Printed circuit board material

Abstract

This document describes dielectric polymer films and printed circuit boards, such as multilayer and high-density interconnect printed circuit boards comprising at least one dielectric polymer film. The dielectric films of this disclosure may be reinforced with glass fibers or not. In some embodiments, the layers and films each have low modulus (e.g., Young's modulus, tensile modulus, or elastic modulus) and / or low dielectric constant. In some embodiments, the layers and films may have low dissipation factors.

Description

Background Technology

[0001] Printed circuit boards, including double-sided, multilayer, flexible, and high-density interconnect printed circuit boards (HDI-PCBs), typically include through-holes for interconnecting different layers of the PCB. For many systems using multilayer PCBs and HDI-PCBs, there is a desire to reduce PCB area while increasing PCB functionality. These advancements are often driven by the miniaturization of components for mobile computing, 4G and 5G applications, avionics, and military applications. To achieve these goals, successive generations of multilayer PCBs and HDI-PCBs have typically used increasingly thinner dielectric materials, employing laser-drilled microvias in the case of HDI or continuous lamination construction.

[0002] There are two main failure modes for vias in PCBs: (1) overstress and (2) low-cycle fatigue. Overstress occurs during reflow at component temperatures typically around 250°C. Reflow often requires multiple passes, and the combination of overstress and / or cyclic fatigue can lead to microvia failure. The second failure mode is low-cycle fatigue (less than 1,000–10,000 cycles) caused by operating conditions, which in extreme cases can vary between -55°C and 135°C. The primary reason for poor reliability in both failure modes is the large difference in the coefficient of thermal expansion (CTE) between copper and the dielectric material. In PCBs, the dielectric material is typically a composite of glass fiber and resin with significant anisotropy, where the Z-axis CTE is much higher than the X and Y-axis CTE due to the constraint of the dielectric material in the X and Y directions (or axes). The stress applied by the dielectric to the copper interconnect is a function of the CTE difference, dielectric modulus, and temperature excursion experienced by the interconnect. To date, existing methods have reduced the CTE difference by filling the polymer / resin used in reinforcing dielectrics with fillers that help lower the CTE and / or increase the crosslinking density. Therefore, the CTE decreases, but not sufficiently to completely reduce the stress, while having undesirable consequences such as a higher glass transition temperature (Tg) and a higher modulus. Furthermore, since the dielectrics used (prepregs and laminates) are reinforced with woven or nonwoven fabrics, the dielectric itself is anisotropic. Typically, the Z-axis CTE is much higher than that in the X and Y directions. The Z-axis modulus is controlled by the resin and is much lower compared to the moduli in the X and Y directions, which are controlled by reinforcing materials such as woven glass cloth. When the CTE in the X and Y axes decreases significantly and the CTE in the Z-axis increases significantly, the anisotropy at Tg... g The increase in modulus is far greater than that in isotropic materials. Due to the presence of reinforcing materials, the dielectric maintains significant rigidity in the Z direction. On the other hand, isotropic films are unaffected by these properties. Existing methods utilize higher crosslinking densities and higher filler loadings to improve modulus and Tg. gThe net effect is that the stress is not reduced much. To minimize the stress on the interconnect and the resulting strain, it is necessary to minimize the stress calculated by multiplying the CTE difference by the dielectric modulus and then by T. g The quantity is given by the product of the difference between the CTE and the lower offset limit. Existing techniques only address the problem of reducing the CTE difference, which leads to undesirably higher modulus and T. g Therefore, lower modulus and lower T values ​​are needed to help reduce interconnect stress. g The system.

[0003] Printed circuit boards are also needed to support data channels (e.g., transmission lines) capable of supporting data rates greater than 28 Gbps (e.g., 56, 112, or 224 Gbps / channel). However, one obstacle to achieving such data rates at high fundamental frequencies (e.g., 8-56 GHz) is the channel loss of conventional transmission lines due to the conductors (e.g., copper) and dielectrics used to form and isolate the transmission lines. Currently, differential signaling uses reinforced laminates with anisotropic and non-uniform dielectric properties. This approach leads to skew due to the fiber weaving effect, as each transmission line encounters a different effective dielectric constant. The bandwidth limitation imposed by the narrow conductor width (a result of the relatively high dielectric constant) and the skew caused by the reinforcement constitutes a significant, potentially insurmountable problem in achieving higher data rates with existing technologies.

[0004] Existing striplines used for data transmission have a dielectric thickness of 3.5 mils to 5 mils and a copper thickness of 18 micrometers to 35 micrometers. The dielectric constant (Dk) of the weave material is preferably not less than 3.0. This is achieved by using low-Dk glass. However, any attempt to reduce Dk by using low-Dk resin will increase skewness. The dielectric constant of the composite material decreases, but the dielectric constant of the reinforcing material remains unchanged, and the decrease in the dielectric constant of the resin increases the gap between the Dk of the resin and the Dk of the reinforcing material, thus increasing skewness.

[0005] Therefore, there is a need for highly reliable dielectric materials that overcome these limitations and printed circuit boards that contain such dielectric materials. Summary of the Invention

[0006] This document describes dielectric layers and films and their applications in printed circuit boards, such as antennas, rigid-flex, flexible, conventional, and high-density interconnect (HDI) printed circuit boards (PCBs). The dielectric films disclosed herein may be reinforced with, for example, glass fibers or not. In some embodiments, the layers and films each have a low Tg g Low modulus (e.g., Young's modulus, tensile modulus, or elastic modulus) and / or low dielectric constant. In some embodiments, the layers and films may have low dissipation factors.

[0007] It is known in the art that the dielectric constant of the lamination materials used for multilayer printed circuit boards and HDI-PCBs is relatively high. This disclosure partially illustrates that low dielectric constant materials used for PCB layers, particularly dielectric polymer films with a dielectric constant less than or equal to about 2.8, enable films of the same dielectric thickness to have wider transmission lines, thereby reducing insertion loss in the circuit board.

[0008] Furthermore, the glass transition temperature T in the dielectric polymer film or layer described in this article g It can be an analogue of the mechanical yield point. For example, the CTE and modulus of a dielectric film can be measured at T... g The above are significant changes. Lower T g This is typically associated with the lower yield strength of the dielectric film. Therefore, when the film material reaches its T... g At this point, the stress on the interconnects of the PCB (e.g., primarily copper) can be significantly reduced to below the yield strength (e.g., that of copper). Furthermore, the use of thermosetting films with low dielectric constants and / or low dissipation factors enables curing and C-grade processes to be carried out at temperatures below 250°C.

[0009] The dielectric polymer film disclosed herein is further characterized by a relatively low T0. g The combination of a relatively low modulus that is substantially isotropic (e.g., a substantially isotropic Young's modulus less than 6 GPa or 5 GPa) has been shown to improve the reliability of the printed circuit boards described herein, including reductions in overstress and low-cycle fatigue, as evidenced by the reduced anisotropy of the film's CTE and the reduction in strain on the copper connections. In a preferred embodiment, the dielectric film described herein has a CTE of... g Below 120°C (e.g., below 100°C). In a preferred embodiment, the dielectric film described herein has a modulus below 5 GPa. Furthermore, in some embodiments, the dielectric polymer film of this disclosure may have a low dissipation factor (e.g., 0.005 or lower), which has been advantageously found to reduce dielectric loss, thereby reducing insertion loss. Dielectric loss is proportional to the dielectric constant, dissipation factor, and the square root of the operating frequency.

[0010] Therefore, this disclosure takes into account the use of materials with low dielectric constants and dissipation factors as dielectric layers and films in printed circuit boards to reduce insertion loss and thus improve signal integrity. Another benefit of a lower dielectric constant is that it increases the linewidth required for a given design impedance. This provides an additional benefit to insertion loss. Furthermore, conductor loss is inversely proportional to linewidth. The wider the linewidth, the lower the insertion loss. Therefore, lower Dk and Df not only contribute to reducing dielectric loss but also to reducing conductor loss. It is also anticipated that using wider lines due to the lower dielectric constant will also contribute to improved process yield, as this negatively impacts process yield when manufacturing printed circuit boards with finer lines. As a result, the polymer films of this disclosure can have relatively low dielectric constants, Tk, and Df as described above. g This improves the dielectric constant, modulus, and / or dissipation factor, and imparts the benefits associated with each of the properties described above. In other embodiments, the polymer film of this disclosure may have a relatively low dielectric constant, T0, and T0 as described above. g Modulus and dissipation factor, therefore due to lower modulus and T g The low dielectric loss due to the film's low Dk and low Df, the reduced conductor loss due to the film's low dielectric constant and the resulting wider traces, and the higher process yield directly resulting from the film's low dielectric constant, all contribute to improved reliability due to reduced stress on interconnects (e.g., vias and microvias). These characteristics enable high-density interconnects, ultra-high operating frequencies, and ultra-high data rates in printed circuit boards. The isotropic nature of the film helps avoid skew problems, unlike existing techniques that use reinforced dielectrics in printed circuit boards. In another embodiment, the printed circuit board of this disclosure is also expected to achieve higher data rates and higher operating frequencies due to lower insertion loss, increased reliability, and increased interconnect density. Therefore, in one embodiment, this disclosure describes a novel transmission line that overcomes the problems described herein by using a unique configuration of a low-dielectric-constant unreinforced film, which allows for the use of wider traces to extend the bandwidth of the communication channel while reducing overall thickness and eliminating significant fiber braid skew.

[0011] On one hand, this article describes a printed circuit board comprising a dielectric layer containing at least one dielectric polymer film, wherein the at least one dielectric polymer film has: (i) a glass transition temperature less than or equal to about 130°C; (ii) a dielectric constant less than or equal to about 2.8; and (iii) an elastic modulus of less than or equal to about 6 GPa that is substantially isotropic when the average temperature of the at least one dielectric polymer film is below the glass transition temperature.

[0012] In some embodiments, the dissipation factor of at least one dielectric polymer film is from about 0.001 to about 0.005.

[0013] In some implementations, the dielectric constant is from about 1.1 to about 2.5.

[0014] In some implementations, the glass transition temperature is from about 25°C to about 110°C.

[0015] In some embodiments, the elastic modulus is less than or equal to about 4 GPa when the average temperature of at least one dielectric polymer film is below the glass transition temperature.

[0016] In some implementations, at least one dielectric polymer film forms part of the transmission line structure of the printed circuit board.

[0017] In some implementations, the dissipation factor of the transmission line is less than or equal to about 0.0025 at 5 GHz. In some implementations, the dissipation factor of the transmission line is less than or equal to about 0.0025 at 10 GHz.

[0018] In some implementations, the width of the transmission line is greater than or equal to about 5 mils.

[0019] In some embodiments, the transmission line is a first transmission line, wherein at least one dielectric polymer film forms a second transmission line on the printed circuit board, wherein the thickness of the dielectric layer between the first and second transmission lines is 0.1 mil to 4 mil.

[0020] In some implementations, the circuit board includes at least one component configured to transmit signals over a transmission line using pulse amplitude modulation (PAM).

[0021] In some implementations, the number of pulse amplitude levels used in pulse amplitude modulation is 2 to 16.

[0022] In some implementations, the circuit board includes at least one component configured to transmit data over a transmission line at a data rate greater than or equal to about 10 Gbps.

[0023] In some implementations, the transmission line is one of a plurality of transmission lines formed of a dielectric polymer film, wherein one or more components of a printed circuit board are configured to transmit data through each of the plurality of transmission lines at a data rate greater than or equal to about 10 Gbps.

[0024] In some implementations, the circuit board is a component of a computing device or a network device.

[0025] In some implementations, the computing device is a desktop computer, laptop computer, server, tablet computer, accelerator, supercomputer, or mobile phone.

[0026] In some implementations, the network device is a switch, router, access point, or modem.

[0027] In some implementations, the thermal conductivity of the dielectric layer or at least one polymer film is as high as 4 W / mK.

[0028] In some implementations, dielectric polymer films are used to fabricate bifacial or multilayer antennas.

[0029] In some implementations, a continuous solvent casting process is used to fabricate the dielectric polymer film.

[0030] In some implementations, the circuit board is a multilayer printed circuit board or a high-density interconnect printed circuit board.

[0031] In some implementations, the dielectric polymer film is in T g The above coefficients of thermal expansion are less than 200 ppm / ℃.

[0032] In some implementations, the dielectric polymer film is in T g The above coefficients of thermal expansion are greater than 200 ppm / ℃.

[0033] In some embodiments, the dielectric polymer film comprises a cross-linked polymer composition.

[0034] On the other hand, this paper discloses a printed circuit board comprising: a core layer; a dielectric layer disposed on a first surface of the core layer, wherein the dielectric layer comprises at least one dielectric polymer film having: (i) a glass transition temperature less than or equal to about 130°C; (ii) a dielectric constant less than or equal to about 2.8; and (iii) an elastic modulus of less than or equal to about 6 GPa that is substantially isotropic when the average temperature of the at least one dielectric polymer film is below the glass transition temperature; and one or more micropores that penetrate the dielectric layer and connect one or more pairs of corresponding conductive traces disposed on opposite sides of the dielectric layer.

[0035] In some implementations, the dielectric layer reduces the risk of one or more microvias failing due to low-cycle fatigue or overstress, compared to the absence of a dielectric layer in a high-density interconnect printed circuit board.

[0036] In some implementations, the core layer is a glass fiber-based dielectric or laminate.

[0037] In some embodiments, the dielectric layer is a first dielectric layer, and the high-density interconnect printed circuit board further includes a second dielectric layer, which includes at least one dielectric polymer film.

[0038] In some embodiments, the circuit board also includes one or more microvias that penetrate the second dielectric layer and connect one or more pairs of corresponding conductive traces disposed on opposite sides of the second dielectric layer.

[0039] In some implementations, the second dielectric layer is disposed on the second surface of the core layer.

[0040] In some embodiments, the circuit board further includes: a third dielectric layer disposed on the first dielectric layer and including at least one dielectric polymer film; and a fourth dielectric layer disposed on the second dielectric layer and including at least one dielectric polymer film.

[0041] In some implementations, the second dielectric layer is disposed on the first dielectric layer.

[0042] In some implementations, the circuit board is a multilayer printed circuit board or a high-density interconnect printed circuit board. Detailed Implementation

[0043] This application relates to various granted patents, published patent applications, journal articles, and other publications, all of which are incorporated herein by reference. In the event of any conflict between any incorporated references and this specification, this specification shall prevail.

[0044] Dielectric materials and films

[0045] Typically, the dielectric materials in the currently disclosed embodiments comprise polymer compositions. Dielectric materials include, but are not limited to, the dielectric films, layers, or sheets described herein.

[0046] In some embodiments, the dielectric layer described herein may include one or more dielectric polymer films described herein. In some embodiments, the dielectric layer described herein may include one, two, three, four, or five dielectric polymer films described herein. In some embodiments, the dielectric layer described herein may include five or more dielectric polymer films described herein.

[0047] In some embodiments, the average thickness of the dielectric layer described herein is from about 0.1 mil to about 6.0 mil (e.g., from about 0.1 mil to about 1.0 mil, from about 0.1 mil to about 2.0 mil, from about 0.1 mil to about 3.0 mil, from about 0.1 mil to about 4.0 mil, or from about 0.1 mil to about 5.0 mil). In some embodiments, the average thickness of the dielectric layer described herein is from about 0.25 mil to about 2.5 mil. In some embodiments, the average thickness of the dielectric layer described herein is from about 0.5 mil to about 2.0 mil. In some embodiments, the average thickness of the dielectric layer described herein is from about 0.5 mil. In some embodiments, the average thickness of the dielectric layer described herein is from about 1 mil. In some embodiments, the average thickness of the dielectric layer described herein is from about 5 mil to about 125 mil. In some embodiments, the average thickness of the dielectric layer described herein is about 0.1 mil, 0.2 mil, 0.3 mil, 0.4 mil, 0.5 mil, 0.6 mil, 0.7 mil, 0.8 mil, 0.9 mil, 1.0 mil, 1.1 mil, 1.2 mil, 1.3 mil, 1.4 mil, 1.5 mil, 1.6 mil, 1.7 mil, 1.8 mil, 1.9 mil, 2.0 mil, 3.0 mil, 3.3 mil, 3.5 mil, 4.0 mil, 5.0 mil, or 6.0 mil. In some embodiments, the average thickness of the dielectric layer described herein is about 5 mil, 10 mil, 15 mil, 20 mil, 25 mil, 30 mil, 35 mil, 40 mil, 50 mil, 60 mil, 70 mil, 80 mil, 90 mil, 100 mil, or 125 mil.

[0048] The dielectric materials described herein may have different properties, such as, but not limited to, glass transition temperature (Tg), coefficient of thermal expansion (CTE), dielectric constant, Young's modulus, film thickness, and thermal conductivity. Exemplary properties of the dielectric materials considered in this disclosure are as follows:

[0049] In some embodiments, the dielectric film of this disclosure may be carried on a substrate such as copper foil or PET. Such copper foil may include a thickness of about 3 micrometers to about 35 micrometers. In some embodiments, the dielectric film may be coated with sputtered copper to a thickness of 0.5 micrometers to 5.0 micrometers using, for example, a physical vapor deposition process. In some embodiments, this disclosure includes laminated materials made by laminating copper foil coated with the dielectric film as described herein, and subsequently pressing them together by hot rolling, said hot rolling using a flatbed press for batch processing.

[0050] Exemplary polymers of this disclosure

[0051] In one embodiment of this disclosure, the dielectric polymer film described herein comprises a crosslinked polymer composition. In some embodiments, the crosslinked polymer composition is present in the dielectric polymer film in amounts of about 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt%, or 99 wt%, based on the total weight of the film. In some embodiments, the crosslinked polymer composition described herein may comprise a crosslinked product of a thermosetting polymer. The thermosetting polymer contains one or more functional groups capable of crosslinking with other reactive groups to produce the crosslinked polymer composition.

[0052] In some embodiments, the functional group is a group that can react with the curing agent. In some embodiments, the functional group is vinyl. In some embodiments, the functional group is within the backbone of the thermosetting polymer (e.g., the alkenyl group of the main chain of polybutadiene). In some embodiments, the functional group is grafted from the thermosetting polymer. In some embodiments, the curing agent is a peroxide reagent. In some embodiments, the thermosetting polymer and the curing agent react in the presence of a catalyst to form a crosslinked polymer composition. In some embodiments, the thermosetting polymer and the curing agent react to form a crosslinked polymer composition without the need for a catalyst. In some embodiments, the reaction of the thermosetting polymer and the curing agent occurs under thermal conditions.

