Electrically conductive adhesives are now commonplace and have contributed immensely to the micro design of everyday consumer electronic devices. iPads, mobile phones, medical devices, flexible PCB’s, wearable conductive clothing, RFID tagging and RFI shielding are just some common applications with which we are all familiar. In this article, Simon Dearing, Managing Director of Eurobond Adhesives, reveals more about the technology and how to use and maximise it.
There are two types of electrically conductive adhesives: isotropic and anisotropic. Isotropic conductive adhesives (ICA) are electrically conductive in all directions and are used in applications such as chip contacting and the bonding of electrically conductive SMDs.
Anisotropic conductive adhesives (ACA) contain special conductive particles in the µm range, which conduct electricity in one direction only. These adhesives are used, for example, in many sensitive structures on circuit boards, such as LCD connections or contacting flexible PCBs, or for bonding antenna structures on RFIDs.
Today, the range of conductive adhesives and their applications is both vast and varied. Conductive adhesives are tailored to suit almost any application and are formulated as either one component products that are thermally curable, or two component products that when mixed together cure at room temperature. For a faster cure time they can be thermally cured. When selecting the right adhesive for a specific project it is important to consider the following points which can be discussed in depth with a specialist adhesive technical adviser from Eurobond:
What type of dispensing method will be employed: for example syringe, stamp, screen print or jet?
· The type of filler required: Silver, Copper or Graphite?
· Paste or a liquid adhesive?
· One or two component product?
· Does the application need an Isotropic or Anisotropic adhesive?
· What pot life best suits your given application?
· What cure time and cure method will be employed?
· What volume resistance does the application require?
· What coefficient of thermal expansion can the project accommodate?
Eurobond offers the Elecolit® range of silver filled, one-component adhesives that can be simply applied with dispensers, jets or screen-printed, as well as two-component products that cure at room temperature and have a longer pot and storage life.
Eurobond Adhesives have a select range of both one and two component electrically conductive adhesives and a range of electrically conductive adhesive tapes. Our high quality technical tapes have been developed for a range of applications in the electronics industry including masking, EMI/RFI shielding, PCB masking, conductive connection and fixing, anti-static and wireless power charging. To discuss your next project contact our technical team at firstname.lastname@example.org or visit our website www.eurobond-adhesives.co.uk.