Footprint Name for Parts With Tabs

The IPC Land Pattern Subcommittee has approved the use of 3 modifiers at the end of Land Pattern names.

The original IPC-7351 footprint naming convention does not include component tolerances, thermal pad sizes, BGA Ball sizes or various pin assignments into account. Therefore, the same component with different tolerances can produce a different land size and spacing with the same footprint name.

A footprint name of SOP50P710X120-14N can have version A, B, C, D which do not indicate the variances.

There are 3 component features that affect the footprint name –

1.    Thermal Tab Size = SOP50P710X120-14NT300

·         T300 = 3.00 mm Square Thermal Pad

·         T300X200 = 3.00 mm X 2.00 mm Rectangle Thermal Pad

2.    Lead Length Tolerance = SOP50P710X120-14NL50

·         L50 = 0.50 mm Nominal Terminal Length

3.    Ball Size = BGA121C50P11X11_600X600X100NB23

·         B23 = 0.23 mm Nominal Ball Diameter

These would be used at the end of the Land Pattern Name only if a new Land Pattern is added to the user library with an identical Land Pattern Name but different T, L or B.

Example: Create a BGA chart that has a default Ball Size for each Pin Pitch.

For component mfr. recommended footprint drop the environment level character after the pin qty. - SOP50P710X120-14