High-TG PCBs

The Glass Transition Temperature (Tg) is one of the most important properties of any epoxy and is the temperature region where the polymer transitions from a hard, glassy material to a soft, rubbery material.

Circuit board material must flame-resistant, it can’t be burned at a certain temperature and only be soften. The temperature point is called the glass transition temperature (Tg).

The higher Tg point means higher temperature requirement during lamination. And the boards will be hard and crisp, which will affect hole and the electrical properties.

Ordinary PCB materials at high temperatures, not only will be soften, deformation, melting and other phenomena, but also the mechanical and electrical properties decline sharply.

General fr4 Tg is 130-140 centigrade, moderate Tg is greater than 150-160 centigrade, High-Tg is greater than 170 degrees.

The higher of Tg, the better performance of PCB heat resistance, moisture resistance, chemical resistance, stability and other characteristics.

FR4 is a code name for grade of Epoxy Glass material.

Tg means Glass Transition Temperature.

When the working temperature reaches to the melting point, that means the temperature exceeds the Tg value, the status of pcb material will be changed from glassy to liquid, which will affect the function of pcb. And this value is related to the stability of the pcb dimension.

As usual, made with Tg ≥ 170℃ pcb material, which is called high Tg printed circuit board. With the rapid development of the electronics industry, high Tg material is widely used in computer, communication equipment, precise apparatus and instrument and etc.

The characteristics of High Tg materials are listed below:



  • Higher heat resistance;
  • Lower Z-axis CTE;
  • Excellent thermal stress resistance;
  • High thermal shock resistance;
  • Excellent PTH reliability.
  • Pcbway offers some popular High Tg materials:
  • S1000-2 & S1170: Shengyi materials;
  • IT-180A: ITEQ material;
  • TU768: TUC material.

The specifications we can make, please check below:

  • Layer: 2-28 layers
  • Pcb size: Min. 10*15mm, Max.500*600mm
  • Finished board thickness: 0.2-3.5mm
  • Copper weight: 1/3oz-4oz
  • Surface Finish: HASL with lead /HASL lead free/Immersion gold/ Immersion silver/Immersion Tin/OSP-Organic Solderability Preservatives – RoHS
  • Soldermask: Green/Red/Yellow/Blue/White/Black/Purple/Matt Black/Matt Green
  • Silkscreen: White/Black
  • Min copper tracks/spacing: 3/3mil
  • Min holes: 0.1mm
  • Quality Grade: Standard IPC II

S1000-2 S1000-2B Lead Free Compatible FR-4 High Tg


Lead-free compatible FR-4.0 laminate
Tg170℃(DSC), UV Blocking/AOI Compatible
High Heat Resistance
Lower Z-Axis CTE
Excellent Through-hole Reliability
Excellent Anti-CAF Performance
Low Water Absorption

Low CTE/Hi-Tg/Excellent Thermal Resistance


S1170G S1170GB Halogen Free FR-4 High Tg


Free of constituents such as halogen,antimony,
red phosphorous,etc.no toxic gas emission and
no hazardous residue during waste
lead free compatible
High Tg halogen-free,Tg 180℃(DMA)
UV Blocking/AOI compatible
Lower Z-axis CTE

High Tg Halogen-free FR-4