Harsh environment packaging

In the last 5-10 years there has been a significant increase in activities in electronics and sensor packaging for harsh environments. To address the technology needs in this area, TWI uses cross-disciplinary teams from its Microtechnology, Ceramics, Glass, Films/Coatings Technology, Polymer Resin, FEA Modelling, Non-destructive/Environmental testing and Manufacturing Processes Groups.

This approach enables all the packaging elements to be considered at an early stage, using equipment and solutions from both inside and outside the traditional electronics/sensors technology industries.

A large number of projects have been performed by TWI for industrial members both singly and collectively. The outcome of a significant amount of work performed at TWI is given in a number of published papers and reports.

Projects performed in the Harsh Environmental Packaging area

The Core Research Programme (CRP). Member companies have free access to these generic R&D projects. The work forms the basis of TWI's multi-million pound funded programme of industrially aligned research. The projects relevant to the Harsh Environment Packaging area are given below.

Development of packaging methods for high temperature electronics

Single Client Projects (SCPs). TWI conducts several hundred of these strictly confidential projects per year. The following list gives an indication of the types of projects and activities undertaken. The Case Studies, which have all been cleared with the sponsoring companies, give further details.

Technical appraisal of design/material requirements for a liquid level sensor
Optical fibre packaging for harsh environments (high pressure/temperature/chemically active)
Replacement of soldered interconnects with welded joints
Development of a low stress, large area die/substrate attach design through FEA/thermal modelling
Verification of thermal modelling software through IR measurements of
power devices
Evaluation of highly accelerated stress testing for high temperature components
Development of high thermal conductivity Al₂O₃ sprayed dielectrics
Joining of SiC with ceramic modified braze alloys
Modification of braze alloys for ceramic/metal joining to reduce thermal stress
Development of active braze alloys with hot pressed SiC
Assessment of high temperature adhesives, resin encapsulants and ceramics for hot water environments.
Assessment of hermetic/vacuum and gas filled packages for sensors
Assessment of packaging technologies for high ambient temperatures
Sealing of Al-SiC MMC Packages
TWI aids in product development Case Study

TWI Published papers and reports related to the Harsh Environment Packaging area

Fernie J A: 'Techniques for bonding ceramics', TWI Bulletin Vol. 31 No. 9/10, Sept/Oct 90, pp 92-93

Harvey D: 'HVOF takes off', TWI Bulletin, Vol. 32, No. 5, Sept/Oct 91, pp 107-109

Sturgeon A: 'Ceramic coatings - a growing technology', TWI Bulletin, Vol. 33, No. 2, March/April 1992, pp 31-35

Sturgeon A: 'Thermal spraying gives a new look to substrate design', TWI Bulletin, Vol. 35, No.4, July/Aug 94, pp 84-87

Sturgeon A: 'Alumina coatings - HVOF using hydrogen', TWI Bulletin, Vol. 35, No. 6, Nov/Dec 94, pp 136-138