Method for manufacturing semiconductor device and collet

Abstract

The invention relates to a collet for crimping a die with an adhesive sheet obtained by a process of singulating a wafer, the collet comprising: a main body portion having a first pressing surface directly transmitting a pressing force from a crimping device; and a protruding portion having a second pressing surface configured with the first pressing surface to form a holding surface of the die with the adhesive sheet and disposed along an outer periphery of the first pressing surface.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a semiconductor device and a chuck used in the method. Furthermore, the chuck is a tool used in the manufacturing process of a semiconductor device for picking up and crimping semiconductor components. Background Technology

[0002] With the increasing multifunctionality of electronic devices, high-capacity stacked MCPs (Multi-Chip Packages) are becoming increasingly common, achieved by layering semiconductor components into multiple levels. Film adhesives are widely used as die-bonding agents when mounting semiconductor components. One example of a multi-level stacked package using film adhesives is a wire-embedded package, such as a memory package suitable for mobile phones or portable audio devices. A semiconductor component is stacked using a highly fluid film adhesive so that the wires connecting to the semiconductor component are well embedded within the film adhesive.

[0003] In recent years, the need for high-speed operation in embedded-wire packaging has gained attention. Previously, a controller chip controlling the operation of the semiconductor device was placed at the top level of a stacked semiconductor element. However, to achieve high-speed operation, packaging technology has been developed that places the controller chip at the bottom level of the semiconductor device. As one type of packaging, in multi-level stacked semiconductor elements, a thickened film adhesive used to bond the second-level semiconductor element, with the controller chip embedded within this film adhesive, has attracted attention. The film adhesive used in this application requires high fluidity to embed the controller chip and the connected wires, as well as to accommodate step differences caused by unevenness on the substrate surface. Patent Document 1 discloses an adhesive sheet with a highly fluid adhesive layer. Patent Document 2 discloses a method for manufacturing a semiconductor device using a film adhesive that has low elasticity and a low glass transition temperature after curing. According to this film adhesive, even when using thin semiconductor elements, warpage of the semiconductor device can be suppressed, resulting in good connection reliability.

[0004] Previous technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2005 / 103180

[0007] Patent Document 2: Japanese Patent No. 6135202 Summary of the Invention

[0008] The technical problem to be solved by the invention

[0009] With the miniaturization and thinning, as well as the increasing multifunctionality and speed of embedded semiconductor devices for controller chips, there is a trend towards increasing controller chip area and decreasing area of ​​secondary semiconductor elements. That is, the area occupied by the controller chip relative to the secondary semiconductor elements is increasing. Furthermore, there is a demand for thinner secondary semiconductor elements, and also a demand for thinner film adhesives for embedding controller chips. In view of these trends, the following issues become more prominent during package manufacturing, especially when pressing films for embedding controller chips.

[0010] • After crimping, gaps remain around the controller chip (creating pores).

[0011] • Resin overflows from the secondary semiconductor element onto the substrate (causing exudation).

[0012] • The second-stage semiconductor element warps (bends) due to insufficient removal of resin from the controller chip.

[0013] Some degree of porosity can be eliminated through the pressure curing process after lamination, but if the porosity is too large, it may not be eliminated. Porosity can cause delamination between the chip and the substrate or cracks in the package during reflow. Exudation can contaminate surrounding lead bonding pads or chips and reduce lead bonding strength. Twists can make multi-level chip stacking difficult or cause semiconductor components to delaminate due to residual stress. Therefore, in the manufacturing process of embedded packages for controller chips, it is strongly required to reduce porosity, exudation, and twists after film lamination.

[0014] To address these issues, various compositional improvements have been made to control the flowability of the film adhesive. However, to reduce porosity and tortuosity after pressing, increasing the film's fluidity tends to increase exudation. Conversely, decreasing the film's fluidity and reducing exudation leads to increased porosity and tortuosity. Thus, there is a trade-off between porosity / tortuosity and exudation, making it difficult to improve these issues solely through material improvements. Furthermore, even changing process conditions such as pressing temperature or pressing load, for example, under high-temperature, high-load pressing, tends to reduce porosity but increase exudation, making it difficult to simultaneously address all the aforementioned issues.

[0015] The present invention was made in view of the above circumstances, and provides a method for manufacturing a semiconductor device that can significantly reduce all porosity, leakage and tortuosity after the process of pressing a second-level chip to embed a first-level chip (e.g., a controller chip) in a film adhesive, and a chuck used in the method.

[0016] means for solving technical problems

[0017] A method for manufacturing a semiconductor device according to one aspect of the present invention includes: (A) a step of mounting a first chip on a substrate; (B) a step of attaching a wafer to an adhesive layer comprising a die-bonding integral film having a substrate film, a pressure-sensitive adhesive layer and an adhesive layer in sequence; (C) a step of monolithizing the wafer into a plurality of second chips; (D) a step of picking up a chip with an adhesive sheet using a chuck, the chip with the adhesive sheet comprising a second chip and an adhesive sheet monolithized from the adhesive layer; and (E) a step of pressing the chip with the adhesive sheet onto a substrate so that the first chip is embedded in the adhesive sheet, wherein the chuck used in step (E) has: a main body having a first pressing surface that directly transmits pressing pressure from a pressing device; and a protrusion having a second pressing surface that, together with the first pressing surface, forms a holding surface for the chip with the adhesive sheet and is disposed along the outer periphery of the first pressing surface.

