| abstract |
An an electronic circuit having improved protection against harsh environments, a preferred embodiment thereof including: a substrate 10 having a top surface 12; an electronic component 14 attached to the top surface of the substrate; a plastic and metal foil laminated barrier 16 having an outer periphery 18 thereabout, the outer periphery being sealably attached to the top surface 12 of the substrate so as to define a closed pocket 20 between the top surface 12 and the barrier 16 within which the electronic component 14 is enclosed; and a desiccant element 50. The desiccant element 50 includes: a case 51 having an internal chamber, an inlet orifice 58, and an outlet orifice 59, wherein the inlet and outlet orifices are each in communication with the internal chamber; a predetermined amount of desiccant material 53 contained within the internal chamber; a normally-open interior valve 54 situated between the inlet orifice 58 and the internal chamber; a normally-closed exterior valve 56 situated between the outlet orifice 59 and the internal chamber; and heating means 52 for selectably heating the desiccant material 53 preferably above a regeneration temperature thereof. The desiccant element 50 is situated such that at least the interior orifice 54 thereof is sealably enclosed within the closed pocket 20. |