Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F1/00—Springs
  • F16F1/36—Springs made of rubber or other material having high internal friction, e.g. thermoplastic elastomers
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
  • G01R1/02—General constructional details
  • G01R1/06—Measuring leads; Measuring probes
  • G01R1/067—Measuring probes
  • G01R1/06711—Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
  • G01R1/06716—Elastic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82B—NANOSTRUCTURES FORMED BY MANIPULATION OF INDIVIDUAL ATOMS, MOLECULES, OR LIMITED COLLECTIONS OF ATOMS OR MOLECULES AS DISCRETE UNITS; MANUFACTURE OR TREATMENT THEREOF
  • B82B1/00—Nanostructures formed by manipulation of individual atoms or molecules, or limited collections of atoms or molecules as discrete units
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
  • G01R1/02—General constructional details
  • G01R1/06—Measuring leads; Measuring probes
  • G01R1/067—Measuring probes
  • G01R1/073—Multiple probes
  • G01R1/07307—Multiple probes with individual probe elements, e.g. needles, cantilever beams or bump contacts, fixed in relation to each other, e.g. bed of nails fixture or probe card
  • G01R1/07314—Multiple probes with individual probe elements, e.g. needles, cantilever beams or bump contacts, fixed in relation to each other, e.g. bed of nails fixture or probe card the body of the probe being perpendicular to test object, e.g. bed of nails or probe with bump contacts on a rigid support
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L22/00—Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
  • G01R1/02—General constructional details
  • G01R1/06—Measuring leads; Measuring probes
  • G01R1/067—Measuring probes
  • G01R1/06711—Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
  • G01R1/06733—Geometry aspects
  • G01R1/06744—Microprobes, i.e. having dimensions as IC details
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
  • G01R1/02—General constructional details
  • G01R1/06—Measuring leads; Measuring probes
  • G01R1/067—Measuring probes
  • G01R1/06711—Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
  • G01R1/06733—Geometry aspects
  • G01R1/0675—Needle-like
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
  • G01R1/02—General constructional details
  • G01R1/06—Measuring leads; Measuring probes
  • G01R1/067—Measuring probes
  • G01R1/06711—Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
  • G01R1/06755—Material aspects
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R3/00—Apparatus or processes specially adapted for the manufacture or maintenance of measuring instruments, e.g. of probe tips
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/0001—Technical content checked by a classifier
  • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49004—Electrical device making including measuring or testing of device or component part
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49147—Assembling terminal to base
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49204—Contact or terminal manufacturing

Definitions

• Carbon nanotubes a material discovered in the early 1990s — have many desirable properties.
• carbon nanotubes can have desirable mechanical properties such as high stiffness, toughness, and resilience.
• carbon nanotubes can have desirable electrical properties such as electrical conductivity. Because of these and/or other properties, carbon nanotubes may be a promising material from which to construct probes for use in such applications as atomic force microscopes (see United States patent application US 2007/0051887). However, such probes are inherently weak in a vertical direction and can be easily deformed past the point of effective use when the probe comes into pressure contact with a surface which causes buckling or deformation the carbon nanotube.
• Resilient, compliant, deformable, or elastic probes (whether mechanical or electromechanical) are typically made of materials other than carbon nanotubes have been used in various applications.
• a group e.g., an array
• Such probes can be electrically conductive and can contact input and/or output terminals of an electronic device (e.g., a semiconductor die or dies) to establish temporary pressure based electrical connections with the electronic device through which test signals can be provided to the electronic device and response signals generated by the electronic device can be sensed. Through such testing, electronic devices can be evaluated to determine whether the devices function properly and/or rate operation of the devices.
• such probes can have one or more particular mechanical properties.
• such a probe can be compliant by compressing, deforming, bending, or otherwise moving in response to a force applied to a contact portion of the probe, and the probe can be resilient by generating a counter force in response to the force applied to the contact portion of the probe and then substantially returning to the original shape, position, or orientation of the probe after the applied force is removed from the contact portion of the probe. It can be desirable in some applications to tune the probes to have particular mechanical properties.
• Other mechanical properties such as toughness, durability, and consistency through repeated use over an extended period of time can also be desirable. For example, it can be desirable for such probes to withstand repeated compressions over extended periods of time without undergoing substantial changes in mechanical properties.
• the probing application is electrical, it can be desirable for such probes to have one or more particular electrical properties. For example, in some applications, it may be desirable that electrical probes have a low electrical resistance and/or a high current carrying capacity. Regardless of whether the probing application is electrical, it can be desirable for the probes to have other desirable properties such as manufacturability.
• the probes there may be a need to form the probes in a pattern (e.g., an array) in which the probes are spaced close to one another (e.g., the pitch or spacing between probes is small).
• a pattern e.g., an array
• the probes can be desirable for the probes to be able to withstand repeated use at extreme temperatures (e.g., high temperatures or low temperatures).
• extreme temperatures e.g., high temperatures or low temperatures.
• Some embodiments of the invention described below can, in some instances, aid in the production and/or use of probes comprising carbon nanotubes that have one or more of the foregoing desirable mechanical, electrical, manufacturability, or other properties.
• columns comprising a plurality of vertically aligned carbon nanotubes can be configured as an electromechanical contact structures or probes.
• the columns can be grown on a sacrificial substrate and transferred to a product substrate, or the columns can be grown on the product substrate.
• the columns can be treated to enhance mechanical properties such as stiffness, electrical properties such as electrical conductivity, and/or physical contact characteristics.
• the columns can be mechanically tuned to have predetermined spring properties.
• the columns can be used as electromechanical probes, for example, to contact and test electronic devices such as semiconductor dies, and the columns can make unique marks on terminals of the electronic devices.
• Figure IA illustrates exemplary columns of carbon nanotubes on a substrate according to some embodiments of the invention.
• Figures IB and 1C show one of the columns of carbon nanotubes in Figure IA.
• Figures 2-5A illustrate an exemplary floating catalyst process of making columns of carbon nanotubes according to some embodiments of the invention.
• Figures 6 and 7 illustrate an exemplary fixed catalyst process of making columns of carbon nanotubes according to some embodiments of the invention.
• Figures 8 and 9 illustrate an exemplary process of transferring columns of carbon nanotubes from a sacrificial substrate to another substrate according to some embodiments of the invention.
• Figure 10 illustrates another exemplary process of transferring columns of carbon nanotubes from a sacrificial substrate to another substrate according to some embodiments of the invention.
• Figures HA and HB illustrate columns of carbon nanotubes on a wiring substrate according to some embodiments of the invention.
• Figures 12-15 illustrate an exemplary process of making columns of carbon nanotubes in which the process includes transferring the columns to a substrate according to some embodiments of the invention.
• Figures 15A- 16 illustrate an exemplary process of growing columns of carbon nanotubes on a wiring substrate, anchoring the columns to the wiring substrate, and/or electrically connecting the columns to the wiring substrate according to some embodiments of the invention.
• Figures 17A-18B illustrate another exemplary process of growing columns of carbon nanotubes on a wiring substrate, anchoring the columns to the wiring substrate, and/or electrically connecting the columns to the wiring substrate according to some embodiments of the invention.
• Figure 19A illustrates an exemplary column of carbon nanotubes with an adhesive wicked throughout the column including into the contact end of the column according to some embodiments of the invention.
• Figure 19B illustrates an exemplary column of carbon nanotubes with an adhesive wicked into a base portion of the column; the contact end of the column has protruding structures according to some embodiments of the invention.
• Figure 20 illustrates treatment of the column of carbon nanotubes of Figure 19B to increase the number of protruding structures protruding from the contact end according to some embodiments of the invention.
• Figure 21 illustrates addition of a conductive material to the column of carbon nanotubes of Figure 20 according to some embodiments of the invention.
• Figures 22A and 22B illustrates an exemplary column of carbon nanotubes with a hollow space that can be filled with an electrically conductive material according to some embodiments of the invention.
• Figure 23A illustrates an exemplary column of carbon nanotubes with protruding structures formed at corners or other points generally along a perimeter of a contact end according to some embodiments of the invention.
• Figures 23B, 23C, 23D, and 23E illustrates exemplary methods for making the column of Figure 23 A according to some embodiments of the invention.
• Figure 24 illustrates an exemplary process of tuning a column of carbon nanotubes to have a particular spring property or properties according to some embodiments of the invention.
• Figure 25 illustrates an exemplary example of tuning a column of carbon nanotubes in accordance with the process of Figure 24 according to some embodiments of the invention.
• Figure 26 illustrates an exemplary test system that includes a contactor with probes comprising columns of carbon nanotubes according to some embodiments of the invention.
• Figure 27 illustrates an exemplary process for making a contactor in the form of a probe card assembly according to some embodiments of the invention.
• Figures 28-34 illustrate an example of the process of Figure 27 in which a probe card assembly shown in Figure 34 is made according to some embodiments of the invention.
• Figure 35 shows a perspective view of the contactor of Figure 26 with probes, which comprise columns of carbon nanotubes, in a pattern that corresponds to a pattern of terminals of the electronic device or devices to be tested according to some embodiments of the invention.
• Figure 36 illustrates an exemplary process for testing and further processing an electronic device or devices in a test system like the test system of Figure 26 according to some embodiments of the invention.
• Figures 37 and 38 illustrate exemplary contact of a probe of the contactor with a terminal of an electronic device of Figure 26 and a probe mark in the form of puncture marks made on the terminal by a probe treated as shown in Figure 20 to have protruding structures at a contact end of the probe according to some embodiments of the invention.
• Figures 40 illustrates an exemplary probe mark in the form of puncture marks left on the terminal by a probe like the probe of Figure 23A according to some embodiments of the invention.
• Figure 40 illustrates an exemplary probe mark in the form of carbon nanotube imprints on the terminal by a probe that generally lacks the protruding structures illustrated in Figure 20 at a contact end of the probe according to some embodiments of the invention.
• Figures 4 IA, 4 IB, and 41C illustrate exemplary semiconductor dies with probe marks on the terminals of the dies like probe marks shown in Figures 38-40.
• Figure 42 illustrates an exemplary prior art probe mark made by a prior art probe that wipes across a terminal of a die.
• Figures 43A and 43B illustrates an exemplary interposer that includes spring contact structures that can comprise columns of carbon nanotubes according to some embodiments of the invention.
• Figure 44 illustrates an exemplary semiconductor die that includes spring contact structures that can comprise columns of carbon nanotubes according to some embodiments of the invention.
• directions e.g., above, below, top, bottom, side, up, down, "x,” “y,” “z,” etc.
• directions are relative and provided solely by way of example and for ease of illustration and discussion and not by way of limitation.
• elements e.g., elements a, b, c
• such reference is intended to include any one of the listed elements by itself, any combination of less than all of the listed elements, and/or a combination of all of the listed elements.
• Figure IA illustrate an exemplary group of columns 104 comprising carbon nanotubes on a substrate 102 according to some embodiments of the invention.
• Substrate 102 can be a growth substrate, an intermediate substrate, or a product substrate, and substrate 102 can be a non- limiting example of a wiring substrate or a product substrate.
• Fifteen columns 104 are shown on substrate 102, but more or fewer columns 104 can be on substrate 102. Indeed, hundreds or thousands of columns 104 can be on substrate 102.
• carbon nanotubes can be fiber- like structures, which can be intertwined in a mass, and columns 104 can comprise an intertwined mass of a plurality of carbon nanotubes. Columns 104 can thus be referred to as carbon nanotube columns.
• an individual carbon nanotube can have a number of attributes including without limitation the following: the number of walls and the thickness of the wall(s) of the carbon nanotube, the diameter of the carbon nanotube, and the chirality (rolling angle) of the carbon nanotube.
• a group of carbon nanotubes intertwined to form a structure like columns 104 can have a number of attributes including without limitation the following: the average spacing between individual carbon nanotubes in the group, the average length of the carbon nanotubes in the group, and the alignment or orientation of the carbon nanotubes in the group.
• each column 104 can comprise vertically aligned carbon nanotubes.
• a column comprising vertically aligned carbon nanotubes can be termed a "vertically aligned" carbon nanotube column. Any of the columns of carbon nanotubes describe herein, including without limitation columns 104, can be vertically aligned carbon nanotube columns.
• a column e.g., column 104 of carbon nanotubes is "vertically aligned” if most (i.e., 50% or more) of the carbon nanotubes that compose the column form a continuous path along a length of the column that start at one end (e.g., end 108) of the column and end at an opposite end (e.g., end 106).
• Figures IB and 1C which illustrate side views of one of columns 104, illustrate examples. In Figures IB and 1C, a few carbon nanotubes 110 that compose a column 104 are illustrated. Column 104 can, however, comprise thousands or hundreds of thousands of such carbon nanotubes 110.
• the carbon nanotubes 110 that compose a column 104 can bend and/or twist and thus be intertwined one with another.
• Figure IB one of the carbon nanotubes HOa is highlighted, and as can be seen, carbon nanotube HOa begins and terminates at the ends 106, 108 of the column 104, and carbon nanotube HOa is continuous between ends 106, 108 (i.e., along a length L of column 104).
• End 106 can be a non- limiting example of a base end, a contact end, a first end, or a second end; end 108 can likewise be a non- limiting example of a base end, a contact end, a first end, or a second end.
• end 108 can likewise be a non- limiting example of a base end, a contact end, a first end, or a second end.
• FIG 1C another of the carbon nanotubes 110b is highlighted, and as can be seen, carbon nanotube 110b also begins and terminates at the ends 106, 108 of the column 104, and carbon nanotube HOb is continuous between ends 106, 108 (i.e., along a length L of column 104).
• Both carbon nanotubes 11 Oa and 11 Ob are thus “vertically aligned” according to the above definition, and as long as a majority (i.e., at least 50%) of the carbon nanotubes in a column 104 in Figure IA are also "vertically aligned," the column 104 can be termed a "vertically aligned carbon nanotube column.”
• a greater percentage than 50% of the carbon nanotubes in a column 104 can be vertically aligned.
• 60%, 70%, 75%, 80%, 90%, 95%, 98%, 99%, or a greater percentage of the carbon nanotubes that compose a column 104 can be vertically aligned.
• a single carbon nanotube can comprise a plurality of tubes that are grown directly one atop the other resulting in a continuous path.
• such tubes can be grown using a fixed catalyst growth method like the exemplary fixed catalyst methods discussed below.
