Patent Description:
<CIT> is entitled "acoustic micro imaging device having at least one balanced linear motor assembly. " <CIT> is entitled "frequency domain processing of scanning acoustic imaging signals. " <CIT> is entitled "tray-fed scanning microscope system and method primarily for immobilizing parts during inspection. " <CIT> is entitled "acoustic micro imaging method and apparatus for capturing 4D acoustic reflection virtual samples. " <CIT> is entitled "scanning acoustic micro imaging method and apparatus for non-rectangular bounded files. " <CIT> is entitled "acoustic micro imaging method and apparatus for capturing 4D acoustic reflection virtual samples. " <CIT> is entitled "frequency domain processing of scanning acoustic imaging signals. " <CIT> is entitled "acoustic micro imaging method providing improved information derivation and visualization. " <CIT> is entitled "automated acoustic micro imaging system and method. " <CIT> is entitled "scanning acoustic microscope system and method for handling small parts. " <CIT> is entitled "method and apparatus for ultrasonic inspection of electronic components. " <CIT> is entitled "controlled-immersion inspection.

<CIT> is entitled "method and system for dual phase scanning acoustic microscopy. " <CIT> is entitled "balanced scanning mechanism. " <CIT> is entitled "acoustic imaging system and method.

<CIT> is entitled "Scanning Acoustic Microscope With Profilometer Function.

For more than one year prior to the filing date of this provisional application, the assignee of this application is currently selling a product called Fast Automated C-SAM® Tray Scanning System ("Facts2 ") and a product called Gen5™ C-Mode Scanning Acoustic Microscope. The promotional materials are available on www. com for both of these products, as well as the operation, service and/or maintenance manuals for both products.

It is known, from <CIT>, methods and systems for compound management and sample preparation. Furthermore, it is known from <CIT>, an integrated robotic sample transfer device.

According to one aspect of the present invention, a scanning acoustic microscope according to claim <NUM> is presented, as well as an acoustic micro imaging system system according to claim <NUM>.

Various examples objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:.

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated. It should be further understood that the title of this section of this specification, namely, "Detailed Description of the Preferred Embodiments" relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.

Referring to <FIG>, a scanning acoustic microscope <NUM> having a scan while loading feature is shown. In <FIG>, the safety door <NUM> is shown in an upright, open position. In <FIG>, the safety door <NUM> is shown in a down, closed position with respect to the tank <NUM>. The safety door <NUM> separates the tank <NUM> into two portions- a first scanning portion <NUM> and a second loading portion <NUM>. Referring to <FIG>, the scanning acoustic microscope <NUM> is adapted to inspect a sample <NUM> (e.g. an integrated circuit package) that is submerged in a coupling medium or fluid <NUM>, such as water. The sample <NUM> can be inspected by itself as is the case, for example, in laboratory applications, or can be, for example, mounted on a tray of other parts to be inspected, which typically is the case in commercial applications.

A pulser <NUM> is under the control of motion controller <NUM> and is used to excite a transducer <NUM> to generate pulses of ultrasonic energy <NUM>, typically at frequencies ranging from <NUM> or lower to <NUM> or higher. The transducer <NUM> is scanned in X, Y and Z coordinates by an X-Y-Z stage <NUM> through an X-Y-Z stage driver <NUM>, which is under the control of controller <NUM>. The X-Y-Z stage driver <NUM> can include conventional brushless DC motors or, if desired, one or more balanced linear motor assemblies that allow the transducer <NUM> to be accelerated more quickly than is the case with conventional motors such as brushless DC motors, stepping motors or brush motors.

The controller <NUM> includes a memory <NUM> and a processor <NUM>. As described in greater detail hereinafter, instructions are stored in the memory <NUM> that, when executed by the processor <NUM>, allow a user to generate a scan path of the transducer <NUM> with respect to a tray of at least one sample(s) <NUM> that are to be inspected.

The transducer <NUM> is adapted to receive reflections of the ultrasonic pulses <NUM> that are directed towards and then reflected by acoustic impedance features present in the sample <NUM>. Such reflection signals are processed by a receiver (not shown) in analog form, and are supplied to a multi-channel processor <NUM>. Digitized versions of the reflection signals can be stored in multi-channel memory <NUM>, and, if desired, shown on display <NUM> (see <FIG>). In a particular embodiment of the present invention, multi-channel memory <NUM> will store, for example, an in- focus A-scan of a plurality of three dimensionally varied points on the surface of or within the interior of the sample <NUM>, as well as profile measurements which can be used to generate visual depictions on the display <NUM> of an external profile of each sample <NUM>. This can be useful to determine, for example, whether the sample <NUM> inspected has warped to any significant degree.

