Embedded Components in PCB

Electronic parts that are integrated into the layers of a printed circuit board (PCB) during the manufacturing process are referred to as embedded components, also known as embedded passive devices or embedded passives. These pieces are enclosed in the PCB, as opposed to their surface-mounted equivalents. Embedded components are preferred because of their ability to increase signal integrity, reduce overall PCB dimensions, save space, and increase the overall reliability of the circuit.

Types of Embedded Components: Typical embedded components encompass resistors, capacitors, inductors, and at times, diodes. These passive components are typically embedded to optimize the PCB's electrical characteristics.

Integration Process: During PCB fabrication, desired components are positioned within the PCB layers before these layers are laminated together. This process entails printing, etching, or laser-cutting the component's patterns onto the PCB layers. Subsequently, the layers are stacked and laminated, effectively encapsulating the components within.

Advantages:

• Space Optimization: Embedded components liberate surface area on the PCB, facilitating the creation of more compact and space-efficient designs.
• Enhanced Signal Integrity: Shorter traces and reduced parasitic effects associated with embedded components tend to enhance signal integrity.

 Challenges:

• Complex Design: Integrating embedded components necessitates meticulous design and planning to ensure optimal electrical performance.
• Manufacturing Expertise: PCB manufacturers require specialized equipment and expertise to craft PCBs featuring embedded components.

Applications: Embedded components are especially prevalent in high-frequency RF (Radio Frequency) and microwave circuits, where preserving signal integrity is paramount. They also find utility in compact consumer electronics and industrial applications.

Testing: Assessing embedded components can be more intricate compared to testing surface-mounted counterparts, often requiring dedicated testing equipment and techniques.

Customization: Embedded component values and types can be tailored to align with the precise requirements of the circuit.

In summary, embedded components, which are passive electronic elements seamlessly integrated into the PCB layers, offer benefits in terms of space efficiency, signal integrity enhancement, and reliability. Their successful utilization demands careful attention to the design and manufacturing considerations.

Allegro PCB Editor supports embedding of passive and active components within the inner substrates of a PCB. This capability is also available in the Allegro Package Designer+ tool.

The main functionality used to place embedded components within the finished board is contained within Allegro PCB Editor. However, the method used to define a component as a candidate to be embedded is a component definition or instance-level property called EMBEDDED_PLACEMENT. This property can be assigned at the schematic level and can be assigned a value of REQUIRED, OPTIONAL, or EXTERNAL ONLY.

Once the property is added in the schematic, the design can be brought in Allegro PCB Editor (with the Miniaturization option).

Use the Cross Section Editor > Embedded column to set Embedded Status and Attach Method.

Once all the above steps are done, the placement will provide you option to place on the inner layers as well.

The 3D Canvas in Allegro PCB Editor also supports viewing of embedded components: