Curved wafer stage

Abstract

To provide an apparatus for transferring a semiconductor die from an arrangement of semiconductor dies to a target.SOLUTION: In an apparatus 1, a wafer chuck includes a rotationally mounted curved shell 122 on which the arrangement of semiconductor dies 2A are arranged. A wafer stage further includes a first motor for rotating the curved shell around a rotational axis. The curved configuration allows for an improved throughput of the wafer stage. A film frame carrier 3 to be used with the wafer stage includes a ring-shaped body with an asymmetric bending stiffness. The asymmetric bending stiffness allows the ring-shaped body to be bent such that the mounting surface of the ring-shaped body changes from a first shape to a second more concave shape, and prevents or limits the ring-shaped body to be bent such that the shape of the mounting surface becomes more convex than the first shape.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] Aspects of the present disclosure relate to an apparatus for transferring semiconductor dies from an array of semiconductor dies to a target. Further aspects of the present disclosure relate to a wafer stage for use in such an apparatus. [Background technology]

[0002] Apparatus for transferring semiconductor dies from a diced semiconductor wafer to a target is known in the art. For example, U.S. Patent Application Publication No. 2009 / 0129998 discloses an apparatus including a wafer stage having a wafer chuck on which the diced semiconductor wafer can be placed and a target stage having a target chuck on which the target can be placed. Both the wafer stage and the target stage include one or more motors for changing the relative positions between the diced semiconductor wafer on the wafer chuck and the target on the target chuck. The apparatus further includes a release unit in the form of a needle for releasing the semiconductor die from the diced semiconductor wafer. The release unit, wafer stage, and target stage are controlled using a controller.

[0003] In known systems, a diced semiconductor wafer is brought close to a target, which may be, for example, a printed circuit board. When a semiconductor die on the semiconductor wafer is aligned with its intended location on the target, a needle is aligned with the semiconductor die. The needle then presses the semiconductor die away from the semiconductor wafer and onto the target.

[0004] The above die transfer is referred to as direct die transfer, more specifically, the die is transferred from the diced semiconductor wafer onto the target without being rested or supported between the steps of releasing the die and placing the die on the target.

[0005] An important figure of merit for the types of machines mentioned above is the number of semiconductor dies that can be transferred per unit time, which is often limited by the step of positioning the semiconductor wafer relative to the target. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent Application Publication No. 2017-140959 Summary of the Invention

[0007] One aspect of the present disclosure relates to providing an apparatus for transferring semiconductor dies from an array of semiconductor dies to a target using a different method in which the array of semiconductor dies is positioned relative to the target. According to one aspect of the present disclosure, the different method of positioning can enable a reduction in the time required to transfer the semiconductor dies onto the target to be achieved.

[0008] According to one aspect of the present disclosure, the wafer chuck of the apparatus includes a curved shell on which an array of semiconductor dies is disposed and rotatably mounted, and the wafer stage further includes a first motor for rotating the curved shell about an axis of rotation.

[0009] The apparatus disclosed in U.S. Patent No. 6,277,623 includes a linear XY stage that uses linear motors configured to displace a semiconductor wafer in the x and y directions. The acceleration obtainable by such wafer stages is limited by the motor topology and power consumption. To improve the performance of these wafer stages, e.g., to increase the positioning speed, a moving coil topology is required. However, this brings with it the associated problem of cooling the moving coil to improve power consumption capabilities.

[0010] According to one aspect of the present disclosure, the acceleration limitations of linear motors are mitigated using a rotatably mounted curved shell in which an array of semiconductor dies may be disposed, the shell being part of a wafer stage and actuated using a first motor configured to rotate the curved shell about an axis of rotation.

[0011] Motors for providing rotary motion provide higher force or torque per unit of heat dissipated and / or higher force / torque per unit of power and per unit weight of magnets used, which means that for a given mass and power level, higher accelerations can be achieved than with a linear magnet motor.

[0012] The apparatus is preferably configured to directly transfer a semiconductor die from the array of semiconductor dies onto the target. The release unit may be configured to release the semiconductor die from the array of semiconductor dies and drop it onto the target. In this case, the release unit is not engaged with the semiconductor die the moment the semiconductor die reaches a desired position on the target. In other embodiments, an auxiliary unit may be used to guide the released semiconductor die to the target. For example, a jet of compressed air may be used to push the released semiconductor die toward the target. In such a case, the semiconductor die may be displaced toward the target against the Earth's gravity.

[0013] The wafer chuck can be configured to support a carrier that carries an array of semiconductor dies. For example, the carrier can be a tape, film, or foil. Additionally, the carrier can be part of a film frame carrier.

[0014] The array of semiconductor dies may be comprised of a diced semiconductor wafer or a structured semiconductor wafer. A structured semiconductor wafer may include multiple semiconductor dies arranged in a pattern that differs from the pattern in which the dies were arranged before dicing the semiconductor wafer from which they originated. Alternatively, a structured semiconductor wafer may include multiple semiconductor dies from different semiconductor wafers. In such cases, the semiconductor dies are individually placed on a carrier such as a film, foil, or tape.

[0015] The rotation axis preferably extends at least approximately parallel to the target chuck. In this way, the position of the release unit can be kept constant when the curved shell is rotated to align the next semiconductor die with the release unit, provided that the next semiconductor die needs to be released in the same position as the previous semiconductor die. Note that the target is typically moved when the next semiconductor die is released. Furthermore, the rotation axis may coincide with the longitudinal axis of symmetry of the curved shell.

[0016] The wafer stage may further include a second motor for translating the curved shell back and forth, preferably along a direction parallel and / or coincident with the axis of rotation. The wafer stage may further include another second motor for translating the curved shell in a direction perpendicular to the direction imparted by the second motor. For example, the second motor and the another second motor may cooperate to translate the curved shell in an XY plane similar to the plane in which the target table of the target stage is translated.

[0017] The wafer stage may further include an auxiliary second motor for translating the curved shell back and forth along a direction perpendicular to the axis of rotation, preferably perpendicular to the target chuck. For example, the auxiliary second motor may be configured to vertically displace the curved shell to ensure or maintain a specific vertical spacing between the released semiconductor die and the target. If such spacing is too small, the target and semiconductor die may come into contact during movement of the target and / or the curved shell. If the spacing is too large, variations in the position and / or orientation of the semiconductor die on the target may become unacceptable.

