Abstract:
Co-planarity adjustment systems and methods, gantries capable of applying high force without imposing moment loads to their bearings, systems and methods for achieving rapid heating and cooling and efficient slidable seal systems capable of sealing a chamber and injecting one or more fluids into the chamber as well as actively recovering portions of such fluid which have migrated into the seal itself are disclosed in the context of thermo-compression bonding systems, apparatuses and methods, although many alternative uses will be apparent to those of skill in the art.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Applications No. 61/822,912, filed May 13, 2013, No. 61/926637, filed Jan. 13, 2014 and No. 61/928,183, filed Jan. 16, 2014. Each of these applications is herein incorporated in its entirety by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to precision bonding of dies to substrates, and more particularly, to a system and methods of use for a “flip-chip” thermo-compression bonding system and subsystems. 
       BACKGROUND OF THE INVENTION 
       [0003]    Existing thermo-compression bonding systems are quickly becoming inadequate as higher demands are placed on such systems by new and rapidly improving technology. Improvements to current thermo-compression bonding systems are required in order to facilitate thermo-compression bonding of the latest and largest dies and substrates. Some key components of such systems, including a description of their capabilities and limitations, are outlined below. 
       Co-Planarity Adjustment System 
       [0004]    In high accuracy thermo-compression bonding applications it is critical to ensure co-planarity of the surfaces of the die and substrate to be bonded. Co-planarity, as used in this disclosure should be read as two opposing surfaces which are parallel to one another, i.e. they occupy the same plane. Attaining co-planarity of the surfaces upon which these components rest is the first step in achieving a uniform bonding of die to substrate; when the die and substrate are perfectly parallel, all solder bumps on the die will make contact with their corresponding substrate bond pads simultaneously, assuming all solder bumps were perfectly formed. Lack of co-planarity results in poor bonding with an uneven gap between die and substrate around the die perimeter once the bonding is completed. This can lead to the bonding process being compromised in the extreme case. In other cases the downstream process step of under-filling the gap between die and substrate is compromised, resulting in yield losses. 
         [0005]    Prior art co-planarity adjustment mechanisms tend to be unduly complicated and do not typically ensure that the corresponding surfaces are parallel across their entire surfaces. One example of such a prior art system is an auto-collimator. An auto-collimator is expensive and complex, requiring a high quality objective lens, capable of producing a collimated beam (parallel light rays) and motors with fine degrees of control, while only providing a point measurement, or the measurement of multiple points. Auto-collimators work by collimating light, using a high quality objective lens and directing the collimated light onto a plane mirror. The separation between the original (i.e. incident) light and the reflected light is then compared. By comparing the separation of the reflected light and adjusting the angle of the working surfaces, the working surfaces can be brought into a parallel relationship. In the foregoing description, a plane mirror should be understood as a mirror having a planar reflective surface. For light rays striking a plane mirror, the angle of reflection equals the angle of incidence, enabling the foregoing measurements. Importantly, a collimated beam of light does not spread out after reflection from a plane mirror, except for diffraction effects. Measurements of co-planarity made using this method are only based on a single point or a small number of single point measurements taken at various locations, however, making this method not particularly well suited to ensuring parallelism of opposing planes across their entire surfaces requiring extreme accuracy. 
         [0006]    Therefore, it is desirable to have an automatic method of ensuring the surfaces that hold the die and substrate are parallel to one another, using the average across the entire surface as the reference. 
       Gantry Without Moment Loading 
       [0007]    Gantries are commonly used in many automated processes to move parts from one place to another with precision. In most gantry designs used for thermo-compression bonding, the placement head is offset in an X or Y axis from the gantry rail/bearing supports, assuming bonding force is applied along a Z-axis and all planes are orthogonal to one another. Using such a gantry to apply force to a part however requires that the force applied not cause an excessive amount of deflection in the gantry itself, which is typically limited by the load carrying ability of the bearings upon which it rides. 
         [0008]    For lower force applications, the moment loads exerted (by the placement head during die placement) on the gantry bearings are negligible. At higher forces however, the moment loads can be significant. For applications requiring both high forces and high accuracy, these moment loads can result in small excursions at the bearing support, which are then amplified at the placement head, since they are offset in X or Y axis from the bearing. This results in placement inaccuracies. High force bonding, in this context, typically involves applying a bonding force of approximately 30-50 Kg. 
         [0009]    Prior art devices would typically use a conveyor belt, moving table, or other system to bring parts to a high force bonding system, which was stationary and which would typically make use of a large welded structure as a support. This structure added complexity and cost to the system and reduced the room available for other subsystems within the thermo-compression bonding system as well as the flexibility of the gantry itself, making a gantry capable of high force application without moment loading commercially desirable. Such a system would ideally allow for 6 degrees of freedom in the thermo-compression bonding system, but would enable the locking out of five of those degrees of freedom during high force bonding. 
       Heating &amp; Cooling System 
       [0010]    Thermo-compression bonding requires heating of a die and substrate in order to initiate bonding. Typically, in flip-chip thermo-compression bonding, the die will have already had small solder bumps applied to the surface to be bonded to the substrate, which has typically has small metal pads applied to the side to be bonded to the die that correspond to the solder bumps on the die. The die and substrate must be heated while pressure is applied in order to bond the die to the substrate. Even a single failed bond can cause a malfunction of the product. Die head heaters are used to heat the die, while substrate heaters are used to heat the substrate. 
         [0011]    Die head heaters used in thermo-compression bonding require high temperature ramp and cooling capability as well as temperature uniformity to ensure reliable thermo-compression bonding. These heaters are typically run at 400-420° C., but may be run to 500° C. in some situations. Substrate heaters are typically kept at lower temperature (˜150° C.) and may not require the high temperature ramp/cooling capability of the bond head heater. 
         [0012]    During thermo-compression bonding, heat is typically applied primarily to the die (typically silicon) since it can handle higher temperatures than the substrate, which is typically made out of organic material. This heat is transferred from the die to the substrate via the aforementioned solder bumps. The substrate acts as a heat sink, pulling heat away from the die. The attach process naturally creates a hot spot at the center of the die whereby the center solder bumps fuse to the substrate pads below, but the bumps at the outer periphery of the die may not. Typically, the larger the die, the larger the temperature gradient between the center and the edge of the die will be. This is true even with a heater which is uniformly heated across the die surface. This may lead to poor attach at the die edges, which is especially problematic in the case of relatively large dies. 
         [0013]    To achieve adequate bonding at the edges of the die using such a system, the die head temperatures may be set higher than would otherwise be required. This exposes portions of the die to higher temperatures than required, which could lead to failure of the die or reliability issues later. The extra heat required by this uneven bonding must also be generated and dissipated during production of each die/substrate combination, resulting in longer cycle times than might otherwise be achievable. 
         [0014]    Another concern regarding thermo-compression bonding heaters is their ability to heat and to dissipate heat quickly. Lowering the ramp-up and ramp-down times are crucial for lowering the overall cycle time and enabling higher production rates. Prior art systems use relatively small heaters with forced air cooling. This can work well for smaller dies, but results in unacceptably long cycle times for larger dies. 
         [0015]    Current workarounds involve the use of trim heaters, which attempt to balance the extra heat loss from the edges by adding a fixed amount of heat back into the edges of the heater. This can also minimize thermal stresses by minimizing uneven expansion. Even with the current state of the art, the centers of such heaters still tend to be relatively hot as compared to other portions of the heater. 
         [0016]    Still another concern regarding heating of a die and substrate in thermo-compression bonding applications is that, during bonding, the exact temperature at the intermetallic interface between the die bumps and the substrate pads is not known and not easy to determine in a dynamic system. In prior art systems, a delay is introduced after the bond head reaches a pre-determined temperature, to ensure the desired die bumps to substrate pad interface temperatures are reached where the bumps melt, alloy and attach to the substrate pad. These delays are empirically determined for a given die/substrate combination, resulting in shorter or longer cycle times and potential under or over heating of the die and substrate. This could be avoided if there was a direct method of determining that bonding had occurred or the pre-determined temperature had been reached. 
         [0017]    Furthermore, the substrate heater arrangement is typically larger than that of the die heater, to cater to a wide range of substrate sizes, and has significant thermal mass. When the die and substrate are brought together and the die is subsequently heated, the substrate with the heater arrangement below acts as a heat sink, pulling heat away. Since the mass of the substrate heater is significantly higher, its temperature does not appreciably change during the bond cycle. It also means that the bond head, typically above the substrate head, must have enough heating power to overcome the ‘drag’ of the heat sink effect of the substrate heater. 
         [0018]    Thus for higher performance, throughput and bonding of larger dies a solution is needed to minimize temperature gradients during the attachment phase of thermo-compression bonding and to allow for more accurate judgment of temperature at the interface between die bumps and substrate pads. 
       Bond Chamber Sealing: 
       [0019]    During the thermo-compression bonding process, it is often necessary to evacuate the bonding chamber of oxygen and other oxidizing agents because of the elevated temperatures used, which may result in unacceptable degradation of the product if not addressed. Typically, nitrogen is used as the inert gas, but other fluids, gases or combinations of either or both are also known. Occasionally, fluids, gases or combinations of either or both which are capable of removing oxidation, especially at lower temperatures, are used as well. 
         [0020]    In the first case, it is desirable to form a sealed bonding chamber to make efficient use of the inert gas. In the second case, it is typically imperative to seal the chamber to prevent the fluid or gas from reacting with other components of the machine, possibly causing degradation, as well as to protect the health and safety of the operators of such machines. Typically, an oxygen sensor would be used to ensure that the chamber was sufficiently evacuated for the intended operation to proceed. 
         [0021]    Current machines have not yet devised a solution which provides efficient sealing while retaining some flexibility to conform to a surface that is not precisely co-planar. Current solutions also fail to offer a seal which may retain its sealing ability while engaging in limited sliding motion in the plane defined by a sealing surface on the substrate head. 
         [0022]    What is needed, therefore, are techniques for sealing a bonding chamber which allow for the efficient usage of inert and oxide removal fluids, gases or combinations of either or both, which can provide effective sealing between surfaces which may not be co-planar while allowing sliding motion in the plane defined by a sealing surface of the substrate head. 
       BRIEF SUMMARY OF THE INVENTION 
       [0023]    Embodiments of the present invention provide a co-planarity adjustment system for bringing two opposing planar surfaces into a parallel relationship. Such a system is particularly useful for thermo-compression bonding, where surfaces on which a die and substrate are held must be kept as parallel as possible to improve cycle times and ensure a full bond is achieved across the full width of the components, although such a system could be incorporated into a variety of machine providing for contact between two planar articles or mating work pieces. 
