Dr. Brian Toleno
Dr. Brian Toleno is the Application Engineering Team leader for Henkel Technologies. He is responsible for the technical service and application engineering for Henkel's electronics assembly materials, including solder paste, underfills, PCB protection materials, and underfills.
Dr. Brian Toleno has submitted responses to the following questions.
Rework of Underfilled Array Packages
In previous yearsreworkable underfill systems tended to be very soft (even at room temperature),low Tg (glass transition) type materials used ...
If you review the articles the two main, statistically significant factors are:
1. Pad Design and
There are ...
Conformal Coating & Humidity
Conformal coating is one method of protecting a PCB from an end use environment. Conformal coatings are a thin layer ...
IR Reflow Issue
Without having more detail it is difficult to diagnose the actual issue. With cracked or failed solder joints you would ...
Oxidation on plated through holes
Silver can indeed tarnish when exposed to different atmospheric contaminates. The most common forms are sulfides which readily form tarnish ...
Proper method to bake PCB's
With respect to baking boards or substrates, typically the reason to do this is to remove absorbed moisture from the ...
Cleaning an assembled board with IPA
Different no-clean solder pastes produce different residues with different characteristics.
You are taking the right approach in checking the compatibility. ...
Lead free BGA's and HASL
One of many issues raised by the transition to Pb-free manufacturing is mixed metal assembly ( http://www.meecc.com/pres2006/Track%203%20-%20Poole.pdf). For a situation ...