Film, Kapton polyimide

The initial applications of polyimldes were as varnishes and overcoat enamels as wire Insulation. Polyimldes provided significant Improvement in high temperature cut through resistance as well as excellent dielectric properties. They continue In use today both as homopolymers and copolymers with amides and ester moieties. Paralleling this technology was the development by duPont of Kapton polyimide film. Kapton enjoys a strong position as a class 22 f organic film. These applications represent the major portion of polyimide consumption. 

Applications to engineering end uses have been slower to develop due to greater demands In processing. The remainder of this discussion Is developed to such engineering applications typified by laminates, composites and molded articles. 

However the constant effort of polyimide suppliers Is to provide materials which will flow during fabrication of parts below 400 F, but which will retain structural stiffness in use of that part at 550 F. The polymer chain stiffness which affords 550 F physicals wrecks havoc with 350-400 F processing. Even low molecular weight prepolymers which can build during cure to higher molecular weight crossllnked structures often do not flow below 400°F unless a species is chosen which sacrifices 550°F thermo-physical properties. 

ACS Symposium Series American Chemical Society Washington, DC, 1974. 

The constraints upon processing described above have not been fully resolved, but progress has been made which permits employment of polylmldes In engineering composites, molded articles and to a very limited extent, structural adhesives. The principal avenues employed are discussed below. 

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As stated, the capability of plasma deposits to reduce the access of water to corrosion-sensitive surfaces may be an important motivation for their application in corrosion protection. In order to study this property, Kapton polyimide film was selected as the substrate because of its high inherent permeability to water and its ability to resist elevated temperatures. The response of Kapton film overcoated by PPHMDSO to the permeation of water vapor is shown in Fig. 1. Clearly, the presence of the organo-silicone plasma film greatly reduces water permeation. The magnitude of the effect is much enhanced when plasma polymers are produced at high T and p. 

DuPont Kapton Polyimide Film, DuPont DeNemours Literature. 

D. J. Parish and B. W. Melvin, Kapton polyimide film in rotating machinery, a paper presented at the 6th Electrical Insulation Conference (IEEE and NEMA), Sep. 1965. 

Toray-DuPont Product Bulletin for Kapton polyimide film. 

We will continue platform extensions, taking Nafion fluoropolymer membranes from chloralkali cells and catalysts to advanced fuel cells, and Kapton polyimide film from flat electronic computer circuits to complex flexible circuits in cell... 

Since the commercialization of Kapton polyimide film by DuPont, more than 30 years ago, a great number of polyimides have been described covering a very... 

Kapton polyimide has been widely used in the electronic industry because of its low dielectric constant, good mechanical properties and high thermal stability. Many applications require good adhesion between Kapton polyimide film and metal. Various processes to improve adhesion of metal to Kapton polyimide have been reported in the literature. DeAngelo et al., (D describe a process to form metal oxides on the surface of polyimide to improve adhesion. Other efforts to improve adhesion of a metal layer involve roughening of the surface of polyimide substrate by methods such as cathodic sputtering (2), chemical attack (2., 1), and reactive ion etching (1,4). 

Polyimides have excellent dielectric strength and a low dielectric constant, but in certain electrolyte solutions they can electrochemically transport electronic and ionic charge. Haushalter and Krause (5) first reported that Kapton polyimide films derived from 1,2,4,5-pyromellitic dianhydride (PMDA) and 4,4 -oxydianiline (ODA) undergo reversible reduction/oxidation (redox) reactions in electrolyte solutions. Mazur et al., (6) presented a detailed study of the electrochemical properties of chemically imidized aromatic PMDA- derived polyimides and model compounds in nonaqueous solutions. Thin films of thermally... 

Kapton Polyimide Film" Summary of Properties, DuPont Technical Bulletin, E-50533 (1982). 

Polyimides for microelectronics use are of two basic types. The most commonly used commercial materials (for example, from Dupont and Hitachi) are condensation polyimides, formed from imidization of a spin-cast film of soluble polyamic acid precursor to create an intractable solid film. Fully imidized thermoplastic polyimides are also available for use as adhesives (for example, the LARC-TPI material), and when thermally or photo-crosslink able, also as passivants and interlevel insulators, and as matrix resins for fiber-reinforced-composites, such as in circuit boards. Flexible circuits are made from Kapton polyimide film laminated with copper. The diversity of materials is very large readers seeking additional information are referred to the cited review articles [1-3,6] and to the proceedings of the two International Conferences on Polyimides [4,5]. 

