IEC 60191-1:2018 pdf download

IEC 60191-1:2018 pdf download.Mechanical standardization of semiconductor devices – Part 1: General rules for the preparation of outline drawings of discrete devices
1 Scope
This part of IEC 601 91 gives guidelines on the preparation of outline drawings of discrete devices, including discrete surface-mounted semiconductor devices with lead count less than 8. For the preparation of outline drawings of surface-mounted discrete devices with a lead count higher or equal to 8, IEC 601 91 -6 should be referred to as well. The primary object of these drawings is to indicate the space to be allowed for devices in equipment, together with other dimensional characteristics required to ensure mechanical interchangeability. Complete interchangeability involves other considerations such as the electrical and thermal characteristics of the semiconductor devices concerned. The international standardization represented by these drawings therefore encourages the manufacturers of devices to comply with the tolerances shown on the drawings in order to extend their range of customers internationally. It also gives equipment designers an assurance of mechanical interchangeability between the devices obtained from suppliers in different countries, provided they allow the space in their equipment that is indicated by the drawings and take note of the more precise information on bases, studs, etc. NOTE Additional details of reference letter symbols used in this document are given in Annex A.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp 3.1 device outline drawing drawing that includes all dimensional characteristics required for the mechanical interchangeability of the complete device Note 1 to entry: The device outline drawing includes the case or body, all terminals and the locating tab if present. 3.2 terminal part of the semiconductor device primarily used in making an electrical, mechanical or thermal connection EXAMPLE Flexible leads, rigid leads, pins, studs, etc. 3.3 case outline drawing drawing that includes all dimensional characteristics required for the mechanical interchangeability of the case or body Note 1 to entry: The case outline drawing does not include the dimensions of the terminals or the locating tab if present, but their positions are shown by dotted lines. 3.4 base drawing drawing that includes all dimensional characteristics required for the mechanical interchangeability of the terminals and mechanical index Note 1 to entry: Examples of these characteristics are: lead length, lead diameters with controlled zones, lead spacing, pitch circle diameter, thickness, width and length of a tab, etc. Note 2 to entry: The diameter or major axis of the case outline should not be given on the base drawing. Note 3 to entry: Many semiconductor devices have identical cases, but differ in the number or the length of terminals. It is also possible to have the same type of base associated with cases that are not identical. Consequently, there are advantages in having: a) a single drawing including only the dimensional characteristics of the case outline and separate drawings for the various bases which can be associated with this case outline.3.6 visual index any single terminal (or omission of) readily distinguished by the eye from others or any distinctive boss, stippled pattern or colour mark adjacent to a terminal 3.7 datum theoretically exact geometric reference (such as axes, planes, straight lines etc.) to which toleranced features are related Note 1 to entry: Datums may be based on one or more datum features of a part. [SOURCE: ISO 5459:201 1 , 3.4] 3.8 seating plane seating base reference plane from which, in general, outline and base dimensions are given 3.9 seated height mounted height distance from the seating plane to the top of any exposed tip or rigid terminal present, otherwise to the top of the outline Note 1 to entry: Flexible terminals should not be included as part of the seated height, but the mounted height should include a minimum allowance necessary for an axially mounted flexible lead to be bent at right angles. 3.1 0 controlled cylindrical zone zone that defines a portion of the body of minimum length over which the diameter is controlled to closer tolerances than is allowed over the full length of the body 3.1 1 stand-off distance from the seating plane to the lowest point of a package