JP2011044497A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device by which an image can be accurately acquired even by a semiconductor chip thin in chip thickness. <P>SOLUTION: In a series of processes of manufacturing the semiconductor device having a plurality of chips laminated on a substrate, a semiconductor chip warped owing to stress as a result of thinning of the semiconductor chip is flattened (STEP 8-1) by pressing a transparent correction plate before the semiconductor chip is picked up from a sheet for fixation such as a dicing tape (STEP 8-3), and the semiconductor chip is imaged in this state to confirm the position and direction, and non-defective/defective mark of the semiconductor chip (STEP 8-2). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor device in which semiconductor chips are stacked on a substrate.

  As the density of semiconductor packages increases, high-density mounting technology for semiconductor chips is required. In the manufacturing process of a semiconductor device, first, elements are formed on the surface of the semiconductor wafer, the back surface of the semiconductor wafer is ground to reduce the thickness of the semiconductor wafer, and the semiconductor wafer is diced into individual semiconductor chips. The separated semiconductor chips are picked up in order. Next, the picked-up semiconductor chip is die-bonded on a substrate such as a wiring board or a lead frame. Thereafter, by performing wire bonding and resin sealing between the semiconductor chip mounted on the substrate and the substrate, semiconductor devices of various shapes are manufactured.

  Prior to picking a semiconductor chip from the dicing sheet, the position / direction of the semiconductor chip and the good / bad mark are confirmed by a wafer detector (for example, a wafer recognition camera). Conventionally, when recognizing a semiconductor chip, a coaxial incident illumination such as halogen illumination or LED illumination is used for the semiconductor chip, and the reflected light is imaged by a wafer detector. And confirming whether the semiconductor chip is a non-defective product or not.

  The semiconductor chip is hardly deformed when the chip thickness is reduced to about 100 μm. However, when the film thickness is further reduced to about 85 μm, it is deformed into a concave shape or a convex shape due to internal stress of the semiconductor chip. For this reason, the light from the semiconductor chip is not uniformly reflected in the conventional coaxial incident illumination, the light cannot be accurately captured by the wafer detector, the recognition rate is lowered, the position / direction of the semiconductor chip, and good / bad The mark cannot be confirmed.

  In contrast to this, conventionally, surface emitting illumination is used, and further, the light emitted from the surface emitting illumination is transmitted through the diffuser plate and then irradiated to the main surface of the semiconductor chip to be picked up, and the reflected light is received by the wafer detector. Thus, it has been proposed to acquire an image of the main surface of the semiconductor chip to be picked up (for example, Patent Document 1).

JP 2008-66452 A

  However, in the method of irradiating the main surface of the semiconductor chip after the irradiation light from the surface-emitting illumination is transmitted through the diffusion plate, it is good if the deformation amount of the semiconductor chip is small, but if the deformation amount is large, the number of illuminations It is difficult to adjust the incident angle of light and the like, and it is necessary to change the arrangement depending on the type and size of the semiconductor chip. When the chip thickness is reduced to 85 μm or less, the warp of 40 μm to 60 μm occurs due to the hardness of the adhesive layer after UV irradiation and the tension of the fixing sheet by the expand, and this method cannot substantially cope with it. There was a problem that it was impossible.

  Further, when the chip thickness is reduced to 85 μm or less, a large force is required at the time of picking up the semiconductor chip (during peeling) due to the effect of the cured adhesive layer after UV irradiation, and the semiconductor chip is removed from the fixing sheet. There was also a problem that cracks occurred when peeling.

  The present invention has been made in view of the above, and in a step of performing position recognition of a semiconductor chip by image acquisition, even if the chip has a thin chip thickness and a large amount of deformation, the image acquisition is accurately performed. An object of the present invention is to provide a method of manufacturing a semiconductor device that can perform accurate position recognition.

  In order to solve the above-described problems and achieve the object, a semiconductor device manufacturing method according to the present invention includes a semiconductor device manufacturing method in which a plurality of chips are stacked on a substrate. Along the line or chip dividing line, a groove deeper than the chip thickness at the time of completion is formed from the semiconductor element formation surface side, a surface protection sheet is pasted on the semiconductor element formation surface of the wafer, and the back surface of the wafer is attached Grinding to the thickness of the chip at completion, separating the wafer into individual chips, attaching a fixing sheet with an adhesive layer formed on the surface to the back of the separated chip, peeling the surface protection sheet, Corresponding to the separated chip, the adhesive layer is cut, the fixing sheet is expanded, the chip is easily peeled off, and the semiconductor element formation surface of the chip is formed with a transparent straightening plate. Chip to correct the warp of the chip, detect the chip position error from the image obtained by picking up the chip, pick up the chip from the fixing sheet, correct the position error of the picked chip and die bond on the substrate It is characterized by doing.

