Browse Prior Art Database

Modelling the Surface of an Adhesion-Promoting Film by Laser Irradiation Without a Mask

IP.com Disclosure Number: IPCOM000036043D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 3 page(s) / 34K

Publishing Venue

IBM

Related People

Butz, M: AUTHOR [+5]

Abstract

In the MLC (multilayer ceramic) field, the delamination of copper from the polyimide bases of the viahole edges is avoided by the aimed application of an organic adhesion promoter.

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 54% of the total text.

Page 1 of 3

Modelling the Surface of an Adhesion-Promoting Film by Laser Irradiation Without a Mask

In the MLC (multilayer ceramic) field, the delamination of copper from the polyimide bases of the viahole edges is avoided by the aimed application of an organic adhesion promoter.

For MLC applications, polyimide layers are used as additional wiring planes for top surface modelling (TSM) or bottom surface modelling (BSM). Viaholes, produced in the polyimide for vertically contacting the MLC substrate, are subsequently filled with metal by additive or electrochemical copper deposition. Characteristic of such viaholes is that their walls are relatively flat (about 40 to 70o). A major problem of such a wiring plane is the frequently insufficient adhesion between the additive copper and the polyimide material along the hole edges. This problem is intensified by heating steps (up to 350oC) to which the polyimide/copper layers are subjected.

Delamination and the occurrence of microcracks can be effectively checked by the application of a suitable adhesion-promoting material between the polyimide and the copper. For this purpose, a silicon oxide layer or an organic adhesion promoter, such as A1100*, may be used. Such a layer must be confined to the area of the viahole edges,

(Image Omitted)

i.e., it must not cover the bases of the holes, as this would prevent the deposition of copper.

The present invention uses a silylatable photoresist or an organic adhesion promoter, such as A1100, which is applied to the modelled polyimide surface by spray or spin coating (Fig. 1). An excimer laser beam of suitable energy density Eo is used to floodlight the sample surface, taking advantage of the fact that there is an energy density threshold Es for the ablation of the resist or the organic adh...