Patent ID: 6900117
Filing Date: 2005-05-31
Classification: H01L

Abstract:
1. A method of bump formation comprising the steps of: patterning a resist layer so as to have a penetrating hole above a pad, the resist layer including a resin and a photosensitive agent, the resin having a property in which cross-linking is caused by either of thermal energy and light energy, the photosensitive agent having properties of causing cross-linking by the thermal energy and increasing absorbability of moisture by the light energy, reaction in the photosensitive agent with the moisture increasing solubility of the resist layer with respect to solvent; heating the resist layer to at least 100° C. and irradiating light on the resist layer at the same time to cause the cross-linking of the resin and the photosensitive agent with the moisture in the resist layer evaporating; and forming a metal layer which is electrically connected to the pad, within the penetrating hole.