laminate

Abstract

A laminate comprising: a first outer copper layer; a second outer copper layer; a multilayer structure having at least three polymer films disposed between the first outer copper layer and the second outer copper layer; wherein adjacent polymer layers of the at least three polymer layers have different dielectric constant Dk values, different thicknesses, or preferably both different Dk values and different thicknesses; wherein the first outer copper layer and the second outer copper layer and adjacent layers of the at least three polymer layers are bonded to one another; wherein a voltage breakdown strength of each of the at least three polymer films is equal to or greater than 200 kV / mm, or equal to or greater than 5 kV at a film thickness of 25 micrometers.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Application No. 63 / 558,158, filed February 27, 2022, which is incorporated herein by reference in its entirety. Background Technology

[0003] This disclosure relates generally to laminates, and particularly to bonded laminates having an outer copper layer.

[0004] With the development of the electric vehicle market, the demand for wireless power transfer solutions for battery charging is expected to increase. The inductive transmitting coils used in such power transfer systems must operate at high power levels (e.g., 150 kW) to complete the charging process within a reasonable timeframe. Therefore, materials suitable for operating inductive transmitting coils at such demanding high power levels are needed in the field of electric vehicles and other applications.

[0005] The following disclosures may be considered useful background information: US20050013998A1, US20100172066A1, US20140160623A1 and US20190326034A1.

[0006] While existing laminates may be useful for their intended purpose, the field involving laminates will advance through structures as disclosed herein. Summary of the Invention

[0007] One embodiment includes a laminate as defined in the appended independent claims. Further advantageous modifications to the laminate are defined in the appended dependent claims.

[0008] In one embodiment, the laminate includes: a first outer copper layer; a second outer copper layer; and a multilayer structure comprising at least three polymer films disposed between the first outer copper layer and the second outer copper layer; wherein adjacent polymer layers among the at least three polymer layers have different dielectric constants Dk and different thicknesses, or preferably both different Dk and different thicknesses; wherein the first outer copper layer, the second outer copper layer, and adjacent layers among the at least three polymer layers are bonded to each other; and wherein the voltage breakdown strength of each of the at least three polymer films is equal to or greater than 200 kV / mm, or equal to or greater than 5 kV at a film thickness of 25 micrometers.

[0009] In one embodiment, the capacitively coupled induction coil includes: one or more of the aforementioned laminates; wherein corresponding first and second outer copper layers are constructed and configured to form the capacitively coupled induction coil.

[0010] The above features and advantages, as well as other features and advantages of the invention, will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings. Attached Figure Description

[0011] Referring to the exemplary non-limiting drawings, in which the same elements are labeled the same:

[0012] Figure 1 A rotational isometric view of a laminate with three polymer film layers sandwiched between two outer copper layers, according to one embodiment, is depicted.

[0013] Figure 2A Figure 2B Figure 2C, Figure 2D Figure 2E Figure 2F, Figure 2G, Figure 2H Figure 2I Figures 2J, 2K, 2L and Figure 2M Side views of various schematic diagrams depicting a multilayer structure of polymer film layers, each having a defined mil thickness, according to one embodiment;

[0014] Figure 3 , Figure 4 and Figure 5 A description is provided for use in conjunction with an implementation scheme. Figure 1 Various short-time breakdown voltage measurements as a function of material thickness for various polymer films used in structures similar to the structure;

[0015] Figure 6 A schematic diagram of a capacitively coupled induction coil according to one embodiment is depicted; and

[0016] Figure 7 A patterned conductor, according to one embodiment, is depicted that is suitable for use with laminates as disclosed herein and for use in capacitively coupled induction coils as disclosed herein.

[0017] Those skilled in the art will understand that the accompanying drawings, further described below, are for illustrative purposes only. It will be understood that, for the sake of brevity and clarity, the elements shown in the drawings are not necessarily drawn to scale. For example, the dimensions or proportions of some elements may be enlarged relative to others for clarity. Furthermore, where deemed appropriate, reference numerals may be repeated in the drawings to indicate corresponding or similar elements, or similar elements may not be repeatedly listed in all the drawings, wherein it will be understood and appreciated that such omissions are inherently disclosed. Detailed Implementation

[0018] As used herein, the phrase “implementation” means “the embodiment disclosed and / or shown herein”, which may not necessarily cover a particular embodiment of the invention according to the appended claims, but is provided herein for the purpose of a full understanding of the invention according to the appended claims.

