Image Sensor Assembly

Challenges with image sensors vs. standard microelectronics packaging

• Sensor and filter position, tilt and rotation.
• Particulate control
• Thermal management/noise reduction
• Stray light

Alter Technology (formerly Optocap), Image Sensor assembly platform is a flexible solution for CMOS, CCD and Focal Plane Array sensor chips into ceramic packages.

Service offering:

• Bespoke package design
• Optics and window design
• Materials procurement
• Flexible – wide range of form factors
• Thermal and mechanical modelling
• Process development and qualification
• Automated volume assembly
• Space heritage for Image sensors

Process Highlights

• Automated Die placement accuracy +/-15µm
• Rotation control 2° to 5°, tilt control <50µm
• Programmable epoxy dispensing pattern
• Thermal or UV snap cure to maintain die position
• Controlled clean environments – ISO7 cleanroom & laminar flow (ISO5)
• CO2 cleaning optimised for sensor and glass.
• Hermetic seam sealing in inert N2 environment
• <5000ppm moisture content
• Black dam dispensing for stray light

Assembly Capabilities:

• Precision die and filter placement
• Specialist particle control procedures
• Stacked die capability
• SMT of passive components
• Flex circuit attach
• Flip chip attach & Au stud bumping
• Optimised wafer saw process for detectors
• Wafer saw for glass and filter substrates

Standard Materials

• Package Substrate: High temp co-fired ceramic
• Lid: Optical grade Borosilicate glass
• Die attach adhesive: Conductive or Non-conductive Epoxy
• Wide range of epoxies in house
• Wire: 17µm-33µm diameter, Au ball bonding
• Wedge bonding for high-rel applications
• Glass Adhesive: Thermal or UV attach epoxy