Several PCB laminate material manufacturers offer halogen-free laminates and prepregs with varying performance, electrical, physical, and thermal properties.
A Printed Circuit Board material that does not contain halogen elements (Chlorine, Bromine, Fluorine) above a certain threshold is considered Halogen-free.
For many years, Brominated Flame Retardants (BFRs) have been used in electronic products to diminish the risk of fire-related injury and damage, however, a growing number of companies are selecting Halogen-free PCBs due to environmental, market and legislative factors.
Typically, the Coefficient of Thermal Expansion (CTE) of halogen-free PCB laminate materials is lower than regular PCBs. In addition, they generally have higher T-288 times and Td temperatures so they can withstand higher reflow temperatures and reflow cycles.
Find out the main differences between 5 of the most commonly used halogen-free printed circuit board laminates.
|EMC||Panasonic||Panasonic||NAN YA||NAN YA|
|Product||EM-370(D)||R-1566W / R-1551W||Meg2 (R-1577 / R-1570)||NPG-150N||NPG-170N|
|Type||Halogen Free High Tg Epoxy||Halogen Free High Tg Epoxy||Halogen Free High Tg Epoxy||Halogen Free Mid Tg Epoxy||Halogen Free High Tg Epoxy|
|IPC-4101E||/127 /128 /130||/127 /128||/127 /128 /130||/127 /128||/127 /128|
|Lead Free Process Compatible||Yes||Yes||Yes||Yes||Yes|
|Tg – Glass Transition Temp
|Td – Decomposition Temp ºC (TGA)||385||350||380||350||360|
|Dk 1 GHz||4.10||4.60||4.14||3.8 – 4.0||4.1 – 4.3|
|Dk 2-3 GHz|
|Dk 10-12 GHz||4|
|Df 1 GHz||0.011||0.010||0.010||0.011-0.013||0.009-0.012|
|Df 2-3 GHz|
|Df 10-12 GHz||0.015||0.013|
|Moisture Absorption (%)||0.10%||0.14%||0.14%||0.20-0.30%||0.20-0.30 %|
|CTE Z Axis (ppm/ºC) Pre Tg||40||40||34||30 – 50||30-50|
|% CTE Z Axis (50-200ºC)||0.022|
|Highest of CTE X, Y Axis (PPM/ºC) Pre Tg||15||15||16||13||13|
|Number of Lamination Cycles||7|
|Peel Strength – 1oz (35μm)||0.788 kN/m||1.8 kN/m||1.3 kN/m||1.40 kN/m||1.23 kN/m – 1.57 kN/m|
|T288 (with copper)||60 min.||3 min.||25 min.||5 min.||5 min.|
|Flexural modulus||0.46 GPa – 0.50 GPa||23 GPa|
|Volume Resistivity||1×1010 MΩ – cm||1×109 MΩ – cm|
|Surface Resistivity||1×108 MΩ|
|Dimensional stability X-Y axis||0.01-0.03 %||0.01-0.03 %|
The increasing demand for environmental-friendly PCBs is driving the need for halogen-free PCB laminate materials. With a variety of manufacturers and products to choose from, the evaluation and the selection process could be time-consuming. But in this article, you can quickly see a comparison of the key characteristics of a few of the most widely used halogen-free materials.