Patent Description:
In a process of mounting a device (e.g., a die) on a substrate, various inspections can be conducted as to whether the process has been properly performed. For example, it can be necessary to determine the three-dimensional shape of the device on the substrate, because failure to place the device at an appropriate position on the substrate can cause defects in the substrate subjected to the process. In the present disclosure, the device can refer to a component or a chipset used as an element in an electronic device such as an electric circuit or a semiconductor device. For example, the device can refer to a coil, a capacitor, a resistor, a transistor, a diode, an LED, or the like. In the present disclosure, the device is not limited to the aforementioned examples.

In determining the three-dimensional shape of a device (i.e., an object), it is possible to inspect an angle of an upper surface of the device with respect to a substrate (i.e., a reference plane). The angle can be utilized to check whether there is no tilt between the device and the substrate. If the device is disposed or mounted so that the lower surface of the device is in close contact with the substrate, or if the device is disposed or mounted in a tilted state with respect to the substrate depending on the application state of a solder or solder ball applied to the substrate, it can cause a defect in the substrate.

In order to inspect the tilt of the upper surface of the device in determining the three-dimensional shape of the device, it is possible to utilize a method of irradiating a light on the device and inspecting the tilt by using a position where the reflected light forms an image. However, in this method, when the device has a mirror surface, the reflection angle is changed greatly even if the device is tilted at a small angle. Therefore, a large space is required to measure the imaging position of the reflected light, which can make it difficult to downsize the inspection equipment. In addition, in order to inspect the tilt of the upper surface of the device, it can be possible to utilize a method of irradiating a structured light to the device, forming a diffraction pattern in the air above the device by the structured light, and inspecting the tilt through the use of a phase change of the diffraction pattern. However, this method can have a disadvantage in that a lot of noise is generated because the diffraction pattern is imaged in the air. <CIT> discloses three-dimensional shape measurement apparatus includinmg a plurality of main pattern illumination parts, a plurality of main image-capturing parts and a control part.

Various embodiments of the present disclosure provide a technique for determining a three-dimensional shape of an object. However, the scope of the present invention is defined by the appended claims.

As one aspect of the present disclosure, there is proposed an apparatus for determining a three-dimensional shape of an object. The apparatus according to one aspect of the present disclosure can be an apparatus for determining a first three-dimensional shape of an object located on a reference plane. The apparatus can include: one or more first light sources configured to irradiate one or more first pattern lights to the object; a second light source configured to sequentially irradiate one or more second pattern lights having a respective phase selected from a phase range; a beam splitter and one or more lenses configured to change optical paths of the one or more second pattern lights so that a beam of light corresponding to the respective phase of the phase range spreads, and evenly arrives at each point of a partial region of an upper surface of the object; an image sensor configured to capture one or more first reflected lights generated by reflecting the one or more first pattern lights from the object and one or more second reflected lights generated by reflecting the one or more second pattern lights from the partial region, wherein the one or more first reflected lights and the one or more second reflected lights pass through the beam splitter (<NUM>) to reach the image sensor (<NUM>); and a processor that is electrically connected to the one or more first light sources, the second light source and the image sensor, and that is configured to determine the first three-dimensional shape of the object based on the one or more first reflected lights and the one or more second reflected lights, characterized in that each of the one or more second pattern lights is a pattern light generated by phase-shifting a pattern light having a pattern in a first direction or a second direction perpendicular to the first direction by an integer multiple of a preset phase interval, wherein the first three-dimensional shape includes an angle of the upper surface of the object with respect to the reference plane, and wherein the processor is further configured to determine the angle of the upper surface of the object with respect to the reference plane based on each light amount value of the one or more second reflected lights.

In one embodiment, the processor can be further configured to determine a second three-dimensional shape of the object based on each of phase changes of the one or more first reflected lights from the one or more first pattern lights, derive a phase value of each of the one or more second reflected lights from each light amount value of the one or more second reflected lights, determine an angle of the upper surface of the object with respect to the reference plane based on the phase value, and determine the first three-dimensional shape of the object by correcting the upper surface of the object indicated by the second three-dimensional shape based on the angle of the upper surface of the object.

In one embodiment, the apparatus according to the present disclosure can further include: a memory configured to store reference information indicating a relationship between the angle of the upper surface of the object with respect to the reference plane and the phase value of each of the one or more second reflected lights, wherein the processor can be further configured to determine the angle of the upper surface of the object with respect to the reference plane based on the phase value and the reference information.

In one embodiment, the apparatus according to the present disclosure can further include: one or more third light sources configured to irradiate illumination lights according to one or more wavelengths toward the object at one or more angles with respect to the reference plane, wherein the image sensor can be further configured to capture one or more third reflected lights generated by each of the illumination lights according to the one or more wavelengths reflected from the object, and the processor can be further configured to determine the second three-dimensional shape of the object based on each of the phase changes of the one or more first reflected lights from the one or more first pattern lights and each of changes in light amounts of the one or more third reflected lights from the illumination lights according to the one or more wavelengths.

In one embodiment, the second light source can be further configured to irradiate a monochromatic light, the beam splitter and the one or more lenses can be further configured to change an optical path of the monochromatic light so that the monochromatic light arrives at the upper surface of the object, the image sensor can be further configured to capture a fourth reflected light generated by reflecting the monochromatic light from the upper surface of the object, and the processor can be further configured to determine the second three-dimensional shape of the object based on each of the phase changes of the one or more first reflected lights from the one or more first pattern lights and a change in a light amount of the fourth reflected light from the monochromatic light.

In one embodiment, the processor can be further configured to derive a reflectance of the upper surface of the object based on the change in the light amount of the fourth reflected light from the monochromatic light and can be further configured to control the second light source to sequentially irradiate the one or more second pattern lights when the reflectance of the upper surface of the object is equal to or greater than a preset reference reflectance.

In one embodiment, each of the one or more first pattern lights can be a pattern light generated by phase-shifting a pattern light having a pattern in a first direction or in a second direction perpendicular to the first direction by an integer multiple of a preset phase interval.

In one embodiment, each of the one or more second pattern lights can be a pattern light generated by phase-shifting a pattern light having a pattern in a first direction or in a second direction perpendicular to the first direction by an integer multiple of a preset phase interval.

In one embodiment, the image sensor can be disposed to face the object at a position vertically upward of an area on the reference plane where the object is located.

In one embodiment, each of the one or more first light sources can be disposed to irradiate the one or more first pattern lights along different optical axes toward the object from above the reference plane.

In one embodiment, each of the one or more third light sources can include a plurality of illumination light sources disposed above the reference plane and spaced apart from each other on a circumference parallel to the reference plane.

In one embodiment, the apparatus according to the present disclosure can further include: a first iris configured to pass the one or more second pattern lights irradiated from the second light source toward the beam splitter; and a second iris configured to pass the one or more second reflected lights traveling from the partial region toward the image sensor, where the each light amount value of the one or more second reflected lights can be determined according to a light amount of light passing through the first iris, reflected by the partial region and passing through the second iris.

As another aspect of the present disclosure, there is proposed a method for determining a three-dimensional shape of an object. The method according to another aspect of the present disclosure can be a method for determining a first three-dimensional shape of an object located on a reference plane. The method according to another aspect of the present disclosure can include: irradiating, by one or more first light sources, one or more first pattern lights to the object; capturing, by an image sensor, one or more first reflected lights generated by reflecting the one or more first pattern lights from the object; sequentially irradiating, by a second light source, one or more second pattern lights having one phase range; changing, by a beam splitter and one or more lenses, optical paths of the one or more second pattern lights so that a beam of light corresponding to a respective phase of the phase range spreads, and arrives at each point a partial region of an upper surface of the object; capturing, by the image sensor, one or more second reflected lights generated by reflecting the one or more second pattern lights from the partial region; and determining, by a processor, the first three-dimensional shape of the object based on the one or more first reflected lights and the one or more second reflected lights.

In one embodiment, determining, by the processor, the first three-dimensional shape of the object can include: determining, by the processor, a second three-dimensional shape of the object based on each of phase changes of the one or more first reflected lights from the one or more first pattern lights; deriving, by the processor, a phase value of each of the one or more second reflected lights from each light amount value of the one or more second reflected lights; determining, by the processor, an angle of the upper surface of the object with respect to the reference plane based on the phase value; and determining, by the processor, the first three-dimensional shape of the object by correcting the upper surface of the object indicated by the second three-dimensional shape based on the angle of the upper surface of the object.

In one embodiment, the method according to the present disclosure can further include: irradiating, by the second light source, a monochromatic light; changing, by the beam splitter and the one or more lenses, an optical path of the monochromatic light so that the monochromatic light arrives at the upper surface of the object; and capturing, by the image sensor, a fourth reflected light generated by reflecting the monochromatic light from the upper surface of the object, wherein determining the second three-dimensional shape of the object can include determining the second three-dimensional shape of the object based on each of the phase changes of the one or more first reflected lights from the one or more first pattern lights and a change in a light amount of the fourth reflected light from the monochromatic light.

The various embodiments described herein are exemplified for the purpose of clearly describing the technical idea of the present disclosure, and are not intended to limit the technical idea of the present disclosure to specific embodiments. The technical idea of the present disclosure includes various modifications, equivalents, alternatives of each of the embodiments described in this document, and embodiments selectively combined from all or part of the respective embodiments. In addition, the scope of the technical idea of the present disclosure is not limited to various embodiments or detailed descriptions thereof presented below as the scope of the present invention is only limited by the appended claims.

