What is solder paste no clean?

What is solder paste no clean?

No-clean flux is really “low-residue” solder paste. Post reflow, it leaves trace amounts of noncorrosive, resinous residue on or around solder joints, varying in color from transparent to amber. The lower the solids content (resins, gelling agents and activators) in the paste, the lower the residue left on the board.

Which solder paste is best?

The most commonly used are the SAC 305 and the 63/37, since they work well on circuit boards. The low temp is great for temperature sensitive devices or those with small components because it is a very easy to solder to work with.

How do you clean no clean solder?

In order to effectively clean and remove no clean solder pastes and no clean flux residues, a polar solvent or a solution of water and saponifier is necessary. Most no clean pastes require an organic saponifier for effective flux removal, but some can be cleaned with inorganic saponifiers.

What happens if you don’t clean flux?

Prevent Corrosion on Components and PCB – Flux residues left on electronic circuit boards are acidic. If they aren’t removed with a cleaning process, the residues can draw in ambient moisture from the air and lead to corrosion of component leads, and PCB contacts.

Is no-clean solder good?

The lower the solids content, the lower the flux residues left on the board. The fluxes in most of today’s no-clean pastes contain 50 percent to 70 percent solids. “In terms of leaving a clean appearance, no-clean solder pastes are as good as any of the water-soluble solder pastes,” says Dixon.

How do you choose solder paste?

When choosing a solder alloy, there are four key considerations: lead content, melting temperature, alloy powder particle size, and joint strength. Lead content, melting temperature, and strength are typically addressed at the same time.

Is no clean flux bad?

Flux residues detract from the cosmetic appearance of the boards. Corrosive no-clean flux activators often are incompletely encapsulated during rework or repair, due to uneven heating from the soldering system. This means the activators are on the exposed circuits, quite likely to cause corrosion and dendrite growth.

Is no clean flux really no clean?

No-Clean Flux actually means that the amount of residue left behind is negligible to the point where there is no need for it to be cleaned. Thus it is in fact just very low residue flux that does not require cleaning in most cases.

Does solder paste contain flux?

A solder paste is essentially powdered solder suspended in flux paste. The tackiness of the flux holds components in place until the soldering reflow process melts the solder. As a result of environmental legislation, most solders today, including solder pastes, are made of lead-free alloys.