[Elecraft] Use more heat - soldering technique caution

[G. Beat]

I would like to caution newcomers and first time builders on the "turning 
the knob" on your
new adjustable soldering station (e.g. Pace, Haako, Weller, Metcal) to 
achieve more heat.

There are actually THREE factors at work to have the proper amount of heat 
transferred to
a joint for soldering (or removal of enamel from a wire)

FIRST step is the heat setting on your solder station that is achieved by 
turning a temperature knob, selecting a "Thermolock" key or a specific 
temperature determined by the tip.  This is the obvious step that everyone 
uses, and then forget the next two steps!

SECOND step is actually more important, matching the type of joint to the 
profile of your iron's tip.  This IS the step that is routinely missed or 
forgotten when soldering a kit with multiple joint types (e.g. surface 
mount, through leads on PC board, or external connectors).

The normal iron tip profiles that are available are: screwdriver; single 
flat and conical.  The length (normal at .60" and long length at 1.0" ) is 
another variable for density and location of the solder joint.  I prefer 
screwdriver for through hole and single flat for wire stripping and some 
external connectors (e.g. switches)

THIRD step is the size (mass) of that tip's profile.  These vary from less 
than 1/32" to 1/4" or greater.  For example, I am building W8ZR's current 
kit - its front panel assembly requires installing numerous toggle switches, 
dual row connection strips, resistors and LEDs.
The issue for this particular assembly was not heat, but rather the varying 
mass of these soldering connections.  For the resistors and LEDs, I used my 
standard 1/16" tip at 700 degrees (PTA7) with .020 solder.  HOWEVER, for 
soldering the toggle switches, I changed to a 3/32" or 1/8" tip (PTB7 or 
PTC7)and .031 solder staying at 700 degrees.  My "dwell tip" on the joint 
and soldering technique stayed the same.

--------------
This problem of assembly technique is NOT unique to Elecraft builders or new 
soldering users.  When I toured the 3Com Ethernet NIC assembly plant eight 
years ago, they were having quality problems with the external connectors 
(e.g. BNC, RJ-45 [8-pin]) on their network cards being assembled by 
automation.  The cards were largely surface mount components being assembled 
in about 10 seconds with normal surface mount assembly techniques.  The 
massive external connectors (in relation to the surface mount components) 
received the most stress (outside world and end users) on the card and were 
subject to marginal soldering joints would eventually fail.  The problem was 
traced to the fact that these connectors were not receiving sufficient heat 
during the automated assembly process.  Until the process was changed, 
manual rework (human hand soldering) was required on these connectors to 
assure a proper attachment/ connection to the board.

So, in summary, when you are faced with a complex PC board type -- you will 
need to change your tips and maybe even the size of your solder -- no matter 
what type of soldering station (knob adjustable or not) you are using.

"Then why is the knob on these adjustable soldering stations?"
That answer has more to do with the various solder formulations being used 
today and new "no lead" solder formulations in response to no lead 
requirements (2006) and initiatives in Japan and Europe.

Today's Tin / Lead formulations:  eutectic 63/37 ratio at 361 F / 183 C  or 
the popular 60/40 ratio at 374 F / 190 C are easily handled with tip 
temperatures in the 600 to 750 degree range.

The new "No Lead" formulations will require additional heat and MORE 
attention to soldering techniques (example above).

Some of the "No Lead" solder formulations that are currently available with 
higher melting temperatures are:
Tin, Silver and Cooper ratio of 96.5/3.0/0.5 with 423 F / 217 C melting 
point or
Tin and Copper ratio of 99.3/0.7 with a 440 F/227 C melting point.

As you can see, this is a 65 to 80 degree difference -- and good soldering 
techniques will be very important.

Greg


> Message: 6
> Date: Sat, 28 Aug 2004 07:24:47 -0700
> From: David Katinsky <dkatinsky at mac.com>
> Subject: Re: [Elecraft] Hakko 808 wanted
> To: "Ron D'Eau Claire" <rondec at easystreet.com>,
> <elecraft at mailman.qth.net>
> Message-ID: <BD55E3BF.1CB1C%dkatinsky at mac.com>
> Content-Type: text/plain; charset="US-ASCII"
>
> I want to second the importance of using enough heat. Initially, I tried 
> to
> remove the enamel at my soldering temp of 750 and it did work, but took
> forever and was fairly frustrating. After deciding to move my temp up to 
> 800
> for this process, it was literally 5x faster and easier.
>
> David N2RDT