UGPCB 6‑Layer Communication High Frequency Hybrid PCB – Ro4350B+FR4 Mixed Dielectric RF Board

When digital and RF systems push beyond multiple GHz, conventional プリント基板材料 hit bottlenecks in signal integrity, 熱安定性, そして インピーダンス制御. UGPCB’s communication high frequency hybrid PCB solves these challenges.

1. 製品の概要

製品名: UGPCB 6‑Layer Communication High Frequency Hybrid PCB
モデル: UG‑HYBRID‑6L‑RF01
主な仕様: 6 レイヤー / Ro4350B+FR4 mixed dielectric / 1.6板厚mm / 210mm × 280mm size / ENIG表面仕上げ / minimum mechanical drilled hole 0.25mm
位置決め: A cost‑effective interconnect solution for RF front‑ends and high‑speed digital mixed circuits. By placing Rogers RO4350B high‑frequency laminate on the top RF signal layers and FR‑4 on the bottom power/ground and low‑speed digital layers, this design balances signal integrity, 熱安定性, そして製造コスト.

2. Definition – What is a High Frequency Hybrid PCB?

あ high frequency hybrid PCB (also called mixed dielectric multilayer board) uses two or more materials with different dielectric properties in one 多層プリント回路基板.

This 6‑layer hybrid PCB has the following stackup:

層	関数	材料	キーパラメータ
L1	RF signal	RO4350B (0.2mm)	Dk=3.48±0.05@10GHz, DF = 0.0037
L2	RF ground	RO4350B	Low‑loss reference plane
L3	High‑speed digital	RO4450™ bondply + FR‑4	Transition, インピーダンスマッチング
L4	Power plane	FR‑4	高ガラス転移温度, 低コスト
L5	Digital signal	FR‑4	Standard epoxy glass
L6	Digital ground	FR‑4	Mechanical support and heat dissipation

“Mixed dielectric construction significantly reduces cost – using high‑frequency material only on the layers that carry RF signals, and FR‑4 for the rest.”

3. 設計ガイドライン

3.1 Critical Material Parameters

This product uses ロジャース RO4350B (ceramic‑filled hydrocarbon laminate) and FR‑4. Key RO4350B specifications (source: Rogers data sheet):

パラメーター	代表値	テスト条件	Reference
Process Dk	3.48±0.05	10GHz	IPC‑TM‑650 2.5.5.5
Design Dk	3.66	10GHz	Copper roughness correction
散逸係数 (Df)	0.0037	10GHz	Low‑loss RF applications
Z‑axis CTE	32 ppm/℃	-55℃ to 288℃	Matches copper (17 ppm/℃)
熱伝導率	0.69 w/m・k	50℃, ASTM D5470	Better than FR‑4
可燃性	UL 94 V‑0	UL standard	For active and high‑power RF

Data source: Rogers Corporation RO4350B™ Laminate Data Sheet

3.2 インピーダンス制御

Impedance control on a 6‑layer hybrid PCB is challenging because of the Dk discontinuity. Use a 3D electromagnetic solver and apply a copper roughness correction factor (typically 1.2–1.5). According to IPC‑2141A, characteristic impedance tolerance for RF PCBs should be within ±7%. UGPCB achieves ±5%.

3.3 Laminate Stackup Design (Total thickness 1.6mm)

• トップ (L1‑L2): RO4350B 0.2mm × 2 = 0.4mm
• Middle (L3): RO4450™ prepreg 0.1mm + FR‑4 core 0.6mm = 0.7mm
• Bottom (L4‑L6): FR‑4 core + prepreg = 0.5mm
• Total: 1.6mm

Use a dynamic pressure curve during lamination to manage stress from CTE mismatch between RO4350B and FR‑4.

