What is Water-soluble solder flux?
The pads of a PCB will be oxidized when exposed to air or get contaminated while handling the board. These oxidized metal surfaces and other contaminants may interfere with the soldering process. Hence, in order to get reliable stronger solder joints, the cleaning of the oxidized metal surfaces and other contaminants is important. In a soldering process, Flux is the chemical agent or cleaning agent used to create reliable strong solder joints by first cleaning oxidized metal surfaces and also helps to prevent the re-oxidation of the metal surface during the soldering as well as promotes the wetting of the molten solder between the metals.
According to IPC J-STD-004B, different types of flux available; water-soluble solder flux is one of the flux types. This flux comes under the category of organic flux and is made up of four major components, activator, vehicle, solvents, and additive.
The activator performs the de-oxidation of oxidized metal surfaces and cleans the corroded metal surface. In water-soluble flux, metal halides such as hydrochloric acid, phosphoric acid, citric acid, and hydrobromic acid are used as activators. The base material of the flux is the vehicle component that helps to prevent the re-oxidation of the metal surface during the soldering process. The organic components such as high-boiling polyols - glycols, diethylene glycol higher polyglycols, polyglycol-based surfactants, and glycerol are used as the vehicle in the water-soluble flux. The solvent and additive component of flux helps to ease the soldering process and inhibiting corrosion.
The water-soluble Flux is a very aggressive cleaner and oxidizer. Even though it provides excellent soldering, after the soldering process, this flux leaves the residues, which are highly corrosive in nature and contains ions that are typically conductive. If residues of water-soluble flux are left unclean, it will create the electrical short in the future. Hence, it is necessary to clean the residues, and the cleaning process is done by using flux removers, such as hot water, deionized water, and detergents.
Usually, the water-soluble flux is available in liquid or semi-liquid form with various package types like Jar/Jug/Bottle/ Syringe/Container. The water-soluble fluxes are mostly suitable for wave soldering of electronic components, where the rosin fluxes are too inactive for the application. As per IPC J-STD-004B, the classifications of water-soluble flux are ORL0/ORL1/ORM0/ORM1/ORH0/ORH1. The selection of a particular classification (for example, ORM1) is based upon applications.
Specification details of water-soluble solder flux:
Classification: Represents the flux classification as per IPC J-STD-004B. Usually, it is under the classification ORL0/ORL1/ORM0/ORM1/ORH0/ORH1. The first two letters represent the type of flux composition, the third letter represents the activator level (low, medium, high), and the fourth letter represents the activator (halide) include or not (0- no halide, 1- halide include).
Package: Represents the package type of RA solder flux. It may be Jar/Jug/Bottle.
Net weight: Represents the net weight in Kg/lbs.
Storage temperature: Represents the storage temperature of the flux in Degree Celsius.
PCB Directory has listed Water Soluble Solder flux from the leading companies. View details, download information and get quotes on flux.
