TWI814944B - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

The method of manufacturing a semiconductor device according to the present disclosure includes: (A) preparing a structure including a substrate, a first wafer disposed on the substrate, and a plurality of wafers disposed around the first wafer on the substrate. a spacer; (B) the step of preparing a wafer with an adhesive sheet, the wafer with an adhesive sheet includes a second wafer that is larger in size than the first wafer, and an adhesive sheet disposed on one surface of the second wafer; (C) disposing the second wafer above the first wafer with the adhesive sheet in contact with the upper surfaces of the plurality of spacers; and (D) sealing the first wafer, the spacers, and the second wafer , and before step (D) is performed, the height of the upper surface of the spacer is consistent with the height of the upper surface of the first wafer.

Description

Semiconductor device and manufacturing method thereof

The present disclosure relates to a semiconductor device, a manufacturing method thereof, and a structure used in the manufacturing of the semiconductor device.

In the past, wire bonding has been widely used when connecting semiconductor chips to substrates. Wire bonding is a method of connecting semiconductor chips and substrates using thin metal wires such as gold wires. In order to meet the requirements for higher functionality, higher integration, and higher speed of semiconductor devices (hereinafter sometimes referred to as "semiconductor packages"), a method called flip chip connection is being promoted. Flip-chip connection is a method in which conductive protrusions called bumps are formed on a semiconductor wafer or a substrate to directly connect the semiconductor wafer and the substrate.

As mentioned above, semiconductor packages are required to be thinner and smaller in addition to higher functionality. As semiconductor packages that require further miniaturization, thinness, and high functionality, chip stack packaging, Package On Package (POP), Through-Silicon Via (TSV), etc. have also begun universal. Since the wafer is configured in a three-dimensional shape rather than a planar shape, the semiconductor package can be reduced in size. For example, Patent Document 1 discloses a semiconductor device in which a first semiconductor element (for example, a controller) is embedded in an adhesive film for adhering to a second semiconductor element.

[Prior art documents]

[Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2015-120836

According to studies by the present inventors, as in the semiconductor device described in Patent Document 1, when the first wafer on the substrate is buried in an adhesive film, there is a problem that voids are easily generated. In addition, when a relatively soft adhesive film with excellent fluidity is used to suppress the occurrence of voids, the position of the second wafer bonded via the adhesive film may be shifted or strained, and it may become difficult to stack multiple wafers on top of this. In addition, it is necessary to use an adhesive film having a sufficient thickness to bury the first wafer, so the semiconductor package tends to become thicker.

The present inventors studied a structure in which, instead of burying the first wafer in an adhesive film, spacers are arranged around the position where the first wafer is placed to form a space, and after the first wafer is placed in the space, the space is filled with a sealing material. . As a result, they found that when filling a space with a sealing material, if there is a deviation between the height of the upper surface of the spacer and the height of the upper surface of the first wafer, filling with the sealing material tends to become difficult.

The present disclosure provides a method for manufacturing a semiconductor device having a structure in which a first wafer is mounted on a substrate and a second wafer is arranged above the first wafer, which can prevent the semiconductor device from becoming excessively thick and can easily implement the use of a sealing material. The operation of sealing the first wafer and the second wafer. In addition, the present disclosure also provides a semiconductor device that is not too thick and has excellent filling properties of the sealing material and is used in the manufacture of the semiconductor device. structure.

The manufacturing method of a semiconductor device according to the present disclosure includes: (A) preparing a structure including a substrate, a first wafer arranged on the substrate, and a first wafer arranged on the substrate and around the first wafer. A plurality of spacers; (B) the step of preparing a wafer with an adhesive sheet, the wafer with an adhesive sheet includes a second wafer that is larger in size than the first wafer, and an adhesive disposed on one surface of the second wafer wafer; (C) the step of arranging the second wafer above the first wafer in such a manner that the adhesive sheet of the wafer with the adhesive sheet is in contact with the upper surfaces of the plurality of spacers; and (D) placing the first wafer , spacer, and the step of sealing the second wafer, and before step (D) is performed, the height of the upper surface of the spacer is consistent with the height of the upper surface of the first wafer. Furthermore, “consistent” here means that the difference between the height of the upper surface of the spacer and the height of the upper surface of the first wafer is less than 10 μm.

Before performing the above step (D), the height of the upper surface of the spacer is consistent with the height of the upper surface of the first wafer. This means that the adhesive sheet of the wafer with the adhesive sheet arranged in the step (C) is also consistent with the height of the first wafer. The upper surface of the wafer is in contact. If the upper surface of the first wafer does not contact the adhesive sheet and there is a gap between them, it will be difficult to fill the gap with the sealing material and voids will easily occur. On the other hand, if the distance between the upper surface of the first wafer and the adhesive sheet is sufficiently widened, the filling performance of the sealing material will be improved, but the semiconductor device will tend to become thicker. In contrast, according to the manufacturing method of the present disclosure, it is possible to achieve both excellent filling properties of the sealing material and thinning of the semiconductor device.

In the manufacturing method of the present disclosure, as long as before performing step (D), The height of the upper surface of the spacer only needs to be consistent with the height of the upper surface of the first wafer. For example, in the structure prepared in step (A), the height of the upper surface of the spacer may be consistent with the height of the upper surface of the first wafer, or in the structure prepared in step (A), the height of the spacer may be The upper surface is higher than the upper surface of the first wafer. In the subsequent step (C), the wafer with the adhesive sheet can be used to flatten the spacer so that the height of the upper surface of the spacer is consistent with the height of the upper surface of the first wafer. .