The terms used herein, including technical or scientific terms, can have meanings that are generally understood by a person having ordinary knowledge in the art to which the present disclosure pertains, unless otherwise specified.

As used herein, the expressions such as "include," "can include," "provided with," "can be provided with," "have," and "can have" mean the presence of subject features (e.g., functions, operations, components, etc.) and do not exclude the presence of other additional features. That is, such expressions should be understood as open-ended terms that imply the possibility of including other embodiments.

A singular expression can include meanings of plurality, unless otherwise mentioned, and the same is applied to a singular expression stated in the claims.

The terms "first", "second", etc. used herein are used to identify a plurality of components from one another, and are not intended to limit the order or importance of the relevant components.

As used herein, the expressions such as "A, B and C," "A, B or C," "A, B and/or C," "at least one of A, B and C," " at least one of A, B or C," "at least one of A, B and/or C," "at least one selected from A, B and C," "at least one selected from A, B or C," and "at least one selected from A, B and/or C" mean each of the listed items or all possible combinations of the listed items. For example, the expression "at least one selected from A and B" refers to (<NUM>) A, (<NUM>) at least one of A, (<NUM>) B, (<NUM>) at least one of B, (<NUM>) at least one of A and at least one of B, (<NUM>) at least one of A and B, (<NUM>) at least one of B and A, and (<NUM>) A and B.

The term "part" used herein can be a conception that comprehensively refers to software, or hardware components such as a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC) and the like, and hardware components such as an optical element and the like. However, the term "part" is not limited to software and hardware. The term "part" can be configured to be stored in an addressable storage medium or can be configured to execute one or more processors. In one embodiment, the term "part" can include components, such as software components, object-oriented software components, class components, and task components, as well as processors, functions, attributes, procedures, subroutines, segments of program codes, drivers, firmware, micro-codes, circuits, data, databases, data structures, tables, arrays, and variables.

The expression "based on" used herein is used to describe one or more factors that influence a decision, an action of judgment or an operation described in a phrase or sentence including the relevant expression, and this expression does not exclude additional factors influencing the decision, the action of judgment or the operation.

As used herein, the expression that a certain component (e.g., a first component) is "connected" to another component (e.g., a second component) means that the certain component is not only connected or coupled to another component directly, but also connected or coupled via a new other component (e.g., a third component).

As used herein, the expression "configured to" has a meaning such as "set to," "having the ability to," "modified to," "made to," "capable of," or the like depending on the context. The expression is not limited to the meaning of "specially designed for hardware. " For example, a processor configured to perform a specific operation can mean a generic-purpose processor capable of performing a specific operation by executing software.

In order to describe various embodiments of the present disclosure, a Cartesian coordinate system having an X axis, a Y axis and a Z axis orthogonal to each other can be defined. As used herein, the expression such as "X-axis direction", "Y-axis direction" or "Z-axis direction" of the Cartesian coordinate system refers to two directions toward which each axis of the Cartesian coordinate system extends, unless specifically defined otherwise in the corresponding description. In addition, the + sign in front of each axis direction can mean a positive direction, which is one of the two directions extending along the corresponding axis, and the - sign in front of each axis direction can mean a negative direction, which is the other of the two directions extending along the corresponding axis.

Direction indicators such as "upward", "upper" and the like used herein are based on the positive Z-axis direction in the accompanying drawings, unless otherwise defined in the description. Direction indicators such as "downward", "lower" and the like refer to the opposite direction thereof.

In the present disclosure, a substrate is a plate or container on which elements such as semiconductor chips or the like are mounted, and can serve as a path for transmitting electrical signals between elements. The substrate can be used for fabricating an integrated circuit or the like, and can be made of a material such as silicon or the like. For example, the substrate can be a printed circuit board (PCB), and can also be referred to as a wafer.

Hereinafter, various embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings and the descriptions of the drawings, the same reference numerals can be assigned to the same or substantially equivalent elements. Furthermore, in the following description of various embodiments, the overlapping descriptions of the same or corresponding elements can be omitted. However, this does not mean that the elements are not included in the embodiments.

<FIG> is a diagram illustrating an apparatus <NUM> according to an embodiment of the present disclosure. The technique for determining a three-dimensional shape of an object according to the present disclosure can be implemented by apparatuses according to various embodiments. The apparatus <NUM> of the present disclosure can determine a three-dimensional shape of an object (e.g., a device) by using various inspection methods. In the present disclosure, the shape of the object can be a concept including both the shape of an object in a three-dimensional space and the color and texture of a surface of an object. In one embodiment, the apparatus <NUM> can perform an inspection using a pattern light and/or an inspection using coaxial deflectometry. In one embodiment, the apparatus <NUM> can further perform an inspection using an illumination light.

In this embodiment, the apparatus <NUM> can include a pattern light irradiation part <NUM>, a deflectometry (DFM) part <NUM>, a measurement part <NUM>, and/or an illumination light irradiation part <NUM>. In one embodiment, the illumination light irradiation part <NUM> can be omitted. The pattern light irradiation part <NUM> can irradiate a pattern light toward an object in order to perform an inspection using the pattern light. The DFM part <NUM> can irradiate a pattern light toward the object in order to perform an inspection using coaxial deflectometry. The measurement part <NUM> can capture the reflected light, which is irradiated by the pattern light irradiation part <NUM> and the DFM part <NUM> and reflected from the object, and can determine the three-dimensional shape of the object. The illumination light irradiation part <NUM> can irradiate an illumination light toward the object in order to perform an inspection using the illumination light. The illumination light can be reflected from the object, captured by the measurement part <NUM>, and used to determine the three-dimensional shape of the object. The specific operations and inspection methods of the respective parts will be described later.

<FIG> is a diagram illustrating an operation process of the apparatus <NUM> according to an embodiment of the present disclosure. The apparatus <NUM> according to the illustrated embodiment can perform an inspection method using a pattern light and/or an inspection method using coaxial deflectometry. The apparatus <NUM> can determine the three-dimensional shape of the object based on the inspection results. The determined three-dimensional shape can be used to determine the adequacy of the performed process. The process in which the apparatus <NUM> performs an inspection using an illumination light will be described later as an additional embodiment.

In this embodiment, one or more pattern light sources <NUM> can irradiate one or more pattern lights <NUM> toward an object located on a reference plane R. The one or more pattern light sources <NUM> can belong to the pattern light irradiation part <NUM>. The one or more pattern light sources <NUM> can be disposed above the reference plane R to irradiate the one or more pattern lights <NUM> toward the object along different optical axes. In one embodiment, the one or more pattern light sources <NUM> can be disposed at intervals from each other on an imaginary circumference positioned above the reference plane R. The one or more pattern lights <NUM> can be reflected from the object. Depending on the shape of the object, the phase of the pattern light <NUM> can be changed before and after reflection. That is, the reflected light <NUM> generated by the reflection of the pattern light <NUM> on the object can have a phase different from that of the corresponding pattern light <NUM>.

An image sensor <NUM> can capture one or more reflected lights <NUM> generated by the reflection of the one or more pattern lights <NUM>. The image sensor <NUM> can belong to the measurement part <NUM>. In one embodiment, the image sensor <NUM> can be disposed to face the object vertically above the region on the reference plane R where the object is located.

The apparatus <NUM> can obtain information about the phase of each of the one or more reflected lights <NUM> and the phase of each of the one or more pattern lights <NUM>. The apparatus <NUM> can determine a primary three-dimensional shape of the object based on a phase change of each of the one or more reflected lights <NUM> and each of the one or more pattern lights <NUM>.

Meanwhile, the one or more pattern light sources <NUM> and the separately installed pattern light source <NUM> can sequentially irradiate one or more pattern lights <NUM>. The pattern light source <NUM> can belong to the DFM part <NUM>. The one or more pattern lights <NUM> can have the same one phase range (e.g., <NUM> to <NUM>×π/<NUM>). In one embodiment, each of the one or more pattern lights <NUM> can be generated by phase shifting one pattern light within the above-described phase range by an integer multiple of a preset phase interval (e.g., π/<NUM>).

The one or more pattern lights <NUM> can travel toward a beam splitter <NUM> through a lens <NUM> and/or other optical elements (e.g., a mirror). In one embodiment, the pattern light <NUM> can travel toward the beam splitter <NUM> via an iris <NUM>. The beam splitter <NUM> can reflect one or more pattern lights <NUM> toward the object. At this time, the beam splitter <NUM> and one or more lenses <NUM> can change optical paths of the one or more pattern lights <NUM> so that a light beam of light corresponding to each phase in the above-described phase range spreads, and arrives at each point of the partial region A of the upper surface of the object. That is, the optical path of the light corresponding to each phase of the pattern light <NUM> can be changed (adjusted) so that the light corresponding to one phase (e.g., <NUM>×π/<NUM>) of the above-described phase range (e.g., <NUM> to <NUM>×π/<NUM>) of the pattern light <NUM> arrives at each point on the plane corresponding to the aforementioned partial region A. The beam splitter <NUM> and the one or more lenses <NUM> can be disposed on the optical path of the pattern light <NUM> so that they can change the optical path. The beam splitter <NUM> and the one or more lenses <NUM> can belong to the DFM part <NUM>.

