Abstract: The present disclosure relates to a production process for a solder electrode, including a step (1) of forming a coating film of a photosensitive resin composition on a substrate having an electrode pad; a step (2) of forming resist having an opening in a region corresponding to the electrode pad by selectively exposing the coating film to light and further developing the film; a step (3) of heating and/or exposing the resist to light; and a step (4) of filling the opening with molten solder while heating the solder. According to the production process for the solder electrode of the present disclosure, development of cracks on a resist surface can be prevented, and solder filling capability can be improved, even when the resist receives high heat during solder filling as in an IMS method, and therefore the solder electrode adapted for the purpose can be appropriately produced.

Abstract: The present invention relates to a production process for a solder electrode, including: a step (1) of forming a coating film of a photosensitive resin composition on a substrate having an electrode pad; a step (2) of forming resist having an opening in a region corresponding to the electrode pad by selectively exposing the coating film to light and further developing the film; and a step (3) of filling the opening with molten solder, in which the photosensitive resin composition contains at least a benzoxazole precursor. According to the production process for the solder electrode of the present invention, development of cracks on a resist surface can be prevented, and solder filling capability can be improved, even when the resist receives high heat during solder filling as in an IMS method, and therefore the solder electrode adapted for the purpose can be appropriately produced.

Abstract: A production process for a solder electrode, including: a step (I) of forming an opening in a portion of a film provided on a substrate having an electrode pad, the portion corresponding to the electrode pad on the substrate, and thereby forming a resist from the film on the substrate, and a step (II) of filling the opening of the resist with molten solder, wherein the resist is composed of at least two layers each containing a resin as a constituent, and a layer (1) of the resist, the layer (1) being closest to the substrate, does not substantially contain a component that thermally crosslinks the resin contained as a constituent in the layer (1) and a component that undergoes thermal self-crosslinking.

Abstract: Provided are a resin composition capable of forming a cured film excellent in elongation properties; a polymer suitable as a component contained in the composition; a cured film formed from the composition; and an electronic part including the cured film. The resin composition includes (A) a polymer containing a structural unit represented by the formula (a1) and a structural unit represented by the formula (a2); and (F) a solvent, wherein in the formula (a1), R1s are each independently a hydrogen atom or hydroxyl group, provided that at least one R1 is hydroxyl group; and R2 is a hydrogen atom or a C1-4 alkyl group; and in the formula (a2), R3s are each independently a group having a cationic polymerizable group, or a hydrogen atom, provided that at least one R3 is a group having a cationic polymerizable group; and R4 is a hydrogen atom or a C1-4 alkyl group.

Abstract: A photosensitive composition capable of forming a cured film having small internal stress; a cured film formed from the composition; and an electronic part including the cured film. The photosensitive composition includes: an alkali soluble resin (A), which includes at least 80% by mass of a novolak resin; a photosensitive compound (B); and a crosslinking agent (C), which includes at least a compound represented by the following formula (C1): wherein R1 is an alkyl group having 1 to 6 carbon atoms or the like; R2 is hydroxyl group or the like; R3 is a (a+1)valent hydrocarbon group or the like; R5 is a (c+1)valent hydrocarbon group or the like; R4 is a single bond or the like; a and c are each independently integers of 1 to 3, wherein the sum a+c is an integer of 3 to 6; and b is an integer of 0 or more.