Patent Application
20160326627
Not applicable.
The present invention relates to an apparatus comprising entwined manifolds suitable for simultaneous vapor deposition from multiple sources to patterned locations on a target object such as a display substrate. The inventive apparatus is also suitable for fluid mixing applications.
Vapor deposition manufacturing techniques have been known for centuries, and are widely used. Two main variants are known: physical vapor deposition (PVD) and chemical vapor deposition (CVD). Physical vapor deposition involves condensation of material from a vapor onto a target surface. Chemical vapor deposition introduces a chemical reaction, so that the deposited material is formed in a chemical reaction at or near the target surface, but is not present in significant quantities in the vapor phase. CVD is a key technology used in the semiconductor industry, and is also widely used in microfabrication, nanotechnology, and specialized coatings. PVD is widely used in the semiconductor, automotive, and aerospace industries, and also for other specialized coatings. Many variants of PVD and CVD are known.
A survey of CVD may be found, for example, in (1) chapter 1 of Chemical Vapour Deposition: Precursors, Processes and Applications, eds. A. G. Jones and M. L. Hitchman, Royal Society of Chemistry, Cambridge, 2008, (2) H. Pederson and S. D. Elliott, Theoretical Chemistry Accounts, vol. 133, no. 5, article 1476, Springer-Verlag 2014, and their respective cited references. A survey of PVD may be found, for example in Physical Vapor Deposition of Thin Films, J. E. Mahan, Wiley-Interscience, New York, 2000. PVD of organic materials is described, for example by Barr in U.S. Pat. No. 2,447,789, and PVD for organic electroluminescent (EL) devices is described, for example, by Tanabe et al. in U.S. Pat. No. 6,296,894.
In many applications, an entire target surface is to be coated, and a single vapor source is applied uniformly to the entire surface. In other applications, a target surface is to be successively coated with multiple layers. In these applications, a sequence of vapor sources are successively applied to the target surface. In still other applications, a target surface is to be coated with a pattern. Masks, including aperture masks and photoresist masks, are widely used to limit deposition to the desired pattern. Successive layers may use different masks.
In a few applications, non-overlapping areas of a target surface are to be coated with different materials. One such common application is in the deposition of emissive materials in an organic EL display, which may have multi-color pixels, comprising for example, red, green, and blue sub-pixels, and different formulations for emissive materials for each color. Vapor deposition through aperture masks is commonly used in such applications, as described, for example, by Tang in U.S. Pat. No. 5,937,272. In an exemplary procedure, a first aperture mask is used to deposit red emissive material in the areas of the red sub-pixels, while leaving areas of green and blue sub-pixels uncoated. A second aperture mask is used to deposit blue emissive material in the areas of the blue sub-pixels, without affecting the red sub-pixels, and leaving the green sub-pixels uncoated. Finally, a third aperture mask is used to deposit green emissive material for the green sub-pixels. Depending on the pixel layout, a mask used for a first color can be translated by a step and re-used for at least a second color. In this way three manufacturing steps are required to deposit emissive materials for three colors, which is disadvantageous for the production cycle time (often referred to as TAKT time).
While this discussion describes three colors, it is known to use a different number of colors in a display, for example four, and even more. Some four-color combinations known in the art include red-green-blue-white (RGBW) and red-green-blue-yellow (RGBY). The considerations described here are similarly applicable to two colors, four colors, and five or more colors.
Prior attempts have been made to speed up the vapor deposition process. In U.S. Pat. No. 4,874,631, Jacobson et al. describe a system for simultaneous deposition of different coatings onto a thin web in a roll-to-roll manufacturing process. Different chambers are used for different coatings. With such a system it is difficult to maintain the precise registration required by fine-pitched pixels of today's commonplace display devices. In U.S. Pat. No. 6,338,874, Law et al. describe speeding up a multi-layer CVD process by performing all coatings within a single chamber. Law's system provides multiple CVD stations within a single chamber, thereby speeding up the turn-around from one coating to the next. However, as separate stations are used, only one CVD process can be performed at one time. Thus the bottleneck for display manufacture, namely requiring three process steps for three non-overlapping coatings, is not addressed by Law et al.
Another technology that has been developed is thermal transfer, in which a donor sheet is prepared offline, placed in proximity to the target surface. See e.g., U.S. Pat. No. 5,688,551 to Littman et al. Material is transferred from donor to target when the donor is heated. The donor may be heated selectively in a pattern. The pattern may be defined by (i) controlling in irradiating source, such as a scanning laser beam, (ii) by arranging absorber pads adjacent to the donor material, so that only material adjacent to an absorber pad is transferred to the target, or (iii) by preparing the donor sheet to have donor material only in defined areas. The pattern may also be defined (iv) using an optical mask, to limit areas of the donor sheet that receive irradiation, or (v) using an aperture mask, so material is only deposited through openings in the aperture mask.
Commonly, a donor sheet is prepared with a single material to be deposited. Accordingly, three steps with three donor sheets are required to deposit emissive materials for three colors. However, if the donor is prepared with material only in defined areas corresponding to sub-pixels, it is possible to prepare a single donor sheet with emissive material of all three colors, and thereby perform thermal transfer of all three colors in a single step. While this is advantageous for TAKT time, this technique suffers from two serious drawbacks. First, the donor sheet with multiple materials must be carefully prepared and is difficult to get properly registered. Secondly, such a donor sheet must be individually prepared for each target device, which becomes prohibitively expensive. Finally, the thermal transfer process itself has other difficulties, such as handling the donor sheets and providing a uniform, controlled irradiation source over a large area. As a result, the thermal transfer process is not widely used in the display industry, and vapor deposition remains the technology of choice.
As a result, there is still a need to provide improved methods and apparatus for vapor deposition, which can enable faster deposition of multi-color pixels with less process steps, lower production cycle time, and lower cost.
The present invention is directed to apparatus and methods for simultaneous vapor deposition from multiple sources onto distinct locations on a target surface.
In a first aspect, a multi-manifold apparatus is provided comprising a plurality of entwined disconnected manifolds. Each manifold has at least one input port and a plurality of output ports. In a PVD application, each input port may be connected to a PVD source. The manifold comprises one or more chambers and a plurality of pathways whereby vaporized material is delivered to the several output ports. In a display application, each output port may be aligned over a respective sub-pixel.
The manifolds are entwined, whereby each input port is simultaneously connected to all its corresponding output ports even as the output ports are arranged in interspersed patterns. For example, in a three-color display application, a red input port may be connected by a red manifold to output ports corresponding to all red sub-pixel locations, even while blue and green input ports are respectively connected to all output ports corresponding to blue and green sub-pixel locations. To achieve this, passageways for the red manifold must pass between multiple passageways of the blue and green manifolds.
