question on boards

[jack_burton]

There is a chemical method for removing solder from the boards, and presumably the fingers- search or look around, it was posted by lazersteve.

 

[kuma]

Hi chief , how are tricks?
I hope your well!

Let me ask one more quick question while I am still in the collecting phase please. One or two of these boards have solder on the fingers... Yes, on the fingers. It was where repairs to the boards were made quickly to get production lines back up and running. Pieces of wire have been soldered from fingers to other places on the boards to replace burned out traces.. My question, if I use the AP method with nothing but trimmed fingers, will this solder cause me a problem ? I have read many times on here that solder can cause a problem..

Thanks guys!!

A little solder shouldn't be a problem with the AP process , heres a link to a recent thread that discussed just that ;

http://tinyurl.com/6u4gqg2

All the best with it and kind regards for now ,
Chris :mrgreen:

( Edited for clarity )

 

[cleanbucket1]

If your dead set on dealing with the boards and the componants, cut the fingers, process those. Theyre easy and usually give a decent yield. For the rest, invest in an air compressor if u dont already have one. Then buy an air chizzel. U can use this chiz to remove the componants from the boards. I suggest you get one of those big rectangle rubbermaid containers u use to store your Xmas decor. and get a large cardboard box and open it up. Place the cardboard inside and around 3 of the 4 sides of the rub made container and chiz them toward that as a back splash sort of way. They will all drop into the container and save a lot of time from many other ways.

GOOD LUCK

 

[element47]

Keep it out, if you can. I know exactly what you mean, having been in the electronics repair game some years back. Try to keep it out. Tin creates problems that are not worth the trouble/value of losing a finger or two. ON THE BOARD that is.

 

[Tewks]

Scraper attachment on my Dremel multimax works for cleaning board. But it does fling the little things around a bit!

 

[Oz]

I hope you guys have "very" good respirators. There is beryllium copper on most mother boards, look up the toxicity of beryllium.
Be safe!
Oz

 

[publius]

I hope you guys have "very" good respirators. There is beryllium copper on most mother boards, look up the toxicity of beryllium.
Be safe!
Oz

From: http://www.osha.gov/dts/hib/hib_data/hib19990902.html A Hazard Information Bulletin.
The current OSHA PELs for beryllium are 2 micrograms/m3 as an 8-hour TWA, 5 micrograms/m3 as a ceiling not to be exceeded for more than 30 minutes at a time, and 25 micrograms/m3 :shock: as a peak exposure never to be exceeded. The OSHA limits have been in place for nearly 30 years and have not been revised in that time. The American Conference of Governmental Industrial Hygienists (ACGIH) current Threshold Limit Value (TLV)* for beryllium is 0.05 micrograms/m3 averaged over an 8-hour work shift. :shock: :shock: :shock:

TWA = Time Weighted Average

 

[kuma]

Hello all , how are tricks?
I hope all is well!

the red dip switches on three of those need to be opened gently as they will contain a small gold over silver ball for each switch, each has six switches so six balls in each.

I'd been wanting to see these gold plated balls for myself as they sounded kind of cool ( :roll: ) , so when I came across one of these dip switches myself the other day I took some pictures so that others who hadn't seen these yet , but wanted too , knew what to expect when they found them and looked inside , :mrgreen:

This is the red DIP Switch before opening ;

http://tinyurl.com/89uar44

This is a reverse angle view of the same switch showing gold plated silver balls , after careful opening with wide pliers ;

http://tinyurl.com/7jsmrqr

This is the small golden balls out of the switch housing , they're next to a cigarette lighter for scale , & they're proper tiny! ;

http://tinyurl.com/7bejob6

All the best for now everybody , and kind regards ,
Chris :mrgreen:

 

[Findm-Keepm]

I hope you guys have "very" good respirators. There is beryllium copper on most mother boards, look up the toxicity of beryllium.
Be safe!
Oz

Where exactly is the BeCu?

I've worked with Printed Circuit boards for 22+ years, and have never heard of BeCu being on them. BeCu is most commonly used in electronics for non-magnetic uses, like leaf springs, tensioners, and heat sinks (Wakefield and AAVID both use BeCu for heat sinks due to it's high thermal conductivity). Other places I'd expect to find BeCu, from experience: rate gyroscopes, non-sparking (Oxygen use) tools, and crimp connectors for humid conditions.

Berylliosis is some serious stuff, and I don't take any Beryllium exposure likely. BeCu is a lower level toxin than beryllium in non-alloy form:

On delivery the material is in solid form and harmless. If the material
is worked up in such a way as to produce airborne particles (through
dry grinding, polishing, electrical discharge machining, melting,
welding etc.) there may be a risk of inhalation. See point 12.
Ordinary handling, punching, moulding and most types of cutting are
harmless. Heat treatment at atmospheric temperatures of up to 400
degrees Celsius is safe, but temperatures above this may release
oxides that are dangerous if inhaled. This risk can be avoided by
conducting heat treatment under protected atmospheric conditions.

I used to work with an inertial navigation device that had rate gyroscopes with beryllium in them - the gyros would fail in a manner that would shred the innards. If we discovered the damage, we had to double bag the stuff, mark it as HAZMAT, and go for a blood screening for 6 months after the incident. Never had any problems, but it takes only one incident to create such.

