Method for manufacturing semiconductor package, and resin set for sealing and underfill formation in semiconductor chip component

Abstract

This method for manufacturing a semiconductor package includes: preparing a connection body provided with a plurality of semiconductor chip components and a semiconductor wafer substrate that has a wafer body and a plurality of first electrodes; forming an underfill; forming a sealing layer for collectively sealing the plurality of semiconductor chip components, thereby forming a sealing body; and forming individual pieces from the sealing body to obtain a plurality of semiconductor components. The plurality of first electrodes are arranged on the wafer body at a minimum pitch of 40 μm or less. The underfill is a cured product of an underfill material, and the sealing layer is a cured product of a sealing material. The linear expansion coefficient of the cured product of the underfill material is 6-30 ppm / °C, and the linear expansion coefficient of the cured product of the sealing material is 5-14 ppm / °C. The flexural modulus of the cured product of the sealing material is 5.0-20 GPa at 25°C.

Description

Method for manufacturing semiconductor package, and resin set for sealing and underfilling semiconductor chip components

[0001] The present disclosure relates to a method for manufacturing a semiconductor package and a resin set for encapsulating and underfilling semiconductor chip components.

[0002] In recent years, the rapid advancement in the functionality of electronic devices, such as AI and HPC, has led to a rapid increase in the size and density of semiconductor packages. Regarding semiconductor package structure, not only has the density of surface mounting increased, but the packaging process has also become more complex and diverse, driven by inorganic (silicon) interposer or organic interposer (Bridge die / RDL) technology, as well as 2.xD packaging using these and 3D packaging technology (HBM / Chiplet) that applies TSV. For example, Resonac Inc., based at its "Packaging Solutions Center," is developing next-generation semiconductor packaging process technology that combines packaging processes and materials from the perspective of its customers (semiconductor manufacturers).

[0003] Semiconductor packages are sometimes manufactured by a method that includes forming an underfill that fills the gap between a semiconductor wafer and a semiconductor chip, and then forming a sealing layer that collectively seals multiple semiconductor chips on the semiconductor wafer (see, for example, Patent Document 1). The underfill is required to sufficiently fill gaps between electrodes such as bumps between the semiconductor wafer and the semiconductor chip.

[0004] JP 2015-067788 A

[0005] If an encapsulation body formed by forming an encapsulation layer that encapsulates multiple semiconductor chips on a semiconductor wafer collectively warps significantly, it can be difficult to properly perform subsequent semiconductor wafer processing. Furthermore, when the semiconductor wafer and semiconductor chips are connected by fine electrodes (bumps), extremely narrow gaps must be filled with underfill. Therefore, as electrodes become finer, it may become more difficult to prevent warpage while also achieving sufficient underfill.

[0006] The present disclosure relates to easily filling the gap between a semiconductor wafer substrate and a semiconductor chip component with underfill even when the electrodes of the semiconductor wafer substrate and the semiconductor chip component are arranged at a narrow interval, and suppressing warping of an encapsulated body having a semiconductor wafer substrate.

[0007] The present disclosure includes the following: [1] A method for manufacturing a semiconductor package, comprising: preparing a connecting body comprising a semiconductor wafer substrate having a wafer body and a plurality of first electrodes, and a plurality of semiconductor chip components having a plurality of second electrodes arranged opposite the first electrodes, the first electrodes and the second electrodes being electrically connected, forming an underfill including a portion that fills the gap between the semiconductor chip components and the semiconductor wafer substrate, forming a sealing layer on the semiconductor wafer substrate that collectively seals the plurality of semiconductor chip components, thereby forming a sealing body having the semiconductor wafer substrate, the plurality of semiconductor chip components, the underfill, and the sealing layer, and singulating the sealing body to obtain a plurality of semiconductor components including wiring members that are the singulated semiconductor wafer substrates and one or more of the semiconductor chip components, wherein the plurality of first electrodes are arranged on the wafer body at a minimum pitch of 40 μm or less, the underfill is a cured product of an underfill material, the sealing layer is a cured product of a sealing material, and the cured product of the underfill material has a linear expansion coefficient of 6 ppm / °C or more and 30 ppm / °C or less,