[0018] Additionally or alternatively, the apparatus further includes a fixed frame and a first carriage, and the second motor and / or the auxiliary second motor are configured to translate the first carriage relative to the fixed frame, and the first motor is configured to rotate the curved shell relative to the first carriage. In this case, the rotation and translation of the curved shell are stacked. In other embodiments, the second motor and / or the auxiliary motor are configured to translate the curved shell relative to the fixed frame, and the first motor is configured to rotate the curved shell relative to the fixed frame. In this case, the rotation and translation are performed independently of each other relative to the fixed frame.

[0019] The curved shell may be at least partially translucent to light having a first wavelength. In this case, the release unit may include a light source, such as a laser, for outputting a beam of light having the wavelength. The array of semiconductor dies may be attached to the tape, foil, or film using a light-absorbing agent, such as a photosensitive adhesive. The light-absorbing agent may be configured to at least locally release its attachment to the array of semiconductor dies when irradiated with light having the wavelength. For example, the light-absorbing agent may be configured to at least locally release its attachment by photoablation and / or by the light-absorbing agent undergoing a chemical reaction as a result of absorbing light. The light source may be configured to illuminate a given semiconductor die of the array of semiconductor dies separately from semiconductor dies adjacent to the given semiconductor die. For example, the light source may be configured to illuminate one semiconductor die of the array of semiconductor dies at a time. However, the release unit may also include a beam splitter configured to receive the beam of light from the light source and split the received beam into multiple additional beams, each configured to illuminate a respective given semiconductor die.

[0020] The light source may be configured to emit light toward the curved shell, preferably approximately perpendicular. The light source is preferably disposed inside and / or above or below the curved shell. Alternatively, the light source may be configured to emit light in a direction approximately parallel to the rotation axis. In this case, the release unit may further include a light-guiding unit. The light source may be configured to emit light toward the light-guiding unit, preferably approximately parallel to the rotation axis, and the light-guiding unit may be configured to guide light from the light source toward the curved shell, preferably approximately perpendicular. In this case, the light source may be disposed outside the curved shell and / or next to the curved shell.

[0021] The light-guiding unit may include one or more mirrors and / or one or more prisms. Furthermore, the light-guiding unit may include one or more actuators, preferably controllable by a controller, configured to change the orientation of the one or more mirrors and / or one or more prisms relative to the incident light from the light source in order to direct the light from the light source into the curved shell at different angles. In this way, the location where the light from the light source strikes the curved shell can be changed, even if the curved shell does not change its position along its longitudinal axis of symmetry. The light-guiding unit may be, for example, MEMS-based. For example, MEMS-based mirrors are relatively lightweight, allowing for fast switching between adjacent dies being transferred.

[0022] Instead of using light, the release unit may alternatively include an engagement element, such as a needle, and an actuator for moving the engagement element into engagement and disengagement with the array of semiconductor dies to release the semiconductor die from the array of semiconductor dies. The engagement element is typically located inside and / or above or below the curved shell.

[0023] As described above, to completely exhaust the semiconductor die array, it is necessary to change the position at which the release unit releases the semiconductor dies from the semiconductor die array. For this purpose, the release unit may include a second carriage equipped with a light source or a combination of actuators and needles, and a third motor for moving the second carriage relative to the curved shell. In this case, the movement of the second carriage and the movement of the curved shell are stacked. Furthermore, typically, the third motor only displaces the second carriage relative to the curved shell along and / or parallel to the longitudinal axis of symmetry of the curved shell. Alternatively, the release unit may include a second carriage equipped with a light source or a combination of actuators and needles, and a third motor for moving the second carriage relative to the fixed frame. Therefore, in this case, the movement of the second carriage and the movement of the curved shell are independent of each other. In both cases, the second carriage may be configured to translate inside and / or above or below the curved shell. Furthermore, when the release unit includes the above-mentioned light source and light guide unit, the light source may be fixed to the fixed frame, and the light guide unit may be attached to the second carriage.

[0024] The target stage may further include a fourth motor and / or a fifth motor for translating the target chuck, preferably in a plane parallel to the rotation axis, and / or an auxiliary fourth motor for translating the target chuck back and forth in a direction perpendicular to the rotation axis, preferably perpendicular to the target chuck. The fourth motor and / or the fifth motor may be arranged to translate the target chuck relative to the fixed frame. Alternatively, movements in two mutually orthogonal directions may be stacked. For example, the fourth motor may displace the third carriage relative to the fixed frame, and the fifth motor may displace the target chuck relative to the third carriage.

[0025] The curved shell may be provided with a coupling unit for enabling the array of semiconductor dies to be coupled to the curved shell. For example, the curved shell may be provided with a plurality of openings. In this case, the apparatus may further include a vacuum unit for generating a suction force applied to the array of semiconductor dies through the plurality of openings. Alternatively or additionally, the curved shell may be provided with a mechanical coupling unit for mechanically coupling the array of semiconductor dies. The array of semiconductor dies is preferably carried by a film frame carrier. In this case, the mechanical coupling unit preferably includes a clamp unit for clamping the film frame carrier onto the curved shell.

[0026] The curved shell can be a cylindrical shell, such as a drum, or a partially cylindrical shell. For example, the shell can be a 1 / n cylindrical shell. When n=2, the shell corresponds to a semi-cylindrical shell. When n=1, the shell corresponds to a cylindrical shell, such as a drum. However, aspects of the present disclosure equally relate to curved shells whose cross-section perpendicular to the axis of rotation and / or longitudinal axis of symmetry is not circular or partially circular. In these cases, it is preferable to translate the curved shell and the target relative to one another to maintain a substantially constant spacing between the target and the subsequently released semiconductor die.

