Kapton Polyimide Film Research Articles

The effect of temperature on the roll graphite films derived from Kapton polyimide films

The effect of temperature on the roll graphite films derived from Kapton polyimide films

POLYIMIDE FILMS IMPLANTED BY MANGANESE IONS

The optical and strength properties of Kapton polyimide films implanted with manganese ions with an energy of 40 keV and a dose of 5·1016 – 1·1017 cm–2 at a current density in the ion beam of 4 μA/cm2 have been studied. It has been experimentally established that during the process of ion implantation, modification of a thin nearsurface layer of polyimide occurs not only on the implanted side, but also on the reverse side of the film. Radiationstimulated modification of the back surface of the polyimide film leads to the formation of a surface layer up to 5 μm thick with increased microhardness. This may be due to the restructuring of metastable defects formed during the film manufacturing process and the simultaneous relaxation of elastic stresses in the surface layer. During the implantation process, a decrease in the intensity of absorption bands with maxima at ~ 2870 and ~ 2750 nm is observed, due to the evaporation of residual water under high vacuum conditions and reactions of residual solvent molecules, as well as radiation-induced processes on by-products of polyimide synthesis.

A study for gamma attenuation behavior of polyimide (PI) film by MPPC

Although lead is a very good radiation shielding material, its toxicity has led researchers to find alternative materials instead of it. Moreover, as the use of Kapton polyimide (PI) film in nuclear power plants and space exploration increases, the need to reveal the radiation degradation properties of this material has come along. In this regard, in the present study, it is aimed to determine the mass and linear attenuation coefficients, half value layer, tenth value layer, mean free path and radiation protection efficiency attenuation parameters for this material, experimentally and theoretically, by using the gammas of the 133Ba radioisotope. Experimental gamma attenuation measurements were made by a spectrometer using a Hamamatsu multi pixel photon counter device with a silicon photomultiplier sensor. The constant fraction discrimination timing method was used to reduce the electronic noise of the spectrometer. The attenuation parameters determined experimentally by following two ways were compared with the theoretical ones obtained from the XCOM program.

Ultra-thin polyimide films play crucial role in protecting NASA telescope

Ultra-thin Kapton polyimide films from DuPont's Electronics & Industrial business are being used to protect the National Aeronautics Space Administration's (NASA) James Webb Space Telescope (JWST) from the sun's light and heat – enabling it to function properly in space.

In-Place Characterization of On-State Voltage for SiC MOSFETs: Controlled Shoot-Through vs. Film Heater

The on-state voltage of MOSFETs is a convenient and powerful temperature-sensitive electric parameter (TSEP) to determine the junction temperature, thus enabling device monitoring, protection, diagnostics and prognostics. The main hurdle in the use of the on-state voltage as a TSEP is the per-device characterization procedure, to be carried out in a controlled environment, with high costs. In this paper, we compare two novel techniques for MOSFET junction temperature estimation: controlled shoot-through and direct heating by resistive heaters embedded in two Kapton (polyimide) films. Both allow in-place characterization of the TSEP curve with the device mounted in its final circuit and assembly, including the working heat sink. The two methods are also validated against the conventional procedure in a thermal chamber.

Study on the electro-optical properties of epoxy resin based polymer dispersed liquid crystal films

Abstrat Polymer dispersed liquid crystal (PDLC) films have been extensively studied for their ability to control the attitude of aircraft by varying the reflectivity of solar sails. However, most of the polymeric matrix of PDLC films are based on polyacrylates, which comprehensive properties such as thermal stability, chemical stability, mechanical strength and radiation resistance can not meet the requirements of the harsh environment in space. In order to improve the radiation resistance of PDLC films, polyimide-epoxy resin PDLC films were prepared by thermal polymerization using Kapton polyimide film as conductive film and two kinds of epoxy resin as monomer in this paper. The electro-optic properties of PDLC films prepared by flexible chain and rigid chain epoxy resin monomers in different ratios were studied and the microscopic morphology of the polymer network of the polyimide PDLC films was observed by scanning electron microscopy (SEM) and the relationship between them was studied.