<FIG> and <FIG> show an exemplary tank <NUM> that has a scanning portion <NUM> and a loading portion <NUM>. A user is allowed to place a fixture <NUM> (see <FIG>) on two rails <NUM> and <NUM> so that a parts loading surface <NUM> is submerged under the coupling fluid <NUM> contained in both portions <NUM> and <NUM> of tank <NUM>. When the fixture <NUM> is located inside the loading portion <NUM> of tank <NUM> outside of the volume enclosed by the safety door <NUM>, the fixture <NUM> is disposed in a "parts loading" position. Although the loading portion <NUM> is shown in the drawings as located to the right of the scanning portion <NUM>, the loading portion <NUM> may be disposed on any side (left, right, front, back) of the scanning portion <NUM>. When the fixture <NUM> is located in the scanning portion <NUM> of tank <NUM> inside of the volume enclosed by the safety door <NUM>, and when the fixture <NUM> is latched in place, the fixture <NUM> is located in an insonifying position. This structure allows, for example, the user to brush any bubbles off of the parts to be inspected as they are loaded on the parts loading surface <NUM>, and then to transfer the fixture <NUM> to the insonifying position without exposing the loaded parts to ambient atmosphere. As readily apparent to one of ordinary skill in the relevant art, the presence of any such bubble on the parts create acoustic impedance features that would disrupt the results of a scan of a part with bubbles.

One advantage of the scanning acoustic microscope <NUM> is that it allows a user to load a second tray of parts to be inspected at the same time that scanning of a first tray of parts is taking place. As best shown in <FIG> and <FIG>, a first tray or fixture 44a is loaded into the scanning portion <NUM> and the safety door <NUM> is lowered. A second tray or fixture 44b is then placed into the loading portion <NUM>. A user places samples <NUM> onto the parts loading surface <NUM> of the second tray 44b and prepares the samples <NUM> for scanning as discussed above. Once the first tray 44a has been scanned, the safety door is opened and the first tray is removed from the scanning portion <NUM> by, for example, raising the first tray 44a out of the scanning portion <NUM> and through the open safety door <NUM>. A third removal portion (not shown) may also be included in the tank <NUM> or attached thereto. The removal portion may be located in the back, to the left, right, or in front of the scanning portion <NUM>, so that the first tray 44a can be slid from the scanning portion <NUM> to the removal portion and then lifted from the scanning acoustic microscope <NUM>. Once the first tray 44a is removed from the scanning portion <NUM>, the second tray 44b can be slid from the loading portion <NUM> into the scanning portion <NUM> via rails <NUM> and <NUM>. A third tray or fixture (not shown) can then be loaded into the loading portion <NUM> and the above process can be repeated.

In the illustrated embodiment of the present invention, the parts loading surface <NUM> of the fixture <NUM> is formed from a solid material such as, for example, glass. In this application, it is possible for through-scanning to take place wherein the transducer <NUM> includes a receptor located on the under side of the fixture <NUM> to capture the acoustic energy that passes through the parts to be inspected and the glass surface. In an alternative embodiment of the present invention, the parts loading surface <NUM> is porous. In this example, it can be formed from a plastic material that is molded to provide a porous parts loading surface <NUM>. In accordance with this alternative embodiment, it is possible to utilize a "waterfall" transducer <NUM> (as shown in <FIG>) in which a stream of coupling fluid <NUM> is emitted towards the sample or parts to be inspected <NUM>, and the ultrasonic pulses <NUM> are emitted inside the coupling fluid stream <NUM>. The "waterfall" transducer <NUM> is located above the parts <NUM> and the water and ultrasonic pulses are directed down toward the parts. It also is possible to apply a vacuum to the underside of the parts through the porous parts loading surface <NUM> that will minimize the possibility that the parts to be inspected will be dispersed during ultrasonic inspection. In this regard, the memory <NUM> of the controller <NUM> includes instructions that, when executed by the processor <NUM>, allow a vacuum to be applied to the underside of the porous parts loading surface <NUM> for a period of time, the vacuum causing air to be draw into and through the porous parts loading surface <NUM> to entrain at least some of the flow of coupling fluid that is dispensed onto the parts and to thereby create a pressure that at least partially immobilizes the parts on the parts loading surface <NUM>.

