Electromagnetic and Radio frequency interference (EMI/RFI) shield design is complex and multi-faceted, combining electrical and mechanical engineering concepts. In practice, shielding is very much an iterative process in which controlling one variable impacts another, leading to even more changes in the design.
One aspect of shield design is knowing which external signals are most critical to keep from interfering with the circuits inside. This is important from the standpoint of material selection, both for the shield structure and any subsequent plating. Knowing the frequency and amplitude of critical signals and how they behave with conductive metals helps you determine the conductivity and thickness required to achieve adequate shielding effectiveness.
Precision stamped components need to be in an assembly-ready condition when they leave the stamper’s facility, and they need to stay in that condition during transportation and storage and until the customer needs them. Moving components between facilities and general handling present many risks to that assembly-ready condition the stamper achieved. That’s why careful packaging is such an important part of the stamping process.
Electronic devices are everywhere these days – from your cell phone to your garage door opener, to the sensors on the security cameras at the grocery store. They’re controlled by internal circuit boards, which send and receive signals with instructions about what to do (i.e. display the phone’s home screen, send power to the garage door actuator, make the camera record when an object passes).
As devices have become smaller to fit inside machines, vehicles, and medical equipment, they have also become more powerful. Their microprocessors run at higher speeds, and send high-frequency signals between circuits that are very close together.
Precision stampers use many types of metals, including aluminum alloys, brass alloys, copper, nickel, steel, stainless steel, silver, and bronze. How do you know which is the right material for each project? It has to do with a variety of mechanical and chemical properties that determine how a given metal will behave during stamping and in the finished product. Designers, engineers, and stampers need to work together to find the right balance between satisfying design intent and manufacturability of a part. Metal properties also impact the manufacturing process itself, including selecting the best tool steel, stamping oils, and plating or other finishing.
Some of the most important properties to consider are discussed listed below; however, there may be additional considerations depending on your specific application.