Kapton-type polyimides

Porous carbon films have been prepared fiom Kapton-type polyimide (PI) to produce supported and unsupported caibon membranes by Hattori et al. [2-4]. They reported that the carbon molecular sieve (CMS) film used for gas separation should be as thin as possible in order to enhance the separation efficiency. However, the thin film should be supported by a porous plate for handling convenience. The flat homogeneous carbon films prepared by pyrolysis at 800°C yielded selectivi-ties of 4.2 [4],... 

Kapton-type polyimide is thermally stable as a result of their high Tg, but the values of CTE, e and WA are 47 ppm, 3.22 (10 GHz) and 2.5%, respectively, so they are not suitable for use in all fields of electronics [36, 37]. The polyimide is insoluble in organic solvents and unprocessable after conversion from polyamic acid. 

Although the Tgs of these polyimides are lower than that of Kapton-type polyimide, some polyimides are soluble in organic solvents. 

PI(3,3 /4, 4 -ODPA/4,4 -ODA) was the smallest, as shown in the polyimides from BPDA and E was maintained at 10 Pa at 400°C as a result of crystallization. The E values of PI(2,3,3, 4 -ODPA/ 4,4 -ODA) and PI(2,2,3, 3 -ODPA/4,4 -ODA) decreased drastically at the Tg, and showed high thermoplasticity. PI(2,3,3, 4 -ODPA/ 4,4 -ODA) could be prepared as thin film because of its high thermoplasticity [43, 45]. As the thin film maintained high strength even after molten adhesion, PI(2,3,3, 4 -ODPA/4,4 -ODA) was used with APICAL AH ( Kapton-type polyimide) as the thin film on the Small Solar Power Sail Demonstrator "IKAROS". Wholly aromatic polyimides without aliphatic moietes have electron-beam-resistant and proton-beam-resistant characteristics in space environments. 

Table 15.2 shows the characteristics of the high-fluorine-content 6FDA/TFDB polyimide and KAPTON (nonfluorinated PMDA/ODA type polyimide, DuPont). The Tg of 6FDA/TFDB (335°C) is a little lower than that of PMDA/ODA because of its flexible -C(CF3)2- groups. However, 6FDA/TFDB has a high decomposition temperature of 569°C. 

Polvimide-Metal Interfaces. Several technological applications including semiconductor packaging and metallization demand a reliable and durable adhesion properties of the metal films. In the development of multilayer devices consist of alternating layers of metal and polyimides several reliable techniques are needed to study both thin films and their interfaces. The usefulness of the nuclear scattering techniques to study the metallization and the associated interfacial elemental diffusion processes under the effects of various temperature and humidity treatments on the metal-polyimide systems, such as Al, Cu, N, and Au on Du Pont Kapton type H have already been reported (21., 22.). Only a couple of examples are presented here to illustrate the ERD application. 

Starting materials and solvents were purchased from Aldrich Chemical Co. acetonitrile (ACN), N,N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP) were obtained anhydrous in Sure/Seal bottles and used as received. The polyamic acid of PMDA-ODA (2545 Pyralin) was supplied by DuPont. The soluble polyimide XU-218, derived from 3,3, 4,4 -benzophenone tetracarboxylic dianhydride (BTDA) and diamino-1,1,3-trimethyl-3-phenylindan isomers (DAPI) was purchased from Ciba-Geigy Corp. The acetylene terminated imide oligomer powder (Thermid MC-600) derived from BTDA, aminophenylacetylene, and 1,3-bis (2-aminophenoxy) benzene (APB) was obtained from National Starch and Chemical Company. Kapton Type II (PMDA-ODA) films were obtained from DuPont Co., Apical polyimide films were obtained from Allied Corp., and Upilex Type-S and Type-R polyimide films derived from 3,3, 4,4 -biphenyl tetracarboxylic dianhydride (BPDA) plus p-phenylenediamine (PDA) and ODA, respectively were obtained from ICI Americas Inc. 

To confront these difficult tasks, we have incorporated old and new solutions. For example, strong yet flexible Kapton polyimide substrates are promising, and the neutral-carrier type ion-selective membranes offer the advantage of using similar fabrication methods for sensors of different ions of interest. We are also working on the biocompatibility problems, and all new designs are subject to in vivo tests. 

