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Rick Perkins

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President
Chem Logic

Rick Perkins is a chemical engineer with more than 33 years of Materials & Processes experience. He has worked with Honeywell Aerospace in high-reliability manufacturing, as well as with several oil-field manufacturing companies. He also has a good understanding of environmental, health, and safety regulations.

Rick Perkins has submitted responses to the following questions.
Contamination From Anti-static Foam
Without knowing the types of materials on this board, it sounds like the advice you have been given is good. ...
What's Causing Cloudy Conformal Coating
I imagine that this is a 2-part polyurethane conformal coating this is cloudy in the "cured" state. If so, the ...
Cleaning Under Low Clearance Components
Yes, more than likely, you are jeopardizing the reliability level of your product by not removing residues from a water-based ...
Is Solder Mask Considered an Insulator
While I cannot speak to the IPC standard requirements, it depends on what reliability specification you are working as to ...
Out-gassing and Cleaning
Outgassing from the solvents will not be an issue if you use one solvent, or a blend of solvents, that ...
QFN Test Failures Caused by Flux
Great question! You have learned the hard way that "No Clean" does not entirely mean "do not clean". The process ...
Removal of Coatings from PCBs
Coating removal from a PCB depends on several factors: 1) type of coating, 2) type of substrate, 3) type of ...
Contamination Using Solvent Dispensers
The first point you must understand is that you are not"actually" cleaning the boards when you use an acid brush ...
Trichloroethylene Alternative
My response might soundcrazy to many in the USA, but I'm taking into account that you are primarilyusing a flammable ...
ESD Grounding - 1 Meg Ohm Resistor
A resistor is used as asafety precaution. Since electrical equipment is alsoconnected to ground ... (some companies do not have ...
Mixing Silicone and Acrylic Conformal Coatings
The mixing of the two conformal coatings is not ideal and if there is away to avoid using the acrylic ...
Conformal Coating Recommendation
There are two best options for an outdoor conformal coating. One is a silcone-based product that can also withstand high ...
ESD Conductive Floor Tile Worry
I have been involved in specifying, installing, and verifying conductiveESD floor tile in several high reliability manufacturing areas. I believe ...
Challenging Cleaning Problem
For this critical unit, theobvious cleaning method is vapor cleaning. Vapor cleaning uses anonflammable hydrocarbon that is boiled to create ...
Stencil Cleaning Procedure
In this process you havemany variables that need to be optimized dependent upon the acceptablereliability level of the CCAs. The ...
Solder Paste Life on the Stencil
Yes, you need to remove thesolder paste on a regular schedule, possibly every 4 hours, and clean thestencil either manually ...
Un-cleaned PCB Assemblies Potted
There are many variablesassociated with your question. For example, was this "washableflux" a water-based OA type of flux or was ...
Cleanliness After Coating Removal
This is a situation whereyou have to prove to yourself (and to your customer) that your rework cleaningprocess is "qualified ...
Zip-lock Bags vs. Heat Sealed Bags
No. Zip lockbags are made from polyethylene, which moisture and other gases can transpire. ...
Class 3 Cleaning Requirements
It is unclear as to whatspecification you are working under. There is no general specificationfor "Class 3" cleanliness. Apparently, there ...
Tacky Substance Under Zero Clearance Parts
If the contaminant is causing you a reliability problem, then it needs to be eliminated or controlled. It would be ...
Flux Oozing from Insulated Wires
When I have seen fluxoozing from between the wire insulation and the wire, the reason has been attributedto the use ...
Dendritic Growth and Contamination at BGA Sites
Obviously this was an erroras all active flux residues must be cleaned. The question is, whattype of active flux exactly, ...
Gold Edge Contact Flux Contamination Failures
Boards that have beenmanufactured with "No-Clean" flux may still require cleaning prior todelivery to service. This depends on the environment ...
Ways to Remove Silkscreen Ink from Pads?
Removing ink is not different than removing solder paste, that is, if the ink is UNcured. However, if the ink ...
DI Water Resistivity Check
A simple conductivity / resistivity probe is all that is needed to make the measurement, and that is about as ...
Fumes from Baking
An oven used to demoisturize the boards would typically operate in the 250 F temperature range. Some nonmetallic materials will ...