (Table 4)). Furthermore, a substantial improvement in blister performance was also observed.

[0115] [Table 3]

[0116] [Table 4]

Claims

1. A water-based alkaline cleaning solution for removing glass filler, (a) A surfactant selected from the group consisting of unsubstituted hexanoic acid, octanoic acid, and decanoic acid or salts thereof, having a concentration of 0.9 to 1.7 g / L, (b) At least one surfactant selected from the group consisting of saturated branched or unbranched C5-C12 alkyl groups having a negatively charged sulfate group, and saturated C3-C8 alkylaminocarboxylates, The saturated C3-C8 alkylaminocarboxylate is defined by formula (III) or (IV): 【Chemistry 1】 [In the formula, R is a branched or unbranched C4-C8 alkyl group.] 【Chemistry 2】 [In the formula, k is an integer between 3 and 8.] A surfactant is a compound of the same thing. (c) At least one compound selected from the group consisting of alkoxylated C5-C10 alkanols and glycoside C5-C10 alkanols, having at least one hydroxyl group and at least one COC group, The alkoxylated C5-C10 alkanols are of formula (I): 【Transformation 3】 [In the formula, p is an integer between 1 and 2, o is an integer between 4 and 10, and m is an integer between 4 and 9.] And, The aforementioned glycoside C5-C10 alkanols are given by formula (II): 【Chemistry 4】 [In the formula, n is an integer between 1 and 5, and m is an integer between 4 and 9.] The compound is, (d) Alkali metal hydroxides with a concentration of 65-200 g / L A water-based alkaline cleaning solution containing [a specific ingredient / method].

2. The aqueous alkaline cleaning agent solution according to claim 1, wherein the concentration of (a) at least one surfactant is 1.0 to 1.5 g / L.

3. The aqueous alkaline cleaning agent solution according to claim 1 or 2, wherein the concentration of at least one surfactant is 0.5 to 10 g / L.

4. The aqueous alkaline cleaning agent solution according to any one of claims 1 to 3, wherein the concentration of at least one compound (c) is 0.6 to 1.3 g / L.

5. The aqueous alkaline cleaning agent solution according to any one of claims 1 to 4, wherein the concentration of the alkali metal hydroxide in (d) is 70 to 100 g / L.

6. The aqueous alkaline cleaning agent solution according to any one of claims 1 to 5, wherein the solution comprises (e) at least one water-soluble alkanolamine selected from the group consisting of monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA).

7. The aqueous alkaline cleaning agent solution according to claim 6, wherein the concentration of at least one water-soluble alkanolamine is 6.5 to 9.0 g / L.

8. A method for removing glass filler from a desmeared substrate in the manufacture of an article having an integrated circuit, comprising a nonconductive layer based on a composite of an organic polymer and a glass filler, and a copper layer bonded to the nonconductive layer, wherein the nonconductive layer has at least one blind microvia within its surface, the bottom of the at least one blind microvia is constructed of the bonded copper layer, and the surface of the nonconductive layer not bonded to the copper layer and the wall of the at least one blind microvia expose the desmeared organic polymer and glass filler, the method comprising the following steps in sequence: (i) Steps to prepare a desmeared substrate, (ii) A step of preparing an aqueous alkaline cleaning agent solution according to any one of claims 1 to 7, (iii) A step of treating the substrate with the aqueous alkaline cleaning agent solution by contacting the substrate with the alkaline cleaning agent solution to remove the glass filler from the organic polymer. Methods that include...

9. The method according to claim 8, wherein the process described in (iii) above is carried out at 55 to 65°C for 3 to 7 minutes.

10. (iv) The method according to claim 8 or 9, further comprising the step of treating the substrate of step (iii) with an activating solution on the surface of the nonconductive layer of the substrate of step (iii) for subsequent metallization.

11. The method according to any one of claims 8 to 10, wherein the copper layer bonded to the nonconductive layer is further bonded to the core layer.

12. Use of an aqueous alkaline cleaning solution according to any one of claims 1 to 7 for removing glass filler from a desmeared substrate comprising a nonconductive layer based on a composite of an organic polymer and a glass filler, and a copper layer bonded to the nonconductive layer, wherein the nonconductive layer has at least one blind microvia within its surface, the bottom of the at least one blind microvia is constructed of the bonded copper layer, and the surface of the nonconductive layer not bonded to the copper layer and the wall of the at least one blind microvia expose the desmeared organic polymer and glass filler.

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