High Power electronics form the crucial interface between the source and the load in nearly every modern electrical system; enabling the efficient control, conversion and conditioning of significant amounts of electrical energy. This field encompasses a diverse range of devices, including battery chargers, DC-DC converters, high-capacity inverters, robust power supplies, precision heating controls and high-speed power switches. These power components are indispensable in shaping raw electrical power into the precise, regulated forms required by countless critical applications.
Power Device Applications & Functional Challenges:
- Industrial applications of high-power electronics underpin essential operations in sectors such as industrial motor drives (pumps, compressors, conveyors), transportation (electric trains, marine propulsion, vehicle charging infrastructure), utility-scale renewable energy integration (solar & wind farm grids) and heavy-duty manufacturing processes (induction heating & welding).Â
- Challenges of handling high-power densities, involves excessive thermal loads that depend on highly efficient thermal management solutions to prevent component failure and ensure long-term reliability. Other key challenges include mitigating high electromagnetic interference (EMI), achieving high power density in compact designs and maintaining system stability under dynamic load conditions.
PCBs: The Power that Enables Power DevicesÂ
PCB Technologies enable power devices by providing our PCBs with specialized technological advances for handling high currents and voltages, unlike standard boards. This is achieved through thicker copper traces, robust substrates, complex materials and innovative designs that safely distribute power to components and effectively dissipate heat. Our expertise also extends to many more must-haves to enable optimum high-power component/device operation.
High-Power PCB Solutions:
- Advanced Thermal Management
- Robust Materials
- High-Density Interconnect (HDI)
- Reliable Data Transmission
- Power & Voltage Handling
Advanced Thermal Management:Â Applications that impose extreme thermal loads must be carefully managed during the PCB design phase; requiring a multidisciplinary approach that combines materials science, mechanical and electrical engineering, along with advanced manufacturing technologies to effectively dissipate heat from components.Â
- Thick Copper Layers: Using 2 oz. (70 μm) or heavier copper layers increases the thermal mass and provides a lower thermal resistance (θJA), acting as a heat dissipater.
- Thermal Vias:Â Plated through-holes placed under or near heat sources to conduct heat directly from component solder pad through the PCB layers to a heat sink or heat-spreading plane; increasing the effective k (thermal conductivity) of the stack-up.
- Metal Core PCBs (MCPCB) or Embedded Metal:Â Using materials like aluminum or copper as the core substrate or embedding copper coins/plugs serving as highly conductive heat spreaders.
- Heat Sinks & Fans:Â Integrated mechanical solutions for forced or passive convection cooling.
Robust Materials:Â Materials with high thermal stability, high dielectric strength and appropriate thermal expansion characteristics.Â
- High Glass Transition Temperature (Tg): Using laminate materials with a high Tg >170∘C, prevents substrate material from softening, delaminating or exhibiting dimensional instability at high operating temperatures.
- Low Coefficient of Thermal Expansion (CTE):Â Materials with a low CTE (especially in Z-axis) minimize mechanical stress on plated through-holes (vias) during thermal cycling, preventing barrel cracking and ensuring connection integrity.
- High Comparative Tracking Index (CTI): The CTI must be high (CTI≥400V) to prevent the formation of conductive carbon pathways (tracking) across the surface of the insulator material under electrical stress and contamination; leading to short circuits.
High-Density Interconnect (HDI):Â For control and signal processing sections of a high-power system to manage the complexity and miniaturization required for modern designs. To increase component density, reduce overall board size/weight and improve electrical performance through shorter signal paths.Â
- Micro-vias: Extremely small laser-drilled vias (typically ≤150μm) used for layer-to-layer connections. Generally blind (connecting an outer layer to an inner layer) or buried (connecting two inner layers).
- Staggered & Stacked Micro-vias:Â Techniques for connecting multiple layers with micro-vias, offering more routing channels than traditional through-vias.
- Fine Pitch Components:Â HDI facilitates the use of advanced, high-pin-count integrated circuits (ICs) with fine pitch Ball Grid Arrays (BGAs) and Quad Flat No-Lead (QFN) packages by providing the necessary fine routing resolution and capture pad size.
Reliable Data Transmission:Â Minimizing signal degradation (attenuation, reflection, crosstalk) to ensure control logic and communication protocols function properly.Â
- Controlled Impedance: Traces carrying high-speed or RF signals are designed with specific dimensions and separated from a reference plane by a precise dielectric thickness to maintain a characteristic impedance (Z0) (50 Ω for single-ended, 100 Ω for differential pairs). This prevents signal reflections.
- Differential Signaling:Â Using a pair of traces (differential pair) to transmit a signal and its inverse. This configuration improves Common-Mode Noise Rejection (CMNR) and reduces Electromagnetic Interference (EMI) by coupling the noise equally onto both lines, which is then canceled out at the receiver.
- Low-Loss Dielectrics: Utilizing materials with a low Dissipation Factor (Df) and a stable Dielectric Constant (ϵr) over frequency (PTFE or specialized epoxy resins) to minimize signal loss (attenuation) at high data rates.
