Dr. Martin Justinek | Process Engineering, BL Sound Solutions, Vienna

As Dr. Martin Justinek sees it, sustainability is about “being fit in the market.” It means always looking for new, better ways to do things, so the company can succeed long term. His recent work with a new wire-bonding process is a perfect example.

Several years ago, when Martin joined the company, BL Sound Solutions was already a recognized leader in loudspeakers for mobile applications, using state-of-theart production lines that had already created billions of successful products.

But Martin and his colleagues in process engineering saw room for improvement, especially with the resistance soldering process used to connect coil wires to a speaker. “The process was difficult to control because it was sensitive to fluctuations in material quality,” explains Martin. “We wanted something more stable with respect to the process itself, so we could achieve higher yield.”

Wire bonding, a technique used throughout the silicon industry, was an option they considered early on. They approached several manufacturers, but found they had special requirements that standard wire-bonding machinery couldn't meet. “Our process uses an enameled wire with isolation on it. That makes a huge difference,” says Martin.

They started looking at other options, but couldn't find anything better than what they already had. Finally, they found a Swiss supplier experienced in wire bonding with insulated wires. “They supplied manufacturers in Asia, but not in the same volumes we have here. What we're doing is new.”

They started with a semi-automated process, then transitioned to a fully automated one. They found that, even running in high volume, the new technique is more predictable and more consistent than the old one. The electrodes used in soldering are replaced with thermodes, which are easier to work with. There's less machinery down-time, and that saves time, money, and energy. An expensive tin-plating process has been eliminated, so the plating process is simpler and cheaper. “Our contact supplier uses fewer chemicals and has less waste to dispose of. Also, since the new contact design has a simpler geometry, our supplier uses less stainless steel and performs fewer punch and bend steps.”

Martin points to other benefits, too. The new contact system is more compact, which is a big bonus in today's miniaturized designs. “Wire bonding lets us create a broader portfolio with new formats, such as printed circuit boards and flexible printed circuits. It also offers the possibility to improve sound performance and, because it's very heat resistant, paves the way for a reflow-solderable speaker.”

From Martin's perspective, the time spent searching for alternatives and experimenting with different techniques was worth it. “The new process gives us the right products at the right time, and that's part of being a sustainable company.”