Photonic device package design, assembly and encapsulation

Photonic devices like Optical transceivers, Solar cells, LED´s (Light Emitting Diodes) etc, have been developed for high speed data communication, power generation and light sources. Photonics include, among others, emission, transmission, switching and sensing of light. GaAs and GaNi are examples of semiconductor materials used to create diodes, able to generate light. Different types of diodes can be made to generate light in the spectrum ranging from Ultra Violet via visible to Infra Red light. VCSEL´s (Vertical Cavity Surface Emitting Laser diodes) can be used for data transmission via thin glass fiber cables and operate mainly at wave lengths around 850 nm. Photo diodes are used as light sensors and are able to receive data in the form of light pulses or modulated light. A photo diode is sensitive for photons striking the diode surface also known as the photo electric effect. When used for environment lightening, LED´s can generate light in a variety of colors in the visible spectrum. Solar cells are light sensitive diodes used in a Photo Voltaic mode and able to convert sun light into electric energy. In most of these applications the diodes require a lens because the light is diffracted and a lens must be used to collimate the light. Due to their application and operating environment these diodes require a different assembly and packaging approach compared to conventional semiconductor devices. The focus of APC (Advanced Packaging Center) is on package design, process development for assembly and encapsulation of these types of devices and the generation of samples and low volume production quantities. The choice of package concept, lens parameters, assembly and encapsulation materials are of utmost importance for the functioning and reliability of the devices. For example the design of optical transceivers requires the package design to be such that no cross talk can take place between transmitter and receiver and the glass fiber cables can be connected - n a reliable way. To limit transmission losses, the assembly process requires high precision lens shapes and accurate placement of transmitter / receiver chips towards their lens centers. Encapsulation material properties like adhesion, transmittance, refractive index, CTE should be taken into account. Photonic devices are often subjected to extreme environments of radiation and heat and have to full fill a life time expectancy of 10 to 20 years.