[0018] The inventors focused on the chuck used when crimping a second chip and conducted research on reducing porosity, leakage, and bending. Specifically, they prototyped chucks of various shapes and explored a chuck form that could significantly reduce all porosity, leakage, and bending. As a result, as described above, it was observed that by utilizing the first pressing surface of the main body and the second pressing surface of the protrusion to form a holding surface for the chip with the adhesive sheet, the pressing force applied from the second pressing surface can be relatively weakened relative to the periphery of the chip with the adhesive sheet. Consequently, all porosity, leakage, and bending can be reduced evenly. Figure 1 (a) and Figure 1 (b) is a schematic cross-sectional view showing the strength of the pressing force when using a clamp, with the size of the arrow indicating the force applied. Figure 1 (a) shows a chuck 10 that has a main body 1 and a protrusion 2. In contrast, Figure 1 (b) The chuck 20 shown is a conventional chuck without a protrusion. Figure 1 (a) indicates a state in which the formation of pores, seepage, and tortuosity is fully suppressed. On the other hand, Figure 1 (b) indicates the state of pores V, exudation B, and tortuosity (warping of chip T2).

[0019] The area of ​​the first pressing surface is preferably larger than the area of ​​the first chip when viewed from above and smaller than the area of ​​the second chip when viewed from above. From the viewpoint of further reducing all porosity, seepage, and tortuosity, for example, the area of ​​the first pressing surface is 20% to 90% of the area of ​​the second chip when viewed from above. From the same viewpoint, the chuck is preferably made of a material with a Shore A hardness of 30 to 95. The thickness of the protrusion is, for example, set in the range of 0.5 mm to 3.0 mm.

[0020] The aforementioned chuck may or may not be used in the picking process of step (D). When the aforementioned chuck is not used in the picking process of step (D), for example, after picking up the chip with the adhesive sheet using other chucks, it is transferred to the intermediate worktable, and after the aforementioned chuck picks up the chip with the adhesive sheet on the intermediate worktable, it is crimped to cover the first chip.

[0021] In this invention, the thickness of the adhesive sheet is, for example, 60 to 150 μm. By having an adhesive sheet thickness of 150 μm or less, exudation can be significantly reduced. The temperature at which the shear viscosity of the adhesive sheet becomes 5000 Pa·s or less is, for example, 60 to 150°C. With this temperature below 150°C, the adhesive sheet becomes highly fluid during the pressing process without overheating, further reducing both porosity and tortuosity.

[0022] Invention Effects

[0023] According to the present invention, a method for manufacturing a semiconductor device is provided that, after the step of pressing a second-level semiconductor element to embed a first-level semiconductor element (e.g., a controller chip) in a film adhesive, can significantly reduce all porosity, leakage, and tortuosity, and a chuck used in the method is provided. Attached Figure Description

[0024] Figure 1 middle, Figure 1 (a) and Figure 1 (b) is a schematic cross-sectional view showing the strength of the pressing force when using a clamp, with the size of the arrow indicating the force applied. Figure 1 (a) indicates the use of a clamp with a protrusion. Figure 1 (b) indicates the use of a clamp without protrusions.

[0025] Figure 2 yes Figure 1 (a) is a three-dimensional view of the clamp shown.

[0026] Figure 3 middle, Figure 3 (a) is Figure 2 A sectional view of line III-III. Figure 3 (b) is Figure 1 (a) shows the bottom view of the clamp.

[0027] Figure 4 middle, Figure 4 (a) and Figure 4 (b) represents respectively Figure 1 (a) is a schematic cross-sectional view of a modified example of the clamp shown.

[0028] Figure 5 middle, Figure 5 (a) and Figure 5 (b) represents respectively Figure 1 (a) is a bottom view of a modified example of the clamp shown.

[0029] Figure 6 middle, Figure 6 (a) and Figure 6 (b) represents respectively Figure 5 (a) and Figure 5 (b) shows a bottom view of a modified example of the clamp.

[0030] Figure 7 This is a cross-sectional view schematically illustrating an example of a semiconductor device.

[0031] Figure 8 This is a cross-sectional view schematically showing an example of a chip with an adhesive sheet, consisting of an adhesive sheet and a second chip.

[0032] Figure 9 It is a schematic representation of manufacturing. Figure 7 The diagram shows a cross-sectional view of the semiconductor packaging process.

[0033] Figure 10 It is a schematic representation of manufacturing. Figure 7 The diagram shows a cross-sectional view of the semiconductor packaging process.

[0034] Figure 11 It is a schematic representation of manufacturing. Figure 7 The diagram shows a cross-sectional view of the semiconductor packaging process.

[0035] Figure 12 It is a schematic representation of manufacturing. Figure 7 The diagram shows a cross-sectional view of the semiconductor packaging process.

[0036] Figure 13 middle, Figure 13 (a)~ Figure 13 (e) is a cross-sectional view schematically illustrating the process of manufacturing a chip with an adhesive sheet. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. Furthermore, in this specification, the term "process" is not limited to an independent process; even if it cannot be clearly distinguished from other processes, it is included in this terminology as long as the desired function of the process is achieved. The numerical range indicated by "~" represents the range encompassed by the values ​​before and after "~" as the minimum and maximum values, respectively. Within the numerical ranges described in stages in this specification, the upper or lower limit of the numerical range for a certain stage can be replaced by the upper or lower limit of the numerical range for other stages. Within the numerical ranges described in this specification, the upper or lower limit of the numerical range can be replaced by the values ​​shown in the embodiments.

[0038] <Clamp>

[0039] Figure 1 (a) is a schematic cross-sectional view showing the state of pressing the second chip T2 using a chuck 10 with protrusions 2. The chuck 10 is used when pressing the second chip T2 obtained through a process of monolithizing a semiconductor wafer W. Furthermore, the second chip T2, together with the adhesive sheet 35P for embedding the first chip T1, constitutes a chip 40 with an adhesive sheet (see reference). Figure 8 ).

