JP2024046799A - Semiconductor manufacturing apparatus and method for manufacturing semiconductor device - Google Patents

Abstract

[Problem] To provide a technology that can improve pick-up accuracy while suppressing increases in pick-up time. [Solution] A semiconductor manufacturing device includes a stage that holds a die, a head in which a collet having a suction hole for suctioning the die is provided, a flow sensor provided in a pipe that communicates with the suction hole, and a control device that acquires correlation data before production. The control device is configured to lower the bottom surface of the collet to a predetermined height from the top surface of the die held on the stage, detect the flow rate of gas flowing through the suction hole of the collet at the predetermined height using the flow sensor, and determine the amount of descent required to land the bottom surface of the collet on the top surface of the die held on the stage based on the correlation data and the flow rate detected at the predetermined height. [Selected Figure] Figure 5

Description

This disclosure relates to semiconductor manufacturing equipment, and is applicable, for example, to die bonders that perform bond head height detection operations.

Semiconductor manufacturing equipment such as die bonders is equipment that uses a bonding material to bond (place and adhere) an element onto a substrate or element. The bonding material is, for example, liquid or film-like resin or solder. The element is, for example, a semiconductor chip, a MEMS (Micro Electro Mechanical System), a die such as a glass chip, etc. The substrate is, for example, a wiring board, a lead frame formed from a thin metal plate, a glass substrate, etc.

For example, in a die bonder, a die is picked up from a semiconductor wafer (hereafter simply referred to as a wafer) using a pick-up head or a collet (suction nozzle) attached to a bond head. The die is then bonded to a substrate by the bond head. In a die bonder, this pick-up and bonding process is repeated in a continuous operation.

To prevent adverse effects such as not reaching the target position or damaging the die when picking up the die, there is a system that automatically measures the amount of descent of the bond head when picking up the die (Patent Document 1).

JP 2014-56980 A

If the bond head is lowered during production based on the amount of descent measured using the technology of Patent Document 1 before production begins, the amount of descent will not be appropriate if there are changes over time during continuous operation. Also, if the bond head is lowered during production based on the amount of descent measured using the technology of Patent Document 1, the pick-up time will increase.

The objective of the present disclosure is to provide a technology that can improve pickup accuracy while minimizing increases in pickup time. 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 semiconductor manufacturing apparatus includes a stage on which a die is held, a head on which a collet having a suction hole for suctioning the die is provided, a flow sensor provided in a pipe communicating with the suction hole, and a control device for acquiring correlation data before production. The control device is configured to lower a lower end surface of the collet to a predetermined height from an upper surface of the die held on the stage, detect a flow rate of gas flowing through the suction hole of the collet at the predetermined height by the flow sensor, and determine an amount of lowering for landing the lower end surface of the collet on the upper surface of the die held on the stage based on the correlation data and the flow rate detected at the predetermined height.

This disclosure makes it possible to improve pickup accuracy while minimizing increases in pickup time.

FIG. 1 is a schematic top view showing an example of the configuration of a die bonder. FIG. 2 is a diagram for explaining the schematic configuration when viewed in the direction of the arrow A in FIG. FIG. 3 is a schematic cross-sectional view showing a main part of the wafer supply unit shown in FIG. FIG. 4 is a flowchart showing a method for manufacturing a semiconductor device using the die bonder shown in FIG. FIG. 5 is a schematic cross-sectional view of the bond head shown in FIG. FIG. 6 is a diagram showing the height of the bond head during a teaching operation before the start of production. FIG. 7 is a graph showing an example of the relationship between the flow rate and the distance obtained in the teaching operation before the start of production. FIG. 8 is a table corresponding to the graph shown in FIG. FIG. 9 is a diagram showing the height of the bond head during the pick-up operation for teaching. FIG. 10 is a diagram showing the height of the bond head in a pick-up operation without teaching. FIG. 11 is a diagram showing the height of the bond head during the bonding operation. 12(a) to 12(e) are conceptual diagrams showing a method of measuring the collet height using a landing detection sensor. FIG. 13 is a diagram showing the height of the bond head during the teaching operation at the time of picking up in the comparative example.

The following describes the embodiments and comparative examples 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 aspect in order to make the description clearer. Furthermore, the dimensional relationships between elements, the ratios of elements, etc. do not necessarily match between multiple drawings.

The configuration of a die bonder, which is one embodiment of a semiconductor manufacturing device, will be described with reference to Figures 1 to 3. Figure 1 is a schematic top view showing an example of the configuration of a die bonder. Figure 2 is a diagram explaining the schematic configuration as viewed from the direction of arrow A in Figure 1. Figure 3 is a schematic cross-sectional view showing the main parts of the wafer supply unit shown in Figure 1.

The die bonder 1 broadly comprises a wafer supply section 10, a pickup section 20, an intermediate stage section 30, a bonding section 40, a transport section 50, a substrate supply section 60, a substrate unloading section 70, and a control section (control device) 80. The Y direction is the front-rear direction of the die bonder 1, the X direction is the left-right direction, and the Z direction is the up-down direction. The wafer supply section 10 is disposed at the front of the die bonder 1, and the bonding section 40 is disposed at the rear. The wafer supply section 10 supplies a die D to be mounted on the substrate S. Here, the substrate S has multiple product areas (hereinafter referred to as package areas P) formed thereon that will ultimately become one package.

