RF filters for use with 5G frequencies

Abstract

An RF filter is provided that includes a resonant element and a polymer composition. The polymer composition contains an aromatic polymer and has a melting temperature of about 240° C. or higher. The polymer composition exhibits a dielectric constant of about 5 or less and a dissipation factor of about 0.05 or less at a frequency of 10 GHz.

Description

[Technical Field]

[0001] Cross-reference of related questions

[0001] This application claims the benefit of filing U.S. Provisional Patent Application No. 62 / 904,109, filed September 23, 2019; U.S. Provisional Patent Application No. 63 / 009,007, filed April 13, 2020; and U.S. Provisional Patent Application No. 63 / 024,574, filed May 14, 2020, which are incorporated herein by reference in their entirety. [Background technology]

[0002]

[0002] Radio frequency ("RF") interference is a significant problem for any wireless communication platform. To address this problem, RF filters (e.g., acoustic filters, cavity filters, etc.) are frequently used to filter out up to 15 bands of 2G, 3G, and 4G radio access methods, as well as Wi-Fi, Bluetooth transmission and reception paths, and GPS receiver reception paths. However, with the transition to 5G applications, such filters are exposed to high frequencies, which can increase power consumption and heat generation. As a result, most conventional RF filters are insufficient for 5G applications due to high-frequency performance requirements. Therefore, there is a need for improved RF filters for use in 5G antenna systems. [Overview of the Initiative] [Means for solving the problem]

[0003]

[0003] According to one embodiment of the present invention, an RF filter comprising a resonator element and a polymer composition is disclosed. The polymer composition contains an aromatic polymer and has a melting temperature of about 240°C or higher. The polymer composition exhibits a relative permittivity of about 5 or less and a dielectric loss tangent of about 0.05 or less at a frequency of 10 GHz.

[0004]

[0004] Other features and aspects of the present invention are described in more detail below.

[0005] A complete and implementable disclosure of the present invention, including its best mode for those skilled in the art, is described in more detail in the remainder of this specification, including references to the accompanying drawings. [Brief explanation of the drawing]

[0005] [Figure 1]

[0006] This is a diagram of one embodiment of a 5G antenna system that can be used in the present invention. [Figure 2A]

[0007] This is a top-down view of an exemplary user computing device including a 5G antenna. [Figure 2B]

[0008] Figure 2A is a side view of an exemplary user computing device. [Figure 3]

[0009] Figure 2A is a magnified view of a portion of the user computing device. [Figure 4]

[0010] This is a side view of a coplanar waveguide antenna array configuration that can be used in a 5G antenna system. [Figure 5A]

[0011] This is a diagram of an antenna array for a large-scale, multi-input, multi-output configuration of a 5G antenna system. [Figure 5B]

[0012] This is a diagram of a formed antenna array that can be used in a 5G antenna system. [Figure 5C]

[0013] This is a diagram illustrating an example antenna configuration that can be used in a 5G antenna system. [Figure 6]

[0014] This is a schematic diagram of one embodiment of an RF SAW filter usable in the present invention. [Figure 7]

[0015] This is a schematic diagram of one embodiment of the RF BAW filter used in the present invention. [Figure 8]

[0016] This is a schematic diagram of another embodiment of the RF SAW filter available in the present invention. [Figure 9]

[0017] It is a schematic diagram of an embodiment of an RF cavity filter that can be used in the present invention.

Embodiments for Carrying Out the Invention

[0006]

[0018] It is understood by those skilled in the art that this consideration is merely an explanation of exemplary embodiments and does not limit broader aspects of the present invention.

[0019] In general, the present invention relates to radio frequency ("RF") filters for use in 5G applications, such as acoustic filters or cavity filters. RF filters typically include one or more resonant elements (e.g., piezoelectric materials, dielectric materials, etc.) capable of producing resonant behavior in a narrow frequency band of desired 5G frequencies, such as about 2.5 GHz or higher, about 3.0 GHz or higher in some embodiments, about 3 GHz to about 300 GHz or higher in some embodiments, about 4 GHz to about 80 GHz in some embodiments, about 5 GHz to about 80 GHz in some embodiments, about 20 GHz to about 80 GHz in some embodiments, and about 28 GHz to about 60 GHz in some embodiments. In particular, according to the present invention, polymer compositions that exhibit low relative permittivity and dielectric loss tangent over a wide frequency range and are particularly suitable for use in 5G applications are used for RF filters (e.g., substrates, housings, etc.). In other words, the polymer composition may exhibit a low relative permittivity of about 5 or less at a typical 5G frequency (e.g., 2 or 10 GHz), about 4.5 or less in some embodiments, about 0.1 to about 4.4 in some embodiments, about 1 to about 4.2 in some embodiments, about 1.5 to about 4 in some embodiments, about 2 to about 3.9 in some embodiments, and about 3.5 to about 3.9 in some embodiments. The dielectric loss tangent of the polymer composition, which is a measure of the energy loss rate, may similarly be about 0.05 or less at a typical 5G frequency (e.g., 2 or 10 GHz), about 0.01 or less in some embodiments, about 0.0001 to about 0.008 in some embodiments, and about 0.0002 to about 0.006 in some embodiments. In fact, in some cases, the dielectric loss tangent may be very low, for example, about 0.003 or less at a typical 5G frequency (e.g., 2 or 10 GHz), about 0.002 or less in some embodiments, about 0.001 or less in some embodiments, about 0.0009 or less in some embodiments, about 0.0008 or less in some embodiments, and about 0.0001 to about 0.0007 in some embodiments.

[0007]

[0020] Traditionally, polymer compositions exhibiting low dielectric loss tangent and relative permittivity were considered to lack sufficient thermal, mechanical properties and processability (i.e., low viscosity) to enable their use in certain types of applications. However, contrary to conventional thinking, polymer compositions have been found to possess both excellent thermal, mechanical properties and processability. For example, the melting temperature of a polymer composition may be, for example, about 240°C or higher, about 260°C in some embodiments, about 280°C to about 400°C in some embodiments, and about 250°C to about 380°C in some embodiments. Even at such melting temperatures, the ratio of the temperature of deflection under load ("DTUL"), a measure of short-term heat resistance, to the melting temperature may still remain relatively high. For example, the ratio may be in the range of about 0.5 to about 1.00, about 0.6 to about 0.95 in some embodiments, and about 0.65 to about 0.85 in some embodiments. A specific DTUL value may be, for example, about 200°C or higher, about 200°C to about 350°C in some embodiments, about 210°C to about 320°C in some embodiments, and about 230°C to about 310°C in some embodiments. Such a high DTUL value can, among other things, enable a fast and reliable surface mount process for mating the structure with other components of the electrical components.

[0008]

[0021] The polymer composition may also have excellent mechanical properties. For example, the polymer composition may exhibit a tensile strength of about 10 MPa or more, about 50 MPa or more in some embodiments, about 70 MPa to about 300 MPa in some embodiments, and about 80 MPa to about 200 MPa in some embodiments. The polymer composition may exhibit a tensile elongation of about 0.3% or more, about 0.4% or more in some embodiments, about 0.5% to about 4% in some embodiments, and about 0.5% to about 2% in some embodiments. The polymer composition may exhibit a tensile modulus of about 5,000 MPa or more, about 6,000 MPa or more in some embodiments, about 7,000 MPa to about 25,000 MPa in some embodiments, and about 10,000 MPa to about 20,000 MPa in some embodiments. The tensile properties may be determined according to ISO Test No. 527:2012 at a temperature of 23°C. Furthermore, the polymer composition may exhibit a flexural strength of about 20 MPa or more, about 30 MPa or more in some embodiments, about 50 MPa or more in some embodiments, about 70 MPa to about 300 MPa in some embodiments, and about 80 MPa to about 200 MPa in some embodiments. The polymer composition may exhibit a flexural elongation of about 0.4% or more, about 0.5% to about 4% in some embodiments, and about 0.5% to about 2% in some embodiments. The polymer composition may exhibit a flexural modulus of about 5,000 MPa or more, about 6,000 MPa or more in some embodiments, about 7,000 MPa to about 25,000 MPa in some embodiments, and about 10,000 MPa to about 20,000 MPa in some embodiments. The flexural properties may be determined according to 178:2010 at a temperature of 23°C. Furthermore, the polymer composition may also have high impact strength, which can be useful when forming thin substrates. For example, the polymer composition may have an impact strength of about 3 kJ / m 2 In some embodiments described above, the load is approximately 5 kJ / m³. 2 In some embodiments described above, the load is approximately 7 kJ / m³. 2 In some embodiments described above, the load is approximately 8 kJ / m³. 2 ~about 40kJ / m 2 In some embodiments, approximately 10 kJ / m³ 2 ~about 25kJ / m 2It may have a notched Charpy impact strength. The impact strength may be determined according to ISO test No. ISO 179-1:2010 at a temperature of 23°C.

[0009]

[0022] Here, various embodiments of the present invention will be described in more detail. I. Polymer composition A. Aromatic polymers

[0023] Generally, polymer compositions contain one or more aromatic polymers. Such polymers are generally considered “high-performance” polymers in that they have relatively high glass transition temperatures and / or high melting temperatures, and are therefore selected to impart a substantial degree of heat resistance to the polymer composition. For example, polymers may have melting temperatures of about 240°C or higher, about 260°C in some embodiments, about 280°C to about 400°C in some embodiments, and about 250°C to about 380°C in some embodiments. Aromatic polymers may also have glass transition temperatures of about 30°C or higher, about 40°C or higher in some embodiments, about 50°C to about 250°C in some embodiments, and about 60°C to about 150°C in some embodiments. The glass transition temperature and melting temperature may be determined using differential scanning calorimetry ("DSC") as is well known in the art, for example by ISO tests No. 11357-2:2013 (glass transition) and 11357-3:2011 (melt).

[0010]

[0024] For example, polyarylene sulfide is a semi-crystalline aromatic polymer suitable for use in polymer compositions. Polyarylene sulfide may be a homopolymer or copolymer. For example, selective combinations of dihalo-aromatic compounds can produce polyarylene sulfide copolymers containing two or more different units. For example, when p-dichlorobenzene is used in combination with m-dichlorobenzene or 4,4'-dichlorodiphenyl sulfone, the formula is:

[0011] [ka]

[0012] A segment having the structure, and formula:

[0013] [ka]

[0014] A segment having the structure, or formula:

[0015] [ka]

[0016] A polyarylene sulfide copolymer containing segments having the structure can be formed.

[0025] Polyarylene sulfides may be linear, semilinear, branched, or crosslinked. Linear polyarylene sulfides typically contain 80 mol% or more of repeating units -(Ar-S)-. Such linear polymers may also contain small amounts of branched or crosslinked units, but the amount of branched or crosslinked units is typically less than about 1 mol% of the total monomer units of the polyarylene sulfide. Linear polyarylene sulfide polymers may be random copolymers or block copolymers containing the repeating units described above. Semilinear polyarylene sulfides may similarly have crosslinked or branched structures in which small amounts of one or more monomers having three or more reactive functional groups are introduced into the polymer. As an example, the monomer component used to form semilinear polyarylene sulfides may include a certain amount of polyhalo-aromatic compounds having two or more halogen substituents per molecule, which are available for the preparation of branched polymers. Such monomers may have the formula R'X n(wherein each X is selected from chlorine, bromine, and iodine, n is an integer from 3 to 6, and R' is a polyvalent aromatic group of valence n that can have up to about 4 methyl substituents, and the total number of carbon atoms in R' is in the range of 6 to about 16) Examples of certain polyhalo-aromatic compounds substituted with more than two halogens per molecule that can be used to form semilinear polyarylene sulfides include 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,3-dichloro-5-bromobenzene, 1,2,4-triiodobenzene, 1,2,3,5-tetrabromobenzene, hexachlorobenzene, 1,3,5-trichloro-2,4,6-trimethylbenzene, 2,2',4,4'-tetrachlorobiphenyl, 2,2',5,5'-tetraiodobiphenyl, 2,2',6,6'-tetrabromo-3,3',5,5'-tetramethylbiphenyl, 1,2,3,4-tetrachloronaphthalene, 1,2,4-tribromo-6-methylnaphthalene, and mixtures thereof.

