Saving my Mac SE/30. My first foray into SMD work

On Mon, 27 Apr 2015, Ian Finder wrote: Modern made top brand SMD aluminum electrolytics (such as Panasonic, Nichicon, Rubycon) also don't tend to exhibit this failure mode. There were two primary causes of the end-seals in the late 1980s to mid 1990s era SMD aluminum electrolytics failing. One was that the "rubber" compound used for the capacitors end-seal didn't hold up well to the higher temperatures used in reflow soldering and would deform. Another was the use of chlorinated solvents to clean boards after soldering. Manufacturers solved the end-seal issue by switching to rubber compounds which could better handle the higher temperatures encountered in reflow soldering. This is why modern parts soldered at even higher temperatures using lead-free solder aren't failing like these early SMD aluminum electrolytics did. Chlorinated cleaning solvents OTOH, are still a problem for aluminum electrolytic capacitors, even for through-hole parts, and most capacitor manufacturers explicitly state in their datasheets not to use them. Not only can chlorinated solvents damage the rubber compound used for the capacitors end-seal, but they can wick into the capacitor and cause the aluminum itself to corrode. It wasn't that those early SMD aluminum electrolytics were shoddy or defective, it was that the electronics industry didn't understand how to handle them during assembly. This is similar to what happened in more recent times when manufacturers first began switching from tin/lead solder to lead-free solder. Instead of replacing process equipment which had been designed for tin/lead process with equipment designed explicitly for lead-free process, many board houses at first tried just running their reflow ovens and wave soldering machines at higher temperatures. In hindsight, the results of doing this sure look to have been predictable.