304-Lead Plastic Ball Grid Array [PBGA] (B-304) Dimensions shown in millimeters a A1 CORNER INDEX AREA 31.00 BSC SQ 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 A B C D E F G H J K L M N P R T U V W Y AA AB AC BALL A1 INDICATOR 26.70 26.35 SQ 26.00 TOP VIEW 28.04 27.94 SQ 27.84 BOTTOM VIEW 1.27 BSC 2.54 2.33 2.12 DETAIL A DETAIL A 1.22 1.17 1.12 0.62 0.56 0.50 0.70 0.60 0.50 SEATING PLANE COMPLIANT TO JEDEC STANDARDS MS-034-BAN-2 0.90 0.75 0.60 BALL DIAMETER COPLANARITY 0.20 MAX