PD&D talks with project manager Christian Ott of SEHO Systems about the company’s latest soldering developments.

Since its foundation 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.

Q. Christian, since the company’s founding more than 37 years ago, SEHO has pioneered numerous innovations in the field of soldering, such as soldering in Nitrogen atmospheres. Tell us about some of the company’s more recent developments.

A. SEHO is actively involved in various research projects with the German government, international universities and industry partners. With this background we continuously develop new products and improve existing products. These developments are transferred to all of our product lines. One of our more recent developments is the implementation of an AOI inspection system in our PowerSelective machine. SEHO started a partnership with a company that has long-standing experience in the field of optical inspection. Therefore, we are able to integrate a proven solution into our selective soldering concept. With this cooperation, we merged our knowhow with our partner’s experience in optical inspection. The result is a turnkey solution for our customers with one interface.  In the field of wave soldering we recently introduced our PowerWave N2 version. With this concept we transferred the experience from our high-end MaxiWave line into a more affordable concept with new features, including programmable distances between the solder nozzle and conveyor. In the reflow product line, we just introduced a void-free solution based on a high pressure technology.

Q. Voids in solder joints are nearly inevitable for common process conditions. How can SEHO help reduce voids in reflow soldering?

A: The solutions currently available are based on vacuum technology, and one main problem with this technology is that the heat transfer is really restricted and the vacuum is applied after the peak zone. To eliminate the voids, vacuum technology uses the difference between 1 bar (14, 5 PSI) and almost zero! With the SEHO solution, we are working with an elevated pressure during the peak zone, up to 4bar (58PSI), and afterwards it is lowered to the atmospheric pressure. The result is a force that is three times stronger to remove the voids as well as increased flexibility in parameters. The real highlight is that the High Pressure MaxiReflow is made for inline applications and also can be used as a standard inline reflow system with high throughput if the pressure process is deactivated. With this concept the customer will really be ready for the future!

Q. How does the new PowerWave N2 with the SEHO tunnel concept reduce Nitrogen and energy consumption?

A. The insulated design of this tunnel concept ensures that emissions from the heaters remain in the process chamber and will not be released to the production environment. The power consumption is reduced up to 15 percent.

The optimized N2 gassing system works with heated Nitrogen. The 360° distribution system ensures even Nitrogen flow with minimal local pressure. Compared to a locally inerted Nitrogen hood, the consumption of N2 is approximately 20 percent less and the dross generation is reduced to 10 percent.

Based on these savings, a new full tunnel machine can be justified within 12 to 24 months. With this concept the customer can improve quality and save money!

Q. You recently won an award for the new automated optical inspection (AOI) system that can be embedded directly in the selective soldering process. Is the AOI feature compatible with other systems besides the Power Selective?

A. The success with the AOI system in the PowerSelective motivates us to mirror this process in other machine concepts. The market will be surprised by our upcoming introductions in this field.

Q. What type of soldering defects is the new AOI feature capable of detecting?

A. With the unique lighting technology, we are able to see solder balls, non-wetting or insufficient wetting, bridging and missing pins on the bottom-side.

Q. What are some of the benefits of embedding an AOI system directly in the selective soldering process?

A. To use the same axis for AOI as for selective soldering makes this process much more affordable. We recognize the failures early in the line and can interlink them to the process data of the soldering process. Further, we can separate all failed PCBs out of production and ensure 100 percent quality for the products leaving our selective solder process. Any product that did not pass the AOI will automatically be transferred to the repair station.

Q. Besides the technical solutions you are offering, how can end-users profit from working with SEHO?

A. Apart from the research projects we are working on, which mainly focus on future technologies, SEHO also works closely with industry partners to bring added value to its customers. These are customer-specific projects on the one hand, but also industry consortiums collaborating on a common approach to whole-line electronic equipment assembly. Additionally, we continuously support customers with SEHO’s outstanding process knowledge, for example with the SEHO Global Process Team or the seminars offered by the SEHO Academy. With the professional development of its staff, every company can achieve added value and reduce its production costs sustainably. Qualified personnel can contribute to the optimum use of a soldering machine. Additionally, qualified employees optimize processes to improve production throughput, reduce cycle times and increase the level of quality, thus reducing overall cost.

Q. What are the current trends in soldering and how does SEHO manage to keep up with the ever-changing industry?

A. The trends for the future are efficiency and technologies. Both of these are mirrored in all of our products and developments. SEHO offers economical standard solutions and individual solutions for our customers. With this philosophy we keep up with market trends and allow our customers to participate in them.