Call us today! (818)610-7900
E-mail: smt@SmartSonic.com
The ORIGINAL Stencil Cleaner

Frequently Asked Questions





Return to Top





Return to Top





Return to Top





Return to Top



I have tried a competitor's ultrasonic stencil cleaner and could not obtain good cleaning results. What makes the Smart Sonic's ultrasonic stencil cleaner different?

The most important factor of any cleaning process is always the chemistry. Smart Sonic's 440-R SMT Detergent is the "backbone" of the cleaning process. Without 440-R SMT Detergent, ultrasonic stencil cleaners will not clean as well.

Smart Sonic introduced the original ultrasonic stencil cleaning process in 1990. We have more experience in ultrasonic stencil cleaning than all other competitors combined.

Return to Top



Can I clean misprinted substrates in a Smart Sonic System?

Yes. Misprinted substrates clean in much the same manner as fine-pitch stencils. Solder paste from within vias will also clean well.

Return to Top



What about cleaning populated misprinted PCBs (Double-sided misprints)?

Populated misprinted PCBs should never be cleaned in a "spray" style stencil cleaner. The solder balls from side "B" will broadcast throughout the wash chamber and contaminate the components on side "A".

A Smart Sonic Ultrasonic Stencil Cleaner does not spray or circulate the wash solution. The PCB can be oriented with the paste side down. When using an ultrasonic stencil cleaner, the solder paste from side "B" falls freely away from the board by gravity. Components on side "A" are less likely to become contaminated with solder balls when using ultrasonics.

When cleaning populated misprints, frequencies should be kept at 40 KHz or higher (the lower the frequency, the more aggressive the cleaning action) and ultrasonic power (power density) should be kept at a minimum. Because of the efficiency of 440-R SMT Detergent, Smart Sonic does not need to use high-powered ultrasonic energy. Research indicates that ultrasonic power should be kept lower than 10 watts per liter of wash solution. Because of the superior cleaning efficiency of 440-R SMT Detergent, Smart Sonic systems are able to clean effectively at less than 10 watts per liter of wash solution! Assuring the utmost safety for populated assemblies. [Total power of ultrasonic energy (watts) / Total capacity of wash tank solution (liters) = Total watts/liter]

Return to Top



Will ultrasonics damage components of a populated misprint?

When ultrasonics was first developed in the 1950s, the technology was very crude and uncontrollable and the PCBs were very cumbersome and delicate. The two technologies were not compatible. Delicate wire bonds would break because of the low (20-25 kHz) and constant frequencies that were used. The lower the frequency, the more aggressive the ultrasonic cleaning action.

Today's ultrasonic systems are the most controllable precision cleaning technology available. The user can control virtually every parameter. In addition, today's PCBs are very compact and durable. The two technologies are now very compatible. Many Smart Sonic customers clean double-sided misprints with their ultrasonic stencil cleaner.

When cleaning populated misprints, frequencies should be kept at 40 KHz or higher (the lower the frequency, the more aggressive the cleaning action) and ultrasonic power (power density) should be kept at a minimum. Because of the efficiency of 440-R SMT Detergent, Smart Sonic does not need to use high-powered ultrasonic energy. Research indicates that ultrasonic power should be approximately 10 watts per liter of wash solution. Smart Sonic systems are able to clean effectively at less than 10 watts per liter of wash solution, assuring the utmost safety for populated assemblies. [Total power of ultrasonic energy (watts) / Total capacity of wash tank solution (liters) = Total watts/liter]

Visit the Resource Articles section of our website for copies of published papers on this subject.

Return to Top



I currently use 3 different solder pastes. Do I need three different stencil cleaners?

No! With Smart Sonic's 440-R SMT Detergent, you will be able to clean any type of solder paste in the same machine at the same time.

Other stencil cleaners use chemistries that only selectively clean a few types of solder paste. They may clean RMA well but fail when attempting to clean no-clean or lead-free. (Alcohol is a good example of a selective or "vertical" type of chemistry).

Return to Top



How can Smart Sonic improve print yields?

