US20210213587A1

US20210213587A1 - Multi-Port Polishing Fixture Assembly and Method of Surface Conditioning a Pick and Place Bond Head

Info

Publication number: US20210213587A1
Application number: US17/071,865
Authority: US
Inventors: Vaibhav D. Patel; John P. Staton; Jonathan M. Manzano; Stephen P. Bathurst
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2020-01-10
Filing date: 2020-10-15
Publication date: 2021-07-15

Abstract

Multi-port polishing fixture assemblies, pick and place bond heads, split holders, and conditioning methods are described. In an embodiment, a multi-port polishing fixture assembly includes a fixture base, a plurality of split holders fastenable to a perimeter surface with a plurality of kinematic plurality of kinematic clamps. The pick and place bond heads may be secured inside the plurality of split holders to reduce edge-fast polishing during conditioning of the distal bond surfaces of the pick and place bond heads.

Description

RELATED APPLICATIONS

This application claims the benefit of priority of U.S. Provisional Application No. 62/959,364 filed Jan. 10, 2020, which is incorporated herein by reference.

BACKGROUND

Field

Embodiments described herein relate to transfer tools for surface mount technology.

Background Information

State of the art surface mount technology (SMT) utilizes a vacuum or electrostatic bonding tool to directly pick electrical components (such as silicon and gallium nitride) from wafers or die and place them on target substrates (such as glass, silicon, printed circuit board, flexible printed circuit board) to create electrical circuits often referred to as surface mount devices (SMD).
Electrical joints can be created on the bottom surface of a component during placement by connecting bond pads with an electrically conductive adhesive bonding material using bonding techniques such as eutectic bonding, soldering, anisotropic conductive paste bonding, etc. Such adhesive bonding techniques can rely on temperature, pressure and the reflow properties of the adhesive bonding material to form a reliable mechanical connection to the substrate.
Electrical connections can also be formed on the top surface of component after placement by subsequent processes. One example of such processing is the deposition of a planarization material followed by patterned metal interconnects. Devices that rely on metal connections formed on a component top surface may also utilize an adhesive bonding material to fix the component to the substrate. The adhesive bonding material may or may not be electrically conductive depending upon connections to be made. Non-conductive adhesive bonding materials include glue, tape, polymer, other adhesive layers, etc. Such thin adhesive layers can be slot die coated, spin coated, dispensed or sprayed onto the substrate.

SUMMARY

Embodiments describe multi-port polishing fixture assemblies, pick and place bond heads, split holders and methods of conditioning pick and pace bond heads with the multi-port polishing fixture assemblies. In an embodiment, a multi-port polishing fixture assembly includes a fixture base with a perimeter surface, a plurality of kinematic clamps fastenable along the perimeter surface, and a plurality of split holders fastenable to the perimeter surface with the plurality of kinematic plurality of kinematic clamps. Such a multi-port polishing fixture may be utilized to condition a pick and place bond head by loading the multi-port polishing fixture assembly with a plurality of pick and place bond heads secured within a corresponding plurality of split holders, and polishing the plurality of pick and place bond heads and corresponding plurality of split holders. In such a configuration, the split holders may act as a sacrificial material flattening the polishing pad of the polishing apparatus before it contacts the pick and place bond head in order to mitigate edge-fast polishing. In a particular embodiment, a pick and place bond head includes an elongate body, a pedestal at a distal end of the elongate body, and a plurality of mesa structures extending from the pedestal. Each mesa structure may include a distal bond surface with one or more vacuum holes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view illustration of a polishing apparatus in accordance with an embodiment.

FIG. 2 is an isometric view illustration showing a distal bond surface of a pick and place bond head in accordance with an embodiment.

FIG. 3 is an isometric view illustration of a pick and place bond head arranged within a split holder in accordance with an embodiment.

FIG. 4 is a schematic top view illustration of a multi-port polishing fixture assembly and close-up top view illustration of a kinematic clamp fastened to a perimeter surface of a fixture base in accordance with an embodiment.

