Wave Soldering SMT

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. Often, these passive components are on the bottom side of a PCB and are held in place by dots of adhesive. In many cases the top-side SMDs are then attached with a reflow oven pass. Much depends on the design of the product and the components used.

Electrovert® Electra™, VectraElite™, and VectraES™ and Vitronics Soltec Delta X wave soldering equipment offers several features that increase process capability and flexibility, enabling wave soldering of SMDs.

  • Omega wave: Electrovert Omega wave features an oscillating vibration in the main wave that promotes wetting around small components.

  • Rotary chip wave: The rotary chip wave promotes wetting to pads and eliminates skips and shadowing caused by taller SMT components.  The feature includes a programmable rotary rpm to control the wave action.

  • Soldering in Nitrogen: The use of nitrogen improves wetting ability. This applies to both through-hole components and SMDs. Nitrogen soldering features include UltraFill™ boundary-type N2 soldering and a nitrogen tunnel (inerts the entire solder pot area).

 

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.
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.
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.