One form of the spacer is a dummy wafer including a wafer and an adhesive sheet provided on one surface of the wafer. As described above, in step (C), when adjusting the height of the spacers by flattening the spacers with the wafer with the adhesive sheet, it is preferable that the dummy wafer has an adhesive sheet that is smaller than the adhesive sheet with the adhesive sheet. The wafer has a soft adhesive. In addition, it is preferable that the adhesive sheet included in the dummy wafer is thicker than the adhesive sheet included in the wafer with the adhesive sheet.

From the viewpoint of increasing the speed of the semiconductor device, it is preferable that the first chip is mounted on the substrate through flip-chip connection. When the first wafer is mounted on the substrate through flip-chip connection, compared with the case where the adhesive film is used to adhere to the substrate, the height of the connection portion is likely to vary. As a result, the height position of the upper surface of the first wafer is easily deviated. produce deviation. Therefore, when mounting the first wafer via flip-chip connection, it is preferable to prepare a structure in which the upper surface of the spacer is higher than the upper surface of the first wafer in step (A), so that in step (C) The height of the spacers can be adjusted by flattening the spacers with the wafer with the adhesive sheet.

The semiconductor device related to the present disclosure includes: a substrate; a first wafer arranged on the substrate; and a plurality of spacers arranged on the substrate and around the first wafer. the second wafer is arranged above the first wafer and is larger in size than the first wafer; the adhesive sheet connects the plurality of spacers to the second wafer; and the sealing material connects the first wafer, the spacers and the second wafer. The wafer is sealed, and the adhesive sheet is in contact with the upper surface of the first wafer. The first chip is, for example, a controller chip.

The semiconductor device can be manufactured by the manufacturing method according to the present disclosure. In the semiconductor device according to the present disclosure, since the adhesive sheet is in contact with the upper surface of the first wafer, it is not too thick and has excellent filling properties of the sealing material.

The present disclosure provides a structure used in the manufacture of the semiconductor device. The structure of the first form includes a substrate, a first wafer arranged on the substrate, and a plurality of spacers arranged on the substrate and around the first wafer, and the height of the upper surface of the spacers is equal to that of the upper surface of the first wafer. The height of the surface is consistent. The structure of the second form includes a substrate, a first wafer arranged on the substrate, and a plurality of spacers arranged on the substrate and around the first wafer, and the upper surface of the spacers is higher than the upper surface of the first wafer. Surface, the spacer includes a material that is flattened so that the height of the upper surface of the spacer is consistent with the height of the upper surface of the first wafer.

The structure of the present disclosure may also be in a form further including a second wafer. The structure of the described form includes: a substrate; a first wafer arranged on the substrate; a plurality of spacers arranged on the substrate and around the first wafer; a second wafer arranged above the first wafer with a size of It is larger than the first wafer; and an adhesive sheet is used to bond the plurality of spacers to the second wafer, and the adhesive sheet is in contact with the upper surface of the first wafer.

According to the present disclosure, a method is provided for mounting a first chip on a substrate and placing a third chip on a substrate. A method of manufacturing a semiconductor device having a structure in which two wafers are arranged above a first wafer can prevent the semiconductor device from becoming excessively thick and can easily seal the first wafer and the second wafer with a sealing material. In addition, according to the present disclosure, there are provided a semiconductor device that is not too thick and has excellent filling properties of the sealing material, and a structure used in manufacturing the semiconductor device.

1: Base material film

2: Adhesive layer

3A: Adhesive layer

8: Crystal cutting and bonding integrated film/membrane

10:Substrate

30A, 30B, 40: Structure

42: Needle

44:Suction clamp

50:Sealing material

100:Semiconductor device

D: Dummy chip (spacer)

D1: Chip

Da: Adhesive tablets

S1: first chip

S2: Second chip

S2a: Wafer with adhesive sheet

S3, S4: chip

Sa: Adhesive tablets

Sc: hardened material (adhesive sheet)

w: line

W:wafer

FIG. 1 is a cross-sectional view schematically showing a first embodiment of a semiconductor device according to the present disclosure.

2(a) and 2(b) are plan views schematically showing an example of the positional relationship between the first wafer and the plurality of dummy wafers.

3(a) to 3(e) are cross-sectional views schematically showing an example of a process of manufacturing a dummy wafer.

4 is a cross-sectional view schematically showing a first embodiment of a structure used in manufacturing a semiconductor device according to the present disclosure.

FIG. 5 is a cross-sectional view schematically showing an example of a wafer with an adhesive sheet.

FIG. 6 is a cross-sectional view schematically showing a state in which the wafer with the adhesive sheet shown in FIG. 5 is press-bonded to the structure shown in FIG. 4 .

7 is a cross-sectional view schematically showing another embodiment of a structure used in manufacturing a semiconductor device according to the present disclosure.

FIG. 8 is a cross-sectional view schematically showing a state in which the wafer with the adhesive sheet shown in FIG. 5 is press-bonded to the structure shown in FIG. 7 .

