Plastic-molded LTS DC-SQUIDs for multichannel biomagnetic measurement systems

Author

Utaka, Y. ; Kido, T. ; Kudo, K.

Author_Institution

MEC Lab., DAIKIN Ind. Ltd., Ibaraki, Japan

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3029

Lastpage

3032

Abstract

A plastic molding technique for SQUIDs has been developed to protect the chip from moisture damage. A 1.5-mm-thick layer of molding compound (epoxy resin, elastic resin, and silica powder) was poured over Ketchen-type DC-SQUID that has Nb/AlO/sub x//Nb Josephson junctions. The moisture resistance of these plastic-molded SQUIDs was examined by subjecting them to temperature and humidity storage tests (60/spl deg/C, 90% relative humidity, 1,000 hours), and then measuring their performance characteristics. The results showed that the plastic packaging protected the chip from moisture damage, while not affecting the noise performance of the SQUIDs. The plastic molding therefore improved reliability and ease in handling of such SQUIDs.

Keywords

SQUID magnetometers; SQUIDs; biomagnetism; biomedical measurement; moisture; niobium; plastic packaging; Ketchen-type DC-SQUID; LTS chip; Nb-AlO-Nb; Nb/AlO/sub x//Nb Josephson junction; elastic resin; epoxy resin; moisture resistance; multichannel biomagnetic measurement; noise; plastic molding; plastic packaging; reliability; silica powder; temperature humidity storage; Biomagnetics; Epoxy resins; Humidity; Moisture; Niobium; Plastics; Powders; Protection; SQUIDs; Silicon compounds;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.621969

Filename

621969