4. 作業原則

シグナルインテグリティ: Dielectric loss dominates high‑frequency loss. The medium attenuation constant is:

$a_d\approx 27.3\times \frac{\text{√}{e}_r}{{\mathrm{<span\; class="tr\_"\; id="tr\_90"\; data-source=""\; data-orig="\lambda ">\lambda </span>}}_0}\times tand(dB\mathrm{/}un私t\mathrm{<span\; class="tr\_"\; id="tr\_91"\; data-source=""\; data-orig="l">l</span>}ength)$

どこ:

• $a_d$ = dielectric attenuation constant
• $e_r$ =相対誘電率 (design value)
• ${\mathrm{<span\; class="tr\_"\; id="tr\_94"\; data-source=""\; data-orig="\lambda ">\lambda </span>}}_0$ = free‑space wavelength
• $tand$ = dissipation factor (Df)

RO4350B has Df = 0.0037 対. FR‑4’s 0.020. That reduces dielectric loss by about 80%, ensuring low‑loss transmission up to 30GHz.

Thermal‑mechanical stability: RO4350B’s Z‑axis CTE of 32 ppm/℃ matches copper (17 ppm/℃) far better than FR‑4 (50–70 ppm/℃). This improves plated through‑hole (PTH) reliability under thermal cycling. Tested per IPC‑TM‑650 2.6.7, the board survives 1000 cycles from -55℃ to 125℃ without delamination.

5. 主要なアプリケーション

UGPCB’s 6‑layer communication high frequency hybrid PCB serves five major areas:

5.1 5G Communication Base Stations (AAU/RRU)

• Frequency bands: 28GHz and 39GHz millimeter wave
• 要件: Insertion loss < 0.31 dB/cm@40GHz, power handling >200 W/m²@38GHz
• Advantage: Hybrid construction cuts material cost by 30–40% vs. all‑high‑frequency material

5.2 77GHz/79GHz Automotive Radar

• Use cases: Autonomous driving 4D imaging radar, blind spot detection, 適応クルーズコントロール
• 要件: Range error <0.25m from -40℃ to 125℃, azimuth resolution 0.08°
• パフォーマンス: IMS 2025 report shows phase consistency of ±0.8° over full temperature range for 77GHz hybrid radar modules

5.3 Satellite Communication Payloads (Ka‑band)

• Frequency range: 17.7 - 31 GHz
• Advantage: 45% weight reduction vs. ceramic substrates while maintaining >85% efficiency

5.4 Fiber‑to‑the‑Home (FTTH) 装置

• Market trend: Global IPTV market from $189.25B (2025) to $421.53B (2030), CAGR 17.4%
• インパクト: High‑bandwidth, low‑latency PCBs are essential

5.5 High‑Speed Digital Mixed‑Signal Systems

• Fields: Medical imaging, industrial high‑frequency inspection, military communication terminals
• 要件: Coexist 10+ Gbps digital signals with GHz‑range RF signals

6. 科学的分類 (per IPC‑2221)

Classification Dimension	カテゴリ	Basis
Material system	Mixed dielectric PCB	RO4350B + FR‑4
Frequency characteristic	RF / マイクロ波基板	Up to 30GHz
レイヤー数	6‑layer multilayer board	6 導電層
Technical difficulty	HDI hybrid lamination	Non‑expansion material matching
応用	Communication RF PCB	テレコムインフラストラクチャ
IPC performance class	IPC‑6012 Class 3	High‑reliability equipment

7. Materials in Detail

7.1 RO4350B High‑Frequency Laminate

• Glass‑reinforced hydrocarbon + セラミックフィラー
• DK: 3.48±0.05@10GHz, temperature coefficient ~ -50 ppm/℃ (-50℃ to +150℃)
• Df: 0.0037@10GHz
• Z‑axis CTE: 32 ppm/℃ – matches copper for PTH reliability
• 熱伝導率: 0.69 w/m・k (対. FR‑4 0.25–0.35)
• UL 94 V‑0 – suitable for active and high‑power RF designs
• Process compatibility: Same FR‑4 processing; no special pre‑treatment needed (unlike PTFE)