[0017]

[0026] In addition to the polymers mentioned above, crystalline polymers can also be used in polymer compositions. Particularly preferred are liquid crystal polymers having a high degree of crystallinity, which allows for effective filling of small spaces. Liquid crystal polymers generally have a rod-like structure and are classified as "thermotropic" insofar as they can exhibit crystalline behavior in their molten state (e.g., thermotropic nematic state). Liquid crystal polymers used in polymer compositions typically have melting temperatures of about 200°C to about 400°C, about 250°C to about 380°C in some embodiments, about 270°C to about 360°C in some embodiments, and about 300°C to about 350°C in some embodiments. Such polymers may be formed from one or more types of repeating units, as known in the art. Liquid crystal polymers are generally, for example, represented by the following formula (I):

[0018] [ka]

[0019] (In the formula, Ring B is a substituted or unsubstituted six-membered aryl group (e.g., 1,4-phenylene or 1,3-phenylene), a substituted or unsubstituted six-membered aryl group condensed to a substituted or unsubstituted five- or six-membered aryl group (e.g., 2,6-naphthalene), or a substituted or unsubstituted six-membered aryl group linked to a substituted or unsubstituted five- or six-membered aryl group (e.g., 4,4-biphenylene); Y1 and Y2 are independently O, C(O), NH, C(O)HN, or NHC(O). It may contain one or more aromatic ester repeating units represented by .

[0020]

[0027] Typically, at least one of Y1 and Y2 is C(O). Examples of such aromatic ester repeating units include, for example, aromatic dicarboxylic acid repeating units (where Y1 and Y2 are C(O) in formula I), aromatic hydroxycarboxylic acid repeating units (where Y1 is O and Y2 is C(O) in formula I), and various combinations thereof.

[0021]

[0028] For example, aromatic hydroxycarboxylic acid repeating units derived from aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid; 4-hydroxy-4'-biphenylcarboxylic acid; 2-hydroxy-6-naphthoic acid; 2-hydroxy-5-naphthoic acid; 3-hydroxy-2-naphthoic acid; 2-hydroxy-3-naphthoic acid; 4'-hydroxyphenyl-4-benzoic acid; 3'-hydroxyphenyl-4-benzoic acid; 4'-hydroxyphenyl-3-benzoic acid, as well as alkyl, alkoxy, aryl, and halogen-substituted derivatives thereof, and combinations thereof, may be used. Particularly preferred aromatic hydroxycarboxylic acids are 4-hydroxybenzoic acid ("HBA") and 6-hydroxy-2-naphthoic acid (HNA). When used, repeating units derived from hydroxycarboxylic acids (e.g., HBA and / or HNA) typically constitute about 40 mol.% or more of the polymer, about 50 mol.% or more in some embodiments, about 55 mol.% to 100 mol.% in some embodiments, and about 60 mol.% to 95 mol.% in some embodiments.

[0022]

[0029] Furthermore, aromatic dicarboxylic acid repeating units derived from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, bis(4-carboxyphenyl) ether, bis(4-carboxyphenyl)butane, bis(4-carboxyphenyl)ethane, bis(3-carboxyphenyl) ether, bis(3-carboxyphenyl)ethane, and alkyl, alkoxy, aryl, and halogen-substituted derivatives thereof, as well as combinations thereof, may be used. Particularly preferred aromatic dicarboxylic acids include, for example, terephthalic acid ("TA"), isophthalic acid ("IA"), and 2,6-naphthalenedicarboxylic acid ("NDA"). When used, repeating units derived from aromatic dicarboxylic acids (e.g., IA, TA, and / or NDA) typically constitute about 1 mol.% to about 40 mol.%, about 2 mol.% to about 30 mol.%, and about 5 mol.% to about 25 mol.%, of the polymer.

[0023]

[0030] Other repeating units can also be used in polymers. For example, in certain embodiments, repeating units derived from aromatic diols such as hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl (or 4,4'-biphenol), 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, bis(4-hydroxyphenyl)ethane, and their alkyl, alkoxy, aryl, and halogen-substituted derivatives, as well as combinations thereof, may be used. Particularly preferred aromatic diols include, for example, hydroquinone ("HQ") and 4,4'-biphenol ("BP"). When used, repeating units derived from aromatic diols (e.g., HQ and / or BP) typically constitute about 1 mol.% to about 40 mol.% of the polymer, about 2 mol.% to about 30 mol.% in some embodiments, and about 5 mol.% to about 25 mol.% in some embodiments. Furthermore, repeating units derived from aromatic amides (e.g., acetaminophen ("APAP")) and / or aromatic amines (e.g., 4-aminophenol ("AP"), 3-aminophenol, 1,4-phenylenediamine, 1,3-phenylenediamine, etc.) may be used. If used, repeating units derived from aromatic amides (e.g., APAP) and / or aromatic amines (e.g., AP) typically constitute about 0.1 mol.% to about 20 mol.% of the polymer, about 0.5 mol.% to about 15 mol.% in some embodiments, and about 1 mol.% to about 10 mol.% in some embodiments. It should also be understood that various other monomer repeating units may be introduced into the polymer. For example, in certain embodiments, the polymer may contain one or more repeating units derived from non-aromatic monomers such as aliphatic or alicyclic hydroxycarboxylic acids, dicarboxylic acids, diols, amides, and amines. Naturally, in other embodiments, the polymer may be "totally aromatic" in that it does not contain repeating units derived from non-aromatic (e.g., aliphatic or alicyclic) monomers.

[0024]

[0031] While not strictly necessary, liquid crystal polymers may be "high naphthenic" polymers insofar as they contain a relatively high content of repeating units derived from naphthenic hydroxycarboxylic acids and naphthenic dicarboxylic acids, such as NDA, HNA, or combinations thereof. That is, the total amount of repeating units derived from naphthenic hydroxycarboxylic acids and / or dicarboxylic acids (e.g., NDA, HNA, or combinations of HNA and NDA) is typically about 10 mol.% or more of the polymer, about 12 mol.% or more in some embodiments, about 15 mol.% or more in some embodiments, about 18 mol.% or more in some embodiments, about 20 mol.% or more in some embodiments, about 30 mol.% or more in some embodiments, about 40 mol.% or more in some embodiments, about 45 mol.% or more in some embodiments, about 50 mol.% or more in some embodiments, about 60 mol.% or more in some embodiments, about 62 mol.% or more in some embodiments, about 68 mol.% or more in some embodiments, about 70 mol.% or more in some embodiments, and about 70 mol.% to about 80 mol.% in some embodiments. While not limited by theory, such "high naphthenic" polymers are thought to reduce the water absorption tendency of polymer compositions, thereby promoting the stabilization of the dielectric constant and dielectric loss tangent in the high-frequency range. Specifically, such high naphthenic polymers, after immersion in water for 24 hours according to ISO 62-1:2008, typically have a water absorption of about 0.015% or less, in some embodiments about 0.01% or less, and in some embodiments about 0.0001% to about 0.008%. High naphthenic polymers may also have a hygroscopicity of about 0.01% or less, in some embodiments about 0.008% or less, and in some embodiments about 0.0001% to about 0.006% after exposure to a humid atmosphere (relative humidity 50%) at a temperature of 23°C according to ISO 62-4:2008.

[0025]

[0032] In one embodiment, for example, repeating units derived from HNA may constitute 30 mol.% or more of the polymer, about 40 mol.% or more in some embodiments, about 45 mol.% or more in some embodiments, 50 mol.% or more in some embodiments, about 60 mol.% or more in some embodiments, about 62 mol.% or more in some embodiments, about 68 mol.% or more in some embodiments, about 70 mol.% or more in some embodiments, and about 70 mol.% to about 80 mol.% in some embodiments. The liquid crystal polymer may also contain various other monomers. For example, the polymer may contain repeating units derived from HBA in an amount of about 10 mol.% to about 40 mol.%, about 15 mol.% to about 35 mol.% in some embodiments, and about 20 mol.% to about 30 mol.% in some embodiments. When used, the molar ratio of HNA to HBA may be selectively controlled within a specific range to facilitate the achievement of desired properties, for example, about 0.1 to about 40, about 0.5 to about 20 in some embodiments, about 0.8 to about 10 in some embodiments, and about 1 to about 5 in some embodiments. The polymer may also contain aromatic dicarboxylic acids (e.g., IA and / or TA) in amounts of about 1 mol.% to about 40 mol.%, about 5 mol.% to about 25 mol.%, and / or aromatic diols (e.g., BP and / or HQ) in amounts of about 1 mol.% to about 40 mol.%, about 5 mol.% to about 25 mol.%, in some embodiments. However, in some cases, it may be desirable to minimize the presence of such monomers in the polymer to facilitate the achievement of desired properties. For example, the total amount of aromatic dicarboxylic acids (e.g., IA and / or TA) may be about 20 mol.% or less of the polymer, about 15 mol.% or less in some embodiments, about 10 mol.% or less in some embodiments, 0 mol.% to about 5 mol.% in some embodiments, and 0 mol.% to about 2 mol.% in some embodiments.Similarly, the total amount of aromatic dicarboxylic acids (e.g., IA and / or TA) may be about 20 mol.% or less of the polymer, about 15 mol.% or less in some embodiments, about 10 mol.% or less in some embodiments, 0 mol.% to about 5 mol.% in some embodiments, and 0 mol.% to about 2 mol.% (e.g., 0 mol.%) in some embodiments.

[0026]

[0033] In another embodiment, repeating units derived from NDA may constitute 10 mol.% or more of the polymer, about 12 mol.% or more in some embodiments, about 15 mol.% or more in some embodiments, and about 18 mol.% to about 95 mol.% in some embodiments. In such embodiments, the liquid crystal polymer may further contain various other monomers, such as aromatic hydroxycarboxylic acids (e.g., HBA) in amounts of about 20 mol.% to about 60 mol.%, about 30 mol.% to about 50 mol.% in some embodiments, aromatic dicarboxylic acids (e.g., IA and / or TA) in amounts of about 2 mol.% to about 30 mol.%, about 5 mol.% to about 25 mol.% in some embodiments, and / or aromatic diols (e.g., BP and / or HQ) in amounts of about 2 mol.% to about 40 mol.%, about 5 mol.% to about 35 mol.% in some embodiments.

[0027]

[0034] Regardless of the specific components and properties of the polymer, liquid crystal polymers may be prepared by first introducing aromatic monomers to be used to form ester repeating units (e.g., aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, etc.) and / or other repeating units (e.g., aromatic diols, aromatic amides, aromatic amines, etc.) into a reaction vessel and initiating a polycondensation reaction. Specific conditions and steps used in such reactions are well known and may be described in more detail in U.S. Patent No. 4,161,470 by Calundann; U.S. Patent No. 5,616,680 by Linstid, III, et al.; U.S. Patent No. 6,114,492 by Linstid, III, et al.; U.S. Patent No. 6,514,611 by Shepherd, et al.; and WO2004 / 058851 by Waggoner. The vessel used in the reaction is not particularly limited, but it is preferable to use one that is typically commonly used in reactions of high-viscosity fluids. Examples of such reaction vessels include agitated tank-type devices having agitators equipped with stirring blades of various shapes, such as anchor-type, multi-stage-type, spiral ribbon-type, screw shaft-type, or modified forms thereof. Further examples of such reaction vessels include mixing devices commonly used in resin compounding, such as kneaders, roll mills, and Banbury mixers.

