Method for removing organic resin from the surface of a substrate

Abstract

The present invention relates to a method for removing an organic resin from a copper surface on a dielectric substrate containing conductive through-holes (TH) and / or conductive blind microvias (BMV), comprising the following steps: (i) applying an organic paste to the dielectric substrate to fill the through-holes (TH) and / or blind microvias (BMV) with the organic paste, wherein, after step (i), at least a portion of the surface of the dielectric substrate is covered with the organic paste; and (ii) curing the organic paste to convert it into a solidified organic resin, wherein, after step (ii), the dielectric (iii) a step of coating at least a portion of the surface of the substrate with an organic resin; and a step of chemically treating the dielectric substrate with a non-aqueous composition to remove the organic resin from the surface of the substrate in order to obtain a chemically treated surface of the substrate, wherein the non-aqueous composition comprises: a) at least one high-boiling point solvent having a boiling point of at least 100°C in a concentration of 80% to 95% by mass; b) at least one carboxylic acid in a concentration of 5% or more and less than 20% by mass; c) at least one anionic aromatic surfactant in a concentration of 0.25% or more and less than 1.5% by mass; and d) 0.25% or more and 1.A step comprising: (iv-1) a step of mechanically treating the chemically treated surface of the substrate obtained after step (iii) with an abrasive to remove residual organic resin from the chemically treated surface of the substrate in order to obtain a mechanically treated surface of the substrate; and / or (iv-2) a step of wet chemically treating the chemically treated surface of the substrate obtained after step (iii) with an oxidizing solution containing an oxidizing agent to remove residual organic resin from the chemically treated surface of the substrate in order to obtain a wet chemically treated surface of the substrate; (v The present invention relates to a method comprising: (i) in some cases, a step of depositing a conductive material, preferably electrolytically removing a coating metal, on a mechanically treated surface obtained after step (iv-1) or on a wet-chemically treated surface of the substrate obtained after step (iv-2) to obtain a conductive surface of the substrate; and (vi) in some cases, a step of further electrolytically removing a coating metal on the conductive surface of the substrate obtained after an optionally selected step (v) or on a mechanically treated surface of the substrate obtained after step (iv-1) or on a wet-chemically treated surface of the substrate after step (iv-2) in order to obtain an electrolytic metal coating surface.

Description

[Technical Field]

[0001] The present invention relates to a method for removing organic resin from a copper surface on a dielectric substrate containing conductive through-holes (THs) and / or conductive blind microvias (BMVs), and to articles obtained by this method. This method is particularly suitable for the manufacture of articles containing VIPPO (via-in-pad-plated over) structures. The present invention further relates to the use of a non-aqueous composition for removing organic resin from the surface of the dielectric substrate. [Background technology]

[0002] Removing organic coatings, such as paint, from metal surfaces, such as steel or aluminum surfaces, is well known in the automotive industry.

[0003] U.S. Patent No. 3,790,489 describes a paint stripping compound for use at high temperatures, comprising a corrosive base of alkali metal hydroxide, alkali metal nitrate, alkali metal chloride, or a catalyst selected from the group consisting of alkali metal permanganate, manganese dioxide, and Cr2O3, preferably an alkali metal carbonate. The parts are fused together for removal and maintained at a temperature of 800°F (approximately 426°C) to 900°F (approximately 482°C).

[0004] However, certain metals, such as zinc, aluminum, copper, and magnesium, or metallic coatings composed of these metals or their alloys, as well as other metals, alloys, and even non-metallic substrates, are subjected to chemical attack or destruction under conditions as taught in U.S. Patent No. 3,790,489. Therefore, such corrosive compositions are generally avoided in the prior art teachings when removing coatings from metals, such as aluminum, magnesium, and zinc.

[0005] One prior art approach based on high-boiling point glycols in stripping compositions is taught in WO2017 / 194449A1, in which stripping from a substrate is achieved by using a non-aqueous stripping composition and a method for stripping an organic coating from a substrate.

[0006] However, removing organic resins from substrates is extremely important in the electronics industry. In particular, organic resins or residues on copper surfaces, for example, need to be removed from dielectric substrates to prevent them from functioning as "etching resists" that can ultimately short-circuit and break circuits, especially during the manufacturing process of printed circuit boards (PCBs).

[0007] Therefore, there is a growing demand for the effective removal of organic resins in the manufacturing process of printed circuit boards (PCBs). Particularly with regard to increased signal speed and high FC-BGA pitch density, the focus of PCB design is shifting to the use of via-in-pad plating over (VIPPO), which is increasingly replacing the conventional dogbone pad structure used in conventional PCBs, enabling shorter signal path lengths and thereby reducing capacitance and inductance.

[0008] In typical VIPPO designs, after the process sequence of drilling through-holes and blind microvias, desmearing, activation, electroless copper deposition, and electrolytic copper deposition, the manufactured PCB is screen printed with a specially designed filling paste to completely fill all plated through-holes and blind microvias with the paste. During the screen printing process, a thin film of resin is applied to the entire PCB surface and hardens during the subsequent curing process. However, this thin film of resin needs to be removed for further processing to build the VIPPO. At that time, it is necessary to ensure that all the filling paste is removed from the PCB surface, and that a highly reliable metal deposit with excellent adhesion and conductivity is then provided.

[0009] U.S. Patent Application Publication No. 2003 / 0074790 relates to a method for manufacturing a resin-filled substrate, comprising the steps of: forming a rough surface on a conductive layer within through-holes before the through-holes are filled with resin; forming a smooth surface on conductive layers formed on the upper and lower parts of the substrate; printing resin using a mask having openings at positions corresponding to the through-holes to selectively fill the through-holes with resin; and curing the resin. The mask may be a screen plate or a metal mask. The openings in the mask are preferably 1.1 to 2.5 times larger in diameter than the diameter of the through-holes. The method further includes a step of mechanically polishing off any excess resin formed on the surface of the through-holes for removal to flatten the surface of the substrate.

[0010] U.S. Patent No. 4,991,359 describes a method for removing a hardened alkali-soluble resin layer by treating a metal-plated substrate with an aqueous sodium carbonate solution to cause the surface to swell, and then polishing the resin layer having the swollen surface, either simultaneously with or after the surface swells.

[0011] This removal is performed by mechanically grinding / polishing / sanding the resin-coated PCB surface. Typically, a grinding machine, buffing roll, or sanding belt is used to remove excess filling paste from the PCB surface after the via-hole filling process. The material of the grinding head may be, for example, silicon carbide. Furthermore, water may be used during grinding / polishing / sanding. The pressure of the grinding head on the surface must be carefully adjusted to minimize the risk of grinding through the copper foil or removing too much resin filler, resulting in an uneven or defective surface. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] U.S. Patent No. 3,790,489 [Patent Document 2] WO2017 / 194449A1 [Patent Document 3] U.S. Patent Application Publication No. 2003 / 0074790 [Patent Document 4] U.S. Patent No. 4,991,359 [Patent Document 5] U.S. Patent No. 7,151,080 [Patent Document 6] WO2017 / 037040A1 [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] Therefore, the first object of the present invention was to overcome the shortcomings of the prior art and to provide an improved means for removing organic resin, i.e., cured organic filler paste, from the copper surface of a wide variety of dielectric substrates, including through-holes (TH) and / or blind microvias (BMV).

[0014] Therefore, a second objective of the present invention was to provide a surface treatment for a wide variety of dielectric substrates to avoid damage to the copper surface of the substrate, in particular to avoid partially removing the copper surface on the substrate or weakening its adhesive properties.

[0015] Therefore, a third object of the present invention was to provide a surface treatment for a wide variety of organic resins that enables metal coating to each substrate, and in particular exhibits excellent adhesive strength for electrolytically produced copper coatings, and is difficult to peel off, especially on blind microvias (BMVs) and / or through-holes (THs) of the substrate.

