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QUALITY CIRCUITS, INC. LEADS
THE CIRCUIT INDUSTRY IN BARE PRINTED
CIRCUIT BOARD CLEANLINESS REQUIREMENTS.
WHY IS THIS IMPORTANT?
With the current use on circuits board
surface of no-clean fluxes and the elimination
of hydrocarbons from the cleaning process,
Ionic Contamination can remain on the
circuit board surface and be encapsulated
into the finished assembly. These entrapped
contaminates can lead to dendritic growth
and long-term assembly failures.
WHAT IS DENDRITIC GROWTH? Dendritic
growth occurs when a contaminate such
as a Chloride Ion combines with moisture,
the condustive circuit, and an electrical
current to create a miniature voltaic
cell. This cell can grow an ionic short
between adjacent circuits causing circuit
failure long after successful in-circuit
testing is completed.
HOW CAN THIS BE PREVENTED? By
starting with the cleanest bare printed
circuit boards possible, long-term failures
attributed to dendritic formation is
significantly reduced.
Quality Circuits, Inc. Solution:
- Deionized water is utilized in all
critical processes.
- A final cleaning step, incorporating
a chemical saponifier, is performed
on all parts once all processing and
inspection is complete.
- A similar cleaning step incorporating
an additional chemical saponifier is
performed immediately following hot
air leveling, the major source of ionic
contamination.
- Special handling techniques are
employed to eliminate recontamination.
- Product is periodically verified
for contamination levels via liquid
ion chromatography. Contaminant measurement,
via liquid ion chromatography, far
exceeds the capability of the “Industrial
Standard” Omega Ion Contamination
meter.
Quality Circuits’ Ion
Chromatography Results
Ionic Species Tested For: Anions: Chloride, Bromide, Sulfate, and Weak Organic
Acid (W.O.A.).
Mean Results based on Micro-Grams
Per Square Inch:
- Chloride: Less than .80
- Bromide: Less than .15
- Sulfate: Less than .60
- W.O.A. Less than .01
TOTAL COMBINED CONTAMINATES:
LESS THAN 1.60
* Industry standards based on Omega
Ion Contaminate Meter results are 10
Micro
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Capabilities
