Wafer Bonding is a critical capability required for wafer-level hermetic packaging or creating 3-D microfluidics devices.
IMT’s bonding allows hermetic and vacuum wafer-level packaging to reduce the cost of post-process die-level packaging and to improve the performance and reliability of the MEMS.
Over 50% of all wafers produced at IMT are wafer bonded.
IMT works closely with the customers’ needs to determine the bonding method that includes the following:
- Au-Au thermal compression
- Glass frit
- Metal alloy (low temperature)
Depending on the bonding method and hermeticity requirements, capabilities include the following:
- Sub-1 mTorr high vacuum bonding using getter
- > 99% hermeticity yields in production – hermeticity verified by probing on-board thermistors
- Vacuum, atmospheric, or partial pressure with unique gases
Although not hermetic, polymer bonding is useful for fabricating microfluidics, creating fluidic channels. Frequently, multiple bonding methods can be combined to achieve the desired final packaging. In addition to hermeticity requirements, other considerations include:
- Design/device footprint
- Temperature budget
- Materials used
- Final packaging and environmental requirements
After bonding, the wafers are protected from environment and fragile MEMS structures are protected. These wafers can continue on-ward, through die singulation and die-level packaging.