Electrically Conductive Adhesives: Frequently Asked Questions (FAQ)
Electrically conductive adhesives play a vital role in electronics and PCB assembly applications. This is due to their unique ability to electrically interconnect while improving reliability, thermal performance and structural bonding.
The electrically conductive adhesives market is estimated to reach a value of £4 billion by 2028, growing at a rate of 8.4%. This growth is accounted for by the increasing electrification of modern industries, leading to increased demands for technologically advanced electronic devices. This leads manufacturers to invest in innovative electrically conductive adhesives, reducing maintenance and production costs while improving product quality and safety.
Here we answer the top frequently asked questions on electrically conductive adhesives:
What are the advantages of electrically conductive adhesives?
The advantages provided by electrically conductive adhesives range from:
- Reducing the number of processing steps, therefore reducing costs
- Low curing temperatures
- Low thermal stresses
- Don’t contain lead
- Able to reduce assembly size and component pitch
- Improved fatigue resistance over solder joints
- Ability to match and be reworked to match specific application requirements, such as curing temperatures
- Compatibility with a range of substrates including non-solderable materials
How do I choose an electrically conductive adhesive for a PCB application?
Before choosing an electronically conductive adhesive, it’s important to consider various factors, including:
- Compatibility with the substrate material
- Operating temperature of the application
- Humidity levels
- Exposure to chemicals
- The adhesive’s thermal conductivity
- The adhesive’s flexibility
- The curing method required
Matching these specifications to that of the chosen adhesive as closely as possible will guarantee the best performance for the adhesive.
How does an adhesive achieve electrical conductivity?
Electrically conductive adhesives achieve their unique properties through the addition of electrically conductive elements such as silver, gold, nickel or carbon.
What are the different types of electrically conductive adhesives?
Electrically conductive adhesives typically come in 2 different forms; isotropic (ICA) or anisotropic (ACA).
Isotropic conductive adhesives contain high loadings of metallic filler materials and are conductive in all directions. They are commonly used as solder replacements in surface mount assemblies.
Anisotropic adhesives contain a lower concentration of metallic filler materials and only conduct in one direction. They are commonly used in flip-chip technology and liquid crystal displays (LCDs).
The majority of liquid adhesives that are electrically conductive use epoxy or silicone chemistries. Electrically conductive adhesives with epoxy chemistries can be used in high-temperature applications, often 150°C or higher. Electrically conductive silicone adhesives are used in high-temperature applications up to 260°C and may be able to withstand somewhat higher temperature conditions.
How is electrical conductivity measured within an adhesive?
Typically, electrical conductivity is measured in ohms centimetres (ohm-cm). This measures the inherent resistance of a material to the flow of electrical current. A highly electrically conductive adhesive will have a low ohm-cm value, while a less electrically conductive adhesive will have a higher ohm-cm value.
Does electrical conductivity vary with curing temperatures?
Typically, the higher the curing temperatures, the greater the electrical conductivity and mechanical properties of the adhesive. This is due to a dense and tighter cross-link in the adhesive.
What electrically conductive adhesives does Antala offer?
At Antala, we offer a wide range of electrically conductive adhesives for a range of industries and applications. These include our range of thermal interface materials, electronic protection solutions, electronic-grade adhesives and sealants, and electronic encapsulants. As well as a wide range of leading electronic protection solutions, our team have over 30 years of experience in supporting electronics manufacturers in all stages of the manufacturing process; from PCB assembly to full device manufacturing.