Laminates have been extensively studied by PA-FTIR and are the subject of extensive investigations by the new much more complex step-scan PA-FTIR techniques. Kapton film is often used to illustrate the analysis of this type of sample. Kapton 200FN919 film is a DuPont product which consists of a 25 pm layer of polyimide laminated between 12.7 pm layers of Teflon. If a high mirror velocity is used then a spectrum of only the Teflon layer is obtained. On the other hand if a slow mirror velocity is used a composite spectrum of the Teflon and polyimide layer is obtained. The difference spectrum (low mirror velocity spectrum minus high mirror velocity spectrum) represents that of the polyimide layer. As illustrated in Figure 2.16 the difference spectrum closely resembles the PA FTIR spectrum of polyimide except for the regions where the strong C-F bands of the Teflon are present. 

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]. 

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.,... 

A number of cell designs have been employed in EXAFS studies of electrochemical systems. Of these, two general types can be identified depending on whether a transmission or a fluorescence mode of detection is employed. In a transmission mode, cells should be designed so as to minimize absorption losses due to the window material, elecrolyte, and the electrode itself. As a result, the windows are typically made of thin films (25/an) of low absorbing materials such as polyethylene and polyimide (Kapton). The electrolyte layer thickness is typically small, and electrodes are generally metal films evaporated on a thin polymer film or small particles dispersed in a low Z matrix. Carbon can be employed in a variety of forms and shapes because of its low absorption. 

The different models include many material parameters and several of these parameters are obtained from fitting of experimental data and have to be adjusted to fit each polymer [9,63]. It is worth mentioning in this context that polyimide is probably the most studied polymer in laser ablation and is also the material for which most ablation models are applied, but great care has to be taken for which type of polyimide the data have been obtained. Polyimide describes a whole group of polymer that can range from soluble polymers to insoluble films and even photosensitive polymers with very different properties [10]. Even products with the same name, such as Kapton , are not one polymer, but there are also many different types of Kapton that are defined with additional letters, for example, HN. 

Polyimide or its most common type Kapton HN (chemical structure shown in Fig. 14.4) is the most studied polymer, as it can be ablated with all common excimer laser wavelengths and pulse lengths (r). Most ablation models are based on Kapton, as its material properties are well characterized. 

Type R and B fiber trademark of Thermo Electric s Thermoplastic Elastomer and Polyimide fiber, respectively. b Nylon, Teflon, and Kapton are trademarks of the E. I. duPont Co. 

The aromatic amine di(4-aminophenyl)ether is employed in the manufacture of polyimide film, designated as Kapton (Du Pont). Other commercial materials of this type introduced by Du Pont in the early 1960s included a coating resin (Pyre ML) and a machinable block form (Vespel). In spite of their high price these materials have found established uses because of their exceptional heat resistance and good retention of properties at high temperatures. 

Kapton Polyimide films available in three types ... 

Tensile specimens of polypropylene, polycarbonate. Mylar (polyester), Nomex (nylon paper), and Kapton (polyimide) had dimensions of 3 mm in width and 10 mm in guage length. The specimen thicknesses were 65 ym for polypropylene, 75 ]lm for polycarbonate, 85 ym for Mylar, 200 ym for Nomex, and 50 ym for Kapton. Their tensile axes were perpendicular to the rolling direction of the sheets. The molecular structures of these specimens are shown in Table I. Epoxy resins were tested by compression. The specimens of epoxy resin were made of Epikote 828 (bisphenol A type) hardened by K61B (tridimethylaminophenol) or polyamide in a teflon mold of 2 mm in diameter and about 6 mm in height. 

Base dielectrics Conductor materials Copper-clad laminates Coverlay Adhesive sheets Polyimide films (Kapton K, E, EN, KJ Apical NP, FP Upilex S) Liquid polyimide resin, PEN film, LCP films Ultra-thin copper foils, sputtered copper, copper alloys, stainless steel foil Adhesiveless laminates (cast type, sputtered/plated type, laminated type) Photoimageable coverlay (PIC) (dry film type, liquid ink type) Hot-melt polyimide film... 

Hot-melt-type (thermoplastic) polyimide films have been developed as high-heat-resistant adhesive materials. Mitsui Chemical s TPI, DuPont s Kapton KJ, Ube s Upicel, and Kaneka s Pixeo are typical examples. These are coated on dimensionally stable polyimide films to ensure good physical performance. 

Only one type of electrical grade polyimide is available in film form and this is manufactured by DuPont under the trade name Kapton . Kapton polyimide is formed by the polycondensation of pyromellitic dianhydride and 4,4 -diamino diphenylether. The reaction proceeds via the intermediate formation of the polyamic acid as described in Section... 

Property Mylar polyester type A 1 mil Kapton polyimide type H 2 mil Dacron-epoxy R/2400 4 mil Nomex nylon type 410 5 mil... 

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