[0028]

[0035] If desired, the reaction may proceed by acetylation of monomers known in the art. This can be achieved by adding an acetylating agent (e.g., acetic anhydride) to the monomer. Acetylation is generally initiated at a temperature of about 90°C. During the initial stages of acetylation, reflux may be used to maintain the gas phase temperature below the point at which the acetic acid byproduct and anhydride begin to distill. The temperature during acetylation is typically in the range of 90°C to 150°C, and in some embodiments, about 110°C to about 150°C. When reflux is used, the gas phase temperature is typically above the boiling point of acetic acid but remains low enough to retain the remaining acetic anhydride. For example, acetic anhydride evaporates at a temperature of about 140°C. Therefore, it is particularly desirable to bring gas-phase reflux into the reactor at a temperature of about 110°C to about 130°C. To ensure a substantially complete reaction, an excess amount of acetic anhydride may be used. The amount of excess anhydride varies depending on the specific acetylation conditions used, including the presence or absence of reflux. It is not uncommon to use an excess amount of acetic anhydride of about 1 to 10 mole percent relative to the total moles of hydroxyl groups present in the reactants.

[0029]

[0036] Acetylation may be carried out in a separate reaction vessel or in situ within the polymerization reaction vessel. If a separate reaction vessel is used, one or more of the monomers may be introduced into the acetylation reactor and then transferred to the polymerization reactor. Similarly, one or more of the monomers may be introduced directly into the reaction vessel without pre-acetylation.

[0030]

[0037] In addition to monomers and optional acetylating agents, other components to facilitate polymerization may also be included in the reaction mixture. For example, catalysts such as metal salt catalysts (e.g., magnesium acetate, tin(I) acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, etc.) and organic compound catalysts (e.g., N-methylimidazole) may be optionally used. Such catalysts are typically used in amounts of about 50 to about 500 million parts per kilogram relative to the total weight of the repeating unit precursor. When separate reactors are used, it is typically preferable, but not essential, to apply the catalyst to the acetylation reactor rather than the polymerization reactor.

[0031]

[0038] The reaction mixture is generally heated to a high temperature in the polymerization reaction vessel to initiate melt polycondensation of the reactants. For example, polycondensation may be carried out in a temperature range of about 250°C to about 380°C, and in some embodiments, about 280°C to about 380°C. For example, one preferred technique for forming aromatic polyesters may involve introducing precursor monomers and acetic anhydride into a reactor, heating the mixture to a temperature of about 90°C to about 150°C to acetylate the hydroxyl groups of the monomers (e.g., to form acetoxy), and then raising the temperature to about 280°C to about 380°C to carry out melt polycondensation. As the final polymerization temperature approaches, volatile by-products of the reaction (e.g., acetic acid) may also be removed so that the desired molecular weight can be easily achieved. The reaction mixture is generally stirred during polymerization to ensure good heating and mass transfer, and thus good material homogeneity. The rotational speed of the stirrer may vary during the reaction, but is typically in the range of about 10 to 100 revolutions per minute ("rpm"), and in some embodiments, about 20 to 80 rpm. To increase the molecular weight in the molten material, the polymerization reaction may also be carried out under vacuum, as applying vacuum makes it easier to remove volatiles formed during the final stage of polycondensation. Vacuum can be created by applying a suction pressure in the range of about 2.27 to 13.6 kg (about 5 to about 30 pounds) ("psi") per 2.54 square cm (1 square inch), and in some embodiments, about 10 to about 20 psi.

[0032]

[0039] After melt polymerization, the molten polymer can typically be discharged from the reactor through an extrusion orifice equipped with a die of the desired shape, cooled, and collected. Generally, the molten material is discharged through a perforating die to form strands, which are then taken into a water bath, pelletized, and dried. In some embodiments, the melt-polymerized polymer may be subjected to a subsequent solid-phase polymerization method to further increase its molecular weight. Solid-phase polymerization can be carried out in the presence of a gas (e.g., air, an inert gas). Suitable inert gases include, for example, nitrogen, helium, argon, neon, krypton, xenon, and combinations thereof. The solid-phase polymerization reaction vessel may be of substantially any design that can maintain the polymer at a desired solid-phase polymerization temperature for a desired residence time. Examples of such vessels may have a fixed bed, a stationary bed, a moving bed, a fluidized bed, etc. The temperature at which solid-phase polymerization is carried out may vary, but is typically in the range of about 250°C to about 350°C. Naturally, the polymerization time varies based on the temperature and the target molecular weight. However, in most cases, the solid-phase polymerization time is about 2 to 12 hours, and in some embodiments, it is about 4 to 10 hours.

[0033]

[0040] When used, the total amount of liquid crystal polymers used in the polymer composition may be about 40 wt.% to about 99 wt.% of the total polymer composition, about 50 wt.% to about 98 wt.% in some embodiments, and about 60 wt.% to about 95 wt.% in some embodiments. In certain embodiments, all of the liquid crystal polymers are "high naphthenic" polymers such as those described above. However, in other embodiments, "low naphthenic" liquid crystal polymers may be used in the composition, where the total amount of repeating units derived from naphthenic hydroxycarboxylic acids and / or dicarboxylic acids (e.g., NDA, HNA, or a combination of HNA and NDA) is less than 10 mol.% of the polymer, about 8 mol.% or less in some embodiments, about 6 mol.% or less in some embodiments, and about 1 mol.% to about 5 mol.% in some embodiments. In certain embodiments, it may be desirable for the low naphthenic polymers to be present only in relatively small amounts. For example, when used, the low naphthenic liquid crystal polymer typically constitutes about 1 wt.% to about 50 wt.% of the total amount of liquid crystal polymers in the composition, about 2 wt.% to about 40 wt.% in some embodiments, about 5 wt.% to about 30 wt.% in some embodiments, and about 0.5 wt.% to about 45 wt.% of the total composition, about 2 wt.% to about 35 wt.% in some embodiments, and about 5 wt.% to about 25 wt.% in some embodiments. In contrast, high naphthenic liquid crystal polymers typically constitute about 50 wt.% to about 99 wt.% of the total amount of liquid crystal polymers in the composition, about 60 wt.% to about 98 wt.% in some embodiments, about 70 wt.% to about 95 wt.% in some embodiments, and about 55 wt.% to about 99.5 wt.% of the total composition, about 65 wt.% to about 98 wt.% in some embodiments, and about 75 wt.% to about 95 wt.% in some embodiments.

[0034] B. Other additives

[0041] Aromatic polymers may be used in neat form in the polymer composition (i.e., 100 wt.%), or a wide variety of other additives may be optionally included in the composition. If used, such additives typically constitute about 1 wt.% to about 60 wt.%, about 2 wt.% to about 50 wt.%, and in some embodiments about 5 wt.% to about 40 wt.%, of the polymer composition. In such embodiments, liquid crystal polymers may similarly constitute about 40 wt.% to about 99 wt.%, about 50 wt.% to about 98 wt.%, and in some embodiments about 60 wt.% to about 95 wt.%, of the polymer composition.

[0035]

[0042] Furthermore, the polymer composition may contain a wide variety of additional optional additives, such as laser-activatable additives, fibrous fillers, particulate fillers, hollow fillers, hydrophobic materials, lubricants, thermally conductive fillers, pigments, antioxidants, stabilizers, surfactants, waxes, flame retardants, anti-sagging additives, nucleating agents (e.g., boron nitride), flow modifiers, coupling agents, antimicrobial agents, pigments or other colorants, impact modifiers, dielectric materials, and other materials added to improve properties and processability. Such optional materials may be used in conventional amounts and in accordance with conventional processing techniques.

[0036] i. Laser-activating additives

[0043] For example, in certain other embodiments, the polymer composition may be “laser-activatable” in the sense that it contains an additive that can be activated by a laser direct structuring (“LDS”) process. In such a process, the additive is exposed to a laser that causes the release of metal. The laser then patterns conductive elements in the portion, leaving a roughened surface containing embedded metal particles. These particles act as nuclei for crystal growth during subsequent plating processes (e.g., copper plating, gold plating, nickel plating, silver plating, zinc plating, tin plating, etc.). The laser-activatable additive generally contains spinel crystals, which may contain two or more metal oxide cluster configurations within a definable crystal formation. For example, the total crystal formation is expressed by the following general formula: AB2O4 (In the formula, A is a metal cation with a valence of 2, such as cadmium, chromium, manganese, nickel, zinc, copper, cobalt, iron, magnesium, tin, titanium, and combinations thereof; B is a metal cation with a valence of 3, such as chromium, iron, aluminum, nickel, manganese, tin, etc., and combinations thereof. It may have.

[0037]

[0044] Typically, in the above formula, A gives the main cation component of the first metal oxide cluster, and B gives the main cation component of the second metal oxide cluster. These oxide clusters may have the same or different structures. For example, in one embodiment, the first metal oxide cluster has a tetrahedral structure, and the second metal oxide cluster has an octahedral cluster. Nevertheless, the clusters can come together to give a single, identifiable crystalline structure with increased sensitivity to electromagnetic radiation. Examples of suitable spinel crystals include, for example, MgAl2O4, ZnAl2O4, FeAl2O4, CuFe2O4, CuCr2O4, MnFe2O4, NiFe2O4, TiFe2O4, FeCr2O4, and MgCr2O4. Copper chromium oxide (CuCr2O4) is particularly suitable for use in the present invention and is available from Shepherd Color Co. under the name "Shepherd Black 1GM".

[0038]

[0045] The laser-activatable additive may constitute about 0.1 wt.% to about 30 wt.% of the polymer composition, about 0.5 wt.% to about 20 wt.% in some embodiments, and about 1 wt.% to about 10 wt.% in some embodiments.

[0039] ii. Fibrous filler

[0046] For example, in one embodiment, fibrous fillers may be used in a polymer composition to improve the thermal and mechanical properties of the polymer composition without significantly affecting its electrical properties. Fibrous fillers typically include fillers that have high tensile strength relative to their mass. For example, the maximum tensile strength of the fibers (determined according to ASTM D2101) is typically about 1,000 to about 15,000 megapascals ("MPa"), about 2,000 to about 10,000 MPa in some embodiments, and about 3,000 to about 6,000 MPa in some embodiments. To facilitate the maintenance of desired dielectric properties, such high-strength fibers may be formed from materials that are generally insulating, such as glass, ceramics or minerals (e.g., alumina or silica), aramid (e.g., Kevlar®, sold by EIduPont de Nemours, Wilmington, Delaware), minerals, polyolefins, polyesters, etc.

[0040]

[0047] Examples of fibrous fillers include glass fibers, mineral fibers, or mixtures thereof. For example, in one embodiment, the fibrous filler may include glass fibers. Particularly preferred glass fibers may include E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S1-glass, S2-glass, etc. In another embodiment, the fibrous filler may include mineral fibers. Examples of mineral fibers include silicates, such as neosilicate, sorosilicate, inosilicate (e.g., calcium inosilicate such as wollastonite; calcium magnesium inosilicate such as tremolite; calcium magnesium iron inosilicate such as actinolite; magnesium iron inosilicate such as antphyllite, etc.), phyllosilicate (e.g., aluminum phyllosilicate such as palygorskite), tectosilicate, etc.; sulfates such as calcium sulfate (e.g., dehydrated or anhydrous gypsum); and mineral wool (e.g., rock or slag wool). Inosilicates such as wollastonite fibers, available from Nyco Minerals under the trade name NYGLOS® (e.g., NYGLOS® 4W or NYGLOS® 8), are particularly preferred.

