BS IEC 60191-1 pdf download

BS IEC 60191-1 pdf download Mechanical standardization of semiconductor devices — Part 1: General rules for the preparation of outline drawings of discrete devices
1 scope and object
This part of lEC 60191 gives guidelines on the preparation of outline drawings of discretedevices.
NOTE For preparation of outline drawings of surface mounted discrete devices IEC 60191-6 should be referred toas well.
The primary object of these drawings is to indicate the space which should be allowed fordevices in an equipment,together with other dimensional characteristics required to ensuremechanical interchangeability.
lt should be noted that complete interchangeability involves other considerations such as theelectrical and thermal characteristics of the semiconductor devices concerned.
The international standardization represented by these drawings therefore encourages themanufacturers of devices to comply with the tolerances shown on the drawings in order toextend their range of customers internationally. lt also gives equipment designers anassurance of mechanical interchangeability between the devices obtained from suppliers indifferent countries，provided they allow the space in their equipment that is indicated by thedrawings and take note of the more precise information on bases, studs,etc.
NOTE Additional details on the standardization philosophy used in this standard are given in Annex B.
Normative references
The following referenced documents are indispensable for the application of this document.For dated references,only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 60191-2:1966,Mechanical standardization of semiconductor devices – Part 2:Dimensions (including all supplements and amendments)
IEC 60191-4，Mechanical standardization of semiconductor devices – Part 4: Coding systemand classification into forms of package outlines for semiconductor device packages
ISO 370，Toleranced dimensions – Conversion from inches to millimetres and vice versa(withdrawn 2000-05)
3 Terms and definitions
For the purposes of this document, the following definitions apply.
3.1
device outline drawing
drawing which includes all dimensional characteristics required for the mechanicalinterchangeability of the complete device. lt includes the case or body,all terminals and thelocating tab if present
3.2
terminal
that part of the semiconductor device primarily used in making an electrical,mechanical orthermal connection. Examples of terminals are flexible leads, rigid leads,pins,studs, etc.
3.3
case outline drawing
drawing which includes all dimensional characteristics required for the mechanicalinterchangeability of the case or body. lt does not include the dimensions of the terminals orthe locating tab if present, but their positions are shown by dotted lines
3.4
base drawing
drawing which includes all dimensional characteristics required for the mechanicalinterchangeability of the terminals and mechanical index
NOTE 1 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 The diameter or major axis of the case outline should not be given on the base drawing.
NOTE 3 Many semiconductor devices have identical cases, but differ in the number or the length of terminals. lt isalso possible to have the same type of base associated with cases which 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,
or
b) a single drawing including only the dimensional characteristics of the base and separate drawings for the
various case outlines which can be associated with this base.
3.5
mechanical index
locating feature, or that portion of the device specifically designed to provide orientation.
NOTE Examples of a mechanical index are: key, keyway, locating tab,etc.
3.6
visual index
any single terminal (or omission of) readily distinguished by the eye from others or anydistinctive boss,stippled pattern or colour mark adjacent to a terminal