IEC 60191-1:2018

IEC 60191-1 ®
Edition 3.0 2018-01
INTERNATIONAL
STANDARD
Mechanical standardization of semiconductor devices –
Part 1: General rules for the preparation of outline drawings of discrete devices
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IEC 60191-1 ®
Edition 3.0 2018-01
INTERNATIONAL
STANDARD
Mechanical standardization of semiconductor devices –

Part 1: General rules for the preparation of outline drawings of discrete devices

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.080.01 ISBN 978-2-8322-5266-6

– 2 – IEC 60191-1:2018  IEC 2018
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 General rules for all drawings . 8
4.1 Drawing layout . 8
4.2 Dimensions and tolerances . 9
4.3 Methods for locating the datum . 10
4.4 Numbering of terminals . 11
4.4.1 General . 11
4.4.2 Single-ended devices with terminals in a linear array . 11
4.4.3 Single-ended devices with terminals in a circular array . 11
4.4.4 Double-ended devices . 11
4.4.5 Devices with terminals disposed in a square or rectangular periphery . 11
4.4.6 Particular case of lozenge – shaped bases . 11
4.4.7 Other devices . 12
5 Additional rules . 12
5.1 Rules for device and case outline drawings . 12
5.2 Rules to specify the dimensions and positions of terminals . 13
5.2.1 General rules . 13
5.2.2 Rules to specify the dimensions and the positions of the terminals on a
base drawing . 13
5.3 Rules for gauge drawings . 13
6 Inter-conversion of inch and millimetre dimensions and rules for rounding off . 14
7 Rules for coding . 14
Annex A (informative) Reference letter symbols . 15
Annex B (informative) Rules to specify the dimensions and positions of terminals on a
base drawing . 18
B.1 Example of dimensioning for a circular base outline with no tab and having
four terminals located symmetrically on a pitch circle . 18
B.1.1 Interpretation of the principle of dimensioning . 18
B.1.2 Checking . 19
B.2 Example of dimensioning for a circular base outline with a tab and having
four terminals located symmetrically on a pitch circle . 19
B.2.1 Interpretation of the principle of dimensioning . 19
B.2.2 Checking . 20
Annex C (normative) General philosophy of flat base devices . 24
Annex D (normative) Special rules for SMD-packages . 26
D.1 General reference . 26
D.2 Lead terminals . 26
D.3 Measuring methods . 26
Annex E (informative) Examples of semiconductor device drawings . 27
Annex F (informative) Former rules for rounding off . 33
F.1 Toleranced dimensions . 33
F.1.1 Maximum and minimum values of toleranced dimensions . 33
F.1.2 Nominal value of toleranced dimensions . 33

F.2 Untoleranced dimensions (maximum only or minimum only) . 33
F.3 Untoleranced nominal dimensions given for general information . 33
F.4 Untoleranced nominal dimensions given to specify true geometrical positions . 34
Annex G (informative) Former rules for coding . 35
G.1 General . 35
G.2 Device outlines . 35
G.3 Bases . 35
G.4 Case outlines . 35
G.5 Type variants and provisional drawings . 35
Bibliography . 36

Figure 1 – Numbering of terminals for the particular case of lozenge – shaped bases . 12
Figure 2 – System to indicate the dimensions of the terminals . 13
Figure B.1 – Circular base outline with no tab . 21
Figure B.2 – Tolerances of terminals. 21
Figure B.3 – Gauge for a circular base outline with no tab . 22
Figure B.4 – Circular base outline with tab . 22
Figure B.5 – Gauge for a circular base outline with tab . 23
Figure C.1 − Example of flat base outline . 25
Figure E.1 – Long form package . 27
Figure E.2 – Post/stud mount package . 27
Figure E.3 – Cylindric package . 28
Figure E.4 – Cylindric in-line package . 29
Figure E.5 – Flange-mounted in-line package . 29
Figure E.6 – Press package . 30
Figure E.7 – SMD-package with flat leads . 30
Figure E.8 – SMD-Package with gull-wing leads . 31
Figure E.9 – SMD-package with no leads . 32

Table A.1 – Dimensions of reference letter symbols . 15

– 4 – IEC 60191-1:2018  IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MECHANICAL STANDARDIZATION OF SEMICONDUCTOR DEVICES –

Part 1: General rules for the preparation of outline drawings
of discrete devices
FOREWORD
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