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Re: Question to Albert

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rickman wrote:

> I reading a bit of the blog by Yossi Kreinin and found the following
> comment by Albert van der Horst...
> 
> http://yosefk.com/blog/my-history-with-forth-stack-machines.html#comment-2536
> 
> "And the pinout! Only hobbyist would try those chips out. There are no
> pins,, just solderareas, with a stride of .4 mm (not mils, 400
> micrometer). Hobbyist trying those out would be probably my age (over
> sixty)."
> 
> The context is the GA144.  I have to agree with most of what he said,
> but I don't understand the portion quoted above.  I assume he is
> complaining about the package rather than the pin out.  In reality I
> think the package was one of the best choices they could have made.  In
> the real world size is a *huge* factor for ICs these days and this was a
> great tradeoff between size and usability.
> 
> While many devices are shipped in BGA sorts of packages (FPGAs and many
> CPUS) this device is in a no lead quad flat pack.  No, this is not so
> great for prototyping by hand, but prototyping by hand is virtually gone
> in the professional world.  Nearly every project uses a PCB on the first
> revision of the board and plan for two or even three spins of the board
> total.
> 
> I like the package because the dimensions are compatible with relaxed
> 6/6 mil trace and space design rules.  This allows a lower board cost.
> Heck, I can get protos from oshpark.com for $10 a square inch with 5/5
> design rules.  (a great deal btw, 3 boards, 2 weeks @ $10/sq inch)
> 
> I hope I understand what Albert meant and am not just ranting about
> nothing.
 
Like Albert, I am also over 60. However, I do not see what the problem is 
with the GA144 even for hand soldered prototype. It probably takes a 
properly laid out PCB as your basis but the soldering in task is quite easy 
to accomplish. My most recent experience with this was on a tiny IC package 
(20 pins) with similarly close pin-spacing.  The technique is to flood 
solder across all pins then use solder-wick to pull the excess away. I find 
a decent angle-poise magnifier is handy when doing this sort of thing and 
access to a microscope for final inspections.


-- 
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Paul E. Bennett IEng MIET.....<email://Paul_E.Bennett@topmail.co.uk>
Forth based HIDECS Consultancy.............<http://www.hidecs.co.uk>
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Going Forth Safely ..... EBA. www.electric-boat-association.org.uk..
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Question to Albert rickman <gnuarm@gmail.com> - 2014-09-17 20:27 -0400
  Re: Question to Albert Paul E Bennett <Paul_E.Bennett@topmail.co.uk> - 2014-09-18 08:08 +0100
    Re: Question to Albert rickman <gnuarm@gmail.com> - 2014-09-18 03:55 -0400
    Re: Question to Albert albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-09-18 10:37 +0000
      Re: Question to Albert rickman <gnuarm@gmail.com> - 2014-09-18 16:30 -0400
      Re: Question to Albert Paul E Bennett <Paul_E.Bennett@topmail.co.uk> - 2014-09-19 01:11 +0100
    Re: Question to Albert Brad Eckert <hwfwguy@gmail.com> - 2014-09-27 17:10 -0700

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