The reason why Isabellenhütte developed Snubber Shunts

The background for the development were customer requests for the use of our low-ohmic shunts as electrical RC snubbers in the automotive and energy sector.

The use of electrical snubber shunts usually requires a high pulse load, ideally with a compact component design. Isabellenhütte's low-ohmic shunts are characterized, among other things, by a high pulse power rating and low inductance combined with a compact size. These factors can often be critical to the application of a resistor as an RC snubber component.

In particular the compact size, low inductance and our flexibility regarding the production with individual film thickness as well as customized resistance values were decisive factors for the inquiry to our company.

The product and its function

An RC snubber (resistor-capacitor snubber) is a combination of two components - a capacitor connected in series with a shunt. Depending on the current and voltage requirements, these components must be dimensioned accordingly.
The function of the complete snubber element is to neutralize interfering high frequencies or voltage peaks, which usually occur when switching inductive loads if the current flow is abruptly interrupted. It is used to achieve better electromagnetic compatibility, for spark suppression at switching contacts and to limit the rate of voltage rise on semiconductor switches (thyristors, IGBTs, bipolar transistors). If this cannot be guaranteed, the device could be destroyed in the worst case by voltage peaks, for example.
At the same time, however, the snubber element may only increase the circuit losses minimally so as not to impair the efficiency of the overall system.  
A balance of the shunt in terms of low resistance value and high pulse power rating and low inductance is therefore very important.

Difference in contrast to our conventional shunts

In contrast to our standard products, the snubber shunt has to withstand a much higher pulse load. In contrast to most applications of our products, such as current measurement, the precision or drifts of RC snubbers play a minor role, because the focus is not on current measurement, but on damping and limiting pulse energy.

Most shunts are only rarely exposed to high pulse loads, while the shunts of an RC snubber are designed exactly for such continuous pulse loads and must withstand significantly higher and more pulses over their life cycle.

What is special about Snubber Shunt of Isabellenhütte in contrast to competitor products

Our product has significant advantages due to the material properties: We use a metal film whose thickness can be adjusted according to the pulse load requirements. The unique design allows a significantly higher pulse load in a compact space compared to wire wound resistors. The thicker the film, the higher the threshold of the pulse load.

Typical use cases and application areas

RC snubber links are used in many applications. Frequent applications are MOSFET circuit breakers, power relays, contactors, etc., for e.g. motor controls or also HVDC applications for DC remote transmission in offshore wind farms.

Manuel Dietermann, Ingmar Georg

Semiconductor inspection equipment equipped with an electron microscope for inspecting wafer surfaces. The electron microscope has two positions requiring precise current measurement. One is for controlling the magnetic field to focus a camera on an evaluation sample and the other is for accurately moving a sample onto a plate. 

Market needs: 
On a 5-year cycle, semiconductors (IC chip, memory) are getting smaller and wafers are structured with more layers, making it difficult to detect failures on the wafer surface. Therefore, the accuracy of inspection equipment also needs to be improved continuously. Typically, a 3 ppm/K shunt is required for such high-precision inspection equipment.

Technical advantages:
The AZ-H contains four terminal shunts with precise tolerance and low TCR. Remarkably, its power rating is 3W of rated power (10W on a heatsink) at 95°C terminal temperature, which is somewhat higher than competitors’ products. Therefore, two competitor shunts can be replaced with one AZ-H, resulting in more accurate current measurement.

Ryota Katsube
Sales Manager Japan

In a distribution project of our partner CODICO, one of the top power tools manufacturers for high quality cordless drills requested a precision shunt meeting their high demands especially for motor control measurement.
In addition to Isabellenhütte, considerable competitors were in use. All manufacturer types were approved by this manufacturer.

With its BVT-M-R001-1.0, Isabellenhütte was able to meet all specific parameters without compromise, which put us in a very good initial position.
Basically, the global acting manufacturer prefers to work together with international assemblers. They leave the procurement of materials exclusively to EMS partners.
In this specific project, two Chinese assemblers from Shenzhen were commissioned, who were also jointly awarded the contract by the manufacturer.