When immersion scanning takes place, the movement of the transducer within the tank of coupling fluid <NUM> causes "whitecaps" in and agitates the coupling fluid in the tank. In order to reduce the chances that this agitation of coupling fluid could cause parts or chips located on a parts bearing tray to be moved during scanning, a very thin sheet or film can be used that is generally transparent to ultrasonic energy and that has low acoustic impedance. The sheet is placed over the top of the parts bearing tray while it is immersed in the coupling fluid to provide at least some hold down force on the parts as some parts may otherwise float to the surface. Certain plastics are suitable for this purpose, and can be about <NUM> mils thick. The sheet Or film also isolates the parts from the turbulence of the moving transducer(s) thereby holding the parts in place. A clip or clips or the like can be used to further secure the sheet or film on top of the parts.

When through scanning takes place, a transducer is placed below the parts loading surface to capture ultrasonic energy that passes through the parts on the parts loading surface of the tray. If the parts loading surface of a fixture is porous, then an additional sheet or film can be used to minimize the effects of turbulence that are created by the movement of the through scan transducer in the coupling fluid that may agitate the parts on the parts bearing tray by traveling through the porous holes. A clip or clips or the like can be used to further secure the additional sheet or film to the bottom of the parts loading surface.

Referring again to <FIG>, the scanning acoustic microscope <NUM> includes a sensor (not shown) for detecting when the safety door <NUM> is disposed in the down, closed position. One purpose of the sensor is to allow X-Y-Z motion stage driver <NUM> to move the transducer <NUM> only when the safety door <NUM> is closed. This feature serves to protect the operator of the scanning acoustic microscope <NUM> from being harmed scanning takes place by, for example, preventing the operator's tie from being caught by the moving transducer <NUM>. The memory <NUM> of the controller <NUM> includes instructions that, when executed by the processor <NUM>, prevent the X-Y-Z stage driver <NUM> from moving the transducer <NUM> except when a "door closed" signal is sent from the sensor.

As shown in <FIG>, <FIG>, and <FIG> and according to the present invention, the safety door <NUM> includes an extension portion <NUM> that extends down into the tank <NUM>. As previously discussed, the tank <NUM> contains an amount of coupling fluid <NUM> through which the transducer <NUM> is moved in, for example, X-Y raster scans during insonification of the parts loaded on surface <NUM> (see <FIG>). Because the transducer <NUM> can be moved quite quickly during insonification waves and other disturbances in the coupling fluid may be created. One purpose of the extension portion <NUM> of the safety door <NUM> is, for example, to minimize the transmission of waves of coupling fluid <NUM> from the scanning portion <NUM> of the tank <NUM> to the second or loading portion <NUM> of the tank <NUM>. This reduces, for example, the agitation or movement of parts to be inspected as they are loaded on parts loading surface <NUM>.

<FIG> is an isometric view of an exemplary fixture <NUM> that can be utilized in accordance with embodiments of the present invention. Fixture <NUM> includes first and second support members <NUM> and <NUM> between which a parts support bracket <NUM> is mounted. Support bracket <NUM> includes an aperture <NUM> in which a part bearing tray can be mounted as discussed in greater detail hereinafter.

Each one of the support members <NUM> and <NUM> includes a first bearing <NUM> and a second bearing <NUM>. The pair of first bearings <NUM> are adapted to engage rail <NUM>, and the pair of second bearings <NUM> are adapted to engage rail <NUM>. <FIG> is a cross sectional view showing particulars of an exemplary embodiment of the present invention. In this example, the first bearings <NUM> are flat to engage an upper surface of the rail <NUM>. This prevents the movement of the fixture <NUM> in a vertical direction perpendicular to the axis of the rail <NUM>. The second bearings <NUM> are generally U-shaped to capture the rail <NUM> and thereby prevent movement of the fixture <NUM> in a direction perpendicular to the axis of the rail <NUM>.

Referring to <FIG>, a fragmentary isometric view of a portion of the tank <NUM> and scanning portion <NUM> is shown which illustrates an exemplary latch that is used to hold the fixture <NUM> in a calibrated insonifying position. The latch includes an extension member <NUM> that is, in the illustrated embodiment, integrally formed as a portion of a first support member <NUM> that is equivalent to first support member <NUM> shown in <FIG>. Extension member <NUM> includes a shoulder portion <NUM> and a mating pin <NUM>. When the mating pin <NUM> is held in contact against abutment pin <NUM> that is affixed to a part of the scanning portion <NUM> of the tank <NUM>, the fixture <NUM> is held in an insonifying position.

