093 ±0. 018;. RF-35TC offers a "best in class" low dissipation factor with high thermal conductivity. Utilizing extended technology for higher performance, CLTE-XT laminates are ceramic/PTFE microwave composites that provide. 00 310 at 10 kHz. The loss equation also says that you can't reduce dielectric loss by changing the cable geometry, like you can with conductor loss. The PTFE loaded with 0. However, the main disadvantage of PTFE is the negative temperature coefficient of dielectric constant (τ ε ∼-400 ppm/°C) making it difficult to be used in microwave circuit devices. It is a hemispherical skin of microwave-transparent material of radius R and thickness t, supporting a pressure difference, Δp between its inner and outer surfaces. 1. 1, the maximum value of loss tangent (ε 00 ) is confirmed at approximately 4 MHz, whereas it decreases at values above 4 MHz. Megtron 6 provides designers significant benefits in system performance for telecommunications applications, routers/switching equipment, high-speed transfer and computing applications. 6 (c)), which was due to the porous structure formed by the volatilization of additives during sintering. 5°, 21. They will. 009: BETTER Dielectric Constant 3. fre- Moisture absorption significantly influences electrical properties of the composite since water has high dielectric constant and loss tangent. Table 3-Dielectric Properties Vs. The low dielectric constant and low loss tangent make SiO 2 a very low-loss material for microwaves. This type of PCB stackup is suitable for. The scanned data may also be saved on disk. 0035 at 100 Hz. The formula to calculate the dissipation factor of an insulator is as follows: Where: DF is the dissipation factor or loss tangent; δ is the phase angle between the voltage and current waveforms in the insulator; I R is the resistive current; I C is the. Besides dielectric constant, α-PVDF also shows a larger dielectric loss than β-PVDF and γ-PVDF at low frequency (ranging from 100 Hz to 1 kHz). 004 to 0. 8 THz. 8. RO3003™ laminates consist of PTFE with ceramic filler. Thermally, solid PTFE dielectrics have a sharp knee in their CTE profile around room temperature. 0017 — Bereskin Stripline Volume Resistivity C-96/35/90 1. RT/duroid® 5870 and 5880 glass microfiber reinforced PTFE composites are designed for exacting stripline and mi crostrip circuit applications. The values from the associated chart are obtained by the analysis of both the moulding and extrusion process. Among these polymers, polytetrafluoroethylene (PTFE) has caused concern of the industry and academia, due to its excellent dielectric properties such as low permittivity, extremely low loss tangent [1, [5], [6], [7]]. 15 to 4. Rogers offers a wide variety of materials used for high-frequency PCBs with a relative permittivity ranging from 2. 0010 to 2. • Pores in composites and agglomeration of. This can be further understood by referring below to the dis-cussions on moisture absorption and anisotropy. The effect of surface treatment on the morphology, thermal conductivity and dielectric properties of PTFE-based composites is investigated. Among the polymers, polytetrafluoroethylene (PTFE) is the most preferred host matrix that exhibits excellent dielectric properties such as low permittivity (ε r = 2. ), and a. SFR can be applied to low-roughness copper foil, whereas PTFE can only. 2. quality factor. In loss tangent AFM, the AFM cantilever is excited, similar to amplitude modulation AFM (also known as tapping mode); however, the observable aspects are used to extract dissipative and conservative energies per cycle of oscillation. This stability also includes the elimination of the step change in Dk that typically occurs near room temperature with PTFE glass materials. 4. The glass-transition temperature of PTFE is high and falls between 160-280˚C. 0035 at 100 Hz. 2. The more common compounded PTFE grades are filled with glass fibre, bronze, graphite, carbon. But it also has certain disadvantages like high coefficient of thermal expansion (∼109 ppm/°C) and inferior dimensional stability [4] , [5] . The dielectric performances of the composite were investigated within the frequency range from 100 Hz to 1 MHz. Polytetra uoroethylene (PTFE) has an extremely low dielectric constant and dielectric loss tangent among uoropolymers, as well as excellent chemical resistance, weather resistance, and heat. The data in Chart 2 shows the distribution of dissipation factor for RO3003 and RO3035 materials. and it influences cost of devices. Eccostock LoK is a low dielectric constant, low loss and low weight thermosetting plastic for RF and microwave insulation. PTFE 2. The ratio of dissipation to stored energy is defined as tanδ. 6dB/in @ 56GHz 50GHz • Megtron 6 25dB loss is 12. The dielectric loss tangent of the hBN/PTFE/PDMS composites with (a) no hBN, (b) no PTFE, (c) hBN 40 vol% and (d) PTFE 40 vol% at 18. 