• There are a number of processes for growing columns 104 which as mentioned above, can be vertically aligned carbon nanotube columns 104, and any known or future developed process can be used to grow columns 104.
• a floating catalyst process and a fixed catalyst process are two exemplary, non- limiting processes for growing columns 104.
• columns 104 can grow on a growth surface in the presence of a source of carbon and a catalyst.
• the columns 104 can be grown as vertically aligned carbon nanotube columns.
• Figures 2-5 illustrate a non-limiting example of a floating catalyst process of growing columns like columns 104 according to some embodiments of the invention.
• a substrate 202 can be provided.
• the substrate 202 can be any structure suitable for supporting the columns.
• suitable substrates 202 include a semiconductor wafer, a ceramic substrate, a substrate comprising an organic material, a substrate comprising an inorganic material, or any combinations thereof.
• a growth material 300 can be deposited on the substrate 202, or alternatively, the substrate 202 can be provided with growth material 300.
• a surface 302 of growth material 300 can be a growth surface 302 on which carbon nanotube columns can be grown.
• Growth material 300 can be any material suitable for growing carbon nanotube columns.
• material 300 can be any material with an oxide film or on which an oxide film can be formed so that growth surface 302 comprises an oxide.
• growth material 300 can be a silicon material, and growth surface 302 can comprise an oxide film on the silicon material. Elements 300 and 302 in Figure 3 can thus be distinct layers.
• substrate 202 can be a silicon substrate (e.g., a blank silicon wafer), in which case, substrate 202 and growth material 300 can be the same layer (i.e., the silicon substrate).
• Growth material 300 is not limited to materials with an oxide film.
• growth material 300 can be quartz.
• a masking layer 402 can be deposited onto the growth surface 302, and openings 404 can be formed in the masking layer 402 exposing selected areas of the growth surface 302.
• carbon nanotube columns (502 in Figure 5) can be grown on the areas of the growth surface 302 exposed through openings 404. Openings 404 can thus be in locations and patterns that correspond to desired locations and cross-sectional shapes of the carbon nanotube columns to be grown.
• the masking layer 402 can comprise any material or materials that can be deposited over growth surface 302 and have openings 404.
• masking layer 402 can comprise a photo reactive material (e.g., a photo resist material) that can be deposited in a blanket layer onto growth surface 302, after which selected portions of the photo reactive material can be cured by exposed to light and the uncured portions of the material removed to form openings 404.
• a photo reactive material e.g., a photo resist material
• suitable materials for masking layer 402 include any material that can be deposited in a pattern that includes openings 404 or deposited and then patterned to have openings 404. Gold is a non- limiting example of such a material.
• carbon nanotube columns 504 can be grown on areas of the growth surface 302 exposed through openings 404.
• the columns 504 can be grown by providing materials (e.g., a gas) comprising a catalyst and a source of carbon in the presence of proper ambient conditions.
• substrate 202 with growth surface 302 and masking layer 402 can be placed in an interior of an enclosure such as a furnace (not shown), and the interior of the enclosure can be heated and a gas comprising a catalyst and a source of carbon can be introduced (e.g., pumped) into the interior of the enclosure.
• a gas comprising a catalyst and a source of carbon can be introduced (e.g., pumped) into the interior of the enclosure.
• the specific catalyst material, carbon source material, and any other materials and the concentrations and mixtures of those materials as well as the specific ambient conditions (e.g., temperature) can be referred to as a "recipe," and any recipe suitable for growing carbon nanotubes on growth surface 302.
• Substrate 202 can be placed in a furnace (not shown), which can be heated to about 750° Celsius.
• a gas comprising xylene (CgHi 0 ) as a carbon source and ferrocene (Fe(CsHs) 2 ) as a catalyst can be mixed with a carrier gas (e.g., argon or another generally inert gas) and introduced (e.g., pumped) into the furnace (not shown).
• a carrier gas e.g., argon or another generally inert gas
• the ratio of ferrocene to xylene mixed with the carrier gas can be about one gram of ferrocene per one hundred milliliters of xylene, and the ferrocene/xylene mixture can be mixed with the carrier gas at a temperature of about 150° Celsius at a rate of about 6 milliliters per hour.
• the foregoing recipe can produce columns 504 that are vertically aligned columns.
• the foregoing recipe is exemplary only, and other materials comprising a catalyst and a source of carbon can be utilized.
• the growth surface 302 can be exposed to the foregoing catalyst and source of carbon at temperatures other than 750° Celsius.
• the exposure of the growth surface 302 to materials comprising a catalyst and a source of carbon at a particular temperature can cause columns 504 to grow from the areas of the growth surface 302 exposed through openings 404 in masking layer 402 as generally shown in Figures 5A and 5B. (Although two columns 504 are shown growing from substrate 202, more or fewer columns 504 can be grown from substrate 202.) As mentioned, columns 504 can be vertically aligned carbon nanotube columns. Columns 504 can be an example of columns 104 in Figure IA, and substrate 202 can be an example of substrate 102.
• any reference herein to columns 104 can include columns 504 as examples of columns 104
• any reference herein to substrate 102 can include substrate 202 as an example of substrate 102.
• the process illustrated in Figures 2-5B is thus one exemplary way in which columns 104 can be grown.
• Figures 6 and 7 illustrate a non-limiting example of a fixed catalyst process of growing columns like columns 104 according to some embodiments of the invention.
• a substrate 202 can be provided as in Figure 2 above.
• a buffer layer 602 can be deposited on substrate 202, and a patterned catalyst layer 604 can be formed on the buffer layer 602.
• buffer layer 602 can also be patterned.
• buffer layer 602 can be patterned to have generally the same or similar pattern as catalyst layer 604.
• the catalyst layer 604 can comprise catalyst material that, as generally discussed above, can cause growth of carbon nanotubes (which can be vertically aligned) in the presence of a source of carbon.
• the buffer layer 602 can provide a buffer between the substrate 202 and the catalyst layer 604.
• the buffer layer 602 can be any material that does not appreciably react with the catalyst material and/or the material that is the source of carbon.
• Aluminum oxide (Al 2 O 3 ) is a non-limiting example of a suitable buffer layer 602.
• Catalyst layer 604 can comprise a material that, in the presence of a source of carbon, causes growth of carbon nanotubes.
• Catalyst layer 604 can be formed by depositing catalyst material only on selected areas of buffer layer 602.
• catalyst layer 604 can formed by depositing catalyst material as a blanket layer of material on buffer layer 602 and then removing selected portions of the deposited catalyst material, leaving the catalyst material in a pattern and shapes that correspond to desired locations and cross-sectional shapes of the carbon nanotube columns to be grown on the catalyst layer 604 (e.g., as shown in Figure 6).
• carbon nanotube columns 704 can be grown on the patterned catalyst layer 604.
• Columns 704 can be grown by providing a material (e.g., a gas) comprising a source of carbon in the presence of proper ambient conditions.
• a material e.g., a gas
• substrate 202 with buffer layer 602 and catalyst layer 604 (as shown in Figure 6) can be placed in an interior of an enclosure such as a furnace (not shown), and the interior of the enclosure can be heated and a gas comprising a source of carbon can be introduced (e.g., pumped) into the interior of the enclosure.
• the specific material that composes the catalyst layer 604, the specific material that composes the source of carbon, and any other materials and the concentrations and mixtures of those materials as well as the specific ambient conditions (e.g., temperature) can be referred to as a "recipe," and any recipe suitable for growing carbon nanotubes on catalyst layer 604 can be used to grow columns 704.
• the catalyst layer 604 can comprise any transition metal.
• the catalyst layer 604 can comprise iron (Fe).
• the catalyst layer can comprise a layer of iron (Fe)
• buffer layer 602 can comprise aluminum oxide (AI 2 O 3 ).
• the thickness of an iron (Fe) film to a an aluminum oxide (AI 2 O3) film can be about 1.2 parts of iron (Fe) to 10 parts of aluminum oxide (AI 2 O3).
• Substrate 202 can be placed in a furnace (not shown), which can be heated to about 750° Celsius, and a hydrocarbon gas can be introduced into the furnace.
• the catalyst layer 604 can catalyze the growth of carbon nanotubes on the patterned catalyst layer 604 from carbon in the hydrocarbon gas.
• the furnace can be operated as follows. For about 10 minutes, while the furnace is at a temperature of about 0° Celsius, an inert gas (e.g., argon) can be pumped through the furnace at a flow rate of about 400 standard cubic centimeters per minute (seem).
• an inert gas e.g., argon
• the inert gas can continue to be pumped through the furnace at a flow rate of about 400 seem.
• a gas containing hydrogen H 2 can be mixed with the inert gas flowing through the furnace (not shown) at about 400 seem.
• the gas containing hydrogen can be H 2 /Ar in a ratio of about 40 parts of H 2 to about 15 parts of Ar.
• a source of carbon can be added to the inert gas flowing through the furnace while maintaining the furnace at 750° Celsius.
• the source of carbon can be a gas comprising C 2 ⁇ ZH 2 ZAr in a ratio of about 10 parts of C 2 H 4 , 40 parts of H 2 , and 10 parts of Ar, which can result in the growth of carbon nanotubes, as shown in Figure 7, on catalyst layer 604 from carbon in the gas.
• the columns 704 can grow from catalyst layer 604 as vertically aligned carbon nanotube columns.
• the foregoing recipe is exemplary only, and other materials can comprise the catalyst layer 604, and a different source of carbon can be utilized.
• the catalyst layer 604 can be exposed to the foregoing source of carbon at temperatures other than 750° Celsius.
• different gas mixtures, flow rates, and time periods can be used.
• the exposure of the catalyst layer 604 to a source of carbon at a particular temperature can cause columns 704 to grow from the catalyst layer 604 as generally shown in Figure 7.
• the columns 704 can be vertically aligned carbon nanotube columns.
• Columns 704 can be an example of columns 104 in Figure 1
• substrate 202 can be an example of substrate 102.
• any reference herein to columns 104 can include columns 704 as examples of columns 104
• any reference herein to substrate 102 can include substrate 202 as an example of substrate 102.
• the process illustrated in Figures 6 and 7 is thus another exemplary way in which columns 104 can be grown.
• the substrate on which the columns 104 are grown can be all or a portion of the product substrate on which the columns 104 are to be used in a final application.
• the substrate on which the columns 104 are grown can be a sacrificial substrate from which the columns can be transferred to an intermediate substrate or a product substrate.
• the "growth substrate" i.e., the substrate on which the columns are grown
• the columns can be transferred to an intermediate substrate or product substrate in any suitable manner.
• Figures 8 and 9 illustrate a non- limiting exemplary process of transferring columns 104 to another substrate.
• Figure 8 illustrates substrate 102 with columns 104 grown on substrate 102, for example, in accordance with one of the processes shown in Figures 2-5B or Figures 6 and 7.
• ends 106 of columns 104 can be brought into contact with an adhesive 804 (e.g., an adhesive material or a material comprising an adhesive) deposited on a substrate 802 to which the columns 104 are being transferred.
• Adhesive 804 can be, for example, an epoxy, which can be a curable epoxy.
• substrate 802 can be a product substrate on which the columns 104 will be used in their final application, or substrate 802 can be an intermediate substrate from which the columns 104 will later be transferred.
• Substrate 802 can be a non-limiting example of a wiring substrate.
• the substrate 102 can be peeled away or otherwise removed from columns 104.
• Adhesive 804 can be any material that adheres ends 106 of columns 104.
• adhesive 804 can be a material that bonds ends 106 of columns 104 to substrate 802 with a greater adhesive strength than columns 104 are attached to substrate 102.
• adhesive 804 can be a curable material that, while in an uncured state, can be in a generally liquid or semi-liquid or otherwise flowable or semi-flowable state.
• adhesive 804 can be electrically conductive.
• adhesive 804 can include electrically conductive materials.
• suitable adhesives 804 include epoxies such as electrically conductive epoxies.
• FIG. 10 illustrates a non-limiting variation.
• adhesive 804 (see Figure 8) can be patterned into deposits 804' of the adhesive 804.
• adhesive 804 can be selectively deposited only in the pattern of deposits 804' shown in Figure 10.
• adhesive 804 can be deposited in a blanket layer as shown in Figure 8, and selected portions of the adhesive 804 can be removed, leaving the deposits 804' of adhesive 804 shown in Figure 10.
• the deposits 804' of adhesive 804 can be in a pattern that corresponds to the pattern of ends 106 of columns 104, and ends 106 of columns 104 can be brought into contact with the deposits 804' of adhesive 804.
• the transfer of columns 104 to substrate 802 in Figure 10 can be like the transfer of columns 104 to substrate 802 as shown in Figures 8-9 and discussed above.
• the pattern of deposits 804' can be patterns other than squares (e.g., circles).
• a process of transferring columns 104 can include transferring the columns 104 to an electronic device in which the columns 104 can be electrically conductive interconnection structures (e.g., spring probes or other types of spring contact structures) that are attached and electrically connected to an electrical terminal, trace, or other conductive element on the electronic device.
• Figures HA and HB (which show respectively a perspective view and a cross-sectional side view) illustrate a non-limiting example.
• columns 104 can be attached, for example, a conductive adhesive 1104, to terminals 1106 (or other electrical elements) of a wiring substrate 1102 (which can be a product substrate), which can include internal wiring 1108 (e.g., electrically conductive traces and/or vias) to other terminals 1110 and/or electrical elements (not shown) such as circuit elements (e.g., integrated circuits, resistors, capacitors, transistors, etc.) (not shown).
• Wiring 1108 can be non- limiting examples of electrical connections.
• Wiring substrate 1102 can be or can be part of an electronic device (not shown) in which the columns 104 are to be used as resilient interconnection structures such as spring probes or other types of spring contact structures.
• Wiring substrate 1102 can be, for example, a wiring substrate such as a printed circuit board or a multiplayer ceramic wiring substrate. Additionally, wiring substrate 1102 can be a semiconductor die into which an electric circuit is integrated. Additionally, wiring substrate 1102 can be other types of substrates to which the columns can be attached (e.g., a semiconductor wafer). Moreover multiple wiring substrates 1102 can be combined in various ways with other wiring substrates 1102 (such as mounted or adhered to a holding or support structure) to form a composite wiring or product substrate (not shown). There are many ways in which columns 104 can be attached to terminals 1104. For example, substrate 802 in Figures 8-10 can be a sheet of conductive material (e.g., a conductive metal such as copper).
