| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method of a white solder resist layer that is rendered into white without containing a white pigment.SOLUTION: A coating film comprising the following white solder resist composition is formed on a wiring board: the white solder resist composition comprises a photopolymerizable compound, a photopolymerization initiator, and an organic compound having a melting point and no photopolymerization property, and contains no coloring agent, or contains a coloring agent by 0.04 mass% or less with respect to the solid content of the composition. The coating film is exposed, and the exposed coating film is heated. In a period from when the coating film is formed and until exposure is completed, the temperature of the coating film is maintained at a temperature lower than the melting point of the organic compound. The heating temperature of the coating film satisfies T≥T-30, where T(°C) is the heating temperature of the coating film and Tis the melting point of the organic compound. |
