Patent ID: 6989591

Claim:
A method for making an integrated circuit of the surface-mount type, comprising, first of all, the manufacture of a package having a rear face and a pin grid array, the array extending under this rear face perpendicular thereto and then the formation at the end of each pin of a ball of low melting point alloy surrounding this end and soldered thereto, wherein, in order to form the ball at the end of each pin: working cells of a cellular plate are distributed at the same pitch as the pins of the package of the integrated circuit are filled with a solder cream formed from the material of the alloy; the pins of the pin grid array of the integrated circuit are inserted into the cells including the solder cream, the integrated circuit being on top of the cellular plate; the cellular plate is heated until the alloy melts; the cellular plate is cooled very quickly so as not to allow the liquid alloy enough time to wick up along the pins; the integrated circuit and the cellular plate secured to the pins of the circuit by the solidified alloy in the cells is then inverted so as to place the cellular plate on top of the integrated circuit, the integrated circuit being suspended from the cellular plate by its pins held in the alloy solidified in the cells; the cellular plate is heated until the solder in the cells melts, causing the integrated circuit to separate from the cellular plate under gravity and causing solder balls to form at the ends of the pins, the alloy having wetted the pins sufficiently for it to remain attached to the pins and solidifying quickly in the form of balls as soon as the integrated circuit separates from the cellular plate, the alloy not having time to spread out along the pins.