Designing with SiP (System-in-Package): Opportunities and Trade-Offs for Embedded Engineers

Introduction: SiP Is Redefining Embedded Integration

As embedded devices shrink while becoming more capable, engineers face mounting challenges in PCB real estate, thermal management, and BOM complexity. Enter System-in-Package (SiP) — a packaging technology that integrates multiple dies (MCU, memory, PMIC, RF, etc.) into a single module.

Unlike traditional SoC integration, SiP allows heterogenous components to be tightly packaged while retaining design modularity and flexibility. But with these advantages come new trade-offs in cost, layout, thermal behavior, and supply chain.

This article provides a practical guide for embedded engineers evaluating SiP options for their next product — what problems it solves, where it fits best, and what to watch out for.

What Is System-in-Package (SiP)?

A SiP integrates multiple ICs and passive components into a single miniaturized package:

MCU or SoC + memory (DRAM, flash)
PMIC, passives, clock sources
RF transceivers (BLE, Wi-Fi, LoRa)
Optional antennas or shielding

It appears on the board as a single BGA or QFN module — simplifying assembly and reducing layout area.

Long-tail keyword example: "What is a System-in-Package and how is it different from SoC?"

Answer: SiP integrates multiple chips in one package but allows for heterogeneity (e.g., different process nodes). SoCs integrate functions onto one die. SiPs provide modularity, faster time to market, and easier upgrades.

Key Benefits of SiP for Embedded Designs

Space savings: Ideal for wearables, sensors, medical implants
Faster time to market: Pre-validated reference designs
Simplified PCB layout: Fewer nets, no DDR trace tuning
Reduced BOM complexity: One part replaces several
Better signal integrity: Short interconnects within the package
Factory calibration: SiPs often include pre-tested RF chains

Examples:

Murata Type 1SC (NB-IoT + MCU + PMIC)
Nordic nRF5340 SiP (dual-core BLE + memory)
Octavo OSD32MP1 (STM32MP1 Linux SiP)

Common SiP Applications

Wearables: Smart rings, fitness trackers
Smart sensors: Asset tracking, environment sensing
Medical devices: Patches, injectors
Industrial IoT: Condition monitoring, low-power nodes
Edge AI: Small modules with integrated AI accelerators

SiP vs. SoC vs. Module: What’s the Difference?

Feature	SiP	SoC	Module
Integration	Multiple dies in one package	One die, high integration	PCB with discrete parts
Flexibility	Medium (configurable BOM)	Low (fixed functions)	High (replaceable chips)
Area savings	Excellent	Good	Moderate
Cost	Medium-high	Low (high volume)	High
Design time	Fast	Long	Fast

Key Design Considerations with SiP

1. Thermal Constraints

Compact packages concentrate heat
Requires solid thermal vias and ground planes
Watch for self-heating with RF and PMIC in one package

2. Power Budget and Regulation

Some SiPs include internal PMICs; others need external rails
Ensure power-up sequencing is well-defined

3. Routing and Assembly

Fewer high-speed signals to route externally
May require controlled impedance pads or blind vias
BGAs demand higher-layer PCBs or via-in-pad designs

4. Testing and Debug

Limited access to internal signals
Rely on debug ports (e.g., SWD, JTAG)
Consider boundary scan or BIST if available

5. EMI and Shielding

SiP may include RF blocks; isolate analog/digital domains
Use PCB shielding cans if SiP lacks internal shielding

Supply Chain and Longevity

Fewer suppliers offer custom SiP configurations
Relying on a single vendor SiP may affect long-term availability
Choose SiPs with strong roadmap and production guarantees

Cost Implications

SiPs reduce design and assembly costs — but may cost more per unit
Ideal for low-volume or space-constrained applications
Evaluate cost of alternate discrete + SoC + PCB layout solution

Summary: When to Use SiP in Embedded Projects

SiP technology bridges the gap between full custom design and off-the-shelf modules. It excels in applications where size, integration, and time to market matter more than cost or absolute performance. Understanding its thermal, electrical, and supply chain implications will ensure a successful deployment.