• substrate 802 Prior to attachment of columns 104 to substrate 802, for example as shown in Figures 8 and 9 or Figure 10, substrate 802 could have been attached to wiring substrate 1102.
• substrate 802 can initially have been an outer, conductive layer of wiring substrate 1102.
• portions of the substrate 802 can be removed (e.g., by etching), leaving terminals 1106, which can thus be remnants (or unremoved portions) of substrate 802.
• adhesive 1104 can be remnants of adhesive 804 in Figures 8 and 9 or deposits 804' of adhesive 804 in Figure 10.
• substrate 802 can be attached to wiring substrate 1102 after columns 104 are attached to substrate 802 as shown in Figures 8 and 9 or Figure 10, and then selective portions of substrate 802 can be removed to form terminals 1106 as discussed above.
• columns 104 can be transferred to terminals 1104 of wiring substrate 1102 generally as shown in Figure 10.
• substrate 802 in Figure 10 can be replaced with wiring substrate 1102, and the deposits 804' of adhesive 804 can be on terminals 1106 of wiring substrate 1102. (Nine terminals 1106 are shown but there can be more or fewer.)
• Ends 106 of columns 104 can then be brought into contact with the deposits 804' of adhesive 804 and substrate 102 peeled away from columns 104 as discussed above. If adhesive 804 is a curable material, deposits 804' can be cured before substrate 102 is peeled away from columns 104.
• Figure 12 illustrates substrate 202 with growth material 300 having a growth surface 302 as generally shown in Figure 3.
• a mass e.g., a continuous film or a continuous forest
• carbon nanotubes 1204 can be grown on the growth surface 302.
• carbon nanotubes can be grown in the same way that columns 504 are grown in Figures 5A and 5B as discussed above except masking layer 402 is not included, and the exposed area of growth surface 302 is not limited to openings 404 in masking layer 402.
• carbon nanotubes can grow from substantially all of the growth surface 302, producing the mass of carbon nanotubes 1204 shown in Figure 12.
• the carbon nanotubes that form mass 1204 can be vertically aligned, and mass 1204 can thus be a vertically aligned carbon nanotube mass.
• Mass of carbon nanotubes 1204 can, alternatively, be grown using other methods, which can include, for example, a fixed catalyst method such as the exemplary fixed catalyst method illustrated in Figures 6 and 7.
• growth material 300 in Figures 12-14 can be replaced with a buffer layer like buffer layer 602 and a catalyst layer like catalyst layer 604 shown in Figure 6 except that the catalyst layer can 604 can be a continuous blanket layer.
• Carbon nanotubes can then be grown from the catalyst layer as generally discussed above with respect to Figure 7, which can produce the mass of carbon nanotubes 1204.
• an end 1206 of the mass of carbon nanotubes 1204 can be brought into contact with deposits 804' of adhesive 804 on substrate 802 of Figure 10. Portions of the end 1206 of the mass of carbon nanotubes 1204 can thus be adhered to substrate 802 by the deposits 804' of adhesive on substrate 802.
• the deposits 804' of adhesive 804 can adhere to the mass of carbon nanotubes 1204 with greater adhesive strength than the mass of carbon nanotubes 1204 is adhered to substrate 202.
• columns 1404 of carbon nanotubes can be pulled out of and thus break away from the mass of carbon nanotubes 1204.
• the columns 1404 can correspond to the portions of the mass of nanotubes 1204 adhered to the substrate 802 by the deposits 804' of adhesive 804. Although nine columns 1404 are shown in Figure 14, more or fewer columns 1404 can be pulled from mass 1204.
• FIG. 12-14 is thus another exemplary process of making columns 104 in Figure 1, and columns 1404 can thus be an example of columns 104.
• Substrate 802 can be an example of substrate 102.
• any reference herein to columns 104 can include columns 1404 as examples of columns 104, and any reference herein to substrate 102 can include substrate 802 as an example of substrate 102.
• Columns 1404 can be attached to terminals 1106 in Figures 1 IA and 1 IB in any manner discussed above with respect to Figures HA and HB.
• FIGS 2-10 and 12-14 illustrate growth of columns 504 or 704 or 1404 (which are grown as part of mass 1204) on a sacrificial substrate 202
• carbon nanotube columns like columns 104 can alternatively be grown on a product substrate (e.g., the substrate on which the columns will be used in their final application.)
• Figures 15A- 16B illustrate an example in which columns 1604 of carbon nanotubes (which can be vertically aligned carbon nanotube columns) can be grown on a wiring substrate 1502 (which can be a product substrate).
• wiring substrate 1502 which can be the same as or similar to wiring substrate 1102, can comprises electrical terminals 1504 (four are shown but there can be more or fewer) that are electrically connected by internal wiring 1508 (e.g., electrically conductive traces and/or vias) to other terminals 1510 or to electrical elements (not shown) such as circuit elements (e.g., integrated circuits, resistors, capacitors, transistors, etc.) (not shown).
• electrical elements e.g., integrated circuits, resistors, capacitors, transistors, etc.
• Wiring 1508 can be non-limiting examples of electrical connections.
• columns 1604 can be grown on terminals 1504 using any of the processes or techniques described or mentioned herein for growing columns of carbon nanotubes.
• columns 1604 can be grown using the floating catalyst process illustrated in and described above with respect to Figures 2-5B.
• a material 1608 with a growth surface 1602 can be deposited onto terminals 1504.
• material 1608 can be the same as or similar to material 300 in Figures 3-5B
• growth surface 1602 can be the same as or similar to growth surface 302.
• Material 1608 can be deposited as a blanket material like material 300 in Figures 2-5B and masked with a masking layer like masking layer 402 with openings like openings 404 defining locations (e.g., over terminals 1504) where columns 1604 are to be grown.
• material 1608 can be patterned such that material 1608 is located only where (e.g., on terminals 1504) columns 1604 are to be grown. Columns 1604 can then be grown from the growth surface 1602 using a floating catalyst process such as the process described above with respect to Figures 5A and 5B. Columns 1604 can be vertically aligned carbon nanotube columns.
• the fixed catalyst process illustrated in Figures 6 and 7 is another example of a process that can be used to grow columns 1604 on terminals 1504.
• material 1608 can be a catalyst layer comprising a catalyst material.
• material 1608 can be the same as or similar to the material that composes catalyst layer 604 in Figures 6 and 7.
• a buffer layer (not shown in Figures 16A and 16B), which can be the same as or similar to buffer layer 602 in Figures 6 and 7, can be deposited between terminals 1504 and material 1608.
• Columns 1604 can then be grown from material 1608 (which in this example can be a catalyst layer) using a fixed catalyst process such as the process described above with respect to Figure 7.
• Columns 1604 can be vertically aligned carbon nanotube columns.
• anchoring structures 1606 can be provided around portions of columns 1604 as shown in Figures 16A and 16B.
• Anchoring structures 1606 can anchor columns 1604 to terminals 1504 and/or wiring substrate 1502 and can thus strengthen the attachment of columns 1604 to terminals 1504 and/or wiring substrate 1502. (Because terminals 1504 can be part of wiring substrate 1502, anchoring columns 1604 to terminals 1504 can be considered anchoring columns 1604 to wiring substrate 1502.)
• Anchoring structures 1606 can comprise any material suitable for deposit around end portions of columns 1604, and the material forming anchoring structures 1606 can be deposited in any suitable manner.
• anchoring structures 1606 can comprise an electrically conductive material that is electroplated onto terminals 1504 and a portion of columns 1604.
• anchoring structures 1606 can comprise a photo reactive material that is deposited as a blanket layer onto wiring 1502. The photo reactive material can be selectively hardened only around a portion of columns 1604, and the unhardened portions of the photo reactive material can be removed.
• anchoring structures 1606 can be the masking layer, in which case anchoring structures 1606 can be located over substantially all of wiring substrate 1502.
• a masking layer (not shown) can be selectively removed, leaving remnants of the masking layer that form anchoring structures 1606 as shown in Figures 16A and 16B.
• Anchoring structures 1606 can comprise other materials.
• anchoring structures 1606 can comprise a curable material that is deposited in a flowable or semiflowable state around columns 1604 and then hardened.
• the anchoring structures 1606 can be electrically conductive and can thus, in addition to anchoring columns 1604 to terminals 1504 and/or wiring substrate 1502, also electrically connect columns 1604 to terminals 1504.
• anchoring structures 1606 need not function to increase appreciably the strength of the attachment of columns 1604 to terminals 1504 and/or wiring substrate 1502 and thus need not be anchoring structures. In such a case, structures 1606 can serve solely or primarily to electrically connect columns 1604 to terminals 1504.
• anchoring structures 1606 function to increase the strength of the attachment of columns 1604 to terminals 1504 and/or wiring substrate 1502, to enhance the strength with which anchoring structures 1608 anchor columns 1604 to terminals 1504 and/or wiring substrate 1502, anchoring structures 1606 can be selected to have a different coefficient of thermal expansion than columns 1604. For example, anchoring structures 1606 can be selected to expand more per unit change in temperature than columns 1604. Anchoring structures 1606 can be deposited around end portions of columns 1604 at a temperature that is below ambient temperature so that as anchoring structures 1606 warm to ambient temperature, anchoring structures 1606 expand and thus "squeeze" columns 1604.
• Figures 17A-18B illustrate another exemplary process of growing carbon nanotube columns on a product substrate and anchoring the columns to the product substrate according to some embodiments of the invention.
• Figures 17A-18B also illustrate another exemplary process of electrically connecting carbon nanotube columns to other electrical elements on the product substrate according to some embodiments of the invention.
• Figures 17A and 17B illustrate an exemplary wiring substrate 1702 (which can be a product substrate and can be similar to wiring substrates 1102 and/or 1502).
• wiring substrate 1702 can comprise a plurality of electrical terminals 1704 (two are shown but there can be more or fewer), which can be electrically connected by internal wiring 1708 (e.g., conductive traces and/or vias) to other terminals 1710 and/or to electrical elements (not shown) such as circuit elements (e.g., integrated circuits, resistors, capacitors, transistors, etc.) (not shown).
• internal wiring 1708 e.g., conductive traces and/or vias
• circuit elements e.g., integrated circuits, resistors, capacitors, transistors, etc.
• Wiring 1708 can be non-limiting examples of electrical connections.
• pits 1705 can be formed (e.g., etched, cut, etc.) into wiring substrate 1702.
• columns 1804 of carbon nanotubes (which can be vertically aligned carbon nanotube columns) can be grown in pits 1705. Consequently, pits 1705 can be formed in locations where columns 1804 are to be grown.
• Columns 1804 can be grown in pits 1705 using any of the processes or techniques described or mentioned herein for growing columns of carbon nanotubes.
• columns 1804 can be grown using the floating catalyst process illustrated in Figures 2-5B and described above with respect to Figures 2-5B.
• growth material 1808 with a growth surface 1802 can be deposited in pits 1705.
• material 1808 can be the same as or similar to material 300 in Figures 3-5B
• growth surface 1802 can be the same as or similar to growth surface 302.
• Columns 1804 can then be grown from the growth surface 1802 using a floating catalyst process such as the process described above with respect to Figures 5 A and 5B.
• the fixed catalyst process illustrated in Figures 6 and 7 is another example of a process that can be used to grow columns 1804 in pits 1705.
• material 1808 can be a catalyst layer comprising a catalyst material.
• material 1808 can be the same as or similar to the material that composes catalyst layer 604 in Figures 6 and 7.
• a buffer layer (not shown in Figures 18A and 18B), which can be the same as or similar to buffer layer 602 in Figures 6 and 7, can be deposited between the bottom of pits 1705 and the material 1808 in the pits 1705.
• Columns 1804 can then be grown from the material 1808 (which in this example is a catalyst layer) using a fixed catalyst process such as the process described above with respect to Figure 7.
• the pits 1705 can anchor the columns 1804 to the wiring substrate 1702. That is, the fact that the columns 1804 are in pits 1705 in wiring substrate 1702 can aid in anchoring columns 1804 to wiring substrate 1702.
• anchoring structures 1806 can be formed on wiring substrate 1702 and around columns 1804 as shown in Figures 18A and 18B. Anchoring structures 1806 can further anchor columns 1804 to wiring substrate 1702 and can thus further strengthen the attachment of columns 1804 to wiring substrate 1702.
• Anchoring structures 1806 can comprise any material suitable for deposit onto wiring substrate 1702 and around columns 1804, and the material can be deposited in any suitable manner.
• anchoring structures 1806 can be like and can be formed or deposited like anchoring structures 1606 in Figures 16A and 16B.
• anchoring structures 1806 can be electrically conductive, and as shown in Figures 18A and 18B, anchoring structures 1806 can be electrically connected to electrically conductive traces 1807, which can electrically connect anchoring structures 1806 — and thus columns 1804 — to electrical elements on or in wiring substrate 1702.
• traces 1807 can connect anchoring structures 1806 — and thus columns 1804 — to terminals 1704.
• one or more of traces 1807 can connect an anchoring structure 1806 (and thus a column 1804) to an electric component such as a resistor, capacitor, or transistor on or in wiring substrate 1702.
• anchoring structures 1806 need not function to increase the strength of the attachment of columns 1804 to wiring substrate 1702 but can merely or primarily electrically connect columns 1804 to traces 1807.
• columns 1604 and 1804 can be examples of the columns 104 in Figure 1
• wiring substrates 1102, 1502 and 1702 can be examples of substrate 102 of Figure 1.
• any reference herein to columns 104 can include columns 1604 and/or columns 1804 as examples of columns 104
• any reference herein to substrate 102 can include wiring substrate 1102, wiring substrate 1502, and/or wiring substrate 1702 as examples of substrate 102.
• columns 1604 can be grown on a sacrificial substrate (e.g., as shown in Figures 2-5B or Figures 6 and 7) and transferred to wiring substrate 1502 (e.g., using any of the techniques shown or discussed above with respect to any of Figures 8-1 IB).
• a sacrificial substrate e.g., as shown in Figures 2-5B or Figures 6 and 7
• wiring substrate 1502 e.g., using any of the techniques shown or discussed above with respect to any of Figures 8-1 IB.
• columns 1604 can be adhered to terminals 1504 using an adhesive like adhesive 804 deposited on terminals 1504.
• columns 1804 can be grown on a sacrificial substrate (e.g., as shown in Figures 2-5B or Figures 6 and 7) and transferred to wiring substrate 1702 (e.g., using any of the techniques shown or discussed above with respect to any of Figures 8-1 IB).
