Forming tool for forming a contoured microelectronic spring mold

Abstract

A forming tool with one or more embossing tooth, and preferably, a plurality of such embossing teeth, arranged on a substantially planar substrate, is disclosed. Each embossing tooth is configured for forming a sacrificial layer to provide a contoured surface for forming a microelectronic spring structure. Each embossing tooth has a protruding area corresponding to a base of a microelectronic spring, and a sloped portion corresponding to a beam contour of a microelectronic spring. Numerous methods for making a forming tool are also disclosed. The methods include a material removal method, a molding method, a repetitive-stamping method, tang-bending methods, and segment-assembly methods.

1 - 34 . (Canceled)  
   
   
       35 : A method for making a microelectronic spring mold forming tool comprising: 
 providing a tool body comprised of tool material;    selectively removing tool material from said tool body to form an embossing surface, said embossing surface comprising at least one embossing tooth protruding from a face of said tool body, wherein an outer surface of said embossing tooth further defines a contour of a microelectronic spring structure.    
   
   
       36 : The method of  claim 35 , further comprising selecting said tool body comprised of a plastic material having a hardness exceeding the hardness of a mold material to be stamped by the forming tool.  
   
   
       37 : The method of  claim 35 , further comprising mounting said embossing surface to a base having an embossing face.  
   
   
       38 : The method of  claim 35 , wherein said selectively removing step comprises making a plurality of cuts in the tool material.  
   
   
       39 : The method of  claim 35 , wherein said selectively removing step comprises making a first plurality of parallel cuts in a first orientation and making at least a second plurality of parallel cuts in at least a second orientation, said first and second orientations being generally co-planar with said embossing surface.  
   
   
       40 : The method of  claim 39 , wherein said selectively removing step further comprises making the second plurality of cuts orthogonal to the first plurality of cuts.  
   
   
       41 : The method of  claim 39 , wherein said selectively removing step further comprises making selected ones of said first plurality of cuts of varying depth.  
   
   
       42 : The method of  claim 39 , wherein said selectively removing step further comprises applying a cutting tool to the tool material.  
   
   
       43 : The method of  claim 42 , wherein said selectively removing step further comprises applying a cutting tool comprising a mechanical cutter.  
   
   
       44 : The method of  claim 42 , wherein said selectively removing step further comprises applying a cutting tool comprising directed laser energy.  
   
   
       45 : The method of  claim 42 , wherein said selectively removing step further comprises applying a cutting tool comprising a shaped grinding wheel.  
   
   
       46 : The method of  claim 45 , wherein said selectively removing step further comprises rotating the grinding wheel about a grinding axis thereof, and moving the grinding wheel in grinding relation to the tool material to form at least one cut in a first orientation and making at least one second cut in at least a second orientation, said first and second orientations being generally co-planar with the embossing surface to be formed.  
   
   
       47 : The method of  claim 35 , wherein said providing step further comprises providing the tool body comprised of a gray scale photopatternable material, and wherein said selectively removing step further comprises exposing a surface of the photopatternable material to light through a gray scale mask.  
   
   
       48 : The method of  claim 47 , wherein said providing step further comprises providing the tool body comprised of a gray scale photopatternable glass.  
   
   
       49 : The method of  claim 35 , wherein said selectively removing step further comprises forming a plurality of embossing teeth having a height between about 5 and 100 mils.  
   
   
       50 : The method of  claim 35 , wherein said selectively removing step further comprises forming a plurality of embossing teeth, at least two of which are separated by less than about 20 mils.  
   
   
       51 : The method of  claim 35 , wherein said selectively removing step further comprises forming a plurality of embossing teeth, at least two of which are separated by less than about 3 mils.  
   
   
       52 : A microelectronic spring mold forming tool fabricated in accordance with the method of  claim 35 .  
   
   
       53 : A method for making a microelectronic spring mold forming tool having an embossing surface comprising a plurality of protruding embossing teeth, the method comprising: 
 providing a substrate comprised of a formable material;    forming a plurality of shaped impressions in a surface of the substrate;    depositing a layer of tool material on the surface of the substrate conforming to the shaped impressions; and    removing the layer of tool material from the substrate, whereby a surface of the tool material comprises an embossing surface having a plurality of embossing teeth defining contours of a plurality of microelectronic spring structures.    
   