  According to the method for manufacturing a semiconductor device according to the present invention, it is possible to accurately acquire an image even with a semiconductor chip having a thin chip thickness, thereby enabling accurate position recognition of the semiconductor chip. Play.

FIG. 1 is a flowchart showing each step of the manufacturing method of the semiconductor device of the first embodiment. FIG. 2 is a diagram showing a semiconductor element forming process for forming a semiconductor element on the surface portion of the wafer. FIG. 3 is a diagram showing a process of forming grooves in the wafer based on the formed individual semiconductor elements. FIG. 4 is a diagram showing a process of attaching a surface protection tape to the wafer. FIG. 5 is a diagram showing a process of grinding and polishing the back surface of the wafer and dividing it into a plurality of semiconductor chips. FIG. 6 is a diagram illustrating a process of mounting the wafer on the fixing sheet. FIG. 7 is a diagram illustrating a process of mounting the wafer on the fixing sheet. FIG. 8 is a diagram illustrating a process of peeling the surface protection tape from the wafer. FIG. 9 is a diagram illustrating a process of cutting the adhesive layer with a laser. FIG. 10 is a diagram showing a process of expanding the dicing tape to cleave the adhesive layer. FIG. 11 is a diagram illustrating a process of picking up the separated semiconductor chip. FIG. 12 is a diagram illustrating a process of die-bonding a picked-up semiconductor chip to a lead frame. FIG. 13 is a diagram illustrating a process of molding a semiconductor chip with a resin. FIG. 14 is a flowchart showing details of the pick-up die bonding process of FIG. FIG. 15 is a perspective view of the die bonder device according to the first embodiment. FIG. 16 is a schematic side view of the wafer detector. FIG. 17 is a perspective view of a transparent correction plate. FIG. 18 is a schematic diagram showing the operations of the transparent straightening plate, the wafer detector, and the pickup collet. FIG. 19 is a schematic diagram showing operations of the transparent correction plate, the wafer detector, and the pickup collet, showing another example of the wafer detector. FIG. 20 is a perspective view of the die bonder according to the second embodiment. FIG. 21 is a bottom view of the pickup collet of the present embodiment. FIG. 22 is a side sectional view of the pickup collet of FIG. FIG. 23 is a schematic diagram illustrating operations of the pickup collet and the wafer detector according to the second embodiment. FIG. 24 is a bottom view showing another example of a pickup collet that is also used as a transparent straightening plate. FIG. 25 is a side sectional view of the pickup collet of FIG.

  Hereinafter, embodiments of a method for manufacturing a semiconductor device will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 13 is a cross-sectional view schematically showing a semiconductor device manufactured by the semiconductor device manufacturing method of the present embodiment. The semiconductor device 50 has nine semiconductor chips (chips) 40 stacked on a substrate 41 such as a wiring board or a lead frame. Each semiconductor chip 40 is electrically connected to the substrate 41 by bonding wires 42. The substrate 41 and the individual semiconductor chips 40 are fixed by an adhesive layer 16 sandwiched between them. The stacked semiconductor chip 40 and bonding wire 42 are sealed with a sealing resin 43. Solder balls 44 are provided on the back surface of the substrate 41.

  The nine semiconductor chips 40 are composed of eight semiconductor chips incorporating NAND flash memory and one semiconductor chip incorporating a drive control circuit as a controller. Each semiconductor chip 40 is thinned, and its thickness is about 20 μm. The thickness of the adhesive layer 16 is about 40 μm, the thickness of the substrate 41 is about 110 μm, and the thickness of the entire semiconductor device 50 is about 770 μm.

  A manufacturing method of the semiconductor device 50 (the thickness of the semiconductor chip 40 to be mounted is approximately 85 μm or less) in which such thinned semiconductor chips 40 are stacked and mounted will be described. First, a series of manufacturing methods of the ultrathin semiconductor device 50 will be described from the beginning to the end, and then specific steps will be described in detail.