Figure 7.42. Experimental setup and eastic recoil detection (ERD) spectra for multiwalled nanotubes, and a Kapton polyimide film. A computer program, SIMRA, is useful to simulate ERD as well as other non-RBS data. Reproduced with permission from Naab, F. U. Holland, O. W. Duggan, J. L. McDaniel, F. D. J. Phys. Chem. B 2005,109, 1415. Copyright 2005 American Chemical Society.

Kapton" Polyimide Film. Physical-Thermal Properties, Bulletin H-2 "Kapton" Polyimide Film — Type H. Summary of Properties, Bulletin H-ID. E. I. Du Pont de Nemours Co.,... 

Kapton Polyimide Film Summary of Properties, Du Pont Company, Wilmington, DE, 1998. 

DuPont Pyralux coverlay act as polymer foil. The composites are made of DuPont Kapton polyimide film, coated on one side with a proprietary B-staged modified acrylic adhesive. 

Figure 11.5 (a) Closed package, (b) Inner layout of the package, including three sets of live electrodes, a battery, the garment, and the PCB shape in a Kapton polyimide film, attached to the fabric using Anorak snaps. 

Kapton Polyimide films available in three types ... 

Kapton Polyimide Film. Product Bulletin H-38492-1, E. I. du Pont and Company. 

Dimensional Stability The dimensional stability of Kapton polyimide film depends on two factors— the normal coefficient of thermal expansion and the residual stresses placed in the film during manufacturing. The latter causes Kapton to shrink on its first exposure to elevated temperatures as indicated in the bar graph in Fig. 22-05. Once the film has been exposed, the normal values for the thermal coefficient of linear expansion, as shown in Table 22-04, can be expected. ]... 

Electrical Properties The most common electrical properties of Kapton polyimide film of various gauges are shown in Tables 22-06 and 22-07. These... 

Effect of Humidity Because the water content of Kapton polyimide film can affect its electrical properties, electrical measurements were made on 0.025 mm film after exposure to environments of varying relative humidities at 23°C.f l... 

Hydrolytic Properties Kapton polyimide film is made by a condensation reaction therefore, its properties are affected by water. Although long-term exposure to boiling water, as shown in the curves in Figs. 22-03 and 22-04, will reduce the level of film properties, sufficient tensile and elongation remain to ensure good mechanical performance. A decrease in the temperature and the water content will reduce the rate of Kapton property reduction, whereas higher temperature and pressure will increase it.t 1... 

Thermal Aging The useful life of Kapton polyimide film is a function of both temperature and oxygen concentration. In accordance with UL-746B test procedures, the thermal life of Kapton was determined... 

Samples for SAXS were prepared in sealed vials as reported elsewhere (2). Two Kapton (polyimide) films (7.5 pm thick) were buffed in the y-direction with an ethanol-wetted tissue paper. About 100 mg of sample were molten at 55°C to a liquid crystal and transferred to a tense, fixed Kapton film. Before cooling to below 35 °C, another Kapton film was put over the sample and both tense films were gently rubbed against each other at -0.5 mm/s in the y-direction for -10 s. Within three minutes the sandwiched sample was mounted in a hot copper block with a hole for the beam, and annealed at 58 1 °C for 30 min prior to the start of a 22-h exposure, during which annealing was continued. 

The addition of electron donors, like dialkyl aniline, to Kapton polyimide film... 

Aqueous amylose solution (1%) was prepared by dissolving amylose powder in hot water (80°C). A 1% salt free aqueous water-soluble chitosan (WSC) was obtained by the dialysis of a WSC solution that included NaCl produced by the neutralization of a dilute hydrochloric acid solution of WSC with NaOH. Each film having a thickness of 40-50 om was prepared by casting the amylose, WSC, or their mixed solutions at 60°C. A film of fully deacetylated chitosan was obtained by casting a 0.1 M aqueous AcOH solution of fully deacetylated chitosan (1%) on a Kapton (polyimide) film. The resulting acidic chitosan film was neutralized with 1M aqueous NaOH followed by washing with water and then dried. 

Kapton Polyimide film, DuPont Kel-F Monochlorotrifluoroethylene, DuPont... 

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