What Are In-Mold Electronics?

Plastic injection molding has come a long way from its humble beginnings in 1872 when the first injection molding machine was patented. Nowadays, injection molding is a constantly-evolving technology touching every aspect of our daily lives. 

One recent advancement includes in-mold electronics (IME), a molding technology made possible by two processes that have existed since the early 1990s. In-mold decoration (IMD) emerged as a molding process for mobile phone keypads and cover lenses. Around the same time, in-mold labeling (IML) was being used to produce high-precision plastic parts with eye-catching colors in unique shapes and sizes. 

In-mold electronics is just another iteration of these two highly-successful approaches—it’s a solution that involves designing and building plastic parts that are lighter and thinner, use less material, and are more visually appealing.

How Does In-Mold Electronics (IME) Work?

First, engineers create a 3D CAD design where all the electronics, including lighting and touch pads, are integrated into the design. Next, the 3D design is recreated in a new 2D format where engineers can incorporate circuits, conductive tracks, connectors, resistors, sensors, and lighting tabs alongside non-conductive inks to create a thin film plastic circuit board.

Next, the thin plastic film is formed, cut, and reduced to fit the final plastic part’s dimensions. These films are then laid within the mold’s cavity. Then the thin film is over-molded with another film to cover all exposed circuitry, connectors, and tabs. This extra layer makes it easier for the engineering and design team to add touch controls.

Benefits

The best part of the in-mold electronics process is that it produces a high-quality plastic part with complex geometries that does not require additional processes like labeling, marking, and painting. Other benefits include:

• Eliminates Rigid Circuit Boards: The ability to combine electronics with everyday consumer products eliminates the need for rigid circuit boards in product designs. This means engineers can design a ready-made solution easily formed and molded to multiple configurations and dimensions. It eases the design process and leads to substantial design improvements.
• Lightweight & Lower Costs: Plastic finished goods produced in the IME process are lighter and use less material, delivering significant savings for companies. Lighter parts are essential in the automotive and aerospace industry, where more lightweight materials and frames are essential.
• Better Protection for Electronics: The IME process also produces highly durable plastic parts that protect electronics from extreme weather environments. The electronics are less likely to corrode or degrade because they’re covered or encapsulated within the plastic component.

Applications

There are numerous applications for this relatively new molding process. Mobile phones, laptops, tablets, and game consoles have electronics embedded in plastic. The automotive industry also uses the process to build dashboards and consoles. The aerospace industry is also a big user of the IME process, as aircraft feature multiple touch pads and controls in the cockpit and galley. Everyday consumer appliances like microwaves, stoves, fridges, dishwashers, and washing and drying machines even make use of in-mold electronics.

Challenges

Molding and curing all graphical interfaces into a 2D substrate presents many challenges, many of which are exacerbated when the 2D substrate and over-molding process must be done at high temperatures.

Eliminating these challenges comes down to having an in-depth understanding of thin film, ink, adhesives, and other process materials. Like any manufacturing process, every step is critical and impacts the quality of the final product. Even making one mistake in the material selection process means the entire project is at risk. 

Lastly, the number of defects that may or may not occur during the IME process is also a big challenge. Once defects occur, the parts cannot be repaired, especially if the over-molded portion is completed since the electronics are completely covered and cannot be accessed. To prevent defects in products, the yield must be constantly monitored. 

Have Questions About In-Mold Electronics? Contact Silver Basis Engineering Today

As challenging as IMD, IML, and IME molding processes are, you can rest assured that Silver Basis Engineering has the necessary knowledge and experience to ensure high-quality results. Founded over 20 years ago, we hold over 511 patents, 20 National Fine Model Awards, and have multiple quality accreditations and certifications. You can learn more about our capabilities by visiting our About Us page. If you have questions about our in-mold electronics process or want to request a quote, please contact us today.