[0027] Having a curved shell in which the die array is disposed provides the possibility of mounting an inspection system near the location where the semiconductor die are released. For example, the apparatus may include a first inspection system configured to inspect semiconductor dies from the array of semiconductor dies before placing them on the target. The first inspection system may be configured to determine the positions and / or orientations of the semiconductor dies in the array of semiconductor dies, and the controller may be configured to control the wafer stage, the target stage, and / or the release unit according to the determined positions and / or orientations. When coupling the array of semiconductor dies to the curved shell, the positions and / or orientations of the semiconductor dies may be changed, for example, due to wrinkles or other distortions of the carrier on which the semiconductor dies are disposed. The first inspection system may record the positions and / or orientations of the semiconductor dies, preferably relative to the curved shell and / or relative to an ideal position and / or orientation of the semiconductor dies. This recorded position can then be used to perform corrections before releasing the dies. For example, if the dies are shifted along a rotation axis relative to their ideal position, the curved shell may be translated slightly in the other direction before the release unit releases the semiconductor dies. In this case, there is no need to change the position of the release unit. In other embodiments, the target is displaced along with the release unit while keeping the curved shell in the same position, and in still further embodiments, the release unit, target and curved shell are all moved.

[0028] The first inspection system may additionally or alternatively be configured to determine whether a semiconductor die of the array of semiconductor dies is damaged. In this case, the controller may be configured to control the wafer stage, the target stage, and / or the release unit to prevent the semiconductor die from being placed on the target if the semiconductor die is determined to be damaged. In this manner, the damaged semiconductor die may be skipped.

[0029] The apparatus may further include a second inspection system arranged to determine whether the semiconductor die has been released from the array of semiconductor dies. The controller may then be configured to control the wafer stage, the target stage, and / or the release unit to release the semiconductor die if it is determined that the semiconductor die has not been released. In this manner, the release unit may attempt to release the semiconductor die again.

[0030] Alternatively or additionally, the apparatus may further include a third inspection system arranged to check whether the semiconductor die is properly placed on the target. In this case, the controller may be configured to store the position of the semiconductor die and / or its intended position on the target. At a later stage, the semiconductor die may be removed from the target in this position.

[0031] The first, second, and / or third inspection systems may include a camera, and the same camera is preferably used for two or more of the first, second, and third inspection systems. The camera of the first, second, and / or third inspection systems may be movably mounted relative to a fixed frame. For example, the camera may be configured to move along the longitudinal axis of symmetry of the curved shell.

[0032] The release unit may be configured to release the semiconductor die arranged in the release position relative to the fixed frame from the array of semiconductor dies. The array of semiconductor dies may include a plurality of semiconductor dies arranged in a matrix of rows and columns, the rows extending at least approximately parallel to the axis of rotation.

[0033] The target may include a column or row of adjacently arranged placement positions where each semiconductor die from the array of semiconductor dies is placed, the column or row of adjacently arranged placement positions extending at least approximately perpendicular or parallel to the rotation axis, respectively. An example of such a target may be a carrier tape including a plurality of cavities in which the semiconductor dies are placed. In this case, the controller may be configured to control the wafer stage to intermittently or continuously rotate the curved shell to place the semiconductor dies in the same column of the array of semiconductor dies on each placement position of the target, and to translate the curved shell to shift to an adjacent column of semiconductor dies in the array of semiconductor dies after the column of the array of semiconductor dies to be placed is exhausted. Furthermore, the controller may be configured to maintain the release position relative to the fixed frame during the translation of the curved shell and shift to an adjacent column of semiconductor dies in the array of semiconductor dies. For example, the release unit may be fixed relative to the fixed frame while the curved shell rotates and translates.

[0034] Additionally, the target may include a plurality of adjacently arranged rows of placement positions on which semiconductor dies from the array of semiconductor dies are placed. In this case, the controller may be configured to control the wafer stage and / or the target stage to cause a relative translational movement between the target and the curved shell after semiconductor dies from the array of semiconductor dies have been placed in all placement positions in the same row on the target. In this case, the controller may be configured to maintain a release position relative to the fixed frame during the relative translational movement between the target and the curved shell. Alternatively, the controller may be configured to maintain the position of the row on the target in a direction parallel to the rotation axis relative to the fixed frame, and to change the release position and shift to the next row on the target after semiconductor dies from the array of semiconductor dies have been placed in all placement positions in the same row on the target.

[0035] The apparatus may include a plurality of the release units described above for substantially simultaneously releasing semiconductor dies from an array of semiconductor dies in different row placement locations on the target, each release unit being independently controllable by the controller.

[0036] According to a further aspect of the present disclosure, there is provided a wafer stage having a wafer chuck having an array of semiconductor dies disposed thereon, the wafer chuck including a curved shell having the array of semiconductor dies disposed thereon and rotatably mounted thereon, the wafer stage further including a first motor for rotating the curved shell about an axis of rotation, the wafer stage further being configured as the wafer stage of the apparatus described above.

[0037] According to a further aspect of the present disclosure, there is provided a film frame carrier, also referred to as a tape frame, configured to be attached to the curved shell of the apparatus described above.

[0038] The film frame carrier includes an annular body having a mounting surface configured to be coupled to a support surface of a flexible carrier film, foil, or tape on which the array of semiconductor dies is disposed, The annular body may have, but is not limited to, a circular, rectangular, or square shape.

[0039] The annular body has asymmetric bending stiffness that allows the annular body to bend such that the mounting surface of the annular body is changed from a first shape to a second, more concave shape, while preventing or limiting bending of the annular body such that the shape of the mounting surface becomes more convex than the first shape. The asymmetric bending stiffness allows the annular body to be gripped on both sides to move the annular body without losing stiffness. This allows for automated transfer of film frame carriers onto a curved shell and / or allows for dicing of wafers while still attached to a flexible carrier film that is then bonded to the annular body. The first shape may correspond to the most convex shape that the mounting surface can achieve.

[0040] The asymmetric bending stiffness can be configured to allow the annulus to bend to reversibly change the mounting surface of the annulus from a first shape to a second, more concave shape. Alternatively, the bending can result in plastic deformation of the annulus.

[0041] The first shape may correspond to an essentially flat shape. Additionally or alternatively, the curvature of the mounting surface when having the first shape is 0.2 mm. -1 and the curvature of the mounting surface when having the second shape is less than 3.3 mm. -1 It can be super.

