RF filter for use at 5g frequencies

Abstract

To provide a radiofrequency (RF) filter comprising a resonator element and a polymer composition for use in 5G applications, such as an acoustic filter or cavity filter.SOLUTION: The polymer composition contains an aromatic polymer and has a melting temperature of about 240°C or more. 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. A cavity filter 1000 contains a housing 1100 and a cover 1110, one or both of which are formed from the polymer composition. Multiple cavities 1102 are formed within the housing 1100 within which resonator elements 1104 may be positioned. The resonator elements 1104 may include a dielectric material and have a cylindrical shape, and a recess or hole may be formed in at least a portion of the cylinder.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] Cross - reference to related applications

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

Background Art

[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 the transmission and reception paths of up to 15 bands of 2G, 3G, and 4G wireless access methods, as well as Wi - Fi, Bluetooth, and GPS receivers. However, with the shift to 5G applications, such filters are exposed to high frequencies, which may increase power consumption and heat generation. As a result, due to high - frequency performance requirements, most conventional RF filters are insufficient for 5G applications. Therefore, there is a need for improved RF filters for use in 5G antenna systems.

Summary of the Invention

Means for Solving the Problems

[0003]

[0003] According to one embodiment of the present invention, an RF filter including 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 dissipation factor 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 enabling disclosure of the present invention, including the best mode thereof for those skilled in the art, is set forth in more detail in the remainder of this specification, including reference to the accompanying drawings.

Brief Description of the Drawings

[0005]

Figure 1

[0006] FIG. 1 is a diagram of an embodiment of a 5G antenna system that can be used in the present invention.

Figure 2A

[0007] FIG. 2A is a top view of an exemplary user computing device including a 5G antenna.

Figure 2B

[0008] FIG. 2B is a side view of the exemplary user computing device of FIG. 2A.

Figure 3

[0009] FIG. 2C is an enlarged view of a portion of the user computing device of FIG. 2A.

Figure 4

[0010] FIG. 3 is a side view of a coplanar waveguide antenna array configuration that can be used in a 5G antenna system.

Figure 5A

[0011] FIG. 4 is a diagram of an antenna array for a massive multiple-input multiple-output configuration of a 5G antenna system.

Figure 5B

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

Figure 5C

[0013] FIG. 6 is a diagram of an exemplary antenna configuration that can be used in a 5G antenna system.

Figure 6

[0014] FIG. 7 is a schematic diagram of an embodiment of an RF SAW filter that can be used in the present invention.

Figure 7

[0015] FIG. 8 is a schematic diagram of an embodiment of an RF BAW filter used in the present invention.

Figure 8

[0016] FIG. 9 is a schematic diagram of another embodiment of an RF SAW filter that can be used 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 will be understood by those skilled in the art that this discussion is merely illustrative of exemplary embodiments and does not limit broader aspects of the present invention.

[0019] Generally, the present invention relates to a radio frequency (“RF”) filter for use in 5G applications such as acoustic filters or cavity filters. The RF filter typically has one or more resonant elements (e.g., piezoelectric materials, dielectric materials, etc.) capable of generating resonance behavior in a narrow frequency band of a desired 5G frequency, such as above about 2.5 GHz, in some embodiments above about 3.0 GHz, in some embodiments from about 3 GHz to about 300 GHz or more, in some embodiments from about 4 GHz to about 80 GHz, in some embodiments from about 5 GHz to about 80 GHz, in some embodiments from about 20 GHz to about 80 GHz, in some embodiments from about 28 GHz to about 60 GHz. In particular, according to the present invention, a polymer composition that exhibits a low relative dielectric constant and dielectric tangent over a wide range of frequencies and is particularly suitable for use in 5G applications is utilized in the RF filter (e.g., substrate, housing, etc.). That is, the polymer composition may exhibit a low relative dielectric constant of about 5 or less, in some embodiments about 4.5 or less, in some embodiments from about 0.1 to about 4.4, in some embodiments from about 1 to about 4.2, in some embodiments from about 1.5 to about 4, in some embodiments from about 2 to about 3.9, in some embodiments from about 3.5 to about 3.9 at a typical 5G frequency (e.g., 2 or 10 GHz). The dielectric tangent of the polymer composition, which is a measure of the energy loss rate, may similarly be about 0.05 or less, in some embodiments about 0.01 or less, in some embodiments from about 0.0001 to about 0.008, in some embodiments from about 0.0002 to about 0.006 at a typical 5G frequency (e.g., 2 or 10 GHz). In fact, in some cases, the dielectric tangent may be very low, e.g., about 0.003 or less, in some embodiments 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 from about 0.0001 to about 0.0007 at a typical 5G frequency (e.g., 2 or 10 GHz).

[0007]

[0020] Conventionally, polymer compositions exhibiting low dielectric tangent and relative permittivity were thought not to simultaneously have sufficiently good thermal, mechanical properties and processability (i.e., low viscosity) to enable their use in certain types of applications. However, in contrast to conventional thinking, polymer compositions have been found to have both excellent thermal and mechanical properties and processability. For example, the melting temperature of the polymer composition may be, for example, about 240 °C or higher, in some embodiments about 260 °C, in some embodiments about 280 °C to about 400 °C, and in some embodiments about 250 °C to about 380 °C. Even at such melting temperatures, the ratio of the heat deflection temperature ( "DTUL"), which is a measure of short-term heat resistance, to the melting temperature may still remain relatively high. For example, the ratio may range from about 0.5 to about 1.00, in some embodiments from about 0.6 to about 0.95, and in some embodiments from about 0.65 to about 0.85. Specific DTUL values may be, for example, about 200 °C or higher, in some embodiments about 200 °C to about 350 °C, in some embodiments about 210 °C to about 320 °C, and in some embodiments about 230 °C to about 310 °C. Such high DTUL values can, in particular, enable the use of a fast and reliable surface mounting process for fitting the structure with other components of the electrical component.

[0008]

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

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

[0010]

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

[0011]

Chemical formula

[0012] and segments having the formula:

[0013]

Chemical formula

[0014] a segment having the structure of, or the formula:

[0015]

Chem.

[0016] A polyarylene sulfide copolymer containing a segment having the structure of can be formed.

[0025] The polyarylene sulfide may be linear, semi-linear, branched, or crosslinked. Linear polyarylene sulfide typically contains 80 mol% or more of the repeating unit -(Ar-S)-. Such linear polymers may also contain a small amount 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. The linear polyarylene sulfide polymer may be a random copolymer or a block copolymer containing the above-mentioned repeating units. Semi-linear polyarylene sulfide may similarly have a crosslinked or branched structure in which a small amount of one or more monomers having three or more reactive functional groups are introduced into the polymer. As an example, the monomer component used for the formation of semi-linear polyarylene sulfide may include a certain amount of polyhaloaromatic compound having two or more halogen substituents per molecule, which is available for the preparation of branched polymers. Such monomers have the formula R’X n(In the formula, each X is selected from chlorine, bromine, and iodine, n is an integer of 3 to 6, R' is a polyvalent aromatic group of valence n that may 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), and can be represented by. Examples of some polyhaloaromatic compounds substituted with more than 2 halogens per molecule that can be used for the formation of semi-linear polyarylene sulfide 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'-tetra-iodobiphenyl, 2,2',6,6'-tetrabromo-3,3',5,5'-tetramethylbiphenyl, 1,2,3,4-tetrachloronaphthalene, 1,2,4-tribromo-6-methylnaphthalene, etc., and mixtures thereof.

