IPC Questions........

When your customer talks: * Humidity is kept under 40% * Particle count under 5MG

He / she is not talking IPC-A-610, Class 2 requirements. He / she is talking about addditional requirements. * Humidity: ANSI-J-STD-001 => 18-30*C, 30-70%RH * Particle count: ** Institute of Environmental Science and Technology (IEST) sets up the criteria and measurement methods to determine cleanroom class [eg, 10, 100, 1000, etc]. Consult their web site and perhaps take one of their courses. ** Technology subcommittee of the IPC Suppliers Council has been trying to gather data on required cleanliness for various board fab operations - lay-up of innerlayers for lamination, phototoool generation, resist exposure, laser direct imaging, etc. Many shops use clean rooms, or clean areas, but there is little yield data for the fab steps with and without clean atmospheres. [D Fritz]

We talked about something similar to this [particle count] not too long ago on SMTnet. Search on => witness plate

There's no shortage of smart customers, eh?

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Is it possible that he was testing you to see if you knew whether or not 610 addressed environmental specs?

I had a consultant that was touring our plant ask me what aspect ratio we used on our stencils. I told him I like to keep it at 1.5 if I can. As it turned out our new VP of operations (pal of the consultant) was standing around the corner listening to see if I was worthy.

Some people are smart, some are not. Either way, if they're sleazy they're trouble.

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