   
       54 : The method of  claim 53 , wherein said forming step further comprises forming a plurality of shaped impressions, wherein each of the shaped impressions is configured to mold at least one embossing tooth having a protruding area, and a sloped portion receding from said protruding area defining a contour of a microelectronic spring structure.  
   
   
       55 : The method of  claim 54 , wherein said providing step further comprises providing the formable material comprised of a layer of impressionable material on a hard substrate.  
   
   
       56 : The method of  claim 54 , wherein said forming step further comprises impressing the formable material with a forming tool.  
   
   
       57 : The method of  claim 56 , wherein said forming step further comprises removing the forming tool after said impressing step, and repeating said impressing step and said removing step on a different portion of the substrate until a desired number of shaped impressions has been formed thereby.  
   
   
       58 : The method of  claim 56 , wherein said forming step further comprises curing the formable material while the forming tool is impressed thereon.  
   
   
       59 : The method of  claim 58 , wherein said forming step further comprises curing the formable material by beaming radiation through the forming tool.  
   
   
       60 : The method of  claim 56 , wherein said forming step further comprises curing the formable material by beaming UV light through the forming tool.  
   
   
       61 : The method of  claim 57 , wherein said forming step further comprises curing the formable material by beaming radiation through the forming tool after said impressing step and prior to said removing step.  
   
   
       62 : The method of  claim 53 , wherein said depositing step further comprises depositing a seed layer of a conductive material over the surface of the substrate, and electroplating the tool material onto the seed layer.  
   
   
       63 : The method of  claim 53 , wherein said depositing step further comprises selecting said tool material from a transparent material.  
   
   
       64 : The method of  claim 53 , wherein said providing step further comprises selecting said formable material from a radiation curable material.  
   
   
       65 : The method of  claim 53 , wherein said providing step further comprises providing the substrate comprised of a layer of photoresist material on a hard substrate, and the step of forming a plurality of shaped impressions comprises patterning the layer of photoresist material photolithographically.  
   
   
       66 : The method of  claim 53 , wherein said forming step further comprises forming the plurality of shaped impressions wherein each of the shaped impressions have a depth no greater than 100 mils.  
   
   
       67 : The method of  claim 53 , wherein said forming step further comprises forming the plurality of shaped impressions wherein the most proximately located ones of said shaped impressions are separated by a pitch between about 5 and 50 mils.  
   
   
       68 : The method according to  claim 53 , wherein said forming step comprises forming ones of said plurality of shaped impressions having a projected shape in a plane parallel to the surface of the substrate, the projected shape comprising a base end, a tip end, and a tapered portion between the base end and the tip end, wherein the tapered portion tapers from a first width adjacent to the base end to a second, narrower width adjacent to the tip end.  
   
   
       69 : The method according to  claim 53 , wherein said forming step further comprises forming a plurality of shaped impressions comprising shaped depressions, and then partially filling ones of the plurality of shaped depressions with a liquid presenting a meniscus shape, wherein the meniscus shape of the liquid defines a molding surface of the shaped depression.  
   
   
       70 : The method of  claim 69 , wherein said partially filling step comprises spin-coating the liquid over the surface of the substrate.  
   
   
       71 : The method of  claim 69 , wherein said partially filling step comprises spraying the liquid onto the surface of the substrate.  
   
   
       72 : The method of  claim 69 , wherein said partially filling step further comprises partially filling ones of the plurality of shaped depressions with the liquid, wherein the liquid is comprised of a photoresist material.  
   
   
       73 : The method of  claim 69 , wherein said partially filling step further comprises partially filling ones of the plurality of shaped depressions with the liquid, wherein the liquid is comprised of a curable polymer, and further comprising curing the polymer after said partially filling step.  
   
   
       74 : The method of  claim 73 , wherein said curing step further comprises heating the liquid to cure the polymer.  
   
   
       75 : The method of  claim 73 , wherein said curing step further comprises exposing the liquid to radiation to cure the polymer.  
   
