| 摘要 |
Identity document consisting of a support and a chip accommodated therein. The support may be produced by laminating different layers, one or more of these layers being provided with an opening for accommodating the chip. Laminating or applying the plastic in another way takes place at a relatively high temperature. During cooling, the support and the chip exhibit different shrinking properties, resulting in stresses which may lead to cracks. It is proposed to provide an auxiliary layer between the layer directly adjoining the chip and the subsequent layer. This auxiliary layer consists of a rubber-like material having a thermal coefficient of expansion which is greater than that of the adjoining two layers. This results in a prestress in the support during the cooling which follows the lamination, thus preventing the formation of cracks. In addition such an auxiliary layer acts as a stop layer for any crack formation which might occur in the first layer directly adjoining the chip. After all, cracks occurring in the latter cannot be easily transferred to the adjoining second layer due to the presence of the auxiliary layer which, as a result of its properties, distributes the stresses evenly over such a layer. |