The constituent manifolds of a multi-manifold are disconnected, which means that there are no internal pathways connecting one manifold to another.
The characterization of input ports and output ports is relative to a conventional PVD application with source material being delivered to a target surface. However, this designation is for convenience only: in some applications, one or more manifolds may be used in reverse. For example, in some CVD applications, pumping is provided to exhaust reaction by-products from the target surface area. In such embodiments, one or more manifolds may be used to deliver precursor material to the vicinity of the target surface, while one or more other manifolds may be used for exhaust. That is, the so-called input ports of an exhaust manifold would actually have outward flow of exhausted material into, for example, a pumping system.
In preferred embodiments, the multi-manifold is a metal structure, comprising metals such as stainless steel or titanium. In other embodiments, the multi-manifold is a polymer structure, or a ceramic structure. In still other embodiments, the multi-manifold is a composite, for example two or more sections of dissimilar materials joined together. In further preferred embodiments, the multi-manifold may have at least one section comprising layers of different materials, such as a polymer skeleton with a plated metal surface.
In a second aspect, the multi-manifold of the present invention is formed using an additive manufacturing (AM) process, sometimes colloquially referred to as 3-D printing. In some embodiments, the additive manufactured part itself comprises the multi-manifold. In other embodiments, an additive manufactured part is joined with other components to form a multi-manifold by any of a variety of technologies known in the art. In some embodiments, different additive manufacturing technologies may be used for two sections of a multi-manifold.
In a third aspect, manifolds in a multi-manifold may contain features to assist with flow-balancing between output ports. These features may include passageway extensions, shaped passages, and elements such as pins, baffles, and slant surfaces.
In a fourth aspect, manifolds in a multi-manifold may contain features to provide streamlined flow, inhibit formation of vortexes, and generally reduce the overall impedance between an input port and an output port.
In a fifth aspect, a multi-manifold is used in a process application during manufacture of a pixilated device. In some embodiments, the pixelated device is an organic electroluminescent display, such as an active matrix organic light-emitting diode (AMOLED) display.
Embodiments described here are not limited to displays, but are broadly applicable to a range of PVD and CVD applications. Embodiments are also applicable to other fields, such as to provide finely controlled mixing of two or more fluid streams.
In a sixth aspect, a multi-manifold is used in a CVD application to deliver precursors to a target surface. First and second precursors may be delivered using corresponding first and second manifolds of the multi-manifold. In some CVD applications, one or more of the manifolds of the multi-manifold may be used in reverse, as an exhaust to collect reaction byproducts.
In a seventh aspect a multi-manifold is used to mix two vapor streams. In engine technology, premixed fuel-air mixtures are well-known to improve combustion efficiency; separate fuel and air streams take time to mix and often have non-uniform concentrations at the time of combustion. A multi-manifold introduces two vapor streams in close proximity to each other, so that the distance over which mixing has to occur (and the associated time for mixing) is greatly reduced. Used this way, a multi-manifold has applications to a range of engine technologies, including vehicular and aerospace. The multi-manifold may also be used in general chemical reactor applications, for both liquid phase and gas phase reactors, where carefully controlled mixing is important.
In an eighth aspect, the multi-manifold can be used to mix two or more fluid streams, including all liquids, or some liquids and some vapors.
In a ninth aspect, a system for manufacturing a product uses a multi-manifold. In some embodiments, the system performs a PVD process step. In some preferred embodiments, the PVD process step comprises deposition of pixel materials onto a display substrate. In other embodiments, the system performs a CVD process step. In other embodiments, the system performs a fluid mixing step. In some embodiments, the system may comprise a chemical reactor, a bubble reactor, or a combustion chamber.
Embodiments of this invention provide faster throughput and lower cost in the manufacture of multi-color displays such as organic electroluminescent displays. The multi-manifold allows all sub-pixels to be vapor deposited simultaneously, significantly reducing production cycle time and improving manufacturing throughput. The multi-manifold is reusable with very long lifetime, so that the initial cost to fabricate a multi-manifold is spread out over many manufacturing operations. Thereby the multi-manifold is very advantageous compared to alternatives presently used or contemplated in the display industry.
As long as the multi-manifold is maintained above vaporization temperature of vapor materials, there will be no significant deposition inside the manifolds. Further, as the multi-manifold is constructed of durable materials such as metal, polymer, and/or ceramic, it is straightforward to flush and clean the manifolds periodically, with gas, an inert liquid, or a solvent, with optional ultrasonication. Furthermore, metal and ceramic embodiments can be baked for optimum vacuum cleanliness.
Embodiments of this invention provide intimate, controlled, uniform mixing of two or more fluid streams, without allowing an opportunity for the fluids to react or mix earlier than desired. Thereby advantageous are obtained in CVD applications, engine technology, and other chemical reactors.
In some CVD embodiments, the use of one or more manifolds of the multi-manifold in reverse, for exhaust, allows efficient collection of reaction by-products, without contamination of neighboring reaction sites.
The following detailed description will be better understood when read in conjunction with the appended drawings, in which there is shown one or more of the multiple embodiments of the present invention. It should be understood, however, that the various embodiments of the present invention are not limited to the precise arrangements and instrumentalities shown in the drawings. Further, because of the widely disparate dimensions of the features shown, these drawings are not to scale.
In this document, the term “sub-pixel” will be used to denote a distinct light-emitting element in any of a display product or a lighting product. Sub-pixels may have different colors and may be grouped together to form pixels. A pixel has at least one of each color sub-pixel, and cannot be sub-divided into smaller pixels. Pixels are usually arranged in a regular two-dimensional array, which is often organized as rows and columns, as will be familiar to one of ordinary skill in the art. Rows and columns are interchangeable.
It is also useful to define the concept of neighboring elements in such an array. Consider first and second elements of such an array, which have respective first and second centroids. The first and second elements are neighbors if the number of distinct points on the top surface of the substrate that are (a) equidistant from first and second centroid, and (b) farther from the centroids of all other elements of the array, is greater than or equal to two. According to this definition of “neighbor” two adjacent squares on a chessboard are neighbors (all except corner points along their common boundary satisfy both conditions (a) and (b)), two diagonally touching squares on the chessboard are not neighbors (the corner where the squares touch is equidistant from four squares of the chessboard, hence this point does not satisfy condition (b), and no other point meets both conditions (a) and (b) either), and two squares remote from each other on the chessboard are not neighbors (all points satisfying condition (a) are closer to the centroid of some third square than to the first and second centroids).
