IR3897MPBF datasheet(45/47 Pages) IRF

45 / 47 page

- 45 -

JANUARY 18, 2013 |DATA SHEET | Rev 3.5

IR3897

4A Highly Integrated SupIRBuck

Single‐Input Voltage, Synchronous Buck Regulator

PD‐97663

SOLDER RESIST

 IR recommends that the larger Power or Land

Area pads are Solder Mask Defined (SMD.)

This allows the underlying Copper traces to be as

large as possible, which helps in terms of current

carrying capability and device cooling capability.

 When using SMD pads, the underlying copper

traces should be at least 0.05mm larger (on each

edge) than the Solder Mask window, in order to

accommodate any layer to layer misalignment.

(i.e. 0.1mm in X & Y.)

 However, for the smaller Signal type leads around

the edge of the device, IR recommends that these

are Non Solder Mask Defined or Copper Defined.

 When using NSMD pads, the Solder Resist

Window should be larger than the Copper Pad

by at least 0.025mm on each edge, (i.e. 0.05mm

in X&Y,) in order to accommodate any layer to

layer misalignment.

 Ensure that the solder resist in‐between the

smaller signal lead areas are at least 0.15mm

wide, due to the high x/y aspect ratio of the

solder mask strip.

Figure 51: Solder resist

* Contact International Rectifier to receive an electronic PCB Library file in your preferred format

IR3897MPBF Datasheet(PDF) 45 Page - International Rectifier