• a sacrificial substrate e.g., as shown in Figures 2-5B or Figures 6 and 7
• wiring substrate 1702 e.g., using any of the techniques shown or discussed above with respect to any of Figures 8-1 IB.
• columns 1804 can be adhered in pits 1705 using an adhesive like adhesive 804 deposited in pits 1705.
• columns 104 can be treated to enhance one or more properties of the columns 104.
• columns 1604 and/or 1804 can be similarly treated as described below, the following discussion uses columns 104 for sake of simplicity.
• columns 104 can be treated to enhance the mechanical stiffness of the columns 104.
• columns 104 can be treated to enhance the electrical conductivity of the columns.
• contact portions of columns 104 can be treated to enhance contact properties of the columns 104.
• Figure 19A shows a detailed view of a column 104 after the column 104 has been adhered to transfer substrate 802 in accordance, for example, with one of the transfer processes discussed above and illustrated in Figures 8-10.
• end 106 of column 104 may have been placed in adhesive 804 (which is shown in partial view in Figure 19A) on substrate 802 (which is also shown in partial view in Figure 19A), adhesive 804 may have been cured, and substrate 102 may have been peeled away from column 104 as in Figures 8 and 9 or Figure 10.
• column 104 may have been transferred to a substrate or object other than substrate 802.
• column 104 may have been attached to terminals 1106 on wiring substrate 1102 by adhesive 1104 in which case adhesive 1104 can replace adhesive 804 in Figure 19A, and a terminal 1106 can replace substrate 802 in Figure 19A.
• column 104 can be attached by an adhesive like adhesive 804 to other substrates like substrate 802 or terminals or other elements or objects.
• column 104 can be comprise a plurality of carbon nanotubes a few of which are illustrated in Figure 19A as carbon nanotubes 110.
• adhesive 804 As adhesive 804 is cured, the adhesive 804 can be drawn by capillary action between individual carbon nanotubes 110 of column 104. In other words, adhesive 804 can "wick" between carbon nanotubes 110 and thus into column 104.
• the adhesive 804 can wick into column 104 starting at end 106 that is disposed in the adhesive 804, and the adhesive can then continue to wick up the column 104 towards an opposite end 108, which, in this example, can be a contact end 1904 (e.g., an end configured to make contact with an object such as a terminal of an electrical device).
• Contact end 1904 can be a non- limiting example of a first end or a second end.
• the distance up column 104 from end 106 that adhesive 804 wicks can depend on a number of factors including, without limitation, the amount of time adhesive 804 is cured, the viscosity of adhesive 804, ambient conditions such as temperature, air pressure, and/or other factors.
• a material that inhibits the spread of adhesive 804 through column 104 can be applied to all or part of column 104.
• parylene (not shown) can be applied (e.g., by chemical vapor deposition) to portions of column 104 to prevent adhesive 804 from spreading into those portions of column 104 or at least to impede or significantly slow the spread of adhesive 804 into those portions of column 104 where the parylene is applied.
• Figure 19A illustrates a non- limiting example according to some embodiments of the invention in which adhesive 804 can wick through all or substantially all of column 104.
• adhesive 804 can be considered to have wicked through substantially all of column 104 if adhesive 804 has wicked through 90% of the length of the column 104.
• the presence of cured adhesive 804 throughout or substantially throughout column 104 can significantly increase the mechanical stiffness of the column 104.
• the mechanical stiffness of column 104 can be 100, 200, 300, 400, 500, or more times greater than the mechanical stiffness of the column 104 without adhesive 804 wicked into the column 104.
• the increase in mechanical stiffness of column 104 can be less than 100 times.
• Figure 19B illustrates a non- limiting example in which adhesive 804 can have wicked only into the portion of column 104 that is near end 106.
• most of the column 104 is substantially free of adhesive 804, and the adhesive 804 is wicked only into a base portion of column 104 near end 106.
• the adhesive 804 can have little to no effect on the stiffness of column 104.
• the examples shown in Figures 19A and 19B are exemplary only, and many variations are possible.
• adhesive 804 can spread from end 106 any distance up column 104 to end 108.
• adhesive 804 can spread into column 104 from end 106 toward opposite end 108 2%, 5%, 10%, 20%, 40%, 60%, 80%, 90%, or 100% of the total length of column 104.
• adhesive 804 can spread into column 104 from end 106 less than 2% of the length of the column 104 or any percentage between the percentages give above.
• the farther adhesive 804 wicks up from end 106 into column 104 the greater the stiffness of column 104.
• column 104 can be treated to create protruding structures 1912 (which can be non-limiting examples of points, features, or structures) at contact end 1904 of column 104, which as discussed above, can be one of the ends 106, 108 (in this example end 108) of column 104 configured to make contact with an electrical device (not shown).
• Structures 1912 can comprise ends or end portions of ones (e.g., a cluster) of carbon nanotubes 110.
• contact end 1904 can be etched to create protruding structures
• Figure 20 illustrates a non-limiting example in which an etching mechanism 2002 can sputter etch contact end 1904 to produce protruding structures 1912 on contact end 1904.
• etching mechanism 2002 can be a sputter etching machine.
• contact end 1904 can be subjected to reactive ion etching to produce protruding structures 1912.
• etching mechanism 2002 can be a reactive ion etching machine.
• Other etching techniques can be used on contact end 1904 to produce structures 1912 or similar structures.
• Such other etching techniques can include without limitation wet etching techniques.
• techniques other than etching can be used to produce structures 1912.
• a mechanical grinding mechanism can be used to roughen the surface of contact end 1904, which can produce protruding-like structures 1912.
• mechanical imprinting techniques can be applied to contact end 1904 to create structures 1912.
• column 104 can also or alternatively be treated to enhance electrical conductivity.
• electrically conductive material can be applied to columns 104 in a number of ways.
• the electrically conductive material can be applied to the outer surface of the column 104, in still other embodiments the electronically conductive material can be applied to individual carbon nanotubes in a column 104, in still other embodiments the electrically conductive material can be dispersed throughout the column 104 (e.g., between individual carbon nanotubes), in still other embodiments, any combinations of the foregoing can be used.
• an electrically conductive material can be deposited generally on the outside of columns 104.
• electrically conductive material can be electroplated or otherwise deposited (e.g., sputtered) onto generally the outside of columns 104.
• electrically conductive material can be applied to individual carbon nanotubes, using for example, atomic layer deposition (ALD) or chemical vapor deposition (CVD) or in the spaces between the individual carbon nanotubes.
• ALD atomic layer deposition
• CVD chemical vapor deposition
• Figure 21 illustrates a column 104 after conductive material 2102 has been added to column 104.
• conductive material 2102 can be deposited on the individual carbon nanotubes or implanted between the individual carbon nanotubes within the column 104 in addition to or alternative to depositing conductive material 2102 generally on the outside of column 104.
• ALD atomic layer deposition
• CVD chemical vapor deposition
• conductive material 2102 can penetrate column 104 and be implanted on and/or around individual carbon nanotubes 110 and/or between individual carbon nanotubes 110 of column 104.
• a thickness of the material 2102 on individual carbon nanotubes 110 can be half or less than half of an average spacing between individual carbon nanotubes 110 that compose the column 104.
• Such treatment of individual carbon nanotubes can enhance the electrical and/or mechanical properties of the individual tubes while permitting the tubes to retain independent motion. For example, as mentioned, such treatment can increase electrical conductivity of column 104 and/or a stiffness of column 104.
• such treatment e.g., the presence of conductive material 2102 on, around, and/or between individual carbon nanotubes that compose column 104) can substantially not interfere with individual movement of ones of the carbon nanotubes with respect to others of the carbon nanotubes that compose column 104.
• a thickness of the material 2102 on individual carbon nanotubes 110 can be half or less than an average spacing between individual carbon nanotubes 110 that compose the column 104 can be half or less than half of the average spacing between carbon nanotubes 110 that compose the column 104, which can leave space between carbon nanotubes 110 that allows individual carbon nanotubes 110 to move with respect to each other.
• Conductive material 2102 can comprise any electrically conductive material and can have a greater electrical conductivity than the carbon nanotubes that compose column 104.
• suitable materials include gold, copper, and other electrically conductive metals as well as electrically conductive non-metals.
• Conductive material 2102 can, in addition to enhancing electrical conductivity of column 104, also enhance a stiffness of column 104.
• non-conductive material can be deposited within column 104 (e.g., on and/or around individual carbon nanotubes 110 and/or between carbon nanotubes 110 of column 104) in the same manner as described above with respect to depositing conductive material 2102.
• non-conductive material can be deposited to enhance a mechanical characteristics (e.g., stiffness) of a column 104.
• Such non-conductive material can be deposited in place of or in addition to conductive material 2102.
• Wicking conductive particles into column 104 can be another non-limiting example of a treatment for enhancing electrical conductivity of a column 104.
• a solution containing conductive particles can be wicked into a column 104.
• such a solution can be wicked into a column 104 using techniques and principles such as those discussed above with respect to wicking adhesive 804 into a column.
• such a solution can contain nano-size particles of a conductive material.
• such a solution can contain silver nanoparticles.
• the nano-sized conductive particles e.g., silver nanoparticles — can wick into a column 104 and lodge on and/or around and/or between ones of the carbon nanotubes 110 that compose the column 104. Those particles can thus enhance the electrical conductivity of the column 104.
• any one or more of the treatments discussed above for enhancing electrical conductivity of a column 104 can be applied to any column 104 regardless of how far from end 106 into column 104 adhesive 804 has wicked, and the treatment can also be applied to a column 104 into which no adhesive 804 has wicked.
• the treatment illustrated in Figure 21 by which conductive material 2102 is added to column 104 to enhance the electrical conductivity of column 104 can be applied to a column 104 regardless of whether the column 104 has been treated as shown in Figure 20 to create structures 1912.
• the structures 1912 shown in Figure 21 need not be present.
• columns 504, 704, 1404, 1604, 1804, 2204, 2304, and 2304' herein are examples of columns 104. Therefore, any one or more of the treatments illustrated in Figures 19A-21 can be applied to any of columns 504, 704, 1404, 1604, 1804, 2204, 2304, and 2304'.
• Figures 22A and 22B illustrates another exemplary process of enhancing the electrical conductivity of a column of carbon nanotubes.
• Figures 22 A and 22B shows a perspective view of a single column 2204, which is attached to a terminal 2206 of a substrate 2202.
• column 2204 can include a hollow portion 2208 (which can be a non-limiting example of an interior cavity), which as shown can extend the length of column 2204 from end 2220 to terminal 2206.
• column 2204 can be grown using any of the techniques described herein for growing columns of vertically aligned carbon nanotubes.
• Hollow portion 2208 can be formed in any suitable manner.
• column 2204 can be grown around a sacrificial plug structure (not shown).
• the process of making columns 504 shown in Figures 2-5B can be modified by placing a sacrificial plug structure in the shape and size of the hollow portion 2208 on part of the area of growth surface 302 exposed by an opening 404 in masking layer 402.
• Columns like columns 504 can then be grown from the area of growth surface 302 exposed by opening 404 and not covered by the sacrificial plug structure.
• Those columns can be like columns 504 except the center of those columns can comprise the sacrificial plug structure (not shown), which can be removed resulting in column 2204 with hollow portion 2208.
• the sacrificial plug structure (not shown) can be removed in any suitable manner including physically pulling the plug structure out of the column 2204 or etching or otherwise dissolving the sacrificial plug structure.
• any of the processes for growing columns of carbon nanotubes illustrated herein can be modified to grow a column of nanotubes around a sacrificial plug structure generally as described above to produce a column like column 2204 with a hollow portion 2208.
• column 2204 can be grown without hollow portion 2208 using any of the growth techniques described herein. Thereafter, hollow portion 2208 can be created by etching or cutting away part of the column.
• Carbon nanotubes (not shown) that compose column 2204 can be vertically aligned, and column 2204 can therefore be a vertically aligned carbon nanotube column.
• the hollow portion 2208 is shown with a square- type cross-section, other types of cross sections are equally contemplated. Regardless of how column 2204 is made, as shown in Figures 22A and 22B, the hollow portion 2208 can be filled with an electrically conductive material 2210, which can be any electrically conductive material 2210 that can be deposited into hollow portion 2208.
• conductive material 2210 can have a greater electrical conductivity than the carbon nanotubes 110 that compose column 104.
• conductive material 2210 can comprise a conductive material with a relatively low melting point that can be deposited into hollow portion 2208 while melted and then allowed to cool.
• conductive material 2210 can be solder.
• conductive material 2210 can be a curable material that is deposited into hollow portion 2208 in a flowable or semi-flowable state and then cured, causing the conductive material 2210 to harden inside hollow portion 2208.
• conductive material 2210 can be a curable conductive epoxy.
• Column 2204 can be an example of the columns 104 in Figure 1, and substrate 2202 can be an example of substrate 102.
• any reference herein to columns 104 can include column 2204 as an example of columns 104
• any reference herein to substrate 102 can include substrate 2202 as an example of substrate 102.
• any of columns 504, 704, 1404, 1604, 1804, 2204, 2304, and 2304' can be configured like column 2204 with a hollow portion 2208 that can be filled with a conductive material like 2210.
• the stiffness of column 2204 can be a function of cross-sectional area and length, whereas electrical conductivity imparted by treating the surface of a column of nanotubes can be a function of surface area.
• Figures 19-22B show one column 104 (or column 2204, which can be an example of column 104), the techniques illustrated in Figures 19-22B for enhancing mechanical stiffness, contact, and/or electrical conductivity properties of columns 104 can be applied to many columns 104. Moreover, the techniques illustrated in Figures 19-22B are exemplary only, and many variations and alternatives are possible.
• Figure 23 A illustrates an exemplary alternative enhancement of the contact properties of a column of carbon nanotubes according to some embodiments of the invention.
• Figure 23A illustrates a column 2304 of carbon nanotubes on a substrate 2300 (shown in partial view), which can be a sacrificial substrate, an intermediate substrate, or a product substrate.
• column 2304 can include peak structures 2312 (which can be non-limiting examples of protruding structures or points, features, or structures) at a contact end 2302 of the column 2304.
• peak structures 2312 can be at corners of contact end 2302 as shown in Figure 23A.
• peak structures 2312 can be in other locations of contact end 2302. Such other locations can be along or in proximity to an outer perimeter or periphery of contact end 2302.
• contact end 2302 can have more or fewer peak structures 2312.
