What is the fluxes types?
Since the biggest difference between PCBA "rinsing process" and "no rinsing process" is débordement, and the main purpose regarding rinsing is "removing flux residue" along with other pollution, and then we should know the dimensions of the types of flux.
1. Inorganic series flux
In typically the early flux, inorganic stomach acids and inorganic salts (such as hydrochloric acid, hydrofluoric acid, zinc chloride, ammonium chloride) were added, which often were called "inorganic fluxes" because inorganic acids in addition to inorganic salts were moderate. Those strong acid, which can up to very good cleaning effect, soldering result and excellent soldering efficiency, but the disadvantage will be that it is additionally extremely corrosive. So the welded board must have the thicker plating layer to be able to withstand strong acid washing. Thus, after using these kinds of "inorganic flux", it need to be strictly rinsed right away in order to avoid corrode the copper evade of the board constantly, and ensure the perform of the board.
2. Organic and natural series flux
Therefore, a few men and women add a poor organic and natural acid (such since lactic acid, citric acid) to the flux to replace the strong acid solution, called "organic flux". Although the degree of rinse will be not as effective as strong acid, as long as the contamination of solder area is not too significant, it can still play a particular amount of cleaning effect. Within other words, the remains after welding can remain on the object for a time frame without significant corrosion. Nevertheless , the poor acid is yet a kind of acid. It still need rinse out to avoid bad rust like line corrosion.
3. Resin and rosin series flux
Because the wash it process is fairly difficult, rather than all electronic elements may be rinsed, such since buzzer, coin battery, pogo pin and so forth.
Later, several men and women added rosin to the flux to exchange typically the original acidic detergent because of it can play some degree to remove the particular oxide. However , when the particular rosin is a monomer, the chemical activity is usually weak, and the moist means of solder is usually not enough. Consequently , it is functional to add a tiny quantity of an active broker to boost its activity. Additionally, rosin is that rosin is active only whenever it becomes liquid. Their melting point is concerning 127 ° C, in addition to the activity can last up to 315 ° C. At present, the particular optimum temperature for lead-free soldering is 240-250 ° C, which is merely within the active temperature selection of rosin, and their solder residue won’t business lead corrosion problems. These special features contribute to rosin widely can be used in the particular welding of the electronic devices equipment.
IPC-J-STD-004 defines several fluxes based on débordement composition: organic (OR), inorganic (IN), rosin (RO), plus resin (RE).
"Rinsing" means by by using a liquid solvent or pure water to be able to clean the board. Considering that the general acidic compound can be dissolved in water, "water" may be used to be able to dissolve and wash, thus it is called wash it.