High-power devices such as photovoltaic systems, energy storage, fast charging, and onboard high-voltage applications have long faced four major pain points: insufficient thick-board strength, susceptibility to aging at high temperatures, severe heating under high current, and structural assembly constraints. The Bayneng Yunboard 6-layer, 6.1mm high-precision stepped-slot PCB—featuring premium base materials, cutting-edge manufacturing processes, and automotive-grade quality control—has become the preferred circuit board solution specifically designed for new energy high-power scenarios.

I. Key Specifications at a Glance

II. Five Core Advantages

6.1mm Ultra-Thick Board + Precision Stepped Slots for Perfect Structural Fit

Customized stepped slots precisely avoid interference with high-power components, copper bars, and connectors, enabling zero internal assembly conflicts. The ultra-thick substrate significantly enhances mechanical strength, offering superior resistance to deformation and impact—ideal for high-stability equipment like power distribution boxes and inverters.

Premium Shengyi S1150 Base Material for Long-Term Reliability in Extreme Conditions

With high Tg and excellent heat resistance, outstanding chemical corrosion resistance, and superior insulation properties, it reliably withstands a wide temperature range of **-40°C to 125°C**. It resists delamination and aging even under prolonged outdoor high-temperature or continuous operational conditions.

12.2:1 Ultra-High Thickness-to-Diameter Ratio + Plated Fill Vias for Low-Loss High-Current Transmission

Achieves 0.5mm micro-via processing on a 6.1mm thick board, with uniform plating in deep holes ensuring stable electrical connectivity. Lower interlayer impedance minimizes heat generation and power loss during high-current transmission, making it suitable for kiloampere-class high-power applications.

End-to-End Intelligent Manufacturing Ensures Dual Compliance in Precision & Quality Control

Equipped with advanced drilling, plating, lamination, and dedicated stepped-slot machinery: drilling accuracy ±0.02mm, slot verticality ≤0.03mm. The entire process adheres strictly to IATF16949 automotive-grade standards, with full traceability from raw materials through every production step to final inspection, ensuring exceptional batch-to-batch consistency.

Rapid Delivery + Full-Cycle Technical Support

Prototype delivery in just 72 hours, with flexible capacity for both small and large batches. Our engineering team engages early in the R&D phase to optimize stepped-slot layout, thermal routing, and thick-board processes. 24/7 after-sales support provides one-stop solutions from design to mass production.

6.1mm 6-Layer High-Precision Stepped-Slot PCB

III. Main Application Scenarios

Photovoltaic Inverters｜Energy Storage PCS Systems｜Onboard High-Voltage PDUs｜High-Power DC Charging Stations｜Industrial DC Power Distribution Equipment

IV. Three Benchmark Customer Case Studies

I. Requirement Alignment (End-to-End Follow-Up, Precise Needs Matching)

1. Client Background: A leading domestic Tier-2 photovoltaic inverter manufacturer specializing in residential and commercial PV solutions, offering 110kW–250kW string inverters with annual shipments exceeding 100,000 units. Core markets include industrial parks in China and emerging overseas regions. This collaboration focuses on custom-developing core PCB components for their next-generation high-efficiency string inverter.

2. Initial Requirements: Submitted via Bayneng Yunboard’s official website inquiry channel, the client specified a need for a 6-layer, 6.1mm-thick PCB for both main control and power boards, with key requirements: “resolve PCB warpage and delamination issues under outdoor high-temperature conditions, reduce high-current transmission losses, and accommodate compact layouts of IGBT modules and heatsinks.”

3. Detailed Requirement Breakdown: Within three working days, Bayneng Yunboard’s technical team completed client engagement via online meetings and preliminary sample testing, clarifying specific needs: ① Base material must endure long-term operation at up to 65°C outdoors and function normally at -40°C startup, meeting IEC 61215 PV industry standards; ② The 6.1mm thick board must exhibit excellent mechanical rigidity to prevent warpage under prolonged outdoor exposure; ③ Stepped slots must precisely avoid IGBT module pins and heatsinks to minimize assembly gaps; ④ Must support 300A+ high-current transmission with interlayer losses below industry average; ⑤ Prototype turnaround ≤72 hours, batch delivery ≤7 days per batch, with annual volume demand of ~30,000 units.

