TECHNET Archives

May 2003

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:
Brian Ellis <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Fri, 2 May 2003 14:27:07 +0300
Content-Type:
text/plain
Parts/Attachments:
text/plain (61 lines)
This has been discussed so many times on this forum and a search in the
archives will give you all the answers you need.

Briefly, THERE IS ***NO*** limit level for the Ionograph or any other
ionic contamination tester. The value you use can be determined ONLY by
yourself because:
a) the figures quoted here by others are related to MIL RMA fluxes
cleaned with a CFC-113 azeotrope
b) they also relate to PCBs as they were manufactured in the late
1960s/early 1970s, i.e., with conductor widths and spacings typically of
0.5 mm or more
c) they were guessed at (nothing more scientific) from instruments that
have not been made for two decades, even if they bear the same name. The
modern ones have entirely different characteristics.
d) Fluxes and cleaning products and processes have changed radically.
e) Surface mount was unknown at that time: the smallest component then
was a TO-18 can or a 1/2 W resistor.
f) We know a lot more about the subject now.

Brian

Poh Kong Hui wrote:
> Hi All,
>
> I would like to know what is the limit level for board cleanliness, if
> using  Ionograph.
> I remember the limit level for using Omegameter is 14, but can't remember
> what unit.
>
> Please enlighten me.
>
> Thanks.
>
> Poh
>
> ---------------------------------------------------
> Technet Mail List provided as a free 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/html/forum.htm for additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
> -----------------------------------------------------
>
>
>
>

---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

ATOM RSS1 RSS2