Electronics Forum | Wed Jan 27 09:00:56 EST 1999 | Chris Fontaine
| | I have boards coated with Humiseal 1B73. At a late point mfg. site we need to remove a series of 0603 resistors for optioning purposes. I have been trying to determine the fastest, easiest way to re-coat the pads after removal. Drying time of the
Electronics Forum | Thu Nov 19 22:48:22 EST 2009 | davef
Since the bubbles: * Are only on the solder connection, we'd guess there must be some compatibility issue between the flux residues and the conformal coat materials. * Occur after curing, we'd guess the cure recipe is too rapid and is entrapping voli
Electronics Forum | Thu Nov 19 05:18:37 EST 2009 | prodivegsr
Hi All, Recently we are working on the conformal coating process using Humiseal chemical 1B73 and thinner 521. Bubbles on component body/joints are seen after gone through the IR Reflow Oven. During the conformal coating, only tiny bubbles seen af
Electronics Forum | Mon Jul 04 14:21:14 EDT 2011 | davef
The three primary causes for bubble generation in solvent-based coatings are: * Air entrapment * Solvent flash-off * Curing the coating too quickly Tell us more about your process including: * When you first notice the bubbles * Extent of the probl
Electronics Forum | Fri Oct 23 15:43:31 EDT 2009 | seankim10
According to 5.2.6.1, it states that defected if Solder balls are not entrapped in no-clean residue or conformal coating. How do you define entrapment or how do you assess if the balls won't dislodge under normal product service environment? The sold
Electronics Forum | Thu Jan 31 13:01:33 EST 2013 | kmots15
Defect if its not coated. Defect - Class 1,2,3 • Solder balls are not entrapped, encapsulated or attached or can become dislodged in the normal service environment. • Solder balls violate minimum electrical clearance.
Electronics Forum | Mon Sep 21 20:45:55 EDT 2009 | davef
10.4. Pre-Cure Examination. Immediately after material application, the uncured conformal coating shall be examined for: a. Bubbles and Air Entrapments. These defects shall be broken by vacuum, with a sharp probe, or other appropriate tools. b. Bridg
Electronics Forum | Thu Nov 30 21:30:00 EST 2023 | ritronusa
Having issues with getting the right formula for a GPD simplecoat machine. We tried a silicone that hardened in our lines and when we try acrylic it is either showing air entrapment or cobwebbing.
Electronics Forum | Wed Mar 27 18:23:01 EST 2002 | kmorris
Does anyone have experience doing conformal coating over Plastic BGA in High-Rel PCB assembly? Is underfill necessary to avoid problems with entrapped air, etc? Our application is a 17x17mm BGA, 256 I/O. We are assembling with a water soluable pas
Electronics Forum | Tue Nov 30 16:50:20 EST 1999 | Dave F
Greg: It depends on the specifics of the flux you are using. You didn�t say. Generally, using a: � "No-clean flux" should create no flux entrapment problems for most applications. � RMA with 25% or more solids as a "no-clean" should create no flu
