Patent Publication Number: US-2023160803-A1

Title: Acoustic particle sizer dip probe and improved sample holder

Description:
FIELD OF THE DISCLOSURE 
     Aspects of the present disclosure relate to apparatus and methods used for or in acoustic particle sizing. Aspects of the disclosure relate to inspecting liquid mediums in various manufacturing processes. 
     BACKGROUND OF THE DISCLOSURE 
     In various industrial processes, acoustic particle sizers are used to ultrasonically categorize particles in a liquid medium. The liquid medium may include one or more colloids or dispersions. For example. when making ink, pigment particles are milled to a desired size. As part of a quality control phase of the manufacturing process, a particle size analyzer is employed to determine the particle size distribution. 
     SUMMARY OF THE DISCLOSURE 
     With some particle sizer systems, it is necessary to divert a sample of the liquid medium into a sample vessel comprising a seal—e.g., an O-ring. The seal comes into contact with each sample, which can result in sample cross-contamination. When contamination occurs, oversize particles from a prior reading could show up in a current reading, resulting in a false positive. 
     An objective of the present disclosure is to eliminate the need to divert the sample from a manufacturing process. Another objective is to provide a probe and sample vessel approach that eliminates or greatly reduces the occurrence of cross contamination between different batches. Other alternative or additional objectives may be served by one or more aspects of the disclosure, e.g., as may become apparent from the following disclosure. 
     Embodiments of the disclosure include any apparatus, machine, system, method, articles (e.g., computer-readable media), or any one or more subparts or subcombinations of such apparatus (singular or plural), system, method, or article, for example, as supported by the present disclosure. 
     One embodiment of the present disclosure is directed to apparatus. At least one ultrasonic pulse transmitter is provided that is configured to transmit an ultrasonic pulse through a target liquid medium. At least one ultrasonic receiver is also provided. A holder is provided that is configured to maintain the pulse transmitter at a controlled position in relation to the target liquid medium, and that is configured to be carried. 
     In one embodiment of a method, ultrasonic pulses are transmitted through a target liquid medium and then received, with one or more transmitters and one or more receivers. The reflected ultrasonic pulses are then received. A vessel is provided to hold the liquid medium without the use of a seal on the vessel. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Example embodiments will be described with reference to the following drawings, in which: 
         FIG.  1    is schematic diagram of one embodiment of a particle sizer system; 
         FIG.  2    is a perspective view of one embodiment of an acoustic particle sizer dip probe; 
         FIG.  3    is a perspective view of a sample station; 
         FIG.  4    shows the illustrated dip probe and sample station in alignment before inserting the dip probe into an opening leading to liquid in the sample cup; 
         FIG.  5    shows the illustrated dip probe and sample station, with the probe fully inserted and releasably secured on a probe mount; 
         FIGS.  6 A and  6 B  show side and top views of an alternative embodiment of a reflector; 
         FIG.  7    shows a perspective view of another embodiment of a reflector; 
         FIG.  8    is a flow chart of a general process to ultrasonically categorize dispersed particles; 
         FIG.  9    is a flow chart of an ink manufacturing process; 
         FIG.  10    is a flow chart of a process of manufacturing semiconductor wafers/chips including use of a chemical mechanical polishing; 
         FIG.  11    is a side view of a portion of an example embodiment of a vertically arranged dip probe; and 
         FIGS.  12 A and  12 B  are perspective views of containers holding a liquid in transit for testing with a hand-held probe. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with one or more embodiments herein, various terms may be defined as follows. 
     Program. A program includes software of a processing circuit. 