• Peak structures 2312 can comprise ends of ones (or clusters) of the carbon nanotubes that compose column 2304.
• Peak structures 2312 can enhance contact properties of contact end 2302.
• contact end 2302 of column 2304 can be pressed against a terminal of an electronic device (not shown) and thereby make a temporary, pressure-based electrical connection with the electronic device.
• the peak structures 2312 can penetrate the terminal including any debris or layer (e.g., an oxide layer) on the terminal and thus enhance the ability of the contact end 2302 to contact the terminal.
• the presence of peak structures 2312 can effectively provide greater pressure against a terminal than a column that lacks peak structures for the same contact force between the column and the terminal, assuming that the columns have generally the same or similar cross-sectional areas.
• any method that produces structures like peak structures 2312 can be used to make column 2304.
• the floating catalyst method illustrated in Figures 2-5B or the fixed catalyst method illustrated in Figures 6 and 7 can be used to grow column 2304.
• the flow of gas containing a catalyst material and a source of carbon if the floating catalyst method is being used or a source of carbon if the fixed catalyst method is being used
• the flow of gas can be altered such that the flow of the gas directed at locations at the end of the column 2304 where peak structures 2312 are desired is increased without increasing the flow of gas to other portions of the end of the column 2304.
• the gas flow directed at other locations at the end of the column 2304 can be substantially decreased or stopped.
• One method for achieving this can be to move a template into position at the desired time where the gas can only flow through desired regions of the template to form the peak structures 2312.
• the concentrations of active ingredients in the gas directed at locations at the end of the column 2304 where peak structures 2312 are desired can be increased without increasing the concentration of the active ingredients in the flow of gas to other portions of the end of the column 2304.
• the foregoing can result in an increased growth rate of carbon nanotubes at the locations at the end of column 2304 where peak structures 2312 are desired.
• FIG. 23B-23E illustrate additional non- limiting examples of techniques for creating a column like column 2304 with peak structures like peak structures 2312 according to some embodiments of the invention.
• Figures 23B and 23C illustrate use of a mechanical imprinting stamp 2330 (which can be a non- limiting example of a molding tool) that can be used to form peak structures 2312.
• a stamp 2330 comprising a mold head 2332 (which can be a non-limiting example of a mold) with the inverse (or negative) shape of the desired peak structures 2312 can be placed over column 2304 and pressed against the end 2302 of column 2304, which as best seen in Figure 23C (which shows a side, cross-sectional view of column 2304 and stamp 2330), can imprint peak structures 2312 into end 2302 of column 2304.
• Figures 23D and 23E illustrate a technique in which a column 2304' like column 2304 can be grown from a growth material 2306 that can be patterned to have a central portion 2309 and one or more extensions 2307 extending from the central portion 2309. (Four extensions 2307 are shown but more or fewer can be used.)
• Column 2304' can be grown on growth material 2306 (which can be like growth material 300 in Figure 3 or catalyst layer 604 in Figure 6) using any of the processes for growing columns of carbon nanotubes disclosed herein including without limitation the processes shown in Figures 2-7. It has been found that the column 2304' can grow generally uniformly from the central portion 2309 of growth material 2306 but can grow at a faster rate on extensions 2307 and in particular near tips of extensions 2307.
• peak structures 2312' can tend to form at corners of column 2304', the corners of column 2304' corresponding to tips of extensions 2307.
• the faster growth at the corners of column 2304' can result in peak structures 2312' as shown in Figure 23E, which can be generally similar to peak structures 2312.
• column 2304 can be an example of the columns 104 in Figure 1
• substrate 2300 can be an example of substrate 102.
• any reference herein to columns 104 can include column 2204 as an example of columns 104
• any reference herein to substrate 102 can include substrate 2300 as an example of substrate 102.
• Columns of carbon nanotubes like columns 104, and in particular vertically aligned carbon nanotube columns can have spring properties. For example, upon application of a force (an applied force) to a free end of a column 104, the column 104 can compress, bend, deform, or move and also generate an opposing force that opposes the applied force. Upon removal of the applied force, the column 104 can substantially recover its original shape and/or position or at least recover a portion of its original shape and/or position (e.g., column 104 can be elastically deformable).
• a force an applied force
• the column 104 can compress, bend, deform, or move and also generate an opposing force that opposes the applied force.
• the column 104 can substantially recover its original shape and/or position or at least recover a portion of its original shape and/or position (e.g., column 104 can be elastically deformable).
• Columns of carbon nanotubes like columns 104 can be tuned to have one or more particular spring properties.
• a column can be tuned by applying a tuning force of a particular level to the column, and the tuning force can impart one or more spring properties that have a value or values that correspond to the level of the tuning force.
• the column will substantially maintain the tuned properties in response to application of forces to the column that are less than the tuning force. If a force that is greater than the original tuning force is applied to the column, the greater force can retune the column, changing the spring properties to correspond to the greater force.
• Figure 24 illustrates an exemplary process 2400 for tuning one or more columns of carbon nanotubes according to some embodiments of the invention.
• the process 2400 of Figure 24 is illustrated and discussed below as tuning a spring constant (also known as k-value or stiffness) of columns 104.
• the process 2400 is not, however, limited to tuning the spring constant of columns 104, nor is the process 2400 limited to tuning spring properties of columns 104. Rather, process 2400 can be used to tune other spring properties of columns 104 or other types of carbon nanotube structures.
• data relating several levels of tuning forces to values or ranges of values for one or more spring properties can be obtained.
• data can be obtained experimentally.
• a column e.g., column 104) of a particular type (e.g., made using a particular growth recipe, having a particular size and shape, etc.) can be used to experimentally obtain data relating particular tuning force levels to particular values or ranges of values for one or more spring properties of that column type.
• a first tuning force can be applied to an experimental column (not shown), which can be like column 104, in a direction that is generally parallel with a length of the column 104. After the first tuning force is applied to the experimental column, tests can be performed on the experimental column to determine values of one or more spring properties.
• tests can be performed on the experimental column to measure its spring constant and the elastic range in which the spring constant is valid.
• the level of the first tuning force can then be noted and associated with the measured spring constant and elastic range.
• a second tuning force that is greater than the first tuning force can be applied to the experimental column, and the resulting spring constant and elastic range of the column can again be measured.
• the level of the second tuning force can then be noted and associated with the measured spring constant and elastic range.
• Table 1 illustrates experimental spring constant and elastic range data for a column 104 made using the exemplary recipe described in paragraph [0051] above.
• a column 104 can be selected as an "experimental” column to which successive tuning forces will be applied to determine the resulting spring constant and elastic range each tuning force imparts to the column 104.
• This selected column 104 can be termed “experimental” because this particular column 104 will be used to obtain the foregoing data rather than as a final working column 104 that will be integrated into a product (e.g., like contactor 2606, which will be discussed with respect to Figure 26 or probe card assembly 3400, which will be discussed with respect to Figure 34).
• the experimental column 104 After applying an initial tuning force of 0.6 grams to a free end (e.g., an end of the column that is configured to move or displace in response to an applied force) of the column 104 selected to be an experimental column, the experimental column 104 was found to have a spring constant of approximately 0.17 grams/micron within an elastic range of 0-5 microns of displacement of the free end. Similarly, after applying another tuning force of 0.7 grams to the free end of the experimental column 104, the experimental column 104 was found to have a spring constant of approximately 0.12 grams/micron within an elastic range of 0-10 microns of displacement of the free end. This process was then repeated with tuning forces of 0.8 grams, 0.9 grams, 1.0 grams, and 1.1 grams of force and the resulting spring contact and elastic range data in Table 1 below was obtained.
• Table 1 is exemplary only and provided solely for purpose of discussion and illustration. Such data can vary for different types of columns. For example, the data can vary based on the recipe used to make the columns the size of the columns, the shape of the columns, etc.
• working columns of the same general type as the experimental column can be tuned to have particular values of the spring properties. These columns can be termed "working” because these columns will be used in products (e.g., like contactor 2606, which will be discussed with respect to Figure 26 or probe card assembly 3400, which will be discussed with respect to Figure 34).
• the working columns of carbon nanotubes should be generally similar to and of the same general type as the experimental column used at 2402.
• the working columns can be made using the same or a similar recipe, generally the same or similar size, and/or generally the same or similar shape as the experimental column used to obtain the data at 2402.
• a particular value or range of values of spring constant can be selected at 2404.
• the experimental data obtained at 2402 can be consulted to determine a tuning force level that is most closely associated with the values or ranges of values of spring constant selected at 2404.
• the tuning force selected at 2406 can be applied to the working columns, which can impart to the working columns a spring constant that is approximately equal to the desired value of spring constant selected at 2404.
• Figure 25 illustrates a non-limiting example of 2404, 2406, and 2408 in process 2400 of Figure 24 in which a column 104 on substrate 102 (see Figure 1) can be tuned using the data in Table 1 above.
• Figure 25 also illustrates exemplary behavior of the column 104 after the column 104 is tuned.
• Column 104 in Figure 25 can be any of the columns discussed herein and identified as an example of column 104, or any other column mentioned herein, such as columns 504, 704, 1404, 1604, 1804, 1904, 2204, 2304, and/or 2304'.
• Substrate 102 (and/or respective substrates for columns 504, 704, 1404, 1604, 1804, 1904, 2204, and/or 2304) can be a sacrificial substrate, an intermediate substrate, or a product substrate and can be the growth substrate on which column 104 was grown or can be a substrate to which column 104 was transferred from a growth substrate.
• Substrate 102 can thus be any of the substrates identified herein as an example of substrate 102.
• the tuning process illustrated in Figure 25 can be performed on column 104 before or after any anchoring structure 1606 and/or 1806 is formed around column 104 and before or after any treatment of column 104 illustrated in Figures 19B-22.
• Figure 25 includes partial views of substrate 102 showing one column 104. As can be seen in Figure 1, however, a plurality (from two to hundreds, thousands, or hundreds of thousands or more) of columns 104 can be on substrate 102, and each column can be tuned (simultaneously, sequentially, or in groups).
• Numerals 2500, 2520, and 2540 in Figure 25 illustrate column 104 in various states during a tuning process in which a tuning force F T is applied (e.g., in a direction that is generally parallel to a length of the column) to a free end 2506 (which can be a non-limiting example of a contact end) of column 104, and numerals 2560 and 2580 in Figure 25 illustrate tuned column 104 responding to a working force Fw applied to the free end 2506 generally in a direction that is parallel to a length of the column 104.
• a tuning force F T is applied (e.g., in a direction that is generally parallel to a length of the column) to a free end 2506 (which can be a non-limiting example of a contact end) of column 104
• numerals 2560 and 2580 in Figure 25 illustrate tuned column 104 responding to a working force Fw applied to the free end 2506 generally in a direction that is parallel to a length of the column 104.
• Free end 2506 can be an end of column 104 that can move in response to an applied force, and free end can thus be end 104 or 106 depending on the specific configuration of column 104 and can correspond to a contact end (e.g., like contact end 1904).
• Numeral 2500 illustrates column 104 in an initial state 2500 before a force has been applied to free end 2506. In initial state 2500, however, column 104 may have already undergone any one or more of the treatment processes illustrated, discussed, or mentioned herein including without limitation the treatment processes illustrated in Figures 19B-22B. Alternatively, in initial state 2500, column 104 may have undergone none of the treatment processes illustrated, discussed, or mentioned herein including without limitation the treatment processes illustrated in Figures 19B-22B.
• a desired spring constant can be selected for column 104.
• the desired spring constant can be selected based on the end or product uses of the columns. For example, it may be determined that, given the particular end or product use of the columns 104, a spring constant of 0.10 grams/micron is desired.
• a tuning force F T that will impart to column 104 a spring constant that is or is approximately 0.10 grams/micron can be determined.
• this can be accomplished by consulting Table 1 above, which shows that applying a tuning force F T of approximately 0.8 grams to free end 2506 of column 104 can tune column 104 to have a spring constant of 0.10 grams/micron within an elastic range of 0-15 microns of displacement of the free end 2506. Then at 2408 of process 2400, the tuning force F ⁇ can be applied to free end 2506 of column 104.
• state 2520 shows column 104 with tuning force F T applied to free end 2506.
• application of the tuning force F ⁇ can compress column 104 and cause reversibly deformable regions 2522 to form along a length of column 104, which can be generally perpendicular to the length of the column 104.
• three regions 2522 are shown on a column 104 in Figure 25, there can be more than three such regions 2522 on a column 104 or less than three regions 2522 on a column 104.
• Buckles or buckling regions in column 104 can be non-limiting examples of reversibly deformable regions 2522.
• the tuning force F ⁇ can be applied to free end 2506 in a direction that is generally parallel to a length of column 104, which in some embodiments can be generally perpendicular to a surface of substrate 102 to which column 104 is attached.
• column 104 can compress in a direction that is generally parallel to the direction of the tuning force F T , which can be generally parallel to the length L of the column 104 and generally perpendicular to the surface of substrate 102 to which column 104 is attached.
• the reversibly deformable regions 2522 can be generally perpendicular to the length L of column 104.
• the greater the tuning force F T the greater the number of reversibly deformable regions 2522 that form.
• Each reversibly deformable region 2522 can have spring properties and can function as an individual spring.
• a plurality of such reversibly deformable regions 2522 along the length of column 104 can function like a plurality of springs in series, and the spring properties of the column 104 can comprise a series sum of the spring properties of the deformable regions 2522.
• a spring constant of column 104 can comprise a series sum of the spring constants of each of the deformable regions 2522.
• k sum is the series sum of the spring constants of a first spring with a spring constant k a , a second spring with a spring constant k b , a third spring with a spring constant k c , and an "nth" spring with a spring constant k n .
• Reversibly deformable regions 2522 along with inherent spring properties of column 104 can be non- limiting examples of a spring mechanism or mechanisms in the column between free end 2506 and the end (which can be a non- limiting example of a base end) of column that is attached to substrate 102. Although shown grouped together, the reversibly deformable regions 2522 need not be adjacent to each other. As mentioned, buckles and/or buckling regions can be non-limiting examples of reversibly deformable regions.
• the tuning force F ⁇ can compress column 104 and displace free end 2506 an initial compression distance 2526, which can be a difference between an initial position 2508 of free end 2506 prior to application of the tuning force F T and a position 2524 of free end 2506 upon application of the tuning force F ⁇ .
• State 2540 shows column 104 after removal of the tuning force F ⁇ .
