Heat resistant solder resist ink(For RPC) TAINEX HRS-1-7W White

Overwhelming heat-resistance of silicone resin

HRS-1-7W is a silicone-based resistor ink which features superb heat resistance and UV-resistant properties. Furthermore, although it consists of a silicone resin, there is no detection of low-molecular siloxane, which may cause electrical contact failure.※1
  •  Feature High heat resistance:The high heat resistance property is achieved with a silicone resin. Almost no reflectance deterioration was detected under the condition of 150℃ for 1000 hours.
  •  Feature Superb UV resistance:The HRS-1-7W is resistant to ultraviolet radiation and almost no deterioration has been noted even when exposed to UV-C irradiation.
  •  Feature Countermeasure against low-molecular siloxane:Even though HRS-1-7W is consisted of silicone resin,there is no detection of low-molecular siloxane, which may cause electrical contact failure.※1

 Feature High heat resistance

Resistance to color change by heat(on copper)

The reflectance deterioration rate after heating the product at 260℃ for 3 cycles was as low as 2%. There was almost no change compared to the initial condition.

  Film thickness L a b Reflection rate
HRS-1-7W Initial 30〜35μm 94.32 -1.22 -0.36 91.12
After 260 deg.C ×10 minutes 3 cycles 94.23 -1.41 0.89 89.00
After 320 deg.C ×2 minutes 94.37 -1.35 0.54 89.80

Feature Superb UV resistance

UV-C Irradiation test (HRS-1-7W, General solder resist ink)

UV-C Irradiation time - Gloss (on copper)

With resistor inks that are based on organic resins including epoxy resin, their luster is deteriorated by UV-C. With HRS-1-7W, however, it is free from any deterioration in luster.

HRS-1-7W Gloss Light reflectance
Voltage resistance
Initial 48.3 90.85 500V OK
After UV-C irradiation for 1000 hours 42.0 89.09 500V OK

HRS-1-7W is free from any insulation breakdown at 500 V even after it has been exposed to UV-C irradiation for 1000 hours.

Feature Countermeasure against low-molecular siloxane※1

Measurement result of low-molecular siloxane content
Amount of low molecular siloxane in the ink (D4-D10)
Types of cyclic
D4 N.D.
D5 N.D.
D6 N.D.
D7 N.D.
D8 N.D.
D9 N.D.
D10 N.D.
Σ Dn(n=4〜10) N.D.
N.D. : Less than 10ppm

HRS-1-7W is a solder resistor ink consisting of a silicone resin which features high light reflectivity due to its white color and superb heat resistance.

Measurement was performed at
Kita-Kanto Analysis Center,
Measurement method: measurement tool:
gas chromatograph (GC/FID)

■Coating film performance

Item Test method HRS-1-7W 2coat type
HRS primer +HRS-1-7W
Hardness JIS K5600-5-4 2H or more 2H or more
Adhesion JIS K5600-5-6 Category 0 Category 0
Solvent resistance Isopropyl alcohol, 5Min immersion OK OK
Acid resistance 10% sulfuric ,30 Min immersion at room temp. OK OK
Alkaline resistance 5% sodium hydrate, 5 Min immersion OK OK
Solder resistance JIS C6481 260 deg.C for 20 sec. OK OK
PCT 121 deg. C for 9 Hr OK OK
Combustibleness UL standard 94V-0 94V-0

■Electric characteristics

Item Test method HRS-1-7W 2coat type
HRS primer +HRS-1-7W
Insulation resistance Initial value 1.8×1012
24V load, 85 deg. C,
RH85%, 1000Hr
After Test
After Test
Surface resistanse JIS C6481-5-10 1.0×1011Ω 1.0×1012Ω
Volume resistivity JIS C6481-5-9 1.0×1013Ω 1.0×1013Ω・cm
Voltage resistance 500V OK OK

*The results above show reference values, not standard values.

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