Paul;
ENTEK is an OSP (anti-oxidant) used to coat bare copper boards prior to
assembly.
Upon exposure to reflow temperature it loses its capability to prevent
copper tarnish and needs to be reapplied if you want to stop oxidation.
Normally applied at the board shop after mask.
Charlie McMahon
----- Original Message -----
From: Paul Klasek <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, February 20, 2000 5:21 PM
Subject: Re: [TN] [LF] Components
> Helps indeed , thx Doug, knew the Nortel (2.5 years in field is not much
> [yet]) & Pan.story , didn't the Castin one .
> What does "Entek PWB pad coating" stands for ? ; organic on copper ?
>
> Paul Klasek
> ResMed
>
> -----Original Message-----
> From: Romm, Doug [mailto:[log in to unmask]]
> Sent: Saturday, 19 February 2000 3:11
> To: [log in to unmask]
> Subject: Re: [LF] Components
>
>
>
> Paul,
>
> TI data on compatibility with the various lead-free pastes is limited to
> date. I have described our history on this issue with water-soluble and
> no-clean Sn/Pb pastes. I have also described what I have seen from other
> sources that have evaluated Ni/Pd finish components with lead-free pastes.
> If you want any specifics on the TI data I am glad to provide it.
>
> Here are my comments:
>
> 1. In the past, TI has conducted evaluations on Sn/Pb water soluble and
> no-clean type pastes from various vendors. This evaluation can be seen
at:
>
> http://www.ti.com/sc/docs/products/logic/package/palladm/index.htm
> <http://www.ti.com/sc/docs/products/logic/package/palladm/index.htm>
>
> The paper I refer to is titled "Evaluation of Water Soluble and No-Clean
> Solder Pastes with Palladium Plated and Solder Plated SMT Devices" (I've
> since learned to shorten the titles of my papers!).
>
> The results of this study did indicate variability in visual wetting
> (contact angle) for Ni/Pd finish depending on the solder paste used. This
> difference was shown to be visual only, not impacting strength of the
solder
> joint, as seen in the study. Fortunately, most of the major solder paste
> vendors' represented in our study have shown good wetting. Even the few
> that showed worse wetting performance have improved their flux chemistry
> over time and we have seen improvement.
>
> 2. The 1 study performed by TI to evaluate performance with a lead-free
> solder paste is located on the same web page above and is titled "Pb-Free
> Solder Joint Evaluation". This evaluation looked at AIM Castin paste in
> conjunction with TI Ni/Pd components. This study showed good wetting
angle
> with Ni/Pd and the Castin paste. See the cross-section photos included in
> the paper. Also, we saw positive lead pull and temp cycle results.
>
> 3. I saw the following papers (with brief summary included below) at the
> Minnesota conference:
>
> Title: Lead-Free - The Nortel Experience
>
> Author: Ken Snowden, Nortel
>
> Highlights: In his introductory information Ken commented that the
> contribution amounts for the lead in a typical joint are
>
> 70% from the solder paste, 25% from the PWB pad, and 5% from the component
> lead. Ken also showed pull strength data after
>
> temp cycle using Entek PWB coating, Ni/Pd component finish, and 2
different
> lead-free alloy solders. The data showed 14.4N
>
> pull strength for Sn/Pb finish solder, 18.1N for Sn/Cu solder, and 18.0N
for
> Sn/Ag solder. This is excellent data on good
>
> pull strength performance for Ni/Pd finished components. Nortel has built
a
> lead-free telephone Sn/Cu paste, Entek PWB pad
>
> coating, various lead-free component finishes (mainly Ni/Pd and pure Sn).
> These phones saw 2.5 years in the field with no
>
> problems. Ken's presentation was very positive for Ni/Pd. Mr. Snowden is
the
> leader of the HDPUG lead-free group in which
>
> TI is participating.
>
>
> Title: The Panasonic Mini Disk Player: Turning a New Leaf in a Lead-Free
> Market
>
> Author: Tom Baggio, Panasonic Factory Automation, Franklin Park, Illinois
>
> Highlights: At the start of the conference Panasonic was presented an
award
> for introduction of their Mini Disk player as a
>
> lead-free product. Tom presented Panasonic's approach and history in the
> lead-free arena. Tom mentioned that several alloy
>
> groups are being investigated for lead-free soldering: Sn/Cu, Sn/Ag,
> Sn/Ag/Bi, Sn/Zn, Sn/Bi. Panasonic chose to target
> Sn/Cu for wave soldering and Sn/Ag/Bi for surface mount soldering in their
> mini disk player. It is commonly known that Bi
>
> reduces the melting point of pure Sn or Sn/Ag alloys allowing minor change
> to current reflow profiles but the Bi affects
>
> solder joint strength. Panasonic is focusing on only 3% Bi to allow use of
> current reflow profile. Tom showed excellent
> lead pull data on Ni/Pd components that they used in build of the mini
disk
> player. Panasonic has gained worldwide recognition for build of this
> lead-free consumer product.
