51N
Multifunctional, High Tg Epoxy Low-Flow Prepreg
51N-LF is a non-DICY multifunctional epoxy low-flow prepreg systemdesigned to provide high reliability through lead-free solder operations.
The high decomposition temperature and high thermal stability of thismaterial is ideal for use in complex rigid-flex fabrication and assembly
operations where minimum resin flow is required.

Features:• Decomposition temperature > 350°C is ideally suited for lead-freesolder processing and offers significant improvement over traditional
FR-4 Epoxysystems.
• Multifunctional epoxy resin system with a Glass transition temperature(Tg) of 170°C thermal cycling PTH reliability• Improved bond adhesion over multiple thermal excursions results inbetter reliability through reflow and rework operations.
• Best-in-class thermal performance for an epoxy system with T260 > 60
minutes, T280 > 30 minutes and T300 = 15 minutes• Electrical and mechanical properties meet the requirements ofIPC-4101B/124 prepreg, modified to be “Low-Flow”• Compatible with lead-free solder processing• RoHS/WEEE compliant

Typical Applications:•Bonding multilayer rigid-flex boards•

Finished PCB assemblies requiring excellent thermal stability•

Dielectric insulators•

Other applications where minimal and uniform resin flow is required

Typical Properties:
Property

51N
Units

Value

Test Method

-4.2
4.1

IPC TM-650 2.5.5.3
IPC TM-650 2.5.5.9

-0.02
0.02

IPC TM-650 2.5.5.3
IPC TM-650 2.5.5.9

MΩ-cm
MΩ-cm

2.6 x 107
3.3 x 107

IPC TM-650 2.5.17.1
IPC TM-650 2.5.17.1

MΩ

2.9 x 107

IPC TM-650 2.5.17.1

MΩ

4.0 x 106

IPC TM-650 2.5.17.1

Volts/mil (kV/mm)
kV
sec1000 (39.4)>120

IPC TM-650 2.5.6.2
IPC TM-650 2.5.6
IPC TM-650 2.5.1

CC

166
170

IPC TM-650 2.4.24
IPC TM-650 2.4.25

Initial
5%
T260
T288
T300
CTE (x,y)*CTE (z)*< Tg

CCminmin
min
ppm/C

354
368
>60
>30
1513-15

IPC TM-650 2.3.41
IPC TM-650 2.3.41
IPC TM-650 2.4.24.1
IPC TM-650 2.4.24.1
IPC TM-650 2.4.24.1
IPC TM-650 2.4.41

ppm/C44

IPC TM-650 2.4.24> Tg
z-axis Expansion (50-260ºC)

ppm/C%2452.6

IPC TM-650 2.4.24
IPC TM-650 2.4.24

Peel Strength to Copper (1 oz/35 micron)
After Thermal Stress
At Elevated Temperatures
After Process Solutions
Young’s Modulus
Flexural Strength
Tensile Strength

lb/in (N/mm)
lb/in (N/mm)
lb/in (N/mm)
Mpsi (GPa)kpsi (MPa)kpsi (MPa)

6.7 (1.2)
6.7 (1.2)
6.4 (1.1)
2.6 (18)84 (578)
6.5 (45)

IPC TM-650 2.4.8
IPC TM-650 2.4.8.2
IPC TM-650 2.4.8
IPC TM-650 2.4.18.3
IPC TM-650 2.4.4
IPC TM-650 2.4.18.3

Compressive Modulus
Poisson’s Ratio (x, y)kpsi (MPa)-1. Electrical Properties
Dielectric Constant (may vary with Resin %)@ 1 MHz@ 1 GHz
Dissipation Factor@ 1 MHz@ 1 GHz
Volume Resistivity
C96/35/90
E24/125
Surface Resistivity
C96/35/90
E24/125
Electrical Strength
Dielectric Breakdown
Arc Resistance2. Thermal Properties
Glass Transition Temperature (Tg)
TMA
DSC
Decomposition Temperature (Td)

3. Mechanical Properties

ASTM D-695
ASTM D-3039

4. Physical Properties
Water Absorption
Specific Gravity
Thermal Conductivity
Flammability%
g/cm3
W/mKclass0.15
1.350.25
Meets V0

IPC TM-650 2.6.2.1
ASTM D792 Method A
ASTM E1461
UL-94* Based on typical thick laminate construction
Results listed above are typical properties, provided without warranty, expressed or implied, and without liability. Properties may vary, depending on design and application. Arlon reserves
the right to change or update these values.

Availability:Arlon PartNumber

Glass Style

Resin %

PressedThickness

Flow Range

51N0672106

720.0022”

60—120 mils

51N0666

106660.0017”

60—120 mils

51N80651080

650.0032”

60—120 mils

51N80601080

600.0027”

60—120 mils

Recommended Process Conditions:
Process inner-layers through develop, etch, and strip using standard industry practices. Usebrown oxide on inner layers. Adjust dwell time in the oxide bath to ensure uniform coating.
Bake inner layers in a rack for 60 minutes at 225F - 250F (107C - 121C) immediately
prior to lay-up. Vacuum desiccate the prepreg for 8 - 12 hours prior to lamination.
Lamination Cycle:•Pre-vacuum for 30 - 45 minutes•Control the heat rise to 8F - 12F (4.5C - 6.5C) per minute between 150F and 300F (65C and 150C)
Panel Size

Pressureincm

psikg/sq cm

12 x 1240 x 40

150

1212 x 1840 x 46

2001416 x 18

30 x 46

250

1818 x 24

46 x 61300

21•Product temperature at start of cure = 360F (182C).
•Cure time at temperature = 90 minutes•Cool down under pressure at ≤ 10F/min (6C/min)Drill at 350-400 SFM. Undercut bits are recommended for vias 0.023” (0.9cm) and smaller
De-smear using alkaline permanganate or plasma with settings appropriate for multifunctional epoxysystems.
Conventional plating processes are compatible with 51N-LF
Standard profiling parameters may be used; chip breaker style router bits are not recommended
Bake for 1 - 2 hours at 250F (121C) prior to solder reflow or HASL51N

North America:9433 Hyssop Drive, Rancho Cucamonga, California 91730
Tel: (909) 987-9533 • Fax: (909) 987-8541
1100 Governor Lea Road, Bear, Delaware, 19701
Tel: (302) 834-2100, (800) 635-9333
Fax: (302) 834-2574
Northern Europe:
44 Wilby Avenue, Little Lever, Bolton, Lancaster, BL31QE, UK
Tel: (44) 120-457-6068 • Fax: (44) 120-479-6463
Southern Europe:
1 Bis Rue de la Remarde, 91530 Saint Cheron, France
Tel: (33) 871-096-082 • Fax: (33) 164-566-489
Northern China:
Room 11/401, No. 8, Hong Gu Road, Shanghai, China, 200336
Tel/Fax: (86) 21-6209-0202
Southern China:
Room 601, Unit 1, Building 6, Liyuanxincun, Road Holiday,
Hua qiaocheng, Nanshan District, Shenzhen City, China
Tel: (86) 755-26906612 • Fax: (86) 755-26921357

Rev 1.2

www.arlon-med.com