Film material comprising spikes and method for the production thereof

Abstract

The invention relates to a sheet material having metal points ( 8 ) and surfaces ( 2 and 3 ) located opposite one another, wherein the sheet material ( 1 ) has through-holes ( 4 ) from one surface ( 2 ) to the surface ( 3 ) located opposite. Those through-holes ( 4 ) are filled with needle-point-shaped conical pins ( 5 ) or through-contacts ( 6 ) of electrically conducting material, whereas the surrounding sheet material in a preferred embodiment of the invention consists of an insulating plastics material ( 7 ). In a further embodiment of the invention, instead of the insulating plastics material ( 7 ) there are provided needle-shaped pins that are surrounded by air or some other gaseous medium. The invention further relates to a method for the production of such a sheet material ( 1 ) and to forms of use of the sheet material ( 1 ).

1 . Sheet material having metal points ( 8 ) and surfaces ( 2  and  3 ) located opposite one another, characterised in that the sheet material has, at a prespecified angle with respect to the surfaces ( 2  and  3 ), through-holes ( 4 ) from one surface ( 2 ) to the surface ( 3 ) located opposite, which taper conically; and the through-holes ( 4 ) have needle-point-shaped conical pins ( 5 ) or through-contacts ( 6 ) of electrically conducting material, whereas the sheet material ( 1 ) consists of insulating plastics material, wherein said points have ball like molded solder material extending said points.  
     
     
         2 . Sheet material according to  claim 1 , characterised in that the area density of the conically tapering pins ( 5 ) or through-contacts ( 6 ) is from 1×10 5  units per cm 2  to 1×10 7  units per cm 2 , preferably from 5×10 5  units per cm 2  to 1×10 6  units per cm 2 .  
     
     
         3 . Sheet material according to  claim 1  or  2 , characterised in that metallic points ( 8 ) of the pins ( 5 ) or through-contacts ( 6 ) project out from the sheet material ( 1 ) on one side.  
     
     
         4 . Sheet material according to one of  claims 1  to  3 , characterised in that the thickness (d) of the sheet material ( 1 ) is from 10 μm to 400 μm, preferably from 20 μm to 300 μm.  
     
     
         5 . Apparatus according to one of  claims 1  to  4 , characterized in that the needle-point-shaped, conically tapering pins ( 5 ) or through-contacts ( 6 ) have a rounding-off radius at the point ( 8 ) of from 20 nm to 100 nm.  
     
     
         6 . Sheet material according to one of  claims 1  to  5 , characterized in that the needle-shaped, conical pins ( 5 ) or through-contacts ( 6 ) have, in their base region ( 9 ), a diameter of less than 10 μm, preferably of from 1 μm to 5 μm.  
     
     
         7 . Use of the sheet material according to one of  claims 1  to  6 , characterised in that the sheet material ( 1 ) is used as connecting material ( 10 ) in the form of a connecting mat between structured conductor track surfaces of two electronic components and automatically provides coupling points by means of densely distributed, needle-point-shaped, conically tapering metallic pins or through-contacts ( 12 ) wherever conductor tracks ( 13 ) have oppositely located contact connection areas ( 14 ) and/or at locations where exposed conductor track areas ( 15 ) of the conductor tracks ( 13 ) of the two electronic components cross one another.  
     
     
         8 . Use of the sheet material according to one of the preceding claims as selectively electrically connecting material for an electronic component consisting of a plurality of stacked semiconductor devices, the sheet material ( 1 ) being arranged between the respective devices.  
     
     
         9 . Use of the sheet material according to one of  claims 1  to  6  as an electrically connecting intermediate layer ( 17 ) between a semiconductor chip ( 18 ) and a system carrier ( 19 ), the system carrier ( 19 ) having conductor tracks ( 13 ) with contact connection areas ( 14 ) and the chip ( 18 ) having contact areas ( 20 ), and the sheet material ( 1 ) establishing, by means of its pins ( 5 ) incorporated in an insulated arrangement, electrical connections between the contact areas ( 10 ) of the chip ( 19 ) and the contact connection areas ( 14 ) of the system carrier ( 19 ) which are located opposite.  
     
     
         10 . Use of the sheet material according to  claim 9 , characterised in that, for the establishment of contact, the sheet material ( 1 ) covers at least the entire surface ( 21 ) of the semiconductor chip ( 18 ) on its active side provided with contact areas ( 20 ), the conductor tracks ( 13 ) of the system carrier ( 19 ) and/or the contact connection areas ( 14 ) of the system carrier ( 19 ) being arranged opposite the contact areas ( 20 ) of the semiconductor chip ( 18 ).  
     
     
         11 . Sheet material according to one of  claims 1  to  5 , characterised in that the sheet material ( 1 ) has, on its surface ( 2 ) on the needle-base side, a metal coating connected to the base ends ( 22 ) of the conically tapering pins ( 5 ) or through-contacts ( 6 ).  
     
     
         12 . Sheet material according to  claim 1 , characterised in that the metallic material ( 25 ) for filling and for extending the points ( 8 ) is a solder ( 26 ).  
     
