Apparatus for removing tiebars after molding of semiconductor chip
An apparatus for removing tiebars of a lead frame after one or more semiconductor components have been encapsulated in a resin to form a package body includes first and second removing stations. The second removing station is provided for removing scraps that may be left between leads of the lead frame after the tiebars have been removed in the first removing station. In the second removing station, the lead frame is positioned on a die. A scrap-cutting punch is moved relative to the die so that projections of the punch are fitted into corresponding holes of the die, thereby pushing the scraps out of the leads and into the holes.
1. An apparatus for removing tiebars of a lead frame after one or more semiconductor components have been encapsulated in a resin to form a package body attached to the lead frame, comprising:
a first removing station including first and second support members opposed to each other for putting the lead frame therebetween, and a tiebar-cutting punch held by the first support member for reciprocation relative to the second support member, the first support member being above the second support member, wherein
the tiebar-cutting punch and second support member have cutters and holes, respectively, engageable with each other,
when the lead frame is put between the first and second support members, the cutters of the tiebar-cutting punch are fitted into corresponding holes of the second support member, cutting and punching out tiebars of the lead frame, and
the second support member includes a scrap-exhausting opening opposite the holes of the second support member for discharging cut portions of the tiebars cut by the tiebar-cutting punch; and
a second removing station including third and fourth support members opposed to each other for putting the lead frame therebetween, and a scrap-removing punch held by the third support member for reciprocation relative to the fourth support member for removing any scraps of the tiebars left between leads of the lead frame after the tiebars have been cut in the first removing station, wherein
the scrap-removing punch and fourth support member have projections and holes, respectively, engageable with each other, and
when the lead frame is put between the third and fourth support members, and the scrap-removing punch is moved relative to the fourth support member, the projections of the scrap-removing punch are fitted into corresponding holes in the fourth support member, pushing the scraps of the tiebars out of the lead frame and into the holes.
2. The apparatus in accordance with claim 1 , wherein the projections of the scrap-removing punch, where the projections enter the holes in the fourth support member, are tapered along a direction of relative reciprocation of the third and fourth support members.
3. The apparatus in accordance with claim 1 , wherein the projections of the scrap-removing punch are made of resin.
4. The apparatus in accordance with claim 1 , wherein the cutters of the tiebar-cutting punch are supplied with gas when the cutters are fitted into the corresponding holes of the second support member.
5. The apparatus in accordance with claim 1 , wherein the projections of the scrap-removing punch, where the projections enter the holes in the fourth support member, have a smaller cross-sectional area than the cutters of the tiebar-cutting punch in a plane transverse to the directions of relative reciprocation of the first and second support members and of the third and fourth support members.