|
Y/N |
Opportunities |
Comments |
| |
I. Material Handling and
Storage |
| |
Control inventory |
Do not allow material to exceed shelf
life. |
| |
Use materials on a first-in, first-out
basis. |
|
| |
Buy appropriate amounts |
Buy materials in small quantities if only small amounts are
required. |
| |
Cover outdoor storage |
Divert clean stormwater away from storage
areas. |
| |
Install spill containment |
Spills can be contained and managed. Reduces wastewater treatment
upsets. |
| |
II. Dragout |
| |
Lengthen dragout time |
Allows more chemical to drip back to process tank, so reduces the
amount of chemical introduced in
rinsewater. |
| |
Establish dragout timing |
Post dragout times at tanks to remind
employees. |
| |
Install drain boards |
Boards and guards minimize spillage or drip guards between tanks and
are sloped away from rinse tanks so dragout fluids drain back to plating
tanks. |
| |
Install drip bare |
Drip bars allow personnel to drain parts hands free without waiting, so
personnel will not use too short a dragout
time. |
| |
Mechanize dragout |
Eliminates possibility of employee using too short a dragout time,
maintains product QA/QC standards if timing is set
properly. |
| |
Reduce pockets on parts |
Place parts on dragout rack to minimize chances of chemical pooling In
corners or in other packets. |
| |
III. Rinsing |
| |
Use static rinses |
Static rinses usually follow the plating bath and capture the most
concentrated dragout for returning to the plating bath or for metal
recovery. |
| |
Use countercurrent rinses |
These rinses dramatically reduce the amount of water required for
rinsing and therefore reduce the amount of wastewater to be treated or
sent for metal recovery. |
| |
Use conductivity sensor |
This sensor gives an indication of the cleanliness of the rinsewater.
Sensor can be designed to trigger clean rinsewater flow when the tank
water gets too dirty. |
| |
Use spray or fog rinsing |
Reduces rinsewater quantity required and can also be used over plating
baths. |
| |
Use foot pump or photo |
These items allow use of water only when sensor to activate rinse
processing parts. A photosensor may be used on automatic plating
lines. |
| |
Agitate rinse bath |
Agitation promotes better rinsing. Agitate water or
part. |
| |
Install flow restrictors |
Restrictors automatically reduce the amount of rinsewater, so operators
do not need to adjust inlet valves. |
| |
IV. Material Recycle, Reuse, and
Recovery |
| |
Reuse deionized rinsewater |
Depending on product, this rinsewater can be reused in a plating bath
as evaporated water makeup. |
| |
Ion exchange on rinsewater |
Ion exchange can be used to concentrate metals in rinsewaters and metal
can be recovered from the ion exchange acid regenerant
stream. |
| |
Reuse spent acid/alkaline |
Spent acid can be used to neutralize an alkaline waste stream
Spent
alkali can be used to neutralize an acid waste
stream. |
| |
Reverse osmosis |
Concentrate dragout for reuse in plating bath; the water stream can
also be reused. |
| |
Evaporation |
Concentrate dragout for reuse; the water condensate can also be
reused. |
| |
Electrowinning |
Recover metals from spent plating baths or ion exchange acid regenerant
streams. |
| |
Reuse mild acid rinsewater |
Use mild acid rinsewater as influent to rinse following alkaline
cleaning bath. Improves efficiency of rinse, so less rinsewater is
required. |
| |
Recover copper sulfate |
On microetch line, recover copper sulfate crystals directly from etch
tank and reuse crystals in copper electroplating
baths. |
| |
Recover particulate copper |
On debur operation, recover particulate copper using centrifuge or
paper filter. Reuse water |
| |
Reclaim etchant |
Send etchant to an off-site reclaimer instead of treating etchant in
wastewater treatment system. |
| |
Reuse spent acids/alkalines |
Use spent acids and alkaline solutions for neutralization reactions in
wastewater treatment system. |
| |
Recycle photoresist stripper |
Decant spent photoresist stripper from polymer residue and recycle
stripper. Do not discharge spent stripper to wastewater treatment
system. |
| |
V. Process Modification |
| |
Eliminate chelated baths |
Change to a nonchelated plating bath to improve metal wastewater
treatment. Chelated streams make it difficult to precipitate metal in
wastewater treatment system. |
| |
Segregate waste streams |
Increases recovery and treatment technology efficiencies. Acidic vs.
alkaline. Concentrated metal (spent baths) vs. dilute metal (rinsewater
streams). Chelated vs. nonchelated
streams. |
| |
Convert to dry floor |
Reduces chances of spills reaching floor drains or causing upset in
wastewater pretreatment plant. |
| |
Buy efficient etch machine |
An efficient etch machine results in less copper in
rinsewater. |
| |
Increase bath temperature |
Evaporates bath water so relatively clean waste rinsewater can be
reused as bath makeup water
Reduces solution viscosity, so more
chemical drains back to process tank during
dragout. |
| |
VI. Process Operation and
Maintenance |
| |
Use deionized (DI) water |
Use DI water in plating baths, static rinses, and if practical in
running rinses
DI water reduces impurities in the plating bath to
extend its life and minimizes the precipitation of minerals in water as
sludge. |
| |
Optimize bath concentrations |
Only replace plating chemical when
necessary. |
| |
Install bath filters |
Lengthens bath life. |
| |
Replace chemicals on electroless copper
baths |
To extend bath life. |
| |
Automate chemical replacement through online analyzers and chemical
flow meters. |
|
| |
Filters can remove particulates and trace contaminant organics in the
process bath, lengthens bath life. Use filter that can be unrolled,
cleaned and reused. |
|
| |
Raw material purity |
Use high quality raw materials in bath so bath will not become
contaminated as quickly. |
| |
Reduce bath dumps |
Optimize bath operation so bath dumps are
infrequent. |
| |
Spill cleanup procedures |
Establish procedures for what to do with a Spill. Mitigates chance of
spill being discharged to wastewater treatment
plant. |
| |
Perform preventive maintenance |
Routinely check for leaks in valves and fittings. Repair
immediately. |
| |
Use continuous passivation on stainless steel
components |
In electroless plating tanks to prevent copper plate-out. Copper
plate-out needs to be stripped with nitric acid. Reduces amount of spent
nitric acid that needs to be
treated |
