Description
High Tg (Glass Transition Temperature) is a key indicator of the heat resistance of PCB substrates. When the operating temperature exceeds the Tg value, the material changes from a rigid “glassy” state to an elastic “rubbery” state, resulting in the following problems:
Decrease in dimensional stability (CTE change rate increased by 3-5 times)
Reduction of the mechanical strength by more than 60%
Deterioration of dielectric properties (Dk/Df fluctuations ≥ 20%)
High TG Rigid PCB Advantages
Heat Resistance: High TG PCBs can maintain their rigidity at high temperatures without softening or deforming. Its glass transition temperature (Tg) is typically greater than 170°C, which means that high-Tg PCBs maintain good performance and stability in high-temperature environments.
Moisture and chemical resistance: High TG PCBs have excellent moisture and chemical resistance and can maintain stable performance in harsh environments, making them suitable for equipment that requires long-term exposure to humid or chemical environments.
Mechanical Properties: High TG PCBs have high strength and stiffness, and can withstand large mechanical stresses and maintain stable performance even under harsh environmental conditions. This makes them have a wide range of application prospects in military, aerospace, and other demanding fields.
Electrical Performance: High TG PCBs have a low dielectric constant and loss angle tangent, which helps to improve the quality of signal transmission and electromagnetic compatibility, and is particularly suitable for high-frequency and high-speed signal transmission applications.
Cost Effectiveness: The relatively low cost of High TG PCBs compared to other high-end circuit board materials makes them especially suitable for manufacturers who need to save costs in high-temperature stability applications.
Processability: The glass fibers and aromatic epoxy resins selected for High TG PCB materials give them good processability and reliability, and they are less susceptible to delamination and settling during processing, making the manufacturing process smoother.
Core Performance Advantages
High-Tg materials (Tg≥170°C) demonstrate significant improvements compared to standard FR-4 (Tg140°C):
|
Performance Metric
|
Standard FR-4
|
High-Tg Material
|
Improvement
|
|
Thermal Decomposition Temp.
|
320°C
|
380°C
|
+18%
|
|
Moisture Resistance
|
85°C/85%RH
|
105°C/85%RH
|
+23%
|
|
Z-axis CTE
|
300 ppm/°C
|
180 ppm/°C
|
-40%
|
|
Ionic Migration Resistance
|
10⁸ Ω
|
10¹⁰ Ω
|
100x
|
Key Features:
• 18% higher thermal stability
• 23% improved moisture resistance
• 40% reduction in Z-axis expansion
• 100-fold increase in ionic resistance
Note: All test data is based on the IPC-TM-650 method. Recommended for lead-free processes requiring ≥260°C reflow temperatures.
High TG Rigid PCB Core parameters
| Item |
Rigid PCB |
| Max Layer |
60L |
| Inner Layer Min Trace/Space |
3/3mil |
| Out Layer Min Trace/Space |
3/3mil |
| Inner Layer Max Copper |
6oz |
| Out Layer Max Copper |
6oz |
| Min Mechanical Drilling |
0.15mm |
| Min Laser Drilling |
0.1mm |
| Aspect Ratio(Mechanical Drilling) |
20:1 |
| Aspect Ratio(Laser Drilling) |
1:1 |
| Press Fit Hole Ttolerance |
±0.05mm |
| PTH Tolerance |
±0.075mm |
| NPTH Tolerance |
±0.05mm |
| Countersink Tolerance |
±0.15mm |
| Board Thickness |
0.4-8mm |
| Board Thickness Tolerance(＜1.0mm) |
±0.1mm |
| Board Thickness Tolerance(≥1.0mm) |
±10% |
| Impedance Tolerance |
Single-Ended：±5Ω(≤50Ω)，±7%(＞50Ω) |
| Differential：±5Ω(≤50Ω)，±7%(＞50Ω) |
| Min Board Size |
10*10mm |
| Max Board Size |
22.5*30inch |
| Contour Tolerance |
±0.1mm |
| Min BGA |
7mil |
| Min SMT |
7*10mil |
| Surface Treatment |
ENIG,Gold Finger,Immersion Silver,Immersion Tin,HASL(LF),OSP,ENEPIG,Flash Gold;Hard gold plating |
| Solder Mask |
Green,Black,Blue,Red,Matt Green |
| Min Solder Mask Clearance |
1.5mil |
| Min Solder Mask Dam |
3mil |
| Legend |
White,Black,Red,Yellow |
| Min Legend Width/Height |
4/23mil |
| Strain Fillet Width |
/ |
| Bow & Twist |
0.3% |
Why Choose US?
Topfast is a manufacturer that focuses on PCB, PCBA manufacturing for over 20 years. We have an excellent r&d team of 28 people. We can help you with a one-stop service. To support you with the whole process from function research and development, product PCB design discussion, PCB manufacturing, component procurement, to PCB assembly.
Our company provides PCB industry solutions for customers in the field of templates and small volumes. With high-quality and on-time delivery of products, we won the market’s wide acclaim. We will continue to focus on customer satisfaction, along with “high quality” and “fast delivery”, and the company will become an electronic circuit service provider worthy of customer trust. Our factory mainly produces ordinary double-sided PCBs, multi-layer PCB boards, HDI PCB boards, metal-based PCB boards, and ceramic PCBs. semiconductor PCB boards, rigid-flex PCB boards, and flexible PCB boards.
Application of PCB
High TG PCBs are used in a variety of high-temperature, high-power, and high-frequency applications, such as high-speed trains, aerospace, smart homes, and medical devices. In these environments, high TG PCBs can ensure the stability and reliability of the circuit boards, reduce the failure rate of the circuit,s and improve the efficiency of the electronic equipment.