Cheers,

Brian
EDIT: Alloy, not allow, and clarity

 

[Oz]

Where exactly is the BeCu?

You are right that it is typically used in non-magnetic spring applications. On computer mother boards you have the expansion card slots and CPU socket that have just that sort of requirement.

 

[Geo]

i cut these off with a scraper and hammer by hand. do you think there is any danger from this?

 

[Oz]

i cut these off with a scraper and hammer by hand. do you think there is any danger from this?

Yes I do!

I have warned about this risk before. You would not catch me doing mechanical deconstruction of computer boards without the proper equipment. Just think of the other metals and elements you are making dust with and ingesting even if you do not worry about beryllium.

September 2, 1999

The Occupational Safety and Health Administration (OSHA) has recently obtained information suggesting that OSHA's current 2 micrograms per cubic meter of air (micrograms/m3) eight-hour time-weighted average (TWA) permissible exposure limit (PEL) for beryllium in the workplace may not be adequate to prevent the occurrence of chronic beryllium disease (CBD), a disabling and often fatal lung disease, among exposed workers.
(Just for reference, a microgram is 1 millionth of a gram)

Please read the rest: http://www.osha.gov/dts/hib/hib_data/hib19990902.html

 

[Findm-Keepm]

i cut these off with a scraper and hammer by hand. do you think there is any danger from this?

Yes I do!

I have warned about this risk before. You would not catch me doing mechanical deconstruction of computer boards without the proper equipment. Just think of the other metals and elements you are making dust with and ingesting even if you do not worry about beryllium.

September 2, 1999

The Occupational Safety and Health Administration (OSHA) has recently obtained information suggesting that OSHA's current 2 micrograms per cubic meter of air (micrograms/m3) eight-hour time-weighted average (TWA) permissible exposure limit (PEL) for beryllium in the workplace may not be adequate to prevent the occurrence of chronic beryllium disease (CBD), a disabling and often fatal lung disease, among exposed workers.
(Just for reference, a microgram is 1 millionth of a gram)

Please read the rest: http://www.osha.gov/dts/hib/hib_data/hib19990902.html

For clarity, that's for pure Beryllium. BeCu has only 2.1% beryllium (remainder is copper and trace cobalt) , and has it's own MSDS. BeCu and Be are two separate metals. The threat from BeCu is less than that for Beryllium. Pure beryllium is not used in electronics - at least not in it's bare form. Alloys such as BeCu and AlBe are prevalent, however, and each carries it's own risks.

Cheers,
Brian

 

[Oz]

For clarity, that's for pure Beryllium. BeCu has only 2.1% beryllium (remainder is copper and trace cobalt) , and has it's own MSDS.

Yes you are correct, beryllium copper is an alloy. So using your 2.1% beryllium figure that means that OSHA has determined that 95.2381 millionths of a gram of your beryllium copper is beyond the safe limit.

 

[Findm-Keepm]

For clarity, that's for pure Beryllium. BeCu has only 2.1% beryllium (remainder is copper and trace cobalt) , and has it's own MSDS.

Yes you are correct, beryllium copper is an alloy. So using your 2.1% beryllium figure that means that OSHA has determined that 95.2381 millionths of a gram of your beryllium copper is beyond the safe limit.

It's the same Exposure limit, regardless of particle size or chemical form. Here's some really good info for all, straight from Brush-Wellman, the leader in Beryllium production, both raw metals and alloys. I attended their Beryllium Exposure half-day Seminar in 2004, but the exposure levels were changed in 2005, so my seminar package and CD-ROM is useless.

Airborne Beryllium Exposure Standards

RESPIRATORY PROTECTION FOR PROCESSING BERYLLIUM-CONTAINING MATERIALS

A P100 (organic vapor and particulates) filter is sufficient, per the second document. Most of us already have a P100 or similar particulate filter.

I guess the bottom line (and getting back to the original topic) is to know your material before cutting/shearing/rendering. Let's be careful, and get that gold.

Cheers,

Brian

 

[malfeces]

Isnt there a large qty of beryllium on the magnetron in microwave ovens?

 

[Smack]

Bottom line....If your breathing anything but what's in fresh air you should take action to correct your error.

 

[g_axelsson]

Where exactly is the BeCu?

You are right that it is typically used in non-magnetic spring applications. On computer mother boards you have the expansion card slots and CPU socket that have just that sort of requirement.

Do you have any reference? I have always had problem with the pins in the PCI-sockets because they are made of phosphor bronze and contains a few percent tin. Phosphor bronze is also springy.
http://en.wikipedia.org/wiki/Phosphor_bronze

A quick search of the net gives :
AMP PCI contact made of phosphor bronze with gold flash or gold plate on nickel in contact area.
http://www.farnell.com/cad/52241.pdf
LGA socket with gold plated beryllium copper springs.
http://www.lgasockets.com/desc/default.htm
PGA-socket with gold plated beryllium copper contacts.
http://www.farnell.com/datasheets/86921.pdf

It looks like PCI-contacts are phosphor bronze and CPU-sockets are beryllium copper.
I haven't been able to find any counter examples with a quick search.

/Göran