X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient: geda-user AT delorie DOT com
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20120113;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type;
        bh=RRVPPeuijHu//wMj2mduvpHucTS9YJEujPjctQa5U3w=;
        b=bXPe1OL0DV6ClttZbSETER4qZzAnnqlVUBrRefoklSbL9zgXmcpyLlL8YJRaF/UtyP
         X80e0SkUINhEP6ngsNzmk2QIyz1LJbitGQS9SRvD9LpunNkhjcodKdTW/Z9n2lkCxkjA
         Y2wfZbV3djxcECgt7DwJPJFgGBSk6JsuOxiQ/rdo9glXNllee+Q0G+MvtXIL0oaaY0xx
         rVJa6XtCjs3+RKkd+CdDcp6Eog0ghkicC5hUujyALECdu3WspKZYeYA1nON9v3qtZ75p
         FzRLn6KUPFd9OAv4MSzWWt3s3TiRcwieKEm5UjcKFmMp7mDDeX9qgUYp/svgEw/ceFrI
         2j0w==
MIME-Version: 1.0
X-Received: by 10.52.117.174 with SMTP id kf14mr3752493vdb.26.1374172195725;
 Thu, 18 Jul 2013 11:29:55 -0700 (PDT)
In-Reply-To: <CAOuGh89iVm_PsWQ1xJGVXGomdeZfUha7FQy_JdMFdDMh_C+HJQ@mail.gmail.com>
References: <CALSZ9goF9oRVUfHM_UDyM60Kr=x4ONsXVtnVe4VJdm=F9YmDBg AT mail DOT gmail DOT com>
	<CAN0Jx-8bMxPQu5AkX80U-3qB=U2HWg0-astWEuDj2cWS-k0ApA AT mail DOT gmail DOT com>
	<CAOuGh89iVm_PsWQ1xJGVXGomdeZfUha7FQy_JdMFdDMh_C+HJQ AT mail DOT gmail DOT com>
Date: Thu, 18 Jul 2013 14:29:55 -0400
Message-ID: <CALSZ9gqP1gbdEAR_MLSdiM_UyX_TfcCF8op8rGUNyB1pJHiRuQ@mail.gmail.com>
Subject: Re: [geda-user] PCB BGA (ball grid array) Package/Footprint
From: Rob Butts <r DOT butts2 AT gmail DOT com>
To: geda-user AT delorie DOT com
Content-Type: multipart/alternative; boundary=bcaec548597496299204e1cd655e
Reply-To: geda-user AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: geda-user AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com
Precedence: bulk

--bcaec548597496299204e1cd655e
Content-Type: text/plain; charset=ISO-8859-1

I'm not sure exactly what you mean here,

I was thinking the pads would have a small detent the IC would settle into
but apparently no such luck.  It would just make it easier to line up.  The
people I have doing my assembly have a hard time as I imagine most people
do.

Thanks


On Thu, Jul 18, 2013 at 12:51 PM, Bob Paddock <graceindustries AT gmail DOT com>wrote:

> > The other is applying a thin layer of
> > flux to the area of the BGA footprint.
>
> Make sure there is a clear path for water flow (cleaning fluids) for
> ingress and egress of the flux.
>
> Makes a difference in reliability of high impedance circuits and ultra
> low power circuits.
>
> "Make it smaller" does not always go well with "make it manufacturable"
> when
>  hard to clean parts (BGA/QFN/LCC/LGA) are surrounded by things like
> bypass caps for example. :-(
>

--bcaec548597496299204e1cd655e
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div>I&#39;m not sure exactly what you mean here,</div><di=
v>=A0</div><div>I was thinking the pads would have a small detent the IC wo=
uld settle into but apparently no such luck.=A0 It would just make it easie=
r to line up.=A0 The people I have doing my assembly have a hard time as I =
imagine most people do.</div>
<div>=A0</div><div>Thanks</div></div><div class=3D"gmail_extra"><br><br><di=
v class=3D"gmail_quote">On Thu, Jul 18, 2013 at 12:51 PM, Bob Paddock <span=
 dir=3D"ltr">&lt;<a href=3D"mailto:graceindustries AT gmail DOT com" target=3D"_bl=
ank">graceindustries AT gmail DOT com</a>&gt;</span> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex"><div class=3D"im">&gt; The other is applying=
 a thin layer of<br>
&gt; flux to the area of the BGA footprint.<br>
<br>
</div>Make sure there is a clear path for water flow (cleaning fluids) for<=
br>
ingress and egress of the flux.<br>
<br>
Makes a difference in reliability of high impedance circuits and ultra<br>
low power circuits.<br>
<br>
&quot;Make it smaller&quot; does not always go well with &quot;make it manu=
facturable&quot; when<br>
=A0hard to clean parts (BGA/QFN/LCC/LGA) are surrounded by things like<br>
bypass caps for example. :-(<br>
</blockquote></div><br></div>

--bcaec548597496299204e1cd655e--