[0017]

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

[0018]

Chemical formula

[0019] (In the formula, Ring B is a substituted or unsubstituted 6-membered aryl group (e.g., 1,4-phenylene or 1,3-phenylene), a substituted or unsubstituted 6-membered aryl group condensed with a substituted or unsubstituted 5- or 6-membered aryl group (e.g., 2,6-naphthalene), or a substituted or unsubstituted 6-membered aryl group linked to a substituted or unsubstituted 5- or 6-membered aryl group (e.g., 4,4-biphenylene); Y 1 and Y 2 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 Y 1 and Y 2 is C(O). Examples of such aromatic ester repeating units include, for example, aromatic dicarboxylic acid repeating units (where Y 1 and Y 2 in Formula I are C(O)), aromatic hydroxycarboxylic acid repeating units (where Y 1 in Formula I is O and Y 2 is C(O)), and various combinations thereof can be mentioned.

[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, etc., as well as their alkyl, alkoxy, aryl, and halogen substituents, 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, the repeating units derived from hydroxycarboxylic acids (e.g., HBA and / or HNA) typically constitute about 40 mol.% or more of the polymer, in some embodiments about 50 mol.% or more, in some embodiments about 55 mol.% to 100 mol.%, and in some embodiments about 60 mol.% to about 95 mol.%.

[0022]

[0029] Also, aromatic dicarboxylic acid repeats 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, etc., as well as their alkyl, alkoxy, aryl, and halogen substituents, and combinations thereof Repeat units 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, the repeat units derived from the aromatic dicarboxylic acid (e.g., IA, TA, and / or NDA) typically constitute from about 1 mol.% to about 40 mol.% of the polymer, in some embodiments from about 2 mol.% to about 30 mol.%, and in some embodiments from about 5 mol.% to about 25 mol.%.

[0023]

[0030] Other repeating units can also be used in the polymer. For example, in certain embodiments, 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, etc., as well as repeating units derived from aromatic diols such as their alkyl, alkoxy, aryl, and halogen substituents, and combinations thereof, may be used. Particularly preferred aromatic diols include, for example, hydroquinone ("HQ") and 4,4'-biphenol ("BP"). When used, the repeating units derived from the aromatic diol (e.g., HQ and / or BP) typically constitute about 1 mol.% to about 40 mol.% of the polymer, in some embodiments about 2 mol.% to about 30 mol.%, and in some embodiments about 5 mol.% to about 25 mol.%. Also, 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. When used, the repeating units derived from the aromatic amide (e.g., APAP) and / or aromatic amine (e.g., AP) typically constitute about 0.1 mol.% to about 20 mol.% of the polymer, in some embodiments about 0.5 mol.% to about 15 mol.%, and in some embodiments about 1 mol.% to about 10 mol.%. 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, amines, etc. Of course, in other embodiments, the polymer may be "wholly aromatic" in that it does not contain repeating units derived from non-aromatic (e.g., aliphatic or alicyclic) monomers.

[0024]

[0031] Although not necessarily required, the liquid crystal polymer may be a "high naphthene" polymer as long as it contains 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 a combination of HNA and NDA) is typically at least about 10 mol.% of the polymer, in some embodiments at least about 12 mol.%, in some embodiments at least about 15 mol.%, in some embodiments at least about 18 mol.%, in some embodiments at least about 20 mol.%, in some embodiments at least about 30 mol.%, in some embodiments at least about 40 mol.%, in some embodiments at least about 45 mol.%, in some embodiments at least about 50 mol.%, in some embodiments at least about 60 mol.%, in some embodiments at least about 62 mol.%, in some embodiments at least about 68 mol.%, in some embodiments at least about 70 mol.%, and in some embodiments from about 70 mol.% to about 80 mol.%. Without being bound by theory, such "high naphthene" polymers are thought to be able to reduce the water absorption tendency of the polymer composition, thereby promoting the stabilization of the relative permittivity and dielectric tangent in the high frequency range. That is, such high naphthene polymers typically have a water absorption of about 0.015% or less, in some embodiments about 0.01% or less, and in some embodiments from about 0.0001% to about 0.008% after immersion in water for 24 hours in accordance with ISO 62-1:2008. The high naphthene polymer may also have a moisture absorption of about 0.01% or less, in some embodiments about 0.008% or less, and in some embodiments from about 0.0001% to about 0.006% after exposure to a humid atmosphere (relative humidity 50%) at a temperature of 23 °C in accordance with ISO 62-4:2008.

[0025]

[0032] In one embodiment, for example, the repeating units derived from HNA may constitute 30 mol.% or more of the polymer, in some embodiments 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, and in some embodiments about 70 mol.% to about 80 mol.%. 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.%, in some embodiments about 15 mol.% to about 35 mol.%, and in some embodiments about 20 mol.% to about 30 mol.%. When utilized, the molar ratio of HNA to HBA may be selectively controlled within a specific range to promote the achievement of desired properties, for example, about 0.1 to about 40, in some embodiments about 0.5 to about 20, in some embodiments about 0.8 to about 10, and in some embodiments about 1 to about 5. The polymer may also contain aromatic dicarboxylic acids (e.g., IA and / or TA) in an amount of about 1 mol.% to about 40 mol.%, in some embodiments about 5 mol.% to about 25 mol.%, and / or aromatic diols (e.g., BP and / or HQ) in an amount of about 1 mol.% to about 40 mol.%, in some embodiments about 5 mol.% to about 25 mol.%. However, in some cases, it may be desirable to minimize the presence of such monomers in the polymer to promote 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, in some embodiments about 15 mol.% or less, in some embodiments about 10 mol.% or less, in some embodiments 0 mol.% to about 5 mol.%, and in some embodiments 0 mol.% to about 2 mol.%.Similarly, the total amount of aromatic dicarboxylic acid (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, the 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 acid (e.g., HBA) in an amount of about 20 mol.% to about 60 mol.%, about 30 mol.% to about 50 mol.% in some embodiments, aromatic dicarboxylic acid (e.g., IA and / or TA) in an amount of about 2 mol.% to about 30 mol.%, about 5 mol.% to about 25 mol.% in some embodiments, and / or aromatic diol (e.g., BP and / or HQ) in an amount 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, the liquid crystal polymer may be prepared by first introducing into a reaction vessel aromatic monomers used to form ester repeating units (e.g., aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, etc.) and / or other repeating units (e.g., aromatic diol, aromatic amide, aromatic amine, etc.) and initiating a polycondensation reaction. The specific conditions and steps utilized in such reactions are well known, such as U.S. Patent No. 4,161,470 to Calundann; U.S. Patent No. 5,616,680 to Linstid, III, et al.; Linstid, I It may be described in more detail in U.S. Patent No. 6,114,492 to II, et al.; U.S. Patent No. 6,514,611 to Shepherd, et al.; and WO2004 / 058851 to Waggoner. The vessel used in the reaction is not particularly limited, but it is desirable to use typically those commonly used in reactions of high-viscosity fluids. Examples of such reaction vessels may include stirred tank type devices having stirrers with various shaped stirring blades, such as anchor type, multi-stage type, helical ribbon type, screw shaft type, etc., or modified forms thereof. Further examples of such reaction vessels may include mixing devices commonly used in resin kneading, such as kneaders, roll mills, Banbury mixers, etc.

[0028]

[0035] If desired, the reaction may proceed by acetylation of the monomers known in the art. This can be achieved by adding an acetylating agent (e.g., acetic anhydride) to the monomer. Acetylation generally starts at a temperature of about 90°C. In the initial stage of acetylation, reflux may be utilized to maintain the gas phase temperature below the point at which acetic acid by-products and anhydrides start 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 typically exceeds 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 provide a gas phase reflux to 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 utilized. The amount of excess anhydride varies depending on the specific acetylation conditions utilized, including the presence or absence of reflux. It is not uncommon to use an excess amount of acetic anhydride of about 1 to about 10 mole percent relative to the total moles of the reactant hydroxyl groups present.