In the block patterns of
Multi-manifolds are described herein as having top and bottom. This is merely a convenience, relative to an operational configuration in which a multi-manifold is operated above a target substrate, with output ports on the bottom of the multi-manifold facing the target substrate. Then, the top surface of the substrate faces the output ports and is termed the facing surface of the target substrate. A PVD source (or, other fluid source, or a pump) is connected to an input port at the top part of the multi-manifold. The manifold provides connectivity between output ports and input port(s). One of ordinary skill in the art will understand that the usage of top and bottom, and related terms, is a matter of convention and used consistently for clarity, whereas in actual practice PVD may be performed upside-down, sideways, or in any other orientation besides downward onto a substrate.
Multi-manifold 60 comprises passageways arranged in layers. Generally, as there are many interspersed output ports, output ports are connected to fine-pitch passageways. At the bottom of the multi-manifold, these passageways are called first-level (or, layer 1) passageways. Generally, each manifold may have only a few input ports, which are consequently larger in size than the first-level passageways. A large passageway may be described as a chamber or a plenum. Indeed the terms “chamber”, “plenum”, “passage”, and “passageway” all refer to confined spaces in which a fluid or vapor can be confined and transported; these terms are used interchangeably throughout this disclosure. Likewise, passageways can be thought of as existing on respective levels of the multi-level structure of a multi-manifold. The passageways on a particular level comprise a layer. Thus, in this disclosure, the terms “level” and “layer” are used interchangeably.
At the lowest level of the multi-manifold, 61R, 61G, 61B, and 61W are first-level passageways for emissive layer materials for red, green, blue, and white sub-pixels respectively, organized as a repeating group of parallel passageways. Each first-level passageway comprises a series of output ports (or, one long output port) on the bottom (not shown). In operation, one passageway 61R can be understood to be aligned with and directly above one stripe of a desired pixel pattern similar to 12 shown in
Above the first layer, passageways are connected to successively higher layers of passageways, with no connection between passageways associated with different sub-pixel colors. In common embodiments, layer 2 comprises passageways that are orthogonal to the passageways of layer 1.
For the purposes of illustration, the passageways for different colors have been shown with different cross-sectional shapes. It will be understood by one of ordinary skill in the art that, while there is no prohibition against using a mix of different shapes (including other shapes not shown), most multi-manifold embodiments will use the same cross-sectional shape for all passageways in a given layer. Further, the passageways have been drawn with a 1:1 cross-sectional aspect ratio, that is height=width. This is by no means necessary. At lower layers, where passageways are very narrow, it may be desirable to have height greater than width, while at higher layers, where passageways are very broad, it may be desirable to have height less than width.
Observing the passageways shown with cylindrical cross-section (associated with red sub-pixels), it can be seen that each passageway 61R at the first level is in contact with passageway 62R at the second level, which is in contact with passageway 63R at the third level, which in turn is in contact with passageway 64R at the fourth level. Each pair of adjoining passageways is connected by an aperture, so that vapor material from passageway 64R can flow into passageway 63R, and thence to passageways 62R and 61R.
Considering just the passageways associated with red sub-pixels, there is an input port and a single chamber at the highest level, and a plurality of output ports at the lowest level. The input port is connected to all output ports through the network of passageways at the several levels. Even where there are multiple input ports, there will in general be considerably more output ports than input ports, and all input ports are connected to all output ports through the network of passageways. All passageways are defined by walls. Accordingly, the input port(s), the output ports, the passageways, and defining walls comprise a manifold associated with the red sub-pixels. Similarly, a different set of input port(s), output ports, passageways, and walls comprise a manifold associated with the green sub-pixels. Similarly, third and fourth sets of ports, passageways, and walls comprise respective manifolds associated with the blue sub-pixels and the white sub-pixels. These manifolds share no ports and share no passageways. There are no connecting paths internal to the multi-manifold by which fluid can mix between the manifold associated with red sub-pixels and the manifold associated with green sub-pixels, or between any pair of the manifolds. The manifolds are entwined, as necessary for each manifold to be able to simultaneously provide connectivity to all of its respective output ports.
Walls are shared only to the extent that a wall may separate a passageway belonging to one manifold from a passageway belonging to a different manifold. Such walls can be considered conceptually to be a laminate of two walls, one facing and confining a passageway of a first manifold, the other facing and confining a passageway of a second manifold. It should be noted that the two walls may not be distinguishable upon physical examination; the conceptual separation of one wall into two is merely a convenience that allows the walls also to be regarded as not being shared between manifolds, so that the manifolds associated with different color sub-pixels can be regarded as wholly distinct.
Additionally, a multi-manifold may comprise some void space, defined as a space that is within the overall extent of the multi-manifold, is not filled with solid, and is not part of any passageway of any constituent manifold. For example, in
As described for the passageways associated with red sub-pixels, so also for the other colors. The two passageways 61G on the first level are connected to passageway 62G on the second level, which in turn is connected to passageway 63G on the third level, and so on. Due to the finite extent of the portion of multi-manifold 60 illustrated in
Accordingly, multi-manifold 60 comprises four manifolds—one each for deposition of red, green, blue and white sub-pixel material. These four manifolds are entwined, and are disconnected from each other, which means that there are no internal paths allowing fluid from one of the manifolds to mix with fluid of another of the manifolds. However, there is no prohibition between two ports of different manifolds being connected to one another externally, either intentionally or inadvertently. In some applications it may be desirable to couple input ports of two manifolds to a same source. For example, a multi-manifold for a four-color display layout may comprise four entwined manifolds, but if the application is a display with RGBG-patterned pixels, i.e. with two green sub-pixels in each pixel, then two of the four manifolds will be used to deposit green sub-pixel material and may be connected to a same common PVD source.
Likewise, there is no prohibition between material from the output ports commingling, which may occur by design or inadvertently. For example, in a display application it may be desirable not to have the deposition of red material end abruptly at the end of the emissive area of a red sub-pixel. Rather it may be desirable to have red material taper off smoothly between the red emissive area and an adjacent emissive area of a blue sub-pixel, and likewise have the blue sub-pixel material taper off gradually from the edge of the emissive area of the blue sub-pixel towards the red sub-pixel. Thereby, in between red and blue sub-pixels, both red and blue sub-pixel materials are commingled, and a smooth surface contour is maintained. In other applications, such commingling is undesirable. Banks may be formed on the target surface, so that each sub-pixel is confined to a recessed area surrounded by banks. If the output ports are brought into close proximity to the raised bank surfaces, even touching, then commingling can be substantially prevented.
As a general rule, each manifold of a multi-manifold has less input ports than output ports. As a general rule, each manifold of a multi-manifold has larger openings for each input port than for each output port.
