JP7652604B2 - Bonding device and method for manufacturing solid-state image pickup device - Google Patents

Description

This disclosure relates to a bonding apparatus and is applicable, for example, to a bonding apparatus that bonds a workpiece to a semiconductor chip.

A bonding device is a device that bonds (places and adheres) semiconductor chips, etc. onto a substrate such as a wiring board or lead frame, or onto an already bonded semiconductor chip, using a resin paste or similar bonding material. A bonding device, for example, repeatedly performs the following operations (tasks): pick up a semiconductor chip, etc. from a semiconductor wafer, etc., by suction using a suction nozzle called a collet attached to the tip of the bonding head, place it in a specified position on the substrate, and bond it by applying a pressing force.

A solid-state imaging device is composed of, for example, a semiconductor chip on which an image sensor and microlenses are formed, a wiring board on which the semiconductor chip is mounted, and a cover glass that protects the semiconductor chip. When performing color imaging, a color filter is formed between the image sensor and the microlens. Some semiconductor chips have a layered structure formed by bonding multiple semiconductor substrates together. The semiconductor chip and the cover glass are bonded with an adhesive formed on the periphery. Here, the image sensor is composed of a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). For example, functional glass with various functional layers added depending on the application, such as AR (anti-reflection), IR (infrared) cut, and gas barrier, may be used as the cover glass.

JP 2016-12695 A

For example, in the manufacture of solid-state imaging devices, a paste-like adhesive may be applied onto a semiconductor chip placed on a wiring board (substrate), and a workpiece such as a cover glass (glass chip) may be bonded onto the adhesive. When the semiconductor chip is mounted at an angle on the substrate due to warping of the substrate or unevenness in the adhesive that bonds the semiconductor chip and substrate, it may be necessary to maintain the inclination of the placed workpiece so that it follows the semiconductor chip. However, because the bonding head holds the workpiece horizontally, when the bonding head places the workpiece on the paste-like adhesive, the workpiece is partially pressed into the paste-like adhesive. As a result, the workpiece may not be able to follow the inclination of the semiconductor chip.

The objective of the present disclosure is to provide a technology that allows a workpiece to follow the inclination of a semiconductor chip. Other objectives and novel features will become apparent from the description of this specification and the accompanying drawings.

A brief summary of representative aspects of this disclosure is given below.
That is, the bonding apparatus comprises a syringe that applies a paste-like adhesive onto a semiconductor chip mounted on a substrate, a bonding head having a collet at the tip of the syringe that adsorbs a workpiece and places the workpiece on the paste-like adhesive applied by the syringe, and a control unit configured to release the adsorption of the workpiece by the collet and drop the workpiece onto the paste-like adhesive at a position where the distance between the highest point of the paste-like adhesive applied on the semiconductor chip and the workpiece is within a predetermined range.

The above bonding device allows the workpiece to follow the inclination of the semiconductor chip.

1 is a top view showing an outline of a bonding apparatus according to an embodiment; 2 is a cross-sectional view showing an outline of the chip supply unit shown in FIG. 1 . FIG. 2 is a side view showing an outline of the preform part shown in FIG. 1 . 2 is a side view showing an outline of a chip supply unit and a bonding unit shown in FIG. 1 . 4 is a flowchart showing a method for manufacturing a solid-state imaging device using the bonding apparatus shown in FIG. 1 . 2 is a diagram showing an outline of a solid-state imaging device manufactured by the bonding apparatus shown in FIG. 1 . 7A to 7C are diagrams illustrating a method for manufacturing the solid-state imaging device shown in FIG. 6 . 7A to 7C are diagrams for explaining problems with the method for manufacturing the solid-state imaging device shown in FIG. 6 . 7A to 7C are diagrams illustrating a manufacturing method of the embodiment of the solid-state imaging device shown in FIG. 6 . 7A to 7C are diagrams illustrating a manufacturing method of a first modified example of the solid-state imaging device shown in FIG. 6 . 13A and 13B are diagrams illustrating a solid-state imaging device after application of a paste adhesive in a second modified example. 13A to 13C are diagrams illustrating a method for manufacturing a solid-state imaging device according to a second modified example in which the semiconductor chip is mounted without being tilted relative to the substrate. 13A to 13C are diagrams illustrating a method for manufacturing a solid-state imaging device according to a second modified example in which a semiconductor chip is mounted at an angle with respect to a substrate. 13A and 13B are diagrams illustrating a solid-state imaging device after application of a paste adhesive in a third modified example. 13A to 13C are diagrams illustrating a method for manufacturing a solid-state imaging device according to a third modified example in which a semiconductor chip is mounted without being tilted relative to a substrate. 13A to 13C are diagrams illustrating a method for manufacturing a solid-state imaging device according to a third modified example in which a semiconductor chip is mounted at an angle with respect to a substrate. 13A and 13B are diagrams illustrating a solid-state imaging device after application of a paste adhesive in a fourth modified example. 13 is a diagram illustrating a vacuum suction system of a collet of a bonding head in a fifth modified example. FIG. 1A to 1C are diagrams illustrating how a workpiece falls while tilting in four directions. 13 is a diagram illustrating a vacuum suction system of a collet of a bonding head in a sixth modified example. FIG.

The following describes the embodiments with reference to the drawings. However, in the following description, the same components are given the same reference numerals and repeated description may be omitted. Note that in the drawings, the width, thickness, shape, etc. of each part may be shown diagrammatically compared to the actual embodiment in order to make the description clearer, but these are merely examples and do not limit the interpretation of this disclosure.

