Electronics Forum | Tue Jul 11 10:13:22 EDT 2006 | SWAG
Over time, you might see problems with delam., blistering and warpage if using FR4 carriers. Depending on volumes, you might consider using durostone or some robust material like that for the production runs. Keep in mind that switching materials w
Electronics Forum | Thu Sep 20 07:18:42 EDT 2018 | proceng1
Has anyone else been experiencing this lately? We have had a rash of boards that come in properly vacuum sealed. We store them in the hot room until we are ready to build, and we get bubbles under the solder mask. We've had 4 different jobs, all di
Technical Library | 2022-01-26 15:22:33.0
Reliability of conformal coatings used to mitigate tin whisker growth depends on their ability to contain tin whiskers. Two key material properties required to assess the reliability of a polyurethane coating are documented experimentally: adhesion strength and puncture strength. A modified blister test using a predefined blister area is employed to assess the adhesion strength and a puncture test is employed to evaluate the puncture strength of the coating. After measuring the properties at time zero, the coatings are subjected to accelerated testing conditions (high temperature/humidity storage and temperature cycling) and the degradations of the coating properties are documented.
Technical Library | 2017-12-11 22:31:06.0
Typical printed circuit board assemblies (PCBAs) processed by reflow, wave, or selective wave soldering were analysed for typical levels of process related residues, resulting from a specific or combination of soldering process. Typical solder flux residue distribution pattern, composition, and concentration are profiled and reported. Presence of localized flux residues were visualized using a commercial Residue RAT gel test and chemical structure was identified by FT-IR, while the concentration was measured using ion chromatography, and the electrical properties of the extracts were determined by measuring the leak current using a twin platinum electrode setup. Localized extraction of residue was carried out using a commercial C3 extraction system. Results clearly show that the amount and distribution of flux residues are a function of the soldering process, and the level can be reduced by an appropriate cleaning. Selective soldering process generates significantly higher levels of residues compared to the wave and reflow process. For conformal coated PCBAs, the contamination levels generated from the tested wave and selective soldering process are found to be enough to generate blisters under exposure to high humidity levels.
| https://www.eptac.com/wp-content/uploads/2015/03/ecss_q_st_70_18c-space-product-assurance-rf-coax-cables.pdf
or crimping. 5.3.2 Inspection of cable a. The supplier shall remove the delivered cable from its container and shall inspect it for dents, nicks, wrinkles, blisters and contamination. b. If dents, nicks, wrinkles, blisters or contamination
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