Power & Voltage Handling: Managing high currents and high potential differences without breakdown or excessive heat generation. Ensures current carrying capacity is sufficient, voltage clearances are maintained and resistive power loss (P=I2R) is minimized.Â
- Current Carrying Capacity: Traces are dimensioned (width and copper thickness) based on the IPC-2152 standard to ensure the temperature rise (ΔT) due to I2R heating is within acceptable limits. Wider and thicker traces are used for high current paths.
- Creepage & Clearance:
- Clearance is the shortest distance through air between two conductors, preventing arcing at high potential differences.
- Creepage is the shortest distance along the surface of the insulator between two conductors, preventing surface flashover or tracking. Both are dictated by the system’s operating voltage, pollution degree and material CTI.
- Power Planes:Â Typically thick, copper layers used for distributing high currents and maintaining low DC resistance (RDC) and low inductance (L) across the board. They also function as effective thermal and EMI shields.
Advanced Miniaturization Solutions for High Power PCBsÂ
Organic Package Substrates & Advanced IC Packaging Solutions are essential in the design and fabrication of High Power PCBs. They address critical challenges of thermal management, power delivery and miniaturization. These key components act as a high-performance, high-density intermediary; bridging the gap between the ultra-fine features of the IC (Chip) and the coarser features of the main PCB (Board).
Organic Package Substrates: An organic package substrate is in itself a high-end PCB, often made of materials like Bismaleimide Triazine (BT) resin or Ajinomoto Build-up Film (ABF). Key functions in high-power applications include:
- Thermal Management
- Heat Dissipation Pathway:Â While organic materials typically have lower intrinsic thermal conductivity than ceramic, high-power organic substrates are engineered with features like internal copper planes and thermal vias to efficiently spread and conduct heat away from the IC silicon die. This is crucial in preventing component overheat causing performance degradation or failure in high-power devices.
- Coefficient of Thermal Expansion (CTE) Matching:Â Advanced organic substrates can offer a low CTE that closely matches the silicon die. This reduces thermal stress on the solder joints (in Ball Grid Arrays or BGAs) during power-up/power-down cycles and high-temperature operation; improving long-term reliability of the high-power assembly.
- High-Density Interconnect (HDI) & Miniaturization
- Scaling Down:Â Finer line widths and spacing (1/1 mil or less) and smaller micro-vias compared to standard PCBs, allows for a greater numbers of connections (high I/O density) to fan out from the small IC die to the larger PCB; enabling the use of powerful, compact chips.
- Build-up Technology:Â Organic substrates often utilize sequential Build-Up (BU) processing with materials like ABF, enabling the fine-pitch wiring and multi-layer structure necessary for advanced IC packages like BGAs.
- Electrical Performance
- Signal & Power Integrity:Â Using low-loss dielectric materials (BT resin) to maintain signal integrity for high-speed digital and RF signals and their structure, allows for low-inductance power delivery paths, which is vital for the stable, high-current power required by modern high-performance processors and power electronics.
Advanced IC Packaging Solutions: Advanced IC packaging, which often rely on organic substrates, are essential enablers of high-power PCBs. Architectures include: Flip-Chip BGA (FCBGA), System-in-Package (SiP, Multi-Chip Module (MCM).
- High-Current Power Delivery
- Reduced Inductance:Â Advanced packages like Flip-Chip (where the die is inverted and connected via solder bumps) on a substrate, reduces the length of the electrical path compared to traditional wire bonding. This minimizes parasitic inductance, which is critical for high-current power switching components (MOSFETs, GaN, SiC devices), where rapid switching can generate destructive voltage spikes (V=LdtdI).
- Power Distribution Network (PDN) Optimization:Â The substrate is designed with dedicated power and ground planes right beneath the IC to ensure a stable, low-impedance power source, a fundamental requirement for high-power chips.
- High-Performance Integration
- System-in-Package (SiP) & MCM:Â Solutions that integrate multiple components (ICs, passives, memory) into a single module on the substrate. For high-power systems, this reduces the overall footprint and shortens the distance between power management circuitry and the load; boosting power efficiency and enhancing transient response.
- Vertical Stacking (3D Integration):Â Die stacking allows for a greater power density in a smaller area, allowing the substrate to handle the concentrated heat and power flow more effectively.
- Mechanical & Environmental Protection
- Mechanical Support:Â The package substrate provides a stable and robust platform that protects the fragile silicon die from mechanical stress (vibration, shock) during assembly and operation.
- Encapsulation:Â A final-step process of encasing the IC and its internal wire bonds in a protective material, like epoxy molding compound (EMC) to shield it from physical damage, moisture and contaminants and to help dissipate heat. This promotes long-term reliability required by high-power, industrial or automotive applications.Â
Sharing the Power
PCB Technologies is with you every step of the way, from initial PCB design, through fabrication, to full system integration. We bring to the table seasoned engineers with cutting-edge know-how, advanced PCB manufacturing processes and our dedicated iNPACK Division for expert miniaturization and IC packaging capabilities.
We’re also an All-in-One Solutions provider with expansive facilities that ensure a speedy transition from prototype to low/mid production volumes all under one roof. In this way, we keep a watchful eye on quality, cost and timelines, while you avoid the uncertainties of jobbing-out to external vendors.
Let’s talk about power devices or any other important projects you’re working on.
