Method and apparatus for moving blocks
An apparatus for dispensing blocks in a fluid over a substrate. The apparatus includes a first tube having a first end and a second end. A compression device is coupled to the first tube. A second tube is connected to the first tube to deliver a slurry having blocks to the first tube. The compression device pulsates at least one block in the slurry which is flowing through a portion of the first tube.
This application is a divisional application of co-pending U.S. patent application Ser. No. 10/086,491, which was filed on Feb. 28, 2002.
FIELD OF THE INVENTIONThe present invention relates generally to a method and an apparatus for distributing particles. More specifically, the invention relates to a method and an apparatus for directing the movement of particles such as blocks to efficiently form electronic assemblies.
BACKGROUNDThe manufacture of electronic assemblies such as display panels is known in the art. One such method involves using fluidic self-assembly (FSA) that is described in U.S. Pat. No. 5,545,291. In FSA, blocks with integrated circuits thereon are placed into a fluid such as water. The combination of blocks in a fluid, referred to as a slurry, is dispensed over recessed regions in a substrate. The recessed regions receive the plurality of blocks and the blocks are subsequently electrically coupled. Although FSA has provided advantages to electronic device manufacturers such as increased speed of assembling an electronic device, for economic reasons it is necessary to dispense an excess amount of blocks, and recover those blocks that fall to the surface of the substrate without settling into recessed regions. Additionally, because FSA is a stochastic process, initially, some of the recessed regions may not be filled by a block. This is problematic because devices manufactured with some recessed regions that lack a block generally operate less efficiently compared to devices in which all of the blocks have been properly placed. A manufacturer may solve this problem by using a variety of methods. For example, the FSA process may be used a second time over the empty recessed regions. Another method involves using a robot to place a block into a particular recessed region. Typically the robot may not place more than one block into one of the recessed regions. Using the robot is a time consuming and expensive process.
There are other challenges inherent in the FSA process. For example, the slurry must be transported from one process chamber to the next. However, typical fluid control components, such as valves, cannot be used because these components could potentially crush a block, thereby polluting the process chamber with particulate matters. The movement of blocks also cannot be controlled near the recessed regions of the substrate to either direct a block to move into a particular recessed region or to move excess blocks away from recessed regions that are already filled. It is therefore desirable to have a method and an apparatus that address these problems associated with conventional systems.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which:
FIGS. 12 to 15 illustrate exemplary methods of depositing blocks onto a substrate using apparatuses of the present invention.
DETAILED DESCRIPTIONIn the following description, numerous specific details such as specific materials, processing parameters, processing steps, etc., are set forth in order to provide a thorough understanding of the invention. One skilled in the art will recognize that these details need not be specifically adhered in order to practice the claimed invention. In other instances, well known processing steps, materials, etc., are not set forth in order not to obscure the invention.
One embodiment of the invention relates to forming an electronic assembly by placing a plurality of blocks into a fluid to create a slurry and moving the slurry in a pulsating motion created by a compressing device coupled to a tube in which the slurry flows. In one embodiment, the pulsating motion of the blocks in the slurry creates a disrupting flow that causes the blocks to be more evenly distributed in the tube by preventing the blocks from settling to the bottom of the tube. The flow also substantially prevents the blocks from dropping or staying in one position on the surface of a substrate that is without recessed regions.
In another embodiment, a dispensing tube having a plurality of nozzles is used to deposit the blocks on the substrate. The dispensing tube is rotatable so as to turn on and off the dispensing of the blocks.
In yet another embodiment, excess blocks are moved by a device that creates a pulsating motion or jet stream flow near the blocks to clear the blocks in a certain area. In one embodiment, this pulsating motion or jet stream flow is created by continuously changing the flow rate. In another embodiment, a vacuum with at least one nozzle is used to remove excess blocks above and around a substrate that are not deposited into recessed regions. In yet another embodiment, a pair of nozzles each carrying a different level of vacuum is used to remove excess blocks wherein a lower vacuum nozzle is used to remove excess blocks near the recessed regions that are already filled with blocks and a higher vacuum nozzle is used to remove excess blocks further away from the recessed regions. The recovered blocks may be sent to a temporary storage area until the blocks can be cleaned and redispensed.
