Method of depth routing an electronic layup and apparatus for effecting such a method

Abstract

A method of depth routing an electronic layup comprised of a dielectric sandwiched between a metal layer and a metal substrate which is then laminated. The method involves first positioning a hardened mask so that the mask is interposed between the metal layer and at least one nozzle of a sandblasting machine, the mask having at least one aperture provided therein. Thereafter, the electronic layup is sandblasted through the at least one aperture by way of the sandblasting machine. The force, size and type of abrasive applied by the sandblasting machine are sufficient to erode the metal layer and the dielectric but not the substrate.

1 . A method of depth routing an electronic layup, the electronic layup comprising a dielectric sandwiched between a metal layer and a metal substrate which is then laminated, the method comprising the steps of:
 a. positioning a hardened mask so that the mask is interposed between the metal layer and at least one nozzle of a sandblasting machine, the mask having at least one aperture provided therein; and   b. sandblasting the electronic layup through the at least one aperture by way of the sandblasting machine   
       wherein the force, size and type of abrasive applied by the sandblasting machine are sufficient to erode the metal layer and the dielectric but not the metal substrate; and the surface of the resulting depth routed metal substrate is substantially even and free from burrs and/or irregularities to increase geographical contact between the metal substrate and at least one electronic component. 
     
     
         2 . A method of depth routing an electronic layup according to  claim 1 , wherein the increased geographical contact increases heat dissipation from the at least one electronic component to the metal substrate. 
     
     
         3 . A method of depth routing an electronic layup according to  claim 1 , wherein the surface of the metal substrate is co-planar. 
     
     
         4 . A method of depth routing an electronic layup according to  claim 1 , further including the step of securing the electronic layup and hardened mask in a jig while maintaining the relative position of the hardened mask to the electronic layup. 
     
     
         5 . A method of depth routing an electronic layup according to  claim 1 , wherein the step of positioning the hardened mask includes the sub-step of positioning the hardened mask no more than 0.5 mm away from the metal layer. 
     
     
         6 . A method of depth routing an electronic layup according to  claim 5 , further including the steps of:
 a. securing the jig to a feeder belt; and   b. controlling the movement of the jig relative to the sandblasting machine by way of the feeder belt.   
     
     
         7 . A method of depth routing an electronic layup according to  claim 1 , wherein the step of sandblasting the metal layer and the dielectric involves the sub-step of directing a fluid stream containing abrasive particles towards the electronic layup. 
     
     
         8 . A method of depth routing an electronic layup according to  claim 7  wherein the abrasive particles comprise at least one of the following types of abrasive particles: aluminium oxide; fused aluminium oxide with titanium; corundum. 
     
     
         9 . A method of depth routing an electronic layup according to  claim 7  wherein the size of the abrasive particles ranges from 5 μm to 2800 μm. 
     
     
         10 . A method of depth routing an electronic layup according to  claim 9 , wherein the mean particle size of the abrasive particles is 10 μm±0.2 μm. 
     
     
         11 . A method of depth routing an electronic layup according to  claim 7 , wherein the pressure of the fluid stream is in the range 0.3 MPa to 2 MPa. 
     
     
         12 . A method of depth routing an electronic layup according to  claim 11 , wherein the pressure of the fluid stream is in the range 3.724×10 5  Pa±0.098×10 5  Pa. 
     
     
         13 . A method of depth routing an electronic layup according to  claim 7 , wherein the fluid stream is a stream of air having a pressure range of 0 to 4.7×10 5  Pa. 
     
     
         14 . A method of depth routing an electronic layup according to  claim 7 , wherein the speed of the fluid stream produced is between 5 m/min and 30 m/min. 
     
     
         15 . A method of depth routing an electronic layup according to  claim 14 , wherein the speed of the fluid stream produced is between 9 m/min and 11 m/min. 
     
     
         16 . A method of depth routing an electronic layup according to  claim 7 , wherein the abrasive particles have a hardness of between 7 and 9 Mohs. 
     
