Offshore Instrumentation

One of the major users of high temperature electronics is the oil industry. For well logging the temperatures may come up to 200°C, and reliability and compact size of the electronic system is of vital importance. Within the field of oil and gas well logging, the use of integrated instrumentation systems that withstand high temperatures aims at increasing the recovery of oil while at the same time reducing costs, emissions and safety hazards. This will benefit the society and increase the competitiveness of oil companies. A secondary impact, is to give the supplier industry access to state of the art technology and thereby to strengthen its competitiveness. On the long term, the technology developed for the high cost, low volume well applications can be extended to cover general process monitoring and thereby impact the competitiveness of a large range of industries. 

During logging, the power and signals are transmitted to topside through a logging cable, and several instruments are connected to this cable. The cable may be up to 10 km long, and has a relatively high resistance down hole. Hence, it is important to keep the power consumption as low as possible and have a low transmission rate of signals. Low power consumption also enhances reliability.

Design and implementation of reliable electronics for high temperature environments involve sensor, integrated electronic components packaging and interconnect design. It is well known that increasing temperatures will highly accelerate the failure mechanisms in the system.

Typical failure mechanisms for the integrated components are hot electrons, electromigration of conductors, increased chemical reactivity at the ohmic contacts as well as increased diffusion of dopants.
 
From the packaging point of view, reliable operation will involve: compatible metal systems (both on the chip, the interconnect material and the metallization on the substrate), mounting (or integration) of passive components on the substrate, hermetic sealing of the system and possibly inert atmosphere.  A reliable packaging will involve the use of new materials and processes, and a focus will be put on high temperature adhesives to reduce the problems encountered with solder systems at high temperature.