[0029]

[0036] Acetylation may be carried out in a separate reaction vessel or in situ within the polymerization reaction vessel. When a separate reaction vessel is utilized, 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 undergoing pre-acetylation.

[0030]

[0037] In addition to the monomer and optional acetylating agent, 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 utilized. Such catalysts are typically used in an amount of about 50 to about 500 parts per million based on the total weight of the repeating unit precursor. When using a separate reactor, it is typically desirable to apply the catalyst to the acetylation reactor rather than the polymerization reactor, but this is not at all essential.

[0031]

[0038] The reaction mixture is generally heated to a high temperature within the polymerization reaction vessel to initiate the melt polycondensation of the reactants. For example, the polycondensation may be carried out within 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 suitable technique for forming an aromatic polyester is to charge the precursor monomers and acetic anhydride into the reactor, heat 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 raise the temperature to about 280 °C to about 380 °C to carry out the melt polycondensation. As the final polymerization temperature approaches, volatile by-products of the reaction (e.g., acetic acid) can 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 rotation speed of the stirrer may vary during the reaction, but is typically about 10 to about 100 revolutions per minute ("rpm"), and in some embodiments is in the range of about 20 to about 80 rpm. To enhance the molecular weight in the melt, the polymerization reaction can also be carried out under vacuum. By applying vacuum, the volatiles formed during the final stage of polycondensation are more easily removed. The vacuum can be created, for example, by applying a suction pressure in the range of about 2.27 to about 13.6 kg (about 5 to about 30 pounds) (「psi」) per 2.54 square cm (1 square inch), and in some embodiments, in the range of 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 melt is discharged through a perforated die to form strands, which are drawn into a water bath, pelletized, and dried. In some embodiments, the melt-polymerized polymer may be subjected to a subsequent solid-state polymerization method to further increase its molecular weight. Solid-state polymerization can be carried out in the presence of a gas (e.g., air, inert gas, etc.). Suitable inert gases include, for example, nitrogen, helium, argon, neon, krypton, xenon, etc., and combinations thereof. The solid-state polymerization reaction vessel can be of substantially any design that can maintain the polymer at the desired solid-state polymerization temperature for the 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-state 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-state polymerization time is about 2 to about 12 hours, and in some embodiments, about 4 to about 10 hours.

[0033]

[0040] When utilized, the total amount of liquid crystal polymer utilized in the polymer composition may be from about 40 wt.% to about 99 wt.% of the total polymer composition, in some embodiments from about 50 wt.% to about 98 wt.%, and in some embodiments from about 60 wt.% to about 95 wt.%. In certain embodiments, all of the liquid crystal polymer is a "high naphthene" polymer such as those described above. However, in other embodiments, 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, in some embodiments about 8 mol.% or less, in some embodiments about 6 mol.% or less, and in some embodiments from about 1 mol.% to about 5 mol.%, and a "low naphthene" liquid crystal polymer may be utilized in the composition. In certain embodiments, it may be desired for the low naphthene polymer to be present in only a relatively low amount. For example, when utilized, the low naphthene liquid crystal polymer typically constitutes from about 1 wt.% to about 50 wt.% of the total amount of liquid crystal polymer in the composition, in some embodiments from about 2 wt.% to about 40 wt.%, in some embodiments from about 5 wt.% to about 30 wt.%, and from about 0.5 wt.% to about 45 wt.% of the total composition, in some embodiments from about 2 wt.% to about 35 wt.%, and in some embodiments from about 5 wt.% to about 25 wt.%. In contrast, the high naphthene liquid crystal polymer typically constitutes from about 50 wt.% to about 99 wt.% of the total amount of liquid crystal polymer in the composition, in some embodiments from about 60 wt.% to about 98 wt.%, in some embodiments from about 70 wt.% to about 95 wt.%, and from about 55 wt.% to about 99.5 wt.% of the total composition, in some embodiments from about 65 wt.% to about 98 wt.%, and in some embodiments from about 75 wt.% to about 95 wt.%.

[0034] B. Other additives

[0041] The aromatic polymer may be utilized in the polymer composition in neat form (i.e., 100 wt.% of the polymer composition), or a wide variety of other additives may optionally be included in the composition. When utilized, such additives typically constitute from about 1 wt.% to about 60 wt.% of the polymer composition, in some embodiments from about 2 wt.% to about 50 wt.%, and in some embodiments from about 5 wt.% to about 40 wt.%. In such embodiments, the liquid crystal polymer may similarly constitute from about 40 wt.% to about 99 wt.% of the polymer composition, in some embodiments from about 50 wt.% to about 98 wt.%, and in some embodiments from about 60 wt.% to about 9 5 wt.%.

[0035]

[0042] Also, 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 - drip additives, nucleating agents (e.g., boron nitride), flow modifiers, coupling agents, antibacterial agents, pigments or other colorants, impact modifiers, dielectric materials, and other materials added to improve properties and processability may be included in the polymer composition. Such optional materials may be utilized in the polymer composition in conventional amounts and according to conventional processing techniques.

[0036] i. Laser-activatable additive

[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. Thereby, the laser draws a pattern of conductive elements on that portion and leaves 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.). Laser activatable additives generally contain spinel crystals, which may include two or more metal oxide cluster configurations within a definable crystal formation. For example, the entire crystal formation may have the following general formula: AB 2 O 4 (wherein, A is a divalent metal cation such as cadmium, chromium, manganese, nickel, zinc, copper, cobalt, iron, magnesium, tin, titanium, etc., and combinations thereof; B is a trivalent metal cation such as chromium, iron, aluminum, nickel, manganese, tin, etc., and combinations thereof) may have.

[0037]

[0044] Typically, A in the above formula provides the main cation component of the first metal oxide cluster, and B provides 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 combine to give a single definable crystalline structure having an increased sensitivity to electromagnetic radiation. Examples of suitable spinel crystals include, for example, MgAl 2 O 4 、ZnAl 2 O 4 、FeAl 2 O 4 、CuFe 2 O4 , CuCr 2 O 4 , MnFe 2 O 4 , NiFe 2 O 4 , TiFe 2 O 4 , FeCr 2 O 4 , MgCr 2 O 4 and the like. Copper chromium oxide (CuCr 2 O 4 ) 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.%, in some embodiments about 0.5 wt.% to about 20 wt.%, and in some embodiments about 1 wt.% to about 10 wt.% of the polymer composition.

[0039] ii. Fibrous filler

[0046] For example, in one embodiment, a fibrous filler may be utilized in the polymer composition to improve the thermal and mechanical properties of the polymer composition without significantly affecting the electrical performance. Fibrous fillers typically include fillers having a 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"), in some embodiments about 2,000 MPa to about 10,000 MPa, and in some embodiments about 3,000 MPa to about 6,000 MPa. To promote the maintenance of the desired dielectric properties, such high-strength fibers are generally made of materials with insulating properties, such as glass, ceramic or mineral (e.g., alumina or silica), aramid (e.g., Kevlar® sold by E.I. duPont de Nemours, Wilmington, Delaware), mineral, polyolefin, polyester, etc.

