Patent ID: 8422238

Claim:
A signal conversion device comprising: a substrate having a rear surface and a frontal surface, the rear surface being provided with a first contact region comprising at least a first contact and a second contact while the frontal surface being provided with a second contact region comprising at least a third contact and a fourth contact; wherein there is an electrical connection between the first and third contacts, and the second and fourth contacts are electrically connected to an IC fabricated using Wafer Level Chip Scale Package (WLCSP) technology, and wherein the IC is disposed at the rear surface or the frontal surface; wherein the substrate is attached to a SIM card by means of adhesion, and the first and second contacts are configured to electrically contact to the SIM card; and wherein a dimension of the substrate is the same as that of the SIM card so that the substrate can be completely adhered to the SIM card.