Browse Prior Art Database

Polyimide Etch Solution

IP.com Disclosure Number: IPCOM000099374D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 1 page(s) / 32K

Publishing Venue

IBM

Related People

Pawlowski, WP: AUTHOR [+2]

Abstract

Disclosed is an etch solution, composed of 1-amino-2-propanol, potassium hydroxide (KOH), and water, to be used for etching features in KAPTON* polyimide film. Etch rates near 2 mils/min can be obtained without the severe etchback observed in aqueous KOH etching processes.

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Polyimide Etch Solution

       Disclosed is an etch solution, composed of
1-amino-2-propanol, potassium hydroxide (KOH), and water, to be used
for etching features in KAPTON* polyimide film. Etch rates near 2
mils/min can be obtained without the severe etchback observed in
aqueous KOH etching processes.

      The etch solution has the advantages of the ethanol/KOH etch
solution described previously (1,2), including high etch rate, low
etch back, and high loading, without the disadvantages of low boiling
point and flash point.  Unlike the ethanol/KOH solution, there is a
very broad maximum in the etch rate at the high end of the alcohol
concentration, which allows for a much wider operating window with
regard to the alcohol concentration (ethanol/KOH gives a narrow
maximum in etch rate centered at 80% alcohol).

      The etch rate can be adjusted by changing either the KOH
concentration or the temperature at which the etch bath is operated.
In addition to KOH, other Group IA hydroxides might also be used,
with the etch rate increasing with increasing molecular weight (2).
Also, other amine substituted alcohols may be used to prepare the
etch solution. *  Trademark of E. I. du Pont de Nemours & Co.
References
    (1)  U.S. Patent 4,426,253.
    (2)  J. A. Kreuz and C. M. Hawkins, Proc. Tech. Program-Annu.
Int. Electron. Packag. Conf. 2nd., 653 (1982).