Lpc2000

It's always entertaining to play "find the right footprint".  The 
IPC footprint that most closely matches this is IPC-563A.  The 
difference?  Lands are 1.6mm x .3mm vs Philips 1.1mm x .285mm.  The 
width difference isn't very significant, but the length is rather 
substantial.  The typical IPC specs are for MMC or "Maximum Material 
Condition", which is basically the large end of all dimensions.  LMC 
("Least Material Condition") doesn't seem to be used much.

    Supposedly, IPC specs are based on real world manufacturing 
feedback, and take into account all the little details that relate to 
making a product manufacturable.  That being said, I am/was using the 
IPC-563A footprint.  I'd be interested in hearing the results of people 
who have had boards made using vapor phase or IR reflow and what pad 
dimensions they use.

    This has always been a pet peeve of mine.  Some manufactures 
reference IPC standards, some JEDEC, some have thier own, and some it's 
just best guess.  Given the choice, I'd prefer they adhered to IPC or 
JEDEC, AND published the spec in the datasheet.  National is really good 
about this.  Others are not.  Referencing the IPC spec is great, but if 
you can't afford to spring for the book, you're hosed.  Luckily, I found 
a copy on the web (< http://tinymicros.com/ipc >) from 1999, which has 
most everything, but does lack TSSOP specs.

    --jc

Joseph Tapay wrote:

> or make your own library entry from official philips footprint drawing 
> as i
> am doing it
> for LQFP48 package
> http://www.semiconductors.philips.com/acrobat/packages/footprint/FOOTPRINT-HTQFP-HLQFP-LQFP-REFLOW.pdf
>
> (i could not find the footprint for HVQFN48 package...)
>
> joseph
>
> ----- Original Message -----
> From: "Leon Heller" <leon_heller@...>
> To: <lpc2100@yahoogroups.com>
> Sent: Wednesday, February 11, 2004 12:55 PM
> Subject: RE: [lpc2100] Footprint for LPC
>
>
> >
> > >From: "vrrraju" <vrrraju@...>
> > >Reply-To: lpc2100@yahoogroups.com
> > >To: lpc2100@yahoogroups.com
> > >Subject: [lpc2100] Footprint for LPC
> > >Date: Wed, 11 Feb 2004 17:46:23 -0000
> > >
> > >Dear Friends,
> > >
> > >I am happy to see that one group is dedicated towards Philips
> > >LPC2100. I am trying to build a board based on Philips LPC2106. I am
> > >looking for the foot print and library for the LPC2100 for Eagle PCB.
> > >I have checked with cadsoft for the same but they haven't uploaded
> > >any library for the Philips LPC. Please if anybody has built the
> > >library for the same in eagle, let me know because it will be of
> > >great help to me.
> >
> > I think there is one in the group's Files area.
> >
> >
> > Leon
> > --
> > Leon Heller, G1HSM Tel: +44 1424 423947
> > Email: aqzf13 at dsl dot pipex dot com
> > WWW: http://www.geocities.com/leon_heller
> >
>