     
         13 . Sheet material according to one of  claims 11  to  12 , characterised in that the metal coating  23  on the surface ( 2 ) on the needle-base side has a conduction pattern ( 27 ).  
     
     
         14 . Sheet material according to one of  claims 11  to  12 , characterised in that the metal coating ( 23 ) has the conduction pattern ( 27 ) of a system carrier ( 19 ) having contact connection areas ( 14 ) for making contact with contact areas ( 20 ) of a semiconductor chip ( 18 ).  
     
     
         15 . Use of the sheet material according to  claim 13  or  claim 14  having a structured metal coating ( 28 ) and having needle-shaped, conically tapering pins ( 5 ) or through-contacts ( 6 ) embedded in a plastics layer ( 7 ), as a system carrier ( 19 ) for an electronic component ( 16 ) having a semiconductor chip ( 18 ) arranged on the system carrier ( 19 ).  
     
     
         16 . Use of the sheet material according to  claim 13  or  14  having a structured metal coating ( 28 ) and having needle-shaped, conically tapering pins ( 5 ) or through-contacts ( 6 ) embedded in a plastics layer ( 7 ), the points ( 8 ) of which are extended by means of solder material ( 26 ), for the production of electronic components ( 16 ) having a semiconductor chip ( 18 ) which is arranged on the sheet material ( 1 ) forming the system carrier ( 19 ) and connected to the solder material ( 26 ) by means of its contact areas ( 20 ).  
     
     
         17 . Sheet material of metal having metal points ( 8 ) and surfaces ( 31 ,  32 ) located opposite one another, characterised in that the sheet material ( 1 ) has, on at least one surface ( 2 ), needle-shaped pins ( 5 ), which protrude from the surface ( 2 ) of the sheet at a prespecified angle and have, in the base region ( 9 ) of the pins ( 5 ), a diameter of less than 10 μm, preferably of from 1 to 5 μm, wherein said points have ball like molded solder material extending said points.  
     
     
         18 . Sheet material according to  claim 17 , characterised in that the thickness (h) of the sheet material ( 1 ), without pins ( 5 ), is from 10 to 50 μm, and the pins ( 5 ) have a length (d) of from 10 μm to 400 μm, preferably from 20 μm to 300 μm.  
     
     
         19 . Sheet material according to one of  claim 17  to  18 , characterised in that the area density of the pins ( 5 ) is from 1×10 5  pins per cm 2  to 1×10 7  pins per cm 2 , preferably from 5×10 5  pins per cm 2  to 1×10 6  pins per cm 2 .  
     
     
         20 . Use of the sheet material ( 1 ) of metal according to one of  claims 17  to  19  for press-on contact areas in semiconductor technology.  
     
     
         21 . Use of the sheet material ( 1 ) of metal according to one of  claims 17  to  18  for electron emission components.  
     
     
         22 . Method for the production of a sheet material ( 1 ) having metal points ( 8 ) and having needle-shaped, conically tapering metallic pins ( 5 ) or through-contacts ( 6 ), which method comprises the following method steps: 
 irradiating a plastics sheet ( 7 ) with ion beams at a prespecified angle,    etching the ion beam tracks in the plastics sheet ( 7 ) to form needle-shaped, conically tapering through-holes ( 4 ) having a surface ( 3 ) on the needle-point side and a surface ( 2 ) located opposite on the needle-base side, wherein an etching solution acts onto the plastics sheet on one side at the needle base surface ( 2 ), and wherein an etching-stopping solution stops the etching process from the side of the needle top surface ( 3 ),    depositing a metal layer ( 29 ) on the surface ( 3 ) on the needle-point side of the etched sheet ( 7 ),    filling the through-holes ( 4 ) with metal pins ( 5 ) or metallic through-contacts ( 6 ) by means of electrodeposition of metal in the through-holes,    etching away the continuous metal layer ( 29 ) on the surface ( 3 ) on the needle-point side.    
     
     
         23 . Method for the production of a sheet material ( 1 ) of plastics material having metal points ( 8 ) and having needle-shaped points ( 8 ), which method comprises the following method steps: 
 irradiating the sheet material ( 1 ) with ion beams at a prespecified angle to the surface ( 2 ) of the sheet material ( 1 ),    etching the ion beam tracks in the sheet material ( 1 ) to form needle-point-shaped, conically tapering through-holes ( 4 ) having a surface ( 3 ) on the needle-point side and a surface ( 2 ) located opposite on the needle-base side, wherein an etching solution acts onto the plastics sheet on one side at the needle base surface ( 2 ), and wherein an etching-stopping solution stops the etching process from the side of the needle top surface ( 3 ),    depositing a metal layer ( 29 ) on the surface ( 3 ) on the needle-point side of the etched surface ( 7 ),    filling the through-holes ( 4 ) with metal pins ( 5 ) by means of electrodeposition of metal in the through-holes ( 4 ),    depositing a continuous metal layer ( 23 ) on the surface ( 2 ) on the base side,    etching the continuous metal layer ( 29 ) on the surface ( 3 ) on the needle-point side.    
     