[0019] While the following detailed description contains numerous details for illustrative purposes, those skilled in the art will understand that many variations and modifications of these details are within the scope of the appended claims. For example, combinations of non-exclusive features are considered inherent to the disclosure herein, where described features are not mutually exclusive and are not mutually exclusive with respect to other described features. Furthermore, common features may be shown together in the various figures, but for the sake of brevity, may not be specifically enumerated in all figures, but will be recognized by those skilled in the art as clearly disclosed features, even if the features may not be enumerated in a particular figure. Therefore, the following exemplary embodiments are set forth without losing the generality of the claimed invention disclosed herein and without imposing limitations upon it.

[0020] As shown and described in the various figures and accompanying text, one embodiment provides a multilayer dielectric laminate having at least three polymer film layers and an outer conductive layer, all bonded together such that each layer is in direct close contact with its corresponding adjacent layer, and each polymer layer has a different dielectric constant Dk value or a different thickness relative to each other.

[0021] As used herein, the term “direct close contact” means contact in the absence of any intervening substance or element, such as when a first polymer layer is bonded or fused to an adjacent polymer layer.

[0022] The dielectric substrates disclosed herein are suitable for high voltage and current intensities associated with the desired power levels required for wireless charging of high-power systems (e.g., 150 kW). The dielectric substrates disclosed herein provide a means to improve dielectric breakdown strength and enhance reliability using rationally designed multilayer stacks of polymer films with different dielectric constants and / or thicknesses. In one embodiment, the multilayer dielectric substrate enables the fabrication of copper-clad laminates suitable for manufacturing high-power inductive transmitting coils.

[0023] Copper-clad laminates are used to manufacture inductive transmitting coils that can operate at high power levels. The laminate core comprises a plurality of thin, low-loss polymer films with different relative permittivity. In one embodiment, high electrical breakdown strength is achieved through a favorable electrical stress distribution by systematically varying the relative positions and thicknesses of the polymer films and the number of layers.

[0024] Uniform dielectric polymer films are commonly used for high-voltage electrical insulation. In contrast, metal-clad dielectric substrates used in the manufacture of printed circuit boards are traditionally non-uniform in composition, except when adhesives are used to bond the metal overlay to the substrate. Paradoxically, the dielectric strength (AC, DC) of non-uniform dielectric substrates typically decreases with increasing thickness. Breakdown is often caused by inhomogeneities within the dielectric, such as porosity (air gaps), chemical impurities, foreign-object-debris (FOD), polymer gels, and other defects. These inhomogeneities are more likely to be present in thicker substrates, leading to partial discharges and potentially resulting in overall electrical, thermal, and electromechanical failures.

[0025] One embodiment disclosed herein includes a plurality of distinct and relatively thin nonpolar polymer film layers exhibiting high dielectric breakdown voltage strength and various relative permittivity, which are bonded or fused together to produce a multilayer composite material. In one embodiment, the variation in the polymer film can be with respect to the film thickness, the dielectric constant (Dk) value of the film, or both the thickness and the Dk value. When a voltage is applied across the thickness of such a composite substrate, each polymer layer acts similarly to a parallel-plate capacitor. Because the capacitor layers are effectively connected in series, the charge transfer on each layer is the same, and therefore the voltage (AC or DC) is proportional to the individual capacitance (C) values. The thickness (T) and relative permittivity (ε) of each layer determine its capacitance. Due to Kirchhoff's laws, the sum of the individual voltage drops must equal the supply voltage. In one embodiment, the plurality of polymer film layers are arranged in a symmetrical stack relative to a horizontal (parallel to the polymer film layers) plane passing through the central plane of the stack, such that a layer on one side of the central plane is a mirror image of a layer on the opposite side of the central plane.

[0026] Figure 1A side view of an exemplary laminate 1000 is depicted, the laminate 1000 having: a first outer copper layer 1100; a second outer copper layer 1200; at least three polymer films 1300 disposed between the first outer copper layer 1100 and the second outer copper layer 1200; wherein adjacent polymer layers 1300.1, 1300.2, 1300.3 among the at least three polymer layers 1300 have different dielectric constants Dk values, different thicknesses, or preferably both different Dk values ​​and different thicknesses; wherein the first outer copper layer 1100, the second outer copper layer 1200, and adjacent layers among the at least three polymer layers 1300 are bonded to each other; and wherein the voltage breakdown strength of each polymer film 1300.1, 1300.2, 1300.3 among the at least three polymer films 1300 is equal to or greater than 200 kV / mm, or equal to or greater than 5 kV at a film thickness (T1, T2, T3) equal to 25 micrometers. Although only three polymer films 1300.1, 1300.2, and 1300.3 are depicted in the figures, it should be understood that the scope of the invention as covered by the appended claims is not so limited and covers any number of polymer films supported by the disclosure herein and suitable for the intended purposes disclosed herein.