It is estimated that up to 72% of all solder defects are a result of the screen printing operation. Thus, having a clean and accurate stencil is a major concern. An SMT stencil that has maintained good structural integrity and has zero contamination within the apertures will produce a better and more consistent print, which reduces incidence of misprints and downtime.

Return to Top



Are all ultrasonic stencil cleaning machines the same?

Yes and no. They are similar in that they all use ultrasonic cavitation as the mechanical scrubbing action. However, some require very high ultrasonic power because of the poor cleaning characteristics of the chemistry used. It has been demonstrated that high power ultrasonics can damage populated PCBs. The cleaning efficiency of 440-R SMT Detergent allows Smart Sonic to use the lowest effective ultrasonic power in the industry, assuring safety when cleaning populated misprints yet effectively cleaning stencils better than any other process. Without the proper chemistry, all ultrasonic stencil cleaners are similar. Some may have a few more "bells and whistles", some may be better engineered ergonomically or for ease of use, but they all use ultrasonic cavitation as the mechanical scrubbing action. For more differences, click here.

Return to Top



Why doesn't the Model 1500 and 1550 totally immerse a 29" (750mm) stencil?

Smart Sonic has been manufacturing ultrasonic stencil cleaners since 1990. We have made the mistake years ago that new competitors are just now experiencing. A 29" stencil is only contaminated a maximum of 25-26 inches from one end. Therefore only 26 inches of the stencil requires immersion. The remaining 3 - 4 inches remains outside of the wash solution and serves as a convenient "handle." Otherwise, the user would need to wear gloves or the stencil would need to be placed into a basket.

Systems that totally immerse a 29" stencil need to be made taller to accommodate the additional 4 inches. This additional height makes it more difficult to load and unload. If the stencil is totally immersed, the user will need to load the stencil into a basket. Now, the user will need to lift the weight of the stencil and basket. The basket handles will be above the stencil which means the user will need to use a step ladder to clear the top of the machine.

OSHA frowns on an operator lifting anything above their shoulders. Therefore an automatic hoist may be required. If a step is used, OSHA may require a handicap ramp installation. A ramp will occupy 3 times the floor space as the cleaner.

Buy making the tank only as large as the required cleaning area, the system is more efficient, uses less wash solution and therefore generates less wastewater.

This is just one of the many advantages that Smart Sonic has gained from years of experience.

Return to Top



Chemistry


Will 440-R SMT Detergent clean SMD adhesives?

Yes! However, cleaning adhesives is not quite as easy as cleaning solder paste. Wash cycle times are usually 2-3 minutes and most adhesives require warm wash water (95 degrees F, 35 degrees C).

Ultrasonic scrubbing (cavitation) is a pulling action caused by the implosion of millions of microscopic vapor bubbles. This pulling action is very affective in cleaning particulate matter (such as solder balls in solder paste). The particulates actually help carry the paste away from the stencil.

Adhesives, on the other hand, are soft, elastic and without particulate matter. Ultrasonic cleaning of adhesives is like "pulling on a rubber band". Contact Smart Sonic for a copy of the recommended protocol for cleaning adhesives with a Smart Sonic Stencil Cleaner.

Return to Top



Will 440-R SMT Detergent clean post solder flux residue from pallets, oven radiators and other tooling?

Yes! This is an excellent application. The only variables are that the wash water should be approximately 120 degrees F (46 degrees C) and the detergent will "load" with flux during the cleaning process. If oven radiators or large quantities of pallets are being cleaned, a filter recirculator system may be required to help keep the wash solution fresh. Smart Sonic is the only ultrasonic stencil cleaner recommended by Permali for cleaning Durostone pallets.

Return to Top



How much chemistry is used to clean stencils? Adhesives? Post solder flux residues?

When cleaning no-clean, RMA and lead-free solder pastes, the Models 1500 and 1550 will use approximately 2 gallons of 440-R SMT Detergent per month. The Model 6000 will use approximately 4 gallons per month. The bath life can be extended up to 6 months with the optional Filter Recirculation System or the EnviroGuard system.

