Curable compositions and insulating films

Abstract

The present invention provides a curable composition and an insulating film. [Solution] This disclosure provides a curable composition comprising (A) a copolymer having at least one reactive group, (B) a crosslinking agent, (C) a polymerization initiator, and (D) boron nitride. This disclosure also provides an insulating film comprising the aforementioned curable composition, which is particularly suitable for manufacturing printed circuit boards (PCBs). The insulating film exhibits excellent electrical properties, including a low dielectric loss tangent (Df) and a low coefficient of thermal expansion (CTE). Furthermore, the insulating film offers significant advantages in reducing production time in PCB manufacturing processes involving plasma etching steps.

Description

[Technical Field]

[0001] This disclosure relates, in general, to curable compositions containing boron nitride, and more particularly to insulating films and / or printed circuit boards containing the same. [Background technology]

[0002] Due to the current trend towards thinner and lighter electronic products, printed circuit boards (PCBs) need to have higher wiring density. A PCB typically consists of multiple insulating and conductive layers stacked on top of each other. To achieve high wiring density, through-holes or blind holes are provided to connect circuits between different conductive layers.

[0003] Conventional via fabrication techniques use laser light as a drilling tool. The friction generated by drilling creates a resin smear on the channel wall. This smear needs to be removed to enable optimal connection. Typically, a wet process is used after laser drilling to remove the smear and form a suitable through-hole. This wet process includes surface cleaning, smear swelling, permanganate desmearing, and neutralization reactions. However, the wastewater and effluent discharged at each step can carry large amounts of hazardous substances, degrading the environment and potentially harming human physical and mental health.

[0004] Compared to subtractive or (modified) semi-additive processes in PCB manufacturing, plasma etching for pattern and / or via formation is considered a more environmentally friendly process because it does not involve wet processes. However, the etching rate of plasma etching is typically too slow to be cost-effective for manufacturing PCBs. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] From the above perspective, there is a need to develop new materials for PCB insulating layers, and the ability to process them using plasma etching processes will bring overall benefits to the printed circuit board industry. [Means for solving the problem]

[0006] To address the aforementioned problems, this disclosure provides a novel resin composition for insulating layers of PCBs. PCBs constructed from this material have higher plasma etching rates without sacrificing their electrical and mechanical properties, such as dielectric loss tangent (DF) and coefficient of thermal expansion (CTE). The novel resin composition is a viable alternative to conventional PCB insulating layers.

[0007] According to one aspect of this disclosure, a curable composition is provided. The curable composition, 100 parts by weight of copolymer (A) having at least one reactive group, 250-350 parts by weight of crosslinking agent (B), 0.5 to 6 parts by weight of polymerization initiator (C), 50 to 900 parts by weight of boron(D) nitride having a median particle size of 10 μm or less and Includes.

[0008] According to a second aspect of the present disclosure, an insulating film comprising the curable composition described above is also provided. The insulating film comprises, in order, a support film, a resin layer composed of the curable composition described above, and a protective film. The resin layer has a thickness of 10 μm to 60 μm.

[0009] A printed circuit board is also provided according to a third aspect of the present disclosure. The PCB is a cured product of the curable composition described above, or comprises an insulating layer made from the insulating film described above. [Brief explanation of the drawing]

[0010] [Figure 1] A cross-sectional view of a test coupon according to one embodiment of the present disclosure is shown. [Modes for carrying out the invention]

[0011] Before we delve into the details of the embodiments described below, some terms will be defined or clarified.

[0012] definition All publications, patent applications, patents, and other references mentioned herein are expressly incorporated herein by reference in their entirety for all purposes, as if they were fully specified unless otherwise noted.

[0013] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in which this invention pertains. In case of any conflict, this specification, including its definitions, shall prevail.

[0014] Unless otherwise specified, all percentages, parts, ratios, etc., are based on weight.

[0015] As used herein, the term “produced from” is synonymous with “contains.” As used herein, the terms “contains,” “includes,” “encompasses,” “incorporates,” “has,” “has,” “contains,” or “contains,” or any other variation thereof, are intended to encompass non-exclusive inclusion. For example, a composition, process, method, article, or apparatus containing a list of elements may not necessarily be limited to those elements alone, and may include other elements that are not explicitly listed or that are inherent to such composition, process, method, article, or apparatus.