[0013] The method according to [1], wherein the cured encapsulant has a linear expansion coefficient of 5 ppm / °C or more and 14 ppm / °C or less, the cured underfill has a linear expansion coefficient greater than the linear expansion coefficient of the encapsulant, and the cured encapsulant has a flexural modulus of 5.0 GPa or more and 20 GPa or less at 25°C. [2] The method according to [1], wherein the semiconductor chip component further has a chip body, the second electrode is provided on the outer surface of the chip body, the underfill is formed to further have a protruding portion that protrudes from between the semiconductor chip component and the wafer body, and the protruding portion in the encapsulant, located between two adjacent semiconductor chip components on the semiconductor wafer substrate, does not form a trench having a depth greater than the minimum distance between the wafer body and the chip body. [3] The method according to [1] or [2], wherein the cured encapsulant has a flexural modulus of 5.0 GPa or more and 18 GPa or less at 25°C. [4] The method according to any one of [1] to [3], wherein the underfill material is a liquid.[5] The method according to any one of [1] to [4], wherein the encapsulant is a powder. [6] The method according to any one of [1] to [5], further comprising removing a portion of the encapsulating layer from the side opposite the semiconductor wafer substrate, thereby forming a flat surface from which the semiconductor chip components are exposed. [7] The method according to any one of [1] to [6], wherein the plurality of first electrodes are arranged on the wafer body at a minimum pitch of 20 μm or less. [8] The method according to any one of [1] to [7], wherein the wiring member is an interposer, and the semiconductor component includes two or more of the semiconductor chip components electrically connected to each other via the wiring member. [9] A resin set for sealing and underfilling semiconductor chip components, comprising: an encapsulating material; and an underfill material, wherein the cured product of the underfill material has a linear expansion coefficient of 6 ppm / °C to 30 ppm / °C, the cured product of the encapsulating material has a linear expansion coefficient of 5 ppm / °C to 14 ppm / °C, the cured product of the underfill material has a linear expansion coefficient greater than the linear expansion coefficient of the cured product of the encapsulating material, and the cured product of the encapsulating material has a flexural modulus of 5.0 GPa to 20 GPa at 25°C.

[10] The resin set according to [9], wherein the cured product of the encapsulating material has a flexural modulus of 5.0 GPa to 18 GPa at 25°C.

[11] The resin set according to [9] or

[10] , wherein the underfill material is a liquid.

[12] The resin set according to any of [9] to

[11] , wherein the encapsulating material is a powder.

[0008] When a semiconductor package is manufactured by a method that includes forming an underfill that fills the gap between a semiconductor wafer substrate and semiconductor chip components, and further forming a sealing layer that collectively seals a plurality of semiconductor chip components on the semiconductor wafer substrate, the gap between the semiconductor wafer substrate and the semiconductor chip components can be easily filled with underfill even if the electrodes of the semiconductor wafer substrate and the semiconductor chip components are arranged at narrow intervals, and warping of the sealed body having the semiconductor wafer substrate can be suppressed.

[0009] Fig. 1 is a process diagram showing an example of a method for manufacturing a semiconductor package; Fig. 2 is a process diagram showing an example of a method for manufacturing a semiconductor package; Fig. 3 is a process diagram showing an example of a method for manufacturing a semiconductor package; Fig. 4 is a process diagram showing an example of a method for manufacturing a semiconductor package; Fig. 5 is a cross-sectional view showing an example of a semiconductor package; Fig. 6 is an enlarged cross-sectional view showing an example of a semiconductor wafer substrate;

[0010] The present invention is not limited to the following examples.

[0011] 1, 2, 3, 4, and 5 are process diagrams showing an example of a method for manufacturing a semiconductor package. The method shown in Figs. 1 to 5 includes the steps of preparing a connection body 100W including a semiconductor wafer substrate W having a wafer main body 10W and a plurality of first electrodes 15, and a plurality of semiconductor chip components 20A, 20B having a plurality of second electrodes 25 arranged opposite the first electrodes 15, forming an underfill 30 including a portion that fills the gap between the semiconductor chip components 20A, 20B and the wafer main body 10W, and forming a sealing layer 40 on the semiconductor wafer substrate W that collectively seals the plurality of semiconductor chip components 20A, 20B, and The method includes forming a sealing body 200W having a semiconductor wafer substrate W, a plurality of semiconductor chip components 20A, 20B, an underfill 30, and a sealing layer 40, removing a portion of the sealing layer 40 from the side opposite the semiconductor wafer substrate W to form a flat surface S3 on which the semiconductor chip components 20A, 20B are exposed, and singulating the sealing body 200W to obtain wiring members 1 which are the singulated semiconductor wafer substrate W, and a plurality of semiconductor components 200 which include the semiconductor chip components 20A, 20B.

