1、 Core process technology
1. Precision lamination and interconnection process
Key technical points of the process, precision control
Inner layer production core board cutting → LDI laser imaging (line width ± 0.05mm) → acid etching → AOI detection line width tolerance ± 0.05mm
Stacking laminated core board and semi cured sheet (PP sheet) alternately → Vacuum hot pressing (180 ℃/400psi) → Cooling and setting interlayer offset ≤ 75 μ m
Laser drilling CO ₂/UV laser drilling blind buried hole (aperture 0.1-0.2mm) → plasma slag removal hole position accuracy ± 0.03mm
Chemical deposition of copper through hole metallization (0.3 μ m) → electroplating thickening (hole copper ≥ 25 μ m) → hole filling electroplating (HDI board) with a depth to diameter ratio ≥ 8:1
Surface treatment ENIG immersion gold (contact area)/OSP (welding area)/immersion silver (high-frequency signal) immersion gold layer thickness 0.05-0.1 μ m
2. Breakthrough in advanced technology
Any Layer Interconnect (ELIC):
The entire board adopts laser micro holes (aperture ≤ 50 μ m), eliminates through holes, and achieves 20+layers of high-density interconnection (mainstream technology for mobile phone motherboards).
Buried resistance and capacitance technology:
The inner layer is embedded with resistor/capacitor components (accuracy ± 5%), reducing surface mounting space by 30%.
Mixed pressure design:
High frequency zone (Rogers RO4350B)+FR-4 digital zone synchronous compression, insertion loss< 0.2dB@10GHz (5G base station application).
2、 Core advantage: Dual leap in performance and integration
1. Electrical and structural performance
Advantages of multi-layer board compared to double-sided board for improvement in indicators
Signal integrity dedicated power supply/layer, impedance control ± 5%, crosstalk reduction 30%, supports 112Gbps transmission
Integrated density supports 0.35mm pitch BGA and increases component density by 5 times for 01005 components
Heat dissipation capability: Inner layer of 2oz thick copper thermal conductivity+heat dissipation via array reduces thermal resistance by 40% (equivalent power consumption)
Reliability passed -55 ℃~150 ℃ thermal cycle 100000 times industrial environment life>15 years
2. Economic breakthrough
Space compression: 12 layer board has a volume 70% smaller than double-sided board (smartphone motherboard thickness ≤ 1.0mm);
System cost reduction: Integrating multiple double-sided board functions, reducing connector and cable costs by 30%.
3、 Application Fields and Typical Cases
1. Communication and Computing (45%)
Application scenario technical solution performance parameters
5G base station AAU antenna 12 layer mixed voltage (FR-4+RO4350B) impedance ± 3%, insertion loss ＜ 0.3dB@28GHz
AI server motherboard 16-20 layers HDI+buried resistor and capacitor support PCIe 5.0 (32GT/s)
Optical module PCB 8-layer ultra-thin board (0.4mm) with high temperature resistance (Tg ≥ 170 ℃)
2. Automotive electronics (25%)
Intelligent driving domain controller:
8-layer aluminum substrate+2oz thick copper, thermal conductivity of 4.0W/mK, vibration resistance of 20G (such as Tesla FSD motherboard).
800V battery management system:
6-layer ceramic filled FR-4, insulation resistance>100G Ω, withstand voltage 3kV.
3. High end consumer electronics (20%)
Folding screen phone: 10 layer rigid flex joint plate, bending radius 3mm (Samsung Galaxy Z Fold).
VR headset: 6-layer HDI board, supports 4K@120Hz Video transmission.
4. Special fields
Medical imaging: Low loss board (Df<0.02), ensuring the accuracy of MRI gradient coils;
Satellite communication: Polyimide multilayer board, resistant to cosmic rays>100krad.
4、 Process Challenges and Countermeasures
Technological progress in challenge solutions
High frequency loss control PTFE mixed pressure+nano ceramic modified resin domestic carbon hydrogen plate (Dk=3.0) mass production
Ultra thin board warping symmetrical stacking design+low CTE material (CTE<10ppm/℃) laser real-time deformation compensation technology
Uneven pulse reverse electroplating and oscillation filling with a depth to diameter ratio of 12:1 for microporous plating, breakthrough in microporous capability
