Why is epoxy the most popular resin?

Epoxy resin is popular in all kinds of applications.  However, it is basically the same in all the applications.  epoxy is hardened when two liquids of equal parts are mixed together. This is a chemical reaction.  It is used in coatings, adhesives and mixed with glass fibers to make what is commonly called fiberglass.  It has excellent water resistance.  In fact, it literally absorbs no water from humidity as well.  This allows it to be the perfect choice for circuit boards.  However, not all fiberglass is made with epoxy, this is simply one example of its use.  There are also G10 and FR4 epoxies that we have talked about in earlier posts.

Epoxy is a very strong material as well. When you mix it with glass it becomes even stronger as the glass gets embedded into it which further strengthens it.  Because of this, this particular material must be machined and is made into flat sheets.  It cannot be injection molded as with many other plastic materials.  It is what they call a thermoset form of plastic, which means that it cannot be melted back down and made into something else.  Recycling is very popular nowadays, but this type of material cannot be recycled in the traditional manner.  

What is a thermoset material?

Why is epoxy the most popular resin

A thermoset material is something like tires.  You have seen where we cannot simply melt it down.  These are materials that are formed by a chemical reaction.  This means that if you try to melt it, it will simply burn.  Epoxy resin has a very high heat tolerance as well because of this, making it a great option for boat engine housing as well as circuit boards.  

Think of a thermoset like a cake.  You put all the ingredients in it, then you mix. You put it in the over and it bakes.  When it is done, you cannot get the egg out of the cake.  The ingredients are all mixed up and it’s now a harder material than it was in batter form.  This is the same way epoxy works.  Although, you should never eat epoxy.

Epoxy is popular because it works for so many applications.  Because of its properties and cost, epoxy is the best choice.  It is water-resistant and strong.  It has a low coefficient property, which means that it doesn’t expand and contract in heat and cold.  This means that it is a very stable component that can be used in a variety of things that will experience a variety of weather conditions.  It doesn’t get weak when hot and will not get brittle when cold.  How it is at any temperature is basically the same.  Because of this, we have used epoxy in a large variety of applications that will be used all over the world.  

Think about all the different applications that you find a circuit board and what types of environments that they will be facing.  There’s a lot.  That’s when the material has to stand up to the environment as well as perform the job.  Epoxy is just that material.