A memory circuit having dual-gate memory cells and a method for fabricating such a memory circuit are disclosed. A heat sink is bonded to a first surface of the substrate, and a cavity is defined by and between the heat sink and the substrate such that a base wall of the cavity is defined by one of the layers with conductor lines thereof being present on the base wall. The height of the solder resist gradually increases from both edges toward a center of the solder resist. The massage device further includes a first motor disposed within the housing and adapted for creating vibration and a battery disposed within the housing and adapted to power the first motor.