Anodic and
Glass-to-Silicon Bonding
Field-assisted bonding of borosilicate glass to silicon, and glass-silicon-glass stacks, for hermetic caps, microfluidic covers, pressure references and vapor cells. Cavities, electrical feedthroughs and alignment handled in the same program.
diameters
temperature
typical
minimum
Glass to silicon, in the configurations MEMS needs
Voltage and heat: conditions are set per material and structure.
Cap and cavity bonding
Etched or drilled glass over silicon structures, or silicon caps over glass, with sealed cavities at atmosphere or controlled pressure.
Microfluidic covers
Glass lids over silicon channels with through-glass ports, or silicon over structured glass; fluidic sealing checked as agreed.
Triple stacks
Silicon-glass-silicon and glass-silicon-glass for vapor cells, optical windows and double-sided sensors. See vapor cells.
Feedthroughs
Metal lines under the bond ring or through-silicon vias for electrical access to the sealed cavity; bond over topography reviewed per layout.
Aligned bonding
Front-to-front and front-to-back alignment to marks on both wafers, typically ±5 µm, tighter on request.
Alternatives
Where the thermal budget rules out anodic bonding, adhesive, low-temperature fusion or eutectic routes. See wafer bonding.
Anodic and Glass-to-Silicon Bonding
Scope and specification options. Every figure is confirmed for your program in the quotation.
Typical ranges
| Parameter | Typical | Note |
|---|---|---|
| Glass | Borosilicate matched to silicon expansion (Borofloat-type, Pyrex-type); alkali-free glass reviewed | Customer-supplied glass accepted after review |
| Silicon | Bare, oxidized (thin) or patterned; SOI | Bond over thin oxide reviewed |
| Temperature and voltage | 300-450 °C; voltage set per stack | Lower temperature with longer time on request |
| Alignment | ±5 µm typical | Marks on both wafers required |
| Cavity pressure | Atmosphere, controlled gas, or reduced pressure | Getter integration on inquiry |
| Inspection | Bond interface by IR imaging and optical inspection; hermeticity or leak test as agreed | Sacrificial dies for pull test on request |
For a bonding quotation
| Item | What helps |
|---|---|
| Both wafers | Materials, thicknesses, existing films and structures on each |
| Bond layout | Bond ring width, cavity sizes, feedthrough routing |
| Alignment | Mark positions and required accuracy |
| Cavity | Required pressure or gas, hermeticity requirement |
| Quantity | Wafer pairs and target date |
Processes usually combined with this work
Questions engineers ask before ordering
Can you use my glass?
Customer-supplied borosilicate is accepted after review; alkali-free glass is reviewed case by case.
What alignment accuracy?
±5 µm typical with marks on both wafers; tighter on request.
Can the cavity be sealed at reduced pressure?
Yes, atmosphere, controlled gas or reduced pressure; getter integration on inquiry.
Start your project.
Initial response within one business day.
Share your process requirements, substrate, and production volume. A Nanosystems JP Inc. engineer gives an initial response, typically within one business day. A written quotation typically follows within 7-10 business days after we receive the required information and complete any prerequisite NDA.