A spring <NUM> biases the pivot member <NUM> for rotation about axis <NUM> in a direction towards the extension member <NUM>. The pivot member <NUM> includes an inclined surface <NUM> and a shoulder portion <NUM>. As the fixture <NUM> and first support member <NUM> are slid along the rails (one of which is shown in <FIG> as rail <NUM>) in a direction towards the latch, the inclined surface <NUM> rides along an outside surface of the shoulder portion <NUM> of the extension member <NUM>. This compresses the spring <NUM>. One of the engagement surfaces of shoulder portions <NUM> and <NUM> is disposed at an angle slightly offset from being perpendicular to the axis of the rail <NUM> so that, when the pins <NUM> and <NUM> touch each other, the bias force applied by the spring <NUM> ensures that the pivot member <NUM> does not rotate, unless a user applies enough force to overcome the spring. This latching mechanism, therefore, prevents the fixture <NUM> from sliding along the rail <NUM> and, in combination with the engagement of the first and second bearings <NUM> and <NUM> with the rails <NUM> and <NUM>, locks the parts containing the fixture <NUM> in an insonifying position. This provides a known location that can be used to allow a user to program a path of movement of the transducer <NUM> with respect to any parts on the parts loading surface <NUM> of a fixture as discussed in greater detail hereinafter.

<FIG> is an isometric view of an exemplary fixture <NUM> that is constructed as shown in <FIG>, but that includes, for example, a plastic tray <NUM> inserted in the aperture <NUM> formed therein. In one embodiment, the plastic tray <NUM> includes projections (not shown) that are interference fit inside of corresponding apertures <NUM> formed in the fixture <NUM>. Alternatively, rotatable pins (not shown) inside the fixture <NUM> can be withdrawn from and then extended to support the plastic tray <NUM>. The tray can be formed from any suitable material (e.g., plastic) and can, in an exemplary application, be formed in a porous manner so that a vacuum can be applied to the underside of the plastic tray <NUM> to reduce part movement during insonification.

Referring to <FIG>, a fragmentary plan view of an alternate embodiment of the present invention is shown. In this example, a parts support tray <NUM> is formed from a material that is at least generally transparent to ultrasonic energy such as, for example, glass. This embodiment is useful for through scan applications where ultrasonic energy passes through parts and then is read on the opposite side from which the energy originated. The parts support tray <NUM> is inserted and supported in the aperture <NUM> formed in a suitable fixture such as fixture <NUM> shown in <FIG>.

The tray <NUM> includes an x-axis ruler section <NUM> and a y-axis ruler section <NUM>. When the tray <NUM> is inserted inside the aperture <NUM> formed in fixture <NUM>, and when the fixture <NUM> is fixed in the insonifying position with the pins <NUM> and <NUM> held in engagement together by the force of the spring <NUM>, the origin <NUM> at the junction of the two ruler sections <NUM> and <NUM> is held at a known position with respect to the initial, at-rest position of the ultrasonic transducer <NUM> due to, for example, the construction of the fixture <NUM>. This allows a user to place parts or chips <NUM> to be inspected on the surface of the tray <NUM> in columns that are separated by spacer bars. The spacer bars are made of a material heavier than that of the parts <NUM> and prevent the chips from moving around on the tray once they are placed thereon. In the example shown in <FIG>, three columns of parts <NUM>, <NUM> and <NUM> are separated by spacer bars <NUM> and <NUM>. Two parts of the same thickness form column <NUM>, three parts of the same width form column <NUM>, and one part forms column <NUM>.

<FIG> is a flow chart that illustrates process steps by which a user can interact with a graphic user interface on the display <NUM> (<FIG>) to program a flight path of transducer <NUM> with respect to a tray of parts such as, for example, tray <NUM> shown in <FIG>. In step <NUM>, a user immerses the fixture <NUM> in the loading portion <NUM> of the tank <NUM>, and then places a number of parts or chips <NUM> to be inspected on the tray <NUM> held inside the fixture <NUM> as, for example, shown in <FIG>. In step <NUM>, the user interacts with the graphic user interface shown on the display <NUM> to enter the x-axis and y-axis starting point for the first chip in the first column on the tray <NUM>. In step <NUM>, the user enters the number of chips in the column. If there is another column of parts or chips <NUM> on the tray <NUM>, step <NUM>, the user enters the x-axis start point of the first chip in that column, step <NUM>. Steps <NUM> and <NUM> are repeated for that new row. This process is completed until the dimensions of all of the parts or chips <NUM> are entered for the total number of columns of parts on the tray <NUM>. Once that is done, step <NUM>, the transducer scan path is computed and then executed so long as the sensor (not shown) indicates that the safety door <NUM> is in the down, closed position.

