Multiple module chip manufacturing configurations

Abstract

To provide assemblies and subassembly modules for manufacture of wafer chips or substrates with solder balls or plated solder balls.SOLUTION: A wafer tool assembly (10) comprises a large number of modules (12-20). The large number of modules (12-20) are connected to one another and all operated by a robotic arm (22) in order to transfer processed wafers (W) from one module to another. The tool assembly comprises a load port (12), a pre-aligner module (14), a binder module (16), a solder ball mount module (18), and a reflow module (20). A wafer inspection (24) and repair module arrangement are also parts of the tool assembly.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001]

[0001] The present invention relates to assemblies and sub - assembly modules for manufacturing a wafer chip or substrate with solder balls or plated solder balls (also called bumps attached to a wafer chip or substrate), and more particularly to a device for processing a wafer with a fluxless or flux - free binder in a connectable configuration of treatment modules that can be interconnected and adapted to change the conditions of such wafer chip manufacturing. For the discussion herein, to avoid confusion, plated solder balls, solder balls, bumps, and the like are all designated as "solder balls".

Summary of the Invention

[0002]

[0002] The present invention relates to the configuration of individual modules incorporated together, including a system for manufacturing a wafer chip on which solder balls are disposed. The modules within the system are each designed to facilitate the efficient manufacture of the components of the chip assembly required for completion.

[0003]

[0003] For marketing purposes, the assembly can be referred to herein by the trade name of the "Symphony" chip assembly configuration or tool.

[0004]

[0004] The Symphony chip assembly tool includes a front-end module (EFEM), a binder application module, a solder ball mount module (SBM), an inspection and repair module, and a reflow module. The front-end module houses a robotic arm for moving wafers between each module and a pre-aligner for the wafer placement process. Further embodiments of the Symphony tool assembly include a side-by-side configuration of multiple reflow modules. The front-end module (EFEM) can also be positioned adjacent to multiple reflow modules to allow their operations to be performed in parallel to increase the throughput of the reflow process. Further embodiments of the Symphony assembly include a dual solder ball mount module configuration configured to increase the throughput of the ball mount step. Such further dual solder ball mount configuration includes a front-end module (EFEM), two solder ball mount (SBM) modules for adjacent parallel processing, a binder application module, and an inspection module. Furthermore, a further embodiment of the Symphony tool assembly includes a single reflow module configuration, the single reflow module configuration being accompanied by its front-end module (EFEM) that performs operations on that single reflow module.

[0005]

[0005] Accordingly, the present invention includes a unified wafer or chip assembly configuration or tool for depositing solder balls onto a wafer substrate for subsequent use in the electronics industry, wherein the wafer assembly configuration includes the configuration of individual wafer processing modules, the configuration of individual wafer processing modules being interconnected to and operated by a central wafer handling robot, the modules including a pre-aligner module for receiving wafers to be processed, a binder module for applying a fluid binder to the upper surface of the wafer, a solder ball mounting module for depositing a number of solder balls onto the wafer, a reflow module for heating and fixing the solder balls onto a pad configuration on the wafer, and an inspection module having a re-examination and analysis and, if necessary, a repair configuration for the solder balls deposited on the wafer. The fluid binder is applied to the wafer by a nozzle configuration supported by a gantry movably positioned directly above the wafer supported therebelow. The number of solder balls are arranged as an array on the solder ball engagement locations of a separation pattern on the wafer after the solder balls have been filtered through a vertical array of perforated solder ball alignment plates movably positioned above the wafer. The air knife is driven laterally relative to the array of solder balls on the wafer surface so that any irrelevant solder balls are pushed away from the wafer surface. The irrelevant solder balls are transferred to a unidirectional channel for collection and subsequent reuse on further wafers.

[0006]

