Automotive Rigid-Flex HDI PCB Prototype | UGPCB – 1+2+1 Stackup, FR-4+PI, 2U만"

1. Market Background: Why Automotive Electronics Need High‑Reliability PCBs

Modern electric vehicles and ADAS systems use more electronic parts every year.
Data from China Commercial Industry Research Institute shows: China’s automotive electronics market reached USD ~169 billion in 2024, 와 10.95% year‑on‑year growth. This demand pushes engineers to replace traditional rigid PCB + wire harnesses with more compact and reliable solutions.

에이 rigid‑flex PCB combines the stability of rigid boards with the bendability of flex circuits.
Industry studies show that switching to rigid‑flex can:

Save ~40% installation space
Reduce vibration‑related failures by ~65%
Lower BOM cost by ~22% through higher integration

The global automotive rigid‑flex PCB market is expected to exceed USD 5 10억 단위로 2025.

UGPCB designed the 자동차 PCB (HDI R‑FPCB) – a high‑density interconnect rigid‑flex board that meets ISO 26262 and IPC‑6012DA Class 3 요구 사항. It is the ideal choice for your automotive rigid‑flex PCB prototype.

HDI R‑FPCB

2. 제품 정의 & 과학적 분류

2.1 제품명 & 모델

제품명: 자동차 PCB (HDI R‑FPCB) – Automotive‑Grade Rigid‑Flex HDI PCB
Model Code: HDI R‑FPCB 1+2+1 구조
Focus Keyword: Automotive rigid‑flex PCB prototype (Yoast SEO focus keyword)

2.2 과학적 분류 (Based on IPC & UL Standards)

Classification Method	기준	범주
By structure	IPC‑2223	Rigid‑Flex Multilayer Board (≥3 conductive layers)
By HDI technology	IPC‑2226	Type III – 2‑step HDI with “1+2+1” stackup, laser microvias
By performance class	IPC‑6013	수업 3 (high‑reliability, continuous operation)
By application	-	Automotive electronics – ECU, ADAS, BMS, infotainment

2.3 주요 매개변수 (Quick Reference Table)

매개 변수	사양
모델	자동차 PCB (HDI R‑FPCB)
재료	FR‑4 + PI (폴리이미드)
Layer stackup	1+2+1 (2‑step HDI rigid‑flex)
솔더 마스크 색상	녹색 / 하얀색
완성 된 두께	1.2 mm
구리 두께	0.035 mm (1 온스)
표면 마감	2U만” (무전해 니켈 침지 금)
최소. 선 너비 / 간격	0.1 mm / 0.1 mm
애플리케이션	Automotive electronics rigid‑flex PCB prototype

테이블 1 – Core specifications of UGPCB Automotive PCB (HDI R‑FPCB).

3. Stackup & 구조: “1+2+1” 2‑Step HDI Rigid‑Flex

3.1 그만큼 1+2+1 Stackup Explained

이것 automotive rigid‑flex PCB prototype features a 1+2+1 HDI build‑up:

층 1 – Outer rigid layer (component mounting & 라우팅)
층 2 – 1st HDI build‑up (매장 / blind microvias)
층 3 – Core layer (contains PI flex area)
층 4 – 2nd HDI build‑up
층 5 – Outer rigid layer (bottom side routing & 납땜)

The flex area stays on the PI core and opens through the rigid coverlay. This design gives you both high routing density (HDI PCB) and 3D bendability (rigid‑flex PCB).

3.2 HDI Classification per IPC‑2226

IPC‑2226 defines HDI by: line width/spacing ≤ 100 μm, microvia pad < 400 μm, and density > 20 pads/cm².
우리의 0.1 mm line/space meets the standard. Laser microvias enable the 1+2+1 structure as II 형 (2‑step HDI) – ideal for automotive electronics.

HDI Type (IPC‑2226)	Build‑up Feature	Typical Application
I 형 I (1‑step)	Single microvia layers on core	소비자 전자 장치
II 형 (2‑step)	Two build‑up layers per side	자동차, 산업의, high‑end devices
III 형 (≥3‑step)	Any‑layer interconnect	Flagship smartphones

3.3 재료: FR‑4 + PI

Rigid areas (FR‑4) – Epoxy glass woven fabric. Provides strong mechanical support for heavy components (커넥터, large ICs).
Flex area (PI) – Polyimide film (FCCL). Tg > 260℃, UL 94 V‑0 rated. Withstands engine‑bay temperatures.

The CTE (coefficient of thermal expansion) difference between PI (16–20 ppm/°C) 그리고 FR‑4 (14–18 ppm/°C) 중요합니다. UGPCB controls lamination parameters to avoid delamination from –40°C to +125°C thermal cycling.

4. Design Guidelines for High‑Performance Rigid‑Flex HDI PCBs

4.1 Fine Line & 공간 (0.1 mm / 0.1 mm)

달성 0.1 mm trace/space with 1 OZ copper allows 50% higher routing density than 0.15 mm designs.
For automotive PCB later assembly, follow these rules:

임피던스 제어 – Match differential pair impedance (90 오 / 100 오) across both FR‑4 and PI zones.
길이 매칭 – Keep intra‑pair mismatch < 0.5 mm on flex area because PI’s Dk (3.4–3.5) differs from FR‑4 (4.2–4.5).