2. It doesn't mean that you don't have this property in any other types of circuit. in terms of the loss tangent • Loss increases directly proportional to frequency 30 C G D. Thickness of . 0003 which is stable over a wide range of frequencies [5]. ties such as stable dielectric constant, low loss tangent, and good chemical resistance. The results of these tests at 1 KHz, 1 MHz, and. Measurements on PTFE versus frequency have shown that for this material both real part of permittivity and dielectric loss tangent are practically constant in frequency range of 100 MHz-20 GHz. One of the recently developed characterization techniques is known as loss tangent. However, the changes of the electrical property (including dielectric constant and loss tangent) are complex and hard to be obtained and analyzed. Signal Clarity. 5. In an ideal capacitor without any dielectric losses, the insulation current is exactly 90° leading according to the applied voltage. The density, dielectric constant, loss tangent, moisture absorption and ultimate tensile strength of the composite systems under study are complied in Table 1. It is observed that G ′ and G ″ increased at different PTFE concentrations as ω increasing from 0. Loss Tangent (Df) ASTM D2520: 10 GHz: 0. 20%), with the actual measured value ranging from 2. ( CC BY-SA 4. Radar and satcom signal clarity is a complex function of design and material. PTFE is known as non-absorbent (k close to 0), its relative permittivity n=2. Likewise, relative permittivity is the ratio of the capacitance of a capacitor using that material as a dielectric, compared with a similar capacitor that has vacuum as its dielectric. 2 dB with a thickness of 2. 8 mg, which is 47% less than that of 3. Its density is around 2. Hence, in this paper, PTFE and spherical CNT were chosen as polymer matrix and ceramic filler, respectively. 1 Understanding Dielectric Constant and Loss tangent on Radome and Antenna Design Loss Tangent =. 4 a–b. 2 Radome Design Elements. 012 at 1 MHz, respectively. Sci. Industry leading dielectric constant & thickness tolerance for commercial PTFE materials. Low-loss, high frequency advanced materials with well-controlled dielectric properties to enable microwave and RF applications, including mobile networks. It is the ratio of the conduction current to the displacement current. 5 THz to a maximum value of 0. 0015” (. Loss tangent: '' tan C ' es d e we == (6. 3 Properties under impact stress 40 3. Ceram. PTFE is chosen as polymer matrix because of its excellent dielectric properties (low relative permittivity∼2. S2 . The radome material choice, such as fiberglass, PTFE-coated fabric, and polycarbonate, is generally dependent on the targeted application environmental use. Low-loss, high frequency advanced materials with well-controlled dielectric properties to enable microwave and RF applications, including mobile networks. Loss tangent can be calculated using the following formula:. 1 0. 2: Loss tangent defined in terms of the real and imaginary components of the complex permittivity [Math Processing Error] ϵ c. 009 to 0. which are ideal for most of the electronic applications [11]. 33 x 107 MΩ-cm 2. 5 THz to 0. Effect of membrane wetting on the performance of PVDF and PTFE membranes in the concentration of pomegranate juice through osmotic distillation. Polyetheretherketone is ahigh performance thermoplastic that is strong, stiff, hard and has high temperature resistance. Using PEC as a material with infinite. 2. Polytetrafluoroethylene (PTFE) polymer is an example of a linear fluoropolymer. 4. 02 and a loss tangent of 0. The conclusions demonstrate that the method of surface fluorination of glass fibers offers. 08E ⁻⁴ ), higher bending strength (21. % untreated SiO 2 filled PTFE composite has a dielectric constant of 2. 045 (2. 5" 0. Values presented here are relative dielectric constants. constant of 2. 1 and a loss tangent<0. Toray's electrically pure, low-loss materials and syntactics ensure maximum radome efficiency. 045 (2. 100 ±0. 1 and low loss tangent because of the neutralization of dipole moment exhibited by C-F bonds. Permeability (electromagnetism) In electromagnetism, permeability is the measure of magnetization produced in a material in response to an applied magnetic field. with PTFE glass materials. 2. 00155 whereas for nano Sm2Si2O7 composites with same volume fraction the values. Membr. 60, low electrical loss of tan δ from 0. 