[labnetwork] Flooring - ISO 5/6

Thu May 14 16:45:26 EDT 2015

Agreed that most clean rooms control humidity and temp to similar levels, irrespective of geographic location.

In industry, when handling chips, we used ESD lotion under nitrile gloves when working with devices for ESD event avoidance.  We also had conductive black gloves and conductive finger cots (lightly conductive nitrile?) black finger tip covers.  Ionizers were in the ceilings or in the equipment in two out of the four production fabs I worked in; these two fabs had product lines that were highly susceptible to discharge damage - others fabs had devices that stand a few hundred volts. Often times, devices would not fail from a catastrophic arcing event, but they would degrade more rapidly from latent failures induced by some ESD damage.

In my experience, the first key to avoiding an ESD event is slow discharging of the charged device.  Frankly, it can be better to pick up a device with plastic tweezers if it's charged rather than picking it up with metal tweezers...which could quickly discharge it.  The second key is that insulating materials need to be discharged with an ionizer...they can't be grounded.

My two cents, FWIW,
Noah Clay
University of Pennsylvania 

Sent from my iPhone

> On May 14, 2015, at 11:04, Robert M. HAMILTON <bob at eecs.berkeley.edu> wrote:
> 
> Fab Colleagues,
> 
> I'd like to broaden the discussion of conductive floors and electrostatic discharge (ESD). I have trouble understanding how it is dealt with. At the outset, I have little experience with ESD as our lab is near the Pacific Ocean with moderate climate. ESD is less an issue for us than in the drier, colder parts of the US. However, given the climate controls in newer fabs it would seem ESD is less and issue within a fab than in the environs.
> 
> To use the lab our members and staff suit up with boots that are dielectric, shoe covers, gowns, caps and then nitrile gloves (we are aware some cleanroom garb is available from conductive materials). Noting this the gloves seem to be a "fly to the ointment" for ESD control. 
> 
> Example. Recently a lab member asked for replacement of ESD wrist straps at our wire bonders. My question is how much protection from ESD is had by a conductive bracelet if the ultimate garb is a pair of dielectric gloves? It seems gloves provide a barrier which acting for and against and ESD strategy. 
> 
> Although oblique to this discussion I'd like to mention we also have a robust ground-grid consisting of a flat 2" copper strap to provide excellent grounds for equipment, particularly rf enabled systems.
> 
> Of note, in a long history of semiconductor research we have not encountered device failures from ESD in our evolving lab environments. Having said this, the University of California Marvell NanoLab was built with conductive vinyl floors.
> 
> Regards,
> Bob Hamilton
> 
> PS I'll digress a bit and share an story. The UC's anthropology library came to us some years back to find a way to neutralize the electrostatic force that bound ancient Egyptian papyrus to the plastic envelopes they were stored in. The papyrus was bound so tightly it tore before breaking loose. We introduced them to Ion Systems, specialist in ESD room control. Ion Systems came up with an effective solution to their problem.
>  
> 
> 
> Robert Hamilton
> University of CA, Berkeley
> Marvell NanoLab Equipment Manager
> Rm 520 Sutardja Dai Hall, MC 1754
> Berkeley, CA 94720
> Phone 510-809-8618 (desk - preferred)
> Mobile 510-325-7557 (my personal mobile)
> E-mail preferred: bob at eecs.berkeley.edu
> http://nanolab.berkeley.edu/
> 
> 
> 
>> On Wed, May 13, 2015 at 5:12 PM, Paul, Jack <Jack.Paul at hdrinc.com> wrote:
>> Greetings Loïk,
>> May I suggest a seamless resilient floor material (sheet vinyl with welded seams) in lieu of epoxy?
>>  
>> There are various sheet vinyl products available that can be installed less expensively than epoxy, and even more important, more easily repaired in an operational cleanroom environment. 
>>  
>> One product we have used successfully is Medintech, by Armstrong, which is a homogeneous sheet vinyl material that can be installed with heat-welded seams and has good chemical resistance as well as static conductivity.  There are other competing products that work just as well (this is by no means a sales pitch for Armstrong!).
>>  
>> Hope this helps.
>>  
>> Best regards,
>> Jack
>>  
>> -----Original Message-----
>> From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Loïk GENCE
>> Sent: Tuesday, May 12, 2015 11:44 AM
>> To: labnetwork at mtl.mit.edu
>> Subject: [labnetwork] Flooring - ISO 5/6
>>  
>>  
>> Dear All,
>>  
>> I would like to get some suggestions about of flooring for a small cleanroom ISO 5/6.
>> We are thinking about a dissipative epoxi flooring with copper tape for grounding.
>>  
>> Do you have some experience with this kind of flooring. Is there an alternative to epoxi?
>>  
>> Thank you for your comments.
>>  
>>  
>> Regards,
>> Loïk
>>  
>>  
>>  
>> --
>> __________________________________________
>> Dr. Loïk Gence
>>  
>> PUC-RIO/CETUC-LABSEM
>>  
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