Plastic Packages for Integrated Circuits Package Outline Drawing W4x5.20 4x5 Array 20 Ball Wafer Level Chip Scale Package (WLCSP) Rev 1 8/09 2.545 ± 0.02 X 2.00 20X 0.32 ± 0.03 Y 4 0.25 3 1.50 2.045 ± 0.02 2 1 0.50 0.10 PIN 1 (A1 CORNER) TOP VIEW E D C B A (4X) 0.50 BOTTOM VIEW PACKAGE OUTLINE 0.33 3 0.025 BSC 0.30 ± 0.015 0.23 ± 0.015 0.32 ± 0.03 SEATING PLANE 0.05 Z 0.10 M Z X Y 0.05 M Z 0.28 Z SIDE VIEW 0.50 4 NSMD TYPICAL RECOMMENDED LAND PATTERN NOTES: 1. Dimensions are in millimeters. 2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994, and JESD 95-1 SPP-10. 1 3. Back side coat 0.25mm thick applied to CSP package top. 4. NSMD refers to non-solder mask defined pad design per Intersil tech brief www.intersil.com/data/tb/TB451.pdf