SIST EN 60191-3:2002

Mechanical standardization of semiconductor devices -- Part 3: General rules for the preparation of outline drawings of integrated circuits

Gives guidance on the preparation of drawings of integrated circuits outlines.

Mechanische Normung von Halbleiterbauelementen -- Teil 3: Allgemeine Regeln für die Erstellung von Gehäusezeichnungen für integrierte Schaltungen

Normalisation mécanique des dispositifs à semiconducteurs -- Partie 3: Règles générales pour la préparation des dessins d'encombrement des circuits intégrés

Donne des indications pour la préparation des dessins d'encombrement des circuits intégrés.

Mechanical standardization of semiconductor devices - Part 3: General rules for the preparation of outline drawings of integrated circuits (IEC 60191-3:1999)

General Information

• Status: Published
• Publication Date: 31-Aug-2002
• ICS: 01.100.25 - Electrical and electronics engineering drawings
• ICS: 31.080.01 - Semiconductor devices in general
• ICS: 31.240 - Mechanical structures for electronic equipment
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Sep-2002
• Due Date: 01-Sep-2002
• Completion Date: 01-Sep-2002
• Ref Project: EN 60191-3:1999 - Mechanical standardization of semiconductor devices - Part 3: General rules for the preparation of outline drawings of integrated circuits

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 60191-3:2002
01-september-2002
Mechanical standardization of semiconductor devices - Part 3: General rules for
the preparation of outline drawings of integrated circuits (IEC 60191-3:1999)
Mechanical standardization of semiconductor devices -- Part 3: General rules for the
preparation of outline drawings of integrated circuits
Mechanische Normung von Halbleiterbauelementen -- Teil 3: Allgemeine Regeln für die
Erstellung von Gehäusezeichnungen für integrierte Schaltungen
Normalisation mécanique des dispositifs à semiconducteurs -- Partie 3: Règles
générales pour la préparation des dessins d'encombrement des circuits intégrés
Ta slovenski standard je istoveten z: EN 60191-3:1999
ICS:
01.100.25 5LVEHVSRGURþMD Electrical and electronics
HOHNWURWHKQLNHLQHOHNWURQLNH engineering drawings
31.080.01 Polprevodniški elementi Semiconductor devices in
(naprave) na splošno general
31.240 Mehanske konstrukcije za Mechanical structures for
elektronsko opremo electronic equipment
SIST EN 60191-3:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 60191-3:2002

---------------------- Page: 2 ----------------------

SIST EN 60191-3:2002

---------------------- Page: 3 ----------------------

SIST EN 60191-3:2002

---------------------- Page: 4 ----------------------

SIST EN 60191-3:2002

---------------------- Page: 5 ----------------------

SIST EN 60191-3:2002

---------------------- Page: 6 ----------------------

SIST EN 60191-3:2002
NORME CEI
INTERNATIONALE IEC
60191-3
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
1999-10
Normalisation mécanique des dispositifs
à semiconducteurs –
Partie 3:
Règles générales pour la préparation
des dessins d'encombrement des circuits intégrés
Mechanical standardization of
semiconductor devices –
Part 3:
General rules for the preparation of outline
drawings of integrated circuits
 IEC 1999 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun procédé, any form or by any means, electronic or mechanical,
électronique ou mécanique, y compris la photo-copie et les including photocopying and microfilm, without permission in
microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: [phone] e-mail: [e-mail] IEC web site http://www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
XA
PRICE CODE
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