• free end 2506 can move to a recovery position 2542, due at least in part to the spring action of reversibly deformable regions 2522.
• the distance 2546 free end 2506 moves to the recovery position 2542 can represent the elastic recovery of column 104, and the distance between recovery position 2542 and the initial position 2508 can represent plastic deformation 2544 of column 104 in response to the tuning force F T .
• Column 104 is now tuned to have a particular spring constant. In the non- limiting example being discussed, column 104 is assumed to have the properties illustrated in Table 1 above, and as discussed above, the tuning force F T applied to the column was 0.8 grams. Per Table 1 above, column 104 can now have a spring constant of 0.10 grams/micron within an elastic range of 0-15 microns of displacement.
• column 104 can function as a spring with a spring constant of 0.10 grams/micron within an elastic range of 0-15 microns of displacement of free end 2506. As long as forces less than the tuning force F T (e.g., in this example, less than 0.8 grams) are applied to free end 2506, column 104 can maintain a generally constant spring constant of 0.10 grams/micron. States 2560 and 2580 in Figure 25 illustrate an example in which a working force Fw that is less than the tuning force F T is applied to free end 2506.
• the working force Fw can cause column 104 to compress generally in a direction that is parallel to the length L of the column 104 (e.g., reversibly deformable regions 2522 compress), which can move free end 2506 from position 2542 to position 2562.
• free end 2506 of column 104 can move substantially back to position 2542 and thus undergo substantial elastic recovery.
• Column 104 can continue to undergo substantial elastic recovery (e.g., move substantially back to position 2542) in response to repeated applications and then removals of a working force Fw that is less than the tuning force F T .
• a force greater than the tuning force F T applied to free end 2506 can function as a new tuning force, which can create an additional reversibly deformable region or reversibly deformable regions 2522 along the length of column 104, which can change the spring constant.
• a new tuning force to free end 2506 of 1.0 grams or approximately 1.0 grams can cause column 104 to have a spring constant of 0.08 grams/micron or approximately 0.08 grams/micron within an elastic range of 0-25 microns displacement or approximately 0-25 microns displacement.
• column 104 can react to application of working forces that are less than the new tuning force generally as shown in states 2560 and 2580 in Figure 25.
• FIGs of carbon nanotubes like columns 104 which as discussed above, can be vertically aligned carbon nanotube columns, can be used in many applications.
• columns 104 can be electromechanical spring probes in a test system for testing devices, such as electronic devices.
• Figure 26 illustrates an exemplary test system 2600 according to some embodiments of the invention in which electromechanical probes 2610 comprise columns of carbon nanotubes like columns 104.
• test system 2600 can include a tester 2602 configured to control testing of one or more electronic devices under test (DUTs) 2614.
• DUTs electronic devices under test
• a plurality of communications channels 2604 and a contactor 2606 can provide a plurality of electrical paths for power and ground and test, response, and other signals between the tester 2602 and DUT 2614.
• Tester 2602 can test DUT 2614 by generating test signals that are provided through communications channels 2604 and contactor 2606 to ones of terminals 2616 of DUT 2614. The tester 2602 can then evaluate response signals generated by DUT 2614 in response to the test signals. The response signals can be sensed at ones of terminals 2616 of DUT 2614 and provided to the tester 2602 through contactor 2606 and communications channels 2604.
• Tester 2602 can comprise electronic control equipment such as one or more computers or computer systems.
• Contactor 2606 can comprise an electrical interface 2608, electrically conductive spring probes 2610, and electrical connections 2618 (e.g., electrically conductive traces and/or vias on or in contactor 2606) through contactor 2606 between the electrical interface 2608 and the probes 2610.
• a layout and number of the probes 2610 can correspond generally to a layout and number of terminals 2616 of DUT 2614 so that ones of probes 2610 can contact ones of terminals 2616 and thereby make pressure-based electrical connections with the ones of the terminals 2616.
• DUT 2614 can be disposed on a moveable chuck 2612, which can move DUT 2614 to align ones of terminals 2616 with ones of probes 2610 and then move DUT 2614 such that the aligned terminals 2616 and probes 2610 are brought into contact with enough force to establish electrical connections between the aligned probes 2610 and terminals 2616.
• contactor 2606 can be moved.
• Electrical interface 2608 which can comprise an electrical interface to channels 2604 — can be connected to communications channels 2604, which can comprise electrical paths to and from tester 2602.
• While electrical interface 2608 is connected to communications channels 2604 and probes 2610 are in contact with terminals 2616, the communications channels, contactor 2606 (including electrical interface 2608 and probes 2610) can provide a plurality of electrical paths between the tester 2602 and terminals 2616 of DUT 2614. Additionally, one or more intermediary substrates (not shown) can be disposed between probes 2610 and contactor 2606.
• DUT 2614 can be one or more dies of an unsingulated semiconductor wafer, one or more semiconductor dies singulated from a wafer (packaged or unpackaged), one or more dies of an array of singulated semiconductor dies disposed in a carrier or other holding device, one or more multi-die electronics modules, one or more printed circuit boards, and any other type of electronic device or devices.
• DUT 2614 in Figure 26 can thus be one or more of any of the foregoing devices or similar devices.
• a semiconductor die can comprise a semiconductor material into which an electric circuit is integrated, and terminals 2616 can be bond pads that provide electrical connections to and from the electric circuit.
• probes 2610 can comprise columns of carbon nanotubes, which can be vertically aligned nanotube columns.
• probes 2610 can comprise columns 104, which can be columns 104 made using any process described herein (e.g., columns 504, 704, 1404, 1604, 1804, 2204, 2304, and 2304') and can also include columns 104 after any one or more of the treatments described herein (e.g., as shown in any of Figures 19A-22B).
• columns 104 that compose probes 2610 can be anchored to contactor 2606 and/or electrically connected to a terminal or other electrical element of contactor 2606 in any manner described herein including any one or more of the examples shown in Figures 1 IA, 1 IB, and 15A-18B.
• Figure 27 illustrates an exemplary process 2700 of making contactor 2606 with probes 2610 comprising columns of carbon nanotubes according to some embodiments of the invention
• Figures 28-34 illustrate an exemplary implementation of process 2700 in which an exemplary contactor 2606 in the form of a probe card assembly 3400 with probes that comprise columns 104 can be made.
• process 2700 is not limited to making a contactor 2606 in the form of a probe card assembly 3400 or a contactor 2606 with probes 2610 that comprise columns 104.
• process 2700 can be used to make a contactor 2606 with probes 2610 comprising other types of columns of carbon nanotubes.
• columns of carbon nanotubes can be obtained at 2702.
• Obtaining columns at 2702 can comprise obtaining previously grown columns, or obtaining the columns at 2702 can comprise growing the columns.
• Figure 28 illustrates a non-limiting example of 2702 of Figure 27.
• obtaining columns 2702 can comprise obtaining columns 104 on substrate 102, which can be the growth substrate on which columns 104 were grown or can be an intermediate substrate to which columns 104 were transferred and on which columns 104 are transported or shipped.
• the columns obtained at 2702 can be transferred to a wiring substrate at 2704 (which can be a non-limiting example of arranging the columns on a first wiring substrate).
• the transferring at 2704 can be accomplished using any of the transfer processes described herein including the transfer processes illustrated in Figures 2-5B and Figures 6 and 7.
• Figures 29 and 30 illustrate a non- limiting example in which columns 104 are transferred from substrate 102 to a wiring substrate 2902, which can comprise electrically conductive terminals 2904 on one surface, electrically conductive terminals 2906 on an opposite surface, and electrical paths 2908 (e.g., traces and/or vias) on and/or through wiring substrate 2902.
• adhesive 804 can be deposited on terminals 2904, and ends 106 of columns 104 can be brought into contact with the adhesive 804 generally as shown, for example, in Figure 10.
• adhesive 804 can be a curable, electrically conductive adhesive.
• adhesive 804 can be cured.
• adhesive 804 can be cured by heating the adhesive 804, by allowing the adhesive 804 to be exposed to ambient air for a particular period of time, or any other suitable manner.
• substrate 102 can be peeled away from columns 104, which can be accomplished generally in the same manner as discussed above with respect to Figure 9. The peeling away of substrate 102 shown in Figure 30 can occur after adhesive 804 is cured.
• adhesive 804 can wick into columns 104.
• transferring columns 104 from substrate 102 to wiring substrate 2902 at 2704 in Figure 27 can result not only in columns 104 being attached at ends 106 to terminals 2904 of wiring substrate 2902 but can also result in each column 104 comprising adhesive 804 wicked into the column 104.
• adhesive 804 can wick only a short distance into column 104 along the length of column 104, adhesive 804 can wick into column 104 along all or substantially all of the length of column 104, or adhesive can wick a distance into column 104 that is between the foregoing extremes.
• adhesive 804 is shown wicked only a short distance into columns 104 generally as shown in Figure 19B.
• pits e.g., like pits 1705 in Figures 17A and 17B
• columns 104 can be adhered to wiring substrate 2902 in the pits (not shown).
• adhesive 804 can be deposited in the pits (not shown), and ends 106 of columns 104 can be inserted into the pits (not shown). The adhesive 804 can then be cured and substrate 102 can be peeled away from columns 104 as discussed above.
• 2704 of Figure 27 can alternatively can accomplished by transferring columns 104 to wiring substrate 2902 using any of the examples discussed above respect to Figures HA and HB.
• wiring substrate 2902 in Figures 28-34 can thus effectively be replaced with wiring substrate 1102 of Figures 1 IA and 1 IB.
• 2702 and 2704 of Figure 27 can be replaced by actions in which columns 104 are grown on wiring substrate 2902.
• columns 104 can be grown on wiring substrate 2902 in the same or similar way as columns 1604 are grown on wiring substrate 1502 in Figures 15A-16B, or columns 104 can be grown on wiring substrate 2902 in the same or similar way as columns 1804 are grown on wiring substrate 1702 in Figures 17A-18B.
• wiring substrate 2902 in Figures 28-34 can thus effectively be replaced with wiring substrate 1502 of Figures 15A-16B or wiring substrate 1702 of Figures 17A-18B.
• columns 104 can be obtained at 2702 attached to wiring substrate 2902, for example, as shown in Figure 31.
• columns 104 can be treated to enhance one or more properties of columns 104.
• contact ends 1904 can be treated — e.g., etched such as by reactive ion etching or sputter etching — to create structures 1912 protruding from contact ends 1904.
• electrically conductive material can be deposited on (e.g., on the outside of) and/or embedded within columns 104 as generally shown in and discussed above with respect to Figure 21. As discussed above, the foregoing can enhance the electrical conductivity of columns 104.
• columns 104 can be grown with or made to have a hollow portion like the hollow portion 2208 of column 2204 shown in Figures 22A and 22B, and the hollow portion can be filled with an electrically conductive material (e.g., like material 2210 in Figures 22A and 22B), which can alternatively or in addition enhance the electrical conductivity of columns 104.
• an electrically conductive material e.g., like material 2210 in Figures 22A and 22B
• Figure 31 illustrate a non-limiting example in which conductive material is embedded on or within columns 104 (e.g., on and/or around individual carbon nanotubes and/or between individual carbon nanotubes that compose a columns 104) using atomic layer deposition or chemical vapor deposition or a similar technique as generally discussed above with respect to Figure 21.
• the presence of conductive material on or embedded within columns 104 is indicated by the dark shading of columns 104 in Figure 31. This can make columns 104 generally like column 104 shown in Figure 21.
• contact ends 1904 of columns 104 in Figure 31 can have protruding structures like structures 1912 shown in Figure 20.
• actions can be taken at 2708 to anchor the columns to the wiring substrate, and/or actions can be taken to electrically connect columns to the terminals of the wiring substrate at 2708.
• a non- limiting example is shown in Figure 32, which shows anchoring structures 3202 provided or formed on wiring substrate 2902 and around columns 104.
• anchoring structures 3202 can be like, and can be made like, anchoring structures 1606 in Figures 16A and 16B.
• Anchoring structures 3202 can be electrically conductive and can thus electrically connect, or enhance an electrical connection between, columns 104 and terminals 2904 on wiring substrate 2902.
• anchoring structures 3202 can be like anchoring structures 1806 show in Figures 18A and 18B, which as shown in Figure 18A and 18B, can connect to electrically conductive traces (e.g., like traces 1807 in Figures 18A and 18B) on wiring substrate 2902.
• electrically conductive traces e.g., like traces 1807 in Figures 18A and 18B
• columns 104 are disposed in pits (e.g., like pits 1705 in Figures 17A and 17B) that are spaced away from terminals 2904 (e.g., like pits 1705 are spaced away from terminals 1704 in Figures 17A and 17B)
• such traces can electrically connect anchoring structures 3202 — and thus columns 104 — to terminals 2904 on wiring substrate 2902.
• one or more spring properties of the columns can be tuned at 2710.
• one or more spring properties of columns 104 can be tuned in accordance with the tuning techniques illustrated in and discussed above with respect to Figures 24 and 25.
• a tuning force that will impart one or more desired spring properties to columns 104 can be determined at 2406 as generally discussed above with respect to Figure 24, and the selected tuning force can be applied (e.g., as in 2408 of Figure 24) to contact ends 1904 of columns 104 to impart to the columns 104 the desired spring properties.
• columns 104 can be tuned to have a particular spring constant value (or a spring constant value that is within a desired range of spring constant values) by applying a particular tuning force to the contact ends 1904 of the columns 104.
• the tuning force can be applied to each column 104 individually.
• Figure 33 which illustrates a non-limiting example according to some embodiments — a generally planar surface 3304 of a plate 3302 can be pressed against contact ends 1904 of columns 104 with the selected tuning force F ⁇ , which can apply the tuning force F T simultaneously to contact ends 1904 of a plurality (including all or less than all) of columns 104.
• contact ends 1904 of columns 104 can be located generally in a plane in space that corresponds to a plane of surface 2608.
• the wiring substrate can be combined at 2712 with one or more components to form contactor 2606.
• Figure 34 shows a non-limiting example in which wiring substrate 2902 is combined with an interface substrate 3402 and electrical interconnectors 3406 to form a probe card assembly 3400, which can be a non- limiting example of the contactor 2606 of the test system 2600 in Figure 26.
• interface substrate 3402 can comprise a board or other substrate structure with electrical interface 2608 to communications channels 2604 (see Figure 26), and interface substrate 3402 can comprise wiring 3412 (e.g., electrically conductive traces and/or vias on or in the interface substrate 3402) through interface substrate 3402 to electrical interconnectors 3406.
