Corrosive Effects of Solder Flux on Printed-Circuit Boards

Conductive Anodic Filament Formation Part II: Electrochemical Reactions Leading to CAF

“…The formation of atacamite, Cu 2 (OH) 3 Cl, has been previously observed in PWB assemblies, 34 and in the atmospheric corrosion of copper in the form of patinas found on statues and rooftops. 35 In addition, from previous electrodissolution studies of copper in chloride solution, the first step in the corrosion of copper will occur according to reactions 9 and 10.…”

An information‐based burn‐in procedure for minimally repaired items from mixed population

“… Illustration 1 Electronic circuit boards are essentially used in most electronic equipments. The faulty solder is the critical cause of electric circuit boards failure, and thus, the importance of high standards in soldering cannot be overemphasized (e.g., –). During the manufacture of the circuit boards, several electronic components, such as integrated circuits, resistors, and condensers, are soldered to printed‐circuit boards.…”

“…As another example, soldered parts or components can fail by incomplete or poor soldering. Also, during soldering, solder flux can remain on the boards and increase its humidity intake, which eventually results in the failures of the components on the boards (see also , , , and references therein). Thus, faulty solder is the ‘shared cause’ for component failures on electric circuit boards.…”

Electronic Materials, Components, and Devices

“…This is particularly likely to occur when the Cu frame leads are coated and their ends are cut and exposed to aggressive environments (or "bare toes"). Kovar leads are subject to stress corrosion cracking when bare or at discontinuities in the coating [11,12]. Tinned leads occasionally are subject to shorting by tin whiskers that grow under the influence of compressive stresses [13][14][15].…”