[0053] The curing agents disclosed herein include, but are not limited to, those used to initiate the curing of the relevant polymers. Examples include, but are not limited to, azides, peroxides, diazo compounds, sulfur, and sulfur derivatives. Free radical agents are particularly desirable as curing initiators. Examples of free radical agents include peroxides, hydroperoxides, and non-peroxide initiators, such as, but not limited to, 2,3-dimethyl-2,3-diphenylbutane. Examples of peroxide curing agents include dicumyl peroxide, α,α-di(tert-butylperoxy)-m,p-dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane-3, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, as well as mixtures comprising one or more of the aforementioned curing initiators. When used, the curing initiator is typically present in an amount from about 0.25% by weight to about 15% by weight based on the total weight of the thermosetting polymer to be cured.

[0054] In some embodiments, the thermosetting polymer is a high-vinyl polymer resin (e.g., a polymer resin having more than 70%, 80%, or 90% vinyl constituent units). In some embodiments, the thermosetting polymer is a low-vinyl polymer resin (e.g., a polymer resin having less than 70%, 60%, 50%, 40%, or 30% vinyl constituent units).

[0055] Examples of thermosetting polymers containing crosslinkable functional groups include, but are not limited to, polyalkylene (e.g., polyethylene, polypropylene, polyisoprene, polynorbornene, polyalkylene terephthalate (e.g., polyethylene terephthalate, polybutylene terephthalate)), polyalkenyl (e.g., polybutadiene and styrene (e.g., impact-modified polystyrene, acrylonitrile-butadiene-styrene, styrene-acrylonitrile), or their grafted derivatives (e.g., polyethylene grafted with maleic anhydride).

[0056] In some embodiments, the thermoset polymer can be crosslinked with another thermoset polymer without a crosslinking agent to produce a crosslinked polymer composition. Examples of thermoset polymers that crosslink with other polymers include polyolefins (e.g., polybutadiene) and polyacetylenes, as well as their derivatives (e.g., silicon-modified).

[0057] Examples of thermosetting polymers containing functional groups capable of crosslinking crosslinking agents include, but are not limited to, polyalkylene (e.g., polyethylene, polypropylene, polyalkylene terephthalate (e.g., polyethylene terephthalate, polybutylene terephthalate)), polyolefins such as polybutadiene, and styrene (e.g., impact-modified polystyrene, acrylonitrile-butadiene-styrene, styrene-acrylonitrile).

[0058] In some embodiments, the dielectric polymer film may further comprise crosslinking units, i.e., free radical acceptor materials generated by crosslinking with the polymer. Acceptor materials can be incorporated into the formulation to modulate the mechanical, physical, or electrical properties of the dielectric material in its cured or uncured state, such as the brittleness, flowability, CTE, adhesion, or other desired properties of the dielectric film (e.g., acrylate, maleimide, vinyl monomer). In some embodiments, the acceptor material is a vinyl-containing epoxy compound. In some embodiments, the acceptor material is an acrylate or methacrylate monomer. In some embodiments, the acceptor material is a diacrylate or dimethacrylate. In some embodiments, the acceptor material is a polyacrylate or polymethacrylate. In some embodiments, the acceptor material is a bismaleimide or polymaleimide. In some embodiments, the acceptor material is SA9000 (acrylate-terminated polyphenylene ether).

[0059] In some embodiments, the thermosetting polymer compositions described herein further comprise poly(arylene ether). Exemplary poly(arylene ethers) disclosed herein include, but are not limited to, poly(2,6-dimethyl-1,4-phenylene ether), poly(2,6-diethyl-1,4-phenylene ether), poly(2,6-dipropyl-1,4-phenylene ether), poly(2-methyl-6-allyl-1,4-phenylene ether), poly(di-tert-butyl-dimethoxy-1,4-phenylene ether), poly(2,6-dichloromethyl-1,4-phenylene ether, poly(2,6-dibromomethyl-1,4-phenylene ether), poly(2,6-di(2-chloroethyl)-1,4-phenylene ether), poly(2,6-xylyl-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), poly(2,6-diphenyl-1,4-phenylene ether), and poly(2,5-dimethyl-1,4-phenylene ether).

[0060] The polymer film also comprises polybutadiene or polyisoprene polymers. As used herein, "polybutadiene or polyisoprene polymers" includes homopolymers derived from butadiene, homopolymers derived from isoprene, and copolymers derived from butadiene and / or isoprene and / or less than 50 wt% of monomers co-curable with butadiene and / or isoprene. Suitable monomers co-curable with butadiene and / or isoprene include monoene-bonded unsaturated compounds such as acrylonitrile, ethyl acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, β-chloroacrylonitrile, α-bromoacrylonitrile, and (meth)acrylic acid C. 1-6 Alkyl esters (e.g., methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, n-propyl methacrylate, and isopropyl methacrylate), acrylamide, methacrylamide, maleimide, N-methylmaleimide, N-ethylmaleimide, itaconic acid, (meth)acrylic acid, alkenyl aromatic compounds as described below, and combinations comprising at least one of the aforementioned mono-alkenyl unsaturated monomers.

[0061] The polymers described herein can be homopolymers (e.g., polyalkylene or poly(aryl ether) homopolymers) or copolymers, including grafted or block copolymers. In some embodiments, the copolymer is an alternating copolymer. In some embodiments, the copolymer is a block copolymer.

[0062] In some embodiments, the block copolymer comprises a block (A) derived from an alkenyl aromatic compound and a block (B) derived from a conjugated diene. The arrangement of blocks (A) and (B) includes linear and grafted structures, including radially branched distal block structures. Examples of linear structures include diblock (AB), triblock (ABA or BAB), tetrablock (ABAB), and pentablock (ABABA or BABAB) structures, as well as linear structures comprising a total of six or more A and B blocks. Specific block copolymers include diblock, triblock, and tetrablock structures, particularly AB diblock and ABA triblock structures.

[0063] In some embodiments, the compound used to provide block (A) is an alkenyl aromatic compound, such as the compound disclosed in U.S. Patent Application No. 9,265,160, which is incorporated herein by reference. In some embodiments, the alkenyl aromatic compound is styrene.

[0064] In some embodiments, the conjugated diene used to provide block (B) includes 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene, particularly 1,3-butadiene and isoprene. Combinations of conjugated dienes can be used. The block (B) derived from the conjugated diene is optionally partially or fully hydrogenated.

[0065] Exemplary block copolymers comprising a block (A) derived from an alkenyl aromatic compound and a block (B) derived from a conjugated diene include styrene-butadiene diblock copolymer (SB), styrene-butadiene-styrene triblock copolymer (SBS), styrene-isoprene diblock copolymer (SI), styrene-isoprene-styrene triblock copolymer (SIS), styrene-(ethylene-butene)-styrene triblock copolymer (SEBS), styrene-(ethylene-propylene)-styrene triblock copolymer (SEPS), and styrene-(ethylene-butene) diblock copolymer (SEB). This polymer is commercially available from Shell Chemical Corporation, for example under the trade names KRATON D-1101, KRATON D-1102, KRATON D-1107, KRATON D-1111, KRATON D-1116, KRATON D-1117, KRATON D-1118, KRATON D-1119, KRATON D-1122, KRATON D-1135X, KRATON D-1184, KRATON D-1144X, KRATON D-1300X, KRATON D-4141, KRATON D-4158, KRATON G1726, and KRATON G-1652.

[0066] Other exemplary polymers that can be used in the dielectric films described herein are disclosed in U.S. Patent Application No. 6,890,635 and U.S. Patent Application No. 9,265,160, both of which are incorporated herein by reference.

[0067] Glass transition temperature (Tg) of the membrane

[0068] In some implementations, the glass transition temperature T of the dielectric material g Temperatures can reach approximately 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, or 130°C. In some embodiments, the dielectric material's T... g Less than or equal to approximately 130°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 120°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 110°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 100°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 90°C. In some embodiments, the T of the dielectric material... gLess than or equal to approximately 80°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 70°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 60°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 50°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 40°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 30°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 25°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 20°C. In some embodiments, the T of the dielectric material... g Less than or equal to approximately 10°C. In some embodiments, the dielectric material's T... g Less than or equal to approximately 5°C. In some embodiments, the T of the dielectric material... g The temperature ranges from approximately 90°C to 130°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 90°C to 120°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 80°C to 110°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 70°C to 100°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 60°C to 90°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 50°C to 80°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 40°C to 70°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 30°C to 60°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 25°C to 50°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 20°C to 50°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 10°C to 40°C. In some embodiments, the dielectric material's T... g The temperature ranges from approximately 5°C to 40°C.

