Polymer Composition for Laser Direct Structuring

Abstract

A polymer composition is provided that includes a laser-activatable additive, a fibrous filler, and a dielectric material distributed within a polymer matrix. The polymer matrix contains at least one thermotropic liquid crystal polymer. Furthermore, the polymer composition exhibits a dielectric constant of greater than or equal to about 10 and a dissipation factor of less than or equal to about 0.1, as determined at a frequency of 2 GHz.

Description

Technical Field

[0001] Cross - reference to related applications

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 889,792, filed on August 21, 2019; U.S. Provisional Patent Application No. 62 / 898,188, filed on September 10, 2019; U.S. Provisional Patent Application No. 62 / 925,271, filed on October 24, 2019; U.S. Provisional Patent Application No. 62 / 951,033, filed on December 20, 2019; U.S. Provisional Patent Application No. 62 / 972,183, filed on February 10, 2020; U.S. Provisional Patent Application No. 63 / 024,555, filed on May 14, 2020; and U.S. Provisional Patent Application No. 63 / 038,956, filed on June 15, 2020, the entire contents of each of which are hereby incorporated by reference.

Background Art

[0002]

[0002] To form the antenna structures of various electronic components, molded interconnected devices ("MIDs") often contain a plastic substrate on which conductive elements or paths are formed. Thus, such MID devices are three-dimensional molded parts with integrated printed conductors or circuit layouts. The formation of MIDs using the laser direct structuring ("LDS") process is becoming increasingly popular. In this process, a computer-controlled laser beam moves over the plastic substrate and activates its surface at the locations where the conductive paths are to be located. Using the laser direct structuring process, conductive element widths and spacings of 150 microns or less can be obtained. As a result, the MIDs formed from this process reduce space and weight in the end use. Another advantage of laser direct structuring is its flexibility. When changing the circuit design, simply reprogram the computer that controls the laser. For this reason, the time and cost from prototyping to final commercial production are significantly reduced. Various materials have been proposed to form the plastic substrates of laser direct structuring MID devices. For example, one such material is a blend of polycarbonate, acrylonitrile butadiene styrene ("ABS"), copper chromite spinel, and bisphenol A diphenyl phosphate ("BPADP") flame retardant. However, one problem with such materials is that the flame retardant tends to have an adverse effect on the mechanical properties of the composition (e.g., heat deflection temperature), making it difficult to use in the laser direct structuring process. Such materials are also not suitable for lead-free soldering processes (surface mount technology) that require high temperature resistance. Another problem is that the materials tend to have a low relative permittivity and a high dissipation factor, making it difficult to use in applications where it is desired for the device to contain more than one antenna.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Therefore, there is a need for a polymer composition that can be activated by direct laser structuring and has a relatively high relative permittivity, while still maintaining excellent mechanical properties and processability (e.g., low viscosity).

Means for Solving the Problems

[0004]

[0004] According to one embodiment of the present invention, a polymer composition is disclosed that includes a laser-activatable additive, a fibrous filler, and a dielectric material distributed in a polymer matrix. The polymer matrix contains at least one thermotropic liquid crystal polymer. Further, the polymer composition exhibits a relative permittivity of about 10 or more and a dielectric tangent of about 0.1 or less, as determined at a frequency of 2 GHz.

[0005]

[0005] Other features and aspects of the present invention are described in more detail below.

[0006] The 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

[0006]

Figure 1

[0007] A front perspective view of one embodiment of an electronic component that can utilize an antenna structure formed by the present invention.

Figure 2

Figure 3

[0008] A top view of an exemplary inverted-F antenna resonator for one embodiment of the antenna structure.

Figure 4

[0009] A top view of an exemplary monopole antenna resonator for one embodiment of the antenna structure.

Figure 5

[0010] A top view of an exemplary slot antenna resonator for one embodiment of the antenna structure.

Figure 6

[0011] Top view of an exemplary patch antenna resonator for one embodiment of the antenna structure.

Figure 7

[0012] Top view of an exemplary multi-branched inverted F antenna resonator for one embodiment of the antenna structure.

Figure 8

[0013] Diagram of a 5G antenna system including a base station, one or more relay stations, one or more user computing devices, and one or more or more Wi-Fi repeaters according to aspects of the present disclosure.

Figure 9A

[0014] Top view of an exemplary user computing device including a 5G antenna according to aspects of the present disclosure.

Figure 9B

[0015] Side view of the exemplary user computing device of FIG. 9A including a 5G antenna according to aspects of the present disclosure.

Figure 10

[0016] Enlarged view of a part of the user computing device of FIG. 9A.

Figure 11

[0017] Side view of a coplanar waveguide antenna array configuration according to aspects of the present disclosure.

Figure 12A

[0018] Diagram of an antenna array for a massive multiple-input multiple-output configuration according to aspects of the present disclosure.

Figure 12B

[0019] Diagram of an antenna array formed by laser direct structuring according to aspects of the present disclosure.

Figure 12C

[0020] Diagram of an exemplary antenna configuration according to aspects of the present disclosure.

Figure 13A

[0021] FIG. 13A is a simplified sequence diagram of a laser direct structuring manufacturing method that can be used to form an antenna system.

Figure 13B

Figure 13C

[0007]

[0022] It will be understood by those skilled in the art that this discussion is only an illustration of exemplary embodiments and does not limit the broader aspects of the present invention.

[0023] Generally, the present invention relates to a polymer composition containing a unique combination of a thermotropic liquid crystal polymer, a dielectric material, a laser-activatable additive, and a fibrous filler. The resulting composition can maintain a high relative dielectric constant, a low dielectric tangent, good mechanical properties, and good processability, yet still be laser-activatable. For example, the polymer composition may exhibit a high relative dielectric constant of about 10 or more, in some embodiments about 10 to about 30, in some embodiments about 11 to about 25, and in some embodiments about 12 to about 24, as determined by the split post resonance method at a frequency of 2 GHz. Such a high relative dielectric constant can facilitate the ability to form thin substrates and further enable the utilization of multiple conductive elements (e.g., antennas) operating with only a minimal level of electrical interference. The dielectric tangent, which is a measure of the energy loss rate, may also be relatively low, for example, about 0.1 or less, in some embodiments about 0.06 or less, in some embodiments about 0.04 or less, in some embodiments about 0.01 or less, and in some embodiments about 0.001 to about 0.006, as determined by the split post resonance method at a frequency of 2 GHz. In particular, the inventors have also surprisingly discovered that the relative dielectric constant and the dielectric tangent can be maintained within the above-described ranges even when exposed to various temperatures such as temperatures from about -30°C to about 100°C. For example, when subjected to the thermal cycle test described herein, the ratio of the relative dielectric constant after thermal cycling to the initial relative dielectric constant may be about 0.8 or more, in some embodiments about 0.9 or more, and in some embodiments about 0.91 to about 1. Similarly, the ratio of the dielectric tangent after exposure to high temperature to the initial dielectric tangent may be about 1.3 or less, in some embodiments about 1.2 or less, in some embodiments about 1.1 or less, in some embodiments about 1.0 or less, in some embodiments about 0.95 or less, in some embodiments about 0.1 to about 0.9, and in some embodiments about 0.2 to about 0.8. The change in the dielectric tangent (i.e., the initial dielectric tangent - the dielectric tangent after thermal cycling) can also be in the range of about -0.1 to about 0.1, in some embodiments about -0.05 to about 0.01, and in some embodiments about -0.001 to 0.

