German ERSA Selective Wave Soldering VERSAFLOW 3/35

With cutting-edge technology and modular design, ERSA selective soldering systems meet the highest demands for flexibility and throughput—perfectly tailored to various needs and budgets. A true classic among classics!



Selective Soldering – The Quality Standard for THT Components
Selective soldering is the process of soldering individual through-hole components on printed circuit boards. This typically includes components with lower heat resistance or those too large for SMD reflow processes. Compared to traditional wave soldering, the thermal input into the assembly is significantly lower, and no solder mask is required. Since soldering parameters can be individually adjusted for each joint, this process ensures the highest quality and repeatability.



Flux
The flux system in a selective soldering machine must meet multiple requirements simultaneously. In addition to precision and speed, high-quality flux processing demands a high degree of reliability. Areas of the PCB not targeted by the selective soldering axis must not come into contact with flux.

To achieve this, we utilize state-of-the-art multi-drop flux heads based on industrial inkjet technology. Instead of being atomized, flux is applied as individual micro-drops precisely onto pre-defined areas. To address flexibility, throughput, and process reliability, ERSA offers a range of options tailored to diverse customer requirements.

Highlights/Options
Multi-drop precision flux application
Up to 4 flux heads can be installed
Dual flux tanks available
Continuous monitoring of flux application
Support for 2 flux modules



Preheating
The purpose of the preheating process is to uniformly heat the printed circuit board before it is transferred to the soldering module. This is achieved using bright infrared emitters, which supply up to 50% of the thermal energy, ensuring the PCB is not thermally shocked upon contact with molten solder.

The demands of lead-free soldering, multi-layer boards, and high-energy selective soldering applications—coupled with the drive for optimal cycle times—require continuously improved thermal performance. Proper activation of flux is especially critical for components with high thermal demands to ensure optimal wetting and capillary action for solder penetration. To meet these diverse challenges, ERSA selective soldering machines can be equipped with up to five preheating modules and optional top heaters.

Highlights/Options
Segmented IR bottom heating for increased throughput
Various full or partial convection top heaters
Pyrometer for temperature monitoring and recording
Programmable heating zones
Powered convection for uniform heating



Micro Wave Soldering
In the basic version of micro wave soldering, a single soldering nozzle is used to solder each joint individually. Since soldering parameters can be set specifically for each joint, this method offers maximum flexibility and the highest quality.

Regardless of the customer's choice of selective wave soldering system, ERSA does not compromise on soldering technology. All ERSA selective soldering machines are equipped with electromagnetic solder pumps. With no moving mechanical parts, this technology minimizes dross formation and significantly reduces crucible maintenance. The pump ensures an extremely consistent flow rate, enabling precise and finely adjustable wave height. Dynamic process parameters such as solder level, wave height, and solder temperature are continuously monitored and recorded.

Highlights
Y and Z-axis variability for maximum flexibility
Individual parameter adjustment per solder joint
360° soldering with no preferred direction
No tooling costs
No lead time required



Multi Wave Soldering
Selective soldering processes achieve economic success when aligned with application requirements and production volume. A key factor here is productivity, i.e., the assembly throughput of the soldering system.

In practice, this is realized through multi-wave soldering technology. The core of the soldering cell is a product-specific soldering tool with custom-designed nozzles that deliver solder precisely and simultaneously to the soldering points of through-hole components. This technology allows a pure soldering time of 2–3 seconds per assembly, independent of the number of components to be soldered. Multi-wave based selective soldering systems ensure a stable, repeatable process with reduced cycle times.

Highlights
Short soldering cycles due to simultaneous soldering
Process time independent of the number of solder joints
"Instant maintenance" (with 2 soldering modules)
Minimal distance achievable to adjacent SMT components
Continuous solder flow for optimal energy transfer