[0069] Coefficient of thermal expansion (CTE) of the membrane

[0070] In some embodiments, the coefficient of thermal expansion (CTE) of the dielectric material at temperatures ranging from 50°C to 250°C is as high as approximately 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 ppm / °C. In some embodiments, the dielectric material at T... g The following CTE values ​​are as high as approximately 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 ppm / °C. In some embodiments, the T of the dielectric material... g The CTE values ​​are as high as approximately 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 240, 250, 260, 270, 280, 290, or 300 ppm / °C. In some embodiments, the CTE is as high as approximately 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 ppm / °C. In some embodiments, in the cured thermosetting composition, at T... g The following CTE values ​​are as high as approximately 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 ppm / °C. In some embodiments, in the cured thermosetting composition, at T... g The coefficients of thermal expansion mentioned above are approximately 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 ppm / ℃. In some embodiments, in the dielectric material T... g Below this, the CTE of the dielectric material is less than or equal to 220 ppm / ℃. In some embodiments, the T of the dielectric material... g Below this, the CTE of the dielectric material is less than or equal to 200 ppm / ℃. In some embodiments, the T of the dielectric material... gBelow, the CTE of the dielectric material is less than or equal to 180 ppm / ℃. In some embodiments, the CTE of the dielectric material is... g Below, the CTE of the dielectric material is less than or equal to 160 ppm / ℃. In some embodiments, the T of the dielectric material... g Below, the CTE of the dielectric material is less than or equal to 140 ppm / ℃. In some embodiments, the T of the dielectric material... g Below, the CTE of the dielectric material is less than or equal to 120 ppm / ℃. In some embodiments, the T of the dielectric material... g Below, the CTE of the dielectric material is less than or equal to 100 ppm / ℃. In some embodiments, the T of the dielectric material... g The CTE of the dielectric material is approximately 90 to approximately 120 ppm / °C. In some embodiments, the CTE of the dielectric material is... g The CTE of the dielectric material is approximately 120 to approximately 150 ppm / °C. In some embodiments, the CTE of the dielectric material is... g The CTE of the dielectric material is approximately 70 to approximately 100 ppm / °C. In some embodiments, the CTE of the dielectric material is... g The CTE of the dielectric material is approximately 60 to approximately 90 ppm / °C. In some embodiments, the CTE of the dielectric material is... g The CTE of the dielectric material is approximately 20 to approximately 60 ppm / °C. In some embodiments, the CTE of the dielectric material is... g The CTE of the dielectric material is approximately 10 to approximately 50 ppm / °C. In some embodiments, the CTE of the dielectric material is substantially isotropic.

[0071] The dielectric constant (Dk) of the film

[0072] In some embodiments, the dielectric material (e.g., a dielectric layer or film) described herein has a dielectric constant of about 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, or 2.8. In some embodiments, the thermosetting composition cured in the currently disclosed embodiments has a dielectric constant of about 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, or 2.8. In some embodiments, the dielectric constant is less than or equal to 2.8. In some embodiments, the dielectric constant is less than or equal to 2.7. In some embodiments, the dielectric constant is less than or equal to 2.6. In some embodiments, the dielectric constant is less than or equal to 2.5. In some embodiments, the dielectric constant is less than or equal to 2.4. In some embodiments, the dielectric constant is less than or equal to 2.3. In some embodiments, the dielectric constant is less than or equal to 2.2. In some embodiments, the dielectric constant is less than or equal to 2.1. In some embodiments, the dielectric constant is less than or equal to 2. In some embodiments, the dielectric constant is less than or equal to 1.9. In some embodiments, the dielectric constant is less than or equal to 1.8. In some embodiments, the dielectric constant is less than or equal to 1.7. In some embodiments, the dielectric constant is less than or equal to 1.6. In some embodiments, the dielectric constant is less than or equal to 1.5. In some embodiments, the dielectric constant is less than or equal to 1.4. In some embodiments, the dielectric constant is less than or equal to 1.3. In some embodiments, the dielectric constant is less than or equal to 1.2. In some embodiments, the dielectric constant is less than or equal to 1.1.

[0073] In some embodiments, the dielectric constant is from about 1.1 to about 2.8. In some embodiments, the dielectric constant is from about 2 to about 2.8. In some embodiments, the dielectric constant is from about 2.1 to about 2.8. In some embodiments, the dielectric constant is from about 2.2 to about 2.8. In some embodiments, the dielectric constant is from about 2.3 to about 2.8. In some embodiments, the dielectric constant is from about 2.4 to about 2.8. In some embodiments, the dielectric constant is from about 2.5 to about 2.8. In some embodiments, the dielectric constant is from about 2.6 to about 2.8. In some embodiments, the dielectric constant is from about 2.7 to about 2.8. In some embodiments, the dielectric constant is from about 2.1 to about 2.7. In some embodiments, the dielectric constant is from about 2.1 to about 2.6.

[0074] In some embodiments, the dielectric constant is about 2 to about 2.5. In some embodiments, the dielectric constant is about 2.1 to about 2.5. In some embodiments, the dielectric constant is about 2.2 to about 2.5. In some embodiments, the dielectric constant is about 2.3 to about 2.5. In some embodiments, the dielectric constant is about 2.4 to about 2.5. In some embodiments, the dielectric constant is about 2 to about 2.4. In some embodiments, the dielectric constant is about 2.1 to about 2.4. In some embodiments, the dielectric constant is about 2.2 to about 2.4. In some embodiments, the dielectric constant is about 2.3 to about 2.4. In some embodiments, the dielectric constant is about 2 to about 2.3. In some embodiments, the dielectric constant is about 2.1 to about 2.3. In some embodiments, the dielectric constant is about 2.2 to about 2.3. In some embodiments, the dielectric constant is about 2 to about 2.2. In some embodiments, the dielectric constant is about 2.1 to about 2.2.

[0075] In some embodiments, the dielectric material of this disclosure may be filled with glass microspheres to further reduce the dielectric constant to 1.8 to 2.5.

[0076] In some embodiments, the dielectric constant of the dielectric material is substantially isotropic. In some embodiments, the dielectric constant of the dielectric material is measured at approximately 1, 5, or 10 GHz. In a preferred embodiment, the dielectric constant of the dielectric material is measured at approximately 5 GHz.

[0077] The dissipation factor (or DF) of the membrane.

[0078] In some embodiments, the dissipation factor of the dielectric material is as high as about 0.01, 0.009, 0.008, 0.007, 0.006, 0.005, 0.004, 0.005, 0.004, 0.003, 0.002, or 0.001. In some embodiments, the dissipation factor of the dielectric material is less than or equal to 0.005. In some embodiments, the dissipation factor of the dielectric material is less than or equal to 0.004. In some embodiments, the dissipation factor of the dielectric material is less than or equal to 0.003. In some embodiments, the dissipation factor of the dielectric material is less than or equal to 0.002. In some embodiments, the dissipation factor of the dielectric material is less than or equal to 0.001. In some embodiments, the dissipation factor of the dielectric material is from about 0.001 to about 0.005. In some embodiments, the dissipation factor of the dielectric material is from about 0.0015 to about 0.0025. In some embodiments, the dissipation factor of the dielectric material is from about 0.002 to about 0.005. In some embodiments, the dissipation factor of the dielectric material is from about 0.003 to about 0.005. In some embodiments, the dissipation factor of the dielectric material is from about 0.004 to about 0.005.

[0079] In some embodiments, the dissipation factor of the dielectric material is substantially isotropic. In some embodiments, the dissipation factor of the dielectric material is measured at approximately 1, 5, or 10 GHz. In a preferred embodiment, the dissipation factor of the dielectric material is measured at approximately 5 GHz.

[0080] Young's modulus (or elastic modulus) of the membrane.

[0081] In some embodiments, the Young's modulus (also known as tensile modulus or elastic modulus) of the dielectric material and / or polymer composition is about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 3, 4, 5, or 6 GPa. In some embodiments, the Young's modulus of the thermosetting composition cured in the currently disclosed embodiments is about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 3, 4, 5, or 6 GPa. In some embodiments, the Young's modulus is less than or equal to about 6 GPa. In some embodiments, the Young's modulus is less than or equal to about 5 GPa. In some embodiments, the Young's modulus is less than or equal to about 4 GPa. In some embodiments, the Young's modulus is less than or equal to about 3 GPa. In some embodiments, the Young's modulus is less than or equal to about 2 GPa. In some embodiments, the Young's modulus is less than or equal to about 1 GPa. In some embodiments, the Young's modulus is from about 0.1 GPa to about 6 GPa. In some embodiments, the Young's modulus is from about 0.1 GPa to about 5 GPa. In some embodiments, the Young's modulus is from about 0.1 GPa to about 3 GPa. In some embodiments, the Young's modulus of the dielectric material is substantially isotropic.

[0082] In some embodiments, the dielectric material is a dielectric film, wherein the thickness of the dielectric film is from about 0.25 kilometres per inch (mil) to about 125 mils. In some embodiments, the thickness is greater than or equal to 1 micrometer (μm). In some embodiments, individual films or sheets of dielectric material and / or polymer composition are stacked and pressed to achieve a thickness of from about 10 mils to about 125 mils.

[0083] In some embodiments, the dielectric material includes a thickness variation of up to about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. In some embodiments, the thickness variation is less than or equal to about 10%. In some embodiments, the thickness variation is less than or equal to about 9%. In some embodiments, the thickness variation is less than or equal to about 8%. In some embodiments, the thickness variation is less than or equal to about 7%. In some embodiments, the thickness variation is less than or equal to about 6%. In some embodiments, the thickness variation is less than or equal to about 5%. In some embodiments, the thickness variation is less than or equal to about 4%. In some embodiments, the thickness variation is less than or equal to about 3%. In some embodiments, the thickness variation is less than or equal to about 2%. In some embodiments, the thickness variation is less than or equal to about 1%. In some embodiments, the thickness variation is from about 1% to about 10%. In some embodiments, the thickness variation is from about 2% to about 9%. In some embodiments, the thickness variation is from about 3% to about 8%. In some embodiments, the thickness variation is from about 4% to about 7%.

