Raspberry Pi A, Руководство пользователя, Страница: 229 / 314

C H A P T E R 1 3
L E A R N I N G T O H A C K H A R D W A R E
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There are also some tricks to handling stripboard that, if ignored, can make things harder
than they have any reason to be:
❍
The copper tracks on the underside of stripboard are not usually coated in any way. As
you touch the tracks, you will tarnish the copper and make it difficult to solder. Avoid
touching the underside of stripboard unless you’re going to use it immediately; if it’s
too late, get some steel wool and give the copper a gentle brush to remove the corro-
sion before attempting to solder.
❍ Unlike a printed circuit board, stripboard has no solder mask —a substance that pre-
vents solder from going anywhere it isn’t supposed to. As a result, soldering is some-
what trickier than it is on a PCB—it’s all too easy to accidentally join tracks together
with too-large a blob of solder. If this happens, use your desoldering wick to remove
the excess solder and try again.
❍ The holes in stripboard make it easy to snap into custom sizes, but leave the edges
ragged. After snapping stripboard, take the time to file down the edges before assem-
bling your circuit. Make sure you wear a face-mask when doing this, because the dust
from stripboard isn’t particularly healthy to breathe.
A Brief Guide to Soldering
Having a soldering iron is one thing, but you also need to know how to use it. Soldering, like
any skill, takes practice to become proficient. If you follow the tips in this section and keep
practising, you’ll be creating clean, tidy solder joins in no time.
WARNING
This may seem obvious, but it’s worth pointing out: soldering irons get extremely hot during
use. Make sure you don’t touch any exposed metal surface, even away from the tip, and be
careful where you put the iron down. If possible, buy an iron with a stand, or obtain a separate
heatproof stand. Never leave a hot iron unattended, and if you drop an iron, don’t be tempted
to try to catch it!
Soldering works by melting a small quantity of metal to form a join between two compo-
nents. If you turn the Raspberry Pi over, you’ll see plenty of evidence of this. All the larger
components are connected using what’s called
through-hole soldering , where the components’
leads are passed through holes in the printed circuit board and then soldered into place.
Smaller components are attached via
surface-mount soldering .
Solder isn’t pure metal—it also contains a substance called flux , which is designed to etch
away any tarnish on the surfaces to be soldered in order to ensure as clean a join as possible.
Most electronic solder includes three to five
cores
of flux. You can also buy flux separately as
a paste or in liquid form, although for most hobby soldering, this isn’t necessary.