Hereinafter, embodiments of the present disclosure will be described with appropriate reference to the drawings. In the following description, the same or equivalent parts are denoted by the same symbols, and repeated explanations are omitted. In addition, unless otherwise specified, positional relationships such as up, down, left, and right refer to the positional relationships based on those shown in the drawings. Furthermore, the dimensional ratio of the drawings is not limited to the ratio shown in the drawings. In addition, in this specification, "(meth)acrylic acid" means "acrylic acid" or the corresponding "methacrylic acid".

<First Embodiment>

(semiconductor device)

FIG. 1 is a cross-sectional view schematically showing a semiconductor device according to this embodiment. The semiconductor device 100 shown in the figure includes a substrate 10, a wafer S1 (first wafer) arranged on the surface of the substrate 10, and two dummy wafers D (spacers) arranged on the surface of the substrate 10 and surrounding the wafer S1. ), a wafer S2 (second wafer) arranged above the wafer S1, and the wafers S3 and S4 laminated on the wafer S2. The electrodes (not shown) on the surface of the substrate 10 are connected to the wafers S2, wafers S3, The wires w that are electrically connected to the wafer S4 respectively; and the sealing material 50 that seals the wafer S1, the wafer S2, the wafer S3, the wafer S4, the dummy wafer D, and the wire w. The hardened material Sc of the adhesive sheet is arranged between the upper surface of the wafer S1 and the upper surfaces of the plurality of dummy wafers D and the wafer S2. In the semiconductor device 100 , the height of the upper surface of the wafer S1 matches the height of the upper surface of the dummy wafer D. That is, the hardened material Sc is in contact with the upper surface of the wafer S1 and the upper surface of the dummy wafer D.

The substrate 10 may be an organic substrate or a metal substrate such as a lead frame. plate. Regarding the substrate 10 , from the viewpoint of suppressing warpage of the semiconductor device 100 , the thickness of the substrate 10 is, for example, 90 μm to 300 μm, or may be 90 μm to 210 μm.

The chip S1 is, for example, a controller chip, and is mounted on the substrate 10 through flip-chip connection. The shape of the wafer S1 when viewed from above is, for example, a rectangle (square or rectangular). The length of one side of the wafer S1 is, for example, 5 mm or less, or may be 2 mm to 5 mm or 1 mm to 5 mm. The thickness of the wafer S1 is, for example, 10 μm to 150 μm, or may be 20 μm to 100 μm.

The wafer S2 is, for example, a memory wafer, and is adhered to the wafer S1 and the dummy wafer D via the hardened material Sc of the adhesive sheet. When viewed from above, wafer S2 has a larger size than wafer S1. The shape of the wafer S2 when viewed from above is, for example, a rectangle (square or rectangular). The length of one side of the wafer S2 is, for example, 20 mm or less, or may be 4 mm to 20 mm or 4 mm to 12 mm. The thickness of the wafer S2 is, for example, 10 μm to 170 μm, or may be 20 μm to 120 μm. Furthermore, the wafer S3 and the wafer S4 are, for example, memory wafers, and are adhered to the wafer S2 via the hardened material Sc of the adhesive sheet. The length of one side of wafer S3 and wafer S4 only needs to be the same as that of wafer S2, and the thickness of wafer S3 and wafer S4 also needs to be the same as that of wafer S2.

The dummy wafer D functions as a spacer that forms a space around the wafer S1. The dummy wafer D includes the wafer D1 and the adhesive sheet Da provided on one surface of the wafer D1. As shown in Figure 2(a), two dummy wafers D (shape: rectangular) can be arranged at positions far away from both sides of the wafer S1, or as shown in Figure 2(b), at the corners corresponding to the corners of the wafer S1. A dummy chip D (shape: square, four in total) is configured at each position. The length of one side of the wafer D1 when viewed from above is, for example, 20 mm or less. It can be 1mm~20mm or 1mm~12mm. The thickness of the wafer D1 is, for example, 30 μm to 150 μm, or may be 80 μm to 120 μm.

As described above, the height of the upper surface of the dummy wafer D matches the height of the upper surface of the wafer S1. For example, by adjusting the thickness of the adhesive sheet Da, the position of the upper surface of the flip-chip connected chip S1 can be made consistent with the position of the upper surface of the dummy wafer D.

An example of a method of manufacturing a dummy wafer D which is one form of a wafer with an adhesive sheet will be described with reference to FIGS. 3(a) to 3(e) . First, the die-cutting-bonding integrated film 8 (hereinafter, sometimes referred to as "film 8") is prepared and placed in a predetermined device (not shown). The film 8 includes the base film 1, the adhesive layer 2, and the adhesive layer 3A in this order. The base film 1 is, for example, a polyethylene terephthalate film (PET (polyethylene terephthalate) film). The adhesive layer 2 has the property of reducing its adhesiveness due to ultraviolet irradiation. The adhesive layer 3A contains a thermosetting resin composition.

As shown in FIGS. 3(a) and 3(b) , the film 8 is attached so that the adhesive layer 3A comes into contact with one surface of the wafer W. The wafer W may be single crystal silicon, polycrystalline silicon, various ceramics, or compound semiconductors such as gallium arsenide. Furthermore, when manufacturing the dummy wafer D, the wafer W does not have to be a semiconductor, and may also be a glass substrate, for example.

