Polymer collar for solder bumps

A method of forming a solder-bumped structure, said method comprising the steps of:

• a. providing a conductive solder bump pad on a surface of a substrate;
• b. providing a pre-formed solder ball, the solder ball having a characteristic reflow temperature, the pre-formed solder ball having a base region and an upper region atop the base region;
• c. applying uncured polymer material over at least the base region of the solder ball, but leaving at least a portion of the upper region free from uncured polymer material;
• d. following step c, placing the base region of the solder ball onto the conductive solder bump pad, thereby applying uncured polymer material to the surface of the substrate over the solder bump pad;
• and
• e. heating the substrate to the reflow temperature of the solder ball to join the base region of the solder ball to the solder bump pad and to at least partially cure the polymer material surrounding the base region of the solder ball while leaving at least a portion of the upper region free of polymer material.

A method of forming solder bumps on an active surface of an integrated circuit, said method comprising the steps of:

• a. providing a first conductive solder bump pad on the active surface of an integrated circuit;
• b. applying uncured polymer material over the first conductive solder bump pad;
• c. following step b., placing a base region of a first pre-formed solder ball into the uncured polymer material and onto the first conductive solder bump pad, the first solder ball having a characteristic reflow temperature;
• and
• d. heating the first solder ball and the integrated circuit to the reflow temperature of the first solder ball to join the base region of the first solder ball to the first conductive solder bump pad and to at least partially cure the polymer material surrounding the base region of the first solder ball, thereby securing the first solder ball to the active surface of the integrated circuit.

A method of forming solder bumps on an active surface of an integrated circuit, said method comprising the steps of:

• a. providing a conductive solder bump pad on the active surface of the integrated circuit;
• b. providing a pre-formed solder ball, the solder ball having a characteristic reflow temperature;
• c. applying uncured polymer material over a base region of the solder ball;
• d. placing the base region of the solder ball onto the conductive solder bump pad, thereby applying uncured polymer material to the active surface of the integrated circuit over the solder bump pad;
• and
• e. heating the solder ball and integrated circuit to the reflow temperature of the solder ball to join the base region of the solder ball to the solder bump pad and to at least partially cure the polymer material surrounding the base region of the solder ball, thereby securing the solder ball to the active surface of the integrated circuit.

A method of forming a solder-bumped structure, said method comprising the steps of:

• a. providing first and second conductive solder bump pads on a surface of a substrate;
• b. applying a first portion of uncured polymer material over the first conductive solder bump pad, and applying a second portion of uncured polymer material over the second conductive solder bump pad, the first and second portions of uncured polymer material being spaced apart from each other;
• c. following step b., placing a base region of a first pre-formed solder ball into the first portion of uncured polymer material and onto the first conductive solder bump pad, and placing a base region of a second pre-formed solder ball into the second portion of uncured polymer material and onto the second conductive solder bump pad, the first and second solder balls having a characteristic reflow temperature;
• and
• d. heating the substrate to the reflow temperature of the first and second solder balls to join the base region of the first solder ball to the first conductive solder bump pad, to join the base region of the second solder ball to the second conductive solder bump pad, and to at least partially cure the polymer material surrounding the base regions of the first and second solder balls.

A method of forming a solder-bumped structure, said method comprising the steps of:

• a. providing first and second conductive solder bump pads on a surface of a substrate;
• b. providing first and second pre-formed solder balls, the solder balls having a characteristic reflow temperature;
• c. applying uncured polymer material over base regions of the first and second solder balls;
• d. placing the base regions of the first and second solder balls onto the first and second conductive solder bump pads, respectively, thereby applying a first portion of uncured polymer material to the surface of the substrate over the first solder bump pad, and thereby applying a second portion of uncured polymer material to the surface of the substrate over the second solder bump pad;
• and
• e. heating the substrate to the reflow temperature of the solder balls to join the base regions of the first and second solder balls to the first and second solder bump pads, respectively, and to at least partially cure the polymer material surrounding the base regions of the first and second solder balls.