Each of the one or more pattern lights <NUM> whose optical paths are changed (adjusted) can reach the object. Since the lights corresponding to the respective phases are irradiated over the entire partial region A of the upper surface of the object in a dispersed manner, the light corresponding to the average amount of the pattern lights <NUM> can arrive at each point of the partial region A. Each of the one or more pattern lights <NUM> arriving at the partial region A can be reflected from the partial region A. The light (hereinafter referred to as reflected light <NUM>) generated by the reflection of the pattern light <NUM> can sequentially pass through the lens <NUM> and the beam splitter <NUM>. In one embodiment, the reflected light <NUM> can pass through an iris <NUM> and, if necessary, can pass through an additionally disposed lens <NUM> to reach the image sensor <NUM>. The image sensor <NUM> can capture each of the one or more reflected lights <NUM>.

When the partial region A of the upper surface of the object is tilted with respect to the reference plane R, only a portion of the light reflected from the partial region A can pass through the iris <NUM> and can be inputted to the image sensor <NUM>. That is, the iris <NUM> passes the pattern light <NUM> toward the beam splitter <NUM>, and the iris <NUM> passes the reflected light <NUM> traveling from the partial region A to the image sensor <NUM>. Accordingly, the light amount value of the reflected light <NUM> captured by the image sensor <NUM> can be determined according to the light amount of the light passing through the iris <NUM>, reflected by the partial region A and passing through the iris <NUM>. At this time, the light captured by the image sensor <NUM> can be the light corresponding to the partial phase range (e.g., <NUM>×π/<NUM> to <NUM>×π/<NUM>) of the above-described phase range (e.g., <NUM> to <NUM>×π/<NUM>) of the initially irradiated pattern light <NUM>. That is, the amount of the light passing through the iris <NUM> and captured by the image sensor <NUM> can vary according to the degree at which the upper surface of the object or the partial region A is tilted with respect to the reference plane R. By using this principle, it is possible to derive the degree of tilt of the reflective surface based on the amount of captured reflected light, which can be referred to as deflectometry in the present disclosure. In particular, as in the illustrated embodiment, when the pattern light <NUM> incident on the object and the reflected light <NUM> reflected from the object travel along substantially the same optical axis, the deflectometry can be referred to as coaxial deflectometry. The specific principle of the deflectometry will be described later.

According to the deflectometry, the apparatus <NUM> can determine the angle of the upper surface of the object with respect to the reference plane R based on the each light amount value of the one or more reflected lights <NUM>. The apparatus <NUM> can determine a secondary three-dimensional shape by correcting the previously determined primary three-dimensional shape by using the determined angle of the upper surface. That is, the apparatus <NUM> can correct the upper surface indicated by the primary three-dimensional shape by using the information on the angle of the upper surface measured according to the deflectometry and can derive a new corrected three-dimensional shape, i.e., a secondary three-dimensional shape. In one embodiment, the correction can be performed by a method of overriding the angle of the upper surface indicated by the primary three-dimensional shape with the angle of the upper surface derived according to the deflectometry. In one embodiment, the correction can be performed by determining an average value of the angle of the upper surface indicated by the primary three-dimensional shape and the angle of the upper surface derived according to the deflectometry as an angle of the upper surface indicated by the secondary three-dimensional shape. The secondary three-dimensional shape is the final three-dimensional shape of the object, and can be used to determine the adequacy of a process such as a mounting process or the like.

<FIG> is a block diagram of the apparatus <NUM> according to an embodiment of the present disclosure. In this embodiment, the apparatus <NUM> can include one or more pattern light sources <NUM>, an image sensor <NUM>, a pattern light source <NUM>, a beam splitter <NUM>, one or more lenses <NUM>, one or more processors <NUM> and/or one or more memories <NUM>. In one embodiment, at least one of these components of the apparatus <NUM> can be omitted, or other components can be added to the apparatus <NUM>. In one embodiment, additionally or alternatively, some components can be integrally implemented, or can be implemented as a singular entity or plural entities. In the present disclosure, one or more processors can be referred to as a processor. The term "processor" can mean one processor or a set of two or more processors, unless the context clearly indicates otherwise. In the present disclosure, one or more memories can be referred to as a memory. The term "memory" can mean one memory or a set of two or more memories, unless the context clearly indicates otherwise. In one embodiment, at least some of the internal and external components of the apparatus <NUM> can be connected to each other through a bus, a general-purpose input/output (GPIO) device, a serial peripheral interface (SPI), a mobile industry processor interface (MIPI), or the like to transmit and receive data and/or signals.

Each of the one or more pattern light sources <NUM> can irradiate one or more pattern lights <NUM> as described above. The pattern light sources <NUM> can generate the pattern lights <NUM> in various ways. For example, the patterns of the pattern lights <NUM> can be formed by a digital method or an analog method. Examples of the digital method include a liquid crystal transmission method using an LCD (Liquid Crystal Display), a liquid crystal reflection method using an LCoS (Liquid Crystal on Silicon), and a mirror reflection method using a DMD (Digital Micromirror Device) or DLP (Digital Light Processing). Examples of the analog method include a method of forming a pattern by using a pattern such as a periodic pattern, a gradient pattern, a lattice pattern or the like. As described above, the one or more pattern light sources <NUM> can be disposed above the reference plane R to irradiate pattern lights <NUM> along different optical axes. In one embodiment, four pattern light sources <NUM> can be arranged at intervals of about <NUM> degrees on an imaginary circumference (<NUM>-way). In one embodiment, eight pattern light sources <NUM> can be arranged at intervals of about <NUM> degrees on an imaginary circumference (<NUM>-way). In one embodiment, the pattern light sources <NUM> can sequentially irradiate one or more pattern lights <NUM> phase-shifted to four buckets. In one embodiment, the one or more pattern lights <NUM> can be generated by phase-shifting one pattern light by an integer multiple of a preset phase interval (e.g., π/<NUM>). For example, if eight pattern light sources <NUM> are used and the one or more phase-shifted pattern lights <NUM> are sequentially irradiated in four buckets, <NUM> (<NUM>×<NUM>) pattern lights <NUM> in total can be irradiated to the object. Accordingly, a total of <NUM> images are captured, and information on the <NUM> phase changes can be used to determine the primary three-dimensional shape of the object.

The image sensor <NUM> can capture one or more reflected lights <NUM> and the reflected light <NUM> as described above. For example, the image sensor <NUM> can be implemented as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) sensor.

Similar to the pattern light sources <NUM>, the pattern light source <NUM> can generate and irradiate pattern lights <NUM> in various ways. In one embodiment, the pattern light source <NUM> can sequentially irradiate one or more pattern lights <NUM> phase-shifted to four buckets. In one embodiment, if the pattern lights <NUM> obtained by phase-shifting the pattern light formed in one direction (hereinafter referred to as a w-axis direction) to four buckets and the pattern lights <NUM> obtained by phase-shifting the pattern light formed in a direction (hereinafter referred to as a v-axis direction) perpendicular to the w-axis direction to four buckets are used, a total of <NUM> (<NUM>+<NUM>) pattern lights <NUM> can be sequentially irradiated. Accordingly, a total of eight images can be captured and used to determine the angle of the upper surface of the object.

The beam splitter <NUM>, the one or more lenses <NUM> and/or other optical elements described above can be variously implemented by optical elements according to methods known in the art of the present disclosure. In one embodiment, the beam splitter <NUM> and/or the one or more lenses <NUM> can be arranged to change the optical paths of the aforementioned pattern lights <NUM> for deflectometry. Alternatively, in one embodiment, the processor <NUM> can adjust the positions, arrangements and related parameters of the beam splitter <NUM> and/or the one or more lenses <NUM> so that the beam splitter <NUM> and/or the one or more lenses <NUM> can change the optical paths of the aforementioned pattern lights <NUM>. In one embodiment, the apparatus <NUM> can also include the iris <NUM> and the iris <NUM> described above.

The processor <NUM> can control at least one component of the apparatus <NUM> connected to the processor <NUM> by driving software (e.g., instructions, programs, etc.). In addition, the processor <NUM> can perform various operations such as calculation, treatment, data generation, processing, and the like related to the present disclosure. In addition, the processor <NUM> can load data or the like from the memory <NUM> or can store data or the like in the memory <NUM>. In one embodiment, the processor <NUM> can determine a primary three-dimensional of the object based on the phase changes of the one or more reflected lights <NUM> from the one or more pattern lights <NUM>. In addition, the processor <NUM> can determine an angle of the upper surface of the object with respect to the reference plane R based on the light amount values of the one or more reflected lights <NUM> according to deflectometry. The processor <NUM> can determine a second (final) three-dimensional shape by correcting the primary three-dimensional shape using the determined angle of the upper surface.

The memory <NUM> can store various kinds of data. The data stored in the memory <NUM> is acquired, processed, or used by at least one component of the apparatus <NUM>, and can include software (e.g., instructions, programs, etc.). The memory <NUM> can include a volatile memory and/or a non-volatile memory. In the present disclosure, the instructions or programs are software stored in the memory <NUM>, and can include an operating system and an application for controlling the resources of the apparatus <NUM>, and/or middleware for providing various functions to the application so that the application can utilize the resources of the apparatus <NUM>. In one embodiment, the memory <NUM> can store instructions that cause the processor <NUM> to perform calculation when executed by the processor <NUM>.

