Microelectronics polymer applications

Finally, for practical reasons it is useful to classify polymeric materials according to where and how they are employed. A common subdivision is that into structural polymers and functional polymers. Structural polymers are characterized by - and are used because of - their good mechanical, thermal, and chemical properties. Hence, they are primarily used as construction materials in addition to or in place of metals, ceramics, or wood in applications like plastics, fibers, films, elastomers, foams, paints, and adhesives. Functional polymers, in contrast, have completely different property profiles, for example, special electrical, optical, or biological properties. They can assume specific chemical or physical functions in devices for microelectronic, biomedical applications, analytics, synthesis, cosmetics, or hygiene. 

Thin films have become ubiquitous in the polymer industry. Fueled by the microelectronics industry and its need for miniature parts, polymer applications have become more demanding. Polymers in these environments have been tested and modeled in laboratories around the world from universities to automobile companies, research surrounding thin films is quickly growing. ... 

D. S. Soane and Z. Martynenko, Polymers in Microelectronics Fundamentals and Applications, Elsevier, Amsterdam, 1989. 

In numerous applications of polymeric materials multilayers of films are used. This practice is found in microelectronic, aeronautical, and biomedical applications to name a few. Developing good adhesion between these layers requires interdiffusion of the molecules at the interfaces between the layers over size scales comparable to the molecular diameter (tens of nm). In addition, these interfaces are buried within the specimen. Aside from this practical aspect, interdififlision over short distances holds the key for critically evaluating current theories of polymer difllision. Theories of polymer interdiffusion predict specific shapes for the concentration profile of segments across the interface as a function of time. Interdiffiision studies on bilayered specimen comprised of a layer of polystyrene (PS) on a layer of perdeuterated (PS) d-PS, can be used as a model system that will capture the fundamental physics of the problem. Initially, the bilayer will have a sharp interface, which upon annealing will broaden with time. 

Various novel applications in biotechnology, biomedical engineering, information industry, and microelectronics involve the use of polymeric microspheres with controlled size and surface properties [1-31. Traditionally, the polymer microspheres larger than 100 /urn with a certain size distribution have been produced by the suspension polymerization process, where the monomer droplets are broken into micron-size in the existence of a stabilizer and are subsequently polymerized within a continuous medium by using an oil-soluble initiator. Suspension polymerization is usually preferred for the production of polymeric particles in the size range of 50-1000 /Ltm. But, there is a wide size distribution in the product due to the inherent size distribution of the mechanical homogenization and due to the coalescence problem. The size distribution is measured with the standard deviation or the coefficient of variation (CV) and the suspension polymerization provides polymeric microspheres with CVs varying from 15-30%. 

It was also observed that, with the exception of polyacetylene, all important conducting polymers can be electrochemically produced by anodic oxidation moreover, in contrast to chemical methoconducting films are formed directly on the electrode. This stimulated research teams in the field of electrochemistry to study the electrosynthesis of these materials. Most recently, new fields of application, ranging from anti-corrosives through modified electrodes to microelectronic devices, have aroused electrochemists interest in this class of compounds... 

Manuelli, A. Knobloch, A. Bernds, A. Clemens, W. 2002. Applicability of coating techniques for the production of organic field effect transistors. 2nd International IEEE Conference on Polymers and Adhesives in Microelectronics and Photonics, POLYTRONIC 2002. pp. 201-204. 

Traditionally, UV curable polymers have been utilized as coatings for wood and vinyl floors, but their applications have increased dramatically over the last twenty years to encompass many diverse areas, including optical fiber coatings (7), adhesives (2), disc replications (3-5), and microelectronics (6). This widespread use of UV cross-linked systems is attributed to their rapid, energy efficient curing and their solvent free, one piece formulations. Typically, UV curable systems require only a small fraction of the power normally utilized in thermally cured systems and their solvent free nature offers an environmentally safer alternative. 

As part of an effort to develop high-performance, high-temperature-resistant polymers for microelectronics applications, we also recently described a series of both partially fluorinated and nonfluorinated poly(aryl ether ketone)s containing amide, amide-imide, cyano oxadizole, or pyridazine groups and characterized their thermal and electrical properties.11... 

Six novel fluorinated poly(aryl ether)s containing 1,4-naphthalene moieties were synthesized in high yield using 2,2-bis[4-( 1 -naphthoxy)phenyl]hexafluoro-propane (1). Oxidative coupling ofl yielded a polymer with high 7, low moisture absorption, and low dielectric constant that could be cast into flexible films. The low dielectric constant and low moisture absorption of 6FNE may make it useful as a dielectric insulator in microelectronics applications. 

Poly(naphthalene) is chemically similar to poly(p-phenylene), which is an insoluble, infusible, low-molecular-weight polymer, all attributes that preclude application in thin-film form in microelectronics. Although these materials possess several very desirable properties, such as high glass transition tempera-... 

The U.S. - Australia Symposium on Radiation Effects on Polymeric Materials contained research presentations on fundamental radiation chemistry and physics as well as on technological applications of polymer irradiation. This paper represents a hybrid contribution of these two areas, examining a field of extensive technological importance. Spin casting of radiation sensitive polymer resists for microelectronic fabrication was studied using photophysical techniques that are sensitive to the fundamental radiation response in the ultraviolet range. 

Following pioneering work by Sen [50] and Risse [51] in the 1980 s, B.F. Goodrich launched a new family of amorphous norbomene-based polymers aimed at a number of microelectronic applications. The polymers are high-priced specialties (up to 6,000 per kg). These new polymers were made possible by a breakthrough in the area of single component catalysts based on Group 10 (Ni and Pd) transition metals [52], These catalysts are characterised by their ability to ... 

These materials are introduced in Chapter 5 and only brief mention of them is necessary here. It is important to appreciate that polymer electrolytes, which consist of salts, e.g. Nal, dissolved in solid cation coordinating polymers, e.g. (CH2CH20) , conduct by quite a different mechanism from crystalline or glass electrolytes. Ion transport in polymers relies on the dynamics of the framework (i.e. the polymer chains) in contrast to hopping within a rigid framework. Intense efforts are being made to make use of these materials as electrolytes in all solid state lithium batteries for both microelectronic medical and vehicle traction applications. 

Recently the synthesis and characterization of novel fluorinated poly(aryl ether)s containing perfluorophenylene moieties " " was also reported. These fluorinated polyethers were prepared by reaction of decafluorobiphenyl with bisphenols. These polymers exhibit low dielectric constants, low moisture absorption, and excellent thermal and mechanical properties. Tough, transparent films of the polymers were prepared by solution-casting or compression-molding. The fluorinated poly(aryl ether)s containing perfluorophenylene moieties are good candidates for use as coatings in microelectronics applications. 

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