Soldering Header SMT Posts

Community PCB Design
1

I bought some Header SMT Posts for a SOT adapter I made, and Im having a hard time soldering these on. Can anyone recommend a way to do it With a soldering iron? I have a Hakko.

[<LINK_TEXT text=“http://www.proto-advantage.com/store/im … 1995ilb2q1”>http://www.proto-advantage.com/store/images/PRODUCTS/MPH100IMP40M-G-V-SP_0.JPG?osCsid=bpqjuu4t4k67sts01995ilb2q1</LINK_TEXT>](Proto Advantage - 0.1" 40 pin Machine Pin Vertical Male Header SMT Posts)

2

Got a link to data on those connectors? As a rule, I try to avoid using SMD headers like this, as it only takes a small force to pull the pads off the PCB.

3

MichaelN:
Got a link to data on those connectors? As a rule, I try to avoid using SMD headers like this, as it only takes a small force to pull the pads off the PCB.

data? [<LINK_TEXT text=“http://www.proto-advantage.com/store/da … G-V-SP.pdf”>http://www.proto-advantage.com/store/datasheets/MPH100IMP40M-G-V-SP.pdf</LINK_TEXT>

I saw [these adapters done in a similar fashion, so I wanted to try it too.](SMT to Through-hole Adapters - Surface Mount Adapters PLCC SOIC TQFP MSOP SSOP TSSOP SOT DIP PQFP QSOP TSOP soic to dip 8-pin)](http://www.proto-advantage.com/store/datasheets/MPH100IMP40M-G-V-SP.pdf)

4

I’d suggest solder paste and a hot plate if you have it (if not, a hot air gun should work). Assuming you’re getting PCBs made (eg 10 for $10 at Seeed or Itead), I would make the pads MUCH larger than recommended in that datasheet (to help prevent the pads pulling off), and just use their recommended pad size as the opening in the soldermask.

If you really want to solder by hand, make the opening in the soldermask slightly elongated, so you can get the tip of the soldering iron in to the junction between the pad and pin.

If possible, add a few vias to tie each pad to a pad on the other side of the PCB. I know it seems like ovekill, but it really does help prevent failures. I once designed a product using SMD headers for use on vehicles, and at least half of them needed to be replaced due to connector failures. We ended up using something lke this, and have had no further failures:

http://users.adam.com.au/mnoble/SMD_Pads.JPG

5

Thanks for the lengthy explanation.

That still leaves me with how to mount/prop up the headers during soldering. I tried doing it by hand, but they wont stay straight.

6

UNTEngineer:
That still leaves me with how to mount/prop up the headers during soldering. I tried doing it by hand, but they wont stay straight.

How about plugging the 2 small strips of header into a DIP socket while soldering? That way they're held at the correct spacing and angle. Solder 2 diagonal pins first, then all the other pins are held in the correct position for soldering.
7

I’ll give that a try when I get a chance. Unfortunately, I dont have solder paste or a heat gun so I cant do any fancy smt work. I thought I could get away with doing it by soldering iron, but I guess not. I’ll have to change the design to go with something a bit more feasible within my means.

Thanks!

8

UNTEngineer:
I thought I could get away with doing it by soldering iron, but I guess not.

You should still be able to - the pads are a bit bigger than the pins, so you should be able to get a soldering iron into the junction. As I said, if you temporarily plug the header strips into a DIP socket, it should hold them in place while soldering.