Interconnecting in Three Dimensions
The function of plastic components is often to protect or carry other parts. A housing, for example, can contain electronic circuits, while a plastic holder may carry a sensor. Bosch researchers are now adding an additional, electronic function, creating a housing that also replaces the circuit board and sensor holder with built-in conductors.
Almost all plastic components - from computer keyboards and telephone handsets to power tool housings - are produced using an injection molding process. Electronic circuit boards are later added as separate modules during the assembly process. However, this could soon change for some vehicle components, thanks to the new MID (Molded Interconnect Device) technology being developed by researchers at Bosch.
The new technology allows electronic circuits to be directly attached to the plastic parts, thereby creating three-dimensional injection molded interconnect devices. The advantages are obvious, as fewer parts are needed to make individual components. As a result, products can be further miniaturized, certain assembly steps can be dispensed with and less material is required.
Bosch favors using two techniques for structuring electronic circuits on plastic surfaces. The two-component technique involves the injection molding of two different types of plastic to create a single component.
One of the two materials used in this process must have a structure or surface composition that allows it to be metallized, as this is required to create conductor lines. The second method uses laser beams to either structure metal-coated surfaces or locally activate the plastic surface so that it can be metallized for the creation of tracks. The interconnect devices can subsequently be assembled with electronic components and bonded with conductive adhesives, for example.
This allows sensor chips, capacitors and integrated circuits to be fully included in a 3D plastic interconnect device. When selecting plastics for these components, the researchers do more than determine that the material is optimally suited for the production process. They must also ensure that it meets the special testing criteria for Bosch products, which require MID components to withstand temperatures of up to 150 degrees Celsius as well as intense vibratory stress, without any sign of damage.
The new technology allows electronic circuits to be directly attached to the plastic parts, thereby creating three-dimensional injection molded interconnect devices. The advantages are obvious, as fewer parts are needed to make individual components. As a result, products can be further miniaturized, certain assembly steps can be dispensed with and less material is required.
Bosch favors using two techniques for structuring electronic circuits on plastic surfaces. The two-component technique involves the injection molding of two different types of plastic to create a single component.
One of the two materials used in this process must have a structure or surface composition that allows it to be metallized, as this is required to create conductor lines. The second method uses laser beams to either structure metal-coated surfaces or locally activate the plastic surface so that it can be metallized for the creation of tracks. The interconnect devices can subsequently be assembled with electronic components and bonded with conductive adhesives, for example.
This allows sensor chips, capacitors and integrated circuits to be fully included in a 3D plastic interconnect device. When selecting plastics for these components, the researchers do more than determine that the material is optimally suited for the production process. They must also ensure that it meets the special testing criteria for Bosch products, which require MID components to withstand temperatures of up to 150 degrees Celsius as well as intense vibratory stress, without any sign of damage.
A laser is used to structure the conductor paths on the molded interconnect device.