The wafer supply unit 10 has a wafer cassette lifter 11, a wafer holder 12, a peeling unit 13, and a wafer recognition camera 14. The wafer supply unit 10 supplies a die D to be mounted on a substrate S. Here, the substrate S has multiple product areas (hereinafter referred to as package areas P) formed thereon that will ultimately become one package.

The wafer cassette lifter 11 moves a wafer cassette (not shown) that stores multiple wafer rings WR up and down to the wafer transport height. A wafer correction chute (not shown) aligns the wafer rings WR supplied from the wafer cassette lifter 11. A wafer extractor (not shown) removes the wafer rings WR from the wafer cassette and supplies them to the wafer holder 12, or removes them from the wafer holder 12 and stores them in the wafer cassette.

The wafer holder 12 has an expand ring 121 that holds the wafer ring WR, and a support ring 122 that is held by the wafer ring WR and horizontally positions the dicing tape DT. The peeling unit 13 is disposed inside the support ring 122.

A wafer W is attached (pasted) onto a dicing tape DT, and the wafer W is divided into multiple dies D. The dicing tape DT is transparent to visible light. A film-like adhesive material DF called a die attach film (DAF) is attached between the wafer W and the dicing tape DT. The adhesive material DF hardens when heated.

The wafer holder 12 is moved in the XY direction by a drive unit (not shown), and moves the die D to be picked up to the position of the peeling unit 13. The wafer holder 12 rotates the wafer ring WR in the XY plane by a drive unit (not shown). The peeling unit 13 moves in the vertical direction by a drive unit (not shown). The peeling unit 13 peels the die D from the dicing tape DT.

The wafer recognition camera 14 determines the pick-up position of the die D to be picked up from the wafer W and inspects the surface of the die D.

The pickup unit 20 has a pickup head 21 and a Y drive unit 23. The pickup head 21 is provided with a collet 22 that suction-holds the peeled die D at its tip. The pickup head 21 picks up the die D from the wafer supply unit 10 and places it on the intermediate stage 31. The Y drive unit 23 moves the pickup head 21 in the Y-axis direction. The pickup unit 20 has various drive units (not shown) that raise and lower, rotate, and move the pickup head 21 in the X direction.

The intermediate stage section 30 has an intermediate stage 31 on which the die D is placed, and a stage recognition camera 34 for recognizing the die D on the intermediate stage 31. The intermediate stage 31 has a suction hole that adsorbs the placed die D. The placed die D is temporarily held on the intermediate stage 31. The intermediate stage 31 is both a placement stage on which the die D is placed, and a pick-up stage on which the die D is picked up.

The bonding section 40 has a bond head 41, a Y drive section 43, a substrate recognition camera 44, and a bond stage 46. The bond head 41 is provided with a collet section 42 that suctions and holds the die D at its tip. The Y drive section 43 moves the bond head 41 in the Y-axis direction. The substrate recognition camera 44 captures an image of a position recognition mark (not shown) in the package area P of the substrate S and recognizes the bond position. The bond stage 46 is raised when the die D is placed on the substrate S, and supports the substrate S from below. The bond stage 46 has a suction port (not shown) for vacuum suctioning the substrate S, and can fix the substrate S. The bond stage 46 has a heating section (not shown) for heating the substrate S. The bonding section 40 has each drive section (not shown) for raising and lowering the bond head 41, rotating it, and moving it in the X direction.

With this configuration, the bond head 41 corrects the pick-up position and posture based on the imaging data of the stage recognition camera 34, and picks up the die D from the intermediate stage 31. Then, the bond head 41 bonds the die D onto the package area P of the substrate S based on the imaging data of the substrate recognition camera 44, or bonds the die D by stacking it on top of a die that has already been bonded onto the package area P of the substrate S.

The transport section 50 has a transport claw 51 that grips and transports the substrate S, and a transport lane 52 along which the substrate S moves. The substrate S moves in the X direction by driving a nut (not shown) of the transport claw 51 provided on the transport lane 52 with a ball screw (not shown) provided along the transport lane 52. With this configuration, the substrate S moves from the substrate supply section 60 along the transport lane 52 to the bonding position, and after bonding, moves to the substrate unloading section 70 and hands the substrate S over to the substrate unloading section 70.

The substrate supply unit 60 removes the substrate S that was stored in the transport jig and transported in from the transport jig and supplies it to the transport unit 50. The substrate unloading unit 70 stores the substrate S transported by the transport unit 50 in the transport jig.

The control unit 80 includes a storage device that stores programs (software) and data for monitoring and controlling the operation of each part of the die bonder 1, a central processing unit (CPU) that executes the programs stored in the storage device, and an input/output device (not shown). The input/output device includes an image capture device (not shown), a motor control device (not shown), an I/O signal control device (not shown), and the like. The image capture device captures image data from the wafer recognition camera 14, the stage recognition camera 34, and the substrate recognition camera 44. The motor control device controls the drive unit of the wafer supply unit 10, the drive unit of the pickup unit 20, the Y drive unit 43 and the Z drive unit 47 of the bonding unit 40, and the like. The I/O signal control device captures various sensor signals such as the landing detection sensor 417 and the flow rate sensor 482 described below, or controls signal units such as switches for lighting devices, etc.

