LISTSERV - TECHNET Archives - LISTSERV.IPC.ORG

TECHNET Archives

May 2004

TechNet@IPC.ORG

	LISTSERV Archives
	TECHNET Home
	TECHNET May 2004

	Log In
	Register

	Subscribe or Unsubscribe

	Search Archives

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 >>]

Subject:	Re: Raw Card warpage
From:	Dwight Mattix <[log in to unmask]>
Reply To:	TechNet E-Mail Forum.
Date:	Wed, 5 May 2004 10:53:51 -0700
Content-Type:	text/plain
Parts/Attachments:	text/plain (48 lines)

At 12:09 PM 5/5/2004 -0500, Victor G. Hernandez wrote:
>Fellow TechNetters,
>
>    At a PWB factory setting is a final baking process permissible to
>correct any warpage prior to customer shipment.

Some customers allow it or do not specify either way.  Some customers
specify against it.  If not specified either way then tacit approval for
"flat baking" is generally assumed to be given.

>Once the sealed bag is
>open and product not used for an extended period of time will the
>warpage return.

Not necessarily. It will only rewarp if the pwb design is unbalanced
(either in dielectric stackup or in metal pattern distribution).  An
unbalanced design will (re)warp to some degree when heated during solder
assembly.

Dwight Mattix
Sr Staff QE, Corp Eng

>Victor G. Hernandez
>
>---------------------------------------------------
>Technet Mail List provided as a service by IPC using LISTSERV 1.8e
>To unsubscribe, send a message to [log in to unmask] with following text in
>the BODY (NOT the subject field): SIGNOFF Technet
>To temporarily halt or (re-start) delivery of Technet send e-mail to
>[log in to unmask]: SET Technet NOMAIL or (MAIL)
>To receive ONE mailing per day of all the posts: send e-mail to
>[log in to unmask]: SET Technet Digest
>Search the archives of previous posts at: http://listserv.ipc.org/archives
>Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
>for additional information, or contact Keach Sasamori at [log in to unmask] or
>847-509-9700 ext.5315
>-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

ATOM RSS1 RSS2

LISTSERV.IPC.ORG