Although both packaging substrates (IC packaging boards) and printed circuit boards (PCBs) serve connection and support functions in electronic devices, there are essential differences between the two in terms of definition, functional positioning, technical parameters, material processes, and application scenarios.
1. Core Definitions and Functional Positioning Differences
1.Packaging Substrate
lDefinition: A special substrate that directly carries chips (ICs), belonging to a high-end subcategory of PCBs. It provides electrical connections, physical support, thermal protection, and multi-pin integration, bridging the chip with external circuits.
lCore Functions:
lHigh-density electrical interconnection: Connecting chips to PCBs through micron-level lines.
lChip protection and heat dissipation: Isolating environmental erosion and conducting chip heat.
lMiniaturization support: Reducing package size and increasing integration (e.g., multi-chip modularization).
2.PCB (Printed Circuit Board)
lDefinition: A general support and electrical connection carrier for electronic components, formed by printing technology to create conductive lines.
lCore Functions:
lCircuit integration: Connecting resistors, capacitors, chips, and other components to form a complete circuit.
lMechanical support and signal transmission: Bearing the weight of components and transmitting digital/analog signals.
lWide application scenarios: Covering consumer electronics, automotive, communication, and other fields.
2. Comparison of Technical Parameters and Structural Complexity
|
Parameter |
Packaging Substrate |
Standard PCB |
Difference Analysis |
|
Line Width/Spacing |
10~130μm (mainstream ≤25μm) |
50~1000μm (mainstream ≥50μm) |
Substrate precision requirements are 5-10 times higher |
|
Number of Layers |
2~10 layers |
1~90+ layers |
PCB has a higher number of layers, but substrate integration density is greater |
|
Unit Size |
<150×150mm (miniaturization) |
Up to 300×210mm (large size) |
Substrate needs to adapt to small chip packages |
|
Minimum Ring Width |
12.5~130μm |
≥75μm |
Substrate ring width is smaller, wiring is more precise |
|
Manufacturing Process |
Mainly semi-additive process (supports 10μm) |
Mainly subtractive process (suitable for 30μm) |
Substrate requires advanced processes to handle ultra-fine lines |
Key Differences: The packaging substrate is characterized by “micron-level precision”, while the PCB focuses more on “macro circuit integration”.
3. Material and Manufacturing Process Differences
1.Material Selection
lPackaging Substrate:
lHigh-performance materials: BT resin (high-frequency applications), ceramics (high thermal conductivity), high-frequency PTFE (low signal loss).
lMetal substrates (aluminum/copper): Enhance heat dissipation, used for power devices.
lPCB:
lMainstream substrate: FR-4 glass fiber epoxy resin (low cost, versatility).
lSpecial scenarios: Metal substrates (heat dissipation), high-frequency boards (5G communication).
2.Manufacturing Process
lPackaging Substrate:
lSemi-additive process (mSAP): Constructs ultra-fine lines (line width <10μm) through chemical copper plating, replacing traditional etching.
lCoreless board technology: Eliminates the core layer, enhancing wiring density.
lComplex hole processing: Micro-holes (<50μm) filling and metallization.
lPCB:
lDominated by subtractive process: Copper-clad boards are etched into shape, a mature process but limited in precision.
lHigh-density interconnection (HDI): Laser drilling + stacking, precision still lower than substrates.
Essential Difference: Substrate processes focus on “micron-level precision processing”, while PCB processes emphasize “macro circuit efficiency”.
4. Application Scenarios and Performance Requirements
|
Dimension |
Packaging Substrate |
PCB |
|
Core Applications |
Chip packaging (BGA/FCBGA/CSP/SiP) |
Complete machine circuit integration (motherboards, power boards, etc.) |
|
Typical Devices |
CPU, GPU, memory chips, RF modules |
Resistors, capacitors, connectors, standard ICs |
|
Performance Requirements |
High-frequency signal integrity, low latency, high heat dissipation efficiency |
General electrical connectivity, mechanical stability |
|
Industry Fields |
Semiconductor packaging, high-end sensors, AI chips |
Consumer electronics, automotive electronics, industrial control |
lTypical Cases:
lIn smartphones, processor chips connect to memory through packaging substrates and are then soldered to the PCB motherboard.
lIn high-speed communication devices, RF modules require ceramic substrates to ensure lossless signals, while control circuits use FR-4 PCBs.
5. Industry Positioning and Evolution Trends
1.Packaging Substrate:
lPositioned as “core materials for semiconductor packaging”, with high technical barriers (investment/process difficulty).
lTrend: Developing towards 10/10μm ultra-fine lines, supporting advanced packaging like Chiplet.
2.PCB:
lPositioned as “basic components of the electronics industry”, with a large market size but obvious homogenization competition.
lTrend: Upgrading to high-frequency and high-speed boards (5G/AI), flexible boards (wearable devices).
6. Conclusion: Overview of Core Differences
|
Comparison Dimension |
Packaging Substrate |
PCB |
|
Essential Role |
The “bridge” between chips and PCBs |
The “carrying platform” for electronic components |
|
Technical Core |
Micron-level interconnection (high density, high precision) |
Macro circuit integration (versatility, cost efficiency) |
|
Materials and Processes |
High-end materials (ceramics/BT) + semi-additive process |
FR-4 substrate + subtractive process |
|
Performance Focus |
Signal integrity, heat dissipation, miniaturization |
Electrical connectivity, mechanical strength |
|
Industry Barriers |
High (precision manufacturing, semiconductor association) |
Medium (mature industry chain) |