Edward, Brian,
The use of halogen-free soldermasks has been recommended to minimize
the potential generation of chlorine dioxins during the combustion of
soldermask. Soldermask contains no flame retardant and so can more
easily and readily burn at lower temperatures given the opportunity.
Although certainly the amount of chlorine involved is small, current
amounts of chlorine present in soldermask can easily be reduced to less
than 900 ppm "halogen-free" levels without significantly affecting
performance or function.
While the industry has to be evaluating more thermally robust
soldermasks for higher temperature lead free assembly processing and
rework applications (for better adhesion without discoloration
during/after thermal excursions including rework) it seems prudent to
include halogen-free soldermasks. We have seen good test results for
halogen free soldermask after 6X 260 C reflow/rework conditions.
Regards,
Karl Sauter
Sun Microsystems
Edward Szpruch wrote:
> Brian,
> I already wrote,that I am not sure about dates, definistions etc.
> We are dealing with suppliers of Solder Mask and they are pushing forward
> "Halogen Free" formulations. This is how I got idea about need for HF solder
> mask. Since I am not sure about the whole issue, I posted this question to
> forum.
> So what are really future regulations on HF ( not related to RoHS
> regulations to be effective next year ).
> Of course I am going to aske our suppliers of Solder Mask why they are
> proposing HF formulations.
> Edward
>
> Edward Szpruch
> Eltek Ltd
> P.O.Box 159 ; 49101 Petah Tikva Israel
> Tel ++972 3 9395050 , Fax ++972 3 9309581
> e-mail [log in to unmask]
> web site : www.eltekglobal.com
>
>
>>-----Original Message-----
>>From: Brian Ellis [SMTP:[log in to unmask]]
>>Sent: ג אפריל 12 2005 10:17
>>To: Environmental Issues; Edward Szpruch
>>Subject: Re: [EN] Halogen Free Solder Mask
>>
>>What gives you the idea of HF being mandatory by 2007? In any case,
>>epoxy resis are rarely halogen free, because the epoxy group is supplied
>>by epichlorohydrin. Granted that most of the resultant chloride in the
>>prepolymerisation reaction is largely removed, but there is always some
>>left, and this assumes a stoichiometric reaction. Most of the halides in
>>normal FR-4 are from TBBPA, which is not targeted by the EU directives.
>>Do you know of any other political entity wanting to ban TBBPA?
>>
>>As for solder masks, there could be 101 (well, nearly!) chemistries
>>involved, and each would have to be taken on its own merits. It would be
>>impossible to generalise.
>>
>>Brian
>>
>>Edward Szpruch wrote:
>>
>>>Hi all,
>>>Recently I have been asked about "Halogen free Solder Mask".
>>>As I understand, "Halogen Free" restrictions on PCB are expexted to be
>>>employed in summer 2007 ( ? ).
>>>What are the definitions of "Halogen free" ???
>>>I had impression,that definition is based on limit of % wt ( 0.1% ???)
>>
>>of
>>
>>>PCB. If this is true , taking into account amount of Solder mask on PCB
>>
>>and
>>
>>>possible % of halogens in Solder Mask formulations , it seems to me,
>>
>>that
>>
>>>such contributions of Halogens originated in Solder Mask is neglible.
>>>Pls comment.
>>>regards to all
>>>Edward
>>>
>>>Edward Szpruch
>>>Eltek Ltd
>>>P.O.Box 159 ; 49101 Petah Tikva Israel
>>>Tel ++972 3 9395050 , Fax ++972 3 9309581
>>>e-mail [log in to unmask]
>>>web site : www.eltekglobal.com
>
>
--
Karl Sauter Staff Engineer, Engineering Technologies
Sun Microsystems Inc.
Office: (650) 786-7663 / x87663
E-mail: [log in to unmask]
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