[0040]

[0047] Examples of the fibrous filler may include glass fiber, mineral fiber, or a mixture thereof. For example, in one embodiment, the fibrous filler may include glass fiber. Particularly preferred glass fibers may include E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S1-glass, S2-glass, and the like. In another embodiment, the fibrous filler may include mineral fiber. Examples of the mineral fiber may include silicates such as nesosilicates, sorosilicates, inosilicates (e.g., calcium inosilicates such as wollastonite; calcium magnesium inosilicates such as tremolite; calcium magnesium iron inosilicates such as actinolite; magnesium iron inosilicates such as anthophyllite, etc.), phyllosilicates (e.g., aluminum phyllosilicates such as palygorskite), tectosilicates, etc.; sulfates such as calcium sulfate (e.g., dehydrated or anhydrous gypsum); those derived from mineral wool (e.g., rock or slag wool), and the like. Inosilicates such as wollastonite fiber available from Nyco Minerals under the trade name NYGLOS® (e.g., NYGLOS® 4W or NYGLOS® 8) are particularly preferred.

[0041]

[0048] Furthermore, the fibrous filler may have a variety of different sizes, but fibers having a specific aspect ratio may promote the improvement of the mechanical properties of the polymer composition. That is, fibrous fillers having an aspect ratio (average length divided by nominal diameter) of about 2 or more, in some embodiments about 4 or more, in some embodiments about 5 to about 50, and in some embodiments about 8 to about 40 may be particularly beneficial. Such fibrous fillers may have a weight average length of, for example, about 10 micrometers or more, in some embodiments about 25 micrometers or more, in some embodiments about 50 micrometers or more to about 800 micrometers or less, and in some embodiments about 60 micrometers to about 500 micrometers. Also, such fibrous fillers may have a volume average length of, for example, about 10 micrometers or more, in some embodiments about 25 micrometers or more, in some embodiments about 50 micrometers or more to about 800 micrometers or less, and in some embodiments about 60 micrometers to about 500 micrometers. The fibrous filler may similarly have a nominal diameter of about 5 micrometers or more, in some embodiments about 6 micrometers or more, in some embodiments about 8 micrometers to about 40 micrometers, and in some embodiments about 9 micrometers to about 20 micrometers. The relative amount of the fibrous filler may also be selectively controlled to achieve the 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 dielectric constant of about 6 or less, in some embodiments about 5.5 or less, in some embodiments about 1.1 to about 5, and in some embodiments about 2 to about 4.8 at a frequency of 1 GHz.

[0042]

[0049] The fibrous filler may be in a modified or unmodified form and may, for example, be sized or chemically treated to improve adhesion to plastics. In some examples, sizing may be applied to the glass fibers to protect the glass fibers and not only smooth the fibers but also improve the adhesion between the fibers and the matrix material. When present, the sizing may include silanes, film formers, lubricants, wetting agents, adhesives, optionally antistatic agents 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-trimethoxysilylpropyl)ethane-1,2-diamine, 3-(2-aminoethyl-amino)propyltrimethoxysilane, N-[3-(trimethoxysilyl)propyl]-1,2-ethanediamine.

[0043]

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

[0044] iii. Hollow filler

[0051] Although not absolutely necessary, the polymer composition may also include one or more hollow inorganic fillers to facilitate achieving the desired relative permittivity. For example, such fillers may have a relative permittivity of about 3.0 or less at 100 MHz, in some embodiments about 2.5 or less, in some embodiments about 1.1 to about 2.3, and in some embodiments about 1.2 to about 2.0. The hollow inorganic filler typically has an internal hollow space or cavity and may be synthesized using techniques known in the art. The hollow inorganic filler may be made from conventional materials. For example, examples of the hollow inorganic filler may include alumina, silica, zirconia, magnesia, glass, fly ash, borate, phosphate, ceramic, etc. In one embodiment, examples of the hollow inorganic filler may 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, although not limited, is at least about 65 wt% SiO 2 , 3 to 15 wt% Na 2 O, 8 to 15 wt% CaO, 0.1 to 5 wt% MgO, 0.01 to 3 wt% Al 2 O 3 , 0.01 to 1 wt% K 2 O, and optionally other oxides (e.g., Li 2 O, Fe 2 O 3 , TiO 2 , B 2 O 3 ). In another embodiment, the composition is about 50 to 58 wt% SiO 2 , 25 to 30 wt% Al 2 O 3 , 6 to 10 wt% CaO, 1 to 4 wt% Na 2 O / K 2O, and may also be other oxides in an amount of 1 to 5% by weight. Further, in one embodiment, the hollow glass filler may contain more alkaline earth metal oxides than alkali metal oxides. For example, the weight ratio of the alkaline earth metal oxide to the alkali metal oxide may be greater than 1, in some embodiments about 1.1 or more, in some embodiments about 1.2 to about 4, and in some embodiments about 1.5 to about 3. Nevertheless, it should be understood that the glass composition 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 about 1 micrometer to about 150 micrometers, in some embodiments about 10 micrometers to about 150 micrometers, and in some embodiments 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 about 5 micrometers to about 20 micrometers, and in some embodiments 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 about 20 micrometers to about 150 micrometers, and in some embodiments about 22 micrometers to about 50 micrometers. In this regard, the hollow inorganic filler may be present in 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 has a Gaussian size 90 distribution. It may have a distribution. In another embodiment, the hollow inorganic filler may have a normal size distribution. In a further embodiment, the hollow inorganic filler may have an abnormal size distribution. Examples of abnormal size distributions include unimodal and multimodal (e.g., bimodal) size distributions. When referring to the above dimensions, such dimensions may be any dimensions. However, in one embodiment, such dimensions refer to the diameter. For example, such a value for the dimension refers to the average diameter of a sphere. Dimensions such as the 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 about 0.8 or more, in some embodiments about 0.85 or more, in some embodiments about 0.9 to about 1.3, and in some embodiments about 0.95 to about 1.05.

[0046]

[0053] Furthermore, the hollow inorganic filler may have a relatively thin wall to assist in reducing the dielectric properties and weight of the polymer composition. The wall thickness may be about 50% or less of the average dimension of the hollow inorganic filler, e.g., the average diameter, in some embodiments about 40% or less, in some embodiments about 1% to about 30%, and in some embodiments about 2% to about 25%. Additionally, the hollow inorganic filler may have a specific true density that enables easy handling and provides a polymer composition with reduced weight. Generally, the true density refers to the quotient obtained by dividing the mass of the hollow filler sample by the true volume of the mass of the hollow filler, and the 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 / cm 3 or more, in some embodiments about 0.2 g / cm 3 or more, in some embodiments about 0.3 g / cm 3 or more to about 1.2 g / cm 3 , in some embodiments about 0.4 g / cm 3 or more to about 0.9 g / cm 3 and may be. The true density may be determined according to 3M QCM 14.24.1.

[0047]

[0054] Even when the filler is hollow, the filler may have mechanical strength that enables maintenance of the integrity of their structures and reduces the possibility of the filler being damaged during processing and / or use. In this regard, the isostatic pressure resistance (i.e., at least 80 vol.%, for example at least 90 vol.% of the hollow filler survives) of the hollow inorganic filler may be about 20 MPa or more, in some embodiments about 100 MPa or more, in some embodiments about 150 MPa to about 500 MPa, and in some embodiments about 200 MPa to about 350 MPa. The isostatic pressure 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, in some embodiments about 0.9 meq / g or less, in some embodiments about 0.1 meq / g to about 0.8 meq / g, and in some embodiments about 0.2 meq / g to about 0.7 meq / g. The alkalinity may be determined according to 3M QCM 55.19. In order to result in a relatively low alkalinity, the hollow inorganic filler may be treated with a suitable acid such as phosphoric acid. Further, the hollow inorganic filler may also include a surface treatment to assist in providing better compatibility with the polymer and / or other components in the polymer composition. By way of example, the surface treatment may be silanization. In particular, examples of the surface treatment agent include, but are not limited to, aminosilane, epoxy silane, etc.

