a A1 BALL CORNER 400-Ball Plastic Ball Grid Array [PBGA] (B-400) Dimensions shown in millimeters 27.20 27.00 SQ 26.80 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 A1 BALL CORNER 1 A B C D E F G H J K L M N P R T U V W 24.20 24.00 SQ 23.80 1.27 BSC Y TOP VIEW DETAIL A DETAIL A 0.60 0.55 0.50 0.70 0.60 0.50 0.90 0.75 0.60 BALL DIAMETER COMPLIANT TO JEDEC STANDARDS MS-034-BAL-2 1.19 1.17 1.15 COPLANARITY 0.20 SEATING PLANE 081909-A 2.49 2.32 2.15 BOTTOM VIEW