FIG. 5A is an isometric view illustration of a two-part split holder in accordance with an embodiment.

FIG. 5B is a schematic top view illustration of a two-part split holder fastened to a perimeter surface of a fixture base in accordance with an embodiment.

FIG. 6A is a side view illustration of a pick and place bond head with a plurality of mesa structures extending from a pedestal in accordance with an embodiment.

FIG. 6B is an isometric view illustration of the pick and place bond head of FIG. 6A showing distal bond surfaces and vacuum holes in accordance with an embodiment.

FIG. 6C is a schematic cross-sectional side view illustration of the pick and place bond head of FIG. 6A showing vacuum holes connected to individual vacuum channels within the pick and place bond head shank in accordance with an embodiment.

FIG. 6D is a schematic cross-sectional side view illustration of the pick and place bond head of FIG. 6A showing vacuum holes connected to a same vacuum channel within the pick and place bond head shank in accordance with an embodiment.

FIG. 7A is an image of a non-conditioned distal bond surface of a pick and place bond head in accordance with an embodiment.

FIG. 7B is a plot of profilometer in the x-direction across the distal bond surface of the pick and place bond head of FIG. 7A.

FIG. 7C is a plot of profilometer in the y-direction across the distal bond surface of the pick and place bond head of FIG. 7A.

FIG. 8A is an image of conditioned distal bond surface of a pick and place bond head in accordance with an embodiment.

FIG. 8B is a plot of profilometer in the x-direction across the distal bond surface of the pick and place bond head of FIG. 8A.

FIG. 8C is a plot of profilometer in the y-direction across the distal bond surface of the pick and place bond head of FIG. 8A.

FIGS. 9A-9G are schematic cross-sectional side view illustrations of a sequence of transferring and integrating components in accordance with an embodiment.