         [0024]    Some embodiments use the concept of master and slave surfaces having respective master and slave planes, where the slave plane is made to conform to the master plane to achieve co-planarity of the respective surfaces. In thermo-compression bonding, the master plane would typically be the plane of the die head working surface and the slave plane would be the plane of the substrate head or platen, although it would be feasible to reverse these roles. 
         [0025]    In embodiments, the slave surface may be lockably mounted on a spherical bearing assembly, whereby the pitch orientation of the slave plane with respect to the reference plane is variable within the limits of the spherical bearing assembly. The variation in pitch can be measured plane to plane or orthogonally axis to axis Such limits may allow as much as +/−five (5) degrees or more with respect to the master or reference plane, but should preferably provide at least +/−two (2) degrees range of pitch motion when unlocked. Such a mechanism would typically be weighted or otherwise biased for self-centering alignment of the slave plane to the assumed orientation of the master plane, or put another way, alignment of their respective axis. The center of the slave surface may be located proximate the center point of rotation of the spherical bearing assembly to ensure motion of the slave surface when the spherical bearing assembly is unlocked and in motion is substantially constrained to changes in pitch orientation with respect to an axis orthogonal to the master plane. A drive mechanism, operating along an axis substantially orthogonal to the master plane, may be configured to bring the master surface and the slave surface into surface contact, which would force the slave plane to conform to the master plane and thereby achieve co-planarity of the two planes. 
         [0026]    To facilitate unlocking of the spherical bearing, typically performed in an automated manner by a controller, with manual operation also a possibility, a spherical bearing release mechanism may be configured to unlock the spherical bearing lock mechanism when actuated, thereby allowing motion of the spherical bearing assembly and movement of the slave plane. 
         [0027]    This release mechanism may also include a fluid system configured upon actuation to apply a first fluid under pressure to the distal end of the locking member so as to overcome the tension and move the locking member so as to disengage the locking contact between the bearing and the bearing seat, and to inject a bearing fluid under pressure between the bearing seat and the bearing whereby the spherical bearing assembly is made functional, and, upon deactivation to reduce pressure of the first fluid and the bearing fluid and thereby allow the lock mechanism to relock the spherical bearing assembly. In some embodiments, the first fluid and bearing fluid may be the same while in others they may differ. Exemplary fluids include nitrogen and air, although those skilled in the art will recognize that many fluids may be used for these purposes. 
         [0028]    The spherical bearing locking mechanism, alluded to above, may be configured to normally hold the spherical bearing assembly in a locked position, whereby the pitch orientation of the slave plane is locked. This is desirable to prevent loss of co-planarity when the system is turned off or high forces are applied. An exemplary spherical bearing lock mechanism may use an axially oriented locking member, having a retaining head and a shaft. The shaft may slidably extend through oversize apertures in the spherical bearing and bearing seat. A distal end of the shaft may normally be held in tension with respect to the bearing assembly to bring the bearing into locking contact with the bearing seat whereby the spherical bearing assembly is immobilized. 
         [0029]    Embodiments of the present invention, described above, could be calibrated to ensure co-planarity of the master and slave planes by unlocking the normally locked spherical bearing assembly, bringing the two planar surfaces together into full surface contact, thereby aligning the pitch orientation of the slave plane with the master plane, locking the spherical bearing assembly, thereby locking the slave plane in a co-planar relationship with the master reference plane, and separating the two planar surfaces. Those embodiments previously described using a fluid system for locking and unlocking of the spherical bearing would also require the user to reduce the first fluid and bearing fluid pressures in order to allow the lock mechanism to relock the spherical bearing assembly, although this could be programmatically controlled, as could any of the foregoing procedures involving achieving co-planarity using the described systems. 
         [0030]    One embodiment of the present invention provides a gantry and force applicator for applying pressure to a work piece. Although such a device is particularly well suited for use in a thermo-compression bonding system, those skilled in the art will recognize that it may also be advantageously used in other systems. Such a gantry and force applicator of the present embodiment is held within a housing with designated x, y and z axis, further including a force receiving surface attached to the housing, located on and oriented orthogonally to the aforementioned z axis. This embodiment also includes a force applicator mechanism attached to the housing, axially aligned with the z axis, located at a substantial distance from a force receiving surface and oriented to apply force in the direction of the force receiving surface. 
         [0031]    The gantry of this embodiment would typically be a multi-motion gantry system mounted to the housing, and having a die bond head system attached to the moving end, with a die head mounted on the die bond head system and oriented to oppose the force receiving surface. This gantry system would typically be configured to provide controllable motion with respect to at least one of x and y axis, thereby enabling the die bond head system to be extended and retracted laterally to and from a position between the force applicator mechanism and the force receiving surface. In embodiments, the die head may also be moved along the z axis towards and away from the force receiving surface, as required to accommodate a work piece positioned there between. 
         [0032]    Such a die bond head system may further include an axially aligned force translator in communication with the die head, configured to translate externally applied force in the z axis to the die head without introducing additional force vectors to the gantry system. When the die bond head system is positioned by the gantry system on the z axis centerline proximate the force receiving surface, an axial extension of the force applicator mechanism could then deliver compressive force through the force translator to the die head surface against the force receiving surface or any work piece disposed there between. 
         [0033]    Alternative embodiments of such a system may position the aforementioned force applicator on the die bond head system, and orient it such that, when extended axially, it contacts the force receiving surface. The same principles relating to translation of this force through a force translator into a die head would also be applicable to this embodiment. An exemplary force translator would be a substantially rigid rod, although those skilled in the art will recognize that there are many other possibilities. 
         [0034]    Another embodiment of the present invention provides an overload protection circuit between the force receiving surface and the die head, whereby force in excess of a predetermined amount causes the force translator to fail so as to protect the die head and any work in progress. In some embodiments, this overload protection circuit may be an air cylinder, although those skilled in the art will recognize that a variety of overload protection circuits may serve these purposes. 
         [0035]    A further embodiment of the present invention further comprises external force load sensors, encoders and micro-motion control capability, allowing the motion of the die head to be controlled as a function of force and distance traversed. Some algorithms may also allow for programmatic prediction of forces through predictive analysis using the output of such measurement instruments. 
         [0036]    Yet another embodiment of the present invention would also include, on the aforementioned die head, a die head heater, temperature sensor, and temperature control circuitry. 
         [0037]    A yet further embodiment of the present invention provides such a system, further including a user interface for control, either automatic, manual or semi-automatic, and monitoring of gantry motion, die head position, externally applied force, and die head temperature. Such a control system may further provide indications of whether the process is running normally or has encountered an abnormal condition. 
         [0038]    One embodiment of the present invention provides a heating system particularly well suited for thermo-compression bonding, although those skilled in the art will recognize it has many additional potential uses. Such a hearing system includes a die heater, a substrate heater and a temperature controller, which may be manual or automatic. 
         [0039]    The aforementioned die heater is operatively connected to a power source and further connected to a bond head system. It is configured to supply heat to a die to be bonded. The aforementioned substrate heater is also in communication with a power source, which may be the same or a different source than that supplying the die head heater, and operatively coupled to a substrate bond station. It is configured to supply heat to a substrate to be bonded. 
         [0040]    Also included in such a system is a temperature control means, which is operatively connected to the aforementioned power source, or sources, for limiting the amount of heating energy supplied to the die and substrate heaters to an amount sufficient to raise their temperature to a predetermined bonding temperature; wherein the die and substrate heaters include a plurality of separately controllable heating regions. 
         [0041]    The aforementioned die and substrate heaters may be electrical resistance heaters, induction heaters, gas heaters, or any other heater capable of providing separately addressable heating regions and sufficient heat to complete the bonding operation at hand. Exemplary heaters using traces of material to provide such differential heating (i.e. separately addressable heating regions) may use tungsten or other materials for their traces and aluminum nitride for their bodies and external portions, since both materials have compatible coefficients of thermal expansion over a wide range of processing temperatures, although those skilled in the art will recognize that a variety of materials could be used. 
         [0042]    In another embodiment of the present invention, the substrate heater may be heated to approximately 150 degrees Celsius while the die heater may be heated to between 400-500 degrees Celsius during a thermo-compression bonding operation of a die to a substrate. 
         [0043]    A further embodiment of the thermo-compression bonding heating system includes a substrate heater having two heater traces, a first heater trace positioned adjacent to a perimeter of the substrate heater and a second heater trace substantially evenly covering a central region of the substrate heater, wherein each heater trace may be independently controlled. Yet further embodiments include heaters having rings of separately and concentrically addressable heating regions or separately addressable heating regions arranged in a grid. 
         [0044]    The foregoing thermo-compression bonding system could be used, in an exemplary process, to selectively apply an excess of heat to a peripheral region of the substrate heater, thereby causing the peripheral region to attain a higher temperature than a central portion of the substrate heater. After differentially heating the substrate heater, heat could then be applied to a central region of said die heater, although the heat could also be applied evenly over the surface of the die heater without exceeding the scope of this disclosure, whereby the difference in heat between the selectively heated regions of the die and substrate heaters are sufficient to cause the heat fluxes of the die and substrate heaters to be in opposition to one another during bonding. This competing heat flux phenomenon is desirable to create more even heating, thereby allowing lower processing temperatures than those of the prior art and a higher process yield, due to decreased waste from incomplete bonding and/or part failure due to prolonged high heat exposure necessitated by the prior art heating devices. 
         [0045]    An alternative heating apparatus could also be used in a variety of processes, although it too is particularly well suited for thermo-compression bonding. Such a heating apparatus includes a heater body having a first surface operatively connected to a thermo-compression, or other, bonding system, a second surface distal from the first surface, for transferring heat to a product to be bonded and at least one cavity sized to accept a heater insert. This cavity, or each cavity in the case of multi-cavity heaters, may contain at least one heater insert, which would be in communication with a power source. The heating apparatus of this embodiment also includes a manifold, which contains a portion of the heater body, this portion typically being adjacent to the second surface of the heater body, and would further include at least one fluid injector. The fluid injector, in this embodiment, includes a proximal end in communication with a fluid supply and a distal end capable of fluid injection operatively coupled to an internal volume of the manifold. A manual or automatic controller could further be operatively connected to the injector or injectors, allowing control of the rate of injection of a fluid into said manifold. Lastly, such a heater would typically include at least one exhaust passage and a control means operatively connected to the power source for adjusting the amount of heating energy supplied to the heaters to an amount sufficient to raise their temperature to a predetermined temperature. 