In one embodiment, the apparatus <NUM> can further include a communication interface (not shown). The communication interface can perform wireless or wired communication between the apparatus <NUM> and a server, or between the apparatus <NUM> and another apparatus. For example, the communication interface can perform wireless communication according to a method such as eMBB (enhanced Mobile Broadband), URLLC (Ultra Reliable Low-Latency Communications), MMTC (Massive Machine Type Communications), LTE (long-term evolution), LTE-A (LTE Advance), UMTS (Universal Mobile Telecommunications System), GSM (Global System for Mobile communications), CDMA (code division multiple access), WCDMA (wideband CDMA), WiBro (Wireless Broadband), WiFi (wireless fidelity), Bluetooth, NFC (near field communication), GPS sensor <NUM> (Global Positioning System), GNSS (global navigation satellite system) or the like. For example, the communication interface can perform wired communication according to a method such as USB (Universal Serial Bus), HDMI (High Definition Multimedia Interface), RS-<NUM> (Recommended Standard-<NUM>), POTS (Plain Old Telephone Service) or the like. In one embodiment, the processor <NUM> can control the communication interface to obtain information necessary to implement the technique according to the present disclosure from a server. The information obtained from the server can be stored in the memory <NUM>. In one embodiment, the information obtained from the server can include information about a substrate or an object, information about the reference plane R, and reference information to be described later.

<FIG> are diagrams for explaining the principle of the above-described coaxial deflectometry. <FIG> is a diagram illustrating a process in which the pattern lights <NUM> are irradiated to the object according to an embodiment of the present disclosure. As described above, in each of the one or more pattern lights <NUM>, the light path of each of the one or more pattern lights <NUM> can be changed so that a beam of light corresponding to each phase in the corresponding phase range (e.g., <NUM> to <NUM>×π/<NUM>) spreads, and arrives at each point of a partial region A of the upper surface of the object. Hereinafter, one pattern light <NUM> will be described as a reference.

As described above, the pattern light source <NUM> can irradiate pattern lights <NUM> corresponding to one phase range. The optical paths <NUM>, <NUM> and <NUM> of the lights corresponding to arbitrary three phases within the aforementioned phase range are shown. Each light can be irradiated to the partial region A of the upper surface of the object through the one or more lenses <NUM>, the iris <NUM> and/or the beam splitter <NUM>. As described above, each beam of light corresponding to one phase among the phase range can be irradiated over the entire partial region A in a dispersed manner. That is, the light <NUM> corresponding to one phase can be irradiated to arrive at each point of the surface corresponding to the partial region A. The lights <NUM> and <NUM> corresponding to other phases of the pattern light <NUM> can also be irradiated to the object in the same manner. Therefore, all the lights corresponding to the respective phases in the above-described phase range can be irradiated to one point of the partial region A on the object. For example, in the illustrated embodiment, all the lights <NUM>, <NUM>, and <NUM> reach each point of the partial region A on the object. Accordingly, the lights having an average light amount of the pattern lights <NUM> corresponding to the above-described phase range can be irradiated to the entire partial region A of the object.

The reflected light <NUM> generated by reflecting the pattern light <NUM> from the partial region A can pass through the iris <NUM> and can be inputted to the image sensor <NUM>. As described above, if the upper surface of the object is tilted with respect to the reference plane R, only a portion of the reflected light <NUM> can pass through the iris <NUM>. A portion of the reflected light <NUM> passing through the iris <NUM> can correspond to a part of the phase range of the pattern light <NUM> irradiated from the pattern light source <NUM>. As a result, an average amount of the lights corresponding to the partial phase range can be captured by the image sensor <NUM>.

In the illustrated example <NUM>, the angle of the upper surface of the object with respect to the reference plane R can be <NUM> degrees. In this case, most of the light reflected from one point of the partial region A can pass through the iris <NUM> and can be captured by the image sensor <NUM>. That is, in the example <NUM>, the light corresponding to the phase section indicated by A and A' can be reflected from the partial region A, can pass through the iris <NUM>, and can be inputted to the image sensor <NUM>.

In the illustrated example <NUM>, the object can be tilted at an angle of <NUM> degrees with respect to the reference plane R. In this case, only a portion of the light reflected from one point of the partial region A can pass through the iris <NUM> and can be captured by the image sensor <NUM>. Specifically, the phase range of the pattern light <NUM> passed through the iris <NUM> can be the section indicated by the straight line <NUM>, whereas the phase range of the reflected light <NUM> passed through the iris <NUM> can be the section indicated by the straight line <NUM>. Accordingly, the light having an optical path passing through both the iris <NUM> and the iris <NUM> can be the light corresponding to the phase section indicated by A and A'. In this case, the light amount of the reflected light <NUM> obtained by the image sensor <NUM> can be an average light amount of the lights corresponding to the phase section indicated by A and A'.

In the illustrated example <NUM>, the object can be tilted at an angle of <NUM> degrees with respect to the reference plane R. In this case, most of the light reflected from one point in the partial region A can not pass through the iris <NUM>. Accordingly, the image sensor <NUM> can not be able to capture the reflected light <NUM>. The angles of the upper surface of the object in the above-described examples <NUM>, <NUM> and <NUM> can be exemplary values selected for description.

That is, the amount of light inputted to the image sensor <NUM> through both the iris <NUM> and the iris <NUM> can be changed depending on the angle of the upper surface of the object. Using the varying amount of reflected light <NUM>, the apparatus <NUM> can determine (derive) the angle of the upper surface of the object.

<FIG> is a diagram illustrating a process in which the reflected lights <NUM> pass through the iris <NUM> according to an embodiment of the present disclosure. The illustrated example can represent a case in which the upper surface of the object is tilted at a predetermined angle with respect to the reference plane R, as in the above-described example <NUM>.

Similarly, the pattern lights <NUM> having one phase range can be irradiated from the pattern light sources <NUM> and can be irradiated to the partial region A of the upper surface of the object in a dispersed manner. Since the upper surface of the object is tilted, only a portion of the reflected lights <NUM> can pass through the iris <NUM> and can be inputted to the image sensor <NUM>. Among the reflected lights of the lights <NUM>, <NUM> and <NUM> incident on the partial region A, only the reflected light whose optical path extends within the range indicated by the thick solid line can pass through the iris <NUM> and can be inputted to the image sensor <NUM>.

A portion of the reflected lights inputted to the image sensor <NUM> can be the light corresponding to a part of the above-described phase range of the pattern lights <NUM> and reflected from the partial region A on the object. As a result, the amount of reflected lights <NUM> obtained by the image sensor <NUM> can be an average amount of the lights corresponding to the part of the above-described phase range of the pattern lights <NUM>.

<FIG> is a diagram illustrating a process in which the reflected lights <NUM> pass through the iris <NUM> according to an embodiment of the present disclosure. In the illustrated embodiment, a portion A1 of the partial region A of the upper surface of the object can not be tilted with respect to the reference plane R, and the other portion A2 can be tilted with respect to the reference plane R.

The light reflected from the non-tilted portion A1 can pass through the iris <NUM> and can be inputted to the corresponding portion of the image sensor <NUM> (thick solid line), as in the above-described example <NUM>. The corresponding portion of the image sensor <NUM> can receive the average light amount of the lights irradiated from the pattern light source <NUM> and corresponding to the above-described phase range. Only a part of the light reflected from the tilted portion A2 can pass through the iris <NUM> and can be inputted to the image sensor <NUM> (thick dotted line), as in the above-described example <NUM>. The corresponding portion of the image sensor <NUM> can receive the average light amount of only the lights irradiated from the pattern light source <NUM> and corresponding to a part of the above-described phase range. A tilt value at each portion of the partial region A on the object can be obtained by using the average light amount values inputted for the respective portions (pixels) of the image sensor <NUM>.

<FIG> is a view showing the states in the iris <NUM> of the pattern lights <NUM> irradiated from the pattern light source <NUM> according to an embodiment of the present disclosure. A pattern of one pattern light <NUM> can have a period. When the phase corresponding to one period is assumed to be 2π, the pattern of the pattern light can gradually become bright during the period from <NUM> to π/<NUM>, the pattern of the pattern light can gradually become dark during the period from π/<NUM> to <NUM>×π/<NUM>, and the pattern of the pattern light can gradually become bright again during the period from <NUM>×π/<NUM> to 2π. As described above, the pattern light source <NUM> can irradiate pattern lights <NUM> having one phase range. This phase range can be appropriately set as needed. In one embodiment, the phase range can be set so as not to be one period of a pattern or a multiple of one period of the pattern. That is, the phase range can be set to a range other than the phase range corresponding to <NUM>, 2π, 4π,. This is because the lights corresponding to the average light amount of the pattern lights <NUM> are irradiated to the partial region A and, therefore, the lights corresponding to the respective phases of the pattern lights can cancel each other when the pattern lights in the phase range corresponding to one period or a multiple of one period are used. Furthermore, in one embodiment, the phase range can be set to be larger than a phase range corresponding to a half period of the pattern lights and smaller than a phase range corresponding to one period of the pattern lights. In addition, in one embodiment, the phase range can be set to be larger than the phase range corresponding to an (N+<NUM>/<NUM>) period of the pattern lights (where N is a natural number) and smaller than the phase range corresponding to an (N+<NUM>) period of the pattern lights. Such a phase range can be set when it is necessary to increase the total amount of pattern lights in order to facilitate the measurement of the reflected light.

