| 摘要 |
PROBLEM TO BE SOLVED: To prevent cream solder from oozing from a printing plate caused by improper transfer of the solder, a defect such as cracking, missing or lacking of a solder terminal, and the improper transfer position of the solder terminal, when the cream solder is printed to form the solder terminal for high density mounting the electronic components by using a metal mask having an opening size of 50 to 150μm and a repetition pitch of 100 to 250μm. SOLUTION: A printing pattern is formed on a conductive substrate having a photosensitive layer by photolithography using a chromium mask. The metal mask is made by electroforming. The metal mask is made to have a Vickers hardness of 200 to 350 HV, and the surface of the metal mask on the side of a printed wiring board is set to have a surface roughness Rz of 1 to 8μm. The printing plate having the metal mask bonded to a metal frame via a thin silk veil is set to have a tension of 0.25 to 0.32 mm. COPYRIGHT: (C)2004,JPO&NCIPI
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