Apparatus and method for depositing and reflowing solder paste on a microelectronic workpiece

A stenciling machine for depositing and reflowing solder paste on a microelectronic workpiece having a plurality of microelectronic dies, the machine comprising:

• a stencil having a plurality of apertures and a heating element coupled to the stencil;
• and
• a controller operatively coupled to the heating element and the stencil, the controller having a computer-readable medium containing instructions to perform a method comprising:
• positioning the stencil at least proximate to the workpiece;
• placing discrete masses of solder paste into the plurality of apertures;
• and
• activating the heating element and thereby reflowing the discrete masses of solder paste while the stencil is positioned at least proximate to the workpiece and while the discrete masses are in the apertures.

A stenciling machine for depositing and reflowing solder paste on a wafer, the stenciling machine comprising:

• a stencil having a plurality of apertures and a plurality of heating elements positioned in the stencil at least proximate to the plurality of apertures;
• and
• a controller operatively coupled to the heating elements and the stencil, the controller having a computer-readable medium containing instructions to perform a method comprising:
• depositing solder paste into the plurality of apertures in the stencil and onto ball-pads of the wafer;
• and
• activating the heating elements and thereby reflowing the solder paste within the plurality of apertures.

A stenciling machine for depositing and reflowing solder paste on a microelectronic workpiece having a redistribution layer with bond-sites, the stenciling machine comprising:

• a stencil having a plurality of apertures and a heat source embedded in the stencil;
• and
• a controller operatively coupled to the heater and the stencil, the controller having a computer-readable medium containing instructions to perform a method comprising:
• positioning the stencil in a first position at least proximate to the redistribution layer with each aperture in the plurality of apertures generally aligned with a corresponding bond-site;
• depositing discrete masses of solder paste onto the bond-sites through the plurality of apertures while the stencil is in the first position;
• and
• reflowing the solder paste while the stencil is in the first position.

A stenciling machine for depositing and reflowing solder paste on a microelectronic workpiece having a plurality of microelectronic dies and a redistribution layer with a dielectric layer over the dies and bond-sites coupled to the dies, the stenciling machine comprising:

• a housing;
• a stencil within the housing movable relative to the microelectronic workpiece between a first position in which the stencil is at least proximate to the redistribution layer of the microelectronic workpiece and a second position in which the stencil is spaced apart from the redistribution layer;
• and
• a heat source within the stencil to reflow discrete masses of solder paste on the bond-sites of the microelectronic workpiece when the stencil is in the first position.