   
       76 : The method of  claim 69 , further comprising solidifying the liquid by cooling after said partially filling step.  
   
   
       77 : The method of  claim 69 , wherein said partially filling step further comprises partially filling ones of the plurality of shaped depressions with the liquid, wherein the liquid comprises a solid in a liquid carrier, and further comprising solidifying the liquid by removing the liquid carrier after said partially filling step.  
   
   
       78 : A microelectronic spring mold forming tool fabricated in accordance with the method of  claim 53 .  
   
   
       79 : A method for making a microelectronic spring mold forming tool, the method comprising: 
 providing a fixture having a mounting surface, the mounting surface having a plurality of protrusions disposed thereon;    providing a sheet of resilient material having a plurality of spaced-apart, integral tangs co-planar with the sheet;    mounting the sheet of resilient material on the mounting surface of the fixture so that selected ones of the plurality of spaced-apart, integral tangs contacts selected ones of the plurality of protrusions to define a plurality of contoured tangs extending from the sheet;    fixing selected ones of said contoured tangs in an extended position; and removing said fixture from the sheet of resilient material.    
   
   
       80 : The method of  claim 79 , wherein said fixing step further comprises depositing a layer of fixative material on the sheet of resilient material.  
   
   
       81 : The method of  claim 80 , further comprising selectively removing a portion of the layer of fixative material from a side of the plurality of contoured tangs.  
   
   
       82 : The method of  claim 81 , wherein said first providing step further comprises selecting the sheet of resilient material comprised of a metal.  
   
   
       83 : The method of  claim 79 , wherein said second providing step further comprises selecting the sheet of resilient material comprised of a metal selected from the group consisting essentially of nickel, titanium, tungsten, cobalt, chromium, iron, aluminum, copper, zinc, tin, and alloys thereof.  
   
   
       84 : The method of  claim 79 , wherein said second providing step further comprises stamping a uniform sheet of resilient material to form the plurality of spaced-apart integral tangs.  
   
   
       85 : The method of  claim 79 , wherein said second providing step further comprises selectively etching a uniform sheet of resilient material to form the plurality of spaced-apart integral tangs.  
   
   
       86 : The method of  claim 79 , wherein said second providing step further comprises ablating a uniform sheet of resilient material to form the plurality of spaced-apart integral tangs.  
   
   
       87 : The method of  claim 80 , wherein said fixing step further comprises selecting the layer of fixative material comprised of materials selected from the group consisting essentially of polymethylmethacrylates, polycarbonates, polyurethanes, AAS plastics, photoresists, novolac resins, and epoxies.  
   
   
       88 : A microelectronic spring mold forming tool fabricated in accordance with the method of  claim 79 .  
   
   
       89 : A method for making a microelectronic spring forming tool having an embossing surface comprising a plurality of protrusions thereon, the method comprising: 
 providing a substrate having a surface;    depositing a layer of resilient material on the surface of the substrate;    patterning the layer of resilient material to define a plurality of plan forms, wherein ones of the plurality of plan forms are configured, viewed in a direction normal to the substrate surface, in the projected shape of a microelectronic spring structure, wherein each of the plan forms comprises a beam area portion and a base area portion;    generating a stress gradient in ones of the plurality of plan forms, whereby the beam area portions of the ones of the plurality of plan forms are deflected away from the surface of the substrate and the base area portions remain attached to the substrate and the plurality of plan forms are disposed in an extended position defining contours of microelectronic spring structures;    fixing selected ones of the plan forms in the extended position by depositing a fixative material covering the plurality of projected shapes; and    removing said substrate from the layer of fixative material.    
   
   
       90 : The method of  claim 89 , further comprising selectively removing a portion of the fixative material from a side of the plurality of plan forms.  
   
   
       91 : The method of  claim 89 , wherein said depositing step further comprises depositing the resilient material selected from the group consisting of nickel, cobalt, chromium, aluminum, copper, tin zinc, iron, and alloys thereof.  
   
   
       92 : The method of  claim 89 , wherein said depositing step further comprises depositing the resilient material comprised of a bi-layer composite of a first material, deposited on the surface of the substrate, and a second material, deposited on the first material.  
   