[0008]

[0024] Conventionally, polymer compositions that are laser-activatable and have a combination of a high relative permittivity and a low dielectric tangent have not been thought 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. The melting temperature of the composition may be, for example, from about 250 °C to about 440 °C, in some embodiments from about 270 °C to about 400 °C, and in some embodiments from about 300 °C to about 380 °C. Even at such melting temperatures, the ratio of the heat deflection temperature (the "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 range, for example, from about 200 °C to about 350 °C, in some embodiments from about 210 °C to about 320 °C, and in some embodiments from about 230 °C to about 290 °C. Such high DTUL values can, inter alia, enable the use of a fast and reliable surface mounting process for fitting the structure with other components of the electrical component.

[0009]

[0025] Furthermore, the polymer composition may have a high impact strength useful in forming thin substrates. The composition may have, for example, at a temperature of 23 °C, determined according to ISO test No. ISO 179-1:2010, of about 0.5 kJ / m 2 or more, in some embodiments from about 1 to about 50 kJ / m 2 and in some embodiments from about 2 to about 40 kJ / m 2 and in some embodiments from about 10 to about 35 kJ / m 2It may have a notched Charpy impact strength. The tensile and flexural mechanical properties of the composition may also be good. For example, the polymer composition may have a tensile strength of about 20 to about 500 MPa, in some embodiments about 50 to about 400 MPa, and in some embodiments about 70 to about 350 MPa; a tensile fracture strain of about 0.4% or more, in some embodiments about 0.5% to about 10%, and in some embodiments about 0.6% to about 3.5%; and / or a tensile modulus of about 5,000 MPa to about 20,000 MPa, in some embodiments about 8,000 MPa to about 20,000 MPa, and in some embodiments about 10,000 MPa to about 20,000 MPa. The tensile properties may be determined in accordance with ISO test No. 527:2012 at a temperature of 23°C. Further, the polymer composition may have a flexural strength of about 20 to about 500 MPa, in some embodiments about 50 to about 400 MPa, and in some embodiments about 100 to about 350 MPa; a flexural elongation of about 0.4% or more, in some embodiments about 0.5% to about 10%, and in some embodiments about 0.6% to about 3.5%; and / or a flexural modulus of about 5,000 MPa to about 20,000 MPa, in some embodiments about 8,000 MPa to about 20,000 MPa, and in some embodiments about 10,000 MPa to about 15,000 MPa. The flexural properties may be determined in accordance with 178:2010 at a temperature of 23°C.

[0010]

[0026] As a result of the above properties, the polymer composition can be easily formed into a substrate, and then one or more conductive elements may be applied to the substrate using a laser direct structuring method ("LDS"). Due to the beneficial properties of the polymer composition, the resulting substrate may have a very small size such as a thickness of about 5 millimeters or less, in some embodiments about 4 millimeters or less, and in some embodiments about 0.5 to about 3 millimeters. If desired, the conductive element may be an antenna (e.g., an antenna resonance element) such that the resulting component can be used in a variety of different electronic components such as mobile phones and automotive devices.

[0011]

[0027] Here, various embodiments of the present invention will be described in more detail. I. Polymer Composition A. Polymer Matrix

[0028] The polymer matrix contains one or more liquid crystal polymers, generally in an amount of about 15 wt.% to about 85 wt.% of the total polymer composition, in some embodiments about 20 wt.% to about 75 wt.%, and in some embodiments about 30 wt.% to about 50 wt.%. 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 or higher, in some embodiments about 220 °C to about 350 °C, and in some embodiments about 240 °C to about 300 °C. The melting temperature may be determined using differential scanning calorimetry ("DSC") as is well known in the art, for example, by ISO test No. 11357-3:2011. Such polymers may be formed from one or more types of repeating units as is known in the art. The liquid crystal polymer is, for example, the following formula (I):

[0012]

Chemical formula

[0013] (wherein 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 to 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)) and may generally contain one or more aromatic ester repeating units represented by

[0014]

[0029] Typically, Y 1and Y 2 At least one of them is C(O). Examples of such aromatic ester repeating units include, for example, aromatic dicarboxylic acid repeating units (Y in formula I 1 and Y 2 is C(O)), aromatic hydroxycarboxylic acid repeating units (Y in formula I 1 is O and Y 2 is C(O)), and various combinations thereof can be mentioned.

[0015]

[0030] For example, 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., and aromatic hydroxycarboxylic acid repeating units derived from these aromatic hydroxycarboxylic acids such 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 (such as HBA and / or HNA) typically constitute about 20 mol.% or more of the polymer, in some embodiments about 30 mol.% to about 70 mol.%, and in some embodiments about 35 mol.% to 60 mol.%.

[0016]

[0031] Aromatic dicarboxylic acid repeating units derived from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, bis(4-carboxyphenyl) ether, bis(4-carboxyphenyl) butane, bis(4-carboxyphenyl) ethane, bis(3-carboxyphenyl) ether, bis(3-carboxyphenyl) ethane, etc., and their alkyl, alkoxy, aryl, and halogen substituents, and combinations thereof, etc. may also 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 repeating units derived from the aromatic dicarboxylic acid (e.g., IA, TA, and / or NDA) typically constitute about 1 mol.% to about 50 mol.% of the polymer, about 10 mol.% to about 45 mol.% in some embodiments, and about 20 mol.% to about 40 mol.% in some embodiments.

[0017]

[0032] 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 alkyl, alkoxy, aryl, and halogen substituents thereof, and repeating units derived from aromatic diols such as 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 50 mol.% of the polymer, about 10 to about 45 mol.% in some embodiments, and about 20 mol.% to about 40 mol.% in some embodiments. 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, about 0.5 mol.% to about 15 mol.% in some embodiments, and about 1 mol.% to about 10 mol.% in some embodiments. It should also be understood that various other monomer repeating units may be introduced into the polymer. For example, in certain embodiments, the polymer may contain one or more repeating units derived from non-aromatic monomers such as aliphatic or alicyclic hydroxycarboxylic acids, dicarboxylic acids, diols, amides, amines, etc. Of course, in other embodiments, the polymer may be "all aromatic" in that it does not contain repeating units derived from non-aromatic (e.g., aliphatic or alicyclic) monomers.

[0018]

[0033] Although not necessarily required, a 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 naphthalene-2,6-dicarboxylic acid ("NDA"), 6-hydroxy-2-naphthoic acid ("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 15 mol.%, and in some embodiments from about 20 mol.% to about 60 mol.%. Unlike many conventional "low naphthene" polymers, the resulting "high naphthene" polymers are believed to be able to exhibit good thermal and mechanical properties. In one particular embodiment, for example, the repeating units derived from naphthalene-2,6-dicarboxylic acid ("NDA") may constitute from about 10 mol.% to about 40 mol.% of the polymer, in some embodiments from about 12 mol.% to about 35 mol.%, and in some embodiments from about 15 mol.% to about 30 mol.%.

[0019] B. Laser-Activatable Additive

[0034] The polymer composition is "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 liberation of metal. Thereby, the laser draws a pattern of conductive elements on that part and leaves a roughened surface containing embedded metal particles. These particles act as nuclei for crystal growth during subsequent plating processes (such as copper plating, gold plating, nickel plating, silver plating, zinc plating, tin plating, etc.). Laser activatable additives typically constitute from about 0.1 wt.% to about 30 wt.% of the polymer composition, in some embodiments from about 0.5 wt.% to about 20 wt.%, and in some embodiments from about 1 wt.% to about 10 wt.%. 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 overall crystal formation has 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) and may have.

[0020]

[0035] Generally, 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 with increased sensitivity to electromagnetic radiation. Examples of suitable spinel crystals include, for example, MgAl 2 O 4 、ZnAl2 O 4 , FeAl 2 O 4 , CuFe 2 O 4 , 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".