[0016] The transitional phrase "consisting of" excludes any elements, processes, or raw materials that are not explicitly stated. In the case of a claim, such phrase would limit the inclusion of materials other than those enumerated in the claim, except for impurities that are ordinarily associated with them. If the phrase "consisting of" appears in a clause of the body of the claim rather than immediately following the preamble, it limits only the elements explicitly stated in that clause, and other elements are not excluded from the claim as a whole.

[0017] The transitional phrase "consisting essentially of" is used to define a material, step, feature, component, or composition, method, or apparatus that includes elements, but only if these additional materials, steps, features, components, or elements do not materially affect the basic and novel characteristics of the claimed disclosure.

[0018] The term "consisting essentially of" occupies an intermediate area between "comprising" and "consisting of".

[0019] The term "comprising" is intended to include embodiments subsumed by the terms "consisting essentially of" and "consisting of". Similarly, the term "consisting essentially of" is intended to include embodiments subsumed by the term "consisting of".

[0020] If a quantity, concentration, or other value or parameter is given as a range, a list of preferred ranges, or a list of upper and lower preferred values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, whether or not the ranges are separately disclosed. For example, if a range "1-5" is recited, the recited range should be interpreted as including ranges "1-4", "1-3", "1-2", "1-2 and 4-5", "1-3 and 5", etc. When a numerical range is recited herein, unless otherwise specified, that range is intended to include its endpoints as well as all integers and fractions within that range.

[0021] Furthermore, unless explicitly stated to the contrary, "or" refers to an inclusive "or" and not an exclusive "or". For example, the condition A "or" B is satisfied by any one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0022] The present disclosure is described in detail below in this specification.

[0023] The present disclosure relates to a curable composition comprising 100 parts by weight of a copolymer (A) having at least one reactive group, 250 to 350 parts by weight of a crosslinking agent (B), 0.5 to 6 parts by weight of a polymerization initiator (C), and 50 to 900 parts by weight of boron nitride (D) having a median particle size of 10 μm or less. The present disclosure relates to a curable composition containing the above.

[0024] In one embodiment of the present disclosure, the copolymer (A) is derived from a composition containing 2~8 an olefin (a-1), 6~20 an aromatic vinyl compound (a-2) and 10~20 an aromatic polyene (a-3). The copolymer (A) may be derived from a composition consisting essentially of 2~8 an olefin (a-1), 6~20 an aromatic vinyl compound (a-2) and 10~20 an aromatic polyene (a-3). Alternatively, the copolymer (A) may be derived from a composition consisting of 2~8 an olefin (a-1), 6~20 an aromatic vinyl compound (a-2) and 10~20 an aromatic polyene (a-3).

[0025] More specifically, the copolymer (A) contains, consists essentially of, or consists of 10 to 70% by weight of 2~8 an olefin (a-1), 10 to 60% by weight of 6~20 an aromatic vinyl compound (a-2) and 1 to 30% by weight of 10~20 an aromatic polyene (a-3), based on the total weight of the copolymer being 100% by weight.

[0026] In the present disclosure, the olefin refers to an unsaturated hydrocarbon having at least one double bond. In one embodiment of the present disclosure, 2~8Olefin (a-1) may be ethylene, propylene, 1-butylene, 2-butylene, isobutylene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, 1-hexene, 2-hexene, 3-hexene, butadiene, isoprene, or a combination thereof.

[0027] In this disclosure, aromatic vinyl compounds refer to aromatic compounds having one vinyl group. In one embodiment of this disclosure, C 6~20 Aromatic vinyl compounds (a-2) may be styrene, methylstyrene, methoxystyrene, monochlorostyrene, dichlorostyrene, trichlorostyrene, monobromostyrene, dibromostyrene, tribromostyrene, iodostyrene, diiodostyrene, triiodostyrene, vinylphenol, 2-methoxy-4-vinylphenol, vinylnaphthalene, vinylanthracene, N-vinylcarbazole, vinylfuran, vinylpyridine, or combinations thereof.