[0027] For example, Figures 2A to 29 Figure 2M Multiple polymer films (without the aforementioned copper layers 1100, 1200) are depicted stacked on top of each other (which will be discussed further below).

[0028] As used herein, the terms dielectric constant Dk and relative dielectric constant ε are used interchangeably.

[0029] Reference Figure 1 For capacitors connected in series, each capacitor carries the same charge, such that:

[0030] Q T = Q1 = Q2 = Q3 (Equation 1)

[0031] in:

[0032] Q T = Total charge on at least three polymer films 1300;

[0033] Q1 = The charge on the first polymer film 1300.1 of at least three polymer films 1300;

[0034] Q2 = the charge on the second polymer film 1300.2 of at least three polymer films 1300; and

[0035] Q3 = The charge on the third polymer membrane 1300.3 of at least three polymer membranes 1300.

[0036] Applying Kirchhoff's voltage law to a closed loop, we obtain:

[0037] V T = V1 + V2 + V3 (Equation 2)

[0038] According to equation (2), distributing the applied voltage across multiple film layers can increase the breakdown voltage of multilayer materials. The dielectric strength of a particular film decreases with increasing thickness; therefore, if the voltage can be distributed across multiple film layers, the multilayer structure will have a higher breakdown voltage even with the same total thickness.

[0039] Simultaneously, the distributed voltage of each film layer can be optimally adjusted in multilayer composite materials. The capacitance C is given by:

[0040] Equation (3)

[0041] in:

[0042] A = Area of ​​the dielectric material in the multilayer capacitor;

[0043] ε o = Dielectric constant of the dielectric material of a multilayer capacitor in a vacuum;

[0044] ε γ = The relative permittivity of the dielectric material in multilayer capacitors; and

[0045] T = Thickness of the dielectric material in the multilayer capacitor.

[0046] By adjusting dielectric films with different dielectric constants, or by using dielectric films with different thicknesses, each layer can have a different capacitance C.

[0047] Given:

[0048] Equation (4)

[0049] in:

[0050] V = Voltage across the capacitor structure;

[0051] Q = the charge on each layer of the multilayer dielectric material in the capacitor structure; and

[0052] C = Capacitance of the capacitor structure.

[0053] According to equation (3), C is directly proportional to ε and inversely proportional to T.

[0054] According to equations (3) and (4), since each layer of the dielectric film in the capacitor structure has the same Q value, the Q value can be adjusted by changing the film thickness and / or the film's ε value. γ To adjust the capacitance C. A film with high dielectric strength can be designed to withstand a high voltage V.

[0055] In one embodiment, the volume resistivity of each of the at least three polymer films 1300.1, 1300.2, and 1300.3 is greater than 1 × 10⁻⁶. 15 Ω-m.

[0056] In one embodiment, each of the at least three polymer films 1300, 1300.1, 1300.2, 1300.3 has a similar dielectric constant Dk of less than 10 at 1 kHz and 23 °C (73 °F).

[0057] In one embodiment, each of the at least three polymer films 1300, 1300.1, 1300.2, 1300.3 has a similar loss factor Df of less than 0.005 at 1 kHz and 23 °C (73 °F).

[0058] In one embodiment, the thickness of each of the at least three polymer films 1300, 1300.1, 1300.2, 1300.3 is equal to or greater than 0.1 mil (2.5 μm) and equal to or less than 10 mil (125 μm).

[0059] In one embodiment, a first outer copper layer 1100, a second outer copper layer 1200, and at least three polymer films 1300 form a laminated stack 1400, wherein the laminated stack 1400 is bonded together or fused together.

[0060] In one embodiment, at least three polymer membranes 1300 are an odd number of polymer membranes 1300.1, 1300.2, and 1300.3, and are arranged symmetrically with respect to the central polymer membrane 1300.2 among the odd number of polymer membranes 1300.1, 1300.2, and 1300.3.

[0061] In one embodiment, each of the at least three polymer membranes 1300, 1300.1, 1300.2, and 1300.3, is a non-polar polymer membrane.

[0062] In one embodiment, each of the at least three polymer membranes 1300, 1300.1, 1300.2, and 1300.3, is a hydrolysis-resistant polymer membrane.

