What is embedded passive technology?
Embedded passive technology refers to the process of integrating passive components such as resistors, and capacitors, directly onto the inner layers of a PCB during the manufacturing process. This technique can increase PCB functionality without increasing the area of the substrate.
Figure 1: Surface mounted resistors and embedded resistors
Comparison between embedded passive technology and surface mount technology
Surface mount technology uses both discrete components (such as resistors, capacitors, and diodes) and integrated circuits (such as chips and packages) that are mounted onto the surface of the PCB by solder joints. On the other hand, embedded passive technology offers planar resistive elements made into a thin film that become part of the etched and printed circuitry on the PCB layer or creates a cavity in which components remain embedded within the printed circuit board. Compared with SMT, embedded components can offer some advantages.
Figure 2: Comparison between surface mount technology and embedded passive technology
Increase routing area: By reducing the number of surface-mounted passive components, embedded passive technology increases the routing area available on the PCB, allowing for the integration of more complex electronic systems and functionalities within a smaller space. This is particularly advantageous for applications that require miniaturization or space-constrained environments, such as mobile devices, wearables, medical devices, and IoT applications. Additionally, the increased packaging density can bring higher performance and more efficient electronic systems.
Improve electrical performance: The direct integration of passive components into the substrate reduces the parasitic capacitance and inductance that can arise from the use of discrete components. Additionally, the closer proximity of the passive components to the active components on the PCB can reduce the signal path length and therefore reduce the resistance and capacitance of the interconnects, which can also improve the electrical performance of the circuit. Reduced losses and noise yield an improvement in electrical signal performance, especially at high frequencies.
A clear disadvantage of embedded passives is that they cannot be replaced in the same manner as surface-mounted or through-hole components if they are defective or damaged. Therefore, it's important to thoroughly test and qualify embedded passive components before they are integrated into the PCB.