Because 440-R SMT Detergent does not react with the solder paste and is not consumed during the cleaning process, the amount of chemistry used to clean solder paste is very predictable.

When cleaning post solder flux residue or SMD Adhesives, the amount of 440-R SMT Detergent used will depend on the amount of contaminant cleaned. If large flux contaminated items are cleaned, such as oven radiators, a filter recirculator system installed on the wash tank will remove excess flux and prolong the life of the chemistry.

Return to Top



How often do I need to change the 440-R SMT Detergent?

440-R SMT Detergent does not react with the solder paste and is not consumed during the cleaning process. The only reason the chemistry need be changed is for preventative maintenance purposes. An ultrasonic bath is a "standing pool of water." As with any standing water, if left long enough, it may begin to develop odors. Because 440-R SMT Detergent is so economical, the fastest and cheapest way to maintenance the wash water is to change it regularly. When cleaning solder paste, we recommend that the wash water be emptied and replaced with fresh solution once per month.

Because 440-R SMT Detergent does not react with the solder paste and is not consumed during the cleaning process, the amount of chemistry used to clean solder paste is very predictable.

When cleaning no-clean, RMA and lead-free, the Models 1500 and 1550 will use approximately 2 gallons of 440-R SMT Detergent per month. The ErgoSonic and Model 6000 will use approximately 3 and 4 gallons per month respectively (based on changing the wash water every four weeks). The bath life can be extended up to 6 months with the optional Filter Recirculation System or the EnviroGuard system.

When cleaning post solder flux residue or SMD Adhesives, the amount of 440-R SMT Detergent used will depend on the amount of contaminant cleaned. If large post-solder flux contaminated items are cleaned, such as pallets and oven radiators, a filter recirculator system installed on the wash tank will remove excess flux and prolong the life of the chemistry.

Return to Top



Can I use other chemistries in Smart Sonic cleaning machines?

Yes. However, the EPA Certification and performance guarantees are based exclusively on the use of 440-R SMT Detergent. If another chemistry is used, the Smart Sonic machine may only perform as well as some other stencil cleaners.

Return to Top



Wastewater Treatment


How is the waste solder paste removed from the stencil cleaner?

The waste solder paste simply falls to the bottom of the wash tank by gravity. Models 1500 and 1550 Series have shallow tanks where the waste solder paste may be easily accessed by wiping the tank bottom after draining the wash solution. An optional removable tray (Quick Kleen Liner) is available to capture the solder paste. The Quick Kleen Liner is removed from the tank bottom, wiped clean and replaced.

The Model 6000 and ErgoSonic incorporate a "Sparge" system that flushes the tank bottom with water, forcing the waste solder paste out a drain outlet and then captured in a gravity trap (Quick Kleen Trap). The solder paste is removed from the trap by simply unscrewing the plastic container. The container is wiped clean and replaced.

The waste solder paste can be recycled via a dross process or dehydrated and melted in a wave solder pot.

Return to Top



Is the Smart Sonic Process closed-loop?

There are three ways to close-loop the Smart Sonic Stencil Cleaning Process:
  1. Incorporate the EnviroGuard Closed-loop Filtration into the process. EnviroGuard filters the rinse and wash water for reuse. Solid waste is collected in cartridge filters. Nothing goes to drain.
  2. Incorporate a wastewater evaporator into the process. Smart Sonic evaporators evaporate the non-hazardous liquid waste to atmosphere and the hazardous solids are separated by gravity for solid waste disposal and/or heavy metal recycling. Nothing goes to drain.
  3. When using only water washable solder paste, the Model 900 and EnviroGuard Stencil Cleaners can be closed-looped by using a simple micron filter to clarify the wash/rinse water for reuse and the DI filtration system used for cleaning assembled PCBs can usually be incorporated to DI water generation.
Return to Top



Certifications and Awards


Why is California EPA Certification and U.S. EPA Verification important?