         [0046]    Such a heating apparatus may also include a passage extending between and through the first and second surfaces, to allow a vacuum to be pulled, for engaging and retaining a part to be bonded or other purposes. 
         [0047]    Such a heating apparatus may further include a plurality of channels adjacent the second surface and within the portion of said heater body contained by the manifold, thereby increasing the surface area and improving the ramping capabilities of the heating apparatus. These channels may be formed of a substantially interlocking array of channels. 
         [0048]    The aforementioned exhaust passage may also be in communication with a vacuum source, a containment chamber and/or a heat exchanger and fluid recycling system. 
         [0049]    The aforementioned heating apparatus could be put to use by heating the heater body to a pre-set temperature, injecting fluid into the manifold, and slowing or stopping the injection of fluid to allow the temperature of the second surface of the heater body to rapidly increase. After bonding, the rate of fluid injection could then be increased to rapidly cool the second surface of the heater body. Importantly, the heater body temperature should not be substantially decreased by the injection of fluid, only the temperature of the second surface, upon which a die would typically be placed for bonding, should be rapidly and controllably altered by the injection of the fluid. An exemplary temperature to keep the heater body at during use would be  600  degrees Celsius for a thermo-compression bonding application. Alternatively, the injectors could inject a variety of fluids, gases, liquid metals, or other materials in order to achieve supplementary heating in addition to cooling. 
         [0050]    One embodiment of the present invention provides a substrate heater designed to closely match the substrate&#39;s overall size with a low thermal mass. The heater has feedback traces close to its top layer, where the substrate is placed. During bonding the substrate heater holds the substrate at a fixed (lower) preset temperature. During bonding, as the die is ramped to a higher temperature, the lower mass substrate heater reacts relatively quickly as the heat flows thru the bumps to the substrate and then to the heater below the substrate. The feedback traces located below the substrate pick up the change in temperature as soon as the heat flows thru the die bumps into the substrate. Instead of a fixed dwell set empirically (prior art) which can and does change due to die/substrate variations, and cleanliness, looking for a change in temperature of the substrate heater allows a user to determine more precisely when the die bumps to substrate pad interface temperatures have been reached resulting in a more robust process. Alternatively, an encoder configured to measure movement of the die bond head system with respect to the z-axis could monitor for a sudden, small, change in the position of the die bond head system, which could also be used to indicate temperature, since such small scale motion would occur upon collapse of the die bumps. 
         [0051]    One embodiment of the present invention provides a slidable seal system, well suited for sealing of a bonding chamber. Such a slidable seal system of this embodiment includes a compliant sealing body (e.g. a bellow) having an upper portion encircling and sealingly engaged to a die head. A first end of the die head would typically remain external to the compliant sealing body, allowing for it to be connected to the remainder of the system. A second, opposite, end of the die head, in this embodiment, would be enveloped by the compliant sealing body. The system further includes a bearing body having a first portion external to the compliant sealing body and a second portion internal to the compliant sealing body. The bearing body is sealingly connected to the compliant sealing body, at an end opposite that connected to the die head. The bearing body of this embodiment further includes a channel on a surface opposing a surface to be sealed against. 
         [0052]    The, surface, which is typically flat, opposing the bearing body is referred to as the seal collar, which may surround a chamber, a bond chamber in some embodiments, positioned opposite and substantially parallel to the bearing body channel. The bearing body also includes at least one seal body, in communication with at least one fluid source, substantially contained within the bearing body channel; the seal body being slightly narrower than the bearing body channel. This relationship between the bearing body and seal forms fluid passageways in the gaps between the bearing body channel and the seal body, providing for controlled fluid communication between the area to be sealed and the at least one fluid source, with a surface of the sealing body proximal the seal collar forming a second sealing surface. Such a seal body also has the benefits of allowing very efficient use of fluids and the ability to reposition the die bond head system for completion of multiple operations or other reasons. 
         [0053]    The seal body may also include one or more vacuum relief passages, in communication with one or more vacuum sources, on the first sealing surface, opposing the second sealing surface. This allows a strong vacuum seal between the first and second sealing surfaces, with the vacuum acting as a vacuum hold down and scavenging any fluids which may escape from the bond chamber during processing. In this way, the first and second sealing surfaces define a sealed cavity therebetween when the seal is active. Lastly, at least one extendable and retractable actuator, in communication with at least one controller, having a first end fixed to a first end of the die head and a second end fixed to the first portion of the bearing body, enable the slidable seal to be retracted from or lowered onto the first sealing surface during operation. These actuators could be linear actuators, piezo actuators or any number of other actuators suitable for extending and retracting when connected between the components previously described. 
         [0054]    In embodiments, the compliant seal of the slidable seal system, described above, is made of polytetrafluoroethylene, in other embodiments it may be made of other materials possessing the required compliance, mechanical strength, temperature stability and chemical resistance, dependent on the nature of the process to be sealed. Furthermore, the fluid used in conjunction with the slidable seal system may be an inert fluid (e.g. nitrogen), an oxide removal fluid (e.g. formic acid), or other fluid appropriate for the process being conducted. 
         [0055]    In another embodiment of the present invention, the seal body of the slidable seal system is an air bearing. This air bearing may be made of porous carbon or other suitable materials. Edges of the air bearing, where it is undesirable to allow the fluid injected therethrough to escape, may additionally be sealed by covering these surfaces with a material or sleeve impregnable to the fluid being injected therethrough. 
         [0056]    The previously described slidable seal system and embodiments thereof may be used by first positioning a part or parts to be acted upon within the sealed cavity created by the seal. The next step would then require positioning the bearing body proximately to the seal collar and activating the actuators to extend, thereby bringing the bearing body proximate to the seal collar. After the bearing body and collar are adjacent to one another, the vacuum source could then be activated to apply vacuum, via the vacuum relief passage, thereby strengthening the sealing force between the first and second sealing surfaces. Lastly, this process may include displacing one or more fluids from the at least one fluid source through the fluid passageways in communication with the sealed area. To unseal the chamber, one would typically terminate the vacuum from the vacuum source, cease displacement of the at least one fluid through the fluid passageways in communication with the sealed cavity. 
         [0057]    In some embodiments requiring oxide removal, formic acid, or other oxide removal fluid, may be injected, followed by nitrogen, to form a barrier to escape of the formic acid, thereby preventing its escape from the slidable seal system, where it may cause damage to other components of the system or merely be wasted. 
         [0058]    In one embodiment of the present invention, a labyrinth seal system for sealing a thermo-compression bonding chamber is disclosed. Such a chamber comprises a substrate bond station, comprising a substrate bonding surface and a substrate bond chamber perimeter, offset from the substrate bonding surface in the two axis occupied by the plane defined by the substrate bonding surface. The substrate bond station further comprises at least two substantially parallel extensions, adjacent to the substrate bond chamber perimeter and oriented orthogonally to the plane defined by the substrate bonding surface. The system also comprises a die bond head system further comprising a die bonding surface and a die bond chamber perimeter, offset from the die bonding surface in the two axis occupied by the plane defined by the die bonding surface, wherein the die bonding surface is substantially co-planar with the substrate bonding surface, the die bond station further comprising at least two substantially parallel extensions adjacent to the die bond chamber perimeter and oriented orthogonally to the plane defined by the die bonding surface. The substantially parallel extensions of the die bond station are offset from and oppose the parallel extensions of the substrate bonding surface such that when the substrate bonding surface and the die bonding surface are brought proximal to one another, the opposing parallel extensions interlock, forming a labyrinth passage therebetween. In some embodiments, there may also be included inlets for introduction of a fluid or for placing the now sealed bonding chamber, sealed by the labyrinth sealing arrangement, under a vacuum. Some such inlets may be in communication with the sealed chamber directly, while others may be in indirect communication with the sealed chamber, via a direct connection to the labyrinth passageways formed by the labyrinth seal. 
         [0059]    In use, bonding would begin by positioning at least work piece to be acted upon on the substrate bonding surface and positioning at least one work piece to be acted upon on the die bonding surface. Next, the substrate and die bonding surfaces would be positioned proximally to one another. When the aforementioned surfaces are adjacent, one or more fluids from at least one fluid source may be introduced to the bond chamber directly or through a passageway in communication with the labyrinth passageway. In some embodiments a vacuum may be introduced as well via either of the aforementioned passageways. The last step to using the labyrinth seal system for thermo-compression bonding is conducting a bonding process and ceasing displacement of the at least one fluid, or vacuum, and removing the bonded work piece. 
         [0060]    The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0061]      FIG. 1  is a top, left side perspective view of a thermo-compression bonding system in accordance with one embodiment of the present invention; 
           [0062]      FIG. 2  is a top, left side perspective view of the thermo-compression bonding system of  FIG. 1 , wherein body panels are removed to expose at least a portion of the internal components of the thermo-compression bonding system; 
           [0063]      FIG. 3  is a front elevation view of a substrate bond station in accordance with one embodiment of the present invention; 
           [0064]      FIG. 4  is a front section view of the embodiment of the substrate bond station of  FIG. 3 ; 
           [0065]      FIG. 5  is a front, right side perspective view of a gantry, a force applicator, a die bond head system and a substrate bond station, including various subsystems, in accordance with one embodiment of the present invention. 
           [0066]      FIG. 6  is a right side view of a gantry, a force applicator, a die bond head system and a substrate bond station, including various subsystems, in accordance with one embodiment of the present invention. 
           [0067]      FIG. 7  is a front, left side perspective view of a die bond head system in accordance with one embodiment of the present invention. 
           [0068]      FIG. 8  is a right side section view of a gantry, a force applicator, a die bond head system and a substrate bond station, including various subsystems, in accordance with one embodiment of the present invention. 
           [0069]      FIG. 9  is a front section view of a die bond head system in accordance with one embodiment of the present invention. 
           [0070]      FIG. 10  is a front, left side exploded perspective view of a thermal control system body in accordance with one embodiment of the present invention. 
           [0071]      FIG. 11  is a top view of a bonding fixture showing a heater lacking heater traces in a central region, causing a centrally flowing heat flux to be produced and providing differential heating and cooling capabilities in accordance with one embodiment of the present invention. 
           [0072]      FIG. 12  is a top view of bonding fixture showing a heater with separate center and peripheral heater traces, providing differential heating and cooling capabilities in accordance with one embodiment of the present invention. 
