SPRACY2 May   2021 TMUX646

 

  1.   Trademarks
  2. 1Small Body nFBGA Package Details
  3. 2PCB Design Guidelines
  4. 3Packaging Tape and Reel
  5. 4Thermal Modeling
  6. 5Board Level Reliability
  7.   A Frequently Asked Questions
    1.     A.1 Small Body nFBGA Package Questions
  8.   B Package Data Sheets

2 PCB Design Guidelines

The PCB design guidelines outlined in the Conductor Width/Spacing section of nFBGA Packaging are still applicable to small body nFBGAs. Figure 2-1, Table 2-1 and Table 2-2 outline examples of specific pad, trace, and width dimensions for small body packages.

GUID-20210428-CA0I-QS48-VF9G-WKGJWQZF5QNK-low.png Figure 2-1 Solder Pad and Trace Dimensions
Table 2-1 Sample Small Body nFBGA Solder Pad Details
Solder Mask Defined Pad (SMD) Non-Solder Mask Defined Pad (SMD)
Package Designator Copper Pad (A) Solder Mask Opening (B) Copper Pad (C) Solder Mask Opening (D)
ZWA 0.35 mm 0.25 mm 0.25 mm 0.35 mm
ZEC 0.30 mm 0.23 mm 0.23 mm 0.30 mm
Table 2-2 Trace Width Spacing Examples
Pitch (mm) Metal Diameter (“A” or ”C”) Trace Width/ Spacing
(“S” or “T”)
SMD pad 0.40 0.35 0.05
0.50 0.10
NSMD Pad 0.40 0.25 0.08
0.50 0.13

TI recommends the use of type 3 or finer solder paste when mounting nFBGA. The use of paste offers the following advantages:

  • It acts as a flux to aid wetting of the solder ball to the PCB land.
  • The adhesive properties of the paste will hold the component in place during reflow.
  • Paste contributes to the final volume of solder in the joint, and thus allows this volume to be varied to give an optimum joint.
  • Paste selection is normally driven by overall system assembly requirements. In general, the "noclean" compositions are preferred due to the difficulty in cleaning under the mounted components.

TI recommends a pressure safety zone in mounting the nFBGA package. Recommended force should be controlled to 5N maximum for static and 2.5N for impact.