TECHNET Archives

September 2015

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
"Thierolf, Chris @ MPSG - SPD" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Thierolf, Chris @ MPSG - SPD
Date:
Tue, 1 Sep 2015 15:48:06 +0000
Content-Type:
text/plain
Parts/Attachments:
text/plain (29 lines)
Hello All,

Can someone help shed light on the impact of Mil-E-917 creepage and clearance requirements for soldered leads to PCBs? I know IPC-2221 defines trace spacing but these are often covered with resist and minimal compared with the Mil-E-917 requirements for electrical components.  When through hole leads of a High voltage capacitor (~1500Vdc) protrude from the PCB with 1/2" spacing, and the potential difference exceeds 800Vdc, there clearly is no conformance to Mil-E-917 (which requires <1"). A slot can be added to PCB between pads to improve creepage, but what about clearance? Conformal coating can be solution for protruding leads, but what about under the base of the cap at the PCB interface? Underfill?

thanks in advance



______________________________________
[Disc3.png]
Chris Thierolf
Principal EE and Project Engineer
L-3 Electronic Systems Segment
SPD Electrical Systems
13500 Roosevelt Boulevard
Philadelphia, PA 19116
Phone: (215) 698-6390    Fax: (215) 677-4736


________________________________
CONFIDENTIALITY NOTE: This electronic transmission, including all attachments, is directed in confidence solely to the person(s) to whom it is addressed, or an authorized recipient, and may not otherwise be distributed, copied or disclosed. The contents of the transmission may also be subject to intellectual property rights and all such rights are expressly claimed and are not waived. Unless specifically modified by L-3 SPD Electrical Systems , the content of this electronic transmission is to be read subject to L-3 SPD Electrical Systems  standard terms of business. This electronic transmission may be intercepted or affected by viruses and L-3 SPD Electrical Systems  accepts no responsibility for any interception or liability for any form of viruses introduced by this electronic transmission. If you have received this transmission in error, please notify the sender immediately by return electronic transmission and then immediately delete this transmission, including all attachments, without copying, distributing or disclosing same.

ITAR CONTROL STATEMENT: In the event this document (or any of the enclosures) contains technical data within the definition of the International Traffic in Arms Regulations or Export Administration Regulations, it is subject to the export control laws of the U.S. Government. Transfer of this data by any means to a foreign person, whether in the United States or abroad, without an export license or other approval from the U.S. Department of State or Commerce, is prohibited.

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

ATOM RSS1 RSS2