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

• 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

• 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

• 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

Test Capability 

•    Sensor Characterization
  • Under illumination, uniform light source.
  • Dark current characterization
  • Custom electronics developments
  • Temperature stabilization setups
• Photodiode Array
  • Precision FemtoAmp Dark Current measurements

•  Radiation Test
  • Proton 10MeV to 200MeV
  • Gamma Low & High dose rates
  • Heavy Ion Beam