Picture shows a SLIM.flex PCB

SLIM.flex PCBs

Smallest Design, Biggest Advantages

SLIM.flex – Anylayer Microvia Technology That Inspires

Small, compact, maximally bendable and highly resilient: These are the requirements for modern printed circuit boards. Whether for research or the medical, vision technology or automotive industries, SLIM.flex meets them with flying colors - even with the smallest housing volumes.

Wherever small and ultra-small sensors are required, the ultra-thin SLIM.flex products are convincing thanks to available standards as well as enormous robustness combined with maximum flexibility. Keyword flexible: This also applies to availability. From individual samples to series production, all variants can be ordered from the experts at Würth Elektronik.

Our Know-how – Your Profit!

Advantages of Smart Würth Elektronik SLIM.flex Technology

  • Extremely thin: Fits even the smallest housings thanks to reduction of thickness by up to 70 percent
  • Anylayer via: Each layer can be connected to each other via laser drilled microvias
  • Dielectric strength: Safe dielectric strength of 500 volts – suitable for higher voltages
  • Highest reliability: Very robust in the soldering process (even with multiple lead-free soldering) and optimally suited for harsh-environment applications
  • High-tech cable harness: Ultra dense, impedance defined or shielded signals in a very small space – 100 percent more signals possible in half the installation space

SLIM.flex in the Particle Accelerator at CERN, Switzerland

Application Example

Intensive, verified quality tests have shown that SLIM.flex can withstand even the highest temperature stress and thus qualifies for use in highly demanding environments. It is not without reason that SLIM.flex is installed in detectors of the world's largest particle accelerator, among others.

SLIM.flex will be installed in the detectors of the new CERN particle accelerator.

Detector in the Lhc Particle Accelerator Cern

SLIM.flex as a High-tech Cable Harness

Application Example

SLIM.flex technology allows ultra-dense, impedance-defined or shielded signals in the smallest possible space. Compared to conventional harnesses, this allows up to 100 percent more signals in half the installation space. Since there are no restrictions on signal routing and geometry in the design of the SLIM.flex harness, the harness can be designed in a very variable way.

Thanks to the universal layer structure, the number of flex layers can be changed as needed during layout without changing the stackup - and at no extra cost. By manufacturing the "harness" using PCB technology, wiring errors as with conventional harnesses can be eliminated. In addition, a reproducible, consistent arrangement of the signal routing is achieved.

The assembly time of the cable harness is drastically reduced by the use of preformed SLIM.flex, and ZIF contacts also eliminate the need to solder the cables or assemble connectors. A SLIM.flex cable harness can also be used as an integrated cable harness in applications with sensitive signals, for example for the smallest image sensors in endoscopes.

SLIM.flex can also be used as a cable assembly.

High-tech Cable Harness

SLIM.flex Design

Relevant Parameters for Production-ready PCB Design

Man sits at two screens and designs circuit boards

Modern printed circuit board solutions are more than just connecting elements. They are the key to progress in electronics. With this in mind, we actively support our customers in development and also offer our own system solutions with electronic functions.

Design Rules

The SLIM.flex Design Rules include all the important parameters you need to make your project successful:

Design Guide

In our Design Guide you will find an overview of all variants of our flex solutions. In addition, our specialists have summarized valuable design tips for you here. This will help you bring your application to success reliably and safely.

SLIM.flex Standard Stackups

Get Started With Your Layout Faster - Thanks to Standardized Stackups

With these stackups, you automatically use market-customary and cost-optimized standards and avoid expensive special setups. They also enable high-quality, cost-effective production with shorter lead times by using stock materials and following standardized production processes.

Here you can find our SLIM.flex standard stackups both in digital form for import into your EDA software, and as PDFs. The digital stackup files for Altium Designer contain not only the stackup but also the material data.

SLIM.flex FAQs

  • thin copper layer thicknesses even on metallized layers with a maximum of 25 µm allow fine structures. For example 75 µm conductors and spacers as well as 200 µm small solder pads for components.
  •  small dielectric distances between the copper layers while ensuring sufficient insulation enable copper-filled microvias with Ø 70 µm.
  •  optimized copper layout favors optimized solder resist design with 70 µm narrow webs and 40 µm clearance.

The SLIM.flex technology is designed for high wiring density. For this reason, the smallest vias in the form of laser-drilled microvias are used as a matter of principle. PTHs would be technically possible, but would then lead to higher copper layers and the loss of the finest structures.


Depending on the number of copper layers, the standard stackups have a thickness between 0.25 mm for 4 layers and 0.46 mm for 8 layers. Locally higher thicknesses can be achieved by stiffeners.


There are several possibilities for assembling SLIM.flex:

Würth Elektronik can supply your SLIM.flex PCB with an FR4 solder carrier, so that assembly is possible on normal automatic machines. In this case, only the array frame can be glued to the solder carrier, so that the PCB is fully flexible again after it has been removed from the frame.


A typical solder carrier is made of FR4 with a material thickness of 0.80 mm. This gives a total thickness with solder carrier of 1.0 mm for a SLIM.flex 4F-Ri. In the area of the solder carrier, backside assembly is not possible.


Yes, definitely. The advantage is that the thin stackups have only a very small expansion in Z-axis! Tests have shown that even under extreme conditions the circuits are extremely reliable.


In addition to quick samples, we also supply series, gladly also in larger quantities.


Physical PCB Sample WE.scope

Understand Würth Elektronik SLIM.flex Technology Playfully

Learn in detail about the possibilities of SLIM.flex technology in terms of design and applications. The WE.scope hand sample shows the practical implementation of a vision concept from the sensor with illumination and cable harness to the coax connector - and all this in the smallest possible space. This hand sample is available both as a physical hand sample and as a digital hand sample.

Webinars SLIM.flex

"More Powerful Than Ever - The New SLIM.flex Technology"

Ultra-thin. Rugged. Flexible like never before. And on top of that: Available with standards and digital stackups. That is SLIM.flex. The WE Circuit Board Technology PCB of the latest generation.
Find out in our webinar how you can benefit from SLIM.flex and from our competent expert advice as well as a complete delivery process of the PCB from a single source.

 

"Miniaturization, mechatronics, microvia: SLIM.flex PCB sample WE.scope!"

Find out more about SLIM.flex, our anylayer microvia flex technology. Wherever small and ultra-small components are used, such as sensors in micro-packages, the ultra-thin SLIM.flex products impress thanks to the available standards and enormous robustness combined with maximum flexibility. In this webinar we will offer you insights into our hand sample WE.scope and what you can learn from it.

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