Patent Application
20250149498
The present invention relates to a position alignment device, a position alignment method, a bonding device, a bonding method, and a method of manufacturing a semiconductor device.
In manufacture of a semiconductor device (which refers to a device that functions by utilizing semiconductor characteristics in general and an electro-optical device, a semiconductor circuit, and an electronic device correspond to the semiconductor device), there is adopted a chip bonding technique in which a wafer having a large number of elements collectively formed therein is diced and separated into individual semiconductor chips, and those semiconductor chips are bonded one by one to a predetermined position of a lead frame or the like. Further, this chip bonding uses a die bonder (bonding device).
The bonding device includes a bonding arm including a collet configured to suction a semiconductor chip of a supply portion, a recognition camera used to observe the semiconductor chip of the supply portion, and a recognition camera used to observe an island portion of a lead frame at a bonding position.
The supply portion includes a semiconductor wafer, and the semiconductor wafer is divided into a large number of semiconductor chips. That is, the wafer is bonded to a pressure-sensitive adhesive sheet (dicing sheet), and this dicing sheet is held by an annular frame. Then, the wafer bonded on this dicing sheet is singulated with the use of a circular blade (dicing saw) or the like to form the chips. Further, the bonding arm holding the collet can move between a pickup position and the bonding position via a transporting mechanism.
Further, the chip is vacuum-suctioned onto this collet through a suction hole opened through a lower end surface of the collet, and the chip is suctioned onto the lower end surface of this collet. When this vacuum suction (evacuation) is released, the chip is separated from the collet.
Next, a die bonding method using this die bonder is described. First, the chip to be picked up is observed by the recognition camera arranged above the supply portion. After the collet is positioned above this chip to be picked up, the collet is moved downward so as to pick up this chip. After that, the collet is moved upward.
Next, the island portion of the lead frame to be subjected to bonding is observed by the recognition camera arranged above the bonding position. After the collet is moved in a direction indicated by the arrow so as to be positioned above this island portion, the collet is moved downward so as to supply the chip to this island portion. Further, after the chip is supplied to the island portion, the collet is moved upward, and then the collet is returned to a standby position above the pickup position.
Incidentally, there is a type of chip that has a rear surface to which a die attach film (DAF) for adhesion to a supplied-to member such as a lead frame or a substrate is attached. The die attach film is an adhesive in the form of a film, and cures by being heated. That is, at the bonding position, the supplied-to member is placed on a stage including a heating part (for example, a heater) and the chip is bonded to the supplied-to member heated to a predetermined temperature. Thus, the chip is bonded to the supplied-to member via the die attach film.
However, with a die bonder including a heating part such as this, thermal deformation of a bonding head, a recognition camera attaching portion, or the like from heating by the heating part causes misalignment of a chip mounting position in some cases. Accordingly, various devices configured to correct misalignment of a chip mounting position have hitherto been proposed (Patent Literature 1 and Patent Literature 2).
In Patent Literature 1, there are described a bonding device and a bonding method that achieve high accuracy of positioning at a packaging position by correcting a mismatch in posture between a pickup imaging camera and a packaging imaging camera. This device includes a pickup imaging part, a placed position imaging part, a die transfer tool, a first examination part, a second examination part, and a correction part. An image of a reference mark can be taken by the pickup imaging part or the placed position imaging part via an optical system which is provided in the die transfer tool and which includes two prisms. The two prisms are supported to the die transfer tool by an optical system support portion, and a first prism out of the two prisms which is provided so as to face the pickup imaging part or the placed position imaging part is provided so that an optical axis of the first prism matches a central axis of the die transfer tool. A second prism out of the two prisms which is provided so as to face the reference mark is provided so as to face the first prism.
In Patent Literature 2, there is described a method for picking up and packaging a semiconductor chip that ensures highly accurate placement irrespective of external situations and changes. In this method, a position of a semiconductor chip to be packaged that is detected by a first camera is supplied in the form of position data associated with a first coordinate system, a position of a place in a substrate at which the semiconductor chip is to be packaged is supplied in the form of position data associated with a second coordinate system, and a position of a bonding head is associated with a third coordinate system.
In the device as described in Patent Literature 1, the correction part corrects a mismatch in posture between a die and a bonding arm as well as a mismatch in posture between a substrate and the die. That is, the device is not aimed for position alignment. It is accordingly required to match the optical axis of the first prism facing the pickup imaging part or the placed position imaging part with the central axis of the die transfer tool, and to provide the second prism facing the reference mark so as to face the first prism. Thus, a configuration of the device becomes complicated, and high assembly accuracy is also required. In addition, a plurality of arithmetic operations are required.