Part of the manufacturing process for semiconductor devices is the process of mounting a die on a substrate and assembling a package. Part of the process of assembling a package is the dicing process of separating the die from the wafer, and the die bonding process of mounting the separated die on the substrate. The die bonding process (manufacturing method for semiconductor devices) using die bonder 1 will be described with reference to FIG. 4. FIG. 4 is a flowchart showing the manufacturing method for semiconductor devices using the die bonder shown in FIG. 1. In the following description, the operation of each part constituting die bonder 1 is controlled by control unit 80.

(Wafer loading process: process S1)
The wafer ring WR is supplied to the wafer cassette of the wafer cassette lifter 11. The supplied wafer ring WR is then supplied to the wafer holder 12. The wafer W is previously inspected for each die by an inspection device such as a prober, and wafer map data indicating whether each die is good or bad is generated and stored in a storage device of the control unit 80.

(Substrate loading process: process S2)
The transport jig storing the substrate S is supplied to the substrate supply section 60. In the substrate supply section 60, the substrate S is removed from the transport jig and fixed to the transport claws 51.

(Pickup process: process S3)
After step S1, the wafer holder 12 is moved so that the desired die D can be picked up from the dicing tape DT. The die D is photographed by the wafer recognition camera 14, and the die D is positioned and its surface inspected based on the image data acquired by photographing. The image data is processed to calculate the amount of deviation (X, Y, and θ directions) of the die D on the wafer holder 12 from the die position reference point of the die bonder, and the die D is positioned. Note that the die position reference point is previously held at a predetermined position of the wafer holder 12 as the initial setting of the device. The image data is processed to inspect the surface of the die D.

The positioned die D is peeled off from the dicing tape DT by the peeling unit 13 and the pick-up head 21. The die D peeled off from the dicing tape DT is attracted to and held by the collet 22 provided on the pick-up head 21, and is transported to and placed on the intermediate stage 31.

The die D on the intermediate stage 31 is photographed by the stage recognition camera 34, and the die D is positioned and its surface inspected based on the image data acquired by photographing. The image data is processed to calculate the amount of deviation (X, Y, and θ directions) of the die D on the intermediate stage 31 from the die position reference point of the die bonder, and positioning is performed. Note that the die position reference point is previously held at a predetermined position on the intermediate stage 31 as the initial setting of the device. The image data is processed to perform a surface inspection of the die D.

The pickup head 21 that transports the die D to the intermediate stage 31 is returned to the wafer supply section 10. The next die D is peeled off from the dicing tape DT according to the procedure described above, and thereafter, the dies D are peeled off one by one from the dicing tape DT according to the same procedure.

(Bonding process: process S4)
The substrate S is transported to the bond stage 46 by the transport unit 50. The substrate S placed on the bond stage 46 is imaged by the substrate recognition camera 44, and image data is acquired by the image capture. The image data is processed to calculate the amount of deviation (X, Y, and θ directions) of the substrate S from the substrate position reference point of the die bonder 1. Note that the substrate position reference point is previously held at a predetermined position of the bonding unit 40 as the initial setting of the device.

The suction position of the bond head 41 is corrected based on the amount of deviation of the die D on the intermediate stage 31 calculated in step S3, and the die D is suctioned by the collet portion 42. The bond head 41 that has suctioned the die D from the intermediate stage 31 bonds the die D to a predetermined location on the substrate S supported by the bond stage 46. The substrate recognition camera 44 photographs the die D bonded to the substrate S, and an inspection is performed based on the image data acquired by photographing to determine whether the die D has been bonded to the desired position, etc.

The bond head 41 that has bonded the die D to the substrate S is returned to the intermediate stage 31. Following the procedure described above, the next die D is picked up from the intermediate stage 31 and bonded to the substrate S. This is repeated until a die D is bonded to all package areas P of the substrate S.

(Substrate removal process: process S5)
The substrate S with the die D bonded thereto is transported to the substrate unloading section 70. In the substrate unloading section 70, the substrate S is removed from the transport claws 51 and stored in a transport jig. The transport jig storing the substrate S is unloaded from the die bonder 1.

As described above, the die D is mounted on the substrate S and is removed from the die bonder 1. Thereafter, for example, the transport jig storing the substrate S on which the die D is mounted is transported to a wire bonding process, where the electrodes of the die D are electrically connected to the electrodes of the substrate S via Au wires or the like. The substrate S is then transported to a molding process, where the die D and the Au wires are sealed with molding resin (not shown) to complete the semiconductor package.

In the case of stacked bonding, following the wire bonding process, a transport jig on which a substrate S on which a die D is mounted is loaded and stored is transported into a die bonder, where the die D is stacked on top of the die D mounted on the substrate S, and after being transported out of the die bonder, the die D is electrically connected to the electrodes of the substrate S via Au wires in a wire bonding process. The dies D above the second level are peeled off from the dicing tape DT by the method described above, then transported to the bonding section and stacked on top of the die D. After the above process is repeated a predetermined number of times, the substrate S is transported to a molding process, where the multiple dies D and Au wires are sealed with molding resin (not shown) to complete the stacked package.

The structure of the bond head 41 will be described with reference to FIG. 5. FIG. 5 is a schematic cross-sectional view of the bond head shown in FIG. 1.

The bond head 41 is connected to a Z drive unit 47 mounted on the stage of a Y drive unit 43. A collet unit 42 is provided on the bond head 41. The collet unit 42 has a collet 421 made of an elastic material such as rubber at its tip and a collet holder 422 to which the collet 421 is attached. The bond head 41 has a movable unit 411, a ball bush 412, a contact piece 413, a head support unit 414, a compression spring 416, and a landing detection sensor 417. The collet unit 42 is connected to a vacuum suction system 48 via the movable unit 411.