[0041]

[0048] Furthermore, while fibrous fillers may have a variety of different sizes, fibers having certain aspect ratios may promote improvements in the mechanical properties of the polymer composition. Specifically, fibrous fillers having aspect ratios (average length divided by nominal diameter) of about 2 or more, about 4 or more in some embodiments, about 5 to about 50 in some embodiments, and about 8 to about 40 in some embodiments may be particularly beneficial. Such fibrous fillers may have a weight-average length of, for example, about 10 micrometers or more, about 25 micrometers or more in some embodiments, about 50 micrometers or more to about 800 micrometers or less in some embodiments, and about 60 micrometers to about 500 micrometers or less in some embodiments. Also, such fibrous fillers may have a volume-average length of, for example, about 10 micrometers or more, about 25 micrometers or more in some embodiments, about 50 micrometers or more to about 800 micrometers or less in some embodiments, and about 60 micrometers to about 500 micrometers or less in some embodiments. The fibrous filler may similarly have a nominal diameter of about 5 micrometers or more, about 6 micrometers or more in some embodiments, about 8 to about 40 micrometers in some embodiments, and about 9 to about 20 micrometers in some embodiments. The relative amount of the fibrous filler may also be selectively controlled to facilitate the achievement of desired mechanical and thermal properties without adversely affecting other properties of the polymer composition, such as its fluidity and dielectric properties. In this regard, the fibrous filler may have a relative permittivity of about 6 or less at a frequency of 1 GHz, about 5.5 or less in some embodiments, about 1.1 to about 5 in some embodiments, and about 2 to about 4.8 in some embodiments.

[0042]

[0049] The fibrous filler may be in a modified or unmodified form and may be sizing or chemically treated, for example, to improve adhesion to the plastic. In some examples, sizing may be applied to the glass fibers to protect them, not only to smooth the fibers but also to improve adhesion between the fibers and the matrix material. If present, the sizing may include silanes, film-forming agents, lubricants, wetting agents, adhesives, optionally antistatic and plasticizers, emulsifiers, and optionally further additives. In one particular embodiment, the sizing may include silanes. Specific examples of silanes are aminosilanes, such as 3-trimethoxysilylpropylamine, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(3-trimethoxysisilanylpropyl)ethane-1,2-diamine, 3-(2-aminoethyl-amino)propyltrimethoxysilane, and N-[3-(trimethoxysilyl)propyl]-1,2-ethane-diamine.

[0043]

[0050] When used, the fibrous filler may constitute, for example, about 1 wt.% to about 40 wt.% of the polymer composition, about 3 wt.% to about 30 wt.% in some embodiments, and about 5 wt.% to about 20 wt.% in some embodiments.

[0044] iii. Hollow filler

[0051] Although not essential, the polymer composition may also include one or more hollow inorganic fillers to facilitate the achievement of a desired dielectric constant. For example, such fillers may have a dielectric constant of about 3.0 or less at 100 MHz, about 2.5 or less in some embodiments, about 1.1 to about 2.3 in some embodiments, and about 1.2 to about 2.0 in some embodiments. Hollow inorganic fillers typically have internal hollow spaces or cavities and may be synthesized using techniques known in the art. Hollow inorganic fillers may be made from conventional materials. For example, examples of hollow inorganic fillers include alumina, silica, zirconia, magnesia, glass, fly ash, borates, phosphates, and ceramics. In one embodiment, examples of hollow inorganic fillers include hollow glass fillers, hollow ceramic fillers, and mixtures thereof. In one embodiment, the hollow inorganic filler includes a hollow glass filler. The hollow glass filler may be made from soda-lime borosilicate glass, soda-lime glass, borosilicate glass, sodium borosilicate glass, sodium silicate glass, or aluminosilicate glass. In this regard, in one embodiment, the composition of the glass may be, but is not limited, at least about 65 wt% SiO2, 3 to 15 wt% Na2O, 8 to 15 wt% CaO, 0.1 to 5 wt% MgO, 0.01 to 3 wt% Al2O3, 0.01 to 1 wt% K2O, and optionally other oxides (e.g., Li2O, Fe2O3, TiO2, B2O3). In another embodiment, the composition may be about 50 to 58 wt% SiO2, 25 to 30 wt% Al2O3, 6 to 10 wt% CaO, 1 to 4 wt% Na2O / K2O, and 1 to 5 wt% other oxides. Furthermore, in one embodiment, the hollow glass filler may contain more alkaline earth metal oxides than alkali metal oxides. For example, the weight ratio of alkaline earth metal oxides to alkali metal oxides may be greater than 1, about 1.1 or more in some embodiments, about 1.2 to about 4 in some embodiments, and about 1.5 to about 3 in some embodiments. Notwithstanding the foregoing, it should be understood that the composition of the glass may vary depending on the type of glass used and still provide the benefits desired by the present invention.

[0045]

[0052] The hollow inorganic filler may have at least one dimension having an average value of about 1 micrometer or more, in some embodiments about 5 micrometers or more, in some embodiments about 8 micrometers or more, in some embodiments from about 1 micrometer to about 150 micrometers, in some embodiments from about 10 micrometers to about 150 micrometers, and in some embodiments from about 12 micrometers to about 50 micrometers. In one embodiment, such an average value may be referred to as the d 50 value. Further, the hollow inorganic filler may have a D of about 3 micrometers or more, in some embodiments about 4 micrometers or more, in some embodiments from about 5 micrometers to about 20 micrometers, and in some embodiments from about 6 micrometers to about 15 micrometers 10 The hollow inorganic filler may have a D of about 10 micrometers or more, in some embodiments about 15 micrometers or more, in some embodiments from about 20 micrometers to about 150 micrometers, and in some embodiments from about 22 micrometers to about 50 micrometers 90It may have a size distribution that can be a Gaussian size distribution, a normal size distribution, or a non-normal size distribution. In one embodiment, the hollow inorganic filler may have a Gaussian size distribution. In another embodiment, the hollow inorganic filler may have a normal size distribution. In a further embodiment, the hollow inorganic filler may have a non-normal size distribution. Examples of non-normal size distributions include unimodal and multimodal (e.g., bimodal) size distributions. When referring to the dimensions above, such dimensions may be arbitrary. However, in one embodiment, such dimensions refer to diameters. For example, such a value for a dimension refers to the average diameter of a sphere. Dimensions such as average diameter may be determined according to 3M QCM 193.0. In this regard, in one embodiment, the hollow inorganic filler may refer to a hollow sphere such as a hollow glass sphere. For example, the hollow inorganic filler may have an average aspect ratio of approximately 1. Generally, the average aspect ratio may be approximately 0.8 or higher, approximately 0.85 or higher in some embodiments, approximately 0.9 to approximately 1.3 in some embodiments, and approximately 0.95 to approximately 1.05 in some embodiments.

[0046]

[0053] Furthermore, the hollow inorganic filler may have relatively thin walls to aid in the dielectric properties and weight reduction of the polymer composition. The wall thickness may be about 50% or less of the average dimensions of the hollow inorganic filler, e.g., average diameter, about 40% or less in some embodiments, about 1% to about 30% in some embodiments, and about 2% to about 25% in some embodiments. Furthermore, the hollow inorganic filler may have a specific true density that allows for easy handling and provides a polymer composition with reduced weight. Generally, true density refers to the quotient obtained by dividing the mass of the hollow filler sample by the true volume of the hollow filler mass, where true volume is referred to as the total volume of the hollow filler. In this regard, the true density of the hollow inorganic filler is about 0.1 g / cm³. 3 In some embodiments, the value is approximately 0.2 g / cm³. 3 In some embodiments, the value is approximately 0.3 g / cm³. 3 More than ~ approx. 1.2g / cm 3 In some embodiments, the concentration is approximately 0.4 g / cm³. 3More than ~ approx. 0.9g / cm 3 This may also be the case. The true density may be determined according to 3M QCM 14.24.1.

[0047]

[0054] Even if the fillers are hollow, they may have mechanical strength that allows for the maintenance of the integrity of their structure and reduces the likelihood of the fillers breaking during processing and / or use. In this regard, the isotactic crush resistance of hollow inorganic fillers (i.e., at least 80 vol.%, e.g., at least 90 vol.%, of the hollow filler survives) may be about 20 MPa or more, about 100 MPa or more in some embodiments, about 150 MPa to about 500 MPa in some embodiments, and about 200 MPa to about 350 MPa in some embodiments. The isotactic crush resistance may be determined according to 3M QCM 14.1.8.

[0048]

[0055] The alkalinity of the hollow inorganic filler may be about 1.0 meq / g or less, about 0.9 meq / g or less in some embodiments, about 0.1 meq / g to about 0.8 meq / g in some embodiments, and about 0.2 meq / g to about 0.7 meq / g in some embodiments. The alkalinity may be determined according to 3M QCM 55.19. To obtain a relatively low alkalinity, the hollow inorganic filler may be treated with a suitable acid such as phosphoric acid. Furthermore, the hollow inorganic filler may also include a surface treatment to help obtain better compatibility with the polymer and / or other components in the polymer composition. For example, the surface treatment may be silanization. In particular, examples of surface treatment agents include, but are not limited to, aminosilanes and epoxysilanes.

[0049]

[0056] When used, the hollow inorganic filler may constitute, for example, about 1 wt.% or more of the polymer composition, about 4 wt.% or more in some embodiments, about 5 wt.% to about 40 wt.% in some embodiments, and about 10 wt.% to about 30 wt.% in some embodiments.

[0050] iv. Particulate filler

[0057] If desired, particulate fillers may be used to improve specific properties of the polymer composition. Particulate fillers may be used in the polymer composition in an amount of about 5 to about 60 parts by weight, in some embodiments about 10 to about 50 parts by weight, and in some embodiments about 15 to about 40 parts by weight per 100 parts of the aromatic polymer used in the polymer composition. For example, the particulate filler may constitute about 5 wt.% to about 50 wt.% of the polymer composition, in some embodiments about 10 wt.% to about 40 wt.%, and in some embodiments about 15 wt.% to about 30 wt.%.

[0051]

[0058] In certain embodiments, particles having specific hardness values ​​may be used to facilitate improvement of the surface properties of the composition. For example, the hardness value may be about 2 or higher on the Mohs hardness scale, about 2.5 or higher in some embodiments, about 3 to about 11 in some embodiments, about 3.5 to about 11 in some embodiments, and about 4.5 to about 6.5 in some embodiments. Examples of such particles include, for example, silica (Mohs hardness 7), mica (Mohs hardness about 3); carbonates such as calcium carbonate (CaCO3, Mohs hardness 3.0) or copper carbonate hydroxide (Cu2CO3(OH)2, Mohs hardness 4.0); fluorides such as calcium fluoride (CaFl2; Mohs hardness 4.0); calcium pyrophosphate (Ca2P2O7, Mohs hardness 5.0), anhydrous dicalcium phosphate (CaHPO4; Mohs hardness 3.5). Examples include phosphates such as hydrated aluminum phosphate (AlPO4·2H2O; Mohs hardness 4.5); borates such as calcium hydroxide borosilicate (Ca2B5SiO9(OH)5, Mohs hardness 3.5); alumina (AlO2, Mohs hardness 10.0); sulfates such as calcium sulfate (CaSO4, Mohs hardness 3.5) or barium sulfate (BaSO4, Mohs hardness 3-3.5), and combinations thereof.