[0042] The annular body may include and / or be at least partially formed by a leaf spring. Furthermore, a surface of the leaf spring may form or be part of the mounting surface. The annular body may further include a limiting means connected to the leaf spring for preventing or limiting bending of the annular body such that the shape of the mounting surface becomes more convex than the first shape. The limiting means may be coupled to the leaf spring at a surface directed away from the mounting surface. Additionally or alternatively, the limiting means may include a plurality of segments connected to the leaf spring, such that when the mounting surface has the first shape, adjacent segments abut against each other to prevent or limit bending of the leaf spring such that the shape of the mounting surface becomes more convex than the first shape, and the segments are configured to move away from the abutment when the leaf spring is bent, causing the mounting surface to transform from the first shape to a more concave shape.

[0043] Alternatively, the annular body may include a plurality of segments, the segments being hinged to one another. For example, each pair of adjacently disposed segments of the plurality of segments may be configured to pivot relative to one another about a respective axis of rotation. Furthermore, the axes of rotation representing the pivotal movement of all pairs of adjacently disposed segments of the plurality of segments may be parallel to one another.

[0044] For at least one pair of adjacently arranged segments among the plurality of segments, one segment may include a first coupling structure disposed at a first end of the first segment, and the other segment may include a second coupling structure disposed at a second end of the other segment. The first coupling structure and the second coupling structure may be hinged to each other to enable the first segment and the other segment to pivot relative to each other about an axis of rotation. The first segment may include the second coupling structure disposed on a second side of the first segment opposite the first side of the first segment. The other segment may include the first coupling structure disposed on a first side of the other segment opposite the second side of the other segment.

[0045] The first coupling structure may include a first opening, and the second coupling structure may include a protruding element rotatably received in the first opening and defining an axis of rotation, The protruding element may be a pin, a rod, or a shaft.

[0046] Alternatively, the first coupling structure may include a first opening, the second coupling structure includes a second opening, and the film frame carrier includes a shaft rotatably received in at least one of the first and second openings and defining an axis of rotation.

[0047] For each pair of adjacently arranged segments of the plurality of segments, one segment may include a first abutment surface and the other segment may include a second abutment surface, and when the mounting surface has a first shape, the first abutment surface and the second abutment surface may be shaped and positioned relative to the rotation axis to abut against each other to prevent the mounting surface from bending the annulus more convex than the first shape.

[0048] The segments may be made of a material selected from the group consisting of steel, aluminum, titanium, polymer, or combinations thereof.

[0049] According to a further aspect of the present disclosure, there is provided an assembly comprising a film frame carrier as defined above and a carrier film, foil or tape having a support surface on which an array of dies is disposed, the carrier film, foil or tape having the array of dies being bonded at its support surface to a mounting surface of the film frame carrier.

[0050] The carrier film, foil, or tape may be provided with an adhesive layer that adheres the array of semiconductor dies to the support surface and bonds the carrier film, foil, or tape to the mounting surface of the film frame carrier. The adhesive layer may include a light-absorbing agent, such as a photosensitive adhesive, that is configured to at least locally release its attachment to the array of semiconductor dies when irradiated with light having the wavelength. The light-absorbing agent may be configured to at least locally release its attachment by photoablation and / or by the light-absorbing agent undergoing a chemical reaction as a result of absorbing the light. More specifically, the energy absorbed by the light-absorbing layer may be used not only to release the semiconductor dies, but also to provide some kind of motive force that drives the semiconductor dies toward the target.

[0051] The array of semiconductor dies is constructed from a diced or structured semiconductor wafer. [Brief explanation of the drawings]

[0052] To enable the features of the present disclosure to be understood in detail, a more particular description will be made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only typical embodiments and should not be considered as limiting the scope of the present disclosure. The drawings are for ease of understanding the present disclosure and, therefore, are not necessarily drawn to scale. Advantages of the claimed subject matter will be apparent to those skilled in the art upon reading this description in conjunction with the accompanying drawings, in which like reference numerals are used to indicate like elements. [Figure 1A]1 illustrates a portion of one embodiment of an apparatus for placing semiconductor dies on a target from an array of semiconductor dies, according to one aspect of the present disclosure. [Figure 1B] FIG. [Figure 2] FIG. 1B is a schematic cross-sectional view corresponding to the device of FIG. 1A. [Figure 3A] 10A-10C illustrate further embodiments and diagrams of an apparatus for placing semiconductor dies on a target from an array of semiconductor dies according to an aspect of the present disclosure. [Figure 3B] 10A-10C illustrate further embodiments and diagrams of an apparatus for placing semiconductor dies on a target from an array of semiconductor dies according to an aspect of the present disclosure. [Figure 3C] 10A-10C illustrate further embodiments and diagrams of an apparatus for placing semiconductor dies on a target from an array of semiconductor dies according to an aspect of the present disclosure. [Figure 3D] 10A-10C illustrate further embodiments and diagrams of an apparatus for placing semiconductor dies on a target from an array of semiconductor dies according to an aspect of the present disclosure. [Figure 3E] 10A-10C illustrate further embodiments and diagrams of an apparatus for placing semiconductor dies on a target from an array of semiconductor dies according to an aspect of the present disclosure. [Figure 4] 1 illustrates a first embodiment of a flexible film frame carrier according to one aspect of the present invention. [Figure 5] 1 illustrates a toroid for a flexible film frame carrier according to one aspect of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0053] In the following, an embodiment will be shown in which semiconductor dies from a diced semiconductor wafer are placed on the target. However, the present invention is not limited to placing semiconductor dies from a diced semiconductor wafer. In general, semiconductor dies can be placed from an array of dies, including, but not limited to, diced semiconductor wafers and structured wafers.

[0054] 1A shows a portion of one embodiment of an apparatus 1 for depositing semiconductor dies 2A from a diced semiconductor wafer 2 onto a target 113, according to one aspect of the present disclosure, where the diced semiconductor wafer 2 is disposed on a carrier film 4 attached to a flexible film frame carrier FFFC 3. Typically, wafers are supplied to the apparatus 1 from a cassette 5, tray, or the like. This may be performed in an automated manner.

