| 摘要 |
PURPOSE: A high melting point flame retardant crystal is provided to have a higher melting point than a welding temperature, thereby effectively manufacturing a high melting point flame retardant crystal which maintains a crystal structure of flame retardant powder in lead-free soldering. CONSTITUTION: A manufacturing method for a high melting point flame retardant crystal comprises a step of obtaining a reaction composition by reducing the concentration of a by-product by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 1,4-naphtoquinone with a dielectric constant of 10 or less; and a step of obtaining a high melting point flame retardant crystal indicated in chemical formula 1 by recrystallizing the reaction composition by dissolving a mixed solvent of one or more selected from ethylene glycol, propylene glycol, diethylene glycol, cyclohexanone, benzyl alcohol, acetic acid ester, and para-hydroxybenzoate. |