DETAILED DESCRIPTION

Embodiments describe multi-port polishing fixture assemblies, pick and place bond heads, split holders, and methods of conditioning pick and pace bond heads with the multi-port polishing fixture assemblies for use in surface mount technology (SMT).
It has been observed that conventional bonding tools used to pick and place components have typically greater than 5 μm surface roughness due to machining processes of vacuum holes (laser, drilling) and surface finishing (electric discharge machining, drilling). Flatness of the pick and place tool is also not controlled and can lead to significant topography of the placed component making it difficult or impossible to form top metal connections after placement. Furthermore, such a surface roughness can also damage (e.g. scratch) top contact pads (e.g. metal) when present on components being transferred, leading to possible failure to form electrical connection after placement.
Furthermore, it has been observed that rougher surfaces can directly translate to adhesive wetting bubbles underneath the transferred component. Adhesive wetting is especially sensitive for ultra-thin (e.g. less than 10 μm) chips. Bubbles or non-uniform wetting eventually can affect component total thickness variation (TTV) during final adhesive curing process beyond 2 μm TTV since roughness of the bonding tools can translate to TTV of the transferred components. This variation can affect planarization and contact making process and demands larger margin and effectively larger chip or component area ultimately impacting cost of the materials. Further, this can impact via size and integrity of electrical connection to top contacts of a transferred component.
In one aspect, embodiments describe a pick and place bond head polishing process that can reduce surface roughness and other machining related manufacturing process non-uniformities. The embodiments can also enable re-using contaminated or damaged pick and place bond heads during the manufacturing process, which can reduce cost for SMD.
In an embodiment a multi-port polishing fixture assembly includes a fixture base with a perimeter surface, a plurality of a plurality of kinematic clamps fastenable along the perimeter surface, and a plurality of split holders fastenable to the perimeter surface with the plurality of kinematic plurality of kinematic clamps. In operation, a plurality of pick and place bond heads can be secured within a corresponding plurality of split holders and then polished with a polishing apparatus including the multi-port polishing fixture assembly positioned over a polishing pad. In accordance with embodiments the split holders, used to clamp the pick and place bond heads, act as a sacrificial material, and provide pressure uniformity to the pick and place bond heads and avoid edge-fast polishing that is prevalent in traditional film or chemical mechanical polishing (CMP) based approaches. In accordance with embodiments, the polishing processes and equipment can be utilized to achieve distal bond surfaces of the pick and place bond heads characterized by an average surface roughness (Ra) of 50 nm-0.5 μm and a flatness of less than 300 nm. This can facilitate the transfer of components with lower resulting TTV on the receiving substrate, and enable reliable top side and/or bottom side electrical connections to be made with the components. Where a pick and place bond head includes multiple mesa structures with multiple distal bond surfaces 202, the flatness (e.g. of less than 300 nm) may be extended across a total surface area including each distal bond surface 202 for every mesa structure 250.
In various embodiments, description is made with reference to figures. However, certain embodiments may be practiced without one or more of these specific details, or in combination with other known methods and configurations. In the following description, numerous specific details are set forth, such as specific configurations, dimensions and processes, etc., in order to provide a thorough understanding of the embodiments. In other instances, well-known semiconductor processes and manufacturing techniques have not been described in particular detail in order to not unnecessarily obscure the embodiments. Reference throughout this specification to “one embodiment” means that a particular feature, structure, configuration, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, configurations, or characteristics may be combined in any suitable manner in one or more embodiments.
The terms “over”, “to”, “between”, and “on” as used herein may refer to a relative position of one layer with respect to other layers. One layer “over” or “on” another layer or bonded “to” or in “contact” with another layer may be directly in contact with the other layer or may have one or more intervening layers. One layer “between” layers may be directly in contact with the layers or may have one or more intervening layers.
Referring now to FIG. 1 an isometric view illustration is provided of a polishing apparatus 100 in accordance with an embodiment. Such a polishing apparatus 100 may include a base 102 which supports a rotatable platen 110 and pivot arm 120 which is positionable over the platen 110. In a particular configuration, one or more joints 122 may be included to adjust position of the pivot arm 120, for example radially swinging motion with a z-direction vector to assemble system components. Joint 122 may additionally provide fine x-y-z positioning of the pivot arm 120.
