Pete,
We have had an ongoing struggle with solder thicknesses specified by a
customer. If a board supplier is truly able to meet the tolerances Mark
stated I would like to know how they are doing it and the equipment they are
using. We went to an outside service that deals only with final finishes and
on 2-sided SMT they wouldn't guarantee .0001-.002. It has a lot to do with
geometry and pad size and limitations of HASL equipment. This is one reason
why many people are investigating alternatives such as white tin.

David Van Wyen
Circuit Technologies, Inc.

-----Original Message-----
From: Pete Nemcik <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Wednesday, January 19, 2000 10:55 AM
Subject: [TN] HASL thickness


>Hi Techneters,
>quoting from a print: "FINISH: CONDUCTOR PATTERNS ON FINISHED BOARD
>SHALL BE SOLDER COATED PER IPC-D-275 AND HOT AIR LEVELED (HASL) TO A
>FINAL THICKNESS OF .0001-.00025 LAYER 1 (TOP), .00025 NOMINAL LAYER 2
>(BOTTOM)."
>Is this realistic? Can anybody do this? Any help and advice is
>appreciated. Any companies capable of doing, please me contact directly.
>
>Thanks!
>
>Peter Nemcik
>Modular Components National Inc.
>Forest Hill, MD 21050
>(410) 879-6553
>FAX (410) 838-7629
>
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