Abstract:
Electrical component assembly (30) comprising a first electrical component (32) comprising an electrical connection protrusion (34) (e.g., a solder bump) made of a first metal solder composition having a first melting point, and a second electrical component (36) comprising an electrical contact (38). A second metal solder composition (40) having a second melting point is formed or otherwise disposed so as to function as an electrical connection between at least a portion of the electrical connection protrusion (34) and the electrical contact (38) of the second electrical component (36). The second melting point is lower than the first melting point, and there is a distinct interface of demarcation between the electrical connection protrusion (34) and the second metal solder composition (40).
Abstract:
The invention relates to an electrical connection (50; 60) between a first electrically conductive component (44) made of a first material and a second electrically conductive component (48; 62; 70) made of a second material. According to the invention, said electrical connection comprises between the electrically conductive components (44, 48; 62; 70) at least two electrically conductive adhesive layers (52, 54, 56) made of different adhesive layer materials and generating said electrical connection.
Abstract:
A lead free solder hierarchy for use in the second level solder connection of electronic components such as joining an electronic module (20) to a circuit board (120). An off-eutectic solder (60) concentration of SnCu or SnAg is used for the module side connection. This off-eutectic solder (60) contains sufficient intermetallics to provide the module side connection with a robust second level assembly and rework process. The off-eutectic composition (60) provides an intermetallic phase structure in the module side fillet during assembly. The intermetallic phase structure eliminates problems of tilt and collapse during second level assembly and aids in rework by providing a more cohesive joint allowing removal of the columns (100) from the board (120) without simultaneous removal from the module (20).
Abstract:
A multiple circuit board package (10) employing solder balls (59) and method and apparatus (100) for fabricating same. Two or more printed circuit boards (64) and a plurality of electronic devices (42) are joined together using solder balls (59). Alternatively, three or more printed circuit boards (64) are joined together using the solder balls (59). A novel and improved solder ball (59) connection is disclosed, along with a fixture (100) for aligning and fixing the disposition of the pads (70) and the solder balls (59) during a heating cycle in which the circuit boards (64) are placed under pressure while the solder balls (59) are re-flowed for making an electrical connection.
Abstract:
The invention relates to a metallic coating, which can be used, for example, for manufacturing electronic components and for interconnecting irreversibly the components into various substrates by employing either low temperature or high temperature solders. It is characteristic for the invention that the coating enables to interconnect electronic components fluxlessly. The invention relates especially to the interconnection technique which is used for example for interconnecting bare chips to the interposer of surface mount package or directly on substrate like printed wiring board or interconnecting surface mount package on printing wiring board. The object of the present invention is in particular the interconnection technique in which the electrolytically deposited solder bumps on electrical contact pads are replaced with self-contained solder balls which make the alloys selection of the bumps more versatile, simpler and cheaper to accomplish. It is in accordance with the present invention to coat solder balls and tin ortin-alloy precoated contact surfaces with the bismuth layer of appropriate thickness. It is also in accordance with the present invention to place bismuth-coated solder particles to contact areas mixed in organic solvent as a paste or as an anisotropically conducted adhesive.