A connector 124 may be fastened along a length of the pivot arm 120. A multi-port polishing fixture assembly 150 may additionally be connected to a distal end portion of the pivot arm 120. In this manner the pivot arm 120 can be adjusted to provide pressure to the multi-port polishing fixture assembly 150 as it is contacted with a polishing pad 112 on the rotatable platen 110.
In an embodiment, a multi-port polishing fixture assembly 150 includes a fixture base 130 with a perimeter surface 131, a plurality of a plurality of kinematic clamps 140 fastenable along the perimeter surface 131, and a plurality of split holders 160 fastenable to the perimeter surface 131 with the plurality of kinematic plurality of kinematic clamps 140. In use, pick and place bond heads 200 are clamped inside the corresponding split holders 160, and fastened to the perimeter surface 131 using the plurality of kinematic clamps 140. Thus, the kinematic clamps 140 can be used to secure the bond heads 200 inside the corresponding split holders 160, as well as to secure the bond heads and split holders 160 to the fixture base 130.
The multi-port polishing fixture assemblies 150 in accordance with embodiments may be utilized to polish a variety of tools, in particular, pick and place bond heads used for high-throughput pick and place of components from a high density source substrate to a lower density target substrate. Exemplary fields of application can include fan-out wafer level packaging, fan-out panel level packaging, etc. Embodiments described herein may be used to condition tools used for the transfer of any ultra-thin components where bond head surface planarity can affect TTV of the transferred component.
FIG. 2 is an isometric view illustration showing a distal bond surface 202 of a pick and place bond head 200 in accordance with an embodiment. As shown, the pick and place bond head 200 may include an elongate body 230 (or shank), a distal bond surface 202, and one or more vacuum holes 210 in the distal bond surface 202. As illustrated, the elongate body 230 may optionally include a distal platform (or pedestal 220) at the distal end of the elongate body. The distal bond surface 202 may be the distal surface of the pedestal 220. The elongate body 230 may have a length that is greater than its width. The elongate body 230 may be used for mounting within a mass transfer tool, as well as within the multi-port polishing fixture assembly 150. The elongate body 230 can assume different geometric shapes, such as cylindrical, cuboid (rectangular), polygonal, etc. In an embodiment, the distal bond surface 202 has a maximum lateral dimension of less than 500 μm. In an embodiment, the vacuum hole(s) 210 each have a maximum width of less than 75 μm. Such dimensions may be exemplary of micro-sized components to be transferred, which can also be susceptible to TTV after placement.
FIG. 3 is an isometric view illustration of a pick and place bond head 200 arranged within a split holder 160 in accordance with an embodiment. In the particular embodiment illustrated the split holder 160 includes a tubular member 161 and one or more slits 164. The slit(s) 164 may be along a longitudinal length of the tubular member 161. In an embodiment, the slit(s) extend from a distal surface 162 of the tubular member 161 and partially down a longitudinal length of the tubular member. In accordance with embodiments, the split holder 160 and pick and place bond head 200 are sized such that the pick and place bond head 200 can be secured inside the split holder 160 (for example, with the kinematic clamps 140) with the distal surface 162 of the tubular member 161 parallel to the distal bond surface 202 of the pick and place bond head 200. During polishing, such an arrangement can provide conditions for pressure uniformity across the distal bond surface 202 with the polishing pad 112. This can mitigate edge fast polishing, and related dishing that occurs along edges of a tool prevalent in traditional polishing techniques.
FIG. 4 is a schematic top view illustration of a multi-port polishing fixture assembly 150 and close-up top view illustration of a kinematic clamp 140 fastened to a perimeter surface 131 of a fixture base 130 in accordance with an embodiment. In the embodiment illustrated, the fixture base 130 is a plate (e.g. metal). A center portion may include contact holes 137, for example to fasten to the connector 124 of the polishing apparatus 100. The perimeter surface 131 of the fixture base 130 may optionally include a plurality of cavities 132 and support tabs 134 between adjacent cavities 132. Such an arrangement may provide additional support for securing the kinematic clamps 140.
