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 used in such an apparatus.

Background Art

[0002] Apparatuses for transferring semiconductor dies from a diced semiconductor wafer to a target are known in the art. For example, Patent Document 1 discloses an apparatus including a wafer stage having a wafer chuck on which a diced semiconductor wafer can be placed, and a target stage having a target chuck on which a target can be placed. Both the wafer stage and the target stage include one or more motors for changing the relative position 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, the wafer stage, and the target stage are controlled using a controller.

[0003] In known systems, a diced semiconductor wafer is brought close to a target, which can be, for example, a printed circuit board. When the semiconductor die on the semiconductor wafer is aligned with the intended position on the target, the needle is aligned with the semiconductor die. Next, the needle is separated from the semiconductor wafer and presses the semiconductor die to transfer it onto the target.

[0004] The above die transfer is called direct die transfer. More specifically, the die is transferred from the diced semiconductor wafer onto the target without being placed or supported between the step of releasing the die and the step of placing the die on the target.

[0005] A key performance indicator for the type of equipment described above is the number of semiconductor dies that can be transferred per unit time. This time 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 [Overview of the project]

[0007] One aspect of the present disclosure relates to an apparatus for transferring semiconductor dies from an array of semiconductor dies to a target, using a different method of positioning the array of semiconductor dies relative to a target. According to one aspect of the present disclosure, this different positioning method makes it possible to achieve a reduction in the time required to transfer the semiconductor dies onto the target.

[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 arranged and rotatably mounted. Furthermore, the wafer stage includes a first motor for rotating the curved shell around a pivot axis.

[0009] The apparatus disclosed in Patent Document 1 includes a linear XY stage that uses linear motors configured to displace a semiconductor wafer in the x and y directions. The acceleration obtained by such a wafer stage is limited by the motor topology and power consumption. To improve the performance of these wafer stages, for example, to increase the positioning speed, a moving coil topology is required. However, this brings with it the associated problem of cooling the moving coils to improve power consumption capacity.

[0010] According to one aspect of the present disclosure, the problem of limited acceleration in a linear motor is mitigated by using a rotatably mounted curved shell on which an array of semiconductor dies may be arranged. This shell is part of a wafer stage and is actuated by a first motor configured to rotate the curved shell around a pivot axis.

[0011] A motor designed to impart rotational motion will provide higher force or torque per unit heat dissipated, and / or higher force / torque per unit power and per unit weight of the magnets used. This means that, for a given mass and power level, it can achieve higher acceleration than a linear magnet motor.

[0012] The apparatus is preferably configured to directly transfer semiconductor dies from an array of semiconductor dies onto a target. A release unit may be configured to release a semiconductor die from the array of semiconductor dies and allow it to fall onto the target. In this case, the release unit is not engaged with the semiconductor die at the moment it reaches the 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 force of gravity.

[0013] A wafer chuck may be configured to support a carrier that holds an array of semiconductor dies. For example, the carrier may be a tape, film, or foil. Furthermore, the carrier may be part of a film frame carrier.

[0014] An array of semiconductor dies may consist of a diced semiconductor wafer or a structured semiconductor wafer. A structured semiconductor wafer may contain multiple semiconductor dies arranged in a pattern different from the pattern arranged on the semiconductor wafer from which the dies originated before dicing. Alternatively, a structured semiconductor wafer may contain multiple semiconductor dies originating 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 axis of rotation preferably extends at least substantially parallel to the target chuck. In this way, if the next semiconductor die needs to be released in the same position as the previous semiconductor die, the position of the release unit can be kept constant when rotating the curved shell to align the next semiconductor die with the release unit. Note that the target is typically moved when the next semiconductor die is released. Furthermore, the axis of rotation 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 along a direction preferably parallel to and / or coincident with the axis of rotation. The wafer stage may further include another second motor for translating the curved shell perpendicular to the direction provided by the second motor. For example, the second motor and the other second motor can 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 in a direction perpendicular to the axis of rotation, preferably perpendicular to the target chuck. For example, the auxiliary second motor may be configured to displace the curved shell vertically to ensure or maintain a specific vertical gap between the semiconductor die being released and the target. If such a gap is too small, the target and the semiconductor die may come into contact during the movement of the target and / or the curved shell. If the gap 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, wherein a second motor and / or an 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 superimposed. In other embodiments, the second motor and / or an 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 above wavelength. The array of semiconductor dies can be attached to a tape, foil, or film using a light-absorbing agent, such as a photosensitive adhesive. The light-absorbing agent may be configured to release its adhesion to the array of semiconductor dies at least locally when irradiated with light having the above wavelength. For example, the light-absorbing agent may be configured to release its adhesion at least locally by photoablation and / or by a chemical reaction as a result of absorbing light. The light source may be configured to irradiate a given semiconductor die in an array of semiconductor dies that is separate from semiconductor dies adjacent to a given semiconductor die. For example, the light source may be configured to irradiate one semiconductor die in an array of semiconductor dies at a time. However, the release unit may include a beam splitter configured to receive a beam of light from the light source and split the received beam into a plurality of further beams, each further beam configured to irradiate its respective given semiconductor die.