The method as described in Patent Literature 2 requires a plurality of arithmetic operations for position alignment. There are accordingly a plurality of parameters, and one incorrect parameter may impair accuracy of this position alignment processing.
In view of the problems described above, the present invention provides a position alignment device, a position alignment method, a bonding device, a bonding method, and a method of manufacturing a semiconductor device, each of which enables accurate position alignment by simple processing.
According to the present invention, there is provided a position alignment device comprising: a target mark provided on a bonding arm; a pickup-side imaging part configured to take an image of a pickup position; a bonding-side imaging part configured to take an image of a bonding position; a pickup-side registration part configured to register a target mark position in a taken image screen of the pickup-side imaging part; a bonding-side registration part configured to register a target mark position in a taken image screen of the bonding-side imaging part; a positional relationship detector configured to detect a positional relationship between the target mark position registered by the pickup-side registration part and the target mark position registered by the bonding-side registration part; a pickup-side offset amount detector configured to detect an offset amount of offset between a target mark position in an image taken by the pickup-side imaging part and the target mark position registered by the pickup-side registration part; a bonding-side offset amount detector configured to detect an offset amount of offset from the target mark position registered by the bonding-side registration part; and a position adjuster configured to adjust bonding coordinates, based on the offset amount detected by the pickup-side offset amount detector, the offset amount detected by the bonding-side offset amount detector, and the positional relationship detected by the positional relationship detector, wherein the registered target mark position is displayed at a position offset from a center in a pickup taken image screen, and the registered target mark position is displayed at a position offset from a center in a bonding taken image screen. To “adjust the bonding coordinates” means to place the target mark position in the taken image screen on the pickup side and the target mark position in the taken image screen on the bonding side at the same coordinates in the respective taken image screens. The amounts of offset of the registered positions of the target mark from the centers in the taken image screens here are each outside at least a range of errors that occur due to design, manufacture, and assembly. That is, the amounts of offset of the registered positions of the target mark from the centers in the taken image screens are each larger than an amount of offset caused by those errors, and the amounts of offset of the registered positions of the target mark from the centers in the taken image screens are each set so as to be outside a tolerable range of errors of the device that occur when measures to prevent the registered positions from being offset are taken.
The present invention enables accurate position alignment by simple processing, regardless of thermal deformation.
An embodiment of the present invention is described below with reference to
The bonding device comprises, as illustrated in
The supply portion 22 has a semiconductor wafer 28 placed on and supported by a wafer support device 27. The semiconductor wafer 28 is divided into many chips which are each denoted by 21. The collet 23 is coupled to a collet holder 29, and the collet 23, the collet holder 29, and others form the bonding arm 30. The bonding arm 30 can move between a pickup position and a bonding position by means of a driver 31. The driver 31 can drive the bonding arm 30 in X-, Y-, θ-, and Z-directions.
Further, the collet 23 vacuum-suctions the chip 21 through a suction hole opened through a lower end surface of the collet 23, and the chip 21 adheres by suction to the lower end surface of the collet 23. When this vacuum suction (evacuation) is released, the chip 21 separates from the collet 23.
The substrate 24 is placed on a stage (not shown). A heating part (for example, a heater) is placed on the stage to heat the substrate 24. The substrate 24 is accordingly put in a high-temperature atmosphere. Once the substrate 24 reaches a predetermined temperature at which thermocompression bonding is executable, bonding of the chip 21 to the substrate 24 is performed, to thereby bond the chip 21 to the substrate via the die attach film.
A suction hole is formed in the stage, and a vacuum source such as a vacuum pump (not shown) is connected to the stage. A suction mechanism comprising the suction hole and the vacuum source serves as a fixing part configured to fix the substrate 24 to the stage. That is, when the vacuum source is driven with the substrate 24 placed on the stage, the substrate 24 is suctioned through the suction hole, and the entirety of the substrate 24 is stuck by suction (fixed) to the stage.
The recognition camera 26 is placed above the supply portion 22, and is used to observe the chip 21 to be picked up. The recognition camera 32 is placed above a bonding position Q, and is used to observe the island portion 25 of the substrate 24 that is to be subjected to bonding. Each of the recognition cameras 26 and 32 may be configured from, for example, a CCD camera or a CMOS camera.