For our partner CODICO, this complex project posed a major challenge, which was mainly due to A) DAP Hong Kong and B) the currency risk.
After an exciting bidding auction End of October, 2020, our partner CODICO was awarded the contract for this project. The excellent cooperation between CODICO and Isabellenhütte was the cornerstone for this success story.

Kevork-Deniz Vartan
Distribution Sales Manager

Isabellenhütte has signed contracts with various branches of Fujitsu Electronics (short: Fujitsu) globally. Together with KAGA in Japan, Fujitsu Electronics becomes the first global distribution partner of Isabellenhütte.
 
As a global company, Fujitsu has offices in countries all around the world. Fujitsu does business throughout the world, backed by a global network of R&D, manufacturing, data centers, system integration, consulting, sales and support operations. Fujitsu draws upon its collective expertise and resources to provide world-class technology and platform products, while also taking advantage of a strong multinational presence to deliver locally-optimized services and solutions.
We all believe that this agreement can furthermore generate a synergistic effect on both companies by the facts that Fujitsu will be able to enhance their product portfolio with our products and we will also be able to have greater access to untapped customers as well as undeveloped markets through Fujitsu’s global sales network, which will result in strengthening the market positions of both companies.

Anton Roth
Global Director Sales Components

With the recent signing of the contract between us, we are pleased to announce that Distrelec Switzerland AG has now officially become our global high service distributor for precision and power resistors.
Distrelec Schweiz AG, headquartered in England, acts as a worldwide catalog distributor, and the intention is for it to cover the area of demand creation for our standard products.  As a globally active company, Distrelec has numerous branches around the world offering consulting, sales, and support services. The stock on hand, which covers the majority of the Isabellenhuette portfolio, can be called up at any time, ensuring uncomplicated and, above all, fast delivery at all times, especially in the small quantity segment. The addition of our products will result in an expansion of Distrelec's portfolio, which will in turn offer improved access to previously untapped markets, thereby potentially generating synergy effects for both parties. We therefore expect the market position of both companies to be significantly strengthened.

Claudia Debus
Distribution Sales Manager

As part of our Isabellenhütte FMx sales and marketing promotion, we are going to launch a product campaign via various digital and analog channels to help us reach the most important players, such as strategic buyers, developers, and constructors.

In addition to search engines and social media campaigns, we will create a dedicated landing page exclusively for the products with the main features and launch advertising campaigns with the industry portals that are most important to us, for example Aspen Core, Bodo´s Power System, Elektronik Industrie, and IEEE in the U.S., in the form of editorial features, white paper publications and ads. We are also going to make an explanatory video and offer  a webinar for existing customers and new leads, as well as providing images, STEP files, and banners for your use.
We will share the listed marketing materials for local use with you via e-mail to support your sales promotion activities on a case-by-case basis.

The next event is the Wide Bandgap Conference 2020 on December 9, 2020, at which Thomas Otto, Head of the Technical Competence Center, will present application solutions based on the FMx and WAx series. Feel free to join the virtual conference, for which you can register here: www.power-conference.com

Corinna Roth
Marketing Manager

With a view to the company development in the coming years, within the framework of the corporate strategy 2020, Isabellenhütte started to think about the long-term development at the Dillenburg site in 2016. This resulted in an integrated site development program, which also included a realignment of logistics.

Since logistics as a support function is jointly responsible for the success of the company, it must also keep pace with the further development of the company and design processes efficiently. In the "New Logistics Conceptual Design," management was presented with approaches that would support the development of logistics in consideration of the corporate strategy, as well as making additional storage capacities available.
At the start of the project, transport matrices, Sankey diagrams and data analysis were used to identify the problems. The results showed insufficient storage capacity, an inhomogeneous material flow, high internal traffic volume and a complex control and feedback structure.