First-level passageways 81 provide output ports (not visible) for discharge of vapor material onto a target. For reference, 87 shows two pixels of a display pattern shown aligned in an operational configuration beneath multi-manifold 80. (These pixels are not part of multi-manifold 80.) These pixels are laid out in a stripe configuration; sub-pixels 88 are directly beneath one 81 passageway. Three septa 85 are shown by dotted patterns; these septa serve to define the extent of each 81 passageway as equal to the length of two pixels 88. That is, a pixel stripe extending across the extent of the display for a length of 2M pixels is fed by M collinear first-level passageways. Each of these collinear first-level passageways is connected to a different second-level passageway 82. As shown, each 81 passageway serves two sub-pixels, each 82 passageway serves four 81 passageways, each 83 passageway serves four 82 passageways, and the one 84 passageway shown serves all three visible 83 passageways.
In layer 1, each passage is in the row direction and has a width of 0.210 mm, which is just the sub-pixel width 0.630 mm divided by 3. (Gaps between sub-pixels and between pixels are ignored in the present discussion for simplicity. The sub-pixel width is taken to be the sub-pixel pitch in the width direction.) There are 3240 passages side-by-side (3 passages for each row of pixels), and the total extent 680 mm matches the extent of the television set. Each passage extends the length of two columns (that is, between two adjacent septa 85) and has a length equal to the row-wise length of two pixels, 2×0.63 mm=1.259 mm (to within a small inconsequential rounding discrepancy).
In layer 2, the passages are in the column direction. Each first-level passage has two mates serving the same pixels for the other two colors. Accordingly, the length 1.259 mm of each first-level passage must be able to accommodate three second-level passages, and the width of each second-level passage is 1.259 mm/3=0.420 mm. The number of side-by-side second-level passages is 2880, which is three passages for every two pixels in the row direction: (1920/2)×3=2880. The total extent of these passages is 1209 mm, which matches the extent of the television set. Each passage extends the length of four rows of pixels, which is 4×0.63 mm=2.518 mm (again, within rounding).
Moving to layer 3, once again the passages are in the row direction. The length of the layer 2 passages must be served by three layer 3 passages, so the width of each passage is 2.518 mm/3=0.839 mm. The number of side-by-side passages is 810; that is, three for every four rows of pixels: (1080/4)×3=810. As a check, the total extent 680 mm matches the extent of the television set. The previous row-wise layer was layer 1, where each passage had a length covering 2 columns. In layer 3, the length is multiplied by four compared to layer 1 (4×1.259 mm=5.037 mm), covering eight columns.
The calculation for layer 4 is similar. Passage width is based off the length of layer 3 passages, and passage length is scaled up from the length of layer 2 passages.
At layer 1 in the passage width direction, 3240 passages are organized side-by-side. In the length direction, each passage has a length of 2 columns, so there are 1920/2=960 collinear first-level passages for each stripe of sub-pixels. Altogether the number of layer 1 passages is 3240×960=3,110,400. Similarly at layer 2, the total number of passages is 2880×(1080/4)=777,600. The total number of layer 2 passages is less than the total number of layer 1 passages. In common designs, the height of passages is comparable and often equal to the width of those passages, particularly at the lower levels. So, as the width of passages increases with increasing layer number, the cross-sectional area of the passages also increases. Sometimes in a design, two successive layers have the same passage width. In the design of
Similarly, the design of
Turning back to
The choice of whether to use septa such as 85 or gaps such as 86 is a matter of design. Generally, septa may be preferred at lower levels because of the smaller dimensions of all features and (for layer 1) very small gaps that may be present between adjacent output ports. Gaps may be preferred at higher levels, in order to minimize dead space of stubs at the ends of a passageway that provide no connection to either an upper or lower layer.
In other embodiments, at least one layer has no septa or gaps, and at least one passageway at that layer is connected to a plurality of passageways at the next higher layer. Presuming that such an embodiment converges to a single chamber at the highest layer, such a manifold has at least one closed loop. If two or more manifolds of a multi-manifold have closed loops, then the manifolds may be interpenetrating, which means that the manifolds have intersecting closed loops such that it is not conceptually possible to separate the manifolds without breaking at least one closed loop.
In the extreme case, and opposite to the tree topology described above, all passageways extend to the full extent of the multi-manifold, all passageways at intermediate layers K are connected to all passageways in layer K−1 and all passageways in layer K+1. A manifold such as this may have a very large number of paths from a single chamber at the highest level to any output port, and may be described as maximally connected.
It is generally desirable to have uniform deposition of vaporized materials over pattern elements across the extent of a display. To achieve this, it is desirable to design each manifold of a multi-manifold to have balanced flow to all its output ports. It is not necessary that flow of two different manifolds be balanced, however as different manifolds within a multi-manifold generally have very similar design, balanced flow between manifolds is often straightforward to achieve. However it should be noted that even identical manifolds may exhibit differences in flow owing to the different characteristics of different vaporized materials and different characteristics of the PVD sources.
Returning to flow balancing within a single manifold, this is equivalent to having equal impedance from the input port to any output port. Since a PVD vapor is a compressible gas, and a heated multi-manifold constrains the PVD vapor to an isothermal condition, we can examine the flow using a form of the general flow equation for isothermal compressible gas flow in a pipe:
Q=C
1·(ΔP0.5)·(D2.5)/(L·f)0.5 (1)
where Q is the flow rate, C1 is a constant of proportionality, ΔP is the pressure drop, L is the pipe length, and f is a friction factor. See e.g. Gas Pipeline Hydraulics, Menon et al., Trafford, 2013, pp. 44-45. Here, an assumption has been made that the pressure drop is relatively small compared to the average pressure. Generally f increases for smaller D, so f can be removed in favor of a higher exponent for D. At low flow rates, f∝1/D, in which case elimination off changes the D exponent to 3. At higher flow rates, different authors use different approximations, with the D exponent typically between 2.6 and 2.7. For the qualitative purpose of the present discussion, an approximate exponent of 2.8 will suffice. Hence
Q=C
2·(ΔP0.5)·(D2.8)/(L0.5) (2)
where C2 is another constant of proportionality.
At any particular layer, there will be N passages through which vapor flows in parallel; N·Q is the total flow through this layer and is the same for all layers, and N·D·L is approximately the total area of the display, which is also constant. Further, we introduce Z=L/D for the aspect ratio of a passage. Rearranging terms, squaring, and absorbing total flow and total area into another constant of proportionality C3, the following formula is obtained:
ΔP=C3·Z3·D−0.6 (3)
Using this formula, it is possible to compare the pressure drop across different layers; higher pressure drop is synonymous with greater impedance to flow. The effect of diameter D is modest: in a TV sized display, D may vary by ˜100 from the lowest layer to the highest layer, with consequently 15× higher pressure drop at the lowest layer. On the other hand, a layer having 5× higher aspect ratio (typically, an upper layer) may have 125× higher pressure drop! So, a short path segment through a passage at this layer (to the next lower layer) has significantly lower impedance than a long path segment at this layer. Consequently, the flow on the short path may be appreciably greater than on the long path, to the detriment of uniform vapor deposition.