[0028] In this disclosure, aromatic polyene refers to an aromatic compound having at least two alkene groups. In one embodiment of this disclosure, C 10~20 Aromatic polyene (a-3) may be divinylbenzene, divinylnaphthalene, divinylanthracene, propenylstyrene, butenylstyrene, 1,2-bis(vinylphenyl)ethane, or a combination thereof.

[0029] In one embodiment of the present disclosure, copolymer (A) may be a copolymer of ethylene, styrene, and divinylbenzene.

[0030] In one embodiment of the present disclosure, copolymer (A) has a number-average molecular weight (Mn) of 15,000 to 100,000, particularly 20,000 to 100,000, more specifically 30,000 to 100,000, and even more specifically 35,000 to 80,000. In addition, copolymer (A) may have 1 to 10 reactive groups per Mn.

[0031] The crosslinking agent (B) can induce a crosslinking reaction of copolymer (A). In one embodiment of the present disclosure, the crosslinking agent (B) has at least one functional group selected from the group consisting of maleimide groups, aromatic vinyl groups, aliphatic vinyl groups, alicyclic vinyl groups, acrylate groups, (meth)acrylate groups, and combinations thereof. The term "(meth)acrylate" includes both acrylate and methacrylate.

[0032] In one particular embodiment of the present disclosure, the functional group is a maleimide group, and the crosslinking agent (B) includes 4,4'-diphenylmethanebismaleimide, m-phenylenebismaleimide, 2,2'-bis[4-(4-maleimidophenoxy)phenyl]propane, 3,3'-diethyl-5,5'-dimethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, or a combination thereof.

[0033] In another specific embodiment of the present disclosure, the crosslinking agent (B) is divinylbenzene, and the functional group is an aromatic vinyl group.

[0034] In another specific embodiment of the present disclosure, the crosslinking agent (B) is a polyether, and the functional group is an aromatic vinyl group.

[0035] In another specific embodiment of the present disclosure, the crosslinking agent (B) is an oligo(phenylene ether) and the functional group is an aromatic vinyl group. The oligo(phenylene ether) may be terminated with a (meth)acrylate group, an acrylate group, a vinylbenzyl group, a vinylbenzoate group, or a combination thereof.

[0036] In another specific embodiment of the present disclosure, the crosslinking agent (B) is an oligo(phenylene ether) terminated with a (meth)acrylate group, and the functional group is a (meth)acrylate group.

[0037] A polymerization initiator (C) can initiate the polymerization of the copolymer (A) and / or the crosslinking agent (B). Non-limiting examples of polymerization initiators (C) include 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,3-dimethyl-2,3-diphenylbutane, 1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, benzoyl peroxides, lauroyl peroxides, di-t-butyl peroxides, di-(2-t-butylperoxyisopropyl)benzene, dicumyl peroxides, t-butylperoxybenzoate, t-butylperoxypivalate, methyl ethyl ketone peroxides, cyclohexanone peroxides, diisopropylperoxydicarbonate, dicyclohexylperoxycarbonate, and combinations thereof.

[0038] The curable compositions of this disclosure utilize boron(D) nitride as a filler. The boron nitride initiator has a median particle size of 10 μm or less. Surprisingly, it has been found that boron(D) nitride can be particularly important for achieving higher plasma etching rates compared to silica. Therefore, in one embodiment of this disclosure, the curable composition does not contain silica.

[0039] The amount of boron nitride (D) may be 50 to 900 parts by weight, particularly 150 to 850 parts by weight, and more specifically 250 to 800 parts by weight, based on 100 parts by weight of copolymer (A).

[0040] In one embodiment of the present disclosure, the curable composition further comprises an additive (E). Non-limiting examples of additives include adhesion promoters, antioxidants, colorants, defoamers, flame retardants, polymerization inhibitors, thickeners, solvents, and combinations thereof.

[0041] In one embodiment of the present disclosure, additive (E) is a flame retardant selected from the group consisting of brominated flame retardants, phosphorus flame retardants, nitrogen flame retardants, and combinations thereof.

