Method and apparatus for soldering with a multiple tip and associated optical fiber heating device

A method for connecting solder balls to pads on substrate comprising the steps of:

• a. providing a substrate having a first pad disposed at one end of a metallized through-hole and a second pad disposed at the other end of the hole;
• b. providing a heating device comprised of:
• at least one tip having a cavity therein;
• a laser,
• a coupling device, optically connected to the laser;
• an optical fiber associated with each tip, each fiber having a first end and a second end, the first end being disposed in the cavity and in thermal contact with said tip, and the second end connected to said coupling device;
• and
• a biasing member associated with each tip, each tip and biasing member being mounted in a support to permit each tip to move axially in said support;
• c. positioning a solder ball against each second pad;
• d. placing each tip in contact with a first pad, biased by said biasing member;
• and
• e. actuating the laser to heat each of said tips through said associated fiber so as to heat each second pad for a time and temperature sufficient to partially fellow the solder of each ball.

A method for connecting solder balls to pads on substrate comprising the steps of:

• a. providing a substrate having a first pad disposed at one end of a metallized through-hole and a second pad disposed at the other end of the hole;
• b. providing a heating device comprised of:
• at least one tip having a cavity therein;
• a laser,
• a coupling device, optically connected to the laser;
• an optical fiber associated with each tip, each fiber having a first end and a second end, the first end being disposed in the cavity and in thermal contact with said tip, and the second end connected to said coupling device;
• and
• a biasing member associated with each tip, each tip and biasing member being mounted in a support to permit each tip to move axially in said support;
• c. positioning a solder ball against each second pad;
• d. placing each tip in contact with a first pad, biased by said biasing member;
• and
• e. actuating the laser to heat each of said tips through said associated fiber so as to heat each second pad for a time and temperature sufficient to partially reflow the solder of each ball.