[0063] In one embodiment, each of the at least three polymer films 1300, 1300.1, 1300.2, 1300.3, is composed of any of the following materials: aromatic polyimide (PI); polyetheretherketone; polyetherimide; polysulfone; polyethersulfone; polyphenylene sulfide (PPS); polyethylene naphthalate (PEN); fluoroalkoxy resin (PFA, soluble polytetrafluoroethylene); liquid crystal polymer (LCP); or thermosetting resin: bismaleimide resin, bismaleimide-triazine resin, cyanate ester resin.

[0064] In one embodiment, one of the at least three polymer membranes 1300, polymer membranes 1300.1, 1300.2, 1300.3, comprises ceramic filler 1350.

[0065] In one embodiment, the ceramic filler 1350 preferably has the characteristics of low Dk, low Df, low electrical conductivity, and high thermal conductivity. Exemplary materials having such preferred characteristics include, for example, boron nitride (BN), alumina (Al2O3), and silicon dioxide (SiO2).

[0066] Table 1 below provides a list of representative material properties for BN, Al2O3, and SiO2.

[0067]

[0068] In one embodiment, a polymer film layer 1300.1, 1300.2, 1300.3 of the multilayer structure may have a nonwoven or woven reinforcing layer comprising organic or inorganic fibers, such as E-glass fiber, NE-glass fiber, aramid paper, mica paper, or nonwoven LCP fiber.

[0069] In one embodiment, at least three polymer layers 1300 are equal to or greater than three polymer layers and equal to or less than 1,000 polymer layers, or equal to or less than 250 polymer layers. For a given final laminate thickness, the number of polymer layers can be maximized based on the thickness and dielectric breakdown strength of each layer (see, for example, Figures 2A to 2B). Figure 2M ).

[0070] While Kirchhoff's voltage law provides a suitable analytical tool for analyzing the theoretical voltage and charge of capacitor structures, this theory does not address the reality of material impurities or defects that can negatively affect the performance of capacitor structures. However, the teachings presented in this paper can address such material impurities or defects to improve the performance of capacitor structures.

[0071] Having multiple thin polymer layers offers advantages over a single polymer layer of the same thickness. Multiple layers reduce the chance that pinholes, voids, porosity, or other defects (foreign particles, gels, fillers, or other agglomerates) can adversely affect the electrical breakdown performance of the dielectric film. Using multilayer polymer films helps to significantly eliminate the occurrence of defects that could extend across the total thickness of the dielectric layer, because the likelihood of overlapping defects in each individual layer is extremely small, and therefore defects in any one layer can be avoided. The probability of electrical failure occurring across the entire thickness of the dielectric is much lower.

[0072] Based on theory, the distribution of electrical stress can be reasonably altered to improve short-term breakdown strength. By systematically changing the interfacial barrier effect exhibited by the relative positions, layer thicknesses, number of layers, and interfacial properties of different films, the long-term electrical treeing that leads to breakdown can be inhibited.

[0073] In addition to high breakdown strength, preferred polymer films should also have dimensional stability, low isotropic coefficient of thermal expansion (CTE), high glass transition temperature, high thermal conductivity, hydrolytic stability, low moisture absorption, good thermal oxidation stability, and relatively stable dielectric constant and loss tangent over a wide temperature range.

[0074] Hydrolysis resistance minimizes susceptibility to aqueous acids and alkalis during printed circuit manufacturing. High thermal conductivity is also advantageous because heat is continuously generated within the insulator during operation. If the rate of heat generation exceeds the rate of heat dissipation, heat-induced polymer degradation may occur.

[0075] Aromatic polyimides (PI), polyetheretherketones (PEKs), polyetherimides, polysulfones, polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), and fluoroalkoxy resins (PFA) are examples of potentially useful hydrolysis-resistant polymer films. Films containing ceramic fillers have proven useful for heat dissipation and dimensional stability. Furthermore, the incorporation of nano / micron-sized ceramic fillers can improve dimensional stability, modulus, reduce the linear coefficient of thermal expansion, and minimize dimensional variations. In-plane residual stresses formed by different polymer films can be addressed by incorporating a certain amount of ceramic filler, for example, 1% to 10% by weight, or 1% to 20% by weight, and a maximum of 30% by weight. Additionally, by providing a nonwoven or woven reinforcing layer comprising organic or inorganic fibers for the multilayer structures disclosed herein, the overall coefficient of thermal expansion of the composite material can be reduced, which contributes to improved dimensional stability and modulus of the laminate.