     
         24 . Method according to  claim 23 , characterised in that, for exposure of the needle-shaped metallic points ( 8 ), with formation of a cavity ( 24 ) surrounding the points ( 8 ), the sheet material ( 1 ) is partially dissolved away on the surface ( 3 ) on the point side.  
     
     
         25 . Method according to  claim 23  or  claim 24 , characterised in that the metal coating  23  on the surface ( 2 ) on the needle-base side of the sheet material ( 1 ) is structured to form conductor tracks and/or contact connection areas.  
     
     
         26 . Method according to  claim 24  or  25 , characterized in that, for filling the cavities ( 24 ) or extending the points ( 8 ), a metallic material ( 25 ) is deposited at the exposed metallic metal points ( 8 ) by means of electrodeposition.  
     
     
         27 . Method according to one of  claims 24  to  26 , characterised in that a solder material ( 26 ) is deposited at the exposed needle-shaped metallic points ( 8 ).  
     
     
         28 . Method according to one of  claims 24  to  27 , characterized in that a solder material ( 26 ) is applied at the exposed needle-shaped metallic points ( 8 ) by means of a flow bath method.  
     
     
         29 . Method according to one of  claims 24  to  28 , characterised in that a solder material ( 26 ) is applied at the exposed needle-shaped metallic points ( 8 ) by means of an immersion bath method.  
     
     
         30 . Method for the production of a metal sheet having metal points ( 8 ) and having exposed needle-shaped pins ( 5 ), which method comprises the following method steps; 
 irradiating a plastics sheet ( 7 ) with ion beams at a prespecified angle,    etching the ion beam tracks in the plastics sheet ( 7 ) to form needle-point-shaped, conically tapering through-holes ( 4 ) having a surface ( 3 ) on the needle-point side and a surface ( 2 ) located opposite on the needle-base side, wherein an etching solution acts onto the plastics sheet on one side at the needle base surface ( 2 ), and wherein an etching-stopping solution stops the etching process from the side of the needle top surface ( 3 ),    depositing a metal layer ( 29 ) on the surface ( 3 ) on the needle-point side of the etched sheet,    filling the through-holes ( 4 ) with metal pins ( 5 ) by means of electrodeposition of metal in the through-holes ( 4 ),    applying a connecting metal layer to the surface ( 2 ) on the needle-base side,    etching the continuous metal layer ( 29 ) on the surface ( 3 ) on the needle-point side,    completely dissolving away the plastics sheet material ( 7 ) between the needle-shaped points ( 4 ).    
     
     
         31 . Method according to one of  claims 22  to  30 , characterised in that a plastics sheet ( 7 ), preferably of poly(bisphenol A carbonate), having a thickness (d) of from 10 μm to 400 μm is irradiated with heavy ions, preferably uranium U 238  ions.  
     
     
         32 . Method according to one of  claims 22  to  31 , characterised in that the heavy ions are accelerated to a kinetic energy of from 8 to 15 MeV.  
     
     
         33 . Method according to one of  claims 22  to  32 , characterised in that there is established an ion irradiation density of from 1×10 5  ions per cm 2  to 1×10 7  ions per cm 2 , preferably from 5×10 5  ions per cm 2  to  1 × 10   6  ions per cm 2 .  
     
     
         34 . Method according to one of  claims 22  to  33 , characterised in that, for etching the ion beam tracks in the plastics sheet ( 7 ), there is used a 6-molar sodium hydroxide solution containing 10% methanol by volume for etching the tracks of the ions at a temperature of from 310 to 320 K to form unilaterally arranged conical through-holes ( 4 ) within a period of from 5 to 16 hours, preferably of from 6 to 10 hours.  
     
     
         35 . Method according to one of  claims 22  to  34 , characterised in that 5% sulphuric acid is used as etching-stopping solution.  
     
     
         36 . Method according to one of  claims 22  to  35 , characterised in that an etching-stopping solution is subjected to a pressure differential of from 100 to 200 hPa with respect to atmospheric pressure.  
     
     
         37 . Method according to one of  claims 22  to  36 , characterized in that deposition of a continuous metal layer ( 29 ) on the surface ( 3 ) on the needle-point side of the etched sheet is carried out by means of sputtering, preferably sputtering of gold, and the sputtered layer is then made thicker by electrodeposition or electroplating using a copper alloy.  
     
     
         38 . Method according to one of  claims 22  to  37 , characterised in that the conical through-holes ( 4 ) are filled by means of electrodeposition of copper.  
     
     
         39 . Method according to one of  claims 24  to  36 , characterised in that exposure of the points ( 8 ) of the deposited metallic conical pins ( 5 ) is carried out by partially dissolving away the plastics sheet ( 7 ) using dichloromethane.  
     
     
         40 . Method according to one of  claims 30  to  39 , characterised in that the plastics sheet material ( 7 ) between the needle-shaped pins ( 5 ) on the metal coating ( 23 ) on the needle-base side is completely dissolved away using dichloromethane.