The configuration of the bonding device in the embodiment will be described with reference to Figures 1 to 4. Figure 1 is a top view showing an outline of the bonding device in the embodiment. Figure 2 is a cross-sectional view showing an outline of the chip supply unit shown in Figure 1. Figure 3 is a side view showing an outline of the preform unit shown in Figure 1. Figure 4 is a side view showing an outline of the chip supply unit and bonding unit shown in Figure 1.

As shown in FIG. 1, the bonding apparatus 10 broadly comprises a chip supply unit 1 that supplies workpieces DG to be mounted on a substrate S, a preform unit 9, a bonding unit 4, a transport unit 5, a substrate supply unit 6, a substrate unloading unit 7, and a control unit 8 that monitors and controls the operation of each unit. The Y-axis direction is the front-to-rear direction of the bonding apparatus 10, and the X-axis direction is the left-to-right direction. The chip supply unit 1 is located at the front side of the bonding apparatus 10, and the bonding unit 4 is located at the back side. Here, semiconductor chips D are mounted on multiple product areas on the substrate S that will ultimately become one package.

As shown in FIG. 2, the chip supply unit 1 has a wafer holder 12 that holds a wafer 11, and a push-up unit 13 that pushes up a workpiece DG from the wafer 11. Here, the workpiece DG is, for example, a glass chip. The wafer 11 is a disk-shaped glass plate to which a dicing tape 16 is attached, and is diced and divided into multiple glass chips. The wafer holder 12 has an expand ring 15 that holds a wafer ring 14, and a support ring 17 that horizontally positions the dicing tape 16 held by the wafer ring 14 and to which multiple workpieces DG are attached. The push-up unit 13 is disposed inside the support ring 17. The control unit 8 moves the wafer holder 12 in the X-axis direction and the Y-axis direction by a driving means (not shown), and moves the workpiece DG to be picked up to the position of the push-up unit 13 (pickup position).

When the wafer holder 12 pushes up the workpiece DG, it lowers the expand ring 15 holding the wafer ring 14. As a result, the dicing tape 16 held by the wafer ring 14 is stretched, widening the gap between the workpieces DG, and the push-up unit 13 pushes up the workpieces DG from below, improving the pick-up of the workpieces DG.

3, the preform unit 9 has a syringe 91, a drive unit (not shown) that moves the syringe 91 in the X-axis direction, the Y-axis direction, and the up-down direction, and a preform camera 94 as an imaging device that grasps the application position of the syringe 91. The preform unit 9 applies the paste adhesive PA with the syringe 91 to the semiconductor chip D mounted on the substrate S transported by the transport unit 5. The syringe 91 is filled with the paste adhesive, and is configured so that the paste adhesive PA is pushed out by air pressure from the tip of the nozzle 92 and applied to the semiconductor chip D mounted on the substrate S.

As shown in FIG. 4, the bonding section 4 has a bonding head 41 equipped with a collet 42 that suction-holds the workpiece DG at its tip, a Y-drive section (not shown) that moves the bonding head 41 in the Y-axis direction, and a substrate recognition camera 44 that captures an image of a position recognition mark (not shown) on the substrate S and recognizes the bonding position. The bonding section 4 picks up the workpiece DG from the chip supply section 1 and bonds it onto the semiconductor chip D coated with the paste adhesive PA on the substrate S that is being transported. At this time, the bonding head 41 corrects the pick-up position and attitude based on the image data of the wafer recognition camera 24, picks up the workpiece DG from the wafer 11, and bonds the workpiece DG onto the semiconductor chip D mounted on the substrate based on the image data of the substrate recognition camera 44.

As shown in FIG. 1, the transport section 5 has a transport lane 52 as a transport path along which the substrate S moves. With this configuration, the substrate S moves from the substrate supply section 6 along the transport lane 52 to the coating position, moves to the bonding position after coating, and after bonding, moves to the substrate unloading section 7 to hand over the substrate S to the substrate unloading section 7.

The control unit 8 includes a memory that stores a program (software) that monitors and controls the operation of each of the above-mentioned parts of the bonding device 10, and a central processing unit (CPU) that executes the program stored in the memory.

Next, a method for manufacturing a solid-state imaging device using the bonding device in the embodiment will be described with reference to FIG. 5. FIG. 5 is a flowchart showing a method for manufacturing a solid-state imaging device using the bonding device shown in FIG. 1.

(Step S11: Wafer/Substrate Loading Process)
A wafer cassette (not shown) storing a wafer ring holding dicing tape 16 to which workpieces DG separated from a wafer 11 are attached is carried into the bonding apparatus 10. The control unit 8 supplies the wafer ring 14 from the wafer cassette in which the wafer ring 14 is stored to the chip supply unit 1. In addition, a substrate S on which a semiconductor chip D is mounted is prepared, and is carried into the substrate supply unit of the bonding apparatus 10.

(Step S12: Preforming process)
The control unit 8 uses the preform camera 94 to obtain an image of the surface of the semiconductor chip D mounted on the substrate S before application, and confirms the surface to which the paste adhesive PA is to be applied. If there are no problems with the surface to be applied, the control unit 8 applies the paste adhesive PA from the syringe 91 to the semiconductor chip D mounted on the substrate S transported by the transport unit 5. The paste adhesive PA is, for example, a UV-curing adhesive. After application, the control unit 8 uses the preform camera 94 to check again whether the paste adhesive PA has been applied accurately, and inspects the applied paste adhesive PA. If there are no problems with the application, the control unit 8 transports the substrate S to the bonding stage 45 by the transport unit 5.

