Epoxy Films, Adhesive Preforms

Epoxy Adhesive Preforms define custom parts that are cut out of an adhesive film material that can come either thermally conductive, or electrically conductive. However, oftentimes they come as both. In addition, some of these films are supported by carriers. These include fiberglass or polyimide films to ease in handling and assembly. Epoxy preforms offer an alternative to conductive thermal pastes that can be difficult for assembly.

Benefits of Epoxy Films

Cleanliness and Cleanup

With epoxy films, since these films can be preformed to shape it minimizes the amount of post-cleaning that is required to be done before, and after bonding is completed.

Consistency of Application

Conductive Thermal Pastes can be inconsistent for the sole reason of how its applied. Depending on who/how it is applied. On the other hand premade epoxy preforms are made the same way every-time. The thickness, cut-outs, and tolerances of the preform can all be held to +/- .002” in some cases.

No Mixing Time

Since Epoxy Preforms are 1 part pre-cut parts, there is no need to mix anything unlike some of the conductive thermal pastes available.

Overall, epoxy preform film materials add a lot of consistency and can lower cost per unit of production.

Benefits/Drawback of Supported Epoxy Films 

Benefits:

1. Handling

I cannot begin to overstate how much easier handling is with a carrier. Unsupported films can fall apart in your hands because of the lack of support. Cutting should be done on the liners, or with the support of something at all times.

Drawbacks:

1. Cutting

Cutting can be a bit more of a challenge with a supported epoxy film. The reason for this is laser cutting is the preferred method of cutting for complex epoxy shapes. Polyimide or fiberglass can make the cut a little rougher or harder to cut through. 

Epoxy Preforms

The material being preformed allows allows for more uniform bond lines and consistent application of the adhesive across the assembly. When there is many cut-outs and close tolerancing using automated machines can offer an incredible amount of consistency. Applications such as bonding to heat-sinks are common for these films. These epoxy films can be laser-cut or die-cut.

Availability of Epoxy Film Materials

Henkel manufactures a number of assembly film options that may be a fit for different applications that require epoxy preforms:

Electrically/Thermally Conductive Films

5025E ™

ECF561E ™

CF3350 ™

ECF550 ™

ECF563 ™

Thermally Conductive Films

5020K ™

561K ™

566K ™

563K ™

506 ™

Epoxy Film Preforms

It is wise to consulate about epoxy film sheet sizes before determining sizes of preforms. With these materials tightly controlled performance characteristics and thickness tolerances availability of size can be tricky.

Storage

Storage is an important consideration with these films. Oftentimes these films are required to be stored at temperatures at freezing or sub-freezing in order to maximize the shelf life. This includes when shipping these materials that they are shipped at temperatures required by their datasheets. Our team generally refers to two different types of ice. There is Blue Ice and there is Dry Ice. Blue Ice keeps the package at around 30-45°F, and Dry Ice keeps the package sub-zero fahrenheit.

Converting

At NEDC, we laser-cut or die-cut epoxy preforms to many different custom shapes for our customers. Epoxy Preforms are usually very intricate with many twists, and turns in the cuts. With these challenges, choosing between die-cutting or laser cutting is a tough choice sometimes.

The delineation between laser-cutting or die cutting is often stratified by a number of factors including:

-Complexity of the cut-outs

-How many preforms are being manufactured

-How big/small the preform is

-Tolerance requirements(recommended +/- .003’’ for cutouts, +/- .005’’ for locations)*

If you have an application that you believe could utilize preforms or assembly films, please contact sales@nedc.com.