           [0073]      FIG. 13  is a top, left side perspective view of a rapid transition thermal management system in accordance with one embodiment of the present invention. 
           [0074]      FIG. 14  is a front section view of a rapid transition thermal management system showing the cooling passages and heater cavities in accordance with one embodiment of the present invention. 
           [0075]      FIG. 15  is a bottom, left side perspective view of a rapid transition thermal management system showing the plurality of intersecting passages adjacent the second surface of the rapid transition thermal management system, in accordance with one embodiment of the present invention. 
           [0076]      FIG. 16  is a section view of a die bond head system adjacent to a substrate bond station, particularly showing seal extensions fixed to each component, offset from one another such that, when brought more closely together, they interlock, forming a labyrinth seal, in accordance with one embodiment of the present invention. 
           [0077]      FIG. 17  is a section view of one portion of the labyrinth bonding chamber seal formed by the interlocking seal extensions shown in  FIG. 16 , in accordance with one embodiment of the present invention. 
           [0078]      FIG. 18  is a front view of a slidable seal system in an unsealed state in accordance with another embodiment of the present invention. 
           [0079]      FIG. 19  is a top, left side perspective section view of a slidable seal system sealingly engaged to a sealing collar in accordance with one embodiment of the present invention. 
           [0080]      FIG. 20  is a front section view of a slidable seal system sealingly engaged to a sealing collar in accordance with one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0081]      FIG. 1  shows an embodiment of a thermo-compression bonding system. As shown in  FIG. 1 , the thermo-compression bonding system  100  includes a housing  102  having at least one controller or user interface  104  in communication therewith. Exemplary controllers include, without limitations, computers, processors, buttons, switches, joysticks, user-actuated devices, and the like. Optionally, the controller  104  may be in physical communication with the housing  102  or may communicate with at least one component within the housing  102  via at least one conduit, computer network, or wireless network. 
         [0082]    Referring again to  FIG. 1 , the housing  102  may comprise one or more body panels  106  which cooperatively form the housing  102 . In another embodiment, the housing  102  may comprise a monolithic structure. Various materials may be used to form at least a portion of the housing  102 . Exemplary materials include, without limitations, steel, aluminum, composites, fiberglass, polymers, alloys, and the like. Further, the housing  102  may include one or more material passages  108  formed therein, the material passages  108  permitting components or materials to be processed to be positioned within and evacuated from the interior portion of the housing  102 . As such, various material handling systems and devices known in the art may be included within the housing  102  or positioned proximate thereto. Exemplary material handling systems include, without limitations, belt systems, guides, substrate/component positioning systems, tray holders, robotic material loading systems, and the like. In addition, at least one access area  110  may be formed in the housing  102  of the thermo-compression bonding system  100 , thereby permitting a user to access and/or view the internal components of the thermo-compression bonding system  100 . In another embodiment, housing  102  may be formed without having at least one of the material passage  108  and/or access area  110  formed therein. 
         [0083]    As shown in  FIG. 1 , at least one indicator  112  may be positioned on or otherwise be in communication with at least one component positioned within or otherwise in communication with the housing  102 . For example, the indicator  112  may be in communication with the controller  104 . During use, the indicator  112  may be used to indicate various aspects of the thermo-compression bonding procedure being conducted by the thermo-compression bonding system  100 . 
         [0084]    Referring again to  FIG. 1 , one or more supports  114  may be coupled or otherwise in communication with the housing  102 . For example, in one embodiment, the supports  114  are coupled to an exterior surface of the housing  102 . In another embodiment, the supports  114  may be coupled to or otherwise in communication with a frame and support structure (not shown) positioned within the housing  102  or positioned outside the housing  102 . In one embodiment, the supports  114  comprise support frames configured to support and elevate the housing  102  from a work surface such as a floor, deck, or similar surface. In another embodiment, the at least one of the supports  114  comprises a vibration isolation device configured to isolate the thermo-compression bonding system  100  from vibrations of the work surface. In still another embodiment, the support  114  may include a vibration damper configured to damp any vibration transmitted from the work surface to the thermo-compression bonding system  100 . Optionally, the supports  114  may be configured to isolate the thermo-compression bonding system  100  from vibrations, electric or static charge, environmental conditions, structural conditions, and the like present in or on the work surface support the thermo-compression bonding system  100 . 
         [0085]    Referring to  FIGS. 1-2 , these figures show various views of an embodiment of a thermo-compression bonding system  100  having at least one body panel  106  removed therefrom, thereby exposing at least a portion of the internal components of the thermo-compression bonding system  100 . As shown, the thermo-compression bonding system  100  may include at least one gantry or movable framework  200  positioned within the housing  102 . The gantry  200  may be coupled to a support frame  116  positioned on or within the housing  102 . The gantry  200  includes a first gantry positioner (not shown) and at least a second gantry positioner (not shown). The first gantry positioner (not shown) permits movement of the gantry  200  along a first line I 1  (X axis), while the second gantry positioner (not shown) permits movement of at least a portion of the gantry  200  along a second line I 2  (Y axis). As shown in  FIG. 2 , the first line I 1  and second line I 2  are orthogonal. Optionally, first and second lines I 1 , I 2 , respectively, need not be orthogonal. As such, the first and second gantry positioners (not shown), enable multi-axial movement of components coupled to the gantry  200 . Any variety of devices may be used to form the gantry  200 , the first gantry positioner (not shown), and/or the second gantry positioner (not shown). For example, in one embodiment, the first and second gantry positioners (not shown) comprise linear motors. In another embodiment, the first and second gantry positioners (not shown) comprise air bearings. Optionally, the any variety of devices may be used to form the gantry  200 , the first gantry positioner (not shown), and/or the second gantry positioner (not shown), including, without limitation, pneumatic drives, screw drives, piezo actuators, electro-mechanical positioners, and the like. 
         [0086]    Referring again to  FIGS. 1-2 , at least one die bond head system  202  having at least one force applicator  204  coupled thereto and at least one substrate bond station  206  are positioned within the housing  102 . In the illustrated embodiment a single die bond head system  202  is coupled to a single substrate bond station  206 . Optionally, any number of die bond head systems  202  may be included within the thermo-compression bonding system  100 . Similarly, any number of substrate bond stations  206  may be included in the thermo-compression bonding system  100 . 
         [0087]    In the embodiment shown in  FIGS. 1-2 , the position of the substrate bond station  206  may be fixed while the die bond head system  202  is coupled to the gantry  200 , thereby permitting the die bond head system  202  to be selectively positioned with respect to the substrate bond station  206 . In another embodiment, the position of the die bond head system  202  may be fixed while the substrate bond station  206  is selectively positioned with respect to the die bond head system  202  and force applicator  204 . Optionally, both the die bond head system  202  and the substrate bond station  206  may be independently movable. 
         [0088]    Further, the thermo-compression bonding system  100  may include any number and variety of additional subsystems therein. For example, in one embodiment, the thermo-compression bonding system  100  includes one or more material handling systems (not shown) configured to retrieve and/or place one or more substrates and/or components on at least one of the die bond head system  202  and the substrate bond station  206 . Exemplary material handling systems include, without limitations, robotics systems, air bearings, belts, tray loading systems, and the like. In another embodiment, the thermo-compression bonding system  100  may include one or more substrate and/or component heating subsystems configured to heat the substrate and/or component prior to placement on the die bond head system  202  and/or substrate bond station  206  or following the bonding process. In another embodiment, the thermo-compression bonding system may include one or more substrate and/or component cleaning systems configured to pre-clean the substrate and/or components. For example, the cleaning system may be configured to limit or eliminate the formation of oxides on the components and/or substrates. In short, the thermo-compression bonding system  100  may comprise a modular system wherein the number and variety of various subsystems, head systems, cameras systems, and the like may be easily added and/or removed from the system. 
       Co-Planarity Adjustment System 
       [0089]    The design of the thermo-compression bonding system  100  responsible for ensuring co-planarity between the die head thermal control system body  700 , located on the die bond head system  202  and the substrate head thermal control system body  500 , located on the substrate bond station  206 , in one embodiment, uses the concept of a master and a slave plane. 
         [0090]    With reference to  FIGS. 3-4 , the master plane is defined by the die head thermal control system body  700  and the slave plane is defined by the substrate head thermal control system body  500 . To maintain simplicity and gantry platform robustness it is desirable to put the remaining 2 degrees of freedom on the station that holds the substrate. The additional two degrees of freedom on the slave plane, in embodiments, are achieved by using a spherical joint  400  that can be ‘unlocked’ to a compliant state, to allow it to conform to the master plane. Once the master and slave planes conform, the spherical joint  400  is locked to ensure the master/slave planarity is maintained. Those skilled in the art will appreciate that any variety of devices may be used to enable such functionality and that the location of each component may be altered without significantly altering the functionality of such components. 
         [0091]    In one embodiment, the spherical joint  400  is a spherical air bearing. When the system is pressurized, a second spherical surface  410  of the spherical joint  400  is separated from an engaging face  412  of the same, which allows for two degrees of freedom in the spherical joint  400 . By subjecting the air bearing to vacuum, the setting can be locked. 
         [0092]    In another embodiment of the present invention, as shown in  FIGS. 3-4 , an alignment body  404  disengages from a first spherical surface  406  on the alignment body support  408  thereby permitting the alignment body support  408  to freely move. For example, in one embodiment the second spherical surface  410  of the alignment body  404  is movable in relation to the engaging face  412 . Optionally, the interface between the second spherical surface  410  and the engaging face  412  comprises a fluid bearing. 
         [0093]    Further embodiments, shown in  FIGS. 3-4 , incorporate a biasing member  402 , which applies a 300-400 pound downward force to a first spherical surface  406  of the spherical bearing, pressing a second spherical surface  410  and an engaging face  412  of the spherical joint  400  together, thus preventing unwanted movement of the two halves of the bearing, even when the system is switched off or during high force operation. The pressure generated by the biasing member is typically overcome by the same pressure used to actuate the spherical air bearing. After application of air pressure to the air bearing and alignment body, unlocking the spherical joint  400 , the bond head will apply a calibration force, ideally the same force used in the specific thermo-compression bonding operation to be conducted, to simulate the exact conditions as will be encountered in actual operation. This force must be at least enough to overcome any friction or cable forces. After the force has been applied and co-planarity has been achieved, the pressure is released and vacuum is applied to the spherical air bearing and biasing member, locking in the setting. 