In another embodiment, the blocks are moved from one process chamber to another process chamber by selectively changing the pressure applied to the slurry that flows through a tube connected to the process chambers. Moving the blocks in the slurry from one point to another is accomplished without using mechanical devices such as valves that are known to damage the blocks. By placing the blocks in the proper process chamber, the blocks may be cleaned or treated.
The embodiment below discusses in detail apparatuses and methods depositing blocks into recessed regions in a substrate. It is to be understood that the recessed regions can be replaced with receptor sites. The receptor sites or the recessed regions can be created into the substrate using techniques such as stamping, embossing, injection molding, and casting, among others. Having receptor sites being recessed is common but is not a limitation of the present invention. When the substrate is an organic material and is an amorphous or semicrystalline polymer, the receptor sites may be embossed into the polymer material with a mold that matches the block size and pitch for the device being produced (e.g., an active matrix LCD). Alternatively the receptor sites can be molded or carved into a surface, or, be designed as a raised area of the substrate. Thus, the receptor sites can be recesses, bosses, protrusions, bulges, or protuberances. The receptor sites need not be recessed regions in the substrate.
Rapid agitation or pulsating of the fluid creates turbulent flow of the slurry and the blocks 75 in the tube 115. By creating turbulent flow, the blocks 75 are distributed over the substrate 150 in a more controllable manner compared to more conventional laminar flow of the blocks 75 in a fluid in a tube.
Also as illustrated in
The distribution line 139 terminates into a block distribution point 137. The distribution line 139 is further coupled to a dispensing tube 138 having a plurality of nozzles 151. As the slurry is passed through the distribution point 137, the slurry comprising the blocks 75 may be divided into, for example, four sectors 149 aligning with the plurality of nozzle 151. The rapid agitation or pulsation caused by the pulsating device 143 continues in the dispensing tube 138. The rapid agitation or pulsation of the slurry inside the dispensing tube 138 created turbulent flow to the slurry which causes the slurry to be distributed over the sectors 149 evenly. The blocks 75 are then dispensed over a substrate 150. The agitation and pulsation of the slurry enables the slurry to be dispensed over the substrate 150 is a more controlled and evenly fashion.
The dispensing device 700 enables uniform dispensing of the blocks 75 through the dispensing tube 708 which enhances the efficiency of deposition of the blocks 75 over the substrate 726. Evenly dispensed blocks 75 makes the dispensing of the blocks 75 through the dispensing orifices much more smoothly. The vibration source 704 coupling to the dispensing tube 708 can vibrate, pulsate, or agitate the slurry inside the dispense tube 708; the vibration source 704 thus facilitates evenly dispensing and leveling of the blocks 75 across the plurality of the dispensing orifices 718. The vibration source 704 also prevents the orifices 708 from being plugged with the blocks 75. Furthermore, for appropriate sized orifices, the vibration source 704 can also control whether or not blocks are dispensed at all. For example, when the vibration source 704 is turned off, no blocks 75 will be dispensed. And, when the vibration source 704 is turned on, the blocks 75 will begin to be dispensed. An example of a suitable vibration source 704 is such as a diaphragm pump, a piezo actuator, or a bellows and piston combination. The vibration source 704 produces a range of frequencies that can be varied depending on the desired results, the required uniformity of dispensing, flow requirement and the size and shape of the blocks 75. In one example, the vibration source is set to produce a frequency ranging from 2 Hz to 2000 Hz.
In another example, the plurality of the orifices 718 is sized according with the size and shape of the blocks 75 that are being dispensed. Not all of the orifices 718 in the dispensing tube 708 need to have the same shape and size. One orifice may have a shape and size different from another orifice. The difference in size and shape of the orifices 718 in one dispensing tube 708 enables blocks 75 having different shapes and size to be deposited on the substrate 726. For example if the blocks 75 are square shaped, the orifices can be designed to have square shapes and slightly larger then the blocks 75, to allow the blocks 75 to flow through. It is to be noted that the shape of the orifices 718 needs not match the shape of the blocks 75 in order for the dispensing device 700 to work. For example, when the shape of the orifices 718 is circular, most blocks 75 having any shape will be able to be dispensed therethrough. It is preferred that the shape and size of the orifices 718 be optimized for the sizes and shapes of the blocks 75 to be dispensed from the orifices 718.