[0076] The bonding layer mitigates the high hygroscopicity of PI, thereby reducing the likelihood of increased dielectric loss and reduced dielectric strength due to absorbed moisture.

[0077] In one exemplary embodiment, a multilayer composite substrate comprising alternating layers of PI film and PFA film is fabricated using a laminating press. Heat and pressure are applied to fuse the film layers together. The choice of films provides a relative permittivity difference of approximately 1.5 units, specifically 3.5 versus 2.0. In both experiments, layers of type 1035 E-glass fabric with thin coatings of polytetrafluoroethylene (PTFE) and fluorinated ethylene propylene (FEP) are incorporated as reinforcement. Details of the exemplary multilayer structure are shown in Figures 2A to 2B. Figure 2M As shown in the schematic diagram.

[0078] Lamination is performed using a pressure of 350 psi and a final platen temperature of 320°C. PFA, which melts in the temperature range of 302°C to 310°C, acts as the bonding medium for the PI layers. PFA bonds well with the relatively smooth copper foil, another advantage being that charge tends to concentrate on the sharp protrusions of a rough conductor surface.

[0079] exist Figures 3 to 5 The breakdown voltages of three different hybrid structures disclosed herein are presented, demonstrating improved breakdown voltages compared to pure PI and pure PFA of the same thickness. As depicted, datasheets for certain pure PI and pure PFA materials are plotted using empirical data and extrapolated to larger thicknesses and higher breakdown voltages, while test data for the hybrid structures are also plotted. As can be seen, according to one embodiment disclosed herein, each hybrid structure exceeds the extrapolated breakdown voltage of pure PI or pure PFA of the same thickness. Furthermore, the improvement in breakdown voltage increases with increasing PI volume fraction. Given that the dielectric strength of PI is expected to be higher than that of PFA, and that higher voltages are distributed to the PI layer rather than the PFA layer, this can be achieved by designing the thickness of each polymer film and using different polymer films (e.g., ABCDCBA; for a more complete grouping of different polymer films, see Figures 2A to 2B). Figure 2M The overall structure can therefore withstand higher breakdown voltages. Although Figure 2A to Figure 2M One arrangement of different polymer films is depicted, but it will be understood that other arrangements are possible and have been conceived herein. For example, a layered arrangement of materials A-B1-B2-C-B2-B1-A is conceived, where A, B, and C are different polymer film materials disclosed herein, and where B1 and B2 are polymer film materials of different thicknesses (see, for example, [link to relevant documentation]). Figure 1 (where material-A is denoted by 1300.1, material-B by 1300.2, and material-C by 1300.3). Any and all such layered arrangements are contemplated and are considered to be at least inherently (if not explicitly) disclosed herein.

[0080] The assessment included Figures 2A to 29. Figure 2M The wide range of materials described herein. These polymer films have similar relative permittivity (PI: 3.4, PPS: 3.0, PEN: 3.2, LCP: 3.3). Thermosetting resin systems (TRs) comprising poly(styrene-butadiene-styrene) (SBS), polyphenylene ether (PPE), and the crosslinking agent triallyl isocyanurate (TAIC) exhibit a relative permittivity of 2.4.

[0081] The studied multilayer structure confirms the improved breakdown voltage, which in Figures 3 to 5 As shown in Figures 2A to 2B. Figure 2M Several laminated structures utilize PI films and bonded films (PPS, PEN, and LCP) of varying thicknesses. The interlayer bonding strength in multilayer structures plays a favorable role in breakdown strength. Optimizing the configuration of the interlayer structure improves layer-to-layer adhesion, thus increasing breakdown voltage. Good interlayer bonding reduces defects such as cracks, cavitation, and delamination, thereby improving electrical insulation properties. In contrast, the surface energy of TRs, which differs significantly from PI and LCP polymer films, results in poor interlayer adhesion and no improvement in breakdown voltage.

[0082] The short-time breakdown voltage measurement value is plotted according to ASTM D-149 Method-A. Figures 3 to 5 The figures in the diagram show that all multilayer substrates withstood over 30,000 volts (AC). Furthermore, the multilayer structures exhibited breakdown voltages exceeding extrapolated values ​​for pure polymer films of considerable thickness. As used herein, the term "pure" is the art's term meaning a polymer film composed solely of the defined polymer material.