(Step S13: Bonding process)
The control unit 8 moves the wafer 11 so that the desired workpiece DG can be picked up from the wafer 11 by the wafer holding table 12, and performs positioning and surface inspection based on data captured by the wafer recognition camera 24. The control unit 8 calculates the amount of deviation (X, Y, and θ directions) of the workpiece DG on the wafer holding table 12 from the workpiece position reference point of the bonding device 10 by image processing. Note that the workpiece position reference point is previously held at a predetermined position of the wafer holding table 12 as the initial setting of the device. The control unit 8 then performs surface inspection of the workpiece DG by image processing.

The control unit 8 also uses the substrate recognition camera 44 to capture an image of the substrate S placed on the bonding stage 45. The control unit 8 calculates the amount of deviation (X, Y, and θ directions) of the substrate S from the substrate position reference point of the bonding device 10 through image processing. Note that the substrate position reference point is previously held at a predetermined position of the bonding unit 4 as the initial setting for the device.

The control unit 8 then translates and lowers the bonding head 41 until it is directly above the workpiece DG to be picked up, corrects the suction position of the bonding head 41 from the calculated amount of deviation of the workpiece DG, and vacuum-sucks the workpiece DG with the collet 42. The control unit 8 then raises, moves horizontally, and lowers the bonding head 41 that has suctioned the workpiece DG from the wafer 11, attaching the workpiece DG to a predetermined location on the semiconductor chip D mounted on the substrate S on the bonding stage 45. The control unit 8 then performs an inspection based on image data captured by the substrate recognition camera 44 to see if the workpiece DG has been bonded in the desired position, etc.

(Step S14: Substrate removal process)
The control unit 8 transports the substrate S to which the workpiece DG is bonded to the substrate unloading unit 7. The control unit 8 removes the substrate S to which the workpiece DG is bonded from the substrate unloading unit 7. The substrate S is unloaded from the bonding apparatus 10.

Next, to clarify this embodiment, the structure and manufacturing method of the solid-state imaging device manufactured by the bonding device in this embodiment will be described with reference to Figures 6 and 7. Figure 6 is a diagram showing an outline of the solid-state imaging device manufactured by the bonding device shown in Figure 1, with Figure 6(a) being a top view and Figure 6(b) being a side view. Figure 7 is a diagram explaining the manufacturing method of the solid-state imaging device shown in Figure 6, with Figure 7(a) being a side view showing the state before the workpiece is placed and Figure 7(b) being a side view showing the state after the workpiece is placed.

As shown in FIG. 6(b), the solid-state imaging device is constructed by stacking a semiconductor chip D, a paste-like adhesive PA, and a workpiece DG in this order on a substrate S. As shown in FIG. 6(a), the substrate S, the semiconductor chip D, and the workpiece DG are each rectangular in a plan view. The substrate S, the semiconductor chip D, and the workpiece DG are smaller in size in that order. The paste-like adhesive PA is also annular in a plan view, and its size is equal to or slightly smaller than that of the workpiece DG. The thickness of the workpiece DG is, for example, about 400 μm, and the height of the paste-like adhesive is, for example, about 125 μm.

The semiconductor chip D is mounted on the substrate S in advance, and the paste adhesive PA is applied onto the semiconductor chip D in the preform section 9. Then, the bonding head 41 suctions and holds the workpiece DG with the collet 42, and transports it directly above the semiconductor chip on which the paste adhesive PA has been applied. At this time, the collet 42 of the bonding head 41, which holds the workpiece DG and performs bonding, is usually positioned horizontally, as shown in FIG. 7(a). In this state, the workpiece DG is pushed into a predetermined position and bonded, as shown in FIG. 7(b). Ideally, the distance between the semiconductor chip D and the workpiece DG (the height of the paste adhesive PA) after bonding will be uniform (KA=KB).

Next, the problem that occurs when bonding a workpiece DG to a semiconductor chip D that is mounted at an angle on a substrate S will be explained using FIG. 8. FIG. 8 is a diagram explaining the problem with the manufacturing method of the solid-state imaging device shown in FIG. 6, where FIG. 8(a) is a side view showing the state before the workpiece is placed, and FIG. 8(b) is a side view showing the state after the workpiece is placed.

When the semiconductor chip D mounted on the substrate S is tilted with respect to the top surface of the substrate S as shown in FIG. 8(a), the work DG is simply pressed in horizontally as shown in FIG. 8(b). As a result, the gap (KA) between the semiconductor chip D and the work DG is narrow at the higher part of the semiconductor chip D (left side of the figure) and the gap (KB) between the semiconductor chip D and the work DG is wide at the lower part of the semiconductor chip D (right side of the figure), resulting in unevenness (KA<KB) based on the horizontal bonding stage 45.

A method for manufacturing a solid-state imaging device in this embodiment that solves the above problems will be described with reference to FIG. 9. FIG. 9 is a diagram for explaining a method for manufacturing the embodiment of the solid-state imaging device shown in FIG. 6, where FIG. 9(a) is a side view showing the state immediately before the workpiece is dropped, FIG. 9(b) is a side view showing the state immediately after the workpiece has been dropped, and FIG. 9(c) is a side view showing the state in which the workpiece has been placed.

