Connecting device

Abstract

In bonding technology for workpieces attached to the surface of a sheet, the invention facilitates the removal of the sheet from the workpiece after bonding. [Solution] In the bonding device, the tip surface of the pressing part has an adsorption surface that holds the first workpiece via the sheet by adsorbing the back surface of the sheet, and a recessed surface that is set back from the adsorption surface around the adsorption surface. The peripheral holding part is the part of the sheet that holds the area surrounding the region to which the first workpiece is attached, and is itself configured in an annular shape and has an annular adsorption surface that adsorbs and holds the entire peripheral area. The pressing part and the peripheral holding part have a sealing structure that seals the space between the outer edge of the recessed surface and the inner surface of the peripheral holding part. As a result, when the sheet is adsorbed to the adsorption surface of the pressing part and the adsorption surface of the peripheral holding part, a sealed space is formed between the adsorption surfaces. The bonding device then reduces the internal pressure of the sealed space when the first workpiece is pressed.

Description

Technical Field

[0001] The present invention relates to a bonding technique for chips and substrates.

Background Art

[0002] Patent Document 1 discloses a technique for holding a chip (such as an LSI or an IC) attached to the surface of an elastically deformable sheet (such as a dicing tape), and pressing and bonding the chip to the surface of a substrate (such as a wafer) through the sheet. In such a bonding technique, it is necessary to peel the sheet from the chip after pressing the chip onto the surface of the substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, in the conventional bonding technique disclosed in Patent Document 1, there may be a case where an event occurs that the sheet cannot be smoothly peeled from the chip after pressing the chip onto the surface of the substrate. When such an event occurs, when trying to pull the sheet away from the chip, the remaining adhesive force between them may cause adverse effects on the chip (such as the bonded chip being peeled off from the surface of the substrate or the chip being damaged). And such adverse effects on the chip may lead to a decrease in productivity and a deterioration in yield.

[0005] Therefore, an object of the present invention is to facilitate the peeling of the sheet from the workpiece after bonding in a bonding technique for a workpiece attached to the surface of the sheet, thereby suppressing adverse effects on the workpiece and improving the peeling speed. [Means for solving the problem]

[0006] The bonding device according to the present invention has the following configuration. The bonding device comprises a sheet holding portion, a pressing portion, and a peripheral holding portion. The sheet holding portion is the part that holds the peripheral edge of the sheet to which the first workpiece is attached. The pressing portion is the part with an adhesive surface formed on its tip surface that holds the first workpiece through the sheet by adsorbing the back surface of the sheet, and it is possible to press the first workpiece onto the surface of the second workpiece by bringing the adhesive surface closer to the surface of the second workpiece. The peripheral holding portion is the part that holds the peripheral region of the sheet to which the first workpiece is attached when the first workpiece is pressed.

[0007] Furthermore, the joining device further comprises the following configuration (Aspect 1). The tip surface of the pressing portion has a recessed surface that is set back from the suction surface around the suction surface. The peripheral holding portion is itself configured in an annular shape and has an annular suction surface that suctions and holds the entire peripheral region. The pressing portion and the peripheral holding portion have a sealing structure that seals the space between the outer edge of the recessed surface and the inner surface of the peripheral holding portion, thereby creating a sealed space between the suction surfaces when the sheet is adsorbed to the suction surface of the pressing portion and the suction surface of the peripheral holding portion in the joining device. When the first workpiece is pressed, the joining device reduces the internal pressure of the sealed space, thereby deforming the portion of the sheet between the suction surface of the pressing portion and the suction surface of the peripheral holding portion toward the recessed surface of the pressing portion.

[0008] According to the above embodiment 1, when the internal pressure of the sealed space is reduced, the difference in height between the suction surface and the receding surface of the pressing part can be used to bend or curve the sheet at the outer edge of the suction surface, and as a result, it becomes possible to increase the peeling angle of the sheet from the first workpiece. By increasing the peeling angle in this way, it becomes possible to make it easier to peel the sheet from the first workpiece after pressing it.

[0009] In the joining device according to the above embodiment 1, the sealing structure may be configured such that a pressing portion is fitted inside the peripheral holding portion without any gaps and in a slidable manner (embodiment 2).

[0010] According to the above embodiment 2, it becomes possible to construct a sealed structure without increasing the number of parts in the device.

[0011] In the bonding device according to embodiment 1 or 2 described above, at least one of the suction surface of the pressing part and the suction surface of the peripheral holding part may be configured to adsorb the back surface of the sheet by vacuum suction, and in such a bonding device, the internal pressure of the sealed space may be reduced by the vacuum suction (embodiment 3).

[0012] According to embodiment 3 described above, since the internal pressure of the sealed space can be reduced by utilizing vacuum suction to adsorb the sheet onto the adsorption surface, there is no need to separately provide a mechanism (pressure reduction unit) for reducing the internal pressure of the sealed space, and as a result the configuration of the bonding device does not need to be complicated.

