VT-441C Laminate/Prepreg

UL Approval: E214381 Version: 05/08/2025 /127/128

Storage Condition & Shelf Life

Prepreg Laminate
Storage Condition Temperature < 23℃ (73℉) < 5℃ (41℉) Room
Relative Humidity < 55% RH / /
Shelf Life 3 Months 6 Months 24 Months

  • The prepreg exceeding shelf time should be retested.
  • Take care in handling thin core laminates as they are easily damaged.
  • If the prepreg is not consumed within 48hrs after opening the vacuum package, it is recommended that the bags be resealed.
  • Material is available in both long and short grain. The grain direction is indicated on the label with an arrow.

Precautions In Handling

  • Please be careful when single ply of 1080 prepreg is designed to the dielectric layer.
  • VT-441C has weaker thermal resistance than regular VT-441. Please be very careful when 8L and higher layer count is designed or dielectric with single ply of 1080.
  • VT-441C Dk is a little higher than VT-441. Please take it into consideration whenever impendence control is required.
  • CTI 600 only can be guaranteed when the full stack-up is from VT-441C material.
  • Please be noticed that the surface roughness and clearness affect CTI rating.

Prepreg Availability

PP Type Resin Content Press Thickness (mil) DK DF
@ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 1GHz @ 2GHz @ 5GHz @ 10GHz
7628 50% 8.0 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
7628 46% 7.5 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
1506 54% 7.0 4.5 4.5 4.4 4.4 0.012 0.012 0.013 0.013
2116 58% 5.0 4.5 4.5 4.4 4.4 0.012 0.012 0.013 0.013
1080 68% 3.1 4.3 4.3 4.2 4.2 0.012 0.012 0.013 0.013
106 76% 2.3 4.1 4.1 4.0 4.0 0.013 0.013 0.014 0.014

Remark: More types could be available upon request. When 2116PP or/and 1080PP is used as the outmost layer, 2-ply minimum is required to ensure CTI 600. 2-Ply 106 prepreg can only withstand CTI 400V.

Laminate Availablity

Core Thickness Stack-up Resin Content DK DF
inches @ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 1GHz @ 2GHz @ 5GHz @ 10GHz
0.008 1-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.012 2-1506 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.015 2-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.016 2-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.018 2-7628 + 1-1080 48% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.020 2-7628 + 1-2116 47% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.024 3-7625 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.028 4-7628 42% 4.7 4.7 4.6 4.6 0.011 0.011 0.012 0.012
0.030 4-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.036 5-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.042 6-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.054 7-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.057 8-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.058 8-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012
0.060 8-7628 46% 4.6 4.6 4.5 4.5 0.011 0.011 0.012 0.012

Dk values are for impedance design More types could be available upon request. In order to satisfy CTI ≥600V, please don’t design 0.10mm in outer layer.

Press Condition

1. Heating rate (Rate of Rise) of material [Material Temperature]: Programmable Press: ≥2.0ºC/min 2. Curing Temperature & Time: >60min at more than 180ºC (356ºF) Material temperature 3. Full Pressure: ≥300psi and temperature to apply full pressure before ≤80ºC 4. Vacuuming should be continued until over 140ºC (284ºF) [Material Temperature] 5. Cold Press condition: Keep Plate @ Room Temperature by water; Pressure:100psi; Keep Time: 60minutes VT-441C Hot Start Cycle.jpg

Typical Drilling Conditions

Diameter Stack Height Spindle (KRPM) Infeed (mm/s) Retract (mm/s) Hit Count
0.25mm 1 PNL/Stack 130 38 300 800
0.30mm 1 PNL/Stack 130 38 300 800
0.60mm 1 PNL/Stack 80 43 300 800

1. Excessive wear of carbide drill bits. Diamond coated drill bits preferred; 2. LE Aluminum sheet and white phenolic entry board are preferred;

Desmearing Process

The de-smearing rate of VT-441C is less than regular VT-441. 1 time vertical de-smearing is preferred. Please examine hole wall to check de-smearing effect. Typical de-smearing rate for reference only:

1x De-smearing Supplier Chemical
0.27mg/cm2 Atotech Alkaline Permanganate

Packaging and baking recommendation

1. It is recommended to bake the board before packaging at 125ºC/4~8h to avoid moisture causing a decrease in heat resistance. 2. If the PCBs needs to be stored for a long time before use, it is recommended to use aluminum foil vacuum packaging. 3. If exceed 3 months after packaging , It is best to bake the PCBs at 125ºC/4~6h before assembly before use.

Downloads for VT-441C