  FIG. 1 is a flowchart showing each step of a series of manufacturing methods of the semiconductor device of the present embodiment. 2 is a semiconductor element forming step for forming a semiconductor element on the surface portion of the wafer, FIG. 3 is a step for forming a groove in the wafer based on each formed semiconductor element, and FIG. 4 is a surface on the wafer. 5 is a process of grinding and polishing the back surface of the wafer to divide it into a plurality of semiconductor chips, and FIGS. 6 and 7 are processes of mounting the wafer on a fixing sheet (dicing tape). 8 is a process of peeling the surface protection tape from the wafer, FIG. 9 is a process of cutting the adhesive layer with a laser, and FIG. 10 is a cleaved adhesive layer by expanding a fixing sheet (dicing tape). 11 shows a step of picking up the separated semiconductor chip, FIG. 12 shows a step of die-bonding the picked-up semiconductor chip to the lead frame, and FIG. The flop is a diagram showing a process for molding a resin.

A method for manufacturing the semiconductor device 50 will be described with reference to the flowchart of FIG. For example, the manufacturing of the very thin semiconductor device 50 in which the thickness of the semiconductor chip 40 to be mounted is approximately 85 μm or less is performed as follows.
[Formation of semiconductor elements]
First, as shown in FIG. 2, various semiconductor elements 12 are formed on the main surface of the wafer 11 by a known process (STEP 1).

[Half cut of wafer]
Next, as shown in FIG. 3, the wafer 11 on which the various semiconductor elements 12 are formed on the main surface is adsorbed and fixed to the chuck table 23 of the dicing apparatus with the semiconductor element forming surface side up by vacuum or other methods. To do. Then, the dicing blade 24 is rotated at an arbitrary number of revolutions, and the groove 22 is cut to a predetermined depth along the dicing line or the chip dividing line while applying cutting water. The depth of the groove 22 is at least 5 μm deeper than the thickness of the chip at the time of completion (STEP 2). Thereafter, the wafer 11 is cleaned and dried.

[Attaching surface protection tape]
Thereafter, a roller 26 or the like is used as shown in FIG. 4 for the purpose of protecting the element forming surface side of the wafer 11 and preventing the semiconductor chips divided by the wafer back surface grinding in the next step from separating from each other. Then, a UV protection tape (surface protection tape) 14 is attached to the element forming surface of the wafer 11 (STEP 3). Note that the UV protection tape 14 may be a tape having no UV protection function as long as UV irradiation performed for the purpose of reducing the adhesive strength of the paste material in a later step is not performed. Further, the UV protection tape 14 is not limited to the roller 26 and may be attached by other methods.

[Wafer back grinding]
Next, backside grinding and polishing of the wafer 11 is performed by a grinding apparatus (not shown), the wafer 11 is cut and separated, and divided into individual semiconductor chips 40 (STEP 4). As shown in FIG. 5, while the wheel 28 with the grindstone 28 a is rotated at a high speed of 4000 to 6000 rpm, the back surface of the wafer 11 on the rotary table 29 is ground to reduce the thickness of the wafer 11. The grindstone is formed, for example, by hardening artificial diamond with a phenol resin. When the grindstone 28 a is lowered while rotating the rotary table 29 and the wheel 28 and the back surface of the wafer 11 is scraped until reaching the groove 22, the wafer 11 is divided into individual semiconductor chips 40.

  This back grinding process is often performed with two axes. After roughing with No. 320-600 in advance with one axis, finish grinding (polishing) is performed on the mirror surface with No. 1500-2000 with two axes, and the streak of the back surface grinding of the wafer 11 is removed. After the wafer 11 is divided into individual semiconductor chips 40, grinding and polishing are continued, and at least the grooves 22 are ground and polished for 5 μm or more. As a result, even if chipping occurs at a portion where the surface formed by dicing and the surface formed by grinding and polishing intersect, this region can be removed (stress relief). If the amount to be ground and polished is increased, larger chipping can be removed. However, the amount of grinding and polishing may be set as required, such as the thickness of the wafer 11 and the thickness of the semiconductor chip 40 when completed. As a result, the thickness of the completed semiconductor chip 40 can be reduced to about 20 μm, for example.