In an embodiment, the perimeter surface 131 includes a plurality of kinematic fixturing patterns 138, which will receive a corresponding plurality of split holders 160. In the illustrated embodiment, the kinematic fixturing patterns 138 are V-grooves, though other configurations may be used, such as semi-circle, rectangle, slot, etc. In an embodiment, the fixture base 130 additionally includes a plurality of threaded holes 136 along the perimeter surface 131 in order to receive a screw 144 of a corresponding kinematic clamp 140. Referring now to the close-up illustration in FIG. 4, in an embodiment a kinematic clamp 140 includes a pressure bar 142 and the screw 144 is threaded through a threaded hole 146 in the pressure bar and into the threaded hole 136 along the perimeter surface 131 of the fixture base 130. In this manner, tightening of the screw 144 will fasten the kinematic clamp 140 to the perimeter surface, upon which the pressure bar 142 will secure the split holder within the fixturing pattern 138 and between the pressure bar 142 and perimeter surface 131. The split holder 160 in turn secures the bond head 200 within the split holder 160.
Also illustrated in FIG. 4 is a pair of dummy rods 400 fastened to the perimeter surface 131 of the fixture base 130 with a kinematic clamp 140. The dummy rods 400 may have similar dimensions as the split holders 160, though this is not required as long as they may be similarly fastened. As described in further detail below the dummy rods 400 may be used to set a polishing height for the tools (e.g. the pick and place bond heads). A plurality of dummy rods 400 may be fastened to the fixture base 130 for setting the polishing height.
It is to be appreciated that the particular embodiment illustrated in FIG. 4 is intended to be a particularly graceful implementation and embodiments are not so limited. For example, the pressure bars 142 may include multiple threaded holes 146 to receive multiple screws 144, or the threaded holes 146 may not be threaded. Alternatively, fastening mechanisms such as springs, clips, etc. may be utilized. As another example, each threaded hole 136 in the fixture base 130 is between two fixturing patterns 138. However, other arrangements and ratios are envisioned. Furthermore, it is to be appreciated that each cavity 132 may receive a corresponding kinematic clamp 140, or a plurality of kinematic clamps 140.
Up until this point embodiments have been described in which the split holder 160 is a physically separate component from the kinematic clamp 140 and fixture base 130. Thus, a tubular split holder 160 may be a discrete component. The split holders 160 in accordance with embodiments can also be designed as being a part of the kinematic clamp 140, fixture base 130, or both.
Referring now to FIGS. 5A-5B, FIG. 5A is an isometric view illustration of a two-part split holder 160 in accordance with an embodiment. FIG. 5B is a schematic top view illustration of a two-part split holder 160 fastened to a perimeter surface 131 of a fixture base 130 in accordance with an embodiment. In the particular embodiment illustrated, a two-part split holder 160 includes a first split holder side 160A and second split holder side 160B, which may be identical. Each split holder side 160A, 160B may include a half-tubular body 163 coupled with a mounting bracket 502. As shown, an interior side of the mounting bracket 502 adjacent the inner surface of the half-tubular body 163 can include a recess 504 and through hole 506. In an embodiment, through holes 506 are longitudinal slots, which will accommodate adjusting a height of the corresponding split holder side in the assembly. For example, this may accommodate eventual polishing down the length of the half-tubular body 163. Screws 514 can be threaded through the through holes 506 and into through holes 139 along the perimeter surface 131 of the fixture base 130 to secure one of the split holder sides. Similarly screws 514 can be threaded through the through holes 506 and into the through holes 149 in the pressure bar 142 of the kinematic clamp 140 to secure the other split holder side. In this manner, each split holder side 160A, 160B can be fixed to a corresponding pressure bar 142 and fixture base 130. Upon threading the screw 144 through the threaded hole 146 in the pressure bar 142 and into the threaded hole 136 along the perimeter surface 131 of the fixture base 130, the kinematic clamp 140 will be fastened to the perimeter surface, upon which the two-part split holder 160 secures the bond head 200 within the two half-tubular bodies 163. Similar to the previous tubular member 161, the half-tubular bodies 163 have a longitudinal length and distal surface 162 that may be arranged parallel to a distal bond surface 202 of a bond head 200.
Up until this point the pick and place bond head 200 has been described as including a single distal bond surface 202, however, embodiments envision bond heads 200 with multiple distal bond surfaces 202, which can be used to pick up a same component together, or each distal bond surface 202 to pick up a separate component. Referring now to FIGS. 6A-6B, FIG. 6A is a side view illustration of a pick and place bond head 200 with a plurality of mesa structures 250 extending from a pedestal 220 in accordance with an embodiment. FIG. 6B is an isometric view illustration of the pick and place bond head of FIG. 6A showing distal bond surfaces 202 and vacuum holes 210 in accordance with an embodiment.