[0012] 1(b) is a cross-sectional view showing a portion of the connection body 100W, and FIG. 2 is a plan view showing the entire connection body 100W. As shown in FIGS. 1 and 2, a plurality of each of two types of semiconductor chip components 20A, 20B are arranged on a single semiconductor wafer substrate W. In this example, a portion corresponding to one semiconductor package to be manufactured is formed by combining one first semiconductor chip component 20A with four second semiconductor chip components 20B arranged around the first semiconductor chip component 20A. The types and number of semiconductor chip components that make up the semiconductor package are not limited to the configuration shown in this example and can be changed as desired.

[0013] The wafer body 10W can be a disk-shaped wiring substrate including wiring. A plurality of first electrodes 15 connected to the wiring within the wafer body 10W are arranged on the circular main surface S1 of the wafer body 10W. The diameter of the main surface S1 of the wafer body 10W may be, for example, 100 mm or more, or 300 mm or more, or 450 mm or less. Even if the wafer body 10W has a large size, warping can be sufficiently suppressed.

[0014] In the example of FIG. 1 , the multiple first electrodes 15 include a group of electrodes connected to the first semiconductor chip component 20A and a group of electrodes connected to the second semiconductor chip component 20B. The multiple first electrodes 15 may be arranged on the wafer main body 10W at a minimum pitch of 40 μm or less. Even when the pitch of the first electrodes 15 is small, the method disclosed herein makes it easy to sufficiently fill the space between the wafer main body 10W and the semiconductor chip components 20A and 20B with underfill 30. FIG. 7 is an enlarged cross-sectional view showing an example of a semiconductor wafer substrate. As shown in FIG. 7 , the pitch p of the first electrodes 15 refers to the distance between the centers of adjacent first electrodes 15 in a plane parallel to the main surface S1 of the wafer main body 10W. The minimum value of the pitch p among the multiple first electrodes 15 arranged on one wafer main body 10W may be 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less. The minimum value of the pitch p of the plurality of first electrodes 15 arranged on one wafer body 10W may be 1 μm or more and 40 μm or less.

[0015] The first electrode 15 may be, for example, a conductive pad, a bump, or a combination thereof. The first electrode 15 may include a metal bump (e.g., a copper bump). The width of the first electrode 15 may be 0.5 μm or more and 35 μm or less. The height of the first electrode 15 may be 0.5 μm or more and 100 μm or less. A solder resist or the like may be provided around each of the multiple first electrodes 15.

[0016] The first semiconductor chip component 20A has a chip body 21A and a plurality of second electrodes 25 provided on the outer surface of the chip body 21A. The second semiconductor chip component 20B has a chip body 21B and a plurality of second electrodes 25 provided on the outer surface of the chip body 21B. The chip body 21A and the chip body 21B may each include one or more bare chips. In the example of FIG. 1 , the second electrodes 25 are metal bumps having conductive columnar portions 25a and solder bumps 25b provided on the columnar portions 25a. The second electrodes 25 are typically arranged at a pitch substantially the same as the pitch of the first electrodes 15 to be connected. The width of the second electrodes 25 may be 0.5 μm or more and 35 μm or less. The height of the second electrodes 25 may be 0.5 μm or more and 100 μm or less.

[0017] A connection body 100W is formed by mounting a plurality of semiconductor chip components 20A, 20B on a semiconductor wafer substrate W (FIG. 1(b) and FIG. 2). The semiconductor chip components 20A, 20B are mounted on the semiconductor wafer substrate W, if necessary, through a normal process such as reflow, so that the first electrode 15 and the second electrode 25 arranged opposite to each other are electrically connected.

[0018] After the connecting body 100W is formed, as shown in FIG. 3A, an underfill 30 is formed, including a portion 30a that fills the gap between the semiconductor chip components 20A, 20B and the wafer main body 10W. A portion of the underfill 30 may protrude from between the wafer main body 10W and the semiconductor chip components 20A, 20B. In other words, the underfill 30 may be formed to further include a protruding portion 30b that protrudes from between the wafer main body 10W and the semiconductor chip components 20A, 20B. Typically, the portion 30a that fills the gap between the semiconductor chip components 20A, 20B and the wafer main body 10W and the protruding portion 30b are integrally formed. The protruding portion 30b partially fills the gap between two adjacent semiconductor chip components 20A, 20B or between adjacent chip bodies on the semiconductor wafer substrate W. The protruding portion 30b may be formed so that the wafer body 10W is exposed between the adjacent semiconductor chip components 20A, 20B. The maximum height of the protruding portion 30b from the wafer body 10W may be smaller than the maximum height of the semiconductor chip components 20A, 20B from the wafer body 10W. The underfill 30 may be substantially free of the protruding portion 30b.