[Installed on fixing sheet]
Thereafter, for the purpose of preventing the semiconductor chips 40 from separating from each other and for facilitating the conveyance of the wafer 11 divided into the individual semiconductor chips 40, the fixing sheet (dicing) is faced upward. (STEP 5). 6 and 7 in a state where a fixing sheet (dicing tape) 31 is stretched in the frame of the annular flat ring 30 as shown in FIG. 6 to prevent the fixing sheet 31 from being loosened or wrinkled. As described above, the wafer 11 is placed on the fixing sheet 31 in the opening of the flat ring 30. Here, an adhesive layer 16 called DAF (Die Attach Film) is formed on the fixing sheet 31. The wafer 11 is fixed on the adhesive layer 16.

  Next, after UV irradiation is performed to reduce the adhesive strength of the paste material of the UV protection tape 14, the UV protection tape 14 is peeled from the wafer 11 as shown in FIG. 8.

[Cutting the adhesive layer by laser]
Thereafter, as shown in FIG. 9, the fixing sheet 31 and the flat ring 30 to which the wafer 11 is fixed are fixed to a chuck table (not shown), and the laser nozzle 33 is moved along the groove 22 formed in the wafer half-cut process. Then, the adhesive layer 16 is cut corresponding to each semiconductor chip 40 (STEP 6). When the cutting process of the adhesive layer 16 is completed, the adhesive layer 16 is in a state of being finely cut corresponding to each semiconductor chip 40.

[Expansion and adhesive layer split]
The wafer 11 from which the adhesive layer 16 has been cut by the laser in this way is irradiated with UV to cure the adhesive layer 16 to reduce the adhesive force, and then a wafer ring holder of a die bonder device described later. Set to 55. Then, as shown in FIG. 10, the fixing sheet 31 is expanded so as to spread toward the periphery, so that the space between adjacent adhesive layers 16 is expanded so that the semiconductor chip 40 (adhesive layer 16). Is made to be easily peeled off from the fixing sheet 31 (STEP 7). At this time, the cut and separated semiconductor chip 40 is in a state of being held in alignment on the fixing sheet 31.

[Pickup / Die Bonding]
Thereafter, the semiconductor chip 40 is picked up and die-bonded by a die bonder device (STEP 8). The semiconductor chip 40 that is cut, separated, aligned, and supported is peeled off from the fixing sheet 31 as follows. That is, as shown in FIG. 11, the target semiconductor chip 40 is moved onto the push-up portion 34 provided at a predetermined position of the wafer ring holder 55, and the fixing sheet 31 side is vacuum-sucked and held. The semiconductor chip 40 is pushed up by the push-up jig 35, and the semiconductor chip 40 is pulled away from the fixing sheet 31 using the stretchability of the fixing sheet 31, and the semiconductor chip 40 is sucked and held by the pickup collet 71. Transfer to a position correction stage (not shown). Then, after correcting the position and direction of the semiconductor chip 40 and the front and back as required, the semiconductor chip 40 is transferred onto the substrate 41 by the die bonding head 53 as shown in FIG.

[Wire bonding, mold, etc.]
Next, as shown in FIG. 13, the electrode terminals of each semiconductor chip 40 and the inner leads of the substrate 41 are electrically connected by bonding wires 42, and the semiconductor chips 40 and the bonding wires 42 are sealed with a sealing resin 43. Then, a solder ball 44 is formed on the back surface of the substrate 41, and the semiconductor device 50 is completed (STEP 9).

[Details of pickup / die bonding process]
Next, the pickup / die bonding process will be described in more detail. As shown in FIG. 14, the pick-up and die-bonding steps include a step of correcting the warp of the target semiconductor chip 40 (STEP 8-1), the position / direction of the semiconductor chip 40 with the warp corrected, and the good / Step of confirming defect mark (STEP 8-2), Step of picking up semiconductor chip 40 after confirmation of position / direction and good / bad mark (STEP 8-3), and picked-up semiconductor chip 40 on substrate 41 And a step of die bonding (STEP 8-4). Then, every time one semiconductor chip 40 is peeled off, the above steps 8-1 to STEP8-4 are repeated.

[Die bonder equipment]
FIG. 15 is a perspective view of the die bonder apparatus (semiconductor manufacturing apparatus) of the present embodiment used in these steps. FIG. 16 is a schematic side view of the wafer detector. FIG. 17 is a perspective view of a transparent correction plate. FIG. 18 is a schematic diagram showing the operations of the transparent straightening plate, the wafer detector, and the pickup collet. As shown in FIG. 15, the die bonder apparatus 100 includes a wafer supply unit 51 to which the wafer 11 from which the adhesive layer 16 has been cut and separated by a laser is supplied, and the supplied wafer 11 is mounted via the wafer supply unit 51. Wafer ring holder 55, feeder 52 for transporting the substrate 41 on which the semiconductor chip 40 is mounted, die bonding head 53 for crimping the semiconductor chip 40 to the substrate 41, and position correction for correcting the position and direction of the semiconductor chip 40 A stage 56, a pickup collet 71 that sucks and holds the semiconductor chip 40, a pickup head 70 that moves the pickup collet 71, and a wafer detector (wafer recognition camera) 60 are provided. In addition, a monitor 81, a color touch panel 82, and a joystick 83 are provided as man-machine interfaces. In the die bonder device 100 of the present embodiment, a transparent correction plate 76 that corrects the warp of the semiconductor chip 40 and a transparent correction plate moving head 75 that moves the transparent correction plate 76 are provided. Here, the pickup head 70 constitutes a moving means for moving the pickup collet 71. The transparent correction plate moving head 75 constitutes a moving means for moving the transparent correction plate 76.

  The wafer ring holder 55 has an expanded structure that clamps the periphery of the fixing sheet 31 and spreads it around. Further, the wafer ring holder 55 is configured to be able to move the X axis and the Y axis and rotate the θ axis (around the Z axis) in order to move the target semiconductor chip 40 to a predetermined position. The pickup head 70 supports the pickup collet 71 so as to be movable along the Y axis and the Z axis. The pickup collet 71 is provided with a suction structure for holding the semiconductor chip 40. The transparent correction plate moving head 75 supports the transparent correction plate 76 so as to be movable along the Y-axis and the Z-axis while being independent of the pickup head 70. In the die bonding head 53, the semiconductor chip suction gripping portion 53a is adapted to move on the X axis, the Y axis, and the Z axis and rotate on the θ axis (around the Z axis), and is picked up from the position correction stage 56. The position / orientation of the semiconductor chip 40 is corrected so that it can be pressed (die bonding) onto the substrate 41. In some cases, the pickup collet 71 directly transfers the wafer ring holder 55 onto the substrate 41 without passing through the position correction stage 56.

[Wafer detector]
A wafer detector (wafer recognition camera) 60 is mounted at a position where the wafer 11 (semiconductor chip 40) on the wafer ring holder 55 can be imaged, and as shown in FIG. A camera 62 provided at one opening end of 61 and a ring illumination 63 provided at the outer periphery of the other opening end of the lens barrel 61 are included. The light emitted from the ring illumination 63 rebounds on the surface of the semiconductor chip 40 and is incident on the camera 62 through the lens barrel 61 to capture an image of the semiconductor chip 40. FIG. 16 shows a state where the semiconductor chip 40 is imaged without using the transparent correction plate 76 of the present embodiment. As the thickness of the semiconductor chip 40 is reduced, the semiconductor chip 40 follows along with the internal stress of the semiconductor chip 40 and the influence of the adhesive layer 16 on the back surface, and the light does not return to normal. is there.

[Transparent straightening plate]
As shown in FIG. 17, the transparent correction plate 76 has a rectangular flat plate shape, and is made of a transparent resin such as acrylic and made of a material having a transmissivity that can recognize the pattern of the semiconductor chip 40. The size in the XY direction is equal to or larger than the size in the XY direction of the target semiconductor chip 40. The transparent correction plate 76 may be any material having a transmittance that allows the pattern of the semiconductor chip 40 to be recognized, and may be made of glass, for example. The size of the transparent correction plate 76 may be larger than the dicing line or chip dividing line of the semiconductor chip 40. By setting it as such a magnitude | size, the deformation | transformation of the sheet | seat 31 for fixation by deformation | transformation of an adjacent semiconductor chip can also be corrected.

  Next, the step of correcting the warpage of the target semiconductor chip 40 (STEP 8-1), the step of confirming the position of the semiconductor chip 40 in which the warp has been corrected and the good / bad mark (STEP 8-2), The operation of the step (STEP 8-3) of picking up the semiconductor chip 40 whose position and good / bad mark have been confirmed will be described with reference to FIG. First, the wafer 11 that has finished the step of cutting the adhesive layer 16 by the laser is set from the wafer supply unit 51 to the wafer ring holder 55. Then, an expansion is performed on the wafer ring holder 55 to spread the fixing sheet 31 toward the periphery.