     Processing circuit. A processing circuit may include both (at least a portion of) computer-readable media carrying functional encoded data and components of an operable computer, including one or more processors, a bus structure, and a memory system. The operable computer is capable of executing (or is already executing) the functional encoded data, and thereby is configured when operable to cause certain acts to occur. A processing circuit may also include: a machine or part of a machine that is specially configured to carry out a process, for example, any process described herein; or a special purpose computer or a part of a special purpose computer. A processing circuit may also be in the form of a general purpose computer running a compiled, interpretable, or compilable program (or part of such a program) that is combined with hardware carrying out a process or a set of processes. A processing circuit may further be implemented in the form of an application specific integrated circuit (ASIC), part of an ASIC, or a group of ASICs. A processing circuit may further include an electronic circuit or part of an electronic circuit. A processing circuit does not exist in the form of code per se, software per se, instructions per se, mental thoughts alone, or processes that are carried out manually by a person without any involvement of a machine. 
     User interface tools; user interface elements; output user interface; input user interface; input/output user interface; and graphical user interface tools. User interface tools are human user interface elements which allow human user and machine interaction, whereby a machine communicates to a human (output user interface tools), a human inputs data, a command, or a signal to a machine (input user interface tools), or a machine communicates, to a human, information indicating what the human may input, and the human inputs to the machine (input/output user interface tools). Graphical user interface tools (graphical tools) include graphical input user interface tools (graphical input tools), graphical output user interface tools (graphical output tools), and/or graphical input/output user interface tools (graphical input/output tools). A graphical input tool is a portion of a graphical screen device (e.g., a display and circuitry driving the display) configured to, via an on-screen interface (e.g., with a touchscreen sensor, with keys of a keypad, a keyboard, etc., and/or with a screen pointer element controllable with a mouse, toggle, or wheel), visually communicate to a user data to be input and to visually and interactively communicate to the user the device&#39;s receipt of the input data. A graphical output tool is a portion of a device configured to, via an on-screen interface, visually communicate to a user information output by a device or application. A graphical input/output tool acts as both a graphical input tool and a graphical output tool. A graphical input and/or output tool may include, for example, screen displayed icons, buttons, forms, or fields. Each time a user interfaces with a device, program, or system in the present disclosure, the interaction may involve any version of user interface tool as described above, e.g., which may be a graphical user interface tool. 
     Referring now to the drawings in greater detail,  FIG.  1    is a schematic diagram of a particle sizer system  10 . The illustrated system  10  includes a dip probe which comprises an ultrasonic transducer  14  and a multiple position reflector  16 . A control and analysis system  24 , sensor(s)  25 , and a sample mixer  20  are also provided. 
     The multiple position reflector  16  is connected to a translation stage  22  for controlling the position of a reflector surface  17 . In the illustrated embodiment, the reflector surface  17  is a stainless steel acoustic reflector (mirror). Its position is controlled to be at multiple positions (gaps) for each sample, in order to produce robust attenuation data used for determining particle size. Reflector  16  is held by a reflector holder bar  15  made of stainless steel in the embodiment. Translation stage  22  comprises a vertical programmable high precision motion/translation stage that adjusts the reflector-transducer gap. In the illustrated embodiment, translation stage  22  connects to a control and analysis system  24 , which may be a processing circuit as described above. Control and analysis system carries a program or logic to control the operation of the different parts of system  10 , and to receive and analyze sensed signals via sensor(s)  25 , the position of the reflector(s)  17 , and reflected ultrasonic pulses that have traversed the liquid medium  18 . 
     The liquid medium  18  being tested includes solid particles or emulsion droplets  19 , the sizes of which are to be determined by the system. In this embodiment, a removable sample-cell cup  12  is provided which is held in place by a plurality of latch pins  25 . The illustrated cup  12  is free of any sensor openings in the side walls, and also does not have (or require) a seal such as an O-ring. By removing the use of a seal such as an O-ring, cross-contamination is reduced. Removing or minimizing the openings in the side walls of the vessel also reduces contamination risks from one sample to another. In addition, it is easier to clean the cup between samples. For example, the cup can be wiped and washed in a sink. It is also possible to simply replace the vessel with a new vessel, and the cost of the vessel is lower because of its simpler design. Per one embodiment, multiple pre-filled sample cups can be used, to allow for faster analysis of multiple samples. 
