Electrically conductive adhesives and tapes

Electrically conductive adhesives and conductive adhesive tapes are now commonplace in manufacturing and have contributed immensely to the micro design of everyday consumer electronic devices.

Examples include smart tablets, mobile phones, touch screens, TVs, medical devices, flexible PCBs, wearable conductive clothing, RFID tagging and RFI shielding. Conductive adhesives and conductive tapes have also seen an upswing in aerospace and automotive applications, too.

Electrically conductive adhesives are usually thermally curing epoxy resin-based adhesives, solvent based air drying adhesives/coatings or UV-curing acrylate-based adhesives augmented with metallic fillers, such as silver. Grade, shape, grain size and grain distribution of the filling material are critical influencers to optimising adhesive conductivity. In addition, a significant contributor to electrical conductivity is the adhesive curing process. Improper curing can cause a deterioration of performance and integrity of the bonded parts.

Electrically conductive adhesives are often used as a more effective alternative to conventional soldering. They are particularly suitable for making electrical contacts on temperature-sensitive substrates, as their curing temperature lies clearly below soldering temperature. In addition, the adhesives are much more flexible than solder and are therefore better able to withstand vibrations.

A further advantage over soldering is that conductive adhesives are lead free. There are two types of electrically conductive adhesives: isotropic and anisotropic. Isotropic conductive adhesives (ICA) are electrically conductive in all directions. They are used in applications such as chip contacting and bonding of electrically conductive SMDs.

Anisotropic conductive adhesives (ACA) contain special conductive particles in the µm range, which conduct electricity only in one direction. These adhesives are used, for example, in many sensitive structures on circuit boards, such as LCD connections or contacting flexible circuits to rigid PCBs, or for bonding antenna structures on RFIDs. 

Eurobond Adhesives offers the Elecolit range of silver filled, single-component and two component conductive adhesives that can easily be applied with dispensers, jets, brushes or screen-printed. Both types can cure either at room temperature or can be accelerated by thermally curing. Innovative hardener systems in many of the one-part epoxy-based adhesives develop ‘cure’ within minutes and these can be used to connect heat sensitive components to printed circuit boards, wave guide plumbing, hybrid circuit assembly, connecting ground wires to components, making conductive tracks or pathways and bonding discrete devices and hybrid circuits.

Other applications include bonding conductive paths in heated car windscreens and mirrors, RFID applications, bonding batteries to foil/film, bonding flexible film LCDs to hard FR4 boards, circuit track repairs, populating PCBs etc, the list is almost endless.

Today of course, the range of conductive adhesives and electrically conductive adhesive tapes and their applications is vast and varied. Conductive adhesives and conductive tapes are tailored to suit almost any application. When selecting the right product for your specific project, it is important to consider the following points and discuss them in depth with your chosen specialist adhesive supplier:

  • The type of dispensing method will you employ ie, syringe, stamp, screen print, jet manually applied tape?
  • The type of conductive filler do you need ie Silver, Copper, Aluminium or Graphite.
  • The viscosity of the adhesive perhaps a paste or a liquid adhesive?
  • Whether it should be an Isotropic or Anisotropic adhesive?
  • Which pot life best suits your particular application?
  • Is there a specific cure time and cure method you need to employ?
  • What volume resistivity does your application require?
  • Does the application require a specific bond line thickness and or specific geometry? If so, then a bespoke die cut shape made from conductive adhesive tape may be best.

Shelf life and storage are important areas to consider too. The conductive filler in one- or two-part materials can potentially separate out from the base resin and sediment onto the bottom of the container necessitating the need to mix/stir the material to evenly re-suspend the conductive particles before use. Storing the adhesive in a refrigerator at around 5°C will slow the process and help prolong its shelf-life.

Some conductive adhesives however, need to be shipped and stored in deep freeze. The catalyst curing mechanism is held in suspended animation until the material is thawed and ready to use. Of course, this type of material can have considerable and costly waste if the complete container is not used as it cannot be re-frozen.

With an ever increasing range of mobile communication devices and electrical goods generally, it is crucial to have good RFI shielding of components and/or products to prevent electromagnetic interferences. Eurobond has a range of electrically conductive adhesive coated foils and conductive transfer adhesive tapes suitable for bonding, masking, shielding, surface protection and electric vehicle battery cell electrolyte sealing tape.

Typically electrically conductive adhesive tape will have a shelf life of approximately two years and is not particularly affected by adverse temperatures during storage. Conductive tapes can be supplied in a roll format, of varying widths, lengths and thicknesses. Their conductive tape products have excellent properties for the high specification demands of the electronics industry in the 21st-century.

High grade acrylic, silicone and electrically conductive adhesives are used in conjunction with the best available films and metal foils to give outstanding results for high-performance consumer electronics, aerospace, automotive, industrial electronics and telecoms.

For more information talk to Eurobonds’ technical team on 01795 427888 or click here.

Eurobond Adhesives Ltd

Bonham Drive
Eurolink Industrial Estate
Sittingbourne
ME10 3RY
UNITED KINGDOM

+44 (0)1795 427888

sales@eurobond-adhesives.co.uk

www.eurobond-adhesives.co.uk

More products
6 days ago
Mould making at Emka for injection moulding of plastics and metals
Emka reports that it is now one of the top three mould makers in Europe – producing 900 moulds a year for plastic injection, including polyamide/glass and Grivery, as well as zinc and aluminium die casting.
1 week ago
Essentra Components cuts energy usage by 15% globally
An innovative energy reduction initiative based on the concept of insulated jackets is helping industrial components manufacturer Essentra Components cut its energy usage when heating machine barrels by 15% and save CO2 emissions in the process.
1 week ago
Bostik launches new engineering and repair adhesives for marine industry
Bostik has launched a range of products including within its engineering adhesives portfolio, Born2Bond, to provide an essential toolbox to support the marine industry in delivering sustainable repairs and manufacturing.
1 week ago
Technical manager retires after long career with Chemique Adhesives
After 34 years with UK adhesives manufacturer Chemique Adhesives, John Bellerby stepped down as technical manager at the end of July.
1 week ago
The countdown begins to Rivetnut’s new website launch
Rivetnut Technology Systems (RTS) will be launching its new website on 8 August, and will be adding new product lines and increasing the available range of products on the site.
2 weeks ago
PEM introduces new buy-back scheme
PEM has introduced a buy-back scheme where customers have the ability to trade in their old PEMSERTER or Haeger machines and can receive up to 8,000 euro in return, where they can put those funds towards a newer upgraded Haeger model.
2 weeks ago
Permabond races to the finish of the Triton Racing team car
When Triton Racing found itself desperate for an adhesive supplier with a stock of a carbon fibre bonding adhesive, with the team’s car’s reveal fast approaching, it turned to Permabond.
2 weeks ago
Spirol launches new and improved website
Visitors to the Spirol website will now find it even easier to connect with the company’s global locations, request technical support, submit an RFQ, as well as purchase product through their integrated eCommerce website.
2 weeks ago
Intertronics supports 3D printed bioelectronics research
When the Department of Automatic Control and Systems Engineering (ACSE) at The University of Sheffield was looking for a way to accurately 3D print bioelectronic sensors, it reached out to Intertronics for support.
3 weeks ago
Southco locks out package theft with secure parcel boxes
When MB Sentinel needed a high quality locking solution for its mailbox and package delivery boxes for residential and commercial buildings, it turned to Southco.

Login / Sign up