[0040] Figure 2 This is a 3D diagram of the chuck 10. Figure 3 (a) is Figure 2 A sectional view of line III-III. Figure 3 (b) is a bottom view of the chuck 10. The chuck 10 has a main body 1 and a protrusion 2 provided on the lower end side of the main body 1. The upper end side of the main body 1 is housed in the chuck clamp H (reference) of the crimping device. Figure 1 (a)). The lower end of the main body 1 has a... Figure 3 The first pressing surface 1f is shown by a dashed line. The pressing force originating from the crimping device (clamp H) is directly transmitted to the first pressing surface 1f. The protrusion 2 has a second pressing surface 2f that, together with the first pressing surface 1f of the main body 1, forms a flat holding surface F. The second pressing surface 2f is disposed along the outer periphery of the first pressing surface 1f and is coplanar with the first pressing surface 1f. Since the pressing force originating from the crimping device is transmitted to the second pressing surface 2f via the main body 1, the pressure applied to the second chip T2 is less than the pressure applied to the first pressing surface 1f.

[0041] By applying localized pressure to the central portion of the second chip T2 through the first pressing surface 1f, the film-like adhesive (adhesive sheet 35P) on the first chip T1 can be effectively removed. As a result, porosity around the first chip T1 can be suppressed, and bending caused by insufficient removal of adhesive components in that area can be reduced. Furthermore, the pressure applied from the protrusion 2 to the periphery of the second chip T2 is relatively small, thereby reducing overflow (exudation) from the end of the second chip T2 to the substrate 50. That is, according to the chuck 10, a pressing pressure distribution suitable for pressing the second chip T2 is applied to the holding surface F.

[0042] The material of the collet 10 can be, for example, natural rubber or synthetic rubber. Examples of synthetic rubbers include butyl rubber, styrene / butadiene rubber (SBR), isoprene rubber (IR), ethylene propylene rubber (EPM), ethylene / propylene / diene rubber (EPDM), polyurethane rubber, silicone rubber, and fluororubber. The collet 10 only needs to have heat resistance appropriate to the temperature conditions used (e.g., pressing temperature), for example, it only needs to be able to withstand temperatures from 50 to 200°C.

[0043] The Shore A hardness of the chuck 10 is preferably 30-95, but can also be 40-90 or 50-80. With the Shore A hardness of the chuck 10 within the above range, crimping can be performed without causing excessive deformation of the second chip T2, and pickup and crimping can be performed with less damage to the second chip T2.

[0044] The chuck 10 can be formed entirely of a single material (e.g., rubber), or it can be formed of a combination of multiple materials. In the latter case, for example, the lower part 10B of the chuck 10 that abuts against the second chip T2 can be made of a material with a Shore A hardness within the aforementioned range (see reference). Figure 3 (a)), and the upper part 10A of the chuck 10 is made of different materials (see reference). Figure 3 (a)). For example, by making the upper part 10A a material with a higher Shore A hardness than the lower part 10B, it is possible to apply further localized pressure to the central portion of the second chip T2 during the crimping process. Even in this case, by keeping the Shore A hardness of the lower part 10B within the aforementioned range, less damage can be caused to the second chip T2 during pickup and crimping. Furthermore, in this embodiment, the lower part 10B is composed of the protrusion 2 and a portion of the lower end of the main body 1 that is continuous therewith and has the same thickness as the protrusion 2. On the other hand, the upper part 10A is a part of the main body 1, referring to the portion from the upper end of the main body 1 to the lower part 10B (i.e., the portion other than the lower part 10B in the chuck 10).

[0045] The shape of the cross-section (first pressing surface 1f) of the main body 1 of the chuck 10 corresponds to the shape of the first chip T1, and in this embodiment, it is square. When the first chip T1 is rectangular, the shape of the cross-section of the main body 1 of the chuck 10 can also be rectangular. The area of ​​the cross-section of the main body 1 of the chuck 10 is preferably larger than the area of ​​the first chip T1 and smaller than the area of ​​the second chip T2. Specifically, the area of ​​the first pressing surface 1f is preferably 20-90% of the area of ​​the second chip T2, or it can be 25-85% or 30-80%. By ensuring that the area of ​​the first pressing surface 1f is within the above range, the pressure applied to the center and ends of the second chip T2 during crimping can be controlled, thereby reducing porosity, seepage, and tortuosity more effectively and evenly.

[0046] The shape of the holding surface F (outer periphery of the protrusion 2) of the chuck 10 corresponds to the shape of the second chip T2, and is square in this embodiment. When the second chip T2 is rectangular, the shape of the holding surface F can also be rectangular. The area of ​​the holding surface F of the chuck 10 (the combined area of ​​the first pressing surface f1 and the second pressing surface f2) is preferably 70 to 110% of the area of ​​the second chip T2, or it can be 80 to 105% or 90 to 100%. By having the area of ​​the holding surface F be 70% or more of the second chip T2, sufficient pressure can be applied to the periphery of the second chip T2, thereby suppressing the generation of pores. On the other hand, by having the area of ​​the holding surface F be 110% or less of the second chip T2, it is possible to suppress picking errors such as picking up adjacent chips along with the chip to be picked up during the picking process.

[0047] The thickness of the upper part 10A of the chuck 10 ( Figure 3 The thickness A shown in (a) is preferably 0.5 to 10 mm, more preferably 1 to 8 mm.

