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Autonomous Robotic Laser Soldering

How this disruptive new emergent technology is radically transforming the through-hole soldering industry




Hand soldering has been the only reliable method of soldering through-hole components since the earliest days of circuit board manufacturing. In the current state of the job market, hand soldering is becoming a lost art. The talent pool of people skilled in hand soldering is in steady decline. With a slimmer workforce, companies struggle to grow beyond current demand and must focus more of their efforts on attracting and retaining talent.


Companies exploring alternatives are beginning to recognize the power of robotic soldering. However, where many companies go wrong is taking a low-budget, experimental approach to robotics. While conventional manual soldering robots may be simple and inexpensive, they are limited in their capability and require extensive human involvement. Companies who save money upfront buying traditional soldering robots will end up spending far more money on labor hours over the long term. This catches many businesses by surprise when they realize how much of their human capital is tied up with the outdated processes of inferior machines. 


The requirements for design, programming, prep, operation, and rework cause such strain that the benefits of robotics appear negligible in comparison to hand-soldering. As a result, companies who chose to buy conventional soldering robots fall short of competitors who are using the new autonomous soldering robots with significantly greater results.


Most people think of robots as machines that operate independently of humans. In the world of through-hole soldering robotics, this is now finally a reality. After over 20 years of research and development, autonomous underside laser soldering robots are here, and they’re causing a rapid industry-wide paradigm shift. The introduction of autonomous soldering robots has completely obsoleted all previous iterations of manual soldering robots. It’s common to see cycle time improvements of 1,000% or more in comparison to hand soldering or conventional soldering robots. A single autonomous robotic soldering assembly line can even outpace a skilled 10-person hand soldering crew. No technology could replace this skill set until now. 


While the initial cost is comparatively steep, the ROI of robotic automation is magnitudes above and beyond that of manual robots, with minimal long-term labor costs as well. Companies that adopt this new technology are quickly setting themselves apart from their competition by a wide margin. 


Contactless Laser Soldering


Laser soldering began as an ambitious experiment 20 years ago in a high-tech Japanese circuit board manufacturing facility. Laser soldering technology had quickly proven to form solder joints with greater speed, precision, and quality compared to conventional iron tip soldering. And with the bulky soldering iron removed from the equation, machines could utilize multiple soldering lasers and solder wire feed tubes, as well as board scanning cameras, projectors, infrared thermometers, and more.


As components become smaller and assemblies become more densely populated, there comes a greater need for high-precision soldering solutions. Reaching every lead with a soldering iron poses a variety of challenges. For hand soldering, an experienced skill set and surgeon-like approach are required. For iron tip soldering robots, every angle, rotation, and multi-step sloping path must be programmed to avoid damaging components or disturbing other solder joints. Programmers must also compensate for the thermal expansion of the soldering iron to avoid damaging the PCB and shifting the position of the soldering iron. Even when everything is programmed correctly, there are still limitations and reliability issues with the soldering iron. After all, electric soldering iron technology is now over 100 years old. 


Contactless laser soldering completely overcomes the most demanding challenges faced with conventional iron tip contact soldering. For a soldering laser, it simply aims and fires. If it can be seen, it can be soldered. With the utilization of multiple soldering lasers in a single robot, cycle times are vastly superior to hand soldering or conventional soldering robots.


Mechanized laser systems can automatically aim and angle multiple laser beams at a time. This allows lasers to overcome nearly all spatial limitations faced by the soldering iron. Laser beams can also be focused into a variety of shapes and sizes, ensuring precise and highly targeted heating for a wide variety of applications. Integrated infrared thermometers can also be utilized in tandem with soldering lasers to ensure that every lead and barrel reaches the ideal soldering temperature every time.


Laser soldering has truly revolutionized the through-hole soldering industry. Not only do lasers consistently produce high-quality solder joints, but they can also solder complete assemblies in record time, all with less human involvement. Laser soldering has proven to be essential in the achievement of fully autonomous through-hole assembly lines. 


Underside Soldering


Conventional top-side soldering robots have always had one major challenge working against them: gravity. Components must be held in place, upside down, so the leads can be soldered from the top side. This requires IPC-610 approved lead clinching or specially designed suspension fixtures. As assemblies get more complex, securing all the components in place becomes a more time and labor-intensive task. That’s why most conventional soldering robots are only soldering simple, low-complexity assemblies. 


Underside soldering, while very difficult for humans, is ideal for robots in an automated assembly line. Underside soldering works with gravity instead of against it, meaning through-hole components can now simply be placed on the top of a circuit board. No special clinching or fixturing is needed. This allows robots to work together in an assembly line to prep components, stuff assemblies, apply flux, and solder every component, all without human intervention. 