[0021] C. Dielectric Material

[0036] To promote the achievement of the desired dielectric properties, the polymer composition also contains a dielectric material. The dielectric material is typically utilized in an amount of about 10 wt.% to about 70 wt.% of the composition, in some embodiments about 20 wt.% to about 60 wt.%, and in some embodiments about 30 wt.% to about 50 wt.%. In certain embodiments, it may be desirable to selectively control the volume resistivity of the dielectric material such that the dielectric material becomes overall semiconductive in nature. For example, the dielectric material may have a volume resistivity of about 0.1 ohm·cm to about 1×10 12 ohm·cm, in some embodiments about 0.5 ohm·cm to about 1×10 11 ohm·cm, in some embodiments about 1 to about 1×10 10 ohm·cm, and in some embodiments about 2 to about 1×10 8 ohm·cm, as determined at a temperature of about 20 °C in accordance with, for example, ASTM D257-14. This may be achieved by selecting a single material having the desired volume resistivity or by blending multiple materials (e.g., insulating and conductive) together such that the resulting blend has the desired volume resistivity.

[0022]

[0037] In one embodiment, for example, an inorganic oxide material that can exhibit a linear response of charge (or polarization) to voltage may be used. These materials may exhibit a total reversible polarization of charge within the crystal structure after the applied electric field is removed. Examples of inorganic oxide materials suitable for this purpose include, for example, ferroelectric and / or dielectric materials. Examples of suitable ferroelectric materials include, for example, barium titanate (BaTiO 3 ), strontium titanate (SrTiO 3 ), calcium titanate (CaTiO 3 ), magnesium titanate (MgTiO 3 ), strontium barium titanate (SrBaTiO 3 ), sodium barium niobate (NaBa 2 Nb 5 O 15 ), potassium barium niobate (KBa 2 Nb 5 O 15 ), calcium zirconate (CaZrO 3 ), titanite (CaTiSiO 5 ), and combinations thereof. Further examples of suitable dielectric materials include, for example, titanium dioxide (TiO 2 ), tantalum pentoxide (Ta 2 O 5 ), hafnium dioxide (HfO 2 ), niobium pentoxide (Nb 2 O 5 ), alumina (Al 2 O 3 ), zinc oxide (ZnO), etc., and combinations thereof. Particularly suitable inorganic oxide materials are particles containing TiO 2 , BaTiO 3 , SrTiO 3 , CaTiO 3 , MgTiO 3 , BaSrTi 2 O 6 and ZnO. Of course, other types of inorganic oxide materials (e.g., mica) can also be used as dielectric materials. Carbon materials such as graphite and carbon black can also be used in the same way.

[0023]

[0038] The shape and size of the dielectric material are not particularly limited, and examples thereof may include particles, fine powders, fibers, whiskers, tetrapods, plates, etc. For example, in one embodiment, the dielectric material may include particles having an average diameter of about 0.01 to about 100 micrometers, and in some embodiments, about 0.10 to about 20 micrometers. In another embodiment, the dielectric material may include fibers and / or whiskers having an average diameter of about 0.1 to about 35 micrometers, in some embodiments, about 0.2 to about 20 micrometers, and in some embodiments, about 0.5 to about 15 micrometers. When utilized, the whiskers may have an aspect ratio of about 1 to about 100, in some embodiments, about 2 to about 80, and in some embodiments, about 4 to about 50. The volume average length of such whiskers may be in the range of, for example, about 1 to about 200 micrometers, in some embodiments, about 2 to about 150 micrometers, and in some embodiments, about 5 to about 100 micrometers.

[0024]

[0039] As described above, various techniques may be utilized to facilitate achieving a desired volume resistivity. For example, in one embodiment, an inorganic oxide material having a volume resistivity of from 0.1 ohm·cm to about 500 ohm·cm, in some embodiments from about 0.5 ohm·cm to about 250 ohm·cm, in some embodiments from about 1 to about 100 ohm·cm, and in some embodiments from about 2 to about 50 ohm·cm, as determined at a temperature of about 20 °C, for example in accordance with ASTM D257-14, may be utilized. As an example of such a material, inorganic oxide whiskers having a three-dimensional structure (e.g., zinc oxide whiskers) may be mentioned. For example, the inorganic oxide whiskers may have a central body and a plurality of acicular crystals extending radially therefrom to form a three-dimensional structure. When such whiskers are incorporated into a resin, the acicular crystals may be very closely spaced from each other, thereby increasing the possibility of forming a stable conductive path. The number of acicular crystals may vary, for example, be about 2 or more, in some embodiments 3 - 8, and in some embodiments 4 - 6 (e.g., 4). For example, when four acicular crystals are present, the whisker may have a "tetrapod" morphology even if one or more of their acicular crystal protrusions may be damaged during processing and / or manufacturing. The central body and / or the basal portion of the acicular crystal may have an average diameter within the ranges described above, for example from about 0.1 to about 35 micrometers, in some embodiments from about 0.2 to about 20 micrometers, and in some embodiments from about 0.5 to about 15 micrometers. The volume average length (from the base to the tip) of the acicular crystal may similarly be within the ranges described above, for example from about 1 to about 200 micrometers, in some embodiments from about 2 to about 150 micrometers, and in some embodiments from about 5 to about 100 micrometers. Such whiskers may be formed, for example, by heat-treating a metal powder (e.g., zinc) having an oxide film on its surface in an atmosphere containing molecular oxygen, as described in U.S. Patent No. 4,960,654 to Yoshinaka et al. As one particularly suitable type of whisker having such characteristics, single crystal tetrapod zinc oxide whiskers available from Panasonic under the trade name Pana-Tetra™ may be mentioned.

[0025]

[0040] In another embodiment, for example, determined at a temperature of about 20 °C in accordance with ASTM D257-14, about 1×10 3 ~ about 1×10 12 ohm·cm, in some embodiments about 1×10 4 ~ about 1×10 11 ohm·cm, in some embodiments about 1×10 5 ~ about 1×10 10 ohm·cm, in some embodiments about 1×10 6 ~ about 1×10 8 A carbon material having a volume resistivity of ohm·cm may be used. For example, a carbon material (e.g., particles, fibers, etc.) having a volume resistivity within the above-mentioned range may be obtained by firing an organic substance (e.g., petroleum tar, petroleum pitch, coal tar or coal pitch) at a high temperature (e.g., 400 °C to 900 °C) in an inert atmosphere, as described in, for example, U.S. Patent No. 8,642,682 to Nishihata et al. The resulting carbon material typically has a high carbon content of about 80 wt.% or more, in some embodiments about 85 wt.% or more, and in some embodiments about 90 wt.% to about 98 wt.%. One particularly suitable type of carbon material having such characteristics is available from Kureha Extron under the trade name Krefine™.