[0048] The thickness of the protrusion 2 (lower part 10B) of the chuck 10 Figure 3 The thickness B) shown in (a) is preferably 0.5 to 3.0 mm, more preferably 0.75 to 2.75 mm, and even more preferably 1.0 to 2.5 mm. With the thickness of the protrusion 2 within the above range, the pressure applied to the center and ends of the second chip T2 during crimping can be controlled, thereby significantly and evenly reducing porosity, seepage, and bending. Furthermore, with the thickness of the protrusion 2 being 0.5 mm or more, it provides sufficient durability for continuous use of the chuck 10.

[0049] The protrusion distance of protrusion 2 ( Figure 3 (a) The distance D) shown is, for example, 0.5 to 4.0 mm, and can be 0.75 to 3.5 mm or 1.0 to 3.0 mm.

[0050] Viewed from above, the centers of the upper part 10A and the lower part 10B of the chuck 10 may or may not be aligned. In other words, the center of the first pressing surface f1 and the center of the holding surface F may or may not be aligned. For example, when using the alignment function of the crimping device, pickup and crimping are performed with the center of the holding surface F of the chuck 10 aligned with the center of the second chip T2. Figure 3 As shown in (b), the upper part 10A and the lower part 10B of the chuck 10 are preferably arranged so that their centers coincide when projected in the vertical direction. In this case, in a semiconductor device designed with the centers of the second chip T2 and the first chip T1 aligned, the reduction of porosity, leakage, and tortuosity can be maximized. Furthermore, in a semiconductor device designed with the centers of the second chip T2 and the first chip T1 not aligned, as long as the first chip T1 is housed within the first pressing surface f1, the reduction of the aforementioned problems can also be expected. On the other hand, as an example where the centers of the upper part 10A and the lower part 10B of the chuck 10 are not aligned, a chuck used in manufacturing a semiconductor device with the centers of the second chip T2 and the first chip T1 not aligned can be cited. In this case, when pressing the second chip T2, it is sufficient to ensure that the center of the upper part 10A (the first pressing surface f1) coincides with the center of the first chip T1.

[0051] like Figure 3 As shown in (a), for example, the side surface 1a of the main body 1 is orthogonal to the upper surface 2a of the protrusion 2; in other words, the angle formed by the two surfaces is 90°. Furthermore, as... Figure 4 (a) and Figure 4 As shown in (b), an inclined portion may be provided at the boundary between the side surface 1a of the main body 1 and the upper surface 2a of the protrusion 2. Figure 4 (a) The inclined portion 3a shown is composed of a plane; on the other hand... Figure 4 (b) The inclined portion 3b shown is composed of a curved surface.

[0052] The chuck 10 has a hole 11 extending from the upper end to the lower end of the main body 1. The hole 11 is used to hold the second chip T2 by attractive force during the pick-up and crimping processes. The diameter of the hole 11 is, for example, 0.1 to 1.0 mm. When the diameter of the hole 11 is 0.1 mm or more, the second chip T2 can be sufficiently held by attractive force; when the diameter is 1.0 mm or less, the reduction in pressing force caused by the hole 11 can be suppressed, and the formation of pores can be sufficiently suppressed.

[0053] For example, such as Figure 5 (a) and Figure 5 As shown in (b), to improve the suction power of the chuck, multiple (e.g., 5 or 9) holes 11 can be provided in the main body 1. Figure 6 (a) and Figure 6As shown in (b), in order to improve the holding force of the holding surface F, a groove 12 connected to the hole 11 and extending to the protrusion 2 can be provided on the holding surface F.

[0054] In both the pick-up and crimping processes, the same chuck 10 can be used, or different chucks can be used. When different chucks are used in the pick-up and crimping processes, after the pick-up chuck (not shown) picks up the second chip T2, it is transferred to the intermediate worktable (not shown). Then, the chuck 10 (crimping chuck) attracts and holds the second chip T2 on the intermediate worktable and transfers it to the substrate for crimping. At this time, since the pick-up and crimping processes are performed in parallel, the productivity is high. Furthermore, since the second chip T5 has been removed from the pressure-sensitive adhesive layer 32 ( Figure 13 The stripped state facilitates the attraction and transfer of the second chip T5 from the intermediate worktable. Therefore, the attraction force of the clamping chuck 10 can be lower than that of the pick-up chuck.

[0055] Semiconductor Devices

[0056] Figure 7 This is a schematic cross-sectional view of a semiconductor device manufactured using a chuck 10. The semiconductor device 100 shown in this figure is a type of embedded semiconductor device, which includes: a substrate 50; a first chip T1 mounted on the surface of the substrate 50; a first sealing layer 35 (cured adhesive sheet) embedded in the first chip T1; a second chip T2 disposed above the first chip T1; and a second sealing layer 45 sealing the second chip T2.

[0057] The substrate 50 has circuit patterns 50a and 50b on its surface. From the viewpoint of suppressing warping of the semiconductor device 100, the thickness of the substrate 50 is, for example, 90 to 180 μm, or 90 to 140 μm. Furthermore, the substrate 50 can be an organic substrate or a metal substrate such as a lead frame.

[0058] The first chip T1 is a controller chip used to drive the semiconductor device 100. The first chip T1 is bonded to the circuit pattern 50a via adhesive 55 and connected to the circuit pattern 50b via wires 61. The shape of the first chip T1, when viewed from above, is, for example, square, but it can also be rectangular. The length of one side of the first chip T1 is, for example, less than 10 mm, but can also be 2–5 mm or 0.5–4 mm. The thickness of the first chip T1 is, for example, 10–170 μm, but can also be 20–100 μm.