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

[0021] The light guide unit may include one or more mirrors and / or one or more prisms. Furthermore, the light guide unit may preferably include one or more actuators controllable by a controller, the one or more actuators being configured to change the orientation of one or more mirrors and / or one or more prisms with respect to incident light from a light source in order to guide light from a light source to a curved shell at different angles. In this way, the location where light from the light source strikes the curved shell can be changed without the curved shell changing its position along its longitudinal axis of symmetry. The light guide unit may be, for example, MEMS-based. For example, MEMS-based mirrors are relatively lightweight and enable high-speed switching between adjacent dies being transported.

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

[0023] As described above, in order to completely exhaust the array of semiconductor dies, the release unit needs to change the position from which it releases the semiconductor dies from the array of semiconductor dies. For this purpose, the release unit may include a second carriage to which a light source or actuator and needle combination is attached, 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 superimposed. Furthermore, typically, the third motor simply 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 to which a light source or actuator and needle combination is attached, and a third motor for moving the second carriage relative to a fixed frame. 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 inward and / or upward or downward of the curved shell. Furthermore, if the release unit includes the light source and light guide unit described above, the light source may be fixed to a fixed frame, and the light guide unit may be attached to a second carriage.

[0024] The target stage may further include a fourth motor and / or a fifth motor for translating the target chuck in a plane preferably parallel to the axis of rotation, and / or an auxiliary fourth motor for translating the target chuck back and forth in a direction perpendicular to the axis of rotation, preferably perpendicular to the target chuck. The fourth motor and / or fifth motor may be arranged to translate the target chuck relative to the fixed frame. Alternatively, movement in two mutually orthogonal directions may be stacked. For example, the fourth motor may displace a 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 to enable coupling of the array of semiconductor dies to the curved shell. For example, the curved shell may be provided with a plurality of openings. In this case, the device 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 clamping 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 are equally applicable to curved shells whose cross-section perpendicular to the axis of rotation and / or the axis of longitudinal symmetry is not circular or partially circular. In these cases, it is preferable to translate the curved shell and the target relative to each other in order to maintain a substantially constant distance between the target and the next released semiconductor die.

[0027] By having a curved shell on which the array of dies is disposed, it provides the possibility of attaching an inspection system near the position where the semiconductor die is released. For example, the apparatus may include a first inspection system arranged to inspect semiconductor dies from an array of semiconductor dies before placing them on a target. The first inspection system may be arranged to determine the position and / or orientation of the 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 according to the determined position and / or orientation. When coupling the array of semiconductor dies to the curved shell, the position and / or orientation of the semiconductor die may be changed, for example, by wrinkles or other distortions of the carrier on which the semiconductor die is disposed. The first inspection system may record the position and / or orientation of the semiconductor die, preferably with respect to the curved shell and / or with respect to the ideal position and / or orientation of the semiconductor die. This recorded position can then be used to perform corrections before releasing the die. For example, when the die is shifted along the axis of rotation with respect to its ideal position, the curved shell may be translated slightly in another direction before the release unit releases the semiconductor die. In this case, there is no need to change the position of the release unit. In other embodiments, the target is displaced together with the release unit while maintaining the curved shell in the same position. In yet further embodiments, the release unit, the target, and the curved shell are all moved.

[0028] The first inspection system may additionally or alternatively be arranged to determine whether the semiconductor dies in the array of semiconductor dies are 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 it is determined that the semiconductor die is damaged. In this way, damaged semiconductor dies can be skipped.

