8-Layer High Speed Rigid-Flex PCB | 6-레이어 리지드 + 2-Layer Flex

As electronic products move toward 고주파, 고속, 경량, and foldable 디자인, traditional rigid PCBs or flexible printed circuits (FPC) alone can no longer meet the demands of complex RF modules, smartphone cameras, or medical endoscopes. As a trusted leader in PCB 제조, UGPCB introduces the 8-Layer High Speed Rigid-Flex PCB. With its unique 6-layer rigid + 2-layer flex integrated structure, this board delivers an optimal balance of 신호 무결성, 기계적 안정성, and space utilization.

This article provides a detailed overview of this 리지드 플렉스 PCB—covering its definition, 재료, manufacturing process, and applications—to help you understand why it is the preferred choice for high-performance module PCBs.

1. Product Overview and Definition

그만큼8-Layer High Speed Rigid-Flex PCB is not simply a rigid board connected to a flex board via a connector. 대신에, it is a unified structure formed by laminatingFR4 (rigid substrate) 그리고PI (폴리이미드, flexible substrate) into a single component.

Structure Breakdown: 리지드 6L (6-layer rigid section) + 플렉스 2L (2-layer flexible section).
Core Positioning: Ideal for compact electronic devices requiring high-speed signal transmission, dynamic flexing, 그리고 높은 신뢰성.

This design eliminates traditional board-to-board connectors, reducing solder joint failure risks while significantly improving 전자기 호환성 (EMC) . It represents a key advancement in 고속 PCB 기술.

2. Design Considerations and Working Principle

디자인 고려 사항

When designing this리지드 플렉스 PCB, UGPCB’s engineering team focuses on three critical areas:

임피던스 제어: For high-speed signals, we strictly control trace width and spacing. This product achieves a minimum 3밀/3밀 추적/공간, ensuring consistent differential impedance (예를 들어, 90Ω or 100Ω).
Transition Zone Protection: The junction between rigid and flex sections is a stress concentration point. We apply teardrop compensation and optimized coverlay openings to prevent circuit breaks during dynamic bending.
Stack-up Symmetry: To avoid warpage caused by CTE (coefficient of thermal expansion) mismatch during high-temperature soldering, the rigid section uses a 6-layer symmetrical stack-up, while the flex section uses high-modulus PI material.

작동 원리

그만큼 flex layer (PI) acts as a bridge connecting multiple rigid functional modules. During bending, the flexible section transmits high-speed data signals (such as MIPI or USB 3.0) and power, while the rigid sections carry high-density BGA 구성 요소 and passive devices. This design enables the entire circuit system to fit into compact or irregular product enclosures.

3. Materials and Key Specifications

UGPCB uses premium materials from leading global brands to ensure electrical performance and reliability. Below are the key specifications for this model:

매개 변수	사양	Technical Insight
기본 재료	FR4 + PI	Rigid section uses high-Tg FR4 (Tg > 150℃) for soldering stability; flex section uses polyimide (PI) for flexibility and heat resistance.
구리 두께	1 온스	완성된 1 oz copper supports higher current loads and helps reduce skin effect loss in고속 신호.
완성된 보드 두께	1.0 mm	Balances mechanical support with thin device requirements.
표면 마감	이머젼 골드	2µ” gold thickness. 아파트를 제공합니다, solderable surface with excellent oxidation resistance, ideal for fine-pitch BGAs and aluminum wire bonding.
최소 구멍 크기	0.2 mm (기계적인)	지원합니다 고밀도 상호 연결 (HDI) 디자인; blind and buried vias can further save routing space.
Minimum Trace / 공간	3밀 / 3밀	Fine-line capability for high-density routing, ensuring signal integrity at high frequencies.

4. Product Classification and Structural Features

과학적 분류

According to IPC-2223 standards, this product is classified as adynamic flex rigid-flex PCB.

구조 별: Asymmetric rigid-flex (6-layer rigid + 2-layer flex).
응용 프로그램에 의해: 고속, 고주파 모듈 PCB.

구조적 특징

Integrated Interconnection: Eliminates connectors, reducing insertion loss and signal reflection. Signal integrity improves by approximately 30% compared to traditional rigid board plus connector solutions.
High Flex Durability: The 2-layer flex section uses rolled annealed (라) 구리, which offers better bending life than electrodeposited (에드) 구리, withstanding tens of thousands of dynamic bends.
Thin and Light: With an overall thickness of 1.0 mm, it saves up to 60% of Z-axis space when folded.

5. Manufacturing Process and Quality Control

UGPCB operates a fully integrated production line to ensure everyhigh-speed rigid-flex PCB meets strict quality standards. The core process includes:

Flex Layer Preparation: PI substrate is processed using inner-layer dry film and etching to form fine circuits (3mil trace width) in the flexible area.
Coverlay Lamination: A coverlay is applied over the flex circuits to protect them and define the bending area.
Rigid Layer Stacking: FR4 prepreg is precisely aligned with the processed flex layer. This is a critical step to ensure resin fills the rigid-flex interface without voids.
라미네이션: The rigid and flex layers are fused under high temperature and pressure.
시추 및 도금: 0.2 mm mechanical drilling is performed, followed by electroless copper plating to establish interlayer connections.
표면 마감: 이머젼 골드 is applied with a controlled thickness of 2µ” to ensure solderability and oxidation resistance.
Routing and Electrical Testing: Laser cutting or die punching shapes the board, 이어서 100% flying probe or fixture testing to guarantee no shorts or opens.

Rigid-Flex PCB Production Process Overview

6. 응용 시나리오

이것8-layer high-speed rigid-flex PCB is designed for high-density, high-reliability applications, 포함:

Smartphones and Wearables: Used in foldable phone mainboard connections and camera module (CCM) 어셈블리, leveraging bending capabilities for hinge integration.
의료 기기: Such as ultrasound endoscopes and hearing aids. The compact size and reliability of rigid-flex PCBs ensure stable signal transmission in critical environments.
자동차 전자: In-vehicle camera modules and LiDAR systems. Meets automotive-grade requirements for vibration resistance and temperature cycling (-40° C ~ 125 ° C).
항공우주 및 국방: Satellite communication modules and missile guidance systems. Reduces weight while maintaining high reliability.
산업 제어: Robot joints and servo motor drives. The flex section absorbs mechanical stress from motion.

7. UGPCB를 선택하는 이유는 무엇입니까??

Manufacturing rigid-flex PCBs presents technical challenges, particularly invoid-free lamination at the rigid-flex interface 그리고controlling material shrinkage of PI. UGPCB addresses these with proven expertise:

Precise Shrinkage Compensation: With extensive data on the different expansion rates of PI and FR4, we maintain layer-to-layer registration within ±2 mil.
High-Speed Signal Assurance: 을 위한 고속 PCB 애플리케이션, we strictly control dielectric constant (DK) 및 소산 인자 (Df), and provide impedance test reports.
Customization Support: From prototypes to mass production, we support tailored 모듈 PCB solutions with reliable lead times.