[SI-LIST] Re: ROHS
- From: "Joel Brown" <joel@xxxxxxxxxx>
- To: <howie03@xxxxxxxxxx>, <herse@xxxxxxxxxxxxxxxxxx>
- Date: Mon, 23 Apr 2007 08:12:10 -0700
Our company manufactures ruggedized computer equipment for the military.
We have no choice but to switch to ROHS assembly because many components are
no longer available with tin lead plating. Although many matte tin plated
components are somewhat compatible with tin lead solder, most ROHS BGAs are
not.
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On
Behalf Of Howard Johnson
Sent: Sunday, April 22, 2007 8:16 AM
To: herse@xxxxxxxxxxxxxxxxxx
Cc: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: ROHS
Dear Mr. Herse,
My understanding talking last Thursday with John Burke of rohsusa.com is
that lead-free SAC solder (SnAgCu) doesn't "wick" as well as lead-bearing
solder does. The SAC solder itself has a reduced propensity to whiskering
(some say it's good enough, military people say not nearly). The limited
wicking properties mean that it may not wick all the way up the leg of a
tin-plated component lead to cover (and protect) the entire lead. Any
exposed tin plating will eventually develop whiskers. Matte tin plating is
markedly less likely to whisker than bright tin, however I regard the
combination of SAC solder and matte tin as inadequate for long service-life
products. Apparently, so does the E.U. commission responsible for RoHS,
because they have granted exemptions to products used for military and
high-reliability telecommunications applications -- these applications get
to keep using lead, at least for a few years.
Best regards,
Dr. Howard Johnson, Signal Consulting Inc.,
tel +1 509-997-0505, howie03@xxxxxxxxxx
www.sigcon.com -- High-Speed Digital Design seminars, publications and films
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On
Behalf Of Conrad M Herse
Sent: Friday, April 20, 2007 9:08 AM
To: ldieguez@xxxxxxxxxx
Cc: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: ROHS
This was recently forwarded to me by a colleague.
Conrad Herse
herse@xxxxxxxxxxxxxxxxxx
On 04/20/07 11:01, Leonard Dieguez wrote:
> A quick poll / question: Has anyone recently had problems relating to
> tin whiskers from the non-leaded solder?
>
>
> Leonard Dieguez
>
>
>
>
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From: "Dr. Howard Johnson" <howie03@xxxxxxxxxx>
To: <hsdd@xxxxxxxxxxxxx>
Subject: [hsdd] High-Speed Digital Design Newsletter - - Rollback the
Lead-Free Initiative -
Date: Wed, 18 Apr 2007 00:04:26 +0000
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