     Per another embodiment, a handheld dip type probe is provided. The instrument operator can conveniently dip the sensor into operator-supplied sample cups without being restricted to a particular sample cup. The sensor can also be used to test liquid mediums in various industrial processes, without requiring removal or dilution (or interruption) of the liquid from the industrial process. A dip type sensor may be conveniently cleaned between samples. 
     The illustrated system  10  may be part of a complete assembly, with the control and analysis component  24  provided in an attached housing. The control and analysis component may be provided in a portable housing and equipped with a rechargeable battery for in-field testing. 
     The systems, methods, and structures disclosed herein may be used to ultrasonically categorize particles in a liquid medium by size range. The liquid medium may be one or more colloids and/or dispersions. More specifically, the systems and methods may be configured to allow measurement of respective sizes of particles in a liquid medium, to produce data and graphical representations showing particle size distribution, solids concentration, and other related information. In select embodiments, the liquid medium is undiverted from its presence in an industrial process, in a process plant pipe, and/or in a chemical reactor. A dip type probe, e.g., may be used to test ink during the manufacture of the same. There is no need to dilute the liquid medium from its normal state in the manufacturing process. A dip type probe as disclosed may also be used in a process of manufacturing a semiconductor, to measure an abrasive slurry used to polish the surface of the semiconductor. 
     In one or more embodiments disclosed herein, ultrasonic transmitters and/or receivers are neither attached to, nor fixed in relation to, nor touching the sample holder which may be, for example, a cell, vessel, or cup. It is also possible to carry out the embodiments without providing any openings in the side walls of the container. 
       FIG.  2    shows another embodiment of a dip type acoustic particle sizer  30 . Generally, the illustrated dip type sizer includes an ultrasonic pulse source (a transceiver type transducer  39 ) configured to both transmit an ultrasonic pulse through a target liquid medium, and to receive pulses reflected back from a reflector  36 . A holder structure  32  is provided to carry the assembly. The illustrated sizer  30  also has a handle  34  for allowing an operator to manually hold and insert the probe into a liquid medium to be tested. 
     As shown, the illustrated sizer  30  includes a base  32  with one or more holders to hold a reflector  36 , a reflector positioner  44 , and transducer  39 . The holders as shown more specifically include a transducer yoke for holding transducer  39 , and an alignment yoke  42  for aligning the direction of transducer  39 , where the transducer is held by a longitudinal shaft. Control/input and output wires  41  are coupled to the transducer, allowing for operation of the transducer and for porting of measured signals to a control and analysis system (not shown in this figure). 
     In this embodiment, the reflector structure includes one reflector  36 , with a reflective surface, e.g., as described above in the embodiment of  FIG.  1   . This portion of the reflector is held by a movable reflector rod  38  that is held by a reflector positioner structure  44 . In this embodiment reflector positioner structure  44  is a programmable high precision motion/translation stage used to adjust the reflector-transducer gap. The programming of this positioner may be implemented by means of software or circuitry in the structure  44 , and/or in the control and analysis system. While such a system is not shown in this figure, one may be provided as described above with respect to  FIG.  1   . 
       FIG.  3    shows an embodiment of a sample station  50  that can be used with the probe shown in  FIG.  2   . The illustrated station  50  includes a support frame  58  that carries a removable sample cup  60 . The sample cup may be secured to the support frame  58 , e.g., with the use of removable pins. A mixer holder  56  is provided that carries a mixer yoke  54  that carries a sample mixer  52 . A sample protective shield  62  is provided in this embodiment, which has a mixer slot  64  that allows for the rotatable mixer shaft to enter the liquid area in the cup. A probe slot  66  is also provided for receiving the probe, e.g., the extended reflector and transducer portions of the sizer shown in  FIG.  2   . 
     The illustrated sample station  50  further includes a probe mount  68  for holding a probe when it is inserted in place, as further shown in  FIGS.  4  and  5   . Mount interface pins  70  and a flanged pin  72  are configured to receive the dip probe, by interfacing with corresponding and mated recesses in the probe. 