[0026]

[0041] Of course, as described above, in order to facilitate the achievement of the desired volume resistance, a conductive material can also be used in combination with an insulating material. The conductive material generally has a volume resistivity of less than about 0.1 ohm·cm, in some embodiments about 1×10 -8 ~ about 1×10 -2 ohm·cm, and the insulating material generally has a volume resistivity greater than about 1×10 12 ohm·cm, in some embodiments about 1×10 13 ~ about 1×10 18It has a volume resistivity of ohm·cm. Suitable conductive materials include, for example, conductive carbon materials (such as graphite, carbon black, fibers, graphene, nanotubes, etc.), metals, and the like. Similarly, suitable insulating materials include the above-mentioned inorganic oxide materials (such as particles), for example, titanium dioxide (TiO 2 ). When utilized, the ratio of the weight percentage of the insulating material in the polymer composition to the weight percentage of the conductive material in the composition may be from about 3 to about 20, in some embodiments from about 7 to about 18, and in some embodiments from about 8 to about 15. For example, the conductive material may constitute about 1 wt.% to about 20 wt.%, in some embodiments about 3 wt.% to about 18 wt.%, and in some embodiments about 5 wt.% to about 15 wt.% of the dielectric material, while the insulating material may constitute about 80 wt.% to about 99 wt.%, in some embodiments 82 wt.% to about 97 wt.%, and in some embodiments about 85 wt.% to about 95 wt.% of the dielectric material. Similarly, the conductive material may constitute about 0.1 wt.% to about 15 wt.%, in some embodiments about 0.5 wt.% to about 12 wt.%, and in some embodiments about 1 wt.% to about 10 wt.% of the polymer composition, while the insulating material may constitute about 20 wt.% to about 60 wt.%, in some embodiments 25 wt.% to about 55 wt.%, and in some embodiments about 30 wt.% to about 50 wt.% of the polymer composition.

[0027] D. Fibrous Filler

[0042] Fibrous fillers may also be utilized in the polymer composition to improve the thermal and mechanical properties of the 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 of insulating nature, such as glass, ceramic (e.g., alumina or silica), aramid (e.g., Kevlar® sold by E.I. duPont de Nemours, Wilmington, Delaware), polyolefin, polyester, etc. Glass fibers such as E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S1-glass, S2-glass are particularly suitable.

[0028]

[0043] Furthermore, the fibers utilized in 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, fibers having an aspect ratio (average length divided by nominal diameter) of about 5 to about 50, in some embodiments about 6 to about 40, and in some embodiments about 8 to about 25 are particularly beneficial. Such fibers may have a weight average length of, for example, about 100 to about 800 micrometers, in some embodiments about 120 to about 500 micrometers, in some embodiments about 150 to about 350 micrometers, and in some embodiments about 200 to about 300 micrometers. The fibers may similarly have a nominal diameter of about 6 to about 35 micrometers, and in some embodiments about 9 to about 18 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 composition, such as its fluidity and dielectric properties. For example, the fibrous filler may be utilized in a sufficient amount such that the weight ratio of the fibrous filler to the combined amount of the dielectric material and the laser-activatable material is about 0.05 to about 1, in some embodiments about 0.05 to about 0.5, in some embodiments about 0.06 to about 0.4, and in some embodiments about 0.1 to about 0.3. The fibrous filler may constitute, for example, about 1 wt.% to about 40 wt.% of the polymer composition, in some embodiments about 3 wt.% to about 30 wt.%, and in some embodiments about 5 wt.% to about 20 wt.%.

[0029]

[0044] A wide variety of additional additives may be included in the polymer composition, such as lubricants, thermally conductive fillers, pigments, antioxidants, stabilizers, surfactants, waxes, flame retardants, anti-drip additives, nucleating agents (e.g., boron nitride), flow modifiers, and other materials added to improve properties and processability. When utilized, such additives typically constitute, for example, about 0.05 wt.% to about 5 wt.% of the polymer composition, and in some embodiments about 0.1 wt.% to about 1 wt.%.

[0030] II. Formation

[0045] 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, a liquid crystal polymer, a dielectric material, a laser activatable additive, a fibrous filler, and other optional additives are melt processed as a mixture in an extruder to form the polymer composition. The mixture may be melt compounded at a temperature of about 250°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 having a plurality of temperature zones. The temperature of the individual zones is typically set within about -60°C to about 25°C relative to the melting temperature of the liquid crystal 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 of the components can be fed to 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 liquid crystal polymer can be applied to the feed port and specific additives (e.g., dielectric materials, laser activatable additives, and fibrous fillers) can be supplied in the same or different temperature zones located downstream therefrom. In any case, the resulting mixture can be melted, mixed, and then extruded through a die. Next, the extruded polymer composition may be quenched and solidified in a water bath, pelletized with a pelletizer, and then dried.

[0031]

[0046] The melt viscosity of the resulting composition is generally low enough to flow easily into the cavities of the mold and form small sized circuit boards. For example, in one particular embodiment, the polymer composition has a melt viscosity of about 5 to about 100 Pa·s, in some embodiments about 10 to about 95 Pa·s, and in some embodiments about 15 to about 90 Pa·s, determined at a shear rate of 1,000 seconds -1 . The melt viscosity may be determined in accordance with 11443:2005.

[0032] III. Substrate

[0047] After formation, the polymer composition can be molded into a substrate of a desired shape. Typically, the molded part is molded using a one-component injection molding process in which dry and preheated plastic granules are injected into a mold. As shown above, a conductive element may then be formed on the substrate using a laser direct structuring process ("LDS"). Activation by the laser causes a physicochemical reaction, the spinel crystals crack and metal atoms are released. 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 a number of microscopic pits and grooves in which copper can adhere during metallization.

[0033]

[0048] If desired, the conductive element can form various different types of antennas, such as an antenna having a resonant element formed from a patch antenna structure, an inverted F antenna structure, closed and open slot antenna structures, loop antenna structures, monopoles, dipoles, planar inverted F antenna structures, hybrids of these designs, etc. The resulting antenna structure may be utilized in a variety of different electronic components. By way of example, the antenna structure may be formed in an electronic component such as a desktop computer, a lightweight computer, a handheld electronic device, an automotive device, etc. In one preferred configuration, the antenna structure is formed in the housing of a relatively small and lightweight electronic component having a relatively small available internal space. Examples of suitable lightweight electronic components include mobile phones, laptop computers, small lightweight computers (e.g., ultra-lightweight computers, netbook computers, and tablet computers), wristwatch devices, pendant devices, headphone and earpiece devices, media players with wireless communication capabilities, handheld computers (sometimes referred to as personal digital assistants), remote controllers, satellite positioning system (GPS) devices, handheld game devices, etc. The antenna may also be integrated with other components such as the camera module, speaker or battery cover of a handheld device.

[0034]

[0049] One particularly suitable electronic component shown in FIGS. 1-2 is the handheld device 10 with a cellular phone function. As shown in FIG. 1, the device 10 may have a housing 12 formed from plastic, metal, other suitable dielectric materials, other suitable conductive materials, or combinations of such materials. A display 14, such as a touch screen display, may be provided on the front face of the device 10. The device 10 may also have a speaker port 40 and other input / output ports. One or more buttons 38 and other user input devices may be used to gather user input. As shown in FIG. 2, the antenna structure 26 is also provided on the back face 42 of the device 10, although it should be understood that the antenna structure may generally be located at any desired location on the device. The antenna structure may be electrically connected to other components within the electronic device using any of a variety of known techniques. Referring again to FIGS. 1-2, for example, the housing 12 or a portion of the housing 12 may function as the conductive ground plane of the antenna structure 26. This is illustrated in more detail in FIG. 3, which shows that the antenna structure 26 is fed by a radio frequency source 52 at a positive antenna feed terminal 54 and a ground antenna feed terminal 56. The positive antenna feed terminal 54 may be coupled to an antenna resonator 58, and the ground antenna feed terminal 56 may be coupled to a ground element 60. The resonator 58 may have a main arm 46 and a shorting stub 48 that connects the main arm 46 to the ground 60.