   
       93 : The method of  claim 92 , wherein said depositing step further comprises depositing the first material having a first rate of thermal expansion greater than a second rate of thermal expansion of the second material.  
   
   
       94 : The method of  claim 93 , wherein said generating step comprises heating the resilient material.  
   
   
       95 : The method of  claim 94 , wherein said generating step comprises bombarding the first material with ions.  
   
   
       96 : The method of  claim 89 , wherein said fixing step further comprises selecting the fixative material comprised of materials selected from the group consisting essentially of polymethylmethacrylates, polycarbonates, polyurethanes, ABS plastics, photoresists, novolac resins, and epoxies.  
   
   
       97 : A microelectronic spring mold forming tool fabricated in accordance with the method of  claim 89 .  
   
   
       98 : A method for making a microelectronic spring forming tool having an embossing surface comprising at least one protrusion thereon, the method comprising: 
 defining a plurality of cross-sectional shapes from a sequence of cross-sections taken through the embossing surface of the microelectronic spring forming tool;    forming a plurality of segments in a layer of material, wherein each segment is shaped according to one of the plurality of cross-sectional shapes; and assembling the plurality of segments in order of the sequence of cross-sections to form the embossing surface.    
   
   
       99 : The method of  claim 98 , wherein said forming step further comprises selectively etching a uniform sheet of resilient material to form the plurality of segments.  
   
   
       100 : The method of  claim 98 , wherein said forming step further comprises ablating a uniform sheet of resilient material to form the plurality of segments.  
   
   
       101 : The method of  claim 98 , wherein said forming step further comprises patterning a layer of photo-patternable material using a lithographic process to form the plurality of segments.  
   
   
       102 : The method of  claim 101 , wherein said forming step further comprises electroplating a metal onto the layer of photo-patternable material after said patterning step to form the plurality of segments.  
   
   
       103 : The method of  claim 98 , wherein said forming step further comprises stamping a uniform sheet of resilient material to form the plurality of segments.  
   
   
       104 : The method of  claim 98 , wherein said assembling step is performed by forming in sequence, in said forming step, each segment of the sequence of cross-sections assembled to a segment immediately preceding it in the sequence.  
   
   
       105 : A microelectronic spring mold forming tool fabricated in accordance with the method of  claim 98 .  
   
   
       106 . (Canceled)  
   
   
       107 : A method for making a microelectronic spring mold forming tool having an embossing surface comprising a plurality of protrusions thereon, the method comprising: 
 providing a substrate having a surface;    depositing a plurality of stand-offs on the surface of the substrate;    attaching a plurality of tangs to the plurality of stand-offs, wherein each of the plurality of tangs is attached, at a fixed end thereof, to at least one of the plurality of stand-offs, and has a free tip distal from the fixed end and an intermediate cantilevered portion between the fixed end and the free tip;    deflecting the free tip of each of the plurality of tangs towards the substrate; fixing the plurality of tangs in a deflected position; and    depositing a filler material between the plurality of tangs and the substrate.    
   
   
       108 : The method of  claim 107 , further comprising depositing the filler material in a layer covering the plurality of tangs and the substrate, and then selectively removing the filler material from everywhere except between the plurality of tangs and the substrate.  
   
   
       109 : The method of  claim 107 , wherein said depositing step further comprises depositing the stand-offs comprised of a material selected from the group consisting of nickel, cobalt, chromium, aluminum, copper, tin, zinc, iron, and alloys thereof.  
   
   
       110 : The method of  claim 107 , wherein said attaching step further comprises selecting the plurality of tangs comprised of a material selected from the group consisting of nickel, aluminum, copper, tin, zinc, iron, and alloys thereof.  
   
   
       111 : The method of  claim 107 , further comprising depositing a material comprising a stepped area disposed over the standoff.  
   
   
       112 : The method of  claim 107 , wherein said fixing step further comprises selecting the filler material comprised of materials selected from the group consisting essentially of polymethylmethacrylates, polycarbonates, polyurethanes, ABS plastics, photoresists, novolac resins, and epoxies.  
   
   
       113 : A microelectronic spring mold forming tool fabricated in accordance with the method of  claim 107.