       FIGS.  4  and  5    show how the sizer  30  (of  FIG.  2   ) may be interfaced with the sample station  50  (of  FIG.  3   ). The sizer  30  and sample station  50  in  FIGS.  4  and  5    correspond to the same elements in  FIGS.  1  and  2   , with different perspective views and modes of assembly/use.  FIG.  4    shows a position in which the probe is ready to be interfaced with the sample station.  FIG.  5    shows the position in which the probe has been fully inserted and securely (removably) mounted via pins  70  and  72  shown in  FIG.  3   . Specifically, as the probe is lowered, its base  32  is brought into contact with the flat surface of probe mount  68 . In the embodiment shown, base  32  has a slot configured to receive the flanged pin  72  shown in  FIG.  3   . Once the flanged pin  72  has fully engaged with the slot, the end portion of base  32  will engage with pins  70  ( FIG.  3   ) via mating recesses on the end of base  32  (not visible in the drawing). As shown in  FIG.  5   , additional sensors may be added. For example, one or more probes  82  may be inserted into the liquid medium portion of the cup, e.g., through an opening in the protective shield  62 . 
       FIGS.  6 A,  6 B, and  7    show different embodiments of a reflector structure that may be used.  FIG.  6 A  shows a side view, and  FIG.  6 B  shows a cut-away top view. In  FIGS.  6 A and  6 B , the reflector  90  has reflector surfaces  91 ,  92 , and  93 , which may be configured as described above with respect to  FIG.  1   , i.e., as stainless steel acoustic reflective surfaces. The surfaces are held by a rotatable shaft  88 . In operation, these reflective surfaces are moved to be beneath the acoustic pulses transmitted by the transducer, e.g., by rotating the shaft per one embodiment. A step or stepper motor may be used to control the position of reflector  90 . A step or stepper motor in this embodiment is possible, because less resolution is required for positional adjustment. This embodiment is therefore less expensive than the embodiment with a translation stage. 
       FIG.  7    shows a perspective view of a reflector structure  102 . A unitary member is provided holding fixed position reflector surfaces  103 ,  104 , and  105 . The unitary member is held by a shaft  110 . In this embodiment, it is expected that the transducer will have a broader transmission path, and will be configured to transmit ultrasonic pulses at all three of the reflector surfaces  103 ,  104 , and  105  (optionally) simultaneously, and receive reflected signals therefrom. 
     While three surfaces are shown in these embodiments, it is possible to provide a smaller or larger number of differently spaced reflective surfaces. Each surface in these embodiments corresponds to a given reflector-transducer gap. It is also possible to move (or not move) these assemblies vertically to adjust each gap or add additional gaps. 
       FIG.  8    shows generally the process of testing that may be controlled by a control and analysis system as described above. In an initial act  802 , the transducer is put in position (the liquid medium typically will have already been put in the vessel)—as shown in  FIG.  5    for that manual embodiment. Alternatively, a mechanical engagement mechanism may be provided for engaging the probe with the liquid medium. In act  804 , the ultrasonic pulses are applied, and the reflected pulses are received at each desired transmission path length. At acts  860  (generally concurrent with act  804 ), the fluid is stirred and one or sensors  808  are operated (e.g., pH, conductivity, temperature, and/or other). At act  810 , signal processing and outputs occur. 
       FIG.  9    shows an example ink manufacturing process, where an inspection is carried out using the probe and vessel embodiment described herein. In this illustrated embodiment, the liquid may be sampled and put in a reusable or disposable vessel, e.g., as shown in  FIG.  1    or  FIG.  3   . Alternatively, the dip probe may be inserted into the liquid medium in its undiverted state in the manufacturing process. 
     In act  902 , mixing occurs, e.g., of solvent, resins, and additives. Then in Act  904 , grinding occurs. For example, a dispersing process is carried out involving wetting, grinding, and dispersing of a pigment. Act act  906 , the liquid medium is in an intermediate storage location. At this stage, an inspection  907  may be carried out without diverting the liquid medium, to determine if the particles in the medium are within a desired size range. In later acts  908  and  910 , finishing and filtration and packaging occur. 