     
         17 . A depth routed electronic layup formed in accordance with the method of  claim 1 . 
     
     
         18 . A depth routed electronic layup according to  claim 17 , wherein the metal layer is copper. 
     
     
         19 . A depth routed electronic layup according to  claim 17 , wherein the metal substrate is either copper or aluminium. 
     
     
         20 . A sandblasting machine configured to be used in the method of  claim 1 , the sandblasting machine configured to produce and direct a fluid stream containing abrasive particles towards the electronic layup. 
     
     
         21 . A sandblasting machine as claimed in  claim 20 , wherein the abrasive particles comprise at least one of the following types of abrasive particles: aluminium oxide; fused aluminium oxide with titanium; corundum. 
     
     
         22 . A sandblasting machine as claimed in  claim 20 , wherein the size of the abrasive particles ranges from 5 μm to 2800 μm. 
     
     
         23 . A sandblasting machine as claimed in  claim 22 , wherein the mean particle size of the abrasive particles is 10 μm±0.2 μm. 
     
     
         24 . A sandblasting machine as claimed in  claim 20 , wherein the pressure of the fluid stream is in the range 0.3 MPa to 2 MPa. 
     
     
         25 . A sandblasting machine as claimed in  claim 24 , wherein the pressure of the fluid stream is in the range 3.724×10 5  Pa±0.098×10 5  Pa. 
     
     
         26 . A sandblasting machine as claimed in  claim 20 , wherein the fluid stream is a stream of air having a pressure range of 0 to 4.7×10 5  Pa. 
     
     
         27 . A sandblasting machine as claimed in  claim 20 , wherein the at least one nozzle is a ceramic nozzle. 
     
     
         28 . A sandblasting machine as claimed in  claim 27 , wherein the at least one nozzle is a 2.6 mm×conical outer×50 mm length nozzle. 
     
     
         29 . A sandblasting machine as claimed in  claim 27 , wherein the at least one nozzle is a 3 mm×conical outer×50 mm length nozzle. 
     
     
         30 . A sandblasting machine as claimed in  claim 20 , wherein the at least one nozzle is a tungsten carbide nozzle. 
     
     
         31 . A sandblasting machine as claimed in  claim 30 , wherein the at least one nozzle is a 4 mm×12.5 mm×41 mm length nozzle. 
     
     
         32 . A sandblasting machine as claimed in  claim 30 , wherein the at least one nozzle is a 6 mm×20 mm×41 mm length nozzle. 
     
     
         33 . A sandblasting machine as claimed in  claim 30 , wherein the at least one nozzle is a 7.5 mm×20 mm×43 mm length nozzle. 
     
     
         34 . A sandblasting machine as claimed in  claim 20 , where the at least one nozzle is a boron carbide nozzle. 
     
     
         35 . A sandblasting machine as claimed in  claim 34 , wherein the at least one nozzle is a 6.3 mm×21 mm×82 mm length nozzle. 
     
     
         36 . A sandblasting machine as claimed in  claim 34 , wherein the at least one nozzle is a 8 mm×21 mm×82 mm length nozzle. 
     
     
         37 . A sandblasting machine as claimed in  claim 34 , wherein the at least one nozzle is a 9 mm×24 mm×82 mm length nozzle. 
     
     
         38 . A sandblasting machine as claimed in  claim 34 , wherein the at least one nozzle is a 10 mm×24 mm×82 mm length nozzle. 
     
     
         39 . A sandblasting machine as claimed in  claim 34 , wherein the at least one nozzle is a 12 mm×24 mm×82 mm length nozzle. 
     
     
         40 . A sandblasting machine as claimed in  claim 20 , wherein the speed of the fluid stream produced is between 5 m/min and 30 m/min. 
     
     
         41 . A sandblasting machine as claimed in  claim 40 , wherein the speed of the fluid stream produced is between 9 m/min and 11 m/min. 
     
     
         42 . A sandblasting machine as claimed in  claim 20 , wherein the abrasive particles have a hardness of between 7 and 9 Mohs.