[0035]

[0050] Various other configurations for electrically connecting the antenna structure are also contemplated. For example, in FIG. 4, the antenna structure is based on a monopole antenna configuration, and the resonant element 58 has a meandering serpentine shape. In such an embodiment, the feed terminal 54 may be connected to one end of the resonant element 58, and the ground feed terminal 56 may be coupled to the housing 12 or another suitable ground plane element. In another embodiment shown in FIG. 5, the conductive antenna structure 62 is configured to define a closed slot 64 and an open slot 66. The antenna formed from the structure 62 may be fed using a positive antenna feed terminal 54 and a ground antenna feed terminal 56. In this type of arrangement, the slots 64 and 66 function as antenna resonant elements for the antenna structure 26. The sizes of the slots 64 and 66 may be configured such that the antenna structure 26 operates in a desired communication band (e.g., 2.4 GHz and 5 GHz, etc.). Another possible configuration for the antenna structure 26 is shown in FIG. 6. In this embodiment, the antenna structure 26 has a patch antenna resonant element 68 and may be fed using a positive antenna feed terminal 54 and a ground antenna feed terminal 56. The ground 60 may be coupled to the housing 12 or another suitable ground plane element of the device 10. FIG. 7 shows yet another exemplary configuration that may be used for the antenna structure of the antenna structure 26. As shown, the antenna resonant element 58 has two main arms 46A and 46B. Arm 46A is shorter than arm 46B and is thus associated with operation at a higher frequency than arm 46B. By using two or more distinct resonant element structures of different sizes, the antenna resonant element 58 can be configured to cover a wider bandwidth or more than one target communication band.

[0036]

[0051] In certain embodiments of the present invention, the polymer composition may be particularly well-suited for use in high-frequency antennas and antenna arrays used in base stations, repeaters (e.g., "femtocells"), relays, terminals, user devices, and / or other suitable components of a 5G system. As used herein, "5G" generally refers to high-speed data communication via radio frequency signals. 5G networks and systems can communicate data much faster than previous-generation data communication standards (e.g., "4G", "LTE"). For example, as used herein, "5G frequency" may refer to a frequency of 1.5 GHz or higher, in some embodiments about 2.0 GHz or higher, in some embodiments 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, in some embodiments about 28 GHz to about 60 GHz. 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 / second and the uplink peak data rate at 10 Gbit / second. As another example, 3 rdThe Generation Partnership Project (3GPP) recently released a new standard for 5G called "5G NR". 3GPP issued "Release 15" in 2018, which defines "Phase 1" as the standardization of 5G NR. 3GPP defines the 5G frequency bands as "Frequency Range 1" (FR1), which generally includes frequencies below 6 GHz, and "Frequency Range 2" (FR2), which is the frequency band in the range of 20 - 60 GHz. The antenna system described in this specification may meet or be regarded as "5G" based on the standards published by 3GPP such as Release 15 (2018) and / or IMT-2020 standards.

[0037]

[0052] To achieve high-speed data communication at high frequencies, the antenna elements and arrays may utilize small feature sizes / spacings (e.g., fine pitch technology) 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 that propagates through the dielectric of the substrate on which the antenna elements are formed (e.g., nλ / 4, where n is an integer). Additionally, beamforming and / or beam steering can be utilized to facilitate transmission and reception across multiple frequency ranges or channels (e.g., multiple-input multiple-output (MIMO), massive MIMO).

[0038]

[0053] The high-frequency 5G antenna element may have various configurations. For example, the 5G antenna element may be a coplanar waveguide element, a patch array (e.g., a mesh grid patch array), or other suitable 5G antenna configurations, or may include these. The antenna element may be configured to provide MIMO, massive MIMO capabilities, beam steering, etc. As used herein, the "massive" MIMO capability generally refers 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. The massive MIMO capability may include 8×8, 12×12, 16×16, 32×32, 64×64 or more.

[0039]

[0054] The antenna element may have various configurations and arrangements and 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 their 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., a 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 within the scope of the present disclosure.

[0040]

[0055] As a result of such small feature sizes, an antenna system 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, and 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 (e.g., be equal to or proportional to) the number of antenna elements.

[0041]

[0056] Referring to FIG. 8, one embodiment of a 5G antenna system 100 is shown that also includes 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 the relay station 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 106 is not necessarily limited by the present invention and includes devices such as 5G smartphones.

[0042]

[0057] The MIMO antenna array 110 may concentrate or direct the radio frequency signal 112 towards the relay station 104 using beam steering. 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 the relative azimuth angle of each device), thereby improving the reception and / or transmission capabilities with respect to the MIMO antenna array 110.

[0043]

[0058] Figures 9A and 9B are, respectively, a top view and a side view 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 Figure 9A, the antenna elements 200, 202 may be configured to perform beam steering (indicated by arrows 204, 206 and corresponding to the relative azimuth angle) in the X-Y plane. Referring to Figure 9B, the antenna elements 200, 202 may be configured to perform beam steering (indicated by arrows 204, 206) in the Z-Y plane.

[0044]

[0059] Figure 10 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 a substrate 308 that can be formed from the polymer composition of the present invention. The antenna array 302 may include a plurality of vertically continuous 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 optionally be 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 continuous elements of the antenna array 302 may correspond to the "feature size" of the antenna array 302 . 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.

[0045]

[0060] Figure 11 is a side view of the configuration of a coplanar waveguide antenna 400. One or more coplanar ground layers 402 may be arranged parallel to the antenna element 404 (e.g., a patch antenna element). Another ground layer 406 may be spaced from the antenna element by a substrate 408 that can be formed from the polymer composition of the present invention. One or more additional antenna elements 410 may similarly be spaced from the antenna element 404 by a second layer or substrate 412 that can be formed from the polymer composition of the present invention. The dimensions "G" and "W" may correspond to the "feature 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.

[0046]

[0061] FIG. 12A is a diagram of an antenna array 500 according to another aspect of the present disclosure. The antenna array 500 may include a substrate 510 that can be formed from the polymer composition of the present invention 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 substantially evenly in the X and Y directions. The dimensions of the antenna elements 520 and / or the spacing therebetween may correspond to the "feature size" of the antenna array 500. Thus, in some embodiments, the dimensions and / or the spacing may be relatively small such that the antenna array 500 is a "fine pitch" antenna array 500 (e.g., less than about 750 micrometers). As illustrated by the ellipsis 522, the number of columns of the antenna elements 520 illustrated in FIG. 12 is shown as merely an example. Similarly, the number of rows of the antenna elements 520 is shown as merely an example.

[0047]

[0062] A synchronized antenna array 500 can be used, for example, to provide a massive MIMO function to a base station (e.g., as described above with respect to FIG. 8). More specifically, the radio frequency interactions between the various elements may be controlled or synchronized to provide a plurality of transmit and / or receive channels. The transmit power and / or receive 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 of FIG. 8. 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 channels for MIMO functions per unit area. For example, the number of channels may correspond to the number of antenna elements (e.g., it may be equal to or proportional thereto).

[0048]

[0063] Figure 12B is a diagram of an antenna array 540 formed by laser direct structuring that can be used to optionally form antenna elements. 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 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. The dimensions may be selected based on the material properties of the substrate. For example, one or more of “w”, “S 1 ” or “S 2 ” may correspond to a plurality of propagation wavelengths (“λ”) of a desired frequency through the substrate material (e.g., nλ / 4, where n is an integer).

[0049]

[0064] As an example, λ is as follows:

[0050]

Equation

[0051] (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) and may be calculated as such.

[0052]

[0065] FIG. 12C is a diagram of an exemplary antenna configuration 560 according to an aspect of the present disclosure. The antenna configuration 560 may include a plurality of antenna elements 562 disposed on parallel long sides of a substrate 564 that can be formed from the polymer composition of the present invention. The various antenna elements 562 may have respective lengths "L" (and the spacing distance 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. 12B for example.

