Method and apparatus for removing known good die

Abstract

Preferred embodiments for methods of removing an integrated circuit (“IC”) from a substrate, where the IC is attached to the substrate by multiple solder connections are disclosed. One preferred embodiment of the inventive methods provides the steps of heating the IC and substrate to the reflow temperature for the solder connections and pulling the IC from the substrate by means of a vacuum force. Another preferred embodiment of the inventive method provides the step of shearing the IC from the substrate after the substrate and IC are heated, but before solder reflow temperature has been reached, and where the shearing force may be programmed through a computer controlled servomotor. Preferred embodiments of certain apparatus applying the inventive methods for removing an integrated circuit from a substrate are also disclosed. One preferred embodiment of the inventive apparatus includes a vented pallet to hold the substrate and IC and through which the vacuum force is applied to pull the IC from the substrate without the use of physical clamping or contact forces applied to the substrate or IC. In a further preferred embodiment of the inventive apparatus, shear elements are provided and used with a programmable servomotor for precisely controlling the forces applied to the substrate and IC as a function of time, temperature and translational distance.