SMD techniques

Hi, can anyone help please?

I have to migrate a number of designs from PTH to Surface mount. Can anyone suggest a concise book or on-line resource that can answer questions such as: -

Do I put mixed (PTH and SMD) components on the same side of the PCB or on opposite sides and what are the associated merits/disadvantages?

and...

When generating the solder-paste mask what alignment marks do PCB manufacturers generally require?

These are but two of many questions I have. I'd be most grateful for any suggestions/advice.

Cheers, Simon

Thanks for the info Bill.

Simon

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Sure, but on the other side :

Having both components variety on the same side requires 2 additional operations:

- solder past screening

- oven reflow that are not necessary if the SMD components are soldered along with the TH ones.

If _all_ the components can withstand wave soldering the most economical way would be SMD on track side, and just one soldering pass.

I usually put SMT debouncing caps on the bottom of the board and everything else on top. I'm a hobbyist though -- not sure how well this works in mass production.

Be sure to put thermal reliefs on the power pins of the SMT pads, similar to through-hole thermal relief. On my first board I had some bad solder joints due to not putting these in.

Chris