[0053]

[0066] FIGS. 13A - 13C are simplified sequence diagrams of a laser direct structuring manufacturing method that can be used to form antenna elements and / or arrays according to aspects of the present disclosure. Referring to FIG. 13A, a substrate 600 may be formed from the polymer composition of the present invention using any desired technique (e.g., injection molding). In a particular embodiment, as shown in FIG. 13B, a laser 602 may be used to activate a laser - activatable additive to form a circuit pattern 604 that may include one or more of antenna elements and / or arrays. For example, the laser can melt conductive particles in the polymer composition to form the circuit pattern 604. Referring to FIG. 13C, the substrate 600 may be immersed in an electroless copper bath to plate the circuit pattern 604 to form antenna elements, element arrays, other components, and / or conductive lines therebetween.

[0054]

[0067] The present invention can be better understood with reference to the following examples. Test Method

[0068] Melt viscosity: The melt viscosity (Pa·s) was measured using a Dynisco LCR7001 capillary rheometer at a shear rate of 400 s -1And the melt temperature may be determined in accordance with ISO Test No. 11443:2005 at a temperature exceeding 15 °C (for example, 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.

[0055]

[0069] Melt temperature: The melt temperature (“Tm”) may be determined by differential scanning calorimetry (“DSC”) as known in the art. The melt temperature is the peak melt temperature of differential scanning calorimetry (DSC) determined by ISO Test No. 11357-2:2013. Based on the DSC procedure, DSC measurements were performed on a TA Q2000 instrument, and the sample was heated and cooled at 20 °C per minute as described in ISO standard 10350.

[0056]

[0070] Heat deflection temperature (“DTUL”): The heat deflection temperature may be determined in accordance with ISO Test No. 75-2:2013 (technically equivalent to ASTM D648-07). More specifically, a 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).

[0057]

[0071] 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 specimen sample with a length of 80 mm, a thickness of 10 mm, and a width of 4 mm. The test temperature may be 23 °C and the test speed may be 1 or 5 mm / min.

[0058]

[0072] 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 carried out on a support span of 64 mm. The test may be performed at the center of an uncut ISO 3167 multi-pass bar. The test temperature may be 23 °C and the test speed may be 2 mm / min.

[0059]

[0073] Izod impact strength without notch and with notch: The Charpy properties may be tested in accordance with ISO test No. ISO179-1:2010 (technically equivalent to ASTM D256-10, method B). This test may be carried out using a 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 out from the center of the multi-pass bar using a single-flute milling cutter. The test temperature may be 23 °C.

[0060]

[0074] Relative permittivity (“Dk”) and dissipation factor (“Df”): The relative permittivity (or relative static permittivity) and dissipation factor are determined using a known split-post dielectric resonance method such as that described by Baker-Jarvis et al., IEEE Trans. on Dielectric and Electrical Insulation, 5(4), 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 dimensions 80 mm × 80 mm × 1 mm was inserted between two fixed dielectric resonators. The resonators were used to measure the permittivity components on the surface of the specimen. Five samples were tested and the average value was recorded. Dielectric measurements can be performed in the low gigahertz region, for example 1 GHz to 2 GHz, using a split-post resonator.

[0061]

[0075] Thermal cycle test: Place the specimen in a temperature control chamber and heat / cool it within the temperature range of -30°C to 100°C. First, heat the sample until it reaches 100°C and then immediately cool it at that point. When the temperature reaches -30°C, reheat the specimen immediately until it reaches 100°C. Twenty-three heating / cooling cycles may be performed over 3 hours.

[0062] Example 1

[0076] Samples 1 to 5 are formed from various combinations of liquid crystal polymer (LCP1, LCP2, LCP3 or LCP4), titanium dioxide, graphite, copper chromite filler (CuCr 2 O 4 )), glass fiber and aluminum trihydrate. LCP1 is formed from 48% HNA, 2% HBA, 25% BP and 25% TA. LCP2 is formed from 43% HBA, 20% NDA, 9% TA and 28% HQ. LCP3 is formed from 73% HBA and 27% HNA. LCP4 is formed from 60% HBA, 4.2% HNA, 17.9% TA and 17.9% BP. The compounding was carried out using an 18 mm single screw extruder. The parts were injection molded to make samples in the form of plates (60 mm × 60 mm).

[0063]

Table 1

[0064]

[0077] Samples 1 to 5 were tested for thermal and mechanical properties. The results are shown in Table 2 below.

[0065]

Table 2

[0066] Example 2

[0078] Samples 6 - 10 are formed from various combinations of liquid crystal polymer (LCP1, LCP2, or LCP3), titanium dioxide, graphite or carbon fiber, glass fiber, aluminum trihydrate, and PPS. The compounding was carried out using an 18 mm single - screw extruder. The parts were injection - molded into plates (60 mm × 60 mm).

[0067]

Table 3

[0068]

[0079] Samples 6 - 10 were tested for thermal and mechanical properties. The results are presented in Table 4 below.

[0069]

Table 4

[0070] Example 3

[0080] Samples 11 - 15 are formed from various combinations of liquid crystal polymer (LCP2, LCP3, or LCP4), titanium dioxide, graphite, copper chromite filler (CuCr 2 O 4 )), glass fiber, and aluminum trihydrate. The compounding was carried out using an 18 mm single - screw extruder. The parts were injection - molded into plates (80 mm × 80 mm × 3 mm).

[0071]

Table 5

[0072]

[0081] Samples 11 - 15 were tested for thermal and mechanical properties. The results are presented in Table 6 below.

[0073]

Table 6

[0074] Example 4

[0082] Samples 16 to 22 are formed from various combinations of liquid crystal polymer (LCP2, LCP3, or LCP4), graphite, carbon fiber, copper chromite filler (CuCr 2 O 4 ), and glass fiber. The compounding was carried out using an 18 mm single-screw extruder. The parts were injection molded into samples in the form of plates (60 mm × 60 mm).

[0075]

Table 7

[0076]

[0083] Samples 16 to 22 were tested for thermal and mechanical properties. The results are shown in Table 8 below.

[0077]

Table 8

[0078] Example 5

[0084] Samples 23 to 27 are formed from various combinations of liquid crystal polymer (LCP2, LCP3, or LCP4), copper chromite (CuCr 2 O 4 ), glass fiber, zinc oxide single crystal, tetrapod whisker (Pana-Tetra (trademark) manufactured by Panasonic), conductive graphite and / or semiconductive graphite (Krefine (trademark) manufactured by Kureha Extron, volume resistivity 3 × 10 7 ohm·cm). The compounding was carried out using an 18 mm single-screw extruder. The parts were injection molded into samples in the form of plates (60 mm × 60 mm).

[0079]

Table 9

[0080]

[0085] Samples 23 to 27 were tested for electrical, thermal and mechanical properties. The results are shown in Table 10 below.

[0081]

Table 10

[0082]

[0086] Sample 27 was also subjected to the above thermal cycle test. After the test, the relative permittivity was determined to be 11.36 and the dielectric loss tangent was 0.1566. Therefore, the ratio of the relative permittivity after the thermal cycle test to the initial relative permittivity was 0.96, and the ratio of the dielectric loss tangent after the thermal cycle test to the initial dielectric loss tangent was 0.75.

[0083] Example 6

[0087] Samples 28 - 30 are formed from various combinations of liquid crystal polymer (LCP2, LCP3, or LCP4), carbon fiber, copper chromite filler (CuCr 2 O 4 ), and glass fiber. The compounding was carried out using a 32 mm twin-screw extruder. The parts were injection molded into samples in the form of plates (80 mm × 90 mm × 3 mm).

[0084]

Table 11

[0085]

[0088] Samples 28 - 30 were tested for thermal and mechanical properties. The results are listed in Table 12 below.