[0042] In one particular embodiment of the present disclosure, additive (E) is a brominated flame retardant. Non-limiting examples of brominated flame retardants include decabromodiphenyl ether, decabromodiphenylethane, brominated styrene, and tetrabromophthalamide.

[0043] In other specific embodiments of the present disclosure, additive (E) is a phosphorus flame retardant. Non-limiting examples of phosphorus flame retardants include inorganic phosphorus, phosphate compounds, phosphorus compounds, hypophosphorous compounds, phosphorus oxidized compounds, phosphazenes, and modified phosphazenes. More specifically, the phosphorus flame retardant may be 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ), or tris(2,6-dimethylphenyl)phosphorus.

[0044] In other specific embodiments of the present disclosure, additive (E) is a nitrogen flame retardant. Non-limiting examples of nitrogen flame retardants include triazine compounds, cyanuric acid compounds, isocyanate compounds, and phenothiazines.

[0045] In one embodiment of the present disclosure, additive (E) is a solvent comprising cyclohexanone, cyclopentanone, isophorone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, naphtha solvents with a boiling point of 100°C to 200°C, or a combination thereof.

[0046] A second aspect of this disclosure relates to an insulating film for manufacturing printed circuit boards. The insulating film is Support membrane and, A resin layer composed of the above-mentioned curable composition, protective film and It includes them in order.

[0047] In one embodiment of the present disclosure, the resin layer has a thickness of 10 μm to 60 μm. In one embodiment of the present disclosure, the support film is a thermoplastic film having a thickness of 10 μm to 50 μm or a metal foil having a thickness of 1 μm to 25 μm. In one embodiment of the present disclosure, the protective film is a thermoplastic film having a thickness of 10 μm to 50 μm.

[0048] In one embodiment of the present disclosure, the support film and the protective film are each independently composed of a polymer material selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polyimide.

[0049] In one embodiment of the present disclosure, the support film is a metal foil selected from the group consisting of Au, Ag, Cu, Al and its alloys.

[0050] In one embodiment of the present disclosure, the resin layer is cured at 100°C to 250°C for 60 to 240 minutes.

[0051] In one embodiment of the present disclosure, the cured resin layer has a dielectric loss tangent (Df) of 0.003 or less when measured at 10 GHz and 23°C.

[0052] In one embodiment of the present disclosure, the cured resin layer has a coefficient of thermal expansion (CTE) of 70 ppm / K or less at 30°C to 120°C.

[0053] In one embodiment of the present disclosure, the cured resin layer has a plasma etching rate of 0.4 μm / min or more, particularly 0.4 to 7.5 μm / min. Plasma etching is performed under a chamber pressure of 2 Pa (15 milliliters) by applying a radio frequency (RF) power of 13.56 MHz, an ignition power of 8000 watts, and a DC bias setting of 5000 watts, using a gas mixture of oxygen, tetrafluoromethane (carbon tetrafluoride, CF4), and nitrogen in a ratio of 2:2:1 and a flow rate of 1250 mL / s for 30 minutes.

[0054] A third aspect of this disclosure relates to a printed circuit board comprising a cured product of the above-mentioned curable composition or an insulating layer made from the above-mentioned insulating film.

[0055] In one embodiment of the present disclosure, the circuit is fabricated by a method that includes a plasma etching step for via and / or trench formation.

[0056] In one embodiment of the present disclosure, the method for forming the circuit is a semi-additive process (SAP) or a modified semi-additive process (mSAP).

[0057] Composition and film preparation The curable compositions of this disclosure comprise the following components: (A) a copolymer having at least one reactive group, (B) a crosslinking agent, (C) a polymerization initiator, (D) boron nitride, and optionally (E) an additive. In one non-limiting embodiment, embodiments of the compositions of this disclosure may be prepared from the components listed in Table A below. Components (A) to (C) and (E) were mixed until fully dissolved to form a base. Component (D) was then added to the base and subsequently dispersed uniformly using a rotary mixer. The compositions were prepared into two different samples: a resin-coated copper (RCC) film structure and a resin sheet structure for further testing.

