An Introduction to Adhesive Bonding

Most industries rely on techniques like screwing, soldering and welding for joining components together. Another reliable method of unification is adhesive bonding. Contrary to the general perception, this technique is not only used to join plastic parts, but automotive, ship and aircraft manufacturing industries have also been using this technique for years to join metallic parts together. Moreover, modern adhesive equipments and innovations have made this unification technique more reliable than ever. Unlike welding or soldering, the equipment used in this technique is considerably cost effective. Manufacturers are also using hybrid bonding techniques by combining the use of adhesives with other joining techniques to produce high quality products.

What is Adhesive Bonding?

Adhesive amalgamation can be defined as the process of uniting different materials together using an inorganic/organic non-metallic agent, known as adhesive. Adhesive serves the purpose of an intermediate layer between two substrates. As an adhesive comes into contact with a material, it undergoes hardening action which enhances the cohesion and surface adherence properties of the adhesive, causing the two surfaces to stick firmly to each other. Adhesives can be soluble or insoluble.

Why Adhesive Bonding?

Unlike metallic joining techniques which were mostly adopted commercially during the World War II by the aircraft industry, adhesive joining is considered as a modern technique. IC fabrication industry relies on this technique for joining composites, semiconductors, plastics and metals. Although manufacturers have a number of options when it comes to selecting a joining method, most of the modern industries prefer adhesive bonding over other joining techniques due to the following reasons:

1. Light Weight

As bolts and nuts are composed of metals, techniques like screwing can increase the weight of the product. On the other hand, adhesives can join two substrates together without increasing the net weight. This is the reason that micro chips fabrication industry relies solely on this bonding technique.

2. Dissimilar Assembling

Unlike other techniques, adhesive bonding allows the assembling of two different materials. For example, welding cannot be used to join a plastic and a metal surface together, as plastic cannot tolerate the welding temperature, but this can be achieved by using an adhesive.

3. No Drilling

Techniques like screwing require the material to be drilled, which wastes some part of the material and impacts its strength. On the other hand, adhesives eliminate the need of drilling holes, thus keeping the geometry of the material intact.

5. Stress Considerations

There are complex design considerations involved in welding, screwing and other joining techniques. For example, precise drawings are needed to determine the stress around a mechanical joint. However, adhesive bonding enables uniform stress distribution, thus increasing the durability of the product.

6. Cost Effectiveness

The technique is not only reliable and widely established, but also cost effective. The equipment required for adhesive joining is affordable and consumes less power.

The technique is not only used in IC fabrication or plastic industries, but mechanical industries are also relying on this bonding technique. If applied properly, adhesive bonding can match the reliability of mechanical joints.