A sensor support part 414a is provided on the top of the head support part 414 and is formed integrally with the head support part 414. The sensor support part 414a has an opening 414b into which the movable part 411 is inserted. The lifting and lowering drive part 474, which will be described later, is connected to the side of the head support part 414. A ball bushing 412, whose opening 412a extends almost vertically, is provided on the bottom of the head support part 414. The movable part 411, which is inserted into the opening 412a of this ball bushing 412, is supported so that it can be freely raised and lowered almost vertically.

A contact piece 413 is attached horizontally at approximately the middle position of the movable part 411. A compression spring 416 is provided between the upper surface of this contact piece 413 and the lower surface of the sensor support part 414a, and the collet part 42 is urged downward by this compression spring 416 via the contact piece 413. Instead of the compression spring 416, the collet part 42 may be urged downward by a cylinder.

The landing detection sensor 417 is a detector that mechanically detects landing during bonding, and is attached by penetrating the sensor support portion 414a. When the lower end surface 421a of the collet 421 is not in contact with another member and is not raised, a predetermined gap (ds) is formed between the lower end surface 417a of the landing detection sensor 417 and the upper surface of the contact piece 413. The landing detection sensor 417 is a gap sensor that detects the distance of that gap.

The Z drive unit 47 has a stage 471 mounted on the Y drive unit 43, and a Z axis 472 that moves up and down relative to the stage 471. The stage 471 is provided with a lifting drive unit (not shown). The lifting drive unit is composed of, for example, a servo motor or step motor, a ball screw, a nut, and a cam. The Z axis 472 moves up and down along the stage 471, which is arranged in the vertical direction, by the lifting drive unit.

The collet 421 has a suction hole with one end open on the lower end surface 421a. The other end of the suction hole of the collet 421 is connected to the suction hole of the collet holder 422, the suction hole of the movable part 411, and a pipe 481 attached to the upper part of the movable part 411.

Pipe 481 is connected to a vacuum supply source (not shown). Pipe 481 is provided with a flow sensor 482 and a valve 483 for detecting the flow rate of air suction by the vacuum supply source. Pipe 481 is connected to pipe 484, which is connected to an air supply source (not shown). Pipe 484 is provided with a valve 485. The vacuum source and air supply source may be included in the vacuum suction system 48 of the die bonder 1, or may be provided outside the die bonder 1. When using a factory vacuum supply source and air supply source, it is preferable to provide a pressure regulator in the vacuum suction system 48.

When valve 485 is closed and valve 483 is opened, air is sucked in through piping 481, the suction holes of movable part 411, the suction holes of collet holder 422, and the suction holes of collet 421, and an adsorption force is generated at the lower end surface 421a of collet 421. When valve 483 is closed and valve 485 is opened, air is blown out through piping 481, the suction holes of movable part 411, the suction holes of collet holder 422, and the suction holes of collet 421.

(Teaching operation before starting production)
In the die bonder 1 configured as described above, the following information is acquired by a teaching operation before the successive operations of actually performing pick-up and bonding (before production starts).

(1) Acquisition of Pickup Height Information (PHD) The control unit 80 acquires pickup height information (PHD) that indicates the height (pickup height (h5)) of the lower end surface 421a of the collet 421 when picking up in continuous operations during production.

(2) Acquisition of correlation data (CD) The control unit 80 acquires correlation data (CD) between the flow rate sucked by the lower end surface 421a of the collet 421 and the distance between the lower end surface 421a of the collet 421 and the upper surface of the die D placed on the intermediate stage 31.

(3) Acquisition of flow measurement height information (FHD) The control unit 80 acquires flow measurement height information (FHD) indicating the height (flow measurement height (h4)) of the lower end surface 421a of the collet 421 at which the teaching operation is performed when actually picking up the die D.

(4) Bond Height Information (BHD)
Bond height information (BHD) indicating the height (bond height (h6)) of the lower end surface 421a of the collet 421 at the time of bonding is obtained.

When performing an actual pick-up operation, the control unit 80 periodically performs a teaching operation using the correlation data (CD) and flow measurement height information (FHD) acquired in a teaching operation before the start of production. This teaching operation acquires descent amount correction information (DCD) for the bond head 41. In the pick-up operation, following the teaching operation, the control unit 80 controls the drive of the bond head 41 using the acquired descent amount correction information (DCD). When performing a bond operation, the control unit 80 controls the drive of the bond head 41 using the descent amount correction information (DCD) and bond height information (BHD).

The teaching operation before the start of production in the die bonder 1 will be described with reference to Figs. 6 to 8. Fig. 6 is a diagram showing the height of the bond head in the teaching operation before the start of production. Fig. 7 is a graph showing an example of the relationship between the flow rate and distance obtained in the teaching operation before the start of production. Fig. 7 is a table corresponding to the graph shown in Fig. 6.

(Step S11)
At the high-speed descent start height (h1), the control unit 80 moves the bond head 41 above the die D placed on the intermediate stage 31 so that the bottom end surface 421a of the collet 421 faces the top surface of the die D. The die D is placed on the intermediate stage 31 in advance by the pickup head 21. The high-speed descent start height (h1) is the height of the bottom end surface 421a of the collet 421 when the bond head 41 moves horizontally between the intermediate stage 31 and the bond stage 46, and is set lower than the height (origin height (h0)) of the bottom end surface 421a of the collet 421 when the Z-axis 472 is at the machine origin in the Z direction.

