White solder resist

This is the white solder resist for LED printing circuit board. Sekisui's white solder resists have high reflectivity and high heat resistant properties (no yellowing). We provide photo-imageable and ultraviolet-cured type.

White photo-imageable solder resist
~SFR-6 series~

This is the white photo-imageable solder resist (WPSR). SEKISUI provide standard and high reflectance WPSR.

Product lineup

Product name SFR-6 KS F
(B2-R603)
SFR-6 KS F
(B2-R802)
Type Standard High reflectance
Properties Reflectance
Al scratch resistance
PCT reliability

Characteristic 1

  1. Super high reflectance (B2-R802) (Filled with high density of TiO2)
  2. Highly heat resistance (no yellowing & highly crack-resistant)
  3. High reliability (PCT etc.)

Characteristic 2

SFR-6 Series have high heat resistance and reliability.

Properties SFR-6 KS F
(B2-R603)
SFR-6 KS F
(B2-R802)
Film thickness/μm 23 23 45
Initial Reflectance (Y value) 85 87 93
b* 0.5 0.1 1.1
Reflow x 3 times Reflectance (Y value) 85 87 92
b* 0.0 0.2 1.2
AI scratch resistant property Method by Sekisui 50g OK 50g OK
PCT Test
121℃ 100%RH 96h
No cracking
No cracking

Reflectance Data of SFR-6 KS F(B2-R603)

SFR-6 KS F(B2-R603) has high reflectance and reliability.

Other properties

Properties SFR-6 KS F
(B2-R603)
SFR-6 KS F
(B2-R802)
Adhesion
ASTM D3002
On FR-4 100/100 100/100
On Cu 100/100 100/100
Pencil hardness IPC-SM-840C 3.5.1 /
IPC-TM-650TM 2.4.27.2
6H 6H
Halogen content Cl (BS EN14582(2007)) <400 ppm <400 ppm
Br (BS EN14582(2007)) None None
RoHS IEC62321
(Cd, Pb, Hg, Cr(VI), PBBs, PBDEs)
None None
Flammability UL94 V-0 V-0

Ink characteristics and recommended process conditions

Ink characteristics

  SFR-6 KS F
(B2-R603)
SFR-6 KS F
(B2-R802)
Color White White
Component Type Two Component Type Two Component Type
Mixing ratio 80:20 80:20
Viscosity (after mixing)
(25℃, 10rpm)
ca. 20 Pa・s ca. 20 Pa・s
After-mixing Life (bellow 25℃) 24 hours 24 hours
Shelf Time (20~25℃) 6 months 6 months

Recommended conditions

  SFR-6 KS F
(B2-R603)
SFR-6 KS F
(B2-R802)
Working condition Please use it under the yellow ramp wherever possible
Mixing 100rpm, 30-60 minutes 25±5℃
Defoaming ca. 10 minutes
Screen printing (23℃) Screen :#100 tetron screen(25μm)
Hold time >10 minutes
Pre-bake 80℃*30 minutes
Exposure 500mJ/cm2 (@365nm) on WPSR 800mJ/cm2 (@365nm) on WPSR
Development Na2CO3 1wt% (30℃) 30~60sec 0.2MPa
Post-bake 150℃*60min

UV-curable White Solder Resist
~SR-10 KC7 Series~

This is the UV-curable white solder resist (UV-SR). SEKISUI provide high reflectance and adhesion UV-SR.

Process Comparison & Properties
of UV and Photo type Characteristics

  1. Only UV Curable
  2. Short production process
Process Pretreatment Screen printing Hold Pre-bake Exposure Development Post-bake
UV type
Photo type >10min 80℃
30min
150℃1h


Properties SR-10 KC7 Series Photo type
Film thickness(μm)

15

23

Initial Reflectance (Y value) 85 85
b*

-1.1

0.5
Reflow 3 times Reflectance (Y value) 85 85
b* 0.0 0.0

Adhesion ASTM D3002

100/100 100/100

Properties of SR-10 KC7 Series

SR-10 KC7 series have high adhesive property and reflectance.



Properties SR-10 KC7 Series
Process Print & UV Curing Print: 1 time Print: 2 time
(SR-10 KC7/SR-10 KC7)
Initial Reflectance (Y value) 85 90
b* -1.1 -0.1
Reflow x 3 times Reflectance (Y value) 85 90
b* 0 1.5
Adhesion ASTM D3002 100/100 100/100

Other properties

Properties SR-10 KC7
Series
Pencil hardness IPC-SM-840C 3.5.1 /
IPC-TM-650TM 2.4.27.2
4H
Halogen content Cl (BS EN14582(2007)) <400 ppm
Br (BS EN14582(2007)) None
RoHS IEC62321
(Cd, Pb, Hg, Cr(VI), PBBs, PBDEs)
None
Flammability UL94 V-0

Ink characteristics and recommended process conditions

Ink Characteristics

  SR-10 KC7 Series
Color White
Component Type One Component Type
Viscosity (25℃, 10rpm) ca. 10 Pa・s
Shelf Time(20~25℃) 6 months

Recommended process conditions

  SR-10 KC7 Series
Working condition Please use it under the yellow ramp wherever possible
Mixing 100rpm, 30-60 minutes at 25±5℃
Screen printing (23℃) Screen: #180-#330 tetrone screen
Exposure 1000mJ/cm2 x2 or 2000mJ/cm2 (@365nm) on WPSR
  • Heat release Fin

    This is the heat release com-
    ponent integrated with metal. It shows high heat releasing / insulation performance.
  • Heat conductive paste

    This is the heat conductive paste with high thermal conductivity.
     
  • Heat release sheet

    This is the thermosetting type epoxy resin sheet with excellent thermal conductivity.
  • Coating / Adhesive Material

    High resolution additive manufacturing with anywhere any shape (lines/circles etc.) printing.