Each of the one or more pattern lights <NUM> can be generated by phase-shifting one pattern light corresponding to the above-described phase range by an integer multiple of a preset phase interval (e.g., π/<NUM>). In one embodiment, the above-described phase interval can be set to a value greater than <NUM> and less than π. The one or more pattern lights <NUM> can be referred to as a <NUM>-th bucket, a first bucket, a second bucket and a third bucket, i.e., four buckets. The respective pattern lights <NUM> generated by the phase shift can also have the above-described phase range α. That is, for example, the respective pattern lights <NUM> can have a phase range of <NUM> to α, a phase range of π/<NUM> to π/<NUM>+α, a phase range of π to π+α, and a phase range of <NUM>×π/<NUM> to <NUM>× π/<NUM>+α. The pattern lights <NUM> for the respective buckets can appear like the illustrated patterns <NUM> in the iris <NUM>. In one embodiment, the region of the pattern light passing through the iris <NUM> can be a circular region <NUM>. Accordingly, the light corresponding to the circular region in the rectangular pattern light irradiated from the pattern light source <NUM> can be irradiated to the object. In one embodiment, the apparatus <NUM> can determine the angle of the upper surface of the object by using only one pattern light <NUM>. However, if the angle of the upper surface of the object is measured by using a plurality of pattern lights, it is possible to reduce various measurement errors such as an error caused by the material of the upper surface of the object, and the like.

The total light amount value of the pattern light <NUM> in the pattern light source <NUM> can be calculated as represented by the following equation.

In Equation <NUM>, I° can be a constant that determines the amplitude of the sinusoidal graph of the pattern of the pattern light <NUM>, and Io can be a constant that determines the offset of the sinusoidal graph of the pattern of the pattern light <NUM>. The total light amount value ILCOS can be derived by integrating the pattern light <NUM> irradiated from the pattern light source <NUM> in the phase range (α to β).

<FIG> is a diagram illustrating reference information according to an embodiment of the present disclosure. As described above, the apparatus <NUM> can determine the angle of the upper surface of the object with respect to the reference plane R based on the light amount value of each of the one or more reflected lights <NUM>. The apparatus <NUM> can derive the phase value of the reflected light <NUM> from the light amount value of the reflected light <NUM>, and can determine the angle of the upper surface of the object by comparing the derived phase value with the reference information.

In the present embodiment, the processor <NUM> can derive a phase value of each of the one or more reflected lights <NUM> from the light amount value of each of the one or more reflected lights <NUM>. When one pattern light <NUM> is reflected from the partial region A of the object and captured by the image sensor <NUM>, the light amount value In of the reflected light can be represented by the following equation.

In Equation <NUM>, A and B can correspond to Io and Io, respectively. ϕ(x, y) can be a phase value of the reflected light reflected from one point (x, y) of the partial region A. α(t) can represent the above-described phase shift amount of the pattern light <NUM>. For example, the light amount values I<NUM>, I<NUM>, I<NUM> and I<NUM> of the reflected lights generated by the plurality of pattern lights <NUM> (i.e., four buckets) phase-shifted at a phase interval of π/<NUM> and reflected from the partial region A can be represented by the following equation <NUM>. Equation <NUM> can be arranged by substituting each phase shift amount α(t) in Equation <NUM>.

As described above, the image sensor <NUM> can capture the light having an average amount of lights corresponding to a part of the phase range of the pattern lights <NUM>. In this regard, the light corresponding to the part of the phase range can vary depending on the angle of the upper surface of the object and/or the bucket of the irradiated pattern light <NUM>. That is, even for the object tilted at the same angle, the configuration of the light corresponding to the above-described part of the phase range can vary according to how much the irradiated pattern light <NUM> is phase-shifted. The amounts of the reflected lights for the respective buckets can be the aforementioned I<NUM>, I<NUM>, I<NUM> and I<NUM>.

The light amount values I<NUM>, I<NUM>, I<NUM> and I<NUM> of the respective reflected lights are values that can be measured by the image sensor <NUM>. A, B and ϕ can be derived by using the above four equations for I<NUM>, I<NUM>, I<NUM> and I<NUM>. Since there are three unknowns, at least three equations are required, and therefore, the measurement through the use of three or more different pattern lights <NUM> can have to be performed at least three times. Accordingly, by rearranging Equation <NUM>, the phase value ϕ of the reflected light can be derived by the following equation.

Through this process, the phase values of the one or more reflected lights <NUM> can be derived from the light amount values of the one or more reflected lights <NUM>, respectively. This derivation process can be performed by the processor <NUM>.

In one embodiment, the memory <NUM> of the apparatus <NUM> can further store the reference information. The reference information can indicate a relationship between the angles of the upper surface of the object with respect to the reference plane R and the phase values of the reflected lights <NUM>. The numerical values indicated by the illustrated reference information are exemplary values, and the values of the reference information can be changed according to embodiments. The relationship between the phase values indicated by the reference information and the tilt angles of the object can be stored in the memory <NUM> as a database through measurement and calculation.

As shown, the reference information can include information about the tilt angles of the object, the light amount values I<NUM>, I<NUM>, I<NUM> and I<NUM> of the reflected lights for the respective buckets measured for the respective angles, and the phase values of the reflected lights derived through the measured light amount values. For example, when the tilt angle of the object is <NUM> degree, the measured light amount values I<NUM>, I<NUM>, I<NUM> and I<NUM> of the reflected lights for the respective buckets can be <NUM>, <NUM>, <NUM> and <NUM>, respectively. The phase value derived from these light amount values can be <NUM> degrees. In one embodiment, the reference information can also include the values A and B in Equation <NUM> described above.

The processor <NUM> can determine the angle of the upper surface of the object with respect to the reference plane R based on the phase value of the reflected light <NUM> and the reference information. The processor <NUM> can determine a corrected second (final) three-dimensional shape by correcting the upper surface indicated by the primary three-dimensional shape through the use of the determined angle of the upper surface.

<FIG> is a diagram illustrating the orientations of the patterns of the pattern lights <NUM> and <NUM> according to an embodiment of the present disclosure. In one embodiment, the pattern light sources <NUM> and <NUM> can generate pattern lights <NUM> and <NUM> having patterns on a rectangular plane. When the axis corresponding to one side of the rectangular plane is assumed to be a w-axis and the axis corresponding to the other side and perpendicular to the w-axis is assumed to be a v-axis, the patterns of the pattern lights <NUM> and <NUM> can be formed in the w-axis direction or the v-axis direction. In one embodiment, each of the one or more pattern lights <NUM> and <NUM> can have a pattern in the w-axis direction or in the v-axis direction perpendicular to the w-axis. In one embodiment, the orientations of the patterns of the pattern lights <NUM> and <NUM> can be set differently for the respective buckets. In one embodiment, an error in determining the three-dimensional shape of the object can be reduced by using a plurality of patterns formed in the respective directions.

<FIG> is a diagram illustrating an inspection process using illumination lights of the apparatus <NUM> according to an embodiment of the present disclosure. Some of the components of the apparatus <NUM> described above are arbitrarily omitted. In one embodiment, the apparatus <NUM> can further perform an inspection using illumination lights. The apparatus <NUM> can determine the primary three-dimensional shape of the object by additionally reflecting the inspection result obtained through the use of the illumination lights in addition to the inspection result obtained through the use of the pattern lights described above.

In this embodiment, the apparatus <NUM> can further include one or more illumination light sources <NUM>. The illumination light sources <NUM> can belong to the illumination light irradiation part <NUM>. Each of the illumination light sources <NUM> can irradiate the illumination light <NUM> toward the object located on the reference plane R. In one embodiment, one illumination light source <NUM> can be implemented in such a form as to include a plurality of illumination light sources (e.g., LED lights) arranged to be spaced apart from each other at predetermined intervals on a circumference. The corresponding circumference can be disposed parallel to the reference plane R. In one embodiment, one illumination light source <NUM> can be implemented as one illumination light source having a columnar shape. The respective illumination light sources <NUM> can be disposed above the reference plane R or the object. The respective illumination light sources <NUM> can be arranged to irradiate the illumination lights to the object along optical axes tilted at one or more angles (e.g., <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, etc.) with respect to the reference plane R. In one embodiment, a total of four illumination light sources <NUM> can be used as shown. In the present disclosure, the illumination lights can be lights according to one or more wavelengths. In one embodiment, the illumination lights can be a red light, a green light or a blue light. The illumination light sources <NUM> can be implemented as RGB light sources, and can include a red light source, a green light source and/or a blue light source. In one embodiment, the illumination light sources <NUM> can simultaneously irradiate at least two lights, and can simultaneously irradiate red, green and blue lights to generate a white light.

The illumination lights <NUM> can be reflected from the object. The image sensor <NUM> can capture the lights (hereinafter referred to as reflected lights <NUM>) formed by the reflection of the illumination lights <NUM>. In this case, the amount of lights captured by the image sensor <NUM> can vary depending on the angles at which the illumination lights <NUM> are irradiated to the object and the angles at which the reflected lights <NUM> are reflected from the object. The shape of the object can be determined based on the light amount values changed before and after reflection.