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

[0030] Alternatively or additionally, the apparatus may further include a third inspection system configured to check whether the semiconductor die is properly positioned on the target. In this case, the controller may be configured to store the position of the semiconductor die and / or the intended position of the semiconductor die on the target. In 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, which is preferably used in two or more of the first, second, and third inspection systems. The cameras of the first, second, and / or third inspection systems may be mounted movably 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 a semiconductor die positioned in a release position relative to a fixed frame from an array of semiconductor dies. The array of semiconductor dies may include a plurality of semiconductor dies arranged in a matrix of rows and columns, where the rows extend at least substantially parallel to the axis of rotation.

[0033] The target may include a column or row of adjacent placement positions where each semiconductor die from an array of semiconductor dies is placed, each column or row of adjacent placement positions extending at least substantially perpendicular or parallel to the axis of rotation. An example of such a target may be a carrier tape containing multiple cavities on which semiconductor dies are placed. In this case, the controller may be configured to control the wafer stage to rotate the curved shell intermittently or continuously to place a semiconductor die in the same column of the array of semiconductor dies on each placement position of the target, and after exhausting the column of the array of semiconductor dies for the dies to be placed, to translate the curved shell to shift to an adjacent column of semiconductor dies in the array of semiconductor dies. Furthermore, the controller may be configured to maintain a release position relative to a fixed frame during the translational motion of the curved shell to 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 is rotating and translating.

[0034] In addition to the above, the target may include multiple rows of adjacent placement positions where each semiconductor die from the array of semiconductor dies is placed. In this case, the controller may be configured to control the wafer stage and / or target stage to cause mutual translational motion between the target and the curved shell after semiconductor dies from the array of semiconductor dies have been placed at all placement positions in the same row on the target. In this case, the controller may be configured to maintain the release position relative to the fixed frame during the mutual translational motion 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 axis of rotation relative to the fixed frame, and after semiconductor dies from the array of semiconductor dies have been placed at all placement positions in the same row on the target, change the release position to shift to the next row on the target.

[0035] The apparatus may include multiple release units described above for substantially simultaneously releasing semiconductor dies from an array of semiconductor dies located in different rows on a target. Each release unit may be controlled independently by a controller.

[0036] A further aspect of the present disclosure provides a wafer stage having a wafer chuck on which an array of semiconductor dies is arranged, the wafer chuck including a curved shell on which the array of semiconductor dies is arranged and which is rotatably mounted, and the wafer stage further includes a first motor for rotating the curved shell about a pivot axis. This wafer stage may further be configured as a wafer stage of the apparatus described above.

[0037] A further aspect of this disclosure provides a film frame carrier configured to be attached to the curved shell of the apparatus described above. The film frame carrier is also called a tape frame.

[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 an array of semiconductor dies is arranged. The annular body may, but is not limited to, a circular, rectangular, or square shape.

[0039] The annular body has asymmetric bending stiffness, which allows the annular body to be bent so that the mounting surface of the annular body changes from a first shape to a more concave second shape, and prevents or limits bending the annular body so that the shape of the mounting surface becomes more convex than the first shape. Due to the asymmetric bending stiffness, the annular body can be gripped on both sides to move the annular body without losing stiffness. This enables the automatic transfer of a film frame carrier onto a curved shell and / or enables dicing of a wafer while it remains attached to a flexible carrier film bonded to the annular body. The first shape may correspond to the most convex shape that the mounting surface can achieve.

[0040] Asymmetric bending stiffness may be configured to allow the annular body to be bent in such a way that the mounting surface of the annular body is reversibly changed from a first shape to a more concave second shape. Alternatively, bending may result in plastic deformation of the annular body.

[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 m -1 It may be less than 3.3m, and the curvature of the mounting surface when it has a second shape is 3.3m -1 It's extremely possible.

[0042] The annular body may include a leaf spring and / or may be formed at least partially by a leaf spring. Furthermore, the surface of the leaf spring may form a mounting surface or be part of a mounting surface. The annular body may further include a restricting means connected to the leaf spring to prevent or limit bending of the annular body such that the shape of the mounting surface is more convex than a first shape. The restricting means may be coupled to the leaf spring at a surface guided away from the mounting surface. Additionally or alternatively, the restricting means may include a plurality of segments connected to the leaf spring, such that, if the mounting surface is a first shape, adjacent segments abut each other to prevent or limit bending of the leaf spring such that the shape of the mounting surface is more convex than the first shape, and the segments are configured to separate from each other when the leaf spring is bent, thereby changing the mounting surface from a first shape to a more concave shape.