[0084] filler

[0085] In some embodiments, at least one dielectric layer further includes a filler. In some embodiments, the filler is selected from aluminum hydroxide, magnesium hydroxide, kaolin, talc, hydrotalcite, calcium silicate, beryllium oxide, boron nitride, glass powder, silica powder, zinc borate, aluminum nitride, silicon nitride, silicon carbide, magnesium oxide, zirconium oxide, mullite, titanium oxide, potassium titanate, hollow glass microspheres, potassium titanate fibers, silicon carbide single crystal filaments, silicon nitride fibers, alumina single crystal fibers, short glass fibers, polytetrafluoroethylene powder, polyphenylene sulfide powder, polystyrene powder, and combinations thereof. In some embodiments, the dielectric layer further includes a flame retardant additive. In some embodiments, the flame retardant additive is a non-halogenated flame retardant additive. In some embodiments, the non-halogenated flame retardant is selected from phosphorus-based flame retardant additives, inorganic-based flame retardant additives, and combinations thereof. In some embodiments, the at least one dielectric layer further comprises an additive selected from heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, free radical stabilizers, antistatic agents, preservatives, tackifiers, toughening agents, rubber particles, pigments, dyes, lubricants, release agents, foaming agents, fungicides, plasticizers, processing aids, deacidifiers, dyes, pigments, stabilizers, foaming agents, nucleating agents, nanotubes, wetting agents, dispersants, synergists, mineral fillers, reinforcing agents, whiskers, inorganic fillers, smoke suppressants, and combinations thereof. In some embodiments, the at least one dielectric layer further comprises one or more metal-filled micropores penetrating the dielectric layer.

[0086] In some embodiments, the dielectric film of this disclosure can be manufactured using a combination of materials, such as functionalized PPE, such as SA9000 available from Sabic, triallyl isocyanurate available from Evonik, triallyl cyanurate available from Evonik and other manufacturers, cyanate esters and bismaleimide resins (e.g., BMI 5100) available from Daiwa Kasei, GMI 2300 available from Shin-AT&C (Korea), and XAD-620 available from Shin-AT&C (Korea). In some embodiments, organic fillers (e.g., high-impact polystyrene, PTFE powder) or inorganic fillers (e.g., fused silica, titanium dioxide, silicon nitride, aluminum nitride, boron nitride) are added to the dielectric film to improve CTE, thermal conductivity and / or other properties. Spherical or non-spherical fillers (e.g., spherical silica), including hollow spherical fillers, can also be used. Flame retardants, such as those available from Clariant, are also used. OP935 or OP945 aluminum polyphosphines, SPB100 (purchased from Otsuka Chemicals), or phosphazenes can also be used as flame retardants for halogen-free applications. Other phosphorus-containing compounds, such as Albemarle's Altexia or ChinYee Chemicals' PQ 60, can also be used alone or in combination with other flame retardants. Halogenated flame retardants, such as Albemarle's Saytex 8010, ethylene-1,2-bis(pentabromophenyl), or BT 93, can be used. Butadiene and styrene copolymers such as Ricon 100, Ricon 184, Ricon 257, and butadiene polymers such as Ricon 300, Ricon 130, Ricon 131, Ricon 134, Ricon 154, Ricon 156, and Ricon 157, available from Total, can be used for crosslinking or as a framework for dielectric films. In some embodiments, a peroxide curing agent can be used in the curing process.

[0087] In some embodiments, the filler of this disclosure may be present in the dielectric film at 0 to 0.1 wt% based on the weight of the dielectric film, 0 to 0.5 wt% based on the weight of the dielectric film, 0 to 1 wt% based on the weight of the dielectric film, 0 to 5 wt% based on the weight of the dielectric film, 1 to 5 wt% based on the weight of the dielectric film, 1 to 6 wt% based on the weight of the dielectric film, 1 to 7 wt% based on the weight of the dielectric film, 1 to 8 wt% based on the weight of the dielectric film, 1 to 9 wt% based on the weight of the dielectric film, 1 to 10 wt% based on the weight of the dielectric film, 10 to 20 wt% based on the weight of the dielectric film, 20 to 30 wt% based on the weight of the dielectric film, 30 to 40 wt% based on the weight of the dielectric film, 40 to 50 wt% based on the weight of the dielectric film, 50 to 60 wt% based on the weight of the dielectric film, 60 to 70 wt% based on the weight of the dielectric film, or up to 70 wt% based on the weight of the dielectric film. In some embodiments, the filler of this disclosure can be in quantities based on the weight of the dielectric film: 0, 0.0001, 0.001, 0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17. 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60% by weight are present in the dielectric film of the present invention.

[0088] film thickness

[0089] In some embodiments, the dielectric polymer film described herein has an average thickness of about 0.1 mil to about 6.0 mil (e.g., about 0.1 mil to about 1.0 mil, about 0.1 mil to about 2.0 mil, about 0.1 mil to about 3.0 mil, about 0.1 mil to about 4.0 mil, or about 0.1 mil to about 5.0 mil). In some embodiments, the dielectric polymer film described herein has an average thickness of about 0.25 mil to about 2.5 mil. In some embodiments, the dielectric polymer film described herein has an average thickness of about 0.5 mil to about 2.0 mil. In some embodiments, the dielectric polymer film described herein has an average thickness of about 3.0 mil to about 5.0 mil. In some embodiments, the dielectric polymer film described herein has an average thickness of about 0.5 mil. In some embodiments, the dielectric polymer film described herein has an average thickness of about 1 mil. In some embodiments, the dielectric polymer film described herein has an average thickness of about 1.5 mil. In some embodiments, the average thickness of the dielectric polymer film described herein is from about 5 mils to about 125 mils. In some embodiments, the average thickness of the dielectric polymer film described herein is about 0.1 mil, 0.2 mil, 0.3 mil, 0.4 mil, 0.5 mil, 0.6 mil, 0.7 mil, 0.8 mil, 0.9 mil, 1.0 mil, 1.1 mil, 1.2 mil, 1.3 mil, 1.4 mil, 1.5 mil, 1.6 mil, 1.7 mil, 1.8 mil, 1.9 mil, 2.0 mil, 3.0 mil, 3.3 mil, 3.5 mil, 4.0 mil, 5.0 mil, or 6.0 mil.

[0090] Peel strength

[0091] In some embodiments, the average peel strength of the film on the adhesive surface (e.g., on a metal laminate) is about 1-10 psi, 2-10 psi, 3-10 psi, 4-10 psi, 5-10 psi, 6-10 psi, 7-10 psi, 8-10 psi, or 9-10 psi. In some embodiments, the average peel strength of the film on the adhesive surface (e.g., on a metal laminate) is about 3-6 psi, 4-6 psi, or 5-6 psi.

[0092] Methods for manufacturing dielectric materials

[0093] This document provides methods for manufacturing the dielectric material as described above. In some embodiments, this document provides methods for manufacturing sheets or films of dielectric material. In some embodiments, the methods for manufacturing sheets and films described herein include solvent casting, melt extrusion, lamination, and coating methods. Non-limiting examples of solvent casting, melt extrusion, lamination, and coating methods can be found, for example, in U.S. Patent Applications Nos. 4,592,885 and 7,172,713, and U.S. Patent Applications Publications Nos. US2009 / 0050842, US2009 / 0054638, and US2009 / 0096962, the contents of which are incorporated herein by reference. Other examples of films formed by solvent casting, melt extrusion, lamination, and coating methods can be found, for example, in U.S. Patent Applications Publications Nos. US2005 / 0133953 and US2010 / 0055356, the contents of which are incorporated herein by reference.

[0094] Continuous solvent casting is a preferred method for providing the dielectric material films described herein. Solvent casting processes can provide compositions with extremely high quality and uniform thickness. A typical solvent casting process includes 1) dissolving and / or dispersing components (e.g., polymers, crosslinking agents, fillers, flame retardants, etc.) in a solvent to produce a varnish; 2) applying the varnish to a substrate (e.g., copper foil) or a cast film (e.g., PET); and 3) evaporating / removing the solvent by drying (e.g., drying in a drying oven) to produce a film of the polymer composition on the substrate or carrier film. The final thickness of the film can be controlled, for example, by passing the varnish through a slit mold. For the casting process to produce a high-quality film, the dissolution of the polymer in the varnish solvent is crucial. The residence time and temperature distribution in the drying oven will determine factors such as the amount of residual solvent in the film and whether the film is a crosslinked polymer composition or a mixture (e.g., thermoplastic). In some embodiments, the polymer composition is a thermoplastic polymer (or thermosetting) composition after the film casting and drying processes. In some embodiments, the polymer composition is a cross-linked thermoplastic composition after the film casting and drying process.

