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SMT electronics assembly manufacturing forum.


Granite Surface and ESD


NAW

#33408

Granite Surface and ESD | 28 March, 2005

We have a granite table out on our production floor. We use the table along with metal parallel bars and a height gauge to measure component height. Some of these boards have components on them that may be ESD sensitive. Does anyone have experience with this situation? What have you done to make the work station ESD safe?

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RDR

#33411

Granite Surface and ESD | 28 March, 2005

Put an Ionizer over the top of it.

Russ

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KEN

#33423

Granite Surface and ESD | 28 March, 2005

Has it been established the surface is not safe?

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#33424

Granite Surface and ESD | 28 March, 2005

We agree with Ken. What does your field meter tell you?

Taking it a step further [erzit backward?], what is it about the measurement that requires the granite surface? Wouldn't an ESD protected bench top be as flat as needed for most gauging like this?

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KEN

#33442

Granite Surface and ESD | 29 March, 2005

If the granite is a problem, how about using some "stati-cide" type of spray.

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#33443

Granite Surface and ESD | 29 March, 2005

Ken: Sprays like you suggest are hydroscopic soaps that should be avoided. If that was the choice, we'd rather go with Russ' ioniczer.

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steve

#33446

Granite Surface and ESD | 30 March, 2005

Granite is a porous material and if anyone decided to clean this material you probably have an insulative barrier thus you would never have static dissipation. Spend $45.00 and put a mat over the granite or spend $80.00 and get an esd laminate material to cover the granite.

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RDR

#33449

Granite Surface and ESD | 30 March, 2005

Doesn't covering a surface plate defeat the purpose?

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RDR

#33450

Granite Surface and ESD | 30 March, 2005

Doesn't covering a surface plate defeat the purpose?

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Steve

#33484

Granite Surface and ESD | 31 March, 2005

Russ if your asking me if covering the surface of the granite defeats the purpose then I'm lost. An ionizer is a very good suggestion but they are not inexpensive. If the table is grounded and the metal bars are on a grounded mat, laminate etc. then you now have a true path to ground. Also ionization does have to be calibrated, balanced both positive and negative ions must be at an equal state. A mat has to be kept relatively clean. Workers are more effective at cleaning than knowing when to balance an ionizer and then of course you have to have a meter to read if the ionizer is in or out of balance. Got an extra $700-$1000.00 to spend go with the ionizer and the tester. Just my thoughts for what they are worth.

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dougs

#33486

Granite Surface and ESD | 1 April, 2005

I think what Russ is getting at is that the granite table is used for it's flat surface to aid in measurement, the flat surface helps to measure heights very accuratly. If you add another surface on top of that then you lose what the granite surface gives you in terms of measurement accuracy. Which goes back to a point made earlier in the thread, why would you need a granite table? I'd have thought you could measure a component pretty well using a set of verniers.

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RDR

#33491

Granite Surface and ESD | 1 April, 2005

Doug you are correct, I was talking about the integrety of the surface for mechanical measurement accuracy, not ESD properties.

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