       FIG.  10    shows a process of manufacturing a semiconductor chip or die, simplified for purposes of showing the pertinence of the inspection of particle size in that process. In act  1002 , deposition and etching occur, where insulative and conductive layers are put in place. Afterwards and interposed in stages of the deposition and etching phases, chemical mechanical polishing/planarization is carried out. This involves the use of an abrasive slurry to polish and thereby planarize the applicable surface at the pertinent point in the process. At this point, at act  1006 , some liquid could be diverted for testing as described above. or the probe could be inserted into a vessel used to store the slurry leading up to and during the polishing process, and the particle sizes can be determined without diversion. 
       FIG.  11    is a side view of a cutaway portion of a vertically arranged dip probe  200 . A transducer housing structure  210  (U-shaped in the example) is provided that is carried by a shaft  212  (shown cutaway in the figure). The probe  200  is shown in its upright position as it would be when dipped down into a liquid being tested. The housing structure  210  has a lower opening  214  and a central cavity  216  for receiving the liquid. The embodiment contemplates that there will be pairs of transducers that face each other, while each transducer is operable in a transmit mode, a receive mode, or a transceiver mode. In another embodiment, transducers are provided on one side (the left or right side in the version shown in  FIG.  11   ), and the paired surface opposite each transducer is a reflective surface. 
     The illustrated embodiment has an uppermost pair of ultrasonic transducers  220   a  and  220   b,  a middle pair  221   a  and  221   b,  and a lower pair  222   a  and  222   b.  Each transducer is operable in a transceiver mode, where it transmits to the opposite surface and receives sound waves reflected back from the opposite surface. Each transducer is also operable to be in a passive mode, where it only reflects sound waves it receives, or in a receive mode where it receives and transduces the sound waves directed at it from the opposite side transducer. Each transducer may also be operated in a transmit mode. In the illustrated embodiment, the transducer surfaces are exposed, but sealed at their periphery so that liquid will not leak into housing structure  210 . The transducers may be cylindrical in shape, with a flat planar surface directed at the opposite surface. 
     In the embodiment as shown, with three pairs of transducers, six or more different length gaps may be provided to measure traversing sound waves. The paths for the sound waves for the size gaps are shown in  FIG.  11    as paths i-vi. As the probe is dipped into the liquid, air is allowed to escape via an air vent cavity  230 . The illustrated probe is easily cleaned as there are no exposed wires or other structures. 
     It is possible to vary the embodiment of  FIG.  11   , by arranging the surfaces and transducers horizontally or at an angle. In addition, a differently shaped housing or no housing may be provided. If there is no housing, or if the housing exposes wires to and from the transducers, the wires may be encased in a chemically resistant conduit. The probe and wires may generally be cleaned with the same solvent used to mix the particles. 
       FIG.  12 A  shows a transit liquid container for carrying a liquid on a ship, truck, or train. The illustrated container  250  may be provided with a rectangular support structure  252  for supporting the tank-type container  250 . An opening  254  is provided at the top of the tank  250  for allowing access to the container&#39;s liquid freight. When the cover (not shown) is removed from opening, a hand-held probe  260  may be inserted into the container at a level where the transducer and gap(s) portions of the probe are immersed into the liquid. The power and control portion of the analysis system, e.g., as shown in  1 , may be contained in a portable carrier (e.g., a backpack carried on the human operator&#39;s back). The probe  260  may be connected to the power and control portion via wires in the embodiment. 
       FIG.  12 B  shows how a probe  270 , also configured to be portable as described above with respect to  FIG.  12 A  (with, for example, a backpack carried power and control unit), may be dipped into liquid carried in a bucket  272  when the bucket&#39;s cover (not shown) is temporarily removed. Such a bucket may be in transit on a truck, train, ship or at an industrial plant or warehouse. 
     The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated.