Resolution and signal loss in acoustic microscopy of encapsulated IC packages

Author

Canumalla, Sridhar ; Oravecz, Michael G. ; Kessler, Lawrence W.

Author_Institution

Sonoscan Inc., Bensenville, IL, USA

fYear

1998

fDate

25-28 May 1998

Firstpage

962

Lastpage

968

Abstract

This paper examines the degradation of resolution and signal strength in pulsed acoustic microscopy of plastic encapsulated ICs. The effects of attenuation of ultrasound in water and plastic encapsulants, and transducer characteristics such as bandwidth, focal length and center frequency, are investigated. Ignoring the consequences of attenuation or spectral characteristics of the transducer could lead to overestimation of the resolution by as much as a factor of two in high frequency inspection. The novel procedure presented in this paper can not only help predict a realistic resolution, but can also be applied in selecting the optimum combination of transducer characteristics for specific materials

Keywords

acoustic microscopy; inspection; integrated circuit packaging; plastic packaging; ultrasonic applications; bandwidth; center frequency; encapsulated IC packages; focal length; high frequency inspection; plastic encapsulated ICs; pulsed acoustic microscopy; resolution; signal loss; transducer characteristics; Acoustic pulses; Acoustic transducers; Attenuation; Degradation; Frequency; Microscopy; Plastics; Signal resolution; Ultrasonic imaging; Ultrasonic transducers;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Components & Technology Conference, 1998. 48th IEEE

Conference_Location

Seattle, WA

ISSN

0569-5503

Print_ISBN

0-7803-4526-6

Type

conf

DOI

10.1109/ECTC.1998.678825

Filename

678825