Looking at the entire company environment, 80 different transport relationships have been identified, which are reflected in approximately 200,000 annual transports. Accordingly, about 13,000 km/year were covered to distribute goods. Transportation outside the production buildings alone accounts for approximately 33% of the transport intensity.
With regard to order picking in the components area, massive growth of approximately 200% was forecast there for the next four years, so that the challenge of > 100 order picking processes per hour would mean a high order picking and sorting effort for the future. Accordingly, the goal was to increase picking performance and improve ergonomics while optimizing space utilization. In cooperation with the start-up company "Motion Miners,” for example, it was found during the project that approx. 40% of order picking activities are carried out in a bent over position.

With the evaluation of the actual situation, various scenarios were worked out, so that in the form of a dual comparison together with the management, a final variant was decided upon.
Finally, at the end of 2018, the decision was made to build a future-oriented and flexible logistics system at the end of the premises and to connect it to the existing goods receiving area.
By the planned construction of a connecting bridge to the highly frequented production building of components and measuring technology, approx. 8,000 transports/year could be reduced and goods could be distributed dry and clean in the form of new delivery concepts.

The traffic volume for deliveries and departures was moved outside the company premises and creates greater efficiency in the process flow with three loading docks. At the same time, the accompanying delivery concept was supplemented by a new access road and the road leading around the company premises was widened by 7.5 m

However, the immediate proximity to the Nanzenbach, as well as the devastating subsoil at the planned location, unintentionally led to creative solutions.
Soil samples have shown that the subsoil is not load-bearing, so that a pile foundation with 6 m long concrete piles and a distance of 1.5 m to each other would have been necessary. In view of the costs, it was decided to build a basement to centralize any supply technology from Isabellenhütte and to create additional storage facilities. This was constructed as a watertight tub with a 60 cm high load-bearing floor slab, whereby approx. 6,000 m³ of earth was excavated.

Thus, the best was made of it and within 15 months a new logistics building was constructed, which is 58 m long, 30 m wide and 12 m high. The gross floor area over 4 floors amounts to 2,900 m², whereby a total of 25,500 m³ of space was converted. In the building itself, 2,200 m³ of concrete and 360 tons of steel were used.
The two 10 m high storage lifts are also located in the basement mentioned above. These extend through an opening in the false ceiling to the top level of the pallet racks. The new picking system for the products of the components works in parallel and communicates as well. This ensures multi-order picking and, for example, 16 orders can be picked simultaneously. A so-called Pick-by-Light system shows the employee which product he has to pick up and where it should be stored. The picking principle has been adapted from an ergonomic point of view and now ensures a goods-to-man principle. Thus the basic storage area was reduced by 70%, the storage capacity increased by 50% and the bending activities during order picking were completely eliminated!

While on the ground floor, the employees take care of the operative logistic processes, the first floor accommodates the administrative areas of logistics, the incoming goods test laboratory and the test equipment monitoring, which has shortened transport and communication routes. The elevator there finally takes you to the bridge. Various materials are provided there to supply and dispose of production.
Due to the coronavirus pandemic and the resulting restrictions, the logistics building was officially opened in September 2020 after a delay. In addition to the words of the management, Mayor Michael Lotz as well as the general contractor Achim Schäfer (KuBus) praised the successful new building.
Correspondingly, a heartfelt thank you goes out to all those involved in the project, since construction was carried out despite these coronavirus times and the project was successfully completed with a special effort in terms of time and costs.
       
Key facts at a glance:

• All inflows and outflows are centralized by logistics
• No external factory traffic on the company premises
• Direct connection of components and measurement technology to logistics
• Expansion of logistics to an internal service provider
• Breathing storage capacity - higher agility
• Interdisciplinary processes are designed efficiently and waste is avoided
• Creation of intelligent supply and delivery concepts
• Usable additional space in cleared existing buildings
• Efficient and modern picking strategies

Stefan Keseberg
Head of Logistics