[0086]

Table 12

[0087]

[0089] Samples 28 - 30 were also subjected to the above thermal cycle test. After the test, the dielectric loss tangents obtained for the samples were determined to be 0.032, 0.025, and 0.020 respectively. Therefore, the ratios of the dissipation after the thermal cycle test of Samples 28, 29, and 30 to the initial dielectric loss tangent were 1.14, 1.26, and 1.13 respectively.

[0088] Example 7

[0090] Samples 31 to 34 are formed from various combinations of liquid crystal polymer (LCP2, LCP3 or LCP4), alumina trihydrate (ATH), titanium dioxide, carbon fiber, copper chromite filler (CuCr 2 O 4 ), and glass fiber. The compounding was carried out using a 32 mm twin-screw extruder. The parts were injection molded into samples in the form of plates (80 mm × 90 mm × 3 mm).

[0089]

Table 13

[0090]

[0091] Samples 31 to 34 were tested for thermal and mechanical properties. The results are shown in Table 14 below.

[0091]

Table 14

[0092] Example 8

[0092] Samples 35 to 40 are formed from various combinations of liquid crystal polymer (LCP2, LCP3 or LCP4), alumina trihydrate (ATH), titanium dioxide, carbon fiber, copper chromite filler (CuCr 2 O 4 ), and glass fiber. The compounding was carried out using a 32 mm twin-screw extruder. The parts were injection molded into samples in the form of plates (80 mm × 90 mm × 3 mm).

[0093]

Table 15

[0094]

[0093] Samples 35 to 40 were tested for thermal and mechanical properties. The results are shown in Table 16 below.

[0095]

Table 16

[0096]

[0094] Samples 38 to 40 were also subjected to the above-described thermal cycle test. After the test, the dielectric tangents obtained for the samples were determined to be 0.01764, 0.0155, and 0.0142, respectively. Therefore, the ratios of the dielectric tangents after the thermal cycle test of Samples 38, 39, and 40 to the initial dielectric tangents were 0.84, 0.91, and 0.89, respectively.

[0097] Example 9

[0095] Samples 41 to 43 are formed from various combinations of liquid crystal polymer (LCP2, LCP3, or LCP4), aluminum trihydrate (ATH), titanium dioxide, carbon fiber, copper chromite filler (CuCr 2 O 4 ), and glass fiber. The compounding was carried out using a 32 mm twin-screw extruder. The parts were injection molded to make samples into plates (80 mm × 90 mm × 3 mm).

[0098]

Table 17

[0099]

[0096] Samples 41 to 43 were tested for thermal and mechanical properties. The results are shown in Table 18 below.

[0100]

Table 18

[0101]

[0097] Samples 41 to 43 were also subjected to the above thermal cycle test. After the test, the relative dielectric constants obtained for the samples were determined to be 14.1, 13.2, and 16.6, respectively. Therefore, the ratios of the relative dielectric constants of Samples 41, 42, and 43 after the thermal cycle test to the initial relative dielectric constants were 0.99, 0.99, and 0.98, respectively. Also, the dielectric tangents obtained for the samples were determined to be 0.020, 0.020, and 0.021, respectively. Therefore, the ratios of the dielectric tangents of Samples 41, 42, and 43 after the thermal cycle test to the initial dielectric tangents were 1.18, 1.18, and 1.10, respectively.

[0102]

[0098] These and other modifications and variations of the present invention can be implemented by those skilled in the art without departing from the spirit and scope of the present invention. Furthermore, it should be understood that the aspects of the various embodiments are interchangeable, both in whole and in part. Furthermore, those skilled in the art will understand that the above description is merely illustrative and thus does not limit the present invention further described in the appended claims. The following shows the description of the claims at the time of filing the application. [Claim 1] A laser-activatable polymer composition comprising a laser-activatable additive, a fibrous filler, and a dielectric material distributed in a polymer matrix, wherein the polymer matrix contains at least one thermotropic liquid crystal polymer, and further wherein the polymer composition exhibits a relative dielectric constant of about 10 or more and a dielectric tangent of about 0.1 or less determined at a frequency of 2 GHz. [Claim 2] The polymer composition according to claim 1, wherein the ratio of the weight percentage of the fibrous filler to the combined weight percentage of the dielectric material and the laser-activatable additive is from about 0.05 to about 1. [Claim 3] The polymer composition according to claim 1 or 2, wherein the thermotropic liquid crystal polymer is an aromatic polyester containing repeating units derived from 4-hydroxybenzoic acid. [Claim 4] The polymer composition according to any one of claims 1 to 3, wherein the thermotropic liquid crystal polymer has a total amount of repeating units derived from naphthenic hydroxycarboxylic acid and / or naphthenic dicarboxylic acid of about 10 mol% or more. [Claim 5] The polymer composition according to claim 4, wherein the thermotropic liquid crystal polymer has a total amount of repeating units derived from naphthalene-2,6-dicarboxylic acid of about 10 mol% or more. [Claim 6] The laser activatable additive has the following general formula: AB 2 O 4 (wherein, A is a divalent metal cation; B is a trivalent metal cation) The polymer composition according to any one of claims 1 to 5, containing a spinel crystal having the above formula. [Claim 7] The spinel crystal is MgAl 2 O 4 , ZnAl 2 O 4 , FeAl 2 O 4 , CuFe 2 O 4 , CuCr 2 O 4 , MnFe 2 O 4 , NiFe 2 O 4 , TiFe 2 O 4 , FeCr 2 O 4 , MgCr 2 O 4 Or a combination thereof, the polymer composition according to claim 6. [Claim 8] The dielectric material has a volume resistivity of about 0.1 ohm·cm to about 1×10 12 ohm·cm, the polymer composition according to any one of claims 1 to 7. [Claim 9] The polymer composition according to claim 8, wherein the dielectric material contains an inorganic oxide material. [Claim 10] The polymer composition according to claim 9, wherein the inorganic oxide material contains titanium dioxide particles. [Claim 11] The polymer composition according to claim 9, wherein the inorganic oxide material contains inorganic oxide whiskers. [Claim 12] The polymer composition according to claim 11, wherein the whisker is a zinc oxide whisker. [Claim 13] The polymer composition according to claim 11, wherein the whisker has a central body and a plurality of acicular crystals radially extending therefrom. [Claim 14] The polymer composition according to claim 8, wherein the dielectric material contains an inorganic oxide material having a volume resistivity of 0.1 ohm·cm to about 500 ohm·cm. [Claim 15] The polymer composition according to claim 8, wherein the dielectric material contains a carbon material having a volume resistivity of about 1×10 3 ~about 1×10 12 ohm·cm. [Claim 16] The polymer composition according to claim 8, wherein the dielectric material contains a conductive material having a volume resistivity of less than about 0.1 ohm·cm and an insulating material having a volume resistivity greater than about 1×10 12 ohm·cm. [Claim 17] The polymer composition according to claim 16, wherein the conductive material contains a carbon material and the insulating material contains an inorganic oxide material. [Claim 18] The polymer composition according to claim 17, wherein the ratio of the weight percentage of the inorganic oxide material to the weight percentage of the carbon material is about 3 to about 20. [Claim 19] The polymer composition according to any one of claims 1 to 18, wherein the fibrous filler contains glass fibers. [Claim 20] 1,000 seconds -1The polymer composition according to any one of claims 1 to 19, having a melt viscosity of about 5 to about 100 Pa·s determined at a shear rate and a temperature of 350 °C. [Claim 21] The polymer composition according to any one of claims 1 to 20, comprising about 15 wt.% to about 85 wt.% of a thermotropic liquid crystal polymer, about 0.1 wt.% to about 30 wt.% of a laser activatable additive, about 10 wt.% to about 70 wt.% of a dielectric material, and about 1 wt.% to about 40 wt.% of a fibrous filler. [Claim 22] The polymer composition according to any one of claims 1 to 21, exhibiting a relative permittivity after being exposed to a temperature cycle of about -30 °C to about 100 °C, wherein the ratio of the relative permittivity after the temperature cycle to the relative permittivity before the thermal cycle is about 0.8 or more. [Claim 23] The polymer composition according to any one of claims 1 to 22, exhibiting a dielectric loss tangent after being exposed to a temperature cycle of about -30 °C to about 100 °C, wherein the ratio of the dielectric loss tangent after the temperature cycle to the dielectric loss tangent before the thermal cycle is about 1.3 or less. [Claim 24] The polymer composition according to any one of claims 1 to 23, exhibiting a dielectric loss tangent after being exposed to a temperature cycle of about -30 °C to about 100 °C, wherein the ratio of the dielectric loss tangent after the temperature cycle to the dielectric loss tangent before the thermal cycle is about 1.0 or less. [Claim 25] Showing a notched Charpy impact strength of about 10 to about 35 kJ / m determined according to ISO test No. ISO 179-1:2010 at a temperature of 23 °C 2 The polymer composition according to any one of claims 1 to 24. [Claim 26] A molded part comprising the polymer composition according to any one of claims 1 to 25. [Claim 27] The molded part according to claim 26, wherein one or more conductive elements are formed on the surface of the part by a method comprising exposing the surface to a laser and then metallizing the exposed surface. [Claim 28] An antenna system comprising the polymer composition according to any one of claims 1 to 25 and a substrate including at least one antenna element configured to transmit and receive radio frequency signals, wherein the antenna system is coupled to the substrate. [Claim 29] The antenna system according to claim 28, wherein the radio frequency signal is a 5G signal.