[0049]

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

[0050] iv. Particulate filler

[0057] If desired, particulate fillers may be utilized to improve certain properties of the polymer composition. The particulate filler is the aromatic polymer 1 utilized in the polymer composition It may be used in the polymer composition in an amount of about 5 to about 60 parts by weight per part, in some embodiments about 10 to about 50 parts by weight, and in some embodiments about 15 to about 40 parts by weight. For example, the particulate filler may constitute about 5 wt.% to about 50 wt.%, in some embodiments about 10 wt.% to about 40 wt.%, and in some embodiments about 15 wt.% to about 30 wt.% of the polymer composition.

[0051]

[0058] In certain embodiments, particles having a specific hardness value may be utilized to promote improvement of the surface properties of the composition. For example, the hardness value may be about 2 or greater, in some embodiments about 2.5 or greater, in some embodiments about 3 to about 11, in some embodiments about 3.5 to about 11, and in some embodiments about 4.5 to about 6.5 based on the Mohs hardness scale. Examples of such particles include, for example, silica (Mohs hardness 7), mica (Mohs hardness of about 3); calcium carbonate (CaCO 3 , Mohs hardness 3.0), or copper carbonate hydroxide (Cu 2 CO 3 (OH) 2 , Mohs hardness 4.0), etc. carbonates; calcium fluoride (CaFl 2 ; Mohs hardness 4.0), etc. fluorides; calcium pyrophosphate (Ca 2 P 2 O 7 , Mohs hardness 5.0), dicalcium phosphate anhydrous (CaHPO 4 ; Mohs hardness 3.5), or aluminum phosphate hydrate (AlPO 4 ·2H 2 O; Mohs hardness 4.5), etc. phosphates; calcium borosilicate hydroxide (Ca 2 B 5 SiO 9 (OH) 5 , Mohs hardness 3.5), etc. borates; alumina (AlO 2 , Mohs hardness 10.0); calcium sulfate (CaSO 4 , Mohs hardness 3.5), or barium sulfate (BaSO 4 , Mohs hardness 3 to 3.5), etc. sulfates, and combinations thereof can be mentioned.

[0052]

[0059] The shape of the particles may vary as desired. For example, in certain embodiments, flakes having a relatively high aspect ratio (e.g., the average diameter divided by the average thickness) of 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 utilized. The average diameter of the particles may be determined, for example, according to ISO 13320:2009 using laser diffraction techniques (e.g., using a Horiba LA-960 particle size distribution analyzer) and may range from about 5 micrometers to about 200 micrometers, in some embodiments from about 30 micrometers to about 150 micrometers, and in some embodiments from about 50 micrometers to about 120 micrometers. 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 suitable. For example, muscovite (KAl 2 (AlSi 3 )O 10 (OH) 2 )、biotite (K(Mg,Fe) 3 (AlSi 3 )O 10 (OH) 2 )、phlogopite (KMg 3 (AlSi 3 )O 10 (OH) 2 )、lepidolite (K(Li,Al) 2-3 (AlSi 3 )O 10 (OH) 2 )、glauconite (K,Na)(Al,Mg,Fe) 2 (Si,Al) 4 O 10 (OH) 2)Any form of mica, including etc., may be commonly used. Granular particles can also be used. Typically, such particles are determined using laser diffraction technology (e.g., using a Horiba LA-960 particle size distribution analyzer) in accordance with, for example, ISO13320:2009, and have an average diameter of about 0.1 to about 10 micrometers, in some embodiments about 0.2 to about 4 micrometers, and in some embodiments about 0.5 to about 2 micrometers. Particularly suitable granular fillers may include, for example, talc, barium sulfate, calcium sulfate, calcium carbonate, etc.

[0053]

[0060] The particulate filler may be formed mainly 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 of the particulate filler, and in some embodiments about 75 wt.% or more (e.g., 100 wt.%). Of course, in other embodiments, flake-shaped and granular particles may be used in combination. In such embodiments, for example, the flake-shaped particles may constitute about 0. 5 wt.% to about 20 wt.%, and in some embodiments about 1 wt.% to about 10 wt.%, while the granular particles may constitute about 80 wt.% to about 99.5 wt.% of the particulate filler, and in some embodiments about 90 wt.% to about 99 wt.%.

[0054]

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

[0055] v. Hydrophobic material

[0062] Hydrophobic materials can also be used in polymer compositions. Without being limited by theory, hydrophobic materials may help reduce the water absorption tendency of the polymer composition, thereby potentially assisting in stabilizing the relative permittivity and dielectric tangent in the high-frequency range. When used, the weight ratio of the hydrophobic material to the liquid crystal polymer is typically from about 1 to about 20, in some embodiments from about 2 to about 15, and in some embodiments from about 3 to about 10. For example, the hydrophobic material may constitute from about 1 wt.% to about 60 wt.%, in some embodiments from about 2 wt.% to about 50 wt.%, and in some embodiments from about 5 wt.% to about 40 wt.% of the total polymer composition. Particularly suitable hydrophobic materials are low surface energy elastomers such as fluoropolymers and silicone polymers. The fluoropolymer may contain, for example, a hydrocarbon backbone polymer in which some or all of the hydrogen atoms are replaced by fluorine atoms. The backbone polymer may be polyolefin-based and may be formed from an unsaturated olefin monomer substituted with fluorine. The fluoropolymer may be a homopolymer of such a fluorine-substituted monomer or a copolymer of a fluorine-substituted monomer, or a mixture of a fluorine-substituted monomer and a non-fluorine-substituted monomer. Together with fluorine atoms, 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 are tetrafluoroethylene (“TFE”), vinylidene fluoride (“VF2”), hexafluoropropylene (“HFP”), chlorotrifluoroethylene (“CTFE”), perfluoroethyl vinyl ether (“PEVE”), perfluoromethyl vinyl ether (“PMVE”), perfluoropropyl vinyl ether (“PPVE”), etc., 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"), polyvinylidene fluoride ("PVDF"), polychlorotrifluoroethylene ("PCTFE"), and TFE copolymers having VF2 and / or HFP, and mixtures thereof.

[0056] II. Formation

[0063] The components used to form the polymer composition may be combined together using any of a variety of 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 the polymer composition. The mixture may be melt kneaded at a temperature of about 200°C to about 450°C in a single-screw or multi-screw extruder. In one embodiment, the mixture can be melt processed in an extruder containing multiple temperature zones. The temperature of each individual zone is typically set within about -60°C to about 25°C relative to the melting temperature of the polymer. By way of example, the mixture can be melt processed using a twin-screw extruder such as a Leistritz 18mm co-rotating fully intermeshing 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 the first barrel by a metering feeder. In another embodiment, different components can be added at different addition points of the extruder, as is known. For example, the polymer can be applied at the feed port and specific additives (e.g., laser-activatable additives and / or other additives) can be supplied at 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. Next, the extruded polymer composition can be quenched and solidified in a water bath, pelletized with a pelletizer, and then dried.

