| 摘要 |
PROBLEM TO BE SOLVED: To prevent a printed circuit part from breaking or becoming defective by, forming recesses on which a light emitting device and so on are mounted on a metal core printed circuit board by pressing a male and a female molds, and by representing a relation between required depthes and a male and a female mold pattern by a quantitative formula. SOLUTION: A punch 30 has a protruded unit 31 having a reduced diameter at a terminal side by truncating of a corn body in parallel with the bottom surface, and a die 40 is provided with a recess part 41 having a reduced diameter at the bottom side corresponding to the punch 3. Let an angle between an imaginary extending line 32' of a terminal face 32 of the protruded body 31 and an inclined face 33 be α, a depth of a recess be L, a punch radius of curvature be R, a punch terminal outer diameter be D, a die bottom part angle β, then a shape of the recess part 41 of the die 40 is quantitatively represented by a formula L<=0.0005α<2> -0.08α+0.05D+K. Here the constant K varies according to the relation of male shape values R, α and a female shape value β and a size of the mold shape which does not generate a failure of the metal core printed circuit board when the required recess depth L is indicated. |