Highly Linear and Stable Flexible Temperature Sensors Based on Laser‐Induced Carbonization of Polyimide Substrates for Personal Mobile Monitoring

AbstractWearable on‐skin electronic devices that can monitor temperature in real time are of significant interest for personalized mobile health monitoring. Here, a flexible temperature sensor directly patterned by laser‐induced carbonization on Kapton polyimide films integrated with flexible printed circuit boards is reported. The proposed sensor design possessing high resistance values exhibits high‐linear and stable response to temperatures when integrated with flexible printed circuit boards (FPCBs) to enable continuous monitoring. The anisotropic conductive film bonding technique is used to obtain the stable real‐time monitoring data under various complex environments. The sensor integration with a wearable patch based FPCB establishes conformal contacts with human skin and allows wireless sensing capabilities smoothly in real time. This kind of approach can enable multifunctional sensors to be directly laser patterned on FPCBs without any additional interfacing.

Splitting a terahertz surface plasmon polariton beam using Kapton film

It has been experimentally shown that a rigid polyimide Kapton film of submillimeter thickness is sufficiently transparent in the frequency range of 1.2–3 THz and can be used for splitting surface plasmon polaritons (SPPs) propagating along a flat conducting surface. The transmittance T and reflectance R measured for SPPs excited by a free-electron laser radiation ( λ = 130 µ m ) in “gold–ZnS layer–air” flat structures are in good agreement with the results of numerical simulations obtained using the rigorous coupled-wave analysis technique. Transmittance of the SPPs decreases slightly when the layer gets thicker. To minimize the SPP radiative losses emerging due to diffraction of the SPPs on the impedance discontinuity, the Kapton film should be placed normal to the guiding surface and brought in good contact with it (the gap must be less than λ / 2 ). The performed experiments clearly demonstrated Kapton films to be very promising for SPP beam splitting in large-scale terahertz SPP devices.

Formation of Plastic Creases in Thin Polyimide Films

Abstract We present a combined experimental and analytical approach to study the formation of creases in tightly folded Kapton polyimide films. In the experiments, we have developed a robust procedure to create creases with repeatable residual fold angle by compressing initially bent coupons. We then use it to explore the influence of different control parameters, such as the force applied, and the time the film is being pressed. The experimental results are compared with a simplified one-dimensional elastica model, as well as a high fidelity finite element model; both models take into account the elasto-plastic behavior of the film. The models are able to predict the force required to create the crease, as well as the trend in the residual angle of the fold once the force is removed. We non-dimensionalize our results to rationalize the effect of plasticity, and we find robust scalings that extend our findings to other geometries and material properties.

A Rectangular Patch Antenna based on Flexible and Non-Flexible Substrates for Wireless Applications

Microstrip antenna is one of the most popular types of printed antenna. It plays an excellent role in today’s world of wireless communication systems. Microstrip antenna offers the advantages of thin profile, light weight, low cost, ease of fabrication and compatibility with the integrated circuitry. In this paper, the design of a rectangular patch antenna based on flexible and non-flexible substrate is presented. First a simple rectangular shape patch antenna using microstrip feeding based on FR4 substrate is designed. The designed antenna operates at a center frequency 2.3 GHz with bandwidth ranging from 2.25 to 2.35 GHz (100 MHz). The same rectangular patch is subjected to two different flexible substrate i.e. Kapton polyimide film with thickness of 0.82 mm and Kapton polyimide film with thickness of 0.85 mm. With Kapton polyimide as substrate having thickness of 0.82 mm resulted in a center frequency of 2.4 GHz with bandwidth ranging from 2.36 to 2.45 GHz (90 MHz). With Kapton polyimide as substrate having thickness of 0.85 mm, the antenna provides a center frequency at 2.3 GHz, with bandwidth ranging from 2.25 to 2.35 GHz (100 MHz). The other radiational parameters (such as impedance matching, radiation pattern, radiation efficiency and gain) from all the three substrate are studied. The antenna based on FR4 substrate is finally fabricated and its results are compared with the simulated ones.

Experimental and numerical analyses of thermal performance of a thin-film multi-layer insulation for satellite application

Multi-layer insulation (MLI) blankets are one of the main components of satellite thermal control system. The past studies have considered infinite heat transfer coefficient in modeling the MLI shields due to the use of reflective thin films such as aluminized Kapton (Polyimide Film Developed by DuPont Company) or aluminized PET (Polyethylene Terephthalate) in MLI shields. Therefore, equal temperature was considered on two sides of a shield and the effect of thermal resistance has been ignored in the total thermal resistance. In the present study, the effects of thermal conductivity of thin film and shield thickness are analyzed. For this purpose, numerical analyses are performed on three types of blankets that are made of Kapton, PET and null shields. The results indicate that the difference in effective emittance of Kapton and PET blanket is 17% to 2% from the thinnest film to the thickest film, respectively. In order to confirm the numerical results, the effective emittance of two types of MLI blankets made of Kapton and PET films is measured under identical conditions. It is concluded that the Kapton blanket has lower effective emittance than PET.