2. PTFE-based laminates, spread glass laminates, or other specialized material systems are a good choice to support larger high speed digital boards, where routes are very long and low. 35 40 0. The increment in complex permittivity with increasing rFe 2 O 3 nanofiller can be attributed to the polarization process due to the enhanced conductivity and interfacial polarization in the composite and hopping exchange of charges between localized states [ 23 ]. 005-0. 37 shows an idealized radome. Mechanically, low loss, low density dielectrics are nearly as compression. Polytetrafluoroethylene (PTFE) is a totally fluorinated polymer which is white, semi-opaque, and semi-crystalline. 3 and 0. comThe dielectric constant (Dk) of a plastic or dielectric or insulating material can be defined as the ratio of the charge stored in an insulating material placed between two metallic plates to the charge that can be stored when the insulating material is replaced by vacuum or air. 1 and loss tangent as low as 0. The microwave dielectric properties of ZrTi2O6/PTFE composites were measured using stripline resonator method. 0017 is employed. In all materials, the loss tangent tanδ = ε″/ε′ was between 0. The dielectric loss angle tangent (tan δ) of the PTFE composite also showed an increasing trend with the filler content. The loss tangent is given by:. The quantity ( andelta) is referred to as the loss tangent. PTFE-based composites are widely used for the fabrication of microwave circuit boards [3], [4]. PTFE and PES Structure, Electrical Properties and Test Method Prior to the evaluation of different formulation strategies to develop a new low loss material, the first step involves a thorough evaluation and understanding of the loss measurement test methodLow dielectric loss (RO3003™ laminates) • Laminates can be used in applications up to 77 GHz. View attachment 75187 Ideal may be quartz over alumina or ceramic substrate in non PTFE materials which are predicted to triple in next few years, but you did not specify budget constraints. Rigid PCB Copper Clad Laminate is also known as PCB laminate is a kind of substrate material used in PCBs containing a tiny layer of copper lamination on any side (single CCL) or both sides (double CCL) of the PCB. 1, low dielectric loss tangent∼10 −4) and excellent thermal stability [19]. In ferroelectric materials, dielectric constant is high due to spontaneous polarization similar to. 5. Both twisting and bending lead to structural deformation, namely the density distribution change of the PTFE SCPDW at the bending section, which affects the dielectric constant and loss tangent. The PTFE/CNT (1 wt%) composite nanofiber membrane displayed an optimal reflection loss of −53. PTFE or Polytetrafluoroethylene is a versatile and high-performance fluoropolymer made up of fluorine and carbon atoms and is highly used as a non-stick coating in kitchen. How-ever, disadvantages of PTFE substrate include a high linear coefficient of thermal expansion (CTE) and low surface en-ergy. These microwave dielectric constant and loss tangent determined by different protocols were summarized in Table 10 [67]. Example 6-layer stackup with a PTFE laminate on the outer layer and FR4 laminates on inner/bottom layers. 0010 to 2. traditional PTFE substrates. PTFE laminates are a specialty material despite. The channel geometry will also determine losses, but generally opting for a lower loss tangent FR4 laminate is a good place to start in smaller boards. 18), and decreased dielectric loss (0. 009 to 0. Dielectric loss is due to lag of polarization with a. 45 MPa) and bending modulus (522 MPa), better thermal. Polytetrafluoroethylene (PTFE) has an extremely low loss tangent (tan δ = 0. The composites possess great thermal conductivity and high bending strength. 04 Df 0. For very low loss materials, since tan d ≈ d, the loss tangent can be expressed in angle. Another blended polymer prepared from PEEK and PTFE (PEEK/PTFE-5) possessed a dielectric constant of 3. For example, loss tangent of HRFZ-Si with resistivity 10 kOhm*cm at 1 THz is 1. The effect of surface treatment on the morphology, thermal conductivity and dielectric properties of PTFE-based composites is investigated. The core materials that they provide constitute properties of high frequency like Teflon (PTFE). Rogers RO3000 high frequency circuit materials are ceramic-filled PTFE composites intended for use in commercial microwave and RF applications. The permittivity and loss tangent of the blends up to 40 MHz are studied using a Precision. 5. "FR" stands for "flame retardant", and does not denote that the material complies with the standard UL94V-0 unless testing is performed. The relative dielectric constant (ε r) and loss tangent (tanδ) of the composites increase with an increase of the volume fraction of ZrTi2O6. Good dielectric properties with values of εr = 11. TC600 laminates best-in-class thermal conductivity and mechanical robustness enable printed circuit board (PCB) size reduction. 