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Ixiasoft
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Ixiasoft
1.3.1. Surface Land Pad Dimension
Intel® has done extensive modeling simulation and experimental studies to determine the optimum land pad design on the PCB to provide the longest solder joint fatigue life. The results of these studies show that a pad design that provides a balanced stress on the solder joint provides the best solder joint reliability. If SMD pads are used on the PCB, the surface land pads should be the same size as the BGA pad to provide a balanced stress on solder joints. If non-solder mask defined pads are used on the PCB, the land pads should be approximately 15% smaller than the BGA pad size to achieve a balanced stress on solder joints.
The following table lists the recommended pad sizes for SMD and NSMD land patterns. You should use NSMD pads for high-density board layouts because the smaller pad sizes allow for more space between vias and trace routing.
BGA Pad Pitch | BGA Pad Opening (A) (mm) (Typical) | Recommended SMD Pad Size (mm) | Recommended NSMD Pad Size (mm) 1 |
---|---|---|---|
1.27 mm (Plastic Ball Grid Array (PBGA)) | 0.60 | 0.60 | 0.51 |
1.27 mm (Super Ball Grid Array (SBGA)) | 0.60 | 0.60 | 0.51 |
1.27 mm (Tape Ball Grid Array (TBGA)) | 0.60 | 0.60 | 0.51 |
1.27 mm (flip-chip) 2 | 0.65 | 0.65 | 0.55 |
1.00 mm (wirebond) 2 | 0.45 | 0.45 | 0.38 |
1.00 mm (flip-chip) 2, 3 | 0.55 | 0.55 | 0.47 |
1.00 mm (flip-chip) 2 APEX 20KE | 0.60 | 0.60 | 0.51 |
0.80 mm UBGA (wirebond) | 0.40 | 0.40 | 0.34 |
0.80 mm UBGA (EPC16U88) | 0.40 | 0.40 | 0.34 |
0.80 mm UBGA (flip-chip) | 0.425 | 0.425 | 0.36 |
0.80 mm UBGA (flip-chip) | 0.45 | 0.45 | 0.38 |
0.50 mm MBGA | 0.30 | 0.27 | 0.26 |
The following table lists the PCB design guidelines for VBGA (also known as WLCSP) 0.4-mm ball pitch.
BGA Pad Pitch | PCB Cu Pad Size NSMD (mm) | Solder Mask Opening NSMD (mm) | PCB Cu Pad Size SMD (mm) | Solder Mask Opening SMD (mm) |
---|---|---|---|---|
0.4 mm VBGA (also known as WLCSP) | 0.22 | 0.32 | 0.32 | 0.22 |
The following figures show the via and routing space available for 1.00-mm, 0.80-mm, and 0.50-mm pitch packages when using NSMD land pads.