PROCESSING RECOMMENDATIONS
For Samtec’s SEARAY™ (SEAM/SEAF Series) Vertical Connectors
©Samtec, Inc., September 2008 Page 1 Rev. J
The method used to solder these high density connectors is the same as that used for many BGA
devices. While BGA’s have spherical solder balls attached to the leads, the SEARAY™ employs
the unique solder charge design.
Fig. 1. Solder Balls on BGA’s v. Solder Charges on SEARAY™.
Another difference is that unlike the uniform grid arrangement of BGAs the solder charges are
offset making the leads appear to be in pairs. The leads themselves are on a .050” x .050” pitch
but because the lead orientation alternates from row to row, the solder charges are positioned
back to back.
Fig. 2. Solder charge locations on adjacent rows – end view.
The tails of the connector are designed to be centered about the solder pads. Figure 2 illustrates
that the solder charges (dark gray) are off-set from the solder pads, but the tails (gold) are
centered about the solder pads.
PROCESSING RECOMMENDATIONS
For Samtec’s SEARAY™ (SEAM/SEAF Series) Vertical Connectors
©Samtec, Inc., September 2008 Page 2 Rev. J
These differences are minor however and customers will have success by following these simple
guidelines:
1. Basic Recommendations
o Minimum stencil thickness to be .005” (0.13mm),
o Follow our recommended footprints, found here:
▪ SEAM – Surface Mount Footprint,
▪ SEAF – Surface Mount Footprint
2. Solder Screen Printing Process
o Complete solder pad coverage is critical. The recommended aperture size of .035"
(0.89mm) is intentionally larger than the pad to ensure that the solder charge comes
into contact with the solder paste. If this does not occur, proper wetting will not be
achieved (see Fig. 3). Automated inspection of each print is recommended. If solder
paste does not completely cover the solder pad the assembly should be rejected,
cleaned and re-printed.
o Stencil cleaning may need to be monitored more frequently to ensure complete solder
pad coverage is maintained.
Fig. 3. Solder charge location relative to solder print. Notice good contact between solder
charges and solder paste.