I

IR3088

Solder Resist

• The solder resist should be pulled away from the metal lead lands by a minimum of 0.06mm. The solder

resist mis-alignment is a maximum of 0.05mm and it is recommended that the lead lands are all Non Solder

Mask Defined (NSMD). Therefore pulling the S/R 0.06mm will always ensure NSMD pads.

• The minimum solder resist width is 0.13mm, therefore it is recommended that the solder resist is completely

removed from between the lead lands forming a single opening for each “group” of lead lands.

• At the inside corner of the solder resist where the lead land groups meet, it is recommended to provide a

fillet so a solder resist width of ≥ 0.17mm remains.

• The land pad should be Solder Mask Defined (SMD), with a minimum overlap of the solder resist onto the

copper of 0.06mm to accommodate solder resist mis-alignment. In 0.5mm pitch cases it is allowable to have

the solder resist opening for the land pad to be smaller than the part pad.

• Ensure that the solder resist in-between the lead lands and the pad land is ≥ 0.15mm due to the high aspect

ratio of the solder resist strip separating the lead lands from the pad land.

• The 4 vias in the land pad should be tented with solder resist 0.4mm diameter, or 0.1mm larger than the

diameter of the via.

Page 32 of 34