What Materials Are Capacitor Plates Made Out Of?

Capacitors come in many forms and can be composed of many different materials.
••• capacitor image by Albert Lozano from Fotolia.com

By definition, capacitor plates are made of conducting materials. This usually means metals, though other materials are also used. In addition to being conducting, capacitor plates need mechanical strength and resistance to deterioration from electrolytic chemicals. On top of that, most capacitors need extremely thin plates to pack the most capacitance in a small package. Manufacturers use ductile metals to make thin plates from foils. The materials must also be inexpensive and have good availability to be suitable for mass production.

Aluminum

Aluminum is a workhorse material for making the majority of capacitors. It’s inexpensive, highly conductive and easily formed into plates or foils.

Tantalum

Capacitors that use tantalum are more temperature and frequency stable than those using aluminum, though tantalum costs more.

Silver

Silver appears in silver-mica capacitors. These also cost more than aluminum plate capacitors, and are used in high-accuracy audio applications.

Other Metals

Other metals are used for capacitor plates in research and specialized applications. Brass is sometimes used in variable air capacitors. Liquid mercury can act as a capacitive plate in a sensor.

Carbon Nanotubes

In 2009, research into very high-capacitance devices led to experiments with carbon nanotubes. Their extremely small size allows for a large, effective plate area and a small gap between plates.

Related Articles

The Advantages of Using Electrolytic Capacitors
How to Calculate Ohms to Microfarads
How Do Thermistors Work?
How Do I Recycle Dewalt 18V Batteries?
Copper Wire Advantages & Disadvantages
Types of Non Polarized Capacitors
How to Tell the Polarity of an Electrolytic Capacitor
Uses of Resistors
Raw Materials Used in the Manufacture of Electronic...
How Does Temperature Affect Metal?
Types & Functions of Capacitors
Uses of Noble Metals
Transition Metals & Their Uses
List Of Conductors
How to Calculate Conductance
Uses for Petroleum Coke
What Metals Make Good Conductors of Electricity?
302 Vs. 304 Stainless Steel
Tin & Lead Alloy Names
How to Read K5M Capacitor Values

Dont Go!

We Have More Great Sciencing Articles!