Mini Components

[Adji]

What  is the deal with these tiny components? Why is it that the 'boutique' world does not use them? I guess it would be VERY fiddly if not impossible to solder by hand, but is there a quality difference?

[Thomas.R]

they are called SMD components (surface mount device) and you just place them on a pcb and then put the pcb in a special oven
wich solders the parts to the pcb. you can do it with a fine soldertip but its very tricky altough i have seen them on this forum

[Quackzed]

as far as i've read, there aren't any quality problems with smd parts. I think it's just that they are tiny and difficult to use that prevents most diyers from using them.
if interested in making a tiny effect you can search 'surface mount' and find a few tips...ive seen a few tutorials on youtube as well...

[Processaurus]

I use them!  This dreaful photograph is a fuzz pedal with all kinds of solid state switching going on.  It uses 805 size parts.  It helps to have a fine tip, fine solder, and a magnifier, but you can just do it without special tools if you have good eyes and are good at soldering.

I haven't ever used the reflow (solder paste/oven) method yet, but plan to sometime.  For one offs it is easier to just solder stuff by hand.  Stuffing a board doesn't seem to take longer than through hole components.  Modding a board isn't that hard if you have some fine, solid core teflon wire, you can stick it onto the resistor pads or even IC legs.

As for quality of components, IC's and transistors are identical to the DIP counterparts, as they are made from the same die.  805 Resistors are 1/10th watt carbon film (don't know if metal film SMT resistors are very common), and the caps are ceramic, hence the full sized film caps where I wanted those (I've seen that in danelectro pedals).

[Adji]

... if you have good eyes and are good at soldering.

Ha! That is me totally screwed then lol.

Cheers for the info guys, I was just curious, it will kill me one day when I touch something I shouldn't!

Process..are there any distinct advantages, other than the fact you can obviously cram a lot more into a small space?

[mattthegamer463]

For DIY'ers I find they're certainly not more beneficial than THT, even a hassle to use.  You must make your own boards for circuits because there's not really much for SMT proto or breadboards, you can't use solderless boards for prototyping, so if you want to design and test you still need all the through-hole components for the circuit.  Plus, pedals are rarely so complex you can't use THT parts to build it in a reasonable size enclosure.  Also, finding parts and chips could be more difficult, since most suppliers would be expecting to deal in large quantities, I imagine.

[amptramp]

There are a couple of advantages for manufacturers:  The surface mount devices are dirt cheap.  They come on a reel that may be $50 and contain 5000 resistors or more, so component costs are minimal and the machinery has to be programmed once and will automatically load all devices on the board.  Also, printed circuit boards are priced by the number and size of holes and these devices don't need any holes.  Drilling through epoxy-glass is very hard on a drill and they have a short life, requiring an operator to stop production to swap out a drill.  Components like the IC with gullwing leads are stable and can tolerate any board flexure but leadless devices are sensitive to any flexing of the board.

The size of the devices is much smaller than discrete leaded devices, even when "Jap mounting" is used, where a resistor may have one lead bent back 180 degrees and both ends plug into board holes with the resistor perpendicular to the board.  (This was used on many transistor radios from the early days.)  And leaded resistors are $0.05 to $0.10 apiece, more than leadless.

Specialized repair stations are common in industry but not with hobbyists as they are table-top size and relatively expensive.

[JKowalski]

The main advantages of SMT over the older through-hole technique are:


Smaller components. Smallest is currently 0.4 x 0.2 mm.

Much higher number of components and many more connections per component.

Fewer holes need to be drilled through abrasive boards.

Simpler automated assembly.

Small errors in component placement are corrected automatically (the surface tension of the molten solder pulls the component into alignment with the solder pads).

Components can be placed on both sides of the circuit board.

Lower resistance and inductance at the connection (leading to better performance for high frequency parts).

Better mechanical performance under shake and vibration conditions.

SMT parts generally cost less than through-hole parts.

Fewer unwanted RF signal effects in SMT parts when compared to leaded parts, yielding better predictability of component characteristics.

Faster assembly. Some placement machines are capable of placing more than 50,000 components per hour.



Well summarized by everyone's friend Wikipedia  

[Adji]

Thanks for all the info guys, good stuff.