Underside soldering robots are almost exclusively conveyor fed, as they’re designed to accompany other robotics systems to achieve full autonomy. These completed robotics systems are the first of their kind to fulfill the duties of workers across multiple departments. Underside soldering simplifies the process and opens the door to total robotic autonomy. 


Programming Essentials


We’ve all heard the rule, “don’t reinvent the wheel”, but that’s what programmers must do when they manually program a conventional soldering robot. When the coordinates needed to create a program are provided by the common CAD file, it seems primitive to locate each point with a teach-pendant. What might take 10 hours to program with a teach-pendant, may only take 10 minutes or less to complete with modern CAD programming technology.


While CAD data has enabled automation of surface mount assembly and optical inspection machines, through-hole soldering has always been a manual process. Hand soldering is often considered an art form, and replicating that with manual programming isn’t always ideal. Thankfully, the long list of intricate programming requirements can all be taken care of automatically by the modern suite of programming essentials. 


CAD data, board scanning, and projection imaging technology all work together to create detailed 3D maps of every circuit board assembly. Not only does this verify the integrity of data, but it’s also used to automatically locate all soldering locations and create programs that are optimized for speed and accuracy. Volumetric calculators are used to quickly create the ideal solder feed parameters for an unlimited variety of component types, hole sizes, and soldering wires. On top of all this, dry runs can be performed with solder samples to automatically develop laser thermal profiles for every component across an assembly. These tasks were once the most time-consuming requirements for manual programming. Now, they are completed automatically, in record time, and with unbeatable precision. 


No longer do programmers need to spend hours in trial-and-error developing soldering parameters for every unique component. The challenges posed by the unseen inner-metallic layers are now a thing of the past. Paired with automatic thermal profile creation, the need for rework during programming is almost completely eliminated. Superior results are now being achieved faster and easier than ever before, thanks to the modern programming essentials.


Fume Extraction and Dust Containment


Leaded solder has long been a preferred solder alloy for its ease of use and lower soldering temperature. But in Europe, lead has been banned due to its numerous health hazards when ingested. While there are “acceptable” levels of lead exposure, there are still immediate health consequences, as lead can cause irreversible brain damage and nervous system damage after it enters the body.


While most know about lead poisoning, fewer people know about the dangers of breathing flux fumes. Solder fumes containing burnt lead and flux contribute to an array of negative health consequences for those working directly with these substances. Asthmatic respiratory distress is the most common health problem reported by workers performing hand soldering, as they are consistently exposed to solder fumes throughout their careers. Most argue that slight exposure is safe, as long as it’s below the officially acceptable level of exposure. But these substances are still toxic, and prolonged exposure inevitably leads to a degree of health consequences. 


Underside soldering robots are housed within a compact sealed environment where solder fumes can be safely and effectively extracted through internal vacuum systems. This results in a 99.99% containment of solder fumes from being released into the environment. Lead dust is also completely contained within these sealed environments, so it can’t be spread and inadvertently ingested by humans. Companies can now utilize leaded solder without any health risks. Not only is automation simplifying and streamlining production, but it is also making facilities safer and healthier places for people to work.




While the through-hole soldering industry has seen a historic decline in skilled workers, modern autonomous robotics offer an ideal remedy to this problem. Companies looking to scale and expand operations no longer have to work as hard just to prevent stagnation. For the longest time, the human hand has been the only reliable way to solder components where conventional robots and selective solder machines could not. Thankfully, those many intricate requirements are now being fulfilled automatically by robotic assembly lines. 


Recent advancements in robotic soldering have finally brought automation to the world of through-hole soldering. Underside soldering robots are the first of their kind to provide the missing link needed to achieve fully autonomous through-hole assembly lines. Underside soldering makes it possible for multiple robots to work together to streamline the through-hole assembly process. Paired with laser soldering and modern programming technology, the need for human involvement is almost completely eliminated.


Underside laser soldering robots are equipped to consistently produce unbeatable solder quality in record times. And by utilizing this technology in an autonomous robotic assembly line, companies are able to freely scale their through-hole operations, regardless of the state of the job market. This level of autonomy has brought a radical paradigm shift to the industry where now the sky is the limit. 


In order to see the best results with this technology, it is strongly recommended to utilize machines that are designed for cross-compatibility. To see how we achieved seamless robotic integration for fully autonomous through-hole assembly, we invite you to visit our website at ( for a virtual tour of our products. We look forward to seeing you there! 

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