(Step S12)
The control unit 80 lowers the bond head 41 at high speed to a low-speed lowering start height (h2), which is the height of the lower end surface 421a of the collet 421 when the bond head 41 starts to lower at a low speed.

(Step S13)
The control unit 80 stops the descent of the bond head 41 and starts the low speed pre-start timer (step S131).

After the low-speed pre-start timer has elapsed a predetermined time, the control unit 80 opens the valve 485 to start blowing air (step S132). At this time, the valve 483 is closed. If the low-speed pre-start timer is set to 0, step S132 is performed without waiting.

(Step S14)
After a predetermined time has elapsed, the control unit 80 closes the valve 485 and opens the valve 483 to start suctioning air (step S141).

The control unit 80 lowers the bond head 41 by a predetermined amount (Δz1) (step S142), and measures the flow rate (FR) of the collet 421 by the flow rate sensor 482 (step S143). The predetermined amount (Δz1) is, for example, several times the control resolution of the elevation drive unit 474.

The control unit 80 checks the flow rate (FR) detected by the flow rate sensor 482 and checks whether the flow rate (FR) is equal to or lower than a predetermined threshold value (FRt) (step S144). The threshold value (FRt) is a value that is preset as a value at which the lower end surface 421a of the collet 421 can be considered to be in contact with the die D.

The control unit 80 repeats steps S142 to S144 until the flow rate (FR) becomes equal to or less than the threshold value (FRt).

After the flow rate measurement is completed, the control unit 80 closes the valve 483 to stop suction (step S145).

The control unit 80 stores the offset amount from the mechanical origin in the Z direction of the Z axis 472 at the height (pickup height (h5)) of the lower end surface 421a of the collet 421 where the flow rate (FR) is equal to or less than the threshold value (FRt) in the memory of the control unit 80 as pickup height information (PHD) (step S146).

(Step S15)
The control unit 80 raises the bond head 41 to a measurement start height (h3) that is a predetermined distance higher than the pickup height (h5). The measurement start height (h3) is the height of the lower end surface 421a of the collet 421 when the measurement of correlation data begins. The measurement start height (h3) is lower than the low-speed descent start height (h2).

(Step S16)
The control unit 80 closes the valve 485 and opens the valve 483 to start suction of air (step S161).

The control unit 80 measures the flow rate (FR) sucked by the collet 421 using the flow rate sensor 482 (step S162).

The control unit 80 stores the measured flow rate (FR) and the height (hc) of the lower end surface 421a of the collet 421 when the flow rate was measured in the memory of the control unit 80 (step S163).

The control unit 80 lowers the bond head 41 by a predetermined amount (Δz2) (step S164), and measures the flow rate (FR) of the collet 421 by the flow rate sensor 482 (step S165). The predetermined amount (Δz2) is a value smaller than Δz1, and is, for example, the amount of control resolution of the elevation drive unit 474.

The control unit 80 stores the measured flow rate (FR) and the height (hc) of the lower end surface 421a of the collet 421 when the flow rate was measured in the memory of the control unit 80 (step S166).
The control unit 80 repeats the processes of steps S164 to S166 until the height of the lower end surface 421a of the collet 421 reaches the pickup height (h5).

Based on the flow rate (FR) and the height (hc) of the lower end surface 421a of the collet 421 stored in the memory, the control unit 80 creates correlation data of the flow rate (FR) and the distance (d) as shown in Figures 7 and 8, and stores the data in the memory of the control unit 80 (step S167). The distance (d) is the difference between the height (hc) of the lower end surface 421a of the collet 421 and the height of the upper surface of the die D (pickup height (h5)).

The control unit 80 sets a flow measurement height (h4 = h5 + dp) that is a predetermined distance (dp) higher than the height of the upper surface of the die D (pickup height (h5)), and stores the offset amount from the machine origin in the Z direction of the Z axis 472 in the memory of the control unit 80 as flow measurement height information (FHD) (step S168). As shown in Figure 7, for example, dp = 15 μm. The flow rate (FRp) at this time is -0.14 L/min.

The offset amount from the machine origin in the Z direction of the Z axis 472 at the pickup height (h5) plus or minus the difference in the distance in the Z direction between the surface of the die D placed on the intermediate stage 31 and the surface of the substrate S placed on the bond stage 46 is stored in the memory of the control unit 80 as bond height information (BHD) (step S169).

(Pickup operation: Teaching operation available)
The pick-up operation of the die D for which the teaching operation is performed during production will be described with reference to Fig. 9. Fig. 9 is a diagram showing the height of the bond head in the pick-up operation for which teaching is performed.

Steps S11 to S13 in the pickup operation are the same as the teaching operation before the start of production. Below, we will explain the differences from the teaching operation before the start of production. Note that the teaching operation shown in Figure 9 may be performed other than during production, that is, before the start or end of production.

(Step S24)
After a predetermined time has elapsed, the control unit 80 starts suction of air by closing the valve 485 and opening the valve 483. The control unit 80 lowers the bond head 41 at a low speed to the flow measurement height (h4) indicated by the flow measurement height information (FHD).

