Controlled Solder Self-alignment Sequence for an Optoelectronic Module without Mechanical Stops

A new flip-chip solder technology has been developed for the precision self-alignment of an optoelectronic module without using mechanical stops. A main feature of the technology is the controlled self-alignment sequence: laser is aligned to a polymer waveguide in the lateral and vertical directions, then it slowly makes a contact with the waveguide in the axial direction. The elimination of the use of mechanical stops significantly simplifies the process. The axial distance between the laser and the waveguide is very small; it is determined by the contacting edges and a tilt angle of 12 o . The lateral alignment accuracy is less than 2 m. Introduction Solder self-alignment is important in the area of optoelectronics. In addition to providing electrical connections, solder is also one of the enabling technologies for passive precision alignments. Between 1990 and 1995, there were at least 60 papers and 8 U.S. patents reporting the different solder technologies developed for optoele..