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Rochey

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Guys,

just spotted this on youtube... thought I'd share.

http://www.youtube.com/watch?v=8hC5ju5slS8

One day... expat audio will be like this.

However, there's a LONG way to go! ;)
 
I've worked a couple of years at an electronics productionfactory, so I had to follow an IPC course, and do some exams as well. So I know a fair bit about ESD protection, and how to modify and repair SMD boards that live up to the IPC standards. ESD safety is of vital importance. It's not that surface mount semiconductors go dead immediately after an electrostatic discharge, but they can get damaged enough to decrease the life span to just a couple of years. Especially SMD stuffed boards are very fragile. Even SMD resistors are easily damaged by ESD.

So, there are guidelines to follow, to avoid ESD.

(well....Now I've started...let's bring this to light, there are probably quite a lot of people here that don't know about ESD protection)

Usually, the humidity in an ESD room is controlled (40-60 percent). Paper and electrostatic plastic materials aren't allowed in such a room, unless they're put inside electrostatic dissipative plastics (like PinkPoly). The floor and table surfaces should have got a resistance of 1meg-10 meg to ground (a straight connection to ground is very dangerous). The same goes for closets, shelves, seats and other furniture. The tools used for production should be ESD safe. (makes sense, but think a while about a screwdriver : is that plastic handle ESD safe ? Or is it an isolator ?!?)

People inside the room should wear ESD protective clothing. This applies to ESD safety shoes, which should connect the person wearing them, via the floor, to ground. This also applies to the mandatory labjacket/shirt, which should cover the T shirt or sweater the person is wearing. This jacket is made from cotton, but is woven with some kind of carbonimpregnated thread. So, this jacket forms actually a cage of Faraday.

But the most important thing : When handling PCA's (Which is a stuffed PCB) you should ALWAYS use a wristband, connected to ground (again, via 1 meg resistance).

A side note for the 1 -10 meg. This value is used to slowly discharge everything from electrostatic charge.

So, actually, ESD protection is very simple in theory.
1. Everything in an ESD safety room should be discharged slowly, and electrostatic charging should be avoided at all times.
2. Isolators should be avoided in an ESD safety room.


Now, back to the video :
I'm mainly referring to the way they handle the PCA's by hand.  Have a look at the woman who's checking the PCB by computer. She isn't wearing ESD protective clothes, but she doesn't use ESD wristbands either .....

And this surprises me a lot. They use state of the art X-ray equipment to check the PCA's. This is a very expensive tool, but then they don't bother to handle the materials with care.....  ???
 
Helterbelter ---

that needs to be it's own post, and added to a META. I'm sure there are many of us here (myself included) that don't do any of that, and wonder why some of our boards don't work.  ;)

One of my colleagues here at TI refers to boards that aren't kept in ESD bags as "Walking wounded" -- because even though the devices can be functional, their performance may be lowered by ESD damage.

I'm "remodelling" my electronics workspace in the garage this weekend. Your data on ESD protection is well timed. Thank you.
 
Oh, well.... The IPC industry standard is bit over the top. To live up to the IPC standard you'd spend rediculous amounts of money.
While you reach 95% of ESD protection if you'd just buy something like this :
http://cgi.ebay.nl/NEW-ANTI-STATIC-MAT-WRIST-STRAP-FOR-PC-LAPTOP-ESD-/350105096774?cmd=ViewItem&pt=UK_Computing_DesktopComponents_RL&hash=item5183e3d246

Get such a mat and wristband, USE IT,  and you're golden. Absolutely good enough for the serious hobbyist and professional. Make sure the mat is connected to ground, and measure the resistance to ground from the surface, and from the wristband to ground. In case the resistance is below 1 meg, connect a resistor in between. clean the surface every now and then. Avoid dust in your working area. Put PCB's in trays when you're not working. Never pile up PCB's (actually PCA's, but you know what I mean).

And make sure you don't wear a sweater made of wool !  ;)

What remains to do, is just common sense. Use the wristband, and make sure you use the proper ESD packaging for the semiconductors.

But you're right, I'll write a new post one of these days, and post it in The Lab. IPC standards : ESD and soldering guidelines... or something like that.  :)
 
i`m using a wireless anti static wrist strap, it use the Corona Discharge Effect http://www.cablesunlimited.com/products/Prod_Individual3.aspx?groupcode=I3381

grounded or not I fell safe with it :D
 
Ha, this reminds me of a wireless antistatic strap that were used a decade ago. They're abanded because they used some kind of radioactive material.

I haven't heard of a CDE strap before. I don't think this is IPC approved already, but that doesn't that mean it isn't good !

12afael said:
grounded or not I fell safe with it :D

Ignorance is bliss  ;)

I don't expect the ad is telling lies. I'm sure that if it does what it says, everybody will be using them in no time. Hell.... I'm going to send an email to the company I worked at, and ask if they know more about this thing.
 
helterbelter said:
Get such a mat and wristband, USE IT,  and you're golden.

I have a similar one. It's my main working surface for all projects. But I always forget to wear the wristband.  :-[

Speaking of RME, I actually completely rehauled a HDSP card, and no ESD damage. I also just finished a big SMD project, and it seems to be working.

Is ESD damage very rare, or is the mat alone pretty good protection?
 
Kingston said:
Speaking of RME, I actually completely rehauled a HDSP card, and no ESD damage. I also just finished a big SMD project, and it seems to be working.

Here I quote myself and Rochey
helterbelter said:
It's not that surface mount semiconductors go dead immediately after an electrostatic discharge, but they can get damaged enough to decrease the life span to just a couple of years.

Rochey said:
One of my colleagues here at TI refers to boards that aren't kept in ESD bags as "Walking wounded" -- because even though the devices can be functional, their performance may be lowered by ESD damage.



Kingston said:
Is ESD damage very rare, or is the mat alone pretty good protection?

ESD damage isn't rare, it's just not something that's easy to see or discover. We DIY enthousiasts are usually not working with SMD. Pin through Hole is a lot better resilient to ESD damage.

some food for thought :
Chinese products.
1 year warranty.
For some reason, a lot of chinese products get broken after 18 months. Howcome ?

simply a lack of ESD protection. It's not a built-in timer device that kills the print after a period of time.

(Btw, not really applicable anymore because the chinese productiontechniques have improved greatly the last 3-4 years, chinese products last longer nowadays).


But, regarding your SMD solderings : Yes, a mat provides a lot of protection on it's own. But better use the strap next time. Also make sure you grounded your solderingstation.


Well... By now it's better move this thing to The Lab.
 
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