VT-772+(LK) / VT-772+(LK2) Laminate/Prepreg

UL Approval: E214381 Version: 07/03/2026 /230/134

Storage Condition & Shelf Life

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

Prepreg exceeding shelf life should be retested.

Precautions in Handling

  • Laminate should be stored flat in a cool dry environment. Avoid bending or scratching the laminate surface.

  • Prepreg should be stored flat in a cool dry controlled environment 23ºC or less and 50% RH or less.
    Extended storage of prepreg should be at a reduced temperature of 5ºC.

  • Open bags of prepreg must be resealed. Prepreg should not be exposed to open environments for more than 8 
    hours total cumulatively under the above conditions or as agreed upon between user and supplier.

  • A first-in-first-out inventory system and a method to track material lot numbers through PWB processing and
    delivery of finished circuits is recommended.

Designing and Inner Layer Process

  • Laminate should be stored flat in a cool dry environment. Avoid bending or scratching the laminate surface.

  • Prepreg should be stored flat in a cool dry controlled environment 23ºC or less and 50% RH or less.
    Extended storage of prepreg should be at a reduced temperature of 5ºC.

  • Open bags of prepreg must be resealed. Prepreg should not be exposed to open environments for more than 8 
    hours total cumulatively under the above conditions or as agreed upon between user and supplier.

  • A first-in-first-out inventory system and a method to track material lot numbers through PWB processing and
    delivery of finished circuits is recommended.

Prepreg Availability

Dk values are for impedance design

VT-772+(LK)

Delivered Thickness (Inches) Glass Style Resin Content Dk Df
@ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 20GHz @ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 20GHz
0.0025 1035 75% 3.02 3.02 3.01 3.00 2.98 0.0015 0.0015 0.0016 0.0017 0.0018
0.0030 1035 78% 2.97 2.97 2.96 2.95 2.93 0.0014 0.0014 0.0015 0.0016 0.0017
0.0030 1078 66% 3.12 3.12 3.11 3.10 3.08 0.0015 0.0015 0.0016 0.0017 0.0018
0.0035 1078 71% 3.07 3.07 3.06 3.05 3.03 0.0015 0.0015 0.0016 0.0017 0.0018
0.0040 1078 75% 3.02 3.02 3.01 3.00 2.98 0.0015 0.0015 0.0016 0.0017 0.0018

VT-772+(LK2)

Delivered Thickness (Inches) Glass Style Resin Content DK DF
@ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 20GHz @ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 20GHz
0.0025 1035 75% 2.82 2.82 2.81 2.8 2.78 0.0011 0.0011 0.0012 0.0013 0.0014
0.0030 1035 78% 2.77 2.77 2.76 2.75 2.75 0.001 0.001 0.0011 0.0012 0.0013
0.0030 1078 66% 2.92 2.92 2.91 2.9 2.88 0.0011 0.0011 0.0012 0.0013 0.0014
0.0035 1078 71% 2.87 2.87 2.86 2.85 2.83 0.0011 0.0011 0.0012 0.0013 0.0014
0.0040 1078 75% 2.82 2.82 2.81 2.8 2.78 0.0011 0.0011 0.0012 0.0013 0.0014

Remark: ① Press thickness test condition---Prepreg lamination size 18”*24”, Copper Foil---1oz/1oz, Flow---about 5%; ② Make laminated prepreg to micro-section and measure the thickness with microscope; this thickness is used for resistance design calculation. ③ The thickness measured with micrometer is 0.2~0.4 mil larger than that measured with micro-section; and mainly used for total thickness design calculation.

Laminate Availablity

Dk values are for impedance design

VT-772+(LK)

Laminate Thickness (Inches) Glass Style Piles Resin Content Dk Df
@ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 20GHz @ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 20GHz
0.002 1035 1ply 68% 3.10 3.10 3.09 3.08 3.06 0.0015 0.0015 0.0016 0.0017 0.0018
0.0025 1035 1ply 75% 3.02 3.02 3.01 3.00 2.98 0.0015 0.0015 0.0016 0.0017 0.0018
0.003 1078 1ply 66% 3.12 3.12 3.11 3.10 3.08 0.0015 0.0015 0.0016 0.0017 0.0018
0.0035 1078 1ply 71% 3.07 3.07 3.06 3.05 3.03 0.0015 0.0015 0.0016 0.0017 0.0018
0.004 1035 2ply 68% 3.10 3.10 3.09 3.08 3.06 0.0015 0.0015 0.0016 0.0017 0.0018
0.005 1035 2ply 75% 3.02 3.02 3.01 3.00 2.98 0.0015 0.0015 0.0016 0.0017 0.0018
0.006 1078 2ply 66% 3.12 3.12 3.11 3.10 3.08 0.0015 0.0015 0.0016 0.0017 0.0018
0.007 1078 2ply 71% 3.07 3.07 3.06 3.05 3.03 0.0015 0.0015 0.0016 0.0017 0.0018

