Method for producing filled vias in electronic components

Abstract

The present invention relates to a process for producing filled vias which are made of two components, a first component which forms a bonding layer between the wall of the via and a second component which forms the core of the via. Preferably, the two components solidify from a melt which includes two immiscible liquids. The first liquid is capable of wetting the wall of the via and the second liquid. The resulting product is also disclosed. Preferably the first component comprises a copper oxide and the second component comprises a conductive metal such as silver or copper.

What is claimed is:  
     
         1 . A product comprising: 
 a) a substrate comprising at least one hole which extends through said substrate; and    b) a multicomponent material filling said hole through said substrate in which said multicomponent material comprises: 
 i) a first component which, when melted, is capable of wetting said substrate in order to form a bond between said first component and said substrate; and  
 ii) a second component which bonds with said first component and which is conductive.  
   
     
     
         2 . The product as claimed in  claim 1  wherein said multicomponent material comprises said first component located between the walls of said hole in said substrate and said second component.  
     
     
         3 . The product as claimed in  claim 1  wherein said substrate comprises a ceramic material.  
     
     
         4 . The product as claimed in  claim 1  wherein said substrate comprises a material selected from the group consisting of alumina, zirconia, aluminum nitride, beryllia, silicon carbide, magnesia, silicon nitride and mullite.  
     
     
         5 . The product as claimed in  claim 1  wherein said first component of said multicomponent material comprises a metal oxide.  
     
     
         6 . The product as claimed in  claim 1  wherein said first component of said multicomponent material comprises a copper oxide.  
     
     
         7 . The product as claimed in  claim 1  wherein said first component of said multicomponent material comprises CuO or Cu 2 O.  
     
     
         8 . The product as claimed in  claim 1  wherein said second component comprises a material capable of efficiently conducting heat.  
     
     
         9 . The product as claimed in  claim 1  wherein said second component comprises a material component capable of efficiently conducting electricity.  
     
     
         10 . The product as claimed in  claim 8  wherein the heat conductivity of said second component is at least 100 W/mK.  
     
     
         11 . The product as claimed in  claim 9  wherein the electrical conductivity of said second component is at least 1×10 4  mhos/cm.  
     
     
         12 . The product as claimed in  claim 1  wherein said hole in said substrate is formed using a laser.  
     
     
         13 . The product as claimed in  claim 1  wherein said hole in said substrate is at least about 2 mils in diameter.  
     
     
         14 . The product as claimed in  claim 1  wherein said hole in said substrate is from about 2 mils to about 50 mils in diameter.  
     
     
         15 . The product as claimed in  claim 1  wherein said hole has a cross-sectional geometry selected from the group consisting of round, oval, slotted, star-shaped, chevron, polygonal and irregular.  
     
     
         16 . The product as claimed in  claim 1  wherein said hole is substantially round.  
     
     
         17 . The product as claimed in  claim 1  wherein said substrate has a thickness of from about 3 mils to about 60 mils.  
     
     
         18 . The product as claimed in  claim 1  wherein the aspect ratio of the thickness of said substrate to the average diameter of said hole is from about 0.5:1 to about 50:1.  
     
     
         19 . The product as claimed in  claim 1  wherein the amount of said first component of said multicomponent material is from about 0.5 mole percent to about 25 mole percent of the total amount of multicomponent material.  
     
     
         20 . The product as claimed in  claim 1  wherein the amount of said first component of said multicomponent material is from about 1 mole percent to about 5 mole percent of the total amount of multicomponent material.  
     
     
         21 . The product as claimed in  claim 1  wherein said multicomponent material filling said hole in said substrate does not substantially protrude above at least one surface of said substrate.  
     
     
         22 . The product as claimed in  claim 1  wherein at least one surface of said component is treated in order to be substantially planar.  
     
     
         23 . The product as claimed in  claim 1  wherein at least one surface of said component is polished in order to provide a relatively smooth surface.  
     
     
         24 . A process for producing a product, said process comprising: 
 a) providing a substrate having at least one hole passing through said substrate;    b) inserting a material into said hole; and    c) firing the assembly in order to form a two liquid system, wherein a first liquid wets both said substrate and a second liquid and upon solidification said first liquid forms a first component and said second liquid forms a second component, wherein said first component forms an effective bond with said substrate and wherein said second component effectively bonds to said first component.    
     
     
         25 . The process as claimed in  claim 24  wherein said substrate comprises a sintered ceramic material.  
     
     
         26 . The process as claimed in  claim 24  wherein said substrate comprise a ceramic material selected from the group consisting of alumina, zirconia, aluminum nitride, beryllia, silicon carbide, magnesia, silicon nitride and mullite.  
     
     
         27 . The process as claimed in  claim 24  wherein said hole is formed in said substrate using a laser.  
     
     
         28 . The process as claimed in  claim 24  wherein said hole is formed in said substrate using a carbon dioxide laser or an excimer laser.  
     
     
         29 . The process as claimed in  claim 24  wherein said hole is formed in said substrate by outlining the shape of said hole using a laser to form a hole larger than the beam of said laser.  
     
