LISTSERV - TECHNET Archives - LISTSERV.IPC.ORG

TECHNET Archives

January 2004

TechNet@IPC.ORG

	LISTSERV Archives
	TECHNET Home
	TECHNET January 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:	MSD Question
From:	Francois Monette <[log in to unmask]>
Reply To:	TechNet E-Mail Forum.
Date:	Thu, 15 Jan 2004 08:38:00 -0500
Content-Type:	text/plain
Parts/Attachments:	text/plain (50 lines)

Hi Don,

The answer really depends on the bake cycle you are using (temperatute and
time). If you bake every seven days I assume that you bake at high
temperature like 125C. As you may be aware the default bake cycle specified
in the IPC/JEDEC standard is 48 hours at 125C. You should also note that the
standard J-STD-033A specifies a maximum cumulative bake time of 48 hours at
125C. In other words only one complete bake cycle is allowed at this
temperature.

The main concern associated with excessive baking is related to the
solderability issues caused by oxidation and intermetallic growth (Ref.
J-STD-033A, section 4.2.7.1). Take note that you can potentially use shorter
bake cycles more than once if you take into account the component MSL, body
thickness and saturation conditions (Ref.J-STD-033A, table 4-1). You may
also use lower temperature cycles like 40C or 90C. Although these bake
cycles are much longer they have no cumulative limit defined in the
standard.

Can you explain what is the reasoning behind this systematic bake schedule.
It sounds like an overkill that can cause a lot of pain.

Regards,

Francois Monette
Cogiscan Inc.
Tel : 450-534-2644
[log in to unmask]
www.cogiscan.com


Date:    Wed, 14 Jan 2004 20:26:55 -0600
From:    Donald Vischulis <[log in to unmask]>
Subject: MSD Question

Just a quick question:  What is your opinion of a MSD control procedure the
requires baking tin/lead terminated (coated) components every 7 days?

Don Vischulis

---------------------------------------------------
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