DIN EN 61249-4-18:2014-07

This standard contains requirements for properties of prepreg that is mainly intended to be used as bonding sheets in connection with laminates according to IEC 61249-2-39 when manufacturing multilayer boards according to IEC 62326-4. Multilayer printed boards comprised of these materials are suitable for lead-free assembly processes. These prepreg materials may also be used to bond other types of laminates, however. The prepreg consist of a reinforcing glass fabric which is impregnated with high-performance epoxide resin, partially cured to the B-stage. The flammability rating is achieved through the use of bromine reacted into the polymer. Inorganic fillers may be used. Contrast agents may be added to enhance processing such as automated optical inspection (AOI). Prepreg according to this standard is of defined flammability (vertical burning test). The flammability rating on fully cured prepreg is achieved through the use of brominated fire retardants contained as an integral part of the polymeric structure. After curing of the prepreg according to the supplier´s instructions, the glass transition temperature is defined to be 170 °C minimum. Prepregs furnished under this standard shall be qualified. Qualification testing shall be performed to demonstrate the manufacturer´s ability to meet the requirements of this standard. Qualification testing shall be conducted at a laboratory compliant with IEC laboratory requirements. The manufacturer shall retain on file the data which supports that the materials meet this standard and shall be readily available for review upon request. The responsible committee is DKE/K 682 "Montageverfahren für elektronische Baugruppen" ("Electronics assembly technology") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.