With three selective soldering systems and two wave soldering systems we bring your success into series production

We also precisely implement your wishes for PCB assembly in THT assembly. With our own parts warehouses on site, we guarantee fast processing and delivery. We would be happy to discuss your order directly with you. Why should we be your contractor for THT assembly? That’s what we show you here. Feel free to write us in a few words what project you have in mind – and we will call you back.

What would you like to know more about on the subject of THT assembly?

On-site component warehouse for fast response time and reliable production of your THT orders

We have a well-stocked component warehouse at our company headquarters in Huntlosen. This is the best starting position to be able to react quickly. That is why we buy strategically worldwide – even independently of specific orders. This means that we can usually react immediately when you have an order for us to place.

THT is the abbreviation of the English term “Through Hole Technology”. THT assembly is always used when wired components are inserted into through-hole plating on the PCB and then connected to the PCB by a soldering process. THT is another technology besides SMD assembly, in which components are applied to the top of the PCB.

The advantages of THT assembly

Although SMT assembly has become increasingly important in recent years, THT assembly remains indispensable. THT assembly creates a strong connection between the components and the PCB. This makes them ideal for larger components – such as transformers and semiconductors – that are exposed to high power, high voltages and mechanical stresses.
Since the components are literally pushed through the PCB, they withstand environmental stresses more reliably. THT components are also easily interchangeable, which is optimal for prototyping and testing.

We carry out all preparatory work from careful component preparation to precise soldering

In order for us to be able to install all components, manual component preparation is often still necessary for THT assembly. Our employees adjust the wires of the components to the exact length and shape. We shorten, bend or bead the wires if necessary in order to optimally install the component on the PCB for its intended purpose.

A printed circuit board is assembled by hand with THT components

The right soldering process for your PCBs in THT assembly

THT assembly is through-hole plating, which creates a vertical electrical connection between the track levels and the PCB. The connection is usually realised by an internally metallised hole in the carrier material of the PCB. The wires of the components are inserted through these holes. They are then soldered to the underside. We have three different soldering processes for this.

1. Wave soldering machine

The boards travel through the wave soldering machine in a special soldering frame – this triggering the respective soldering programme by means of a transponder. The solder bubbles past the underside of the board. It wets the underside, but only adheres to the pins and ensures permanent contact after cooling. So with the wave soldering machine we can solder a complete PCB in seconds. Wave soldering is also very reliable. Combined with speed, this feature makes wave soldering ideal for large-scale PCB assembly. A wave soldering machine consumes small amounts of solder because the solder is reused.
We use our ERSA wave soldering system for soldering with leaded or lead-free solder.

Eine Leiterplatte, die in der THT-Lötwelle verlötet wird

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2. Selective soldering system

In the selective soldering system, the solder is dispensed from a small nozzle. This automatically moves under the PCB and applies solder joints at defined points. The closer the distances between the components, the smaller the solder nozzle must be. The distance from SMD components to THT solder joints should be at least 2.5 millimetres for machine selective soldering. Our ERSA selective soldering systems are equipped with 1-crucibles or 2-crucibles for lead-free solder. Selective soldering usually works in three steps:

  1. Apply flux. A flux improves the wetting of a pin to be soldered and removes any oxide layers that may have formed. The flux also reduces the interfacial tension.
  2. Preheating and PCB assembly. Preheating helps to optimise the soldering process and avoids thermal shock.
  3. The actual soldering with a solder nozzle. This is adapted to the specific requirements of the board.
Ein Bildschirm, der einen Ausschnitt aus dem Prozesse des selektiven Lötens anzeigt

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Here you will find a deep insight into the processes and the advantages and disadvantages of selective soldering.

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3. Hand soldering

In some cases, our employees also solder by hand. This is the case, for example, if the number of pieces is small. This saves us the initial costs of automation. We also solder temperature-sensitive components such as batteries or cables by hand. Moreover, manual soldering supports machine selective soldering if components have already been applied to the underside using the SMD process.
All our soldering processes take place using inert gas. We use nitrogen for this, which displaces the oxygen and thus prevents unwanted oxidation. The advantage: You get a visually and technically flawless soldering result.

Eine Leiterplatte mit THT-Bauteilen wird manuell gelötet.

Your technological advantages with A+B Electronic

  • Whether prototype, small or large series in THT assembly: We implement your idea through our precise manufacturing.
  • High component mix? It’s no problem for us, of course. We plan the assembly efficiently.
  • We test the technical feasibility of your order in advance.
  • We optimise the set-up for efficient production of your assemblies, if you like. We are happy to work closely with your development department to achieve this.
  • We plan material logistics for the long term through international purchasing and efficient on-site warehousing.

Our Ersa VERSAFLOW soldering machine for flexible soldering

We use the Ersa VERSAFLOW 4/55, a selective soldering machine of the latest product generation. It ensures a flexible production flow with two soldering modules. The integrated CAD-4 assistant also makes it possible to create the soldering programmes already offline in order to change products more quickly.

How we realise your projects as an EMS partner

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“A+B Electronic is a reliable and trustworthy partner with whom we have had a very good business relationship for many years.”

Manfred Meereis, Plasmatreat GmbH

A+B Electronic in 2023




customer projects


assemblies delivered

85 million

components installed

Printed circuit board assembly is becoming more and more demanding: We install components in a large mix in smaller and smaller sizes. We use our broad range of machinery to implement your order in a targeted manner, and we also optimally equip special component geometries. You want short delivery times for small series as well as for large series. Thanks to our strategic purchasing and warehousing, components are reliably available at short notice. This is how we minimise delivery times.

The individual steps of THT assembly

  • Assembling the printed circuit board with the THT components
  • Soldering with the solder wave, selective soldering or hand soldering
  • Revision and manual visual inspection
  • Functional check and final quality check on request

Our quality control for THT assembly

After THT production, all assemblies are carefully checked. Because intensive quality control is a matter of course for us. If errors are detected, they are corrected by our revision staff. This means that only flawless parts arrive at your premises or directly at your customer’s premises. Learn more about our quality assurance here.

We deliver – also directly to your customers

You decide whether we send the fully assembled assemblies to you or directly to your customers. Our delivery service offers individual packaging options. For you, this is an opportunity to outsource the logistics to us as well. You may notice: We are more than your extended workbench. Take advantage of our expertise and routine in the field of logistics and unit assembly.

We will be happy to advise you after the pilot series

We approach PCB assembly in partnership with our customers. Consultation is therefore a natural part of product development for us. And even if consultation and some involvement in development is not part of the current mandate: If we notice something about the assembly, or if we have a bellyache about an arrangement, we will get in touch with you immediately. We think along with your project.
After you’ve tested the pilot series in use, we’ll be happy to advise you – and look for optimisation possibilities together, if need be. The organisation of our production is flexible in order to be able to respond to new requirements at any time. Do you work with regularly recurring orders? We proactively approach our customers to ensure the availability of all components without waiting times.

Assembled printed circuit boards are packaged in an ESD-compliant manner
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PCB assembly at A+B Electronic: Quality Made in Germany

When you choose A+B Electronic, you secure the advantages that Made in Germany brings you:

  • High availability and fast delivery times
  • Careful production by our trained staff
  • Direct contact for ordering and service at our head office in Lower Saxony
  • Transparency across the entire supply chain: Production and working conditions, materials, compliance with environmental standards
Other Services

With two modern production lines, we can precisely assemble versatile component sizes from 01005, a high component mix and components with special component geometries and solder them in reflow ovens.

Our service as an EMS partner if you want to outsource your unit assembly.

For additional quality control, we offer you joint planning of a test concept for your assemblies or devices.