Archives: Landing Domains

Sapphire wafers and substrates come in many orientations, the most common being A-Plane and C-Plane (very machinable) and R-Plane (difficult to machine). Each offers different optical characteristics unimportant for mechanical applications. This is a difficult material to dice, however Valley’s process produces the least amount of chipping possible. On edges which require an optical quality surface, Valley also offers optical edge and angle polishing of these end faces.

For a complete summary of dicing capabilities click here.

Dicing related Web sites:

• https://valleydesign.com/custom-dicing/wafer-dicing/ Wafer dicing
• https://valleydesign.com/custom-dicing/edge-rounding/ Diced chip and substrate edge-rounding
• https://valleydesign.com/custom-dicing/custom-dicing/ Custom wafer dicing, cutting, sawing and singulating
• https://valleydesign.com/custom-dicing/thin-dice Thin dice by thinning after dicing
• https://valleydesign.com/sapphire-wafers Sapphire wafers and substrates

The company’s 30 year experience with ferrite materials allows to advise customers concerning tolerances, surface finishes and chip specifications. Dicing, shaping and polishing services are provided for both R&D as well as high volume production. Other services include chamfering, edge polishing, lapping, thinning and wafering.

For a complete summary of company’s dicing capabilities click here. This service is available on both, East and West coasts.

Optically polished mirror surfaces on Aluminum typically range from 20 to 30 Angstroms Ra. Under ideal conditions Valley has achieved 8 Angstrom Ra surface finish on 6061T6 aluminum, but in general the surface finish attainable depends on many variables including material quality, part size, shape and thickness.

Optically superpolished fused silica wafers with 3 Angstrom Ra surface finish are being done at production level quantities. This level of surface finish is usually a requirement for critical MEMS surfaces.

The surface finish of a polished fused silica wafer can be improved by repolishing to reach 3 – 4 Angstrom Ra superpolished smoothness. If the polished surfaces have been compromised during processing, these surfaces also can be improved by repolishing to 3 – 4 Angstrom level with minimal stock removal.

Standard polish on Fused Silica with 5.1 to 6.7 Angstrom Ra surface finish – prior to superpolishing.

 

 

 

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WYKO Scan of a Super-Polished Surface with 3.4 to 3.9 Angstrom Ra surface finish.

 

 

To enable applications of all types, submounts spacers, bases, carriers and shim parts are manufactured from various materials including 7059 Glass, Soda Lime Glass, Fused Silica, Aluminum Nitride (AlN), Silicon Carbide (SiC), Sapphire, ALON, Alumina, Silicon, Steatite, and many others. Tolerances can be held within a few microns, and flatness to fractions of a lightband. These shims and spacers may be lapped, or optically polished.

Applications may include:

• Ceramic submounts for polarization optics
• Laser diode spacers / submounts
• Glass spacers for planar lightwave circuits (PLC’s)
• Silicon transmission line spacers
• RF submounts / spacers
• Micropackaging for optical and electronic components
• Aluminum oxide polarization optics submounts
• Aluminum Nitride spacers for TIA submounts
• Interconnect spacers for TOSA packaging

For other related information on these products and for shims and spacers readily available from stock, click here.

Reflectivity of uncoated optically polished molybdenum is greater than 90% for wavelengths longer than 1.8 microns. Pure vacuum ARC cast low carbon is the preferred material for polished molybdenum (Mo) mirrors.

Benefits of optically polished Moly / molybdenum laser mirrors:

• High reflectivity at the CO2 10.6 micron wavelength
• High anti-corrosion capability
• Highest CO2 CW laser damage threshold
• Surface finish: 20/10 scratch/dig; <20 Angstroms Ra
• Standard flatnesses: lambda/2, lambda/4, lambda/10

Laser drilled polyimide

Top view of drilled polyimide wafer

Polyimide wafers are ideal where requirements include the need for interconnecting with low dielectric constant material, high speed, high density substrates for 3-D System-in-Package and Package-on-Package applications.

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• Polymer wafers for InGaP thin-film microdisk resonators
• Temporary bonding for two-stage transfer of thin films from one substrate to another
• Polymer microfluidic device fabrication
• Polymer electrical and optical input-output interconnects

For innovative engineering, prototyping and manufacturing solutions, Valley Design offers lapping, polishing and precision sizing of all polymer wafers and substrates with no size or thickness limitations.

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Polyimide coatings applications:

• Multilayer and thin film uses
• Protective overcoat for semiconductor chips
• Flip chip bonding applications
• Interlayer dielectrics
• Structural layers in micromachining
• Lithographic processes

There are many benefits from using planarized polyimide coatings. By planarizing polyimide coatings, applied as liquid onto a substrate by:

• Spin coating
• Spraying
• Extrusion
• Dip coating,

The surface will be polished to a near defect free level for better functioning as a dielectric and will provide improved yield in polyimide patterning applications.

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Polyimide Substrate Flexibility

Web pages on solar cells on polyimide substrates:

• High efficiency thin film solar cells on flexible polymer sheet
• Non-Vacuum Processing on CIGS Solar Cells on Flexible Polymeric Substrates
• CuInAlSe p-type absorber on IR transparent polyimide substrate
• Thin film solar cells for space applications

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