Adhesive tapes take the pressure out of mobile phone production

Pressure-sensitive adhesive tapes are fast emerging as the modern, effective way to join components in a number of industries and mobile phones are no exception. Rod Daley reports.

Today pressure-sensitive adhesive (PSA) tapes are providing cost-effective solutions to OEMs and component manufacturers, having applications in many of the stages of mobile phone construction. As well as standard bonding applications, they can be used in very specialised applications, thanks to the number of technological innovations over the past few years.

PSAs can be supplied in a number of formats: transfer films, which are used to transfer a coating of adhesive to a specific surface; single-faced tapes, for fixing a tape film to another surface; or double-faced tapes which bond two surfaces leaving a film between them. They can be coated on to a variety of substrates and supplied in rolls or die-cut to specific shapes.

Four recent innovations offer products which are electronically clean, optically clear, electrically conductive or electro-magnetic interference (EMI) shielding.

Electronically-clean adhesive products are free from acrylic-acids, have low volatile organic compound (VOC) low outgassing and low extractable ions thereby eliminating fogging, potential oxidising and corrosion of conductive circuitry. Typically this makes these products particularly suitable for spacers for touch screens where they reduce corrosion of indium tin oxide (ITO) films.

Optically-clear adhesive products have been developed to meet the production needs of liquid crystal displays and the various combinations of optical films that need to be bonded to them are suitable for bonding flexible and flexible-to-rigid materials where environmental durability, low haze, excellent clarity and high light transmission are required.

Electrically-conductive adhesives (an adhesive type that has been patented by Adhesives Research) are suitable for electrical interconnection and EMI gasket applications. They offer homogenous conductive properties and high bonding strengths with excellent stability and reliability ­ essential if the integrity of the circuit is to be maintained, while EMI shielding tapes can be made with conventional metal foils or metallised fabric.

These new product groups add to the large number of applications for which conventional double-faced bonding systems are suitable, such as component assembly (lens gaskets, speakers, microphones and battery packs) or touch-screen integration.

Many benefits

With such a wide variety of product options available, it is not surprising that equipment or component specifiers are sometimes unaware of many of the potential applications and benefits that a PSA could bring to the production process.

Adhesives Research is helping companies identify those applications and to developing the products which are most suitable. For some time now, the company has been working closely with OEMs and component manufacturers such as plastic moulders, die cutters and LCD manufacturers. This approach of integrating with the supply chain means that the products specified will be compatible with every stage of the production process.

With nearly one third of company resources dedicated to R&D, Adhesives Research has the capabilities to define, develop and produce the product most suitable for the identified purpose.

Enquiry No 49

Rod Daley is with Adhesives Research Europe, Great Dunmow, Essex, UK. www.adhesivesresearch.com

Recent Issues