In the illustrated embodiment, the pick and place bond head 200 includes an elongate body 230, a pedestal 220 at a distal end of the elongate body 230, and a plurality of mesa structures 250 extending from the pedestal. The pedestal 220 may be an integral distal portion of the elongate body, or alternatively a discrete shape or part of the pick and place bond head 200. Each mesa structure 250 may include a distal bond surface 202 including one or more vacuum holes 210. In an embodiment, each distal bond surface 202 has a maximum lateral dimension of less than 500 μm. In an embodiment, each vacuum hole 210 has a maximum width of less than 75 μm.
The vacuum holes in accordance with embodiments are then connected to one or more vacuum channels within the pick and place bond head 200 for connection to a vacuum source of the mass transfer tool to which the pick and place bond heads 200 will be attached. FIGS. 6C-6D illustrate non-limiting examples of different vacuum channels. In the exemplary embodiment illustrated in FIG. 6C, the individual vacuum channels 270 extend through the mesa structures 250, pedestal 220, and elongate body 230. For example, the vacuum channels can extend through an axial length of the elongate body 230. The individual vacuum channels 270 can optionally merge into shared vacuum channels (and thus be fluidly connected) within the pedestal 220 and/or elongate body 230. In the particular embodiment illustrated in FIG. 6D, the individual channels 270 are merged into a shared channel 235 within the pedestal 220 and/or the elongate body 230. A variety of configurations are possible. In accordance with embodiments the arrangement of vacuum channels 270 and shared channel 235 can be included in the embodiment illustrated in FIG. 2.
The pick and place bond heads 200 in accordance with embodiments may be conditioned with the polishing apparatus 100 before first use, or after use during a sustained period of operation with a mass transfer tool. For example, conditioning prior to initial use may remove defects or surface roughness characteristic of manufacturing process non-uniformities. Conditioning after sustained use can address damaged or contaminated distal bond surfaces. In both applications, the conditioned distal bond surfaces 202 can be characterized by an average surface roughness (Ra) of 50 nm-0.5 μm in an embodiment. In an embodiment, a conditioned distal bond surface 202 is characterized by a flatness of less than 300 nm. In an embodiment, a total surface area including each distal bond surface 202 for every mesa structure 250 is characterized by a flatness of less than 300 nm. Thus, the flatness may be translated across each mesa structure 250 in the pick and place tool. Such parameters may facilitate the ability to transfer flat components with proper adhesive wetting. Additionally, refurbishing of contaminated or damaged pick and place bond heads 200 in a manufacturing process can reduce cost for surface mount devices (SMD).
In an embodiment, an exemplary conditioning process includes loading a multi-port polishing fixture assembly 150 with a plurality of tools (e.g. pick and place bond heads 200) secured within a corresponding plurality of split holders 160, and polishing the plurality of tools and corresponding plurality of split holders, for example, to average surface roughness (Ra) of 50 nm-0.5 μm and flatness of less than 300 nm.
Loading the multi-port polishing fixture assembly 150 may include fastening the plurality of split holders 160 to a perimeter surface 131 of a fixture base 130 with a plurality of kinematic clamps 140. In some embodiments, the split holders 160 (and pick and place bond heads 200) may be loosely fastened initially in order to set a polishing height, and only tightly fastened in place after setting the polishing height. Setting the polishing height may include, prior to polishing, loading one or more dummy rods 400 into the multi-port polishing fixture similarly as the split holders 160, and clamped tight. Dummy rods 400 may, for example, have similar dimensions as the split holders 160, as shown in FIG. 4. The dummy rods 400 are then pressed against the polishing pad 112. The polishing height can then be set for the plurality of tools (pick and place bond heads 200) and split holders 160 by applying pressure to the proximal ends of the pick and place bond heads 200 and split holders 160 so that they also are pressed against the polishing pad, followed by tightly fastening the plurality of tools (pick and place bond heads 200) and split holders 160 in place at the polishing height. Thus, the length of the split holders 160, bond head 200, and dummy rods 400 extending between the polishing pad 112 and the multi-port polishing fixture assembly 150 are equal. Once the polishing height has been set, the polishing operation may be performed with the pick and place bond heads 200 and split holders 160 secured in place.
In accordance with embodiments, the pick and place bond heads 200 are loaded such that the split holders 160 and distal bond surfaces 202 are planar to each other. The split holders 160 act as a sacrificial material flattening the polishing pad 112 before it contacts the pick and place bond head 200. In accordance with embodiments, an exemplary polishing pad 112 may be an alumina (Al₂O₃) lapping film. For example, this may be a 0.3-5.0 micron alumina lapping film with no adhesive. The polishing fluid may be deionized (DI) water. In such an embodiment, an abrasive slurry is not utilized.
