KMRD-015A Low Temperature Cure Dielectric for Wafer-Level Packaging RDL

KMRD-015A is a negative tone, low temperature cure polyamide photo-dielectric for redistribution and buffer layers. It is reactive to broadband and i-Line exposure systems, aqueous developed and compatible with industry standard edge bead removers and back-rinse solvents.


Material Attributes:

  • Negative tone, photo-imageable dielectric
  • Alkaline developable (0.26N TMAH)
  • Single stage, low temperature cure, 1h @ 185°C
  • Low shrinkage/film loss during process
  • Good chemical and thermal stability
  • Excellent processability and process latitude
  • Excellent HAST and TCT performance
7 µm L/S 10 µm Film Thickness
7 µm via 7.0 µm Film Thickness

Lithography Process

TypeLiquid Negative Tone
Available Film Thickness
5 to 15 µm (EBR: CP)
Soft Bake95°C , 2 minutes
Exposure Dose200 mJ/cm2 (EVG Broadband Mask Aligner)
550 mJ/cm2 (i-Line Nikon Stepper)
(intensity measured at 365 nm)
Post Exposure Bake110°C, 2.5 minutes
Develop2.38% TMAH (60-90 seconds)
Cure1 hour, 185°C
[ single stage ]

Cured Film Properties

PropertyValue
Mechanical PropertiesYoung’s Modulus2.0 GPa
Tensile Strength80 MPa
CTE α1 (<Tg)60 ppm/°C
Elongation70%
Internal Residual Stress20 MPa
Thermal PropertiesTg (DMA)240°C
5% Weight Loss Temperature in N2287°C
5% Weight Loss Temperature in Air283°C
Electrical PropertiesVolume Resistivity3 x 1016 Ohm·cm
Breakdown Voltage390 V/µm
Dielectric Constant, 1GHz3.2
Dissipation Factor , 1GHz0.018
Moisture Absorption23°C/85%RH, 24 hours0.3%
ReliabilityHAST 85°C/85%RHPassed 1,000 hours
HAST 135°C/ 85%RHPassed 100 hours
Bias HAST 85°C/85%RH. Cu Migration. 5/5 µm L/SPassed 168 hours
TCT -55°C to +125°CPassed 2,000 cycles

Reliability

TCT (-55°C to +125°C): PASSED > 2,000 cycles
Cu substrate; 10 µm film thickness; 10 µm gap

>1,000 Cycles
>2,000 Cycles

HAST: PASSED cross cut test
Cu substrate; 10 µm film thickness

85°C/85%RH 1,000 hours
135°C/85%RH 100 hours