7.2 FR‑4 Epoxy Glass Laminate

• Woven glass fabric + エポキシ樹脂
• DK: 4.2–4.8 (1MHz–1GHz), Df: 0.020–0.025
• 料金: 1/5 に 1/10 of RO4350B

7.3 RO4450™ High‑Frequency Bondply

• Bonding layer between RO4350B and FR‑4
• DK: 3.52±0.05@10GHz (gradient transition)
• Df: 0.0040@10GHz

7.4 ENIG Surface Finish (エレクトロレスニッケルイマージョンゴールド)

• ニッケルの厚さ: 3–6μm (IPC‑4552 Class 2)
• 金の厚さ: 0.05–0.10μm
• 利点: はんだ付け性, flatness, 耐酸化性, fine‑pitch BGA assembly
• 標準: IPC‑4552

8. 性能仕様

8.1 電気性能

パラメーター	価値	テスト方法
Characteristic impedance (RF layers)	50Ω ±5% (customizable)	IPC‑2141A
DK (RF layers @10GHz)	3.48±0.05	IPC‑TM‑650 2.5.5.5
Insertion loss	0.31 dB/cm @40GHz	Microstrip line VNA
Dielectric strength	≥40 kV/mm	IPC‑TM‑650 2.5.6
絶縁抵抗	>10⁹ Ω (normal condition)	IPC‑TM‑650 2.5.17
Withstanding voltage	1000 VDC, 60s no breakdown	IPC‑TM‑650 2.5.7

8.2 機械的性能

パラメーター	価値	テスト方法
Thickness tolerance	±10％	IPC‑6012
寸法安定性	<0.3 mm/m	IPC‑TM‑650 2.2.4
皮の強度 (1oz銅)	≥1.0 N/mm	IPC‑TM‑650 2.4.8
Flexural strength	≥350 MPa	IPC‑TM‑650 2.4.4
Pad pull‑off force	≥5.0 kg/cm²	IPC‑TM‑650 2.4.21

8.3 熱性能

パラメーター	価値	テスト方法
TG (FR‑4 area)	≥150℃ (TG150)	IPC‑TM‑650 2.4.25
Thermal stress	288℃, 10s × 5 サイクル	IPC‑TM‑650 2.4.13
サーマルサイクリング	-55℃ ↔ 125℃, 1000 サイクル, 剥離はありません	IPC‑TM‑650 2.6.7
Lead‑free reflow	260℃, 5 サイクル	IPC/JEDEC J‑STD‑020
Moisture sensitivity level	MSL 1	IPC/JEDEC J‑STD‑020

8.4 Reliability Certifications

• IPC‑6012 Class 3 – high‑reliability equipment
• IPC‑6018B – qualification for high‑frequency (電子レンジ) プリント基板
• UL 94 V‑0
• MIL‑PRF‑31032 - 1000 thermal cycles from -55℃ to 125℃

100% flying probe electrical test + あおい. End‑product meets IPC‑A‑600 Class 3.

9. 構造的特徴

Asymmetric 6‑layer hybrid build:

• L1‑L2 (RO4350B): RF front‑end (PA, LNA, フィルター) – signal integrity critical zone
• L3 (transition): Impedance matching and signal layer change – isolates RF from high‑speed digital
• L4‑L6 (FR‑4): Power management, digital control, mechanical support – low‑cost conventional circuits

ENIG finish: Flat surface ensures consistent impedance control. Supports BGA, QFN, fine‑pitch packages. Gold layer protects copper and guarantees solderability after long storage.

精密掘削 & PTH: Minimum mechanical hole diameter 0.25mm (HDI microvias down to 0.1mm available). Hole copper thickness ≥20μm (IPCクラス 3). Plasma treatment with different gas mixtures for RO4350B and FR‑4 layers.

