Method of making a semiconductor chip assembly with a bump/base heat spreader and a dual-angle cavity in the bump

A method of making a semiconductor chip assembly, comprising:

• providing a bump and a ledge, wherein the bump includes first, second and third bent corners, first and second sidewalls and a floor, the second bent corner is between the first and third bent corners, the first sidewall extends between the first and second bent corners, the second sidewall extends between the second and third bent corners and the floor is adjacent to the third bent corner, the bump defines a cavity that faces in a first vertical direction, has an entrance at the ledge, is shaped by the first, second and third bent corners, the first and second sidewalls and the floor and has a first angle relative to the floor at the first sidewall and a second angle relative to the floor at the second sidewall, the bump is adjacent to and integral with the ledge at the first bent corner, is spaced from the ledge at the second and third bent corners and extends vertically from the ledge in a second vertical direction opposite the first vertical direction and the ledge extends laterally from the bump in lateral directions orthogonal to the vertical directions;
• providing an adhesive, wherein an opening extends through the adhesive;
• providing a substrate that includes a conductive layer and a dielectric layer, wherein an aperture extends through the substrate;
• mounting the adhesive on the ledge, including inserting the bump into the opening, wherein the bump extends through the opening;
• mounting the substrate on the adhesive, including inserting the bump into the aperture, wherein the bump extends into the aperture, the adhesive is sandwiched between the ledge and the dielectric layer and is non-solidified and the dielectric layer is sandwiched between the conductive layer and the adhesive;
• then
• applying heat to melt the adhesive;
• moving the ledge and the substrate towards one another, thereby moving the bump in the second vertical direction in the aperture and applying pressure to the molten adhesive between the ledge and the substrate, wherein the pressure forces the molten adhesive to flow in the second vertical direction into a gap located in the aperture between the bump and the substrate;
• applying heat to solidify the molten adhesive, thereby mechanically attaching the bump and the ledge to the substrate;
• then
• providing a plated through-hole that extends through the ledge, the adhesive, the dielectric layer and the conductive layer;
• then
• providing a pad, a terminal, a base and a flange;
• providing a conductive trace that includes the pad, the terminal, the plated through-hole, a selected portion of the ledge that is adjacent to the plated through-hole and spaced from the bump and a selected portion of the conductive layer that is adjacent to the plated through-hole and spaced from the bump, wherein the plated through-hole is in an electrically conductive path between the pad and the terminal;
• providing a heat spreader that includes the bump, the base and the flange, wherein the bump is adjacent to the flange at the first bent corner and is spaced from the flange at the second and third bent corners, is adjacent to the base at the third bent corner and the floor and is spaced from the base at the first and second bent corners and extends vertically from the base in the first vertical direction, the base covers the bump in the second vertical direction, extends laterally from the bump in the lateral directions and includes a selected portion of the conductive layer that is spaced from the conductive trace and the flange includes a selected portion of the ledge that is adjacent to and integral with and extends laterally from the bump;
• then
• mounting a semiconductor device on the bump, wherein the semiconductor device is located within the cavity, extends beyond the first bent corner in the second vertical direction but not the first vertical direction, extends beyond the second bent corner in the first and second vertical directions and extends beyond the third bent corner in the first vertical direction but not the second vertical direction and the bump provides a recessed die paddle and a reflector for the semiconductor device;
• electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal;
• and
• thermally connecting the semiconductor device to the bump, thereby thermally connecting the semiconductor device to the base.