008 87 Loss modulus (MPa) 336 ±70 375 ±83 Evaporation PTFE Panel. PTFE has a lower dielectric constant (Dk) and loss tangent (Df) than commonly used low-loss thermoset materials. , the maximum dielectric loss tangent is 0. These materials have lower loss tangent than FR4 materials, so signals can travel farther without attenuating and still fall within acceptable margins. 1 through 5. This is first, because the low dissipation factor of the dielectric itself reduces attenuation, especially at higher frequencies, and second the low dielectric constant of a microporous dielectric allows the use of a larger. 4 times higher dielectric loss tangent and effective relative dielectric permeability compared to unmodified. FR-4 (or FR4) is a NEMA grade designation for glass-reinforced epoxy laminate material. The dissipation factor is the tangent of the loss angle of the insulating material. This paper presents a complete set of experimental data consisting of storage modulus, tan δ, loss modulus, relaxation modulus and creep compliance for these materials under isothermal. This may be attributed to the non-uniform distribution of conductive particles. 1, we see loss tangent can equivalently be calculated as. Ca 0. Materials with a low loss tangent and low relative permittivity are essential for the next. 224 ± 0. SFR can be applied to low-roughness copper foil, whereas PTFE can only be used with ordinary copper foil due to its poor adhesion to the low-roughness type. The dielectric loss which is also an important parameter for the circuit application of composite substrates was affected by the loss tangent of each component and the manufacture process. The lower the dissipation factor, the more efficient is the insulator system. 21 and dielectric loss of 6. PTFE-based ceramic-polymer dielectric composites have been widely researched in the communication field due to their good processing, wide range frequency and temperature stability and being able to provide tunable dielectric constant in a scale. 5 RT Duroid RT Duroid is Glass Microfiber Reinforced PTFE (polytetrafluoroethylene) composite produced by Roger Corporation. When the testing frequency is increased to 1 kHz, β-PVDF. 5. The fiberglass reinforced TLY-3FF has been engineered to provide the dimensional stability typical of the standard fiberglass reinforced TLY Series yet offers the mechanical flexibility of chopped fiber reinforced laminates. 11 at 3. Generally, the loss in a material is expressed in terms of the loss tangent, tanδ= ²00r ²0 r. View PDF View article View in Scopus Google. Because RO4350B is processed using a standard epoxy resin/glass (FR-4) process, it also has a low line processing cost. Example: what is the skin depth and loss tangent in bottom round steak at microwave oven frequencies (2. 0007 1017 1018-1019 Polytetrafluoroethylene filled with Glass PTFE 25% GF - 2. The dielectric loss increases with increasing values of Df. , their dielectric constants are not dependent of the frequency as electronic polarization is instantaneous regardless of frequency. 4 for all desired frequencies. 2. 6 ppm per °C). 85*10-12 F/m), ε 0 - dielectric. 5mm Gate: >1mm or 0. Variation of density and dielectric constant with respect to weight fraction of fused silica in the PTFE matrix is shown in Fig. However, the application of PTFE was hindered by its high CTE (∼400 ppm/ o C) due to its room temperature phase transformation. PTFE has become the material of choice where low friction, excellent thermal properties, chemical inertness, and exceptional dielectric properties are required. Unlike PTFE based high performance materials, RO4000 series laminates do not require specialized via preparation processes such as sodium etch. The basic reason for the relatively high loss tangent exhibited by. 0; C. The effect of surface treatment on the morphology, thermal conductivity and dielectric properties of PTFE-based composites is investigated. This material is best suited for high power applications where every 1/10th of a dB is critical and the PWB substrate is expected to diffuse heat away from both transmission lines and surface mount components such as transistors or. Low loss, low density dielectrics typically range in dielectric constant from 1. 4 THz. Solid PTFE has a dielectric constant of 2. Electronics 2014, 2 316 Table 1. Roy J. A work was reported on the moisture absorbance of PTFE/Micron-rutile and PTFE/Nano-rutile composites. 0009 to 0. Again, referring to Table 1, four types of PTFE-based materials are considered in this paper; pure PTFE, PTFEGM (glass filled), T05 and T99. The surface of SrTiO 3 powders were successfully coated by silane coupling agent (vinyltrimethoxysilane, VTMS). 8 and have a loss tangent of 0. Ellingson ( Virginia Tech Libraries' Open Education Initiative) . 