Friday, June 22, 2018
Archive >  February 2013 Issue >  Special Features: Assembly and Packaging > 

Keeping Wave and Selective Soldering Up to Date
MaxiReflow system for pressurized soldering.

Voids in solder joints are nearly inevitable in everyday processing conditions. The solutions currently available are based on vacuum technology, but this technology has a problem: the heat transfer is really restricted and the vacuum is applied after the peak heating zone. To eliminate the voids, vacuum technology uses the difference between 1 bar (14.5PSI) and almost zero air pressure.

At SEHO, we have gone in a different direction — working with an elevated pressure in the peak zone, up to 4 bar (58PSI), and then lowering it to atmospheric pressure (1 bar). The result is a force that is three times stronger than standard atmospheric pressure, which eliminates the voids as well as providing increased flexibility in working parameters. And while the High Pressure MaxiReflow is made for inline applications, it can also be used as a standard inline reflow system with high throughput if the pressure process is deactivated. With this technology in place, the customer will really be ready for the future.

Soldering Developments
Since its founding in 1976, SEHO has become the worldwide contact partner whenever soldering is involved. Company solutions are based on performance, flexibility, efficiency and technical progress. SEHO?s business activities and production organization are oriented according to the principles of sustained future-compatible development. With its systems, the company provides customers with a sustained and resource economizing production facility. It continuously develops its technology in order to provide customers with a competitive advantage.

Since the company's founding more than 37 years ago, SEHO has introduced numerous innovations in the field of soldering, such as soldering in Nitrogen atmospheres.

Incorporating AOI in Soldering
A recent development is the implementation of an AOI inspection system in the PowerSelective machine. SEHO started a partnership with a company that has long-standing experience in optical inspection, making it possible to integrate a proven solution into its selective soldering systems. This cooperative venture effectively merged the company's expertise with the partner's experience in optical inspection. The result is a turnkey solution that has just one interface.

SEHO recently introduced its PowerWave N2 wavesoldering system, transferring experience from the high-end MaxiWave line into a more affordable concept. New features of the system include programmable distances between the solder nozzle and conveyor. In addition, the company has also introduced a void-free solution based on high-pressure technology.

Reducing Nitrogen and Energy
The new PowerWave dramatically reduces Nitrogen and energy consumption by using an insulated tunnel design concept which ensures that emissions from the heaters remain in the process chamber and will not be released to the production environment. The power consumption has been reduced by as much as 15 percent. The optimized N2 gassing system works with heated Nitrogen. The 360° distribution system ensures even Nitrogen flow with minimal local pressure.
High pressure chamber integrated in the SEHO MaxiReflow for a void-free soldering process.

Compared to a locally inerted Nitrogen hood, N2 consumption is approximately 20 percent less and the dross generation is reduced to 10 percent. Based on these savings, ROI for a new full tunnel machine can be within 12 to 24 months. Thus this new concept and design allows the user to improve quality and save money.

Embedding AOI
The company recently won an award for the new automated optical inspection (AOI) system that can be embedded directly in the selective soldering process in the Power Selective system. We are planning to incorporate this process in other machine concepts. Because of special lighting technology used in this AOI system, we are able to see solder balls, non-wetting or insufficient wetting, bridging and missing pins on the bottom-side.

Using the same axis for AOI as for selective soldering, this AOI system becomes very affordable. Finding failures early in the production line can be used to adjust the selective soldering process. It also allows the user to separate all failed PCBs from the line ensuring 100 percent quality for the products leaving the selective solder process. Any product that fails the AOI will automatically be transferred to the repair station.

Added Value
The company works closely with industry partners to bring added value to its customers. These are customer-specific projects, but also involve industry consortiums collaborating on a common approach to whole-line electronic equipment assembly. In addition, we continuously support customers with our extensive process knowledge — offering seminars at the SEHO Academy, as well as analysis and suggestions from the SEHO Global Process Team. By utilizing these resources, every company's professional development staff can achieve added value and substantially reduce its production costs. Today's trends in soldering call for increased levels of efficiency and technology. SEHO offers economical standard solutions as well as individual solutions for customers. This approach keeps the company and our customers abreast of market trends while allowing customers to participate in these changes as they occur.

Contact: Seho North America, Inc., 1420 Jamike Drive, Erlanger, KY 41018 859-371-7346 fax: 859-282-6718 E-mail: Web: or

Add your comment:

Full Name:

search login