---------------------- Page: 7 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 3 –
CONTENTS
Page
FOREWORD . 5
Clause
1 General. 9
2 Terminology and definitions. 9
3 Cross-referencing of packages . 15
4 Terminal identification – Numbering of terminals. 15
5 Dimensions and reference letter symbols. 21
6 Drawing layout . 31
7 Dimensioning and tolerances. 31
8 Inter-conversion of inch and millimetre dimensions, and rules for rounding-off . 31
9 Definition of families. 31
10 Examples of drawings . 33
11 Design procedure for dimensions of integrated circuit packages . 33
12 Rules for mounting integrated circuit packages into carriers. 33
13 Bending of terminals of QUIL packages . 37
14 Pin grid arrays. 41
15 Rule for orientation of integrated circuit packages in handling and
shipping carriers such as stick magazines and rails . 41
Annex A (normative) Limits applicable for the dimensions of integrated circuit
package outlines . 43
Annex B (informative) Example drawings showing cross-referencing of packages,
utilization of reference letter symbols, terminal identification and index area. 49
Annex C (normative) Terminal identification and numbering of terminals of devices with
terminals disposed in three or more rows in each orthogonal direction. 81
Annex D (normative) Recommended dimensions of integrated circuit packages
of form G family. 85
Annex E (normative) General rules for the preparation of outline drawings of packages
of form G intended for automated handling . 87
Annex F (normative) General rules for the preparation of outline drawings
of pin grid arrays . 95
Annex G (normative) Rule for orientation of integrated circuit packages in handling
and shipping carriers such as stick magazines and rails. 103
Annex H (normative) Bottom view method for terminal No. 1 recognition . 107
Annex K (normative) Gate burrs, mold flash and protrusions . 113

---------------------- Page: 8 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MECHANICAL STANDARDIZATION OF
SEMICONDUCTOR DEVICES –
Part 3: General rules for the preparation of outline drawings
of integrated circuits
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60191-3 has been prepared by subcommittee 47D: Mechanical
standardization of semiconductor devices, of IEC technical committee 47: Semiconductor
devices.
This second edition cancels and replaces the first edition published in 1974, amendment 1
(1983), amendment 2 (1995), IEC 60191-3A (1976), IEC 60191-3B (1978), IEC 60191-3C
(1987), IEC 60191-3D (1988), IEC 60191-3E (1990) and IEC 60191-3F (1994).
The text of this standard is based on the following documents:
FDIS Report on voting
47D/299/FDIS 47D/322/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with ISO/IEC Directives, Part 3.

---------------------- Page: 9 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 7 –
Annexes A, C, D, E, F, G, H and K form an integral part of this standard.
Annex B is for information only.
The committee has decided that the contents of this publication will remain unchanged until 2005.
At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition; or
• amended.

---------------------- Page: 10 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 9 –
MECHANICAL STANDARDIZATION OF
SEMICONDUCTOR DEVICES –
Part 3: General rules for the preparation of outline drawings
of integrated circuits
1 General
1.1 Scope
This part of IEC 60191 gives guidance on the preparation of drawings of integrated circuit
outlines.
1.2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 60191. For dated references, subsequent amendments
to, or revisions of, any of these publications do not apply. However, parties to agreements
based on this part of IEC 60191 are encouraged to investigate the possibility of applying the
most recent editions of the normative documents indicated below. For undated references, the
latest edition of the normative document referred to applies. Members of IEC and ISO maintain
registers of currently valid International Standards.
IEC 60191-1:1966, Mechanical standardization of semiconductor devices – Part 1: Preparation
of drawings of semiconductor devices
IEC 60191-2:1995, Mechanical standardization of semiconductor devices – Part 2: Dimensions
IEC 60191-4:1999, Mechanical standardization of semiconductor devices – Part 4: Coding
system and classification into forms of package outlines for semiconductor devices
ISO 1101-1,  Geometrical Product Specification (GPS) – Geometrical tolerancing –
1)
Generalities, definitions, symbols, indications on drawings
ISO 2692:1988, Technical drawings – Geometrical tolerancing – Maximum material principle
2 Terminology and definitions
For the purpose of this part of IEC 60191, the following definitions apply.
2.1
package outline drawing
the drawing of a package which specifies the dimensional characteristics and other closely
associated features which are required for mechanical interchangeability.
___________
1)
To be published.