The wafer W and the adhesive layer 3A are cut using a dicing blade (see FIG. 3(c) ). The wafer W is singulated into wafers D1 by dicing. The adhesive layer 3A is divided into individual pieces by cutting to become an adhesive sheet Da. Thereafter, as shown in FIG. 3(d) , the adhesive layer 2 is irradiated with ultraviolet rays, thereby reducing the adhesive force between the adhesive layer 2 and the adhesive layer 3A. After ultraviolet irradiation, as shown in Figure 3(e), by expanding the base film 1, The dummy wafers D are separated from each other. The dummy wafer D is pushed up with the needle 42 to peel off the dummy wafer D from the adhesive layer 2 , and the dummy wafer D is sucked by the suction jig 44 to pick up the dummy wafer D.

(Method for manufacturing semiconductor device)

A method of manufacturing the semiconductor device 100 will be described with reference to FIGS. 4 to 6 . The method of manufacturing the semiconductor device 100 includes the following steps (A) to (D).

(A) The step of preparing the structure 30A including the substrate 10, the wafer S1 arranged on the substrate 10, and a plurality of dummy wafers D arranged on the base 10 and around the wafer S1 (see Figure 4).

(B) The step of preparing the wafer S2a with an adhesive sheet including the wafer S2 and the adhesive sheet Sa provided on one surface of the wafer S2 (see FIG. 5 ).

(C) The step of arranging the wafer S2 above the wafer S1 so that the adhesive sheet Sa contacts the upper surfaces of the plurality of dummy wafers D and the upper surface of the wafer S1 (see FIG. 6 ).

(D) A step of sealing wafer S1, wafer S2, wafer S3, wafer S4, dummy wafer D, and the like.

[(A) Step]

Step (A) is a step of preparing the structure 30A shown in FIG. 4 . The structure 30A includes a substrate 10, a wafer S1 arranged on the surface of the substrate 10, and a plurality of dummy wafers D. The height of the upper surface of the wafer S1 is consistent with the height of the upper surface of the dummy wafers D. For example, first, the chip S1 is mounted on a predetermined position on the substrate 10 through flip-chip connection. Place it, and then press the dummy chip D at the specified position. The pressure bonding treatment is preferably performed under conditions of 80°C to 180°C and 0.01MPa to 0.50MPa for 0.5 seconds to 3.0 seconds, for example. By adjusting the pressing force applied to the dummy chip D, the height of the upper surface of the dummy chip D can be adjusted. The adhesive sheet Da of the dummy wafer D may be completely hardened in step (A), or may be incompletely hardened in step (C) and completely hardened in step (C).

[(B) Step]

Step (B) is a step of preparing the wafer S2a with the adhesive sheet shown in FIG. 5 . The wafer S2a with an adhesive sheet includes a wafer S2 and an adhesive sheet Sa provided on one surface of the wafer S2. The wafer S2a with the adhesive sheet can be obtained through a cutting step using, for example, a die-bonding integrated film (see Figures 3(a) to 3(e)).

[(C) Step]

Step (C) is a step of arranging the wafer S2a with the adhesive sheet above the wafer S1 so that the adhesive sheet Sa comes into contact with the upper surfaces of the plurality of dummy wafers D and the wafer S1. More specifically, the wafer S2 is press-bonded to the upper surface of the dummy wafer D and the upper surface of the wafer S1 via the adhesive sheet Sa. The pressure bonding treatment is preferably performed under conditions of 80°C to 180°C and 0.01MPa to 0.50MPa for 0.5 seconds to 3.0 seconds, for example. Next, the adhesive sheet Sa is hardened by heating. This hardening treatment is preferably performed for 5 minutes or more under conditions of 60°C to 175°C and 0.01MPa to 1.0MPa, for example. Thereby, the adhesive sheet Sa becomes the hardened material Sc.

In the structure 30A according to this embodiment, as described above, the height of the upper surface of the wafer S1 matches the height of the upper surface of the dummy wafer D. Therefore, take The adhesive sheet Sa is in contact with both the upper surface of the dummy wafer D and the upper surface of the wafer S1. FIG. 6 is a cross-sectional view schematically showing the structure obtained through step (C). Since the structure 40 shown in this figure has no gap between the cured material Sc and the wafer S1, excellent filling properties of the sealing material can be achieved in step (D).

After step (C) and before step (D), wafer S3 is placed on wafer S2 via an adhesive sheet, and wafer S4 is further placed on wafer S3 via an adhesive sheet. The adhesive sheet only needs to be the same thermosetting resin composition as the above-mentioned adhesive sheet Sa, and is cured by heating to become a cured product Sc (see FIG. 1 ). Thereafter, the wafer S2, the wafer S3, the wafer S4 and the substrate 10 are electrically connected respectively through the wire w. Furthermore, the number of wafers stacked above the wafer S1 is not limited to three in this embodiment, and may be appropriately set.

[(D) Step]

Step (D) is a step of sealing the wafer S1, the wafer S2, the wafer S3, the wafer S4, the dummy wafer D, and the wire w with the sealing material 50. After this step, the semiconductor device 100 shown in FIG. 1 is completed.

(Thermosetting resin composition)

The thermosetting resin composition constituting the adhesive sheet Da and the adhesive sheet Sa will be described. The thermosetting resin composition according to this embodiment passes through a semi-hardened (B-stage) state and can become a fully-cured (C-stage) state through subsequent hardening treatments. The thermosetting resin composition contains epoxy resin, hardener and elastomer, and may include inorganic fillers and hardening accelerators as needed.

[Epoxy resin]

The epoxy resin is not particularly limited as long as it has a connecting function for curing. Bifunctional epoxy resins such as bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and bisphenol S-type epoxy resin can be used; phenolic novolac-type epoxy resins such as phenol novolak-type epoxy resin and cresol novolak-type epoxy resin can be used Varnish type epoxy resin, etc. In addition, generally known resins such as polyfunctional epoxy resin, glycidyl amine type epoxy resin, heterocycle-containing epoxy resin, or alicyclic epoxy resin can be used. One type of the resin may be used alone, or two or more types may be used in combination.

[hardener]

Examples of the curing agent include phenol resins, ester compounds, aromatic amines, aliphatic amine groups, and acid anhydrides. Among these, from the viewpoint of reactivity and stability over time, phenol resin is preferred. Examples of commercially available phenolic resins include Phenolite KA and TD series manufactured by Dainippon Ink and Chemicals (DIC) Co., Ltd., and Milex XLC manufactured by Mitsui Chemicals Co., Ltd. - series and XL series (such as Merak XLC-LL), HE series (such as HE100C-30) made by Japan AIR WATER Co., Ltd., MEHC-7800 series made by Meiwa Chemical Co., Ltd. (such as, MEHC-7800-4S). One type of the hardener may be used alone, or two or more types may be used in combination.

Regarding the blending amounts of the epoxy resin and the phenol resin, from the viewpoint of curability, the equivalent ratio of the epoxy equivalent to the hydroxyl equivalent is preferably 0.30/0.70~0.70/0.30, more preferably 0.35/0.65~0.65/0.35. , and the best is 0.40/0.60~0.60/0.40, and the best is 0.45/0.55~0.55/0.45. By keeping the blending ratio within the stated range Within the range, it is easy to achieve a sufficiently high level of hardening and fluidity.

[Elastomer]

Examples of the elastomer include acrylic resin, polyester resin, polyamide resin, polyimide resin, silicone resin, polybutadiene, acrylonitrile, epoxy-modified polybutadiene, and butene. dianhydride-modified polybutadiene, phenol-modified polybutadiene and carboxyl-modified acrylonitrile.

From the viewpoint of solubility and fluidity in a solvent, the elastomer is preferably an acrylic resin, and further preferably glycidyl acrylate, glycidyl methacrylate, or the like having an epoxy group or a glycidyl group. Acrylic resins such as epoxy group-containing (meth)acrylic copolymers obtained by polymerizing functional monomers that serve as cross-linkable functional groups. Among the acrylic resins, an epoxy group-containing (meth)acrylate copolymer and an epoxy group-containing acrylic rubber are preferred, and an epoxy group-containing acrylic rubber is more preferred. Epoxy group-containing acrylic rubber is a rubber with an epoxy group, which is mainly composed of acrylate, mainly including copolymers such as butyl acrylate and acrylonitrile, and copolymers such as ethyl acrylate and acrylonitrile. Furthermore, the acrylic resin may have not only an epoxy group but also a crosslinking functional group such as an alcoholic or phenolic hydroxyl group or a carboxyl group.

Commercially available acrylic resins include SG-70L, SG-708-6, WS-023 EK30, SG-280 EK23, and SG-P3 solvent-modified products manufactured by Nagase ChemteX Co., Ltd. Trade name, acrylic rubber, weight average molecular weight: 800,000, Tg: 12°C, solvent: cyclohexanone), etc.

The glass transition temperature (Tg) of the acrylic resin is preferably -50°C to 50°C, more preferably -30°C to 30°C. The weight average molecular weight (Mw) of acrylic resin is better 100,000 to 3 million, preferably 500,000 to 2 million. By blending an acrylic resin with an Mw in the above range into a thermosetting resin composition, it is easy to form the thermosetting resin composition into a film shape, and it is easy to appropriately control the strength, flexibility, and viscosity in the film form. In addition, both reflowability and embedability tend to improve. Here, Mw refers to a value measured by gel permeation chromatography (GPC) and converted using a standard curve based on standard polystyrene. Furthermore, by using an acrylic resin with a narrow molecular weight distribution, there is a tendency that an adhesive sheet with excellent embedability and high elasticity can be formed.

The amount of acrylic resin contained in the thermosetting resin composition is preferably 20 to 200 parts by mass, more preferably 30 to 100 parts by mass relative to 100 parts by mass of the epoxy resin and epoxy resin hardener in total. parts by mass. Within this range, fluidity control during molding, handleability at high temperatures, and embedding properties can be improved.

[Inorganic filler]

Examples of the inorganic filler include: aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, nitride Boron, crystalline silica, amorphous silica. The inorganic filler may be used alone or in combination of two or more.

From the viewpoint of improving adhesiveness, the average particle diameter of the inorganic filler is preferably 0.005 μm to 1.0 μm, more preferably 0.05 μm to 0.5 μm. From the viewpoint of compatibility of solvents and resin components and bonding strength, the surface of the inorganic filler is preferably chemically modified. Suitable materials for chemically modifying the surface include silane coupling agents. Examples of types of functional groups of the silane coupling agent include vinyl, propylene, Enyl group, epoxy group, mercapto group, amine group, diamine group, alkoxy group, ethoxy group.