[0006] The present invention also includes a process for manufacturing a chip assembly in a unified wafer assembly system for use in the electronics industry, the process comprising: a step of removing a wafer from a front opening by a robot, wherein the wafer is transported to a pre-aligner for centering; a step of transferring the wafer to a binder station by a robot, wherein a binder fluid is applied to the wafer; a step of carrying the wafer onto a chuck at a first wafer operating position opening of a solder ball mounting station by a robot; a step of aligning the wafer by a camera configuration for subsequent wafer orientation using a stencil hole pattern; a step of transferring the wafer to a second wafer operating position opening where a stencil is present; a step of moving the wafer support chuck upward to lift the wafer to within a distance of the stencil, i.e., less than the diameter of a solder ball; and a step of identifying a reference mark on the wafer by a camera verification configuration on an overhead solder ball head as part of a movable gantry. The process involves verifying the wafer alignment by viewing the wafer through a stencil, moving the solder ball head to the appropriate position directly above the wafer once the wafer alignment has been verified, distributing the solder balls from the solder ball storage area on the solder ball head through a funnel to a distribution cup, then to a distribution plate, allowing them to fall through multiple perforated plates, dropping the solder balls onto a perforated stencil, bringing the solder ball head close to the stencil, activating the solder ball head so that the brush is directly above the stencil, moving the brush back and forth across the wafer without contacting the wafer to push the solder balls into the remaining holes on the wafer, blowing compressed dry air across the stencil with an air knife on the gantry to collect any unmounted solder balls into a vacuum-compatible collection chamber for subsequent reuse, and lowering the chuck and wafer positions in the solder ball mounting module for robotic pickup.The process includes the steps of transporting a solder ball-loaded wafer to a solder ball inspection and / or repair station; transporting the solder ball-loaded wafer to a chuck in the loading lock station / first chamber of a reflow module by a robot and purging oxygen from the first station; holding the wafer on the chuck by vacuum and rotating the chuck to advance toward the second station for preheating; raising the wafer's position through the chuck on an elevator to the top ring of the chamber of the second station to reach the maximum reflow temperature before melting; lowering the wafer's position through the chuck by an elevator to return it to the wafer on the chuck so that it can reach a controlled reflow temperature, wherein the wafer is then rotated toward the third station of the reflow module; separating the wafer from the chuck by a vacuum plate, wherein the wafer is cooled by nitrogen below the plate and above the wafer, and the vacuum drawn in through the chuck holds the wafer horizontally and flat thereon; and rotating the chuck back toward the first station to unload the finished wafer. ,

[0007]

[0001] The object and advantages of the present invention will become clearer when viewed in conjunction with the following drawings. [Brief explanation of the drawing]

[0008] [Figure 1]

[0003] This is a schematic plan view of the assembly tool configuration, which also shows the robot arm configuration for transferring wafers from station to station within the assembly tool assembly. [Figure 2]

[0004] This is a perspective view of a binder module for applying binder fluid to a wafer under construction. [Figure 3]

[0005] This is a partial side elevation view of the binder coating chamber shown in Figure 6A. [Figure 4]

[0006] This is a partial perspective view of a wafer support plate or chuck for lifting the wafer above into the binder coating enclosure. [Figure 5]

[0007] This is a perspective view of a solder ball mount module and its associated optical inspection configuration, showing a robotic arm for supplying wafers to the solder ball mount module. [Figure 6]

[0008] Figure 9 is a perspective view of the solder ball mount module, which includes an inspection optical device and a camera configuration showing a gantry configuration. [Figure 6A]

[0009] This is a side elevation view of a brush head showing the final or distribution of solder balls onto the main distribution plate and several auxiliary distribution plates below it. The sweeper configuration is mounted at the bottom of the brush head, and the stencil shown directly below it is spaced above the wafer supported by the chuck. [Figure 7]

[0010] This is a lower perspective view of the ball brush configuration. [Figure 8A]

[0011] This is a perspective view of the inspection module of this assembly, which is used to inspect the wafer to ensure that all solder balls are correctly positioned on the wafer before reflow. A line scan camera located at the top of the inspection module observes the wafer downwards on the support chuck to capture an image of the entire wafer for computer analysis. [Figure 8B]

[0011] This is a side elevation view of the inspection module of the assembly, which is used to inspect the wafer to ensure that all solder balls are correctly positioned on the wafer before reflow, and a line scan camera located at the top of the inspection module observes the wafer downwards on the support chuck to capture an image of the entire wafer for computer analysis. [Figure 8C]

[0011] This is a side elevation view of the inspection module of the assembly, which is used to inspect the wafer to ensure that all solder balls are correctly positioned on the wafer before reflow, and a line scan camera located at the top of the inspection module observes the wafer downwards on the support chuck to capture an image of the entire wafer for computer analysis. [Figure 8D]

[0012] This is an exploded perspective view of the repair station that complements the inspection module. [Figure 9]

[0013] This is a perspective view of an open reflow module, which includes a chamber with three stations: an loading lock station, a reflow station, and a warpage control station. Wafers are moved from station to station within the chamber by a rotating carrier disk. [Modes for carrying out the invention]

[0009]

[0014] This disclosure, in its general mode, includes an apparatus and process for processing wafers for use in the electronics industry, the apparatus and process being as follows: A wafer to be processed is removed from a raw wafer stack by a robotic arm. The wafer is transported to a pre-alignment station and centered on a carrier. The wafer is transported to an adjacent binder module station. Binder fluid is applied to the wafer. The wafer is then removed by a robotic arm and sent to a solder ball mounting station module. The wafer is aligned by a camera at a first support opening to orient the wafer along the line to match the stencil hole pattern. The wafer is transported to a second support opening solder ball mounting module where the stencil is located. A chuck is moved upward to support the wafer in a position very close to directly below the stencil (the distance between the wafer and the stencil is less than the diameter of a solder ball). Solder balls are dropped from the storage section of the solder ball mounting module into a cup and perforated plate distribution configuration, the solder balls pass through the perforated plate configuration and through the holes of the alignment stencil and fall onto the wafer directly below, the ball-mounted wafer is brushed and treated with compressed dry air, thereby achieving solder ball placement and removal of excess solder balls from the wafer, and the wafer is transferred to a reflow station for final heat treatment and cooling of the solder ball-mounted wafer. Such process procedures are listed as steps that the apparatus of the present invention performs in order to produce suitable chips in the electronics industry.