Eqn. (1) can be seen to imply that for a given flow rate, pressure drop varies as D−5. Accordingly, it might be expected that the dominant contribution to flow impedance should come from the first level of an inventive manifold of the type described above, and the result of Eqn. (3) may be surprising. However, the inventive manifold is different from a simple pipe section. As D decreases going toward lower levels, the number of parallel passageways correspondingly increases. Furthermore, the passageway lengths also decrease. Accordingly, the contribution of a layer to flow impedance increases only modestly as diameter decreases, and a small change in aspect ratio may counteract this effect completely.
Therefore, it is important that passages be designed to balance flow for different paths.
The easiest way to balance flow is to design each layer to be a symmetric two-way split. This means that a passage at layer K (for some K>1) connects to exactly two passages at layer K−1. With a two-way split, if the paths are equal, then their impedance contributions at layer K are also equal. If the attached lower layer networks of passages are identical, then the flow at layer K will be split equally between the two attached layer K−1 passages.
However, even a two-way split may require careful design.
A two-way flow-balanced split can be extended to a four-way split.
However, it may not always be possible to use only two-way splits. For example, the prime factorization of 1080=23·33·5. Accordingly, only three layers can be arranged as a two-way split. Beyond that, one possibility is for some layers must be split according to multiples of 3 or 5. Another possibility is to have unbalanced passageways at some level: for example 3.5=15=4+4+4+3, so that a 15-way split can be achieved by combining 3×4-way splits (each of which can be a cascade of two 2-way splits) and 1×3-way split. Another difficulty may arise even when 2-way splits are possible: for example 2048=211. Implemented as two-way splits, this requires 11 layers just for grouping of passageways in one dimension, with a similar number of layers likely required for grouping passageways in the orthogonal direction. A multi-manifold design with 20 or more levels may be considered unduly complex, and it may be desired to have a lower layer count for reasons of cost and size.
Luckily, there are other strategies for balancing flow. One such strategy is to introduce additional impedance into all paths, so that the additional impedance reduces the impact of impedance variations inherent in the network of passages.
From these examples, it is seen that even a modest addition of a fixed impedance to each of unequal paths can make a significant reduction to the variation in current or flow. A large fixed impedance added to each path makes a larger reduction in the variance of current or flow. Each of these solutions is suitable in situations where variations in impedance are not well characterized at the time of design, e.g. variations due to manufacturing tolerances, or when variations in impedance may be different according to process conditions. Finally, in situations where the impedance variations are well-characterized at the time of design, it is possible to exactly compensate for the impedance variations and balance flows across all paths.
A simple and effective way to add impedance is to design an orifice at the aperture between passageways of adjacent layers. Referring back to apertures 115 in
At the left end of passage 152 is a deflector 153 having a wedge shape. The principal direction of vapor flow in passage 152 is parallel to the axis of passage 152. Accordingly, vapor molecules impinging on the lower surface of deflector 153 are likely to be channeled into passage 151L. Leftward traveling vapor molecules impinging on the upper surface of deflector 153 are directed away from passage 151L. Finally, for vapor molecules impinging on the left wall of passage 152 above the upper surface of deflector 153, the upper surface casts a shadow over passage 151L and reduces the likelihood that the vapor molecules will find their way into passage 151L. Thus deflector 153 affects vapor flow from passage 152 into passage 151L. By varying the position and size of deflector 153, a suitable flow-balancing effect can be achieved.
Feature 154 is a baffle that directly introduces an impedance to flow within passage 152. Feature 155 is simply a pin that introduces an impedance to flow within passage 152 and also distorts flow lines. Pin 155 can be positioned directly above one particular passage 151 in order to increase the deflection of vapor molecules into that particular passage 151, or it can be positioned between two passages 151. Variable design features of pin 155 include its thickness, its height, and its axial position relative to the passages 151. Feature 156 is a pair of circumferential ridges along the inside wall of passage 152. Similar to baffle 154, ridges 156 serve to directly introduce impedance into the flow within passage 152. Features 157 and 158 are a chamfer and a vane respectively that serve to directly affect flow lines of vapor molecules within passage 152, and thereby increase the deflection of vapor molecules into the passage 151 between them.
Finally, extension tube 159 can also be used to reduce flow into the rightmost passage 151. In the absence of extension 159, rightward traveling vapor molecules reaching the right end of passage 152 could either be deflected downward into passage 151R, or could be reflected back to the left. In collisional flow, it is difficult for a leftward traveling molecule to make headway against a rightward traveling flow. Hence vapor molecules are preferentially deflected into passage 151R. Extension 159 serves to provide a buffer volume in which increasing numbers of vapor molecules can try to forge a leftward path, so that at passage 151R there is no longer a preponderance of rightward flowing vapor molecules, and the likelihood of deflection into passage 151R is reduced.
Any of these features can have varying features in the direction perpendicular to the plane of the figure, according to the needs of a particular design. Further, it will be apparent to one or ordinary skill in the art that these and other flow control features can be combined in any suitable combination.
Mechanical features of passageways can also be applied to streamline flow and reduce flow impedance. This may be done throughout the architecture of a multi-manifold, as it is generally desirable for a multi-manifold to have lower impedance. It may also be done at select locations, to balance impedance between different paths. Such features may include smooth bends in passageways, passageways of large cross-section, and auxiliary passageways. Interior walls may also be chemically or electropolished to make the walls smoother.
The impedance between two points may be considered to be the pressure difference between those points at a given flow. Comparing two output ports fed from the same input port, a first one may have lower flow than a second, while they discharge into the same space. Then, the path from input port to first output port would be said to have higher impedance than the path from input port to second output port. Or simply, the first output port would be said to have higher impedance. Of course, in most applications it is desirable that all output ports have the same impedance, so that all output ports of a particular manifold deliver substantially equal amounts of material to respective locations on a target surface.
Eqn. (3) suggests an alternative technique for balancing the flow. A modest increase in aspect ratio at layer 1 can be used to make the layer 1 contribution to overall flow impedance dominant, thus greatly reducing the effect of any imbalances introduced at higher levels, and simplifying the design process. The tradeoff lies in having considerably higher flow impedance than is otherwise necessary.
