----- Original Message ----- From: "Julian Kain" Subject: [EE] SMT/THT choices for PCB > Some things you should know: the PCB will be 4-layers (2 signal, 2 > power/gnd). The board will be professionally manufactured, but not > professionally soldered (though I do have access to reflow equipment). > Generally, cost is very important -- this is a school project. If you are going to hand solder the board, I would probably go with the thru hole. It isn't unreasonable to hand solder SMT parts, but it is a lot more time consuming. In small quantities, SMT parts seem to be generally more expensive than thru hole, as well. The big win for SMT comes when you can place the parts by machine. Thru hole also gives you some room to run traces under parts which can sometimes save you a layer. Not so sure that for an MPEG thingie you really need the separate power and ground layers. For an RF device maybe, but generally it's not something you need and it does add to the cost. Interestingly, if you were manufacturing the board yourself, I would say SMT. Drilling all those holes is a pain. But as far as I can tell, you don't save manufacturing cost by leaving them out, unless you have a bunch of holes of different sizes. --McD -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist