โลโก้ UGPCB
ภาพรวมผลิตภัณฑ์: What Is a Nickel-Palladium-Gold Double-Sided PCB?
A nickel-palladium-gold double-sided PCB (also known as an ENEPIG double-sided PCB) คือ แผงวงจรพิมพ์ that features the Electroless Nickel Electroless Palladium Immersion Gold (เกี่ยวกับ enepic) surface finish on both sides of the board. This advanced surface treatment builds upon the traditional double-sided PCB structure by adding a palladium layer between the nickel and gold deposits, creating a robust tri-layer composite finish that delivers superior solderability, wire bonding performance, and environmental stability.
UGPCB’s nickel-palladium-gold double-sided PCB uses Kingboard KB6160A FR-4 copper-clad laminate as the base material. The board measures 49.6 × 32.8 mm with a thickness of 1.6 mm and a copper foil thickness of 1 ออนซ์ (ประมาณ 35 μm). The solder mask is green with white silkscreen characters. With a minimum aperture of 0.27 mm and a minimum line width/spacing of 0.27 × 0.3 มม, this ENEPIG PCB delivers precision manufacturing combined with high-quality surface finishing.
The nickel-palladium-gold PCB is widely recognized as a “universal surface finish” in the electronics industry. It serves a broad range of applications, รวมถึงโทรคมนาคม, อุปกรณ์อิเล็กทรอนิกส์สำหรับผู้บริโภค, การควบคุมอุตสาหกรรม, security systems, อุปกรณ์อิเล็กทรอนิกส์ยานยนต์, power supplies, smart home devices, อุปกรณ์การแพทย์, and military/aerospace systems.
ข้อกำหนดทางเทคนิคที่สำคัญ
| พารามิเตอร์ | ข้อมูลจำเพาะ |
|---|---|
| ลามิเนต | Kingboard KB6160A FR-4 |
| ความหนาของบอร์ด | 1.6 มม |
| จำนวนเลเยอร์ | Double-sided |
| Board Size | 49.6 × 32.8 มม |
| รูรับแสงขั้นต่ำ | 0.27 มม |
| Minimum Line Width/Spacing | 0.27 × 0.3 มม |
| Copper Foil Thickness | 1 ออนซ์ (≈35 μm) |
| พื้นผิวเสร็จสิ้น | Nickel-Palladium-Gold (เกี่ยวกับ enepic) |
| หน้ากากบัดกรี / Legend | Green solder mask / White silkscreen |
Laminate Details: KB6160A FR-4 Copper-Clad Laminate
KB6160A is a high-performance FR-4 copper-clad laminate manufactured by Kingboard Laminates Holdings Ltd. This material is specifically designed for standard double-sided printed wiring board (PWB) การผลิต. It complies with the IPC-4101/21 specification sheet. Key properties include:
- การปิดกั้น UV (UVB) ความสามารถ: Prevents light transmission during imaging, improving pattern transfer accuracy and yield
- Excellent dimensional stability: Ensures precision throughout the manufacturing process
- Superior heat resistance and mechanical properties: Meets high-reliability application requirements
- อุณหภูมิการเปลี่ยนแก้ว (ทีจี): 135องศาเซลเซียส (DSC method)
- อุณหภูมิการสลายตัวทางความร้อน (TD): 305องศาเซลเซียส (TGA method)
- Z-Axis CTE (α1/α2): 58 ppm/° C (< ทีจี) / 286 ppm/° C (> ทีจี)
- ค่าคงที่ไดอิเล็กตริก (ดีเค): 4.58
- ปัจจัยการกระจาย (ฟ): 0.022
- ความต้านทานระดับเสียง: 1 × 10⁸ MΩ-cm
- การดูดซับความชื้น: 0.21%
- คะแนนความไวไฟ: UL94 V-0
(Data above are sourced from the Kingboard KB6160A Technical Data Sheet, with test methods per IPC-TM-650 series standards.)
The ENEPIG Surface Finish: A Detailed Explanation
What Is ENEPIG?
ENEPIG stands for Electroless Nickel Electroless Palladium Immersion Gold. It is an electroless chemical surface treatment that sequentially deposits three metal layers—nickel, แพลเลเดียม, and gold—onto the copper circuitry of a พีซีบี.
The tri-layer structure of ENEPIG consists of:
- Bottom Layer – Electroless Nickel (ใน): Thickness of 3–5 μm. This layer acts as a diffusion barrier, preventing copper migration to the surface while providing mechanical support and a foundation for soldering.
- Middle Layer – Electroless Palladium (Pd): Thickness of 0.05–0.1 μm. This critical barrier layer prevents interaction between nickel and gold, eliminating galvanic corrosion.
- Top Layer – Immersion Gold (AU): Thickness of 0.03–0.05 μm. This thin layer provides excellent solderability and oxidation protection.
According to IPC-4556A (the latest 2025 revision), ENEPIG deposit thickness requirements are specified as follows:
- Nickel layer: 3 ไมโครเมตรถึง 6 μm (measured at average ± 4σ)
- Palladium layer: 0.05 ไมโครเมตรถึง 0.30 μm (measured at average ± 4σ)
- Gold layer: Minimum 0.030 μm, maximum 0.07 μm (measured at below average − 4σ)
(Thickness specifications above are based on IPC-4556A, Specification for Electroless Nickel/Electroless Palladium/Immersion Gold (เกี่ยวกับ enepic) Plating for Printed Boards.)
The ENEPIG Process Flow
UGPCB’s nickel-palladium-gold double-sided PCBs follow a standardized electroless plating process:
Degreasing → Micro-etching → Pre-dipping → Activation → Electroless Nickel Plating → Electroless Palladium Plating → Immersion Gold Plating → Drying
Each process step includes multiple rinsing stages to ensure plating quality and adhesion. The chemical reactions involved include both oxidation-reduction reactions and displacement reactions.
Core Advantages of Nickel-Palladium-Gold Double-Sided PCBs
1. Complete Elimination of the “Black Pad” Defect
The ENIG (ทองคำแช่นิเกิลแบบไม่ใช้ไฟฟ้า) process has long been plagued by the “Black Pad” defect—a condition where gold attack on the nickel layer leads to brittle solder joints and premature failure. ENEPIG solves this problem by introducing a palladium barrier layer between nickel and gold, preventing direct contact and eliminating grain boundary corrosion. Industry data shows that ENEPIG reduces black pad occurrences by nearly 90% compared to ENIG. Under extreme temperature cycling conditions, ENEPIG demonstrates up to 30% higher reliability than ENIG.
2. Superior Wire Bonding Capability
ENEPIG surface finishes offer excellent bonding performance for both gold and aluminum wires. The palladium layer widens the process window for gold wire bonding, enabling reliable wire bonds even with thinner gold deposits. In many applications, ENEPIG supports wire bonding strengths exceeding 10 grams for both gold and aluminum wire bonds. This makes nickel-palladium-gold double-sided PCBs particularly suitable for semiconductor packaging and hybrid assembly applications requiring wire bonding.
3. Excellent Solderability and Multiple Reflow Tolerance
ENEPIG surface finishes provide excellent solderability with both leaded and lead-free solders (including SAC305 alloy). ENEPIG-finished PCBs can withstand up to 10 reflow cycles without significant degradation.
4. Extended Shelf Life
Thanks to the protective palladium layer, ENEPIG surface finishes offer superior oxidation and corrosion resistance. This translates to a significantly longer shelf life compared to other surface finishes. According to IPC guidelines, ENEPIG surface finishes can achieve IPC Category 3 shelf life of at least twelve months.
5. Greater Design Flexibility
Unlike electrolytic nickel-gold processes, ENEPIG is an electroless process that requires no busbars or plating leads. This allows more boards to be processed simultaneously in the same plating bath, increasing overall throughput. นอกจากนี้, ENEPIG imposes no routing restrictions, providing greater flexibility for high-density circuit designs.
How Nickel-Palladium-Gold Double-Sided PCBs Work
The Synergistic Action of Three Plating Layers
The exceptional performance of nickel-palladium-gold double-sided PCBs stems from the precise synergy of the three plating layers:
① Nickel Layer (Ni-P Alloy) – The Foundation Barrier
The nickel layer serves as the foundation of the ENEPIG structure. Its primary function is to block copper atom diffusion to the surface, preventing the formation of brittle Cu-Sn intermetallic compounds (ไอเอ็มซี) during soldering or high-temperature exposure. Nickel thickness is typically controlled between 3–6 μm, with phosphorus content strictly maintained at 7–9% to balance hardness and corrosion resistance.
② Palladium Layer (Pd) – The Critical Barrier and Activation Layer
The palladium layer is the defining feature that distinguishes ENEPIG from ENIG. It acts as a “partition wall,” preventing migration and grain boundary corrosion between nickel and gold. The palladium layer must be thick enough to block nickel diffusion to the gold surface and prevent excessive corrosion of the electroless nickel deposit.
③ Gold Layer (AU) – Protection and Solderability
The thin outer gold layer protects the nickel from oxidation while providing low contact resistance and excellent solderability. Because the palladium layer provides isolation, the gold layer in ENEPIG can be made thinner (0.03–0.05 μm) without compromising reliability, which helps reduce material costs to some extent.
Classification of Nickel-Palladium-Gold Double-Sided PCBs
UGPCB’s nickel-palladium-gold double-sided PCB can be scientifically classified across multiple dimensions:
By Number of Layers
- Double-Sided PCB: Conductive circuits are distributed on both sides of the substrate, with electrical connections established through plated through-holes (บ่น).
โดยวัสดุฐาน
โดยพื้นผิวเสร็จสิ้น
- เกี่ยวกับ enepic (อิเล็กโทรไลต์นิกเกิลอิเล็กโทรไลเซิลแพลเลเดียม) : Tri-layer composite plating structure.
By Application Domain
- High-Reliability General-Purpose PCB: Suitable for telecommunications, อุปกรณ์อิเล็กทรอนิกส์ยานยนต์, อุปกรณ์การแพทย์, การบินและอวกาศ, การควบคุมอุตสาหกรรม, และอีกมาก.
By Manufacturing Precision
- PCB ที่มีความแม่นยำ: Minimum aperture of 0.27 มม, minimum line width/spacing of 0.27 × 0.3 มม.
ผังกระบวนการผลิต
UGPCB’s nickel-palladium-gold double-sided PCB production follows a comprehensive manufacturing workflow:
Stage 1: Substrate Preparation
- การตัดวัสดุ: KB6160A copper-clad laminate is cut to the required dimensions.
- การขุดเจาะ: Mechanical drilling with a minimum aperture of 0.27 มม.
- Electroless Copper Deposition & Panel Plating: Through-hole metallization.
Stage 2: Circuit Formation
- การถ่ายโอนรูปแบบ: Dry film lamination → Exposure → Development.
- Circuit Etching: Removal of excess copper to form the circuit pattern.
- Aoi (การตรวจสอบด้วยแสงอัตโนมัติ) : Ensuring circuit accuracy.
Stage 3: หน้ากากประสานและตำนาน
- Solder Mask Printing: Green ink application to protect circuits and prevent solder bridging.
- Legend Printing: White silkscreen characters.
Stage 4: พื้นผิวเสร็จสิ้น (เกี่ยวกับ enepic)
- Degreasing: Removal of surface contaminants.
- Micro-Etching: Light etching of copper surface to enhance adhesion.
- Pre-Dipping: Pretreatment before activation.
- การเปิดใช้งาน: Deposition of catalytic palladium seed layer on copper.
- Electroless Nickel Plating: Deposition of nickel layer (3–5 μm).
- Electroless Palladium Plating: Deposition of palladium layer (0.05–0.1 μm).
- Immersion Gold Plating: Deposition of gold layer (0.03–0.05 μm).
- Drying: Completion of surface finish.
Stage 5: การตรวจสอบขั้นสุดท้าย
- การทดสอบไฟฟ้า: Ensuring electrical continuity and isolation.
- การตรวจสอบภาพ: Checking surface quality.
- การบรรจุหีบห่อ & Shipping.
การใช้งานทั่วไป
UGPCB’s nickel-palladium-gold double-sided PCBs are widely used across numerous industries:
อุปกรณ์โทรคมนาคม
- สถานีฐาน, routers, switches
- High-frequency communication modules, RF devices
อุปกรณ์อิเล็กทรอนิกส์ยานยนต์
- หน่วยควบคุมเครื่องยนต์ (กล่อง ECU)
- In-vehicle infotainment systems
- อดาส (ระบบช่วยเหลือผู้ขับขี่ขั้นสูง)
- BMS (Battery Management Systems) for new energy vehicles
อุปกรณ์การแพทย์
- Medical implantable devices
- Diagnostic instruments, อุปกรณ์ติดตามผู้ป่วย
การบินและอวกาศ & การป้องกัน
- Spacecraft and satellite electronics
- Aviation control systems
การควบคุมอุตสาหกรรม & Security
- PLC (Programmable Logic Controllers)
- Industrial motor drives
- Security and surveillance equipment
อุปกรณ์อิเล็กทรอนิกส์สำหรับผู้บริโภค & บ้านอัจฉริยะ
- Smartphone motherboards
- Smart home control modules
- Wearable devices
ทหาร & เพาเวอร์อิเล็กทรอนิกส์
- Military electronic systems
- Power modules, power converters
Why Choose UGPCB for Nickel-Palladium-Gold Double-Sided PCBs?
✅ IPC Standards Compliance
UGPCB’s nickel-palladium-gold double-sided PCBs are manufactured in strict accordance with IPC-4556A. The KB6160A laminate complies with IPC-4101/21, ensuring full standardization from base material to surface finish.
✅ Precision Manufacturing Capabilities
With a minimum aperture of 0.27 mm and minimum line width/spacing of 0.27 × 0.3 มม, UGPCB meets the demands of high-density interconnect (HDI) and fine-pitch component assembly.
✅ High-Reliability Assurance
ENEPIG surface finish reduces black pad defects by nearly 90% and delivers up to 30% higher reliability than ENIG under extreme temperature fluctuations. Products withstand multiple reflow cycles and meet J-STD-003 หมวดหมู่ 3 durability requirements.
✅ Professional Technical Support
The UGPCB team provides full-process technical support, from Gerber file review and BOM optimization to PCBA assembly.
Inquiries & Ordering
Ready to turn your design into a high-quality nickel-palladium-gold double-sided PCB?
📧 Email: sales@ugpcb.com
📞 Phone: +86-135 4412 8719
🌐 Website: www.ugpcb.com
📋 Ordering Process:
- Submit Gerber files, ระเบิด, and design documentation.
- UGPCB’s engineering team performs DFM (ออกแบบเพื่อการผลิต) ทบทวน.
- Order confirmation and delivery schedule.
- Manufacturing and quality control.
- Shipping and logistics tracking.
ไม่ว่าคุณจะต้องการ PCB Prototyping or volume production, UGPCB is committed to delivering high-quality nickel-palladium-gold double-sided PCBs and professional technical services.
Data Source Declaration
The technical data and standard specifications cited in this document are sourced from the following authoritative organizations:
- IPC-4556A: Specification for Electroless Nickel/Electroless Palladium/Immersion Gold (เกี่ยวกับ enepic) Plating for Printed Boards (2025 revision)
- IPC-4101/21: Specification for Base Materials for Rigid and Multilayer Printed Boards – the specification sheet applicable to KB6160A
- Kingboard KB6160A Technical Data Sheet (Kingboard Laminates Holdings Ltd.)
- IPC-TM-650: คู่มือวิธีทดสอบ – the standard test methods used for material property measurements
- เจ-STD-003: Solderability Tests for Printed Boards – the solderability testing standard
- UL94: Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances – flammability rating standard
All data cited above are sourced from the official standards and technical documents listed, ensuring accuracy and authority.