         [0094]    The die and substrate holding planes can be made co-planar as a part of the system setup, prior to running the system, or at a user defined frequency (time based or based on the number of parts run) during a production run, to ensure high reliability attach. This process should also be completed if components on the system are changed or adjusted during maintenance. 
         [0095]    With regards to using the above-described system to obtain co-planar surfaces; with the spherical joint  400  unlocked the die bond head system  202  is positioned on top of the substrate bond station  206 . The die bond head system  202  is then moved down in the Z axis, by the gantry  200 , to bring the die and substrate holding planes into intimate contact. The gantry head then applies a preset force to ensure the substrate holder plane ‘self aligns’ to the die holder plane. The unlocked spherical joint  400  ensures that the planes are able to self-align. 
         [0096]    With the gantry  200  pushing downwards in the Z-axis and forcing the die and substrate holder planes into a parallel relationship, the force generator  280 , an air cylinder in some embodiments, is then retracted. The biasing member  402  then extends to its original length, pushing the forcer  414  down, in turn locking the spherical joint  400  in place. The gantry  200  may then release pressure from the substrate bond station  206 . 
         [0097]    Once co-planarity is achieved, the position of the substrate bond station  206  is fixed by controllably retracting the force generator  280  in the co-planarity system body thereby resulting in the alignment body  404  re-engaging the alignment body support  408 . A biasing force is applied to the alignment body support  408  via the alignment body  404  by the biasing member  402 , a die spring in some embodiments. Those skilled in the art will appreciate that any variety of alternate devices and systems may be used to fix the position of the substrate bond station  206 . For example, mechanical systems, magnetic systems, vacuum systems, pneumatic systems, and/or any combination thereof may be used to fix the position of the substrate bond station  206  to ensure co-planarity. 
         [0098]    In one embodiment, the force generator  416  comprises at least one air cylinder or air bearing. Those skilled in the art will appreciate that any variety of devices may be used to form the force generator  280 . 
         [0099]    This process of adjusting the orientation of the slave plane to that of the master plane may be a set-up or calibration procedure ahead of production runs. 
         [0000]    Gantry without Moment Loading 
         [0100]      FIG. 5  shows an embodiment of a thermo-compression bonding subsystem, a gantry capable of high force application without moment loading. 
         [0101]      FIGS. 5-9  show detailed views of the interface of the gantry  200  and the placement head body  702  as well as additional embodiments and features. As shown, the gantry  200  includes at least one placement head body support  602  configured to have at least a portion of the placement head  70  coupled thereto. The placement head body support  110  includes at least one slide assembly  604  positioned thereon. In the illustrated embodiment, the slide assembly  604  enables the placement head body  702  to move along the line I 3 , which is substantially parallel to the longitudinal axis of the thermo-compression bonding system. More succinctly stated, the slide system  604  enables movement of the placement head system  702  along the Z axis relative to the X axis and Y axis described above. As such, components or devises engaged by or retained by the die bond head system  202  may be moved in the XYZ and theta planes (as such, four (4) degrees of freedom) via the first gantry positioner (not shown), second gantry positioner (not shown), the motor  908  (see  FIG. 9 ), and the z slide system  604  (see  FIG. 6 ). 
         [0102]    Referring again to  FIGS. 5-9 , the slide assembly  604  may include a slide assembly housing  802  having at least one drive motor  804  therein. In one embodiment, the drive motor  804  comprises an electro-mechanical drive. Optionally, the drive motor  804  may comprise a linear motor, pneumatic drive system, and the like. Further, the slide assembly housing  802  may include one or more drive tracks  806  thereon, the drive track  120  configure to movably engage at least one placement head track  808  on the placement head body  702 . During use, the drive motor  804  receives at least one control signal from the controller  104  (See  FIG. 1 ) and reacts in response thereto, resulting in movement of the placement head track  808  supporting the placement head body  702  relative to the drive track  120 . As such, movement of the placement head body  702  along the Z axis may be achieved. 
         [0103]    In one embodiment, a force applicator  204  is detachably coupled to die bond head system  202 . The force applicator  204  may be configured to provide precise, incremental displacement control of the die head thermal control system body  700 . As such, the force applicator  204  may be coupled to a support member  208  positioned within the housing  102 . Optionally, the support member  208  may be coupled to or integral to support framework (not shown) formed within the housing  102 . In another embodiment, the force applicator  204  may alternatively be non-detachably coupled to the die bond head system  202 . 
         [0104]    Referring now to  FIG. 6 , a force applicator receiver  600  is configured to receive and/or engage at least a portion of the force applicator  204 , thereby permitting the force from the force applicator  204  to be transferred to the force rod  800  via the load cell  900 . Optionally, one or more auxiliary force applicator receivers (not shown) may be formed on at least a portion of the placement head body  702 . Like the force applicator receiver  600 , the auxiliary force applicator receiver (not shown) may be configured to have any variety of force applicators  900  coupled thereto thereby enabling the force from the force applicator  204  to be transferred to the force rod  800  via the load cell  900 . 
         [0105]    In further embodiments, as shown in  FIGS. 5-9 , a load cell  900  is used to measure the force applied. The load cell  900  can also be used to enable the thermo-compression bonding system  100  to detect contact between a die and substrate. In one embodiment, the load cell  900  comprises a piezo actuated device, although those skilled in the art will appreciate that any variety of devices may be used to form the load cell  900 . 
         [0106]    Still further embodiments incorporate an overload protection system, analogous to a fuse in an electrical circuit. Embodiments of the present invention utilize an air cylinder arrangement, which will collapse should a set force be exceeded, to accomplish this. Such an air cylinder may be located either within the die bond head system or the substrate bond station  206 . 
         [0107]    Referring still to  FIGS. 5-9 , at least one load cell  900  may be positioned within the placement head body  702 . In one embodiment, the load cell  900  comprises a piezo actuated device, although those skilled in the art will appreciate that any variety of devices may be used to form the load cell  900 . For example, the load cell  900  may comprise electro-mechanical devices, pneumatic devices, and the like. 
         [0108]    During use, the load cell  900  may be actively monitored via any number of load sensors  304  or others similar devices located within or proximate to the load cell  900 . For example, the controller  104  may be in communication with the load cell  900  to actively monitor the force or load ramps being selectively applied by the force rod  800  by the force applicator  204  (See  FIG. 2 ). As such, the load cell  900  may be coupled to the force rod  800  with one or more load couplers  902 . Optionally, at least one load cell  900  may be directly coupled to at least one force applicator  204 . Further, optionally, any number of load cells  90  may be located anywhere within the thermo-compression bonding system  100  (See  FIG. 1 ). In the illustrated embodiment, the load cell  900  is positioned with or proximate to at least one load cell support  904 , the load cell support  904  configured to position the load cell  900  at a desired location within the placement head body  702 . 
         [0109]    In the embodiment illustrated in  FIG. 9 , the load sensors  304  are positioned on the load cell support  904  and placement head body  702 . Optionally, those skilled in the art will appreciate that the load sensors  304  may be located anywhere on the placement head body  702  or the die bond head system  202 . Optionally, load sensors  304  may be similarly positioned on the substrate bond station  206 . In another embodiment, the load cell  900  and load sensor  304  may be configured to provide information to the controller  104 . For example, the load cells  900  and load sensor  304  and at least one encoder (not shown) may be used to provide force and distance data to the controller  104 , thereby enabling detection of various conditions, including, for example, melt sensing or detection. 
       Heating and Cooling System 
       [0110]    In one embodiment, as illustrated in  FIGS. 16 , at least one of the die head thermal control system body  700 , substrate head thermal control system body  500  and bonding fixture  306  is configured to provide heat to at least one of a die supported by the die head thermal control system body  700  and a substrate positioned on or in close proximity to the bonding fixture  306  thereby controllably coupling the die to the substrate. In one embodiment, at least one of the die head thermal control system body  700 , substrate head thermal control system body  500  and bonding fixture  306  is uniformly heated or cooled. 
         [0111]    Referring to  FIG. 10 , an exploded view of a substrate head thermal control system body  500  is shown. The substrate head thermal control system body  500  comprises a cover  1000 , to transfer heat, a primary heater  1002 , generally used for ramping temperatures, a secondary heater  1004 , generally used for holding temperatures, a clamp  1006 , for holding the system together, a cooling block  1008 , for allowing airflow through the system, a seal  1010 , for isolating the upper portion of the system, a main heater body  1012 , a distribution block  1014 , and a manifold or base  1016 . These components can be made of any material having sufficient thermal and mechanical strength; however, in embodiments the cover  1000 , primary heater  1002 , cooling block  1008 , and main heater body  1012  may be made of aluminum nitride. In other embodiments, the clamp  1006  is made of steel, the seal  1010  is made of polytetrafluoroethylene, the distribution block  1014  is made of aluminum oxide and the manifold or base  1016  is made of 7075-T6 aluminum. Those skilled in the art will appreciate that any number of materials could be used. 
         [0112]    Optionally, sections or regions of the substrate head thermal control system body  500  and die head thermal control system body  700  may be selectively heated or cooled. For example,  FIGS. 11-12  show different embodiments of heaters configured to differentially heat regions of a substrate positioned on or proximate to the heater surface  302  positioned on the bonding fixture  306 . As shown, a first thermal region  1100  and at least a second thermal region  1102  may be formed within the bonding fixture  306 . As such, differential heating of portions of the substrate positioned on the heater surface  302  coupled the bonding fixture  306  may be accomplished. In one embodiment, a first thermal region  1100  is heated to a first temperature T 1  via a first conduit  1200  while a second thermal region  1102  is heated to a second temperature T 2  via a second conduit  1202  wherein T 1  is greater than T 2 . In the alternative, the first thermal region  1100  may be heated to a first temperature T 1  via the first conduit  1200  while the second thermal region  1102  is heated to a second temperature T 2  via the second conduit  1202 , wherein T 2  is greater than T 1 . A typical conduit would be made of tungsten, while a typical thermal region in contact with a substrate would be made of aluminum nitride, however, any materials having sufficient conductivity, thermal stability, and substantially similar coefficients of thermal expansion could be used. 
         [0113]    The embodiment depicted in  FIG. 11  discloses a differential heating system wherein the heat is provided to at least one of the first thermal region  1100  and/or the second thermal region  1102  and permitted to flow via the thermal conductivity characteristics of a substrate positioned thereon to a central portion  1104  of the substrate. The size of the ‘hole’ can be selected to cater to a number of substrate die combinations where the die outer dimensions are similar. 
