Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: Adam Seychell
To: Homebrew_PCBs@yahoogroups.com
Sent: Saturday, March 07, 2009 2:46 PM
Subject: Re: [Homebrew_PCBs] 1 and 3 mil lines


.

Adam this email was in reply to this message below.

(NOTE, All I said was I would run under
smd parts to save using a jumper. This
was to Phil and I do it all the time. I do
not claim to make whole boards using
1 Mil traces. As a mater of fact I always
use largest traces I can. As the packages
get smaller you reach a point that you can't
go between them.)

This was the message to which I was replying.

PHIL,

I make my regular run up to the smd and then I go with a 1 to 3 mil
line through the smd and then go back to the regular trace.
This will eliminate nost jumpers.

Derward myerick KD5WWI

----- Original Message -----
From: Myc Holmes
To: Homebrew_PCBs@yahoogroups.com
Sent: Monday, February 23, 2009 9:45 AM
Subject: Re: [Homebrew_PCBs] Re: Surface Mount


Hi Phil,
I agree with you on all points. There is one "gotcha" with surface mount --
it is more difficult to layout the pcb since placing tracks between the pins
is near impossible. You end up with many more vias or jumpers.

Myc

On Mon, Feb 23, 2009 at 10:29 AM, pgdion1 <pgdion1@...> wrote:

> Hi Jerry,
> Once you get used to SMD, you'll never want to do through hole again!
> I try to minimize all holes just to save drilling (which for me is the
> biggest pain). Once you get used to them, the SMD parts are actually
> pretty nice to work with. 0805's are the nicest and still have the
> values marked on the package, but the 0603 size is good too if you
> need to save space.
>
> As for traces, beating 15/15 is no problem with TT. 10/10 is easily
> obtained and I do it regularly (usually 12/12 rules with 10/10 where I
> need it like the TQFP's). In a pinch, I can do 8/8 although consistent
> traces and spaces at this level can be difficult as I still apply my
> toner with a hand iron ... to little pressure and the trace gets
> sparse, to much and ... where's the space? It's very doable though and
> many boards have a few 8/8's on them.
>
> My printer is an HP (both my 1200 and the 8000 series at work do an
> excellent job ... the 1200 with reman cartridges is actually slightly
> better).
>
> Hey, cool microscope for this ... the Dino Lite PC scopes. Just got
> one at work and it is excellent! A little pricey at $320 but really a
> nice little scope. There are many off brands for under $100 at Amazon
> (some around 50 to 60, not as nice as the Dino Lite though). I'm going
> to try one of those for home and hope it's not too cheesy.
>
> Phil (KA0HBG)
>
> --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>, "
> jerrytr2.com" <jerry@...> wrote:
> >
> > Hello,
> >
> > Since encountering this group a month or so ago, I have refined my
> > toner transfer process to the point that I am able to reliably do 15-
> > mil traces. Maybe smaller. Hope so.
> >
> > I'm doing a home project and have settled on PIC24F
> > microcontrollers. The latest version needs USB, and all the PICs
> > that support USB are surface mount. So I have been dragged kicking
> > and screaming into the 21st century.
> >
> > I bought an Aoyue 968 hot-air SMD rework station and some fine
> > tweezers and have been having a good time scrounging parts off some
> > defunct computer boards - just to get used to the tool. I'm going to
> > need a microscope - half of these parts just look like bits of dirt!
> >
> > One part I scrounged is the same package as the 24FJ256GB106
> > processor I'm planning to use - a 64-pin TQFP. Good LORD those pins
> > are small. Can Toner Transfer make boards this tight? According to
> > the spec sheet, the pin pitch is .5mm, or about 20 thousandths of an
> > inch. So the traces need to be 10 thousandths of an inch, and will
> > only have 10 thousandths of separation. Ouch.
> >
> > - Jerry Kaidor
> >
>
>
>

[Non-text portions of this message have been removed]



Messages in this topic (21) Reply (via web post) | Start a new topic
Messages | Files | Photos | Links | Database
Be sure to visit the group home and check for new Links, Files, and Photos:
http://groups.yahoo.com/group/Homebrew_PCBs
MARKETPLACE
From kitchen basics to easy recipes - join the Group from Kraft Foods

Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch format to Traditional
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe NOTE, All I said was I would run under
smd parts to save using a jumper. This
was to Phil and I do it all the time. I do
not claim to make whole boards using
1 Mil traces. As a mater of fact I always
use largest traces I can.
.


[Non-text portions of this message have been removed]