[0016] Therefore, a fourth object of the present invention was to provide a wide variety of surface treatments for dielectric substrates that can be included in a conventional process sequence for manufacturing articles including VIPPO (Via-in-Pad Plating Over) structures without making significant changes to other process steps in, for example, vertical and / or horizontal processes, in order to reduce manufacturing costs. [Means for solving the problem]

[0017] The above first to fourth objects are a method for removing an organic resin from a copper surface on a dielectric substrate including conductive through-holes (TH) and / or conductive blind micro-vias (BMV), comprising the following steps: (i) applying an organic paste to the dielectric substrate to fill the through-holes (TH) and / or blind micro-vias (BMV) with the organic paste, after step (i), at least a part of the surface of the dielectric substrate is covered with the organic paste; (ii) curing the organic paste to change the organic paste into a solidified organic resin, after step (ii), at least a part of the surface of the dielectric substrate is covered with the organic resin; (iii) chemically treating the dielectric substrate with a non-aqueous composition to obtain a chemically treated surface of the substrate and removing the organic resin from the surface of the substrate, the non-aqueous composition comprising: a) at least one high-boiling solvent having a boiling point of at least 100 °C, selected from the group consisting of alcohols having the general chemical formula R-OH (where R is a C4-C 30 hydrocarbon group) at a concentration of 80% to 95% by mass, preferably 81 wt.% to 91% by mass; b) at least one carboxylic acid, preferably at least one hydroxycarboxylic acid, more preferably selected from the group consisting of 2-hydroxy-propionic acid, tartaric acid and glycolic acid, at a concentration of 5% to less than 20% by mass, preferably 4% to 9% by mass, more preferably 7% to 8% by mass; c) at least one anionic aromatic surfactant selected from the group consisting of at least one c10-c16 alkylbenzene sulfonic acid and toluene sulfonic acid at a concentration of 0.25% to less than 1.5% by mass, preferably 0.5% to 1% by mass; and d) A concentration of 0.25% by mass or more and less than 1.5% by mass, preferably a concentration of 0.5% to 1% by mass, of at least one nonionic acetylene diol surfactant selected from the group consisting of preferably at least one C8 - C12 alkynediol, more preferably 2,4,7,9 - tetramethyldec - 5 - in - 4,7 - diol comprising or consisting of those, and a process (iv - 1) After step (iii), to obtain a mechanically treated surface of the substrate, mechanically treating the chemically treated surface of the substrate obtained in step (iii) with an abrasive tool to remove the remaining organic resin from the chemically treated surface of the substrate; and / or (iv - 2) After step (iii), wet - chemically treating the chemically treated surface of the substrate obtained with an oxidation solution containing an oxidizing agent to remove the remaining organic resin from the chemically treated surface of the substrate and obtain a wet - chemically treated surface of the substrate (v) In some cases, depositing a conductive material, preferably electroless deposition of a coated metal, on the mechanically treated surface obtained after step (iv - 1) or on the wet - chemically treated surface of the substrate obtained after step (iv - 2) to obtain a conductive surface of the substrate (vi) In some cases, for obtaining an electrolytic metal - coated surface, further electrolytic deposition of a coated metal on the conductive surface of the substrate obtained after an optional step (v) or on the mechanically treated surface of the substrate obtained after step (iv - 1) or on the wet - chemically treated surface of the substrate after step (iv - 2) (vii) In some cases, for obtaining a VIPPO (via - in - pad plating over) structure, structuring the electrolytic deposition on the electrolytic metal - coated surface of step (vi) and the solder pads, preferably tin solder pads is solved according to the first aspect of the present invention by a method comprising

[0018] The amount of all components of the above non - aqueous composition and optionally further components added up to 100% by mass (wt.%) of the composition, or in other words the total of all components, does not exceed 100% by mass in total.

[0019] This method removes excess organic resin and residual uncured organic paste (filler paste) from the substrate surface, particularly from the copper surface of printed circuit boards, while leaving the organic resin in conductive through-holes (THs) and / or conductive blind microvias (BMVs).

[0020] This method, particularly the mechanical treatment by step (iv-1) and / or the wet chemical treatment by step (iv-2), enables the effective removal of loosely or weakly bonded surface resin from the vicinity of through-holes (THs) and / or blind microvias (BMVs) of the substrate, especially dielectric substrates.

[0021] When both processing steps (iv-1) and (iv-2) are applied, it is preferable that the mechanical treatment by step (iv-1) is applied before the wet chemical treatment by step (iv-2). This may be useful, for example, when there is a large amount of residual uncured organic paste or when the chemical resistance of the cured organic resin is low. In this case, the wet chemical treatment step (iv-2) can also be used to prepare the surface for subsequent metallization. However, in certain cases, it may also be useful to start with step (iv-2) followed by (iv-1). This may be useful, for example, when the chemical resistance of the organic resin is higher.

[0022] Therefore, steps (iv-1) and / or (iv-2) ensure that, after the dielectric substrate is pre-chemically treated with a non-aqueous composition during step (iii), the organic resin is completely removed from the surface of the dielectric substrate, particularly from the copper surface, allowing for excellent deposition following the conductive material during step (v) and / or the painted metal during step (vi). Preferably, after applying step (iii), it is sufficient to apply only step (iv-1) or step (iv-2) to complete the cleaning.

[0023] This method avoids damage to the dielectric substrate surface, copper surface, and / or non-conductive surface of the PCB due to grinding. Preferably, this method eliminates the grinding step using a grinding device.

[0024] By performing deposition of an optional conductive material, preferably electrolytic deposition of a coating metal, on the mechanically treated surface obtained after step (iv-1) or on the wet chemically treated surface of the substrate obtained after step (iv-2), an effective activated layer is deposited on each treated surface, and optionally allows for further electrolytic deposition of a coating metal onto the conductive surface of a subsequent substrate.

[0025] Furthermore, because the efficiency of processing steps (iii) and (iv-1) or (iv-2) is high, wastewater treatment can be simplified, energy and time consumption can be reduced, and as a result, manufacturing costs can be reduced compared to the processing steps of prior art.

[0026] The first to fourth objectives described above are resolved according to the second embodiment with respect to an article obtained by the method according to the first embodiment. The article is further processed by further cleaning and metallization steps to obtain an article containing a VIPPO (Via-in-Pad Plating Over) structure.

[0027] The article includes a superior metal coating corresponding to the advantages summarized above.

[0028] The first to fourth objectives described above are solved according to a third embodiment, which uses a non-aqueous composition according to the method of the first embodiment to remove organic resin from the surface of a dielectric substrate containing through-holes (TH) and / or blind microvias (BMV) in order to manufacture articles containing VIPPO (Via-in-Pad Plating Over) structures. [Modes for carrying out the invention]

[0029] Brief description of the examples In the examples, samples 1, 2, and 3 are examined in relation to the variation in the chemical treatment process of each substrate surface with respect to the optical properties obtained after the nickel plating surface is subsequently acquired.

[0030] In the comparative example, aqueous samples 5 and 6 were compared with a non-aqueous treatment solution (sample 4), and the change in pH related to the optical properties of the copper surface obtained afterward was investigated. Further details are provided in the "Examples" section of the following text.

[0031] Detailed description of the invention General definition In the context of the present invention, the terms “at least one” or “one or more” mean “one, two, three or more” (and are interchangeable).

[0032] In the context of this invention, the term "and / or" includes all combinations of one or more of the relevant listed items.

[0033] In the context of the present invention, the terms “deposition,” “coating,” and “plating” are used interchangeably herein. In the context of the present invention, the terms “layer,” “coating,” and “precipitate” are used interchangeably herein.

[0034] In the context of this invention, the term "dielectric" means nonmetallic, and therefore nonconductive.

[0035] In the context of this invention, the term "aqueous solution" means that the aqueous solution contains 50% by mass (wt.%) or more of water.

[0036] In the context of the present invention, the term “desmearing process” means a wet chemical treatment performed after drilling THs and BMVs, and more particularly a method for removing residues such as particles generated by laser drilling or mechanical drilling of the surface of a dielectric substrate to form through-holes (THs, also called through-hole vias (THVs)) and / or blind microvias (BMVs) in the substrate. The wet chemical treatment includes at least an etching agent, preferably an acidic or alkaline aqueous permanganate solution.

[0037] In the context of the present invention, the copper surface of the dielectric substrate to be processed is understood as the copper surface of the copper layer deposited on the dielectric substrate, and the substrate includes through-holes (THs) and blind microvias (BMVs).

