Infineon PG-TO220, Руководство пользователя

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Additional information 10 of 31 Revision 4.0
2021-10-11
Recommendations for board assembly of Infineon transistor outline
type packages
Printed circuit board
2 Printed circuit board
This section addresses specifically the surface-mount TO SMD and HSOG packages.
2.1 Routing
Printed circuit board design and construction are key factors for achieving solder joints with high reliability.
Packages with exposed pads should not be placed opposite to each other on either side of a PCB when doing
double-sided mounting. This will stiffen the assembly and cause solder joints to fatigue earlier than in a design
in which the components are offset. Furthermore, the board stiffness itself has a significant influence on the
reliability of the solder joint interconnect if the system is used in critical temperature-cycling conditions
2.2 Pad design
The quality and reliability of interconnect solder joints to the board are affected by:

Pad type (solder mask defined, SMD or non-solder mask defined, NSMD)

Specific pad dimensions

Pad finish (also called metallization or final finish)

Via layout and technology
For optimal heat dissipation in high-current applications, the SMD pad type is preferred beause it allows for
large copper areas under the solder mask layer of the PCB. Beside the power application aspect, the SMD
design type can also be beneficial in terms of routing flexibility. Mixing different pad definition types in one
footprint is not recommended due to the typical alignment tolerances between the solder mask and the copper
layer.
It is generally possible to layout the board pad with the same dimensions as the exposed die pad of the
package. If the exposed die pad protrudes on one or more sides of the package body, it can be helpful to
increase the board pad slightly in this area to improve self-centering of the component during reflow soldering.
Figure 8 shows examples of pad and stencil designs for a PG-TO263-7-2 package without and with vias in pad.
Figure 8 Examples of a pad and stencil design for a PG-TO263-7-2 package without (left) and with
(right) vias in pad.