[0043] Alternatively, the annular body may include multiple segments, which are hinged to each other. For example, each adjacent pair of segments among the multiple segments may be configured to pivot relative to each other around their respective axes of rotation. Furthermore, the axes of rotation representing the pivotal motion of all adjacent pairs of segments among the multiple segments may be parallel to each other.

[0044] For at least one pair of adjacent segments among a plurality of segments, one segment may include a first coupling structure located at a first end of the first segment, and the other segment may include a second coupling structure located at a second end of the other segment. The first and second coupling structures may be hinged to each other so as to allow the first and other segments to pivot relative to each other around an axis of rotation. The first segment may include the second coupling structure located on the second side of the first segment opposite to the first side of the first segment. The other segment may include the first coupling structure located on the first side of the other segment opposite to 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. This protruding element may be a pin, a rod, or a shaft.

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

[0047] For each pair of adjacent segments among the above-mentioned multiple segments, one segment may include a first abutment surface, and the other segment may include a second abutment surface. The first and second abutment surfaces may be molded and positioned with respect to the axis of rotation so as to abut each other, in order to prevent the annular body from bending so that the mounting surface becomes more convex than the first shape, if the mounting surface has a first shape.

[0048] The segments may be manufactured from materials selected from the group consisting of steel, aluminum, titanium, polymers, or combinations thereof.

[0049] A further aspect of the present disclosure provides 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 arranged, wherein the carrier film, foil, or tape having the array of dies is coupled to a mounting surface of the film frame carrier at its support surface.

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

[0051] The arrangement of semiconductor dies consists of diced or structured semiconductor wafers. [Brief explanation of the drawing]

[0052] To enable a more detailed understanding of the features of this disclosure, a more specific description is provided with reference to embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show typical embodiments and should not be considered to limit the scope of this disclosure. The drawings are provided to facilitate understanding of this disclosure and are therefore not necessarily drawn to a specific scale. The merits of the claimed subject matter will become apparent to those skilled in the art by reading this description in conjunction with the accompanying drawings, which use similar reference numerals to illustrate similar elements. [Figure 1A]This document shows a part of an embodiment of an apparatus for placing semiconductor dies onto a target from an array of semiconductor dies, according to one aspect of this disclosure. [Figure 1B] This is a corresponding schematic diagram. [Figure 2] This is a schematic cross-sectional view corresponding to the apparatus in Figure 1A. [Figure 3A] Further embodiments and figures of an apparatus for placing semiconductor dies onto a target from an array of semiconductor dies, according to one aspect of this disclosure, are shown. [Figure 3B] Further embodiments and figures of an apparatus for placing semiconductor dies onto a target from an array of semiconductor dies, according to one aspect of this disclosure, are shown. [Figure 3C] Further embodiments and figures of an apparatus for placing semiconductor dies onto a target from an array of semiconductor dies, according to one aspect of this disclosure, are shown. [Figure 3D] Further embodiments and figures of an apparatus for placing semiconductor dies onto a target from an array of semiconductor dies, according to one aspect of this disclosure, are shown. [Figure 3E] Further embodiments and figures of an apparatus for placing semiconductor dies onto a target from an array of semiconductor dies, according to one aspect of this disclosure, are shown. [Figure 4] A first embodiment of a flexible film frame carrier according to one aspect of the present invention is shown. [Figure 5] An annular body for a flexible film frame carrier according to one aspect of the present invention is shown. [Modes for carrying out the invention]

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

[0054] Figure 1A shows part of one embodiment of an apparatus 1 for placing a semiconductor die 2A onto a target 113 from a diced semiconductor wafer 2, according to one aspect of the present disclosure. Here, the diced semiconductor wafer 2 is placed on a carrier film 4 attached to a flexible film frame carrier FFFC 3. Typically, the wafer is supplied to the apparatus 1 from a cassette 5, tray, or the like. This can be done in an automated manner.

[0055] The FFFC3, whose cross-section is shown in Figure 5, includes an annular body 30 having a mounting surface 31 bonded to a support surface 43 of the carrier film 4. Here, the flexible carrier film 4 includes a backing / support layer 42, typically made of polyvinyl chloride, which is covered by an adhesion layer 41. Using this latter layer, a diced semiconductor wafer 2 containing multiple semiconductor dies 2A adheres to the backing layer 42.