[0019] The underfill 30 can be a cured product formed by curing a thermosetting underfill material. The underfill material may be a liquid or a film at room temperature (25°C). When the underfill material is a liquid, the underfill 30 can be formed, for example, by a method including injecting the underfill material between the wafer body 10W and the semiconductor chip components 20A, 20B, and then curing the underfill material by heating.

[0020] After the underfill 30 is formed, as shown in FIG. 3B , a sealing layer 40 is formed on the semiconductor wafer substrate W to collectively seal the plurality of semiconductor chip components 20A, 20B. This forms a sealed body 200W including the semiconductor wafer substrate W, the plurality of semiconductor chip components 20A, 20B, the underfill 30, and the sealing layer 40. At this stage, the sealed body 200W may be configured such that the entire semiconductor chip components 20A, 20B are covered by the integral sealing layer 40 on the semiconductor wafer substrate W. In the sealed body 200W, the sealing layer 40 may be formed to entirely cover the protruding portion 30b. The sealing layer 40 may be formed without first removing a portion of the protruding portion 30b to form a trench in the protruding portion 30b. In this case, the protruding portion 30b does not substantially form a trench in the sealed body 200W. In the sealing body 200W, the protruding portion 30b does not need to form a trench having a depth greater than the minimum value of the distance between the wafer body 10W and the chip bodies 21A and 21B.

[0021] The sealing layer 40 may be a cured product formed by curing a thermosetting sealing material. The sealing material may be a powder. The sealing layer 40 may be formed, for example, by compression molding the powder sealing material.

[0022] The combination of the underfill material and the encapsulant can be selected so that the linear expansion coefficient of the cured product of the underfill material is greater than the linear expansion coefficient of the cured product of the encapsulant. Underfill materials that form cured products with large linear expansion coefficients tend to have high fluidity before curing, which can contribute to improved filling properties. On the other hand, encapsulants that form cured products with small linear expansion coefficients can suppress warping of the encapsulated body 200W. Therefore, by combining an underfill material that forms a cured product with a relatively large linear expansion coefficient with an encapsulant that forms a cured product with a relatively small linear expansion coefficient, it is possible to easily achieve both sufficient underfill filling and suppression of warping of the encapsulated body 200W. For example, when filling gaps where electrodes are provided at a small pitch of 40 μm or less with underfill, it can be particularly beneficial to use an underfill material with high fluidity while avoiding its effect on warping.

[0023] For example, the cured underfill material may exhibit a linear expansion coefficient of 6 ppm / °C or more and 30 ppm / °C or less. The cured encapsulant may exhibit a linear expansion coefficient of 5 ppm / °C or more and 20 ppm / °C or less, or 5 ppm / °C or more and 14 ppm / °C or less. When the cured underfill material and encapsulant exhibit linear expansion coefficients within these ranges, particularly excellent effects can be achieved in terms of the underfill filling properties and suppression of warpage. A cured underfill material with a linear expansion coefficient of 30 ppm / °C or less is advantageous in terms of suppressing warpage of the connector after the underfill 30 is formed and before the encapsulating layer 40 is formed. From the same viewpoint as above, the linear expansion coefficient of the cured underfill material may be 7 ppm / °C or more, 8 ppm / °C or more, 9 ppm / °C or more, 10 ppm / °C or more, 11 ppm / °C or more, 12 ppm / °C or more, 13 ppm / °C or more, 14 ppm / °C or more, 15 ppm / °C or more, 16 ppm / °C or more, 17 ppm / °C or more, 18 ppm / °C or more, 19 ppm / °C or more, or 20 ppm / °C or more, or may be 29 ppm / °C or less, 28 ppm / °C or less, 27 ppm / °C or less, 26 ppm / °C or less, 25 ppm / °C or less, 24 ppm / °C or less, 23 ppm / °C or less, or 22 ppm / °C or less. From a similar viewpoint, the linear expansion coefficient of the cured product of the encapsulating material may be 6 ppm / °C or more, 7 ppm / °C or more, or 8 ppm / °C or more, or may be 19 ppm / °C or less, 18 ppm / °C or less, 17 ppm / °C or less, 16 ppm / °C or less, 15 ppm / °C or less, 14 ppm / °C or less, 13 ppm / °C or less, 12 ppm / °C or less, 11 ppm / °C or less, 10 ppm / °C or less, or 9 ppm / °C or less.