[0095] In some embodiments, the sheet or film is disposed on a carrier or release liner, such as, but not limited to, PET, release-treated PET, biaxially oriented polypropylene, and other common carriers or release liner. In some embodiments, the sheet or film is disposed on copper foil. In some embodiments, the polymeric film composition is non-sticky to the touch. In some embodiments, the polymeric film composition is plastic enough to be peeled off from the carrier film and placed on an object. In some embodiments, the composition on the carrier film can be placed on a substrate, passed through a roller laminator, and then the carrier film is peeled off, leaving the polymeric composition on a new substrate. In some embodiments, the substrate to be laminated is copper foil or sheet. In some embodiments, the substrate to be laminated is copper clad (etched, partially etched, or unetched) or bare copper glass fiber core. In some embodiments, the sheet or film is metal-clad (e.g., copper) or unclad. In some embodiments, the sheet or film is unreinforced (e.g., unreinforced, excluding woven or nonwoven glass fabrics, organic woven or nonwoven).

[0096] In some embodiments, the polymer composition is dispersed in a solvent and provided as a varnish composition. In some embodiments, the varnish composition is stabilized for several days (e.g., before the varnish gels due to crosslinking of the polymer and crosslinking agent). In some embodiments, the varnish composition is stabilized for several weeks before gelation occurs. In some embodiments, the varnish composition is stabilized for several months before gelation occurs. In some embodiments, the varnish composition is cast onto a carrier film. In some embodiments, the carrier film is polyethylene terephthalate (PET) or PET treated to further promote the release of the polymer composition. In some embodiments, the varnish composition is cast onto copper foil.

[0097] In a preferred embodiment, the dielectric film of this disclosure can be carried on a substrate such as copper foil or PET. Such copper foil may include a thickness of about 3 micrometers to about 35 micrometers. In some embodiments, the dielectric film can be coated with sputtered copper to a thickness of 0.5 micrometers to 5.0 micrometers using, for example, a physical vapor deposition process. In some embodiments, this disclosure includes a laminated material made by laminating copper foil coated with the dielectric film as described herein, and subsequently pressing them together by hot rolling, the hot rolling being batch-processed using a flatbed press.

[0098] Printed circuit board containing transmission lines formed of dielectric polymer film

[0099] In one embodiment, this document provides a printed circuit board comprising one or more transmission lines formed from the compositions described herein (e.g., dielectric polymer films).

[0100] Transmission lines can be used as any type of conductor (e.g., high-speed conductors). In some instances, at least one transmission line is formed in or on an outer layer of a PCB (e.g., a microstrip as a microstrip transmission line). In some instances, at least one transmission line is formed in or on an inner layer of a PCB (e.g., a stripline). Transmission lines can be single-ended or differential.

[0101] At a signal frequency of 10 GHz (e.g., signal transmission rate), the dissipation factor of at least one transmission line can be 0.0010, 0.0015, 0.0020, 0.0021, 0.0022, 0.0023, 0.0024, 0.0025, 0.0026, 0.0027, 0.0028, 0.0029, 0.0030, 0.0035, or 0.0040.

[0102] At least one transmission line may have a width of 1 to 4 mils, 4 to 6 mils (e.g., 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, or 6.0 mils), or greater than 6 mils (e.g., 6 to 20 mils). The unit "mil" refers to 1 / 1000 of an inch.

[0103] In some instances, transmission lines (e.g., first transmission line and second transmission line) can be formed in vertically adjacent layers of a PCB. In such instances, the thickness of the dielectric layer between the first and second transmission lines can be less than 3 mils (e.g., 0.1 mil to 3 mils), 3 mils to 5 mils (e.g., 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 mils), or greater than 5 mils (e.g., 5 to 20 mils).

[0104] In some instances, the transmission line can carry signals modulated using any modulation scheme, including but not limited to pulse amplitude modulation (PAM). The number of pulse amplitude levels used in a pulse amplitude modulation scheme can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16.

[0105] In some instances, the transmission line is capable of carrying data at data rates between 28 and 224 Gbps (e.g., 28, 56, 112, or 224 Gbps).

[0106] In some embodiments, the PCB comprising one or more transmission lines formed from the compositions described herein may be flexible. In some embodiments, the flexible PCB may have an elastic modulus from 0.01 GPa to 6 GPa (e.g., 1 GPa, 2 GPa, 3 GPa, 4 GPa, or 5 GPa). In some embodiments, the flexible PCB may have an elastic modulus less than or equal to 6 GPa (e.g., less than or equal to 1 GPa, less than or equal to 2 GPa, less than or equal to 3 GPa, less than or equal to 4 GPa, or less than or equal to 5 GPa). In some embodiments, components of the flexible PCB may include one or more sensor devices (e.g., wearable sensors). In some embodiments, the PCB comprising one or more transmission lines formed from the compositions described herein can be used to manufacture antennas. For example, at least one dielectric polymer film can be used to manufacture bifacial or multilayer antennas.

[0107] In some instances, a PCB is a component of a computing device (e.g., desktop computer, laptop computer, server, tablet computer, accelerator, supercomputer, mobile phone, etc.) or a network device (e.g., switch, router, access point, modem, etc.). Such a computing or network device can be configured to communicate with remote devices using any suitable wireless communication technology or standard (e.g., 4G, 5G, 6G, etc.) via the PCB.

[0108] For use in the manufacture of PCBs comprising one or more transmission lines formed of a dielectric polymer film, the film may be provided in the form of an adhesive sheet or in a cured form (e.g., in the form of a c-stage corelaminate).

[0109] Printed circuit boards containing dielectric materials

[0110] In one embodiment, this document provides a printed circuit board comprising one or more insulating layers (also referred to herein as “dielectric layer,” “dielectric material,” or “dielectric film”), wherein the insulating layer comprises the composition described herein.

[0111] Advanced PCBs can include components (such as capacitors, resistors, or active devices) embedded in a substrate. PCBs can be single-sided (one copper layer), double-sided (two copper layers), or multi-layered (e.g., multiple copper layers separated by dielectric material), allowing for high component density. Multilayer PCBs are complex composite structures, typically comprising a series of reinforcing resin and copper foil layers. Conductors on different layers can be connected via "through-holes" or plated through-holes. Laminates used in PCB applications are manufactured through a process known as pre-lamination.

[0112] In some embodiments, the printed circuit board includes a hybrid design in which the central core is a glass fiber-based dielectric (or laminate), and at least one or more outer insulating layers comprise a polymer dielectric film. In some embodiments, the hybrid design has more than one glass fiber-based dielectric material, and at least one or more other insulating layers comprise a polymer dielectric film. In some embodiments, the printed circuit board is multilayered, double-sided, or single-sided. In some embodiments, sheets or films are used in a continuous build process. In some embodiments, sheets or films are used in a continuous build process in which the central core is a glass fiber laminate.

[0113] The printed circuit boards (e.g., HDI-PCBs) described herein may include one or more dielectric materials (e.g., one or more dielectric films) and one or more copper layers.

[0114] In some embodiments, at least one of the dielectric films has a T g The following stresses are 15 MPa to 30 MPa, or 15 MPa to 20 MPa.

[0115] In some embodiments, at least one of the dielectric films has a T g The stresses mentioned above are from 1 MPa to 3 MPa (e.g., about 1.5 MPa).

[0116] The tensile stress (such as overstress failure mode) applied to the copper during PCB assembly is as follows:

[0117]

[0118] Where σ Cu Let α be the tensile stress of copper in the z-direction. Eq and α Cu The coefficients of thermal expansion in the z-direction for equivalent materials (dielectric and copper together) and pure copper are T, respectively. assem and T amb E represents assembly temperature and ambient temperature, respectively. Cu Let be the Young's modulus of copper in the z-direction.

[0119] The equivalent coefficients for dielectric materials and copper are given by the following mixture rule:

[0120]

[0121] E Eq =V Di E Di +V Cu E Cu (3)

[0122] Among them, E Di ECu and E Eq Let α be the modulus of dielectric, copper, and equivalent material in the Z direction, respectively. Di α Cu and α Eq are the coefficients of thermal expansion of dielectric, copper, and equivalent material in the z-direction, respectively, and V. Di and V Cu These represent the volume fractions of dielectric and copper in the affected area of ​​the circuit board, respectively.

[0123] By substituting appropriate values, the above equation can also be used to calculate the glass transition temperature T of the dielectric. g The above temperatures.

[0124] Because it is lower than T g and higher than T g The coefficient of thermal expansion and the modulus in the z-direction can be approximated as constant values, therefore equation (1) can be rewritten as:

[0125]

[0126] The subscript b indicates that it is below T. g The subscript 'a' indicates that it is higher than T. g The subscript 'e' indicates elasticity, the subscript 'p' indicates plasticity, and T... yield This is the temperature at which the stress in copper exceeds the yield stress of copper.

[0127] Stress / Strain under Thermal Cycling and Operating Conditions

[0128] The tensile stress applied to the copper under operating conditions is shown below:

[0129]

[0130] Where T LB and T UB These are the lower and upper limits of the operating range, respectively.

[0131] Because it is lower than T g and higher than T g The coefficient of thermal expansion and the modulus in the z-direction can be approximated as constant values, therefore equation (5) can be rewritten as:

[0132] a) If the upper limit is higher than T yield But lower than T g :

[0133]

[0134] b) If the upper limit of the operating condition is lower than T yield :

[0135]

[0136] The total strain of copper is the sum of elastic strain and plastic strain.

[0137] a) If the strain becomes plastic

[0138]

[0139] Where ε Cu For the strain of copper, σ Y，Cu The yield stress of copper

[0140] b) If the strain is elastic:

[0141]

[0142] If equation (9) applies, it means that the copper strain is below the yield value, and the failure mode becomes high-cycle fatigue, which is similar to an almost infinite lifespan in the case of using this device.

