From: Jan Panteltje on
On a sunny day (Tue, 12 Jan 2010 22:08:24 -0800 (PST)) it happened
"miso(a)sushi.com" <miso(a)sushi.com> wrote in
<b94e73a6-b94e-4d28-8cf1-1b09447e7924(a)g25g2000yqd.googlegroups.com>:

>On Jan 9, 11:35�am, "Abby Brown" <abbybr...(a)charter.net> wrote:
>> Hi,
>>
>> I mentioned to a friend that I was reluctant to take on a
>> project requiring hand soldering a number of SMDs. �He suggested
>> plasma soldering is now used because it heats faster so less
>> heat travels to the package. �I couldn't find much about the
>> units other than they are used for lead-free solder. �Is plasma
>> soldering suitable for home use or are they strictly high end?
>>
>> I last soldered SMDs in my DEC days. �The only specialized piece
>> of equipment was a hot air jet preheat the area. �We held the
>> SMD in place with a finger while tacking down the corners then
>> soldered the remaining leads. �There were the occasional finger
>> slip and burned fingers. It was an order of magnitude more
>> difficult that soldering in a DIP. �DIPs would be too large for
>> this project.
>>
>> Are there other tools now available for hand soldering SMDs that
>> I should know about?
>>
>> Thanks,
>> Gary
>
>Is it possible the suggestion was for a Metcal? Not plasma, but RF
>powered. I know people who swear by them, but it seems much too
>complicated of a way to melt solder. Damn expensive. The manufacturing
>has been moved to China, so I don't know if the quality has gone down.
>Metcals always seem to be broken.

Indeed, I do not understand the Metcal hype eiteyr.
I googled on that, and it seems to be a weird way to do things.
There is the old Weller, and that works with a resistive heater,
and I now have have a much cheaper other one that is adjustable and even has an
auto shutoff timer, and has been working OK now for many years.
http://www.testberichte.de/test/produkt_tests_conrad_electronic_voltcraft_ls50_p59358.html
Waht is so special about a Metcal, except the price?

From: Michael A. Terrell on

Jan Panteltje wrote:
>
> Indeed, I do not understand the Metcal hype eiteyr.
> I googled on that, and it seems to be a weird way to do things.
> There is the old Weller, and that works with a resistive heater,
> and I now have have a much cheaper other one that is adjustable and even has an
> auto shutoff timer, and has been working OK now for many years.
> http://www.testberichte.de/test/produkt_tests_conrad_electronic_voltcraft_ls50_p59358.html
> Waht is so special about a Metcal, except the price?


The old Weller stations used a Bang-Bang controller. They caused
reliability problems with CMOS & FETs in our products and were banned
from the production floor, including the cable line so they couldn't be
moved around. For one thing, the tips weren't grounded, and the current
pulse could induce a pulse into the PC board. They were replaced with
Ungar 'Loner' irons with electronic temperature controls and a tip
ground that could be kept under our required three ohm limit.


--
Greed is the root of all eBay.