[0083] Reference Figure 6 and Figure 7 , combined Figure 1 In one embodiment, any application of the laminate 1000 disclosed herein and falling within the scope of the appended claims includes an arrangement in which the first outer copper layer 1100 and the second outer copper layer 1200 are constructed and configured to form segments or the entire capacitively coupled induction coil 2000. In one embodiment, the induction coil 2000 is formed by appropriately patterning the first outer copper layer 1100 and the second outer copper layer 1200 to form conductors, for example... Figure 7The A conductor and B conductor are depicted on laminates 1000.1 and 1000.2, and then a plurality of laminates 1000.1 and 1000.2 with patterned conductors are stacked to produce an induction coil 2000. In one exemplary embodiment of the stack of the plurality of laminates 1000.1 and 1000.2 in the coil 2000, the A conductor and B conductor alternate with each other in an arrangement of stacked ABAB conductor layers or BABA conductor layers. In another exemplary embodiment, the A conductors are electrically connected to each other via electrical path 500A, and the B conductors are electrically connected to each other via electrical path 500B.

[0084] Although specific combinations of individual features have been described and illustrated herein, it will be understood that these specific combinations of features are for illustrative purposes only, and any combination of any such individual feature may be employed according to the embodiments, whether or not such combinations are explicitly stated, and any combination of any such individual feature is consistent with the disclosure herein. Any and all such combinations of features disclosed herein are contemplated and are considered to be within the understanding of a person skilled in the art when the application is considered as a whole, and are considered to be within the scope of the invention disclosed herein, provided that they fall within the scope of the invention as defined by the appended claims in a manner that would be understood by a person skilled in the art.

[0085] Although the invention has been described herein with reference to exemplary embodiments, those skilled in the art will understand that various changes may be made and elements may be substituted with equivalents without departing from the scope of the claims. Various modifications may be made to adapt particular situations or materials to the teachings of the invention without departing from the essential scope of the invention. Therefore, it is intended that the invention be limited to one or more specific embodiments disclosed herein as the best or only mode contemplated for carrying out the invention, but rather that the invention encompass all embodiments falling within the scope of the appended claims. Exemplary embodiments have been disclosed in the drawings and description, and although specific terminology and / or dimensions may be used, they are used in a general, exemplary, and / or descriptive sense only, and not for limiting purposes, unless otherwise stated, and therefore the scope of the claims is not limited thereto. When an element, such as a layer, film, region, substrate, or other described feature, is referred to as "on another element" or "joined with another element," it may be directly on or joined with other elements, or intermediate elements may be present. In contrast, when an element is referred to as "directly on another element" or "directly joined with another element," no intermediate elements are present. The use of the terms "first," "second," etc., does not indicate any order or importance, but is used to distinguish one element from another. The use of the terms "a," "an," etc., does not indicate a limitation of quantity, but indicates the presence of at least one referred item. The use of the terms "top," "bottom," "upper," "lower," "left," "right," "front," "back," etc., or any reference to orientation, does not indicate a limitation on the structure, as the structure can be observed from more than one orientation; therefore, it indicates a relative structural relationship between one or more associated features as disclosed herein. The term "comprising," as used herein, does not exclude the possibility of including one or more additional features. Furthermore, any background information provided herein is intended to disclose information that the applicant believes may be relevant to the invention disclosed herein. It is not necessary to intentionally acknowledge, nor should it be interpreted, that any such background information constitutes prior art to one embodiment of the invention disclosed herein.

[0086] In view of all the foregoing, it will be understood that various aspects of the implementation scheme are disclosed herein, based on, but not limited to, at least the following aspects and / or combinations thereof.

[0087] Aspect 1: A laminate comprising: a first outer copper layer; a second outer copper layer; a multilayer structure comprising at least three polymer films disposed between the first outer copper layer and the second outer copper layer; wherein adjacent polymer layers among the at least three polymer layers have different dielectric constants Dk and different thicknesses, or preferably have both different Dk values ​​and different thicknesses; wherein the first outer copper layer and the second outer copper layer and adjacent layers among the at least three polymer layers are bonded to each other; wherein each polymer film among the at least three polymer films has a voltage breakdown strength equal to or greater than 200 kV / mm, or equal to or greater than 5 kV at a film thickness of 25 micrometers.

[0088] Aspect 2: The laminate according to Aspect 1, wherein: the volume resistivity of each of the at least three polymer films is greater than 1 × 10⁻⁶. 15 Ω-m.

[0089] Aspect 3: A laminate according to any one of Aspects 1 to 2, wherein: each of the at least three polymer films has a similar dielectric constant of less than 10 at 1 kHz and 23 °C (73 °F).