Eqn. (3) also provides the motivation for the relatively complex structure of inventive multi-manifold embodiments described herein. An alternative simple structure can be imagined, where first-level passages have length equal to the extent of a target display, and are fed from one or both ends directly from a single chamber. (The end feed is necessary for this simple design in order to provide access to more than one set of interspersed output ports.) In essence, such a simple structure is similar to a multi-manifold having only two layers: a first layer in which passageways have width (and hydraulic diameter) equal to the sub-pixel stripe width, and a second layer that is a single chamber. For a typical display product or motherglass, such a first-level passage may have a length of about 1 meter, whereas the diameter of a first-level passage may be about 200 μm, giving an aspect ratio Z=(1 m/200 μm)=5,000. Accordingly the pressure drop for such a configuration is extraordinarily high. Furthermore, the flow impedance varies greatly from the single chamber to different output ports, leading to a formidable challenge trying to balance flows. Multi-layer manifolds of the style described above provide a particularly effective solution for providing low impedance balanced flow.
In a multi-manifold embodiment having a suitably flow-balanced manifold, the impedance variation from an input port to any output port is capped at +/−T % relative to the average flow impedance from the input port to any output port. Commonly the variation is limited to +/−10% (that is, T=10), preferably +/−5% (that is T=5), and often +/−2% (that is, T=2).
With this background, a complete manifold architecture can be considered.
In this design, two-way splits are chosen for the lowest layers as far as possible. Thereby, flow balancing is obtained without delicate fabrication of fine mechanical features at very small scale. Starting at layer 8, splits greater than two are incorporated into the design.
Both of these complete designs have passageway widths that are non-decreasing as the layer number increases. Generally, the passage widths increase from layer to layer, although in some embodiments a row-wise layer has passage widths that are equal to the passage widths of the preceding column-wise layer. This is a common but not necessary feature. It is easily possible, although not desirable, to design an inventive embodiment in which a manifold has progressively increasing layer widths among row-wise layers, and progressively increasing passage widths among column-wise layers, but where passage width in layer K+1 is less than the passage width of layer K.
The architecture shown for one manifold can be replicated for two other required manifolds, and a multi-manifold comprising three such entwined manifolds can be fabricated according to the concept illustrated in
It is also possible to design a multi-manifold in which not all manifolds share the same architecture, and yet the manifolds fit together in three dimensions. For a simple example, consider a multi-manifold for PVD of a four-color (RGBW) stripe display, similar to those described above. To adapt this for an RGBG stripe display, where every second stripe is green, it is possible to start with the RGBW manifold and merge the manifolds for G and W wherever passages of adjacent layers are in contact. Turning back to
The discussion above is primarily directed to multi-manifold embodiments in which output ports of constituent manifolds are organized as stripes. Although many features and principles of multi-manifolds are equally applicable irrespective of the patterns of output ports, there are some aspects to which particular care must be given for other output port layouts.
In
Thus stripe 204 comprises an alternating sequence of output ports 203, that may be considered to be green and red ports in keeping with the color conventions of
Accordingly, any particular passageway 201 can be part of a green manifold, in which case a red output port is blocked and cannot be connected to a red manifold, or this passageway can be part of a red manifold, in which case a green output port is blocked. Further, the first-level passageways cannot readily extend in a direction parallel to a second-level passage 205, since the stripe 204 is surrounded by output ports of other colors (blue and white, following
The aforementioned difficulties notwithstanding, striped first-level passageways remain a preferred design element even for multi-manifolds whose output ports are arranged in a block pattern. A few embodiments are presented below.
While the embodiments described above make no mention of septa or segmenting, one of ordinary skill in the art will understand that all the same features and considerations are applicable to striped first-level passageways for block-patterned output ports as were discussed above for stripe-patterned output ports. Particularly, first-level passageways may have a length equal to the full extent of the multi-manifold, a target display, or they may be segmented to cover integer groups of output ports, including groups of two or four output ports.
An advantage of the stripe embodiments for first-level passages is that end effects are minimal, and may even be non-existent.
It should be noted that for a square pixel (such as pixel 43 shown in
Because the stripe first-level passages are substantially similar to those previously described (in context of striped output ports and
In order to alleviate manufacturing and process issues that may be incumbent upon very narrow first-level passageways,
It should be noted that the edge pixels (for example, above or to the right of sub-pixel group 243W) do not neatly fall within groups of four sub-pixels. To address such an end effect, several approaches are possible. Firstly, edge sub-pixels may not be subject to the same tight constraints of deposition uniformity as are interior sub-pixels, and some deviation in flow uniformity may be acceptable. Then, flow balancing may be achieved by suitable design of the passageways, by a variety of techniques including those discussed above. Alternatively, dummy sub-pixels can be incorporated around the edges of the display, so that for vapor deposition all blocks of four sub-pixels are complete. Illustrative dummy sub-pixels 244R, 244G, 244B are shown; 245 is a group of four sub-pixels that has been completed by the addition of two dummy sub-pixels 244B. The dummy sub-pixels are not electrically connected as active display elements, and the fact they are not part of any 2×2 pixel is of no consequence.
Embodiments for 2×2 block patterns of output ports are not limited to stripe first-level passageways. For example,
One of ordinary skill in the art will appreciate that first-level structures for block-patterned pixel layouts are not limited to those discussed here; other architectures of a multi-manifold are possible and within the scope of the present invention. Similarly, block-patterned output port layouts are not limited to the 2×2 block patterns or square pixels as discussed here; multi-manifolds for other block patterns and pixel shapes can be readily designed, keeping within the scope of the present invention.
Multi-manifolds embodying the present invention may be manufactured from a variety of materials using a variety of manufacturing methods. Commonly, metal, polymer or plastic, and ceramic materials are used. Additive manufacturing methods are available for all of these classes of materials, and can be used advantageously to manufacture the intricate constructions of entwined and possibly interpenetrating networks of passageways.
However, some additional steps may be required following additive manufacturing to render the result of the additive manufacturing process into a useful multi-manifold suitable for deployment in a process application.
At step 280, the walls of a multi-manifold are formed by an additive manufacturing process. At step 281, the interior surfaces are polished, by a technique such as chemical polishing, electro-polishing, or a mechanical flush with an abrasive slurry and optional ultrasonication. At step 282, fittings are attached. Fittings may include input port fittings, fittings for mechanical fixturing such as hooks, bolts, standoffs, and other fixturing elements as are well-known in the art, and electrical appurtenances such as a resistive heater or a grounding strap. Fittings may often be advantageously fabricated separately from the additive manufacturing process, or even purchased, for reasons including cost, material compatibility, and special material requirements. Attachment of fittings may be performed by a variety of well-known techniques including but not limited to one or more among adhesives, mechanical fasteners, soldering, welding, brazing, and fusion bonding. At step 283, the multi-manifold is cleaned, by any one or more of a variety of techniques including but not limited to chemicals, heating, plasma, and irradiation, performed singly or in combination. Baking is well-suited for metal or ceramic multi-manifolds, and ill-suited for polymer multi-manifolds. Baking provides particularly good cleanliness for semiconductor, display, and other processes where high vacuum is involved or contamination is particularly a concern. Baking under vacuum is effective at driving off water vapor.