(Step S25)
The control unit 80 stops the descent of the bond head 41 and measures the flow rate of the liquid sucked by the collet 421 using the flow rate sensor 482 .

(Step S26)
The control unit 80 compares the flow rate (FRp) corresponding to the flow rate measurement height information (FHD) with the flow rate (FRm) measured in step S25 based on the correlation data (CD) stored in the memory. If the two match, the control unit 80 lowers the bond head 41 by the flow rate measurement height (h4) indicated by the flow rate measurement height information (FHD).

When the flow rate (FRp) and the flow rate (FRm) do not match, the height (h) of the lower end surface 421a of the collet 421 fluctuates (h = h4 + α (α is a positive or negative number)). The control unit 80 calculates the distance (dm) corresponding to the measured flow rate (FRm) from the correlation data (CD) and lowers the bond head 41 by the distance (dm). dm is the amount of lowering corrected for dp, and dm = dp - α. α is the amount of correction.

(Step S27)
The control unit 80 picks up the die D with the bond head 41 .

(Pickup operation: no teaching operation)
The above-mentioned teaching during the pick-up operation is not performed every time, but is performed periodically after a predetermined period of time has elapsed. The pick-up operation of the die D without teaching will be described with reference to Fig. 10. Fig. 10 is a diagram showing the height of the bond head during the pick-up operation without teaching.

Steps S11 to S13 in the pick-up operation without teaching are the same as the pick-up operation with teaching shown in Figure 9. Below, we will explain the differences from the pick-up operation with teaching.

(Step S34)
After a predetermined time has elapsed, the control unit 80 starts suction of air by closing the valve 485 and opening the valve 483. The control unit 80 lowers the bond head 41 at a low speed (e.g., 10 μm/min) to the position (pickup height (h5)) indicated by the pick-up height information (PHD).

(Bond operation)
The bonding operation of the die D will be described with reference to Fig. 11. Fig. 11 is a diagram showing the height of the bond head during the bonding operation.

Steps S41 to S43 in the bonding operation are the same as steps S11 to S131 in the teaching operation before production begins.

(Step S44)
Based on the bond height information (BHD) stored in memory and the amount of descent (dp or dm) determined in step S27 during the pick-up operation, the control unit 80 lowers the bond head 41 at a low speed (e.g., 5 μm/min) to a position at the bond height (h7), and lands the die D on the substrate S.

(Step S45)
The control unit 80 continues to lower the bond head 41 by a predetermined amount even after the die D comes into contact with the substrate S. At this time, the collet member 42 retreats by the predetermined amount that was lowered after the die D came into contact, but since a pressing force is applied by the compression spring 416, a pressing load is applied to the die D attracted and held by the collet member 42. By maintaining this state for a preset bonding time, the die D is bonded to the substrate S.

The bond head 41 is lowered, and when the landing detection sensor 417 detects that a predetermined gap (predetermined interval) has formed between the lower end surface 417a and the upper surface of the contact piece 413, it is determined that the die D and the substrate S have come into contact. Note that the landing detection sensor 417 typically uses a displacement sensor or the like, and in order to ensure stable detection, the predetermined interval is set so that detection is performed with a sensitivity difference of about several tens of μm from the original landing position of the reference collet (in a pressed-in state).

The collet height can be measured using the landing detection sensor 417. The method of measuring the collet height using the landing detection sensor 417 will be explained with reference to Figs. 12(a) to 12(e). Figs. 12(a) to 12(e) are conceptual diagrams showing the method of measuring the collet height using the landing detection sensor.

Figure 12 (a) shows the landing position of the reference collet. The control unit 80 stores the landing position (ho) of the reference collet on the linear scale on the device side as the origin by pre-teaching.

Figures 12(b) and 12(d) show cases where the height of the reference collet and the collet to be measured are the same. As shown in Figure 12(b), the control unit 80 lowers the bond head 41 from a position (hs) above a preset landing point at a predetermined pitch (p) while checking the landing detection sensor 417. Here, hs is the indicated value of the linear scale, and for example, hs = 100 μm. Also, for example, p = 5 μm.

As shown in FIG. 12(d), the landing detection sensor 417 is set at a predetermined distance (do) so that it detects landing when the sensitivity difference is ha from the original landing position of the reference collet (in a pressed-in state). In other words, do = ds - (ho - ha). Here, ds is the gap between the bottom end surface 417a of the landing detection sensor 417 and the top surface of the contact piece 413 when not touching the ground. For example, ha is set to several tens of μm.

The control unit 80 measures the collet height by reading the indication value of the linear scale when the landing detection sensor 417 detects the landing (do = ds - (ho - ha)). If the height of the collet 421 has not changed since pre-teaching, the value of the linear scale will be the same as ha, which is set as the sensitivity difference.

Figures 12(c) and 12(e) show cases where the height of the reference collet and the collet to be measured are different. When the height of the collet 421 has changed since pre-teaching, as shown in Figure 12(e), if the bond head 41 is lowered so that the gap between the bottom end surface 417a of the landing detection sensor 417 and the top surface of the contact piece 413 is a specified distance (do), when the value of the linear scale becomes hb, for example, as shown in Figure 12(c), it can be seen that the height of the collet 421 has increased by (Δh = hb - ha).