• Interface substrate 3402 can be, for example, a printed circuit board or other type of wiring board.
• Electrical interconnectors 3406 can be any electrical connectors that can electrically connect ones of wiring 3412 and terminals 2906 of wiring substrate 2902. In some embodiments, electrical interconnectors 3406 can be flexible or compliant. Non-limiting examples of electrical connectors 3406 include electrical wires, electrically conductive springs, and solder. Other non-limiting examples of interconnectors 3406 include electrically conductive posts, balls, pogo-pins, and bump structures.
• An interposer (e.g., like interposer 4300 shown in Figures 43A and 43B) is yet another non-limiting example of electrical interconnectors 3406.
• An interposer can, in some embodiments, comprise a wiring substrate (e.g., 4302 of Figures 43A and 43B) that can be disposed between interface substrate 3402 and wiring substrate 2902.
• a first set of electrically conductive spring contacts (e.g., like 104 extending from one side of 4302 in Figures 43A and 43B) can extend from the interposer wiring substrate (not shown) to wiring 3412, and a second set of electrically conductive spring contacts (e.g., like 104 extending from the other side of 4302 in Figures 43 A and 43B) can extend from the interposer wiring substrate to terminals 2906 on wiring substrate 2902.
• the first set of electrically conductive spring contacts can be electrically connected (e.g., by 4308 in Figure 43B) through the interposer wiring substrate to the second set of electrically conductive spring contacts.
• Wiring substrate 2902 which together with terminals 2906 and probes 2610 comprising columns 104 can compose a probe head 3410 — can be attached to the interface substrate 3402 by brackets 3408.
• wiring substrate 2902 can be attached to interface substrate 3402 by other means including without limitation screws, bolts, clamps, and/or other types of fasteners.
• wiring substrate 2902 can be attached to another component of probe card assembly 3400 (e.g., a stiffener plate (not shown) or an attachment structure by which probe card assembly 3400 is attached to or mounted in or on a test housing (not shown)).
• probe card assembly 3400 can comprise a plurality of probe heads like probe head 3410, and the position or orientation of one or more of the probe heads (e.g., like probe head 3410) can be independently adjustable. If electrical interconnectors 3406 are flexible, electrical interconnectors 3406 can maintain electrical connections between wiring 3412 and terminals 2906 even as a position or orientation of probe head 3410 (or multiple probe heads 3410 if probe card assembly 3400 has multiple probe heads 3410) is adjusted or changed with respect to interface substrate 3402.
• probe card assembly 3400 can be an example of contactor 2606 and can thus be used as contactor 2606 in test system 2600.
• Probes 2610 of probe card assembly 3400 can make pressure based electrical connections with terminals 216 of DUT 2614 as, for example, chuck 2612 moves ones of terminals 2616 into contact with ones of probes 2610 (e.g., columns 104 in Figure 34).
• Probe card assembly 3400 in Figure 34 is exemplary only, and many variations are possible.
• wiring substrate 1102 in Figures 1 IA and 1 IB can be substituted for wiring substrate 2902 in Figure 34.
• columns 104 can be grown on wiring substrate 2902 rather than being transferred from substrate 102 to wiring substrate 2902.
• 2702 and 2704 in process 2700 of Figure 27 can be replaced with actions of growing columns 104 on terminals 2906 of wiring substrate 2902.
• the process illustrated in Figures 15A-16B can be used to grow columns 104.
• wiring substrate 2902 in probe card assembly 3400 of Figure 34 can be replaced with wiring substrate 1502 with columns 1604 (in place of columns 104 in Figure 34) as shown in Figures 16A and 16B.
• the process illustrated in Figures 17A- 18B can be used to grow columns 104.
• wiring substrate 2902 in probe card assembly 3400 of Figure 34 can be replaced with wiring substrate 1702 with columns 1804 (in place of columns 104 in Figure 34) as shown in Figures 18A and 18B.
• Process 2700 of Figure 27 is exemplary only and many variations are possible.
• the order of 2702, 2704, 2708, 2710, and/or 2712 can be changed in some embodiments.
• 2710 can be performed before 2704, 2706, and/or 2708.
• 2708 can be performed before 2706.
• 2712 can be performed before 2706, 2708, and/or 2710.
• the probe card assembly 3400 shown in Figure 34 is but one example of a contactor 2606 (see Figure 26).
• Contactor 2606 can take other forms.
• contactor 2606 can comprise a flexible membrane contactor.
• contactor 2606 can consist essentially of wiring substrate 2902.
• wiring substrate 2902 can be contactor 2606.
• terminals 2906 can be electrical interface 2608 in Figure 26, and columns 104 can be probes 2610.
• Many other variations are possible.
• FIG. 35 which shows a perspective view of wiring substrate 2606 with columns 104 as probes and a partial perspective view of DUT 2514 with terminals 2516 (which can be, for example, bond pads), illustrates examples of such advantages.
• contact ends 1904 which as mentioned above can correspond to end 106 or end 108 of columns 104 of columns 104 (which compose probes 2610) can be disposed in a pattern that corresponds to a pattern of ones of terminals 2516 on DUT 2514.
• a pitch 3512 and/or 3514 of terminals 2516 can be defined as a distance (corresponding to 3512 and/or 3514) between centers of adjacent terminals 2516 as shown in Figure 35.
• a pitch 3502 and/or 3504 of columns 104 can similarly be defined as a distance (corresponding to 3502 and/or 3504) between centers of contact ends 1904 of adjacent columns 104 as also shown in Figure 35.
• a pitch 3502 of columns 104 can be approximately equal (e.g., within an acceptable tolerance or margin of error) to a pitch 2512 of terminals 2516.
• each column 104 can move (e.g., compress, buckle, deform, etc.) substantially only generally along a vertical axis 3420 that is oriented along a length of the column 104 in response to contact with a terminal 2516, which can product a force on contact ends 1904 that can be generally parallel with vertical axis 3420 (which can be generally parallel with the lengths of columns 104).
• vertical axis 3420 can also be generally perpendicular to the surface of wiring substrate 2902 from which columns 104 extend, which can also be generally perpendicular to the surface of DUT 2514 on which terminals 2516 are disposed.
• Vertical axis 3420 can also be generally parallel to a direction of a force against contact end 1904 of a probe 2610 arising from contact between the probe 2610 and a terminal 2516. Because movement of contact ends 1904 is substantially only along vertical axis 3420, a pitch 3502 and/or 2504 of columns 104 can be significantly smaller (or tighter) than probes (not shown) whose movement in response to contact with terminals (e.g., like terminals 2516) of a DUT (e.g., like DUT 2514) includes a substantial component that is not along vertical axis 3420. This is because any component of the movement of adjacent probes that is perpendicular to vertical axis 3420 can cause contact portions of the adjacent probes to move toward each other.
• a minimum pitch for such probes typically must be greater than the amount of movement of the contact portions of adjacent probes towards each other; otherwise, contact portions of adjacent probes could contact each other.
• a pitch 3502 and/or 3504 at least as small (or tight) as twenty microns can be achieved for columns 104 shown in Figure 35, which means that columns 104 shown in Figure 35 can contact a DUT 2514 with terminals 2516 with a pitch 3512 and/or 3514 as small (or tight) as twenty microns.
• a pitch 3502 and/or 3504 of less than twenty microns can be achieved for columns 104 shown in Figure 35.
• test system 2600 of Figure 26 and test process 3600 of Figure 36 can be and can operate generally the same as shown and described.
• Figure 36 illustrates an exemplary process 3600 for testing DUTs (e.g., like DUT 2614) in a test system like test system 2600 of Figure 26.
• DUTs e.g., like DUT 2614
• one or more DUTs can be placed on a stage at 3602.
• one or more DUTs 2614 can be placed on stage 2612 of test system 2600 of Figure 26.
• ones of probes 2610 which as discussed above can comprise columns 104 as shown in Figures 34 and 35
• ones of terminals 2516 of DUT 2614 can be brought into contact at 3604.
• stage 3602 can be moved to align ones of terminals 2516 with ones of probes 2610, and stage can then be moved to bring the aligned ones of terminals 2516 and probes 2610 into contact with each other.
• contactor 2606 can be moved. The foregoing contact between the ones of probes 2610 and terminals 2516 can establish temporary, pressured based electrical connections between the ones of probes 2610 and terminals 2516.
• This contact between the ones of the probes 2610 and the ones of the terminals 2516 can generate a force on probes 2610 (and thus columns 104) at contact end 1904 that is generally parallel with a length of columns 104, which can cause the columns 104 to deform elastically and in a direction that is generally parallel to the length of the column and the direction of the force.
• DUT 2514 can be tested at 3606.
• tester 2602 in Figure 26 can send power and ground and test signals to circuitry integrated into DUT 2514 through communications channels 2604 and contactor 2606 to ones of the DUT terminals 2616 that probes 2610 are in contact with, and tester 2602 can sense response signals generated by DUT 2514 (e.g., by the circuitry integrated into DUT 2514) in response to the test signals by sensing the response signals through ones of probes 2610 that are in contact with DUT terminals 2616, contactor 2606, and communications channels 2604. Tester 2602 can then compare the sensed response signals to expected response signals.
• the tester 2602 can conclude that DUT 2514 functions correctly and passes the testing; otherwise, tester 2602 can conclude that DUT 2514 is defective.
• the DUTs 2514 that passed the testing at 3606 can be further processed at 3608.
• the dies can be packaged or otherwise prepared at 3608 for shipping to end users of the dies at 3610.
• probe marks sometimes referred to as "scrub marks"
• probe marks can also be referred to as contact marks.
• probes 2610 comprise columns 104 of carbon nanotubes
• probe marks left on DUT terminals 2516 by probes 2610 can be unique and at least visibly distinct from scrub marks made by needle probes, cantilever type probes, or other types of probes.
• Figure 37 shows a partial view of a terminal 2516 of DUT 2514 being brought into contact with a probe 2610 (which is also shown in partial view) comprising a column 104
• Figure 38 shows terminal 2516 being moved out of contact with probe 2610.
• marks 3802 made on a surface 3704 of terminal 2516 by probe 2610 consist essentially of small punctures made in the surface 3704 by the protruding structures 1912 protruding from the contact end 1904 of probe 2610.
• the marks 3802 are located in a limited area (illustrated in Figure 38 by perimeter 3804) on the surface 3704 of terminal 2516.
• the limited area 3804 can correspond to the contact area of contact end 1904 of probe 2610. (The portion of contact end 1904 that faces terminal 2516 can be referred to as the face of contact end 1904.
• Limited area 3804 can correspond to an area of the face of contact end 1904.
• limited area 3804 can be seventy (or less) microns by seventy (or less) microns (which can correspond to an area of 4900 square microns), which as stated above, can be, in some embodiments, the approximate dimensions of the contact area of contact end 1904.
• the size of each puncture mark 3802 can typically be less than 25 square microns on the surface 3704 of terminal 2516 and typically penetrates less than 5 microns into terminal 2516 from the surface 3704.
• each puncture mark 3802 can typically be less than 20, 15, or 10 square microns on the surface 3704 of terminal 2516 and typically penetrates less than 4, 3, or 2 microns into terminal 2516 from surface 3704.
• the total area on the surface 3704 of a terminal 2516 disturbed by puncture marks 3802 can be less than 30% of the total area of the surface 3704 of the terminal 3516.
• the total area on the surface 3704 of a terminal 2516 disturbed by puncture marks 3802 can be less than 25%, 20%, 15%, 10%, or 5% of the total area of the surface 3704 of the terminal 3516.
• the percentage of the limited area bounded by perimeter 3804 disturbed (or occupied) by marks 3802 can be less than or equal to 40%, 30%, 20%, or 15%. In some embodiments, the percentage of the limited area bounded by perimeter 3804 disturbed (or occupied) by marks 3802 can be 40% or more or 15% or less.
• indentations 3902 e.g., spot depressions
• a contact end 1904 of a column 104 not treated to produce structures 1912 — and thus lacking pointed or protruding-like protruding structures — can be, at least at a microscopic level, uneven.
• contact end 1904 comprising, for example, a cluster of ends of carbon nanotubes that protrude slightly from other ends of carbon nanotubes that form the contact end 1904.
• the foregoing can cause indentations 3902 in surface 3704 of terminal 2516.
• Indentations 3902 can be located in a limited area (illustrated in Figure 39 by the area bounded by perimeter 3904) on the surface 3704 of terminal 2516.
• the limited area 3904 can correspond to the contact area (e.g., the contact face) of contact end 1904 of probe 2610. (The portion of contact end 1904 that faces terminal 2516 can be referred to as the face of contact end 1904.
• Limited area 3904 can correspond to an area of the face of contact end 1904.
• limited area 3904 can be seventy (or less) microns by seventy (or less) microns (which can correspond to an area of 4900 square microns), which as stated above, can be, in some embodiments, the approximate dimensions of the contact area of contact end 1904.
• the size of each indentation 3902 can typically be less than about 5 microns across the indentation 3902 on the surface 3704 of terminal 2516, and indentations 3902 typically penetrate less than 5 microns into terminal 2516 from the surface 3704.
• each indentation 3902 can typically be less than 4, 3, or 2 microns across the indentation and can typically penetrate less than 4, 3, or 2 microns into terminal 2516 from surface 3704.
• the total area on the surface 3704 of a terminal 2516 disturbed (or occupied) by indentations 3902 can be less than 30% of the total area of the surface 3704 of the terminal 3516.
• the total area on the surface 3704 of a terminal 2516 disturbed by indentations 3902 can be less than 25%, 20%, 15%, 10%, or 5% of the total area of the surface 3704 of the terminal 3516.
• the percentage of the limited area bounded by perimeter 3904 disturbed (or occupied) by indentations 3902 can be less than or equal to 40%, 30%, 20%, or 15%. In some embodiments, the percentage of the limited area bounded by perimeter 3904 disturbed (or occupied) by indentations 3902 can be 40% or more or 15% or less.
• probe 2610 can alternatively comprise column 2304, which as shown in Figure 23A can comprise peak structures 2312.
• peak structures 2312 can be located at corners of contact end 2302 of column 2304.
• Figure 40 illustrates surface 3704 of DUT terminal 2516 after a probe comprising a column 2304 and terminal 2516 are brought into contact (e.g., as at 3604 in Figure 36).