[0058] [Table 1]

[0059] The preparation procedures for the examples, comparative examples, and reference examples are described below, and the relative weights of each component, excluding the weight of the solvent, are shown. [Examples]

[0060] Example E1 12 g of LDM-02C (copolymer (A)), 12 g of MIR3000 (crosslinking agent (B)), 12 g of BMI70 (crosslinking agent (B)), 8 g of Elpac HC-G0024 (crosslinking agent (B)), 4 g of DVB (crosslinking agent (B)), 0.4 g of DCP (polymerization initiator (C)), 2 g of KBM403 (additive (E)), and 0.34 g of DISPERBYK-2155 (additive (E)) were mixed and stirred until thoroughly dissolved. Then, 34 g of PT132 (boron nitride (D)) was added, and the mixture was uniformly dispersed using a high-speed rotary mixer to prepare a resin varnish.

[0061] The obtained resin varnish was coated onto a support film MT18FL-3μm (a two-layer copper foil with an upper layer having a thickness of 3μm and a lower layer having a thickness of 18μm) at a coating speed of approximately 60 mm / s using a suitable quadruple-layer applicator (purchased from GMA Machinery, Taiwan) on an automated coating machine (model Coatmaster 510, purchased from Erichsen GmbH). The coated film was then dried at 100°C for 3 minutes in a circulating oven (model DCM704, purchased from Channel Instruments, Taiwan). After drying, the film was covered with 38X (protective film) to form a resin-coated copper (RCC) film structure sample.

[0062] In addition, a resin varnish was coated onto 38X (protective film) and dried at 100°C for 3 minutes. Then, the dried film was covered with MA411 (protective film) to form a resin sheet structure.

[0063] The thickness of the resin composition layer was 30 μm for the two structures described above.

[0064] Example E2 The preparation procedure for Example E1 was followed, except that the amount of PT132 (boron nitride (D)) was adjusted to 50 g and the amount of DISPERBYK-2155 (additive (E)) was adjusted to 0.5 g.

[0065] Example E3 The preparation procedure for Example E1 was followed, except that the amount of PT132 (boron nitride (D)) was adjusted to 93g and the amount of DISPERBYK-2155 (additive (E)) was adjusted to 0.93g.

[0066] Example E4 The preparation procedure for Example E2 was followed, except that the amount of Elpac HC-G0024 (crosslinking agent (B)) was adjusted to 12 g and DVB (crosslinking agent (B)) was not used.

[0067] Example E5 The preparation procedure for Example E2 was followed, except that the amount of DVB (crosslinking agent (B)) was adjusted to 12 g and Elpac HC-G0024 (crosslinking agent (B)) was not used.

[0068] Example E6 The preparation procedure for Example E2 was followed, except that Elpac HC-G0024 (crosslinking agent (B)) was replaced with 8 g of OPE2st-1200 (crosslinking agent (B)).

[0069] Comparative example CE1 The preparation procedure for Example E1 was followed, except that PT132 (boron nitride (D)) was replaced with SO-1500 (filler (D')).

[0070] Comparative Example CE2 The preparation procedure for Example E2 was followed, except that PT132 (boron nitride (D)) was replaced with SO-1500 (filler (D')).

[0071] Comparative Example CE3 The preparation procedure for Example E3 was followed, except that PT132 (boron nitride (D)) was replaced with SO-1500 (filler (D')).

[0072] Reference example RE1 The preparation procedure for Example E2 was followed, except that LDM-02C (copolymer (A)) was replaced with FG1901GT (polymer (A')).

[0073] Reference example RE1 The preparation procedure for Example E2 was followed, except that LDM-02C (copolymer (A)) was replaced with Ricon 154 (polymer (A')).

[0074] The components of the above-mentioned examples, comparative examples, and reference examples are listed in Table B. The materials are listed in Table B by their dry mass. The examples, comparative examples, and reference examples were prepared in a similar manner. The difference between the examples and comparative examples lies in the filler used: the examples use boron nitride, while the comparative examples use silica. The difference between the examples and reference examples lies in the type of copolymer / polymer.