As regards step 280, a variety of additive machining processes are available. ASTM International (earlier known as the American Society for Testing and Materials) has published Standard F2792-12a, which organizes additive machining technologies into seven classes: binder jetting, directed energy deposition, material extrusion, material jetting, powder bed fusion, sheet lamination, and vat photopolymerization. Of these, a type of powder bed fusion process known as Direct Metal Laser Sintering (DMLS) is readily available for fabrication of parts in metals such as tungsten and stainless steel. See e.g. U.S. Pat. Nos. 4,863,538; 4,938,816; 5,658,412; 5,730,925; and 5,753,274. The powder fusion technology is also applicable to plastic and ceramic materials, and may also be used to form composite structures. DMLS works directly with metal and is well-suited for fabrication of multi-manifolds intended for high-temperature applications in clean environments. DMLS is available for fabrication of parts with wall thicknesses down to 100 um and below, which is suitable many applications, including flat panel television displays. A DMLS process can be used to manufacture all the walls of a multi-manifold, defining its plurality of entwined passages belonging to a plurality of disconnected manifolds. Thus, some multi-manifolds can be manufactured as a single piece entirely using DMLS, or an equivalent additive manufacturing process with ceramic or polymer powders. Further descriptions of additive manufacturing processes may be found, for example, in U.S. Pat. Nos. 4,247,508; 4,575,330; 5,059,266; and 5,204,055.
For some applications, a finer pitch of output ports is required. Projection microstereolithography has been demonstrated to create structures with structural elements below 5 μm in width. See for example, Sun et al., Sensors & Actuators, vol. A 121, pp. 113-120, 2005; and Zheng et al., Science, vol. 344, no. 6190, pp. 1373-1377, 2014. These attainable dimensions are suitable for multi-manifolds for the manufacture of all conventional displays, including phones, tablets, computer displays, and televisions, even some microdisplays, and for many other applications as well.
Projection microstereolithography works by building a polymer structure, which can be converted to metal by subsequent steps of metal plating and thermal removal of the polymer. Such a process is shown in
The procedure described above forms multi-manifold walls around the photopolymer. In applications where projection microstereolithography is only used for finer pitch passageways close to the output ports, it is also practical to use an inverse process. In this case, the polymer form occupies the space that will ultimately become passageways of a multi-manifold. This process is shown in
For some applications, such as large flat panel televisions, or Gen 5.5 and up motherglass, a multi-manifold may have large extent, even greater than 1 m. In such cases it may be desirable to find a lower cost manufacturing technique to make the upper levels of the multi-manifold, closer to the input port. Because of the larger dimensions, a variety of conventional manufacturing technologies are available, including casting, metal injection molding, welding, and machining. For example prefabricated pipe or tubing sections may be machined to fit, and welded together. Sheet metal forming may also be used.
As suggested above, in some embodiments a multi-manifold may be manufactured in sections, which are subsequently connected together. Sections may be organized in the vertical direction. Such sections may include, for example, a lowest section manufactured using projection microstereolithography, a midsection manufactured using DMLS, and an upper section manufactured from metal tube using conventional techniques. Sections may also be organized in the horizontal direction, for convenience in manufacture of pieces having smaller extent than a large motherglass. For example the area of a motherglass may be covered by a 2×2 group of DMLS sub-assemblies. However, such subdivision in a horizontal direction is a matter of convenience: in U.S. 2015/0076732, Kemmer et al. have addressed the problem of additive manufacturing of large structures.
Each section of a multi-manifold may itself be considered a multi-manifold, since it has walls, entwined passageways, a smaller number of input ports (at its highest layer), and a larger number of output ports (at its lowest layer).
In U.S. 2014/0074274, Douglas et al. address the problem of joining 3-D printed structures, and describe adding features to a sub-assembly to facilitate locating and attaching sections of a final product. As regards the joining step, brazing is particularly well-suited to joining metal or ceramic parts with deep blind joints.
While the discussion above has focused on metal multi-manifolds, the fabrication of multi-manifolds of other materials is also within the scope of this class of embodiments. The additive processes described above are available for polymer and ceramic manufacture also. Likewise a variety of joining technologies is also available. Polymers and plastics may be joined by fusion bonding or ultrasonic welding. Ceramics can be joined to ceramics and other materials using ultrasonic welding, brazing, transient liquid phase bonding, sol-gel chemical bonding, microwave heating, and polymer infiltration bonding. See for example, Hanson et al., Materials World, Vol. 6, No. 9, pp. 524-36, September 1998. Some of these technologies are also suitable for plastics and metal. Finally, adhesives are available for joining most material combinations. Choice of suitable joining technology is dependent on factors including the materials to be joined, the size and surface conditions of the joining surfaces, external accessibility of the joining surfaces, and whether joining materials are compatible with the application in which the multi-manifold is to be used.
It will be understood by one of ordinary skill in the art that
In the multi-manifold schematic symbol, the broad bottom edge of the trapezoid represents the plane of output ports at the lowest level of the multi-manifold, while the narrow top edge represents the input ports at the highest level of the multi-manifold. An arrow denotes each constituent manifold, pointing in the direction of fluid transport. Usually, arrows will point from the narrow input port edge to the broad output port edge.
The pattern of each manifold's output ports defines a corresponding pattern on the facing surface of target substrate 325. Since the output port patterns of manifolds 322, 323, 324 are interspersed, interspersed deposition patterns can be formed in a single process step. Interspersed patterns may be stripes, regular repeating rectangular blocks, combination patterns involving blocks with their mirror-image and/or rotated counterparts, triangular blocks, hexagonal blocks, combinations of these, or any other tiling pattern.
Preferred embodiments of the fourth class appear in the field of manufacturing flat panel displays, particularly pixelated multi-color organic light emitting diode (OLED) displays. In such embodiments, the target substrate is a display substrate, and each manifold delivers material for a patterned layer for pixels of a respective color. Commonly, the patterned layer is an emissive layer, and PVD sources provide vaporizable emissive layer materials, which are delivered through the multi-manifold as vapor, and deposited according to respective pixel patterns as an emissive layer. Other layers such as a hole transport layer may also be deposited patterned according to sub-pixel color. Sub-pixel colors may include two or more (preferably, three or more) among red, green, blue, white, and yellow.
While
One of ordinary skill in the art will understand that
Conversely, it may be desirable to have some spread of deposited material beyond the boundaries of each output port, in particular to avoid abrupt edges in the profile of deposited material. Accordingly, in some embodiments, a gap between the target substrate and the output ports is purposefully maintained, and the gap height may be comparable to the transverse dimension of a wall thickness separating adjacent ports. In other embodiments, the gap height may be comparable to the transverse dimension of the output port. Comparable dimensions are understood to mean two dimensions that are within a factor of two, when measured in the same units.