Accordingly, this bonding the device uses recognition camera 26 placed above the pickup position P to observe the chip 21 to be picked up and, as illustrated in
Next, the recognition camera 32 placed above the bonding position Q is used to observe the island portion 25 of the lead frame (substrate) 24 that is to be subjected to bonding, and, as illustrated in
As illustrated in
In this case, the computer basically comprises an input part having an input function, an output part having an output function, a storage part having a storing function, a calculation part having a calculating function, and a controller having a control function. The input function enables information from an outside to be read into the computer. The read data and program are converted into signals in a format suitable for a computer system. The output function enables, for example, a result of calculation and stored data to be displayed on the outside. The storage part stores and saves, for example, a program, data, and a result of processing. The calculating function enables processing of data through a calculation or comparison in accordance with a command in the program. The control function enables the command in the program to be deciphered and an instruction to be issued to each of the parts. The control function enables overall control of all the parts of the computer. Examples of the input part include a keyboard, a mouse, a tablet, a microphone, a joystick, a scanner, and a capture board. Further, examples of the output part include a monitor, a speaker, and a printer. Examples of the storage part include a memory, a hard disk, a CD, a CD-R, a PD, and an MO. Examples of the calculation part include a CPU, and examples of the controller includes a CPU and a motherboard.
This position alignment device comprises, as illustrated in
The pickup-side imaging part 36 can be configured from the recognition camera 26, and the bonding-side imaging part 39 can be configured from the recognition camera 32. The target mark 35 is configured from, for example, a protruding piece or a concave portion, as a site colored in some manner. The target mark 35 in this case appears at a position offset from a center of a screen in each of a screen 50 of the camera 26 and a screen 51 of the camera 32. Accordingly, when the collet 23 attached to the bonding arm 30 is positioned above the pickup position P as illustrated in
As illustrated in
Here, an offset amount “m” (see
The pickup-side registration part 37 registers the position of the target mark 35 on the screen 50 of the pickup-side imaging part 36 when the collet 23 attached to the bonding arm 30 is positioned above the pickup position P. That is, in a case in which the target mark 35 is at the registered position in an image of the target mark 35 taken by the pickup-side imaging part 36, the collet 23 is in a state of being positioned exactly above the pickup position P. Accordingly, the chip 21 located at the pickup position P can be picked up by moving the collet 23 in this state downward.
The bonding-side registration part 40 registers the position of the target mark 35 on the screen 51 of the bonding-side imaging part 39 when the collet 23 attached to the bonding arm 30 is positioned above the bonding position Q. That is, in a case in which the target mark 35 is at the registered position in an image of the target mark 35 taken by the bonding-side imaging part 39, the collet 23 is in a state of being positioned exactly above the bonding position Q. Accordingly, the chip 21 can be bonded at the bonding position Q by moving the collet 23 in this state downward.
The positional relationship detector 42 detects a relationship between coordinates of a target mark 35P of the screen 50 of the pickup-side imaging part 36 and coordinates of a target mark 350 of the screen 51 of the bonding-side imaging part 39.
The pickup-side offset amount detector 38 detects, in an image of the target mark 35 taken by the pickup-side imaging part 36, offset amount of the target mark 35 from the registered position of the target mark 35 that is registered by the pickup-side registration part 37.
The bonding-side offset amount detector 41 detects, in an image of the target mark 35 taken by the bonding-side imaging part 39, offset amount of the target mark 35 from the registered position of the target mark 35 that is registered by the bonding-side registration part 40.
The position adjuster 43 adjusts the bonding coordinates based on an offset amount detected by the pickup-side offset amount detector 38, an offset amount detected by the bonding-side offset amount detector 41, and the positional relationship detected by the positional relationship detector 42.
Incidentally, the pickup-side registration part 37, the bonding-side registration part 40, the positional relationship detector 42, the pickup-side offset amount detector 38, the bonding-side offset amount detector 41, the position adjuster 43, and other parts can be configured by the computer described above.
Next, a method of manufacturing with use of the alignment device configured as described above is described. This positioning method comprises, as illustrated in
First, in an initial state in which a side including the bonding arm 30 is not affected from heat, the pickup-side imaging step S1 in which the pickup-side imaging part 36 takes an image of the pickup position P and the bonding-side imaging step S2 in which the bonding-side imaging part 39 takes an image of the bonding position Q are executed. The pickup-side registration part 37 then stores coordinates of the target mark 35P on the screen 50 of the pickup-side imaging part 36 in the initial state. The bonding-side registration part 40 also stores coordinates of the target mark 350 on the screen 51 of the bonding-side imaging part 39 in the initial state.