[0052]

[0059] The particle shape may vary as desired. For example, in certain embodiments, flake-shaped particles with relatively high aspect ratios (e.g., average diameter divided by average thickness) such as about 10:1 or more, in some embodiments about 20:1 or more, and in some embodiments about 40:1 to about 200:1 may be used. The average diameter of the particles may be in the range of about 5 micrometers to about 200 micrometers, in some embodiments about 30 micrometers to about 150 micrometers, and in some embodiments about 50 micrometers to about 120 micrometers, determined using laser diffraction techniques according to ISO 13320:2009 (e.g., using a Horiba LA-960 particle size distribution analyzer). Suitable flake-shaped particles may be formed from natural and / or synthetic silicate minerals, such as mica, halloysite, kaolinite, illite, montmorillonite, vermiculite, palygorskite, pyrophyllite, calcium silicate, aluminum silicate, wollastonite, etc. For example, mica is particularly preferred. For example, muscovite (KAl2(AlSi3)O 10 (OH)2), biotite (K(Mg,Fe)3(AlSi3)O 10 (OH)2), phlogopite (KMg3(AlSi3)O 10 (OH)2), red mica (K(Li,Al) 2-3 (AlSi3)O 10 (OH)2), glauconite (K,Na)(Al,Mg,Fe)2(Si,Al)4O 10 Any form of mica containing (OH)2, etc., may be commonly used. Granular particles can also be used. Typically, such particles have an average diameter of about 0.1 to about 10 micrometers, about 0.2 to about 4 micrometers in some embodiments, and about 0.5 to about 2 micrometers in some embodiments, determined using laser diffraction techniques (e.g., using a Horiba LA-960 particle size distribution analyzer) in accordance with ISO 13320:2009. Particularly suitable granular fillers may include, for example, talc, barium sulfate, calcium sulfate, calcium carbonate, etc.

[0053]

[0060] The particulate filler may be formed primarily or entirely from one type of particle, such as flake-shaped particles (e.g., mica) or granular particles (e.g., barium sulfate). That is, such flake-shaped or granular particles may constitute about 50 wt.% or more, and in some embodiments about 75 wt.% or more (e.g., 100 wt.%) of the particulate filler. Naturally, in other embodiments, flake-shaped and granular particles may be used in combination. In such embodiments, for example, flake-shaped particles may constitute about 0.5 wt.% to about 20 wt.%, and in some embodiments about 1 wt.% to about 10 wt.%, of the particulate filler, while granular particles may constitute about 80 wt.% to about 99.5 wt.%, and in some embodiments about 90 wt.% to about 99 wt.%.

[0054]

[0061] If desired, the particles may also be coated with a fluorinating additive to facilitate improved processing of the composition, such as resulting in better mold filling, internal lubrication, and mold release. Examples of fluorinating additives include fluoropolymers containing hydrocarbon backbone polymers in which some or all of the hydrogen atoms are substituted with fluorine atoms. The backbone polymer may be polyolefin-based and may be formed from fluorine-substituted unsaturated olefin monomers. The fluoropolymer may be a homopolymer of such fluorine-substituted monomers, a copolymer of fluorine-substituted monomers, or a mixture of fluorine-substituted and non-fluorine-substituted monomers. Along with fluorine atoms, the fluoropolymer may also be substituted with other halogen atoms, such as chlorine and bromine atoms. Typical monomers suitable for forming the fluoropolymers used in the present invention include tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, chlorotrifluoroethylene, perfluoroethyl vinyl ether, perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, and mixtures thereof. Specific examples of suitable fluoropolymers include polytetrafluoroethylene, perfluoroalkyl vinyl ethers, poly(tetrafluoroethylene-co-perfluoroalkyl vinyl ethers), fluorinated ethylene propylene copolymers, ethylene tetrafluoroethylene copolymers, fluorinated polyvinylidene, polychlorotrifluoroethylene, and mixtures thereof.

[0055] v. Hydrophobic materials

[0062] Hydrophobic materials can also be used in polymer compositions. While not theoretically limited, hydrophobic materials may help reduce the water absorption tendency of polymer compositions, thereby potentially supporting the stabilization of the dielectric constant and dielectric loss tangent in the high-frequency range. When used, the weight ratio of liquid crystal polymer to hydrophobic material is typically about 1 to about 20, about 2 to about 15 in some embodiments, and about 3 to about 10 in some embodiments. For example, the hydrophobic material may constitute about 1 wt.% to about 60 wt.% of the total polymer composition, about 2 wt.% to about 50 wt.% in some embodiments, and about 5 wt.% to about 40 wt.% in some embodiments. Particularly preferred hydrophobic materials are low surface energy elastomers such as fluoropolymers and silicone polymers. Fluoropolymers may contain, for example, hydrocarbon backbone polymers in which some or all hydrogen atoms are substituted with fluorine atoms. The backbone polymer may be polyolefin-based and may be formed from fluorine-substituted unsaturated olefin monomers. The fluoropolymer may be a homopolymer of such fluorine-substituted monomers, a copolymer of fluorine-substituted monomers, or a mixture of fluorine-substituted and non-fluorine-substituted monomers. Along with the fluorine atom, the fluoropolymer may be substituted with other halogen atoms such as chlorine and bromine atoms. Representative monomers suitable for forming the fluoropolymers used in the present invention include tetrafluoroethylene ("TFE"), vinylidene fluoride ("VF2"), hexafluoropropylene ("HFP"), chlorotrifluoroethylene ("CTFE"), perfluoroethyl vinyl ether ("PEVE"), perfluoromethyl vinyl ether ("PMVE"), perfluoropropyl vinyl ether ("PPVE"), and mixtures thereof.Specific examples of suitable fluoropolymers include polytetrafluoroethylene ("PTFE"), perfluoroalkyl vinyl ether ("PVE"), poly(tetrafluoroethylene-co-perfluoroalkyl vinyl ether) ("PFA"), fluorinated ethylene propylene copolymer ("FEP"), ethylene tetrafluoroethylene copolymer ("ETFE"), fluorinated polyvinylidene ("PVDF"), polychlorotrifluoroethylene ("PCTFE"), and TFE copolymers having VF2 and / or HFP, as well as mixtures thereof.

[0056] II. formation

[0063] The components used to form a polymer composition may be combined using any of the various different techniques known in the art. For example, in one particular embodiment, an aromatic polymer and other optional additives are melt-processed as a mixture in an extruder to form a polymer composition. The mixture may be melt-kneaded in a single-screw or multi-screw extruder at a temperature of about 200°C to about 450°C. In one embodiment, the mixture can be melt-processed in an extruder having multiple temperature zones. The temperature of each zone is typically set within about -60°C to about 25°C relative to the melt temperature of the polymer. As an example, the mixture can be melt-processed using a twin-screw extruder such as a Leistritz 18mm co-rotating full-mesh twin-screw extruder. A general-purpose screw design can be used to melt-process the mixture. In one embodiment, the mixture containing all the components can be fed into the feed port of a first barrel by a metering feeder. In another embodiment, different components can be added at different addition points in the extruder, as is known. For example, the polymer can be applied to the feed port, and specific additives (e.g., laser-activatable additives and / or other additives) can be supplied in the same or different temperature zones located downstream thereof. In any case, the resulting mixture can be melted, mixed, and then extruded through a die. The extruded polymer composition may then be quenched and solidified in a water bath, granulated in a pelletizer, and then dried.

[0057]

[0064] In addition to being mixed during the melting process, additives (e.g., hydrophobic materials) can also be incorporated into the polymer matrix during the formation of aromatic polymers. For example, aromatic precursor monomers used to form the polymer may be reacted in the presence of additives (e.g., in a polymerization apparatus). In this method, the additives can be physically incorporated into the resulting polymer matrix. Additives can be introduced at any point, but it is preferable to apply them typically before melt polymerization is initiated and typically together with other aromatic precursor monomers for the polymer. The relative amount of additives added to the reaction varies, but is typically about 0.1 wt.% to about 35 wt.% of the reaction mixture, about 0.5 wt.% to about 30 wt.% in some embodiments, and about 1 wt.% to about 25 wt.% in some embodiments.

[0058]

[0065] Regardless of how the components are incorporated into the composition, the resulting melt viscosity is generally low enough to flow easily into the mold cavity and form small-sized electrical components. For example, in one particular embodiment, the polymer composition melts in 1,000 seconds. -1 The melt viscosity may be approximately 500 Pa·s or less, approximately 250 Pa·s or less in some embodiments, approximately 5 Pa·s to approximately 150 Pa·s in some embodiments, approximately 5 Pa·s to approximately 100 Pa·s in some embodiments, approximately 10 Pa·s to approximately 100 Pa·s in some embodiments, and approximately 15 to approximately 90 Pa·s in some embodiments, which is determined by the shear rate. II. RF filter

[0066] As described above, the RF filter of the present invention typically includes one or more resonant elements (e.g., piezoelectric materials, dielectric materials, etc.) capable of producing resonant behavior in a narrow frequency band at a desired 5G frequency. The specific configuration and operation of the filter may vary as known to those skilled in the art. For example, the RF filter may be an acoustic filter such as a surface acoustic wave (SAW) filter, a bulk acoustic wave (BAW) filter, or a film bulk acoustic resonator (FBAR or TFBAR). Such acoustic filters generally utilize piezoelectric materials such as quartz, lithium tantalate, lithium niobate, lanthanum gallium silicate, or aluminum nitride. For example, in a SAW filter, an electrical input signal is converted into an elastic wave by alternatingly arranged metal interdigital transducers (IDTs) fabricated on a piezoelectric substrate. In a BAW filter, the piezoelectric substrate is sandwiched between two electrodes and acoustically isolated from the surrounding medium. In this method, the elastic wave is excited and reflected by the electrical input signal and propagates perpendicularly to form a standing elastic wave. The thin outer layer acts as an acoustic reflector, preventing elastic waves from escaping into the substrate. In an FBAR filter, a cavity is etched beneath the active region, and therefore the air / crystal interfaces on both sides of the resonator trap the elastic waves.

[0059]

[0067] Apart from acoustic filters, other types of RF filters can also be used. For example, a cavity filter may be used in which resonant elements (e.g., dielectric materials) are arranged in a plurality of cavities formed within a housing structure. One of the most frequently used resonators in cavity filters is a coaxial resonator structured to have a cylindrical body in which holes or recesses are formed. Suitable dielectric materials may include, for example, titanate-based, niobate-based, and / or tantalate (BZT)-based dielectric materials, such as barium titanate, strontium titanate, and barium strontium titanate.

[0060]

[0068] RF filters, regardless of their specific configuration, can utilize the polymer compositions of the present invention, which have low dielectric constant and dielectric loss tangent, resulting in good performance in a wide variety of ways at 5G frequencies. For example, in acoustic filters, the polymer composition may be used to form a substrate for supporting a resonant element (e.g., a piezoelectric material). In such embodiments, the resonant element may be supported by the substrate by directly distributing the resonant element on the substrate. Alternatively, various other layers (e.g., reflectors, adhesives, etc.) may be located between the substrate and the resonant element. Referring to Figure 6, for example, one embodiment of a SAW filter 100 is shown, where an electrical input signal is provided via an electrical port 102 (i.e., an I / O pad) and converted into an elastic wave by alternatingly arranged metal interdigital transducers 104 created on a piezoelectric substrate 106. If desired, a piezoelectric substrate may be formed from the polymer composition of the present invention. 106 A substrate 108 supporting the piezoelectric substrate 116 may also be provided. Similarly, referring to Figure 7, one embodiment of the BAW filter 110 is shown, where the piezoelectric substrate 116 is located between an upper metal layer 112 and a lower metal layer (not shown). In this method, elastic waves are excited in response to an electrical input signal supplied thereto through an electrical port 118. If desired, a substrate 128, formed from the polymer composition of the present invention and supporting the piezoelectric substrate 116, may also be provided directly or indirectly via a metal layer. When the polymer composition is used for a substrate such as that shown in Figure 6 or 7, it may optionally contain laser-activatable additives so that conductive elements (e.g., transducers, metal layers, etc.) can later be formed on the substrate using laser direct structuring ("LDS"). Laser activation causes a physicochemical reaction in which the spinel crystal cracks and metal atoms are released. These metal atoms may act as nuclei for metallization (e.g., reductive copper coating). Furthermore, the laser creates a microscopically irregular surface, polishing the polymer matrix to create numerous microscopic depressions and grooves, into which copper can adhere during metallization.