That is, the processor <NUM> can obtain a change in the light amount of each of the one or more reflected lights <NUM> from each of the illumination lights <NUM> according to one or more wavelengths. The processor <NUM> can determine the above-described primary three-dimensional shape of the object based on the change in the light amount. In one embodiment, the processor <NUM> can determine the primary three-dimensional shape of the object by both the inspection result obtained using the pattern lights and the inspection result obtained using the illumination lights. In this case, the processor <NUM> can determine the primary three-dimensional shape of the object based on the phase change of each of the one or more reflected lights <NUM> from each of the one or more pattern lights <NUM> and the change in the light amount of each of the one or more reflected lights <NUM> from each of the illumination lights <NUM> according to one or more wavelengths. Thereafter, as described above, the processor <NUM> can determine a second (final) three-dimensional shape of the object by correcting the primary three-dimensional shape through the use of the determined angle of the upper surface. In one embodiment, if four illumination light sources <NUM> are used to sequentially irradiate a red light, a green light and a blue light, a total of <NUM> (<NUM>×<NUM>) illumination lights can be irradiated to the object. Accordingly, a total of <NUM> reflected lights can be captured by the image sensor <NUM> and can be used to determine the primary three-dimensional shape of the object.

<FIG> is a diagram illustrating a process in which the pattern light source <NUM> additionally irradiates a white light <NUM> according to an embodiment of the present disclosure. Some of the components of the apparatus <NUM> described above are arbitrarily omitted. In one embodiment, the pattern light source <NUM> of the apparatus <NUM> can further irradiate the white light <NUM>. A more accurate primary three-dimensional shape of the object can be determined using the information about the reflected light <NUM> of the white light <NUM>.

In the present embodiment, the pattern light source <NUM> can irradiate at least one monochromatic light such as a red light, a green light, a blue light and a white light. For example, the pattern light source <NUM> can irradiate a white light <NUM>. By controlling an element that generates a pattern in the pattern light source <NUM>, a white illumination light without a pattern can be irradiated from the pattern light source <NUM>. The white light <NUM> can travel along an optical path similar to that of the above-described pattern light <NUM>. The beam splitter <NUM> and the one or more lenses <NUM> can change the optical path of the white light <NUM> so that the white light <NUM> arrives at the upper surface of the object. For example, the white light <NUM> can travel to the beam splitter <NUM> via the lens <NUM>, the iris <NUM> and other optical elements. The beam splitter <NUM> can change the optical path of the white light <NUM> so that the white light <NUM> faces the upper surface of the object.

The white light <NUM> can be reflected from the upper surface of the object. Depending on the shape of the object, the light amount of the white light <NUM> can be changed before and after reflection. That is, the light amount of the white light <NUM> and the light amount of the reflected light <NUM> can be different from each other. The reflected light <NUM> can travel toward the beam splitter <NUM>, and the beam splitter <NUM> can pass the reflected light <NUM> to the image sensor <NUM>. The image sensor <NUM> can capture the reflected light <NUM>.

The processor <NUM> can determine the shape of the object based on the value of the light amount changed before and after reflection. That is, the processor <NUM> can obtain a change in the light amount of the reflected light <NUM> from the white light <NUM> and can determine the primary three-dimensional shape of the object based on the change in the light amount. In one embodiment, the processor <NUM> can determine the primary three-dimensional shape of the object by using both the inspection result obtained using the pattern light and the inspection result obtained using the white light. In this case, the processor <NUM> can determine the primary three-dimensional shape of the object based on the phase change of each of the one or more reflected lights <NUM> from each of the one or more pattern lights <NUM> and the change in the light amount of the reflected light <NUM> from the white light <NUM>. Thereafter, as described above, the processor <NUM> can determine a second (final) three-dimensional shape of the object by correcting the primary three-dimensional shape using the determined angle of the upper surface.

In one embodiment, the apparatus <NUM> can determine the secondary three-dimensional shape by performing the inspection using the coaxial deflectometry only when a preset criterion is satisfied. Otherwise, the apparatus <NUM> can determine only the primary three-dimensional shape. This is to reduce the time required for the inspection process by performing an additional inspection on the upper surface of the object only when necessary. In one embodiment, when the reflectance of the upper surface of the object is equal to or greater than a preset reference reflectance, the apparatus <NUM> can additionally perform an inspection on the object using the coaxial deflectometry. If the upper surface of the object is a mirror surface or a surface which is mirror-finished after a reflow process, it can be difficult to accurately measure the shape of the upper surface of the object only by the inspection using the illumination lights or the pattern lights. Accordingly, when it is determined that the upper surface of the object is a mirror surface (i.e., when the reflectance is equal to or greater than a preset reference reflectance), the apparatus <NUM> can additionally perform an inspection using the coaxial deflectometry.

Specifically, the processor <NUM> can obtain light amount information of the white light <NUM> from the pattern light source <NUM> and can obtain light amount information of the reflected light <NUM> from the image sensor <NUM>. The processor <NUM> can derive the reflectance of the upper surface of the object based on the change in the light amount of the reflected light <NUM> from the white light <NUM>. When the derived reflectance of the upper surface is equal to or greater than the preset reference reflectance, the processor <NUM> can control the pattern light source <NUM> to sequentially irradiate the one or more pattern lights <NUM> described above. In one embodiment, the information about the preset reference reflectance can be stored in the memory <NUM>.

In one embodiment, the apparatus <NUM> can first perform an inspection using pattern lights and then perform an inspection using deflectometry. That is, the reflected light <NUM> can be captured by first irradiating the pattern light <NUM>, and then the reflected light <NUM> can be captured by irradiating the pattern light <NUM>. In one embodiment, the inspection using the illumination lights can be performed prior to the inspection using the deflectometry.

As one embodiment, the apparatus <NUM> can determine a three-dimensional shape by imaging the reference plane R, the object, or both the reference plane R and the object using pattern lights, and then can derive the angle of the upper surface of the object using deflectometry.

That is, when the upper surface of the object is a mirror surface, it is possible to check the reference surface R using the pattern lights. However, it can be difficult to accurately restore the three-dimensional shape of the object. Therefore, the information on the upper surface of the object relative to the reference plane R and the information on the three-dimensional shape of the object can be accurately derived based on the information on the angle of the upper surface of the object derived using the deflectometry.

<FIG> is a diagram illustrating an apparatus <NUM> according to an embodiment of the present disclosure. The apparatus <NUM> is an apparatus corresponding to the above-described DFM part <NUM> and can determine the angle of the upper surface of the object located on the reference plane R. At least one component in the apparatus <NUM> can be implemented as a removable device and can be coupled to an apparatus <NUM>. If the apparatus <NUM> is not coupled, a coaxial 2D light source can be attached to the location where the apparatus <NUM> was coupled. The coaxial 2D light source can irradiate at least one monochromatic light selected from a red light, a green light, a blue light and a white light. The coaxial 2D light source can be implemented through an optical element such as an LED or the like. By irradiating a 2D monochromatic illumination light through the detachable apparatus <NUM> or the coaxial 2D light source, a more accurate 3D shape restoration can be performed according to an object.

The apparatus <NUM> can be an apparatus including the pattern light irradiation part <NUM>, the measurement part <NUM> and/or the illumination light irradiation part <NUM> described above. The apparatus <NUM> can determine the above-described primary three-dimensional shape of the object on the reference plane R. When the apparatus <NUM> is coupled to the apparatus <NUM>, there can be provided a configuration similar to that of the apparatus <NUM> described above. The combination of the apparatus <NUM> and the apparatus <NUM> can determine the above-described second (final) three-dimensional shape of the object in the same manner as performed by the apparatus <NUM>. That is, the apparatus <NUM> can determine a primary three-dimensional shape of the object by performing an inspection using pattern lights and/or an inspection using illumination lights, and the apparatus <NUM> can determine an angle of the upper surface of the object. A secondary three-dimensional shape can be determined by correcting the primary three-dimensional shape of the object using the angle of the upper surface. In some embodiments, the process of correcting the primary three-dimensional shape of the object and determining the secondary three-dimensional shape can be performed by the apparatus <NUM> or the apparatus <NUM>.

Specifically, the pattern light source <NUM> of the apparatus <NUM> can sequentially irradiate one or more pattern lights <NUM>. The pattern light source <NUM> and the patterned lights <NUM> can correspond to the pattern light source <NUM> and the pattern lights <NUM>, respectively. Similarly to the pattern lights <NUM>, the respective pattern lights <NUM> can have the same one phase range. In addition, the respective pattern lights <NUM> can be generated by phase-shifting the pattern lights having patterns in a w-axis direction or a v-axis direction by an integer multiple of a preset phase interval.

The beam splitter <NUM> and the one or more lenses <NUM> can change the optical paths of the one or more pattern lights <NUM>. The beam splitter <NUM> and the one or more lenses <NUM> can correspond to the beam splitter <NUM> and the one or more lenses <NUM>, respectively. Similarly to the beam splitter <NUM> and the one or more lenses <NUM> described above, the beam splitter <NUM> and the one or more lenses <NUM> can change the optical paths of the one or more pattern lights <NUM> so that the lights corresponding to the respective phases in the above-described phase range can reach the partial region A of the upper surface of the object in a dispersed manner. In one embodiment, other necessary optical elements (e.g., mirrors) can be additionally used to change the optical paths. In one embodiment, the pattern lights <NUM> can pass through the iris <NUM> before being inputted to the beam splitter <NUM>.

The one or more pattern lights <NUM> can be reflected from the partial region A of the object. The lights (hereinafter referred to as reflected lights <NUM>) formed by the reflection of the pattern lights <NUM> can pass through the beam splitter <NUM>, the iris <NUM>, other lenses <NUM> and the like, and can be inputted to the image sensor of the apparatus <NUM>. This image sensor can correspond to the above-described image sensor <NUM>.

The apparatus <NUM> can obtain information <NUM> about the one or more reflected lights <NUM> from the apparatus <NUM>. The apparatus <NUM> can determine an angle of the upper surface of the object with respect to the reference plane R based on the information <NUM>. The process of determining the angle of the upper surface can be the same as the process described above in respect of the apparatus <NUM>. In one embodiment, the information <NUM> can include information indicating a light amount value of each of the one or more reflected lights <NUM>.

As described above, the apparatus <NUM> is an apparatus including the pattern light irradiation part <NUM>, the measurement part <NUM> and/or the illumination light irradiation part <NUM> described above, and can perform an inspection using the pattern lights and/or the illumination lights. Specifically, the apparatus <NUM> can include one or more pattern light sources (corresponding to the pattern light sources <NUM>), an image sensor (corresponding to the image sensor <NUM>), and/or a processor (corresponding to the processor <NUM>). The pattern light sources can irradiate one or more pattern lights (corresponding to the pattern lights <NUM>) to the object. The image sensor can capture the reflected lights (corresponding to the reflected lights <NUM>) of the pattern lights (corresponding to the pattern lights <NUM>). The image sensor can also capture the reflected lights (corresponding to the reflected lights <NUM>) of the pattern lights <NUM>. The processor can determine a primary three-dimensional shape of the object based on the captured reflected lights, and can transmit information indicating the determined primary three-dimensional shape to the apparatus <NUM>.

<FIG> is a block diagram of an apparatus <NUM> according to an embodiment of the present disclosure. In one embodiment, the apparatus <NUM> can include a pattern light source <NUM>, a beam splitter <NUM>, one or more lenses <NUM>, a communication interface <NUM>, one or more processors <NUM> and/or one or more memories <NUM>. In one embodiment, at least one of these components of the apparatus <NUM> can be omitted, or other components can be added to the apparatus <NUM>. In one embodiment, additionally or alternatively, some components can be integrally implemented, or can be implemented as a singular entity or plural entities. In one embodiment, at least some of the internal and external components of the apparatus <NUM> can be connected to each other through a bus, a general-purpose input/output (GPIO) device, a serial peripheral interface (SPI), a mobile industry processor interface (MIPI), or the like to transmit and receive data and/or signals.

The pattern light source <NUM>, the beam splitter <NUM> and the one or more lenses <NUM> can correspond to the pattern light source <NUM>, the beam splitter <NUM> and the one or more lenses <NUM> described above, and can perform the same and similar operations to perform an inspection according to deflectometry.

The communication interface <NUM> can be implemented in a manner similar to the communication interface of the apparatus <NUM> described above. The communication interface <NUM> can be controlled by the processor <NUM> to communicate with the apparatus <NUM>. For example, the communication interface <NUM> can obtain information <NUM> about one or more reflected lights <NUM> from the apparatus <NUM>.

The processor <NUM> can be implemented in a manner similar to the processor <NUM> of the apparatus <NUM> described above. The processor <NUM> can control the communication interface <NUM> to obtain information <NUM> on one or more reflected lights <NUM> and can determine the angle of the upper surface of the object with respect to the reference plane R based on the information <NUM>.

In one embodiment, the processor <NUM> of the apparatus <NUM> can derive a phase value of each of the one or more reflected lights <NUM> from a light amount value of each of the one or more reflected lights <NUM>. The processor <NUM> can determine an angle of the upper surface of the object with respect to the reference plane R based on the derived phase value. This process can correspond to the process in which the above-described processor <NUM> derives the phase value from the light amount value of each of the reflected lights <NUM> and determines the angle of the upper surface from the phase value. In one embodiment, the memory <NUM> can store reference information similarly to the memory <NUM>, and the processor <NUM> can determine the angle of the upper surface based on the phase value of each of the reflected lights <NUM> and the reference information.

In one embodiment, the apparatus <NUM> can transmit information indicating the derived angle of the upper surface to the apparatus <NUM> so that the apparatus <NUM> can determine a secondary three-dimensional shape. Specifically, the processor <NUM> can control the communication interface <NUM> to transmit information indicating the derived angle of the upper surface to the apparatus <NUM>. As described above, the apparatus <NUM> can determine the primary three-dimensional shape of the object through an inspection using pattern lights and/or illumination lights. The information indicating the angle of the upper surface can be used by the apparatus <NUM> to determine a secondary three-dimensional shape by correcting the upper surface of the object indicated by the primary three-dimensional shape.

In one embodiment, the apparatus <NUM> can obtain information indicating the primary three-dimensional shape of the object from the apparatus <NUM> and can directly determine a secondary three-dimensional shape using the information. Specifically, the processor <NUM> can control the communication interface <NUM> to obtain information about the primary three-dimensional shape of the object determined by the apparatus <NUM>. The processor <NUM> can determine a secondary three-dimensional shape by correcting the upper surface of the object indicated by the primary three-dimensional shape based on the determined angle of the upper surface.

In one embodiment, the pattern light source <NUM> can further irradiate a white light, and the beam splitter <NUM> and the one or more lenses <NUM> can change the optical path of the white light so that the white light arrives at the upper surface of the object. This can correspond to irradiating the white light <NUM> by the pattern light source <NUM> of the apparatus <NUM> described above. As described above, the white light can be reflected from the upper surface of the object. The apparatus <NUM> can capture the reflected light and can determine the primary three-dimensional shape of the object based on a change in the light amount of the reflected light from the white light.

In one embodiment, the processor <NUM> can control the communication interface <NUM> to obtain information indicating the reflectance of the upper surface of the object from the apparatus <NUM>. When the reflectance of the upper surface is equal to or greater than a preset reference reflectance, the processor <NUM> can control the pattern light source <NUM> to sequentially irradiate one or more pattern lights <NUM>. This can correspond to controlling the pattern light source <NUM> based on the reference reflectance by the processor <NUM> of the apparatus <NUM> described above.

<FIG> and <FIG> are diagrams showing examples of the methods that can be performed by the apparatuses <NUM> and <NUM> according to the present disclosure. The methods according to the present disclosure can be computer-implemented methods. Although the respective steps of the method or algorithm according to the present disclosure have been described in a sequential order in the illustrated flowchart, the respective steps can be performed in an order that can be arbitrarily combined by the present disclosure, in addition to being performed sequentially. The description in accordance with this flowchart does not exclude making changes or modifications to the method or algorithm, and does not imply that any step is necessary or desirable. In one embodiment, at least some of the steps can be performed in parallel, repetitively or heuristically. In one embodiment, at least some of the steps can be omitted, or other steps can be added.

<FIG> is a diagram illustrating one example of a method <NUM> for determining a three-dimensional shape of an object, which can be performed by the apparatus <NUM> according to the present disclosure. The apparatus <NUM> according to the present disclosure can perform the method <NUM> in determining a first three-dimensional shape (e.g., the secondary three-dimensional shape) of the object located on the reference plane. The method <NUM> according to an embodiment of the present disclosure can include: step S1710 of irradiating one or more first pattern lights to an object; step S1720 of capturing one or more first reflected lights; step S1730 of sequentially irradiating one or more second pattern lights having one phase range; step S1740 of changing optical paths of the second pattern lights so that a beam of light corresponding to a respective phase of the phase range spreads, and arrives at each point of a partial region; step S1750 of capturing the one or more second reflected lights; and/or step S1760 of determining a first three-dimensional shape of the object based on the one or more first reflected lights and the one or more second reflected lights.

In step S1710, one or more first light sources (e.g., the pattern light sources <NUM>) of the apparatus <NUM> can irradiate one or more first pattern lights (e.g., the pattern lights <NUM>) to the object. In step S1720, the image sensor <NUM> can capture one or more first reflected lights (e.g., the reflected lights <NUM>) generated by reflecting the one or more first pattern lights (e.g., the pattern lights <NUM>) from the object.

In step S1730, the second light source (e.g., the pattern light source <NUM>) can sequentially irradiate one or more second pattern lights (e.g., the pattern lights <NUM>) having one phase range. In step S1740, the beam splitter <NUM> and the one or more lenses <NUM> can change optical paths of the one or more second pattern lights (e.g., the pattern lights <NUM>) so that a beam of light corresponding to a respective phase of the phase range spreads, and arrives at each point of a partial region A of the upper surface of the object. In step S1750, the image sensor <NUM> can capture one or more second reflected lights (e.g., the reflected lights <NUM>) generated by reflecting the one or more second pattern lights (e.g., the pattern lights <NUM>) from the partial region A.

In step S1760, the processor <NUM> can determine a first three-dimensional shape (e.g., a secondary three-dimensional shape) of the object based on the one or more first reflected lights (e.g., the reflected lights <NUM>) and the one or more second reflected lights (e.g., the reflected lights <NUM>).

In one embodiment, step S1760 of determining the first three-dimensional shape (e.g., the secondary three-dimensional shape) (S1760) can include determining, by the processor <NUM>, a second three-dimensional shape (e.g., the primary three-dimensional shape) of the object based on each of the phase changes of the one or more first reflected lights (e.g., the reflected lights <NUM>) from the one or more first pattern lights (e.g., the pattern lights <NUM>). In addition, step S <NUM> can include deriving, by the processor <NUM>, a phase value of each of the one or more second reflected lights (e.g., the reflected lights <NUM>) from the each light amount value of the one or more second reflected lights (e.g., the reflected lights <NUM>). Moreover, step S1760 can include determining, by the processor <NUM>, a first three-dimensional shape (e.g., the secondary three-dimensional shape) of the object by correcting the upper surface of the object indicated by the second three-dimensional shape (e.g., the primary three-dimensional shape) based on the angle of the upper surface.