Spreading of deposited material may also be desirable when an output port has smaller dimensions than a corresponding deposition area. However spreading should be restricted to a maximum of at most S % of deposited material from an output port reaching the deposition area of a neighboring output port of a different manifold. Preferably S is less than or equal to 10, desirably S is less than or equal to 5, commonly S is less than or equal to 2, and in some embodiments, S is less than or equal to 1. Close proximity between output ports of a multi-manifold and a facing surface of a target substrate may be defined in terms of S; for example, any distance at which the fraction of (green) deposited material reaching the deposition area of a neighboring (red) output port is less than 1%.
One of ordinary skill in the art will recognize that different embodiments may use different numbers of manifolds. For example, some embodiments will provide only one precursor flow through one manifold to the reaction zone. Other embodiments may provide three, or even more, precursor flows to the reaction zone. The multi-manifold may also be used to deliver one or more inert gases, such as Nitrogen or Argon, to the reaction zone. The inert gas facilitates entrainment of precursor gases, improves the consistency of mixing and reaction rate, and enables better process control. Further, a separate manifold of the multi-manifold may be used, for example, to introduce a tracer. The tracer may be delivered continuously throughout the process, or it may be applied according to a predetermined temporal profile, according to diagnostic needs of the application.
The use of the multi-manifold for an exhaust function provides for consistent and quick removal of reaction byproducts and unspent reaction material, and greatly reduces cross-contamination between one portion of the reaction zone and another. However, some embodiments may not use the multi-manifold for an exhaust function at all.
In embodiments providing CVD on a semiconductor wafer, each reaction zone may correspond to a functional block on the wafer. The functional block may be a die, a solar cell, a circuit block within a die, a sensor, or a nanomachine, according to the particular application. In other embodiments, the reaction zones may collectively serve to process a single larger area on the wafer. To avoid gaps in the reaction region between reaction zones, embodiments may provide translational motion in one or two dimensions in an amount on the order of the pitch between output ports of a single manifold, to smooth out any variations in the CVD deposition thickness.
In some embodiments of this class, mixing chamber 364 is a reaction chamber, such as a combustion chamber, which may be part of an engine. In some embodiments, all fluids delivered into mixing chamber 364 are gaseous, while in other embodiments, all delivered fluids are liquids. In still other embodiments, at least one fluid is a liquid, while at least one other fluid is gaseous. Further embodiments may transport fluid as a liquid through a manifold, but have the liquid vaporize as it emerges from output ports of a multi-manifold. Other embodiments may transport fluid as a gas through a manifold, but have the gas dissolve or condense into a liquid phase as the gas emerges from output ports of a multi-manifold.
In other embodiments, the first fluid is a gas 385, while the second fluid is a liquid. For these embodiments, 386 in
Referring again to
Additionally, embodiments of the invention are well suited to the use of tracers. One or more delivered fluids may comprise a tracer. Radioactive tracers and/or dyes may be used.
A system for manufacturing a display may incorporate a multi-manifold as described above. Such a system may comprise a plurality of PVD sources, the multi-manifold, a target substrate, and a chamber housing at least part of the multi-manifold and the target substrate, and fitted with conveyances for mechanical transport of the target substrate, relative positioning of the target substrate and the multi-manifold, pumping, and process monitoring equipment. The PVD sources are connected to input ports of the multi-manifold, and the multi-manifold is positioned in close proximity to the target substrate. In some preferred embodiments, the display may be an organic electroluminescent display, sometimes referred to as an OLED display, and the PVD sources may comprise host and/or dopant materials for emissive layers of sub-pixels of different emissive colors.
A system for coating a product in a patterned PVD process may incorporate a multi-manifold as described above. Such a system may comprise some or all of the same elements described above for the display manufacturing system. One or more PVD sources are connected to input ports of the multi-manifold, and the multi-manifold is positioned in close proximity to the target substrate.
A system for coating a product in a CVD process may incorporate a multi-manifold as described above. Such a system may comprise one or more CVD sources, the multi-manifold, a target product, and a chamber housing at least part of the multi-manifold and the target substrate, and fitted with conveyances for mechanical transport of the target substrate, relative positioning of the target substrate and the multi-manifold, pumping, and process monitoring equipment. In some embodiments, a pump is provided connected directly to one or more input ports of the multi-manifold, for the purpose of providing exhaust from one or more reaction zones above the target substrate. In some embodiments, the system comprises exactly one CVD source. In other embodiments, the system comprises exactly two CVD sources. In further embodiments, the system comprises three or more CVD sources. The one or more CVD sources are connected to input ports of the multi-manifold.
A system for fluid mixing may incorporate a multi-manifold as described above. Such a system may comprise one or more fluid sources, the multi-manifold, and a discharge chamber housing at least part of the multi-manifold, and fitted with conveyances including pumping equipment for discharging mixed or spent fluid or other materials from the discharge chamber, and process monitoring equipment. The fluid sources may be sources of gas, liquid, suspensions, colloids, smoke, and mixed-phase fluids such as aerosol streams or liquids with entrained bubbles. The discharge chamber may be a chemical reactor, a bubble reactor, and/or a combustion chamber.
Furthermore, manufacturing systems are not limited to just one multi-manifold. A system may employ two or more multi-manifolds. Two or more multi-manifolds may be operated simultaneously over different portions of a target object, including on opposite sides of the target object. Two or more multi-manifolds may be operated in sequential stages of a manufacturing process. Finally, two or more multi-manifolds may be operated in parallel on adjacent production lines.
The equipment connected to the input ports of a multi-manifold may include a load lock facility for replacing material in a connected PVD source, CVD source, or fluid source.
Process monitoring equipment may include devices for monitoring pressure, temperature, position, and/or material flow.
While specific embodiments have been described in detail in the foregoing detailed description and illustrated in the accompanying drawings, it will be appreciated by those of ordinary skill in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure and the broad inventive concepts thereof. It is understood, therefore, that the scope of the present invention is not limited to the particular examples and implementations disclosed herein, but is intended to cover modifications within the spirit and scope thereof as defined by the appended claims and any and all equivalents thereof.
All U.S. patents and patent application publications referenced above are hereby incorporated by reference as if set forth in full.
This patent is a continuation of commonly assigned, co-pending U.S. Ser. No. 14/703,624, filed May 4, 2015, titled “Entwined manifolds for vapor deposition and fluid mixing” by Rohatgi et al, and which is incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14703624 | May 2015 | US |
| Child | 14705571 | US |