It is envisioned that the dispensing tube 708 may have several lines of orifices placed around the dispensing tube 708. Each of the lines of orifices includes the plurality of orifices 718 located longitudinally along the line. Having several lines of orifices may be useful to speed up the deposition process.
The diameters and shapes of the plurality of the orifices 718, the vibration level applied by the vibration source 704, the rotation of the dispensing tube 708, and time are among the factors that control the rate of depositing the blocks 75 onto the substrate. Any variation of the above parameters may be done to optimize deposition rate.
The apparatus 800 includes at least one process chamber. As shown in
In the embodiment shown in
In the embodiment shown in
One exemplary scheme of transporting of the blocks 75 is referred to as a pressure regulating mechanism. The varying of the pressure that the slurry sees in each chamber regulates the transporting of the blocks 75 from one process chamber to the next. The slurry would move to the chamber at lower pressure. In one example, the slurry comprising the blocks 75 is flown along in the transferring line 850 in the direction of arrow “I.” The pressure P1 coming from the pressure line 822 is high (e.g., 5-10 psi). The pressure P2 coming from the pressure line 824 is about the same or less than the pressure P1 coming from the pressure line 822 (e.g., 3-8 psi). The blocks 75 are pushed into the process chamber 810 through tube 852 in the direction of arrow “II” and continue to move along the direction of the arrow “III” out of the processing chamber 810.
In another example, the transferring line 850 includes a screen 860 placed along the transferring line 850 behind the tube 852. Examples of a screen 886 include a mesh or a sieve, preferably made of a plastic material, having size sufficient to stop the blocks 75 from passing through. With the screen 852 in place, the block 75 are pushed into the process chamber 810 as opposed to moving along the transferring line 850 and bypassing the process chamber 810. With the high pressure continued, the blocks 75 continue to move with the slurry in the direction of arrow “III” into another portion of the transferring line 850. The blocks 75 continue to move with the slurry in the direction of arrow “IV” and be pushed into the process chamber 820 in the direction of arrow “V.” The lower pressure P2 coming from the pressure line 824 in the direction of arrow “VI” prevents the blocks 75 from continuing along the transferring line 850 pass the process chamber 820. The blocks 75 are thus dispensed into the process chamber 820 through tube 856.
In the example where the process chamber 820 is a dispensing device, the blocks 75 can be dispensed over a substrate according to some of the embodiments discussed above. The process chamber 820 may include an outlet tube 858 for releasing excess fluid from the process chamber 820. A pump 836 may be used to direct the excess fluid from the process chamber 820. In this example, the pump 836 may generate a pressure P3 that is less than P1 (e.g., less than 5 psi) to prevent back flow from the process chamber 820.
In yet another embodiment, the pressure line 822 includes a screen 870 to prevent the blocks 75 from entering the pressure line 822. Similarly, the pressure line 824 also includes a screen 871 to prevent the blocks 75 from entering the pressure line 824. Examples of a screen 870 or 871 include a mesh or a sieve having size sufficient to stop the blocks 75 from passing through.
By moving the blocks 75 between mini process chambers, the blocks 75 may be cleaned, treated, or recycled independently of each mini process chamber. The cleaning process typically would involve recirculation of the devices in deionized water, organic solvent such as acetone or isopropanol, or FSA solution. The recirculation stream is filtered to remove any undesirable particulate matter. The treatment process is typically any number of types of surface oxidation or surface chemistry. For example, the blocks 75 may be filtered from the slurry, passed into a station for rinsing with pure water, and dispensed into another batch of fluid used to make a slurry or the same slurry.
The dispensing device 902 can be any of the dispensing devices described above (e.g., dispensing device 100, 135, and 700) which is used to dispense the blocks 75. In the example shown in
The clearing device 904 is essentially a container storing a fluid used to clear the excess blocks 75 off the substrate 910. The clearing device 904 further has at least one nozzle 905 for the fluid to flow therethrough. The clearing device 904 is configured such that it can jet out the fluid at a variable rate allowing the dispensing device 904 to move excess the blocks 75. In one example, the fluid flow is set at a rate such that the fluid flow is able to clear the excess blocks 75 off the substrate 910.
