Help with surface mount work

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I've never had a custom PCB made before.

Recently I started having a few cool ideas for things I could make, but I'm kind of stuck on all the ins and outs of having a PCB loaded and soldered.

Is there anywhere that I can read about the details?

For instance... say I have the option to choose between five different styles of package, is it going to be a problem is I suddenly change from using SMA to SMB or D-PAK when all the rest of my components are SOT-223 or SOT-8?

Or, when should I use DIP over SMD? Or even stranger... what's the difference between Dual In-Line Package and Dual In-Line anyway?

I need to know what the manfufacturers will be picky about and want me to change. Things like, what kind of soldering and board layouts I should use?

I would greatly appreciate any help with this!
 

fab

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Joined 2004
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If you intend to populate yourself your pcb, I would not go to use SMD (surface mount devices) devices (SOT-08 and SOT-223). The SMD main purpose is to use less space in pcb but SMD needs automatic pick-and-place machine. I have already worked for several years as a product designer in an hybrid circuit manufacture where normally the SOT-08 or -223 devices were mounted by machine and very occasionnally mounted by humans (re-worked bad mounted circuits). But believe me it is not easy...

Normally in each electronic devices book from distributors or manufacturers (Newark, Arrow, Philips, etc.), theys show a picture and dimensions of each package types. For small transistors, we ususally use TO-92 package. For IC, use DIP. Mid-power transistors are sometimes TO-39 or TO-220. Power transistors TO-220, TO-3, TO-3P, etc.

If you go to a local pcb manufacturer like I do for prototypes, talking with the person who will corrdinate the job will be usefull for you.
If you want to go directly with a professional firm then you can normally:
1) provide yourself the components to them with proper identification based on the silkscreen designation on your pcb.
2) provide the list of devices part numbers with package (of course they must fit with the pcb) that the firm will find for you. They will choose for you the manufacturer of the parts.
3) specify the manufacturer (Motorola, Philips, etc.) along with part number, packages.

For the soldering, use Sn/Pb alloy but for the final specific choice depends on their soldeing process if automatic (flux type, no-flux type, etc.)

The only way to be sure is to talk directly with the proper person at your selected pcb firm.

Good luck!
 
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