Abstract: A method for utilizing a dry film is provided. A dry film is pressed onto a substrate, such as a wafer. The dry film includes a photoresist layer tightly attached to the substrate and an exposed carrier film with light transmission. Before exposure and development, the carrier film of the dry film is cleaned in a darkroom, wherein the cleaning method may include a step of chemical spraying and a step of rinsing through DI water. Accordingly, the contaminant on the carrier film can be removed. In addition, the dry film burrs can be also removed. Thus, an excellent production yield for sequent exposure and development can be achieved.

Abstract: A method for forming conductive bumps is applied to a wafer. An under-bump-metallurgy structure and a first photo resist layer are subsequently formed on the wafer. The first photo resist layer, such as a dry film, is patterned to have some openings and then a second photo resist layer is filled into the openings, in which the thickness of the second photo resist layer is fewer than or equal to the thickness of the first photo resist layer. The second photo resist layer is then patterned to have some openings. Next, a conductive layer is formed in the openings and then both the first and second photo resist layers are removed. With the conductive layer as a mask, the exposed under-bump-metallurgy structure is removed and then the conductive layer is reflowed to form some conductive bumps. With two kinds of photo resist layers, the conductive bumps can be provided with increased heights and decreased pitches.

Abstract: A method for forming conductive bumps is applied to a wafer. An under-bump-metallurgy structure and a first photo resist layer are subsequently formed on the wafer. The first photo resist layer, such as a dry film, is patterned to have some openings and then a second photo resist layer is filled into the openings, in which the thickness of the second photo resist layer is fewer than or equal to the thickness of the first photo resist layer. The second photo resist layer is then patterned to have some openings. Next, a conductive layer is formed in the openings and then both the first and second photo resist layers are removed. With the conductive layer as a mask, the exposed under-bump-metallurgy structure is removed and then the conductive layer is reflowed to form some conductive bumps. With two kinds of photo resist layers, the conductive bumps can be provided with increased heights and decreased pitches.