[0010]

[0015] Here, in particular, Figure 1 A detailed reference to the drawing shows a schematic representation of the configuration of the unified chip assembly tool 10. The chip assembly tool 10 includes an input port 12, a pre-aligner module 14, a binder module 16, a solder ball mount module 18, and a reflow module 20, each of which is operated by sequential input and output by a central robotic arm configuration 22. The binder module is shown in the figure. 2 Now, let's look at the perspective view, Figure 3 This is shown in the side elevation view.1 The figure also shows an inspection module 24, which, in addition to inspection, may include the placement or repair of improperly delivered wafers. 8 This will be disclosed in more detail in section D.

[0011]

[0016] figure 1 The operation of the chip assembly tool 10, as shown in the figure, begins at the input port, where the wafer "W" is taken in from the Front Opening Unified Pod (FOUP) and transferred to the binder module 16. The effector of the robot arm 22 is shown in the figure. 3 As shown in the figure, wafer "W" is placed on the support pins 30. These support pins 30 have vacuum cups at their tips, and the vacuum cups are shown in the figure. 4 As shown in Figure 22, this is for holding the wafer "W" after it has been placed on the vacuum support plate 32 by the robot arm 22. 3 and figure 4 As shown, the position of the plate 32 is raised by a pneumatic actuator 34 to lift the wafer "W" into the binder coating enclosure 36. Support pins 30 are embedded directly beneath the surface of the support plate 32 and rise as the position of the plate 32 increases. As the support plate 32 rises, it engages with the wafer "W", and the vacuum drawn in through the support plate 32 holds the wafer "W" tightly to the support plate 32. The support plate 32 has three independently controlled vacuum zones, each of which is composed and defined by a series of vacuum channels 40, as shown in the figure. 4 This is most clearly shown in [figure]. In addition to holding the wafer W, the multi-zone design allows the plate 32 to hold the bent wafer horizontally flat. When the support plate reaches the top of the stroke, the support plate moves as shown in [figure]. 4 The wafer W engages with a clamping ring 42 as shown in the figure, and the ring 42 functions as a hard stop. The inner edge of the clamping ring 42 presses against the outer edge of the wafer W, forming a liquid-tight seal. 3By means of one or more nozzles 44 as shown, in the figure 3 the liquid binder "B" is dispensed as represented, and the nozzles 44 scan the wafer "W" one or more times. The nozzles 44 evenly distribute the fluid binder "B" by spraying the fluid binder "B" in a fan pattern substantially perpendicular to the scanning direction. The nozzles 44 are supported by a gantry 46 as shown in the figure 3 and the movement of the gantry is driven by a belt drive 48 by a computer-controlled linear actuator as shown in the figure 5 . After depositing the binder B, the air knife 50 scans the wafer and injects a curtain of compressed dry air thereon as shown in the figure 3 . The force of the compressed dry air diffuses, whereby the deposited binder stretches thinly and a uniform thin film remains on the wafer. The air knife 50 is mounted on the same gantry frame 46 as the nozzles 44, and the scanning movements of the two systems are mechanically coupled but are controlled independently of each other and can operate simultaneously or at different times. Also, the air knife 50 blows off excess binder "B" from the wafer. The excess binder flows across the clamping ring 42 through a channel 52 at the top of the ring 42 and down into a collection container 54 as shown in the figure 3 . The binder flows out on one side towards a drain port connected to the collector, and the excess binder is stored for future reuse. After applying the binder, the vacuum support chuck 56 descends, the vacuum of the crack and the support pins is released, and the robot 22 removes the wafer "W" from the binder module 16. The height, spacing and angle of the binder dispensing nozzles can be adjusted manually. Different lengths and spacings can be used to optimize the dispensing pattern of the binder. Also, the height and angle of the air knife 50 can be adjusted manually. The volume of the binder to be dispensed is controlled by the dispensing time, the storage tank pressure and a manual knob on the nozzle itself. The flow rate of the compressed dry air through the air knife 50 is shown in the figure 1It is controlled by the combination of the mass flow controller and the orifice of the equipment panel 60 as shown. By bringing the air knife 50 close to the surface of the wafer "W", the force of the air curtain is concentrated, and generally, a thinner binder film is formed. Also, the air knife 50 is also used to clean wafers where solder balls are missing or misaligned, and such wafers require repair at the repair station 198 as shown in FIG. 8 D. The air knife 50 blows all the solder balls SB of the excessive binder from the wafer "W". The binder enclosure 36 is exhausted so that no binder material remaining by air transfer escapes and contaminates the parts of the tool assembly.