[0075] [Table 2]

[0076] Measurement of plasma etching rate of RCC film Test coupon preparation The RCC films of the above examples, comparative examples, and reference examples were further processed as follows to prepare coupons for plasma etching tests: Lamination: A 15cm x 20cm RCC film was laminated using a vacuum laminator onto an EM526 H / H core board (15cm x 20cm, 0.6mm thick) pre-treated with CZ-8100 (a pre-treatment solution prepared by MEC). The vacuum laminator was heated to 100°C, vacuumed for 30 seconds, and then laminated at 100°C for 90 seconds at 7kgf / cm². 2 It was pressurized. Curing: The layered samples were cured in an air-flow oven at 130°C for 30 minutes, 180°C for 30 minutes, and then at 200°C for 90 minutes. Copper removal: After curing, the support film MT18FL (carrier copper of the RCC film) was removed. Tenting: A hard mask window (40 μm / 40 μm line / space pattern) was formed on the surface of the cured sample (without carrier). The sample was then cut into 5 cm x 5 cm pieces to serve as test coupons.

[0077] The structure of the test coupon is shown in Figure 1. The test coupon comprises a core layer EM526 (11) and its coating copper (12), a dielectric layer 20 (curable composition of this disclosure), and a metal hard mask 30. The following plasma treatment etches the dielectric layer 20 through a window in the hard mask 30.

[0078] Plasma etching and measurement Coupons for the examples, comparative examples, and reference examples were subjected to plasma treatment, and the etching depth was measured using a 3D optical microscope (Olympus Lext OLS5100, 50× objective lens). The etching depth was calculated by subtracting the thickness of the hard mask from the depth from the surface. The etching rate was calculated by dividing the etching depth by the treatment time. The test results for each coupon are listed in Table C.

[0079] [Table 3]

[0080] As shown in Table C, the plasma etching rates of Examples E1-E6 of this disclosure are higher than 0.4 μm / min. In contrast, Comparative Examples CE1-CE3 have relatively low plasma etching rates and may not be suitable for industrial applications. This indicates that boron nitride may be important for achieving higher plasma etching rates, particularly compared to silica.

[0081] Measurement of Df and CTE of resin sheets Sample preparation The resin sheets from the Examples, Comparative Examples, and Reference Examples were further processed as follows to prepare samples for measuring DF and CTE: Lamination: Multiple resin sheets measuring 10cm x 10cm were laminated together, and a single dielectric layer with a thickness of 60μm was formed using a vacuum laminator. The vacuum laminator was heated to 100°C, vacuumed for 30 seconds, and then laminated at 100°C for 90 seconds at 7kgf / cm². 2 It was pressurized. Curing: The layered samples were cured in an air-flow oven at 130°C for 30 minutes, 180°C for 30 minutes, and then at 200°C for 90 minutes. PET film removal: After curing, the protective layer 38X (PET film) was removed.

[0082] The dielectric loss tangent (Df) of the dielectric / insulating layer was measured by the resonant cavity method at a frequency of 10 GHz. The coefficient of thermal expansion (CTE) was measured using a TA Instruments TMA 650 thermomechanical analyzer. Samples were heated to 280°C, cooled to room temperature, and then reheated at a rate of 5°C / min with a preload of 0.098 N. The CTE was calculated from the gradient of dimensional change with respect to temperature from 50°C to 100°C during the second heating cycle. The test results for each sample are listed in Table D.

[0083] [Table 4]

[0084] As shown in Table D, the insulating films of Examples E1-E6 having the curable composition exhibit excellent electrical properties, including a low dielectric loss tangent (Df) and a low coefficient of thermal expansion (CTE). In contrast, the insulating films of Comparative Examples CE1-CE3 are undesirable because they exhibit a higher dielectric loss tangent (Df) in addition to the lower plasma etching rates discussed above. As for the Reference Examples, they have comparable plasma etching rates, as shown in Table C, but this is achieved at the expense of a relatively high coefficient of thermal expansion (CTE) of >75. The comparison between the Examples and Reference Examples shows that, without copolymer (A) of the Disclosure, an insufficient coefficient of thermal expansion (CTE) may be exhibited despite an acceptable plasma etching rate.

[0085] Furthermore, the insulating film of this disclosure offers significant advantages in reducing production time in PCB manufacturing processes involving plasma etching.

[0086] The curable compositions of this disclosure are particularly suitable for manufacturing printed circuit boards (PCBs).