In this case, as illustrated in
The positional relationship detection step S5 in which the positional relationship detector 42 detects a positional relationship between the coordinates stored as the position of the target mark 35P on the screen 50 and the coordinates stored as the position of the target mark 350 on the screen 51 is then executed. This enables detection of a relationship between the coordinates on the respective screens. That is, when the target mark 35P on the screen 50 has coordinates (a, b), the target mark 350 on the screen 51 is given coordinates (c, d).
Under this settings, pickup operation in which the bonding arm 30 is driven so that the collet suctions the chip 21 to be picked up and bonding operation in which the bonding arm 30 is driven so that the picked-up chip 21 is bonded can be executed in order.
For each operation, the chip 21 to be picked up is observed with use of the recognition camera 26 placed above the pickup position P, and the island portion 25 of the lead frame (substrate) 24 to be subjected to bonding is observed with use of the recognition camera 32 placed above the bonding position Q.
The observation may reveal that, as illustrated in
That is, in the position alignment device according to the present invention, an image of the pickup position P can be taken by the pickup-side imaging part 36 and an image of the bonding position Q can be taken by the bonding-side imaging part 39. A mark position of the target mark 35 provided on the bonding arm 30 in the taken image screen 50 of the pickup-side imaging part 36 can be registered by the pickup-side registration part 37, and a mark position of the target mark 35 provided on the bonding arm 30 in the taken image screen 51 of the bonding-side imaging part 39 can be registered by the bonding-side registration part 40. Further, a positional relationship between the target mark position registered by the pickup-side registration part 37 and the target mark position registered by the bonding-side registration part 40 can be registered by the positional relationship detector 42. Further, the bonding coordinates can be adjusted by the position adjuster 43, based on the offset amount detected by the pickup-side offset amount detector 38 and the positional relationship detected by the positional relationship detector 42.
For example, when the target mark 35 is at a position of coordinates P (a, b) in relation to an origin (center: the intersecting point of diagonals of the screen 50) of the taken image screen 50 of the pickup-side imaging part 36, the collet 23 attached to the bonding arm 30 is successfully placed above the pickup position P and set so as to pick up an object (the chip 21) to be picked up. When the target mark 35 is at a position of coordinates Q (c, d) in relation to an origin (center: the intersecting point of diagonals of the screen 51) of the taken image screen 51 of the bonding-side imaging part 39, the collet 23 is successfully set so that an object (the chip 21) to be bonded is bonded.
Further, as illustrated in
That is, in the above-mentioned case in which the coordinates of the target mark 35 in an image actually taken by the pickup-side imaging part 36 are offset from the registered coordinate position by (+1, +1), and the coordinates of the target mark 35 in an image actually taken by the bonding-side imaging part 39 are offset from the registered coordinate position by (+2, +2), the position of the target mark 35 on the bonding side is offset by an amount that is larger by (+1, +1) than on the pickup side. To adjust, the bonding-side coordinates are shifted by (−1, −1). Accordingly, when the registered coordinate position on the pickup side and the registered coordinate position on the bonding side differ from each other, that is, when the registered coordinates on the bonding side are Q (c, d) whereas the registered coordinates on the pickup side are P (a, b), adjustment can be made so that the pickup-side offset amount is reflected on the bonding-side offset amount.
Accordingly, irrespective of the pickup-side coordinates and the bonding-side coordinates at the time of registration, adjustment can be made so that the pickup-side offset amount is reflected on the bonding-side offset amount. That is, the bonding-side offset amount can be adjusted to the pickup-side offset amount. Thus, the position offset at the pickup position P can be reflected on the position offset at the bonding position Q, and the object (chip 21) picked up at the pickup position P can be bonded accurately and steadily at the bonding position Q.
According to the alignment device of the present invention, bonding operation (work) in a state in which a chip mounting position is misaligned can effectively be prevented, and highly accurate bonding operation (work) unaffected by thermal deformation of the bonding device is executable. Accordingly, position alignment can be executed accurately by simple processing without being affected by the thermal deformation. In the bonding device comprising this alignment device and in a bonding method that uses the alignment method, the collet 23 attached to the bonding arm 30 can accurately be aligned to a position above the bonding position Q by simple processing, and steady bonding operation (work) can be achieved.
Incidentally, in general (as a general rule), position alignment devices of the related art of this type are set so that the registered position of the target mark 35 is displayed at the center in the pickup taken image screen and the bonding taken image screen. Accordingly, the related art requires designing and assembly of relatively high accuracy. However, a position alignment device set so that the registered position can be shifted does not require such designing and assembly of high accuracy, and can improve productivity.
