Molding die for sealing semiconductor device with reduced resin burrs

A molding die comprising a first mold half and a second mold half to be clamped together to sandwich a leadframe therebetween and to receive resin flowing in the direction from a front side to a rear side of said molding die,

• said first mold half having, successively in the direction of the resin flow, a resin inlet, a first runner for defining a first runner space communicated with said resin inlet at a front side of said runner, a first rising slope formed at a rear side of said first runner, a first gate formed at a rear edge of said first rising slope for defining a first gate space between said first gate and the leadframe, and a first cavity communicated with said first runner space through said first gate space,
• said second mold half having, successively in the direction of the resin flow, a resin well, a second rising slope formed at a rear side of said resin well, a second gate formed at a rear edge of said second rising slope for defining a second gate space between said second gate and the leadframe, and a second cavity communicated with said resin well through said second gate space,
• wherein, said first mold half and said second mold half are clamped together, said first gate and said first cavity are located opposite to said second gate and said second cavity, respectively, and
• wherein a length of said resin well taken in the direction of the resin flow is larger than a length of said first rising slope taken in the direction of the resin flow.