Claims

1. A laser-activatable polymer composition comprising a laser-activatable additive, a fibrous filler, and a dielectric material distributed in a polymer matrix, wherein the polymer matrix contains at least one thermotropic liquid crystal polymer, the dielectric material contains carbon fibers, and further wherein the polymer composition exhibits a relative permittivity of 10 or more and a dielectric loss tangent of 0.1 or less determined at a frequency of 2 GHz, and the fibrous filler does not contain carbon fibers.

2. The polymer composition according to claim 1, wherein the ratio of the weight percentage of the fibrous filler to the combined weight percentage of the dielectric material and the laser-activatable additive is from 0.05 to 1.

3. The polymer composition according to claim 1 or 2, wherein the thermotropic liquid crystal polymer is an aromatic polyester containing repeating units derived from 4-hydroxybenzoic acid.

4. The polymer composition according to any one of claims 1 to 3, wherein the thermotropic liquid crystal polymer has a total amount of repeating units derived from 10 mol% or more of naphthenic hydroxycarboxylic acid and / or naphthenic dicarboxylic acid.

5. The polymer composition according to claim 4, wherein the thermotropic liquid crystal polymer has a total amount of repeating units derived from 10 mol% or more of naphthalene-2,6-dicarboxylic acid.

6. The polymer composition according to any one of claims 1 to 5, wherein the laser-activatable additive contains a spinel crystal having the following general formula: (wherein, AB ２ O ４ A is a divalent metal cation; B is a trivalent metal cation)

9. The polymer composition according to claim 8, wherein the dielectric material contains an inorganic oxide material.

10. The polymer composition according to claim 9, wherein the inorganic oxide material contains titanium dioxide particles.

7. The spinel crystal is MgAl ２ O ４ , ZnAl ２ O ４ , FeAl ２ O ４ , CuFe ２ O ４ , CuCr ２ O ４ , MnFe ２ O ４ , NiFe ２ O ４ , TiFe ２ O ４ , FeCr ２ O ４ , MgCr ２ O ４ The polymer composition according to claim 6, comprising or a combination thereof.

8. The dielectric material has a volume resistivity of 0.1 ohm·cm to 1×10 １２ ohm·cm, and the polymer composition according to any one of claims 1 to 7.

11. The polymer composition according to claim 9, wherein the inorganic oxide material contains inorganic oxide whiskers.

12.

16. The polymer composition according to claim 11, wherein the whisker is a zinc oxide whisker.

13.

18. The polymer composition according to claim 11, wherein the whisker has a central body and a plurality of needle-like crystals radially extending therefrom.

19. The polymer composition according to claim 11. ​ ​

14. The polymer composition according to claim 8, wherein the dielectric material comprises an inorganic oxide material having a volume resistivity of 0.1 ohm·cm to 500 ohm·cm.

15. The dielectric material contains a carbon material having a volume resistivity of 1×10 ３ to 1×10 １２ Ω·cm, and the polymer composition according to claim 8.

16. The dielectric material includes a conductive material having a volume resistivity of less than 0.1 ohm·cm and an insulating material having a volume resistivity greater than 1×10 １２ ohm·cm, and the polymer composition according to Claim 8.

17. The polymer composition according to claim 16, wherein the conductive material comprises a carbon material and the insulating material comprises an inorganic oxide material.

18. The polymer composition according to claim 17, wherein the ratio of the weight percentage of the inorganic oxide material to the weight percentage of the carbon material is 3 to 20.

19. The polymer composition according to any one of claims 1 to 18, wherein the fibrous filler comprises glass fiber.

20. 1,000 seconds －１ and a shear rate of －１ and 5 to 100 Pa·s determined at a temperature of 350°C The polymer composition according to any one of claims 1 to 19, having a melt viscosity of

21. 15 wt.% to 85 wt.% of a thermotropic liquid crystal polymer, 0.1 wt.% to 30 wt.% of the laser activatable additive, 10 wt.% to 70 wt.% of the dielectric material, and 1 wt.% to 40 wt.% of the fibrous filler. The polymer composition according to any one of claims 1 to 20.

22. Exhibiting a relative permittivity after being exposed to a temperature cycle of -30°C to 100°C, and the ratio of the relative permittivity after the temperature cycle to the relative permittivity before the thermal cycle is 0.8 or more. The polymer composition according to any one of claims 1 to 21

23. Exhibiting a dielectric tangent after being exposed to a temperature cycle of -30°C to 100°C, and the ratio of the dielectric tangent after the temperature cycle to the dielectric tangent before the thermal cycle is 1.3 or less. The polymer composition according to any one of claims 1 to 22

24. Exhibiting a dielectric tangent after being exposed to a temperature cycle of -30°C to 100°C, and the ratio of the dielectric tangent after the temperature cycle to the dielectric tangent before the thermal cycle is 1.0 or less. The polymer composition according to any one of claims 1 to 23

25. At a temperature of 23°C, according to ISO test No. ISO 179-1:2010, determined to be 10 to The polymer composition as described.

26. A molded part comprising the polymer composition according to any one of claims 1 to 25.

27. The molded part according to claim 26, wherein one or more conductive elements are formed on the surface of the part by a method comprising exposing the surface to a laser and then metallizing the exposed surface. The molded part.

28. 35 kJ / m ２ showing the notched Charpy impact strength of any one of claims 1 to 24 The polymer composition according to any one of claims 1 to 25, and transmitting and receiving radio frequency signals ​ ​ ​ ​ ​ ​ ​ ​ An antenna system including a substrate including at least one antenna element configured to do so The antenna system, wherein the antenna system is coupled to the substrate. **Claim 29**: The antenna system according to claim 28, wherein the radio frequency signal is a 5G signal.

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