4.2 굽힘 반경 계산 (IPC‑2223)

Rigid‑flex PCBs must respect minimum bend radii for reliability.
According to IPC‑2223 and industry practice:

$아르 자형_{중 나 N, 에스 티 에이 티 나 기음} = (6 에게 12) \times 티_{flex}$ $아르 자형_{중 나 N, 디 와이 nami 기음} \geq 10 \times 티_{flex}$

어디 $티_{flex}$ = total flex area thickness (구리 + coverlay).
For a typical 0.2 mm flex stack, the static minimum radius is 1.2–2.4 mm. UGPCB recommends R ≥ 6 mm for dynamic bending in door hinges or seat adjusters.

Flexible Circuit Bend Area Design: Routing Rules and Best Practices for Rigid-Flex PCBs

4.3 Rigid‑Flex Transition Zone – Key Points

45° tapered interface – Avoids stress concentration.
Route traces parallel to bend axis – Never cross the bend area perpendicularly.
Teardrop pads & rounded coverlay openings – Distribute mechanical stress.
사용 0.5 OZ copper on high‑flex zones - 1 OZ is stronger but less flexible.

Rigid-Flex PCB Design: Best Practices and Essential Principles

5. 제조 공정 흐름 (ISO & IPC Compliant)

UGPCB follows IPC‑6013D for rigid‑flex qualification. 주요 단계:

Inner layer imaging – FR‑4 core and PI flex layer separately. AOI checks 0.1 mm lines.
레이저 드릴링 (눈이 먼 / buried microvias) - CO₂ laser removes FR‑4; UV laser for < 50 µm holes.
desmear & electroless copper – Activates hole walls for plating.
Via filling & panel plating – Blind vias filled with copper (무효율 < 5%).
Sequential lamination – Builds the 1+2+1 stack in two steps. Flex area is masked during rigid layer lamination.
외부 층 & 솔더 마스크 – Green or white LPI solder mask applied.
2U만” 표면 마감 – IPC‑4552 compliant: 3–7 µm Ni + ≥0.05 µm Au. Double gold thickness for corrosion resistance.
라우팅 & electrical test - 100% flying probe or fixture test.

6. 성능 & Reliability Data (IPC‑TM‑650)

시험	상태	Requirement	기준
Dielectric withstanding voltage	≥1000 VDC	No breakdown	IPC‑TM‑650 2.5.7
단열성 저항 (normal)	≥10^11 Ω	통과하다	IPC‑TM‑650 2.5.3
열 사이클링	–40°C ↔125°C, 1000 사이클	No delamination, ΔR < 10%	IPC‑TM‑650 2.6.7
Damp heat	85℃ / 85% RH, 1000시간	IR ≥ 10^9 Ω	IPC‑6013 Class 3
Vibration	10–2000 Hz, 20g, 4h/axis	No intermittent opens	ISO 16750‑3
Dynamic bending	r = 5 mm, 5000 사이클	No open circuit	산업 표준

All tests follow IPC‑TM‑650 methods and IPC‑6013 Class 3 요구 사항.

7. 주요 특징 & 응용 시나리오

7.1 Why Choose This Automotive Rigid‑Flex HDI PCB

1+2+1 HDI + rigid‑flex – High density plus bendability.
0.1 mm line/space – Supports BGA pitch ≤ 0.5 mm.
UL 94 V‑0 – Flame retardant (extinguishes within 10 초).
2U만” – Double gold thickness for 10–15 year automotive life.
Quick‑turn prototype – Samples ready in 7–10 days.

7.2 Typical Use Cases for Your Automotive Electronics PCB Prototype

ECU (엔진 제어 장치) – Sensor signals integrated directly on PI flex, eliminating connectors.
ADAS domain controller – Radar / camera modules need high‑speed signals and folding structures.
Infotainment system – Replace FPC + BTB connectors with one rigid‑flex PCB.
BMS (배터리 관리 시스템) – Stacked voltage/temperature channels with UL 94 V‑0 compliance.
Automotive camera module – Flex section bends through door hinges without wire harness.

8. Why Partner with UGPCB for Your Automotive Rigid‑Flex PCB Prototype?

IPC member + UL certified – Full compliance with IPC‑6012DA & IPC‑6013D.
16,000 m² modern plant – Annual capacity 600,000 m², dedicated HDI production line.
Free DFM review - 15+ years average experience. UGPCB helps you optimize stackup and bend radius.
Fast prototype delivery – 7–10 days for rigid‑flex samples.
Free engineering consultation – CTE mismatch analysis, impedance tuning, and SMT assembly advice.

9. Get a Quote – Start Your Automotive Rigid‑Flex HDI PCB Prototype Today

Submit your Gerber files or share your technical requirements. UGPCB responds within 2 hours with a free stackup recommendation and price estimate.

Contact us now – simply fill in the brief form below:

Company name
핸드폰 / 위챗 / 왓츠앱
Design needs or target budget

UGPCB helps you build high‑reliability, high‑integration automotive electronics – one rigid‑flex PCB at a time.

Declaration

All specifications and data in this document are based on IPC‑2223, IPC‑2226, IPC‑6013, UL 94, and publicly available market reports (China Commercial Industry Research Institute, 2025). UGPCB reserves the right to update technical data. Please contact UGPCB sales for the latest engineering guidelines.

리지드 플렉스 PCB/

자동차 PCB (HDI R‑FPCB) – High‑Reliability Rigid‑Flex HDI PCB Prototype for Automotive Electronics

1. Market Background: Why Automotive Electronics Need High‑Reliability PCBs