[0012]

[0017] The operation of the chip assembly tool 10 continues with the removal of the solder ball-loaded wafer "W" by the robot arm 22 as shown in FIG. 1 and FIG. 5 The solder ball-loaded wafer "W" is roughly aligned at the pre-aligner of the loading port 12. The solder ball-loaded wafer "W" is then transferred to the solder ball mounting module 18 for optical alignment of the solder balls on the wafer W as shown in FIG. 8 , FIG. 9 and FIG. 10 The wafer vacuum support chuck starts from the loading position where it receives the wafer from the robot arm 22. The wafer plate has support pins with vacuum cups and a set of several independently controlled vacuum channels or zones on the surface of the support plate. The wafer "W" is first loaded onto the support pins and fixed by the vacuum cups. The pins are recessed in the vacuum support chuck. Thereby, the position of the wafer drops to the chuck surface, and the wafer is held by the vacuum zone. FIG. 5As shown in the figure, the stage is actuated in the X, Y, and Z directions by a precision ball screw pressed by a linear actuator. A high-precision turntable also rotates the wafer "W" on the beta stage. All wafer support movements are computer-controlled through appropriate circuits. The wafer stage is then moved as shown in the figure. 5 Move the wafer to the alignment window cutout portion 70 of the upper mounting plate 66 as shown in the figure. 5 and 6 The two downward-facing observation cameras 60, 62 shown in Figure 1 are positioned above the wafer "W" so that each camera observes a predetermined different location on the wafer. Each camera 60, 62 is mounted laterally to a mounting plate 66 to an independently operating linear drive unit 64. Both actuators are shown in Figure 1. 5 and 6 The cameras are successively mounted on the gantry frame 74 shown in Figure 1, and the gantry 74 can be operated along the longitudinal axis of the mounting plate using one or two precision ball screw actuators. Each camera 60, 62 takes an image of only a portion of the wafer "W", and a suitable computer (not shown) uses this information to determine the exact location of the wafer in an X, Y, theta configuration. The stage is shown in Figure 1. 5 The wafer is moved vertically and horizontally through the second stencil window 78 of the mounting plate as shown in the figure. The Z-direction movement of the stage raises the position of the wafer "W" so that the top surface of the wafer "W" is just touching the bottom surface of the stencil 80 or slightly below the bottom surface of the stencil 80. The computer control system already knows the precise orientation of the stencil 80 and, combined with its knowledge of the wafer orientation, can position the wafer so that it aligns with the stencil 80 with high accuracy before being separated in the Z direction. 6 The verification camera 82 shown in the figure is configured to confirm the final placement of the wafer "W" relative to the stencil 80. 6By using the pneumatic actuator 86 shown, the verification camera 82 moves downward to focus on the stencil 80 and the wafer "W". The verification camera 82 then moves upward to clearly capture the subsequent movement of the ball-mounted head 90.

[0013]

[0018] The chip assembly tool continues to operate, with the solder ball mounting head moving to a position directly above stencil 80, then lowering to a distribution position, making only slight contact with stencil 80. (Figure) 7 The rotating free member 88 shown in the figure tilts the storage section 102, releasing a predetermined volume of solder balls SB onto the main distribution plate. The solder balls SB then move downward through several levels of holes in the auxiliary distribution plate to further diffuse, and are then finally dispersed across the surface of the stencil 80. 7 The brush head 96 shown in Figure is driven by a pneumatic actuator 98. The brush head 96 includes a series of sweeping members 100 (such as a wire, a pressurized perforated tube drilled along its underside, or the same), 7 The sweep members 100 shown reach the back surface of the brush head 96, protrude downward, and are in slight contact. If the sweep members 100 are wires, these wires are placed under slight tension, and as a result, each portion of the wire shown is drawn in a straight line parallel to the surface of the stencil 80. The straight portion of each sweep member wire 100 extends a distance greater than the diameter of the wafer "W" being processed. Maintaining the wires 100 parallel to the stencil surface ensures uniform spacing between the wires 100 and the stencil 80. The gaps between the wires in the stencil, if present, can be controlled to hold solder balls SB between each pair of wires so that solder balls SB cannot pass freely underneath. When the position of the brush head 96 is lowered, 7The computer-controlled electromagnetic vibrator 102 shown drives the brush head 96 with small vibrations parallel to the plane of the stencil 80 and perpendicular to the axis of the wire or tube 100. The vibrations with small amplitude are designed to move solder balls SB over small distances between the wire or pressurized air tube 100 without damaging the stencil 80. During vibration, the brush head 96 also moves back and forth in a limited overall motion, parallel to the stencil 80 and perpendicular to the wire or tube 100, to ensure that any point on the stencil 80 is swept by the vibrating wire or pressurized tube 100. The parallel movement of the sweeping member wire or pressurized tube 100 also ensures that the holes in the stencil 80 are not blocked throughout the entire duration of the diffusion operation, thereby preventing solder balls from filling those clogged holes. After diffusing the solder balls SB, each hole in the stencil 80 should contain one solder ball SB, so that when the wafer and the stencil are separated from each other, one solder ball SB remains on each pad on the wafer. There may be excess solder balls SB on the stencil 80 that did not fill the holes, and these excess or excessive solder balls must be removed before lowering the wafer. The brush head 96 moves up and down out of the way shown in the figure. 3 The air knife 50 shown sweeps the stencil 80, pushing all excess solder balls SB to the rear of the stencil 80. The airflow from the air knife 50 is strong enough to push away all solder balls that did not remain in the holes, but not strong enough to brush away any accumulated solder balls. The air knife 50 pushes the balls under a flap, which acts as a one-way gate to prevent the solder balls from being pushed back into the stencil 80. The solder balls are collected at the rear edge of the stencil 80 and sucked up by an overhead vacuum duct. From there, the solder balls are transported to a collection container, where all solder balls are separated from the airflow and stored for later reuse.