[0038] In conductive through-holes (THs) and conductive blind microvias (BMVs), "conductive" means that the copper layer is also deposited on the walls of the THs and BMVs that make up the conductive through-holes (THs) and conductive blind microvias (BMVs). The copper layer is deposited equally, and the THs and BMVs are not filled with copper.

[0039] In the context of the present invention, the term "alkyl" means a saturated linear or branched monovalent hydrocarbon radical having 1 to 18 carbon atoms (C1-C18). 18 ) refers to alkyl groups, which may, in some cases, be independently substituted with one or more substituents as described below. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and their high homologs, and all their isomers.

[0040] In the context of the present invention, the term "alkyne" (or "alkynyl") refers to an unsaturated linear or branched monovalent hydrocarbon radical (C2-C2) having at least one triple bond and 8 to 12 carbon atoms. 30 The alkyne group refers to a group that may be independently substituted with one or more substituents, as will be described later. Examples of alkyne groups include, but are not limited to, octa-4-yne, deca-5-yne, or dodeca-6-yne.

[0041] In the context of this invention, the term "aromatic" refers to a monovalent aromatic hydrocarbon radical (C6-C6) having 6 to 20 carbon atoms, obtained by removing one hydrogen atom from one carbon atom of an aromatic ring system such as an aryl group. 20) refers to aryl groups. Aryl groups also include bicyclic radicals containing an aromatic ring condensed on an aromatic carbocyclic ring. Typical aryl groups include, but are not limited to, radicals derived from benzene (phenyl), substituted benzenes, naphthalenes, etc. The aryl group may be independently substituted with one or more substituents as described herein below.

[0042] Alkyl, alkynyl, and aryl atoms may each be substituted, and at least one hydrogen atom may be substituted with a halogen atom.

[0043] In the context of the present invention, the term "hydrocarbon group" refers to a chemical group having a linear or branched skeleton consisting exclusively of carbon atoms, where two adjacent carbon atoms are bonded together via single, double, or triple bonds, or are members of an aromatic ring, and this skeleton further includes hydrogen atoms bonded to carbon atoms. These hydrogen atoms may be partially substituted with halogen atoms and thus form part of the hydrocarbon group. The hydrocarbon group does not contain a hydroxyl group. More preferably, the hydrocarbon group may be a linear or branched alkyl, a linear or branched alkenyl, a linear or branched alkyne, a cycloalkyl, or a cycloalkenyl, and includes bicyclic and tricyclic highly condensed alicyclic groups. These compounds are aliphatic hydrocarbon groups. Furthermore, the hydrocarbon group may preferably be aryl, arylalkylene, arylalkenylene, arylalkylene, arylcycloalkylene, or arylcycloalkenylene, and may include bicyclic or tricyclic highly condensed aryl groups, where the alkylene in arylalkylene, the alkenylene in arylalkenylene, and the alkylene in arylalkylene are linear or branched groups as described above, and the cycloalkylene in arylcycloalkylene and the cycloalkenylene in arylcycloalkenylene may form highly condensed alicyclic ring systems. In the latter case, the difunctional group has one bond to the OH group of a high-boiling alcohol. The hydrocarbon group that is arylalkylene, arylalkenylene, arylalkylene, arylcycloalkylene, or arylcycloalkenylene is an aromatic aliphatic group. In the latter case, the difunctional group has one bond to the OH group of a high-boiling alcohol. Hydrogen atoms bonded to cycloalkyl groups, cycloalkylene groups, cycloalkenyl groups, cycloalkenylene groups, and aryl groups may be partially substituted by halogen atoms, and further by alkyl groups, alkenyl groups, and / or alkynyl groups. More specifically, the term "C4-C" as used herein refers to... 30The "hydrocarbon group" refers to a group having a skeleton containing 4 to 30 carbon atoms including all the skeletal carbon atoms contained in an alkyl group, an alkenyl group, and / or an alkynyl group that substitute the hydrogen atoms of a cycloalkyl group, a cycloalkylene group, a cycloalkenyl group, a cycloalkenylene group, and an aryl group. More specifically, the term "C4-C 20 The "hydrocarbon group" refers to a group having a skeleton containing 4 to 20 carbon atoms including all the skeletal carbon atoms as described previously herein. Similarly, the term "C4-C 10 The "hydrocarbon group" refers to a group having a skeleton containing 4 to 10 carbon atoms including all the skeletal carbon atoms as described previously herein. Therefore, the term "C1-C 20 The "hydrocarbon group" refers to a group having a skeleton containing 1 to 20 carbon atoms including the skeletal carbon atoms as described previously. Regarding the meaning of the term "C1-C 20 As far as the meaning of the "hydrocarbon group" is concerned, a group having only 1 carbon atom ("C1 hydrocarbon group") refers to this group being methyl, and as far as the meaning of the term "C1-C 20 As far as the meaning of the "hydrocarbon group" is concerned, a group having 2 carbon atoms ("C2 hydrocarbon group") refers to this group being ethyl, ethenyl or ethynyl.

[0044] In the context of the present invention, the term "about" related to a concentration value (mass% or wt.%), a temperature value, a treatment time value, or a thickness value means the indicated exact (average) value and the range of concentration values, temperature values, treatment time values, or thickness values that are ±30% with respect to this average value. For example, "about ३ mass%" means exactly 3 mass% and the range from 30% of 3 mass% - 3 mass% (= 3 mass% - 0.9 mass% = 2.1 mass%) to 30% of 3 mass% + 3 mass% (= 3 mass% + 0.9 mass% = 3.9 mass%), and thus the range of 2.1 mass% to 3.9 mass%. The ranges of values defined by "about" indicated for the operating temperature, treatment time, or thickness are understood correspondingly, and the relative percentage for the temperature value is based on the °C scale (±30% of 40 °C is ±12 °C). < First aspect The present invention, in a first aspect, is a method for removing organic resin from a copper surface on a dielectric substrate containing conductive through-holes (THs) and / or conductive blind microvias (BMVs), comprising the following steps: (i) A step of applying an organic paste to a dielectric substrate in order to fill through-holes (TH) and / or blind microvias (BMV) with the organic paste, wherein after step (i), at least a portion of the surface of the dielectric substrate is covered with the organic paste. (ii) A step of curing the organic paste to transform it into a solidified organic resin, wherein after step (ii), at least a portion of the surface of the dielectric substrate is coated with the organic resin. (iii) A step to obtain a chemically treated surface of the substrate, in which the dielectric substrate is chemically treated with a non-aqueous composition to remove the organic resin from the surface of the substrate, wherein the non-aqueous composition is a) General chemical formula R-OH (wherein R is C4~C) 30 At least one high-boiling point solvent having a boiling point of at least 100°C, selected from the group consisting of alcohols having a hydrocarbon group, in a concentration of 80% to 95% by mass, preferably 81 wt.% to 91 wt.%; b) At least one carboxylic acid, preferably at least one alpha-hydroxycarboxylic acid, more preferably 2-hydroxypropionic acid, in a concentration of 5% to 20% by mass, preferably 4% to 9% by mass, more preferably 7% to 8% by mass; c) At least one anionic aromatic surfactant selected from the group consisting of at least one C10-C16 alkylbenzene sulfonic acid, preferably in a concentration of 0.25% by mass or more and less than 1.5% by mass, preferably in a concentration of 0.5% by mass to 1% by mass; and d) At least one nonionic acetylenediol-based surfactant, preferably selected from the group consisting of at least one C8-C12 alkyne diol, and more preferably 2,4,7,9-tetramethyldeca-5-in-4,7-diol, with a concentration of 0.25% by mass or more and less than 1.5% by mass, preferably 0.5% to 1% by mass. Processes including, (iv-1) In order to obtain a mechanically treated surface of the substrate, the chemically treated surface of the substrate obtained after step (iii) is mechanically treated with an abrasive to remove any remaining organic resin from the chemically treated surface of the substrate, and / or (iv-2) A step to obtain a wet chemically treated surface of the substrate obtained after step (iii) by wet chemical treatment with an oxidizing solution containing an oxidizing agent, thereby removing the remaining organic resin from the chemically treated surface of the substrate, (v) In some cases, a step to obtain a conductive surface of the substrate by depositing a conductive material on the mechanically treated surface obtained after step (iv-1) or on the wet chemically treated surface of the substrate obtained after step (iv-2), preferably by electrolytic deposition of the coated metal, (vi) In some cases, in order to obtain an electrolytic metal coating surface, a step of further electrolysis of the coating metal on the conductive surface of the substrate obtained after step (v), or on the mechanically treated surface of the substrate obtained after step (iv-1), or on the wet chemically treated surface of the substrate after step (iv-2), (vii) In some cases, in order to obtain a VIPPO (Via-in-Pad Plating Over) structure, the process of structuring the electrolytic deposition of the electrolytic metal coating surface and solder pad, preferably tin solder pad, in step (vi) and This applies to methods that include [specific methods].

