Forming an array of metal balls or shapes on a substrate

A method for transferring an array of metal balls on a polymer layer to an array of metal contacts on a substrate comprising:

• selecting an array of contacts on a substrate;
• forming a flux over respective contacts of said array of contacts on said substrate;
• forming on said substrate a first mask having through-hole openings corresponding to respective contacts of said array of contacts;
• said through-hole openings having a depth and a width for receiving metal balls of said array of metal balls on said polymer layer;
• said first mask having mechanical strength to maintain a shape of said through-hole openings under shear forces to permit shearing said metal balls of said array of metal balls;
• positioning respective metal balls of said array of metal balls on said polymer layer into said through-hole openings of said first mask;
• moving said first mask sideways with respect to said polymer layer and said array of metal balls at least the width of a metal ball to shear said array of metal balls and stopping said moving said first mask sideways whereby said metal balls of said array of metal balls are sheared free from said polymer layer in said through-hole openings over said flux and respective contacts;
• heating said metal balls to reflow said metal to bond to or wet said respective contacts in a presence of said flux;
• and
• solidifying said metal over said contacts.

Apparatus for forming a tape containing solidified metal comprising:

• a first tape having a length and having a plurality of through-hole cavities therein;
• a second tape having a length and having an upper surface;
• said first and second tape capable of withstanding a temperature of molten metal;
• first and second guides spaced apart to provide a path there between for joining one surface of said first tape to said upper surface of said second tape to form a third tape having blind cavities;
• and
• a first work station and a second work station positioned in series after said first and second guides along a path taken by said third tape;
• said first work station having an injection molding solder tool for injecting molten metal into said blind cavities,
• said second work station having a temperature below the temperature of molten metal to solidify said molten metal in said blind cavities.

Apparatus for transferring metal solidified in cavities in a first layer of a tape comprising:

• a tape containing solidified metal in cavities in a first layer and having a second layer having an upper surface bonded to a lower surface of said first layer, said upper surface of said second layer forming a bottom wall of said cavities, said tape having a width, thickness and length;
• a first work station comprising first and second guides spaced apart to provide a first path there between and for directing said second layer and solidified metal along a second path and for separating and directing said first layer without said solidified metal along a third path;
• a second work station and a third work station positioned in series after said first work station along said second path taken by said second layer;
• said second work station having a substrate with a first mask thereon having corresponding openings in a pattern matching a pattern of said solidified metal on said second layer;
• said openings in said first mask having a width and depth to receive said solidified metal, said openings in said first mask having sidewalls to withstand predetermined lateral forces,
• said second workstation having a means for positioning said pattern of openings of said first mask to receive said pattern of solidified metal on said second layer, and for moving said first mask together with said second layer as said second layer is moved to a third work station,
• said third work station having a plate for applying pressure to said lower surface of said second layer and means for moving said substrate and first mask laterally with respect to said second layer to shear off said solidified metal in respective openings of said first mask and means for moving said first mask, solidified metal and substrate away from said second layer whereby said solidified metal has been transferred.

Apparatus for transferring a metal array on a surface of a tape to a substrate comprising:

• a tape head having first and second guides for guiding a tape past a work station on said tape head, said work station positioned on a path between said first and second guides,
• said work station having a plate for supporting said tape, said metal array having a pattern of spaced apart solidified metal on said upper surface of said tape;
• means for aligning said pattern at said work station with a mask on a substrate,
• means for moving said tape from said first guide to said second guide to position said metal array at said work station,
• means for positioning said work station to position said solidified metal of said metal array in respective openings of said mask on said substrate, and
• means for moving said tape relative to said mask a distance whereby solidified metal of said metal array on said tape is sheared off at times said solidified metal in respective openings is resisted by a sidewall of said respective openings of said mask on said substrate.