An electrically conductive adhesive is a glue that is primarily used for electronics. The electric conductivity is caused by a component that makes ca. 80% of the total mass of an electrically conductive adhesive. This conductive component is suspended in a sticky component that holds the electrically conductive adhesive together. The particles of the conductive component are in contact to each other and in this way make electric current possible.

Composition

The conductive component can be

silver Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical co ...

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...

, copper or

graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on lar ...

. Other conductive materials are possible but unusual. The adhesive component can be a varnish,

synthetic resin Synthetic resins are industrially produced resins, typically viscous substances that convert into rigid polymers by the process of curing. In order to undergo curing, resins typically contain reactive end groups, such as acrylates or epoxides. ...

, or

silicone A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking ...

. Variations in conductive component's type and concentration change the

resistivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...

of the adhesive. A typical silver-based conductive adhesive such as that made by Electrolube contains ingredients in the following proportions: They are specifically formulated in paste (micro-particles) for use in scanning electron microscopy (SEM) and other electron optical applications find use in producing or repairing

printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich struct ...

(PCB) tracks, to paint-on an electrical screen, or to make electrical connections to non-solderable surfaces.

Applications

* One could fix a defective conductor on a printed circuit board using an electrically conductive adhesive. In the same way, one could fix a defective rear windscreen heater on a car using an electrically conductive adhesive. * If just a small current is needed, a temperature-sensitive electronic element can be electrically connected to a circuit using an electrically conductive adhesive instead of

soldering Soldering (; ) is a process in which two or more items are joined by melting and putting a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, soldering does not invol ...

. * Electrically conductive adhesives can be used to paint the inner surface of plastic boxes containing electronic devices. This makes a

Faraday cage A Faraday cage or Faraday shield is an enclosure used to block electromagnetic fields. A Faraday shield may be formed by a continuous covering of conductive material, or in the case of a Faraday cage, by a mesh of such materials. Faraday cages ...

saving the internal components from

electromagnetic radiation In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) ligh ...

. * Electrically conductive adhesives are used in SEM to fix and ground the sample to avoid

electrostatic Electrostatics is a branch of physics that studies electric charges at rest (static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for ambe ...

charging of the surface.

Composition

Applications

References

Further reading