[0056] The annular body 30 has asymmetric bending rigidity, which allows the annular body 30 to be bent so that the mounting surface 31 changes from a first shape, as shown in the upper diagram of Figure 5, to a more concave second shape, as shown in the middle diagram of Figure 5. At the same time, the asymmetric bending rigidity prevents the annular body 30 from being bent so that the shape of the mounting surface 31 becomes more convex than the first shape.

[0057] The annular body 30 includes a leaf spring 32 and a plurality of segments 34, each connected to the leaf spring 32 using their respective connectors 33. In the first shape, adjacent segments 34, more specifically, the surface 35A of one segment 34A and the surface 35B of the adjacent segment 34B, are in contact with each other. As a result, the annular body 30 cannot be bent by moving the left and right ends upward relative to the central portion of the annular body 30 shown in Figure 5. However, the reverse is also possible, where the mounting surface 31 takes on a more concave shape. This is shown in the central figure of Figure 5. Here, segments 34A and 34B are not in contact. The shape deformation of the annular body 30 can be reversed by using the leaf spring 32. However, embodiments in which bending from the first shape to the second shape involves plastic deformation are equally possible. In such embodiments, the annular body 30 may be discarded after use.

[0058] Another embodiment of the annular body 30 for FFFC having asymmetrical bending rigidity is shown in Figure 4. In this embodiment, the annular body 30 includes a plurality of hinged segments 34. For example, Figure 4 shows segments 34A and 34B. These segments each include openings 36A and 36B, in which a shaft 37 is positioned, hinged to segments 34A and 34B. 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 rotatable in the other openings 36A and 36B. Alternatively, the shaft 37 may rotatable in both openings 36A and 36B.

[0059] In Figure 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 Figure 5, the mounting surface 31 can be coupled 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 is more convex. However, it is possible to bend the annular body 30 so that the mounting surface 31 is more concave. Note that surfaces 35A and 35B may be positioned in different locations. For example, they may be substantially collinear with the shaft 37, even if their longitudinal positions are different.

[0060] Referring again to Figure 1A, the FFFC3, which has a diced semiconductor wafer 2 embodied and positioned thereon as shown in Figure 5, can be mounted on a rotatably mounted curved shell 122 that can rotate around a rotation axis 122A. For this purpose, the curved shell 122 may be provided with a number of small openings that can apply attractive force to the FFFC3. Alternatively, the FFFC3 may be mounted on the curved shell 122 by mechanical mounting such as a clamp.

[0061] Note that for illustrative purposes, Figure 1A does not show the annular body 30 for the semiconductor wafer 2 positioned in the curved shell 122. Furthermore, Figure 1A shows that the segment 34 having a longitudinal symmetry axis parallel to the rotation axis 122A is generally elongated.

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

[0063] Figure 1B schematically shows the apparatus of Figure 1A. As shown, apparatus 1 includes a controller 100 that controls the target stage 110, wafer stage 120, and release unit 130 based on data received from inspection system 140. Controller 100 further controls a dispensing device 150 configured to distribute small droplets of conductive adhesive 151, solder, etc., 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 positioned. For example, the target stage 110 may include a motor MT0 for translating the target chuck 112 along the x-direction parallel to the rotation axis 122A, a motor MT2 for translating the target chuck 112 along the z-direction perpendicular to the support surface 112A of the target chuck 112, and a motor MT1 for translating the target chuck 112 along the 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 placed. 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 around 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 this disclosure is not limited to the motor combinations described above. The 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] The inspection system 150 may include one or more optical cameras for recording images of the semiconductor wafer 2 and / or the semiconductor dies 2A placed therein, and / or the target 113. Based on these recorded images, which may be still images or moving images, the controller 100 controls the target stage 110, the wafer stage 120, and / or the release unit 130 to ensure that each semiconductor die 2A to be placed is positioned in the intended location on the target 113. This placement process will be described in detail below with reference to Figure 2.

[0069] Figure 2 is a schematic cross-sectional view corresponding to the apparatus of Figure 1A, where a target 113, for example, a printed circuit board, is shown. The target 113 includes a number of intended placement locations where semiconductor dies 2A from a diced semiconductor wafer 2 need to be placed. Before placing the semiconductor dies 2A, droplets 151 of conductive adhesive, solder, etc., are supplied, for example, distributed onto the target 113 by a distribution 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 column C. Similarly, the semiconductor die 2A may be arranged in a matrix of rows r and column c on the semiconductor wafer 2. Here, it is assumed that column c on the diced semiconductor wafer 2 and column C on the target 113 extend perpendicular to the longitudinal axis of symmetry and / or rotation axis 122A of the curved shell 122, respectively.

