SiPhotonics/PIC

The acronyms SiPh and PIC represent Silicon Photonics and Photonic Integrated Circuit, respectfully.

Various websites on the internet defines Silicon Photonics as: Silicon photonics is the innovative study and application of photonic systems for generating, processing, manipulating and otherwise using light for faster data transmission both between and within microchips. Silicon is used as the optical medium. Operation is in infrared wavelengths (commonly 1.55 micrometers), which are used in fiber-optic telecommunication systems. Silicon photonics, with its ultra-fast data transfer between and within microchips, will significantly determine future progress in computer technology and the continuation of Moore’s law.

Another perspective of a Photonic Integrated Circuit can be simply defined as the following, where electrons and photons work together on a common medium or a platform where photonic circuitry works together with electronic circuitry on a common system platform.
The possibilities are endless with the integration of photons and electrons on a common medium. For example, a hybrid integration of photonic and electronic circuitry using silicon photonic components require ultra-fine flip chip interconnections for energy efficiency, single-mode optical interfaces (laser to waveguide, waveguide to waveguide or waveguide to fiber) require sub-micron alignment and placement accuracy and PCBs may require embedded optical waveguides and couplers to facilitate optical ICs.

A fundamental SiPh design requires an edge emitting laser diode to be eutectically bonded to silicon. Typically, the laser diode is bonded into a cavity, where the cavity is precisely etched into a silicon wafer. The challenge is the position and bonding of the laser diode so the emitted photons are aligned accurately enough to the waveguide opening such that the photon energy is not attenuated. Many creative solutions and processes have been developed to obtain an effective result that is efficient and production worthy without the use of active alignment techniques.

Product Offering

ASMPT AMICRA GmbH offers two die attach solutions to address the SiPh/PIC market segment. We primarily serve the high volume production segment of the SiPh/PIC market.

NANO supports:

• Die placement accuracies down to ±0.2μm @ 3σ with cycle times down to 20 to 30 seconds/bond or 180 to 120 UPH

AFC Plus supports:

• Die placement accuracies down to ±0.5μm @ 3σ with cycle times down to 20 to 30 seconds/bond or 180 to 120 UPH

NOVA Plus supports:

• Die placement accuracies down to ±1.5μm @ 3σ with cycle times down to 3 seconds/bond or 1,200 UPH

Our ASMPT AMICRA Systems support the following bonding processes:

• Bonding Die (VCSEL and PIN) with Silver Filled Epoxy Process
• Bonding Die (VCSEL and PIN) with a AuSn Eutectic Process
• Bonding a Lens with UV Curable Adhesive Process
• Bonding Edge Emitting Laser Die with a AuSn Eutectic Process

Process Overview

A capacity/bulk of materials like die or lenses and substrates can be manually loaded or automatically presented to the AMICRA system. The die or lens can be presented to the machine in waffle packs, gel packs or wafers (film frames or grip rings). The substrates can be presented to the machine one at a time or in custom trays, or the AMICRA system can load each substrate to the bonding stage automatically, provided the substrates are presented in wafer, waffle packs or gel packs.

Epoxy or UV adhesive can be applied to the die via die dipping or applied via pin transfer (epoxy stamping) or via through a variety of standard dispensing systems, located at the bond station or located upstream prior to the bond station:

• Time Pressure Vacuum Dispenser
• Volumetric/Auger Dispenser
• Jet Dispenser

Note: The AMICRA systems are essentially a vision driven die attach machine consisting of 4x automatic vision systems located throughout the machine, all imaging systems (camera, optics and illumination) are fixed to a very rigid structure made of granite. Imaging systems are located:

• Pick-up Station with a precision X-Y Table
• Mapping/Alignment Station consisting of an upward looking camera and a downward looking camera
• Bond Station with a precision X-Y Table

A single or dual pick and place bondhead(s) are mounted to a linear motor where either a die, lens or flip chip die are picked up, via a vacuum tool, from the Pick-up Station and either the:

• Die are transported to the Mapping/Alignment Station for alignment then moved to the Bond Station where the die is bonded to epoxy
• Lenses are transferred to the Bond Station where they are placed into the UV adhesive while UV light is projected on to the Lens until the adhesive is cured and bonded.
• Flip chip die or laser die, p-side down, is transferred to the Mapping/Alignment Station where the bumps or critical alignment features of the die are mapped to a feature on the backside of the die, i.e. the die corner for alignment and finally, the die is transferred to the Bond Station where laser heat is applied to the substrate or silicon wafer, while the die is being eutectically bonded in-situ while maintaining the required placement accuracy.

Additional Key Features, Options and Capabilities

• Dynamic Alignment with 3x levels of Post Bond Inspection
• Flip Chip System
• HEPA Filter with Ionizer
• Heated Bond Tool
• Laser Soldering System
• Pulse Heater
• Wafer Heater
• Wafer Substrate Loader & FOUP Loader
• Substrate Magazine Loader
• Active Bond Force
• Supports 300mm Wafers and Large Substrates up to 550mm x 600mm
• Bonding Resolutions <0.1μm
• Autocollimator for Parallelism Calibration