[0090] Aspect 4: A laminate according to any one of Aspects 1 to 3, wherein: each of the at least three polymer films has a similar loss factor of less than 0.005 at 1 kHz and 23 °C (73 °F).

[0091] Aspect 5: A laminate according to any one of Aspects 1 to 4, wherein: the thickness of each of the at least three polymer films is equal to or greater than 0.1 mil (2.5 μm) and equal to or less than 10 mil (125 μm).

[0092] Aspect 6: A laminate according to any one of Aspects 1 to 5, wherein: the first outer copper layer, the second outer copper layer and the at least three polymer films form a laminated stack; wherein the laminated stack is bonded together or fused together.

[0093] Aspect 7: A laminate according to any one of Aspects 1 to 6, wherein: the at least three polymer films are an odd number of polymer films and are arranged symmetrically with respect to the central polymer film among the odd number of polymer films.

[0094] Aspect 8: A laminate according to any one of Aspects 1 to 7, wherein: each of the at least three polymer films is a nonpolar polymer film.

[0095] Aspect 9: A laminate according to any one of Aspects 1 to 7, wherein: each of the at least three polymer films is a hydrolysis-resistant polymer film.

[0096] Aspect 10: The laminate according to Aspect 9, wherein: each of the at least three polymer films is composed of any of the following materials: aromatic polyimide (PI); polyetheretherketone; polyetherimide; polysulfone; polyethersulfone; polyphenylene sulfide (PPS); polyethylene naphthalate (PEN); fluoroalkoxy resin (PFA); liquid crystal polymer (LCP); thermosetting resin; bismaleimide resin; bismaleimide-triazine resin; or cyanate ester resin.

[0097] Aspect 11: A laminate according to any one of Aspects 1 to 10, wherein: one of the at least three polymer films comprises a ceramic filler.

[0098] Aspect 12: The laminate according to Aspect 11, wherein: the ceramic filler has a Dk value equal to or greater than 3 and equal to or less than 11, a DF value equal to or greater than 0.0001 and equal to or less than 0.005, a resistivity value equal to or greater than 10^10 ohm-m and equal to or less than 10^20 ohm-m, and a resistivity value equal to or greater than 1 W / m K is equal to or less than 200 W / m The thermal conductivity value of K.

[0099] Aspect 13: The laminate according to aspect 12, wherein: the ceramic filler comprises any one or a mixture of the following: SiO2, Al2O3 and BN.

[0100] Aspect 14: A laminate according to any one of Aspects 1 to 13, wherein: one layer of the multilayer structure comprises a nonwoven or woven reinforcing layer, the nonwoven or woven reinforcing layer comprising organic or inorganic fibers.

[0101] Aspect 15: The laminate according to aspect 14, wherein: one layer comprises E-glass fiber, NE-glass fiber, aramid paper, mica paper or nonwoven LCP fiber.

[0102] Aspect 16: A laminate according to any one of Aspects 1 to 15, wherein: the at least three polymer films are equal to or greater than three polymer films and equal to or less than 1,000 polymer films.

[0103] Aspect 17: The laminate according to aspect 16, wherein: the at least three polymer films are equal to or less than 250 polymer films.

[0104] Aspect 18: A laminate according to any one of Aspects 16 to 17, wherein: each of the at least three polymer films has a thickness equal to or greater than 0.1 mil and equal to or less than 17 mil.

[0105] Aspect 19: A laminate according to any one of Aspects 1 to 18, wherein: the at least three polymer films are arranged symmetrically with respect to a central plane, the central plane bisecting the at least three polymer films along a plane parallel to the at least three polymer films.

[0106] Aspect 20: A laminate according to any one of Aspects 1 to 19, wherein: the at least three polymer films comprise an odd number of polymer films.

[0107] Aspect 21: A laminate according to any one of Aspects 1 to 19, wherein: the at least three polymer films comprise an even number of polymer films.

[0108] Aspect 22: The laminate according to any one of aspects 1 to 21, wherein: the first outer copper layer and the second outer copper layer are constructed and configured to form a capacitively coupled induction coil.

[0109] Aspect 23: A capacitively coupled induction coil comprising: one or more laminates according to any one of aspects 1 to 22; wherein respective first and second outer copper layers are constructed and configured to form a capacitively coupled induction coil.