In one example, the clearing device 904 is positioned near substrate 910 in order to more easily direct the stream of the fluid at the nozzle 905. The clearing device 904 may also be coupled to a compression device or a pulsating device 907 which can pulsate the slurry. As the pulsation device 907 applies pulsation to the fluid, the flow rate of the fluid and the pressure applied to the fluid rapidly change within the local area between the fluid flow and the substrate 910. The pulsation from the pulsating device 907 causes the fluid flow to change rapidly.
In another example, the dispensing device 904 is coupled to a motor device that can pulsate or agitate the fluid in the clearing device 904. In this example, the motor device takes place of the pulsating device 907. The pulsation created by the motor device also causes rapid change (but small) in the pressure that affects the flow of the fluid. This rapid change in pressure breaks the static friction between the surface of substrate 910 and the blocks 75. This allows the blocks 75 to move freely generally following the direction of the flow of the fluid along the nozzle 905. With the blocks 75 flowing in the direction of the fluid flow because of the pulsation applied to the dispensing device 900, the blocks 75 may be cleared or removed from an area over substrate 910.
In another embodiment of the invention, the clearing device 904 can alternately jets out the fluid and takes in the fluid creating a net flow rate of approximately zero. The fluid moves back and forth, without a net positive flow of fluid coming out of the clearing device 904. Having the clearing device 904 jetting in and out the fluid creating rapid change in the static friction between the surface of the substrate 910 and the blocks 75, it is much more easy to control the clearing and removal of excess blocks of an area over the substrate 910. In contrast, in conventional systems, it is difficult to control clearing or the removal of excess the blocks 75 because laminar flow of fluid such as deionized water is typically used. Generally, it takes a much greater amount of flow than laminar flow to break the temporary bond that exists between the blocks 75 and the substrate 910.
The dispensing device 1002 of
The clearing device 1004 of
Each of the vacuum channel 1032 and 1034 terminates into at least one small orifice at the tip of the nozzle head 1030. The clearing device 1004 further couples to a fixture 1039 which is able to move the clearing device 1004 across the web line of the substrate 1010.
In operation, the clearing device 1004 moves behinds the dispensing device 1002. As vacuum is applied to each of the low vacuum channel 1032 and the high vacuum channel 1034, the excess blocks 75 (those not deposited into receptor sites on the substrate 1010) are sucked into the nozzle head 1030 into either the low vacuum channel 1032 or the high vacuum channel 1034. A variety of vacuum level gradients may be used in a controllable fashion to apply different suction forces over substrate 1010 to remove or recover the blocks 75.
For example, the low vacuum channel 1032 may use a pressure ranging from 0.50 psi to 0.80 psi above the substrate 1010 to provide enough force to remove excess the blocks 75 that are not deposited in the recessed regions. The low vacuum pressure will not disturb or remove the blocks 75 that are placed in recessed regions. The low vacuum pressure may just slightly lift the excess blocks 75 off the substrate. Additionally, the high vacuum channel 1034 may use a pressure ranging from 0.01 psi to 0.5 psi to apply a stronger force to remove the excess blocks 75. For instance, when the low vacuum channel 1032 applies just enough force to lift the excess blocks 75 off the substrate 1010, the high vacuum channel 1034 followed immediately and applies a stronger force to completely remove the excess blocks 75 off the substrate 1010. In another example, the low vacuum pressure generates a force such that the slurry above the substrate 1010 has a flow rate ranging from about 0.2 L/min to 0.7 L/min. And, the high vacuum pressure generates a force such that the slurry above the substrate 1010 has a flow rate ranging from about 1 L/min to 3 L/min. Both the high and low vacuum channels may send the recovered the blocks 75 to a temporary storage area such as a container (not shown) where the blocks 75 may be cleaned and redispensed. Alternatively, the high and low vacuum channels may also send the blocks 75 back to the dispensing tube 1002 to recycle the blocks 75 such that they may be re-dispensed.
