The packaging technology of power management IC (PMIC) directly affects the heat dissipation performance, electrical characteristics, size adaptability, and final application scenarios of the chip. According to current industry practices, packaging forms can be classified into the following three categories, and typical cases are used to illustrate their design logic and application adaptability:
1、 Traditional packaging form: mature technology, strong universality
DIP (Dual In Line Package)
Structure: Double row pins directly inserted into PCB through holes, early standard packaging form.
Features: High mechanical strength, easy manual welding, but large size, low pin density (generally ≤ 100 pins), poor heat dissipation.
Typical applications: Low power management modules (such as early versions of CL4056E lithium battery charging IC) or basic voltage stabilization circuits in industrial control boards.
SOP/SOI (Small Form factor Packaging/Surface Mount Packaging)
Structure: Surface Mount Technology (SMT), with pins extending in a "seagull wing" shape from both sides.
Upgrade direction: Derive thin versions (such as TSOP, SSOP), further compressing thickness and pin spacing.
Representative model: Xinlian CL4056E (ESOP8 package), used for 1A lithium battery charging management, balancing miniaturization and cost control.
SOT (Small Shape Transistor Package)
Structure: Metal or plastic packaging, with few pins (usually ≤ 6), optimized for low-power design.
Applicable scenarios: LDO (Low Dropout Voltage Regulator) in wearable devices, such as headphone charging case power management.
2、 Advanced high-density packaging: the core of miniaturization and high efficiency
QFN (Leadless Quad Flat Package)
Innovation point: Metal heat dissipation pads are installed at the bottom, which conduct heat through the PCB; Pin free design reduces parasitic inductance.
Advantages: High power density (such as a synchronous buck circuit with an efficiency of 96%), compact size (typically 4 × 4mm).
Case: Nanxin NX9813 (QFN4x536), supporting 5V/3.4A fast charging and TypeC protocol, used for mobile power SOC.
WLCSP (Wafer Level Chip Size Packaging)
Technical essence: Packaging is directly completed on the wafer, with a size of ≈ bare chip (without packaging substrate).
Extreme miniaturization: such as Nordic nPM1100 (2.075 × 2.075mm), integrated with USB charger+DC/DC voltage reduction, used for powering nRF53 Bluetooth SoC, with a PCB footprint of only 23mm ².
BGA (Ball Grid Array Packaging)
Design features: Bottom solder ball array replaces pins, high I/O density (hundreds to thousands), excellent high-frequency characteristics.
Applicable fields: Multi channel power management PMIC, such as server CPU power supply module.
3、 Packaging for high-performance and high integration requirements
LGA (Grid Array Packaging)
Structure: The bottom metal pad contacts the PCB and has stronger vibration resistance than BGA.
Scenario: Vehicle grade PMIC (such as engine control unit) needs to withstand mechanical stress and high temperature.
3D stacked packaging (such as PowerStack) ™）
Technology integration: Vertical stacking of multiple chips (such as controllers+MOSFETs) to reduce interconnect losses.
Case: Microchip MCP16701 (8 × 8mm VQFN package) integrates 8 buck converters and 4 LDOs for AI acceleration card power supply, saving 48% of area compared to discrete solutions.
Comparison Table of Key Dimensions for Packaging Selection
|Package type | Pin form | Typical size range | Heat dissipation performance | Typical application scenarios|
|DIP | Dual row direct insertion pins | Large (>10 × 10mm) | Low | Experimental board, industrial basic module|
|SOP/TSOP | Wing shaped pins on both sides | Medium (5 × 6mm) | Medium | Consumer Electronics Power Management IC|
|QFN | Bottom pad+surrounding contacts | Compact (3 × 3~5 × 5mm) | High | Fast charging IC, mobile device PMIC|
|WLCSP | Wafer level solder balls | Extremely small (≈ chip) | Medium | Wearable devices, microsensors|
|BGA/LGA | Full Bottom Array Solder Balls/Pads | Flexible (5 × 5~40 × 40mm) | Extremely High | PMIC for Server and FPGA Matching|
4、 The core logic of packaging selection
Space limitation: WLCSP (such as nPM1100) is preferred for wearable devices; Mobile power banks tend to be QFN (NX9813).
Power and heat dissipation: Choose QFN/BGA for current>3A; Multi output requires 3D stacking (MCP16701).
Cost and process: DIP/SOP is suitable for low complexity designs; BGA needs to be equipped with reflow soldering and X-ray inspection equipment.
Protocol support: Fast charging/multi port output ICs (such as USB PD) require high pin counts, promoting the popularization of QFN/BGA.
In the future, PMIC packaging will continue to evolve towards system level packaging (SiP), integrating digital control, power devices, and passive components to achieve dual breakthroughs in "power density" and "functional integration" in the fields of AIoT and electric vehicles.