[0055] The FFFC 3, the cross section of which is shown in Figure 5, comprises an annular body 30 having an attachment surface 31 bonded to a support surface 43 of a carrier film 4. Here, the flexible carrier film 4 comprises a backing / support layer 42, typically made of polyvinyl chloride, covered by an adhesive layer 41. Using this latter layer, a diced semiconductor wafer 2 containing a plurality of semiconductor dies 2A is attached to the backing layer 42.

[0056] Annular body 30 has asymmetric bending stiffness that allows it to bend such that mounting surface 31 is changed from a first shape, as shown in the top view of Figure 5, to a second, more concave shape, as shown in the middle view of Figure 5. At the same time, the asymmetric stiffness prevents it from being bent such that the shape of mounting surface 31 becomes more convex than the first shape.

[0057] The annular body 30 includes a leaf spring 32 and multiple segments 34, each connected to the leaf spring 32 using a respective connector 33. In the first shape, adjacent segments 34, more specifically, surface 35A of one segment 34A and surface 35B of the adjacent segment 34B, abut one another. As a result, the annular body 30 cannot be bent by moving the left and right ends upward relative to the center portion of the annular body 30, as shown in FIG. 5. However, the reverse is also possible, where the mounting surface 31 assumes a more concave shape. This is shown in the center view of FIG. 5. Here, segments 34A and 34B are not abutting. The use of the leaf springs 32 allows the shape deformation of the annular body 30 to be reversible. However, embodiments in which bending from the first shape to the second shape involves plastic deformation are also possible. In such embodiments, the annular body 30 may be discarded after use.

[0058] Another embodiment of a ring 30 for an FFFC with asymmetric flexural stiffness is shown in FIG. 4. In this embodiment, the ring 30 includes multiple hinged segments 34. For example, FIG. 4 shows segments 34A and 34B. These segments include openings 36A and 36B, respectively, through which a shaft 37 is disposed, with segments 34A and 34B hingedly connected to each other. This is shown in more detail in the cross-sectional views corresponding to lines L1 and L2. The shaft 37 may be fixedly connected to one of segments 34A and 34B and may rotate in openings 36A and 36B in the other. Alternatively, the shaft 37 may rotate in both openings 36A and 36B.

[0059] In FIG. 4, the mounting surface 31 of the annular body 30 is shown in a first shape, which is essentially flat. Similar to the embodiment shown in FIG. 5, the mounting surface 31 can be bonded to the support surface 43 of the carrier film 4. Segments 34A and 34B include abutting surfaces 35A and 35B, respectively. The positioning of surfaces 35A and 35B relative to the shaft 37 determines that the annular body 30 cannot be bent so that the mounting surface 31 becomes more convex. However, it is possible to bend the annular body 30 so that the mounting surface 31 becomes more concave. Note that surfaces 35A and 35B may be located in different positions. For example, they may be located at different longitudinal positions or substantially collinear with the shaft 37.

[0060] 1A, an FFFC 3 embodied as shown in FIG. 5 and having a diced semiconductor wafer 2 disposed thereon may be attached to a rotatably mounted curved shell 122 that can rotate about a rotation axis 122A. To this end, curved shell 122 may be provided with a number of small openings through which suction force can be applied to FFFC 3. Alternatively, FFFC 3 may be attached to curved shell 122 by a mechanical attachment such as a clamp.

[0061] It should be noted that for purposes of illustration, Figure 1A does not show the annulus 30 for the semiconductor wafer 2 disposed in the curved shell 122. Furthermore, Figure 1A shows that the segments 34 are generally elongated, with their longitudinal axes of symmetry parallel to the axis of rotation 122A.

[0062] By rotating and translating the curved shell 122, the diced semiconductor wafer 2 can be positioned relative to the target 113 on which the semiconductor die 2A is disposed. The target 113 is placed on the support surface 112A of the target chuck 112. Once properly positioned, a release unit (not shown in FIG. 1A ) is used to release the semiconductor die 2A from the diced semiconductor wafer 2, thereby allowing the semiconductor die 2A to be placed in its intended position on the target 113.

[0063] Figure 1B shows a schematic representation of the apparatus of Figure 1A. As shown, the apparatus 1 includes a controller 100 that controls the target stage 110, the wafer stage 120, and the release unit 130 based on data received from an inspection system 140. The controller 100 further controls a dispensing device 150 configured to dispense small droplets of conductive adhesive 151, solder, or the like onto the target 113.

[0064] The target stage 110 includes one or more motors for controlling the position of the target chuck 112 on which the target 113 is disposed. For example, the target stage 110 may include a motor MT0 for translating the target chuck 112 along an x-direction parallel to the rotation axis 122A, a motor MT2 for translating the target chuck 112 along a z-direction perpendicular to the support surface 112A of the target chuck 112, and a motor MT1 for translating the target chuck 112 along a y-direction perpendicular to the x- and z-directions.

[0065] The wafer stage 120 includes one or more motors for controlling the position of the curved shell 122 on which the semiconductor wafer 2 is disposed. For example, the wafer stage 120 may include a motor MW0 for translating the curved shell 122 along the x direction, a motor MW2 for translating the curved shell 122 along the z direction, and a motor MW3 for rotating the curved shell 122 about a rotation axis 122A.

[0066] The release unit 130 may include a motor MR0 for translating the light source 132 in the x-direction.

[0067] It should be noted that the present disclosure is not limited to the combination of motors described above: target stage 110, wafer stage 120, and release unit 130 may include more or fewer motors and / or motors for translation in different directions.

[0068] Inspection system 150 may include one or more optical cameras for recording images of semiconductor wafer 2 and / or semiconductor dies 2A disposed therein, and / or target 113. Based on these recorded images, which may be still or moving images, controller 100 controls target stage 110, wafer stage 120, and / or release unit 130 to ensure that each semiconductor die 2A that is placed is placed in its intended position on target 113. This placement process is described in more detail below with reference to FIG. 2.

[0069] 2 is a schematic cross-sectional view corresponding to the apparatus of FIG. 1A. Here, a target 113, e.g., a printed circuit board, is shown. The target 113 includes a plurality of intended placement locations where semiconductor dies 2A from a diced semiconductor wafer 2 need to be placed. Prior to placing the semiconductor dies 2A, droplets 151 of conductive adhesive, solder, etc. are provided, e.g., dispensed, onto the target 113 by a dispensing device 150.