[0046] It has been found that the method and process according to the present invention result in a more effective and gentler removal of organic resins, particularly organic epoxy resins, from each substrate, enabling a particularly effectively cleaned surface on which further electrolytic deposition of conductive materials and / or further electrolytic deposition of coating metals can be achieved. In particular, the adhesion of the deposited conductive material and / or deposited further coating metals on the copper surface is significantly improved, as is the adhesion of the deposited conductive material and / or deposited further coating metals on the filled TH and BMV organic resins.

[0047] Processes (i) and (ii) Preferably, the organic paste applied during step (i) includes epoxy paste, polyester paste, polyurethane paste, and acrylic paste, and more preferably, the organic paste applied during step (i) includes epoxy paste used for subsequent VIPPO application. Preferably, an epoxy paste based on bisphenol A with a molecular weight (MW) of 700 or less can be used, for example, as the THP-100DX1 product, supplied by Taiyo America, Inc., 2675 Antler Drive, Carson City, NV89701.

[0048] Preferably, in order to obtain a solidified organic resin, the curing of the organic paste performed during step (ii) includes a thermosetting step, more preferably at 130°C to 160°C, and most preferably at 150°C.

[0049] Preferably, the curing of the organic paste performed during step (ii) is carried out for a period of 30 to 60 minutes, preferably 45 minutes.

[0050] The solidified organic resin derived from the cured organic paste material is preferably chemically different from the dielectric substrate material. In other words, only the solidified organic resin can be removed from the dielectric substrate in processing step (iii), while the dielectric substrate remains chemically inert (cannot be removed) throughout processing step (iii).

[0051] Process (iii) Therefore, the non-aqueous composition of the present invention used in step (iii) comprises four main components and optionally additional components, the main components being a) to d) described above.

[0052] By using a non-aqueous composition, highly efficient removal of solidified organic resin from the substrate surface can be achieved even at low operating temperatures. Combining the selected surfactant with the solvent and carboxylic acid is thought to provide the strongest effect on the elution and removal of polymer resin, and its good miscibility with water may further assist in improving subsequent substrate rinsing.

[0053] One further advantage of the present invention is that the preferred surfactant level is lower than that found in prior art strippers. Furthermore, when using a low-foaming surfactant or a suitable blend of a low-HLB surfactant and a high-HLB surfactant in the present invention, the surfactant further assists in washing away the non-aqueous solution from the treated parts while simultaneously controlling the foaming problem in the subsequent rinsing step. Thus, foaming problems do not actually occur, and defoamers or other countermeasures are unnecessary. This can improve the efficiency of the removal process, along with its cost-effectiveness.

[0054] By actively and efficiently removing the organic resin from the substrate, the operating temperature during step (iii) can be reduced compared to the operating temperature reported in U.S. Patent No. 7,151,080 as necessary for effective stripping, for example, an operating temperature well above 100°C. The operating temperature can be significantly reduced to a low value of 30°C to 90°C, more preferably to, for example, 60°C to 85°C. Similarly, the processing time of step (iii) can be shortened compared to conventional methods because the non-aqueous composition is more efficient than the prior art composition. This is due to the combination of solvent and co-solvent compared to the prior art composition.

[0055] The non-aqueous composition actively and effectively removes organic resin from each substrate at conventional or lower temperatures, in conventional processing times or shorter processing times, without damaging the substrate substrate damaged by prior art release agents.

[0056] The non-aqueous composition further comprises components that are stable under working conditions, particularly at the operating temperature necessary for effectively removing organic resins. Furthermore, the non-aqueous composition meets the safety requirements of staff working with it.

[0057] The composition used according to step (iii) of the present invention is non-aqueous, meaning that the non-aqueous composition is essentially water-free. Some water uptake from the environment may occur during the procedure. Preferably, water is not intentionally added to the non-aqueous composition. Generally, the water content in the non-aqueous composition should be less than 1% by mass, preferably less than 0.5% by mass, more preferably less than 0.1% by mass, and most preferably less than 0.01% by mass, even during the operation. Water contained in the non-aqueous composition does not adversely affect the paint removal performance. On the other hand, if water is contained in the non-aqueous composition, the removal performance of organic pastes and / or solidified organic resins is reduced. However, in either case, if water is present in the non-aqueous composition, the composition usually tends to exhibit chemical attack on soft metals such as aluminum, zinc, copper, and magnesium. Such chemical attack is thought to be due to the ionization of acid compounds or hydroxide compounds present in the non-aqueous composition, and therefore the ions generated by this ionization can corrode these metals. Therefore, by omitting the addition of water to the non-aqueous composition, the present invention is suitable for use on sensitive substrates. Accordingly, as used herein, the term “essentially waterless” means a water content that does not ionize the potassium hydroxide or acid component to the extent that it attacks the aluminum, magnesium, copper, or zinc substrate.

[0058] The high-boiling point solvent that can be used in the non-aqueous composition of the present invention can be selected from a wide variety of different high-boiling point alcohols, specifically high-boiling point alcohols having the general chemical formula R-OH, for example, with boiling points suitable for operating temperatures of 30°C to 90°C. More preferably, the non-aqueous composition according to the present invention is operated at a temperature in the range of 60°C to 90°C, most preferably 65°C to 85°C, and temperatures set higher within this range are suitable for removing resin. Therefore, according to the present invention, the boiling point of at least one high-boiling point alcohol is at least 100°C. The boiling point can be as high as 200°C or 300°C or even higher, and its maximum value is limited by the energy produced by heating the non-aqueous composition and by the thermal stability of the substrate material.

[0059] According to a preferred embodiment of the present invention, the non-aqueous composition has the general chemical formula R-OH (wherein R is an arylalkylene and aryl is C6-C6). 10 The solution contains at least one high-boiling point solvent, which is a compound having an aryl group (preferably, and a C1-C6 alkylene group).

[0060] According to a more preferred embodiment of the present invention, since good removal performance has been demonstrated by a benzyl alcohol-based non-aqueous composition, the non-aqueous composition comprises at least one high-boiling point solvent, which is benzyl alcohol (C6H5-CH2-OH) or another phenylalkylene compound.

[0061] In the most common method of the present invention described above regarding the chemical processing steps, the non-aqueous composition contains four main components. In a preferred embodiment, these main components are combined within a specified relative ratio, and in a preferred embodiment of the present invention, the non-aqueous composition is a) At least one high-boiling point solvent in an amount of 81% to 95% by mass; b) 5% to 20% by mass of at least one carboxylic acid, preferably at least one hydroxycarboxylic acid; c) At least one anionic aromatic surfactant in a concentration of 0.25% to 1.5% by mass, preferably at least one C10-C16 alkylbenzene sulfonic acid; and d) At least one nonionic acetylenediol-based surfactant, preferably at least one C8-C12 alkyne diol, in a concentration of 0.25% to 1.5% by mass. It may include, or may consist of, These components constitute 100% by mass of the non-aqueous composition. If the non-aqueous composition contains more than one of components a, b, c, and d, the concentrations previously shown herein represent the total concentration of all compounds for each of these components.

[0062] If the non-aqueous composition contains additional components in addition to the above-mentioned components a, b, c, and d, the proportions of each component are adjusted as appropriate.

[0063] In another preferred embodiment of the present invention, the non-aqueous composition further comprises the following components: a) 90% by mass of at least one high-boiling point solvent, preferably benzyl alcohol; b) 8% by mass of at least one alpha-hydroxycarboxylic acid, preferably 2-hydroxypropionic acid; c) 1% by mass of at least one C10-C16 alkylbenzene sulfonic acid; and d) 1% by mass of at least one C8-C12 alkyne diol, preferably 2,4,7,9-tetramethyldeca-5-in-4,7-diol It includes or consists of.

