Computers are one of the
most common electronic pieces of equipment being handled at present.
That makes them very susceptible to ESD discharges. Further below we will provide some warnings,
cares and guidelines as to how handle such equipment from an
ElectroStatic damaging event. Perhaps we will discourage the
untrained to pulling PCs apart themselves and point them to leave it to
the Tech guys which are trained to do it. Our goal here is to help you
to reduce the build up of static charges and/or obtain the
neutralisation of charges away from you and/or the ESD sesitive
We will not get into the higher level of PC handling applied at the manufacturer level.
As information about
generic damage produced to electronic components can be found
elsewhere in this site we will concentrate in areas directly related
to computers. So, if you have no ESD training and insist in doing it
yourself get protection beforehand. Get a good clear space on a table, if this table
is of the metallic type the better as no power will be
applied to any of the components, while you are going to do your
job, right? (handling powered equipment on a conductive metallic
table is not a good idea, trust me).
If you don't
have an ESD protective wriststrap, get one now, they are fairly
inexpensive. Ground yourself to an earth (say the frame of a desktop
PC), also you can clip your wriststrap alligator to a metallic frame
in order to dissipate the charges on you out, this will reduce
density charges on you, hence reducing dangerous potentials.
And you will be very much on your way...
And you will be very much on your way...
|Now, assuming you work on computers, say you do repairs, you assembly them together, etc... you will need to follow more stringent procedures. A control of the environment where you do your work is important. Read elsewhere on this site the effect over the build up of charges of a low and hight Relative Humidity, basically a higher RH keeps build up of charges low, but too much of it and electronics will start to experience corrosion.... The use of a standard earth grounded wriststrap is mandatory. Do not handle PCBs item off their shielding bags ot pull out ICs from their anti-static protective plastic tubes without your wrist strap securely earthed and fastened. When taking off dirty PCB use a CRC (or equivalent) electronics or contact cleaner and give it a good wash, here you may need a small and bristle brush (a soft toothbrush?) to dislodge dirt/grime around components. Also before replacing back a clean PCB you may use a good contacts inhibitor to provide a lasting protection to components, use it lightly. Use special remove/inserting tools when replacing CHIPS on PCBs. Also your workstation must be provided with certain ESD protective precautionary devices, like a grounded protective flooring mat (need to wear heel straps) and also you want a desktop static semi conductive mat (with an online resistor of at least 1MOhm 0.5W +/-10%). To walk about the workplace you may have to wear cordless antistatic protective wriststraps. All your service tools need to be of conductive material. Get rid of from your workstation any insulating type materials like plastics, papers, etc... If the whole place has a conductive or static dissipative flooring and you must wear a foot strap it must be applied to both shoes (straps to have an online resistance of at least 1MOhm 0.5W +/-10% each).|
|Now, you may be a PC repair Techo and need to go out to the field to handle broken PCs or NoteBooks and occasionally will need to pull apart a PC. Carry an anti-static field service kit, this is more or less like a workstation on a mat that can be carried around, it should have all you need from an ESD protection viewpoint, for example, a working surface made of conductive or semiconductive plastic of around 10mm in thickness. The sheet is provided with a snap type fastener to connect a 5-10m long ground cord. The fastening socket will also accept the plugging of your wrist strap, coiled grounding cord of some 3m long. This will protect you from zapping PCBs, or other delicate electronic devices. The field kits are available from ESD retailers. However you may take to your repair shop a PCB to fix, when sending back the repaired unit is not a good idea to slip in the shielding bag where the PCB is, an invoice page, put on separate plastic bag taped on top.|
|Damage to your PC may be produced by an unquantifiable number of chaotic events that can never never be reproduced exactly the same. The microelectronics in todays PCs and NoteBooks are ever more dense. They are very sensitive to different levels of electrostatic discharges. Severe damage to an electronic device is the easiest to fix, a bit expensive though, find the problem or replace module. The other kind, degrades or weakens the electronic components but it does not necessarily fail it in the short term future, it probably will pass most test, this potential fault has the tendency to be cumulative when submitted to repeated events.|