Electromagnetic Shielding and Sealing (EMI/RF)
(Electromagnetic Compatibility)

Electromagnetic Compatibility (EMI/RF)

The electromagnetic compatibility (EMC) is the ability for an equipment to work without generating or undergo electromagnetic interferences or disturbances.

Electromagnetic Interferences

Electromagnetic interferences might be generated by high tensions, radiofrequencies, or thunder for example. Several normes certify the ability for an equipment to be compliant.to electromagnetic interferences (EMI).
The electromagnetic interferences are transmitted from one electronic device to another by radiation or conduction through printed circuit track or connectors (PCB).

The necessity to master the electromagnetic compatibility of the equipment

Every systems are exposed to magnetic fields (low frequencies) and electromagnetic fields (high frequencies). All is a mater of measure and control. The level of electromagnetic compatibility must comply to local and international legislation. The equipment must be functional without disturbing close electronic equipment.
Without taking into account the electromagnetic compatibility (EMC) these electromagnetic perturbations can lead to major dysfunctions or general failures on complete installations. For example, in the industrial sector. The presence of electronic equipment subject to electromagnetic interferences means that the constraints in terms of electromagnetic compatibility must be seriously taken into account both at the component level and at the equipment level.

Principe de la protection électromagnétique - Compelma la compatibilité électromagnétique

A strongest security against electromagnetic interferences (EMI) is required in control and measurement installations. the main goal is to minimize the radiation and thus prevent interference with other areas or equipment.

Application Field of Electromagnetic Compatibility (EMC)

Every fields are concerned by the Electromagnetic Compatibility (EMC). Compelma team is working every day on worldwide electromagnetic projects. As defence, aerospace, IT, telecommunications, medical and industrial.

How does Compelma work on your Electromagnetic Compatibility (EMC) Projects?

Compelma engineers have an extensive background on electromagnetic compatibility (EMC) projects, especially for each kind of field and industry. Compelma handles the protection against EMI and RF on your electronic project. Our goal is to let you concentrate on your activity and your add value. Compelma makes you earn time and costs, for a better efficiency on your projects.

Electromagnetic Shielding (RFI/EMI)

Electromagnetic shielding is mainly used to protect electronic equipment from electronic parasites and radiofrequencies interferences. The electromagnetic shielding is based on the Faraday cage principle. The goal is to reflect electromagnetic fields or to absorb these EM waves.

Principle of the Electromagnetic Shielding (EMI, RFI)

Blindage électromagnétique - Compelma la compatibilité électromagnétique

How to Choose the Correct Technology for Electromagnetic Compatibility (EMC)

Compelma advise you to about the best material and design for each setup and configuration, for an efficient electromagnetic shielding. These EMC/RF shielding products avoid that the electromagnetic fields, enter or leave a specific equipment.

Example of an Electromagnetic Shielding (EMC)

For example, in the case of a microwave, the mesh laminated with the window blocks the electromagnetic waves that heat the food. Light waves, with a shorter wavelength, pass through the mesh (even if it is also electromagnetic waves).

A Complete Setup for Electromagnetic Shielding

Compelma ensures a complete providing of your electromagnetic shielding setup. The EMI shielding of the electrical circuit and the sealing (EMC and IP). The electromagnetic shielding of your electronic equipment is tailor made by Compelma for the highest efficiency and by taking in account :
- The material compatibility (soldering compatibility and galvanique couples)
- Use and environment constraints
- Mechanical strengths and constraints (load, assembly process, fixation, dimensions, tolerances, weight...)
- Material and process costs

Concretely, What are the Solutions for Electromagnetic Compatibility (EMI and FR)

Compelma provides different EMI/RF products (standard or custom) depending on your specifications. Each project is studied to choose the best technologies and products for your electromagnetic problematics.
To isolate and protect electronic components and openings:
- EMI/RF Cover and Frame, custom or tailor made
- Mesh for ventilation opening
- Conductive foil and mesh
- Copper Mesh film
To absorb electromagnetic waves by Joule effect:
- EMI/RF absorbers (Ferrites and Loaded Foam)
- Loaded elastomers and Silicons (extruded, cut, molded)
For connection and grounding:
- Spring finger contacts (SMT)
- Metallic gaskets
For EMI ad IP sealing:
- Wire oriented silicone
- Loaded silicone gasket
- Bi-material gasket (silicone and loaded silicone)

Integration of Electromagnetic Shielding

We strongly advise to think about the electromagnetic compatibility (EMC) at the beginning of any electronic project. Electromagnetic interferences are often observed and measured too late during the conception of electronic products. A product blocked for commercialization just after the final electromagnetic tests is really expensive and penalazing.

Good Practices for Electromagnetic Compatibility on Electronic Assembly

Few good practices must be applied during the complete conception process.

Deflectors / Chicane to Prevent Electromagnetic Leaks

Using chicanes for assembly to get the larger cover surface between two elements.

Chicanes dans un assemblage électromagnétique - Compelma
How to Assemble Partition to avoid Electromagnetic Leaks

the same logic is to apply for assembly between partition. The contact must be maximal between the two parts of the assembly. It helps to contain electromagnetic waves.

Assemblage compatibilité électromagnétique Compelma - CEM - EMI
Galvanic Couples and Electromagnetic Compatibility (EMC)

Some equipment must work on harsh environment. With humidity for example. The sealing against electromagnetic interferences and fluid is ensured by specific gaskets.
Two different metals with an electrolyte (sea water for example) are working as a battery and will generate a small electrical power.
It might occurs a corrosion leading to diminution of the resistivity and so of the efficiency of the electromagnetic shielding.
Choosing the right material to minimize or avoid natural galvanic process is part of the Compelma expertise.

Couples galvaniques - Compelma, la compatibilité électromagnétique
Gaskets for Electromagnetic Sealing

EMI and RF gasket integration must be anticipated as soon as possible. Indeed the grooves and fixation must be integrated to your electronic conception (especially for high IP sealing specifications).

Assemblage pour une protection électromagnétique - Compelma
Conductivity and Electromagnetic Compatibility

For the highest electromagnetic sealing performances, the grounding contact between mechanical element must be maximal. Compelma team searches and tests every day new technologies and material to keep you at the cutting edge of the technology. Our goal is to propose the materials with the highest conductivity to get the maximal EMI/RF shielding effect.

Assemblage pour une conductivité électronique élevée - Compelma, compatibilité électromagnétique

As Example, our team has develop a transparent Cu Mesh Film for electromagnetic shielding of windows. It is not an ITO film (the most common product with lower performances) but a photo-manufactured copper mesh. The final shielding product is more resistant (especially against oxydation) and conductive (conductivity of pure copper) than an ITO film.

Advices for Electromagnetic Compatibility Integration (EMC)

Our main goal at Compelma, is to advise you on your Electromagnetic Compatibility. for that, we used our technical knowledge and experience to secure your electronic project and developments against electromagnetic problematics.

A Question? A project? Please contact us using the tchat or our contact form. We are pleased to help you.

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Bureau d'étude CEM et thermique Compelma - EMI and thermal management