[0014]

[0019] figure 6A schematic representation of the brush head 21 and solder ball mounting module 18 is shown, and a funnel 23 is shown that drops solder balls SB onto a perforated main distribution plate 25, through which the solder balls fall onto auxiliary distribution plates 27 and 29. Directly below the auxiliary distribution plates 27 and 29, a perforated stencil 31 is shown. The stencil 31 is shown above a wafer "W" placed on a support chuck 33, and a pad 35 is placed on the wafer W. The sweeper configuration 37 is schematically shown attached to the shared brush 21.

[0015]

[0020] Different processes may use solder balls of different sizes and compositions, and therefore, avoiding cross-contamination is extremely important. Each type of solder ball has its own dedicated storage compartment, brush, and collection container. These components can be mechanically and / or electronically adapted to prevent mixing of components for use with different solder balls.

[0016]

[0021] First, the diagram 1 The inspection module 24 shown in Figure is used to inspect the wafer "W" after the solder balls have been placed to ensure that all solder balls are properly positioned before reflow. The robot 22 is shown in Figure 8 A wafer "W" on which solder balls SB as shown in A are mounted, 8 The wafer "W" is loaded into the support pin configuration 106, which has a vacuum cup on top of it as shown in B. Once the pin configuration 106 supports the wafer "W", they move downward by being driven by a pneumatic actuator, as shown in Figure 8 As shown in B, it is recessed in the vacuum support plate 108. The support plate 108 includes a set of several independently controlled vacuum channels or zones, some of which attract the wafer when the support pins are lowered. 8 The line scan camera 110 shown in A is located on top of the inspection module 24, as shown in Figure 8Observe downwards as shown in A. The support chuck and wafer are moved parallel to each other across the field of view of the line scan camera 110 to capture an image of the entire wafer "W". The support chuck is actuated by a computer-controlled precision ball screw and can be illuminated by an artificial light source configuration. The wafer image is automatically analyzed to identify defects such as missing solder balls, excess solder balls, or solder balls that are misaligned relative to the wafer. Those wafers that pass the inspection proceed to the reflow module, while those wafers that fail the inspection are repaired or stored in a buffer station for later reprocessing.

[0017]

[0022] Such a repair station 198 is shown in Figure 8The inspection camera assembly 200 is shown in D and includes a base frame 210 supporting a control panel 212, a number of controls 214, a granite inspection slab 216 mounted on the base frame 210, a pick-and-place arm 220 mounted for movement in the X direction, a scanner drive assembly chuck 222 positioned on the granite inspection slab 216 for movement in the Y direction, and an inspection camera assembly 200. The inspection light assembly 202 is shown in the up position directly above the scanner drive assembly chuck 222. When in the down position, the inspection light assembly 202 provides light that allows the inspection camera assembly 200 to view the wafer W on the scanner drive assembly chuck 222. The scanner drive assembly 222 moves the wafer below the camera assembly 200, enabling the generation of an image of the entire wafer. The locations of missing solder balls and extra or incorrectly placed solder balls are identified from this image, and their coordinates are described in a control computer system associated with the equipment panel 212. The inspection light 202 can be moved to an up position, thereby allowing the pick-and-place arm 222 to move directly over the wafer W on the scanner drive assembly chuck 222. The pick-and-place assembly is as a needle hub configuration 230, including a vacuum configuration. While the pick-and-place assembly 220 remains directly over the wafer, the pick-and-place assembly 220 removes and disposes of any misplaced solder balls.

