Patent ID: 7919851

Claim:
A laminated substrate primarily comprising: a core layer having a first surface and a second surface; a first metal layer formed on the first surface of the core layer; a second metal layer formed on the second surface of the core layer; a first solder mask formed on the first surface of the core layer to cover the first metal layer; a second solder mask formed on the second surface of the core layer to cover the second metal layer; and a die-attaching layer partially covering the second solder mask; wherein the thicknesses of the first solder mask and the second solder mask are the same and the first solder mask and the second solder mask have different CTEs to reduce warpage of the laminated substrate; wherein the CTE of the die-attaching layer is greater than the one of the second solder mask and the CTE of the first solder mask is greater than the one of the second solder mask.