         [0114]    In contrast,  FIG. 12  shows an alternate embodiment of an exemplary differential heating system which includes a first thermal region  1100  formed by a first conduit  1200  and at least a second thermal region formed by at least a second conduit  1202 . Those skilled in the art will appreciate that any number of thermal regions may be formed by any number of conduits coupled to or otherwise formed within at least one of the substrate head thermal control system body  500  or die head thermal control system body  700 . 
         [0115]    For certain applications, based on the device metallurgies it may be beneficial to maintain the die and substrate at a temperature differential during the bonding process. For reliable bonding the differential needs to be held at the desired value to minimize coefficient of thermal expansion mismatch issues. 
         [0116]    In the previously described embodiments, heater traces or conduits placed adjacent to the periphery of a given heater may be used to add heat into the system in such a way that the center of the substrate is no longer hotter than surrounding material. This may be accomplished by varying the ratio of trim to main heater to force heat flow to flow into the center of the heater, rather than towards its edges. Some embodiments include thermocouples attached at various points to facilitate real-time monitoring. In a typical process, the main heater may be set between 50-100% of full power with the trim heater set to between 25% and 50% of full power. Alternatively, a heater with separately addressable concentric rings of traces or quadrant heaters, having individually addressable heating sections arranged in a grid, could also be employed. 
         [0117]    In practice, the substrate heater may be kept slightly below its desired temperature set-point prior to bonding. After the die is placed on the substrate the bond head is ramped to its desired temperature. At the same time (or after a small dwell) the substrate heater is energized to elevate the substrate temperature to its desired set-point. 
         [0118]    By design, the embodiments shown in  FIGS. 11-12 , force the substrate heat flux to flow inward from the substrate edges to the center while the bond head pushes heat outward from the die center towards the edges. This opposing heat flux phenomena is effective to smooth out the temperature gradients from the center of the die to the periphery, enabling superior uniformity of bonding of die to substrate. 
       Fluid Injection for Cooling 
       [0119]    For thermo-compression bonding, a die and substrate need to be brought to their final bonding temperatures, while under compression, in order to join the solder bumps on the die to their corresponding metalized pad on a substrate. If the die and substrate are exposed to higher temperatures for prolonged durations it can cause issues, such as oxide creation, which can compromise the integrity of the bonded product. Thus, the ability to ramp temperatures up quickly to bonding temperatures is critical. Furthermore, once the bonding is completed the temperatures need to be brought down quickly in order to ‘freeze’ the components in place. The ability to ramp the temperature down quickly is therefore also a critical requirement. Since the time to ramp temperatures up and down are a part of the overall bonding cycle time, the ability to ramp temperatures up and down quickly also contributes to a reduction in the overall cycle time. 
         [0120]      FIGS. 13-15  show various views of an embodiment of a rapid transition thermal management system  1300  adapted for use in manufacturing applications. More specifically, the rapid transition thermal management system  1300  shown in  FIGS. 13-15  is well suited for use in thermal compression bonding applications. In other embodiments, the rapid transition thermal management system  1300  disclosed herein is useful in the manufacture of advanced microelectronic packages and devices. Optionally, the rapid transition thermal management system  1300  disclosed herein may be used in die bonding applications, biotechnology applications, and the like. 
         [0121]    As shown in  FIGS. 13-15 , the rapid transition thermal management system  1300  includes at least one heater device  1302  having at least one injector  1304  positioned proximate thereto. In the embodiment shown in  FIG. 1 , four injectors  1304  are positioned proximate to the heater body  1306  of the heater device. In another embodiment, a single injector  1304  may be used. Optionally, any number of injectors  14  may be used with the present system. The injectors  1304  may be in fluid communication with one or more sources of fluid, one or more pumps, pressure regulators, flow meters, sensors, and the like. Exemplary fluids include, without limitations, water, coolants, gases, viscous materials, and the like. Further, one or more pumps or similar devices may be used to pressurize the fluids injected into the heater body  1306  of the heater device  1302 . 
         [0122]    Referring again to  FIGS. 13-15 , at least one manifold  1308  may be positioned on or proximate to the heater body  1306  of the heater device  1302 . In one embodiment, the manifold is coupled to the heater body  1306  in a sealed relation. As such, fluids or coolants introduced into the heater body  1306  by the injectors  1304  may contained therein. Further, the manifold  1308  may include one or more exhaust passages  1310  thereon, thereby permitting fluids or coolants to be evacuated from the heater body  1306  during use. An interior portion of the manifold  1308  may define a fluid or coolant region or reservoir  1312  therein. Further, the exhaust passage  1310  may be coupled to an external collection reservoir, evacuation pump, or other system (not shown) configured to evacuate and/or collect the coolant injected by the injectors  1304  and contained within the coolant reservoir formed in the manifold  1308 . 
         [0123]    Referring still to  FIGS. 13-15 , the heater body  1306  may comprise a monolithic body formed from any variety of materials. Exemplary materials include, without limitations, aluminum, copper, copper-tungsten alloys, various metals, alloys, ceramic materials or coatings, composite materials, and the like. Optionally, the heater body  1306  may be manufactured from one or more materials and, as such, the heater body  1306  may comprise a laminar structure. In one embodiment, the heater body  1306  is manufactured from a material having a high thermal conductivity. 
         [0124]    Referring again to  FIGS. 13-15 , the heater body  1306  includes a first surface  1314  thereon. At least one passage or lumen  1316  may be formed on the first surface  1314  of the heater body  1306 . In one embodiment, the lumen  1316  traverse through the heater body  1306  and is in communication with a second surface  1400  formed on the heater body  1306 , the second surface  1400  formed distally from the first surface  1314 . Optionally, as shown in  FIGS. 1-3 , the lumen or passage may include at least one passage extension  1318  which extends from at least one of the first surface  1314  and/or second surface  1400 . Optionally, the passage extension  1318  may include one or more coupling devices, threads, or the like formed thereon, thereby permitting the passage extension  1318  to be coupled to an external component (not shown). In one embodiment, the passage extension  1318  may be coupled to an external vacuum source (not shown), thereby permitting a vacuum force to be applied to a device or component positioned proximate to the second surface  1400  of the heater body  1306 . For example, in one embodiment the vacuum force applied via the passage  34  of the heater body  1306  proximate to the second surface may be used to selectively couple one or more die, substrates, or components to the second surface  1400  of the heater body  1306 . As such, optionally, the second surface  1400  may include one or more features, indents, features, fiducials, registrations, or the like thereon to aid in positioning and retaining at least one component thereon. 
         [0125]    Still again referring to  FIGS. 13-15 , the heater body  1306  may include one or more insert receivers  1320  formed on at least one sidewall  1402 . As shown in  FIGS. 1 and 2 , the one or more heater inserts  1404  may be positioned within the insert receivers  1320  (See  FIG. 3 ) formed on the sidewall  1402 . In one embodiment, the heater inserts  1404  comprise ceramic heaters. Optionally, the heater inserts  1404  may comprise propane heating devices or induction heaters. In short, any variety of heating devices may be used as heater inserts  1404 . Further, any number of insert receivers  1320  may be formed on the heater body  1306 , the insert receivers  1320  configured to receive any number of heater inserts  1404  therein. Optionally, the insert receivers  1320  may traverse the heater body  1306  or, in the alternative, may terminate within the heater body  1306 . 
         [0126]    As shown in  FIG. 13-15 , one or more cooling passages  1322  may be formed in the heater body  1306 . In the illustrate embodiment the cooling passages  1322  are formed on the heater body  1306  proximate to the second surface  1400 . Optionally, the cooling passages  1322  may be formed anywhere on the heater body  1306 . Further, the cooling passages traverse the heater body  1306 . Optionally, the cooling passages  1322  may terminate within the heater body  1306 . Further, the cooling passages may be formed one any surface of the heater body  1306 . For example, as shown in  FIG. 2 , the cooling passages  1322  may be positioned proximate to the second surface  1400  of the heater body  1306  and configured to be positioned proximate to the cooling region  1312  formed in the manifold  1308 . As such, during use, coolants injected into the manifold  1308  by the injectors  14  may flow through the various coolant passages  1322  formed in the heater body  1306 . Additional embodiments could also use a variety of fluids to provide supplemental heating through these same channels. 
         [0127]    As shown in  FIGS. 13-15 , the cooling passages  1322  may be formed having one passage walls  1500  which may intersect neighboring cooling passages  1322 . As such, the various intersecting channels configured to receive coolant therein may be formed by the cooling passages  1322  formed in the heater body  1306 . As shown in  FIG. 4 , the cooling passages  1322  may be similarly sized. In the alternative, the various cooling passages be of varying sizes. The formation of the cooling passage exposing the passage walls  1500  greatly increases the surface area of the heater body  1306 , thereby increasing the thermal exchange between the heater body  1306  and the coolant flowing through the cooling passages  1322 . 
         [0128]    During use, the rapid transition thermal management system  1300  described herein may be used with any variety of assembly systems, including thermo-compression bonding systems as well as a wide variety of pick and place die bonding systems, microelectronic packaging systems, and the like. 
         [0129]    Once positioned within the assembly system, the injectors  14  are coupled to source of coolant (not shown) and the exhaust passage  18  is coupled to an external collection reservoir (not shown). Lastly, at least one of the lumens  34  and/or passage extensions  50  (if present) may be coupled to at least one vacuum source (not shown). 
         [0130]    To initiate thermo-compression bonding, with the rapid transition thermal management system  1300  coupled to the assembly system, the heater body  1306  of the rapid transition thermal management system  1300  is heated to a desired temperature by activating the heater inserts  1404  located within the insert receivers  1320 . As such, the second surface  1400  of the heater body  1306  may be configured to remain at an elevated temperature, thereby heating a die, substrate, and/or component coupled to the second surface  1400  of the heater body  1306  to a desired temperature. For example, the heater body  1306  and the second surface  1400  of the heater body  1306  may be configured to remain at a temperature of about  600 ° C. As such, the heater body  1306  may be configured to operate as a thermal reservoir. Further, the temperature of the second surface  1400  of the heater body  1306 , and the die, substrate, and/or component coupled to the second surface  1400  of the heater body  1306 , may be easily and controllably lowered by flowing coolant through the injectors  14  and into the cooling passages  1322  formed in the heater body  40 . For example, the flow of coolant through the cooling passages  1322  may reduce the temperature of the second surface  1400  of the heater body  1306  to a temperature of about 400° C. In addition, the coolant may be evacuated from the heater body  1306  via the exhaust device  18 . As a result, the temperature of the heater body  1306  may be easily and quickly increased or reduced. 