[0018]

[0023] The inspection light 202 is moved to the up position, thereby allowing the pick-and-place assembly 220 to move near and directly above the wafer W. By remaining directly above the wafer, the pick-and-place assembly 220 can be used to replace the wafer. First, the pick-and-place assembly 220 removes and disposes of any incorrectly placed solder balls. Next, the pick-and-place assembly 220 adds any solder balls that are determined to be missing to the wafer. The pick-and-place assembly 220 can reach any location on the wafer by utilizing linear X and Y driven movement. Between these functions, the use of 200 pick-and-place cameras mounted between actuators is possible to directly observe and verify the placement or removal of a single solder ball. This verification is important during the test. Once the wafer is repaired, the pick-and-place assembly 220 is moved to Figure 8 As shown in D, move to the left so as not to obstruct. Finally, the inspection light assembly 202 moves downward, allowing the inspection camera 200 and scanner drive 222 to create a second image of the wafer. If no errors are found, the wafer is removed from the inspection and station and transferred to the reflow module, where another wafer may be brought in for repair.

[0019]

[0024] The reflow module 20, which is extensively shown and discussed in concurrently pending patent application No. 15 / 998,295 (having its own reference number), is incorporated herein by reference and shown in Figure 9 As shown in the figure, it currently consists of an open chamber 120 and has three stations: an input lock or first station 122, a reflow or second station 124, and a warpage control station 126. 9The diagram shows the reflow module in an open state. During processing, the chamber is closed and sealed to the surrounding environment. Wafers are moved from station to station within the chamber by a rotating carrier disk 128. The disk 128 has multiple slots for sequential wafer processing. Each slot is shown in the diagram. 4 Carriering as shown in the figure and similarly in the figure 4 The wafer is positioned within the support ring, as shown in the figure. 4 A clamping ring, as shown, may also be used, which holds the wafer horizontally flat during processing and in the reflow chamber 20. While the wafer is in the reflow chamber, the outer edge of the wafer is sandwiched between the clamping rings of the support ring, forming a temporary annular hold-down.

[0020]

[0025] The loading lock or first station 122 of the reflow module 20 accepts a new wafer, and the loading lock vacuum support chuck and base plate are raised together by acting the main pneumatic cylinder. This mechanism pulls the clamping ring away from the support ring toward the upward position. An auxiliary pneumatic ring is actuated to lower the position of the support plate relative to the base plate, thus exposing the support. The loading lock door is opened by a pneumatic actuator, which moves the door in a parallel motion and lifts it. The wafer is loaded by a robot and is held in place by the vacuum cups at the tips of the support pins. The vacuum support chuck is raised and engages with the wafer. The vacuum zone on the chuck, as previously described, is activated to hold the wafer horizontally flat. The lowering mechanism lowers the position of the clamping ring and locks it into the support ring. The mechanism can also provide an additional downward force on the clamping ring to assist in horizontally flattening the wafer. This additional downward force may be necessary in cases where vacuum alone is insufficient for horizontally flattening the wafer. When the loading lock door is closed and the base plate rises, a sealed mini-chamber is created. After the wafer is loaded, this chamber is purged with nitrogen, creating an oxygen-free atmosphere. The support chuck is the base plate, and no oxygen is introduced into the rest of the chamber. This movement also returns the wafer to the position of the carrier disk.

[0021]

[0026] The reflow station or second station 124 of the reflow module 20 includes three computer-controlled heating elements, as shown in Figure 9The diagram shows a lower heater, an upper heater, and a ring heater. The primary purpose of the lower heater is to conductively heat the wafer "W" by direct contact with the wafer assembly. Here, the wafer assembly consists of the wafer, a support ring, and a clamping ring. The upper heater is used to further stepwise convectively heat the wafer within the tower, which is part of the reflow station above the desk. The ring heater is used to prevent heat loss at the edges and improve the temperature uniformity of the wafer. A temperature gradient exists between the upper and lower heaters. The wafer can be positioned at different heights within the tower, thereby controlling the determination of its convective heating rate (i.e., temperature). The high-temperature wall conducts heat from the upper heater of the ring heater, creating a more stable stepwise temperature gradient within the tower. The high-temperature wall portion may be the same component that supports and transfers heat from the upper heater.