[0070] As shown in Insert I, the target 113 may be provided with a plurality of droplets 151 arranged in rows R and columns C. Similarly, the semiconductor dies 2A may be arranged in a matrix of rows r and columns c on the semiconductor wafer 2, where the columns c on the diced semiconductor wafer 2 and the columns C on the target 113 are assumed to extend perpendicular to the longitudinal axis of symmetry and / or the axis of rotation 122A of the curved shell 122, respectively.

[0071] After the droplets 151 are deposited or otherwise positioned on the target 113, the target 113 is moved under the curved shell 122 to receive the semiconductor die 2A to be released from the diced semiconductor wafer 2. To that end, a release unit 130 is used.

[0072] The curved shell 122 has, at least for the most part, a constant cross section along the axis of rotation 122A. The curved shell 122 can be a partially circular or cylindrical shell. Various examples of cross sections of the curved shell 122 are shown in FIG. 1A, where example A corresponds to a partially cylindrical shell, example B corresponds to a cylindrical shell, and example C corresponds to a further partially cylindrical shell, i.e., a semi-cylindrical shell.

[0073] 2, the release unit 130 includes a laser source 132 that emits a beam of light 133 through the curved shell 122 onto the semiconductor die 2A being released from the carrier film 4. To that end, the curved shell 122 is at least partially translucent to at least the light coming from the laser source 132. The curved shell 122 may be made of a completely translucent material, or certain areas of the curved shell 122 are translucent while other areas are not. For example, the curved shell 122 may be made of glass, quartz, or fused silica.

[0074] The adhesive layer 41 includes a light-absorbing agent, such as a photosensitive adhesive. When the adhesive layer 41 is irradiated with light from the laser source 132, it releases its attachment to the semiconductor die 2A. For example, light absorption can cause a chemical reaction of the light-absorbing agent, resulting in a decrease in the adhesive properties of the adhesive layer 41. Additionally or alternatively, light absorption can cause a sudden and localized temperature increase. This can lead to local ablation and / or even the generation of gaseous components that can propel the released semiconductor die 2A toward the target 113.

[0075] After releasing the attachment, the semiconductor die 2A falls into its intended placement location on the target 113. The motor M3 then rotates the curved shell 122 to align another semiconductor die 2A with the laser source 132. The curved shell 122 and the target 113 are then translated relative to one another so that the next intended placement location is in the correct position relative to the curved shell 122.

[0076] As shown in FIG. 2 , various inspection systems may be installed. The inspection systems may be used to inspect the semiconductor dies 2A from the diced semiconductor wafer 2 before they are placed on the target 113. Such inspection may include determining the position and orientation of the semiconductor dies 2A. This allows for final corrections to be made, for example, by translating the curved shell 122, the target 113, and / or the laser source 132 before releasing the semiconductor dies 2A. Note that each semiconductor die 2A may deviate slightly from its ideal position and / or orientation. Such deviations may occur during dicing and / or when mounting the FFFC 3 on the curved shell 122. Such deviations can be recorded by one or more cameras 141 of the inspection system 140. Because the curved shell 122 is at least locally translucent, the cameras 141 may also be positioned inside the curved shell 122.

[0077] Another or the same camera may be used to check whether semiconductor die 2A is damaged before releasing the die. If semiconductor die 2A is determined to be damaged, controller 100 of apparatus 1 may decide to skip that semiconductor die.

[0078] Another or the same camera may also be used to check whether the semiconductor die 2A has been released. If it is determined that the semiconductor die has not been released, a new release attempt may be made.

[0079] Inspection system 140 may also use camera 142 to check that droplet 151 is correctly placed on target 113 and / or to monitor or check the position and / or orientation of target 113 .

[0080] It should be noted that the curvature of the curved shell 122 allows the camera of the inspection system 140 to be placed in close proximity to the semiconductor die 2A that needs to be inspected.

[0081] 3A-3E illustrate a further embodiment of an apparatus for depositing semiconductor dies directly onto a target from a diced semiconductor wafer, according to one aspect of the present disclosure.

[0082] Each of the embodiments shown in Figures 3A-3E includes a fixed frame 160 that serves as a reference for the various movements within the device.

[0083] 3A, motor MT0 is used to translate carriage 111 in the x-direction relative to frame 160. Motor MT1 is used to translate target chuck 112 in the y-direction relative to carriage 111. Additionally, motor MW3 is used to rotate curved shell 122 relative to frame 160.

[0084] The laser source 132 is mounted on a carriage 131 that translates in the x-direction relative to the frame 160 using a motor MR0.

[0085] The apparatus of FIG. 3A can be used to place multiple semiconductor dies 2A on the target 113 in multiple spaced rows extending perpendicular to the axis of rotation 122A.

[0086] For example, the target 113 can be translated in the y direction while the curved shell 122 is rotated to place semiconductor dies 2A that will be located in the same row on the semiconductor wafer 2. Once a row on the semiconductor wafer 2 is exhausted, the laser source 132 and the target chuck 112 are translated in the x direction so that both the target chuck 112 and the laser source 132 are aligned with the next row of semiconductor dies 2A on the semiconductor wafer 2. Once a complete row on the target 113 has been filled, the target chuck 112 is moved in the x direction to position a new row to be filled below the curved shell 122.

[0087] In the embodiment shown in FIG. 3B, the target chuck 112 can be translated only in the y-direction using motor MT1. The curved shell 122 can be rotated relative to the carriage 121 using motor MW3. The carriage 121 can then be translated in the x-direction using motor MW0. The laser source 132 mounted on the carriage 131 can be translated in the x-direction relative to a frame 160, which is partially omitted for illustrative purposes, using motor MR0. Motor MR0 may include, for example, a ball screw, a lead screw, a belt drive, or a linear motor to translate the carriage 131.

[0088] The apparatus shown in FIG. 3C differs from the embodiment shown in FIG. 3B in that motor MRO translates carriage 131 relative to carriage 121 instead of frame 160.

[0089] Figures 3D and 3E are cross-sectional views corresponding to the apparatus shown in Figure 3A. More specifically, target chuck 112 can translate in the x and y directions, while curved shell 122 can only rotate relative to frame 160. Laser source 132 can translate only in the x direction relative to frame 160 using motor MR0.

