2002 Teccor Electronics
Thyristor Product Catalog
AN1004 - 1
http://www.teccor.com
+1 972-580-7777
4
Mounting and Handling of Semiconductor Devices
Introduction
Proper mounting and handling of semiconductor devices, particu-
larly those used in power applications, is an important, yet some-
times overlooked, consideration in the assembly of electronic
systems. Power devices need adequate heat dissipation to
increase operating life and reliability and allow the device to
operate within manufacturers' specifications. Also, in order to
avoid damage to the semiconductor chip or internal assembly,
the devices should not be abused during assembly. Very often,
device failures can be attributed directly to a heat sinking or
assembly damage problem.
The information in this application note guides the semi-
conductor user in the proper use of Teccor devices, particularly
the popular and versatile TO-220 and TO-202 epoxy packages.
Contact the Teccor Applications Engineering Group for further
details or suggestions on use of Teccor devices.
Lead Forming — Typical Configurations
A variety of mounting configurations are possible with Teccor
power semiconductor TO-202, TO-92, DO-15X, and TO-220
packages, depending upon such factors as power requirements,
heat sinking, available space, and cost considerations. Figure
AN1004.1 shows typical examples and basic design rules.
Figure AN1004.1
Component Mounting
These are suitable only for vibration-free environments and low-
power, free-air applications. For best results, the device should
be in a vertical position for maximum heat dissipation from con-
vection currents.
Standard Lead Forms
Teccor encourages users to allow factory production of all lead
and tab form options. Teccor has the automated machinery and
expertise to produce pre-formed parts at minimum risk to the
device and with greater convenience for the consumer. See the
“Lead Form Dimensions” section of this catalog for a complete
list of readily available lead form options. Contact Teccor for
information regarding custom lead form designs.
Lead Bending Method
Leads may be bent easily and to any desired angle, provided that
the bend is made at a minimum 0.063" (0.1" for TO-218 package)
away from the package body with a minimum radius of 0.032"
(0.040" for TO-218 package) or 1.5 times lead thickness rule.
DO-15X device leads may be bent with a minimum radius of
0.050”, and DO-35 device leads may be bent with a minimum
radius of 0.028”. Leads should be held firmly between the pack-
age body and the bend so that strain on the leads is not transmit-
ted to the package body, as shown in Figure AN1004.2. Also,
leads should be held firmly when trimming length.
A
B
C
D
SOCKET TYPE MOUNTING:
Useful in applications for testing or
where frequent removal is
necessary. Excellent selection of
socket products available from
companies such as Molex.
AN1004