As shown in FIG. 9(a), the control unit 8 stops the lowering operation of the bonding head 41 when the workpiece DG held by the collet 42 is at a position a predetermined distance (Ha) away from the highest height of the paste-like adhesive PA applied on the semiconductor chip D. Then, as shown in FIG. 9(b), the control unit 8 releases the suction of the workpiece DG by the collet 42, drops it, and places the workpiece DG on the semiconductor chip D. As shown in FIG. 9(c), when the application height of the paste-like adhesive PA is uniform, the distance between the semiconductor chip D and the workpiece DG becomes uniform (KA=KB). Note that when the suction of the workpiece DG by the collet 42 is released, the descent operation of the bonding head 41 does not need to be stopped. For example, the descent operation of the bonding head 41 may be stopped after the suction of the workpiece DG by the collet 42 is released.

The predetermined distance (Ha) is a height at which the paste adhesive PA is not pushed in when the workpiece DG falls, and is preferably 0 μm or more and 50 μm or less. The height (H) at which the collet 42 releases the workpiece DG is always set to a position at which the predetermined distance (Ha) is 0 μm or more and 50 μm or less, taking into account the variation in the heights of the paste adhesive PA, the semiconductor chip D, and the substrate S. That is, in this embodiment, the height (Hb) of the paste adhesive PA is not measured each time the workpiece DG is placed. Here, the height (H) is, for example, the height from the upper surface of the bonding stage 45 to the lower surface of the workpiece DG.

According to this embodiment, the collet 42 of the bonding head 41 does not force the workpiece DG into the paste adhesive PA. This allows the workpiece DG to conform to the paste adhesive PA. Therefore, when the paste adhesive PA is applied to a uniform height, the workpiece DG can be placed parallel to the semiconductor chip D even if the semiconductor chip D is tilted.

In addition, according to this embodiment, when the semiconductor chip D is tilted, the workpiece DG is placed on the semiconductor chip D so as to tilt it from a state in which the applied surface of the paste-like adhesive PA including the semiconductor chip D and the workpiece DG to be placed on it are not parallel. This allows the workpiece DG to be placed while removing the air from inside the annularly applied paste-like adhesive PA, and suppresses the external expansion of the paste-like adhesive PA.

<Modification>
Below, some representative modified examples of the embodiment are exemplified. In the following description of the modified examples, the same reference numerals as those in the above-mentioned embodiment may be used for parts having the same configuration and function as those described in the above-mentioned embodiment. The description of such parts may be appropriately cited within the scope of technical inconsistency. Furthermore, a part of the above-mentioned embodiment and all or a part of the multiple modified examples may be appropriately applied in a composite manner within the scope of technical inconsistency.

(First Modification)
The manufacturing method of the solid-state imaging device in the first variant will be explained using Figure 10. Figure 10 is a diagram explaining the manufacturing method of the first variant of the solid-state imaging device shown in Figure 6, where Figure 10(a) is a side view showing the state during the collet's downward operation, Figure 10(b) is a side view showing the state just before the workpiece is dropped, and Figure 10(c) is a side view showing the state with the workpiece placed.

In this embodiment, the height (Hb) of the paste adhesive PA applied to the semiconductor chip D (including variations in the paste adhesive PA, the semiconductor chip D, and the substrate S) is evaluated beforehand before continuous operation, and the height (H) at which the collet 42 releases the workpiece DG is always set to a position that is a predetermined distance (Ha). In this modified example, during continuous operation, after the paste adhesive PA is applied, the height (Hb) from the top surface of the preform stage 95 or the bonding stage 45 to the highest part of the paste adhesive PA is measured for each substrate, each row, or each application by a range finder 46 using a sensor or optical camera, etc., and the height at which the collet 42 releases the workpiece DG is set to a position that is Hb.

As shown in FIG. 10(a), the semiconductor chip D is tilted relative to the substrate S. The paste adhesive PA is applied to a uniform height. In this case, the part where the height of the paste adhesive PA is higher than other parts within the application area of the annular paste adhesive PA is the highest side of the semiconductor chip D placed on the substrate S.

As shown in FIG. 10(b), the control unit 8 stops the lowering operation of the bonding head 41 at a position where the work DG held by the collet 42 is at the same height as the highest height (Hb) of the paste adhesive PA applied on the semiconductor chip D. At this time, the distance (KA) between the semiconductor chip D and the work DG at the highest position of the paste adhesive PA is smaller than the distance (KB) between the semiconductor chip D and the work DG at the lowest position of the paste adhesive PA (KA<KB). Then, the control unit 8 releases the suction of the work DG by the collet 42 and drops the work DG, and the work DG is placed on the semiconductor chip D as shown in FIG. 10(c). At this time, the distance between the semiconductor chip D and the work DG becomes uniform (KA=KB).

In this modified example, the workpiece DG is released from the collet 42 at a height (H = Hb, Ha = 0) where the workpiece DG comes into contact with the highest part of the paste adhesive PA. That is, the workpiece DG is released from the collet 42 at the moment (the moment) the workpiece DG comes into contact with the paste adhesive PA. As a result, since the workpiece DG is in contact with one side of the annular paste adhesive PA when the workpiece DG is released from the collet 42, it is possible to prevent the workpiece DG from shifting and falling. That is, it is possible to prevent the workpiece DG from shifting its position when it is dropped. It is also possible to prevent the θ shift of the workpiece DG when it is dropped.

(Second Modification)
A method for manufacturing a solid-state imaging device in the second modification will be described with reference to Figs. 11 to 13. Fig. 11 is a diagram for explaining a solid-state imaging device after application of a paste-like adhesive in the second modification, Fig. 11(a) is a top view of a main part of the solid-state imaging device, and Fig. 11(b) is a side view of the solid-state imaging device shown in Fig. 11(a) before a workpiece is placed on the solid-state imaging device. Fig. 12 is a diagram for explaining a method for manufacturing a solid-state imaging device in the second modification when a semiconductor chip is mounted without tilting with respect to a substrate, Fig. 12(a) is a side view showing a state during a collet descending operation, Fig. 12(b) is a side view showing a state immediately before a workpiece is dropped, and Fig. 12(c) is a side view showing a state in which a workpiece is placed. Fig. 13 is a diagram for explaining a method for manufacturing a solid-state imaging device in the second modification when a semiconductor chip is mounted with a tilt with respect to a substrate, Fig. 13(a) is a side view showing a state during a collet descending operation, Fig. 13(b) is a side view showing a state immediately before a workpiece is dropped, and Fig. 13(c) is a side view showing a state in which a workpiece is placed.

In the embodiment and the first modified example, the application height of the paste adhesive PA is uniform, but in the second modified example, as shown in FIG. 11(b), one protrusion PAa is provided that is higher than the application height of the annular paste adhesive PA. As shown in FIG. 11(a), the protrusion PAa is the application start point and end point of the annular paste adhesive PA. The protrusion PAa may be formed by changing the discharge amount per unit time of the nozzle 92 provided on the syringe 91 or by slowing down the nozzle operation. The protrusion PAa is circular when viewed from above, and its size is approximately the same as the width of the applied annular paste adhesive PA.

As shown in FIG. 12(a), the semiconductor chip D is mounted without being tilted relative to the substrate S. In this case, the portion where the height of the paste adhesive PA is the highest compared to other portions within the application area of the annular paste adhesive PA is the protruding portion PAa.

As shown in FIG. 12(b), the control unit 8 stops the lowering operation of the bonding head 41 at a position where the work DG held by the collet 42 is at the same height as the highest height (Hb) of the paste adhesive PA applied on the semiconductor chip D. At this time, the distance (A) between the semiconductor chip D and the work DG at the protruding portion PAa is the same as the distance (B) between the semiconductor chip D and the work DG at other positions of the protruding portion PAa of the paste adhesive PA (KA=KB). Then, the control unit 8 releases the suction of the work DG by the collet 42 and drops the work DG, and the work DG is placed on the semiconductor chip D as shown in FIG. 12(c). At this time, the protruding portion PAa is flattened by the load of the work DG, and the distance between the semiconductor chip D and the work DG becomes uniform (KA=KB).

As shown in FIG. 13(a), the semiconductor chip D is tilted relative to the substrate S. In this case, the portion of the paste-like adhesive PA that is higher than other portions within the application area of the annular paste-like adhesive PA is the protrusion PAa. Here, the protrusion PAa is higher than the height of the top surface of the paste-like adhesive PA at the highest side of the semiconductor chip D when the semiconductor chip D is mounted at an angle relative to the substrate S.

As shown in FIG. 13(b), the control unit 8 stops the lowering operation of the bonding head 41 at a position where the work DG held by the collet 42 is at the same height as the highest height (Hb) of the paste adhesive PA applied on the semiconductor chip D. At this time, the distance (KA) between the semiconductor chip D and the work DG at the protruding portion PAa is larger than the distance (KB) between the semiconductor chip D and the work DG at the highest side of the semiconductor chip D (KA>KB). Then, the control unit 8 releases the suction of the work DG by the collet and drops the work DG, so that the work DG is placed on the semiconductor chip D as shown in FIG. 13(c). At this time, the protruding portion PAa is flattened by the load of the work DG, and the distance between the semiconductor chip D and the work DG becomes uniform (KA=KB).

In this modified example, the workpiece DG is released from the collet 42 at a height (H = Hb, Ha = 0) where the workpiece DG comes into contact with the protruding portion PAa of the paste adhesive PA. That is, the workpiece DG is released from the collet 42 at the moment (the moment) the workpiece DG comes into contact with the protruding portion PAa. This makes it possible to prevent the workpiece DG from shifting and falling when it is released from the collet 42. That is, it is possible to prevent the workpiece DG from shifting in position when it is dropped.

(Third Modification)
A method for manufacturing a solid-state imaging element in the third modified example will be described with reference to Figs. 14 to 16. Fig. 14 is a diagram for explaining a solid-state imaging device after application of a paste-like adhesive in the third modified example, Fig. 14(a) is a top view of a main part of the solid-state imaging device, and Fig. 14(b) is a side view of the solid-state imaging device shown in Fig. 14(a) before a workpiece is placed on the solid-state imaging device. Fig. 15 is a diagram for explaining a method for manufacturing a solid-state imaging device in the third modified example when a semiconductor chip is mounted without tilting with respect to a substrate, Fig. 15(a) is a side view showing a state during a collet descending operation, Fig. 15(b) is a side view showing a state immediately before a workpiece is dropped, and Fig. 15(c) is a side view showing a state in which a workpiece is placed. Fig. 16 is a diagram for explaining a method for manufacturing a solid-state imaging device in the third modified example when a semiconductor chip is mounted with a tilt with respect to a substrate, Fig. 16(a) is a side view showing a state during a collet descending operation, Fig. 16(b) is a side view showing a state immediately before a workpiece is dropped, and Fig. 16(c) is a side view showing a state in which a workpiece is placed.

In the second modified example, one protrusion PAa is provided on the annular paste adhesive PA, but in the third modified example, as shown in FIG. 14, two protrusions PAa, PAb are provided on the annular paste adhesive PA. As in the second modified example, the protrusions PAa, PAb are the application start and end points of the annular paste adhesive PA. The protrusions PAa, PAb may be formed by changing the discharge amount per unit time of the nozzle 92 provided on the syringe 91 or by slowing down the nozzle movement speed.

As shown in FIG. 15(a), the semiconductor chip D is mounted without being tilted relative to the substrate S. In this case, the protrusions PAa and PAb are the parts where the height of the paste adhesive PA is the highest compared to other parts within the application area of the annular paste adhesive PA.

As shown in FIG. 15(b), the control unit 8 stops the lowering operation of the bonding head 41 at a position where the work DG held by the collet 42 is at the same height as the highest height (Hb) of the paste adhesive PA applied on the semiconductor chip D. At this time, the distance (KA) between the semiconductor chip D and the work DG at the protrusion PAa is the same as the distance (KB) between the semiconductor chip D and the work DG at the protrusion PAb (KA=KB). Then, the control unit 8 releases the suction of the work DG by the collet 42 and drops the work DG, so that the work DG is placed on the semiconductor chip D as shown in FIG. 15(c). At this time, the protrusions PAa and PAb are flattened by the load of the work DG, and the distance between the semiconductor chip D and the work DG becomes uniform (KA=KB).

As shown in FIG. 16(a), the semiconductor chip D is tilted relative to the substrate S. In this case, the portion of the paste adhesive PA that is higher than other portions of the application area of the annular paste adhesive PA is the protrusion PAb. Here, the protrusion PAa is lower than the height of the protrusion PAb at the highest side of the semiconductor chip D when the semiconductor chip D is mounted at an angle relative to the substrate S.

As shown in FIG. 16(b), the control unit 8 stops the lowering operation of the bonding head 41 at a position where the work DG held by the collet 42 is at the same height as the protruding portion PAa of the paste-like adhesive PA applied on the semiconductor chip D. At this time, the upper portion of the protruding portion PAb is crushed by the work DG, so the distance (KA) between the semiconductor chip D and the work DG at the protruding portion PAa is larger than the distance (KB) between the semiconductor chip D and the work DG at the highest side of the semiconductor chip D (KA>KB). Then, the control unit 8 releases the suction of the work DG by the collet 42 and drops the work DG, so that the work DG is placed on the semiconductor chip D as shown in FIG. 16(c). At this time, the protruding portion PAa is flattened by the load of the work DG, and the distance between the semiconductor chip D and the work DG becomes uniform (KA=KB).

In this modified example, the workpiece DG is released from the collet 42 at a height (H = Hb, Ha = 0) where the workpiece DG contacts the protruding portion PAa of the paste adhesive PA. This makes it possible to prevent the workpiece DG from shifting and falling when it is released from the collet 42. In other words, it is possible to prevent the workpiece DG from shifting its position when it is dropped. It is also possible to prevent the θ shift of the workpiece DG when it is dropped.

(Fourth Modification)
The manufacturing method of the solid-state imaging element in the fourth modified example will be described with reference to Fig. 17. Fig. 17 is a diagram for explaining the solid-state imaging device after application of the paste-like adhesive in the fourth modified example, Fig. 17(a) is a top view of the main part of the solid-state imaging device, and Fig. 17(b) is a side view of the solid-state imaging device shown in Fig. 17(a) before a workpiece is placed on it.

In the third modified example, one protrusion PAa, PAb is provided on each of the two opposing sides of the annular paste adhesive PA, but in the fourth modified example, as shown in FIG. 17, two protrusions PAa, PAb may be provided on one side of the annular paste adhesive PA. The protrusions PAa, PAb are the application start and end points of the annular paste adhesive PA, as in the third modified example. The protrusions PAa, PAb may be formed by changing the discharge amount per unit time of the nozzle 92 provided on the syringe 91 or slowing down the nozzle operation. In this modified example, the method of placing the work DG on the semiconductor chip D to which the annular paste adhesive PA is applied is the same as in the third modified example. This makes it possible to prevent the work DG from shifting and falling when the work DG is released from the collet 42. That is, it is possible to prevent the work DG from shifting when the work DG is dropped. It is also possible to prevent the θ shift of the work DG when the work DG is dropped.

(Fifth Modification)
A method for manufacturing a solid-state imaging device in the fifth modified example will be described with reference to Fig. 18 and Fig. 19. Fig. 18 is a diagram for explaining a vacuum suction system of a collet of a bonding head in the fifth modified example, Fig. 18(a) is a top view, Fig. 18(b) is a cross-sectional view of line A-A in Fig. 18(a), and Fig. 18(c) is a bottom view. Fig. 19 is a diagram for explaining that a workpiece falls tilted in four directions, Fig. 19(a) is a side view showing a state in which suction is released from the front side, Fig. 19(b) is a side view showing a state in which suction is released from the rear side, Fig. 19(c) is a side view showing a state in which suction is released from the right side, and Fig. 19(d) is a side view showing a state in which suction is released from the left side.

The collet 42 has four independent vacuum suction systems IA, IB, IC, and ID. Each of the vacuum suction systems IA, IB, IC, and ID has a plurality of suction ports 42a, which are openings provided on the lower surface (bottom surface) of the collet 42, a horizontal suction section 42b that communicates between the plurality of suction ports 42a, and a vertical suction section 42c that communicates with the horizontal suction section 42b. The lower surface of the collet 42, which abuts against the upper surface of the workpiece DG, is divided into four areas corresponding to the four vacuum suction systems IA, IB, IC, and ID. The lower surface of the collet 42 is rectangular and is divided into four areas by two diagonals. For example, the multiple suction ports 42a of the vacuum suction system IB extend along the direction of one side of the lower surface of the collet 42 (X-axis direction), and the outer suction ports 42a are long and the inner suction ports 42a are short.

When the suction of the front vacuum suction systems IB, IC, and ID is released and then the suction of the rear vacuum suction system IA is released, as shown in FIG. 19(a), the rear side of the workpiece DG remains suctioned to the collet 42 while the front side of the workpiece DG is released from the collet 42, and the workpiece DG tilts with its front side facing down.

When the rear vacuum suction systems ID, IA, and IB are released and then the front vacuum suction system IC is released, as shown in FIG. 19(b), the front side of the workpiece DG remains attached to the collet 42 while the rear side of the workpiece DG is released from the collet 42, and the workpiece DG tilts with its rear side facing down.

When the right-side vacuum suction systems IA, IB, and IC are released and then the left-side vacuum suction system ID is released, as shown in FIG. 19(c), the left side of the workpiece DG remains attached to the collet 42 while the right side of the workpiece DG is released from the collet 42, and the workpiece DG tilts with its right side facing down.

When the suction of the left vacuum suction systems IC, IA, and ID is released and then the suction of the right vacuum suction system IB is released, as shown in FIG. 19(d), the right side of the workpiece DG remains suctioned to the collet 42 while the left side of the workpiece DG is released from the collet 42, and the workpiece DG tilts with the left side facing down.

By dividing the vacuum suction system of the collet into separate parts and staggering the timing of the suction release, it is possible to drop the chip at any angle. This makes it possible to drop the workpiece DG at an angle so that the air can escape, even if the top surface of the paste adhesive PA is flat and horizontal.

(Sixth Modification)
The method for manufacturing a solid-state imaging device in the sixth modified example will be described with reference to Fig. 19 and Fig. 20. Fig. 20 is a diagram for explaining a vacuum suction system of a collet of a bonding head in the sixth modified example, Fig. 20(a) is a top view, and Fig. 20(b) is a bottom view.

The collet 42 has four independent vacuum suction systems IA, IB, IC, and ID. Each of the vacuum suction systems IA, IB, IC, and ID has a plurality of suction ports 42a, which are openings provided on the lower surface (bottom surface) of the collet 42, a plurality of horizontal suction sections 42b that communicate between the plurality of suction ports 42a, and a plurality of vertical suction sections 42c that communicate with the horizontal suction sections 42b. The lower surface of the collet 42, which abuts against the upper surface of the workpiece DG, is divided into four areas corresponding to the four vacuum suction systems IA, IB, IC, and ID. The lower surface of the collet 42 is rectangular, and is divided into four areas by two straight lines passing through the midpoints of the two opposing sides. For example, multiple suction ports 42a are arranged in a grid pattern along the sides of the underside of the collet 42, and vertical suction sections 42c and suction ports 42a located at the corners of the collet 42 are linearly connected by horizontal suction sections 42b, and other suction ports 42a are connected to these horizontal suction sections 42b directly or via other horizontal suction sections 42b.

When the suction of the front vacuum suction systems IA and ID is released and then the suction of the rear vacuum suction systems IB and IC is released, as shown in FIG. 19(a), the rear side of the workpiece DG remains suctioned to the collet 42 while the front side of the workpiece DG is released from the collet 42, and the workpiece DG tilts with the front side facing down.

When the rear vacuum suction systems IB and IC are released and then the front vacuum suction systems IA and ID are released, as shown in FIG. 19(b), the rear side of the workpiece DG is released from the collet 42 while the front side of the workpiece DG remains attached to the collet 42, and the workpiece DG tilts with its rear side facing down.

When the right vacuum suction systems IA and IB are released and then the left vacuum suction systems IC and ID are released, as shown in FIG. 19(c), the left side of the workpiece DG remains attached to the collet 42 while the right side of the workpiece DG is released from the collet 42, and the workpiece DG tilts with its right side facing down.

When the suction of the left vacuum suction systems IC and ID is released and then the suction of the right vacuum suction systems IA and IB is released, as shown in FIG. 19(d), the right side of the workpiece DG remains suctioned to the collet 42 while the left side of the workpiece DG is released from the collet 42, and the workpiece DG tilts with the left side facing down.

The disclosure made by the present inventors has been specifically described above based on the embodiments and modifications, but it goes without saying that the present disclosure is not limited to the above embodiments and modifications, and various modifications are possible.

For example, in the second to fourth modified examples, one or two protrusions are provided on the annular paste adhesive PA, but three or more protrusions may be provided.

In addition, in the fifth and sixth modified examples, four vacuum suction systems are provided, but two, three, or five or more vacuum suction systems may be provided.

In the embodiment, a glass chip is used as the workpiece DG, but the workpiece in the semiconductor chip D having a light receiving element for light other than visible light (e.g., infrared light) may be a silicon chip.

In the embodiment, an example has been described in which the paste adhesive PA is applied in a ring shape onto the semiconductor chip D, but when a semiconductor chip (die) separated from a semiconductor wafer is stacked on top of the semiconductor chip D, the paste adhesive PA may be applied onto the semiconductor chip D in a shape other than a ring shape (for example, an X-shape or Z-shape).

In the embodiment, an example has been described in which the work DG picked up by the bonding head 41 from the chip supply unit 1 is bonded to a semiconductor chip D mounted on the substrate S. However, an intermediate stage may be provided between the chip supply unit 1 and the bonding unit 4, the work DG picked up by the pickup head from the chip supply unit 1 may be placed on the intermediate stage, and the work DG may be picked up again from the intermediate stage by the bonding head 41 and bonded to the semiconductor chip D mounted on the substrate S.

Reference Signs List 8: Control unit 10: Bonding device 41: Bonding head 42: Collet 91: Syringe D: Semiconductor chip DG: Workpiece PA: Paste-like adhesive S: Substrate

Claims (13)

a syringe for applying a paste adhesive onto a semiconductor chip mounted on a substrate;
a bonding head having a collet at its tip for adsorbing a workpiece and for placing the workpiece on the paste adhesive applied by the syringe;
a control unit configured to stop the descent of the bonding head at a position where a distance between the highest point of the paste adhesive applied on the semiconductor chip and the workpiece is within a predetermined range, release the suction of the workpiece by the collet positioned horizontally, and drop the workpiece onto the paste adhesive;
Equipped with
The predetermined range is a distance within which the paste adhesive is not pushed in by the lowering of the bonding head and the dropping of the workpiece. 2. The bonding apparatus of claim 1,
A bonding apparatus, wherein the predetermined range is 0 μm or more and 50 μm or less. a syringe for applying a paste adhesive in a circular shape to a semiconductor chip mounted on a substrate;
a bonding head having a collet at its tip for adsorbing a workpiece and for placing the workpiece on the paste adhesive applied by the syringe;
A control unit;
Equipped with
The control unit is
providing a protrusion when applying a ring-shaped paste adhesive onto the semiconductor chip using the syringe;
The lowering operation of the bonding head is stopped at a position where the lower surface of the workpiece contacts the protruding portion,
The collet is configured to release the suction of the workpiece so that the workpiece falls onto the paste-like adhesive,
A bonding apparatus, wherein the protrusions are application start and end points of the paste adhesive. 4. The bonding apparatus according to claim 3,
The control unit is configured to measure the height of the protrusion using a sensor or an optical camera. 4. The bonding apparatus according to claim 3,
The bonding device has two or more protruding portions on the paste adhesive. a syringe for applying a paste adhesive in a circular shape to a semiconductor chip mounted on a substrate;
a bonding head having a collet at its tip for adsorbing a workpiece and for placing the workpiece on the paste adhesive applied by the syringe;
A control unit;
Equipped with
The control unit is
when applying the annular paste adhesive onto the semiconductor chip by the syringe, a protrusion is provided by changing the discharge amount per unit time of a nozzle of the syringe or slowing down a moving speed of the nozzle;
A bonding apparatus configured to release the suction of the workpiece by the collet and drop the workpiece onto the paste adhesive. 7. The bonding apparatus of claim 6,
The control unit is configured to measure the height of the protrusion using a sensor or an optical camera. 7. The bonding apparatus of claim 6,
The bonding device has two or more protruding portions on the paste adhesive. In the bonding apparatus according to any one of claims 1, 3 and 6,
The control unit is a bonding apparatus configured to position the workpiece so that the bonding head releases the workpiece from a state in which the surface of the semiconductor chip on which the paste adhesive is applied and the workpiece are not parallel to each other. 10. The bonding apparatus of claim 9,
The control unit is configured to divide a vacuum suction system of the collet into a plurality of independent areas and to stagger the timing of releasing suction for each area. A step of carrying a substrate on which a semiconductor chip is mounted into a bonding device having a bonding head having a collet at its tip for adsorbing a workpiece;
a coating step of coating the semiconductor chip with a paste adhesive in a circular shape;
a bonding step of placing the work on the paste adhesive;
having
The bonding step includes:
stopping the lowering operation of the bonding head at a position where a distance between the highest point of the paste adhesive applied on the semiconductor chip and the workpiece is within a predetermined range;
The collet is horizontally positioned to release the workpiece from its suction, thereby dropping the workpiece onto the paste adhesive;
The method for manufacturing a solid-state imaging device, wherein the predetermined range is a distance that does not cause the paste adhesive to be pushed in by the descent of the bonding head and the drop of the workpiece. A step of carrying a substrate on which a semiconductor chip is mounted into a bonding device having a bonding head having a collet at its tip for adsorbing a workpiece;
a coating step of coating the semiconductor chip with a paste adhesive in a circular shape;
a bonding step of placing the work on the paste adhesive;
having
The coating step provides a protrusion when coating a circular paste-like adhesive on the semiconductor chip,
The bonding step includes:
The lowering operation of the bonding head is stopped at a position where the lower surface of the workpiece contacts the protruding portion,
The suction of the workpiece by the collet is released to drop the workpiece onto the paste-like adhesive;
The method for manufacturing a solid-state imaging device, wherein the protrusion is a start point and an end point of application of the paste adhesive. A step of carrying a substrate on which a semiconductor chip is mounted into a bonding device having a bonding head having a collet at its tip for adsorbing a workpiece;
a coating step of coating the semiconductor chip with a paste adhesive in a circular shape;
a bonding step of placing the work on the paste adhesive;
having
the applying step includes providing a protrusion by changing the discharge amount per unit time of a nozzle of a syringe or slowing down the moving speed of the nozzle when applying the annular paste adhesive onto the semiconductor chip;
The bonding step includes:
The lowering operation of the bonding head is stopped at a position where the lower surface of the workpiece contacts the protruding portion,
The method for manufacturing a solid-state imaging device further comprises releasing the suction of the workpiece by the collet and dropping the workpiece onto the paste-like adhesive.

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