The unique characteristics and success of the Voltage Switchable Dielectric™ (VSD™) materials are made possible through the marriage of nanotechnology and polymer chemistry.
Voltage Switchable Dielectric™ (VSD™) Material
A Voltage Switchable Dielectric™ (VSD™) material is a polymer nano-composite that functions as an insulator (dielectric) during normal circuit operation and becomes conductive when the voltage increases beyond a predefined characteristic voltage. The VSD material becomes an insulator again after the voltage drops back below the characteristic voltage to normal operating levels. This unique property, coupled with the ability to tailor the characteristic voltage, opens up several new areas in electronics. The VSD materials are commercialized under various Shocking Technologies™ trademarks, including XStatic™ and XSeed™.
While a VSD™ material functions as an insulator, the normal current path is not affected. When the rapid increase in voltage triggers the protection properties of the VSD™ material during an ESD event (i.e., clamping voltage), its ability to carry large amounts of current is enabled.
A key feature of an XStatic™ material is its ability to clamp high voltage ESD events almost instantaneously. This animation shows the corresponding response of the XStatic™ material to the ESD transient pulse over time.
How do VSD™ materials work?
In a typical application, a layer of XStatic™ material is placed adjacent to - and in contact with - the ground plane. During an ESD event, the voltage and current ramp almost instantaneously. If the circuit has proper access to the XStatic™ layer, no matter where a high voltage pulse is introduced into the device, the XStatic™ material will react to it by clamping the voltage and shunting the excess current to ground very fast. The net result is that protected ICs and other circuit elements mounted on the board or substrate are shielded from the transient voltage spike that would otherwise damage them. No matter where the high voltage static charge enters the product, the following animation demonstrates a typical path of the excess current as it is drawn away from the active and passive components, thereby providing system level protection.
Our applications engineers and our customers (OEM/IDM) jointly perform an assessment of the product requirements that includes design, usage, operating life, etc., as well as the product’s existing or projected vulnerabilities to high voltage ESD. On-chip surge protection is also assessed along with system level architecture, material choices and construction. A clamping voltage that provides a sufficient protection buffer is then determined.
With the clamping voltage defined, integration into the product is accomplished in two ways:
a.
Through the physical integration of the XStatic™ material within the board or substrate, and
b.
Through the layout of the traces and vias to enable proximity connection to the XStatic™ layer.
All circuits and components with proximity connection to plated-through-hole (PTH) and blind vias in contact with the VSD™ layer achieve protection down to the threshold voltage that is now integrated into the system design. Additional detail on designing with VSD™ materials can be obtained by contacting our design and applications engineering team at sales@shockingtech.com.
