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| === Devices and materials === A lot can be done on a very thin planar surface. Other things cannot be done easily. Here are some common electronic devices: ||<#80FF80>'''Thin Planar''' ||<#FF8080>'''Non-planar''' || ||<#F0FFF0> Printed circuit laminates (ultrathin) ||<#FFF0F0> Connectors || ||<#F0FFF0> Resistors ||<#FFF0F0> cooling fins || ||<#F0FFF0> Planar Capacitors ||<#FFF0F0> Wound foil capacitors || ||<#F0FFF0> pixel sensor arrays ||<#FFF0F0> lenses || ||<#F0FFF0> liquid crystal light modulators ||<#FFF0F0> LEDs (?) || ||<#F0FFF0> Striplines ||<#FFF0F0> Coax || ||<#F0FFF0> Microwave-frequency inductors ||<#FFF0F0> Low frequency inductors and transformers || ||<#F0FFF0> surface acoustic wave (SAW) resonators ||<#FFF0F0> crystals || ||<#F0FFF0> beam lead interconnect ||<#FFF0F0> wirebonds and solderbumps || Silicon is the construction material of choice - the solar cell is made of silicon, and the processors and memory are also. Here are some relevant properties of silicon, !SiO2 glass, gallium arsenide, copper, aluminum, and tantalum, which will make up 99% of the weight of a server-sat: || property || Si || !SiO2 || !GaAs || Cu || Al || Ta || || Density g/cm^3 || 2.33 || 2.65 || 5.32 || 8.96 || 2.7 || 16.7 || || Thermal Coefficient of Expansion 10-6/K || 2.6 || 0.5 || 5.7 || 16.5 || 23.1 || 6.3 || || Heat Capacity J/g-K || 0.71 || 0.74 || 0.33 || 0.38 || 0.90 || 0.14 || || Thermal Conductivity W/m-K || 149 || 1 || 55 || 401 || 237 || 58 || || Youngs Modulus GPa || 150 || 73 || 86 || 110 || 70 || 186 || || Tensile Strength MPa || 7000 || 50 || 57 || 210 || 40 || 200 || || Atomic Weight (avg/atom) || 28 || 20 || 72.3 || 63.5 || 27 || 181 || || Resistivity nano-ohm-m || - || - || - || 17 || 27 || 131 || || Dielectric Constant || 11.8 || 3.9 || 12.9 || - || - || - || Data mostly from wikipedia and various places online. Tensile strength untrustworthy, and many parameters are anisotropic. Use only for rough estimates. MORE LATER === Factories === |
Manufacturing Server Sky
Devices and materials
A lot can be done on a very thin planar surface. Other things cannot be done easily. Here are some common electronic devices:
Thin Planar |
Non-planar |
Printed circuit laminates (ultrathin) |
Connectors |
Resistors |
cooling fins |
Planar Capacitors |
Wound foil capacitors |
pixel sensor arrays |
lenses |
liquid crystal light modulators |
LEDs (?) |
Striplines |
Coax |
Microwave-frequency inductors |
Low frequency inductors and transformers |
surface acoustic wave (SAW) resonators |
crystals |
beam lead interconnect |
wirebonds and solderbumps |
Silicon is the construction material of choice - the solar cell is made of silicon, and the processors and memory are also. Here are some relevant properties of silicon, SiO2 glass, gallium arsenide, copper, aluminum, and tantalum, which will make up 99% of the weight of a server-sat:
property |
Si |
SiO2 |
GaAs |
Cu |
Al |
Ta |
Density g/cm^3 |
2.33 |
2.65 |
5.32 |
8.96 |
2.7 |
16.7 |
Thermal Coefficient of Expansion 10-6/K |
2.6 |
0.5 |
5.7 |
16.5 |
23.1 |
6.3 |
Heat Capacity J/g-K |
0.71 |
0.74 |
0.33 |
0.38 |
0.90 |
0.14 |
Thermal Conductivity W/m-K |
149 |
1 |
55 |
401 |
237 |
58 |
Youngs Modulus GPa |
150 |
73 |
86 |
110 |
70 |
186 |
Tensile Strength MPa |
7000 |
50 |
57 |
210 |
40 |
200 |
Atomic Weight (avg/atom) |
28 |
20 |
72.3 |
63.5 |
27 |
181 |
Resistivity nano-ohm-m |
- |
- |
- |
17 |
27 |
131 |
Dielectric Constant |
11.8 |
3.9 |
12.9 |
- |
- |
- |
Data mostly from wikipedia and various places online. Tensile strength untrustworthy, and many parameters are anisotropic. Use only for rough estimates.
MORE LATER
Factories
Much of the manufacturing for Server Sky can happen in Washington County, Oregon, around Hillsboro.
The main component by weight is the solar cell. The Solar World plant in Hillsboro is the largest solar cell manufacturer in the US - certainly the most highly automated. The solar cells in their illustrations look like 100 millimeter diameter, but perhaps they can learn to make larger ones.
The most complicated components are the microprocessors. Some version of the Intel Atom may be suitable. For a server-sat, it is preferable to use a fast, deep submicron, 1V processor with heavy doping (less sensitive to radiation damage) and at least an epi substrate. A trench isolated SOI process is preferred. AMD processors are all trench isolated SOI. Intel's Penryn process, with thick Hafnium oxide gates and work-function controlled gate metalization, will also be more radiation resistant. Over time, most process improvements desirable for high performance processors will also be desirable for radiation hardness.
The most radiation sensitive components are likely to be the flash memory. These incorporate error correction, but software error correction and frequent rewrites may be necessary to correct for radiation induced charges.
The gallium arsenide radios will probably be made by Triquint.
The LCD material will be pretty simple. It will need to survive freezing, and the LCDs should be divided into separately-addressed cm-sized cells so that meteorite punctures will not disable a whole LCD. That said, they only need to switch very slowly, and consequently have wide flexibility in operating voltage. They will probably be constructed from a 1 micron layer of LCD material between two pieces of indium oxide coated 30 micron thick glass (which is commercially available). This is standard technology, and has been manufactured locally by startups such as Sarif and Steridian, and is currently manufactured by Sharp in Vancouver, Washington.
Washington county companies such as D.W. Fritz build wafer handling equipment .
MORE LATER