[0087] Fabrication of PCBs using curable compositions Step 1: Preparation of a substrate with an existing electrical circuit. A PCB board with an existing electrical circuit was fabricated using EM526 (a core board supplied by Elite Electronic Material Co. Ltd., with a thickness of 64 μm and a copper thickness of 22 μm).

[0088] Step 2: Laminating RCC coupons onto the substrate The RCC coupon from Example 1 was laminated onto a substrate using a laminator (Vigor, VLPH-150 ton vacuum laminator). After lamination, the lower layer of the support film was removed, and the structure from top to bottom consisted of copper, resin, and substrate.

[0089] Step 3: Metal patterning to form a hard mask A photoresist layer was formed by laminating a dry film (Riston® DI61, 15 μm thick, manufactured by DuPont Electronics, Inc.) onto the copper layer of the substrate from step 2 using a roll laminator at 100°C, a pressure of 1.4 MPa, and a rolling speed of 1.0 m / min.

[0090] A photoresist pattern was formed using a direct exposure patterning machine (FDi3, ORC) with the desired pattern. Uncured portions of the photoresist layer were peeled and removed by treating with a 2% Na2CO3 solution for 3 minutes, then rinsed with DI water and dried.

[0091] The unmasked copper areas were etched in a conventional horizontal line at a rate of 1 m / min using a sodium persulfate (Na2S2O8) solution (130 g / L) until completion, followed by rinsing with DI water and drying. The photoresist pattern was then stripped and removed by treatment with a 10% NaOH solution for 90 seconds, followed by rinsing and drying to form a copper hard mask on the substrate.

[0092] Step 4: Plasma etching of the dielectric layer The exposed dielectric layer was removed by plasma etching using a reactive ion etching plasma system (Linco Tech). The process gas was a mixture of CF4 (500 ml / sec), O2 (500 ml / sec), and N2 (250 ml / sec) for 30 minutes with an ignition power of 8 kW and a DC bias of 5 kW to expose a portion of the underlying conductor.

[0093] Step 5: Formation of the seed layer A seed layer was formed by sputtering copper using a PVD coating machine (UVAT Technology Co., model: UHSD-060302T) with a standard concentration of 4N copper. The resulting copper layer had a thickness of 0.8 μm.

[0094] Step 6: Addition of photoresist pattern layer A photoresist layer was formed on a copper layer by laminating a dry film (Riston® DI61, 25 μm thick, manufactured by DuPont Electronics, Inc.) using a roll laminator at 100°C, a pressure of 1.4 MPa, and a rolling speed of 1.0 m / min.

[0095] Photoresist patterns were generated using a direct exposure patterning machine (ORC FDi3) with conventional test patterns from PCB manufacturers, including line / space sets at 15 μm / 15 μm. Uncured portions of the photoresist layer were peeled and removed by treating with a 2% Na2CO3 solution for 3 minutes, rinsed with DI water, and dried.

[0096] Step 7: Filling trenches and vias by metal deposition The trenches and vias were filled with copper by electroplating. The coupons were plated to a copper thickness of 22 μm using a plating solution (DuPont SFP2M) for 40 minutes at 23.13 ASF (amplitude per square foot).

[0097] Step 8: Removal of photoresist The photoresist pattern was removed by treatment with a 10% NaOH solution for 90 seconds.

[0098] Step 9: Removal of the hard mask layer Flash etching to remove the hard mask layer Immerse the coupon in a 5 vol% sulfuric acid solution for 20 seconds. Transfer the coupon to the etchant solution (ST121-M from Chemtronic Technology) for 48 seconds. Rinse with DI water to remove any remaining solution. It was done by [the person / organization].

[0099] After the flash etching process, a new circuit layer containing vias and conductor wires was completed.

