Frequently Asked Questions - 3Gmetalworx Inc.

What material choices are available? Which material is better? What shapes can be produced? Are there height restrictions? What if there are circuit traces or components passing through a shield wall? What about connectors, or openings for inspection and test? Can ventilation be provided for heat dissipation? How many cavities can be provided in multi-cavity configuration? How does the cover attach to the fence? Are your product solutions RoHS compliant? How can I ensure effective grounding of the internal partitions to the cover? How does your product perform?
What material choices are available?	Top >>
3Gmetalworx offers two choices of material. For commercial or indoor applications, we recommend tin-plated mild steel, which is pre-plated. For defense, marine, avionic or outdoor applications, we recommend Nickel Silver alloy, which offers excellent corrosion protection with no additive plating required.
Which material is better?	Top >>
For cost containment, tin-plated steel is better. But because it is pre-plated, any cut edge will be exposed steel. In certain environments or applications where corrosion is a concern, a non-ferrous alloy like Nickel Silver should be used to eliminate the possibility of failure due to corrosion. Steel should be the starting point, but where corrosion concerns dictate, Nickel Silver alloy should be specified.
What shapes can be produced?	Top >>
Almost any shape can be produced for cans or fence sets, but most designs are rectangular in nature. Multi-cavity shapes are often more complex and can result in irregular perimeters. Costs can be reduced by keeping shapes as basic as possible during PCB layout, and by designing footprint corners in increments of 45 degrees. In legacy cases where optimization is no longer possible, any feasible configuration can be fabricated.
Are there height restrictions?	Top >>
There are practical minimums in terms of heights, but this depends somewhat on the other shield parameters. Cans at 0.080” or taller and fences at 0.140” or taller usually require no special consideration, and there is no maximum height restriction to date. It is possible to go below these figures, but early consultation is recommended. Multi-cavity packages, or those with connectors, can often run into other design factors that affect package height considerations.
What if there are circuit traces or components passing through a shield wall?	Top >>
Trace relief notches at the PCB plane can be produced to allow circuit traces to pass through walls or partitions. Similarly, openings can be designed to suit components that interfere with the shield in any way. The shape and size can be varied and the top of such openings can be rounded or square.
What about connectors, or openings for inspection and test?	Top >>
Any required openings can be incorporated into the design. For some connector designs, both the cover and fence may require special openings. Some openings will result in structural weakness which may require additional consideration. In such cases, we can advise on the exact design solution for incorporating connectors. Simpler openings require no special consideration.
Can ventilation be provided for heat dissipation?	Top >>
Perforations can be provided on cans or covers, and where the package height permits, on fence walls. For multi-cavity designs, thermal relief may be employed selectively on certain cavities to reduce cost. It is best to resist the temptation to perforate everything and to think optimally in terms of airflow condition and heat sources. In extreme cases, however, it is possible to perforate most of the metalwork while preserving effective shielding performance.
How many cavities can be provided in multi-cavity configuration?	Top >>
Some designs that are complex may require ten or more cavities, while others may require only two or three. One multi-cavity package can usually accommodate as many individual shields as required, provided that the height of all cavities is kept uniform. Packages with a stepped covers can be produced, although not all such designs are feasible.
How does the cover attach to the fence?	Top >>
There are dimples formed on the inside of the cover flanges, and coordinated holes pierced through the fence walls. When the cover is placed on the fence, the dimples snap into the holes, providing secure retention. This feature is standard on all fence and cover packages. For additional retention, we offer folding or twisting tabs that pass through the cover to provide positive retention under shock loads.
Are your product solutions RoHS compliant?	Top >>
Yes, both standard material options are compliant. On request, we offer RoHS Certification on either of our standard materials, with certification specific to the part number. Our shields contain only metal and are entirely recyclable as well.
How can I ensure effective grounding of the internal partitions to the cover?	Top >>
In many cases, no additional steps are required. In certain cases, absorbers are utilized together with metalwork. For multi-cavity designs, we can provide a number of aperture segmentation strategies designed to limit inter-compartmental leakage. Generally, gaskets are not utilized for managing cavity leakage.
How does your product perform?	Top >>
In a test comparing a 3Gmetalworx solution to our leading competitor’s equivalent product, our product delivered an attenuation advantage of 10dB at lower frequencies and 20dB at 3 GHz.