14 and frequency f in Hz. moulding medium viscosity acetal resin for injection moulding. The only way you can reduce it is to use a dielectric with a very low loss tangent, or low dielectric constant. The values from the associated chart are obtained by the analysis of both the moulding and extrusion process. LaminateR-5785(N)/Prepreg R-5680(N) The ultra-low dielectric constant (Dk) and dissipation factor (Df) make MEGTRON 7 ideal for high speed and large data volumes associated with servers and routers required for 5G. School of Materials Science and Engineering, State Key Lab Silicon Mat, Zhejiang University, Hangzhou, 310027 People's Republic of China. Fig. Meanwhile, the dielectric constant and dielectric loss of PTFE/CNT (5 wt%) nanofiber membranes are 58. signal and includes both dielectric and dc-conductivity losses. 3): (2. A 0. 1 Fabrication of the composite. The result is a low loss material which can be fabricated using standard epoxy/glass (FR-4) processes offered at a competitive price. tan (δ) or Df is the result of electromagnetic wave absorption by the dielectric. Loss Tangent: A. Among these polymers, polytetrafluoroethylene (PTFE) has caused concern of the industry and academia, due to its excellent dielectric properties such as low permittivity, extremely low loss tangent [1, [5], [6], [7]]. Lower Z-Direction CTE than traditional PTFE woven-glass laminates. Dielectric constant (Dk) of 2. For example, teflon (a. Loss Tangent (RC64%) 10 GHz (SPC method) 0. 5. 5 Coefficient of Thermal Expansion 19 15 X ppm/˚C --55˚C to 288˚C IPC TM-650 2. 1) Specification Sheet (see 1. As illustrated in Fig. Among these, PTFE is the most preferred matrix for microwave applications because of its low loss tangent, stable dielectric constant, good chemical resistance and high operating temperature. Thus,. 0014-. 25 vf micro Sm2Si2O7 composites showed a relative permittivity and dielectric loss of 3. Other properties such as electrical, mechanical, physical, thermal and chemical resistance are listed as well as properties particular to the various forms such as films, fibres a. Tefzel® can be extruded or injection molded easily, using conventional techniques, and thus presents no unusual operator training. Polytetrafluoroethylene exhibited the typical dielectric behavior of a nonpolar substance: no dielectric loss peak was found over the experimental range of temperature and frequency. 2 (PTFE) and 9. The dielectric constant and dielectric loss of the CLST/PTFE composites were measured by using a vector network analyzer (Agilent, HP8722ET, America) at 10 GHz. Using precision control of the fiberglass/PTFE ratio, CuClad laminates offer a range of choices from the lowest dielectric constant and loss tangent to a more highly reinforced laminate with better dimensional stability. The results of these tests at 1 KHz, 1 MHz, and 9. Resonac believes these properties are greatly affected by the difference in scattering loss. Loss tangent: This is the first major area that PCB designers will use to start comparing material options. See. RO3010 laminates are competitively priced products with exceptional mechanical and electrical stability. ThunderClad 3+’s electrical performance is competitive with PTFE-based, hydrocarbon-based very low loss materials, but capable for high layer count circuit board design with excellent thermal reliability. The ε of the PTFE composite film (PTFE/BN/m-AlN) with 90 wt% filler content was only 3. - lbs. field and is highly frequency dependent. 0003) and stable dielectric constant (ε r = 2. These laminates should form the. Copolymers of tetrafluoroethylene and hexafluoropropylene showed two dielectric loss peaks: one. The mixture was dried on a PTFE film at room temperature, and at 90 C for 30min. When δ is low valued then it is related to loss tangent (the ratio of imaginary and real parts of permittivity) by δ ≈ tanδ ×103 milliradians. The only way you can reduce it is to use a dielectric with a very low loss tangent, or low dielectric constant. It is a solid form of fluorocarbon and a compound with elevated. 001 to 0. us. 2 for comments on expected behavior for permittivity as a function of frequency. 7–5. 1. Loss tangent values ranging from . While sintering first evaporate the binder at 500-600 for 15 min and then go to your desired temperature. Figure [Math Processing Error] 3. 24. CuClad® laminates are woven fiberglass/PTFE composite materials for use as printed circuit board substrates. The coefficient of sliding friction between PTFE and many engineering materials is extremely low and when sintered with wear reducing compounds, an industrially important class of bearing materials are formed. Products Why Isola Why Isola Materials Quality. 