[0059] The second chip T2 has an area larger than the first chip T1. The second chip T2 is mounted on the substrate 50 via the first sealing layer 35 to cover the entire first chip T1 and a portion of the circuit pattern 50b. The shape of the second chip T2, when viewed from above, is, for example, square, but it could also be rectangular. The length of one side of the second chip T2 is, for example, less than 20 mm, but could also be 3–18 mm, 4–15 mm, or 4–12 mm. The thickness of the second chip T2 is, for example, 20–400 μm, but could also be 20–120 μm. The second chip T2 is connected to the circuit pattern 50b via a wire 62 and is sealed by the second sealing layer 45.

[0060] The first sealing layer 35 is made of adhesive sheet 35P (reference). Figure 8 It is composed of a solidified substance. Additionally, such as Figure 8 As shown, adhesive sheet 35P and chip T2 are essentially the same size. Figure 8 The chip 40 with adhesive sheet is composed of adhesive sheet 35P and a second chip T2. As described later, the chip 40 with adhesive sheet is manufactured through a dicing process and a pick-up process (see reference). Figure 13 ).

[0061] <Methods for Manufacturing Semiconductor Devices>

[0062] The manufacturing method of the semiconductor device 100 will be described. First, as follows... Figure 9 As shown, a structure 70 is fabricated having a substrate 50 and a first chip T1 mounted on the substrate 50. That is, the first chip T1 is disposed on the surface of the substrate 50 via an adhesive 55. Then, the first chip T1 and the circuit pattern 50b are electrically connected by a wire 61.

[0063] Next, as Figure 10 As shown, the adhesive sheet 35P of the chip 40 with adhesive sheet is pressed to the substrate 50 using the clamp 10. This embeds the first chip T1 and the wire 61 into the adhesive sheet 35P.

[0064] The thickness of the adhesive sheet 35P can be appropriately set according to the thickness of the first chip T1, for example, 60-150 μm, or 70-140 μm or 75-135 μm. The shear viscosity of the adhesive sheet 35P at 80°C is preferably 500 Pa·s or higher, or 800 Pa·s or higher or 1000 Pa·s or higher. The temperature at which the shear viscosity of the adhesive sheet 35P is below 5000 Pa·s is preferably in the range of 60-150°C.

[0065] The pressing temperature of the adhesive sheet 35P relative to the substrate 50 is preferably 50–200°C, more preferably 80–150°C. If the pressing temperature is appropriately high, the viscosity of the adhesive sheet 35P decreases and its fluidity increases, thereby improving the embedding of the first chip T1, the wires 61, and the step differences of the circuit patterns 50a, 50b, etc., on the surface of the substrate 50. Furthermore, since the wettability of the adhesive sheet 35P with the first chip T1 and the substrate 50 is improved, the interfacial adhesion tends to increase. However, if the pressing temperature is too high, the fluidity of the adhesive sheet 35P increases, thus tending to increase the overflow (exudation) of the adhesive composition (adhesive sheet 35P) originating from the end of the second chip T2 onto the substrate 50. The pressing time is preferably 0.5–10 seconds, more preferably 1–5 seconds. Figure 11 As shown, the first chip T1 and the wire 61 are embedded with adhesive sheet 35P through a crimping process.

[0066] Next, the adhesive sheet 35P is cured by heating. Thus, the adhesive sheet 35P becomes a cured product (first sealing layer 35). Figure 12 The curing temperature can be set to approximately 50–250°C. The curing time can be set to approximately 10 seconds–3 hours. To eliminate any residual porosity after the pressing process, pressure can be applied at 0.3–0.9 MPa during the heating process. After electrically connecting the second chip T2 to the circuit pattern 50b via wire 62, the semiconductor device 100 is completed by sealing the second chip T2 with the second sealing layer 45 (see reference). Figure 7 ).

[0067] <How to manufacture a chip with an adhesive layer>

[0068] refer to Figure 13 (a)~ Figure 13 (e), for Figure 8 An example of the fabrication method of the chip 40 with adhesive sheet shown will be described. First, a die-cutting and bonding integrated film 30 (hereinafter referred to as "film 30") is disposed on a predetermined device (not shown). Film 30 sequentially comprises a substrate film 31, a pressure-sensitive adhesive layer 32, and an adhesive layer 35A. The substrate film 31 is, for example, a polyethylene terephthalate film (PET film). The semiconductor wafer W is, for example, a thin semiconductor wafer with a thickness of 20 to 120 μm. The semiconductor wafer W can be monocrystalline silicon, polycrystalline silicon, various ceramics, gallium arsenide, or other compound semiconductors. In addition, film 30 may further include a protective film (not shown) provided to cover the adhesive layer 35A.

[0069] like Figure 13 (a) and Figure 13As shown in (b), the film 30 is attached such that the adhesive layer 35A is in contact with one side of the semiconductor wafer W. This process is preferably performed at a temperature of 50–120°C, and more preferably at a temperature of 60–100°C. At temperatures above 50°C, good adhesion between the semiconductor wafer W and the adhesive layer 35A can be obtained; at temperatures below 120°C, excessive flow of the adhesive layer 35A can be suppressed in this process.

[0070] like Figure 13 As shown in (c), the semiconductor wafer W, pressure-sensitive adhesive layer 32, and adhesive layer 35A are cut. Thus, the semiconductor wafer W is monolithically formed into the second chip T2. The adhesive layer 35A is also monolithically formed into an adhesive sheet 35P. As a cutting method, methods using a rotary blade or a laser can be cited. Alternatively, thin-film forming can be achieved by grinding the semiconductor wafer W before cutting it.

