Eagle View: Our THT department
THT at Ginzinger electronic systems
The production of complex electronics consists of many process steps. The THT department is an essential part of the assembly production. It assembles components that cannot be assembled automatically on the SMD production line.
The competent and experienced team led by Stefan Schlägl, Head of THT, thoroughly inspects all customer products on a daily basis.
From machine soldering to visual inspection, manual soldering, depaneling, complete commissioning including mechanical assembly, and finally the installation of software - these are all activities that our THT department performs. The team is responsible for ensuring that customer assemblies are tested, assembled and forwarded to the warehouse ready for shipment.
This is the first process step in the THT department. A team of six takes customer assemblies from SMD production and adds THT components to them, which, for example, cannot be assembled automatically with the SMD line due to their size and weight.
Although the designs at Ginzinger are basically aimed at producing as much as possible automatically in SMT, this is not possible for some components. These include connectors, relays, transformers, DC/DC converters, but also certain capacitors and resistors. They are assembled manually onto the circuit boards by the employees in accordance with the production documentation.
This requires a high degree of concentration and accuracy, but also special sensitivity so that neither the components nor the PCB are damaged during assembly. Subsequently, soldering is carried out by machine using selective or wave soldering.
This is where printed circuit boards and assemblies are inspected. Are all components assembled? Are all components in the correct position? Is the orientation of the poles correct? The soldering quality is also assessed here. If defects or even faults are found, they are reworked and corrected. In advance, the THT visual inspection takes over the inspection of the already assembled SMD components on the printed circuit boards.
Manual soldering is another field of activity. There are components that cannot be soldered by machine. These are reassembled and soldered manually (e.g. temperature-sensitive components). The separation of printed circuit board blanks by laser or milling also falls within the scope of visual inspection.
Soldering processes in THT
In addition to the reflow soldering process, there are three other soldering processes used at Ginzinger:
here, heat and solder are applied to the soldered joint by hand (using the classic soldering iron)
Wave soldering (by machine)
On the Ersa Powerflow full-tunnel wave soldering system, assemblies already assembled are transported under nitrogen by means of a transport system over a solder wave made of liquid solder. In this way, components are soldered to the printed circuit board.
Selective soldering (machine)
With the Ecoselect 4 selective soldering system from Ersa, individual THT components can be soldered quickly, fully automatically and with maximum precision. It is also available for manual soldering. It is ideally suited for small to medium-sized series.
Challenges for the future
In the field of THT, despite the high degree of automation and the fact that the share of THT components continues to decrease, much of the work at Ginzinger electronic systems is still classic "manual work". This cannot be replaced without further ado.
Stefan Schlägl, Head of THT, comments:
"There are components that are delivered in bulk. these cannot be further processed automatically, i.e. with a robot. A classic example of this are varistors or heavy transformers. The "feel" for the correct handling of sensitive components and the trained eye to see whether a solder joint is good or bad can hardly be replaced by automated systems."
Nevertheless, efforts are being made to bridge the gap between manual and automated processes and, above all, to further optimize visual inspection. This is necessary to continuously improve quality and costs.
For Stefan Schlägl, there is also another important issue: error prevention. This already starts with manual assembly.
"Here, we are currently evaluating intelligent assistance systems to check assembled components. Once these are soldered, the components are "married" to the assembly. Subsequent troubleshooting is not an option, as it is very time-consuming and cost-intensive," says Schlägl. Assistance systems then already sound the alarm when components are missing or the polarity is reversed.
These assistance systems are designed to help our employees avoid errors. For Schlägl, it is important that these are assistance systems, not control instruments.
When asked what the benefit of his department is for the customer, the answer comes promptly: "We are there for our customers," says Schlägl. "Our customers can be assured that highly qualified employees are working every day to ensure that their assemblies are comprehensively visually inspected, tested, mechanically assembled, ready to be put into operation and shipped to them. We take care of their products until delivery."