In LP Viewer found PLB library files:   PCBM-STARTER.PLB09 BGA7351B.PLB09 SMN7351B.PLB09 SMM7351B.PLB09 SML7351B.PLB09 CNA7251.PLB09 CNB7251.PLB09 CNC7251.PLB09 CNP7251.PLB09 THA7251.PLB09 THB7251.PLB09 THC7251.PLB09 THP7251.PLB09     Answer

PCBM-STARTER = BGA & SMN combined with Mfr data added.   CN = Connectors   TH = Through-hole   SM = Surface Mount   A = Most Annular Ring for Through-hole B = Nominal Annular Ring for Through-hole C = Least Annular Ring for Through-hole P = Proportional (The Annular Ring grows larger as the hole gets bigger for Through-hole)   SML = Least SMT Pad SMN = Nominal SMT Pad SMM = Most SMT Pad   BGA only comes in "Nominal" format   这里的Most ,Nominal , Least说的是封装在制作时的一个思维标准。Most 用于密度小的板子（pad 尺寸最大），Nominal用于密度适中的（pad尺寸中等），Least适用于密度大板子（pad尺寸最小）。