[0143] The dielectric materials described herein can be used, for example, in the printed circuit board industry. For instance, materials with low Tb content in the building blocks... g Low-modulus and / or low-CTE dielectric films (not reinforced with glass fiber) can be used, for example, in high-density interconnect (HDI) printed circuit boards to achieve higher reliability and increased interconnect density. In other embodiments, the dielectric film enables the use of stacked vias that persist after assembly and have high fatigue life under desired operating conditions.

[0144] These benefits include more isotropic performance, uniformity and the ability to achieve dielectric thicknesses below 25 micrometers, improved dielectric spacing, enhanced adhesion to materials including metals such as copper, increased microvia reliability, substrate toughening, and elimination of weaving effects that plague woven fabric-reinforced composites and cause skew or timing problems in high-speed digital transmission on printed circuit boards. Beyond chip packaging, high-density interconnect boards, standard double-sided and single-sided boards, motherboards, sequential laminates, high-layer boards and standard-layer boards, and flexible boards used in IoT devices, camera modules, infotainment systems, mobile phones, tablets, and other consumer electronics will also benefit significantly from this new technology. Furthermore, the potential improvements in laserability and increased production volume due to the absence of glass, the ability to overcome dielectric thickness barriers, a potential 20% to 30% reduction in board thickness, reduced printed circuit board weight, reduced stress on copper-plated vias, reduced Z-expansion to increase microvia reliability, thickness control, and improved crack resistance are some of the expected benefits of this technology. These metal-clad or unclad films or sheets also help to address differential skewness because they possess uniform, isotropic properties in films or unreinforced forms (unwoven reinforcements).

[0145] In some embodiments, a sheet or film of dielectric material is provided on a carrier or release film, such as, but not limited to, PET, treated or surface-modified PET, biaxially oriented polypropylene, and other common carriers or release liner. In some embodiments, the polymer composition has sufficient plasticity to allow it to be peeled off from the carrier as a film and placed on an object. In some embodiments, the composition on the carrier film can be placed on a substrate, laminated, and then the carrier film is peeled off, leaving the polymer composition on a new substrate. In some embodiments, the substrate to be laminated is a copper foil or sheet. In some embodiments, the substrate to be laminated is a copper-clad (etched, partially etched, or unetched) or copper bare glass fiber core. In some embodiments, the sheet or film is metal-clad (e.g., copper) or unclad. In some embodiments, the sheet or film is unreinforced (e.g., unreinforced, not containing woven or nonwoven glass fabric, organic woven or nonwoven fibers (e.g., micron or nano-sized inorganic or organic fillers)).

[0146] Methods for manufacturing PCBs containing dielectric materials

[0147] In one embodiment, the process of forming a laminate for a printed circuit board includes the following operations:

[0148] A. If an electrical laminate is required, one or more sheets of prepreg are stacked or laminated with one or more sheets of conductive material (e.g., copper foil) in alternating layers.

[0149] B. The laminated sheets are pressed under elevated temperature and pressure for a sufficient time to fully bond the prepreg composition and form a laminate. The temperature of this lamination step is typically between 100°C and 230°C. The lamination step typically lasts from 1 minute to 200 minutes, most commonly from 10 minutes to 90 minutes. The lamination step can optionally be performed at a higher temperature for a shorter time (e.g., in a continuous lamination process) or at a lower temperature for a longer time (e.g., in a low-energy pressing process).

[0150] C. Optionally, the resulting laminate, such as a copper-clad laminate, can be post-treated for a period of time under high temperature and environmental pressure. The post-treatment temperature is typically between 120°C and 250°C. The post-treatment time is typically between 30 minutes and 12 hours.

[0151] In one embodiment, this document provides a method of manufacturing or assembling a printed circuit board, including introducing the sheet or film described herein. In some embodiments, the board is a high-density interconnect board (HDI board). In some embodiments, the board is used for semiconductor chip packaging applications. In some embodiments, the sheet or film is used to eliminate skewing between differential lines. In some embodiments, the sheet or film is placed under a top copper sheet to eliminate pad pits during lead-free assembly. In some embodiments, the sheet or film is used to fill a heavy copper (>3 oz / sq ft) layer. In some embodiments, the film is used to enhance the thermal conductivity in packaged LEDs or other high-power device applications, and is generally used to improve the thermal conductivity in printed circuit boards. In some embodiments, the sheet or film, which is covered on both sides, is used for embedding capacitor layers. In some embodiments, the sheet or film is used to embed silicon or other intercalation materials used in 2.5D chip packaging applications or other embedded component packages.

[0152] In some implementations, the printed circuit board is a high-density interconnect (HDI) printed circuit board. HDI printed circuit boards differ from other PCBs in that they use a stacking technology, where circuit boards are stacked layer by layer, requiring far fewer process steps than traditional multilayer processes. HDI is widely used in applications that prefer smaller circuit board sizes. For many systems using HDI-PCBs, it is desirable to reduce the PCB area while increasing functionality. This advancement is often driven by the miniaturization of components in mobile computing, 4G and 5G applications, avionics, and military applications. To achieve these goals, successive generations of HDI-PCBs have typically used increasingly thinner dielectric materials and laser-drilled microvias.

[0153] In some embodiments, the printed circuit board is of the 1+n+1 type, where n layers can be multi-layered sub-assemblies, and in most cases, the minimum value of n is 2, meaning a double-sided core laminate. In these embodiments, one layer on either side is made of a film containing a polymer. In some embodiments, the printed circuit board is multi-layered, double-sided, or single-sided. In some embodiments, sheets or films are used in a continuous build process. In some embodiments, the printed circuit board is a high-density interconnect (HDI) printed circuit board. In some embodiments, the high-density interconnect printed circuit board using layers comprising a polymer dielectric film is an i+n+i structure, where i is greater than or equal to 2. In some embodiments, the HDI 1+n+1 structure or i+n+i structure layer where i is greater than or equal to 2 uses a polymer dielectric film with a thickness of 0.25 mils to 4 mils. In some embodiments, polymer-containing layers are used for any layer of the HDI board, and the thickness is 0.25 mils to 4 mils. In some embodiments, the HDI 1+n+1 or i+n+i structured stack (where i is greater than or equal to 2) or any HDI layer is fabricated using a subtractive etching technique. In some embodiments, the HDI 1+n+1 or i+n+i structured stack (where i is greater than or equal to 2) or any HDI layer is fabricated using a modified semi-additive (mSAP) or fully additive technique. In some embodiments, the stack includes a polymer dielectric film sputtered with a thin copper layer. In some embodiments, the stack has a nano-copper layer on one side of its surface.

[0154] Other methods are used to manufacture prepregs and laminates for PCB applications, such as the hot melt method, in which B-stage epoxy is melted and pressed onto a reinforcing substrate.

[0155] The dielectric layer of a PCB may contain vias. In some implementations, vias can be filled with a sheet or film by placing them directly on the areas that need filling (including gaps between holes, traces, or package traces). This may involve the use of copper (e.g., heavy copper), in which case it is difficult to fill with resin by other means. Resin filling can be performed across the entire board or concentrated in only a small area.

[0156] In some embodiments, a thin layer (e.g., a very thin layer) of the polymer composition is used between a metal (e.g., copper) and the thermosetting or thermoplastic material to which the metal is to be bonded. In some embodiments, a thin layer (e.g., a very thin layer) of the polymer composition is located between a top metal layer of a printed circuit board and the thermosetting or thermoplastic material to which the metal is to be bonded.

[0157] definition

[0158] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0159] The articles “a” and “an” can be used in this text to refer to one or more species or layers (i.e., at least one species or layer) of the grammatical object of the article. For example, “analogy” refers to one or more species or layers of analogues.

[0160] All ranges listed in this article include endpoints, including endpoints of ranges that list "between" two values.

[0161] As used herein, “about” will be understood by one of ordinary skill in the art and will vary to some extent depending on the context in which it is used. If the use of a term is unclear to one of ordinary skill in the art in the context of its use, then “about” will mean a maximum of ±10% for that particular term.

[0162] As used herein, “thermoplastic” or “thermoplastic polymer composition” is understood to mean a plastic material or polymer that becomes flexible or malleable above a certain temperature and solidifies upon cooling.

[0163] As used herein, “thermosetting,” “thermosetting material,” or “thermosetting polymer composition” is understood to mean a polymer or resin in a soft solid or viscous state that, through curing, irreversibly becomes an insoluble polymer network that, once hardened, cannot be reheated and melted back into a liquid form.

[0164] As used herein, “printed circuit board” refers to a system of mechanical support and electrical connections for electronic, optical, and / or optoelectronic components. For example, a printed circuit may be a thin layer of copper foil laminate on one or both sides of a primary insulating substrate (e.g., FR-4 glass epoxy). As used herein, “printed circuit board assembly or component” refers to an electronic, optical, and / or optoelectronic component of a PCB (e.g., an electronic, optical, and / or optoelectronic component connected by conductive traces, pads, or other features that can be etched from copper sheets laminated on a non-conductive substrate).

[0165] As used in this article, the term "microvia" can refer to a through-hole that passes through a single layer of a PCB.

[0166] As used herein, "laminate" refers to a composite material comprising one or more layers of prepreg, which may optionally be covered with metal (e.g., copper) foil on one or more sides, and formed into a final product by heating and pressurizing. The laminates described herein may be cured or uncured.

