High-Tg FR-4 PCBs utilize specialized polyfunctional epoxy resin systems engineered with a glass transition temperature (>= 170 C or >= 180 C via DSC) to prevent resin softening under severe thermal loads. Designed to maintain mechanical rigidity, tensile strength, and electrical insulation during continuous operation at elevated temperatures, preventing structural delamination in multi-layer architectures.

Technical Specifications

Parameter	Standard High-Tg Capability	Premium High-Tg Option
Glass Transition Temp. (Tg)	>= 170 C (DSC)	>= 180 C (DSC)
Decomposition Temp. (Td)	>= 340 C (TGA)	>= 360 C (TGA)
Z-Axis CTE (50 C to 260 C)	30 - 40 ppm/C	< 25 ppm/C
Dielectric Constant (Dk, at 1 GHz)	4.4 (+/- 0.2)	4.2 (+/- 0.15)
Dissipation Factor (Df, at 1 GHz)	0.020	0.015
Layer Count	1 - 32 Layers	Up to 48 Layers
Board Thickness	0.4 mm - 6.0 mm	+/- 5% precision tolerance
Copper Weight	0.5 oz - 6 oz	Heavy copper up to 10 oz
Min. Trace / Space	3.5 mil / 3.5 mil	3 mil / 3 mil
Surface Finishes	ENIG, HASL (Lead-Free), OSP, Immersion Silver	Hard Gold, Selective Gold plating

Key Features

Thermal Endurance: Withstands multiple lead-free SMT reflow cycles (260 C peak profile) without copper pad lifting, blistering, or delamination.

Low Z-Axis Expansion: Controls thermal expansion along the vertical axis, preventing micro-cracking of copper barrels in plated through-holes (PTH).

Moisture Resistance: Low moisture absorption rate (< 0.15%) preserves surface insulation resistance (SIR) in humid field conditions.

High Electrical Tracking Resistance: CTI rating of >= 600V, preventing electrical breakdown under high DC voltage stress.

Applications

Automotive Electronics: Engine control units (ECUs), under-hood sensor boards, and high-power LED lighting modules operating in high-ambient-heat zones.

Industrial Power Electronics: Switch-mode power supplies (SMPS), motor drives, and industrial inverters handling high continuous current loads.

Telecommunications Infrastructure: Base station power amplifiers and high-frequency routing modules requiring strict dielectric stability.

Medical Equipment: Patient monitor internal power distribution boards and imaging system control units requiring high reliability.

Customization

Impedance-Controlled Stack-ups

Stack-up design calculated via Polar Si8000 matching specific dielectric constraints and track geometries.

Material Sourcing

Laminate cores sourced from verified suppliers (e.g., Shengyi S1170/S1141, Isola, Panasonic) meeting UL 94V-0 flammability ratings.

Advanced Routing & Via Options

Blind and buried vias, resin-filled and copper-capped vias per IPC-4761 Type VII, edge plating, and countersunk mounting holes.

Quality Control

Incoming Material Verification: Dielectric thickness and copper foil peel strength measured using optical thickness gauges and tensile testers prior to fabrication.

Inner Layer Inspection: Automated Optical Inspection (AOI) performed on 100% of inner layers to detect copper shorts and etching anomalies prior to oxide treatment and lamination.

Impedance Testing: Panel-edge test coupons verified via TDR (Time Domain Reflectometers) to ensure controlled impedance remains within +/- 10%.

Electrical & Continuity Testing: 100% netlist testing executed via Flying Probe systems (prototypes) and bed-of-nails fixtures (volume runs).

In-House Reliability Verification: Solder float testing (288 C for 10 seconds), microsection analysis, and thermal shock testing performed on production sample coupons.

Manufacturing & Certifications

Manufacturing Facilities: Equipped with automated direct imaging (DI) lines, Hitachi high-speed CNC drilling systems, vacuum lamination presses, and horizontal copper electroplating lines ensuring uniform deposition in high-aspect-ratio holes.

Quality Certifications:

ISO 9001:2015 Quality Management System
IATF 16949:2016 Automotive Quality Management
ISO 14001:2015 Environmental Management
UL Certified (E-File mapping specific laminate builds)

Execution Standards: Fabrication strictly complies with IPC-A-600 (Acceptability of Printed Boards) and IPC-6012 (Qualification and Performance Specification for Rigid Printed Boards) for IPC Class 2 and Class 3 production.

Packaging & Delivery

Packaging Specification: Vacuum-sealed anti-static ESD bags packed with silica gel desiccant and bubble wrap inside double-wall corrugated cartons. Moisture Barrier Bags (MBB) deployed for moisture-sensitive high-Tg builds.

Logistics & Freight: Expedited air freight via DHL, FedEx, and UPS for quick-turn prototypes; sea freight or DDP air freight channels for volume manufacturing runs.

FAQ

Q: What is the exact glass transition temperature (Tg) of your standard High-Tg material?

A: Our standard High-Tg FR-4 material features a Tg of >= 170 C measured by Differential Scanning Calorimetry (DSC), with 180 C options available for extreme operating environments.

Q: Will High-Tg FR-4 PCBs delaminate during lead-free assembly?

A: No. The elevated decomposition temperature (Td >= 340 C) and restricted Z-axis thermal expansion prevent blistering or pad lifting across multiple lead-free reflow cycles peaking at 260 C.

Q: What data inputs are required to start production?

A: Production requires RS-274X Gerber files (or ODB++), an IPC-compliant drill file, and a fabrication drawing specifying finished board thickness, outer/inner copper weights, surface finish, and IPC Class level.

Q: How is controlled impedance verified on finished boards?

A: Test coupons are integrated into the panel margins matching your trace dimensions. Every panel is measured using a TDR test system, and a comprehensive impedance report ships with the batch.

Q: What are the standard lead times for prototypes and batch production?

A: Prototype fabrication requires 3 to 5 business days depending on layer count and finish. Volume production typically runs on a 10 to 15 business day schedule.

Q: Are these High-Tg PCBs compliant with environmental standards?

A: All manufactured boards comply with RoHS (Directive 2011/65/EU) and REACH regulations, with halogen-free laminate options available upon request.