The landing detection sensor 417 can detect the height while holding the die D. Note that the collet height is calculated based on the corrected amount of descent calculated in step S26, and if there is a discrepancy between the collet height measured using the flow sensor and the collet height measured using the landing detection sensor, the predetermined interval (do) may be calibrated. This calibration may be performed periodically.

To clarify this embodiment, a comparative example will be described using FIG. 13. FIG. 13 shows the height of the bond head during the teaching operation at the time of pick-up in the comparative example.

Steps S11 to S13 in the comparative example are the same as the teaching operations before production starts. Below, we will explain the differences from the teaching operations before production starts.

(Step S54)
After a predetermined time has elapsed, the control unit 80 closes the valve 485 and opens the valve 483 to start suctioning air (step S541).

The control unit 80 lowers the bond head 41 by a predetermined amount (Δz1) (step S542), and measures the flow rate (FR) of the collet 421 by the flow rate sensor 482 (step S543). The predetermined amount (Δz1) is, for example, 10 μm.

The control unit 80 checks the flow rate (FR) detected by the flow rate sensor 482 and checks whether the flow rate (FR) is equal to or lower than a predetermined threshold value (FRt) (step S544). The threshold value (FRt) is a value that is preset as a value at which the lower end surface 421a of the collet 421 can be considered to be in contact with the die D.

The control unit 80 repeats steps S542 to S544 until the flow rate (FR) becomes equal to or less than the threshold value (FRt).

After the flow rate measurement is completed, the control unit 80 closes the valve 483 to stop suction (step S545).

The control unit 80 stores the offset amount from the mechanical origin in the Z direction of the Z axis 472 at the height (pickup height (h5)) of the lower end surface 421a of the collet 421 where the flow rate (FR) is equal to or less than the threshold value (FRt) in the memory of the control unit 80 as pickup height information (PHD) (step S546).

(Step S55)
The control unit 80 raises the bond head 41 from the pickup height (h5) to a height (h3') that is a predetermined distance higher. The height (h3') is the height of the lower end surface 421a of the collet 421 when fine search begins. The height (h3') is lower than the low-speed descent start height (h2).

(Step S56)
The control unit 80 closes the valve 485 and opens the valve 483 to start suction of air (step S561).

The control unit 80 lowers the bond head 41 by a predetermined amount (Δz1) (step S562), and measures the flow rate (FR) of the collet 421 by the flow rate sensor 482 (step S563). The predetermined amount (Δz1) is, for example, 2 μm.

The control unit 80 checks the flow rate (FR) detected by the flow rate sensor 482 and checks whether the flow rate (FR) is equal to or lower than a predetermined threshold value (FRt) (step S564). The threshold value (FRt) is a value that is preset as a value at which the lower end surface 421a of the collet 421 can be considered to be in contact with the die D.

The control unit 80 repeats steps S562 to S564 until the flow rate (FR) becomes equal to or less than the threshold value (FRt).

The control unit 80 stores the offset amount from the mechanical origin in the Z direction of the Z axis 472 at the height (pickup height (h5)) of the lower end surface 421a of the collet 421 where the flow rate (FR) is equal to or less than the threshold value (FRt) in the memory of the control unit 80 as pickup height information (PHD) (step S565).

(Step S57)
The control unit 80 picks up the die D with the bond head 41 .

In the comparative example, the lowering of the bond head 41 and the flow rate measurement are performed twice, divided into a coarse search (step S54) and a fine search (step S56). In contrast, in the embodiment, after the head is lowered to a certain height (step S24), the flow rate measurement is performed only once (step S24). The head is then lowered by the correction value obtained from the correlation data (step S26). Compared to the comparative example, the embodiment performs flow rate measurements much less frequently, so the lowering time of the bond head 41 is shorter and the pick-up time is shorter.

According to the embodiment, one or more of the following effects can be obtained.

(a) It is possible to reduce the height teaching time using the flow sensor during continuous operation (production).

(b) By storing correlation data for each collet type (size, hole diameter, etc.) that corresponds to the product variety, it becomes unnecessary to create correlation data by performing height teaching before starting production, for example, every time the collet is replaced. This is because even if there is variation in height when the collet is manufactured, the height can be corrected by teaching at the time of picking up.

(c) By performing teaching each time the material is picked up, highly accurate landing detection based on the flow rate can be performed in a relatively short time. This eliminates the need for a low-impact mode in which the bond head's descent speed is slowed down before landing (to about 1/10 the speed of the slow descent described above) to reduce the impact of landing. This also makes it possible to reduce processing time.

(d) By checking the detection position of the landing detection sensor mounted on the bond head, it becomes possible to calibrate this position using height detection data based on the flow rate detected during pick-up.

(e) The above (d) makes it possible to periodically calibrate the landing detection sensor. This allows the sensitivity deviation of the landing detection sensor to be periodically calibrated without affecting throughput, making it possible to perform stable bonding over time.

(f) Height detection data based on the flow rate detected during pick-up makes it possible to provide feedback to the landing position during bonding. This makes it possible to stably maintain height accuracy during bonding and reduce impact loads. The distance between the bottom end surface of the collet and each stage can vary depending on the collet's installation condition or changes over time. However, the positions of the pickup stage (wafer holder, intermediate stage) and the surface of the bond stage are known. And because the distance between the bottom end surface of the collet and the surface of the pick-up stage can be accurately known, the positions of the bottom end surface of the collet and the surface of the bond stage can also be accurately known. In other words, the collet height can be precisely controlled, making it possible to prevent impacts during bonding.

