EMI / RFI Shielding products

Photofab supply EMI / RFI Shielding cans and solutions using various intelligent design techniques.

Shielding or screening cans are commonly manufactured in Nickel Silver (maintains solderability with no post coating required), or traditionally in either brass or mild steel coated with either tin or nickel plating (depending on your requirements). The full process is available, including forming, plating, soldering and / or spot welding.

The whole manufacturing process is managed in-house by one of our experienced and technically trained account managers. We can ensure full traceability and offer exceptional lead-times from as little as 24 hours, this service is backed up with ISO 9001, 14001, 18001 and SC21 accredited processes.

Features of EMI / RFI Products through chemical milling

• Solder Joints – Butt jointed corners with tin plate finish, allows corners to be soldered for increased screening.
• Spot Welding – Overlapping joint corners with tin plate finish are spot welded for increased screening.
• Locking Tabs / Locating Holes – an alternative to soldering, allowing greater rigidity.
• Dividers – provide discreet screening within the frame.
• Holes / Cut Outs – can be incorporated as requested.
• Anti Solder Migration Barrier – prevents solder creepage up the sides of its PCB mounting screening enclosures during automated and reflow soldering processes.
• Spring Fingered Lids – easy access and excellent attenuation.
• Push Fit Lids – easy access and good attenuation.
• PCB Locations – lancings or brackets can be specified to act as guides or supports.
• Locking Pins – for exact positioning and retention, deal for reflow soldering applications.
• Half Etch Pins – pins that are easily bent, to lock the shielding can into place.
• Common Metal Types – Copper, Brass, Mild Steel, Stainless Steel and Nickel Silver.
• Common Plating Types – Tin plate (Bright and Electrolytic) and Nickel plate.
• RoHs Compliance – All standard metal used for shielding cans are RoHS compliant. The types of plating we offer will always be RoHS compliant, unless you state otherwise. Please note that Hot Tin Dip is not RoHS compliant.

The Benefits of EMI / RFI Shielding at PCB Level

EMI / RFI Shielding at PCB board level – A deceptively simple technique for controlling EMI (Electro-Magnetic Interference). Perhaps the most common technique to keep harmful interference out and also unwanted emission in.

Solutions at product enclosure level – Why this is unadvisable
Practical EMI shielding requires considerable engineering skill to give good results. However, at product enclosure level, it can be complex and expensive when taking into account both additional material and assembly costs. Also, effective enclosure shielding usually requires substantial filtering of all cables, which pass out of the product right at the point where they penetrate the enclosure shield.

Why use EMI / RFI Shielding at PCB level?
EMI Shielding at PCB level is simple with low cost. Board level shielding solutions can be used to achieve an EMI performance that would be far more difficult and costly at product enclosure level.

At board level, shielding cans can be used selectively on problem areas of a circuit, directly tackling components with emissions that are too high or are too sensitive.

In brief, PCB shielding cans are simple metal boxes that are easily soldered in place. Dealing with EMC problems at this level, ensures component and assembly costs are low and the appearance and ease of maintenance of the product are not compromised.

Effect on emissions
With this method of execution, the circuit board tracking and wiring is shielded inside the can solution. Due to space, contained tracks and wires are consequently very short and not very efficient as aerial radiating RFI or EMI. Furthermore, filtering to reduce overall emissions to an acceptable level, may be minimal if required at all.

If you require a specific material or advice on EMI / RFI shielding please call one of our technical account managers on 01480 226699