From the viewpoint of controlling the fluidity and fracture properties of the thermosetting resin composition, as well as the tensile elastic modulus and adhesive force after curing, the amount of the inorganic filler is 100 parts by mass of the resin component of the thermosetting resin composition. The content is preferably 20 to 200 parts by mass, more preferably 30 to 100 parts by mass.

[hardening accelerator]

Examples of the hardening accelerator include imidazoles and derivatives thereof, organophosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts, and the like. From the viewpoint of moderate reactivity, imidazole compounds are preferred. Examples of imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, and the like. The hardening accelerator may be used alone or in combination of two or more.

The content of the hardening accelerator of the thermosetting resin composition is preferably 0.04 to 3 parts by mass, more preferably 0.04 to 0.2 parts by mass relative to 100 parts by mass of the epoxy resin and the epoxy resin hardener in total. . When the added amount of the hardening accelerator is within this range, both hardening properties and reliability can be achieved.

<Second Embodiment>

In the first embodiment, the structure 30A in which the height of the upper surface of the dummy wafer D matches the height of the upper surface of the wafer S1 is prepared in the step (A). However, the structure 30A may be prepared in the step (A). A structure is prepared in which the upper surface of the dummy wafer D is higher than the upper surface of the wafer S1. The structure 30B shown in FIG. 7 includes a substrate 10, a wafer S1 arranged on the substrate 10, and a plurality of dummy wafers D arranged on the substrate 10 and around the wafer S1. The upper surface of the dummy wafer D is higher than the wafer S1. of upper surface.

Before the step (D) of the first embodiment (the step of sealing with the sealing material 50), the height of the upper surface of the dummy wafer D may be equal to the height of the upper surface of the wafer S1. However, the height of the upper surface of the dummy wafer D may be equal to the height of the upper surface of the wafer S1. , the adhesive sheet Da of the dummy wafer D is flattened with the wafer S2a with the adhesive sheet, so that the height of the dummy wafer D becomes consistent with the height of the upper surface of the wafer S1 (see FIG. 8 ). When wafer S1 is mounted on the substrate 10 through flip-chip connection, the height of the connection portion of the flip-chip tends to vary by about 5 μm. As a result, the height position of the upper surface of wafer S1 varies by about 5 μm. Taking this deviation into consideration, the position of the upper surface of the dummy wafer D is set to be approximately 8 μm to 12 μm higher than the set position of the upper surface of the connected wafer S1. This eliminates the need to adjust the upper surface of the dummy wafer D in step (A). The height is strictly consistent with the height of the upper surface of wafer S1.

In the present embodiment, the adhesive sheet Da of the dummy wafer D includes a material that is flattened by the wafer S2a with the adhesive sheet. Specifically, it is preferable that the adhesive sheet Da of the dummy wafer D is softer than the adhesive sheet Sa of the wafer S2a with the adhesive sheet. As a method of making the adhesive sheet Da softer than the adhesive sheet Sa, for example, the content of the thermosetting resin of the adhesive sheet Da is greater than that of the adhesive sheet Sa, or the content of the elastomer or inorganic filler of the adhesive sheet Da is increased. The content is less than the adhesive tablet Sa.

It is preferable that the adhesive sheet Da of the dummy wafer D is thicker than the adhesive sheet Sa of the wafer S2a with the adhesive sheet. In this embodiment, for example, the thickness of the adhesive sheet Da is 1.1 times to 8 times the thickness of the adhesive sheet Sa, or may be 1.2 times to 6 times.

The embodiments of the present disclosure have been described in detail above, but the present invention It is not limited to the above embodiment. For example, in the above-mentioned embodiment, the case where the chip S1 is mounted by flip-chip connection is exemplified. However, the chip S1 may be fixed to the substrate 10 with an adhesive and then electrically connected by wire bonding.

Hereinafter, the present disclosure will be described in detail through examples, but the present invention is not limited to these examples.

<Production of follow-up film>

Using the components shown in Table 1, varnish A and varnish B of the adhesive composition were prepared in the following procedure. First, after preparing the [epoxy resin], [hardener] and [filler] described below, cyclohexanone is added and stirred. Thereafter, [elastomer], [hardening accelerator] and [coupling agent] are added and stirred until each component is uniform, thereby obtaining a varnish of an adhesive composition.

[Elastomer]

Acrylic rubber: Manufactured by Nagase Chemical Co., Ltd., trade name "HTR-860P-3", weight average molecular weight 800,000, glass transition point: 12°C

[Epoxy resin]

Cresol novolak type epoxy resin: manufactured by Dongdu Chemical Co., Ltd., trade name "YDCN-700-10", epoxy equivalent: 210

Bisphenol F epoxy resin: DIC Co., Ltd., trade name "EXA-830CRP", epoxy equivalent: 159

[hardener]

Phenol resin: Manufactured by Mitsui Chemicals Co., Ltd., trade name "Milles XLC-LL", softening point: 75°C, hydroxyl equivalent 175

[filler]

Silica filler: manufactured by Japan Aerosil Co., Ltd., trade name "R972", average particle size is 0.500μm

