Browse Prior Art Database

Surrogate Alignment Tabs

IP.com Disclosure Number: IPCOM000050117D
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 3 page(s) / 67K

Publishing Venue

IBM

Related People

Locke, CH: AUTHOR

Abstract

This article describes method, apparatus and device structure for aligning a multilayer ceramic capacitor body with a mask used to form interconnections at the capacitor's terminal tabs. The method, apparatus and device structure feature use of "surrogate" tabs arranged to be in alignment with the capacitor's terminal tabs. The surrogate tabs are additionally exposed at a capacitor body face so that alignment of the terminal tabs with the interconnection mask may be accomplished with reference to the surrogate tabs.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Surrogate Alignment Tabs

This article describes method, apparatus and device structure for aligning a multilayer ceramic capacitor body with a mask used to form interconnections at the capacitor's terminal tabs. The method, apparatus and device structure feature use of "surrogate" tabs arranged to be in alignment with the capacitor's terminal tabs. The surrogate tabs are additionally exposed at a capacitor body face so that alignment of the terminal tabs with the interconnection mask may be accomplished with reference to the surrogate tabs.

The capacitor structure to which this article relates is shown in Fig. 1. As shown, capacitor 1 is comprised of multiple laminations 2, each having a patterned metallized plate 3 with terminal tabs, e.g., 4A, 4B, 4C. The capacitor is formed by combining laminations 2 and interconnecting multiple terminal tabs 4A, 4B, 4C with terminal strips 5A, 5B, 5C, respectively. Selective interconnection of the terminal strips enables the capacitor and voltage rating of the structure to be varied, as is known in the art.

In forming the capacitor interconnections, it has been found difficult to align the mask used to pattern interconnection strips 5A, 5B, 5C with respective terminal tabs 4A, 4B, 4C. This is particularly true of metallization at the capacitor terminal tab face and, thereafter, back etching the layer to form the strips. As can be appreciated, where the capacitor face is blanket metallized, tabs 4A, 4B, 4C are covered and unavailable for visual alignment.

In accordance with the teaching of this article, tabs 4A, 4B, 4C can be aligned with the interconnection mask by providing the capacitor laminations with surrogate tabs 7A, 7B, 7C. Tabs 7A, 7B, 7C, may be extensions of plate 3 or, as shown in Fig. 1, displaced from terminal tabs 4A, 4B, 4C. The principal consideration, however, is that tabs 7A, 7B, 7C be in alignment with terminal tabs 4A, 4B, 4C, i.e., in the same plane and same lateral position. In preferred form, to assure maintenance of alignment during fabrication and thereafter, tabs 7A, 7B, 7C are made of the same material as plate 3 and are applied to lamination 2 in the same manner and at the same time as plate 3.

Additionally, surrogate tabs 7A, 7B, 7C are configured to be exposed at a face 8 of the capacitor body other than the capacitor body's terminal...