Integrated passive devices (IPDs), also known as integrated passive components (IPCs) or embedded passive components (EPC), are electronic components where resistors (R), capacitors (C), inductors (L)/coils/chokes, microstriplines, impedance matching elements, baluns or any combinations of them are integrated in the same package or on the same substrate. Sometimes integrated passives can also be called as embedded passives,[1][2] and still the difference between integrated and embedded passives is technically unclear.[3][4] In both cases passives are realized in between dielectric layers or on the same substrate.
The earliest form of IPDs are resistor, capacitor, resistor-capacitor (RC) or resistor-capacitor-coil/inductor (RCL) networks. Passive transformers can also be realised as integrated passive devices like by putting two coils on top of each other separated by a thin dielectric layer. Sometimes diodes (PN, PIN, zener etc.) can be integrated on the same substrate with integrated passives specifically if the substrate is silicon or some other semiconductor like gallium arsenide (GaAs).[5][6]
^Lu, D.; Wong, C.P. (2017). Materials for Advanced Packaging,2nd edition. Springer, Chapter 13. pp. 537–588. ISBN978-3-319-45098-8.