[0013] A joining device according to any of the above embodiments 1 to 3 may have the following configuration (embodiment 4). The pressing part may have a slide pin, and the slide pin may be configured to slide in a direction perpendicular to the suction surface of the pressing part, and to protrude from a predetermined position within the suction surface by sliding. In such a joining device, before pressing the first workpiece, the internal pressure of the sealed space may be reduced, the tip of the slide pin may be made to protrude from the suction surface of the pressing part to a predetermined height, and then, when pressing the first workpiece, the tip of the slide pin may be retracted until it is at the same height as the suction surface of the pressing part.

[0014] According to embodiment 4 described above, by making the tip of the slide pin protrude from the suction surface of the pressing part to a predetermined height before pressing the first workpiece, the sheet can be deformed into a convex shape on the suction surface of the pressing part, and as a result, a force (peeling force) that peels the sheet away from the first workpiece can be generated. At this time, the peeling angle of the sheet from the first workpiece is large as described above. Therefore, by generating the above-mentioned peeling force, the adhesive force of the first workpiece to the sheet can be efficiently weakened. By weakening the adhesive force between the first workpiece and the sheet in this way before pressing the first workpiece, it becomes possible to further facilitate the peeling of the sheet away from the first workpiece after pressing (joining) the first workpiece.

[0015] In the joining apparatus according to Embodiment 4 described above, after pressing the first workpiece, when retracting the suction surface of the pressing part from the surface of the second workpiece, the suction surface of the pressing part may be retracted first without retracting the slide pin, thereby pressing the first workpiece with only the slide pin, and then the slide pin may also be retracted (Embodiment 5).

[0016] According to embodiment 5 described above, by retracting only the suction surface of the pressing part first without retracting the slide pin, the sheet is peeled off up to the area around the slide pin, and at that time it becomes easier to create a peeling angle between the first workpiece and the sheet. As a result, it becomes possible to further facilitate the peeling of the sheet from the first workpiece after pressing (joining) the first workpiece. [Effects of the Invention]

[0017] According to the present invention, in a bonding technology targeting a workpiece attached to the surface of a sheet, it becomes possible to easily peel the sheet from the workpiece after bonding, thereby improving the peeling speed while suppressing adverse effects on the workpiece. [Brief explanation of the drawing]

[0018] [Figure 1](A) Conceptual diagram showing the bonding apparatus according to the embodiment, and (B) Conceptual diagram showing an enlarged view of the pressing mechanism and its surrounding configuration included in the bonding apparatus. [Figure 2] Conceptual diagram showing the configuration at each point of the posture adjustment mechanism that three-point supports the piezo stage. [Figure 3] (A) Conceptual diagram showing the state change of the bonding apparatus caused by the execution of the bonding process, and (B) Conceptual diagram showing the next state change. [Figure 4] (A) Conceptual diagram showing an enlarged view of the pressing mechanism and its surrounding configuration of the bonding apparatus in the state shown in Fig. 3(B), and (B) Enlarged view of the J1 region in Fig. 4(A). [Figure 5] Conceptual diagram showing the state change of the bonding apparatus caused by the execution of the bonding process. [Figure 6] Conceptual diagram showing the state change of the bonding apparatus caused by the execution of the bonding process. [Figure 7] (A) Conceptual diagram showing the state change of the bonding apparatus caused by the execution of the bonding process, and (B) Enlarged view of the J2 region in Fig. 7(A). [Figure 8] (A) Conceptual diagram showing the state change of the bonding apparatus caused by the execution of the bonding process, and (B) Conceptual diagram showing the next state change. [Embodiments for Carrying Out the Invention]

[0019] [1] Embodiment [1-1] Bonding Apparatus Fig. 1(A) is a conceptual diagram showing the bonding apparatus according to the embodiment. This bonding apparatus is a device that presses and bonds a chip (such as an LSI or IC; hereinafter referred to as "first workpiece W1") to the surface of a substrate (such as a wafer; hereinafter referred to as "second workpiece W2"), and includes a holding mechanism 1, a pressing mechanism 2, an alignment stage 3, a detection sensor 4, and a control device 5.

[0020] The holding mechanism 1 includes a sheet holding portion 11, a table 12, and a drive portion 13.

[0021] The sheet holding portion 11 is a part that holds the peripheral edge of an elastically deformable sheet Sw (such as a dicing tape) while applying tension to the sheet Sw. In this embodiment, such a sheet Sw is prepared with multiple first workpieces W1 attached to one side thereof, and is held in the sheet holding portion 11 with that side facing downwards.

[0022] Table 12 is the part that holds the second workpiece W2 at a position below the sheet Sw held by the sheet holding part 11, and is equipped with a chuck function (such as vacuum suction or electrostatic chuck) for fixing the second workpiece W2. Here, a circuit is formed on the second workpiece W2, and a predetermined position corresponding to the circuit (specifically, a predetermined position to which connection to the circuit is possible) is set on the surface of the second workpiece W2 as the joining position Pt of the first workpiece W1. Therefore, the second workpiece W2 is held in table 12 with the joining surface with the first workpiece W1 (the surface on which the joining position Pt of the first workpiece W1 is provided) facing upward.

[0023] The drive unit 13 is a mechanism that enables vertical movement of the table 12 and position adjustment of the table 12 in the horizontal plane, and is composed of, for example, a ball screw and a motor. With the position adjustment of the table 12 by such a drive unit 13, when joining one workpiece (hereinafter referred to as "target workpiece Wt") selected from a plurality of first workpieces W1 attached to the sheet Sw to its corresponding joining position Pt, it becomes possible to perform a position adjustment (position adjustment that does not require high precision) to make the joining position Pt face the target workpiece Wt before performing the joining. After such a position adjustment, high-precision position adjustment (alignment) of the target workpiece Wt with respect to the joining position Pt is performed by the piezo stage 31, which will be described later.

[0024] In this embodiment, the joining device is configured to join multiple first workpieces W1 attached to a sheet Sw by pressing them one by one onto the surface of a second workpiece W2 (specifically, the corresponding joining position Pt). Specifically, it is as follows:

[0025] The pressing mechanism 2 comprises a pressing section 21, a peripheral holding section 22, and drive sections 23 and 24.

[0026] The pressing portion 21 is the part that presses the target workpiece Wt, which is attached to the sheet Sw, against the surface of the second workpiece W2. Specifically, a suction surface 21p is formed on the tip surface 21a of the pressing portion 21 (the bottom surface in the example of Figure 1(A)) to hold the target workpiece Wt via the sheet Sw by adsorbing the back surface of the sheet Sw. In this embodiment, the suction surface 21p has a configuration (area, shape, etc.) that enables it to hold only the target workpiece Wt via the sheet Sw. Furthermore, this suction surface 21p is configured to adsorb the back surface of the sheet Sw by vacuum suction. In addition, the pressing portion 21 is configured to move up and down by the power of the drive unit 23. A more specific configuration will be described later, but the pressing portion 21 is configured to move up and down independently of the peripheral holding portion 22 which will be described below.

[0027] With such a pressing portion 21, after holding the target workpiece Wt with its suction surface 21p, the pressing portion 21 is lowered to bring the suction surface 21p closer to the surface of the second workpiece W2, thereby enabling the target workpiece Wt to ​​be pressed against the surface of the second workpiece W2 (see Figure 7(A)).

[0028] The peripheral holding portion 22 is the part that holds the area surrounding the region on the sheet Sw to which the workpiece Wt is attached when the workpiece Wt is pressed. Specifically, the peripheral holding portion 22 is configured in an annular shape and has an annular suction surface 22p that adsorbs and holds the entire peripheral region. In this embodiment, this suction surface 22p is configured to adsorb the back surface of the sheet Sw by vacuum suction. Furthermore, the peripheral holding portion 22 is configured to move up and down by the power of the drive unit 24.

[0029] With this peripheral holding portion 22, when the target workpiece Wt is pressed by the pressing portion 21, the peripheral region of the sheet Sw to which the target workpiece Wt is attached can be held by the suction surface 22p and kept in the same position (see Figure 7(A)). As a result, when the target workpiece Wt is pressed, the sheet Sw can be appropriately flexed inside the suction surface 22p.

[0030] Furthermore, the pressing mechanism 2 has the following configuration. Figure 1(B) is a conceptual diagram showing an enlarged view of the pressing mechanism 2 and its surrounding configuration. As shown in this figure, the tip surface 21a of the pressing portion 21 has a recessed surface 21q that is set back from the suction surface 21p around the suction surface 21p. As a result, the tip surface 21a is formed in a platform shape with a raised central portion. The pressing portion 21 and the peripheral holding portion 22 have a sealing structure that seals the space between the outer edge of the recessed surface 21q and the inner surface of the peripheral holding portion 22. As a result, when the sheet Sw is adsorbed onto the suction surface 21p of the pressing portion 21 and the suction surface 22p of the peripheral holding portion 22, a sealed space Qs can be formed between the suction surfaces 21p and 22p (see Figures 3(B) and 4(A)).

[0031] In this embodiment, the above-described sealing structure is constructed by fitting the pressing portion 21 into the inside of the peripheral holding portion 22 without any gaps and in a slidable manner (see Figure 1(B)). This makes it possible to construct a sealing structure without increasing the number of parts in the joining device.

[0032] With such a sealed structure, by reducing the internal pressure of the sealed space Qs when the first workpiece W1 is pressed, it becomes possible to deform the portion of the sheet Sw between the suction surface 21p of the pressing portion 21 and the suction surface 22p of the peripheral holding portion 22 toward the retracted surface 21q of the pressing portion 21 (see Figure 4(A)). In this embodiment, the internal pressure of the sealed space Qs is reduced by vacuum suction when the sheet Sw is adsorbed onto the suction surfaces 21p and 22p.

[0033] This allows the sheet Sw to be curved or bent at the outer edge of the suction surface 21p by utilizing the step difference between the suction surface 21p and the retracted surface 21q of the pressing portion 21 (see Figure 4(A)), and as a result, it becomes possible to increase the peeling angle θp of the sheet Sw from the first workpiece W1 (see Figure 4(B)). By increasing the peeling angle θp in this way, it becomes possible to make it easier to peel the sheet Sw from the first workpiece W1 after pressing the first workpiece W1.

[0034] Furthermore, since the internal pressure of the sealed space Qs can be reduced by utilizing vacuum suction to adsorb the sheet Sw onto the adsorption surfaces 21p and 22p, there is no need to separately provide a mechanism (pressure reduction section) to reduce the internal pressure of the sealed space Qs, and as a result, the configuration of the bonding device does not need to be complicated.

[0035] In addition to the above configuration, the pressing portion 21 has a slide pin 211 (see Figure 1(B)). This slide pin 211 is configured to slide in a direction perpendicular to the suction surface 21p of the pressing portion 21, and to protrude from a predetermined position within the suction surface 21p by this sliding. In this embodiment, the predetermined position is set to be the center position of the suction surface 21p. Furthermore, the sliding of the slide pin 211 is performed by the power of the drive unit 212.

[0036] More specifically, the pressing portion 21 is provided with a guide hole 210 that opens onto the suction surface 21p of the pressing portion 21, for slidably installing the slide pin 211. The slide pin 211 is capable of sliding along the guide hole 210 and can reciprocate between a position where its tip is retracted into the guide hole 210 (see Figure 4(A)) and a position where its tip protrudes from the guide hole 210 (see Figure 8(A)). In this embodiment, the slide pin 211 is provided in a state where it is fitted snugly and slidably into the guide hole 210 so that the inside of the guide hole 210 also becomes a vacuum when vacuum is applied. Details of the operation and function of this slide pin 211 will be described later.

[0037] The alignment stage 3 (see Figure 1(A)) is a composite of multiple stages designed to enable high-speed and high-precision position adjustment of the pressing mechanism 2. Specifically, the alignment stage 3 comprises a piezo stage 31 and a wide-range stage 32 that allows for position adjustment over a wider area than the piezo stage 31. The piezo stage 31 is mounted on the wide-range stage 32, and the pressing mechanism 2 is mounted on the piezo stage 31. Here, the piezo stage 31 uses a piezo element as its drive source, enabling high-precision (nano-order precision) position adjustment of the stage. On the other hand, the wide-range stage 32 uses a ball screw and a motor as its drive source, enabling high-speed movement of the stage over a wide area.

[0038] With this alignment stage 3, the position adjustment of the pressing mechanism 2 can be performed in two stages using the wide-range stage 32 and the piezo stage 31. Specifically, the wide-range stage 32 moves the pressing mechanism 2 over a wide area at high speed without requiring high precision, and then the piezo stage 31 makes it possible to adjust the position of the pressing mechanism 2 with high precision (nano-order precision).

[0039] Therefore, when aligning the target workpiece Wt with respect to the joining position Pt provided on the surface of the second workpiece W2, the wide stage 32 allows the pressing mechanism 2 to be moved at high speed to a position where the target workpiece Wt can be held from the back side (in other words, a position above the corresponding joining position Pt).

[0040] Furthermore, since the sheet Sw is elastically deformable, even after the target workpiece Wt is held on the suction surface 21p via the sheet Sw, the position adjustment of the pressing mechanism 2 by the piezo stage 31 (i.e., the position adjustment of the target workpiece Wt) can be performed while elastically deforming the sheet Sw. Therefore, the alignment of the target workpiece Wt with respect to the joining position Pt can be performed with high precision by the piezo stage 31 without being affected by the sheet Sw. Thus, it becomes possible to significantly improve the accuracy of the alignment with respect to the joining position Pt.

[0041] Thus, the joining device of this embodiment makes it possible to achieve both high-speed movement of the pressing mechanism 2 over a wide area and high-precision position adjustment of the target workpiece Wt relative to the joining position Pt. As a result, it becomes possible to perform high-precision alignment of the target workpiece Wt relative to the joining position Pt, one by one, at high speed, even when the joining positions Pt are scattered over a wide area.

[0042] In this embodiment, the alignment stage 3 further includes a posture adjustment mechanism 33 (see Figure 2) that enables posture adjustment of the piezo stage 31 relative to the wide stage 32. Specifically, the posture adjustment mechanism 33 is configured to support the piezo stage 31 at three points relative to the wide stage 32.

[0043] Figure 2 is a conceptual diagram showing the configuration at each point of the attitude adjustment mechanism 33 that supports the piezo stage 31 at three points. At each point, the attitude adjustment mechanism 33 is configured by erecting a piezo actuator 331 on the wide stage 32, which is capable of adjusting the amount of protrusion of the movable part 331A, and supporting the piezo stage 31 by bringing the tip of the movable part 331A into contact with the back surface of the piezo stage 31. In the example in Figure 2, the main body 331B of the piezo actuator 331 is shown to be connected to the piezo stage 31 via an annular leaf spring 332 in order to stabilize the support state of the piezo stage 31 by the piezo actuator 331.

[0044] With this posture adjustment mechanism 33, it becomes possible to adjust the posture of the piezo stage 31 so that it is parallel to the wide-range stage 32.

[0045] Furthermore, when the target workpiece Wt is pressed against the surface of the second workpiece W2, a force equivalent to the pressure generated at that time (the reaction force applied to the piezo stage 31 at that time) is concentrated at three points (piezo actuators 331) that support the piezo stage 31. Therefore, the posture adjustment mechanism 33 incorporates a pressure sensor 333 that measures the force (force equivalent to the pressure) applied to the piezo stage 31 at these three points (see Figure 2). This allows the pressure generated when the target workpiece Wt is pressed against the surface of the second workpiece W2 to be measured by the pressure sensor 333.

[0046] The detection sensor 4 (see Figure 1(A)) is a sensor that detects alignment marks formed on the first workpiece W1 and the second workpiece W2.

[0047] In this embodiment, each first workpiece W1 and the portion of the second workpiece W2 where the joining position Pt of the first workpiece W1 is located constitute a pair of joining targets to be joined together. Then, one pair of joining targets selected from all pairs (the target workpiece Wt and the portion of the second workpiece W2 where the joining position Pt of the target workpiece Wt is located) is subjected to alignment before joining. During the alignment, their relative positional relationship is adjusted by the drive unit 13 of the holding mechanism 1 (positional adjustment that does not require high precision) so that they overlap each other (opposing each other) when viewed from a direction perpendicular to a two-dimensional virtual plane (horizontal plane in this embodiment) (vertical direction in this embodiment). From that state, further adjustment is performed by high-precision positional adjustment (alignment) by the piezo stage 31 so that a predetermined positional relationship is achieved (the position of the target workpiece Wt when viewed from the vertical direction coincides with the joining position Pt).

[0048] In this embodiment, alignment marks are formed on each pair of joining objects in order to enable high-precision alignment as described above for any pair of joining objects.

[0049] The detection sensor 4 is an image sensor that acquires an image including the image or shadow of the alignment marks (the image or shadow of the mark on the target workpiece Wt side and the corresponding mark on the second workpiece W2 side) by detecting light from a light source 41 (not shown). In this embodiment, IR light (infrared light) is used as the light from the light source 41, and the sheet Sw and table 12 are made of materials that can transmit IR light. In addition, the IR light may be extracted by passing the light from the light source 41 through a bandpass filter.

[0050] Furthermore, the detection sensor 4 is installed on the wide-area stage 32 together with the piezo stage 31. Therefore, if you want to acquire an image including the alignment marks with the detection sensor 4, the light source 41 is positioned so that light shines onto the alignment marks from the back side of the sheet Sw (the top side in Figure 1(A)). This allows the detection sensor 4 to detect the reflected light from the alignment marks. On the other hand, if you want to acquire an image including the shadows of the alignment marks with the detection sensor 4, the light source 41 is positioned so that light shines onto the alignment marks from the back side of the table 12 (the bottom side in Figure 1(A)). This allows the detection sensor 4 to detect the transmitted light that casts shadows on the alignment marks.

[0051] Furthermore, in this embodiment, light incident on the suction surface 21p of the pressing part 21 from the alignment mark side is used to acquire an image (an image of the alignment mark or an image including its shadow) by the detection sensor 4. Specifically, this is as follows: The pressing mechanism 2 has an optical path Rm formed therein to transmit light incident on the suction surface 21p of the pressing part 21 from the alignment mark side to the detection sensor 4 (see Figure 1(A)). In this embodiment, in order to realize the formation of such an optical path Rm, the pressing part 21 is made of a material that can transmit IR light (such as quartz or acrylic).

[0052] With this detection sensor 4 and its related configuration, alignment using alignment marks (correction of misalignment) can be performed while observing the alignment marks with the detection sensor 4 provided on the wide-area stage 32. Therefore, alignment using alignment marks can be performed with the target workpiece Wt close to the second workpiece W2 (see Figure 5). As a result, after alignment, the target workpiece Wt can be pressed against the surface of the second workpiece W2 without causing any misalignment (see Figure 7(A)). Thus, the accuracy of alignment with respect to the joining position Pt can be significantly improved.

[0053] The control device 5 consists of a processing device (such as a CPU) and a storage device (such as RAM or ROM), and controls each part of the bonding device (such as the holding mechanism 1, pressing mechanism 2, alignment stage 3, and detection sensor 4) according to a control program installed in the bonding device. In this embodiment, the control device 5 can perform the bonding process described below.

[0054] Here, the control program described above may be stored in a readable state on a portable storage medium (e.g., flash memory) before installation in the bonding device, or it may be stored in a downloadable state on another server. Furthermore, the bonding process described below is not limited to being implemented in software by executing the program, but may also be implemented in hardware by a processing circuit built within the bonding device.

[0055] [1-2] Joining process Figures 3(A) to 8(B) are conceptual diagrams that sequentially show the changes in the state of the joining device that occur when the joining process is performed.

[0056] When the joining process begins, the control device 5 first controls the wide stage 32 to move the pressing mechanism 2 at high speed to a position where it can hold the target workpiece Wt from the back side (in other words, a position above the corresponding joining position Pt) in order to align the target workpiece Wt with the joining position Pt provided on the surface of the second workpiece W2 (step S101; see Figure 3(A)). At this time, the control device 5 also performs a position adjustment (a position adjustment that does not require high precision) to bring the joining position Pt opposite the target workpiece Wt by controlling the drive unit 13 to adjust the position of the table 12 while observing the alignment marks (the mark on the target workpiece Wt side and the corresponding mark on the second workpiece W2 side) provided on the target workpiece Wt and the joining position Pt with the detection sensor 4.

[0057] After step S101, the control device 5 controls the drive units 23 and 24 of the pressing mechanism 2 to lower the pressing unit 21 and the peripheral holding unit 22, thereby causing the back surface of the area of ​​the sheet Sw to which the target workpiece Wt is attached to be attached to the suction surface 21p of the pressing unit 21 by vacuum suction, and the back surface of the surrounding area to be attached to the suction surface 22p of the peripheral holding unit 22 by vacuum suction (step S102; see Figure 3(B)). At this time, the control device 5 aligns the suction surface 21p of the pressing unit 21 and the suction surface 22p of the peripheral holding unit 22 on the same plane. The control device 5 also controls the drive unit 212 to retract the tip of the slide pin 211 into the guide hole 210 (see Figure 4(A)).

[0058] As a result, the target workpiece Wt is held by the suction surface 21p of the pressing part 21 via the sheet Sw, and the area surrounding the region of the sheet Sw to which the target workpiece Wt is attached is held by the suction surface 22p of the peripheral holding part 22.

[0059] Furthermore, in step S102, by adhering the sheet Sw to the suction surface 21p of the pressing portion 21 and the suction surface 22p of the peripheral holding portion 22, a sealed space Qs is formed between these suction surfaces 21p and 22p. Then, the internal pressure of the sealed space Qs is reduced by vacuum suction at these suction surfaces 21p and 22p.

[0060] As a result, the portion of the sheet Sw between the suction surface 21p of the pressing portion 21 and the suction surface 22p of the peripheral holding portion 22 deforms toward the retracted surface 21q of the pressing portion 21. This deformation of the sheet Sw allows the sheet Sw to be curved or bent at the outer edge of the suction surface 21p of the pressing portion 21 (see Figure 4(A)), and as a result, it becomes possible to increase the peel angle θp of the sheet Sw relative to the first workpiece W1 (see Figure 4(B)). In this embodiment, by lowering the pressing portion 21 while keeping the peripheral holding portion 22 in the same position, this peel angle θp gradually increases.

[0061] By increasing the peeling angle θp in this way, it becomes easier to peel the sheet Sw from the first workpiece W1 after pressing the first workpiece W1. In other words, it becomes easier to peel the sheet Sw from the first workpiece W1 after pressing (joining) the first workpiece W1.

[0062] After step S102, the control device 5 controls the piezo stage 31 to adjust the position of the pressing mechanism 2 with high precision (nano-order precision) (step S103; see Figure 5).

[0063] Specifically, the control device 5 observes an image containing the image or shadow of the alignment marks (image or shadow of the mark on the target workpiece Wt and the corresponding mark on the second workpiece W2) provided on the target workpiece Wt and the joining position Pt using the detection sensor 4, and performs high-precision position adjustment of the target workpiece Wt so that the two corresponding marks precisely overlap. This ensures high-precision alignment of the target workpiece Wt with respect to the joining position Pt.

[0064] After step S103, the control device 5 maintains a reduced internal pressure in the sealed space Qs before pressing the first workpiece W1, and causes the tip of the slide pin 211 to protrude from the suction surface 21p of the pressing part 21 to a predetermined height (step S104; see Figure 6).

[0065] This allows the sheet Sw to be deformed into a convex shape on the suction surface 21p of the pressing part 21, and as a result, a force (peeling force) that peels the sheet Sw from the first workpiece W1 can be generated. Here, the predetermined height is set so that even if the sheet Sw is deformed into a convex shape on the suction surface 21p, the first workpiece W1 will not be adversely affected (such as the first workpiece W1 being damaged due to bending).

[0066] Furthermore, at this point, the peel angle θp of the sheet Sw relative to the first workpiece W1 has already become large, as described above. Therefore, by generating the above-mentioned peeling force, the adhesive force of the first workpiece W1 to the sheet Sw can be efficiently weakened. By weakening the adhesive force between the first workpiece W1 and the sheet Sw in this way before pressing the first workpiece W1, it becomes possible to further facilitate the peeling of the sheet Sw from the first workpiece W1 after pressing (joining) the first workpiece W1.

[0067] After step S104, the control device 5 controls the drive unit 23 of the pressing mechanism 2 to lower the pressing unit 21, thereby pressing the target workpiece Wt onto the surface of the second workpiece W2 (step S105; see Figure 7(A)). At this time, the control device 5 controls the drive unit 212 to retract the tip of the slide pin 211 until it is at the same height as the suction surface 21p of the pressing unit 21. The control device 5 also lowers the pressing unit 21 until the output of the pressure sensor 333 reaches the target value (in other words, until the pressing force reaches the target value).

[0068] Furthermore, in step S105, the control device 5 keeps the peripheral holding portion 22 in the same position when lowering the pressing portion 21. This allows the sheet Sw to be appropriately flexed when pressing the target workpiece Wt, and as a result, it is possible to gradually increase the peeling angle θp of the sheet Sw relative to the first workpiece W1 (see Figure 7(B)).

[0069] After step S105, the control device 5 controls the drive unit 23 of the pressing mechanism 2 to raise the pressing unit 21, thereby retracting the suction surface 21p of the pressing unit 21 from the surface of the second workpiece W2 (step S106; see Figure 8(A)). At this time, the control device 5 further controls the drive unit 212 to retract only the suction surface 21p of the pressing unit 21 first without retracting the slide pin 211, thereby pressing the first workpiece W1 with only the slide pin 211. Subsequently, the control device 5 controls the drive unit 212 to retract the slide pin 211 as well (step S107; see Figure 8(B)).

[0070] By retracting only the suction surface 21p of the pressing portion 21 first without retracting the slide pin 211, the sheet Sw can be peeled off up to the area around the slide pin 211, and at that time it becomes easier to generate a peeling angle θp between it and the first workpiece W1. As a result, it becomes possible to further facilitate the peeling of the sheet Sw from the first workpiece W1 after pressing (joining) the first workpiece W1.

[0071] Thus, according to this embodiment, in a bonding technology targeting a first workpiece W1 attached to the surface of a sheet Sw, it becomes possible to easily peel the sheet Sw from the first workpiece W1 after bonding, thereby improving the peeling speed while suppressing adverse effects on the first workpiece W1. The control device 5 then performs this bonding process (steps S101 to S107) one by one on the multiple first workpieces W1 attached to the sheet Sw.

[0072] [2] Variant [2-1] First variation In the joining device described above, the sealing structure that seals the space between the outer peripheral edge of the recessed surface 21q and the inner peripheral surface of the peripheral holding portion 22 may be constructed by interposing a bellows or an elastic body (such as a leaf spring) between them.

[0073] [2-2] Second variation In the bonding apparatus described above, the pressing mechanism 2 is not limited to a configuration in which both the suction surface 21p of the pressing part 21 and the suction surface 22p of the peripheral holding part 22 can adsorb the back surface of the sheet Sw by vacuum suction. It may be appropriately modified to a configuration in which only one of the suction surfaces can adsorb the back surface of the sheet Sw by vacuum suction.

[0074] [2-3] Third variation In the bonding apparatus described above, the pressing mechanism 2 may be appropriately modified to reduce the internal pressure of the sealed space Qs in a configuration independent of the configuration that uses vacuum suction to adsorb the sheet Sw onto the adsorption surfaces 21p and 22p. Specifically, the pressing mechanism 2 may be appropriately modified to include a dedicated pressure reduction unit for reducing the internal pressure of the sealed space Qs.

[0075] [2-4] Fourth variation In the control process described above, the control device 5 may perform the following process. The control device 5 measures the pressure generated when pressing in step S105 using pressure sensors 333 at three points supporting the piezo stage 31. The control device 5 then feeds back the three measured values ​​obtained at that time to the control of the attitude adjustment mechanism 33, thereby adjusting the attitude of the piezo stage 31 so that all three measured values ​​are within a predetermined range for the next pressing. Here, the predetermined range is set so that it is permissible to estimate that the piezo stage 31 is parallel to the wide-range stage 32 when all three measured values ​​are within that range.