• marks 4002 made on a surface 3704 of terminal 2516 by a probe 2610 comprising column 2304 can consist essentially of small punctures made by peak structures 2312.
• peak structures 2312 can be located at corners of contact end 2302 of column 2304, and marks 4002 made by the peak structures 2312 can be located in corners of an area (illustrated in Figure 40 by perimeter 4004).
• the limited area 4004 can correspond to the contact area of contact end 2302 of column 2304. (See Figure 23A.) (The portion of contact end 1904 that faces terminal 2516 can be referred to as the face of contact end 1904.
• Limited area 4004 can correspond to an area of the face of contact end 1904.)
• limited area 4004 can be seventy (or less) microns by seventy (or less) microns (which can correspond to an area of 4900 square microns), which as stated above, can be, in some embodiments, the approximate dimensions of the contact area of contact end 2304.
• column 2304 can have four peak structures 2312 as shown in Figure 23A, or column 2304 can have more or fewer than four peak structures 2312.
• the surface 3704 of terminal 2516 shown in Figure 40 can therefore have more or fewer marks 4002.
• each puncture mark 4002 can typically be less than 20 square microns on the surface 3704 of terminal 2516 and typically penetrates less than 5 microns into terminal 2516 from the surface 3704. In various embodiments, each puncture mark 4002 can typically be less than 15 square microns, 10 square microns, or 5 square microns on the surface 3704 of terminal 2516 and typically penetrates less than 4, 3, or 2 microns into terminal 2516 from surface 3704. Depending on size and number of peak structures 2312 at the contact end 2302 of each column 2304, the total area on the surface 3704 of a terminal 2516 disturbed by puncture marks 4002 can be less than 15% of the total area of the surface 3704 of the terminal 3516.
• the total area on the surface 3704 of a terminal 2516 disturbed by puncture marks 4002 can be less than 10%, 5%, or 3% of the total area of the surface 3704 of the terminal 3516.
• the percentage of the limited area bounded by perimeter 4004 disturbed (or occupied) by marks 4002 can be less than or equal to 40%, 30%, 20%, or 15%. In some embodiments, the percentage of the limited area bounded by perimeter 4004 disturbed (or occupied) by marks 4002 can be 40% or more or 15% or less.
• Figure 41A illustrates an exemplary semiconductor die 2514', which can be a non- limiting example of DUT 2514. As shown, die 2514' can have a plurality of terminals 2516', which can be, for example, bond pads. Figure 41A illustrates terminals 2516' after terminals 2516' have been contacted by probes 2610 configured as in Figures 37 and 38 (i.e., probes 2610 comprise columns 104 treated to produce structures 1912 at a contact end 1904 of the columns 104 (see Figure 20)) and tested as illustrated in process 3600 of Figure 36.
• probes 2610 configured as in Figures 37 and 38 (i.e., probes 2610 comprise columns 104 treated to produce structures 1912 at a contact end 1904 of the columns 104 (see Figure 20)) and tested as illustrated in process 3600 of Figure 36.
• probe marks on terminals 2516' of die 2514' can consist essentially of (i.e., be generally limited to) puncture marks 3802 located within a perimeter 3904 that corresponds to a contact end 1904 of a probe 2610 as shown in Figure 38.
• the puncture marks 3802 can be made by structures 1912 protruding from the contact ends 1904 of probes 2610.
• the puncture marks 3802 on terminals 2514' can be as described above with respect to Figure 38.
• Figure 4 IB illustrates die 2514' with terminals 2514' after terminals 2514' have been contacted by probes 2610 configured as discussed above with respect to Figure 39 (i.e., probes 2610 comprise columns 104 whose contact ends 1904 were not treated to produce structures 1912 at a contact end 1904 of the columns 104 (see Figure 20)) and tested as illustrated in process 3600 of Figure 36.
• indentations 3902 on terminals 2516' of die 2514' can consist essentially of (i.e., be generally limited to) indentations 3902 located within a perimeter 3804 that corresponds to a contact end 1904 of a probe 2610 as shown in Figure 39.
• the indentations 3902 can be made by ends of carbon nanotubes that compose the columns 104 that compose the probes 2610.
• the indentations 3902 on terminals 2514' can be as described above with respect to Figure 39.
• Figure 41C illustrates another exemplary semiconductor die 2514", which can be another non-limiting example of DUT 2514.
• die 2514 can have a plurality of terminals 2516", which can be, for example, bond pads.
• probes 2610 of contactor 2606 (see Figures 26 and 35) or probe card assembly 3400 in Figure 34 can comprise columns 2304 in Figure 23A.
• probes marks on terminals 2516" of die 2514" can consist essentially of (i.e., be generally limited to) puncture marks 4002 located within along a perimeter 4004 that corresponds to a contact end 2302 of a probe 2610 (comprising a column 2304 as shown in Figure 23A) as shown in Figure 40.
• the semiconductor dies 2514' and 2514" in Figures 40A-41C are exemplary only, and many variations are possible.
• the number and layout of terminals 2516', 2516" on each die 2514', 2514" are exemplary only.
• Die 2516' can have a different number of terminals 2516', which can be laid out in a different pattern than shown in Figure 40.
• die 2516" can have a different number of terminals 2516", which can be laid out in a different pattern than shown in Figure 41.
• Figure 42 illustrates a typical probe mark 4208 made by a typical prior art probe (not shown) configured to contact a terminal 4204 of a die 4202 and then wipe across the terminal 4204.
• probe mark 4208 typically consists of a gauge or trench in the surface 4206 of the terminals 4204.
• the probe mark 4208 typically extends from a heel portion 4210 corresponds to initial contact with the prior art probe (not shown) to a toe portion 4212, which typically corresponds to the end of the prior art probe's (not shown) wiping motion across the terminal 4204.
• the probe mark 4208 is thus created as the prior art probe (not shown) contacts the heal portion 4210 and then wipes across the terminal 4204 to the toe portion 4212.
• a width W of the probe mark 2408 can correspond generally to a width of the portion of the prior art probe (not shown) that contacts terminal 4204; a length L of the probe mark 2408 can correspond generally to a length of the wiping motion of the prior art probe (not shown) across the terminal 4204; and a depth D of the probe mark 2408 from the surface 4206 into terminal 4204 can correspond generally to an over travel distance, which can be the distance the prior art probe (not shown) and/or terminal 4204 is moved toward the other after initial contact between the prior art probe (not shown) and terminals 4204.
• Some typical examples of W, D, and L include W of 20 microns, L of 20 microns, and D of 10 microns.
• a debris pile 4214 typically forms at the toe portion 4212 of the probe mark 4208.
• the debris pile 4214 can comprise, among other things, material of the terminal 4202 and/or material (e.g., an oxide film) on the surface 4206 of the terminal 4202 that is dug out terminal 4202 and/or scrapped off of the surface 4206 of terminal 4202 as the prior art probe (not shown) wipes from the heel portion 4210 of the probe mark 4208 to the toe portion 4212.
• the exemplary probe marks consisting essentially of puncture marks 3802 shown in Figure 38, indentations 3902 in Figure 39, or puncture marks 4002 shown in Figure 40 can be more advantageous than the prior art probe mark shown in Figure 42.
• probe marks on a terminal can cause several problems.
• probe marks can prevent a wire from being bonded to a terminal.
• the terminals of a semiconductor device are often connected to conductors of a protective package by wires.
• the probe mark can decrease the effective life of the bond between the wire and the terminal.
• a probe mark can weaken a terminal, causing the terminal to loosen or even detach from the semiconductor device.
• puncture marks 3802 on surface 3704 of terminal 2516 shown in Figure 38 are much less than discontinuities created by probe mark 4208 and debris pile 4214 on the surface 4206 of terminal 4202 in Figure 42, puncture marks 3802 are less likely than the prior art probe mark 4208 and debris pile 4214 to cause any of the problems discussed above with respect to probe marks.
• the indentations 3902 in Figure 39 and the puncture marks 4002 shown in Figure 40 likewise are much smaller and create less discontinuities on surface 3704 of terminal 2516 than the prior art probe mark 4208 and debris pile 4214 and therefore are less likely to cause any of the problems discussed above with respect to probe marks.
• probe mark 4208 is much larger than any one of the puncture marks 3802 in Figure 38, the indentations 3902 in Figure 39, or any one of the individual puncture marks 4002 in Figure 40.
• probe mark 4208 and debris pile 4214 disturb a larger percentage of the surface 4206 of terminal 4204 than puncture marks 3802 in Figure 38 disturb of the surface 3704 of terminal 2516', the indentations 3902 in Figure 39 disturb of the surface 3704 of terminal 2516', or puncture marks 4002 in Figure 40 disturb of the surface 3704 of terminal 2516".
• FIG. 43A and 43B illustrate another exemplary application in which columns 104 can comprise spring contact structures (e.g., interconnect structures) of an interposer 4300.
• Interposer 4300 can comprise a wiring substrate 4302 (e.g., a printed circuit board, a ceramic substrate, or other wiring substrate) to which columns 104 are attached.
• columns 104 (which can be non-limiting examples of first spring contact structures and second spring contact structures) can be attached to opposing sides (which can be examples of a first surface and a second surface) of the wiring substrate 4302.
• some of columns 104 can be attached to terminals 4306 on one side of wiring substrate 4302, and others of columns 104 can be attached to terminals 4306 on an opposite side of wiring substrate.
• Wiring 4308 (e.g., traces and/or vias in or on wiring substrate 4302) can electrically connect terminals on the one side of wiring substrate 4302 with terminals 4306 on the opposite side of the wiring substrate 4302 and thereby also electrically connect columns 104 on the one side of wiring substrate 4302 with columns 104 on the opposite side of wiring substrate 4302.
• Wiring 4308 can be non-limiting examples of electrical connections.
• Columns 104 can be grown using any technique or process described or mentioned herein.
• columns 104 can be grown on a sacrificial substrate (e.g., substrate 202), for example, as shown in Figures 2-7 and 12-14, and transferred to wiring substrate 4302 (e.g., using any of the techniques illustrated in 8-1 IB or 12-14).
• columns 104 can be grown on terminals 4306 of wiring substrate 4302 using any applicable technique or process described or mentioned herein.
• columns 104 can be grown on terminals 4306 in the same manner as columns 1604 are grown on terminals 1504 in Figures 15A-16B.
• columns 104 can be grown in pits (not shown) in wiring substrate 4302 in the same way that columns 1804 are grown in pits 1705 in Figures 17A-18B.
• columns 104 can be treated using any one or more of the treatments illustrated in Figures 19- 22B or otherwise described or mentioned herein, and columns 104 can be anchored to terminals 4306 and/or wiring substrate 4302 by anchoring structures 4304, which can be like anchoring structures 1606 in Figures 16A and 16B or anchoring structures 1806 in Figures 18A and 18B or using any anchoring technique described or mentioned herein.
• anchoring structures 4304 can be like anchoring structures 1606 in Figures 16A and 16B or anchoring structures 1806 in Figures 18A and 18B or using any anchoring technique described or mentioned herein.
• columns 104 can be like columns 2204 or 2304.
• Figure 44 illustrates another exemplary application in which columns 104 can comprise spring contact structures (e.g., interconnect structures) attached to terminals (e.g., bond pads) 4404 of a semiconductor die 4402, which can be a non-limiting example of a wiring substrate.
• Die 4402 can be any type of semiconductor die.
• die 4402 can comprise memory or data storage circuitry, digital logic circuitry, processor circuitry, etc.
• terminals 4404 can be electrically connected to the circuitry integrated into die 4402 and can thus provide input and output for signals, power, and ground.
• Columns 104 can be grown using any technique or process described or mentioned herein. Moreover, columns 104 can be grown on a sacrificial substrate (e.g., substrate 202), for example, as shown in Figures 2-7 and 12-14, and transferred to die 4402 (e.g., using any of the techniques illustrated in 8-1 IB or 12-14). Alternatively, columns 104 can be grown on terminals 4404 of die 4402 using any applicable technique or process described or mentioned herein. For example, columns 104 can be grown on terminals 4404 in the same manner as columns 1604 are grown on terminals 1504 in Figures 15A-16B.
• columns 104 can be grown in pits (not shown) in die 4402 in the same way that columns 1804 are grown in pits 1705 in Figures 17A-18B.
• columns 104 can be treated using any one or more of the treatments illustrated in Figures 19-22B or otherwise described or mentioned herein, and columns 104 can be anchored to terminals 4404 and/or die 4402 by anchoring structures (not shown) which can be like anchoring structures 1606 in Figures 16A and 16B or anchoring structures 1806 in Figures 18A and 18B or using any anchoring technique described or mentioned herein.
• anchoring structures not shown
• columns 104 can be like columns 2204 or 2304.
• Die 4404 can be a singulated die (i.e., singulated from the silicon wafer on which die 4404 was made), and die 4404 can be packaged or unpackaged. Alternatively, die 4404 can be unsingulated from the wafer on which it was made. For example, columns 104 can be attached to die 4402 while die 4402 is still part of the wafer on which die 4402 was made. In some embodiments, columns 104 can be attached to some or all of the dies (e.g., like die 4402) on a silicon wafer before the dies are singulated from the wafer.
• the dies e.g., like die 4402
• such dies can be tested in a test system like test system 2600 of Figure 26 and in accordance with a test process like process 3600 of Figure 36.
• columns 104 can be attached to terminals 2616 of DUT 2614 and probes 2610 on contactor 2606 can be replaced with flat terminals configured to contact the columns 104 extending from terminals 2616 of DUT 2614. If probe card assembly 3400 is used as contactor 2606, probes 2610 can likewise be replaced with flat terminals.
• Columns 104 (and thus columns 504, 704, 1404, 1604, 1804, 2204, 2304, and 2304') as well as probes 2610 can be non- limiting examples of spring contact structures, probes, spring probes, first spring contact structures, second spring contact structures, or test probes.
• columns 104 are attached to and/or electrically connected to terminals of a wiring substrate
• columns 104 can be attached to other electrical elements on or in a wiring substrate.
• a terminal can be a non-limiting example of an electrical element.
• columns 104 (and thus columns 504, 704, 1404, 1604, 1804, 2204, 2304, and 2304') as well as probes 2610 can be non- limiting examples of spring contact structures, probes, spring probes, first spring contact structures, second spring contact structures, or test probes.

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• 2007
  • 2007-10-13 US US11/872,008 patent/US8130007B2/en not_active Expired - Fee Related
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