US industry used more than $210 million of tantalum in 2020. One of the main uses for tantalum is in tantalum capacitors. A tantalum capacitor is a key component of devices ranging from smartphones to cars.
Learn more about tantalum and the important role tantalum capacitors play in a broad range of industries.
Properties of Tantalum
Tantalum is a hard, blue-gray lustrous metal. It has the chemical symbol Ta and atomic number 73. The tantalum atomic mass is 180.9479.
Tantalum is a refractory metal. Refractory metals are very resistant to heat and wear. The tantalum melting point is 3017ºC.
Tantalum is almost totally immune to chemical attack at temperatures below 150ºC. It’s very dense and resistant to corrosion. It’s also very ductile.
Tantalum is biocompatible and hypoallergenic.
Forms of Tantalum
Tantalum is available in a variety of forms. Pure tantalum metal comes in shapes like ingots, strips, sheets, and wire. Tantalum tungsten alloy and tantalum niobium alloy are other options.
You can choose from tantalum powder compounds like tantalum pentoxide, tantalum pentachloride, tantalum carbide, and tantalum silicide.
Other forms of tantalum like lithium tantalate wafers are available as well. You can also use a powder like Stanford Advanced Materials tantalum pentoxide to produce lithium tantalate single crystals. You can then cut the crystals into wafers.
Uses for Tantalum
The properties of tantalum make it ideal for a variety of applications. Tantalum uses include:
- Chemical process equipment
- Nuclear reactors
- Missile parts
- Surgical appliances
- Glass for camera lenses
- Jewelry and luxury watches
Electrolytic capacitors and vacuum furnace parts make up around 60% of its use. Tantalum is a critical part of many modern electronics and components.
What Is a Tantalum Capacitor?
A tantalum capacitor is a type of passive electrolytic capacitor. It has three main components:
- An anode, which is the positive plate
- An oxide layer that acts as the dielectric
- A cathode, which is the negative plate
In a tantalum capacitor, the anode is a small pellet of tantalum metal ground into a fine powder and sintered at high temperatures. It’s very porous with a large surface area. The dielectric oxide is very thin.
For wet-type tantalum capacitors, the oxidized anode rests in a liquid electrolyte. Solid tantalum capacitors have a manganese dioxide electrolyte as the cathode.
Advantages of a Tantalum Capacitor
The main advantage of a tantalum capacitor is that it gives a higher level of capacitance for a given volume and weight. The large surface area of the anode and the thin oxide layer contribute to this characteristic. The oxide is very stable over time and under different operating frequencies.
The capacitance of a tantalum capacitor won’t decrease over time. Tantalum capacitors don’t have mechanisms that will wear out as the device gets older.
Tantalum capacitors usually have a lower equivalent series resistance (ESR). ESR creates lost power and reduced efficiency. In other words, tantalum capacitors are more efficient and have less leakage current.
The high heat resistance of tantalum metal means that tantalum capacitors will work at higher temperatures.
Uses for Tantalum Capacitors
Tantalum capacitors are very reliable and give good service when the usage is within their rated limits. One common use is filtering power supply rails in smartphones and tablets where space is an issue.
They’re often found in military and automotive hardware that must be reliable. Tantalum capacitors are stable over time. They don’t have an electrolyte that will dry out.
Tantalum capacitors can handle higher capacitance values. This makes them a good choice for medical implantable devices like pacemakers that need quick bursts of high capacitance and charge.
Tantalum capacitors are a good choice for sensitive analog applications. Sample-and-hold circuits can hold signal levels longer because of the capacitor’s low leakage current (ESR).
Popularity of Tantalum Capacitors
Tantalum is critically important to modern electronics. One of its most important uses is in tantalum capacitors. A tantalum capacitor offers advantages beyond other types of capacitors.
For a wide range of uses, a tantalum capacitor will get the job done better.
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