Claims

1. A laminate, comprising: First outer copper layer; Second outer copper layer; A multilayer structure comprising at least three polymer films disposed between the first outer copper layer and the second outer copper layer; The adjacent polymer layers in the at least three polymer layers have different dielectric constants Dk and different thicknesses, or preferably have both different Dk values ​​and different thicknesses. The first outer copper layer and the second outer copper layer, as well as adjacent layers of the at least three polymer layers, are bonded to each other; The voltage breakdown strength of each of the at least three polymer films is equal to or greater than 200 kV / mm, or equal to or greater than 5 kV at a film thickness of 25 micrometers.

2. The laminate according to claim 1, wherein: The volume resistivity of each of the at least three polymer films is greater than 1×10⁻⁶. 15 Ω-m.

3. The laminate according to any one of claims 1 to 2, wherein: Each of the at least three polymer films has a similar dielectric constant of less than 10 at 1 kHz and 23 °C (73 °F).

4. The laminate according to any one of claims 1 to 3, wherein: Each of the at least three polymer films has a similar loss factor of less than 0.005 at 1 kHz and 23 °C (73 °F).

5. The laminate according to any one of claims 1 to 4, wherein: The thickness of each of the at least three polymer films is equal to or greater than 0.1 mil (2.5 μm) and equal to or less than 10 mil (125 μm).

6. The laminate according to any one of claims 1 to 5, wherein: The first outer copper layer, the second outer copper layer, and the at least three polymer films form a laminated stack. The laminated stacks are bonded together or fused together.

7. The laminate according to any one of claims 1 to 6, wherein: The at least three polymer films are an odd number of polymer films and are arranged symmetrically with respect to the central polymer film among the odd number of polymer films.

8. The laminate according to any one of claims 1 to 7, wherein: Each of the at least three polymer films is a nonpolar polymer film.

9. The laminate according to any one of claims 1 to 7, wherein: Each of the at least three polymer membranes is a hydrolysis-resistant polymer membrane.

10. The laminate according to claim 9, wherein: Each of the at least three polymer films is composed of any of the following materials: aromatic polyimide (PI); polyetheretherketone; polyetherimide; polysulfone; polyethersulfone; polyphenylene sulfide (PPS); polyethylene naphthalate (PEN); fluoroalkoxy resin (PFA); liquid crystal polymer (LCP); thermosetting resin; bismaleimide resin; bismaleimide-triazine resin; or cyanate ester resin.

11. The laminate according to any one of claims 1 to 10, wherein: One of the at least three polymer films contains a ceramic filler.

12. The laminate according to claim 11, wherein: The ceramic filler has a Dk value equal to or greater than 3 and equal to or less than 11, a DF value equal to or greater than 0.0001 and equal to or less than 0.005, a resistivity value equal to or greater than 10^10 ohm-m and equal to or less than 10^20 ohm-m, and a W / m value equal to or greater than 1. K is equal to or less than 200 W / m The thermal conductivity value of K.

13. The laminate according to claim 12, wherein: The ceramic filler includes any one or a mixture of the following: SiO2, Al2O3, and BN.

14. The laminate according to any one of claims 1 to 13, wherein: One layer of the multilayer structure includes a nonwoven or woven reinforcing layer comprising organic or inorganic fibers.

15. The laminate according to claim 14, wherein: The layer comprises E-glass fiber, NE-glass fiber, aramid paper, mica paper, or nonwoven LCP fiber.

16. The laminate according to any one of claims 1 to 15, wherein: The at least three polymer films are equal to or greater than three polymer films and equal to or less than 1,000 polymer films.

17. The laminate according to claim 16, wherein: The at least three polymer films are equal to or less than 250 polymer films.

18. The laminate according to any one of claims 16 to 17, wherein: Each of the at least three polymer films has a thickness equal to or greater than 0.1 mil and equal to or less than 17 mil.

19. The laminate according to any one of claims 1 to 18, wherein: The at least three polymer films are arranged symmetrically with respect to a central plane, which bisects the at least three polymer films along a plane parallel to the at least three polymer films.

20. The laminate according to any one of claims 1 to 19, wherein: The at least three polymer films comprise an odd number of polymer films.

21. The laminate according to any one of claims 1 to 19, wherein: The at least three polymer films comprise an even number of polymer films.

22. The laminate according to any one of claims 1 to 21, wherein: The first and second outer copper layers are constructed and configured to form a capacitively coupled induction coil.

23. A capacitively coupled induction coil, comprising: One or more laminates according to any one of claims 1 to 22; The corresponding first and second outer copper layers are constructed and configured to form a capacitively coupled induction coil.

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