In another example, a flexible scraper 1036 is slidably coupled to the nozzle head 1030 of
In yet another example, the clearing device 1004 of
For example, the nozzle 1123 may use a low vacuum pressure (e.g., 0.50 psi to 0.80 psi) above recessed regions 80 to provide enough force to remove the excess blocks 75 nearby the recessed regions 80. The removal of the excess blocks 75 with the low vacuum may occur without disturbing or removing the blocks 75 that are already placed in recessed regions 80. A high vacuum (e.g., 0.01 psi to 0.50 psi) is applied to the nozzle 1125 to provide a stronger force to remove excess the blocks 75 between the recessed regions 80 on the substrate 1120 (e.g., regions 81 of
At block 1420, blocks are removed off the substrate by a clearing device which is coupled to at least one vacuum applying pressure to a nozzle head within the clearing device sucking excess blocks off the substrate. In one example, the vacuum is activated causing at least one block of the plurality of blocks to enter the nozzle head of the clearing device. It will be appreciated that a variety of gradients in the vacuum may be used. For example, a high vacuum ranging from 0.01 psi to 0.50 psi may be used to remove excess blocks between the recessed regions. Alternatively, a low vacuum ranging from 0.50 psi to 0.80 psi may be used when the block clearing device is above recessed regions to provide sufficient force to remove excess blocks near the recessed regions but without disturbing or removing the blocks that are already assembled in recessed regions. In one example, the nozzle head comprises a low vacuum channel and a high vacuum channel. A low vacuum pressure (e.g., pressure ranging from 0.50 psi to 0.80 psi) is applied to the low vacuum channel to lift the excess blocks off the substrate. A high vacuum pressure (e.g., pressure ranging from 0.01 psi to 0.50 psi) is applied to the high vacuum channel to completely remove the excess blocks off the substrate into the clearing device.
At block 1430, the recovered blocks are placed into a container for storage. Subsequently, the blocks may then be cleaned and then redispensed using the techniques described herein.
In an alternative method, the dispensing tube includes a filter coupling to an outlet tube through which excess fluid is removed from the transfer chamber. In this method, the outlet tube is coupled to a pump which is turned on as the slurry is being dispensed into the transfer chamber. The fluid is sucked out of the transfer chamber while the filter help retaining the plurality of the blocks inside the chamber. To dispense the plurality of blocks, the pump is turned off, the blocks would descend to the bottom of the tube. The vibration source is turned on to even distribute the plurality of blocks longitudinally along the dispensing tube. The plurality of blocks then assembles and falls into the orifice areas and be dispensed outside through the plurality of orifices.
In the preceding detailed description, the invention is described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
Claims
1. A method for dispensing a plurality of blocks over a substrate comprising:
- pulsating a fluid flowing in a first tube coupling to a compression device that pulsates said fluid;
- dispensing a plurality of blocks from a second tube into said fluid, each of said plurality of blocks has an integrated circuit; and
- while pulsating said fluid, dispensing said blocks and said fluid over a substrate having a plurality of receptor sites wherein said plurality of blocks couples to said receptor sites on said substrate.
2. An apparatus as in claim 1, said compression device controls a rate for said dispensing said plurality of blocks over said receptor sites.
3. A method for moving a plurality of blocks comprising:
- removing excess blocks off a substrate with a block clearing device wherein said block clearing device couples to at least one vacuum pump which applies a pressure to a nozzle head included within said block clearing device wherein said excess blocks are sucked into said nozzle when said pressure is applied.
4. A method as in claim 3 wherein said nozzle head further comprises a low vacuum channel and a high vacuum channel wherein a low vacuum pressure is applied to said low vacuum channel and a high vacuum pressure is applied to said high vacuum channel.
5. A method as in claim 4 wherein a pressure ranging from about 0.01 psi to 0.5 psi is applied to said high vacuum channel and another pressure ranging from about 0.50 psi to 0.80 psi is applied to said low vacuum channel.
6. A method as in claim 4 further comprising:
- applying said low vacuum pressure to said low vacuum channel to lift said excess blocks off said substrate; and
- applying said high vacuum pressure to said high vacuum channel to remove said excess blocks off said substrate.