10. 製造工程の流れ

18 key steps:

① IQC → ② Inner layer imaging (RF and digital separately) → ③ Brown oxide → ④ Pre‑lamination plasma activation → ⑤ Hybrid lay‑up → ⑥ High‑pressure lamination (dynamic pressure curve) → ⑦ X‑ray target drilling → ⑧ Mechanical drilling (0.25mm分) → ⑨ Plasma desmear (dual cycle) → ⑩ Electroless copper → ⑪ Outer layer imaging → ⑫ Pattern plating (銅 + 錫) → ⑬ Outer layer etching (tin strip) → ⑭ AOI → ⑮ Solder mask → ⑯ ENIG → ⑰ Electrical test → ⑱ Final inspection/packaging

Critical process details:

• Pre‑lamination plasma (step 4): CF₄‑N₂‑O₂ for FR‑4; helium (He) for RO4350B
• Lamination curve (step 6): Dynamic pressure – FR‑4 cures first (~180℃), then pressure and temperature rise to >200℃ for RO4350B
• 掘削 (step 8): Step feed and tool life management handle hardness difference
• デスミア & PTH (steps 9‑10): Dual‑cycle process due to different chemical behaviors; hole copper ≥20μm

11. 競争上の優位性

Cost‑performance balance: All‑RO4350B 6‑layer material costs >$200/m². Hybrid uses RO4350B only on 25% of thickness →30‑40% material cost reduction.

信頼性: RO4350B Z‑axis CTE = 32 ppm/℃ matches copper (17 ppm/℃). Full FR‑4 has 50‑70 ppm/℃. Hybrid reduces PTH stress. Passes 1000 cycles -55℃ to 125℃ (IPC‑TM‑650 2.6.7).

寸法安定性: Low CTE reduces warpage, improves SMT yield.

Direction	RO4350B CTE	FR‑4 CTE (典型的な)
X‑axis	10 ppm/℃	14 ppm/℃
Y‑axis	12 ppm/℃	16 ppm/℃
Z‑axis	32 ppm/℃	50‑70 ppm/℃

Vs. full PTFE (例えば。, ロジャース RT/デュロイド):

特徴	RO4350B+FR‑4 hybrid	Full PTFE
Process compatibility	Standard FR‑4 line	Special equipment & treatment
PTH metallization	標準	Sodium naphthalene or plasma
寸法安定性	素晴らしい (glass reinforced)	貧しい, flows
料金	30‑50% lower	高い

12. まとめ & Inquiry Guidance

UGPCB’s 6‑layer communication high frequency hybrid PCB is the ideal interconnect for RF/digital mixed signal systems. It serves 5G base stations, satellite Ka‑band payloads, 77GHz automotive radar, and high‑speed digital applications. By placing RO4350B only on the critical RF layers, we achieve optimal performance at a significantly lower cost.

Key data recap:

✅ Dk = 3.48 ± 0.05 @10GHz (Rogers official)
✅ Df = 0.0037 @10GHz
✅ Z‑axis CTE = 32 ppm/℃ (matches copper)
✅ Insertion loss ≤ 0.31 dB/cm @40GHz (IPC‑6018B verified)
✅30‑40% material cost reduction 対. all‑high‑frequency material
✅ Passes 1000 thermal cycles -55℃ ↔ 125℃

Limited‑time prototyping offer

📩 Get your custom quote and technical proposal

UGPCB offers a 7‑working‑day quick‑turn service for 4‑ to 10‑layer hybrid PCBs. 私たちが提供するのは free DFM analysis.

👉 Send your Gerber files and stackup design to our technical support email. We will reply with a technical assessment and precise quote within 4 時間.

UGPCB – Your trusted hybrid high‑frequency PCB manufacturer. From prototype to volume production, we deliver one‑stop 6‑layer mixed dielectric solutions to accelerate your 5G and millimeter‑wave radar products.

*Data sources: Rogers Corporation RO4350B™ Data Sheet, IPC‑6012D/6018B standards, IPC‑TM‑650 test methods, GSMA 2026 telecom outlook, IMS 2025 International Microwave Symposium technical report.*