11/16/2023 0 Comments Non toxic soldering flux![]() ![]() Google Patents Non-corrosive soldering flux and method of making sameÄownload PDF Info Publication number US3003901A US3003901A US67920A US6792060A US3003901A US 3003901 A US3003901 A US 3003901A US 67920 A US67920 A US 67920A US 6792060 A US6792060 A US 6792060A US 3003901 A US3003901 A US 3003901A Authority US United States Prior art keywords flux camphor alcohol solution parts Prior art date Legal status (The legal status is an assumption and is not a legal conclusion. Google Patents US3003901A - Non-corrosive soldering flux and method of making same ![]() Add a drop of deionised water and see if the residue is water soluble then compare conductivity with a control drop of the deionised water, taking care to use clean electrodes and immerse them the same distance with the same separation.US3003901A - Non-corrosive soldering flux and method of making same ![]() * If you are intending to use denatured Ethanol as a single cleaning stage, you will probably want to test the conductivity of the residue if there was any apparent. Keep all bulk IPA containers tightly stoppered, and only dispense enough for a few days use. As IPA forms an azeotrope with water, (87.7% IPA by weight), and absorbs moisture from the air, if you ever need to use it for rapid water removal, you need drier IPA than that, so that traces of moisture aren't left behind as it evaporates. Blotting off as much denatured Ethanol as possible followed by an IPA rinse (without drying in between) is usually adequate. On less sensitive circuits, you can probably skip the aqueous cleaning phase unless a water soluble flux was used, or objectionable streaking was left after drying. The board can then be dried with no risk of iron component leads and other parts rusting, or heat damage due to prolonged and excessive drying temperatures. On sensitive high impedance circuits its only the first stage of a cleaning process and needs to be followed by an aqueous phase to remove ionic contamination and then by a good technical grade of 95% (or purer) IPA to quickly remove the residual water from the aqueous cleaning phase + any detergent residue. Also observe the last of the liquid closely as it evaporates to see if it is oily. ![]() However, before using denatured Ethanol on anything sensitive, its advisable to evaporate about a ml to dryness on a watchglass (or similar concave glass surface) using warm air or other gentle heat source, and note if there is any objectionable residue *. 95% denatured Ethanol is great for getting the crud off really dirty boards - wave soldered or reflowed with no defluxing then used in a poorly ventilated room by chain-smokers till a crust of gooey cigarette tar has built up on every surface. I've used denatured Ethanol and Isopropanol (IPA). There will be plenty more contamination in the bathwater just from the smelly guy sitting in the tub. It will still get the board much cleaner than it was before. For basic cleaning, it doesn't matter if there's a trace of something else in there. Pure isopropyl would be useful for final rinse, if you needed it. Along with all the flux residue you were trying to clean off. If you just leave the ethanol to dry on the board, of course the bitrex will remain on the board. Or the ethanol has to at least suspend it while you brush it off. If it wasn't soluble in the 5% water, it would just settle to the bottom of the container and wouldn't serve it's purpose, no? The 5% water also has to dissolve the ionic contamination from the board you're cleaning. I don't really care if there's a little trace of bitrex in there. Hardware store sells it in big tin containers which are a convenient size/shape to sit on a shelf along with all my other solvents and finishes which I conveniently buy at the same store. Isopropyl will slowly absorb water from the air that you let into the container it stabilizes at 91% 3. smell is much less noticeable/objectionable to me 2. But even here, I have never encountered any problem with ethanol. There is no PCB component/plastic that I have encountered which is noticeably degraded or dissolve in short exposure to ACTEONE, let alone ethanol. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |