FlexLink in Conversation: Material flow, line integration, and ergonomics in SMT manufacturing

Material flow, ergonomics, integration

SMT manufacturing faces a paradoxical problem: the lines are highly automated, but production often stalls over small details in the material flow. Transport problems, missing buffer modules, or insufficient traceability can be just as costly as machine downtime. 

Together with our partners, we want to eliminate these bottlenecks. To this end, we spoke with Christian Werner, Business Development Manager PCB/Electronics DACH at FlexLink. He explains why line integration, ergonomic workstation modules, and intelligent buffer systems are crucial—and how collaboration with CTS makes manufacturing more stable and competitive.

Your new system relies on contactless identification. What specific sources of error in everyday use does this eliminate?

Many electronics manufacturers still rely on traditional labeling on the assembly module - a process that causes more problems than it solves. “Labels slow down the line cycle, are not particularly durable, and are often applied late in the line,” explains Christian Werner. This makes complete traceability virtually impossible - and over the years, the high costs of consumables add up.

With the new 1-LV-R laser marking system, FlexLink is taking a different approach: contactless marking takes place right at the start of the line. The laser source does not wear out and applies codes of all kinds to the circuit boards permanently and reliably. “This not only saves money in the long term, but also offers our customers the flexibility they need for changing production requirements,” says Werner.

Your three-stage excavation station can remove defective circuit boards directly from the flow. What does this mean for yield and cycle time stability?

A common disruptive factor in SMT lines: defective circuit boards block the material flow and disrupt the cycle. FlexLink addresses this problem with a three-stage good/bad removal station. “The line cycle remains stable – and at the same time, the yield increases,” explains Christian Werner.

The increased capacity gives the operator valuable time to analyze errors and stabilize the process without bringing the entire line to a standstill. An additional advantage is that the solution is significantly more cost-effective than large buffer towers.

Your FIFO buffer module regulates cooling after reflow. Why is precise cooling a basic requirement for quality and rework?

Quality control in SMT lines has changed dramatically in recent years. Modern 3D AOI systems operate with high resolution and reliability – but also detect even the smallest deviations. “With today's AOIs, you can quickly, reliably, and effectively detect the proverbial fly in the ointment,” explains Werner.

However, this sensitivity has a downside: even the smallest disturbances, such as excessive temperatures on the circuit boards after reflow, can produce false error results. “That's why you have to be very careful to ensure that the boards are cooled down sufficiently before they go into the AOI.”

This is where the FIFO buffer module comes into play. It supplements the cooling zones of the oven and allows the operator to set the cooling time for each individual board. “This prevents pseudo-errors and ensures that the AOI results are reliable – without unnecessary rework and without compromising process reliability.”

Your workstation module combines automation and ergonomics. How important is the human-machine interface for the future of modern SMT lines?

Artificial intelligence has greatly improved inspection systems in SMT manufacturing in recent years. However, despite all the progress that has been made, one thing remains true: humans are still indispensable. “No matter how good modern inspection systems have become thanks to AI, it is still humans who train these machines,” says Christian Werner.

Even supposedly perfect systems make mistakes – and in the end, it is the skilled worker who checks, corrects, and ensures quality. “This is the only way to maintain a consistently high yield,” he emphasizes.

FlexLink combines automation and manual labor with ergonomically designed workstation modules. Here, employees can inspect, restock, and check components without disrupting the workflow. “No matter how far automation has come, well-trained skilled workers cannot be replaced so quickly,” says Werner.

Which technical interfaces are the biggest stumbling blocks in today's SMT lines—and how do you address them with modular concepts?

Hardly any production manager can do without them, and yet they are the biggest source of errors: interfaces. “We encounter a large number of them every day,” explains Christian Werner. "There are highly standardized and proven interfaces, new ones that are yet to become standard, proprietary solutions from third-party providers, and finally customer-specific connections to ERP or MES systems.

In PCB handling and interlinking in particular, these transitions determine whether a line runs smoothly or comes to a standstill. FlexLink deliberately addresses this complexity in a modular way. “Our systems are designed so that we can work with standardized or customized solutions depending on the requirements. This allows us to seamlessly connect processes and take a leading role in horizontal communication.”

Where do you see European electronics manufacturers in comparison to Asia and the US - and how does your technology help them remain internationally competitive?

The requirements for electronics manufacturers vary dramatically around the world. “In Central Europe, there is a lot of engineering and, above all, small series production. In Asia, on the other hand, large-scale series production dominates – often with the same products for years on end, without the line ever being changed,” explains Christian Werner.

There is also a difference in terms of personnel: while highly qualified specialists work on the lines in Europe, the level of training in Asia is generally lower. This has an impact on the technical requirements. “European manufacturers need highly flexible systems that can be set up very quickly – not least because labor costs are significantly higher.”

Safety and flexibility often play a lesser role in Asia, with the focus instead on efficiency in mass production. “We are familiar with these differences from our daily work and develop systems that suit both worlds. But the requirements could hardly be more different.”

Your extraction station can remove up to three faulty circuit boards at the same time. How big is the difference in throughput if this does not happen on a daily basis – and how do production managers immediately notice this bottleneck?

In SMT lines, it is often not the major defects but minor malfunctions that prove costly. One example is defective circuit boards that are not removed from the process in time. “If the operator is busy with other modules or loading magazines, this can very quickly lead to a line stoppage,” explains Christian Werner

This risk can be significantly reduced with a three-stage removal station. It picks up several defective boards at the same time, thereby stabilizing the material flow and preventing a drop in throughput. The difference is immediately apparent to production managers: instead of unplanned stops, the cycle remains constant—and the line remains productive.

With the FIFO buffer: To what extent does the quality after reflow depend directly on whether the boards “cool down” properly - and how much rework can be avoided as a result?

At first glance, the temperature of the circuit boards after the reflow process does not seem to be a major issue. In fact, however, it determines how stable a line runs. If boards are not cooled down sufficiently, the number of pseudo-errors at the AOI increases dramatically.

“It doesn't directly damage the boards themselves if they go into the AOI too warm. But the testing systems are extremely sensitive,” explains Werner. The result: false error messages, additional testing effort, and unnecessary rework.

A FIFO buffer with integrated cooling acts as a stabilizer here. It ensures that the boards enter inspection at the correct temperature – the line cycle remains constant, the pseudo-error rate decreases, and output increases.

Many lines stop due to minor transport problems. Where are the biggest weak points in material flow in practice - and how have you addressed them technically?

It is not always complex errors that bring an SMT line to a standstill. Often, a minor cause is enough. “Many people don't want to believe it, but most transport problems arise simply because machines or modules shift unnoticed,” explains Werner. A typical scenario: An employee leans against a transport module that is not fixed in place – and the circuit board gets stuck at the transition.

The result: the material flow stops, the line comes to a standstill. Technically, this risk can be easily and permanently avoided. “Our recommendation is to anchor the modules firmly to the floor. Doweling may sound trivial, but it reliably prevents processes from being interrupted by such minor issues,” says Werner.

Many projects fail at interfaces: the machine supplier blames the conveyor technician, who blames the automation engineer. How do you ensure that this discussion does not arise in your company?

When projects stall, the cause is rarely the machine itself—it is almost always the interfaces. A classic scenario: the machine supplier refers to the handling manufacturer, who in turn refers to the automation specialist. In the end, the manufacturer is left with a line that is at a standstill.

“We avoid this by defining interfaces clearly and bindingly,” explains Werner. Standards apply at the horizontal level that leave no room for interpretation. And where special solutions are needed, FlexLink relies on early coordination with all third parties involved. “We test such interfaces intensively before the machines even arrive at the customer's site. This ensures that integration does not become a risk.”

When a line comes to a standstill: Who takes responsibility—and how do you coordinate this between AdoptSMT, FlexLink, and CTS?

When a line comes to a standstill, one thing is crucial for the manufacturer: quick help. Who is ultimately formally responsible plays a secondary role at this point. “There are numerous possible constellations for how responsibility is distributed – but the crucial thing is that the service works,” explains Werner.

FlexLink sees itself as a manufacturer that supports the sales force in selecting the right machines, provides advice, and also provides service support after the purchase. What makes the collaboration with CTS and AdoptSMT so special is that each partner contributes its own strengths without the customer having to manage three different projects. “For the manufacturer, it basically doesn't matter who they buy from – the consulting, support, and ultimately the service are all interlinked. It is precisely in this three-way constellation that we are extremely powerful.”

From the customer's perspective: What is the tangible advantage of having three specialists in one team - instead of three quotes and three contact persons?

For pavers, it makes a big difference whether they have to coordinate three separate offers or have a well-coordinated team at their side. “Our customers can rely on us not only to act as a team, but also to work as one,” says Werner.

Each partner contributes its area of expertise: AdoptSMT with spare parts and refurbishment, CTS with warehouse and intralogistics solutions, and FlexLink with line integration and handling. Instead of working side by side, their expertise intertwines. “This gives our customers the best possible support – far beyond individual solutions. That's what makes our partnership unique and creates added value that couldn't be achieved alone.”

In Europe, production lines are often smaller and production volumes more variable than in Asia. What technical differences does a European production line need in order to run profitably?

A direct comparison shows that European SMT manufacturing differs fundamentally from that in Asia or the US. While large series run over long periods of time there, smaller orders and frequent product changes dominate here. “This means that our lines have to be much more flexible and can be converted more quickly,” explains Werner.



Added to this are higher labor costs in Europe, which further increase the pressure on efficiency. Variability is therefore not a nice-to-have, but a prerequisite for profitability. “We rely on intelligent software solutions that automate product changeovers and massively reduce setup costs.”

The result: European manufacturers remain competitive despite smaller series and higher costs – not through sheer speed, but through their ability to respond flexibly and precisely to changing requirements.

What role does automation play in a high-wage country—is it cost reduction or rather risk minimization against a shortage of skilled workers?

In high-wage countries such as Germany and the US, automation has long been more than just a question of efficiency. “Of course, cost reduction is the main focus – the higher investments in automated systems quickly pay for themselves through reduced personnel costs,” says Werner.

But the reality in factories shows that it's not just about money, but also about the shortage of skilled workers. “In the past, well-trained electronics technicians worked on the production line. Today, it is often retrained hairdressers or bakers. With highly automated systems, even they can reliably operate the processes after a short training period.”

Automation thus becomes a double lever: it reduces costs – and at the same time compensates for the gaps that the labor market is leaving behind more and more clearly.

In practice, do you see that customers today tend to prefer “step-by-step” solutions (e.g., starting with a smart warehouse) rather than going straight to full automation?

Many manufacturers ask themselves the question: Should everything be automated at once, or is it better to do it in stages? “You shouldn't rush into anything. The path to the smart factory works best step by step,” says Werner.

A master plan is important, but experience shows that projects change along the way and priorities shift. “That's why it makes sense to start with a smart warehouse and gradually replace or retrofit the input and output devices on the lines. Magazines can still be transported manually at first – and the AMR will follow later.”

This approach not only saves money, but also keeps production flexible. Those who take this approach remain capable of acting even when market conditions change – and build the smart factory on a stable foundation.