i just asked a very simple question, and got a perfect answer within a few minutes. thanks for your insite, tho.
----- Original Message ----- From: "Bevan Weiss" <[EMAIL PROTECTED]> To: "Protel EDA Discussion List" <[email protected]> Sent: Monday, December 26, 2005 2:24 PM Subject: Re: [PEDA] Touch up Solder mask? > > Given the larger cost of the manufacturer producing the package with a > thermal pad on the bottom of the chip, and the extra packaging > challenges present (ie placing the die in intimate contact with the > thermal pad) then it is preferred to connect up the thermal pad to a > copper area on the board, and to have this copper area large enough to > dissipate the heat required. > > If using the chip in a very low power mode (ie not using the full > designed capabilities of the chip) then it may be easier to not connect > the thermal pad to anything, however if you don't know whether your > design will indeed remain within the reduced power dissipation limits, > then you should always follow the manufacturers recommendations > regarding the copper connectivity of the thermal pad. The manufacturer > generally always recommends connecting it to a copper area on the > component side, and then vias to conduct heat away from the component > side copper to a more exposed copper region. > > no. its optional, for additional cooling if required. it's not. > > > > ----- Original Message ----- > > From: "Jim Walker" <[EMAIL PROTECTED]> > > To: "Protel EDA Discussion List" <[email protected]> > > Sent: Sunday, December 25, 2005 2:58 PM > > Subject: Re: [PEDA] Touch up Solder mask? > > > > > > > >> Forgive me if I am missing the point but isn't the pad on the bottom of > >> the IC there for the purpose of being soldered to a matching pad on the > >> board? Isn't it necessary for heat sinking or grounding? > >> > >> Jim Walker > >> Walker Power Design, Inc. > >> www.walkerpowerdesign.com > >> > >> > >> Leonard Gabrielson wrote: > >> > >>> Thanks very much guys!! > >>> Len G. > >>> > >>> > >>> ----- Original Message ----- > >>> From: "Harry Selfridge" <[EMAIL PROTECTED]> > >>> To: "Protel EDA Discussion List" <[email protected]> > >>> Sent: Saturday, December 24, 2005 3:37 PM > >>> Subject: Re: [PEDA] Touch up Solder mask? > >>> > >>> > >>> > >>> > >>>> Here's a page for an overcoat touchup pen sold by DigiKey: > >>>> > >>>> > > http://rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=75&M=CW3300G > > > >>>> and here's a page for high temperature Kapton tape that can be used > >>>> as a temporary solder resist covering: > >>>> > >>>> > >>> > > http://rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=19&M=5413%20%201/2%22 > > > >>>> Regards - Harry > >>>> > >>>> > >>>> > >>>> > >>>> At 01:44 PM 12/24/2005, you wrote: > >>>> > >>>> > >>>>> oops. let me try this again... > >>>>> > >>>>> Hello all, > >>>>> > >>>>> I have an 8-pin SOIC that has an exposed ground pad on the bottom of > >>>>> it (Analog Devices AD8000), and find that there are a couple of vias > >>>>> under the IC that I am afraid might be shorted by this pad. > >>>>> > >>>>> Does someone know of where to buy a small quantity of touch-up > >>>>> solder mask so I can cover the IC pad or the vias before wave > >>>>> > > soldering? > > > >>>>> Thanks much, & Merry Christmas. > >>>>> > >>>>> > >>>> snip > >>>> > >>>> > >>>> > >>>> ____________________________________________________________ > >>>> You are subscribed to the PEDA discussion forum > >>>> > >>>> To Post messages: > >>>> mailto:[email protected] > >>>> > >>>> Unsubscribe and Other Options: > >>>> http://techservinc.com/mailman/listinfo/peda_techservinc.com > >>>> > >>>> Browse or Search Old Archives (2001-2004): > >>>> http://www.mail-archive.com/[email protected] > >>>> > >>>> Browse or Search Current Archives (2004-Current): > >>>> http://www.mail-archive.com/[email protected] > >>>> > >>>> > >>> > >>> > >>> ____________________________________________________________ > >>> You are subscribed to the PEDA discussion forum > >>> > >>> To Post messages: > >>> mailto:[email protected] > >>> > >>> Unsubscribe and Other Options: > >>> http://techservinc.com/mailman/listinfo/peda_techservinc.com > >>> > >>> Browse or Search Old Archives (2001-2004): > >>> http://www.mail-archive.com/[email protected] > >>> > >>> Browse or Search Current Archives (2004-Current): > >>> http://www.mail-archive.com/[email protected] > >>> > >>> > >>> > >> ____________________________________________________________ > >> You are subscribed to the PEDA discussion forum > >> > >> To Post messages: > >> mailto:[email protected] > >> > >> Unsubscribe and Other Options: > >> http://techservinc.com/mailman/listinfo/peda_techservinc.com > >> > >> Browse or Search Old Archives (2001-2004): > >> http://www.mail-archive.com/[email protected] > >> > >> Browse or Search Current Archives (2004-Current): > >> http://www.mail-archive.com/[email protected] > >> > >> > >> > > > > > > > > ____________________________________________________________ > > You are subscribed to the PEDA discussion forum > > > > To Post messages: > > mailto:[email protected] > > > > Unsubscribe and Other Options: > > http://techservinc.com/mailman/listinfo/peda_techservinc.com > > > > Browse or Search Old Archives (2001-2004): > > http://www.mail-archive.com/[email protected] > > > > Browse or Search Current Archives (2004-Current): > > http://www.mail-archive.com/[email protected] > > > > > > > > > > > > ____________________________________________________________ > You are subscribed to the PEDA discussion forum > > To Post messages: > mailto:[email protected] > > Unsubscribe and Other Options: > http://techservinc.com/mailman/listinfo/peda_techservinc.com > > Browse or Search Old Archives (2001-2004): > http://www.mail-archive.com/[email protected] > > Browse or Search Current Archives (2004-Current): > http://www.mail-archive.com/[email protected] > ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[email protected] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