[0022]

[0027] After a wafer is indexed from the loading lock into the reflow station, it must be preheated. Preheating is most effectively achieved by convective heating of the wafer in the tower, close to the upper heater. The upper heater can be set to any temperature, but is usually set considerably higher than the lower heater. Therefore, the higher the wafer is positioned in the reflow station, the hotter the environment becomes and the faster it heats up. Lifting pins driven by servo motors raise the wafer assembly and control its height. A temperature sensor on the support ring contacts the wafer and accurately monitors its temperature in real time. By combining wafer temperature monitoring and wafer height control, the user can obtain excellent control over the wafer's temperature profile. At its highest position, the support ring contacts a hard stop mounted on the upper heater. The stop prevents the wafer assembly from directly contacting the top of the tower, preventing damage to both the tools and the wafer. The stop also conducts heat from the upper heater to the support ring, thereby heating the ring and quickly lowering the convective heater. Due to the much larger thermal mass, the temperature difference between the support ring and clamp and the wafer itself widens, reducing the temperature uniformity of the wafer. By convective heating of the support ring, the difference in heating rate between the wafer and the support ring is minimized, improving the temperature uniformity of the wafer. After preheating, the lifting pins return the wafer assembly to its position on the desk. Then, driven by a pneumatic component, the lower heater rises and contacts the bottom of the wafer, and the support ring, in direct contact with the wafer, quickly raises the wafer to a uniform study temperature. At this temperature, the solder balls on the wafer melt and adhere to their respective pads on the wafer. The wafer is held by a vacuum channel in the lower heater, which can apply vacuum force to the wafer as needed. The vacuum helps to hold the bent wafer horizontally flat and improves conductive heating of the wafer in terms of both speed and uniformity. After contacting the wafer for a certain period of time, the lower heater descends on the wafer and indexes to the next station.

[0023]

[0028] As the wafer temperature rises, solder balls adhere to those pads on the wafer even before reflow, causing metal diffusion between the solder balls and pads, unnecessarily melting the binder. The liquid binder begins to evaporate at high temperatures, and by the time the wafer leaves the reflow station, all of the binder has evaporated. To facilitate oxide removal and solder reflow, the reflow station, along with the rest of the chamber, maintains an oxygen-free reducing atmosphere. This atmosphere is a mixture of nitrogen gas and a reducing gas (such as formic acid). After the reflow station itself, the reducing gas mixture is introduced through holes in the sides of the high-temperature wall, and in addition, binder vapor is discharged through holes in the top of the tower, ultimately proceeding towards the reflow station exhaust port. Between the main tool exhaust and the reflow station exhaust, a binder condensation system can be placed in a line. This condensation system condenses the binder vapor, removing it from the exhaust flow and preventing the binder vapor from reaching the equipment's exhaust system.

[0024]

[0029] figure 9The diagram shows a warpage control station 126 (i.e., the third station of the reflow module 20), where the wafer and wafer assembly maintain the warpage control station at a temperature above that of the heater and vacuum plate. The process begins with placing the vacuum plate on the heater, bringing both to the same temperature. The plate and heater are each actuated by their own pneumatic cylinders. The plate and heater first move together to make contact with the wafer. This rapidly and uniformly cools the wafer below the solder solidification temperature. Similar to a vacuum support chuck, the three vacuum zones of the plate apply vacuum force to the wafer, allowing it to be held horizontally flat. This improves the conduction of the wafer between the plates, especially if the wafer is prone to warping. The plate is then detached, maintaining its back grip on the wafer. Here, nitrogen gas is introduced into channels on the plate to actively cool it. The cooling rate can be adjusted by changing the nitrogen flow via a mass flow controller. Instead of convective cooling of the wafer while it is freely suspended in the chamber during cooling, maintaining contact between the wafer and the plate minimizes, and even eliminates, residual stress on the wafer. This reduces wafer warping when the wafer is later released from the ring clamp. A nitrogen showerhead above the wafer can also convectively cool the wafer through a jet of nitrogen gas. After the plate / wafer system has cooled sufficiently, the vacuum is released and the plate is separated from the wafer. Here, the wafer is cooled solely by convection until it leaves the station. While the wafer cools, the plate descends and comes into contact with the heater again. This heats the plate to its starting temperature in preparation for the next wafer.

[0025]

[0030] Although the pneumatic members are controlled independently, the resulting plate and heater motions are coupled within a limited range. The wafer pneumatic member controls the absolute position of the heater by its own up and down positions relative to the chamber. The plate pneumatic can be effectively considered as a plate / heater separator. The plate pneumatic does not control the absolute position of the plate, but rather determines whether the plate is positioned upwards or in contact with the heater.