[0090] 3D, a laser source 132 emits a beam of light 133 through the translucent curved shell 122 onto the attachment layer where the semiconductor die 2A is attached to the carrier film. Alternatively, the release unit 130 may include a needle and a needle actuator for engaging and disengaging the needle with the underlying semiconductor die. In this case, the needle actuator and the needle are both located inside the curved shell 122 and both translate in the x-direction.

[0091] 3E, laser source 132 is mounted on the outside of curved shell 122. Laser source 132 emits a beam of light 133 toward mirror unit 134. Mirror unit 134 deflects the light into and through curved shell 122. Mirror unit 134 may include one or more mirrors and one or more mirror actuators to allow for changing the deflection angle. Mirror unit 134 can be translated in the x-direction using motor MR0, which can be embodied as, for example, a linear motor.

[0092] Although the present invention has been described above using detailed embodiments thereof, the present invention is not limited to these embodiments, and instead various modifications can be made without departing from the scope of the present invention as defined by the appended claims and their equivalents.

[0093] Particular and preferred aspects of the invention are set out in the accompanying independent claims. Combinations of features from the dependent and / or independent claims are not limited to those set out in the claims and may be combined as appropriate.

[0094] The scope of the present disclosure includes any novel feature or combination of features, explicitly or implicitly disclosed, or any generalization thereof, whether or not related to the claimed invention or whether or not it alleviates any or all of the problems addressed by the invention. The applicant hereby gives notice that new claims may be formulated to such features during prosecution of this application or any such further application derived therefrom. In particular, with reference to the appended claims, features of the dependent claims may be combined with features of the independent claims, and features of each independent claim may be combined in any suitable manner, not just in the specific combinations recited in the claims.

[0095] Features that are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable subcombination.

[0096] The word "comprising" does not exclude other elements or steps, and the words "a" or "an" do not exclude a plurality. Reference signs in the claims are not to be construed as limiting the scope of the claims. [Explanation of symbols]

[0097] 1 device 2. Semiconductor wafers 2A semiconductor die 3 film frame carriers 4. Carrier film 5 cassettes 30 cyclic bodies 31 Mounting surface 32 Leaf spring 33 Connection 34, 34A, 34B segments 35A, 35B Contact surface 36A, 36B opening 37 Shaft 41 Adhesion layer 42 Backing Layer 43 Support surface 100 Controllers 110 Target Stage 111 Carriage Target Stage 112 Target Chuck 113 Target 120 wafer stage 121 Carrier wafer stage 122 Curved Shell 122A Rotating shaft 130 Release Units 131 Carrier Release Unit 132 Laser Source 133 Beam of Light 134 Mirror unit 140 Inspection System 141, 142 Camera 150 Distribution device 151 adhesive / solder droplets 160 fixed frame M0 X-direction motor M1 y-direction motor M2 z-direction motor M3 Motor rotation

Claims

1. 1. An apparatus for transferring semiconductor dies from an array of semiconductor dies to a target, comprising: a wafer stage having a wafer chuck on which the array of semiconductor dies is disposed; a target stage having a target chuck on which targets are disposed on which semiconductor dies from the array of semiconductor dies are placed; a release unit for releasing a semiconductor die from the array of semiconductor dies; a controller for controlling the release unit, the wafer stage, and the target stage; the wafer chuck includes a curved shell on which the array of semiconductor dies is disposed and rotatably mounted, the wafer stage further including a first motor for rotating the curved shell about a rotation axis; The apparatus wherein the curved shell is a cylindrical shell or a partially cylindrical shell.

2. 10. The apparatus of claim 1, wherein the apparatus is configured to directly transfer the semiconductor die from the array of semiconductor dies onto the target, and / or the release unit is configured to release the semiconductor die from the array of semiconductor dies and drop it onto the target.

3. 10. The apparatus of claim 1, wherein the wafer chuck is configured to support a carrier carrying the array of semiconductor dies, the carrier being selected from the group consisting of a tape, a film, and a foil, and the carrier being part of a film frame carrier.

4. the array of semiconductor dies is made from a diced or structured semiconductor wafer; and / or the rotation axis extends at least approximately parallel to the target chuck; and / or The apparatus of claim 1 , wherein the axis of rotation coincides with a longitudinal axis of symmetry of the curved shell.

5. the wafer stage further includes a second motor for translating the curved shell back and forth along a direction parallel and / or coincident with the axis of rotation, and / or the wafer stage further includes an auxiliary second motor for translating the curved shell back and forth along a direction perpendicular to the axis of rotation and perpendicular to the target chuck; the apparatus further comprises a fixed frame and a first carriage, and the second motor and / or the auxiliary second motor are configured to translate the first carriage relative to the fixed frame, and the first motor is configured to rotate the curved shell relative to the first carriage; or 2. The apparatus of claim 1, further comprising a fixed frame, wherein the second motor and / or auxiliary second motor are configured to translate the curved shell relative to the fixed frame, and the first motor is configured to rotate the curved shell relative to the fixed frame.

6. the curved shell is provided with a coupling unit for enabling the array of semiconductor dies to be coupled to the curved shell; the curved shell is provided with a plurality of openings, the apparatus further comprising a vacuum unit configured to generate a suction force applied to the diced semiconductor wafer through the plurality of openings; and / or 2. The apparatus of claim 1, wherein the curved shell is provided with a mechanical coupling unit for mechanically coupling the array of semiconductor dies, the array of semiconductor dies being carried by a film frame carrier, and the mechanical coupling unit includes a clamp unit for clamping the film frame carrier onto the curved shell.