The disclosure made by the present inventors has been specifically described above based on the embodiments, but it goes without saying that the present disclosure is not limited to the above embodiments and can be modified in various ways.

For example, in the embodiment, an example was described in which the pickup height, etc. was taught based on the suction flow rate from the collet, but the pickup height, etc. may also be taught based on the air flow rate ejected by the collet.

In the embodiment, an example of teaching using a flow sensor during pickup has been described, but a flow sensor and a landing detection sensor may also be used together.

In the embodiment, an example of a bond head that picks up a die from an intermediate stage and bonds it to a substrate held on a bond stage has been described. This is not limited to this, and the present invention can also be applied to a pick-up head that picks up a die from a wafer holder and places it on the intermediate stage. In this case, the wafer holder is the first stage, and the intermediate stage is the second stage.

In the embodiment, an example has been described in which a die picked up from a wafer by a pick-up head is placed on an intermediate stage, and the die is picked up from the intermediate stage by a bond head. This is not limited to this, and the present invention can also be applied to direct bonding, in which a die picked up from a wafer by a bond head is bonded to a substrate without a pick-up head or intermediate stage. In this case, the wafer holder is the first stage, and the bond stage is the second stage.

In addition, in the embodiment, a DAF is attached to the back surface of the wafer, but the DAF is not necessary.

In addition, although the embodiment has one pickup head and one bond head, there may be two or more of each.

In the embodiment, a die bonder is used as an example, but the invention can also be applied to flip chip bonders and chip mounters.

1...Die bonder (semiconductor manufacturing equipment)
31... Intermediate stage (stage)
41... Bond head (head)
421: collet 421a: lower end surface 481: pipe 482: flow rate sensor 80: control unit (control device)
D... Die

Claims (11)

a stage on which the die is held;
a head provided with a collet having a suction hole for adsorbing the die;
a flow rate sensor provided in a pipe communicating with the suction hole;
A control device configured to acquire correlation data between a distance between a lower end surface of the collet and an upper surface of a die held by the stage and a flow rate of gas flowing through the suction hole of the collet detected by the flow sensor before production;
Equipped with
The control device includes:
lowering a lower end surface of the collet to a first predetermined height from an upper surface of the die held by the stage;
At the first predetermined height, the flow rate of the gas flowing through the suction hole of the collet is detected by the flow rate sensor;
A semiconductor manufacturing apparatus configured to perform a teaching operation to determine an amount of descent for landing the lower end surface of the collet on an upper surface of a die held by the stage, based on the correlation data and the flow rate detected at the first predetermined height. 2. The semiconductor manufacturing apparatus according to claim 1,
The control device is configured to perform the teaching operation during production of the semiconductor manufacturing device. 2. The semiconductor manufacturing apparatus according to claim 1,
The control device, prior to production,
setting a lower end surface of the collet at a second predetermined height from an upper surface of the die held by the stage, the second predetermined height being higher than the first predetermined height;
A semiconductor manufacturing apparatus configured to perform a teaching operation to acquire the correlation data by lowering the lower end surface of the collet from the second predetermined height to the height of the upper surface of the die held by the stage, and then raising it again to the first predetermined height. 2. The semiconductor manufacturing apparatus according to claim 1,
The control device is a semiconductor manufacturing device configured to perform the teaching operation every time a predetermined number of pick-up operations are performed. 2. The semiconductor manufacturing apparatus according to claim 1,
The semiconductor manufacturing apparatus further comprises a second stage on which the die or a substrate on which the die is mounted is placed. 6. The semiconductor manufacturing apparatus according to claim 5,
The control device is configured to determine the amount of lowering for landing the lower end surface of the collet on the substrate, a die placed on the substrate, or an upper surface of the second stage based on the correlation data and the flow rate detected at the first predetermined height. 6. The semiconductor manufacturing apparatus according to claim 5,
the stage is a wafer holder,
the second stage being a bond stage;
The head of the semiconductor manufacturing equipment is a bond head. 2. The semiconductor manufacturing apparatus according to claim 1,
The head includes a landing detection sensor,
The control device is configured to confirm a detection position of the landing detection sensor based on the correlation data and the flow rate detected at the first predetermined height. 2. The semiconductor manufacturing apparatus according to claim 1,
The head includes a landing detection sensor,
The control device is further configured to measure a height of the collet by the landing detection sensor during the teaching operation. 2. The semiconductor manufacturing apparatus according to claim 1,
The control device is configured to detect a flow rate of the gas blown out from the suction hole of the collet by the flow rate sensor. a step of carrying a wafer into a semiconductor manufacturing device including a stage for holding a die, a head provided with a collet having a suction hole for suctioning the die, a flow sensor provided in a pipe communicating with the suction hole, and a control device configured to acquire, before production, correlation data between a distance between a bottom surface of the collet and an upper surface of the die held by the stage, and a flow rate of gas flowing through the suction hole of the collet detected by the flow sensor;
a step of lowering a lower end surface of the collet from an upper surface of the die held by the stage to a first predetermined height, detecting a flow rate of gas flowing through the suction hole of the collet at the first predetermined height with the flow rate sensor, and determining an amount of lowering for landing the lower end surface of the collet on the upper surface of the die held by the stage based on the correlation data and the flow rate detected at the first predetermined height;
A method for manufacturing a semiconductor device comprising the steps of:

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