>If the flux was not activated (ran in another area of the board), the flux should be removed from the board. Any Comments? A: We agree. In order for its �benigness� to take effect, NC flux is affected by: * Type of flux * Amount of flux * Proper activation.
> To accomplish this you should wash the entire board (which we have washers for) A: Makes sense.
>If the flux was restricted to the area of repair, the flux can be removed with a q-tip and alcohol or another spot cleaner. Any Comments? A: We disagree. Points of discussion are: * Flux goes a lot farther than the heat from the soldering iron reaches. That isopropanol carrier takes that flux places you would not believe. We don�t know how you plan to �restrict the repair flux to the area of repair�. * Spot cleaners do not clean the surface. They spread the residues over a broader area and, so, make them less visable.
> I am concerned that if the flux and Terpine is not wiped from the board the Terpine could leave a residue. If so, is this residue harmful to the board? A: Your intuition is correct. Terpine and the flux res probably should be removed from your board.
Terpenes are derived from citrus peels or pine bark, and are common ingredients in various household cleaners and deodorizers. They are effective in removing flux from printed circuit boards and other similar operations. Terpine is a commonly used saponifier used in semi-aqueous cleaning. For instance, the Bioac line from Petroferm contains terpenes. As mentioned by an earlier poster, saponifiers have a pH of ~11 when diluted.
Terpenes are generally recyclable, are biodegradable, and effluents may have fuel value. The disadvantages of using a terpine include a low flash point, high initial equipment costs, may require a modification to the wastewater discharge permit due to increased oxygen demand, and could cause adverse respiratory effects in sensitive individuals.
Semi-aqueous cleaners can be a mixture of water and hydrocarbons, which require both a rinsing and drying step in the cleaning process. Common semi-aqueous cleaners include terpenes and other hydrocarbons. Some closed-loop cleaning systems are available to lessen these negative effects.
reply »