7. a first inspection system positioned to inspect a semiconductor die from the array of semiconductor dies prior to placement on the target; the first inspection system is arranged to determine positions and / or orientations of semiconductor dies in the array of semiconductor dies, and the controller is configured to control the wafer stage, the target stage, and / or the release unit in response to the determined positions and / or orientations; and / or the first inspection system is arranged to determine whether a semiconductor die of the array of semiconductor dies will be damaged, and the controller is configured to control the wafer stage, the target stage, and / or the release unit to prevent the semiconductor die from being placed on the target if it is determined that the semiconductor die will be damaged; and / or the apparatus further includes a second inspection system arranged to determine whether a semiconductor die has been released from the array of semiconductor dies, and the controller is configured to control the wafer stage, the target stage, and / or the release unit to release the semiconductor die if it is determined that the semiconductor die has not been released; and / or the apparatus further includes a third inspection system arranged to check whether the semiconductor die is properly placed on the target, the controller being configured to store the position of the semiconductor die and / or the intended position of the semiconductor die on the target; 10. The apparatus of claim 1, wherein the first inspection system, the second inspection system, or the third inspection system includes a camera used by two or more of the first inspection system, the second inspection system, and the third inspection system.

8. the curved shell is at least partially translucent to light having a first wavelength, the release unit includes a light source for outputting a beam of light having the wavelength, the array of semiconductor dies is adhered to one material selected from the group consisting of a tape, a foil, and a film using a light absorbing agent, the light absorbing agent being configured to at least locally release its adhesion to the array of semiconductor dies when illuminated by light having the wavelength; the light absorber is configured to at least locally release its attachment by photoablation and / or by the light absorber undergoing a chemical reaction as a result of absorbing the light, and / or the light source is configured to irradiate the given semiconductor die of the array of semiconductor dies that is distinct from semiconductor dies adjacent to the given semiconductor die, and the releasing unit includes a beam splitter configured to receive the beam of light from the light source and split the received beam into a plurality of further beams, each further beam configured to irradiate a respective given semiconductor die; The device of claim 5 , wherein the light source is configured to emit light generally perpendicularly toward the curved shell.

9. the target stage further includes a fourth motor and / or a fifth motor for translating the target chuck in a plane parallel to the rotation axis, and / or an auxiliary fourth motor for translating the target chuck back and forth along a direction perpendicular to the rotation axis, the direction perpendicular to the target chuck; the fourth motor and / or the fifth motor are arranged to translate the target chuck relative to the fixed frame; 6. The apparatus of claim 5, wherein the fourth motor is configured to displace a third carriage relative to the fixed frame, and the fifth motor is configured to displace the target chuck relative to the third carriage.

10. the release unit is configured to release the semiconductor die, which is disposed in a release position relative to the fixing frame, from the semiconductor die arrangement; The apparatus of claim 5 , wherein the array of semiconductor dies comprises a plurality of semiconductor dies arranged in a matrix of rows and columns, the rows extending at least approximately parallel to the axis of rotation.

11. 9. The apparatus of claim 8, wherein the releasing unit further comprises a light guiding unit, wherein the light source is configured to emit light toward the light guiding unit substantially parallel to the rotation axis, and the light guiding unit is configured to direct light from the light source toward the curved shell substantially perpendicularly, the light guiding unit comprising one or more mirrors and / or one or more prisms, and the light guiding unit comprises one or more actuators controllable by the controller, the one or more actuators configured to change an orientation of the one or more mirrors and / or one or more prisms with respect to incident light from the light source to direct light from the light source into the curved shell at different angles.

12. the target includes adjacently arranged columns or rows of placement positions on which each semiconductor die from the array of semiconductor dies is placed, the adjacently arranged columns or rows of placement positions extending at least approximately perpendicular or parallel to the rotation axis, respectively; the controller is configured to control the wafer stage to intermittently or continuously rotate the curved shell to place a semiconductor die in the same column of the array of semiconductor dies on each placement position of the target, and to translate the curved shell to shift the placed die to an adjacent column of semiconductor dies in the array of semiconductor dies after the column of the array of semiconductor dies has been used up; 11. The apparatus of claim 10, wherein the controller is configured to maintain the released position relative to the fixed frame during translation of the curved shell to shift to an adjacent row of semiconductor dies in the array of semiconductor dies.

13. the release unit includes a second carriage on which the light source or the combination of the actuator and the needle is attached, and a third motor for moving the second carriage relative to the curved shell, the second carriage being configured to translate inside and / or above or below the curved shell, the light source being fixed to a fixed frame, and the light guide unit being attached to the second carriage, or 12. The device of claim 11, wherein the release unit includes a second carriage on which the light source or a combination of an actuator and a needle is attached, and a third motor for moving the second carriage relative to the fixed frame, the second carriage being configured to translate inside and / or above or below the curved shell, the light source being fixed to the fixed frame, and the light guide unit being attached to the second carriage.

14. the target includes a plurality of adjacently arranged rows of placement positions on which a respective semiconductor die from the array of semiconductor dies is placed, and the controller is configured to control the wafer stage and / or the target stage to cause a relative translational movement between the target and the curved shell after all of the placement positions in the same row on the target have been placed with semiconductor dies from the array of semiconductor dies, and the controller is configured to maintain the release position relative to the fixed frame during the relative translational movement between the target and the curved shell, or the controller is configured to maintain the position of the row on the target in a direction parallel to the rotation axis relative to the fixed frame, and to change the release position and shift to a next row on the target after all of the placement positions in the same row on the target have been placed with semiconductor dies from the array of semiconductor dies; The apparatus of claim 12 , wherein the apparatus includes a plurality of the release units for simultaneously releasing semiconductor dies from the array of semiconductor dies at different row placement locations on the target.

15. 10. A wafer stage configured for use in the apparatus of claim 1, the wafer stage having a wafer chuck on which an array of semiconductor dies is disposed, the wafer stage comprising: the wafer chuck includes a curved shell on which the array of semiconductor dies is disposed and rotatably mounted, the wafer stage further including a first motor for rotating the curved shell about a rotation axis.

16. 3. A wafer stage configured for use in the apparatus of claim 2, the wafer stage having a wafer chuck on which an array of semiconductor dies is disposed, the wafer stage comprising: the wafer chuck includes a curved shell on which the array of semiconductor dies is disposed and rotatably mounted, the wafer stage further including a first motor for rotating the curved shell about a rotation axis.

17. 10. A wafer stage configured for use in the apparatus of claim 5, the wafer stage having a wafer chuck on which an array of semiconductor dies is disposed, the wafer stage comprising: the wafer chuck includes a curved shell on which the array of semiconductor dies is disposed and rotatably mounted, the wafer stage further including a first motor for rotating the curved shell about a rotation axis.

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