MM provide component solutions to designers targeting high temperature solutions for Oil and Gas, space and industrial applications to levels of 200C+.
High Temperature Electronics
Markets such as Energy, Space and Avionics can benefit from components with operational performance outside the existing Defence ranges of -55/+125C. Key markets such as exploration support with down hole monitoring, deep space missions and high altitude avionics all push operational reqts towards 200C.
A number of applications today require electronics to operate in extremely harsh environment conditions. Operation temperature of 150°C and higher are required for energy exploration as well as other emerging applications such as geophysical services, avionics and industrial process control. Environments like these require electronics designed and manufactured specifically to withstand such temperature extremes.
Typically Hybrid Multi-Chip Modules can be utilised for these applications of High Temperature and Harsh Environment Electronics for Deep Space to Deep Earth applications. Additional features such as Wafer Level Packaging, Physical Design Modeling, Finite Element Analysis, RF/signal conditioning and digital embedded system designs enable increased operational reliability.
Thick Film circuits
When considering extreme temperature operation alternatives to pcb laminates such as Thick film ccts become useful. Fired at temps over 300 C, the technology has reliability proving in many automotive applications. Component attach is then realiased with conductive epoxy films using packaged or bare die components. Thick film hybrid technology is a widely-used technology for the manufacture of a ceramic or other type of circuit boards. Due to its high degree of integration, thick film substrates form the basis of High Density Packages (HDP). In an initial manufacturing phase, the structures are applied by means of a silk-screen process onto the relevant substrate material such as aluminium oxide (Al203) or alumina (AIN). Conductors, resistors, insulations and overglazes can be manufactured. Gold, silver and platinum or palladium alloys are generally used as conductive materials. The standard thick film process are printing, drying and firing. The firing process at about 850 °C guarantees the final film properties such as electrical values and adhesive strength.
Thick film technology enables a very simple and flexible manufacture of multilayers with several conductive layers on the front and back side of the substrate. Minimum structure resolutions of 80 – 100 µm can be achieved with this technology. Printed resistors can be trimmed to a output signal of a hybrid circuit. In principle all electronic components can be assembled on a thick film substrate. Therefore solderable as well as bondable surfaces are available
The benefits compare to traditional printed circuit boards are in the thermal and electrical properties of the thick film substrate material. Ceramics are very heat-conductive and as one of the chip base materials, are therefore optimally matched to the TCE of silicon. The above mentioned structure resolutions and the integration of printed, passive components make a circuit miniaturisation possible.
Due to the positive properties of the ceramic base material, thick film circuits are used as a priority in areas which are characterised by harsh environmental conditions (high/low temperatures, temperature changes, moisture, vibrations, accelerations etc.). This technology meets the requirements of the highest integration, reliability, lifetime and environmental compatibility. Areas of application include industrial electronics, medical electronics as well as automotive and aerospace industry.
Knowles Capacitors manufactures COG chip capacitors designed and tested to operate from -55°C to 200°C. Product applications include harsh environments such as oil exploration and automotive/avionics engine compartment circuitry. Product is available as surface mount chips in sizes 0805 to 7565. Leaded encapsulated devices in sizes 1515 to 7565 for additional high temperature capacitors.Feedthros and shielding solutions are also available for high temp applications