As electronic devices continue to shrink while growing in power and functionality, the demand for compact, high-performance PCBs has surged. One of the most critical technologies enabling this trend is the stacked microvia. But what exactly are stacked microvias, and why are they so important in 2025?
1. Introduction to Stacked Microvias
What Are Microvias?
Microvias are tiny vias—typically less than 150 microns in diameter—used to connect different layers in a PCB, especially in HDI (High-Density Interconnect) boards. Unlike traditional through-holes, microvias are laser-drilled and only span a few layers.
Definition and Structure of Stacked Microvias
Stacked microvias are multiple microvias aligned vertically, connecting three or more layers. They are filled and plated to form a solid vertical interconnect, unlike staggered microvias, which offset vias across layers.
2. The Role of Stacked Microvias in Modern PCB Design
Why Microvias Matter in HDI PCBs
In high-speed and compact devices, signal integrity and space optimization are key. Stacked microvias allow for greater routing density, reduced layer count, and improved signal flow—all essential in modern PCB design.
Stacked vs. Staggered Microvias: Key Differences
| Type | Alignment | Reliability | Cost | Density |
| Stacked | Vertical stack | High (with proper filling) | Higher | Very High |
| Staggered | Offset | Higher fatigue resistance | Lower | Moderate |
3. Applications of Stacked Microvias
Stacked microvias are found across industries where miniaturization and performance are critical:
- Smartphones and Wearables: Needed for compact form factors with multi-layer routing.
- Automotive Electronics: Enable high-reliability ADAS, EV battery management, and infotainment systems.
- High-Frequency Devices: Ensure stable performance at GHz frequencies.
- Medical and Aerospace: Support lightweight and ultra-reliable embedded electronics.
4. Advantages of Using Stacked Microvias
- Space-Saving and Miniaturization: Essential for slim and portable products.
- Improved Electrical Performance: Shorter vertical interconnects mean less signal loss and better EMI performance.
- Enhanced Routing Density: Supports more complex circuits in smaller boards.
- Better Thermal Management: Efficient heat dissipation through filled vias.
5. Manufacturing Process of Stacked Microvias
Creating stacked microvias involves several advanced steps:
- Laser Drilling: Precise drilling of microvias on inner layers.
- Sequential Lamination: Layer-by-layer buildup to enable stacking.
- Via Filling and Copper Plating: Conductive filling ensures strong electrical connection.
- Inspection and Testing: AOI, cross-section analysis, and stress testing ensure long-term reliability.
6. Common Challenges and How to Overcome Them
Reliability Issues
Poor via filling or plating can lead to delamination, cracking, or open circuits under thermal or mechanical stress.
Solution: Use advanced electroplating and laser systems and ensure tight process control.
Manufacturing Cost
Stacked microvias increase fabrication time and tooling cost.
Solution: Optimize design to use stacked microvias only where absolutely necessary.
7. Stacked Microvias vs. Other Via Types
| Via Type | Layers Connected | Layers Connected | Use Case |
| Through-Hole | All | Low | Simple, low-density PCBs |
| Blind Vias | Outer to inner | Medium | Medium-density, 4-6 layer PCBs |
| Microvias | One or more pairs | High | HDI PCBs |
| Stacked | Multiple inner | High | Ultra HDI, space-critical apps |
8. How Much Do Stacked Microvias PCBs Cost in 2025?
The price of stacked microvias PCBs in 2025 depends on layer count, complexity, and volume:
- 4-Layer HDI PCB with stacked microvias: ~$150–$250 per m²
- 8-Layer HDI PCB: ~$280–$400 per m²
- 10+ Layer Ultra HDI: $450–$700+ per m²
Key cost drivers:
- Via count and stacking level
- Type of lamination (sequential lamination increases cost)
- Quantity and turnaround time
9. Choosing the Right PCB Manufacturer for Stacked Microvias
Selecting the right supplier is critical for quality and cost efficiency. Look for:
- Experience in HDI PCB fabrication
- Advanced laser and via filling equipment
- Strict QC and IPC Class 3 certification
Why Choose KingSunPCB?
At KingSunPCB, we offer:
- 12+ years of experience in stacked microvias PCBs
- Full in-house production and testing
- Competitive pricing and global shipping
Request a quote today to get a fast, customized offer for your HDI PCB needs.
10. Conclusion
Stacked microvias are essential for advanced PCB miniaturization in 2025. As the demand for compact, high-speed electronics continues to grow, understanding and leveraging this technology will be critical for engineers and product designers. By partnering with experienced manufacturers like KingSunPCB, you can ensure both performance and reliability in your next-generation devices.