CMOS Image Sensors

Packaging & Integration

The first application to bring 3D integration into volume production is the CMOS image sensor. Manufacturers of these sensors are using through silicon vias (TSV’s) and 3D stacking to make the sensors smaller, especially for cell phone camera applications. One of the main reasons that the makers CMOS image sensors adopted TSV’s into their manufacturing processes is that the sensors, unlike most other semiconductor devices, must be mounted face-up. For this reason, traditional wafer level packaging (WLP), which uses solder balls mounted on the face of the chip and then turned upside down, would not work.

3D Integration also enables improved performance and enhanced functionality for CMOS Image Sensors. The combination of a CMOS Image Sensor (CIS) with Digital Signal Processing (DSP) or Logic provides enhanced camera sensitivity, reduced fixed pixel noise, and improved charge transfer and pixel readout speed.

SUSS MicroTec provides production bond cluster solutions for Fusion Bonding, Metal Diffusion, and Adhesive Bonding used to create today’s state-of-the-art backside Illuminated CMOS Image Sensors.

• Wafer-Level Cameras providing a high potential for cost-reduction in the low end camera market are considered to be a major trend that will have a tremendous impact on the current optics and digital camera industry.

  Wafer-level optics require new processing technologies and therefore a close co-operation of optics and semiconductor industry with equipment suppliers.

• SUSS MicroOptics, the Swiss-based micro-optics branch of SUSS MicroTec is an expert in the field development of high-quality micro-optics on 8" wafer developing Microlens Projection Lithography (MPL).

Complementing the WLC solution portfolio with process equipment dedicated specifically for WLC SUSS MicroTec presents a whole set of technologies for manufacturing thus leading the way in wafer-level optics.

The new MA8 mask aligner combines all three non-semiconductor technologies required for WLC:

• Stamp manufacturing
• SUSS Microlens Imprint Lithography (SMILE)
• Wafer Level Packaging of 8" opto-wafers

In production, the MA8 Mask Aligner is combined with a DSM8 or DSM200 for double-side imprint and wafer-to-wafer alignment accuracy testing.