Surface Mount Assembly

[jebediah]

Hi, could SMDs be assembled by soldering(in quantities)?
Does anyone know any good assembly companies, that are reasonable for quantities of a few dozen?

Thanks a lot.

 

[BrianG]

If by "soldering" you mean old-style automated wave soldering the answer is no. The whole point about surface mount parts is that they are very small and the components can only be soldered on the side they mount on, which rules out automated wave soldering as the solder will "bridge" most of the pins due to surface tension of the solder, even with the application of lots of flux. The accepted method is by hot air re-flow soldering, where the component leads and circuit board pads are pre-tinned, requiring no additional solder to be added.

It is possible to hand-solder some surface mount components and ICs, but this requires minute soldering irons and extreme skill. As a consequence it is normally reserved for rectification of occasional faulty joints on boards, not as a routine volume production method.

 

[pic16c74]

You can solder a few SMT boards if they are not that heavily populated with 'pcbexpress.com' mask method. It is a simple and low-quantity oriented process, involving only a few bucks more for the mask. If you want to handle this over to a manufacturing house, there are several in the US that can handle this, but expect a couple of thousands on setup fees and other charges.

If you can give more details about the card I could be more detailed about my reply, I've done fine-pitch SMT card assembly on prototypes under the 30X microscope (which is no-fun but at least it can be done).

Hope this helps.
R.A.