ZX-News #09 15 октября 1996

Железо

Iron - Tips of the wizard. - How to handle the PCB and its elements.

              Tips Wizard



             Igor Majorov, 1996



                 HI, ALL!


  Here again we met. Today let's talk about how to deal with 
pechatnoy board and its components.



  The printed circuit board consists of a sheet
foil getinaksa or PCB,
on which are etched conductive paths.


  The board has openings (holes), where
will then be soldered circuit elements, well, then
there are all sorts of details.


  Typically, these vent obluzheny already, so
that no problems arise. But if
got "left" card, then before the assembly
printed conductors and contact pads
need to prepare for soldering - clear
from the oxide film and contamination.


  If the date of manufacture boards gone
a lot of time and a metal coating darkened (oxidized), it must 
first clean up its fine to shine sandpaper, and then - rinse 
thoroughly with alcohol. After degreasing, all pads board brush 
applied to a thin layer of rosin flux. (Composition,%: Rosin - 
15-18, the rest is alcohol; Rosin - 6, Glycerin - 14, ethyl 
alcohol - everything else).



  Radioelements and chips also need to prepare for assembly and 
soldering. For of their findings (leg) form (attached

them the desired shape), cut to
length, if necessary, sanded and ludyat
(See ZxNews N8).


  Forming can be done with tweezers, mini pliers or other 
similar instruments / devices. 


  Since the adhesion foil
Pay is low and decreases when heated, then try to keep the 
soldering iron does not warming cost more than 5 seconds.



  Soldering boards should apply solder
low melting point: POSCO 50,
PIC 61 and other power soldering iron - no more
35-40 Tues Soldering iron should have needle-like sting and 
ostrozatochennoe obluzhennoe. 


  Soldering of circuit elements is performed as well as 
soldering 2 obluzhennyh wires, ie insert details in the right 
leg openings and heat them alternately.



       That's it! Until we meet again.


  If you have any questions please call
Tel: 275-5712 (after 18:00), to ask Igor.

P.S. When writing this article partly on materials from the 
book: "Practical Webmaster tips lover ".



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