         [0131]    With the temperature of the second surface  1400  of the heater body  1306  reduced, at least one die, substrate, or component is positioned proximate to the lumen  1316  located on the second surface  1400  of the heater body  1306 . The external vacuum source (not shown) may then be activated, thereby resulting in the die, substrate, and/or component being coupled to the second surface  1400  of the heater body  1306  using vacuum force. As such, the die, substrate, and/or component will be heated to a desired temperature. One or more parts to be coupled to the die, substrate, and/or component may then be positioned thereon. Thereafter, the flow of coolant through the passages  1322  may be reduced or stopped, which results in the temperature of the second surface  1400  of the heater body  1306  to controllably rise, thereby melting an adhesive or epoxy located on the die, substrate, and/or component and coupling the part thereto. 
         [0132]    In one embodiment, the temperature of the second surface  1400  quickly and controllably rises to an elevated temperature. In an alternate embodiment, the temperature of the second surface  1400  may be configured to slowly and controllably rise to an elevated temperature. 
         [0133]    Once the part is coupled to the die, substrate, and/or component, the flow of coolant through the cooling passages  1322  of the heater body  1306  may begin or be increased. The coolant injected through the injectors  1304  results in the temperature of the second surface  1400  of the heater body  1306  to controllably decrease, thereby resulting in the adhesive and/or epoxy of the die, substrate, and/or component to harden, thereby coupling the part to the die, substrate, and/or component. In one embodiment, the flow of coolant through the injectors  14  results in the temperature of the second surface  1400  to quickly and controllably decrease. In an alternate embodiment, the flow of coolant through the injectors  1304  results in the temperature of the second surface  1400  to slowly and controllably decrease. 
         [0134]    Thereafter, the completed component assembly may be removed from the rapid transition thermal management system  1300 . Optionally, those skilled in the art will appreciate that the temperature of the second surface  1400  of the heater body  1306  may be easily and repeatedly cycled from an elevated temperature to a lower temperature or, in the alterative, held at a desired temperature. 
       Bond Chamber Sealing 
       [0135]      FIGS. 16-20  show embodiments of a bond chamber seal system. More specifically,  FIGS. 16-17  disclose a labyrinth seal system, formed during bonding by seal extensions  318  of the seal body  2002 , which are aligned substantially orthogonally to the system X and Y axis and axially aligned with the system Z axis and are made to interlockingly engage seal extensions  318  on the seal collar  202 , which are also aligned substantially orthogonally to the system X and Y axis and axially aligned with the system Z axis but facing the seal extensions of the seal body  2002 , thereby forming the labyrinth seal passage  1700 . 
         [0136]      FIGS. 18-20  show a slidable seal system  810  configured to create a closed environment containing at least a portion of the substrate head thermal control system body  500 , die head thermal control system body  700  and bonding fixture  306 . The slidable seal system  810  may include at least one substrate head thermal control system body  500  having one or more passages  1802  formed therein and at least one die head thermal control system body  700 . In one embodiment, the bearing system comprises at least one air bearing. Optionally, those skilled in the art will appreciate that any number and variety of bearing systems may be used with the present system. 
         [0137]    Referring again to  FIGS. 18-20 , the bearing body  1808  may include one or more extensions  1802  configured to have one or more actuators  1810  coupled thereto. During use, the actuators  1810  may be activated to controllably move at least one component forming the slidable seal system  810  along the Z axis. As such, at least one actuator  376  may be in communication with at least one controller or processor (not shown). In one embodiment, the actuators  1810  comprise linear motors. In another embodiment, the actuators  1810  may comprise piezo-actuators. Optionally, any variety of actuators  1810  may be used with the present system. Further, at least one of the bearing body  1808  and/or extension  1802  may be manufactured from any variety of materials, including, without limitations, porous carbon, aluminum, stainless steel, steel, various alloys, composite materials, plastics, and the like. 
         [0138]    In some embodiments, the at least one passage  1802  may be in fluid communication with at least one source of a fluid (not shown). Exemplary fluids include, without limitations, nitrogen, oxygen, helium, hydrogen, various purge gases, inert gases and materials, vacuum sources, pressure sources, sensors, pressure gauges, cameras, thermocouples, epoxy sources, solder sources, and the like. Further, at least one passage  1802  may be in communication with the bonding chamber  308 , thereby permitting the delivery and removal of at least one fluid from the bonding chamber  308 . 
         [0139]    Referring again to  FIGS. 16-18 , at least one plate member  1804  is coupled to or positioned proximate to the die head thermal control system body  700 . In one embodiment, the plate member  1804  is constructed from aluminum. Those skilled in the art will appreciate that the plate member  1804  may be manufactured from any variety of materials. One or more compliant bodies or bellows  1806  may be positioned proximate to the die head thermal control system body  700 . The compliant body  1806  is coupled in sealed relation to at least one bearing body  1808 . The bearing body  1808  is configured to selectively engage or be positioned proximate to the seal collar  310  of the substrate thermal control system  2000  in sealed relation, thereby positioning the bonding chamber  308  within a sealed environment. As such, the compliant body  1806  and bearing body  1808  cooperatively form a slidable seal system  810  configured to be controllably moved along the Z axis. 
         [0140]    As shown in  FIG. 18 , the bearing body  1808  include at least one fluid passage  312  formed therein. In one embodiment, the fluid passage  312  is in communication with at least one source of fluid. For example, in one embodiment, the fluid passage  312  is in communication with a nitrogen source (not shown). In another embodiment, the fluid passage  312  is in communication with an alternate source of inert fluid materials. Optionally, the fluid passage  312  may be in communication with any fluid source 
         [0141]    Still referring to  FIGS. 16-18 , at least one seal body  2002  may be positioned within the fluid passage  312  formed within the bearing body  1808 . In one embodiment, the seal body  2002  is manufactured from at least one porous material or alloy. For example, in one embodiment, the seal body  2002  is manufactured from porous carbon. In another embodiment, the seal body  2002  is manufactured from one or more non-porous material. 
         [0142]    As shown, the seal body  2002  includes at least one vacuum relief or passage  2004  formed thereon. In the illustrated embodiment, a single vacuum relief  2004  is formed on the seal body  2002 , although those skilled in the art will appreciate that any number of vacuum reliefs  2004  may be formed thereon. As shown, the vacuum relief  2004  is located on the seal body  2002  proximate to the seal collar  310 . Further, the vacuum relief  2004  may include one or more vacuum ports (not shown) formed therein. The vacuum port  2200  may be in fluid communication with at least one source of vacuum (not shown). 
         [0143]    Referring again to  FIGS. 16-18 , a first seal surface  2100  and at least a second seal surface  2102  is formed on the seal body  2002  by the vacuum relief  2004 . Those skilled in the art will appreciate that any number of seal surfaces may be formed on the seal body  2002 . 
         [0144]    With reference still to  FIGS. 16-18 , during use a die is securely retained by the die head thermal control system body  700 . Similarly, a substrate is positioned on and retained by the substrate head thermal control system body  500 . Thereafter, the die head thermal control system body  700  is positioned proximate to the substrate head thermal control system body  500  as described above. Once positioned, the actuators  1810  are activated, thereby resulting in the bearing body  1808  extending to the seal collar  310 . The compliant body  1806  permits the bearing body  1808  to extend to a position proximate to the seal collar  310  while remaining coupled to the die head thermal control system body  700 . 
         [0145]    Referring again to  FIGS. 16-18 , the seal body  2002  contained within the bearing body  1808  is positioned proximate to the seal collar  310  of the substrate thermal control system  2000 . Thereafter, activation of the actuators  1810  is terminated. A vacuum force is applied to the vacuum relief  2004 . In addition, one or more fluids may be flowed in to the fluid passage  312  formed in the bearing body  1808 . For example, nitrogen may be flowed into the fluid passage  312 . As shown in  FIG. 18 , a purge fluid (e.g. Nitrogen or other inert gases) may be flowed through the fluid passage  312  an evacuated into the bonding chamber  308  proximate to the first seal surface  2100 . In addition, purge fluid may be flowed through the fluid passage  312  an evacuated from the seal system  362  proximate to the second seal surface  2102 . As such, unlike prior art seal configurations, the slidable seal system  810  present herein permits the seal body  2002  to couple to the seal collar  310  using a vacuum force applied via the vacuum relief  2004  formed thereon, while flowing a purge fluid through the fluid passage  312  formed in the bearing body  1808 . 
         [0146]    Once the die is bonded to the substrate, the vacuum coupling force applied by seal body  2002  via the vacuum relief  2004  is terminated. Further, the flow of purge gas through the fluid passage  312  is stopped. Finally, the bearing body  1808  is retracted from the seal collar  310  by the actuators  1810 , thereby permitting the die/substrate unit to be removed from the thermo-compression bonding system. 
       Calibration and General Procedures 
       [0147]    With reference to  FIGS. 1-20 , described above, the following will provide a detailed description of a calibration process and thermo-compression bonding process using the aforementioned thermo-compression bonding system  100 , described herein. 
         [0148]    In one embodiment, the calibration process is user-initiated. In another embodiment, the calibration process may be initiated at pre-determined intervals based on time of use, number of wafers or substrates processed inspection results, and the like. In short, the calibration process may be run at any time desired. In one embodiment, to calibrate the system, the user actuates the controller  104  and selects the calibration option on the user interface (if present). Thereafter, the gantry  200  cycles through an initial alignment process and positions die bond head system  202  at a position approximately aligned with the substrate bond station  206 . In one embodiment, the rough alignment position may be based on historical locations stored in the controller  104 . In the alternative, one or more camera systems (e.g. camera assembly  608 ), laser alignment systems, optical systems, computer numerical control processing systems and the like may be used to obtain a rough alignment of the die bond head system  202  to the substrate bond station  206 . During this alignment process, the first gantry positioner (not shown), second gantry positioner (not shown), theta positioning system  704 , and z slide assembly  604  (i.e. four (4) degrees of freedom) may be configured to position the die head thermal control system body  700 , located on the die bond head system  202 , at a desired location proximate to the substrate bond station  206 . 