[0064] Components a, b, c, and d constitute 100% by mass of the non-aqueous composition.

[0065] The operating temperature of method step (iii) may be set to at least about 30°C, preferably at least about 40°C, more preferably at least about 60°C, and even more preferably at least about 65°C. Furthermore, the operating temperature of method step (iii) may be set to a maximum of about 150°C or higher, more preferably at a maximum of about 90°C, even more preferably at a maximum of about 85°C, and most preferably at 80°C. According to yet more preferred embodiments of the present invention, the operating temperature of method step (iii) is about 65°C to about 85°C.

[0066] Most preferably, step (iii) is carried out at a temperature of 60°C to 90°C, more preferably 65°C to 85°C, and most preferably 80°C.

[0067] Preferably, step (iii) is performed for a period of 1 to 15 minutes, more preferably 2 to 5 minutes.

[0068] Typically, the removed resin material remains in the non-aqueous composition and accumulates in the non-aqueous bath over time. If partially removed parts still have patches of resin, they are transferred to a rinsing bath, where these resins can be removed during this rinsing process. In this case, the rate of resin accumulation in the non-aqueous bath can be reduced, advantageously extending the life of the bath.

[0069] Non-aqueous compositions may also be sprayed onto the substrate surface to be removed. They may be used in combination with dipping treatment either before or after spray application, or both.

[0070] A preferred method for removing the resin from the substrate is the following sub-step of step (iii) of the method: iii-a) A step of preparing the non-aqueous composition of the present invention in a tank apparatus; iii-b) A step of bringing the substrate into contact with a non-aqueous composition in a tank device in order to remove the organic resin; iii-c) A process of completely removing organic resin from the substrate by applying high-pressure water spray to the substrate surface. Includes.

[0071] The high-pressure water spray applied in step iii-c generally has a pressure of 5 bar to 250 bar.

[0072] The non-aqueous composition is heated in step iii-a) and / or step iii-b), preferably in step iii-b), at a temperature of 30°C to 90°C, preferably 65°C to 85°C, for 1 to 15 minutes, thereby removing or peeling the resin from the substrate.

[0073] Process (iv-1) or process (iv-2) Further method steps (iv-1) and / or (iv-2) enable the effective removal of any residual organic resin from the substrate surface that was not removed from the surface during the previous method step (iii).

[0074] Preferably, between step (iii) and step (iv-1), or between step (iii) and step (iv-2), a first rinsing step: (r-1) A step of rinsing the chemically treated surface of the substrate obtained after step (iii) with a first rinse solution, more preferably a first rinse solution containing distilled water. This will be executed.

[0075] The first rinsing step enables effective treatment of the substrate surface after step (iii) and before the subsequent mechanical treatment (iv-1) or wet chemical treatment (iv-2).

[0076] Preferably, a second rinsing step after step (iv-1) or after step (iv-2): (r-2) A step of rinsing the mechanically treated surface of the substrate obtained after step (iv-1) or the chemically treated surface of the substrate obtained after step (iv-2) with a second rinse solution, more preferably an acidic aqueous solution, most preferably a second rinse solution containing sulfuric acid. This will be executed.

[0077] The second rinsing step makes it possible to effectively treat the surface of the substrate before the deposition of an optional conductive metal during step (v) and / or the electrolysis of an optional further coating metal during step (vi).

[0078] Preferably, step (iii) (or (iii-b)) and / or step (iv-2) are performed in the presence of ultrasound provided by an ultrasonic emitter.

[0079] More preferably, during step (iii) (or (iii-b)), the ultrasonic parameter of the ultrasonic device is 40 kHz.

[0080] More preferably, during step (iv-2), the ultrasonic parameters of the ultrasonic device are 40 kHz and 120 kHz.

[0081] Preferably, step (iv-1) includes bringing a chemically treated surface of the substrate into contact with a rotating brush, the rotating brush more preferably comprising a nylon filament having a ceramic element, which enables gentle cleaning of the copper surface.

[0082] By applying such a rotating brush after the chemical treatment of step (iii) (or (iii-b)), effective mechanical removal of any remaining organic resin can be ensured during the mechanical removal step (iv-1). In particular, the ceramic element bonded to the nylon filament of the rotating brush enables particularly effective removal of the organic resin. This soft brush treatment effectively avoids damage to the copper surface.

[0083] Preferably, step (iv-1) is carried out at room temperature, preferably 20°C to 25°C.

[0084] Preferably, step (iv-1) is performed for 15 seconds to 5 minutes, more preferably for 30 seconds to 60 seconds.

[0085] Preferably, step (iv-1) is performed on the wetted surface of the substrate.

[0086] Preferably, step (iv-2) is carried out at a temperature of 55°C to 90°C, more preferably 65°C to 85°C.

[0087] Preferably, step (iv-2) is performed for a period of 2 to 10 minutes, more preferably for 12 minutes.

[0088] Preferably, the oxidizing agent used during step (iv-2) includes sodium permanganate or potassium permanganate.

[0089] Preferably, the oxidizing agent is present in the oxidizing solution in an amount of 35 g / l to 70 g / l relative to the total volume of the solution.

[0090] Preferably, step (iv-2) optionally includes at least two sub-steps (de) after the rinsing step, where, (de-2) Etching steps using an oxidizing solution and (de-3) reduction steps are applied. These sub-steps may include steps of applying a treatment solution containing a treatment agent as shown below. In some cases, sub-step (de) includes a (de-1) expansion step performed before the (de-2) etching step, and sub-step (de-1) includes a step of applying a first treatment agent, preferably an expansion agent, to the surface of the substrate to obtain an expanded surface of the substrate.

[0091] Preferably, in step (iv-2), only the (de-2) etching step and the (de-3) reduction step are used.

[0092] In one embodiment of the present invention, sub-step (de) includes sub-steps (de-2) and (de-3), where sub-step (de-2) includes applying an oxidizing agent, more preferably potassium permanganate, as a second processing agent to the surface of the substrate to obtain an etched surface of the substrate, and sub-step (de-3) includes applying a third processing agent, preferably a reducing agent, to the surface of the substrate, preferably the etched surface of the substrate.

[0093] In the sub-steps using the first, second, and third treatment agents, they are preferably dissolved in an aqueous treatment solution.

[0094] Preferably, the first treatment agent, more preferably the leavening agent, comprises an organic solvent that penetrates the through-hole and BMV-exposed resin surface, most preferably a glycol ether and / or lactam. Most preferably, the leavening agent is a commercially available Securiganth MV leavening agent.

[0095] Preferably, a first treatment agent, more preferably a swelling agent, is applied at a concentration of 200 ml / l to 500 ml / l relative to the total volume of the first treatment solution.

[0096] Preferably, the first treatment solution containing the leavening agent has a pH of 9.5 to 12.

[0097] Preferably, the sub-step (de-1) is carried out at a temperature of 55°C to 85°C, more preferably 60°C to 70°C.

[0098] Preferably, sub-process (de-1) is performed for a period of 2 to 15 minutes, preferably 5 to 10 minutes.

[0099] Preferably, the oxidizing solution as the second treatment solution is selected to be an alkaline oxidizing solution containing potassium permanganate. Most preferably, the etching agent is commercially available Securigans MV P-Etch.

[0100] Preferably, the oxidizing agent as the second treatment agent contains potassium permanganate and is applied at a concentration of 35 g / l to 70 g / l relative to the total amount of the oxidizing solution as the second treatment solution.

[0101] Preferably, the sub-step (de-2) is carried out at a temperature of 55°C to 90°C, more preferably 65°C to 85°C, and most preferably 75°C.

[0102] Preferably, sub-step (de-2) is performed for a period of 2 to 20 minutes, more preferably for 12 minutes.

