FR-2 (Flame Resistant 2) is a NEMA designation for synthetic resin bonded paper, a composite material made of paper impregnated with a plasticized phenol formaldehyde resin, used in the manufacture of printed circuit boards. Its main properties are similar to NEMA grade XXXP (MIL-P-3115) material, and can be substituted for the latter in many applications.
FR-2 sheet with copper foil lamination on one or both sides is widely used to build low-end consumer electronic equipment. While its electrical and mechanical properties are inferior to those of epoxy-bonded fiberglass, FR-4, it is significantly cheaper. It is not suitable for devices installed in vehicles, as continuous vibration can make cracks propagate, causing hairline fractures in copper circuit traces. Without copper foil lamination, FR-2 is sometimes used for simple structural shapes and electrical insulation.
FR-2 can be machined by drilling, sawing, milling and hot punching. Cold punching and shearing are not recommended, as they leave a ragged edge and tend to cause cracking. Tools made of high-speed steel can be used, although tungsten carbide tooling is preferred for high volume production.
Adequate ventilation or respiration protection are mandatory during high-speed machining, as it gives off toxic vapors.
^ abcdefgMehdorn, Walter (1949). Kunstharzpreßstoffe und andere Kunststoffe - Eigenschaften, Verarbeitung, Anwendungen(PDF) (in German) (3 ed.). p. 240. doi:10.1007/978-3-662-12205-1. ISBN978-3-662-12206-8. (PDF) from the original on 2021-03-20. Retrieved 2021-03-20. (viii+355 pages)
^. Archived from the original on 2006-08-04. Retrieved 2006-08-05.
^"Pertinax – ein traditionsreiches Material mit neuer Zukunft" (in German). Müller Ahlhorn. 2014-01-06. from the original on 2020-12-03. Retrieved 2021-03-20.
this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, december, 2017, learn, when. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources FR 2 news newspapers books scholar JSTOR December 2017 Learn how and when to remove this template message FR 2 Flame Resistant 2 is a NEMA designation for synthetic resin bonded paper a composite material made of paper impregnated with a plasticized phenol formaldehyde resin used in the manufacture of printed circuit boards Its main properties are similar to NEMA grade XXXP MIL P 3115 material and can be substituted for the latter in many applications Contents 1 Applications 2 Properties 3 Fabrication 4 Trade names and synonyms 5 See also 6 References 7 Further readingApplications editFR 2 sheet with copper foil lamination on one or both sides is widely used to build low end consumer electronic equipment While its electrical and mechanical properties are inferior to those of epoxy bonded fiberglass FR 4 it is significantly cheaper It is not suitable for devices installed in vehicles as continuous vibration can make cracks propagate causing hairline fractures in copper circuit traces Without copper foil lamination FR 2 is sometimes used for simple structural shapes and electrical insulation Properties editProperty ValueDielectric constant or relative permittivity 4 5 1 MHzDissipation factor 0 024 0 26 1 MHzDielectric strength 29 kV mm 740 V thou Fabrication editFR 2 can be machined by drilling sawing milling and hot punching Cold punching and shearing are not recommended as they leave a ragged edge and tend to cause cracking Tools made of high speed steel can be used although tungsten carbide tooling is preferred for high volume production Adequate ventilation or respiration protection are mandatory during high speed machining as it gives off toxic vapors Trade names and synonyms editCarta 1 Haefelyt Lamitex Paxolin Paxoline Pertinax 1 taken over by Lamitec 2 and Dr Dietrich Muller GmbH in 2014 3 Getinax in the Ex USSR Phenolic paper Presszell 1 Repelit 1 Synthetic resin bonded paper SRBP Turbonit 1 Veroboard Wahnerit 1 See also editFormica plastic Micarta 1 References edit a b c d e f g Mehdorn Walter 1949 Kunstharzpressstoffe und andere Kunststoffe Eigenschaften Verarbeitung Anwendungen PDF in German 3 ed p 240 doi 10 1007 978 3 662 12205 1 ISBN 978 3 662 12206 8 Archived PDF from the original on 2021 03 20 Retrieved 2021 03 20 viii 355 pages lamitec de Archived from the original on 2006 08 04 Retrieved 2006 08 05 Pertinax ein traditionsreiches Material mit neuer Zukunft in German Muller Ahlhorn 2014 01 06 Archived from the original on 2020 12 03 Retrieved 2021 03 20 Further reading editIndustrial Laminated Thermosetting Products National Electrical Manufacturers Association NEMA 2012 02 01 2011 1998 NEMA LI 1 1998 R2011 Retrieved from https en wikipedia org w index php title FR 2 amp oldid 1171898629, wikipedia, wiki, book, books, library,
