Temperature sensing and prediction in ic sockets

Abstract

An apparatus is provided which preferably combines temperature sensing and prediction for more accurate temperature control of integrated circuits. An IC temperature sensing and prediction device includes a current sensing device that measures current passing through an IC, and a temperature control apparatus that measures a surface temperature of the IC. The device further includes an electronic controller that calculates the power consumed by the IC according to the measured current and adjusts the temperature of a heater or cooler responsive to the measured surface temperature and power consumption.

1 . An integrated circuit (IC) temperature sensing and prediction device, comprising:
 a current sensing device arranged to measure an amount of current passing through an IC package;   an electronic controller to receive a first signal from the current sensing device, the first signal representing the amount of current passing through the IC package; and   a temperature control apparatus to change a surface temperature of the IC package, wherein the electronic controller further receives a second signal from the temperature control apparatus, the second signal representing the surface temperature of the IC package.   
   
   
       2 . The device of  claim 1 , wherein the temperature control apparatus comprises:
 a temperature sensor arranged to thermally contact the IC package and measure the surface temperature of the IC package; and   a heater or cooler arranged to directly contact the IC package.   
   
   
       3 . The device of  claim 1 , wherein the electronic controller calculates an amount of power consumed by the IC package according to an amount of voltage drop across the current sensing device. 
   
   
       4 . The device of  claim 3 , wherein the controller is programmed to change the temperature of the heater or cooler responsive to the measured surface temperature and the calculated power consumed by the IC package. 
   
   
       5 . A system for testing IC packages, comprising:
 a testing chamber;   a testing board arranged within the testing chamber;   an IC package arranged on the testing board;   a temperature sensor arranged to thermally contact the IC package;   a heater or cooler arranged to directly contact the IC package;   a current sensing device arranged to sense an amount of current passing through the IC package;   an electronic controller arranged to receive signals from the temperature sensor and the current sensing device, wherein the electronic controller is programmed to change the temperature of the heater or cooler responsive to an amount of power consumed by the IC package and the measured surface temperature of the IC package.   
   
   
       6 . The system of  claim 5 , wherein the electronic controller calculates the amount of power consumed by the IC package by measuring an amount of voltage drop across the current sensing device. 
   
   
       7 . The system of  claim 5 , wherein the electronic controller is further programmed to determine if the IC package is defective according to a comparison of the amount of power consumed by the IC package and the measured surface temperature of the IC package. 
   
   
       8 . A system for testing IC packages, comprising:
 a testing board arranged within the testing chamber;   an IC package arranged on the testing board;   a temperature sensor arranged to thermally contact the IC package;   a heater or cooler arranged to directly contact the IC package;   a current sensing device arranged to sense an amount of current passing through the IC package;   an electronic controller arranged to receive signals from the temperature sensor and the current sensing device, wherein the electronic controller is programmed to change the temperature of the heater or cooler responsive to an amount of power consumed by the IC package and the measured surface temperature of the IC package.   
   
   
       9 . A system according to  claim 8 , including:
 means for comparing the measured surface temperature with the measured power consumption; and   means for determining that the IC is defective if the measured surface temperature is not consistent with the measured power consumption according to the thermal profile of the IC.   
   
   
       10 . A system according to  claim 8 , the electronic controller including:
 means for predicting a junction temperature of the IC according to a mathematical equation, the mathematical equation expressed as Tj=Tc +Pθjc, wherein Tj is the junction temperature of the IC, Tc is the surface temperature of the IC, P is the amount of power consumed by the IC, and θjc is a junction-to-case thermal resistance; and   means for adjusting the surface temperature of the IC according to the predicted junction temperature of the IC, wherein adjusting the surface temperature of the IC includes calculating a temperature adjustment value to the measured surface temperature according to the measured power consumption and the thermal profile of the IC.