     
         30 . The process as claimed in  claim 24  wherein said hole is formed in said substrate using a laser beam to outline a shape selected from the group consisting of round, slotted, oval, star-shaped, chevron, polygonal and irregular.  
     
     
         31 . The process as claimed in  claim 24  wherein said hole is formed in said substrate using a fixed laser and by moving said substrate in order to form the desired pattern.  
     
     
         32 . The process as claimed in  claim 24  wherein a plurality of holes are formed in said substrate.  
     
     
         33 . The process as claimed in  claim 24  wherein said hole is formed in said substrate by maintaining said substrate in a fixed position and moving a laser beam in a desired pattern using a reflective device.  
     
     
         34 . The process as claimed in  claim 24  wherein said hole is formed in said substrate using a laser beam which is split into multiple beams using reflective and/or refractive devices in order to form more than one hole at a time.  
     
     
         35 . The process as claimed in  claim 24  wherein said hole is formed when said substrate is in a green state.  
     
     
         36 . The process as claimed in  claim 24  wherein said hole is formed when said substrate is in a green state by using a punch and die to form said hole.  
     
     
         37 . The process as claimed in  claim 24  wherein said hole is formed in said substrate using a drill.  
     
     
         38 . The process as claimed in  claim 24  wherein said hole is formed in said substrate by placing sacrificial materials in a substrate in a green state which form the desired holes during sintering.  
     
     
         39 . The process as claimed in  claim 24  wherein said solid member is a wire having a core of the second component coated with said first component.  
     
     
         40 . The process as claimed in  claim 24  wherein said material is a solid member comprising a core of a second metal coated with a first metal.  
     
     
         41 . The process as claimed in  claim 24  wherein said material is a copper-coated silver wire.  
     
     
         42 . The process as claimed in  claim 24  wherein said material is formed by plating copper on a silver wire.  
     
     
         43 . The process as claimed in  claim 24  wherein said material is formed by electrolytically coating a first component on a wire comprising a second component.  
     
     
         44 . The process as claimed in  claim 24  wherein said material has a size and geometry such that when it is inserted into said hole, it remains therein.  
     
     
         45 . The process as claimed in  claim 24  wherein said material is chiefly made of a single component which, during processing is transformed into two components.  
     
     
         46 . The process as claimed in  claim 24  wherein said material comprises copper.  
     
     
         47 . The process as claimed in  claim 24  wherein said material is a copper wire.  
     
     
         48 . The process as claimed in  claim 24 , wherein said material is an alloy comprising either a first component and a second component or materials which, during processing can be converted to either said first component or said second component.  
     
     
         49 . The process as claimed in  claim 24  wherein said material is inserted into said hole using a process comprising the steps of: 
 a) providing said material in the form of a wire;  
 b) placing said wire in a device which can direct said wire into said hole;  
 c) placing said device adjacent said hole and metering a length of wire into said hole; and  
 d) cutting said wire thereby leaving a portion in said hole.  
 
     
     
         50 . The process of  claim 49  wherein the actuating of the cutting of said wire is accomplished by a method selected from the group consisting of: 
 a) when the distal end of said wire contacts an electrically conductive device placed at the distal end of said hole thereby completing an electrical circuit, actuating a cutting device to cut said wire to a desired length, which remains in said hole;  
 b) metering a predetermined length into said hole and cutting said wire when such length has been inserted into said hole;  
 c) metering said wire into said hole for a predetermined period of time and cutting said wire when such time is elapsed;  
 d) metering said wire into said hole until a sensor is activated thereby actuating the cutting of said wire;  
 e) employing a sequencing device to actuate the cutter; and  
 f) employing a capacitance device to actuate said cutter.  
 
     
     
         51 . The process as claimed in  claim 24  wherein said assembly is fired at a temperature of from about 960° C. to about 1350° C.  
     
     
         52 . The process as claimed in  claim 24  wherein said assembly is fired at a temperature of from about 960° C. to about 1200° C. and wherein said second component is silver.  
     
     
         53 . The process as claimed in  claim 24  wherein said assembly is fired at a temperature of from about 1218° C. to about 1350° C. and wherein said second component is copper.  
     
     
         54 . The process as claimed in  claim 24  wherein said assembly is fired for a period of time from about one minute to about sixty minutes.  
     
     
         55 . The process as claimed in  claim 24  wherein said assembly is fired for a period of time from about one minute to about thirty minutes.  
     
     
         56 . The process as claimed in  claim 24  wherein said assembly is fired for a period of time from about five minutes to about twenty minutes.  
     
     
         57 . The process as claimed in  claim 46  wherein said assembly is held in a free hanging position during firing so that there is no contact between the area of said hole and any other solid object.  
     
     
         58 . The process as claimed in  claim 24  further comprising the step of smoothing at least one surface of said component to form a substantially smooth surface.  
     
     
         59 . The process as claimed in  claim 24  wherein said material is inserted into said hole in a molten liquid form.  
     
     
         60 . The process as claimed in  claim 24  wherein at least a portion of said material is oxidized during said firing step to form said first liquid.  
     
     
         61 . The process as claimed in claim  60  wherein said oxidized material is copper oxide.