Most Ionizers Used in PCBA Use Corona Ionization with a Fan to Convey Ions to the Target Object(s)

•One parameter of an ionizer is the amount of air flow

DC (Isostat) Ionizer Technology from SCS/3M

Ion Technology: Isostat steady state DC corona Models: 963 and 960

Theory of Operation: DC ionizer inherently balanced to 30v using Law of Conservation of Charge.

Con

• Poor balance and slow decay times when emitter points are dirty.

Pro• Good balance and decay times when emitter points are clean.

+/- 30 volts

AC Ionizer Technology From Transforming Technologies

Piezoelectric AC

68 KH

z O

scillator

Piezoelectric “Transformer”

Ion Technology: AC Corona Models: IN5110 and IN5120 Theory of Operation: AC ionizer inherently balanced to 10v using the Law of Conservation of Charge.

Pro• Better balance• Faster decays• Easier to clean• Emitters easier to replace

Con• Emitters still need periodic cleaning to maximize decays

AC vs DC Technology

HV

AC

• Separated emitter points minimizes ion recombination, but requires a fan to mix ions

• Inherently balanced to 30v with clean emitters using the Law of Conservation of Charge applied to DC ionizer • Ion balance degrades as emitters become contaminated and wear. Decay times lengthen

• Requires frequent cleaning and emitter replacement due to polarity dedicated emitters

• Bipolar ion emitter design requires nominally more airflow to reduce ion recombination • Inherently balanced to 10v using the Law of Conservation of Charge applied to AC ionizer

• Infrequent cleaning due to bipolar ion emitters. Balance remains good

• Preferred for PCBA applications for limited maintenance

+HV-HV

DC

SCS IsoStat Ionizer TechnologyMaintenance Requirements

(from 963 Owners Manual)

What they say…

SCS IsoStat Ionizer TechnologyMaintenance Requirements

(from 963 Owners Manual)

What they mean…

• When emitter points become dirty, the internal circuitry of the ionizer will automatically adjust to emit

an equal amount of positive and negative ions.

• Applying the Law of Conservation of Charge works better for AC ionization than DC. 10v vs 30v when ionizers are clean. Dirty emitters make it worse.

• Contamination on the needlepoint may inhibit ionization (decay times).

• Emitter contamination affects all ionizer decay times.

• The emitter points are located behind the fan. • Removing the back fan cover is not easy, making cleaning with a swab difficult.

• Be careful not to damage points during cleaning. • The 963 and 960 both use Tungsten Wire for emitters. This wears unevenly and is difficult to replace. Wire can

be easily deformed, affecting balance.

AC Technology • Inherently balanced AC ionizers require no periodic adjustment• Infrequent cleaning and emitter replacement requirements compared to DC

technology• Transforming Technology’s IN5110 and IN5120 ionizers have a quick release grid to

minimize the time to clean the replaceable emitter points.

Grill pops off IN5110 and IN5120 with no tools for

point cleaning

Unscrew 963/960 grill to clean emitter

points

Conclusions

• AC ionizing blowers maintain better balance and better decay times than DC blowers

• The Law of Conservation of Charge works more precisely with AC ionization

• Cleaning an AC ionizer is easier and less time consuming than with DC ionizers due to design

• Tungsten wire emitters are easily bent and damaged during the cleaning process

• AC technology is the preferred ionization method for PCBA manufacturing