Kathy Palumbo wrote:
>
> Eddie,
>
> Here, here, I couldn't agree with you more!
>
> The only problem I have with HASL is the board warpage issue. It maybe okay
> for .04" thick boards, but when you start getting down to the .015" thick
> boards it does become a hassle (pardon the pun).
>
> I am still in the process of looking at alternative coatings for our
> product, and am currently evaluating the Silver Immersion coating. I am
> very pleased so far with some of the results I am getting, but still have a
> ways to go.
>
> Just my two cents.
>
> Thanks,
> Kathy Palumbo
>
> > ----------
> > From: Eddie Brunker[SMTP:[log in to unmask]]
> > Sent: Friday, April 17, 1998 1:52 AM
> > To: [log in to unmask]
> > Subject: Re: [TN] PWB Surface Finishes and Solderability Conference
> >
> > Thanks for the reply,
> >
> > I'm sorry for the abrassive manner with which I put my comments foward.
> > I'm
> > passionate about this industry, love the work etc..
> > I feel there is too much misinformation in our industry though. It is
> > generally related to having a product to sell.
> >
> > The new wonder finish is like the miracle way to loose weight without
> > having
> > to go on a diet.
> > I'm aware that some OEMs have an issue with board finish.
> >
> > Consider the following scenario:-
> >
> > Manager/sales staff of OEM meets Manager of customer/design house.
> >
> > Yeah we can build that!
> >
> > Manager brings board back to Engineers and says we are going to build
> > this.
> >
> > Engineer says the pad dimensions are totally inadequate we should have
> > some
> > input into the design stage to help the customer design his assembly for
> > manufactuability.
> >
> > Manager says no, no, no! We might put our customer off if we did that.
> >
> > Decision is made to use flat finish to try to improve the adhesion of wet
> > paste to the pad while printing, as there is such an inadequate pad
> > dimension/geometry.
> >
> > The fact is if the product is designed with adequate pads then ordinary
> > HASL
> > finish does the job well.
> >
> > Unfortunately there is no drive to push design for manufacturability,
> > probably because there is no company to benifit.
> >
> > We don't need a miracle cure, WE NEED EDUCATION.
> >
> > There is one major defect with HASL that is it's dome of solder. This
> > presents us with no problems at 20 thou pitch on connectors, QFPs and
> > SSOICs.
> >
> > Don't fall into the trap of trying to create flat HASL finish either. You
> > run into other problems.
> >
> > The cleanliness aspect may be a factor for some too. But I'm sure this can
> > easily be addressed by talking to the suppliers about the flux technology
> > and cleaning methods.
> >
> > Thanks again,
> >
> >
> >
> > At 16:10 16/04/98 -0500, you wrote:
> >
> > and yes, there was a bit of
> > >HASL-bashing, but it was mainly done by the OEMs and assemblers, they are
> > not finding
> > >it to be acceptable.
> >
> > >I must tell you that no one is advocating HASL to me for the next
> > generation of
> > >surface mount PCBs. The conventional wisdom being (you might disagree)
> > that
> > the pads
> > >are simply not planar enough. HASL's advantages and disadvantages are
> > fairly well
> > >understood, which may be another reason why no one wants to do a
> > presentation on it
> > >at my conference.
> > >
> > >
> > >John Riley
> > >Director of Education
> > >IPC
> > >2215 Sanders Road
> > >Northbrook, IL 60062-6135
> > >(pho) 847-509-9700 ext. 308
> > >(fax) 847-509-9798
> > >
> > >
> > >
> >
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> ################################################################Dear Eddie and others,
The concerns and questions of those who have no issues with HASL are well
uinderstood and certainly well respected. However, there is a much bigger
picture with respect to final finishes that involves more than to HASL or
not. Having had the opportunity to participate in the first solderability
summit last year, I can tell you that the IPC's only objective was to
provide a forum for its members to hear first hand what others were doing
in this arena. After all, we can all make our own decisions as to what
will work best for our respective companies.
Having spent a fair amount of time in Japan and other Asian countries, I
have seen for myself that non hasl finishes account for over 40% of the
finished pwb's. There are a multitude of reasons why these compoanies
have made those choices, among them, cost, coplanarity, ease of solder
paste application, etc.
Thanks and best regards
Mike Carano
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