1
3D CAD
- A designer can use most 3D CAD packages to create and submit a design
- The design can be an assembly with any number of parts
- Multiple variations of a design or even different devices can be produced
on a single wafer as long as they all have the same layer scheme - Simulation tools can be used to analyze the design
- Most commonly, the simulation models mechanical behavior, but can also be used for thermal, fluidic, etc.
2
Layerize™
- MICA Freeform™ uses the industry standard "STL" or SolidWorks® file format
- Proprietary software converts the device into discrete, two-dimensional layers
- The thickness of each layer is specified during the layerization process
3
Layout / Photomask Generation
- CAD software is used to layout multiple copies of the device on a wafer
- Depending on the size of the device, dozens to thousands of devices can fit on a wafer
- A typical layout will include diagnostic structures to aid manufacturing
- The CAD data is used to produce photomasks (like a negative used in photography)
4
Release Layer
- A small amount of sacrificial material is electroplated on the ceramic wafer
- This layer will be chemically etched at the end of the fabrication process to allow the devices to release from the wafer
5
Lithography
- A very precise thickness of photoresist is then applied to the wafer
- The appropriate photomask is then placed on top of the recently applied photoresist and aligned to the previous layer
- The mask is exposed to an ultraviolet light which creates a pattern
- The pattern is developed to produce a "mold" for the deposition process
6
Patterned Electrodeposition
- The wafer is placed into an electro-deposition cell; this is filled with a solution that is rich in the ions of the metal to be deposited
- An electrical current is passed through the cell causing the metal to be deposited on the wafer
- Proprietary MICA Freeform™ techniques are used to engineer the electrical field and control the deposition of the desired metal
7
Stripping
- The photoresist is then chemically removed
8
Sacrificial Deposition
- The sacrificial material (copper) is deposited into the area where the photo-resist was removed
- The purpose of the sacrificial material is to act as a stable, electrically-conductive scaffold on which the subsequent layers will be fabricated
- The sacrificial material fills in the gaps between parts on each layer
9
Planarization
- Both the sacrificial and structural materials are planarized to the same level, establishing the desired layer thickness
- The planarization system ensures that the thickness, flatness, and parallelism of each layer is controlled to within 2 microns
10
Repeat
- The process (steps 5–9) are repeated for each layer in the design
11
Etch Release
- All sacrificial material is etched from the wafer
- This removes the sacrificial material from the devices, frees individual parts so they can move, and causes the parts to become detached from the wafer