  Thereafter, the wafer ring holder 55 is moved along the X axis and the Y axis, and the semiconductor chip 40 to be picked up comes to the imaging position of the wafer detector 60 (in this embodiment, vertically below the wafer detector 60). Like that. Next, the transparent correction plate moving head 75 moves the transparent correction plate 76 above the semiconductor chip 40 to be picked up (FIG. 18A), and then lowers the transparent correction plate 76 to a predetermined height. Thereby, the transparent correction plate 76 presses the element forming surface of the semiconductor chip 40 with a predetermined pressure. The target semiconductor chip 40 is flattened so as to be pressed and spread on the lower surface of the transparent correction plate 76.

  In this state, the wafer detector 60 images the surface of the semiconductor chip 40, and the image data obtained by the imaging is binarized or multi-valued to detect the position of the semiconductor chip 40 and discriminate between good and defective products. Mark detection is performed. The light emitted from the wafer detector 60 is reflected uniformly on the surface of the semiconductor chip 40. The determination of the non-defective product / defective product of the semiconductor chip 40 may be performed by using the data on the location of the non-defective product / defective product stored in the wafer 11 in the upper process. When it is determined that the product is defective, the corresponding semiconductor chip 40 is discarded. Thereafter, the transparent correction plate moving head 75 retracts the transparent correction plate 76 out of the operating range of the pickup collet 71 ((b) of FIG. 18).

  In the subsequent process, as in the known method for manufacturing a semiconductor device, the multi-stage push-up jig 35 pushes up from the back surface (FIG. 11), and the extensibility of the fixing sheet 31 is utilized to make the semiconductor chip 40 from the fixing sheet 31. The semiconductor chip 40 is sucked and held by the pickup collet 71 and transferred to the position correction stage 56. Then, after correcting the position and direction of the semiconductor chip 40 and the front and back as necessary, the semiconductor chip 40 is transferred onto the lead frame by the die bonding head 53 and overlapped with the substrate 41 or the semiconductor chip 40 previously mounted. And crimping (FIG. 18 (c)).

  The wafer detector 60 is not limited to the type shown in FIG. 16, but may be of the type shown in FIG. In the wafer detector 60 </ b> B shown in FIG. 19, the parallel light emitted from the surface emitting illumination 66 provided on the side of the apparatus is refracted by the half mirror 67 toward the semiconductor chip 40. Irradiation of light from the ring illumination 63 is also performed at the same time. The lights of both illuminations are combined, the parallel light rebounds on the surface of the semiconductor chip, is incident on the camera 62 via the lens barrel 61, and an image of the semiconductor chip 40 is taken. When such a type of wafer detector 60B is used, an image with higher resolution can be obtained and the reliability can be improved.

  As described above, the semiconductor device manufacturing method of the present embodiment is a semiconductor chip 40 in a series of manufacturing steps of a semiconductor device 50 in which a plurality of semiconductor chips 40 are stacked on a substrate 41 such as a wiring board or a lead frame. In this pickup process, prior to picking up the semiconductor chip 40 from a fixing sheet such as a dicing tape, the semiconductor chip 40 warped by the stress due to the thinning of the semiconductor chip 40 is flattened by a transparent straightening plate, and this state Then, the semiconductor chip 40 is imaged and the position / direction of the semiconductor chip and the good / bad mark are confirmed. Even for a semiconductor chip having a small chip thickness and a large amount of deformation, the light emitted from the wafer detector 60 is uniformly reflected on the surface of the semiconductor chip 40. Thereby, image acquisition can be performed accurately and the position of the semiconductor chip can be accurately recognized.

  Further, in the pick-up process of the semiconductor chip 40, the warped semiconductor chip 40 is flattened by the transparent correction plate 76 before the semiconductor chip 40 is peeled off from the fixing sheet 31 such as a dicing tape. As the stress is released and the shape of the semiconductor chip 40 changes on the fixing sheet 31, the fixing with the fixing sheet 31 is released, and the semiconductor chip 40 is more easily peeled off, and the generation of cracks at the time of peeling the semiconductor chip is reduced. .