<FIG> illustrates an exemplary alternative embodiment for allowing a user to program a flight path of the transducer <NUM> with respect to the parts placed on tray <NUM>. In this embodiment, the tray <NUM> is loaded with parts or chips <NUM>, step <NUM>, a picture of the tray <NUM> is taken by a camera (not shown) associated with the scanning acoustic microscope <NUM>, and then the picture is shown on the display <NUM>, step <NUM>. The user then traces the outline of a first one of the parts <NUM> shown on the display <NUM> using an appropriate user input device <NUM> (see <FIG>) such as, for example, a mouse or keyboard, step <NUM>. If there is another part on tray <NUM>, step <NUM>, then step <NUM> is repeated. This process is repeated until the outlines of all parts <NUM> on tray <NUM> are traced. When the process is completed, the flight path of the transducer <NUM> with respect to tray <NUM> is computed and then executed so long as the sensor (not shown) indicates that the safety door <NUM> is in the down, closed position.

Other alternatives for programming the flight path of the transducer <NUM> are within the scope of the invention disclosed and claimed herein. For example, the memory <NUM> of controller <NUM> could include a library of parts of known dimensions. In accordance with this alternative exemplary embodiment, the user could enter the part numbers of the parts forming the individual columns on tray <NUM>, together with the x-axis starting points of each column. The flight path could then be programmed by reference to the known dimensions of the parts. Further alternatively, transducer flight paths can be stored in the memory <NUM> for a given arrangement of parts on the tray <NUM>.

<FIG> illustrates a flow chart that allows a user to interact with an appropriate graphic user interface shown on the display <NUM> to provide additional options available when the tray <NUM> is scanned. In steps <NUM> and <NUM>, the user indicates whether a "fast" scanning mode is to be executed for the parts on the tray <NUM>. When "fast" mode is selected, the entire area of the tray <NUM> that is covered by parts or chips to be inspected is insonified in one x-y raster scan as opposed to having an individual x-y raster scan for each part. A software routine is executed after the scan data is generated to reject and not save data from locations on the tray <NUM> where no parts are located. The use of the "fast mode" maximizes the time at which transducer <NUM> is moved at top speed. By utilization of balanced linear motors to cause the transducer <NUM> to move in the x and y directions of an x-y raster scan, transducer time at top speed is further maximized, thereby further shortening the total scan time. If each part is to be scanned individually, a user indicates that preference by indicating the same in step <NUM>.

In steps <NUM> and <NUM>, a user indicates a preference to take profile measures of each part located on tray <NUM>. Profile measurements are useful to determine whether or not, for example, each part is warped. The graphic user interface can be programmed to allow profile measurements to be taken for some or all of the parts on tray <NUM>, and to allow internal measurements to be taken as well or not at all with respect to particular parts.

In steps <NUM> and <NUM>, a user indicates a preference to take focused A-scan measurements at three dimensionally varied points inside of particular ones or all of the parts on the tray <NUM>. In particular, the transducer <NUM> is used to interrogate each sample on tray <NUM> at three- dimensionally varied locations in the sample. Data developed by the transducer <NUM> includes for each location interrogated a digitized A-scan for that location. The developed data is stored in a data memory. This allows the creation of a "virtual sample" of acoustic impedance features inside of each sample on tray <NUM> that can be analyzed at a later time or sent to appropriate personnel at widely dispersed locations.

In step <NUM>, the controller <NUM> computers the flight path of the transducer <NUM> with respect to the tray <NUM>, and then executes the same so long as the sensor (not shown) indicates that the safety door <NUM> is in the down and locked position.

It should be noted that some users of the device disclosed and claimed herein may take action to defeat the action of the sensor that indicates the position of the safety door <NUM>. Such users do this so that they can cause a tray of parts to be inspected with the user is loading a second tray with parts and programming the transducer flight path. It is the applicants' specific intention to try to obtain patent protection on the sale of the machine disclosed and claimed herewith where the sensor has been defeated.