VT-772+(LK2)

Laminate Thickness (Inches) Glass Type Piles Resin Content Dk Df
@ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 20GHz @ 1GHz @ 2GHz @ 5GHz @ 10GHz @ 20GHz
0.002 1035 1ply 68% 2.90 2.9 2.89 2.88 2.86 0.0011 0.0011 0.0012 0.0013 0.0014
0.0025 1035 1ply 75% 2.82 2.82 2.81 2.80 2.78 0.0011 0.0011 0.0012 0.0013 0.0014
0.003 1078 1ply 66% 2.92 2.92 2.91 2.90 2.88 0.0011 0.0011 0.0012 0.0013 0.0014
0.0035 1078 1ply 71% 2.87 2.87 2.86 2.85 2.83 0.0011 0.0011 0.0012 0.0013 0.0014
0.004 1035 2ply 68% 2.90 2.90 2.89 2.88 2.86 0.0011 0.0011 0.0012 0.0013 0.0014
0.0045 1035 2ply 71% 2.87 2.87 2.86 2.85 2.83 0.0011 0.0011 0.0012 0.0013 0.0014
0.005 1035 2ply 75% 2.82 2.82 2.81 2.8 2.78 0.0011 0.0011 0.0012 0.0013 0.0014
0.006 1078 2ply 66% 2.92 2.92 2.91 2.9 2.88 0.0011 0.0011 0.0012 0.0013 0.0014
0.007 1078 2ply 71% 2.87 2.87 2.86 2.85 2.83 0.0011 0.0011 0.0012 0.0013 0.0014

More types could be available upon request.

Press Condition

  • Laminate should be stored flat in a cool dry environment. Avoid bending or scratching the laminate surface.

  • Prepreg should be stored flat in a cool dry controlled environment 23ºC or less and 50% RH or less.
    Extended storage of prepreg should be at a reduced temperature of 5ºC.

  • Open bags of prepreg must be resealed. Prepreg should not be exposed to open environments for more than 8 
    hours total cumulatively under the above conditions or as agreed upon between user and supplier.

  • A first-in-first-out inventory system and a method to track material lot numbers through PWB processing and
    delivery of finished circuits is recommended.
VT-770 770LK PressCycle.jpg

Typical Drilling Parameters

  • Drilling parameters should be adjusted depending on hole size, layer count, panel thickness, stack count and stack height etc.
  • Please adjust drilling parameters after checking qualities of through holes.
  • Suggest Drilling parameter as below:

Diameter (mm) Spindle Speed (krpm) Feed Rate (IPM) Chip Load (IPM) Hit Counts
0.10 200~300 25~38 800 1000
0.20 150~200 38~50 800 1000
0.30 100~150 38~60 800 1000
0.40 80~100 40~50 800 1000

Smear, resin cracking or nail heading may occur if drilling condition doesn’t match material.

Laser Drilling

  • Drilling parameters should be adjusted depending on hole size, layer count, panel thickness, stack count and stack height etc.
  • Please adjust drilling parameters after checking qualities of through holes.
  • Suggest Drilling parameter as below:
VT-772+(LK2) Laser Drilling.jpg

Desmearing Process

  • Drilling parameters should be adjusted depending on hole size, layer count, panel thickness, stack count and stack height etc.
  • Please adjust drilling parameters after checking qualities of through holes.
  • Suggest Drilling parameter as below:

Process Temperature (ºC) Gas Mixture Power (W) Duration (min)
Parameter 80-100 10%CF4 , 80% O2, 10% N2 4000 60-80

Typical Chemical conditions. (Atotech chemical)

Process Temperature ℃ Duration (min)
Sewll 60-70 5-10
Permanganate Oxidizer 70-80 10-15

If use other chemical, please consult the chemical supplier for suggested conditions. Please consult the chemical supplier for suggested conditions.

Packaging and Baking Recommendation

  • Drilling parameters should be adjusted depending on hole size, layer count, panel thickness, stack count and stack height etc.
  • Please adjust drilling parameters after checking qualities of through holes.
  • Suggest Drilling parameter as below:

Downloads for tec-speed 8.1 & 8.2 H-PK VT-772+(LK) & VT-772+(LK2)