|
Sputtering is commonly used because the adhesion of deposited metals is excellent. The basic bondable metallization scheme for thin-film substrates contains TiW as the adhesion layer and Au as the conductor layer (TiW/Au). When resistors are required Tantalum Nitride is added (TaN/TiW/Au). TaN is available from 10 to 200 ohms/square sheet resistivities. Multi-ohms per square films are also available on single circuit designs.
Solderable metallization shemes are also available by adding Ni and/or Cu to these films (TiW/Au/Cu/Ni/Au). Bondable and solderable metallization schemes can be achieved on a single design. Palladium can also be added as a solderable film when using high-temperature eutectics. Many different combinations are available for your design. Please consult with our sales department for more information.
|
|
|
| TiW/Au |
450 |
Yes |
Not Recommended |
Yes |
Run Out issue |
| TaN/TiW/Au |
450 |
Yes |
Not Recommended |
Yes |
Run Out issue |
| TiW/Pd/Au |
450 |
Yes |
Yes |
Yes |
Yes |
| TaN/TiW/Pd/Au |
450 |
Yes |
Yes |
Yes |
Yes |
| TiW/Ni/Au |
425* |
Yes |
Yes |
Yes |
Yes |
| TaN/TiW/Ni/Au |
425* |
Yes |
Yes |
Not Recommended |
Yes |
| TiW/Au/Cu/Ni/Au |
425* |
Yes |
Yes |
Yes |
Yes |
| TaN/TiW/Au/Cu/Ni/Au |
425* |
Yes |
Yes |
Yes |
Yes |
| TiW/Au/Ni/Au |
425* |
Yes |
Yes |
Yes |
Yes |
| TiW/Au/Ni/Au |
425* |
Yes |
Yes |
Yes |
Yes |
*Limited time
Note: Pb/Sn solderable and wire bondable on the same circuit can be achieved with special processes.
|
|
Metallizations Offered
|
|
|
|
Other metallizations and thicknesses are available. Please contact our sales department for information.
|
|
SEM Profile
|
|
Metal Stack
|
|
Layers
|
| Typical Applications |
Conductor and resistor applications that require traditional processing |
| Advantages |
Cost effective standard assembly practices; can integrate TaN into the film; bondable |
| Disadvantages |
Not Pb/Sn compatible |
| Pb/Sn Solderability |
Poor |
| Allowble Die Attach Method |
Epoxies; Au/Ge eutectic; Au/Si eutectic; Au/Sn eutectic |
| Typical TCR |
-100 ±50ppm/°C |
| Recommended Front Side Metal |
Sputtered 10–200ohms/sq TaN if resistors are required
Sputtered TiW: 300–800Å (0.03–0.08µm)
Sputtered Au: 20µ"–200µ", typical = 120µ" (0.5–5µm, typical = 3µm)
Plated Au: 20µ"–500µ", typical = 120µ" (0.5–12.7µm, typical = 3µm)
|
| Backside Metal |
Same as front side without the TaN layer |
| Typical Applications |
Conductor - resistor applications that allow bonding and soldering |
| Advantages |
Best for Au/Si assemblies and limited eutectic leaching; can integrate TaN into the film |
| Au/Si Solderability |
Best |
| Pb/Sn Solderability |
Good |
| Allowble Die Attach Method |
Epoxies; Au/Si eutectic; Au/Sn eutectic; Au/Ge eutectic; Pb/Sn |
| Typical TCR |
-100 ±50ppm/°C |
| Recommended Front Side Metal |
Sputtered 10–200 ohms/sq TaN if resistors are required
Sputtered TiW: 300–800Å (0.03–0.08µm)
Sputtered Au: 20µ"–200µ", typical = 120µ" (0.5–5µm, typical = 3µm)
Plated Au: 20µ"–500µ", typical = 120µ" (0.5–12.7µm, typical = 3µm)
|
| Backside Metal |
Same as front side without the TaN layer |
| Typical Applications |
Conductor applications that require Pb/Sn soldering |
| Advantages |
Solderable for Pb/Sn assemblies; can be bondable as long as TaN is not present |
| Disadvantages |
Wire bonding problems may be experienced due to Ni-Au diffusion when devices processed > 300°C;
TaN is not recommended due to processing Ni-Au diffusion > 300°C
|
| Pb/Sn Solderability |
Best for Pb/Sn assemblies |
| Allowble Die Attach Method |
Epoxies; Au/Si eutectic; Au/Sn eutectic; Au/Ge eutectic; Pb/Sn |
| Typical TCR |
-100 ±50ppm/°C |
| Recommended Front Side Metal |
TaN is not recommended due to passivation above > 300°C, Ni diffusion
Sputtered TiW: 300–800Å (0.03–0.08µm)
Sputtered Ni: 1500–2000Å (0.15–0.2µm)
Sputtered Au: 20µ"–40µ" (0.5–1.0µm) for solderable thin gold
Plated Au: 20–500µ" (0.5–12.7µm) for bondable thicker gold
|
| Backside Metal |
Same as front side without the TaN layer |
| Typical Applications |
Conductor-resistor applications with high conductivity film that requires Pb/Sn soldering |
| Advantages |
High conductivity film; can integrate TaN into the film;
Solderable Gold/Bondable Gold can be achieved on the same ciruit
|
| Pb/Sn Solderability |
Best |
| Allowble Die Attach Method |
Epoxies; Au/Si eutectic; Au/Sn eutectic; Au/Ge eutectic; Pb/Sn |
| Typical TCR |
-100 ±50ppm/°C |
| Front Side Metal |
Sputtered 10–200 ohms/sq TaN if resistors are required
Sputtered TiW: 300–800Å (0.03–0.08µm)
Sputtered Au: 20–40µ" (0.5–1.0µm)
Electroplated Cu: 20–1,000µ" (0.5–25.4µm)
Electroplated Ni: 20–500µ" (0.5–12.7µm)
Electroplated Au: 20–500µ" (0.5–12.7µm) for solderable use thin gold, for bondable use thick gold
|
| Backside Metal |
Same as front side without the TaN layer |
| Typical Applications |
Conductor-resistor applications that require Pb/Sn soldering |
| Advantages |
Best for Pb/Sn assemblies; can integrate TaN into the film;
Solderable Gold/Bondable Gold can be achieved on the same ciruit
|
| Pb/Sn Solderability |
Best |
| Allowble Die Attach Method |
Epoxies; Au/Si eutectic; Au/Sn eutectic; Au/Ge eutectic; Pb/Sn |
| Typical TCR |
-100 ±50ppm/°C |
| Front Side Metal |
Sputtered 10–200 ohms/sq TaN if resistors are required
Sputtered TiW: 400–800 Ansgtroms
Sputtered Au: 20µ"–40µ" (0.5–1.0µm)
Electroplated Ni: 20–500µ" (0.5–12.7µm)
Electroplated Au: 20–500µ" (0.5–12.7µm) for solderable use thin gold, for bondable use thick gold
|
| Backside Metal |
Same as front side without the TaN layer |
|
|
|
|
|
|
|
|
|
|
|
|
