chip capacitors selection guide      chip capacitors selection guide

Image credit: RS Components | Newark / element14

 

Chip capacitors are passive integrated circuit (IC) components that store electrical energy.

 

About Chip Capacitors

Chip capacitors are simply capacitors manufactured as integrated circuit (IC) devices, also known as chips or microchips. They are typically square or rectangular, with the length and width of the device determining its power rating. Chip capacitors typically do not have leads and mount directly onto a printed circuit board (PCB), and are therefore considered surface mount (SMT) products.

 

chip capacitor selection guide

A circuit board with mounted SMD components. A chip capacitor is highlighted at top center.

Image credit: ham-radio.com

 

The following images describe the manufacturing of multi-layer ceramic chip capacitors (MLCC).

 

chip capacitors selection guide  chip capacitors selection guide

Initial (left) and final stages of chip capacitor manufacturing.

Image credit: Johnson Dielectrics

 

Package Standards

Rectangular surface mount components, such as chip capacitors, are sometimes referred to by standard metric or imperial codes. These codes are listed below, first in imperial size with metric code in parentheses, then nominal metric dimensions. Note the direct correlation between the metric code and nominal size.

  • 01005 (0402): 0.4 x 0.2 mm
  • 0201 (0603): 0.6 x 0.3 mm
  • 0402 (1005): 1 x 0.5 mm
  • 0603 (1608): 1.6 x 0.8 mm
  • 0805 (2012): 2 x 1.25 mm
  • 1008 (2520): 2.5 x 2 mm
  • 1206 (3216): 3.2 x 1.6 mm
  • 1210 (3225): 3.2 x 2.5 mm
  • 1806 (4516): 4.5 x 1.6 mm
  • 1812 (4532): 4.5 x 3.2 mm
  • 2010 (5025): 5 x 2.5 mm
  • 2512 (6432): 6.4 x 3.2 mm
  • 2920: 7.4 x 5.1 mm

Tantalum chip capacitor dimensions are specifically standardized by the Electronic Industries Alliance (EIA) and are based in part on metric codes, with an added code for maximum device height. For example, the nominal dimensions of an EIA 2012-12 capacitor are 2 mm x 1.2 mm x 1.2 mm (length x width x height).

 

Specifications

 

Packing Method

Chip capacitors, like many other small electronic components, may be packed in tape reels, trays, or shipping tubes. All three methods provide compatibility with standard pick-and-place machines and other assembly equipment.

  • Tape reels consist of carrier tape with embossed cavities for individual components. After components are mounted on the tape, a cover tape seals the devices and the carrier tape is wound onto a reel. Tape and reel assemblies provide the advantage of component isolation. Tape is well-suited to SMT components.
  • Trays (or rails) are molded into rectangular outlines containing uniformly-spaced pockets for storing components. Trays are typically used to pack and ship components with leads, and are stacked and bound together to facilitate shipping and handling.
  • Shipping tubes are rigid PVC containers which protect components during shipping and provide proper component orientation and positioning.

chip capacitors selection guide    chip capacitors selection guide   

Tape reel (left) and packing tray. Image credit: TJSKL | Kalindi

 

Dielectric Type

A capacitor's attributes, as well as capacitance, are heavily influenced by the dielectric (insulating) material between the device's plates. Typical dielectric materials can be classified into three general groups: film, electrostatic, and electrolytic.

 

chip capacitors selection guide

Capacitor applications by type. Image credit: Elcap

 

Film

Film capacitors feature thin plastic film as a dielectric, and may be metallized, meaning that metal electrodes are previously vapor-deposited on the film. Common film capacitor materials include polyester, polypropylene, and polystyrene.  Film capacitors are excellent general-purpose devices with high dielectric strengths, low moisture absorption, and high insulation resistance. Capacitors with single-layer dielectrics have slightly poorer temperature stability and resistance, while multi-layer dielectrics enable smaller device sizes and improved temperature stability.

chip capacitors selection guide

Cross-section of a typical film capacitor. Image credit: Elcap

 

Electrostatic

Electrostatic capacitors feature dielectric materials that naturally support an electrostatic field — which is crucial to the device's energy-storing function — and do not conduct electrical current. These devices may use a number of different dielectric materials, which are listed below along with their attributes or typical applications.

  • Air - high voltage applications.
  • Ceramic - excellent for use in timing applications. Depending on the specific ceramic material, may exhibit relatively high capacitance deviation over a wide temperature range.
  • Glass - high voltage applications. Very stable, reliable, and resistant to radiation.
  • Mica - highly stable, good temperature coefficient, excellent endurance and reliability.

  • Oil - suitable for DC applications. Oil dielectrics often require maintenance and may need to be larger than other devices to suit their intended use.

Electrolytic

Electrolytic capacitors feature one plate comprised of a liquid electrolyte to achieve greater capacitance using a small package. Some electrolytic capacitors may be capable of several farads of capacitance.

 

Standards

Chip capacitors may be subject to different standards, many of which are developed and published by the Electronic Industries Alliance (EIA). Common chip capacitor standards include:

References

 

Johnson Dielectrics - Ceramic Chip Capacitor Basics

 


Related Products & Services

  • Aluminum Electrolytic Capacitors

    Aluminum electrolytic capacitors use an electrolytic process to form the dielectric. Wet electrolytic capacitors have a moist electrolyte. Dry or solid electrolytic capacitors do not.

  • Capacitors

    Capacitors are electronic components used for storing charge and energy. In their simplest form, capacitors consist of two conducting plates separated by an insulating material called the dielectric.

  • Ceramic Capacitors

    Ceramic capacitors have a dielectric made of ceramic materials.

  • Film Capacitors

    Film capacitors are insulated with polyester, polycarbonate, polypropylene, polystyrene, or other dielectric materials.

  • High Voltage Capacitors

    High voltage capacitors are used for storing charge and energy in high voltage applications. 

  • Tantalum Capacitors

    Tantalum capacitors are used in smaller electronic devices including portable telephones, pagers, personal computers, and automotive electronics. 

  • Ultracapacitors

    Ultracapacitors store charges (energy) by physically separating positive and negative charges (unlike batteries which do so chemically).  Very high power densities can be achieved by this method.