[0061]

[0069] As described above, the RF filter may also include a housing that covers one or more elements of the filter (e.g., a resonant element, a support substrate, etc.) to form individual packages. In such embodiments, the housing may be made from the polymer composition of the present invention. Referring to Figure 8, for example, an example of an RF filter package 10 is shown, which contains a resonant element 14 (e.g., a piezoelectric material) supported by the substrate 18 described above. In this embodiment, an adhesive 24 is used to bond the substrate 18 to the resonant element 14, but this is by no means mandatory. If desired, the substrate 18 may be formed from the polymer composition of the present invention. A housing 20 is also provided to cover the resonant element 14 and the substrate 18 to provide protection and structural integrity. If desired, the housing 20 may be formed from the polymer composition of the present invention. Optionally, vias 26 extending to the resonant element 14 are formed through the substrate 18. Next, metal wiring 28 for providing electrical connections is formed / patterned in the package 10, the wiring 28 being formed in vias 26, reaching I / O pads 30 on the front of the resonant element 14, and exiting onto the surface of the dielectric layer 18. The polymer composition used for the substrate 18 and / or housing 20 may optionally include laser-activatable additives so that the wiring 28 and / or pads 30 can be formed using a laser direct structuring process ("LDS"). If desired, air cavities 34 may also be provided in the adhesive layer 24 to allow proper vibration by the resonant element 14 and the resulting generation of elastic waves. Input / output (I / O) connections 38 (e.g., solder balls) may also be provided on the metal wiring 28 to connect the package 10 to an external device (not shown), such as a printed circuit board.

[0062]

[0070] In the embodiments discussed above and shown in Figures 6-8, the polymer composition of the present invention is used in an acoustic RF filter. However, as mentioned above, various other RF filter configurations can also utilize the polymer composition. For example, in one embodiment, the RF filter may be a cavity filter. Referring to Figure 9, for example, one embodiment of a cavity filter 1000 is shown, which is a housing. 1100The housing 1100 includes a cover 1110, one or both of which may be formed from the polymer composition of the present invention. As shown, a plurality of cavities 1102 in which the resonant element 1104 can be located may be formed within the housing 1100. A resonant element 1104 suitable for this purpose may include, for example, a dielectric material. Although not essential, the resonant element 1104 may have a cylindrical shape, and recesses or holes may be formed in at least a portion of the cylinder. Naturally, a disc-shaped resonator can also be used as needed, and resonators having any of the various known shapes are applicable to embodiments of the present invention. The resonant element 1104 may be connected to the bottom of the cavity by using bolts or the like. If desired, the housing 1100 may contain metal plating (e.g., silver or copper), which can be formed by laser direct structuring if the polymer composition contains a laser metal-activatable additive. The filter housing 1100 and cover 1110 may have a ground potential, and a pressing member 2000 may be used in the insertion region 1450 to apply the pressure required for tight pressing in order to facilitate obtaining desired electrical characteristics and to ensure good fastening. The position of the insertion region 1450 formed in the cover 1110 may correspond to the position of the resonator 1104. III. Purpose

[0071] RF filters may be used in a wide variety of different applications. In certain embodiments, RF filters are configured for use in 5G antenna systems in particular. More specifically, RF filters are configured to filter out specific frequencies outside the 5G frequency band that would interfere with the desired signal to and from the antenna system, and otherwise interfere with other electrical components such as low-noise amplifiers (LNAs), oscillators, or transceivers. As used herein, “5G” generally refers to high-speed data communication using radio frequency signals. 5G networks and systems can communicate data at much faster speeds than previous generations of data communication standards (e.g., “4G”, “LTE”). Various standards and specifications have been published that quantify the requirements for 5G communication. For example, the International Telecommunications Union (ITU) published the International Mobile Telecommunications-2020 (“IMT-2020”) standard in 2015. The IMT-2020 standard defines various data transmission standards for 5G (e.g., downlink and uplink data rates, latency, etc.). The IMT-2020 standard specifies uplink and downlink peak data rates as the minimum data rates that 5G systems must support for uploading and downloading data. The IMT-2020 standard sets the downlink peak data rate requirement at 20 Gbit / s and the uplink peak data rate at 10 Gbit / s. As another example, 3 rdThe Generation Partnership Project (3GPP®) recently published a new standard for 5G called "5G NR". In 2018, 3GPP® issued "Release 15," which defines "Phase 1" as the standardization of 5G NR. 3GPP® defines the 5G frequency band as "Frequency Range 1" (FR1), which generally includes frequencies below 6 GHz, and "Frequency Range 2" (FR2), which includes frequencies in the range of 20 to 60 GHz. However, as used herein, "5G frequency" may refer to systems that utilize frequencies greater than 60 GHz, for example, up to 80 GHz, up to 150 GHz, and up to 300 GHz. As used herein, "5G frequency" may refer to frequencies of approximately 2.5 GHz or higher, approximately 3.0 GHz or higher in some embodiments, approximately 3 GHz to approximately 300 GHz or higher in some embodiments, approximately 4 GHz to approximately 80 GHz in some embodiments, approximately 5 GHz to approximately 80 GHz in some embodiments, approximately 20 GHz to approximately 80 GHz in some embodiments, and approximately 28 GHz to approximately 60 GHz in some embodiments.

[0063]

[0072] 5G antenna systems generally utilize high-frequency antennas and antenna arrays used in base stations, repeaters (e.g., "femtocells"), relay stations, terminals, user devices, and / or other suitable components of a 5G system. Antenna elements / arrays and systems may meet or be considered "5G" based on standards published by 3GPP®, such as Release 15 (2018), and / or the IMT-2020 standard. To achieve such high-speed data communication at high frequencies, antenna elements and arrays generally utilize small feature sizes / spacing (e.g., fine-pitch technology) and / or advanced materials that can improve antenna performance. For example, feature size (spacing between antenna elements, width of antenna elements), etc., generally depends on the wavelength ("λ") of the desired transmit and / or receive radio frequency propagating through the circuit board on which the antenna elements are formed (e.g., nλ / 4, where n is an integer). Furthermore, beamforming and / or beam steering can be utilized to facilitate transmission and reception across multiple frequency ranges or channels (e.g., multiple input multiple output (MIMO), large-scale MIMO). High-frequency 5G antenna elements may have various configurations. For example, a 5G antenna element may be a coplanar waveguide element, a patch array (e.g., a mesh grid patch array), or other suitable 5G antenna configurations, or may include these. The antenna element may be configured to provide MIMO, large-scale MIMO functionality, beam steering, etc. As used herein, "large-scale" MIMO functionality generally refers to the provision of a large number of transmit and receive channels by an antenna array, e.g., eight transmit (Tx) channels and eight receive (Rx) channels (abbreviated as 8×8). Large-scale MIMO functionality may include 8×8, 12×12, 16×16, 32×32, 64×64 or more.

[0064]

[0073] Antenna elements may be manufactured using various manufacturing techniques. For example, antenna elements and / or related elements (e.g., ground elements, feed lines, etc.) may utilize fine-pitch techniques. Fine-pitch techniques generally refer to small or minute spacings between their components or leads. For example, feature dimensions and / or spacings between antenna elements (or between antenna elements and the ground plane) may be about 1,500 micrometers or less, 1,250 micrometers or less in some embodiments, 750 micrometers or less in some embodiments (e.g., center-to-center spacing of 1.5 mm or less), 650 micrometers or less, 550 micrometers or less in some embodiments, 450 micrometers or less in some embodiments, 350 micrometers or less in some embodiments, 250 micrometers or less in some embodiments, 150 micrometers or less in some embodiments, 100 micrometers or less in some embodiments, and 50 micrometers or less in some embodiments. However, it should be understood that smaller and / or larger feature sizes and / or spacings may be utilized. As a result of such small feature dimensions, antenna configurations and / or arrays with a large number of antenna elements can be achieved within a small footprint. For example, an antenna array may have an average antenna element density of more than 1,000 antenna elements per square centimeter, more than 2,000 antenna elements per square centimeter in some embodiments, more than 3,000 antenna elements per square centimeter in some embodiments, more than 4,000 antenna elements per square centimeter in some embodiments, more than 6,000 antenna elements per square centimeter in some embodiments, and more than approximately 8,000 antenna elements per square centimeter in some embodiments. Such a dense arrangement of antenna elements can provide more channels for MIMO functionality per unit area of ​​the antenna region. For example, the number of channels may correspond to the number of antenna elements (for example, they may be equivalent or proportional).

[0065]

[0074] Referring, for example to Figure 1, the 5G antenna system 100 may include a base station 102, one or more relay stations 104, one or more user computing devices 106, one or more Wi-Fi repeaters 108 (e.g., “femtocells”) and / or other suitable antenna components of the 5G antenna system 100. The relay station 104 may be configured to facilitate communication between the user computing device 106 and / or other relay stations 104 and the base station 102 by relaying or “repeating” signals between the base station 102 and the user computing device 106 and / or the relay station 104. The base station 102 may include the relay station 104, the Wi-Fi repeater 108 and / or a MIMO antenna array 110 configured to receive and / or transmit radio frequency signals 112 directly to the user computing device 106. 106 This includes, but is not necessarily limited by, devices such as 5G smartphones.

[0066]

[0075] The MIMO antenna array 110 may utilize beam steering to focus or direct radio frequency signals 112 toward the relay station 104. For example, the MIMO antenna array 110 may be configured to adjust its elevation angle 114 toward a heading angle 116 defined in the XY and / or ZY planes, as well as toward the Z direction. Similarly, one or more of the relay station 104, user computing device 106, and Wi-Fi repeater 108 may utilize beam steering to improve their receiving and / or transmitting capabilities toward the MIMO antenna array 110 by directionally tuning the sensitivity and / or transmission of devices 104, 106, and 108 toward the base station 102's MIMO antenna array 110 (for example, by adjusting one or both of the relative elevation and / or relative azimuth angles of each device).

[0067]

[0076] Similarly, Figures 2A and 2B are a top view and a side view, respectively, of an exemplary user computing device 106. The user computing device 106 may include one or more antenna elements 200, 202 (for example, arranged as each antenna array). Referring to Figure 2A, the antenna elements 200, 202 may be configured to perform beam steering in the XY plane (indicated by arrows 204, 206, corresponding to relative azimuth angles). Referring to Figure 2B, the antenna elements 200, 202 may be configured to perform beam steering in the ZY plane (indicated by arrows 204, 206).

[0068]

[0077] Figure 3 is a simplified schematic diagram of multiple antenna arrays 302 connected using each feedline 304 (e.g., to a front-end module). The antenna arrays 302 can be mounted on the side 306 of the substrate 308, as described and illustrated with respect to Figures 4A-4C, for example. The antenna arrays 302 may include multiple vertically connected elements (e.g., a mesh grid array). Thus, the antenna arrays 302 may generally extend parallel to the side 306 of the substrate 308. A shield may optionally be provided on the side 306 of the substrate 308 so that the antenna arrays 302 are located outside the shield relative to the substrate 308. The vertical spacing distance between the vertically connected elements of the antenna arrays 302 is the antenna array 302 This may correspond to the "feature size". Therefore, in some embodiments, these spacing distances may be relatively small (e.g., less than about 750 micrometers) so that the antenna array 302 is a "fine-pitch" antenna array 302.

[0069]

[0078] Figure 4 is a side view of the configuration of a coplanar waveguide antenna 400. One or more coplanar ground layers 402 may be arranged parallel to the antenna elements 404 (e.g., patch antenna elements). Another ground layer 406 may be separated from the antenna elements by a substrate 408. One or more further antenna elements 410 may be separated from the antenna elements 404 by a second layer or substrate 412, which may be a circuit board as described herein. Dimensions "G" and "W" may correspond to the "characteristic size" of the antenna 400. Dimension "G" may correspond to the distance between the antenna elements 404 and the coplanar ground layer 406. Dimension "W" may correspond to the width (e.g., line width) of the antenna elements 404. Thus, in some embodiments, dimensions "G" and "W" may be relatively small (e.g., less than about 750 micrometers) so that the antenna 400 is a "fine-pitch" antenna 400.