Silica filler: manufactured by Admatechs Co., Ltd., trade name "SC-2050-HLG", specific surface area 110m/g

[hardening accelerator]

1-cyanoethyl-2-phenylimidazole: manufactured by Shikoku Chemical Industry Co., Ltd., trade name "2PZ-CN"

[Coupling agent]

γ-Mercaptopropyltrimethoxysilane: manufactured by Nippon Unicar Co., Ltd., trade name "NUC A-189"

γ-Ureidopropyltriethoxysilane: Manufactured by Japan Unica Co., Ltd., trade name "NUC A-1160"

On the base film (release-treated polyethylene terephthalate film, thick Degree: 38μm), apply varnish A on it. The base film was heated and dried at 140° C. for 5 minutes to prepare an adhesive sheet A1 (thickness: 20 μm) and an adhesive sheet A2 (thickness: 40 μm). Except using varnish B instead of varnish A, adhesive sheet B (thickness 40 micrometers) was produced in the same manner as above.

<Measurement of melt viscosity of adhesive sheet>

Using a rotational viscoelasticity measuring device (ARES-RDA, manufactured by TA Instruments Japan Co., Ltd.), the melt viscosity of the adhesive sheet was measured according to the following procedure. First, the base film is peeled off from the adhesive sheet, and then a plurality of adhesive layers are bonded together at 70° C. to obtain a laminated film with a thickness of 160 μm or more. This was punched into a circle with a diameter of 8 mm, and then clamped with two clamps (diameter: 8 mm) to obtain a sample for measurement. Measurement was performed under the following conditions, and the value at 80° C. was defined as the melt viscosity of the adhesive sheet. The melt viscosity of the subsequent sheets A1 and A2 is 24000Pa. S, then the melt viscosity of sheet B is 2000Pa. S.

‧Frequency: 1Hz

‧Measurement starting temperature: 35℃

‧Measurement end temperature: 150℃

‧Heating rate 5℃/min

(Example 1)

The adhesive sheet A1 (thickness: 20 μm) is attached to the semiconductor wafer (thickness: 90 μm). The semiconductor wafer was diced into 5.0 mm×5.0 mm semiconductor wafers using a dicing machine (DFD-6361 manufactured by DISCO). Use a flexible die-bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.) at 120℃/0.1MPa/1 The organic substrate dried at 150° C. for 1 hour was thermocompression-bonded under conditions of 1 second to obtain a substrate with a semiconductor wafer.

Next, the adhesive sheet B (thickness: 40 μm) was attached to the semiconductor wafer (thickness: 80 μm). The semiconductor wafer was diced into wafers of 1.5 mm×6.0 mm using a dicing machine (DFD-6361 manufactured by Disco). Using a flexible die bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.), the above-mentioned wafer was placed on an organic substrate on both sides of a 2mm space that separated the above-mentioned semiconductor wafer at 120°C/0.1MPa/1 second. Perform thermocompression bonding as a dummy wafer.

Next, on the semiconductor wafer (thickness: 50 μm), HR-900T-20-N50 (Hitachi Chemical Co., Ltd. ), thickness of adhesive layer: 20μm). Thereafter, the semiconductor wafer was diced into wafers of 6.0 mm×12.0 mm using a dicing machine (DFD-6361 manufactured by Disco). Using a flexible die bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.), the semiconductor wafer and two dummy wafers are thermally compressed at 100°C~120°C/0.05MPa~0.20MPa/0.5 seconds~2.0 seconds superior. Then, the adhesive was hardened by heating at 150° C. for 1 hour in a 7 kg pressurized atmosphere. Thereby, a structure including a substrate, two dummy wafers, and two semiconductor wafers is obtained.

(Comparative example 1)

The adhesive sheet A1 (thickness: 20 μm) is attached to the semiconductor wafer (thickness: 90 μm). The semiconductor wafer was diced into 5.0 mm×5.0 mm semiconductor wafers using a dicing machine (DFD-6361 manufactured by DISCO). Use a flexible die-bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.) at 120℃/0.1MPa/1 The organic substrate dried at 150° C. for 1 hour was thermocompression-bonded under conditions of 1 second to obtain a substrate with a semiconductor wafer.

Next, the adhesive sheet A2 (thickness: 40 μm) is attached to the semiconductor wafer (thickness: 90 μm). The semiconductor wafer was diced into wafers of 1.5 mm×6.0 mm using a dicing machine (DFD-6361 manufactured by Disco). Using a flexible die bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.), the above-mentioned wafer was placed on an organic substrate on both sides of a 2mm space that separated the above-mentioned semiconductor wafer at 120°C/0.1MPa/1 second. Perform thermocompression bonding as a dummy wafer.

Next, on the semiconductor wafer (thickness: 50 μm), HR-900T-20-N50 (Hitachi Chemical Co., Ltd. ), thickness of adhesive layer: 20μm). Thereafter, the semiconductor wafer was diced into wafers of 6.0 mm×12.0 mm using a dicing machine (DFD-6361 manufactured by Disco). Using a flexible die bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.), the semiconductor wafer and two dummy wafers were thermally compressed at 120°C/0.10MPa/1.0 seconds. Then, the adhesive was hardened by heating at 150° C. for 1 hour in a 7 kg pressurized atmosphere. Thereby, a structure including a substrate, two dummy wafers, and two semiconductor wafers is obtained.