In order to illustrate effectiveness of the polishing apparatus 100 and conditioning sequence in accordance with embodiments, an as received pick and place bond head 200 was inspected and surface contour were measured with a profilometer, followed by conditioning and again inspecting and measuring the surface contour after conditioning. In this particular example, conditioning was performed with a 5.0 micron alumina polishing pad, 20 rotations per minute (RPM) platen speed, 0.5 pounds of force applied to the multi-port polishing fixture assembly 150, with DI water, for 60 second polishing time.
Images of the pick and place bond head distal surfaces 202 are provided in FIGS. 7A and 8A, respectively, for as-received and post conditioning. The visible contour shows bright (white) areas corresponding to nominal value, and darker regions corresponding to variable heights (+/−). FIGS. 7B and 8B, respectively, are plots of profilometer data in the x-direction across the distal bond surface of FIGS. 7A and 8A for as-received and post conditioning. FIGS. 7C and 8C, respectively, are plots of profilometer data in the y-direction across the distal bond surface of FIGS. 7A and 8A for as-received and post conditioning. Notably, in addition to reduced surface roughness, the profilometer data additionally illustrates a reduction in dishing around the distal bond surface 202 edges, which can contribute to planarity improvement, and hence TTV of a transferred component.
Improved planarity across the distal bond surfaces 202 in accordance with embodiments may facilitate the ability to provide a more uniform pressure to a component during pick and place, and in particular, placement onto a receiving substrate. In an embodiment, placement of a component onto a receiving substrate include heat and/or pressure, and potentially reflow or deformation of an adhesive bonding material. Application of non-uniform pressure due to surface roughness or insufficient flatness of the distal bond surfaces 202 can result in non-uniform wetting or bubbles underneath the transferred components and unacceptable TTV of the placed components. This can affect the ability to make either or both top side or bottom side connections to the placed components.
FIGS. 9A-9G are schematic cross-sectional side view illustrations of a sequence of transferring and integrating components 910 in accordance with an embodiment. The particular sequence is illustrated as making both top side and bottom side electrical connections, though embodiments do not require such. For example, only top side or bottom side electrical connections may be made. As shown in FIG. 9A a pick and place bond head 200 including one or more distal bond surfaces 202 is positioned over an array of components 910 on a carrier substrate 902. The distal bond surfaces 202 are then contacted with a corresponding plurality of components 910, as shown in FIG. 9B. Application of vacuum pressure may then be utilized to pick up the plurality of components 910 a shown in FIG. 9C.
The plurality of components can then be positioned over a receiving substrate 920. As shown in FIG. 9D, the receiving substrate may have one or more bonding layers 922 (e.g. solder, paste, film, tape, glue, etc.) for receiving the corresponding components 910. Individual conductive bonding layers 922 may be placed to make electrical connection with individual component contact pads. Alternatively, individual or a common non-conductive bonding layer 922 (e.g. adhesive film, tape, glue, etc.) can be applied for receiving the components 910.
As shown in FIG. 9E, the components 910 are brought into contact with the bonding layers 922, which may include heat and pressure, and deformation of the bonding layers 922. In accordance with embodiments, flatness of the distal bond surfaces 202 contributes to reflow/deformation of the bonding layer(s) 922, underside wetting of the components 910 with the bonding layer(s) 922 and hence resultant TTV of the components 910 after placement onto the receiving substrate. Referring now to FIG. 9F, one or more filler layers 930 (e.g. planarization layers) can be formed around the components 910. In an embodiment, this is a single insulating material layer, though this could be multiple layers, and can include electrical routing. This may be followed by the formation of one or more contact layers 940 (e.g. metal layer, etc.) over the filler layers 930 and components 910. Electrical contact with the components 910 may be aided by low TTV of the components 910.
In utilizing the various aspects of the embodiments, it would become apparent to one skilled in the art that combinations or variations of the above embodiments are possible for conditioning a bond head surface. Although the embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the appended claims are not necessarily limited to the specific features or acts described. The specific features and acts disclosed are instead to be understood as embodiments of the claims useful for illustration.