---------------------- Page: 11 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 11 –
2.2
seating plane
a plane which designates the plane of contact of the package, including any stand-off, with the
surface on which it will be mounted.
NOTE – This plane is often used as the reference plane.
2.3
base plane
a plane drawn parallel to the seating plane through the lowest point of the package, excluding
any stand-off.
2.4
gauging plane
a plane perpendicular to the terminals, at which the position of the terminals is controlled.
NOTE – In some packages, two or more of the above-mentioned planes may coincide.
2.5
terminal position
one of a series or equally spaced locations on a circle or on a row, which may or may not be
occupied by a terminal.
2.6
visual index
a reference feature (e.g. mark, chamfer, notch, tab, depression, etc.) which identifies the first
terminal position.
2.7
index area
the area in which a portion or all of the visual index should lie.
2.8
mechanical index
a feature (e.g. tab, notch, flat, groove, etc.) which provides orientation during automatic
handling.
Where possible, the mechanical index should coincide with the visual index.
2.9
index centre line or datum line
a centre line through a visual index feature (e.g. tab) which is used to orientate the index with
the first terminal position.
2.10
grid reference corner
the first terminal position (viewed from the free end of the terminals) in an alphanumeric grid
system.
2.11
terminal row
a series of equally spaced terminal positions which are located on a straight line.
2.12
terminal circle
a series of equally spaced terminal positions which are located on a circle.

---------------------- Page: 12 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 13 –
2.13
gauging zone
a control zone within which positional tolerances for the terminal axes or the planes of terminal
symmetry are specified.
2.14
dambar
metal barrier extending between adjacent leads to restrict the flow of mold compound material
between and along leads.
2.15
dambar protrusion
the presence of excess metal extending outward from the edge of a lead shoulder.
The width of the protrusion is the perpendicular distance from the defined lead edge to the
outermost portion of the excess metal. The length of the protrusion is the largest dimension of
the excess metal parallel to the defined lead edge (see figure 1a).
2.16
dambar intrusion
the absence of metal causing a discontinuity along the intended profile of a lead shoulder.
The depth of the intrusion is the perpendicular distance from the defined lead shoulder edge to
the innermost edge of the region of absent metal. The length of the intrusion is the largest
dimension of the region of absent metal parallel to the defined lead edge (see figure 1b).
IEC  739/98 IEC  740/98
Figure 1a – Protrusion Figure 1b – Intrusion
Figure 1 – Dambar protrusion and intrusion

---------------------- Page: 13 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 15 –
2.17
mold flash
opaque mold compound material attached to the finished part and extending onto, between,
and/or around adjacent leads and package edges.
2.18
interlead (window) flash
opaque mold compound material attached to an area between adjacent leads remaining after
dambar trim operations.
2.19
protrusion
plastic or metal excess material remaining from the molding and trim/form/singulation
operations.
2.20
gate burrs
excess metal material remaining after singulating the package from its leadframe at the mold
gate area.
3 Cross-referencing of packages
The classification into forms of package outlines for semiconductor devices in IEC 60191-4 has
superseded the form descriptions of forms 1 - 5 below. The cross-referencing to forms 1 - 5 is
given for information purposes only.
Cross-referencing is achieved by using the drawings in annex B as follows.
3.1 Form 1 (axial) – figures B.1, B.2, B.3, B.4, B.5 and B.6
3.2 Form 2 (axial) – figures B.7, B.7a, B.8 and B.9
3.3 Form 3 (axial) – figures B.10, B.11 and B.12
3.4 Form 4 (peripheral) – figures B.13, B.14, B.15, B.16, B.16a, B.17 and B.18
3.5 Form 5 (special)
This form, for which there are no examples given in annex B, refers to figures which are
combinations of axial and peripheral or which, for other reasons, e.g. leadless packages, do
not fit in the axial or peripheral categories.
4 Terminal identification – Numbering of terminals
Where possible, device terminals should be identified according to the following rules.
4.1 Devices with terminals disposed in linear array (see figure B.2)
The terminals are considered as being viewed from their free ends. The terminal nearest the
visual index should be numbered as No. 1, the other terminals should be numbered
progressively from terminal No. 1.