Environmental regulations are constantly changing. A stencil cleaner that is legal today might not be legal in the near future. In the early 1990s, virtually everyone was cleaning with CFC solvents. Today's regulations disallow CFCs. Many companies have purchased equipment to utilize other solvents, such as alcohol or terpenes. Today's regulations have restricted the use of these solvents, because of VOC (volatile organic compound) emissions and/or fire, explosion and safety hazards placed upon the user, resulting in additional process changes and equipment purchases.

A California EPA Certified Process and U.S. EPA Verified Process provides the user with specific information relevant to Environmental Safety, user safety and process efficacy.

Return to Top



Is CAS Certification (Clean Air Solvent) by the South Coast Air Quality Management District important?

Smart Sonic's 440-R SMT Detergent was the first stencil cleaning chemistry to be CAS Certified in 1997. However, CAS Certification certifies only the chemistry from its original container. It does not take into account the resulting waste stream. Stencil cleaning has been identified as the most hazardous process confronting an SMT assembler because of the lead from the solder paste and because of some of the hazardous chemistries associated with cleaning raw solder paste. Just because a chemistry is CAS Certified does not mean that the process is environmentally safe. Only California EPA Certification and U.S. EPA Verification encompass the entire cleaning process and waste streams.

Return to Top



Has Smart Sonic ever received an industry award? Why is that important?

Yes, The Smart Sonic Stencil Cleaning Process has received more industry awards than any other cleaning process. This is important because experts within the industry have evaluated the process and have acknowledged its advantages and merits.

Awards include:
  • 2005 Global Technology Award for "Best Cleaning Product" (440-R SMT Detergent)
  • 1995 SMT Vision Award for "Best Cleaning Product" (440-R SMT Detergent)
  • 1998 SMT Vision Award for "Best Cleaning Product" (Model 5000 Stencil Cleaner)
  • Canadian High Technology Award for "Excellence in Packaging and Production"
  • NEPON West Milton S. Kiver Award for "Excellence in Packaging and Production" (Finalist)
  • Clean Air Solvent (CAS) Certification by the South Coast Air Quality Management District
  • Passed California EPA Certification (1999)
  • Completed U.S. EPA Environmental Technology Verification (ETV) Program*
  • Nominated for the U.S. Presidential Green Chemistry Challenge Award.
Return to Top



Service & Warranty


What is the warranty?

Warranty: All Smart Sonic Stencil Cleaners are backed by the best warranty in the industry. The ultrasonic transducers are unconditionally guaranteed not to crack, depolarize, deteriorate or become detached from the radiating surface for ten years. The Ultrasonic Generator is guaranteed to be free from defects in workmanship and materials for a period of two years and the remainder of the Smart Sonic Stencil Cleaner is guaranteed for one year. All guarantees include parts and labor, f.o.b. Smart Sonic.

Plus, when using Smart Sonic's 440-R SMT Detergent, all Smart Sonic Stencil Cleaners are guaranteed to clean any type of solder paste from any fine-pitch stencil!

Return to Top



What about maintenance?

Smart Sonic Stencil Cleaners are very easy to maintain:
  • Change wash water (every 4 weeks without filtration)
  • Wipe down work deck (weekly)
  • Check all hoses and fittings (monthly)
  • Blow off electronics (monthly)
EnviroGuard Closed-loop System
  • Change filters as needed
Wastewater Evaporators:

EZ-0
  • Clean out process chamber (weekly)
  • Blow-off electronics (monthly)
  • Wet vacuum reservoir tank (6 months)
  • Change thermal transfer media (yearly)
SE-1
  • Clean out process tank (monthly)
  • Blow-off electronics (monthly)
Return to Top



What about service?

Factory service is available. However, the Smart Sonic systems are designed so local personnel can perform service, a tremendous post warranty advantage. Machine designs are very simple and straightforward. Complete electrical, plumbing, mechanical and layout schematics are provided with every Operations Manual. Free unlimited technical support is available to all Smart Sonic customers.

Return to Top




* Information on the performance characteristics of this technology can be found at www.epa.gov/etv, or call Smart Sonic at 1(818) 610-7900 for a copy of the ETV verification report. Use of the ETV® Name or Logo does not imply approval or certification of this product nor does it make any explicit or implied warranties or guarantees as to the product performance.