7. A method as in claim 3 further comprising:
- pulsating a dispensing device that dispenses a slurry comprising a plurality of blocks wherein said slurry include said excess blocks while dispensing said plurality of blocks over a substrate having a plurality of receptor sites to receive said plurality of blocks.
8. A method for moving a plurality of blocks comprising:
- removing excess blocks off a substrate having a plurality of blocks being dispensed thereto with a block clearing device, said block clearing device comprising a fluid container and a compression device, wherein said fluid container releases a fluid to over said substrate while said compression member causes said fluid to pulsate as said fluid is being released.
9. A method as in claim 8 wherein said removing excess blocks off said substrate includes alternately jetting out and taking in said fluid to create a net flow rate of approximately zero.
10. A method as in claim 8 further comprising:
- using a dispensing device and dispensing a slurry having said plurality of blocks over said substrate, said substrate further having a plurality of receptor sites to receive said plurality of blocks; and
- while dispensing said slurry, pulsating said slurry.
11. A method comprising:
- moving a slurry from a first process chamber to a second process chamber using a pressure regulation mechanism, said slurry comprising a plurality of blocks dispensed in a fluid, each of said plurality of blocks having integrated circuits disposed thereon; and
- performing an action on at least one block, said action is one of cleaning said at least one block or treating said at least one block.
12. A method as in claim 11 further comprising cleaning at least one block of said plurality of blocks in said first process chamber.
13. A method as in claim 11 further comprising treating at least one block of said plurality of blocks in said second process chamber.
14. A method as in claim 11, wherein said first chamber is selected from a group consisting a recovering station, a recycling station, a dispensing station, and a cleaning station.
15. A method as in claim 11, wherein said second chamber is selected from a group consisting of a recovering station, a recycling station, a dispensing station, and a cleaning station.
16. A method for dispensing a plurality of blocks over a substrate comprising:
- dispensing a slurry having said plurality of blocks and a fluid into a dispensing tube having a plurality of orifices;
- vibrating said slurry using a vibration source coupling to said dispensing tube while dispensing said plurality of blocks to a substrate having a plurality of receptor sites to receive said plurality of blocks, said plurality of blocks are dispensed through said plurality of orifices.
17. A method as in claim 16 wherein said vibration and said slurry comprises said vibration source vibrating said slurry with frequencies ranging from 2 HZ to 2000 HZ.
18. A method as in claim 16 further comprising rotating said dispensing tube using a rotation mechanism compiling to each side of dispensing tube.
19. A method as in claim 18 wherein said rotating includes rotating said dispensing tube from a 0-degree position to a 90-degree position.
20. A method as in claim 18 wherein said rotating includes rotating said dispensing tube such that said plurality of orifices face downward and directly above said substrate to dispense said plurality of blocks.
21. A method as in claim 18 wherein said rotating includes rotating said dispensing tube such that said plurality of orifices face away from said substrate to stop dispensing said plurality of said blocks over said substrate.
22. A method as in claim 16 further comprising:
- dispensing said slurry into a transfer chamber located within said dispensing tube through an inlet tube disposed into a first end of said transfer chamber;
- removing excess fluid from said slurry from said transfer chamber through an outlet tube coupled to a second end of said chamber using a vacuum source compiling to said outlet tube and turning off said vacuum source to distribute said plurality of blocks over said plurality of orifices.
23. A method as in claim 16 further comprising:
- turning on and off said vibration source to control said dispensing a slurry wherein when said vibration source is turned on, said slurry is being dispensed and wherein when said vibration source is turned off, said slurry is not being dispensed.
Type: Application
Filed: Jun 13, 2006
Publication Date: Nov 30, 2006
Inventors: Gordon Craig (Palo Alto, CA), Ming Chan (Milpitas, CA), Cornelius Sutu (Pittsburg, CA), Omar Alvarado (Santa Clara, CA), Hoang Pham (Milpitas, CA), Mark Hadley (Newark, CA)
Application Number: 11/452,444
International Classification: B05D 1/12 (20060101); B05D 3/00 (20060101);