---------------------- Page: 14 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 17 –
4.2 Devices with terminals disposed on a single circular array (see figures B.10 and B.11)
The terminals are considered as being viewed from their free ends. The terminal, the centre of
which is past the datum line of the visual index should be numbered as No. 1, the other
terminals should be numbered progressively in a clockwise sequence from terminal No. 1.
Where omission of one terminal in an otherwise equally spaced array identifies the datum line,
the position of the omitted terminal should not be numbered; but in a fixed modular circuit
array, any location of omitted terminal which does not define a datum line shall be numbered.
4.3 Devices with terminals disposed on multiple circular arrays (see figure B.12)
The rules given in 4.2 will be applied as follows: the terminals located on the pitch circle of the
largest diameter should be numbered A1, A2, A3, etc., the terminals located on the other pitch
circles of decreasing diameter should be numbered progressively B1, B2, B3, etc., C1, C2, C3,
etc.
4.4 Devices with terminals disposed on a square or rectangular periphery
(see figures B.1, B.3, B.4, B.6, B.7, B.7a, B.8, B.9, B.13, B.14, B.25, B.16, B.16a, B.17
and B.18)
Visual identification of the top of the device should be provided. The means of identification of
terminal position No. 1 should also be provided. These identifications may be combined.
When terminal No. 1 marking is required on the bottom side of the package, the following
convention is used (see figures H.1 and H.2).
The terminal positions should be numbered progressively in an anti-clockwise direction around
the periphery of the device as viewed from the top. The terminal position No. 1 shall be the first
position anti-clockwise from the means of identification.
Each terminal shall be identified by the number of its position. Terminals may not necessarily
be present in all the numbered positions, but those present shall have the number of the
position.
When a terminal occupies more than one terminal position, this terminal should be identified by
the number of the first and last occupied terminal positions, these two numbers being
separated by a dash.
(For a theoretical example, see figure 2.)
When the device presents more than two rows of terminals in one direction, because the
folding of the terminals emerging in one plane has been made in more than two planes, the
terminals should be numbered progressively in correspondence with the position of their point
of emergence from the body of the device.
(For a theoretical example, see figure 3.)

---------------------- Page: 15 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 19 –
Figure 2 – Theoretical example showing how to number the terminals of a device
with terminals disposed on a rectangular periphery and with some of them
occupying more than one terminal position
Figure 3 – Example showing how to number the terminals of a "QUIL" package

---------------------- Page: 16 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 21 –
4.5 Devices with terminals disposed in three or more rows in each orthogonal
direction (see figure B.5)
1) The terminal position should be on an orthogonal network of equal pitch respectively in both
directions.
2) Terminal positions shall be numbered whether or not a terminal is present.
3) With the device viewed from the free end of the terminals and from the index area in the
lower left:
a) the first vertical row is numbered 1, the other vertical rows are numbered progressively
from 1;
b) the first horizontal row is lettered A, the other horizontal rows are lettered in alphabetical
order from A (without using I, O, Q, S, X and Z).
(Figure C.1 shows an example of this designation system.)
4) When more than 20 rows are possible, the rows after row Y (the 21st) shall be given an
alphabetical prefix, AA, the 22nd AB, etc.
(Figure C.2 shows an example of a device having two rows near to the edges of the long
side of the package and with a pitch equal to "e" in one direction and "2e" in the other and
with a distance equal to "20e" between the inner two rows.)
5 Dimensions and reference letter symbols
5.1
seated height (A)
distance from the seating plane to the highest point of the package.
5.2
stand-off height (A )
1
distance between the seating plane and the base plane.
5.3
package height (A )
2
distance from the base plane to the highest point of the package.
5.4
terminal circle diameter (∅a, ∅a , ∅a , etc.)
A B
diameter of the circle upon which the terminal positions are located. ∅a should be used for the
largest pitch circle diameter when there is more than one pitch circle present.
5.5
stand-off major dimension (B)
major dimension of the stand-off cross-section.
5.6
stand-off minor dimension (B )
1
minor dimension of the stand-off cross-section.
5.7
stand-off diameter (∅B)
diameter of the stand-off cross-section.