[0071] Next, as Figure 13 As shown in (d), when the pressure-sensitive adhesive layer 32 is, for example, a UV-curable type, the pressure-sensitive adhesive layer 32 is cured by irradiating it with ultraviolet light, thereby reducing the adhesive strength between the pressure-sensitive adhesive layer 32 and the adhesive sheet 35P. Figure 13 As shown in (e), after irradiation with ultraviolet light, the second chips T2 are separated from each other by expanding the substrate film 31. Simultaneously, the chip 40 with the adhesive sheet is peeled off from the pressure-sensitive adhesive layer 32 by pushing with the roller 42, and the chip 40 with the adhesive sheet is picked up by the chuck 10. Figure 10 As shown, the chip 40 with adhesive sheet thus obtained is used to manufacture a semiconductor device 100. Furthermore, as described above, in picking up the chip 40 with adhesive sheet, other clamps can be used instead of clamp 10. Also, when the pressure-sensitive adhesive layer 32 is pressure-sensitive, ultraviolet irradiation is not required.

[0072] Example

[0073] The following describes embodiments of the present invention. However, the present invention is not limited to these embodiments.

[0074] <Example 1>

[0075] (Crimping of the first chip)

[0076] On a 12-inch semiconductor wafer with a thickness of 60 μm, an HR-5104T-10 adhesive layer (10 μm thick) manufactured by Hitachi Chemical Co., Ltd. was attached at 65°C. These wafers were then cut into 5 mm × 5 mm pieces to obtain the first chip with the adhesive layer. The first chip with the adhesive layer was then pressed onto a substrate. A DB800-HSD manufactured by Hitachi High-Technologies Corporation was used for pressing. The pressing conditions were set to 120°C, 1.0 s, and 0.2 MPa. A substrate with a thickness of 130 μm and a solder resist (AUS308) formed on its surface was used as the substrate. After pressing, the adhesive layer was pressure-cured at 140°C, 0.7 MPa, and 1 h. Curing was performed using a fully automated pressure oven PCOA-01T manufactured by NTT Advanced Technology Corporation.

[0077] (Crimping of the second chip)

[0078] On a 12-inch semiconductor wafer with a thickness of 60 μm, a controller chip embedding film FH-4013T-120 (adhesive layer thickness 120 μm) manufactured by Hitachi Chemical Co., Ltd. was attached at 65°C. Next, a second chip with an adhesive sheet was obtained by cutting these chips into 10 mm × 10 mm pieces. Then, the second chip with the adhesive sheet was pressed onto the substrate on which the first chip was attached. The pressing conditions were set to a temperature of 120°C, a time of 1.5 s, and a pressure of 0.2 MPa.

[0079] • Crimping device: DB800-HSD (manufactured by Hitachi High-Technologies Corporation)

[0080] · Clamp

[0081] Maintain the shape of the surface: a 10mm × 10mm square.

[0082] The shape of the first pressing surface: a 5mm x 5mm square.

[0083] Protrusion distance: 2.5mm Figure 3 (a) Distance D)

[0084] Thickness of the upper part of the chuck: 4mm Figure 3 (a) shows the thickness A)

[0085] Thickness of the lower part (protrusion) of the chuck: 2mm Figure 3 (a) shows the thickness B)

[0086] Material: Rubber with a Shore A hardness of 70

[0087] Location and number of adsorption pores: There is one in the center of the main body.

[0088] Diameter of the adsorption pore:

[0089] After crimping using the aforementioned clamps, the adhesive sheet was pressure-cured at 140°C, 0.7 MPa, and for 1 hour. This yielded the sample described in Example 1. A fully automatic pressure oven, PCOA-01T, manufactured by NTT Advanced Technology Corporation, was used for curing.

[0090] <Example 2>

[0091] Except for the use of a square clamp with a first pressing surface of 6mm×6mm (protrusion distance: 2.0mm) when pressing the second chip (size: 10mm×10mm) with adhesive sheet, the sample was obtained in the same manner as in Example 1.

[0092] <Example 3>

[0093] Except for the use of a square clamp with a first pressing surface of 7mm × 7mm (protrusion distance: 1.5mm) when pressing the second chip (size: 10mm × 10mm) with adhesive sheet, the sample was obtained in the same manner as in Example 1.

[0094] <Example 4>

[0095] Except for the use of a square clamp with a first pressing surface of 8mm × 8mm (protrusion distance: 1.0mm) when pressing the second chip (size: 10mm × 10mm) with adhesive sheet, the sample was obtained in the same manner as in Example 1.

[0096] <Examples 5-8>

[0097] Except for the use of a chuck with a protrusion thickness of 1.5 mm when crimping the second chip (size: 10 mm × 10 mm) with adhesive sheet, the samples involved in Examples 5 to 8 were obtained in the same manner as in Examples 1 to 4.

[0098] <Comparative Example 1>

[0099] Except for the use of the following clamp when crimping the second chip (size: 10mm × 10mm) with adhesive sheet, the sample was obtained in the same manner as in Example 1.

[0100] Maintain the shape of the surface: a 5mm x 5mm square

[0101] Protrusion: None

[0102] Thickness of main body: 4mm

[0103] <Comparative Example 2>

[0104] Except for the use of a square clamp (without protrusions) with a holding surface of 6mm×6mm when pressing the second chip (size: 10mm×10mm) with adhesive sheet, the sample was obtained in the same manner as in Example 1.

[0105] <Comparative Example 3>

[0106] Except for the use of a square clamp (without protrusions) with a holding surface of 7mm×7mm when pressing the second chip (size: 10mm×10mm) with adhesive sheet, the sample was obtained in the same manner as in Example 1.