[0057]

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

[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 cavities of the mold and form small-sized electrical components. For example, in one particular embodiment, the polymer composition has a melt viscosity of about 500 Pa·s or less, in some embodiments about 250 Pa·s or less, in some embodiments about 5 Pa·s to about 150 Pa·s, in some embodiments about 5 Pa·s to about 100 Pa·s, in some embodiments about 10 Pa·s to about 100 Pa·s, in some embodiments about 15 to about 90 Pa·s, as determined at a shear rate of 1,000 seconds -1 . II. RF filter

[0066] As described above, the RF filter of the present invention typically includes one or more resonating elements (e.g., piezoelectric materials, dielectric materials, etc.) capable of producing resonance behavior in a narrow frequency band at the desired 5G frequency. The specific configuration and operation of the filter may vary as is known to those skilled in the art. For example, the RF filter may be a surface acoustic wave (SAW) filter, a bulk acoustic wave (BAW) filter It may also be an acoustic filter such as 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, aluminum nitride, etc. For example, in a SAW filter, an electrical input signal is converted into an elastic wave by alternately arranged metal interdigital transducers (IDTs) formed on a piezoelectric substrate. In a BAW filter, a piezoelectric substrate is sandwiched between two electrodes and acoustically isolated from the surrounding medium. In this method, an elastic wave is excited and reflected, propagating vertically to form a standing elastic wave. The thin outer layer acts as an acoustic reflector to prevent the elastic wave from escaping into the substrate. In an FBAR filter, a cavity is etched under the active region, so that the air / crystal interfaces on both sides of the resonator capture the elastic wave.

[0059]

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

[0060]

[0068] An RF filter can utilize the polymer composition of the present invention regardless of its specific configuration. The polymer composition has a low relative permittivity and dielectric tangent, and provides good performance in a variety of ways at 5G frequencies. For example, in an acoustic filter, the polymer composition may be used to form a substrate for supporting a resonant element (e.g., a piezoelectric material). In such an embodiment, the resonant element may be supported by the substrate by disposing the resonant element directly on the substrate. Alternatively, various other layers (e.g., a reflector, an adhesive, etc.) may be located between the substrate and the resonant element. Referring to FIG. 6, for example, an 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 is converted into an elastic wave by alternately arranged metal interdigital transducers 104 formed on a piezoelectric substrate 106. If desired, a substrate 108 formed from the polymer composition of the present invention and supporting the piezoelectric substrate 104 may also be provided. Similarly, referring to FIG. 7, an embodiment of a BAW filter 110 is shown, where a piezoelectric substrate 116 is located between an upper metal layer 112 and a lower metal layer (not shown). In this method, an elastic wave is excited in response to an electrical input signal provided thereto via 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 the metal layer. When the polymer composition is utilized on a substrate such as those shown in FIG. 6 or FIG. 7, it may optionally contain a laser-activatable additive so that conductive elements (e.g., transducers, metal layers, etc.) can be formed later using laser direct structuring ("LDS") on the substrate. Activation by the laser causes a physicochemical reaction, the spinel crystals crack and metal atoms are liberated. These metal atoms may act as nuclei for metallization (e.g., a reducing copper coating). Further, the laser creates a microscopically irregular surface, abrading the polymer matrix to create numerous microscopic pits 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., resonant elements, support substrates, etc.) to form individual packages. In such embodiments, the housing may be made from the polymer composition of the present invention. Referring to FIG. 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 essential. 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. Then, metal wiring 28 is formed / patterned in the package 10 to provide an electrical connection therein. The wiring 28 is formed in the vias 26, reaches the I / O pads 30 on the front surface of the resonant element 14, and exits to the surface of the dielectric layer 18. The polymer composition used for the substrate 18 and / or the housing 20 may optionally include a laser-activatable additive so that the wiring 28 and / or the 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 associated generation of elastic waves. Input / output (I / O) connections 38 (e.g., solder balls) are also 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] As considered above and in the embodiments shown in FIGS. 6 - 8, the polymer composition of the present invention is utilized in acoustic RF filters. However, as described 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 FIG. 9 for example, an embodiment of a cavity filter 1000 is shown, which contains a housing 1000 and 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 a resonance element 1104 can be located may be formed within the housing 1100. A resonance element 1104 suitable for this purpose may include, for example, a dielectric material. Although not essential, the resonance element 1104 may have a cylindrical shape, and recesses or holes may be formed in at least a part of the cylinder. Naturally, a disk-shaped resonator can also be used if necessary, and resonators having any of various known shapes are applicable to embodiments of the present invention. The resonance element 1104 may be connected to the bottom of the cavity by using bolts or the like. If desired, the housing 1100 may contain a metal plating (e.g., silver or copper), which can be formed by direct laser structuring when 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 that applies the pressure required for tight pressing may be used in the insertion region 1450 to facilitate obtaining desired electrical characteristics and to provide a good fastening. The position of the insertion region 1450 formed in the cover 1110 may correspond to the position of the resonator 1104. III. Use

[0071] RF filters may be used in a wide variety of different applications. In certain embodiments, the RF filter is configured for use particularly in 5G antenna systems. More specifically, the RF filter is configured to receive and / or transmit signals to and from the antenna system and to filter out and remove specific frequencies outside the 5G frequency band that would otherwise interfere with the desired signal to other electrical components such as low noise amplifiers (LNAs), oscillators or transceivers. As used herein, "5G" generally refers to high-speed data communication by radio frequency signals. 5G networks and systems can communicate data much faster than previous generation data communication standards (e.g., "4G", "LTE"). Various standards and specifications for quantifying the requirements of 5G communication have been published. As an 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 criteria for 5G (e.g., downlink and uplink data rates, latency, etc.). The IMT-2020 standard defines the uplink and downlink peak data rates as the minimum data rates for uploading and downloading data that a 5G system must support. The IMT-2020 standard sets the downlink peak data rate requirement at 20 Gbit / sec and the uplink peak data rate at 10 Gbit / sec. As another example, 3 rd Generation Partnership Project (3GPP (registered trademark)) recently published a new standard for 5G called "5G NR". 3GPP (registered trademark) issued "Release 15" in 2018, which defines "Phase 1" as the standardization of 5G NR. 3GPP (registered trademark) divides the 5G frequency band generally into "Frequenc Define "y Range 1" (FR1) and "Frequency Range 2" (FR2) as a frequency band in the range of 20 to 60 GHz. However, the "5G frequency" used in this specification may refer to a system that utilizes frequencies in the range greater than 60 GHz, for example, up to 80 GHz, up to 150 GHz, and up to 300 GHz. The "5G frequency" used in this specification may refer to frequencies of about 2.5 GHz or higher, in some embodiments 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, and in some embodiments about 28 GHz to about 60 GHz.

[0063]

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

[0064]

[0073] The antenna element may be fabricated using various manufacturing techniques. As an example, the antenna element and / or related elements (e.g., ground element, feed line, etc.) may utilize fine pitch technology. Fine pitch technology generally refers to the small or fine spacing between those components or leads. For example, the characteristic dimension and / or spacing between antenna elements (or between the antenna element and the ground plane) may be about 1,500 micrometers or less, in some embodiments 1,250 micrometers or less, in some embodiments 750 micrometers or less (e.g., center-to-center spacing of 1.5 mm or less), 650 micrometers or less, in some embodiments 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 50 micrometers or less. However, it should be understood that smaller and / or larger characteristic sizes and / or spacings may be utilized. As a result of such small characteristic dimensions, an antenna configuration and / or array having a large number of antenna elements within a small installation area can be achieved. For example, the antenna array may have an average antenna element density of more than 1,000 antenna elements per square centimeter, in some embodiments 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 more than about 8,000 antenna elements per square centimeter. Such a dense arrangement of antenna elements can provide a larger number of MIMO-capable channels per unit area of the antenna region. For example, the number of channels may correspond to the number of antenna elements (e.g., be equivalent thereto or be proportional). A dense arrangement of antenna elements can provide a larger number of MIMO-capable channels per unit area of the antenna region. For example, the number of channels may correspond to the number of antenna elements (e.g., be equivalent thereto or be proportional).

