Particle Counter Results - Interpreting Data for a Class 100,000 Cleanroom

[azaplas]

Hi everyone,

I have a question about reading the results from our particle counter data. I took readings using the ".01 Cubic Feet" Sample Volume.

The results I acquired came out to be (in one of the areas of the clean room):
0.5 µm: 300
1 µm: 100
5 µm: 0

We have a Class 100,000 cleanroom, so I would like to know if anyone can help me interpret my data. (We are not required to have a clean room, but we installed one to help improve the instances of burnt diodes for our laser product.) I am comparing to the FED STE209E table standard for now for ease of conversion calculations, but I know that it is no longer used for validations.

Particle_counter
(I went there to look at the STE209E table breakdown).

Any guidance and help is greatly appreciated! Thank you!

 

[Al Rosen]

Hi everyone,

I have a question about reading the results from our particle counter data. I took readings using the ".01 Cubic Feet" Sample Volume.

The results I acquired came out to be (in one of the areas of the clean room):
0.5 µm: 300
1 µm: 100
5 µm: 0

We have a Class 100,000 cleanroom, so I would like to know if anyone can help me interpret my data. (We are not required to have a clean room, but we installed one to help improve the instances of burnt diodes for our laser product.) I am comparing to the FED STE209E table standard for now for ease of conversion calculations, but I know that it is no longer used for validations.

Particle_counter
(I went there to look at the STE209E table breakdown).

Any guidance and help is greatly appreciated! Thank you!

A 100,000 class clean room must have no more than 100,000 0.5µm particles per cubic ft. Your sample is 0.01 cubic ft. Multiply your 0.5 µm result by 100 to get 30,000, which is within the requirements for a 100,000 clean room.

 

[MIREGMGR]

Maybe I don't understand your technology and risk, but I'd think if your focus is diode failures due to arc-across you might want to focus not just on particle count minimization but also on particle chemistry.

I'd think that particles based on silicon or light-metal-oxide chemistry would be relatively acceptable, whereas substantially organic particles would have much more hazard potential.

Obviously particle type analysis is much more complicated than just counting, but I'd think it would correlate better with your actual risk...and identifying that as the actual goal would provide better direction to the engineers tasked with making the cleanroom actually solve the problem.

 

[Ajit Basrur]

Just for Info- FED STD 209E is obsoleted long back and you can refer to ISO 14064

 

[Al Rosen]

Just for Info- FED STD 209E is obsoleted long back and you can refer to ISO 14064

That should be ISO14644.

 

[Ajit Basrur]

That should be ISO14644.

My apologies - I was working simultaneously on a presentation for ISO 14064 - Green House Gas Emissions

Thanks for the correction

 

[azaplas]

Hi Al, thanks for the calculation breakdown. MIREGMGR, thank you for the suggestion. We hadn't thought about the different particle types, but that does seem like something that can affect the performance of the diodes. Thanks everyone!

 

[aproddutoor]

Hi everyone

I know this is not related to this thread but I have a question of my own for a class 100,000 clean room. How frequently do you have to monitor the room for the number of 0.5, 1.0, 5.0 micron particles?

I know the frequency of monitoring might vary from application to application. But I'm looking for some input on the factors it depends on?

Thanks

 

[Al Rosen]

Hi everyone

I know this is not related to this thread but I have a question of my own for a class 100,000 clean room. How frequently do you have to monitor the room for the number of 0.5, 1.0, 5.0 micron particles?

I know the frequency of monitoring might vary from application to application. But I'm looking for some input on the factors it depends on?

Thanks

See post 11.

 

[aproddutoor]

I've attached the section in 14644-2 that addresses this.

Thanks a lot for the attachment that clears my questions.

Do you an Annex B that talks about the monitoring plan based on the risk assessment?