[0076] Specifically, the control device 5 uses the three measured values ​​to calculate values ​​such as the amount of deviation of the measured values ​​from a reference value (such as a center value) within a predetermined range and the difference between the measured values. Based on the calculated values, it can adjust the amount of protrusion of the movable part 331A of each piezo actuator 331 so that all three measured values ​​are within the predetermined range during the next pressing operation.

[0077] This control process makes it possible to adjust the position of the piezo stage 31 so that it is parallel to the wide-area stage 32 each time the target workpiece Wt is pressed against the surface of the second workpiece W2. This makes it possible to keep the piezo stage 31 parallel to the wide-area stage 32 at all times.

[0078] [2-5] Fifth variation The joining device described above may be modified as appropriate to perform the joining of the first workpiece W1 and the second workpiece W2 in a position where their joining surfaces are oriented laterally (horizontally).

[0079] [2-6] Sixth variation The bonding apparatus described above can be applied not only when bonding a chip (first workpiece W1) to a substrate (second workpiece W2), but also when bonding a chip (first workpiece W1) to another chip (second workpiece W2).

[0080] The above-described embodiments and modifications should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims, rather than by the above-described embodiments and modifications. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the claims.

[0081] Furthermore, from the above-described embodiments and modifications, a part of the configuration of the joining device may be extracted as the subject of the invention, or a part or all of the joining process (including the corresponding control method and joining method), or even a program for executing them, may be extracted. [Explanation of symbols]

[0082] 1 Retention mechanism 2. Pressing mechanism 3 Alignment Stages 4. Detection Sensors 5 Control device 11 Sheet holding section 12 tables 13 Drive unit 21 Pressing part 21a Tip surface 21p suction surface 21q Retraction plane 22 Peripheral holding part 22p suction surface 23, 24 Drive unit 31 Piezo Stage 32 Wide-ranging stages 33 Posture adjustment mechanism 41 Light source Pt joint position Qs Closed space Rm optical path Sw Seat W1 1st Work W2 2nd Work Wt Target Work 210 Guide holes 211 Slide pins 212 Drive unit 331 Piezo actuator 331A Moving part 331B Main body 332 Leaf spring 333 Pressure Sensor θp peeling angle

Claims

1. The first workpiece is a sheet holding part that holds the peripheral edge of the sheet to which the sheet is attached, A suction surface is formed on the tip surface of the sheet, which holds the first workpiece through the sheet by adsorbing the back surface of the sheet, and a pressing portion is provided which allows the first workpiece to be pressed against the surface of the second workpiece by bringing the suction surface close to the surface of the second workpiece. When the first workpiece is pressed, the peripheral holding portion holds the area surrounding the region of the sheet to which the first workpiece is attached, Equipped with, The tip surface of the pressing portion has a recessed surface formed around the suction surface, which is set back from the suction surface. The peripheral holding portion is itself configured in an annular shape and has an annular suction surface that adsorbs and holds the entire peripheral region. The pressing portion and the peripheral holding portion have a sealing structure that seals the space between the outer peripheral edge of the recessed surface and the inner peripheral surface of the peripheral holding portion, thereby forming a sealed space between the suction surfaces when the sheet is attached to the suction surface of the pressing portion and the suction surface of the peripheral holding portion. A joining device that, when pressing the first workpiece, reduces the internal pressure of the sealed space, thereby deforming the portion of the sheet between the suction surface of the pressing portion and the suction surface of the peripheral holding portion toward the retracted surface side of the pressing portion.

2. The sealing structure is configured by fitting the pressing portion into the inside of the peripheral holding portion without any gaps and in a slidable manner, as described in claim 1.

3. The bonding apparatus according to claim 1 or 2, wherein at least one of the suction surface of the pressing portion and the suction surface of the peripheral holding portion is configured to adsorb the back surface of the sheet by vacuum suction, thereby reducing the internal pressure of the sealed space by vacuum suction.

4. The pressing portion has a slide pin, which is configured to slide in a direction perpendicular to the suction surface of the pressing portion, and to protrude from a predetermined position within the suction surface by sliding. Before pressing the first workpiece, with the internal pressure of the sealed space reduced, the tip of the slide pin is made to protrude from the suction surface of the pressing part to a predetermined height. The joining device according to claim 1 or 2, wherein, when the first workpiece is pressed, the tip of the slide pin is retracted until it is at the same height as the suction surface of the pressing part.

5. The joining device according to claim 4, wherein, after pressing the first workpiece, when the suction surface of the pressing part is retracted from the surface of the second workpiece, only the suction surface of the pressing part is retracted first without retracting the slide pin, thereby pressing the first workpiece with only the slide pin, and then the slide pin is also retracted.

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