PIP212-12M Datasheet, PDF (17/21 Pages) NXP Semiconductors – DC-to-DC converter powertrain

Philips Semiconductors
PIP212-12M
DC-to-DC converter powertrain
[4] These packages are not suitable for wave soldering. On versions with the heatsink on the bottom side, the
solder cannot penetrate between the printed-circuit board and the heatsink. On versions with the heatsink
on the top side, the solder might be deposited on the heatsink surface.
[5] If wave soldering is considered, then the package must be placed at a 45° angle to the solder wave
direction. The package footprint must incorporate solder thieves downstream and at the side corners.
[6] Wave soldering is suitable for LQFP, QFP and TQFP packages with a pitch (e) larger than 0.8 mm; it is
definitely not suitable for packages with a pitch (e) equal to or smaller than 0.65 mm.
[7] Wave soldering is suitable for SSOP, TSSOP, VSO and VSSOP packages with a pitch (e) equal to or larger
than 0.65 mm; it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.5 mm.
[8] Image sensor packages in principle should not be soldered. They are mounted in sockets or delivered
pre-mounted on flex foil. However, the image sensor package can be mounted by the client on a flex foil by
using a hot bar soldering process. The appropriate soldering profile can be provided on request.
[9] Hot bar soldering or manual soldering is suitable for PMFP packages.
15. Mounting
15.1 PCB design guidelines
The terminals on the underside of the package are rectangular in shape with a rounded
edge on the inside. Electrical connection between the package and the printed-circuit
board is made by printing solder paste onto the PCB footprint followed by component
placement and reflow soldering. The PCB footprint shown in Figure 17 is designed to form
reliable solder joints.
The use of solder resist between each solder land is recommended. PCB tracks should
not be routed through the corner areas shown in Figure 17. This is because there is a
small, exposed remnant of the leadframe in each corner of the package, left over from the
cropping process.
Good surface flatness of the PCB lands is desirable to ensure accuracy of placement after
soldering. Printed-circuit boards that are finished with a roller tin process tend to leave
small lumps of tin in the corners of each land. Levelling with a hot air knife improves
flatness. Alternatively, an electro-less silver or silver immersion process produces
completely flat PCB lands.
9397 750 14586
Preliminary data sheet
Rev. 02 — 2 March 2005
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
17 of 21