In one embodiment, determining the angle of the upper surface can include determining, by the processor <NUM>, the angle of the upper surface with respect to the reference plane R based on the phase value and the reference information.

In one embodiment, the apparatus <NUM> can further include one or more third light sources (e.g., illumination light sources <NUM>). In addition, determining the second three-dimensional shape (e.g., the primary three-dimensional shape) of the object can include determining, by the processor <NUM>, a second three-dimensional shape (e.g., a primary three-dimensional shape) of the object based on each of changes in the phases of the one or more first reflected lights (e.g., the reflected lights <NUM>) from the one or more first pattern lights (e.g., the pattern lights <NUM>) and each of changes in the light amounts of the one or more third reflected lights (e.g., the reflected lights <NUM>) from the illumination lights <NUM> according to one or more wavelengths.

In one embodiment, the method <NUM> can further include: irradiating a white light <NUM> by a second light source (e.g., the pattern light source <NUM>); changing an optical path of the white light <NUM> by the beam splitter <NUM> and the one or more lenses <NUM> so that the white light <NUM> arrives at the upper surface of the object; and/or capturing, by the image sensor <NUM>, a fourth reflected light (e.g., the reflected light <NUM>) generated by reflecting the white light <NUM> from the upper surface of the object.

In one embodiment, determining the second three-dimensional shape (e.g., the primary three-dimensional shape) can include determining, by the processor <NUM>, the second three-dimensional shape (e.g., the primary three-dimensional shape) of the object based on each of changes in the phases of the one or more first reflected lights (e.g., the reflected lights <NUM>) from the one or more first pattern lights (e.g., the pattern lights <NUM>) and a change in the light amount of the fourth reflected light (e.g., the reflected light <NUM>) from the white light <NUM>.

In one embodiment, the method <NUM> can further include: deriving, by the processor <NUM>, a reflectance of the upper surface of the object based on a change in the light amount of the fourth reflected light (e.g., the reflected light <NUM>) from the white light <NUM>; and/or controlling a second light source (e.g., the pattern light source <NUM>) to sequentially irradiate one or more second pattern lights (e.g., the pattern lights <NUM>) when the reflectance of the upper surface of the object is equal to or greater than a preset reference reflectance.

<FIG> is a diagram illustrating an example of a method <NUM> for determining an angle of an upper surface of an object, which can be performed by the apparatus <NUM> according to the present disclosure. The method <NUM> according to an embodiment of the present disclosure can include: step S1810 of sequentially irradiating one or more first pattern lights; step SI820 of changing optical paths of the first pattern lights so that a beam of light corresponding to a respective phase of a phase range spreads, and arrives at each point of a partial region; step S1830 of obtaining first information about one or more first reflected lights from a first apparatus; and/or step S1840 of determining an angle of an upper surface of an object with respect to a reference plane based on the first information.

In step S1810, the first light source (e.g., the pattern light source <NUM>) can sequentially irradiate one or more first pattern lights (e.g., the pattern lights <NUM>) having one phase range. In step S1820, a beam splitter (e.g., the beam splitter <NUM>) and one or more lenses (e.g., the lens <NUM>) can change optical paths of the one or more first pattern lights (e.g., the pattern lights <NUM>) so that a beam of light corresponding to a respective phase in the phase range spreads, and arrives at each point of a partial region A of the upper surface.

In step S1830, a first processor (e.g., the processor <NUM>) can obtain, from a first apparatus (e.g., the apparatus <NUM>), first information (e.g., the information <NUM>) about one or more first reflected lights (e.g., the reflected lights <NUM>) generated by reflecting the one or more first pattern lights (e.g., the pattern lights <NUM>) from the partial region A.

In step S1840, the first processor (e.g., the processor <NUM>) can determine an angle of the upper surface with respect to the reference plane R based on the first information (e.g., the information <NUM>).

In one embodiment, determining the angle of the upper surface can include deriving, by the first processor (e.g., the processor <NUM>), a phase value of each of the one or more first reflected lights (e.g., the reflected lights <NUM>) from the each light amount value of the one or more first reflected lights (e.g., the reflected lights <NUM>); and/or determining, by the first processor (e.g., the processor <NUM>), the angle of the upper surface with respect to the reference plane R based on the derived phase value.

In one embodiment, the method <NUM> can further include: transmitting, by the first processor (e.g., the processor <NUM>), second information indicating the angle of the upper surface to the first apparatus (e.g., the apparatus <NUM>). The second information can be used by the first apparatus (e.g., the apparatus <NUM>) to determine a second three-dimensional shape (e.g., the primary three-dimensional shape) of the object by correcting the upper surface of the obj ect indicated by the first three-dimensional shape (e.g., the primary three-dimensional shape).

In one embodiment, the method <NUM> can further include: obtaining, by the first processor (e.g., the processor <NUM>), third information indicating a first three-dimensional shape (e.g., the primary three-dimensional shape) of the object from the first apparatus (e.g., the apparatus <NUM>); and/or determining, by the first processor (e.g., the processor <NUM>), a second three-dimensional shape (e.g., the secondary three-dimensional shape) of the object by correcting the upper surface of the object indicated by the first three-dimensional shape (e.g., the primary three-dimensional shape) based on the angle of the upper surface.

In one embodiment, the method <NUM> can further include: irradiating, by a first light source (e.g., the pattern light source <NUM>), a white light; and/or changing, by a beam splitter (e.g., the beam splitter <NUM>) and one or more lenses (e.g., the lens <NUM>), an optical path of the white light so that the white light arrives at the upper surface of the object.

In one embodiment, the method <NUM> can further include: obtaining, by the first processor (e.g., the processor <NUM>), fourth information indicating a reflectance of the upper surface from the first apparatus (e.g., the apparatus <NUM>) by controlling a communication interface <NUM>; and/or controlling a first light source (e.g., the pattern light source <NUM>) to sequentially irradiate one or more first pattern lights (e.g., the pattern lights <NUM>) when the reflectance of the upper surface is equal to or greater than a preset reference reflectance.

According to various embodiments of the present disclosure, the determination of the three-dimensional shape of the object can be improved by efficiently measuring the tilt of the upper surface of the object using the light amount of the reflected light reflected from the object (e.g., a die). Whether the entire substrate mounting process is properly performed can be inspected through the three-dimensional shape of the object.

According to various embodiments of the present disclosure, the tilt of the object is not inspected based on the image formation position of the reflected light from the object. Therefore, it is possible to facilitate the downsizing of the inspection apparatus.

According to various embodiments of the present disclosure, the tilt of the object is not inspected based on the diffraction pattern formed in the air above the object. Therefore, it is possible to perform a noise-robust inspection.

Various embodiments of the present disclosure can be implemented as software recorded on a machine-readable recording medium. The software can be software for implementing the various embodiments of the present disclosure described above. The software can be inferred from various embodiments of the present disclosure by programmers in the art to which the present disclosure belongs. For example, the software can be instructions (e.g., code or code segments) or programs that can be read by a device. The device is a device capable of operating according to instructions called from a recording medium, and can be, for example, a computer. In one embodiment, the device can be the apparatuses <NUM> and <NUM> according to embodiments of the present disclosure. In one embodiment, the processor of the device can execute the called instructions so that components of the device can perform a function corresponding to the instructions. In one embodiment, the processor can be one or more processors according to the embodiments of the present disclosure. The recording medium can refer to any type of device-readable recording medium in which data is stored. The recording medium can include, for example, a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like. In one embodiment, the recording medium can be one or more memories. In one embodiment, the recording medium can be implemented in a distributed form in computer systems connected by a network. The software can be distributed, stored and executed in a computer system or the like. The recording medium can be a non-transitory recording medium. The non-transitory recording medium refers to a tangible medium irrespective of whether data is stored semi-permanently or temporarily, and does not include a signal propagating in a transitory manner.

Claim 1:
An apparatus for determining a first three-dimensional shape of an object located on a reference plane, comprising:
one or more first light sources (<NUM>) configured to irradiate one or more first pattern lights to the object;
a second light source (<NUM>) configured to sequentially irradiate one or more second pattern lights having one phase range;
a beam splitter (<NUM>) and one or more lenses (<NUM>) configured to change optical paths of the one or more second pattern lights so that a beam of light corresponding to the respective phase of the phase range spreads, and arrives at each point of a partial region of an upper surface of the object;
an image sensor (<NUM>) configured to capture one or more first reflected lights generated by reflecting the one or more first pattern lights from the object and one or more second reflected lights generated by reflecting the one or more second pattern lights from the partial region, wherein the one or more first reflected lights and the one or more second reflected lights pass through the beam splitter (<NUM>) to reach the image sensor (<NUM>); and
a processor (<NUM>) that is electrically connected to the one or more first light sources (<NUM>), the second light source (<NUM>) and the image sensor (<NUM>), and that is configured to determine the first three-dimensional shape of the object based on the one or more first reflected lights and the one or more second reflected lights,
characterized in that $
each of the one or more second pattern lights is a pattern light generated by phase-shifting a pattern light having a pattern in a first direction or a second direction perpendicular to the first direction by an integer multiple of a preset phase interval,
wherein the processor (<NUM>) is further configured to determine an angle of the upper surface of the object with respect to the reference plane based on each light amount value of the one or more second reflected lights, and $
determine the first three-dimensional shape by correcting a previously determined second three-dimensional shape using the determined angle of the upper surface.