This part of IEC 60893 belongs to a series which deals with industrial rigid laminated sheets based on thermosetting resins for electrical purposes. This series comprises 4 parts: - Part 1: Definitions, designations and general requirements (IEC 60893-1) - Part 2: Methods of test (IEC 60893-2) - Part 3: Specifications for individual materials (IEC 60893-3) - Part 4: Technical Report - Typical values (IEC 60893-4) This standard contains one of the parts which form Part 3. Part 7: Requirements for rigid laminated sheets based on polyimide resins This part of IEC 60893 contains the requirements for industrial rigid laminated sheets for electrical purposes based on polyimide resins and different reinforcements. Special applications and distinguishing properties are given in Table 1. This amendment introduces reworked limits for various property requirements for all types of industrial rigid laminated sheets for electrical purposes based on thermosetting resins for electrical purposes. These new limits are based on knowledge which has been gained in International Evaluations. Materials which conform to this standard meet established levels of performance. However, the selection of a material by a user for a specific application should be based on the actual requirements necessary for adequate performance in that application and not based on this standard alone. At DIN and VDE the responsible Committee is K 181 "Feste elektrische Isolierstoffe" (AK 181.0.6 "Schichtpressstoffe") ("Solid electrical insulating materials" (AK 181.0.6 "Laminates")) of the DKE (German Commission for Electrical, Electronic and Information Technologies).