Chip-to-Chip Optoelectronics SOP on Organic Boards or Packages

Abstract

In this paper, we demonstrate compatibility of hybrid, large-scale integration of both active and passive devices and components onto standard printed wiring boards in order to address mixed signal system-on-package (SOP)-based systems and applications. Fabrication, integration and characterization of high density passive components are presented, which includes the first time fabrication on FR-4 boards of a polymer buffer layer with nano scale local smoothness, blazed polymer surface relief gratings recorded by incoherent illumination, arrays of polymer micro lenses, and embedded bare die commercial p-i-n photodetectors. These embedded optical components are the essential building blocks toward a highly integrated SOP technology. The effort in this research demonstrates the potential for merging high-performance optical functions with traditional digital and radio frequency (RF) electronics onto large area and low-cost manufacturing methodologies for multifunction applications.Index Terms-optical interconnections, optical planar waveguides.

The SOP for Miniaturized, Mixed-Signal Computing, Communication, and Consumer Systems of the Next Decade

“…17. The evanescent coupling efficiency from the waveguide to a p-i-n is measured to be 3% at and 1.55 [42]. In this way, high speed chip to chip data communication on SOP is realized through the optical devices of photodetectors, waveguides, gratings and other optical components.…”

“…Suzuki et al [43] reports a surface roughness of over a distance of 5000 after BCB planarization of a high FR-4 board. In another paper in this issue, Chang [42] reports an average surface roughness of 4 nm over 5 and over 500 for a low temperature board planarization process. Although few researchers report on interface adhesion, photo-definable Siloxane-based waveguides passed the "Scotch tape" vertical pull test.…”

“…For an Ultem(core)/BCB(cladding) waveguide, prepared by RIE, the reported loss [45], [46] is 1.34 dB/cm at 1330 nm. A photodefinable, epoxy-based Siloxane Oligomer had a measured optical loss of 1.43 dB/cm at the same wavelength [42], and a second photodefinable polymer had a measured loss of 0.2 dB/cm at 1330 nm [42]. Reliability issues such as thermal cycling and accelerated optical aging are seldom reported.…”

“…Fabrication and integration technologies are being developed for micro lenses, micro mirrors, switches and couplers, as well as wavelength pro- cessing components such as gratings, photonic crystals, arrayed waveguide gratings, multimode interference. Recent global developments in this area can be found elsewhere in this issue [42].…”

In-plane Optical Interconnection with High Coupling Efficiency between Optical Chips and Waveguides

“…Optical interconnections technology has a wide bandwidth, so it is a promising technology for high speed interconnections between chips. Georgia Institute of technology is working hard with proposing that in-plane optical interconnection without lenses and 45 degree mirrors is potentially an efficient solution to integrate optical interconnections on printed circuit boards [1][2][3]. The objective of this research is to demonstrate high coupling efficiency between optical chips and waveguides, which is one of the advantages of in-plane optical interconnections to propagate high speed signals.…”