Polyimides manufacture

M. W. Ranney, Polyimide Manufacture, Noyes Data Corp., Park Ridge, New Jersey, 1971. 

L. A. Laius, Polyimides, Thermally Stable Polymers, Plenum-Press, New York, 1987 M.W. Ranney, Polyimide Manufacture, Noyes Data Corp, Park Ridge, N.J., 1971 C. Feger, M.K. Kojastech, and J.E. McGrath, (ed.-s), Polyimides. Chemistry, Characterization and Materials, Elsevier, 1989 D. Wilson, P. Hergenrother, and H. Stenzenberger (eds.), Polyimides, Chapman and Hall, 1990. D. M. Munoz, M. Celle,. J.G. de la Campa, J. de Abajo and A. E. Lozano, Macromolecules, 2009, 42 (15), 5892... 

Kinel Polyimide, manufactured by Rhone Poulenc, France. 

Polyimide fiber is made from an aromatic heterocyclic polymer, and P84 is the brand name of the polyimides manufactured by Evonik Fibers with a trilobal fiber cross section (Fig. 2.25). P84 is a fully imidized polyimide derived from aromatic dianhydrides and aromatic diisocyanates and has a glass transition temperature of 315°C. The fibers start to carbonize at temperatures beyond 370°C. Due to the aromatic structure, the polymer and fibers are inherently nonflammable. An FOl of 38% can be measured. P84 can be used for temperatures up to 260°C, depending on the environment [71]. Typical properties of P84 are introduced in Table 2.67. 

Many cellular plastics that have not reached significant commercial use have been introduced or their manufacture described in Hterature. Examples of such polymers are chlorinated or chlorosulfonated polyethylene, a copolymer of vinyUdene fluoride and hexafluoropropylene, polyamides (4), polytetrafluoroethylene (5), styrene—acrylonitrile copolymers (6,7), polyimides (8), and ethylene—propylene copolymers (9). 

Printed circuit boards manufacture is aided by the use of KMnO. Alkaline permanganate solution is used to remove resin smeared on the interior hole wall of multilayered printed circuit boards. Additionally the hole wall is etched, resulting in a surface with excellent adhesion characteristics, for electrodeless copper (250). The alkaline permanganate etchback system containing >60 g/L KMnO and 40-80 g/L NaOH at 70—80°C, is effective for difunctional, tetrafiinctional, and polyimide resin substrates, where the level of etchback is direcdy proportional to the immersion time (10—20 min) (251). 

A number of dielectric films are deposited by the spin-on technique. In this case the film s constituent molecules are dissolved in a solvent to form a hquid. After spinning the Hquid over a semiconductor surface the solvent is driven off with a baking step, leaving behind the thin dielectric film. Common films include polyimide and benzocyclobutene (BCB). The deposition process for these films is simple, making it attractive for a manufacturing process. 

Biaryl derivatives bearing reactive groups have become increasingly important in industry. Uses for this class of compounds are constantly being developed in the production of high performance polymers. Materials such as 3,3, 4,4 -biphenyl-tetracarboxylic dianhydride 1 and 4,4 -biphenol 2 are monomers employed in the manufacture of high performance polyimides or polyesters. Applications for this family of molecules have also been found both in the dye industry and in the pharmaceutical industry. 

Manufacture of Printed Wiring Boards. Printed wiring boards, or printed circuit boards, are usually thin flat panels than contain one or multiple layers of thin copper patterns that interconnect the various electronic components (e.g. integrated circuit chips, connectors, resistors) that are attached to the boards. These panels are present in almost every consumer electronic product and automobile sold today. The various photopolymer products used to manufacture the printed wiring boards include film resists, electroless plating resists (23), liquid resists, electrodeposited resists (24), solder masks (25), laser exposed photoresists (26), flexible photoimageable permanent coatings (27) and polyimide interlayer insulator films (28). Another new use of photopolymer chemistry is the selective formation of conductive patterns in polymers (29). 

Condensation polyimides or SP-polyimides from the solvent-phase reaction of an aromatic tetra-acid with a diamine. Despite the thermoplastic form they are infusible and generally insoluble. Consequently, the producer can only mould this type. It is particularly convenient for the manufacture of thin parts and films, coatings... 

BMI or aminobismaleimides or addition polyimides from the reaction of a diamine and a bismaleimide to make a prepolymer that is then cured by an excess of diamine. This type is particularly convenient for the manufacture of thick parts. 

Optical properties of the material are less critical for microchips hyphenated with MS than for devices with on-chip optical detection where low background absorption or fluorescence is mandatory. Thus, completely opaque polymers like glassy carbon or polyimide " can be used as microfabrication substrates. Furthermore, polymer microchips are of great interest because their potentially low manufacturing costs may allow them to be disposable. Methods used for the fabrication of plastic chips include laser ablation and molding methods. 

Mixed xylenes are used as an octane improver in gasoline and for commercial solvents, particularly in industrial cleaning operations. By far, most of the commercial activity is with the individual isomers. Para-xylene, the most important, is principally used in the manufacture of terephthalic acid and dimethyl terephthalate en route to polyester plastics and fibers (Dacron, films such as Mylar, and fabricated products such as PET plastic bottles). Ortho-xylene is used to make phthalic anhydride, which in turn is used to make polyester, alkyd resins, and PVC plasticizers. Meta-xylene is used to a limited extent to make isophthahc acid, a monomer used in making thermally stable polyimide, polyester, and alkyd resins. 

Baseline Process. DuPont PI2545, PI2555 and Hitachi PIQ as received from the manufacturer, were spun in a class 100 clean room environment at appropriate spin speeds to achieve 0.5 - 6 y film thickness. The silicon wafer substrates were pre-spun (5K rpm, 30") with 0.05% DuPont VM651 (y-amino propyltriethoxy silane) adhesion promoter in 95/5 (v/v) methanol/HzO. The polyimide film cast on the silane-coated silicon wafer was pre-baked... 

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