Application Notes—Analog Optical Isolators
The best policy is one which prevents tarnish from forming. Tarnish,
which is a compound formed when silver reacts with sulfur (Ag
2
S), can
be prevented by keeping the components away from sulfur or sulfur
compounds. Since two major sources of sulfur are room air and paper
products, it is best to store the devices in protective packaging such as
a “silver saver” paper or tightly sealed polyethylene bags.
After soldering, it is necessary to clean the components to remove any
rosin and ionic residues. For a listing of recommended cleaning agents
please refer to Application Notes #3.
2.
3.
The exact requirement of the cleaning process will vary from
customer to customer and application to application.
Additives and concentrations will vary from supplier to supplier.
Because of these uncertainties, our recommendation is that all
customers carefully evaluate their own cleaning process and draw their
own conclusions about the effectiveness and reliability of the process.
PerkinElmer cannot assume any responsibility for damage caused by
the use of any of the solvents above or any other solvents used in a
cleaning process.
APPLICATION NOTE #3
Recommended Cleaning Agents
The construction of an AOI consists of a cast epoxy LED, ceramic
photocell, a molded case and epoxy as the end fill. This construction
allows a wide variety of cleaning agents to be sued after soldering.
In many cases the devices will be exposed to a post solder cleaning
operation which uses one or more solvents to remove the residual
solder flux and ionic contaminants. Only certain cleaning solvents are
compatible with the plastics used in the AOI packages.
Recommended
Arklone A
Arklone K
Arklone F
Blaco-Tron DE-15
Blaco-Tron DI-15
Freon TE
Freon TES
Freon TE-35
Freon TP
Freon TF-35
Genesolv D
Genesolv DE-15
Genesolv DI-15
Isopropyl Alcohol
Water
Acetone
Carbon Tetrachloride
Methyl Ethyl Ketone
Methylene Chloride
Trichloroethylene (TCE)
Xylene
Trichloroethane FC-111
Trichloroethane FC-112
Freon TF
Freon TA
Freon TMC
Freon TMS
Genesolv DA
Genesolv DM
Genesolv DMS
Not Recommended
This listing of recommended/not recommended solvents represents
only a very small percentage of available chemical cleaning agents.
Even with this list of recommended solvents it is important to be aware
that:
1.
Solvent exposure times should be as short as possible.
68
PERKINELMER [ PERKINELMER OPTOELECTRONICS ]
