Poly(α,α,α′,α′‐tetrafluoro‐p‐xylylene)

Abstract

synopsisPoly(a,cr,a',a'-tetrafluoro-p-xylylene) was prepared by the pyrolysis of cyclo-di- (a,a,a',a'-tetrafluom-p-xylylene) and by the pyrolysis of a,a'-bis(alkylsulfony1)-a,a,a',a'-tetrafluoro-pxylene. The pyrolysis of a,a'-dibromo-a,a,cr',a'-tetrafluoro-pxylylene also gave the polymer, but the method is less satisfactory. Poly(a,a,a',a'-tetrafluoro-pxylylene) shows remarkable thermal and oxidative stability at elevated temperatures. Useful mechanical and electrical properties are retained after aging for 3000 hr at 250' in air. After initial change due to crystallization, tensile strength remains near 10,000 psi, elongation above 5%, and dielectric constants and dissipation factors at approximately 2.4 and .001, respectively.

Electrical Conductivity of Parylene F at High Temperature

“…2 Polyparaxylylene (PPX) films, usually referred to as parylene (PA), are semicrystalline polymeric materials widely used in microelectronics as interlayers due to their low dielectric constant, high thermal stability, and low gas and moisture permeability. 3,4 They therefore appear to be potential candidates for surface electrical insulation of power electronic components due to their physical properties and the compatibility of their deposition process. Indeed, contrary to PIs deposited by spincoating, the most prominent advantage of PAs is the solventless room-temperature vapor deposition polymerization (VDP) process, which allows deposition of conformal submicron and micron (from 100 nm to 75 lm) films without formation of pinholes.…”

Low dielectric constant Parylene-F-like films for intermetal dielectric applications

“…5,6,8 Specifically, Parylene films have dielectric constants of 2.35-2.95 at 1 MHz and are stable at temperatures up to 400-500°C. 6 In particular, Parylene-F type films ( -CF 2 -C 6 H 4 -CF 2 -) n have a reported decomposition temperature of 530°C and a low frequency dielectric constant that ranges between 2.35 to 2.75, which depends on the deposition conditions and post deposition treatments.…”

“…6 In particular, Parylene-F type films ( -CF 2 -C 6 H 4 -CF 2 -) n have a reported decomposition temperature of 530°C and a low frequency dielectric constant that ranges between 2.35 to 2.75, which depends on the deposition conditions and post deposition treatments. [4][5][6][7][8] At present, there are two methods for depositing Parylene-F films. In Gorham's method, the solid dimer ( -CF 2 -C 6 H 4 -CF 2 -) 2 is sublimed and then cracked at 720-730°C to produce the monomer which is polymerized on the substrate to obtain Parylene-F films.…”

“…In Gorham's method, the solid dimer ( -CF 2 -C 6 H 4 -CF 2 -) 2 is sublimed and then cracked at 720-730°C to produce the monomer which is polymerized on the substrate to obtain Parylene-F films. 8,9 In a second, more recent, method CF 2 Br-C 6 H 4 -CF 2 Br precursor is passed over a bed of Zn catalyst particles maintained at 350°C to strip the Br atoms forming the reactive ( -CF 2 -C 6 H 4 -CF 2 -) monomer which is subsequently polymerized on the substrate surface. 6 A simpler process that is compatible with current dielectric deposition reactors and processes would be preferred.…”

Real-time crystallization in fluorinated parylene probed by conductivity spectra

“…Poly(a,a,a 0 ,a 0 -tetrafluoro-p-xylylene) fluorinated parylene (-CF 2 -C 6 H 4 -CF 2 -), owning a dielectric constant between 2.25 and 2.9, 10 a high thermal stability above 520 C, 11,12 presents the peculiarity to have simultaneously a very high T c ($400 C 13 ) and a low T g (between 16 C 14 and 100 C 15,16 ). Its good thermal and electrical properties match with the required electrical insulation layers for high temperature electronic devices (exposing materials up to 350 C).…”