4. Requirement Confirmation & Solution Proposal: Based on these needs, Bayneng Yunboard delivered a customized solution specifying Shengyi S1150 high-heat-resistance base material, 12.2:1 thickness-to-hole ratio with plated fill vias, and client-specific stepped-slot geometry aligned with their inverter internal layout. Preliminary process parameters and delivery plans were submitted, and the client confirmed the proposal within three working days, initiating prototyping.

II. Process Challenges (Precise Pain Point Identification, Core Challenge Breakdown)

Considering the outdoor operating conditions and product characteristics of photovoltaic inverters, this project faced four core process challenges—common pain points in the industry for thick-board stepped-slot PCBs:

1. Thick-Board Warpage Resistance: The 6.1mm ultra-thick (6-layer laminated) board is prone to uneven interlayer stress during lamination, causing warpage. If deformation exceeds 0.3mm, it cannot fit into the inverter’s compact internal layout, compromising IGBT module assembly and thermal performance.

2. High-Temperature Reliability: Outdoor PV environments experience wide temperature swings (-40°C to 65°C). Standard base materials tend to age or delaminate over time, especially under sustained high temperatures, increasing PCB conduction impedance and destabilizing high-current transmission—potentially causing inverter failure.

3. Stepped-Slot Machining Precision: Slots must precisely clear IGBT modules and heatsinks, requiring depth tolerance ≤0.03mm, verticality error ≤0.02mm, and burr-free, chip-free edges. Otherwise, excessive assembly gaps reduce thermal efficiency and structural stability.

4. High-Current Transmission Loss: Power boards must carry 300A+, but achieving uniform plating in 0.5mm-diameter deep holes on a 6.1mm board is challenging. Non-uniform plating increases interlayer impedance, raising transmission losses and reducing inverter conversion efficiency.

III. Resolution Process (Technical Breakthrough, End-to-End Control)

To address these challenges, Bayneng Yunboard formed a dedicated task force integrating R&D, production, and QA teams, implementing targeted solutions with full-process tracking to ensure closed-loop resolution:

1. Warpage Mitigation for Thick Boards: Optimized lamination parameters using a “segmented lamination + constant-temperature curing” approach: lamination temperature controlled at 170°C±5°C, with pressure ramped in stages (0.3MPa → 0.5MPa → 0.8MPa), each held for 30 minutes to balance interlayer stress. Base materials underwent pre-baking (120°C, 2 hours) to remove moisture before lamination. Finished boards were cooled under dedicated fixtures to maintain warpage within 0.2mm.

2. High-Temperature Reliability Enhancement: Strictly selected Shengyi S1150 high-Tg (150°C) heat-resistant base material with proven thermal stability and anti-aging performance. All incoming materials underwent 100% inspection to ensure compliance with IEC 61215. Layout design was optimized with adjusted layer spacing and copper thickness to enhance thermal dissipation.

3. Stepped-Slot Precision Machining: Utilized industry-leading high-precision stepped-slot machining centers equipped with CCD vision positioning (accuracy ±0.01mm). Prior to machining, the client’s 3D inverter layout was imported for simulation to refine slot dimensions and tool paths. Real-time sampling (1 in every 10 boards) monitored slot depth, verticality, and edge smoothness, with precision polishing applied immediately if burrs were detected.

4. High-Current Loss Reduction: Enhanced via-fill plating using a combination of acid copper plating and pulse plating, with current density set at 2.5A/dm² and plating duration extended to 60 minutes to ensure uniform deep-hole coverage (plating thickness ≥25μm). Hole wall roughness was minimized to reduce contact impedance. Prototype transmission loss tests guided fine-tuning until client requirements were met.

