WTi/Au
Typical Applications	Devices processed at high temperatures, such as Au/Ge eutectic bonding temps
Advantages	Film withstands excursions to 450°C
Disadvantages	Barrier layer recommended for eutectics
Temperature Guidelines	450°C for 30 minutes
Pb/Sn, Au/Sn Solderability	Possible diffusion/enrichment
Allowable Die Attach Methods	· Epoxies · Au/Ge eutectic · Au/Si eutectic · Au/Sn solder · Pb/In eutectic
Typical TCR	n/a
Front Side Metal	· Sputtered WTi 300-500Å · Sputtered Au 20-300µ"
Back Side Metal	Same as front side
WTi/Ni/Au
Typical Applications	Devices processed at higher temperatures requiring a solderable film
Advantages	Film withstands brief excursions to 325°C
Disadvantages	Wire bonding problems may be possible due to Ni-Au diffusion when devices processed > 300°C
Temperature Guidelines	300°C for 120 minutes
Pb/Sn, Au/Sn Solderability	Good
Allowable Die Attach Methods	· Pb/Sn solder · Au/Sn solder · Epoxies · Pb/In eutectic
Typical TCR	n/a
Front Side Metal	· Sputtered WTi 300-500Å · Sputtered Ni 2,000-5,000Å · Sputtered Au 20-300µ"
Back Side Metal	Same as front side
WTi/Au/Cu/Ni/Au
Typical Applications	High conductivity film allowing for wire bonding and/or soldering after high temp. processing
Advantages	· High conductivity film · Pb/Sn & Au/Sn solderable
Disadvantages	Wire bonding problems may be possible due to Ni-Au diffusion when devices processed > 300°C
Temperature Guidelines	300°C for 120 minutes
Pb/Sn, Au/Sn Solderability	Good
Allowable Die Attach Methods	· Pb/Sn solder · Au/Sn eutectic · Epoxies · Pb/In eutectic
Typical TCR	n/a
Front Side Metal	· Sputtered WTi 300-500Å · Sputtered Cu 40µ" · Electroplated Cu 40-2000µ" · Electroplated Ni 50-150µ" · Electroplated Au 50-250µ"
Back Side Metal	Same as front side
TaN/WTi/Au
Typical Applications	Devices processed at high temperatures, such as Au/Ge eutectic bonding temps
Advantages	· Film withstands excursions to 450°C · Passivated TaN films offer good humidity resistance
Disadvantages	· Not Pb/Sn or Au/Sn Solderable · Should be fully sputtered in order to provide blister free films
Temperature Guidelines	Stabilize resistors at 425°C for 30.120 minutes
Pb/Sn, Au/Sn Solderability	Poor
Allowable Die Attach Methods	· Epoxies · Au/Ge eutectic · Au/Si eutectic · Au/Sn eutectic · Pb/In eutectic
Typical TCR	-100 ± 50 ppm/°C
Front Side Metal	· Sputter 10-200 Ω/sq. TaN · Sputtered WTi 300-500Å · Sputtered Au 20-300µ"
Back Side Metal	Same as front side without the TaN layer
TaN/WTi/Ni/Au
Typical Applications	Devices processed at higher temperatures requiring a solderable film
Advantages	· Pb/Sn & Au/Sn solderable · Passivated TaN films offer good humidity resistance
Disadvantages	Wire bonding problems may be possible due to Ni-Au diffusion when devices processed > 300°C
Temperature Guidelines	Stabilize resistors at 325°C for 60 minutes
Pb/Sn, Au/Sn Solderability	Good
Allowable Die Attach Methods	· Pb/Sn solder · Au/Sn solder · Epoxies · Pb/In eutectic
Typical TCR	-100 ± 50 ppm/°C
Front Side Metal	· Sputter 10-200 Ω/sq. TaN · Sputtered WTi 300-500Å · Sputtered Ni 2,000-5,000Å · Sputtered Au 20-300µ"
Back Side Metal	Same as front side without the TaN layer
NiCr/Ni/Au
Typical Applications	Designs requiring precision resistors with low TCR's
Advantages	Low TCR's (0 ± 50 ppm/°C) · Pb/Sn & Au/Sn solderable
Disadvantages	Wire bonding problems may be possible due to Ni-Au diffusion when devices processed > 300°C
Temperature Guidelines	Stabilize resistors at 325°C for 60 minutes
Pb/Sn, Au/Sn Solderability	Good
Allowable Die Attach Methods	· Pb/Sn solder · Au/Sn solder · Epoxies · Pb/In eutectic
Typical TCR	0 ± 50 ppm/°C
Front Side Metal	· Sputter 50-200 Ω/sq. NiCr · Sputtered Ni 2,000-5,000Å · Sputtered Au 20-300µ"
Back Side Metal	Same as front side (NiCr for adhesion only)