[0107] <Comparative Example 4>

[0108] Except for the use of a square clamp (without protrusions) with a holding surface of 8mm×8mm when pressing the second chip (size: 10mm×10mm) with adhesive sheet, the sample was obtained in the same manner as in Example 1.

[0109] <Comparative Example 5>

[0110] Except for the use of a square clamp (without protrusions) with a holding surface of 10mm×10mm when pressing the second chip (size: 10mm×10mm) with adhesive sheet, the sample was obtained in the same manner as in Example 1.

[0111] (Evaluation of porosity)

[0112] The porosity was evaluated by using an ultrasonic digital imaging diagnostic device (IS-350, manufactured by Insight Co., Ltd.) and observing the specimens (after pressing and after pressure curing) involved in the examples and comparative examples using transmission method. Observations were conducted under the following conditions.

[0113] • Transmitter-side probe: 35MHz

[0114] • Receiver-side probe: 25MHz

[0115] • Scan length

[0116] X: 240mm

[0117] Y: 70mm

[0118] Spacing: 0.1mm

[0119] In the obtained observation images, the porous areas are displayed as black. Only a 10mm × 10mm chip portion was cut out using Photoshop (registered trademark, Adobe Systems Co., Ltd.) and binarized. Areas without pores were set to white, and areas with pores were set to black, and the porosity was calculated based on their ratio. The number of samples was set to N = 4, and the average value was used as the porosity. Using the porosity of the sample (after crimping) involved in Comparative Example 5 as a benchmark, the porosity improvement effect of the samples (after crimping) involved in other test examples was calculated using the following formula.

[0120] Pore ​​improvement effect (%) = [(Porosity of Comparative Example 5) - (Porosity of other test examples)] / (Porosity of Comparative Example 5) × 100

[0121] (Evaluation of Leakage)

[0122] The amount of exudation (originating from the overflow distance of the adhesive at the end of the second chip) of the samples involved in the examples and comparative examples was measured using a microscope (STM7-LF, Olympus Corporation). The top, bottom, left, and right sides of the second chip were observed, and the maximum value of each side was recorded. The number of samples was set to N=4, and the average value of each side was taken as the exudation amount. Based on the exudation amount of the sample involved in Comparative Example 5 (after pressure curing), the exudation improvement effect of the samples involved in other test examples (after pressure curing) was calculated using the following formula.

[0123] Exudation improvement effect (%) = [(exudation amount of Comparative Example 5) - (exudation amount of other test examples)] / (exudation amount of Comparative Example 5) × 100

[0124] (A complex evaluation)

[0125] The tortuosity of the samples involved in the examples and comparative examples was measured using a Digimatic Indicator (ID-H0530, manufactured by Mitutoyo Corporation). Specifically, the measurement points were the upper left, upper right, center, lower left, and lower right points of the second chip, and the tortuosity was calculated by subtracting the minimum value from the maximum value. The number of samples was set to N=4, and the average value was used as the tortuosity. Based on the tortuosity of the sample involved in Comparative Example 5 (after pressure curing), the tortuosity improvement effect of the samples involved in other test examples (after pressure curing) was calculated using the following formula.

[0126] Improvement in tortuosity (%) = [(Tortuosity of Comparative Example 5) - (Tortuosity of other test cases)] / (Tortuosity of Comparative Example 5) × 100

[0127] The evaluation results are shown in Tables 1 and 2. The evaluations in the tables are based on the following criteria.

[0128] • Value of porosity improvement effect of the crimped sample

[0129] S: 50% or more

[0130] A: More than 30% but less than 50%

[0131] B: 20% or more but less than 30%

[0132] C: 10% or more but less than 20%

[0133] D: Less than 10%

[0134] • The presence or absence of pores in the sample after pressure curing

[0135] A: Non-porous

[0136] D: Porous

[0137] • Value of exudation improvement after pressure curing

[0138] S: 50% or more

[0139] A: More than 30% but less than 50%

[0140] B: 20% or more but less than 30%

[0141] C: 10% or more but less than 20%

[0142] D: Less than 10%

[0143] • Value of tortuosity improvement after pressure curing

[0144] S: 30% or more

[0145] A: More than 20% but less than 30%

[0146] B: 10% or more but less than 20%

[0147] C: 0% or more and less than 10%

[0148] D: Less than 0%

[0149] As shown in Table 1, in all embodiments except for the porosity after crimping in Example 1, improvements over Comparative Example 5 were confirmed in all aspects of porosity, exudation, and tortuosity. Regarding Example 1, although the porosity after crimping was slightly worse, the porosity was eliminated after pressure curing. The reason for the worse porosity after crimping in Example 1 is believed to be that the face of the main body of the clamp (first pressing surface) was 5mm × 5mm, which was too small for the 10mm × 10mm second chip, thus making it impossible to press to the periphery of the second chip's end during crimping. Furthermore, regarding porosity, when the face of the main body was 6mm × 6mm and 7mm × 7mm, there was a trend towards further improvement compared to 8mm × 8mm. It is believed that the smaller the face of the main body, the greater the pressure applied to the center of the second chip, thereby enabling the removal of resin from the upper part of the first chip. Therefore, it is speculated that because the resin flows around the second chip, or the warping in the concave direction of the second chip during crimping is reduced, it is difficult to capture porosity.

[0150] Regarding exudation, it is known that there is a tendency to improve as the surface area of ​​the main body of the clamp becomes smaller. The reason for this is that if the surface area of ​​the main body is smaller, the pressure applied to the end of the semiconductor chip is reduced, or the resin on the top of the first chip is easier to remove, the warping of the second chip in the concave direction during pressing is reduced, and the moment when the end of the second chip with the adhesive sheet contacts the substrate is delayed.

