Browse Prior Art Database

Integrated Optical Channel

IP.com Disclosure Number: IPCOM000100550D
Original Publication Date: 1990-May-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 3 page(s) / 96K

Publishing Venue

IBM

Related People

Frech, R: AUTHOR [+4]

Abstract

In distinction to prior art channels, the integrated optical channel described in this article requires much less space, is easier to integrate and does not limit the assembly area and card cross-section.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Integrated Optical Channel

       In distinction to prior art channels, the integrated
optical channel described in this article requires much less space,
is easier to integrate and does not limit the assembly area and card
cross-section.

      These advantages are obtained by using a technology which suits
present chip and package integration densities by being adaptable to
flip chip devices and multichip modules, which drastically reduces
both the box and the card area.

      Fig. 1 shows a typical channel concept.  The bus adapter is
connected by a broad bus to the processing unit (PU) and to I/O
channels by analog-to-digital (A/D) or digital-to-analog (D/A)
converters and light-emitting diodes (LEDs) which are either
receiving or transmitting the data stream on fiber-optic cables.

      The basic idea is to integrate all optical channel devices in
one multichip module.  Integration on a single module is possible
even with the PU chips.

      Fig. 2 shows the multilayer ceramic (MLC) multichip module
(MCM) with the attached optical cable.  Chip 1 represents standard
chips, such as A/D or D/A converters, the bus adapter or PU chips.
These are assembled in the conventional flip chip C4 technology on
the surface of the MCM or a TCM (thermal conduction module).  The
transmitting or receiving chip (chip 2) is also connected by C4
technology but upside down to the module.  The module ceramic cap
provides the fanout of the few signals and power/ground connections
to the module.

      Fig. 3 shows two alternatives both using standard C4 balls.
The slight elevation inside the cap is standard...