Embodiment 2. FIG.
FIG. 20 is a perspective view of the die bonder (semiconductor manufacturing apparatus) of the second embodiment. FIG. 21 is a bottom view of the pickup collet of the present embodiment. FIG. 22 is a side sectional view of the pickup collet of FIG. In the die bonder device 101 of the present embodiment, the pickup collet 77 also has the function of the transparent straightening plate of the first embodiment. That is, in the present embodiment, the pickup collet and the transparent correction plate are combined. Therefore, as shown in FIG. 20, the die bonder device 101 of the present embodiment is more transparent than the die bonder device 100 of the first embodiment shown in FIG. ) 75 is omitted.

  21 and 22, the pickup collet 77 has a rectangular flat plate-like collet body 77 a made of a transparent resin such as acrylic and made of a material having a transmittance that allows the pattern of the semiconductor chip 40 to be recognized. The size of the collet body 77a in the XY direction is equal to or larger than the size of the target semiconductor chip 40 in the XY direction. The Z-direction thickness a of the collet body 77a is such that the bending strength is 3N (Newton) or more.

  On the lower surface of the collet main body 77a, a plurality of suction ports 77b for sucking and gripping the semiconductor chip 40 as a suction structure are formed in a substantially central portion. Four suction ports 77b are formed in the center and at positions spaced equally by 90 degrees. The suction passages 77c communicating with the suction ports 77b extend in a cross shape from the central portion toward the suction ports 77b. The suction ports 77b and the suction passages 77c are arranged in accordance with the position of the semiconductor chip 40 performed by the wafer detector 60 and It is formed at a position where there is no hindrance to the defect mark confirmation operation. That is, when recognizing the position (including the orientation) of the semiconductor chip 40, the wafer detector 60B detects, for example, the contour shape around the semiconductor chip 40, and does not use the image at the center. The good / bad mark is marked at a position where it does not overlap the suction port 77b and the suction passage 77c even if the position is slightly shifted.

  In order for a pressure sensor (not shown) that detects the presence or absence of the adsorbed semiconductor chip 40 to operate satisfactorily, the opening diameter b of the suction port 77b is a difference of 5 kpa or more when the semiconductor chip 40 is not adsorbed. The passage diameter is as follows.

  FIG. 23 is a schematic diagram showing operations of the pickup collet and the wafer detector of the present embodiment. The operation of the pickup collet 77 that is also used as a transparent straightening plate is as follows. First, the pickup head 70 moves the pickup collet 77 above the semiconductor chip 40 to be picked up ((a) in FIG. 23), and then lowers the pickup collet 77 to a predetermined height. The target semiconductor chip 40 is flattened so as to be pushed and spread by the pickup collet 77. In this state, the position of the semiconductor chip 40 and the good / bad mark are confirmed by the wafer detector 60B (FIG. 23B).

  Thereafter, the multi-stage push-up jig 35 pushes up from the back surface (FIG. 11), peels off the semiconductor chip 40 from the fixing sheet 31 using the stretchability of the fixing sheet 31, and air from the suction port 77b of the pickup collet 77. The semiconductor chip 40 is sucked and held and transferred to the position correction stage 56. Then, after correcting the position of the semiconductor chip 40 and the front and back as required, it is transferred onto the lead frame by the die bonding head 53 ((c) of FIG. 23).

  The pickup collet 77 according to the present embodiment is made of a transparent resin such as acrylic, but may be made of a material having a transmissivity that can recognize the pattern of the semiconductor chip 40, and may be made of, for example, glass. .

  According to the method of manufacturing a semiconductor device having such a configuration, in addition to obtaining the same effect as the method of manufacturing the semiconductor device of the first embodiment, the configuration of the semiconductor manufacturing device is simplified. Cost can be reduced. In addition, since the manufacturing tact time is shortened, the cost of the semiconductor device as a product can be reduced.

  FIG. 24 is a bottom view showing another example of a pickup collet that is also used as a transparent straightening plate. FIG. 25 is a side sectional view of the pickup collet of FIG. In the pickup collet 78 shown in FIGS. 24 and 25, a cross-shaped suction groove 78b for sucking and gripping the semiconductor chip 40 is formed on the lower surface of the collet body 78a. The suction groove 78b has a width of about 0.5 mm and a depth of about 0.2 mm. A suction passage 78c communicating with the suction groove 78b extends from the central portion toward one end of the collet body 78a. The suction grooves 78b and the suction passages 78c are formed at positions that do not hinder the position of the semiconductor chip 40 and the good / bad mark confirmation operation performed by the wafer detector 60, as shown in FIGS. Yes.

