Materials are needed to replace the estimated 50,000 metric tons of tin-lead solder currently used each year, because of toxicity concerns, but there are no "drop-in" replacements for eutectic tin-lead solder. Electrically Conductive Adhesives (ECAs), which are also known as conductive epoxies, are becoming increasingly common to replace solders in a variety of functions, applications and industries. This report covers the three main categories of conductive adhesives available as safe and environmentally-sound solder alternatives.
The key applications include:
- Photovoltaic modules - Traditional ECAs have suffered from poor stability when applied to copper and tin metals, but improved ECAs for PV applications have been available since 2010. Lower temperature interconnections can allow thinner wafers, and reduce warpage and breakage of solar cells. ECAs are expected to be used for interconnection in 20% of solar cells by 2025.
- LCD and OLED displays - ACFs have found a particular niche market in packaging flat panel displays.
- Touch panels - The damage to the substrates can be reduced by lowering the bonding temperature during assembly. ECAs can allow lower temperature bonding.
- LEDs - It is quick and cheap to mount LEDs using conductive adhesives and the thermal penalty is tolerable if the adhesive layer is kept thin.
- RFID chips - Conductive adhesives are used for mounting temperature-sensitive chips on smart cards, because of low curing temperatures.
There are increasing opportunities for these materials as these industries move towards curved screens, flexible displays, in-mould electronics, displays designed for automotive, and e-textiles, all of which have stringent requirements for conductive adhesives.
Isotropic Conductive Adhesives have a high loading of metallic fillers (often silver) and must be carefully screen-printed or dispensed into discrete dots. They are reliable and compatible with reel-to-reel processing. There is research towards using nano-sized fillers to enable ink-jetting for higher precision, and ensuring the ICP also works as a structural adhesive.
Anisotropic Conductive Pastes are simple and cost-effective because of the low-loading of filler particles and ease of processing. The minimum pitch width is poor, and so application is limited.
Applications of ACF in 2015
Currently, 74% of Anisotropic Conductive Film (ACF) is used in the manufacture of LCD or OLED displays. Displays are becoming more widely used in consumer electronics, aerospace, defence, automotive, and infrastructure sectors. UV-thermal cure mechanisms must be developed to lower cure temperature to allow plastic substrates for flexible displays. However, this market is still set to diversify with the market for ACF in non-display applications reaching over $1 billion by 2026, due to the reliable properties, thinness and ease of processing. Metallic coatings on polymeric particles will allow lower cost fillers.
This report offers worldwide coverage of the Electrically Conductive Adhesives, most of which are manufactured in Asia-Pacific but start-ups and innovation exists in Europe and North America. The report is based on extensive research, includes twelve primary interviews with the market leading manufacturers. It includes forecasts by revenue, split by technology and function, until 2026.