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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