UNDERSTANDING THE 'IMMUNITY LEVEL' AND 'EM COMPATIBILITY' OF ELECTRONIC PACKAGING WITH EMBEDDED EMI SHIELDING

摘要

The European community directive 89/336/EEC defines the "electromagnetic compatibility" as the ability for two or more electronic components or units to co-exist without interference. This is more clearly stated in the forefront text of the EEC Directive:".For providing adequate protection for radio-communications and the devices, apparatus or systems whose performance may be degraded by electromagnetic disturbance produced by electrical and electronic apparatus against the degradation caused by such disturbances". From the electronic packaging development standpoint this matter has clearly a double aspect. The first one addresses the component package capability in "keeping-out" external electromagnetic waves, while the second aspect is the property of the same packaging technique in containing the device electromagnetic waves emissions detrimental to the other neighboring components. Products miniaturization trends are making traditional EMI shielding techniques more and more difficult to be used adding major system design concerns. Electronic packages with embedded EMI shields are a possible solution to these problems. They allow the realization of systems with different components in close proximity reducing the need to implement shields at system level. "Immunity level" and "Electromagnetic compatibility" represents the level of effectiveness of EMI shielding and an understanding of this properties in the electronic package design becomes a key factor. This paper introduces to the work performed in designing an experiment to validate the effectiveness of an embedded EMI shielding into a EGA cavity down electronic package. The task included a test board design with an embedded patch microstrip antenna, the antenna design within the dimensional limitation given by the physical outline of the electronic module, and the overall system gain optimization for performance within the desired frequencies range.