[0065]

[0074] Referring to FIG. 1, for example, 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 base station 102 and the user computing device 106 and / or other relay stations 104 by relaying or “repeating” signals between the base station 102 and the user computing device 106 and / or between the relay stations 104. The base station 102 may include a MIMO antenna array 110 configured to receive and / or transmit radio frequency signals 112 with the relay station 104, the Wi-Fi repeater 108, and / or directly with the user computing device 106. The user computing device 306 is not necessarily limited by the present invention and includes devices such as 5G smartphones.

[0066]

[0075] The MIMO antenna array 110 may utilize beam steering to concentrate or direct the radio frequency signal 112 towards the relay station 104. For example, the MIMO antenna array 110 may be configured to adjust the elevation angle 114 with respect to the heading angle 116 defined in the X-Y plane and / or the Z-Y plane, as well as with respect to the Z direction. Similarly, one or more of the relay station 104, the user computing device 106, and the Wi-Fi repeater 108 may utilize beam steering to directionally tune the sensitivity and / or transmission power of the devices 104, 106, 108 with respect to the MIMO antenna array 110 of the base station 102 (e.g., by adjusting one or both of the relative elevation angle and / or relative azimuth angle of each device), thereby improving the reception and / or transmission capabilities with respect to the MIMO antenna array 110.

[0067]

[0076] Similarly, FIGS. 2A-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 (e.g., arranged as each antenna array). Referring to FIG. 2A, the antenna elements 200, 202 may be configured to perform beam steering in the X-Y plane (shown by arrows 204, 206 and corresponding to the relative azimuth angle). Referring to FIG. 2B, the antenna elements 200, 202 may be configured to perform beam steering in the Z-Y plane (shown by arrows 204, 206).

[0068]

[0077] FIG. 3 is a simplified schematic diagram of a plurality of antenna arrays 302 connected using each feed line 304 (e.g., to a front-end module). The antenna array 302 can be attached to the side surface 306 of the substrate 308, for example, as described and illustrated with respect to FIGS. 4A-4C. The antenna array 302 may include a plurality of vertically connected elements (e.g., a mesh grid array). Thus, the antenna array 302 may generally extend parallel to the side surface 306 of the substrate 308. A shield may be optionally provided on the side surface 306 of the substrate 308 such that the antenna array 302 is located outside the shield with respect to the substrate 308. The vertical spacing distance between the vertically connected elements of the antenna array 302 may correspond to the "characteristic size" of the antenna array 320. Thus, in some embodiments, these spacing distances may be relatively small (e.g., less than about 750 micrometers) such that the antenna array 302 is a "fine pitch" antenna array 302. In some embodiments, these spacing distances may be relatively small (e.g., less than about 750 micrometers) such that the antenna array 302 is a "fine pitch" antenna array 302.

[0069]

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

[0070]

[0079] FIG. 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 of substantially equal size in the X and / or Y directions (e.g., square or rectangular). The plurality of antenna elements 520 may be spaced apart substantially evenly in the X and Y directions. The dimensions of the antenna elements 520 and / or the spacing therebetween may correspond to the “characteristic size” of the antenna array 500. Thus, in some embodiments, the dimensions and / or the spacing may be relatively small (e.g., less than about 750 micrometers) such that the antenna array 500 is a “fine pitch” antenna array 500. As illustrated by the ellipsis 522, the number of columns of the antenna elements 520 shown in FIG. 5 is shown as an example only. Similarly, the number of rows of the antenna elements 520 is shown as an example only.

[0071]

[0080] Using the synchronized antenna array 500, for example, a base station can be provided with a massive MIMO function (e.g., as described above with respect to FIG. 1). More specifically, the radio frequency interaction between various elements can be controlled or synchronized, and a plurality of transmission and / or reception channels may be provided. The transmission power and / or reception sensitivity may be directionally controlled to concentrate or direct the radio frequency signal, for example, as described with respect to the radio frequency signal 112 in FIG. 1. The synchronized antenna array 500 can provide a large number of antenna elements 522 within a small installation area. For example, the synchronized antenna 500 may have an average antenna element density of more than 1,000 antenna elements per square centimeter. Such a dense arrangement of antenna elements can provide a larger number of MIMO-capable channels per unit area. For example, the number of channels may correspond to the number of antenna elements (e.g., be equivalent to or proportional to it).

[0072]

[0081] FIG. 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 that connect the antenna elements 542 (e.g., to other antenna elements 542, a front-end module, or other suitable components). The antenna elements 542 may have respective widths "w" and the spacing distances "S 1 " and "S 2 " (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, "w", "S 1 " or "S 2One or more of them may correspond to a plurality of propagation wavelengths (「λ」) of a desired frequency passing through the substrate material (e.g., nλ / 4, where n is an integer).

[0073]

[0082] As an example, λ is as follows:

[0074]

Number

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

[0076]

[0083] FIG. 5C is a diagram of 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 disposed along parallel long sides of a substrate 564. The various antenna elements 562 may have respective lengths 「L」 (and the spacing therebetween) 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 the desired frequency for the substrate material, as described above with reference to FIG. 5B, for example.

[0077]

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

[0085] Melt viscosity: The melt viscosity (Pa·s) was determined in accordance with ISO test No. 11443:2005 using a Dynisco LCR7001 capillary rheometer at a shear rate of 1,000 s -1 and a melt temperature above 15 °C (e.g., about 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 known in the art. The melting temperature is the peak melting temperature of differential scanning calorimetry (DSC) determined according to ISO Test No. 11357-2:2013. Based on the DSC procedure, DSC measurements performed on a TA Q2000 instrument were used, and the sample was heated and cooled at 20 °C per minute as described in ISO standard 10350.

[0079]

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

[0080]

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

[0081]

[0089] Flexural modulus, flexural stress and flexural elongation: The flexural properties may be tested in accordance with ISO Test No. 178:2010 (technically equivalent to ASTM D790-10). This test may be performed on a 64 mm support span. The test may be carried out at the center of an uncut ISO 3167 multi-pass bar. The test temperature may be about 23 °C, and the test speed may be 2 mm / min.

[0082]

[0090] Izod Impact Strength without Notch and with Notch: The Charpy properties may be tested in accordance with ISO Test No. ISO 179-1:2010 (technically equivalent to ASTM D256-10, Method B). This test may be performed using Type 1 specimen size (length 80 mm, width 10 mm, and thickness 4 mm). When testing the notched impact strength, the notch may be a Type A notch (0.25 mm base radius). The specimens may be cut from the center of the multi-pass bar using a single-flute milling machine. The test temperature may be approximately 23 °C.

[0083]

[0091] Relative Dielectric Constant (“Dk”) and Dissipation Factor (“Df”): The relative dielectric constant (or relative static dielectric constant) and dissipation factor are determined in accordance with IEC 60250:1969. Such techniques are also described in Baker-Jarvis, et al., IEEE Trans. on Dielectric and Electrical Insulation, 5(4), page 571 (1998) and Krupka, et al., Proc. 7 th International Conference on Dielectric Materials: Measurements and Applications, IEEE Conference Publication No. 430 (September 1996). More specifically, a plate-shaped sample with a size of 80 mm × 80 mm × 1 mm is inserted between two fixed dielectric resonators. The resonator measures the dielectric constant component on the surface of the specimen. Five samples may be tested and the average value is recorded.