Electrical and thermal analyses of a second generation high temperature superconducting magnet with vanadium III oxide and Kapton polyimide film insulation materials under an over-pulse current

In this study, we developed a novel simulation code to analyze a second-generation high-temperature superconductor (HTS) magnet that was insulated with a polyimide film and vanadium III oxide (V2O3). In particular, V2O3 is one of the metal–insulator transition materials that has resistivity that varies with temperature. For its commercialization for large-scale HTS magnet applications, the HTS magnet that uses V2O3 is expected to achieve both of the desired characteristics, specifically, (a) high electrical and thermal stabilities for the non-insulated coils, and (b) prompt controllability of the insulated coils. First, an equivalent electrical-circuit model is proposed to develop a simulation code for the analysis of electrical and thermal characteristics of polyimide and V2O3. Then, all simulated results were compared with experimental results of a small-scale HTS single pancake coil and discussed to verify the reliability of the developed simulation code.

Business Roundup

BUSINESS Business Roundup ShareShare onFacebookTwitterWechatLinked InRedditEmail C&EN, 2019, 97 (10), p 21March 11, 2019Cite this:C&EN 97, 10, 21AbstractDuPont will spend $220 million to expand production of Kapton polyimide film and Pyralux laminated circuit board materials at its Circleville, Ohio, facility. The new capacity will come on line in 2021 to supply consumer electronics, telecommunication, defense, and automotive customers. OCI, a fertilizer and methanol producer with plants in the US, Europe, and Africa, says it has been approached by a firm interested in buying its methanol business. Published reports say the Saudi company Sabic is interested in the business. J.M. Huber will acquire Miller Chemical & Fertilizer from Dunes Point Capital. Miller, based in Hanover, Pennsylvania, has 100 employees and makes crop-protection chemicals, fertilizers, and other horticultural products. Carbon Engineering, a Canadian developer of a chemical method for capturing CO2 from the atmosphere, has received a $6 million investment from the mining company BHP. Carbon Engineering recently won investments from Chevron and Occidental Petroleum. Celanese plans to addView: PDF | Full Text HTML

Properties of Polyimide Film after Electron Beam Irradiation with a Dose of 1 GGy

The results of the performance tests of a three-layer foil separator for a high-current electron gun of an ELA excimer laser are presented. The separator consisted of two layers of thin titanium foil with a polyimide film between them. Such a composition withstood 5630 electron beam pulses with duration of 80 ns and an energy density per pulse of about 9 J/cm2. In this case, the polyimide film (Dupont Kapton polyimide film) with a thickness of 38 μm was irradiated with a dose of 1 GGy. The initial and induced absorption of this film was measured in the range from 20 to 0.4 μm. The mechanical tensile strength of the irradiated film decreased by 17 times.

Design of Reduced Graphene Oxide Based Piezo-Resistive Type Acoustic Sensor on Flexible Kapton for Underwater Applications

Micro Electro Mechanical Systems (MEMS) vector sensor is a recent advancement in the field of underwater acoustic sensors. The major incentive provided by this acoustic vector sensor is that it provides information about the direction of the incoming acoustic source signal in addition to the measurement of the pressure associated with the acoustic signal. We are reporting a design of a MEMS acoustic vector sensor for underwater applications using piezoresistive film of Reduced Graphine Oxide (RGO), realized on kapton (polyimide) film as the starting material. The sensor is designed and fabricated by deposition of RGO on a kapton, which is a flexible substrate by the method of drop casting making the process simple, low-cost and scalable. The application of the piezoresistive transduction principle and ingenious structure of the vector sensor based on bionic principle improves miniaturization and the low-frequency sensitivity. The fabricated sensor shows a repeatable response in both static and dynamic conditions, to the applied strain due to the acoustic signal in a given direction. The experimental results show that fabricated sensor based on MEMS technology and piezoresistive effect is feasible and it possesses intrinsic two-dimensional directivity. The fabricated device has given good response for the low-frequency acoustic signals due to the effect of piezoresistive transduction principle and the resonance frequency of the device is found to be around 80 Hz with the displacement sensitivity around 3 mV/mm and 2 mV/mm of X and Y axis directions respectively.

