INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

CASE STUDY # 93

1. Headline: Raw material substitution and new technology in

the manufacture of microelectronics.

2. Background: See below.

3. Cleaner Production Principle: Material substitution, new

technology

4. Description of Cleaner Production Application: Copper

sheet metal in the manufacture of flexible electronic

circuits must be clean. The sheets were formerly sprayed

with ammonium persulfate, phosphoric acid, and sulfuric

acid. 3M replaced this cleaning process with a specially

designed mechanical device that uses rotating brushes and

pumice as an abrasive to clean the copper sheet metal.

Material/Energy Balances and Substitutions

WASTES: Pumice

sludge

5. Economics:

CAPITAL COST: $59,000

MONTHS TO RECOVER: 36

DIRECT COST: $15,000/year

WASTE PRODUCTION: 40,000 lb/year

IMPACT: Reduced volume of

disposed waste and eliminate hazardous

waste management costs.

6. Advantages: See above.

7. Constraints: No information provided.

8. Contacts and Citation:

"Proven Profit from Pollution Prevention," D. Huisingh, L.

Martin, H. Hilger, N. Seldman, The Institute for

Self-Reliance 2425 18th Street, N.W., Washington, D.C.,

1985, case study 32, Page 127.

Name and Location of

Company:

Minnesota Mining and Manufacturing (3M)

Columbia, MO

United States

c/o Mike Koeningsberger

TEL: 1 (612) 778-4523

9. Keywords: United States, USA, microelectronic, printed

circuit board, new technology, material substitution,

acid, mechanical cleaning, copper, ISIC 3670.

10. Reviewer's Comments: This case study was originally

abstracted for the United States Environmental Protection

Agency's Pollution Prevention Information Clearinghouse.

It underwent a UNEP IE funded technical review in 1994 for

quality and completeness. It was edited for the ICPIC

diskette by UNEP IE in July 1995.

(DOCNO: UNEP01.52 306-001-A-027)