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20 DESIGN007 MAGAZINE I FEBRUARY 2024 e printed circuit has traditionally served as the platform for mounting and intercon- necting active and passive components on the outer surfaces. Companies attempting to improve functionality and minimize printed circuit board size now consider embedding a broad range of components within the circuit structure. e fact is that more than 70% of the com- ponents occupying space on a typical printed circuit board are passive (resistors, capaci- tors, inductors). Although most discrete pas- sive components on a board's surface will have small outlines, they can occupy up to 50% of its surface area. A key issue is dealing with the shrinking surface area required on the circuit board for passive components and the inter- connect complexity of the larger, higher I/O components sharing the same space. e solu- tion for many applications is to distribute most of the passive components directly onto the circuit pattern within the subsurface layers of the multilayer circuit board. Processes have steadily evolved for embed- ding and interconnecting a wide range of com- mon passive components: resistor, capacitor, and inductor elements. e materials incorpo- rated into the circuit board during manufacture become an integral part of the PCB's structure. Graphically represented in Figure 1 are exam- ples of the most common formed passive com- ponents that may be considered for embedding. • Formed resistors: Several companies have developed material sets and fabrication processes for forming thick- and thin-film resistor elements. • Formed capacitors: e capacitor dielec- tric separating the copper surfaces of the power and ground plane is an organic polymer thick film or ceramic thin film composite. • Formed inductors: A specific inductance can be formed within the copper circuit pattern, configured in a spiral-like geometry. Tips and Tricks for Embedding Resistor Components Designers Notebook Feature Column by Vern Solberg, CONSULTANT Figure 1: Formed passive component examples.