[0103] Preferably, the third treatment agent, more preferably the reducing agent, comprises an acid, most preferably sulfuric acid or hydrochloric acid, citric acid, ascorbic acid subphosphate, or other reducing agent capable of reducing metal residues from the previous step, most preferably hydroxylammonium sulfate or hydrogen peroxide, and a polymer containing nitrogen atoms and / or positively charged nitrogen atoms. Most preferably, the reducing agent is a commercially available Securigans MV reducing conditioner.

[0104] Preferably, a third treatment agent, more preferably a reducing agent, is applied at a concentration of 75 ml / l to 125 ml / l relative to the total volume of the third treatment solution.

[0105] Preferably, the third treatment agent, more preferably a reducing agent, contains 80 ml / l to 100 ml / l of 50 w / w% sulfuric acid relative to the total amount of the third treatment solution.

[0106] Preferably, the sub-step (de-3) is carried out at a temperature of 40°C to 55°C, more preferably 40°C to 50°C, and most preferably 50°C.

[0107] Preferably, sub-step (de-3) is performed for a period of 0.5 to 5 minutes, preferably 4 minutes.

[0108] Preferably, following sub-step (de-3), a cleaning step is performed using a cleaning solution containing a cleaning agent, wherein the cleaning agent preferably contains an additive that can reduce the surface tension of water as a surfactant, and optionally, more preferably, a polymer such as a polymer having nitrogen atoms and / or quaternary nitrogen atoms that can be adsorbed onto a previously treated surface, along with at least one inorganic base and / or organic base, such as an amine or aliphatic amine and similar, such as ammonia, or an inorganic acid such as sulfuric acid or hydrochloric acid, or an organic acid such as sulfonic acid, carbonic acid, acetic acid, or glycolic acid, which removes dirt or organic residues and produces a clean metal surface on the substrate. Most preferably, the cleaning agent is selected from commercially available Securigant MV Cleaner C1 V8, Securigant MV Cleaner 902PF, or Securigant MV Cleaner GFR-S1, or Cleaner Cupra Pro S2 EU.

[0109] Preferably, the detergent contains 0 g / l to 30 g / l of sodium hydroxide relative to the total volume of the cleaning solution.

[0110] Preferably, the washing process is carried out at a temperature of 30°C to 70°C, more preferably 50°C to 60°C, and most preferably 60°C.

[0111] Preferably, the first cleaning step is performed for a period of 0.5 to 6 minutes, preferably 1 to 5 minutes.

[0112] Optional process (v) Preferably, step (v) is carried out by adding a metal-activating composition to precipitate, for example, a metal layer on a wet-chemically treated surface of a substrate, particularly on a wet-chemically treated surface of an organic resin solidified in TH and / or BMV, the metal layer may be deposited as, for example, metallic palladium or metallic copper, as a film, colloid, or in the form of ions, and then reduced. The metal layer may be a pure metal layer or may contain further metals as a metal alloy.

[0113] Preferably, the metal-activating composition includes, for example, at least one palladium ion source or copper ion source. Furthermore, the solution may include other metal ion sources such as ruthenium ion source, rhodium ion source, palladium ion source, osmium ion source, iridium ion source, platinum ion source, copper ion source, silver ion source, nickel ion source, cobalt ion source, gold ion source, and mixtures thereof. The palladium ions or copper ions and the further metal ions are adsorbed onto the wet-chemically treated surface of the substrate and subsequently reduced, or adsorbed as a reduced metal, for example, a colloid or particles, for example, a palladium colloid or a copper colloid, where the palladium colloid may contain tin, or the copper colloid may contain palladium.

[0114] Preferably, the activating composition is a commercially available Neoganth MV activator available from Atotek Germany LLC.

[0115] Preferably, the activating composition may contain carbon, a conductive polymer, or metal ions or metal colloids containing, for example, copper, palladium, or palladium-tin, for subsequent electrolytic direct metallization.

[0116] Optional process (vi) To obtain an electrolytic metal coating surface, further electrolytic deposition of the coated metal by step (vi) enables effective deposition of the metal coating on the substrate surface.

[0117] Preferably, the additional coating metal used during the electrolytic output process (vi) is selected from copper, nickel, or an alloy thereof, and more preferably copper.

[0118] Preferably, the electrolytic plating step (vi) is performed by applying an electrolytic copper plating bath that is well known in the art for this purpose.

[0119] Preferably, the electrolytic copper plating bath comprises copper ions, an electrolyte (usually a strong acid, such as sulfuric acid, fluoroboric acid, or methanesulfonic acid), chloride ions, optionally one or more levelers, optionally one or more brighteners, and optionally one or more carriers. These compounds are known in the art and are disclosed, for example, in WO2017 / 037040A1 (pages 21, line 1 to 22, line 27).

[0120] Preferably, step (vi) is carried out for a period of 30 to 120 minutes, preferably 90 minutes, and / or at a temperature of 10°C to 50°C, preferably 32°C.

[0121] Preferably, step (vi) is performed by applying a current density of 1 ASD to 25 ASD, preferably by applying a current density of 3 ASD to 15 ASD.

[0122] Preferably, method steps (i), (ii), (iii), (iv), (v) and / or (vi) are performed in a horizontal or vertical process.

[0123] This makes it possible to effectively adapt the method according to the first embodiment to several manufacturing scenarios, thereby improving the flexibility of the method.

[0124] According to the present invention, a horizontal process or a vertical process refers to the orientation of the substrate between each method process (i), (ii), (iii), (iv), (v) and / or (vi).

[0125] During the horizontal process, the substrate, in particular, which is to be formed as a plate, is transported horizontally through method steps (i), (ii), (iii), (iv), (v) and / or (vi) such that the lower side of the substrate faces towards the floor and the upper side of the substrate is oriented away from the floor. During the horizontal process, the substrate is preferably transported by a transport device so that it is processed in different processing modules between each method step (i), (ii), (iii), (iv), (v) and / or (vi).

[0126] During the vertical process, the substrate, in particular, which is formed as a plate, is transported vertically through method steps (i), (ii), (iii), (iv), (v) and / or (vi) such that one of the lateral edges of the substrate faces toward the floor and the opposite lateral edge of the substrate faces away from the floor.

[0127] substrate Preferably, conductive through-holes (THs) and / or conductive blind microvias (BMVs) in the dielectric substrate include copper surfaces deposited on the walls of the THs and BMVs within the dielectric substrate. The copper layer on the copper surface is deposited equally (thinly and according to the surface structure of the walls), and the THs and BMVs are not filled with copper.

[0128] Preferably, after step (ii), the organic resin completely fills the conductive TH and conductive BMV, and the organic resin is not removed from the conductive TH and conductive BMV during steps (iii), (iv-1), or (iv-2).

[0129] Preferably, the substrate according to the present invention includes HDI, MLB manufacturing substrates and / or IC substrate products having excellent features, more preferably having a through-hole (TH) aspect ratio of 1:3 to 1:18 and / or a blind microvia (BMV) aspect ratio of 1:0.5 to 1:2.3 for horizontal plating application, or more preferably having a through-hole (TH) aspect ratio of 1:3 to about 1:30 and / or a blind microvia (BMV) aspect ratio of 1:1 or 1:1.15 or less to 1:2.3 for vertical plating application.

[0130] Preferably, the precipitation of an optional conductive material by step (v) is carried out using a palladium species, a conductive polymer, or a carbon species as the activating composition.

[0131] Preferably, the substrate, in particular a dielectric substrate having at least one dielectric surface to be treated, comprises an organic polymer selected from resins and / or plastics and blends thereof, wherein the resins and plastics are more preferably selected from the group consisting of epoxy resins, isocyanate resins, bismaleimidotriazine resins, phenylene resins, and polyesters, and even more preferably selected from polyethylene terephthalate (PET), polyimide (PI), polytetrafluoroethylene, acrylonitrile-butadiene-styrene (ABS) copolymer, polyamide (PA), polycarbonate (PC), liquid crystal polymers (LCP) such as cyclic olefin copolymer (COC), Ajinomoto build-up film (ABF, ABF / epoxy type substrate), or plastics manufactured for photosensitive interlayer insulators, as well as mixtures and blends thereof, or composites based on mixtures of the organic polymer with the organic polymer, or with non-conductive filler particles such as glass fillers and / or silica fillers and / or glass fabrics. The substrate may also be a glass substrate or a silicon substrate.