Claims

1. A wafer assembly apparatus for depositing solder balls onto a wafer substrate for subsequent use in the electronics industry, comprising a wafer processing module configuration, wherein the wafer processing module configuration is interconnected to and operated by a central wafer handling robot to provide a unified system, the wafer processing module comprising an input port, a pre-aligner module for receiving wafers to be processed, and a binder module for applying a fluxless fluid binder to the upper surface of the wafers to be processed, wherein the fluxless fluid binder is configured to evaporate completely from the upper surface of the wafers to be processed at a high temperature in a reflow station, and further comprising one or more nozzles configured to spray and evenly distribute the fluxless fluid binder across the upper surface of the wafers to be processed, after the fluxless fluid binder has been sprayed and evenly distributed across the upper surface of the wafers to be processed A binder module further comprising an air knife configured to deliver a curtain of compressed air, wherein the curtain of compressed air from the air knife for diffusing the fluxless binder applied across the upper surface of the wafer leaves a uniform thin film of fluxless fluid binder across the upper surface of the wafer; a solder ball mounting module for depositing a number of solder balls onto the wafer to be treated; an inspection module including a re-examination analysis and insertion and extraction configuration for any solder balls deposited on the wafer to be treated that have been misplaced; and a reflow module for heating and fixing the solder balls onto a pad configuration on the wafer to be treated, wherein the pre-aligner module is positioned to receive the wafer to be treated, and the binder module is positioned to hold each wafer by a support pin configuration having a vacuum cup on it during binder spray deposition and binder application, thinning, and excess binder removal operations, and the pre-alignment operation of the wafer to be treated in the pre-aligner module,A wafer assembly apparatus comprising: a transfer operation to a support pin configuration having a vacuum cup on top of a solder ball mount module for verification of optical alignment by multiple cameras; a solder ball distribution stencil; a solder ball distribution storage unit on the stencil for controlled discharge of solder balls to the wafer to be treated below the stencil; means for recovering inappropriate solder balls and excess binder; and a three-station reflow module for final transfer for heat treatment of the loaded wafer to be treated or collection of the completed wafer, wherein the three-station reflow module consists of three stations including a loading lock station, a reflow station, and a warpage control station, and the wafer to be treated is moved from station to station in the three-station reflow module by a rotating carrier disk.

2. The wafer assembly apparatus according to claim 1, wherein the fluid binder is coated onto the wafer at room temperature or high temperature in a reflow station and is configured to evaporate completely from the top surface of the wafer, and the one or more nozzles include a nozzle configuration supported by a gantry that is movable directly above the wafer supported therebelow, and any excess binder is collected and used for further wafers.

3. The wafer assembly apparatus according to claim 2, wherein a number of solder balls are arranged as an array on the solder ball engagement locations of a separation pattern on the wafer after the solder balls have been filtered through a vertical array of perforated solder ball alignment plates movably positioned above the wafer.

4. The wafer assembly apparatus according to claim 3, wherein an air knife is driven laterally with respect to the array of solder balls on the upper surface of the wafer so that any unrelated solder balls are pushed away from the surface of the wafer.

5. The wafer assembly apparatus according to claim 4, wherein any unrelated solder balls are transferred to a unidirectional channel for collection and subsequent reuse on further wafers.

6. A wafer assembly apparatus for depositing solder balls onto a wafer substrate for subsequent use in the electronics industry, comprising a configuration of individual wafer processing modules, wherein the configuration of the individual wafer processing modules is interconnected to and operated by a central wafer handling robot for moving wafers from module to module, and the modules include a pre-aligner module for receiving wafers to be processed, a binder module for applying a fluid binder to the upper surface of the wafer, a solder ball mount module for depositing a number of solder balls onto the wafer, a reflow module for heating and fixing the solder balls onto a configuration of pads on the wafer, and an inspection module for reviewing and analyzing the solder balls deposited on the wafer, wherein the process involves a loading port module for receiving the wafers to be processed. A wafer assembly apparatus comprising a binder module for holding each wafer by support pins and support plates during binder spray deposition and binder application, thinning, and removal of excess binder operations, and a solder ball mount module for transfer to support pins and support plates for pre-alignment of the wafer at the input port and optical alignment reassembly by multiple cameras, comprising a solder ball distribution stencil, a solder ball distribution storage unit located below the stencil for controlling the discharge of solder balls onto the wafer located below the stencil, and means for recovering improper solder balls and excess binder, a three-station reflow module for heat treatment of the mounted wafer and final transfer for finished wafer collection, wherein the three-station reflow module comprises three stations including an input lock station, a reflow station, and a warpage control station, and the wafers to be treated are moved from station to station in the three-station reflow module by a rotating carrier disk.

7. The wafer assembly apparatus according to claim 6, wherein the fluid binder is applied to the wafer by a nozzle configuration supported by a main computer-controlled gantry movably positioned directly above the wafer supported therebelow.

8. A wafer assembly apparatus according to claim 7, wherein a number of solder balls are arranged as an array on the solder ball engagement locations of a separation pattern on the wafer after the solder balls have fallen through a vertical array of perforated solder ball alignment plates vibrably positioned above the wafer.

9. The wafer assembly apparatus according to claim 8, wherein an air knife supported by the main gantry is driven laterally with respect to the array of solder balls on the upper surface of the wafer so that any unrelated solder balls are pushed away from the surface of the wafer.

10. The wafer assembly apparatus according to claim 9, wherein any unrelated solder balls are transferred to a one-way channel by passing through a one-way valve for collection and subsequent reuse on further wafers.

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