Ian just for reference here is the SMT Plus sizing.

        This is for the standard SOT23. (SMT Plus has over a dozen SOT23
variations covering metrics and all the other minor variations.)

Reflow
X+2E pad edges: 2.87mm
Z pad edges 2.82mm

Wave
X+2E pad edges: 2.87mm
Z pad edges 3.48mm

        So your pattern and Philips would be very close for overall sizing.
There could be significant differences in the pad sizes by what I have seen
in the past for manufacturer's or others land patterns. SMT Plus follows
some pretty stringent rules for pad sizing and now, ten years after I took
the course, I still see SMT Plus following the same rules time and time
again in their new footprints.

Sincerely,
Brad Velander.

Lead PCB Designer
Norsat International Inc.
Microwave Products
Tel   (604) 292-9089 (direct line)
Fax  (604) 292-9010
email: [EMAIL PROTECTED]
http://www.norsat.com


-----Original Message-----
From: Ian Wilson [mailto:[EMAIL PROTECTED]]
Sent: Monday, August 12, 2002 5:14 PM
To: Protel EDA Forum
Subject: Re: [PEDA] Philips Wave and Reflow Footprints(Ex:IPC Footprint
Standards)


As an example:

The SOT23 reflow footprint takes up 3.3x3 mm while the wave takes up
4.5x4.6mm.

The IPC standard has a 8x8!! placement courtyard. Like, yeah right. Someone 
tell me this is a typo - at that size I may as well us a TO-92.

Taking the distance of the outer edge of a pad on one side of the SOT-23 to 
the outer edge of the other pad (the IPC Z dimension):

Philips Reflow: 2.7mm
My footprint: 2.95 mm
IPC: 3.6mm
Philips Wave: 4mm


************************************************************************
* Tracking #: D3A9B4BF6B16E946A00629F1497D0874C6828E74
*
************************************************************************

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* To post a message: mailto:[EMAIL PROTECTED]
*
* To leave this list visit:
* http://www.techservinc.com/protelusers/leave.html
*
* Contact the list manager:
* mailto:[EMAIL PROTECTED]
*
* Forum Guidelines Rules:
* http://www.techservinc.com/protelusers/forumrules.html
*
* Browse or Search previous postings:
* http://www.mail-archive.com/proteledaforum@techservinc.com
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Reply via email to