[0100] It will be apparent to those skilled in the art that various modifications and variations of the disclosed embodiments are possible. This specification and the examples are illustrative only, and the true scope of this disclosure is intended to be indicated by the following claims and their equivalents. [Explanation of symbols]

[0101] 11 Core Layers 12 Coated copper 20 Dielectric layer 30 Metal Hard Masks

Claims

1. A curable composition, 100 parts by weight of copolymer (A) having at least one reactive group, and 250 to 350 parts by weight of crosslinking agent (B), 0.5 to 6 parts by weight of polymerization initiator (C), 50 to 900 parts by weight of boron nitride (D) having a median particle size of 10 μm or less and A curable composition containing the following:

2. The copolymer (A) is C 2~8 Olefin (a-1), C 6~20 Aromatic vinyl compound (a-2) and C 10~20 The curable composition according to claim 1, derived from a composition comprising aromatic polyene (a-3).

3. The copolymer (A) is composed of 10 to 70% by weight of the copolymer C, based on the total weight of the copolymer which is 100% by weight. 2~8 Olefin (a-1), 10 to 60% by weight of the above C 6~20 Aromatic vinyl compound (a-2) and 1 to 30% by weight of the C 10~20 The curable composition according to claim 2, derived from a composition comprising aromatic polyene (a-3).

4. The curable composition according to claim 1, wherein the copolymer (A) has a number average molecular weight (Mn) of 15,000 to 100,000 and a number of reactive groups per Mn of 1 to 10.

5. The curable composition according to claim 1, wherein the crosslinking agent (B) has at least one functional group selected from the group consisting of a maleimide group, an aromatic vinyl group, an aliphatic vinyl group, an alicyclic vinyl group, an acrylate group, a (meth)acrylate group, and combinations thereof.

6. The curable composition according to claim 1, wherein the polymerization initiator (C) is selected from 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,3-dimethyl-2,3-diphenylbutane, 1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, di-(2-t-butylperoxyisopropyl)benzene, dicumyl peroxide, t-butylperoxybenzoate, t-butylperoxypivalate, methyl ethyl ketone peroxide, cyclohexanone peroxide, diisopropyl peroxydicarbonate, dicyclohexyl peroxycarbonate, and combinations thereof.

7. The curable composition according to claim 1, further comprising an additive (E), wherein the additive (E) is selected from the group consisting of adhesion promoters, antioxidants, colorants, defoamers, flame retardants, polymerization inhibitors, thickeners, solvents, and combinations thereof.

8. The curable composition according to claim 7, wherein the additive (E) is a solvent comprising cyclohexanone, cyclopentanone, isophorone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, a naphtha solvent with a boiling point of 100°C to 200°C, or a combination thereof.

9. An insulating film for fabricating printed circuit boards, Support membrane and, A resin layer comprising the curable composition described in claim 1, protective film and The insulating film comprises the following in order, and the resin layer having a thickness of 10 μm to 60 μm.

10. The insulating film according to claim 9, wherein the support film and the protective film are each independently composed of a polymer material selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polyimide.

11. The insulating film according to claim 9, wherein the support film is a metal foil selected from the group consisting of Au, Ag, Cu, Al and their alloys.

12. The insulating film according to claim 9, wherein the cured resin layer has a dielectric loss tangent (Df) of 0.003 or less when measured at 10 GHz and 23°C, and the curing is performed at 100°C to 250°C for 60 to 240 minutes.

13. The insulating film according to claim 9, wherein the cured resin layer has a coefficient of thermal expansion (CTE) of 70 ppm / K or less at 30°C to 120°C, and the curing is performed at 100°C to 250°C for 60 to 240 minutes.

14. The cured resin layer has a plasma etching rate of 0.4 μm / min or more, and the plasma etching is performed using oxygen, tetrafluoromethane (carbon tetrafluoride, CF4). 4 The insulating film according to claim 9, wherein the curing is carried out under a chamber pressure of 2 Pa (15 milliliters) by applying a 13.56 MHz radio frequency (RF) power, an 8000 watt ignition power, and a 5000 watt DC bias at a flow rate of 1250 mL / second for 30 minutes using a gas mixture of ) and nitrogen in a 2:2:1 ratio, and the curing is carried out at 100°C to 250°C for 60 to 240 minutes.

15. A printed circuit board comprising an insulating layer which is a cured product of the curable composition described in claim 1.

16. The printed circuit board according to claim 15, wherein the circuit is fabricated by a method including a plasma etching step for via and / or trench formation.

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