Claims

What is claimed is:

1. A multi-port polishing fixture assembly comprising:

a fixture base including a perimeter surface;

a plurality of kinematic clamps fastenable along the perimeter surface; and

a plurality of split holders fastenable to the perimeter surface with the plurality of kinematic plurality of kinematic clamps.

2. The multi-port polishing fixture assembly of claim 1, wherein each split holder comprises a tubular member, and a slit in the tubular member extending from a distal end of the tubular member.

3. The multi-port polishing fixture assembly of claim 2, wherein the slit partially extends down a longitudinal length of the tubular member.

4. The multi-port polishing fixture assembly of claim 1, wherein each split holder comprises a pair of half-tubular bodies.

5. The multi-port polishing fixture assembly of claim 1, wherein the plurality of split holders are secured to the corresponding plurality of kinematic clamps.

6. The multi-port polishing fixture assembly of claim 1, wherein the plurality of split holders are physically separate from the corresponding plurality of kinematic clamps.

7. The multi-port polishing fixture assembly of claim 1, wherein the perimeter surface includes a plurality of kinematic fixturing patterns to receive the plurality of split holders.

8. The multi-port polishing fixture of claim 7, wherein each kinematic fixturing pattern is a V-groove.

9. The multi-port polishing fixture assembly of claim 1, wherein each kinematic clamp includes a pressure bar and screw threaded through the pressure bar.

10. The multi-port polishing fixture assembly of claim 9, wherein the fixture base includes a plurality of threaded holes along the perimeter surface, each hole to receive the screw of a corresponding kinematic clamp.

11. A method of conditioning a pick and place bond head comprising:

loading a multi-port polishing fixture assembly with a plurality of tools secured within a corresponding plurality of split holders; and

polishing the plurality of tools and corresponding plurality of split holders.

12. The method of claim 11, further comprising:

loading the multi-port polishing fixture assembly with a plurality of dummy rods;

pressing the plurality of dummy rods against a polishing pad;

setting a polishing height for the plurality of tools and corresponding plurality of split holders; and

fastening the plurality of tools and corresponding plurality of split holders at the polishing height.

13. The method of claim 11, wherein loading the multi-port polishing fixture assembly with the plurality of tools secured within a corresponding plurality of split holders comprises fastening the plurality of split holders to a perimeter surface of a fixture base with a plurality of kinematic clamps.

14. A pick and place bond head comprising:

an elongate body;

a pedestal at a distal end of the elongate body; and

a plurality of mesa structures extending from the pedestal, each mesa structure including a distal bond surface including one or more vacuum holes.

15. The pick and place bond head of claim 14, wherein the one or more vacuum holes extend through an axial length of the elongate body.

16. The pick and place bond head of claim 14, wherein the one or more vacuum holes is a plurality of vacuum holes fluidly connected to a shared vacuum channel in the pick and place bond head.

17. The pick and place bond head of claim 14, wherein the distal bond surface is characterized by an average surface roughness (Ra) of 50 nm-0.5 μm.

18. The pick and place bond head of claim 14, wherein the distal bond surface is characterized by a flatness of less than 300 nm.

19. The pick and place bond head of claim 14, wherein a total surface area including each distal bond surface of the pick and place bond head is characterized by a flatness of less than 300 nm.

20. The pick and place bond head of claim 14, wherein the distal bond surface has a maximum lateral dimension of less than 500 μm.

21. The pick and place bond head of claim 20, wherein each vacuum hole has a maximum width of less than 75 μm.