DIN EN 61240:2017-08

This standard provides general rules for drawing all dimensional and geometrical characteristics of a surface-mounted piezoelectric device enclosure in order to ensure comparability and inter-changeability of all outline drawings of surface-mounted devices (referred to in this standard as SMD) for frequency control and selection. The enclosures of quartz crystal resonators and oscillators are standardized in this third edition of IEC 61240. Regarding the current situation of many quartz crystal device suppliers, many suppliers use their own enclosure layouts in their catalogues. For the convenience of consumers, general rules of enclosure layout and definition of size shall be uniformly specified. The reasons for the revision of IEC 61240:2012 are that the height of the packaging should not be included in a drawing, only the overall height of the enclosures should be shown and for small enclosure types, size tolerances in smaller enclosures do not meet the conditions defined in Annex A. In the newly proposed general rules for enclosure drawings, only the overall height of the enclosures should be shown and the size tolerance in smaller enclosures will be revised. Additional clauses of the standard include the title of the outline drawing, composition of the outline drawing, requirements for terminal leads, requirements for the terminal land area and connections of terminal leads. Informative Annex A describes miniaturized leadless ceramic enclosures of piezoelectric devices (SMD) for frequency control and selection. Informative Annex B contains an example of terminal connections for surface-mounted piezoelectric devices (SMD) for frequency control and selection. The responsible committee is DKE/K 642 "Piezoelektrische Bauteile zur Frequenzstabilisierung und -selektion" ("Piezoelectric and dielectric devices for frequency control and selection") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.