[0071] After the droplet 151 is deposited or otherwise positioned on the target 113, the target 113 is moved under the curved shell 122 to receive the semiconductor die 2A, which is released from the diced semiconductor wafer 2. A release unit 130 is used for this purpose.

[0072] The curved shell 122 has a constant cross-section along the axis of rotation 122A, at least for the majority of its length. The curved shell 122 may be a partially circular or cylindrical shell. Various examples of the cross-section of the curved shell 122 are shown in Figure 1A. Here, 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] Continuing to refer to Figure 2, the release unit 130 includes a laser source 132 that emits a beam of light 133 through a curved shell 122 onto the semiconductor die 2A, which is released from the carrier film 4. For this purpose, the curved shell 122 is at least partially translucent with respect to 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 may be translucent while other areas are not. For example, the curved shell 122 may be made of glass, quartz, or fused silica.

[0074] The adhesion layer 41 contains a light-absorbing agent, such as a photosensitive adhesive. When light from the laser source 132 is shone on the adhesion layer 41, the adhesion to the semiconductor die 2A is released. For example, light absorption triggers a chemical reaction in the light-absorbing agent, resulting in a decrease in the adhesive properties of the adhesion layer 41. Additionally or alternatively, light absorption may cause a rapid and localized temperature rise. This may even lead to localized ablation and / or the generation of gaseous components that can propel the released semiconductor die 2A toward the target 113.

[0075] After releasing the adhesion, the semiconductor die 2A falls to its intended position on the target 113. Then, the motor M3 rotates the curved shell 122 to align another semiconductor die 2A with the laser source 132. Furthermore, the curved shell 122 and the target 113 are translated relative to each other so that they are in the correct position relative to the curved shell 122 to reach the next intended position.

[0076] As shown in Figure 2, various inspection systems can be installed. The inspection system may be used to inspect the semiconductor die 2A from the diced semiconductor wafer 2 before it is placed on the target 113. Such inspection may include determining the position and orientation of the semiconductor die 2A. This allows for final correction to be performed, for example, by translating the curved shell 122, target 113, and / or laser source 132 before releasing the semiconductor die 2A. It should be noted that each semiconductor die 2A may be slightly deviated from its ideal position and / or orientation. Such deviations may occur during dicing and / or when mounting the FFFC 3 onto the curved shell 122. Such deviations can be recorded by one or more cameras 141 of the inspection system 140. Since 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 the semiconductor die 2A is damaged before releasing the die. If it is determined that the semiconductor die 2A is damaged, the controller 100 of the apparatus 1 may decide to skip that semiconductor die.

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

[0079] The inspection system 140 may also use a camera 142 to check that the droplet 151 is correctly placed on the target 113 and / or monitor or check the position and / or orientation of the 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 positioned in close proximity to the semiconductor die 2A that needs to be inspected.

[0081] Figures 3A to 3E show further embodiments of an apparatus for directly placing a semiconductor die 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 to 3E includes a fixed frame 160 that serves as a reference for various movements within the device.

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

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

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

[0086] For example, by rotating the curved shell 122 while translating the target 113 in the y-direction, a semiconductor die 2A can be placed in the same row on the semiconductor wafer 2. When the 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 the entire row on the target 113 is filled, the target chuck 112 is moved in the x-direction to position a new row to be filled beneath the curved shell 122.

[0087] In the embodiment shown in Figure 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 the frame 160, which is partially omitted for illustrative purposes, using motor MR0. Motor MR0 may include, for example, a ball screw, lead screw, belt drive, or linear motor to translate the carriage 131.

[0088] The apparatus shown in Figure 3C differs from the embodiment shown in Figure 3B in that the motor MR0 translates the carriage 131 relative to the carriage 121 instead of the frame 160.

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

[0090] In Figure 3D, the laser source 132 emits a beam of light 133 through a translucent curved shell 122 onto the deposition layer on which the semiconductor die 2A adheres to the carrier film. Alternatively, the release unit 130 may include a needle and a needle actuator for engaging and disengaging the needle from the semiconductor die below. In this case, both the needle actuator and the needle are located inside the curved shell 122 and both are translated in the x-direction.

