Fluxing Applications

Of the many flux products developed for soldering applications, most electronics assemblers prefer to use no-clean, low solids formulations, in part because they eliminate the post-reflow cleaning or defluxing process step.

Virtually all fluxes are designed to perform multiple functions:

  • Chemical:

    • Clean the surface to be soldered to allow wetting;

    • Function as a chemical blanket over the surfaces to be soldered, thereby preventing oxidation during heating;

  • Physical:

    • Reduce surface tension of the molten solder, thereby enabling the solder to flow and wet solderable surfaces;

  • Thermal:

    • Facilitate the transfer of heat to solderable surfaces.

The Electrovert® Electra™, VectraElite™, and VectraES™ all offer fluxing solutions for multiple applications and processes:

  • ServoJet™: Design utilizes multiple spray jet technologies that maximize upward force, providing excellent topside penetration and precision flux deposition control. Its features include:

    • Precision selective fluxing;

    • OA version for aggressive fluxes;

    • Dual head version for recipe controlled dual flux capability.

  • ServoSpray™: Design utilizes an air-atomized single spray nozzle technology that provides a value-based fluxing solution. Its features include:

    • Excellent flux deposition;

    • Selective fluxing capability;

    • Dual head version for recipe controlled dual flux capability.

  • ServoSonic™: Design utilizes ultrasonic atomizer air delivery technology. Its features include:

    • All wetted nozzle parts are titanium;

    • Technology works well with high solid fluxes;

    •  Selective fluxing capability.

 

As board assemblies become increasingly complex and difficult to solder, board manufacturers are looking for wave solder machines that can provide closed-loop process control and automatic features.
In the demanding environment of lead-free soldering, it is important to understand the different characteristics of lead-free materials. Wetting times for lead-free alloys are slower than those of tin/lead, and flow characteristic are more viscous.
As PCB designs become more complex, thicker, and denser, through-hole soldering is becoming more difficult. The introduction of lead-free alloys compounds these problems because lead-free alloys don’t wet as well as lead-bearing alloys, and deeper holes (due to PCB thickness) make thorough hole-filling less certain in many cases.
As the complexity of PCB assemblies continues to increase, many electronics assemblers are seeking a solution in a wave soldering machine.
Wave Soldering Award-winning wave soldering technologies have long met the demanding throughput and process control challenges of applications such as lead-free wave soldering.
Even though most SMT soldering is achieved through reflow, some assemblies require that some of the Surface Mounted Devices (SMDs) on a board, such as chip components, must be wave soldered.