Interposer and method for producing holes in an interposer

Abstract

An interposer for electrical connection between a CPU chip and a circuit board is provided. The interposer includes a board-shaped base substrate made of glass having a coefficient of thermal expansion ranging from 3.1×10 −6 /K to 3.4×10 −6 /K. The interposer further includes a number of holes having diameters ranging from 20 μm to 200 μm. The number of holes ranging from 10 to 10,000 per square centimeter. Conductive paths running on one surface of the board extend right into respective holes and therethrough to the other surface of the board in order to form connection points for the chip.

1 - 17 . (canceled) 
     
     
         18 . An interposer for electrical connection between a CPU chip and a circuit board, comprising:
 a single-layered board-shaped base substrate made of glass having a first and a second board surface, the glass of the base substrate having a coefficient of thermal expansion ranging from 3.1×10 −6 /K to 3.4×10 −6 /K;   a number of holes extending between the first and second board surfaces, the number ranging from 10 to 10,000 per square centimeter, the holes having diameters that range from 20 μm to 200 μm and have a center-to-center distance in a range from 50 μm to 700 μm; and   conductive paths running on the first board surface and extend into the holes to the second board surface to form connection points for the CPU chip.   
     
     
         19 . The interposer as claimed in  claim 18 , wherein the glass of the base substrate has an alkali content of less than 700 ppm. 
     
     
         20 . The interposer as claimed in  claim 18 , wherein the glass of the base substrate has an arsenic or antimony content of less than 50 ppm. 
     
     
         21 . The interposer as claimed in  claim 18 , wherein the coefficient of thermal expansion is 3.2×10 −6 /K. 
     
     
         22 . The interposer as claimed in  claim 18 , wherein the base substrate has a thickness that ranges from 30 μm to 1,000 μm. 
     
     
         23 . The interposer as claimed in  claim 18 , wherein the number of holes ranges from 1,000 to 3,000 per square centimeter. 
     
     
         24 . The interposer as claimed in  claim 18 , wherein the diameter does not exceed 100 μm. 
     
     
         25 . The interposer as claimed in  claim 18 , wherein the center-to-center distance ranges from 150 μm to 400 μm. 
     
     
         26 . The interposer as claimed in  claim 18 , wherein the holes have an edge-to-edge distance of at least 30 μm. 
     
     
         27 . The interposer as claimed in  claim 18 , wherein the base substrate has holes of different diameters. 
     
     
         28 . The interposer as claimed in  claim 18 , further comprising:
 a ratio of the center-to-center distance to the diameter that ranges from 1 to 10;   a ratio of an edge-to-edge distance of the holes to the diameter that ranges from 1 to  9; and      a ratio of a board thickness of the base substrate to the diameter that ranges from 0.1 to 25.   
     
     
         29 . The interposer as claimed in  claim 18 , wherein the holes have edges between the first and/or second board surface and an inner hole wall that are rounded-broken. 
     
     
         30 . A method for producing holes in an interposer, comprising the steps of:
 providing single-layered boards of glass as a base substrate to be perforated;   aligning a multiple laser beam array to predetermined perforation points of the base substrate;   triggering focused laser pulses in a wavelength range between 1600 and 200 nm in which the glass is at least partially transparent and with a radiation intensity that causes local non-thermal destruction of the glass along a respective filamentary channel; and   widening the filamentary channels to a desired diameter of the holes.   
     
     
         31 . The method as claimed in  claim 30 , wherein the widening step comprises electro-thermal heating and evaporation of perforation material due to dielectric breakdowns. 
     
     
         32 . The method as claimed in  claim 30 , wherein the widening step comprises directing reactive gases onto the perforation points.