[0167] As used herein, "prepreg" refers to an adhesive layer of dielectric material that may or may not be reinforced. The polymer compositions described herein can be used as prepregs for manufacturing laminates. Thermoplastic polymers are used without any fiber reinforcement. Prepregs are also commonly referred to as adhesive sheets.

[0168] As used in this paper, the term “substantially” means a high degree of approximation (e.g., within + / -10% for quantifiable properties), but does not require absolute precision or a perfect match.

[0169] As used in this article, the term "T" g The terms “glass transition temperature” and “glass transition temperature” are used interchangeably in this article.

[0170] Example

[0171] The following examples are provided to illustrate the implementation schemes described herein and should not be construed in any way as limiting the scope of the implementation schemes.

[0172] Abbreviations: DK: Dielectric constant; DF: Dissipation factor; CTE: Coefficient of thermal expansion.

[0173] Example 1 - Preparation and Properties of Dielectric Films

[0174] Table 1 lists the low T values. g Specific examples of dielectric films combining low modulus, low dielectric constant, and low dissipation factor, and some of their properties. The composition was obtained by: 1) mixing the components in a melt-mixing apparatus (i.e., solvent-free method); or 2) mixing in a solvent and uniformly dispersing in a high-speed rotary mixer to obtain a varnish; subsequently, the varnish was applied to a 2-mil PET film with a rod and dried in an oven to a residual solvent level of <1%, resulting in a composite film with a thickness of approximately 1 to 3 mils. Physical and electrical data were obtained by stacking the dielectric films and consolidating them using a 6×6-inch hydraulic press at a pressure of 250 Psi, followed by curing at 330°F for 30 minutes to form a film with a thickness of 0.6 mm. Ricon 257 is a low molecular weight, high vinyl butadiene-styrene copolymer manufactured by Total (USA). Ricon 154 is a low molecular weight, high vinyl polybutadiene resin manufactured by Total (USA). KR05 is a high molecular weight, primarily 1,4-addition styrene-butadiene copolymer manufactured by Ineos (Germany). SR8983 is a high molecular weight, primarily 1,4-addition styrene-butadiene copolymer manufactured by Lion Elastomers (USA). SA9000 is a methacrylate-terminated polyphenylene ether manufactured by SABIC (USA). GMI 5100 is a bismaleimide manufactured by SHIN-AT&C (Korea). The filler and phosphorus-based flame retardant OP935 is manufactured by Clariant (Europe). OP935. GB consists of glass microspheres manufactured by 3M (USA). Fused silica is teco-sil-10 manufactured by Imerys Refractory Mineral (USA). PTFE powder is SST-4mg manufactured by Shamrock Technologies (USA). AGE is allyl glycidyl ether from Sigma-Aldrich (USA). This is a peroxide catalyst manufactured by Arkema (USA). The reported Dk (dielectric constant) and Df (dissipation factor) values ​​were obtained at 5 GHz using a split-pillar dielectric resonator. The reported CTE values ​​were obtained using a thermomechanical analyzer (TMA). The reported Young's modulus and Tg values ​​were obtained using a dynamic mechanical analyzer (DMA). The peel strength measurements correspond to the weight of one ounce of copper.

[0175] Table 1

[0176]

[0177] Example 2 - Performance of the dielectric film of this disclosure

[0178] Table 2 illustrates the improved performance of the dielectric film in the currently disclosed embodiments compared to films known in the art, thereby enhancing PCB performance. The improved performance includes reduced insertion loss (“16 GHz dB / inch loss” in Table 2) and dielectric constant (“DK” in Table 2), as described in more detail below. The improved performance also includes reduced stress on vias (“plastic strain” in Table 2), thereby improving PCB reliability.

[0179] Calculations based on dielectric constant, dissipation factor, and skewness

[0180] The speed data in Table 2 were generated using Avishtech's commercial electronic design automation software (such as Gauss2D and Gauss Stack) (e.g., by calculation).

[0181] Insertion loss αc is calculated using the following formula:

[0182]

[0183] in ω is the angular frequency, and μ is the permeability (for example, for copper, it is equal to 4π × 10⁻⁶). -7 H / m), σ is the conductivity (copper equals 5.88 × 10⁻⁶). 7 S / m), w is the width, Z0 is the characteristic impedance, and ε is the dielectric constant of the material.

[0184] The prior art used for comparison includes a 3.5 mil thick dielectric and 0.5 oz copper. As shown in Table 2, the dielectric constant of the dielectric material used in the prior art can be at least 3.2 (e.g., 3.2 or 3.4). As shown in Table 2, the insertion loss of the dielectric material used in the prior art can be at least 1.24. The transmission line operates as a differential pair with an impedance of approximately 85 ohms to 100 ohms. The prior art can use woven glass fabrics with a low dielectric constant (“DK” in Table 2), where the “DK” value in Table 2 is at least 3.2 and the Tg is at least 170°C. Because the dielectric constants of glass and resin are very different, this can cause skew problems, which can be mitigated to some extent by rotation or hardware (such as re-timers).

[0185] In contrast, as shown in Table 2, the dielectric films in the currently disclosed embodiments (e.g., Ex1, Ex2, and Ex4-Ex11) include non-fiber braided reinforcing films with a dielectric constant equal to or less than 2.8 (e.g., 2.8, 2.6, 2.4, or 2.1), which enable wider lines without skew and reduced insertion loss, and enable longer-distance communication at faster rates.

[0186] Calculation based on Tg / modulus

[0187] Table 3 provides copper properties and size assumptions for HDI printed circuit boards with copper-filled vias.

[0188] Table 3

[0189]

[0190]

[0191] Sample calculations were performed based on the parameters provided in Table 3 and the empirically derived dielectric physical properties in Table 1. Table 4 shows the results using a T at 170°C. g PCBs made from conventional existing materials of prepreg have low Dk, DF, modulus and T as shown in Table 1. g A comparison of PCBs made with Ex9 dielectric material.

[0192] Table 4

[0193]

[0194]

[0195] The substantially isotropic, low-T material using this disclosure g Films with low modulus, low Dk, and low Df show data indicating that copper stress remains below yield strength, while for films with higher T in the art... gMaterials subjected to stress exceeding their yield strength can experience permanent deformation, leading to premature failure—in some cases, even during assembly itself. Because, for example, the stress calculated using the oriented film Ex9 is below the yield stress of copper, copper exhibits elasticity and does not experience low-cycle fatigue, indicating very high reliability. In contrast, conventional existing materials currently used in the prior art (in this case, T at 170°C)... g The prepreg material leads to much higher stress. These results indicate a higher likelihood of failure due to fatigue caused by overstress and plastic strain when using the current set of materials.

[0196] Table 2

[0197]

[0198]

[0199] The stress was calculated for the other dielectric films described in Table 1. As shown in Table 2, the stress was compared with the high T of the prior art. g Compared to other materials, these are essentially isotropic and low-T g Materials with low modulus, low Dk, and low Df exhibit zero or substantially small plastic strain. Furthermore, as shown in Table 2, this disclosure demonstrates low insertion loss. Therefore, it is proven that PCBs with higher reliability and higher speed can be manufactured using this disclosure.

[0200] equivalent

[0201] Those skilled in the art will recognize, or be able to determine, using only conventional experiments, the various equivalents of the specific embodiments described herein. These equivalents are intended to be included within the scope of the following claims.

Claims

1. A dielectric thermoset polymer composition configured as a base layer in a printed circuit board, wherein a thermoset polymer in the dielectric thermoset polymer composition comprises a polyalkylene, a grafted derivative or copolymer of a polyalkylene, a polyalkenylene, a derivative or copolymer of a polyalkenylene, a polyalkynylene, a derivative or copolymer of a polyalkynylene, a poly(arylene ether), or a copolymer of a poly(arylene ether); and wherein the dielectric thermoset polymer composition has: (i) a glass transition temperature less than 135 °C; (ii) a dielectric constant less than 2.8; and (iii) a tensile modulus less than or equal to 3 GPa when the average temperature of the dielectric thermoset polymer composition is less than the glass transition temperature (Tg) of the dielectric thermoset polymer composition; wherein the tensile modulus is substantially isotropic.

2. The dielectric thermoset polymer composition of claim 1, wherein the polyalkenylene is polystyrene.

3. The dielectric thermoset polymer composition of claim 1, wherein the dissipation factor of the polymer composition is less than 0.

01.

4. The dielectric thermoset polymer composition of claim 1, wherein the dissipation factor of the polymer composition is less than 0.

006.

5. The dielectric thermoset polymer composition of claim 1, wherein the glass transition temperature of the polymer composition is less than 130 °C.

6. The dielectric thermoset polymer composition of claim 1, wherein the tensile modulus is less than 2 GPa when the average temperature of the polymer composition is less than the glass transition temperature (Tg) of the polymer composition.

7. A printed circuit board comprising the dielectric thermoset polymer composition of claim 1.

8. A printed circuit board comprising: (i) a core layer; (ii) the dielectric thermoset polymer composition of claim 1 disposed on a first face of the core layer; and (iii) one or more vias penetrating the dielectric thermoset polymer composition.

9. The printed circuit board of claim 8, wherein the core layer is a fiberglass-based core layer. ​

Images