IEC 63378-2-1:2024

Thermal standardization on semiconductor packages - Part 2-1: 3D thermal simulation models of semiconductor packages for steady-state analysis - Discrete packages

IEC 63378-2-1:2024 specifies three-dimensional (3D) thermal models of discrete semiconductor packages (TO-243, TO-252 and TO-263), utilized in the steady-state thermal analysis of electronic devices to estimate junction temperatures accurately.
This model is assumed to be made by semiconductor suppliers and to be used by assembly makers of electronic devices.

General Information

• Status: Published
• Publication Date: 21-Oct-2024
• ICS: 31.080.01 - Semiconductor devices in general
• Technical Committee: SC 47D - Semiconductor devices packaging
• Drafting Committee: WG 2 - TC 47/SC 47D/WG 2
• Current Stage: PPUB - Publication issued
• Start Date: 01-Nov-2024
• Completion Date: 22-Oct-2024

Standards Content (Sample)

IEC 63378-2-1 ®
Edition 1.0 2024-10
INTERNATIONAL
STANDARD
Thermal standardization on semiconductor packages –
Part 2-1: 3D thermal simulation models of semiconductor packages for steady-
state analysis – Discrete packages

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IEC 63378-2-1 ®
Edition 1.0 2024-10
INTERNATIONAL
STANDARD
Thermal standardization on semiconductor packages –

Part 2-1: 3D thermal simulation models of semiconductor packages for steady-

state analysis – Discrete packages

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.080.01  ISBN 978-2-8322-9816-9

– 2 – IEC 63378-2-1:2024 © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Attributes of 3D thermal models . 5
4.1 General . 5
4.2 TO-243 . 6
4.3 TO-252 . 8
4.4 TO-263 . 10
Annex A (normative) Contribution analysis in the case of TO-252 . 12
A.1 Attributes of a sample package . 12
A.2 Simulation validation . 14
Bibliography . 15

Figure 1 – Dimensions of TO-243 . 6
Figure 2 – Dimensions of TO-252 . 8
Figure 3 – Dimensions of TO-263 . 10
Figure A.1 – Sample package of TO-252. 12
Figure A.2 – Results of contribution analysis. 13
Figure A.3 – Accuracy comparison . 14

Table 1 – Attributes for TO-243 . 7
Table 2 – Attributes for TO-252 . 9
Table 3 – Attributes for TO-263 . 11
Table A.1 – Attributes and their range of a sample package . 12

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
THERMAL STANDARDIZATION ON SEMICONDUCTOR PACKAGES –

Part 2-1: 3D thermal simulation models of semiconductor
packages for steady-state analysis – Discrete packages

FOREWORD
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IEC 63378-2-1 has been prepared by subcommittee 47D: Semiconductor devices packaging, of
IEC technical committee 47: Semiconductor devices. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
47D/976/FDIS 47D/982/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

– 4 – IEC 63378-2-1:2024 © IEC 2024
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 63378 series, published under the general title Thermal
standardization on semiconductor packages, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
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THERMAL STANDARDIZATION ON SEMICONDUCTOR PACKAGES –

Part 2-1: 3D thermal simulation models of semiconductor
packages for steady-state analysis – Discrete packages

1 Scope
This part of IEC 63378 specifies three-dimensional (3D) thermal models of discrete
semiconductor packages (TO-243, TO-252 and TO-263), utilized in the steady-state thermal
analysis of electronic devices to estimate junction temperatures accurately.
This model is assumed to be made by semiconductor suppliers and to be used by assembly
makers of electronic devices.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
detailed model
semiconductor package model which has both the structures of each portion, such as die or
moulding or terminal, and the material properties for thermal analysis
Note 1 to entry: This model is often simplified to some extent.
4 Attributes of 3D thermal models
4.1 General
Clause 4 shows the attributes such as dimensions and thermal properties of three different type
of TO-packages. These attributes are used to estimate junction temperatures.

– 6 – IEC 63378-2-1:2024 © IEC 2024
4.2 TO-243
Figure 1 and Table 1 show the attributes which TO-243 thermal simulation models shall have.

Figure 1 – Dimensions of TO-243

Table 1 – Attributes for TO-243

Attribute Symbol Value Unit
Package thickness A m
Terminal width b m
b
Heat spreader width m
b
Centre terminal width m
Terminal thickness C m
Package width D m
Package body length E m
Terminal pitch e m
H
Span m
E
Dimension
Terminal length L m
L
Exposed terminal length m
L
Heat spreader length m
S
Die width X m
Die length Y m
Y
Die length offset m
Die thickness Z m
Z
Die attach thickness m
d
k
Thermal conductivity of die W/(m × K)
d
k
Thermal conductivity of die attach W/(m × K)
da
Thermal
conductivity
k
Thermal conductivity of molding W/(m × K)
m
k
Thermal conductivity of heat spreader W/(m × K)
s
NOTE 1 The default thermal conductivity of molding is 0,6 W/(m∙K) and that of heat spreader is 300 W/(m × K).
The thermal conductivity of die and die attach varies a lot according to the material adopted.
NOTE 2 The thickness of molding is the same as package thickness "A".
NOTE 3 The length and width of the die attach are the same as those of die X and Y.
NOTE 4
...