  In order for a pressure sensor (not shown) that detects the presence or absence of the adsorbed semiconductor chip 40 to operate satisfactorily, the passage diameter c of the suction passage 78c is 5 kpa or more when the semiconductor chip 40 is not adsorbed. The passage diameter is different. Other configurations are substantially the same as those shown in FIGS. 21 and 22. The pick-up collet 78 having such a shape can be operated in substantially the same manner as that shown in FIGS.

DESCRIPTION OF SYMBOLS 11 Wafer 12 Semiconductor element 14 Protection tape 16 Adhesive layer 22 Groove 23 Chuck table 24 Dicing blade 26 Roller 28 Wheel 28a Grinding wheel 29 Rotary table 30 Flat ring 31 Fixing sheet (dicing tape)
33 Laser nozzle 34 Push-up part 35 Multi-stage push-up jig 40 Semiconductor chip (chip)
DESCRIPTION OF SYMBOLS 41 Board | substrate 42 Bonding wire 43 Sealing resin 44 Solder ball 50 Semiconductor device 51 Wafer supply part 52 Feeder 53 Die bonding head 55 Wafer ring holder 56 Position correction stage 60, 60B Wafer detector 61 Lens barrel 62 Camera 63 Ring illumination 66 Surface light emission Illumination 67 Half mirror 70 Pickup head 71, 77, 78 Pickup collet 75 Transparent correction plate moving head 76 Transparent correction plate 77a Collet body 77b Suction port 77c, 78c Suction passage 78a Collet body 78b Suction groove 81 Monitor 82 Color touch panel 83 Joystick 100 101 Bonder device

Claims (6)

In a manufacturing method of a semiconductor device in which a plurality of chips are stacked on a substrate,
Along the dicing line or chip dividing line of the wafer on which the semiconductor element is formed, a groove deeper than the thickness of the completed chip is formed from the semiconductor element forming surface side,
Affixing a surface protection sheet on the semiconductor element forming surface of the wafer,
Grinding the backside of the wafer to the thickness of the finished chip, separating the wafer into individual chips,
Affixing a fixing sheet having an adhesive layer formed on the surface to the back surface of the separated chip, peeling off the surface protection sheet,
Corresponding to the separated chip, cutting the adhesive layer,
Expand the fixing sheet to make the chip easy to peel off,
Correct the warp of the chip by pressing the semiconductor element forming surface of the chip with a transparent correction plate,
Detecting a position error of the chip from an image obtained by imaging the chip;
Pick up the chip from the fixing sheet,
A method of manufacturing a semiconductor device, wherein the picked-up chip is die-bonded on a substrate while correcting a position error. The method for manufacturing a semiconductor device according to claim 1, wherein a collet that picks up the chip from the fixing sheet and the transparent correction plate are moved by the same moving means. An adsorption structure that can adsorb and hold the chip on the transparent straightening plate is formed, and the chip is pressed by the transparent straightening plate from a state in which the chip is pressed by the transparent straightening plate to correct the warp of the chip. The semiconductor device manufacturing method according to claim 2, wherein the semiconductor device is picked up. The adsorption structure is configured at the center of the transparent straightening plate,
The method for manufacturing a semiconductor device according to claim 3, wherein a position error of the chip is detected by performing image processing on an image of an outer peripheral portion of the chip. The chip is inspected before the step of imaging the chip, the inspection result is marked on the chip, and the marking is also confirmed from the image. A method for manufacturing the semiconductor device according to the item. A semiconductor chip pick-up method in which the semiconductor chips are picked up from a state in which the individually cut and separated semiconductor chips are aligned and carried on a fixing sheet, and the picked-up semiconductor chips are die-bonded on a substrate. There,
Expand the fixing sheet to make the chip easy to peel off,
Correct the warp of the chip by pressing the semiconductor element forming surface of the chip with a transparent correction plate,
Detecting a position error of the chip from an image obtained by imaging the chip;
Pick up the chip from the fixing sheet,
A method of picking up a semiconductor chip, wherein the picked-up chip is die-bonded on a substrate while correcting a position error.

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