Example

[0084] Example 1

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

[0085]

Table 1

[0086]

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

[0087]

Table 2

[0088] Example 2

[0094] Samples 4 to 10 are formed from various combinations of liquid crystal polymer (LCP1 and LCP3), copper chromite filler (CuCr 2 O 4 ), glass fiber, alumina trihydrate (“ATH”), lubricant (polyethylene wax) and polytetrafluoroethylene (“PTFE1” or “PTFE2”). LCP3 is formed from 43% HBA, 9% TA, 29% HQ and 20% NDA. PTFE1 is a powder of polytetrafluoroethylene particles having a D50 particle size of 4 μm and a D90 particle size of 15 μm. PTFE2 is a powder of polytetrafluoroethylene particles having a D50 particle size of 40 μm. The compounding is carried out using an 18 mm single-screw extruder. The parts are injection molded into samples in the form of plates (60 mm × 60 mm).

[0089]

Table 3

[0090]

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

[0091]

Table 4

[0092] Example 3

[0096] Sample 11 contains 100 wt.% of LCP4 for use in RF filters, which is formed from 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 to 24 are formed from various combinations of liquid crystal polymer (LCP2), milled and / or flat chopped glass fiber strands (aspect ratio = 4), mica (MICA1 and MICA2), and silica. MICA1 has an average particle size of 25 micrometers, and MICA2 has an average particle size of 60 micrometers. The compounding was carried out using an 18 mm single-screw extruder. The parts are injection molded to make the samples into plates (60 mm × 60 mm).

[0095]

Table 6

[0096]

[0098] Samples 12 to 19 were tested for thermal and mechanical properties. The results are described in the following table.

[0097]

Table 7

[0098] Example 5

[0099] Sample 20 contains 100 wt.% of LCP5 for use in RF filters, which is formed from 73% HNA and 27% HBA. The sample is injection molded into a plate (60 mm × 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.% of LCP6 for use in RF filters and 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.% of LCP7 for use in RF filters and 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.% of LCP8 for use in RF filters It 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.% of LCP9 for use in RF filters. It is formed from 76% HNA and 24% HBA. The sample is injection molded into a plate (60 mm × 60 mm) and tested for thermal and mechanical properties. The results are described below.

[0107]

Table 12

[0108] Example 10

[0104] Samples 25 - 26 are formed from various combinations of liquid crystal polymers (LCP9 and LCP4) and PTF E1. The compounding was carried out using an 18 mm single - screw extruder. The parts are injection molded to make the samples into plates (60 mm × 60 mm).

[0109]

Table 13

[0110]

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

[0111]

Table 14

[0112] Example 11

[0106] Samples 27-28 may be used in RF filters. Sample 27 is a 70w Sample 1 contains 65 wt.% LCP3 and 30 wt.% PTFE1, and sample 28 contains 65 wt.% LCP3 and 35 wt.% PTFE1. Samples 27-28 were tested for thermal and mechanical properties. The results are listed below.

[0113] [Table 15]

[0114]

[0107] These and other modifications and variations of the present invention are intended to be within the spirit and scope of the present invention. It will be understood that the present invention can be practiced by those skilled in the art without departing from the spirit and scope of the present invention. Moreover, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Moreover, those skilled in the art will appreciate that the foregoing description is merely illustrative, and thus does not limit the invention as further described in the appended claims.

Claims

1. 1. An RF filter comprising a resonant element and a polymer composition, the polymer composition comprising an aromatic polymer and having a melting temperature of about 240° C. or greater, the polymer composition exhibiting a dielectric constant of about 5 or less and a dielectric loss tangent of about 0.05 or less at a frequency of 10 GHz.

2. The RF filter of claim 1 , wherein the filter is an acoustic filter comprising a piezoelectric material.

3. The RF filter of claim 2 wherein a transducer is formed on the piezoelectric material.

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

5. The RF filter of claim 2 , wherein the acoustic filter includes a substrate supporting the piezoelectric material.

6. The RF filter of claim 5 , wherein the substrate comprises the polymer composition.

7. The RF filter of claim 2 , further comprising a housing covering the resonating element.

8. The RF filter of claim 7 , wherein the housing comprises the polymer composition.

9. 9. An RF filter according to claim 1 which is a cavity filter including a housing defining a cavity within which the resonant element is received.

10. 10. The RF filter of claim 9, wherein the resonating element is a dielectric material.

11. 10. The RF filter of claim 9, wherein the housing comprises the polymer composition.

12. 10. The RF filter of claim 9, further comprising a cover over the housing, the cover comprising the polymer composition.

13. 13. The RF filter of claim 1, 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.

14. 14. The RF filter of claim 1, wherein the aromatic polymer comprises from about 40 wt. % to about 99 wt. % of the polymer composition.

15. 15. The RF filter according to claim 1, wherein the aromatic polymer is a polyarylene sulfide.

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

17. 17. The RF filter of claim 16, wherein the liquid crystal polymer contains repeat units derived from one or more aromatic dicarboxylic acids, one or more aromatic hydroxycarboxylic acids, or a combination thereof.

18. 18. The RF filter of claim 17, wherein the aromatic hydroxycarboxylic acid comprises 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, or a combination thereof.

19. 18. The RF filter of claim 17, wherein the aromatic hydroxycarboxylic acid comprises terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, or a combination thereof.

20. 20. The RF filter of claim 17, wherein the liquid crystal polymer further contains repeat units derived from one or more aromatic diols.

21. 21. The RF filter of claim 20, wherein the aromatic diol comprises hydroquinone, 4,4'-biphenol, or a combination thereof.

22. 17. The RF filter of claim 16, wherein the liquid crystal polymer is fully aromatic.

23. 17. 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.

24. 17. 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.

25. 25. The RF filter of claim 1, wherein the polymer composition further comprises a fibrous filler.

26. 26. The RF filter of claim 25, wherein the fibrous filler comprises glass fibers.

27. 26. The RF filter of claim 25, wherein the fibrous filler has an aspect ratio of about 2 or greater.

28. 28. The RF filter of claim 1, wherein the polymer composition further comprises a particulate filler.

29. 30. The RF filter of claim 28, wherein the particulate filler comprises mica.

30. 30. The RF filter of claim 1, wherein the polymer composition further comprises a laser activatable additive.

31. 31. The RF filter according to any of the preceding claims, wherein the polymer composition exhibits a relative dielectric constant of about 1.5 to about 4 at a frequency of 2 GHz.

32. 32. The RF filter of claim 1, wherein the polymer composition exhibits a dissipation factor of less than or equal to about 0.0009 at a frequency of 2 GHz.

33. 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.

34. 34. The 5G antenna system of claim 33, wherein the antenna elements have a feature size of less than about 1,500 micrometers.

35. 34. The method of claim 33, wherein the 5G radio frequency signal has a frequency greater than about 28 GHz. G antenna system.

36. 34. The 5G antenna system of claim 33, wherein the at least one antenna element comprises a plurality of antenna elements arranged in an antenna array.

37. 37. The 5G antenna system of claim 36, wherein the plurality of antenna elements are separated by a spacing distance of less than about 1,500 micrometers.

38. 37. The 5G antenna system of claim 36, wherein the plurality of antenna elements includes at least 16 antenna elements.

39. 37. The 5G antenna system of claim 36, wherein the plurality of antenna elements are arranged in a grid.

40. 37. The 5G antenna system of claim 36, wherein the antenna array is configured for at least eight transmit channels and at least eight receive channels.

41. 37. The 5G antenna system of claim 36, wherein the antenna array has an average antenna element density of greater than 1,000 antenna elements per square centimeter.

42. 34. The 5G antenna system of claim 33, further comprising a base station, said base station comprising said antenna element.

43. 43. The 5G antenna system of 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.

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