Chris Palin

Chris Palin has submitted responses to the following questions.

Conformal Coating in Nitrogen Environment
Ipresume that you are using nitrogen to pressurize the pressure pot on thecoating system containing the coating and possibly power ...

Conformal Coating Press Fit Connectors
Firstly there are two schools of thought regarding press fit connectors and conformal coating.One theory says coat the complete assembly ...

Conformal Coating Recommendation
The basic material type required would be an acrylic conformal coating designed for LED applications such as HumiSeal 1B73LED. You ...

Dam & Fill vs. Conformal Coating
Dam & Fill is generally used for mechanical protection of flip chip, BGA or wire bonded chips. It does also ...

Un-cleaned PCB Assemblies Potted
To give an exact answer I would need to know exactly what the flux is.Generally speaking fluxes that are designed ...

Coating Scored Panels Prior to Separation
This is quite commonplace practice.Providing that the coating has good adhesion to the PCB surface it will not delaminate duringde-panelisation. ...

Cleanliness After Coating Removal
There are different ways to remove polyurethane coatings as you know.Use of specific stripping chemicals.Dry powder micro abrasion.The chemical method ...

Conformal Coating Over Heat Sinks
Regarding coating of heat sinks with conformal coating.Here is a calculation based on the thermal conductivity of acrylic resin being ...

Conformal Coating in Low Humidity Environments
Conformal coatings provide a breathable membrane protecting from humidity and contamination. They will all vary slightly in resistivity depending on ...

HASL vs. Immersion Gold
If electronics are being used in a corrosive chemical environment it would be advised to use a polyurethane conformal coating ...

Uneven Conformal Coating
I am surprised that this is happening only on the matte finnish boards! If the issue were related to surface ...

Exposed Leads on Conformally Coated Boards
I presume that you are clipping them to test them and therefore making contact to the lead. You are effectively ...

Circuit Board Exposed to Rain
That really depends on a two factors:What was the quality of the rain water? A difficult one to answer but ...

Conformal Coating Over No-Clean Flux
The short answer is yes. The majority of circuit boards that are coated are no clean. However it is a ...

Conformal Coating Cross Contamination
The short answer is, keep the Acrylic and Polyurethane on one line and the Silicone on a dedicated line. Silicone ...

Cleaning Conformal Coated Boards After Rework
There is no need to put a reworked conformaly coated PCB through an aqueous wash system after rework. In fact ...

Conformal Coating and Moisture Absorption
Boards can be kept indefinitely in room temperature and humidity conditions as conformal coatings are breathable and will allow moisture ...

Organic Flux Residue Concerns
There are many variables here so a definitive answer is not possible. You should first consider the following points:Is the ...

How To Mask Areas During Conformal Coating
There are basically two options open to you if you are hand spraying with a solvent based conformal coating.Use a ...

Problems with Bubbles in Conformal Coating
The reason that you have bubbles between and behind component legs is probably due to the viscosity (high) and thickness ...

Contamination Prior to Conformal Coating
HumiSeal are not aware of any issues related to "Pink bubble material" My only question would be, does this material ...

Re-plating lead-free components for tin/lead assembly
As you are an aerospace manufacturer you may be conformaly coating the boards. If so HumiSeal has just completed a ...

Which to Use - Rosin Flux or Water Soluble?
Rosin based fluxes use natural rosin as the activator to clean the metals so that the liquid alloy can coalesce ...

Epoxy Bonding Problems on RoHS Boards
This is related to the surface energy of the solder resist. High surface energy is good, low surface energy is ...

Affects of Silicone Migration
Silicone conformal coatings have been linked to relay failures due to contamination over time. Silicones also have a tendency to ...

No clean flux stains during reflow
Most people want minimal flux residue left on a circuit board. This is achieved by volatising as much of the ...

Alternative to Conformal Coating
There are many types of conformal coating and many ways to apply them. I am not aware of any die ...

Conformal coating and connector holes
This only generally happens with solvent based conformal coatings as 100% solids coatings tend to be higher in viscosity. Solvent ...