5. Delivery Assurance: Expedited prototyping was launched on a dedicated production line, completing samples within 72 hours with accompanying test reports. Mass production leveraged fully automated lines under strict IATF16949 controls, with real-time in-process sampling to guarantee consistency. Logistics coordination ensured on-time batch deliveries.

IV. Acceptance Results (Quantified Metrics Validating Delivery Value)

The client conducted comprehensive testing per IEC 61215 and agreed-upon acceptance criteria. All results met or exceeded requirements, leading to successful approval:

1. Mechanical Performance:

① Warpage: 0.15mm (spec ≤0.3mm);

② Impact strength: ≥15J/cm², no fracture or deformation;

③ Stepped-slot accuracy: depth error 0.02mm, verticality error 0.015mm, burr-free edges, assembly gap ±0.04mm (client requirement: ±0.05mm).

2. High-Temperature Reliability:

① Thermal cycling (-40°C to 65°C, 100 cycles): no delamination or cracking, stable conduction impedance;

② Long-term high-temp test (65°C, 8000 hours): no material aging, solder pads intact, stable conduction;

③ Damp heat aging (40°C, 95% RH, 1000 hours): no oxidation or short circuits, excellent insulation.

3. High-Current Transmission Performance:

① 300A continuous load (24 hours): temperature rise of 11°C (industry avg: 20°C);

② Transmission loss reduced by 18% vs. client’s previous PCB;

③ Inverter efficiency increased by 0.3% (from 98.2% to 98.5%).

4. Delivery Performance:

① Prototype cycle: 72 hours (met);

② Batch delivery: 6 days/batch (met);

③ Batch yield: 99.8% (client requirement ≥99.5%);

④ Traceability: Each PCB has a unique code linking to base material, process steps, and test data.

Conclusion: All specifications met client and industry standards. Mass production commenced with positive feedback, and the client plans to expand collaboration.

Case 2: Energy Storage – Southeast Asia PCS Power Unit

Client: Major Southeast Asian energy storage system integrator

Requirement: Withstand high-temperature, high-humidity environments and frequent bidirectional 500A charge/discharge surges

Results: No degradation in conduction performance after 1,000 cycles; stepped slots integrated seamlessly with cooling modules, improving thermal efficiency by 22%; full CE/CQC certifications obtained; stable monthly output of 5,000+ units supporting a 1GWh energy storage deployment.

Case 3: High-Power DC Fast Charging – 180–360kW Charging Pile

Client: Top-tier domestic EV charger component supplier

Requirement: Kiloampere-level current with low temperature rise, strong EMI immunity, and compatibility with complex internal structures

Results: Only 15°C temperature rise under 1000A continuous operation (vs. industry standard of 25°C); passed national EMC immunity tests; rapid structural iterations shortened overall project timeline by 15 days.

These three projects validate the core competitiveness of Bayneng Yunboard’s 6.1mm 6-layer high-precision stepped-slot PCB, demonstrating our technical capability, production capacity, and end-to-end service advantages:

1. Technical Expertise: Capable of precisely solving industry-wide challenges including thick-board warpage, high-current transmission, high-precision stepped-slot machining, and adaptation to high-temperature/humidity environments—with tailored process solutions for diverse scenarios;

2. Production Capacity: Fully automated lines enable rapid prototyping (as fast as 48 hours) and scalable mass production, with strict automotive-grade quality control ensuring consistent batch yields above 99.7% to meet varied client demands;

3. Service Advantage: Dedicated technical teams provide end-to-end support, rapid response to evolving needs, efficient design iterations, and assistance with international certifications and standards alignment—delivering an integrated “product + service” solution that reduces clients’ R&D and production costs while accelerating time-to-market.

Choosing Bayneng Yunboard means more than just a custom high-precision stepped-slot thick PCB:

✔ Premium base materials + cutting-edge processes for all new energy high-power, harsh-environment applications

✔ Automotive-grade quality control with comprehensive global certifications—worry-free for export and automotive projects

✔ Rapid prototyping + flexible mass production to support both R&D iterations and large-scale delivery

✔ Full-cycle technical partnership—from design optimization to mass production, we’re with you every step of the way