[0070]

[0079] Figure 5A is a diagram of one embodiment of the antenna array 500. The antenna array 500 may include a substrate 510 and a plurality of antenna elements 520 formed thereon. The plurality of antenna elements 520 may be substantially uniform in size in the X and / or Y directions (e.g., square or rectangular). The plurality of antenna elements 520 may be substantially uniformly spaced in the X and Y directions. The dimensions of the antenna elements 520 and / or the spacing between them may correspond to the “characteristic size” of the antenna array 500. Thus, in some embodiments, the dimensions and / or spacing may be relatively small so that the antenna array 500 is a “fine-pitch” antenna array 500 (e.g., less than about 750 micrometers). The number of columns of the antenna elements 520 illustrated in Figure 5, as shown by the ellipsis 522, is shown only as an example. Similarly, the number of rows of the antenna elements 520 is shown only as an example.

[0071]

[0080] A tuned antenna array 500 can be used to provide, for example, a base station with large-scale MIMO functionality (as described above with respect to Figure 1, for example). More specifically, the interaction of radio frequencies between various elements may be controlled or tuned to provide multiple transmit and / or receive channels. The transmit power and / or receive sensitivity may be directionally controlled to concentrate or direct the radio frequency signal, as described, for example, with respect to the radio frequency signal 112 in Figure 1. The tuned antenna array 500 can accommodate a large number of antenna elements 522 within a small footprint. For example, the tuned antenna 500 may have an average antenna element density of 1,000 or more antenna elements per square centimeter. Such a dense arrangement of antenna elements can provide more MIMO channels per unit area. For example, the number of channels may correspond to the number of antenna elements (for example, they may be equivalent or proportional).

[0072]

[0081] Figure 5B is a diagram of an embodiment of the antenna array 540. The antenna array 540 may include a plurality of antenna elements 542 and a plurality of feed lines 544 connecting the antenna elements 542 (e.g., to other antenna elements 542, a front-end module, or other suitable components). The antenna elements 542 may each have a width "w" and spacing distances "S1" and "S2" between them (e.g., in the X and Y directions, respectively). These dimensions may be selected to achieve 5G frequency communication at a desired 5G frequency. More specifically, the dimensions may be selected to tune the antenna array 540 to transmit and / or receive data using radio frequency signals within the 5G frequency spectrum (e.g., greater than 2.5 GHz and / or greater than 3 GHz and / or greater than 28 GHz). The dimensions may be selected based on the material properties of the substrate. For example, one or more of "w", "S1", or "S2" may correspond to multiple propagation wavelengths ("λ") of a desired frequency passing through the substrate material (e.g., nλ / 4, where n is an integer).

[0073]

[0082] For example, λ is as follows:

[0074]

number

[0075] (In the formula, c is the speed of light in a vacuum, ε R (where f is the relative permittivity of the substrate (or surrounding material) and f is the desired frequency.) It can also be calculated as follows.

[0076]

[0083] Figure 5C shows an exemplary antenna configuration 560 according to an aspect of the present invention. The antenna configuration 560 may include a plurality of antenna elements 562 arranged on parallel long sides of a substrate 564. The various antenna elements 562 may have lengths "L" (and spacing distances between them) that tune the antenna configuration 560 to receive and / or transmit at a desired frequency and / or frequency range. More specifically, such dimensions may be selected based on the propagation wavelength λ at a desired frequency for the substrate material, as described above with reference to, for example, Figure 5B.

[0077]

[0084] The present invention can be better understood by referring to the following examples. Test method

[0085] Melt viscosity: Melt viscosity (Pa·s) was measured using a Dynisco LCR7001 capillary rheometer at a shear rate of 1,000 s. -1 The melting temperature may also be determined according to ISO Test No. 11443:2005 at a temperature exceeding 15°C (e.g., approximately 350°C). The rheometer orifice (die) had a diameter of 1 mm, a length of 20 mm, an L / D ratio of 20.1, and an inlet angle of 180°. The barrel diameter was 9.55 mm + 0.005 mm, and the rod length was 233.4 mm.

[0078]

[0086] Melting temperature: The melting temperature ("Tm") may be determined by differential scanning calorimetry ("DSC") as is known in the art. The melting temperature is the peak melting temperature of differential scanning calorimetry (DSC) as determined by ISO test No. 11357-2:2013. Using DSC measurements performed on a TA Q2000 instrument according to the DSC procedure, the sample was heated and cooled at 20°C per minute as described in ISO standard 10350.

[0079]

[0087] Temperature of deflection under load ("DTUL"): The temperature of deflection under load may be determined according to ISO Test No. 75-2:2013 (which is technically equivalent to ASTM D648-07). More specifically, a specimen sample measuring 80 mm in length, 10 mm in thickness, and 4 mm in width may be subjected to an edgewise three-point bending test with a specified load (maximum external fiber stress) of 1.8 megapascals. The specimen is lowered into a silicone oil bath and the temperature is increased at 2°C per minute until the specimen deflects by 0.25 mm (0.32 mm in ISO Test No. 75-2:2013).

[0080]

[0088] Tensile modulus, tensile stress, and tensile elongation: Tensile properties may be tested according to ISO Test No. 527:2012 (technically equivalent to ASTM D638-14). Measurements of modulus and strength may be performed on the same test specimen with a length of 80 mm, a thickness of 10 mm, and a width of 4 mm. The test temperature may be approximately 23°C, and the test speed may be 1 or 5 mm / min.

[0081]

[0089] Bending modulus, bending stress, and bending elongation: Bending properties may be tested according to ISO Test No. 178:2010 (technically equivalent to ASTM D790-10). This test may be performed on a support span of 64 mm. The test may be performed at the center of an uncut ISO 3167 multipurpose bar. The test temperature may be approximately 23°C, and the test speed may be 2 mm / min.

[0082]

[0090] Charpy impact strength with and without notches: Charpy impact strength may be tested according to ISO test No. ISO179-1:2010 (technically equivalent to ASTM D256-10, Method B). This test may be performed using a Type 1 specimen size (80 mm in length, 10 mm in width, and 4 mm in thickness). When testing impact strength with notches, the notch may be a Type A notch (0.25 mm base radius). Specimens may be cut from the center of a multipurpose bar using a single-tooth milling machine. The test temperature may be approximately 23°C.

[0083]

[0091] Relative permittivity ("Dk") and dielectric loss tangent ("Df"): Relative permittivity (or relative static permittivity) and dielectric loss tangent are determined according to IEC 60250:1969. Such techniques are also found in Baker-Jarvis, et al., IEEE Trans. on Dielectric and Electrical Insulation, 5(4), p. 571 (1998) and Krupka, et al., Proc. 7 th This is described in the International Conference on Dielectric Materials: Measurements and Applications, IEEE Conference Publication No. 430 (September 1996). More specifically, a plate-shaped sample measuring 80 mm × 80 mm × 1 mm was inserted between two fixed dielectric resonators. The dielectric constant component on the surface of the sample was measured using the resonators. Five samples may be tested, and the average value was recorded. [Examples]

[0084] Example 1

[0092] Samples 1-3 for use in RF filters were formed. LCP1 was formed from 60% HBA, 4% HNA, 18% TA, and 18% BP. LCP2 was formed from 48% HNA, 2% HBA, 25% BP, and 25% TA. The formulation was carried out using an 18mm single-screw extruder. The parts were injection molded to form the samples into plates (60mm x 60mm). The formulation is described below.

[0085] [Table 1]

[0086]

[0093] Samples 1-3 were tested for thermal and mechanical properties. The results are described below.

[0087] [Table 2]

[0088] Example 2

[0094] Samples 4-10 were formed from various combinations of liquid crystal polymers (LCP1 and LCP3), copper chromate filler (CuCr2O4), glass fibers, alumina trihydrate ("ATH"), lubricant (polyethylene wax), and polytetrafluoroethylene ("PTFE1" or "PTFE2"). LCP3 was formed from 43% HBA, 9% TA, 29% HQ, and 20% NDA. PTFE1 is a powder of polytetrafluoroethylene particles with D50 particle size of 4 μm and D90 particle size of 15 μm. PTFE2 is a powder of polytetrafluoroethylene particles with D50 particle size of 40 μm. Formulation was carried out using an 18 mm single-screw extruder. The parts were injection molded to form the samples into plates (60 mm × 60 mm).

[0089] [Table 3]

[0090]

[0095] Samples 4-10 were tested for thermal and mechanical properties. The results are shown in the table below.

[0091] [Table 4]

[0092] Example 3

[0096] Sample 11 contains 100 wt.% LCP4 for use in RF filters, which is composed of 62% HNA, 2% HBA, 18% TA, and 18% BP. The sample is injection molded into a plate (60 mm × 60 mm) and tested for thermal and mechanical properties. The results are described below.

[0093] [Table 5]

[0094] Example 4

[0097] Samples 17-24 were formed from various combinations of liquid crystal polymer (LCP2), milled and / or flattened chopped glass fiber strands (aspect ratio = 4), mica (MICA1 and MICA2), and silica. MICA1 had an average particle size of 25 micrometers, and MICA2 had an average particle size of 60 micrometers. Formulation was carried out using an 18 mm single-screw extruder. The parts were injection molded to form the samples into plates (60 mm × 60 mm).

[0095] [Table 6]

[0096]

[0098] Samples 12-19 were tested for thermal and mechanical properties. The results are shown in the table below.

[0097] [Table 7]

[0098] Example 5

[0099] Sample 20 contains 100 wt.% LCP5 for use in RF filters, which is composed of 73% HNA and 27% HBA. The sample is injection molded into a plate (60 mm x 60 mm) and tested for thermal and mechanical properties. The results are described below.

[0099] [Table 8]

[0100] Example 6

[0100] Sample 21 contains 100 wt.% LCP6 ​​for use in RF filters, which is formed from 78% HNA, 2% HBA, 10% TA, and 10% BP. The sample is injection molded into a plate (60 mm × 60 mm) and tested for thermal and mechanical properties. The results are described below.

[0101] [Table 9]

[0102] Example 7

[0101] Sample 22 contains 100 wt.% LCP7 for use in RF filters, which is formed from 79% HNA, 2% HBA, 14% TA, and 14% BP. The sample is injection molded into a plate (60 mm × 60 mm) and tested for thermal and mechanical properties. The results are described below.

[0103] [Table 10]

[0104] Example 8

[0102] Sample 23 contains 100 wt.% LCP8 for use in RF filters, which is formed from 48% HNA, 2% HBA, 25% NDA, and 25% BP. The sample is injection molded into a plate (60 mm × 60 mm) and tested for thermal and mechanical properties. The results are described below.

[0105] [Table 11]

[0106] Example 9

[0103] Sample 24 contains 100 wt.% LCP9 for use in RF filters, which is formed from 76% HNA and 24% HBA. The sample is injection molded into a plate (60 mm x 60 mm) and tested for thermal and mechanical properties. The results are described below.

[0107] [Table 12]

[0108] Example 10

[0104] Samples 25-26 were formed from various combinations of liquid crystal polymers (LCP9 and LCP4) and PTFE1. The compounding was carried out using an 18mm single-screw extruder. The parts were injection molded to form the samples into plates (60mm x 60mm).

[0109] [Table 13]

[0110]

[0105] Samples 38-39 were tested for thermal and mechanical properties. The results are shown in the table below.

[0111] [Table 14]

[0112] Example 11

[0106] Samples 27 and 28 may be used in RF filters. Sample 27 contains 70 wt.% LCP3 and 30 wt.% PTFE1, and sample 28 contains 65 wt.% LCP3 and 35 wt.% PTFE1. Samples 27 and 28 were tested for thermal and mechanical properties. The results are described below.