[0132] The dielectric substrate, such as a resin material or a plastic material, preferably comprises a material commonly used in the electronics industry, which is metallized. The material of the dielectric substrate is chemically different from solidified organic resins derived from organic pastes.

[0133] Preferably, the organic polymer includes a polyimide resin or an epoxy resin, and the polyimide resin may be modified by the addition of polysiloxane, polycarbonate, polyester, etc.

[0134] Preferably, the epoxy resin may be a glass filler epoxy substrate material comprising a combination of epoxy resin and glass filler, or a glass filler epoxy substrate material with a high glass transition temperature, which is modified to have low thermal expansion and a high glass transition temperature.

[0135] Preferably, the glass filler is selected from borosilicate glass, quartz glass, silica glass, and / or fluorinated glass. The silicon preferably includes polysilicon (including doped polysilicon such as p-doped polysilicon and n-doped polysilicon) and single-crystal silicon, silicon oxide, silicon nitride, and silicon oxynitride. The various filler sizes have a diameter in the range of 0.01 μm to 5 μm, preferably with an average diameter of 0.5 μm.

[0136] Glass fibers, like glass fillers, are selected from borosilicate glass, quartz glass, silica glass, and / or fluorinated glass. These are woven with individual glass fibers having diameters ranging from sub-micrometers to several micrometers. They provide mechanical stability to the printed circuit board and, together with the resin used, significantly influence the mechanical and thermal properties of the printed circuit board material.

[0137] The composite of the non-conductive layer is preferably a build-up film, such as an epoxy-based material. The size of the embedded glass filler is an average diameter of 0.5 μm and a maximum of 5.0 μm.

[0138] Second aspect According to a second aspect, the present invention relates to a substrate having a chemically treated surface of a substrate obtained by the method according to the first aspect. More specifically, the present invention relates to an article obtained by the method according to the first aspect.

[0139] The substrate or article may be further processed by subsequent cleaning and metallization steps to obtain an article containing a VIPPO (Via-in-Pad Plating Over) structure.

[0140] Preferably, the foregoing regarding the method according to the first aspect of the present invention is similarly applicable to the substrate of the second aspect of the present invention, and is preferred as described above.

[0141] Third aspect According to a third aspect, the present invention relates to the use of a non-aqueous composition by the method of the first aspect for removing an organic resin from the surface of a dielectric substrate containing a copper surface and conductive through-holes (THs) and / or conductive blind microvias (BMVs) in order to manufacture an article containing a VIPPO (Via-in-Pad Plating Over) structure.

[0142] Preferably, the foregoing regarding the method according to the first aspect of the present invention is similarly applicable to the use of the third aspect of the present invention, and those described as preferred are preferred.

[0143] In preferred uses of non-aqueous compositions, further mechanical or wet chemical treatments to remove the organic resins described above are not required. [Examples]

[0144] In the following embodiments, various samples are provided to specify a method for removing organic resin from the surface of a substrate.

[0145] I. Variation in processing time The following three samples (Sample 1, Sample 2, and Sample 3), each including substrates used in the manufacturing process of printed circuit boards (PCBs), are described. Each substrate is an FR-4 dielectric substrate with through-holes (TH), and copper layers are deposited on the upper and lower sides of the substrate, as well as on the walls of the through-holes (TH).

[0146] In subsequent steps, an epoxy-based organic paste is applied to the dielectric substrate to completely fill the through-holes (TH), and a 5 μm to 7 μm thick layer of the paste is also provided on top of the copper layers deposited on the upper and lower sides of the substrate.

[0147] Subsequently, the organic paste is applied to each substrate and heat-cured by applying a temperature of 150°C under vacuum for 45 minutes. This curing process converts the epoxy-based organic paste into a solidified organic epoxy resin that fills the through-holes (TH) and covers the copper layer on both the upper and lower sides of the substrate.

[0148] Next, in order to obtain a chemically treated surface of the dielectric substrate, each dielectric substrate is chemically treated with a non-aqueous composition to remove the organic epoxy resin from the substrate surface.

[0149] The non-aqueous composition (example of the present invention) was, for all four samples, a) 91% by mass of benzyl alcohol; b) 6.5% by mass of 2-hydroxypropionic acid; c) 1.25% by mass of at least one C10-C16 alkylbenzene sulfonic acid; and d) 1.25% by mass of 2,4,7,9-tetramethyldeca-5-in-4,7-diol It consists of.

[0150] Sample 1: According to Sample 1, the non-aqueous composition is applied at 80°C for 110 seconds.

[0151] Sample 2: According to Sample 2, the non-aqueous composition is applied at 80°C for 200 seconds.

[0152] Sample 3: According to Sample 3, the non-aqueous composition is applied at 80°C for 10 minutes.

[0153] Next, during the first rinsing step, the chemically treated surfaces of each dielectric substrate with all samples 1, 2, and 3 were treated at 60°C for 60 seconds using a first rinsing solution containing distilled water, and the first rinsing step was performed while ultrasound was present.

[0154] Next, the rinsed surface of each dielectric substrate is chemically treated at 75°C for 12 minutes using an oxidizing solution containing 70 g / L potassium permanganate and 50 g / L sodium hydroxide as oxidizing agents, according to sub-step (de-2). This treatment with the oxidizing solution effectively removes any residual organic resin from the surface of each dielectric substrate.

[0155] Subsequently, a second rinsing step is performed by applying a second rinsing solution containing sulfuric acid aqueous solution at 50°C for 1 minute.

[0156] Next, as a third treatment agent in sub-step (de-3), a reducing agent containing 100 ml / L of Securigans MV reducing conditioner (hydroxylammonium sulfate-based) and 35 ml / L of sulfuric acid is applied to the substrate surface at 50°C for 4 minutes to obtain a reduced surface of the substrate. After that, a third rinsing step and drying step are performed.

[0157] Subsequently, the cleaning agent is applied to the reduced surface of the substrate at room temperature for 5 minutes, and then a fourth rinsing step is performed.

[0158] Subsequently, during the etching process, Securigan Etch Cleaner C (potassium caroate-based) is applied at 25°C for 1 minute, and then the fifth rinsing step is performed.

[0159] To analyze the efficiency of removing organic epoxy resin from the top and bottom surfaces of each dielectric substrate using samples 1, 2, and 3, a subsequent plating process was performed by immersing each substrate in an electrolytic nickel bath at 40°C for 30 minutes while applying a voltage of approximately 3ASD. Nickel was used for good visual inspection, but copper was deposited with the same result (not shown).

[0160] The nickel-coated metal surfaces or copper surfaces obtained from each substrate using samples 1 to 6 are visually analyzed and qualitatively evaluated in terms of their surface properties, particularly regarding any surface defects such as stains, spots, and the presence of exposed copper. In this regard, "-" represents a low-quality surface, "--" and "---" represent an even lower-quality surface where defects such as organic resins and / or corrosion appear on the surface, "0" represents average surface quality, "++" represents good surface quality, and "+++" represents excellent surface quality.

[0161] The results are summarized in Table 1.

[0162] [Table 1]

[0163] As can be derived from Table 1, from all three samples 1, 2, and 3, sample 1 shows a uniform nickel plating with minimal presence of any surface defects such as stains, spots, and exposed copper, leading to the conclusion that it is possible to effectively remove the organic epoxy resin from each surface of the dielectric substrate using a non-aqueous composition.

[0164] II. Comparison of Non-Aqueous Compositions vs. Aqueous Compositions of the Present Invention Objective: To remove surface epoxy resin without damaging the substrate. Three dielectric substrates were treated with respect to the deposition of epoxy-based organic matter as described above in -I. Variation in Treatment Time-. After curing, one of each dielectric substrate containing the solidified organic epoxy resin layer was chemically treated with the non-aqueous composition of the present invention (Sample 4) used in I. above, and this procedure was stopped after a rinsing step using ultrasound. To obtain the chemically treated surface of the dielectric substrate, two dielectric substrates were treated with comparative aqueous compositions (Sample 5 (acidic) and Sample 6 (alkaline)) to remove the organic epoxy resin from the substrate surface. The optical properties of the copper surface of the chemically treated substrate were determined as follows.