         [0149]    Thereafter, with the die bond head system  202  positioned proximate to the substrate bond station  206 , the co-planarity of the substrate bond station  206  may be adjusted (to ensure co-planarity between the die head thermal control system body  700  and the substrate head thermal control system body  200 ) using the co-planarity system body  300 . During the co-planarity adjustment process, the position of the die head thermal control system body  700  provides a reference for the co-planarity system body  300 . As such, the seal collar  202  on the substrate thermal control system  200  is positioned proximate to the seal system  810  located on the die head thermal control system body  700 . In one embodiment, seal body  2002  engages the seal collar  202 . Optionally, a vacuum may be introduced into the bonding chamber  308 , thereby increasing the coupling forces between the die bond head system  202  and substrate bond station  206  to aid in the co-planarity adjustment process. 
         [0150]    With the seal collar  202  on the substrate thermal control system  200  positioned proximate to the seal system  810 , located on the die head thermal control system body  700 , the force generator  416  may be actuated, thereby resulting in the forcer  414  at least partially traversing the alignment orifice  418  and engaging the alignment body  404 . As a result, the alignment body  404 , which is loosely positioned within the alignment orifice  418 , is advanced from the alignment orifice  418 , thereby unlocking the co-planarity system body  300 . 
         [0151]    The force applicator  204 , located on the die bond head system  202 , may then be actuated, thereby resulting in a biasing force being applied to the force rod  800 , located within the die bond head system  202 . In one embodiment, the biasing force being applied to the force rod  800  by the force applicator  204  comprises a force extending therefrom the force applicator  204 . In the alternative, the biasing force being applied by the force rod  800  by the force applicator  204  comprises a force retracting thereto the force applicator  204 . As such, the biasing force applied by the force applicator  204  may be constant or variable. The biasing force applied by the force rod  800  is applied via the die head thermal control system body  700 , located within the die bond head system  202 , thereby providing a stable reference for the co-planarity adjustment process. In the alternative, the force applicator  204  and dashpot  906  may be configured to withdraw the force rod  52  into the die bond head system  202 , thereby resulting in the die head thermal control system body  700  contacting the bearing system  320 . As a result, the die bond head system  202  and die head thermal control system body  700  become a substantially rigid body. In summary, in one embodiment, the thermo-compression bonding system  100  may be configured to apply at least one biasing force via at least one of the force applicator  204 , the dashpots  78 , and the weight of the die head thermal control system body  700 . 
         [0152]    Once co-planarity is achieved, the position of the substrate bond station  206  is fixed by controllably retracting the force generator  416  in the co-planarity system body thereby resulting in the alignment body  404  re-engaging the alignment body support  408 . A biasing lock force is applied to the alignment body support  408  via the alignment body  404  by the biasing member  402 . Those skilled in the art will appreciate that any variety of alternate devices and systems may be used to fix the position of the substrate bond station  206 . For example, mechanical systems, magnetic systems, vacuum systems, pneumatic systems, and/or any combination thereof may be used to fix the position of the substrate bond station  206  to ensure co-planarity. 
         [0153]    Once the co-planarity system body  300  has been locked, the force rod  800 , positioned within the die bond head system  202 , may be disengaged and the die bond head system  202  may decouple from the fixed substrate bond station  206 . Thereafter, thermo-compression bond processes may begin. 
         [0154]    To process a substrate, the controller  104  moves the gantry  200 , having the die bond head system  202  thereon, to a tray containing one or more substrates thereon. Those skilled in the art will appreciate that the substrate described herein may be defined as a semiconductor wafer, die, component, waveguide, semiconductor device, optical device, and the like. For example, in one embodiment, the thermo-compression bonding system  100  may be configured to precisely position one or more components on a semiconductor wafer. In an alternate embodiment, the thermo-compression bonding system  100  may be configured to precisely position one or more dies or similar semiconductor devices on die substrates, thereby forming a multiple stack semiconductor device. Optionally, a single bonding process may be conducted by placing multiple components on a substrate and conducting a single bonding process. In the alternative, multiple boding processes may be conducted on a single substrate by placing a single component on the substrate, conducting a bonding process, a repeating the component placement/bonding process numerous times. 
         [0155]    The die head thermal control system body  700 , located on the die bond head system  202 , is positioned proximate to a substrate and is configured to controllably engage and retain the substrate therein. In one embodiment, a vacuum force is applied to the die head thermal control system body  700  via at least one fluid passage formed thereon. For example, at vacuum force may be controllably applied to the die head thermal control system body  700  via the fluid passage  312  and at least one port formed in or proximate to the recess chamber  308 . Optionally, any variety of retaining forces or retaining devices may be positioned on the die head thermal control system body  700  to permit the controlled retention of at least one substrate and/or component by the die head thermal control system body. 
         [0156]    Thereafter, the die bond head system  202  is positioned proximate to the substrate bond station  206  by at least one of the first gantry positioner (not shown), the second gantry positioner (not shown), the z slide assembly  604 , and the theta positioning system  704 . With the die bond head system  202  positioned, the force retaining the substrate within the thermal control body  210  is deactivated, thereby precisely positioning the substrate on the bonding fixture  306  located within the bonding chamber  308  of the substrate thermal control system  200 . Optionally, a vacuum force may be applied to the substrate via the retaining port  314  which is in communication with the inlet  420  via the passage  236 . In another embodiment, any variety of retaining devices may be positioned within the chamber  308  to securely position the substrate on the bonding fixture  306 . 
         [0157]    With substrate positioned, the die bond head system  202  may then be actuated to controllably engage and retain at least one component located within a tray. Like the substrate retention and positioning process, the die bond head system  202  is made to controllably engage and retain at least one component. Thereafter, the die bond head system  202 , having at least one component retained thereby, is positioned proximate to the substrate bond station  206 . In one embodiment, a camera assembly  608  having a first camera, looking upwards at the component retained by the die bond head system  202 , and at least a second camera, looking downwards at the substrate, may be actuated to determine the positioned and orientation of the component relative to the substrate. If needed, the die bond head system  202  may be moved along the X axis, Y axis, Z axis, and about Theta (rotationally) to precisely adjust the position of the component relative to the positioning reference of the substrate. In one embodiment, the camera assembly  608  may be configured to use one or more features, edges, and/or physical characteristics of the component and/or substrate as positioning references. In another embodiment, the camera assembly  608  may use one or more fiducials or alignment marks on at least one of the component or substrate to aid in positioning. 
         [0158]    Once the position of the component, relative to the substrate, has been determined, the camera assembly  608  is withdrawn and the z slide system  604  is actuated to position the seal body  2002 , located on the seal system  810 , to engage the seal collar  202  on the substrate head body  316 . The use of a bellows and air bearing seal arrangement has been discussed previously in this disclosure. Here, the process will be discussed using the labyrinth bonding chamber  308  sealing arrangement in accordance with another embodiment of the present invention. More specifically, the seal extensions  318  of the seal body  2002 , which are aligned substantially orthogonally to the system X and Y axis and axially aligned with the system Z axis, are made to interlockingly engage the seal extensions  318  on the seal collar  202 , which are also aligned substantially orthogonally to the system X and Y axis and axially aligned with the system Z axis but facing the seal extensions of the seal body  2002 , thereby forming the labyrinth seal passage  1700 . Thereafter, a vacuum may be introduced into the bonding chamber  308  formed by the die head thermal control system body  700 , on the die bond head system  202 , and the substrate head thermal control system body  500 , on the substrate bond station  206 . 
         [0159]    Thereafter, one or more fluids may be introduce into at least one of the labyrinth passage  1700  (see  FIGS. 16-17 ) and/or the bonding chamber  308  formed by offset, interlocking seal extensions  318  located on the die head thermal control system body  700 , on the die bond head system  202 , and the substrate head thermal control system body  500 , located on the substrate bond station  206 . For example, one or more inert fluids may be introduced into the labyrinth passage  1700  (see  FIGS. 16-17 ) thereby creating a pressurized fluid barrier within the labyrinth passage  1700  (see  FIGS. 16-17 ). Exemplary inert fluid include, without limitations, nitrogen and the like. 
         [0160]    With the pressurized fluid barrier present within the fluid passage  312  or labyrinth seal passage  1700  (see  FIGS. 16-17 ), dependent on which seal arrangement is used, one or more oxide-reducing or oxide-purging fluids may be introduced into the bonding chamber  308 . In one embodiment, nitrogen and formic acid are flowed through the bonding chamber  308 , although those skilled in the art will appreciate that any variety of fluids may be introduced into the bonding chamber  308  through at least one of the fluid passages  312 . As such, in one embodiment, the thermo-compression bonding system includes one or more sensors configured to determine the chemical composition of one or more fluid flowing into or from the bonding chamber  308 . For example, one or more sensors may be configured to monitor the fluids exhausted from the bonding chamber  308  to detect the presence and levels of oxides, formic acid, out-gassed materials, and/or contaminants. During use the seal system  810  and the pressurized fluid barrier present within the fluid passage  312  or labyrinth seal passage  1700  (See  FIGS. 16-17 ), dependent upon which seal embodiment is in use, restricts or prevents the purge fluids from entering or exiting the bonding chamber  308  through routes other than the fluid passages  312 . 
         [0161]    With the bonding chamber  308  purged of unwanted materials, the substrate and components located within the bonding chamber  308  may be heated to bond the component to the substrate. In one embodiment, the heating process comprises a rapid ramp rate heating and cooling cycle. The rapid ramp heating and cooling cycle is configured to rapidly heat a bonding agent (e.g. solder, adhesive, etc.) on the substrate or component to permit reflow of the die bumps or bonding pads positioned thereon. In one embodiment, the component retained by the die head thermal control system body  700  is positioned on or proximal to the substrate. Thereafter, heat may be rapidly applied to the bonding fixture  306  via at least one conduit  234  located therein. Optionally, the substrate head thermal control system body  500  may be similarly heated. 
         [0162]    Once reflow of the bonding agent is achieved the temperature of the bonding fixture  306  is rapidly cooled to a temperature less than the melting point of the bonding agent, thereby coupling the component to the substrate. With the component bonded to the substrate the flow of purging fluid via the passage  312  may be terminated and any remaining fluids may be evacuated from the bonding chamber  308 . Similarly, the fluid passage  312  or labyrinth passage  1700  (see  FIGS. 16-17 ), dependent upon which embodiment of the seal is in use, may be purged. Thereafter, the z slide assembly  604  may be actuated which results in the seal body  180  disengaging the seal collar  202 . Finally, the processed substrate having one or more components precisely bonded thereto may be removed from the thermo-compression bonding system  100 . 
         [0163]    The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.