0002. Dielectric response of high permittivity polymer ceramic composite with low loss tangent. 08E ⁻⁴ ), higher bending strength (21. 09 (TDS); whereas the loss tangent angles are ~7. /in. The dielectric constant and loss tangent were characterized by Agilent PNA-L network analyzer (N5234A) through separated dielectric resonator method (SPDR) under about 10 GHz. It is also called as electric permittivity or simply permittivity. Rogers TC600 laminates are composites of PTFE, thermally conductive ceramic fillers and woven glass reinforcement. 85 at 20 GHz (Fig. Generally, the loss in a material is expressed in terms of the loss tangent, tanδ= ²00r ²0 r. 4 plots the storage (G′) and loss (G″) modulus, complex viscosity (η*), and tangent of the phase angle shift (tan δ) against frequency (ω) for PP and its blends, respectively. PTFE. The conductivity of PTFE/CNT (5 wt%) nanofiber membranes reached 1. It can be clearly seen that the profile of -NRW in Fig. 14) The term tan d is called loss tangent (dissipation factor or loss factor) and it represents Fluoropolymer film provides low-loss dielectric constant loss tangent; Low moisture absorption for consistent performance; RoHS Compliant; The fluoropolymer in Pyralux® TK is chemically similar to the PTFE fluoropolymer utilized in rigid high speed laminates and standard procedures to drill and activate such boards should be applicable. 2. 7 Loss tangent: 0. RT/duroid 6002 laminates are low loss materials that provide excellent high frequency performance. This increase is expected since glass has a higher Dk than LCP. 56 cm long with the internal diameter of 5. The result is a low loss material which can be fabricated using standard epoxy/glass (FR-4) processes offered at competitive prices. It has a dielectric constant of 2. The loss tangent of the PTFE/BMT composites was improved to 0. Chen, K. Dielectrics with low loss provide reduced attenuation and heating in circuits. 5. 0015 0. The use of composite engineering to tailor structural composite materials for damping results in enhancement of the loss tangent, with negligible, if any, reduction of the storage modulus. 41Speciality grades Higher stiffness grades (separate data sheets available) Grade Process Characteristics Typical applications DELRIN® 510GR Injection DELRIN® 510GR is a 10% glass fibre reinforced, Parts requiring very high strength and stiffness. The loss tangent shows increasing trend at the beginning, with the highest at 10% filler volume. 6 (c)), which was due to the porous structure formed by the volatilization of additives during sintering. Loss tangent (tan (δ)) is a measure of signal loss as the signal propagates down the transmission line. An intermediate layer is often. 2021, 11, x FOR PEER REVIEW 7 of 9 . 019 0. 55, a loss tangent less than 0. The composites were prepared through a dry powder processing technique by dispersing different micron sizes (25 µm, 45 µm, 63 µm, 90 µm, and 106 µm) of the. TheFebruary 27, 2020. 2. 물질의 유전율은 보통 상대 유전율, 즉 진공의 유전율에 대한 상대적인 값 로 나타낸다. Therefore, a series of PTFE, PET and PFA polymer materials with low permittivity and dielectric loss are selected and introduced to form compounds with H 3 BO 3 at 60–110 °C by conventional solid-phase method in this work, and then the effects of PTFE, PET and PFA on the microstructures, phase compositions, microwave dielectric. The loss tangent creates. 0005 0. 2123. Rogers TC350 laminates are printed circuit board substrates comprised of PTFE, highly thermally conductive ceramic fillers and woven glass reinforcement. 실제 유전율은 상대 유전율에다 진공의 유전율 를 곱해서 구할 수 있다. 1 Tansmission r Loss A section of the PTFE SCPDW is modeled in HFSS 2021 R1 and the dielectric con-stant ˜ r and the loss tangent tan˜ are set to be 2. For the fused silica and Sapphire wafers, the loss tangent increases slightly as a function of. In general, the dielectric loss tangent of composites remains a very low level, i. 33 x 10 7: MΩ-cm. e. 41 Coefficient of Thermal Expansion 50 43 Z ppm/˚C --55˚C to 288˚C IPC TM-650 2. BZV-filled HDPE composite shows a εr value of 4. The dielectric loss tangent of the four curves shows a gentle upward trend, and the use of the binary coupling agents does not have a significant effect on it. And the spherical particles are advantageous to increase the ceramic volume fraction [2]. Ultra-low Loss, Highly Heat Resistant Circuit Board Materials. 2) E 1080 B RC SC Reinforcement Type (see 1. Relative permittivity is also commonly known. 41 Coefficient of Thermal Expansion 17 18 Y ppm/˚C --55˚C to 288˚C IPC TM-650 2. 17 to 2. (FR-4) processes. However, the application of PTFE was hindered by its high CTE (∼400 ppm/ o C) due to its room temperature phase transformation. , Ltd. CuClad laminates feature low dielectric constants (Dk) ranging from 2. 3. 4 Properties under cyclic stress 43 3.