(Comparative example 2)

The adhesive sheet A1 (thickness: 20 μm) is attached to the semiconductor wafer (thickness: 90 μm). The semiconductor wafer was diced into 5.0 mm×5.0 mm semiconductor wafers using a dicing machine (DFD-6361 manufactured by DISCO). Use a flexible die-bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.) at 120℃/0.1MPa/1 The organic substrate dried at 150° C. for 1 hour was thermocompression-bonded under conditions of 1 second to obtain a substrate with a semiconductor wafer.

Next, the adhesive sheet A1 (thickness: 20 μm) is attached to the semiconductor wafer (thickness: 110 μm). The semiconductor wafer was diced into wafers of 1.5 mm×6.0 mm using a dicing machine (DFD-6361 manufactured by Disco). Using a flexible die-bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.), the above-mentioned wafer is used as a dummy wafer and is thermocompression-bonded to the above-mentioned semiconductor wafer with a space of 2 mm under the conditions of 120°C/0.1MPa/1 second. on both sides of the organic substrate.

Next, on the semiconductor wafer (thickness: 50 μm), HR-900T-20-N50 (Hitachi Chemical Co., Ltd. ), thickness of adhesive layer: 20μm). The semiconductor wafer was diced into wafers of 6.0 mm×12.0 mm using a dicing machine (DFD-6361 manufactured by Disco). Using a flexible die bonding machine (DB-830HSD manufactured by Hitachi High-Tech Instruments Co., Ltd.), the semiconductor wafer and two dummy wafers were thermally compressed at 120°C/0.10MPa/1.0 seconds. Then, the adhesive was hardened by heating at 150° C. for 1 hour under a 7 kg pressurized atmosphere. Thereby, a structure including a substrate, two dummy wafers, and two semiconductor wafers is obtained.

(Production and evaluation of semiconductor packages)

A sealing material (trade name: CEL-9750ZHF) manufactured by Hitachi Chemical Co., Ltd. was molded on the structures of the Examples and Comparative Examples under the conditions of 175°C/6.75MPa/120 seconds, and the process was performed at 175°C for 5 seconds. After a few hours of hardening treatment, a semiconductor package is obtained. Through ultrasound imaging diagnostic system (Insight) Co., Ltd., Insight-300, Scanning Acoustic Microscope (SAM)) to observe peeling and the presence of voids inside the semiconductor package. In addition, a cross-section of the obtained semiconductor package was observed to confirm the heights of the semiconductor wafer and dummy wafer.

If there are no peeling or voids inside the semiconductor package, it will be judged as "A" if it is good, and if there is peeling or voids it will be judged as "B". In addition, the difference in height between the upper surface of the semiconductor wafer and the upper surface of the dummy wafer is described as "A" if it is less than 10 μm, and "B" is described as if it is 10 μm or more. The results are shown in Table 2.

[Industrial availability]

According to the present disclosure, there is provided a method for manufacturing a semiconductor device having a structure in which a first wafer is mounted on a substrate and a second wafer is arranged above the first wafer, which can prevent the semiconductor device from becoming excessively thick and can easily implement sealing. sealing the first wafer and the second wafer. In addition, according to the present disclosure, there are provided a semiconductor device that is not too thick and has excellent filling properties of the sealing material, and a structure used in manufacturing the semiconductor device.

10:Substrate

50:Sealing material

100:Semiconductor device

D: Dummy chip (spacer)

D1: Chip

Da: Adhesive tablets

S1: first chip

S2: Second chip

S3, S4: chip

Sc: hardened material (adhesive sheet)

w: line

Claims (4)

A method of manufacturing a semiconductor device, including: (A) preparing a structure, the structure including a substrate, a first wafer disposed on the substrate, and a first wafer disposed on the substrate and disposed on the first wafer. A plurality of spacers around the wafer; (B) the step of preparing a wafer with an adhesive sheet, the wafer with an adhesive sheet including a second wafer larger in size than the first wafer, and a second wafer disposed on the first wafer. An adhesive sheet on one side of the two wafers; (C) the step of arranging the second wafer above the first wafer in such a manner that the adhesive sheet contacts the upper surfaces of the plurality of spacers; and (D) the step of sealing the first wafer, the spacer and the second wafer, and before performing the step (D), the height of the upper surface of the spacer is equal to the height of the upper surface of the first wafer. The height of the surface is consistent, and the spacer is a dummy wafer including a wafer and an adhesive sheet provided on one surface of the wafer, and the adhesive sheet included in the dummy wafer is smaller than the adhesive sheet with the wafer. The adhesive sheet included in the wafer is soft, in the structure prepared in step (A), the upper surface of the spacer is higher than the upper surface of the first wafer, in step (C) By using the wafer with the adhesive sheet to flatten the spacer, the height of the spacer is equal to the height of the upper surface of the first wafer. consistent. In the method of manufacturing a semiconductor device according to claim 1, the adhesive sheet included in the dummy wafer is thicker than the adhesive sheet included in the wafer with the adhesive sheet. The manufacturing method of a semiconductor device according to claim 1 or 2, wherein the first chip is mounted on the substrate through flip-chip connection. A semiconductor device is manufactured by the manufacturing method of a semiconductor device as described in any one of items 1 to 3 of the patent application scope.

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