>
>
> 4. TI is participating in several industry consortia (HDPUG, Innolot,
EIAJ,
> Components FOCUS Group) and additional university group evaluations that
> will provide independent evaluations of Ni/Pd finish components with the
> primary lead-free solder pastes being considered by the industry.
>
> 5. TI is also performing internal evaluations on several of the lead-free
> options. We will likely publish our results in the future.
>
>
> I hope this information gives you an idea on past and current work.
>
> Regards, Doug Romm
> Member Group Technical Staff
> Texas Instruments
>
>
>
>
>
> -----Original Message-----
> From: Paul Klasek [ mailto:[log in to unmask]
<mailto:[log in to unmask]>
> ]
> Sent: Thursday, February 17, 2000 6:11 PM
> To: Romm, Doug; [log in to unmask]; [log in to unmask]
> Subject: RE: [TN] Tin/Silver Paste and Palladium
>
>
> Ryan , as far as Palladium recommended fluxing/process , perhaps if you'd
> forwarded your original to Doug ;
> he'd be likely more than sufficiently across your puzzle .
> Doug, as yo gave few good insights on LF ; there is a debate on TN
seemingly
>
> on palladium wetting ;
> my apologies to drag you across to coals .
>
> I'd be interested in recommended paste myself = to reflow TI finish
> optimally ;
> i'd presume extensive validations would be done/documented ?
>
> Thanks a lot
>
> Paul Klasek
> http://www.resmed.com <http://www.resmed.com>
>
> -----Original Message-----
> From: Romm, Doug [ mailto:[log in to unmask] <mailto:[log in to unmask]> ]
> Sent: Thursday, 17 February 2000 4:32
> To: [log in to unmask]
> Subject: Re: [LF] Components
>
>
>
> Hans, yes, there are lead-free components (other than passives) available
in
>
> the market. This forum is not intended as a marketing source, but I will
> mention to you that Texas Instruments supplies Ni/Pd finished components
> (lead-free) now. This lead-free finish has been in the market since 1989
> and to date over 30 billion Ni/Pd components are in the field. You can
see
> technical information on this finish at this web site:
>
> http://www.ti.com/sc/docs/products/logic/package/palladm/index.htm
> <http://www.ti.com/sc/docs/products/logic/package/palladm/index.htm>
> < http://www.ti.com/sc/docs/products/logic/package/palladm/index.htm
> <http://www.ti.com/sc/docs/products/logic/package/palladm/index.htm> >
>
> Of course, one of the major issues with lead-free processing and plastic
> packages is the dramatic increase in peak reflow temperature with some of
> the alloys, with the peak sometimes as high as 260C. TI, along with other
> components suppliers, is working with industry consortia to characterize
> moisture performance of current package technology at these higher reflow
> temperatures.
>
>
> Best regards, Doug Romm
>
>
>
> -----Original Message-----
> From: <Hans Juergen Bauer> [ mailto:[log in to unmask]
> <mailto:[log in to unmask]>
> < mailto:[log in to unmask] <mailto:[log in to unmask]> > ]
> Sent: Wednesday, February 16, 2000 10:45 AM
> To: [log in to unmask]
> Subject: [LF] Components
>
>
> Dear Colleagues,
>
> is in this circle participating anyone, who takes care of the
> components, soldered with leadfree processes??
> As I resume a lot of the last messages, nobody is realizing the
> suffer of a lot of component commodities. It is clear, that a
> board with only some different ceramic components on it, is
> solderable leadfree. What about telecoms boards, containing a
> lot of different kind of components?
>
> I am curious about the answer,
>
> Hans Juergen
>
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> -----Original Message-----
> From: Romm, Doug
> Sent: Wednesday, February 16, 2000 11:32 AM
> To: 'Leadfree Electronics Assembly E-Mail Forum.'; [log in to unmask]
> Subject: RE: [LF] Components
>
>
> Hans, yes, there are lead-free components (other than passives) available
in
> the market. This forum is not intended as a marketing source, but I will
> mention to you that Texas Instruments supplies Ni/Pd finished components
> (lead-free) now. This lead-free finish has been in the market since 1989
> and to date over 30 billion Ni/Pd components are in the field. You can
see
> technical information on this finish at this web site:
>
> http://www.ti.com/sc/docs/products/logic/package/palladm/index.htm
> <http://www.ti.com/sc/docs/products/logic/package/palladm/index.htm>
>
> Of course, one of the major issues with lead-free processing and plastic
> packages is the dramatic increase in peak reflow temperature with some of
> the alloys, with the peak sometimes as high as 260C. TI, along with other
> components suppliers, is working with industry consortia to characterize
> moisture performance of current package technology at these higher reflow
> temperatures.
>
>
> Best regards, Doug Romm
>
>
>
> -----Original Message-----
> From: <Hans Juergen Bauer> [ mailto:[log in to unmask]
> <mailto:[log in to unmask]> ]
> Sent: Wednesday, February 16, 2000 10:45 AM
>
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