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Question about air particles in SMT area

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JW

#41372

Question about air particles in SMT area | 4 May, 2006

Hello, During a recent customer audit, one of their auditors asked if we measured airborne particles in our SMT operation area. Within their operations, they mentioned a concern when placing micro-BGA's. My question is: do some SMT lines use a pseudo-clean room standard for air particle counts? We do monitor temperature and humidity and our SMT room is kept relatively clean but do many people measure air particles? Is there a standard for this?

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Chunks

#41385

Question about air particles in SMT area | 5 May, 2006

This used to ba a hot topic years ago. But surface mount equipment does not need to be in a clean room. Your product may need to be , which would drive toward a "standard". Some people assume that "clean room" mean "high quality".

Next time have them wear a mooon suit while everyone else is wearing their usual clothing.

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#41401

Question about air particles in SMT area | 6 May, 2006

Hi,

We have had some failures due to particles, but only larger visible particles such and you should not need a real "clean room" but it's important to make sure things are kept clean, and sweep and mop as often as you need to make sure everything stays clean.

A good indication is to check the tops of the machines daily, and if they remain clean, your ok, but if you see particles on the machine, then a similar amount have fallen on your PCB's while on conveyers, so look to see how large the particles are. Would they cover a micro BGA pad?

Grant

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#41403

Question about air particles in SMT area | 6 May, 2006

There is a ISO Standard 14644-1 Class Limits, but I don't know if if this is applicable in the "so callled" SMT standard production scenaraio and if so, what class would it be? I hope that some other nice guys will correct me, or have i totally lost the fundamental?

However (assuming that I have lost it) this raises an intersting question: How clean should/must the SMT-production area be to be able to produce the products whithin the stipulated IPC/customer-req.s?

We usally open the windows in the summer season (Not in the SMT-machine production area, No windows there and also humid/temp controlled room), when the weather is extrem.

Now; dust and "particles" gets in our facility through these open windows; one ca easily tell by just using a fingertip and drag over the desk or a book shelf (our site is not located in a desert). Even if we close the windows, we still have the ventilation system who drags the "particles" around... We think we Don't have a problem with this, just a reflection that came into my mind.

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#41423

Question about air particles in SMT area | 9 May, 2006

Determine the extent of the problem using a witness plate and having it analyzed by an air quality laboratory such as: http://www.state.sd.us/denr/DES/AirQuality/aaconsultants.htm

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JW

#41433

Question about air particles in SMT area | 9 May, 2006

To All,

Thank you for your replies and opinions, this is helpful!

JW

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