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

[0092] The present invention has been described above using its detailed embodiments. However, the present invention is not limited to these embodiments. Rather, various modifications are possible without departing from the scope of the invention as defined by the appended claims and equivalents.

[0093] Specific preferred embodiments of the present invention are described in the appended independent claims. Combinations of features from the dependent and / or independent claims are not limited to those described in the claims and may be combined as appropriate.

[0094] The scope of this disclosure includes any novel features or combinations of features, or any generalizations thereof, explicitly or implicitly disclosed, whether relating to the claimed invention or mitigating any or all of the problems addressed by the invention. The applicant hereby notifies that new claims may be made for such features during the examination of this application or any further such application derived therefrom. In particular, with reference to the attached claims, features of dependent claims may be combined with features of independent claims, and each feature of an independent claim may be combined in any suitable manner, not only in the specific combinations enumerated in the claims.

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

[0096] The term “including” does not exclude other elements or steps, and the terms “one (a)” or “one (an)” do not exclude multiple elements or steps. Reference numerals in the claims should not be construed as limiting the claims. [Explanation of symbols]

[0097] 1 device 2 Semiconductor wafers 2A Semiconductor Die 3. Film frame carrier 4 Carrier film 5 cassettes 30 Ring bodies 31 Mounting surface 32 leaf springs 33 Connection part 34, 34A, 34B segments 35A, 35B Contact surface 36A, 36B opening 37 Shaft 41 Adhesion layer 42 Backing Layers 43 Support surface 100 controllers 110 Target Stages 111 Carriage Target Stage 112 Target Chuck 113 Target 120 wafer stage 121 Carrier Wafer Stage 122 Curved Shell 122A Rotating shaft 130 Liberation Units 131 Carrier Liberation Unit 132 Laser Source 133 Beam of Light 134 Mirror Unit 140 Inspection Systems 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. A device for transferring semiconductor dies from an array of semiconductor dies to a target, A wafer stage having a wafer chuck on which the array of semiconductor dies is arranged, A target stage having a target chuck on which a target on which a semiconductor die is placed from the array of semiconductor dies is positioned, A release unit for freeing semiconductor dies from the array of semiconductor dies, The release unit, the wafer stage, and the target stage are all controlled by a controller, The wafer chuck includes a curved shell on which the array of semiconductor dies is arranged and rotatably mounted, and the wafer stage further includes a first motor for rotating the curved shell around a pivot axis. The curved shell is a cylindrical shell, or a partially cylindrical shell, in this apparatus.

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

3. The apparatus according to claim 1, wherein the wafer chuck is configured to support a carrier that supports the arrangement of semiconductor dies, the carrier is selected from the group consisting of tape, film and foil, and the carrier is part of a film frame carrier.

4. The arrangement of the semiconductor die is composed of a diced semiconductor wafer or a structured semiconductor wafer, and / or The rotation axis extends at least substantially parallel to the target chuck, and / or The apparatus according to claim 1, wherein the axis of rotation coincides with the vertical 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 to and / or coincident with the rotation axis, 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 rotation axis and perpendicular to the target chuck. The apparatus further includes a fixed frame and a first carriage, wherein the second motor and / or an 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 The apparatus according to claim 1, further comprising a fixed frame, wherein the second motor and / or an auxiliary second motor is 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 coupling units that enable coupling the array of semiconductor dies to the curved shell. The curved shell is provided with a plurality of openings, and the apparatus further includes a vacuum unit configured to generate an attractive force applied to a diced semiconductor wafer through the plurality of openings, and / or The apparatus according to 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 is supported by a film frame carrier, and the mechanical coupling unit includes a clamping unit for clamping the film frame carrier onto the curved shell.

