The encapsulation lid comprises at least two glass layers of different
compositions, a first layer called the bottom layer, which is continuous,
and at least a second layer, which is discontinuous and designed so as to
define cavities or anfractuosities in this lid. Preferably, the glass
layers other than the first layer are preferably formed from
low-melting-point frits, thereby allowing such lids to be manufactured
economically, without recourse to glass machining.