---------------------- Page: 17 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 23 –
5.8
terminal width (b)
major dimension of the cross-section of a terminal.
5.9
other terminal width(s) (b , b , b , etc.)
1 2 3
5.10
terminal diameter(s) (∅b, ∅b , ∅b , ∅b , ∅b , etc.)
0 1 2 3
diameter of the circumscribed circle containing the terminal.
NOTE – ∅b and ∅b usually refer to diameters which are closely controlled over a specified terminal length (see
0 2
figures B.10 and B.11).
5.11
terminal thickness (c)
minor dimension of the cross-section of a terminal.
5.12
package length (D)
major dimension of the package, excluding terminals, measured in a plane parallel to the
seating plane.
NOTE – If terminals are presented for mounting in two opposite directions only, they are deemed to extend in the
width direction (E) (see figure B.16a).
5.13
other package length(s) (D , D , etc.)
1 2
other package length(s), usually smaller than
D.
5.14
∅
package diameter ( D)
major diameter of the package, excluding terminals, measured in a plane parallel to the seating
plane.
5.15
other package diameter(s) (∅D , ∅D , etc.)
1 2
other package diameter(s), usually smaller than ∅D.
5.16
stand-off spacing(s), linear (d, d , d , d , d , etc.)
1 2 A B
linear spacing(s) between true positions of stand-off centres.
5.17
package width (E)
minor dimension of the package, excluding terminals, measured in a plane parallel to the
seating plane.
5.18
other package width(s) (E , E , etc.)
1 2
other package width(s), usually smaller than E.
5.19
terminal spacing, linear (e, e , e , e , e , etc.)
1 2 A B
linear spacing between true positions of terminal centres.

---------------------- Page: 18 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 25 –
5.20
flange zone height (F)
overall dimension of the flange zone, including any fillet, measured from the base plane.
5.21
flange height (F )
1
flange dimension excluding any fillet.
5.22
package length zone (G )
D
Length of a zone which includes the actual package length, package irregularities and the
uncontrolled part of any peripheral terminals which are presented for mounting in the length
direction.
5.23
package width zone (G )
E
length of a zone which includes the actual package width, package irregularities and the
uncontrolled part of any peripheral terminals which are presented for mounting in the width
direction.
5.24
package diameter zone (∅G)
diameter of a zone which includes the actual package diameter, package irregularities and the
uncontrolled part of any peripheral terminals which are presented for mounting radially.
5.25
overall length (H )
D
largest overall dimension, including package length, of peripheral terminals which are
presented for mounting in the length direction.
5.26
overall width (H )
E
largest overall dimension, including package width, of peripheral terminals which are presented
for mounting in the width direction.
5.27
overall diameter (∅H)
largest overall diameter of peripheral terminals which are presented for mounting radially.
5.28
index height or depth (h)
height or depth of index feature.
5.29
index width (j)
width of index feature.
5.30
index length (k)
length of index feature.
On cylindrical packages, the index length (e.g. tab) is measured from the actual diameter ∅D
of the device.