[0113] [Table 15]

[0114]

[0107] These and other modifications and variations of the present invention shall not deviate from the spirit and scope of the present invention. It can be implemented by those skilled in the art without omission. Furthermore, it should be understood that the various embodiments are interchangeable, both in whole and in part. Moreover, those skilled in the art will understand that the foregoing description is merely illustrative and does not limit the invention to what is further described in the appended claims. The following is a description of the claims as they were at the time of filing the application. [Claim 1] An RF filter comprising a resonant element and a polymer composition, wherein the polymer composition contains an aromatic polymer and has a melting temperature of about 240°C or higher, and the polymer composition exhibits a relative permittivity of about 5 or less and a dielectric loss tangent of about 0.05 or less at a frequency of 10 GHz. [Claim 2] The RF filter according to claim 1, wherein the filter is an acoustic filter containing a piezoelectric material. [Claim 3] The RF filter according to claim 2, wherein a transducer is formed on the piezoelectric material. [Claim 4] The RF filter according to claim 2, wherein the piezoelectric material is located between the upper metal layer and the lower metal layer. [Claim 5] The RF filter according to claim 2, wherein the acoustic filter includes a substrate that supports the piezoelectric material. [Claim 6] The RF filter according to claim 5, wherein the substrate contains the polymer composition. [Claim 7] The RF filter according to claim 2, further comprising a housing covering the resonant element. [Claim 8] The RF filter according to claim 7, wherein the housing contains the polymer composition. [Claim 9] The RF filter according to any one of claims 1 to 8, which is a cavity filter that includes a housing that defines a cavity in which the resonant element is received. [Claim 10] The RF filter according to claim 9, wherein the resonant element is a dielectric material. [Claim 11] The RF filter according to claim 9, wherein the housing contains the polymer composition. [Claim 12] The RF filter according to claim 9, further comprising a cover that covers the housing, the cover comprising the polymer composition. [Claim 13] The RF filter according to any one of claims 1 to 12, wherein the aromatic polymer has a glass transition temperature of about 30°C or higher and a melting temperature of about 240°C or higher. [Claim 14] The RF filter according to any one of claims 1 to 13, wherein the aromatic polymer constitutes about 40 wt.% to about 99 wt.% of the polymer composition. [Claim 15] The RF filter according to any one of claims 1 to 14, wherein the aromatic polymer is polyarylene sulfide. [Claim 16] The RF filter according to any one of claims 1 to 15, wherein the aromatic polymer is a liquid crystal polymer. [Claim 17] The RF filter according to claim 16, wherein the liquid crystal polymer contains repeating units derived from one or more aromatic dicarboxylic acids, one or more aromatic hydroxycarboxylic acids, or a combination thereof. [Claim 18] The RF filter according to claim 17, wherein the aromatic hydroxycarboxylic acid comprises 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, or a combination thereof. [Claim 19] The RF filter according to claim 17, wherein the aromatic hydroxycarboxylic acid comprises terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, or a combination thereof. [Claim 20] The RF filter according to claim 17, wherein the liquid crystal polymer further contains repeating units derived from one or more aromatic diols. [Claim 21] The RF filter according to claim 20, wherein the aromatic diol comprises hydroquinone, 4,4'-biphenol, or a combination thereof. [Claim 22] The RF filter according to claim 16, wherein the liquid crystal polymer is fully aromatic. [Claim 23] The RF filter according to claim 16, wherein the liquid crystal polymer contains repeating units derived from 6-hydroxy-2-naphthoic acid in an amount of about 30 mol.% or more. [Claim 24] The RF filter according to claim 16, wherein the liquid crystal polymer contains repeating units derived from 6-hydroxy-2-naphthoic acid in an amount of about 50 mol.% or more. [Claim 25] The RF filter according to any one of claims 1 to 24, wherein the polymer composition further comprises a fibrous filler. [Claim 26] The RF filter according to claim 25, wherein the fibrous filler includes glass fibers. [Claim 27] The RF filter according to claim 25, wherein the fibrous filler has an aspect ratio of about 2 or more. [Claim 28] The RF filter according to any one of claims 1 to 27, wherein the polymer composition further comprises a particulate filler. [Claim 29] The RF filter according to claim 28, wherein the particulate packing material includes mica. [Claim 30] The RF filter according to any one of claims 1 to 29, further comprising a laser-activatable additive in the polymer composition. [Claim 31] The RF filter according to any one of claims 1 to 30, wherein the polymer composition exhibits a relative permittivity of about 1.5 to about 4 at a frequency of 2 GHz. [Claim 32] The RF filter according to any one of claims 1 to 31, wherein the polymer composition exhibits a dielectric loss tangent of about 0.0009 or less at a frequency of 2 GHz. [Claim 33] A 5G antenna system comprising an RF filter according to any one of claims 1 to 32, and at least one antenna element configured to transmit and receive 5G radio frequency signals. [Claim 34] The 5G antenna system according to claim 33, wherein the antenna element has a characteristic size of less than approximately 1,500 micrometers. [Claim 35] The 5G radio frequency signal has a frequency greater than approximately 28 GHz, according to claim 33. G Antenna System. [Claim 36] The 5G antenna system according to claim 33, wherein the at least one antenna element includes a plurality of antenna elements arranged in an antenna array. [Claim 37] The 5G antenna system according to claim 36, wherein the plurality of antenna elements are spaced apart by a distance of less than approximately 1,500 micrometers. [Claim 38] The 5G antenna system according to claim 36, wherein the plurality of antenna elements include at least 16 antenna elements. [Claim 39] The 5G antenna system according to claim 36, wherein the plurality of antenna elements are arranged in a grid. [Claim 40] The 5G antenna system according to claim 36, wherein the antenna array is configured for at least eight transmission channels and at least eight reception channels. [Claim 41] The 5G antenna system according to claim 36, wherein the antenna array has an average antenna element density of more than 1,000 antenna elements per square centimeter. [Claim 42] The 5G antenna system according to claim 33, further comprising a base station, wherein the base station includes the antenna element. [Claim 43] The 5G antenna system according to claim 42, further comprising at least one of a user computing device or a repeater, wherein at least one of the user computing device or repeater base station comprises the antenna element.

Claims

1. An RF filter comprising a resonant element and a housing containing a polymer composition, wherein the polymer composition contains an aromatic polymer and has a melting temperature of about 240°C or higher, the polymer composition exhibits a relative permittivity of about 5 or less and a dielectric loss tangent of about 0.05 or less at a frequency of 10 GHz, and the aromatic polymer contains a liquid crystal polymer containing repeating units derived from 6-hydroxy-2-naphthoic acid in an amount of about 30 mol.% or more and repeating units derived from 4-hydroxybenzoic acid.

2. The RF filter according to claim 1, wherein the RF filter is an acoustic filter containing a piezoelectric material.

3. The RF filter according to claim 2, wherein the transducer is formed on the piezoelectric material.

4. The RF filter according to claim 2, wherein the piezoelectric material is located between the upper metal layer and the lower metal layer.

5. The RF filter according to claim 2, wherein the acoustic filter includes a substrate that supports the piezoelectric material.

6. The RF filter according to claim 5, further comprising the substrate containing the polymer composition.

7. The RF filter according to claim 2, wherein the housing covers the resonant element.

8. An RF filter according to any one of claims 1 to 7, wherein the filter is a cavity filter including the housing, and the housing defines a cavity therein in which the resonant element is housed.

9. The RF filter according to claim 8, wherein the resonant element is a dielectric material.

10. The RF filter according to claim 8, further comprising a cover that covers the housing, wherein the cover further comprises the polymer composition.

11. The RF filter according to any one of claims 1 to 10, wherein the aromatic polymer has a glass transition temperature of about 30°C or higher and a melting temperature of about 240°C or higher.

12. The RF filter according to any one of claims 1 to 11, wherein the aromatic polymer constitutes about 40 wt.% to about 99 wt.% of the polymer composition.

13. The RF filter according to claim 1, wherein the liquid crystal polymer contains repeating units derived from one or more aromatic dicarboxylic acids.

14. The RF filter according to claim 13, wherein the aromatic dicarboxylic acid includes terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, or a combination thereof.

15. The RF filter according to claim 13, wherein the liquid crystal polymer further contains repeating units derived from one or more aromatic diols.

16. The RF filter according to claim 15, wherein the aromatic diol comprises hydroquinone, 4,4'-biphenol, or a combination thereof.

17. The RF filter according to claim 1, wherein the liquid crystal polymer is fully aromatic.

18. The RF filter according to claim 1, wherein the liquid crystal polymer contains repeating units derived from 6-hydroxy-2-naphthoic acid in an amount of about 50 mol.% or more.

19. The RF filter according to any one of claims 1 to 18, wherein the polymer composition further comprises a fibrous filler.

20. The RF filter according to claim 19, wherein the fibrous filler includes glass fibers.

21. The RF filter according to claim 19, wherein the fibrous filler has an aspect ratio of about 2 or more.

22. The RF filter according to any one of claims 1 to 21, wherein the polymer composition further comprises a particulate filler.

23. The RF filter according to claim 22, wherein the particulate filler contains mica.

24. The RF filter according to any one of claims 1 to 23, further comprising a laser-activatable additive in the polymer composition.

25. The RF filter according to any one of claims 1 to 24, wherein the polymer composition exhibits a relative permittivity of about 1.5 to about 4 at a frequency of 2 GHz.

26. The RF filter according to any one of claims 1 to 25, wherein the polymer composition exhibits a dielectric loss tangent of about 0.0009 or less at a frequency of 2 GHz.

27. A 5G antenna system comprising an RF filter according to any one of claims 1 to 26, and at least one antenna element configured to transmit and receive 5G radio frequency signals.

28. The 5G antenna system according to claim 27, wherein the antenna element has a characteristic size of less than approximately 1,500 micrometers.

29. The 5G antenna system according to claim 27, wherein the 5G radio frequency signal has a frequency greater than approximately 28 GHz.

30. The 5G antenna system according to claim 27, wherein the at least one antenna element includes a plurality of antenna elements arranged in an antenna array.

31. The 5G antenna system according to claim 30, wherein the plurality of antenna elements are spaced apart by a distance of less than approximately 1,500 micrometers.

32. The 5G antenna system according to claim 30, wherein the plurality of antenna elements include at least 16 antenna elements.

33. The 5G antenna system according to claim 30, wherein the plurality of antenna elements are arranged in a grid.

34. The 5G antenna system according to claim 30, wherein the antenna array is configured for at least eight transmission channels and at least eight reception channels.

35. The 5G antenna system according to claim 30, wherein the antenna array has an average antenna element density of more than 1,000 antenna elements per square centimeter.

36. The 5G antenna system according to claim 27, further comprising a base station, wherein the base station includes the antenna element.

37. The 5G antenna system according to claim 36, further comprising at least one of a user computing device or a repeater, wherein at least one of the user computing device or repeater base station comprises the antenna element.

38. The RF filter according to claim 1, wherein the liquid crystal polymer has a molar ratio of 2.7 to 40 of repeating units derived from 6-hydroxy-2-naphthoic acid to repeating units derived from 4-hydroxybenzoic acid.

39. An RF filter comprising a resonant element and a housing containing a polymer composition, wherein the polymer composition contains an aromatic polymer and has a melting temperature of about 240°C or higher, the polymer composition exhibits a relative permittivity of about 5 or less and a dielectric loss tangent of about 0.0015 or less at a frequency of 10 GHz, and the aromatic polymer contains a liquid crystal polymer containing repeating units derived from 6-hydroxy-2-naphthoic acid in an amount of about 30 mol.% or more and repeating units derived from 4-hydroxybenzoic acid.

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