Свойства полиимидной пленки после облучения электронным пучком с дозой 1 GGy

AbstractThe results of the performance tests of a three-layer foil separator for a high-current electron gun of an ELA excimer laser are presented. The separator consisted of two layers of thin titanium foil with a polyimide film between them. Such a composition withstood 5630 electron beam pulses with duration of 80 ns and an energy density per pulse of about 9 J/cm^2. In this case, the polyimide film (Dupont Kapton polyimide film) with a thickness of 38 μm was irradiated with a dose of 1 GGy. The initial and induced absorption of this film was measured in the range from 20 to 0.4 μm. The mechanical tensile strength of the irradiated film decreased by 17 times.

Splitting of terahertz surface plasmons by polyimide films

Terahertz (THz) surface plasmons (SPs) can be effectively used in THz communication lines, information processing devices, spectroscopic measurements of submicron dielectric layers, and metal surface quality control. Such applications necessitate implementation of various optical schemes, including splitting of THz SPs on the guiding surface. This work is the first experimental demonstration of the fact that a polyimide kapton film of submillimetre thickness can effectively split THz SPs. Measurements of the transmission and reflection coefficients of SPs on gold-ZnS layer plane structures using monochromatic radiation of the Novosibirsk free-electron laser (λ = 130 μm) have shown good accordance with theoretical calculations.

Characterisation of smart CFRP composites with embedded PZT transducers for nonlinear ultrasonic applications

Embedded piezoelectric lead zirconate titanate (PZT) transducers in carbon fibre reinforced plastic (CFRP) composites are typically electrically insulated by interlaying materials such as polyimide Kapton films between the PZT and the laminate ply. However, the presence of polymeric films may cause debonding at the layer interface, thus reducing the structural performance. This paper proposes an alternative insulation technique in which PZTs are covered by a thin patch of woven E-glass fibre fabric for enhanced adhesion with the surrounding epoxy matrix. An analysis of variance on experimental test results showed that the compressive, flexural and interlaminar shear strengths of plain CFRP specimens were equal to the means of the smart CFRP composite (0.41 < p-value < 0.58), but significantly higher than those of Kapton specimens (0.0001< p-value < 0.05). Moreover, a post-test fractographic analysis indicated that damage opening in Kapton specimens was significantly larger (p-value = 0.03) than that in plain specimens. Brooming failure compression was also the same for the smart CFRP composite and plain samples, whereas Kapton specimens failed by through-thickness shear. Finally, nonlinear ultrasonic experiments were conducted on CFRP laminates with artificial in-plane delamination using glass fibre insulated PZTs. Remarkably, the effect of second harmonic generation was found to be nearly two times higher than conventionally surface-bonded PZTs.

Quench Behavior of 2G HTS Coils With Polyimide Film and MIT Material Under Over Pulse-Current

This paper presents the quench behavior of second-generation (2G) high-temperature superconducting (HTS) coil insulated with a Kapton polyimide film or metal-insulator transition (MIT) materials, which could enhance the thermal stability and magnetic field-control performance of a 2G HTS magnet. For the quench test, overcurrent experiments using pulse-current shooting were conducted to investigate the thermal quench behavior and thermal stabilities of two HTS coils co-wound by polyimide or MIT materials against a large overcurrent pulse. The experimental results of the two insulation materials were compared to verify the superior thermal performance of the MIT material as the turn-to-turn insulation. Further, the applicability of the MIT material on a 2G HTS magnet system was discussed according to the experimental results.

Enhancement of microwave absorption properties on modified kapton film by ion implantation process

Kapton-polyimide films have been modified by using ion implantation of Fe and Gd ions at dose 1 × 1017 ions/cm2 and energy ions 30 keV. From X-ray diffractions (XRD) were verified the existence phases such as iron oxide, or Gd-oxide and graphitic carbon. Vibrating sample magnetometer (VSM) measurement the films showed a paramagnetic behavior. Microwave absorption (MWA) properties were measured by vector network analyzer (VNA) at X band range (8-12GHz). VNA measurement results showed the enhancement of MWA from -22dB for Kapton original film to -35dB for S11 vector direction and until -40 dB for S22 vector direction of modified Kapton film by Fe and Gd ions. It can be concluded that the nanostructure of embedded Fe-oxide or Gd-oxide nanoparticles on the near surface of Kapton film take a role and gives a rise the MWA properties of film.