---------------------- Page: 19 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 27 –
5.31
terminal length(s) (L, L )
0
length(s) of terminal available for mounting, measured from the seating plane.
NOTE – L usually refers to that part of the terminal over which the diameter (∅b ) is closely controlled (see
0 0
figure B.11).
5.32
terminal length(s) (L , L )
D E
controlled terminal zone(s) for mounting, measured from ends of peripheral terminals.
5.33
terminal length(s) (L , L , L , etc.)
1 2 3
terminal length(s) measured from the base plane.
NOTE – L – L usually refers to that part of the terminal over which the terminal diameter ∅b is closely controlled.
2 1 2
5.34
mounted length (M )
D
distance measured parallel to the seating plane, in the D direction, between the outer faces of
the outer rows of terminals, when the device is fully seated in the holes of a given gauge (see
notes 1 and 2 of 5.35).
5.35
mounted width (M )
E
distance measured parallel to the seating plane, in the E direction, between the outer faces of
the outer rows of terminals, when the device is fully seated in the holes of a given gauge.
NOTE 1 – M (M ) is measured between two planes, perpendicular to the seating plane, which are in contact with
D E
the outer faces of the terminals in the outer rows at their widest point above the seating plane, when viewed parallel
to the transversal (longitudinal) centre line (centre line in the E(D) direction) of the device.
Figure 4 shows an example of holes in a gauge for QUIL packages, in which the device will be seated.
Figure 4 – Example of holes in a gauge for QUIL packages
NOTE 2 – M (M ) max. is chosen to be equal to the sum of the terminal rows spacing and the mounting hole
D E
diameter, rounded up to the first decimal value.

---------------------- Page: 20 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 29 –
5.36
quantity of terminal positions (n)
total quantity of potential terminal positions in accordance with the specified terminal position
designation system. The actual quantity of terminals present may be less than (n).
5.37
allowable quantity of missing terminals (n )
1
maximum quantity of terminal positions which can be unoccupied.
5.38
package mounting hole diameter (∅p)
diameter of the hole in the package for mounting.
5.39
terminal emergence height (Q)
distance from the seating plane to the underside of the terminals where they emerge from the
package.
5.40
terminal emergence dimension (Q )
1
distance from the top surface of the package to the top surface of terminals where they emerge
from the package.
5.41
other terminal emergence dimensions (Q , Q , etc.)
2 3
dimensions of other terminal features.
5.42
package overhang(s) (Z, Z , Z , etc.)
1 2
distance from the end terminal true position to the extremity of the package.
In the case where the terminals extend beyond the package, Z, Z shall be specified as zero.
1
Negative dimensions shall not be used.
The overhang at the opposite end of the package, if different from Z, shall be designated as Z
1
(see figure B.1).
NOTE – It is recommended that the minimum and maximum values of Z (Z ) fulfil one of the following relations:
1
e
Z ≤
2
e
<≤Ze
2
3e
eZ<≤ etc.
2
5.43
index datum angle(s) (α, α , α , etc.)
A B
angular spacing between the index feature (datum) and the first terminal true position on a
terminal circle.
α should be used for the angular spacing between the index feature and the first terminal
A
located on the largest diameter circle.

---------------------- Page: 21 ----------------------

SIST EN 60191-3:2002
60191-3 © IEC:1999 – 31 –
5.44
terminal spacing, angular (β, β , β , etc.)
A B
angular spacing between true positions of terminal centres.
β refers to the largest diameter circle
A
5.45
angle(s) base (γ, γ , γ , etc.)
1 2
other angular features associated with the base.
5.46
Terminal spread, angular (θ)
Angle between the terminal and a line perpendicular to the seating plane.
5.47
angle(s), package (θ , θ , etc.)
1 2
other angular features associated with the package.
6 Drawing layout
The requirements of 1.1 of IEC 60191-1 are applicable.
7 Dimensioning and tolerances
The requirements of 1.2 of IEC 60191-1 are applicable, except for 1.2.9.
The principles given in ISO 1101, are also applicable. The limits which should normally be
given for the dimensions listed in clause 5 above are contained in the table of annex A.
8 Inter-conversion of inch and millimetre dimensions,
and rules for rounding-off
The requirements of 1.3 of IEC 60191-1 are applicable.
9 Definition of families
(For information only; see also clause 3.)
9.1 Family
...