Browse Prior Art Database

Direct View Matrix Addressable Displays Employing Integrated Circuit Drivers

IP.com Disclosure Number: IPCOM000043834D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 3 page(s) / 46K

Publishing Venue

IBM

Related People

Barclay, DJ: AUTHOR [+2]

Abstract

An integrated package for a direct-view matrix display of the electrochromic or liquid crystal type consists of a substrate for supporting, on one side, an array of display electrodes constituting picture elements of the display and, on the other side, a plurality of integrated circuit driver chips in which sub-arrays of transistor switches are formed. The switches are electrically connected to the display electrodes through conductive paths in the substrate. The relatively high device density on the chips is matched with the lower areal density of the display electrodes by means of a fan-out of the conductive paths between them. An example of one such display is shown schematically in Fig.

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Direct View Matrix Addressable Displays Employing Integrated Circuit Drivers

An integrated package for a direct-view matrix display of the electrochromic or liquid crystal type consists of a substrate for supporting, on one side, an array of display electrodes constituting picture elements of the display and, on the other side, a plurality of integrated circuit driver chips in which sub-arrays of transistor switches are formed. The switches are electrically connected to the display electrodes through conductive paths in the substrate. The relatively high device density on the chips is matched with the lower areal density of the display electrodes by means of a fan-out of the conductive paths between them. An example of one such display is shown schematically in Fig. 1 in which the substrate is a multilayer ceramic (MLC) body 10 with internal conductive planes and through-via connections between the planes. An array of display electrodes 11, each of which forms a picture element ("pel") of the display, is formed on the surface of the substrate. The electrodes 11 are enclosed by a cover 12 to form part of an electrochromic display cell. The cell contains an electrochromic substance, e.g., heptyl viologen, in solution and other electrodes (not shown), such as counter and reference electrodes. A suitable electrochromic cell structure and formulation is described in European Patent Application Publication No. 0 083 668-A1. The areal density of the pels 11 is chosen for the resolution required in a directly viewed display. The drive circuitry for the display is provided by a number of integrated circuit chips 13 mounted on the underside of the substrate. These chips include sub-arrays of field-effect transistor switches each of which is operable to switch write or erase current to a respective display electrode. The electrical paths 14 between the switching transistors and the electrodes 11 are formed by conventional metallization within the multilayer ceramic substrate 10. In order to improve yield and minimize internal resistances within the chips, the areal density of the switching transistors and the other circuit devices is significantly higher than that of the pel electrodes 11. To match the two densities the internal paths 14 within the MLC substrate 10 are made to fan-out, as shown schematically in Fig. 1. Connection of the chips 13 to the internal conductors 14 is effected by conventional solder reflow techniques in which the chip is provid...