[0165] Sample 4 (Example of the present invention) a) 90.1% by mass of benzyl alcohol; b) 8% by mass of 2-hydroxypropionic acid; c) 1.0% by mass of at least one C10-C16 alkylbenzene sulfonic acid; and d) 1.0% by mass of 2,4,7,9-tetramethyldeca-5-in-4,7-diol

[0166] The non-aqueous composition of sample 4 is applied at 80°C for 200 seconds.

[0167] Sample 5 - Comparative Acidic Aqueous Composition 300 ml of the non-aqueous composition of sample 4 was mixed with 700 ml of water, and the pH was adjusted to 3.5.

[0168] The comparative acidic aqueous composition of Sample 5 is applied at 80°C for 200 seconds.

[0169] Sample 6 - Comparative alkaline aqueous composition 400 ml of the non-aqueous composition of Sample 1 was mixed with 600 ml of water, and the pH was adjusted to 12.

[0170] According to Sample 6, the alkaline aqueous composition is applied at 80°C for 200 seconds.

[0171] The results are summarized in Table 2.

[0172] [Table 2]

[0173] As can be derived from Table 2, the non-aqueous composition (Sample 4) makes it possible to effectively remove the organic epoxy resin from each surface of the dielectric substrate, resulting in the copper surface showing no corrosion and exhibiting a superb copper-like surface color.

[0174] In contrast, the acidic aqueous comparative composition of sample 5 was mainly able to remove the organic epoxy resin, but on the other hand, it strongly attacked the copper surface, showing many areas of corrosion.

[0175] Even worse were the results for sample 6. In this case, the alkaline aqueous comparative composition for sample 6 was insufficiently able to remove the organic epoxy resin. Larger portions of the organic epoxy resin remained visible on the surface. Furthermore, the alkaline aqueous comparative also strongly attacked the untreated copper surface, showing numerous corrosion spots, especially around the through-holes.

Claims

1. A method for removing organic resin from a copper surface on a dielectric substrate containing conductive through-holes (THs) and / or conductive blind microvias (BMVs), comprising the following steps: (i) A step of applying the organic paste to the dielectric substrate in order to fill the through-holes (TH) and / or blind microvias (BMV) with the organic paste, wherein after step (i), at least a portion of the surface of the dielectric substrate is covered with the organic paste. (ii) A step of curing the organic paste to transform it into a solidified organic resin, wherein after step (ii), at least a portion of the surface of the dielectric substrate is coated with the organic resin. (iii) A step of chemically treating the dielectric substrate with a non-aqueous composition to remove the organic resin from the surface of the substrate in order to obtain a chemically treated surface of the substrate, wherein the non-aqueous composition is a) A solution of the general chemical formula R-OH (wherein R is C) at a concentration of 80% to 95% by mass, preferably 81 wt.% to 91 wt.%. 4 ~C 30 At least one high-boiling point solvent having a boiling point of at least 100°C, selected from the group consisting of alcohols having a hydrocarbon group. b) At least one carboxylic acid, preferably at least one hydroxycarboxylic acid, in a concentration of 5% by mass or more and less than 20% by mass, preferably 4% to 9% by mass, more preferably 7% to 8% by mass, c) At least one anionic aromatic surfactant selected from the group consisting of at least one C10-C16 alkylbenzene sulfonic acid and toluene sulfonic acid, in a concentration of 0.25% by mass or more and less than 1.5% by mass, preferably in a concentration of 0.5% by mass to 1% by mass, d) At least one nonionic acetylenediol-based surfactant, preferably selected from the group consisting of at least one C8-C12 alkyne diol, and more preferably 2,4,7,9-tetramethyldeca-5-in-4,7-diol, with a concentration of 0.25% by mass or more and less than 1.5% by mass, preferably 0.5% by mass to 1% by mass. Processes including, (iv-1) A step of mechanically treating the chemically treated surface of the substrate obtained after step (iii) with an abrasive to remove any remaining organic resin from the chemically treated surface of the substrate in order to obtain a mechanically treated surface of the substrate; and / or (iv-2) A step of wet chemically treating the chemically treated surface of the substrate obtained after step (iii) with an oxidizing solution containing an oxidizing agent, to remove the remaining organic resin from the chemically treated surface of the substrate, to obtain a wet chemically treated surface of the substrate, (v) In some cases, a step of depositing a conductive material, preferably electrolytically ejecting a coated metal, on the mechanically treated surface obtained after step (iv-1) or on the wet chemically treated surface of the substrate obtained after step (iv-2) to obtain a conductive surface of the substrate, (vi) In some cases, in order to obtain an electrolytic metal coating surface, a step of further electrolysis of the coating metal on the conductive surface of the substrate obtained after step (v), or on the mechanically treated surface of the substrate obtained after step (iv-1), or on the pre-wet chemically treated surface of the substrate after step (iv-2), (vii) In some cases, in order to obtain a VIPPO (Via-in-Pad Plating Over) structure, the step of structuring the electrolytic deposition of the electrolytic metal coating surface and solder pad, preferably tin solder pad, in step (vi) and Methods that include...

2. The method according to claim 1, wherein step (iii) and / or step (iv-2) are performed in the presence of ultrasound provided by an ultrasonic emitter.

3. The method according to claim 1 or 2, wherein step (iv-1) includes bringing the chemically treated surface of the substrate into contact with a rotating brush, the rotating brush preferably comprising a nylon filament having a ceramic element.

4. The method according to any one of claims 1 to 3, wherein step (iii) is performed at a temperature of 60°C to 90°C, preferably for a period of 1 to 15 minutes.

5. The method according to any one of claims 1 to 4, wherein step (iv-1) is performed at room temperature, preferably for 15 seconds to 5 minutes.

6. The method according to any one of claims 1 to 5, wherein step (iv-1) is performed on the wet surface of the substrate.

7. The method according to any one of claims 1 to 6, wherein step (iv-2) is carried out at a temperature of 55°C to 90°C, preferably 65°C to 85°C.

8. The method according to any one of claims 1 to 7, wherein step (iv-2) is performed for a period of 2 to 20 minutes, preferably 12 minutes.

9. The method according to any one of claims 1 to 8, wherein the oxidizing agent used during step (iv-2) comprises potassium permanganate.

10. The method according to any one of claims 1 to 9, wherein the oxidizing agent used during step (iv-2) is present in the oxidizing solution in an amount of 35 g / l to 70 g / l relative to the total volume of the solution.

11. Step (iv-2) may include at least two sub-steps (de) after the rinsing step, (de-2) An etching step using the oxidizing solution and (de-3) a reduction step are applied. The method according to any one of claims 1 to 10.

12. The method according to claim 11, wherein the sub-step (de) includes an expansion step (de-1) performed before the etching step (de-2).

13. An article obtained by the method described in any one of claims 1 to 12.

14. The use of a non-aqueous composition for removing organic resin from the surface of a dielectric substrate including a copper surface and conductive through-holes (TH) and / or conductive blind microvias (BMV) in order to manufacture an article including a VIPPO (Via-in-Pad Plating Over) structure, wherein the non-aqueous composition is a) A solution of the general chemical formula R-OH (wherein R is C) at a concentration of 80% to 95% by mass, preferably 81 wt.% to 91 wt.%. 4 ~C 30 At least one high-boiling point solvent having a boiling point of at least 100°C, selected from the group consisting of alcohols having a hydrocarbon group; b) At least one carboxylic acid, preferably at least one hydroxycarboxylic acid, in a concentration of 5% by mass or more and less than 20% by mass, preferably 4% by mass to 9% by mass, more preferably 7% by mass to 8% by mass; c) At least one anionic aromatic surfactant selected from the group consisting of at least one C10-C16 alkylbenzene sulfonic acid and toluene sulfonic acid, preferably in a concentration of 0.25% by mass or more and less than 1.5% by mass, preferably in a concentration of 0.5% by mass to 1% by mass; and d) At least one nonionic acetylenediol-based surfactant, preferably selected from the group consisting of at least one C8-C12 alkyne diol, and more preferably 2,4,7,9-tetramethyldeca-5-in-4,7-diol, with a concentration of 0.25% by mass or more and less than 1.5% by mass, preferably 0.5% by mass to 1% by mass. Includes, use.

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