Method and apparatus for soldering electric terminals to double-sided circuit boards
Multilayer flexible printed circuit tape
Method for making terminal bumps on semiconductor wafers
Method of forming solder bump terminals on semiconductor elements
Solder delivery system
Photosensitive coating composition and the use thereof for protective purposes
ApplicationNo. 743970 filed on 08/12/1991
US Classes:29/830, Assembling bases29/831, Assembling formed circuit to base29/840, By metal fusion228/180.22, Lead-less (or "bumped") device228/215, By confining filler257/E23.065, Flexible insulating substrates (EPO)257/E23.069Spherical bumps on substrate for external connection, e.g., ball grid arrays (BGA) (EPO)
ExaminersPrimary: Gorski, Joseph M.
Assistant: Vo, Peter
Attorney, Agent or Firm
International ClassH05K 003/36
AbstractA method of bonding a flexible circuitized substrate to a circuitized substrate (e.g., printed circuit board) to interconnect selected circuitry of both substrates using solder. Solder paste is applied over conductive pads on the circuitized substrate and organic dewetting material (e.g., epoxy coating) adjacent thereto. The flexible substrate, having conductors located within and/or traversing an aperture in the flexible substrate's dielectric, is positioned above the solder paste and heat is applied (e.g., in an oven). The paste, dewetting from the organic material, "balls up" and substantially surrounds a solder member (ball) attached to a bridging portion of the flexible substrate's conductor, thereby connecting both substrates. A frame member may be used to align the flexible substrate, both during solder member attachment thereto, as well as for aligning the flexible substrate having solder members attached, to the respective solder paste locations on the lower substrate.
Field of SearchBeam lead frame or beam lead device
With component orienting
By metal fusion
By metal fusion bonding
On flat or curved insulated base, e.g., printed circuit, etc.
Assembling formed circuit to base
Assembling to base an electrical component, e.g., capacitor, etc.
Simultaneous bonding of multiple joints (e.g., dip soldering of printed circuit boards)
By confining filler
Gas or vapor