The bonding device of the present invention uses the collet 23 attached to the bonding arm 30 to pick up the chip 21 at the pickup position P, transports the picked-up chip 21 to the bonding position Q, and bonds the chip 21 at the bonding position Q, and comprises the position alignment device described above.
The bonding device of the present invention is capable of accurately aligning the collet 23 attached to the bonding arm 30 to a position above the bonding position Q by simple processing, and is accordingly capable of steady bonding operation (work).
According to the position alignment method of the present invention, an image of the pickup position P can be taken in the pickup-side imaging step S1, and an image of the bonding position Q can be taken in the bonding-side imaging step S2. Further, the mark position of the target mark 35 provided on the bonding arm 30 can be registered in the taken image screen of the pickup-side imaging part 36 in the pickup-side registration step S3, and the mark position of the target mark 35 provided on the bonding arm 30 can be registered in the taken image screen of the bonding-side imaging part 39 in the bonding-side registration step S4. Further, in the positional relationship detection step S5, the positional relationship between the target mark position registered in the pickup-side registration step S3 and the target mark position registered in the bonding-side registration step S4 can be registered. Further, in the position adjustment step S7, the bonding coordinates can be adjusted based on the offset amount detected in the pickup-side offset amount detector 38, the offset amount detected in the bonding-side offset amount detector 41, and the positional relationship detected in the positional relationship detection step S5.
As a position alignment method, position alignment is executable with use of the position alignment device. Accordingly, irrespective of the pickup-side coordinates and the bonding-side coordinates at the time of registration, adjustment can be made so that the pickup-side offset amount is reflected on the bonding-side offset amount. That is, the bonding-side offset amount can be adjusted to the pickup-side offset amount. Thus, the position offset at the pickup position P can be reflected on the position offset at the bonding position Q, and the object (chip 21) picked up at the pickup position P can be bonded accurately and steadily at the bonding position Q.
The bonding method comprises a pickup step in which the chip 21 is picked up at the pickup position P with the collet 23 attached to the bonding arm 30, a transportation step in which the chip 21 picked up in the pickup step is transported to the bonding position, and a bonding step in which the chip 21 is bonded at the bonding position Q, and uses the position alignment method described above to execute position alignment prior to the pickup step, or after a predetermined length of time passes since the pickup step.
According to the bonding method of the present invention, bonding operation (work) in a state in which the chip mounting position is misaligned can effectively be prevented, and highly accurate bonding operation (work) unaffected by thermal deformation of the bonding device is executable.
In the bonding method, position alignment is executable prior to the pickup step or after a predetermined length of time passes since start of the pickup step. In the case of execution prior to the pickup step, position alignment can be executed before the work of bonding the chip 21 to the island portion 25 of the substrate 24. In the case of execution after an elapse of the predetermined length of time, position alignment can be executed when position misalignment is surmised to have occurred due to heat caused as a result of executing the bonding work for the predetermined length of time.
A semiconductor device utilizing semiconductor characteristics can be manufactured by supplying the chip 21 to a supplied-to member (for example, the substrate 24) with the use of the alignment device described above. That is, a semiconductor device can be manufactured with the use of the position alignment device according to the present invention or the bonding device according to the present invention, and with the use of the position alignment method according to the present invention or the bonding method according to the present invention.
A high-quality electro-optical device, semiconductor circuit, or electronic device, or the like can accordingly be configured from the manufactured semiconductor device.
The present invention is not limited to the embodiment described above, and various modifications can be made thereto. For example, the position offset amount and the position offset direction vary depending on the material, size, and the like of a device. Incidentally, in one bonding device, a chip placed at a pickup position is picked up with a pickup collet, the chip stuck to the pickup collet by suction is supplied to an intermediate stage, the chip supplied onto the intermediate stage is picked up with a bonding collet, and the chip stuck to the bonding collet by suction is supplied to the bonding position. The alignment device according to the present invention may be applied to this type of bonding device.
In the embodiment described above, coordinate correction is executed when the coordinates of the registered target mark position on the pickup side and the coordinates of the registered target mark position on the bonding side indicate different positions. However, coordinate correction may be executed also when the former coordinates and the latter coordinates indicate the same position. Further, the offset amount in an actually taken image of the pickup side and the offset amount in an actually taken image of the bonding side are not limited to the amounts given in the embodiment.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-053227 | Mar 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/040438 | 10/28/2022 | WO |