7. The system further includes a first inspection system configured to inspect semiconductor dies from the array of semiconductor dies before they are placed on the target, The first inspection system is arranged to determine the position and / or orientation of the 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 according to the determined position and / or orientation, and / or The first inspection system is configured to determine whether or not the semiconductor dies in the array of semiconductor dies are damaged, and the controller is configured to control the wafer stage, the target stage and / or the release unit to prevent the semiconductor dies from being placed on the target if it is determined that the semiconductor dies are 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, the controller being 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 positioned 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, The apparatus according to claim 1, wherein the first inspection system, the second inspection system, or the third inspection system includes cameras used in 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 attached to one material selected from the group consisting of tape, foil, and film using a light absorber, the light absorber is configured to release at least locally its attachment to the array of semiconductor dies when irradiated with light having the wavelength. The light absorber is configured to release its adhesion at least locally by photoablation and / or by a chemical reaction as a result of absorbing the light, and / or the light source is configured to irradiate a given semiconductor die in an array of semiconductor dies separate from semiconductor dies adjacent to a given semiconductor die, and the release 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 given semiconductor die. The apparatus according to claim 5, wherein the light source is configured to emit light substantially perpendicular to 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 in a direction perpendicular to the rotation axis and perpendicular to the target chuck. The fourth motor and / or fifth motor are arranged to translate the target chuck relative to the fixed frame, The apparatus according to claim 5, wherein the fourth motor is configured to displace the 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 a semiconductor die positioned in a release position relative to the fixed frame from the arrangement of semiconductor dies. The apparatus according to claim 5, wherein the arrangement of semiconductor dies includes a plurality of semiconductor dies arranged in a matrix of rows and columns, and the rows extend at least substantially parallel to the axis of rotation.

11. The apparatus according to claim 8, wherein the release unit further includes a light guide unit, the light source is configured to emit light toward the light guide unit substantially parallel to the axis of rotation, the light guide unit is configured to guide light substantially perpendicularly from the light source toward the curved shell, the light guide unit includes one or more mirrors and / or one or more prisms, the light guide unit includes one or more actuators controllable by the controller, the one or more actuators are configured to change the orientation of one or more mirrors and / or one or more prisms with respect to incident light from the light source in order to guide light from the light source toward the curved shell at different angles.

12. The target includes a column or row of adjacent placement positions on which each semiconductor die from the array of semiconductor dies is placed, each of the columns or rows of adjacent placement positions extending at least substantially perpendicular or parallel to the axis of rotation, and 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 after exhausting the column of the array of semiconductor dies on which the dies to be placed are used, to translate the curved shell to shift to an adjacent column of semiconductor dies in the array of semiconductor dies, The apparatus according to claim 10, wherein the controller is configured to maintain the released position relative to the fixed frame during the translational motion of the curved shell and shift to an adjacent row of semiconductor dies in the array of semiconductor dies.

13. The release unit includes a second carriage to which the light source or actuator and needle combination is attached, and a third motor for moving the second carriage relative to the curved shell, wherein the second carriage is configured to translate inside and / or above or below the curved shell, the light source is fixed to a fixed frame, and the light guide unit is attached to the second carriage, or The apparatus according to claim 11, wherein the release unit includes a second carriage to which the light source or a combination of actuator and 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 adjacent rows of placement positions where each semiconductor die from the array of semiconductor dies is placed, and the controller is configured to control the wafer stage and / or target stage to cause mutual translational motion between the target and the curved shell after semiconductor dies from the array of semiconductor dies have been placed in all placement positions within the same row on the target, and the controller is configured to maintain the release position with respect to the fixed frame during the mutual translational motion 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 axis of rotation with respect to the fixed frame, and after semiconductor dies from the array of semiconductor dies have been placed in all placement positions within the same row on the target, change the release position and shift to the next row on the target, The apparatus according to claim 12, wherein the apparatus includes a plurality of release units for simultaneously releasing semiconductor dies from an array of semiconductor dies located in different rows on the target.

15. A wafer stage configured for use in the apparatus described in claim 1, having a wafer chuck on which an array of semiconductor dies is arranged, The wafer chuck includes a curved shell on which the array of semiconductor dies is arranged and rotatably mounted, and the wafer stage further includes a first motor for rotating the curved shell around a pivot axis.

16. A wafer stage configured for use in the apparatus described in claim 2, having a wafer chuck on which an array of semiconductor dies is arranged, The wafer chuck includes a curved shell on which the array of semiconductor dies is arranged and rotatably mounted, and the wafer stage further includes a first motor for rotating the curved shell around a pivot axis.

17. A wafer stage configured for use in the apparatus described in claim 5, having a wafer chuck on which an array of semiconductor dies is arranged, The wafer chuck includes a curved shell on which the array of semiconductor dies is arranged and rotatably mounted, and the wafer stage further includes a first motor for rotating the curved shell around a pivot axis.

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