[0151] Regarding warping, similar to exudation, it is observed that the effect tends to improve as the surface area of ​​the main body of the chuck decreases. It is believed that a smaller surface area of ​​the main body allows for greater pressure applied to the center of the second chip, thereby removing resin from the upper part of the first chip. This reduces warping in the concave direction of the second chip and decreases warping. Furthermore, it is confirmed that a slightly thinner protrusion tends to improve the situation. This is because a thinner protrusion reduces the pressure applied to the tip of the second chip.

[0152] The clamps used in Comparative Examples 1-5 have a previously known shape. When the holding surface is 5mm×5mm or 6mm×6mm, the bending is significantly improved; however, the small holding surface results in residual pores at the very ends (corners) of the semiconductor chip after pressing, which cannot be eliminated even after pressure curing. Furthermore, exudation is found to worsen significantly. This is believed to be because the smaller holding surface leads to higher pressure applied to the semiconductor chip, causing excessive resin flow on the upper and surrounding parts of the controller chip.

[0153]

[0154]

[0155] Industrial availability

[0156] According to the present invention, a method for manufacturing a semiconductor device is provided that, after the step of pressing a second-level semiconductor element to embed a first-level semiconductor element (e.g., a controller chip) in a film adhesive, can significantly reduce all porosity, leakage, and tortuosity, and a chuck used in the method is provided.

[0157] Symbol Explanation

[0158] 1-Main body, 2-Protrusion, 3a, 3b-Inclined parts, 10-Clamping head, 10A-Upper part, 10B-Lower part, 11-Hole, 12-Groove, 30-Integrated film for die bonding, 31-Substrate film, 32-Pressure-sensitive adhesive layer, 35-First sealing layer, 35A-Adhesive layer, 35P-Adhesive sheet, 40-Chip with adhesive sheet, 45-Second sealing layer, 50-Substrate, 100-Semiconductor device, F-Holding surface, f1-First pressing surface, f2-Second pressing surface, H-Clamping fixture (pressing device), T1-First chip, T2-Second chip, W-Semiconductor wafer.

Claims

1. A method for manufacturing a semiconductor device, comprising: The process of mounting the first chip on the substrate; In the process of attaching the adhesive layer of a die-jointing integral film having a substrate film, a pressure-sensitive adhesive layer and an adhesive layer in sequence to a wafer; The process of converting the wafer into multiple second chips; The process of picking up a chip with an adhesive sheet using a first chuck, wherein the chip with the adhesive sheet includes the second chip and an adhesive sheet formed by monolithizing the adhesive layer; and The chip with the adhesive sheet is pressed onto the substrate using a second clamp, so that the first chip is embedded in the adhesive sheet. The second clamp has: a main body having a first pressing surface that directly transmits pressing pressure from the crimping device; and a protrusion having a second pressing surface that, together with the first pressing surface, forms a holding surface for the chip with adhesive sheet and is disposed along the outer periphery of the first pressing surface. The protrusion distance of the protrusion is 0.75–4.0 mm. The area of ​​the first pressing surface is 36% to 64% of the area of ​​the second chip when viewed from above. In the second chuck, the lower part that abuts against the second chip is made of a material with a Shore A hardness of 30 to 95, and the upper part is made of a material with a higher Shore A hardness than the lower part. The lower part is composed of the protrusion and the lower end of the main body that is continuous with it and has the same thickness as the protrusion. The upper part is a part of the main body and refers to the part from the upper end of the main body to the lower part.

2. The method for manufacturing a semiconductor device according to claim 1, wherein, The area of ​​the first pressing surface is larger than the area of ​​the first chip when viewed from above.

3. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein, The thickness of the protrusion is 0.5 mm to 3.0 mm.

4. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein, The thickness of the adhesive sheet is 60–150 μm.

5. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein, The adhesive sheet has a shear viscosity below 5000 Pa·s at a temperature in the range of 60–150 °C.

6. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein, The second chuck is used as the first chuck to pick up the chip with the adhesive sheet.

7. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein, The chip with adhesive sheet is pressed together by applying a smaller pressure to the periphery of the chip with adhesive sheet than to the center of the chip with adhesive sheet.

8. A chuck for pressing a chip with an adhesive sheet obtained through a wafer monolithization process, the chip with the adhesive sheet comprising a second chip and an adhesive sheet formed by monolithizing an adhesive layer, the chuck comprising: The main body has a first pressing surface that directly transmits the pressing pressure from the crimping device; and The protrusion has a second pressing surface that, together with the first pressing surface, forms a retaining surface of the chip with adhesive sheet and is disposed along the outer periphery of the first pressing surface. The protrusion distance of the protrusion is 0.75–4.0 mm. The area of ​​the first pressing surface is 36% to 64% of the area of ​​the second chip when viewed from above. The chuck has a lower part that abuts against the second chip, which is made of a material with a Shore A hardness of 30 to 95, and an upper part that is made of a material with a higher Shore A hardness than the lower part. The lower part consists of the protrusion and the lower end of the main body that is continuous with it and has the same thickness as the protrusion. The upper part is a part of the main body and refers to the portion from the upper end of the main body to the lower part.

9. The chuck according to claim 8, wherein, The thickness of the protrusion is 0.5 mm to 3.0 mm.

10. The chuck according to claim 8 or 9, wherein, When the pressing force originating from the crimping device is applied between the main body and the retaining surface, a pressing force less than that of the first pressing surface is transmitted to the second pressing surface.

Images