Based on the ECN-273259 drawing for the TLH-020-0.50-G-D part, there should only be one two rows of contacts, as there are only two rows listed as solderable. Why does the 2D footprint contain 4 rows of pads if there should only be 2?
Added 4 weeks ago.
Thanks for reaching out. There are only 2 rows of solderable contacts and they are they only ones with electrical connections. As per the inner rows of non-solderable structural support pad, we added them as polygons in the copper layer because they are still pads added to achieve coplanarity between inner and outer rows, it helps to ensure optimal contact position for soldering as Samtec suggest here (page 6). However, we did not add paste openings in the non-solderable support pads as they will not be soldered onto the PCB and this is something you can share with your fabrication house.
The inclusion of the inner support pads are recommended, but you may choose to forego them as long as you understand the design intent and the potential ramifications (solder joint damage, soldering quality due to lifted leads).
Let me know if you have any questions about it.
Answered 4 weeks ago.