In steps <NUM> and <NUM>, it is determined if a user has placed a second fixture <NUM> into the loading portion <NUM> of the tank <NUM> while a scanning operation inside of the scanning portion <NUM> of the tank <NUM> is taking place. If so, then the user interacts with an appropriate graphic user interface shown on the display <NUM> to program the transducer flight path while the insonification of the other tray takes place. This allows the operator's time to be more efficiently used to reduce total labor costs for a fixed amount of parts to be inspected. Instead of having an operator wait for a scan to be completed, the operator can, instead, use that previous down time to program the transducer flight path for another tray of parts to be inspected.

One aspect of the present invention is that the memory <NUM> of the controller <NUM> contains instructions that, when executed by the processor <NUM>, cause a graphic user interface <NUM> to be shown on the display (see <FIG>), allow a user to enter information about the arrangement of parts that are manually loaded on a parts loading surface of a first fixture that is immersed in a coupling fluid, and computer a flight path of an ultrasonic transducer with respect to the parts on the first fixture, all of which takes place generally simultaneously with the ultrasonic transducer actually being used to inspect parts located on a second fixture immersed in the coupling fluid. These instructions can include, if desired, instructions that, when executed by the processor <NUM>, allow the user to select whether a single x-y raster scan should be taken for all of the parts on the tray. These instructions can include, if desired, instructions that, when executed by the processor <NUM>, allow a user to selectively program for each part whether internal measurements and/or external profile measurements should be made for each part. These instructions can include, if desired, instructions that, when executed by the processor <NUM>, allow A-scans to be taken at three dimensionally varied points inside of one, some or all of the parts to be inspected.

A second aspect of the invention concerns the manner in which a user interacts with the graphic user interface to enter data about the arrangement of parts on the tray. In one embodiment, the user enters information about the x and y axis boundaries of the parts to be inspected that are arranged in columns on the fixture and that are separated by spacer bars. In a second embodiment, the user enters information about the model numbers of the parts to be inspected, with the transducer scan path being calculated by reference to known dimensions of the entered parts that are stored in the memory <NUM>. In a third embodiment, an actual picture of the parts loaded fixture is shown on the display screen, with the user tracing the outline of each part shown on the screen. In a fourth embodiment, a representation of the parts loading surface is shown on the display screen, with the user tracing the outline of each part by means of a cursor or other graphics device.

One advantage of the present invention is that it promotes efficient use of an operator's time. In particular, instead of waiting for the scanning of a particular tray of parts to be completed, the operator can take that time to program the transducer flight path of a second tray of parts. A second advantage of the present invention is that, by utilization of the safety door <NUM>, the area of the scanning acoustic microscope <NUM> in which the transducer <NUM> is located can be positioned at the front of the microscope close to the operator. This allows, for example, for easier maintenance of the scanning acoustic microscope <NUM>, and easier replacement of transducers if a different type of scan is to be employed on a next tray. Moreover, there is no requirement that, to remove a tray of parts which already has been inspected, the inspected parts tray must pass above or below another tray that is adapted to be loaded while the other tray is being inspected.

Claim 1:
A scanning acoustic microscope (<NUM>), comprising:
• a transducer (<NUM>) operable to develop ultrasonic energy;
• a controller (<NUM>) configured to control a scan path of the transducer (<NUM>);
• a tank structure (<NUM>) including a loading portion (<NUM>) and a scanning portion (<NUM>), wherein the loading and scanning portions are in fluidic communication with each other, wherein the structure (<NUM>) is configured to hold a coupling fluid (<NUM>) such that the coupling fluid (<NUM>) is free to flow between the loading portion (<NUM>) and the scanning portion (<NUM>);
means responsive to the controller (<NUM>) for moving the transducer (<NUM>) in the coupling fluid (<NUM>) and along the scan path with respect to a plurality of parts disposed in a scanning area of the scanning portion (<NUM>); and
a safety enclosure (<NUM>) movable between an open position permitting to access to the scanning portion (<NUM>) and a closed position enclosing the scanning portion (<NUM>) to prevent user contact with the transducer (<NUM>),
the scanning acoustic microscope (<NUM>) being characterized in that:
the moving means are configured to move the transducer (<NUM>) along the scan path outside the loading portion (<NUM>), and in that:
the safety enclosure (<NUM>) includes an extension portion (<NUM>) that extends down into the tank structure (<NUM>) to separate the scanning portion (<NUM>) from the loading portion (<NUM>) when the safety enclosure (<NUM>) is in the closed position,
so as to minimize the transmission of waves of coupling fluid from the scanning portion to the loading portion and to allow a tray of parts (44b) to be prepared in the loading portion (<NUM>) of the structure (<NUM>) while another (44a) is being scanned.