[0024] The linear expansion coefficient of the cured product can be the slope of the tangent to the curve in a temperature range lower than the glass transition temperature, or the slope of the line connecting two points on the curve in a temperature range lower than the glass transition temperature, in a thermal expansion curve showing the relationship between the dimensions of a test piece of the cured product measured by thermomechanical analysis and the temperature. The glass transition region is usually observed as a portion where the slope of the thermal expansion curve changes significantly. The linear expansion coefficient of the cured underfill material can be the slope of the line connecting the 10°C point and the 30°C point on the thermal expansion curve. The linear expansion coefficient of the cured encapsulant can be the slope of the line connecting the 50°C point and the 70°C point on the thermal expansion curve.

[0025] The flexural modulus of the cured product of the encapsulant may be 5.0 GPa or more and 20 GPa or less at 25° C. When the flexural modulus of the cured product of the encapsulant is within this range, warping of the encapsulated body can be particularly effectively suppressed. From the same viewpoint, the flexural modulus of the cured product of the encapsulant at 25° C. may be 6.0 GPa or more, 6.5 GPa or more, 7.0 GPa or more, 7.5 GPa or more, 8.0 GPa or more, 8.5 GPa or more, 9.0 GPa or more, 9.5 GPa or more, 10 GPa or more, 11 GPa or more, or 12 GPa or more, or may be 19 GPa or less, 18 GPa or less, 17 GPa or less, 16 GPa or less, 15 GPa or less, 14 GPa or less, or 13 GPa or less. The flexural modulus of the cured encapsulant can be a value measured at 25°C by a three-point support bending test using a rectangular test piece having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm.

[0026] The underfill material for forming the underfill 30 can be, for example, a thermosetting resin composition containing a thermosetting component. The underfill material may also contain an inorganic filler. The sealing material for forming the sealing layer 40 can be a thermosetting resin composition containing a thermosetting component and an inorganic filler. In this case, the linear expansion coefficient of the cured product of the underfill material or sealing material can be adjusted by, for example, the content of the inorganic filler, the average particle size of the inorganic filler, or a combination thereof.

[0027] When the content of the inorganic filler is small, the linear expansion coefficient of the cured product tends to be large. From the viewpoint of adjusting the linear expansion coefficient, the content of the inorganic filler in the underfill material may be smaller than the content of the inorganic filler in the encapsulant. The content of the inorganic filler in the underfill material may be 0 mass% or more, 5 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, or 50 mass% or more, based on the mass of the underfill material, and may be 70 mass% or less, 67 mass% or less, less than 67 mass%, 65 mass% or less, or 60 mass% or less. The content of the inorganic filler in the encapsulant may be 70 mass% or more, 75 mass% or more, or 80 mass% or more, based on the mass of the inorganic filler, and may be 95 mass% or less, or 90 mass% or less.

[0028] When the average particle size of the inorganic filler is small, the underfill material tends to fill more easily between the semiconductor wafer substrate and the semiconductor chip component. From the viewpoint of adjusting the filling property, the average particle size of the inorganic filler in the underfill material may be smaller than the average particle size of the inorganic filler in the encapsulant. The average particle size of the inorganic filler in the underfill material may be 0.1 μm or more and 5.0 μm or less, or may be 4.0 μm or less, 3.0 μm or less, or 2.0 μm or less. The average particle size of the inorganic filler in the encapsulant may be more than 5.0 μm and 20 μm or less. The average particle size of the inorganic filler may be the cumulative 50% diameter on a volume basis, determined from the particle size distribution measured by laser diffraction.

[0029] The inorganic filler may be, for example, particles or short fibers (e.g., glass fibers) containing one or more selected from silica, calcium carbonate, clay, alumina, silicon nitride, silicon carbide, boron nitride, calcium silicate, potassium titanate, aluminum nitride, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, aluminum hydroxide, magnesium hydroxide, zinc borate, and zinc molybdate. The inorganic filler may be silica particles, particularly spherical silica particles. The inorganic filler may be surface-treated with a silane coupling agent or the like.

[0030] The thermosetting component contained in the underfill material may include, for example, an epoxy resin and its curing agent.

[0031] Some or all of the epoxy resins constituting the thermosetting component may be liquid at 25°C. Examples of epoxy resins include diglycidyl ether-type epoxy resins, novolac-type epoxy resins, glycidyl ester-type epoxy resins, glycidyl amine-type epoxy resins, linear aliphatic epoxy resins, and alicyclic epoxy resins. The diglycidyl ether-type epoxy resin may be, for example, the diglycidyl ether of bisphenol A, bisphenol F, bisphenol AD, bisphenol S, or hydrogenated bisphenol A. The novolac-type epoxy resin is a compound obtained by epoxidizing a novolac resin formed from a phenol and an aldehyde, and examples thereof include orthocresol novolac-type epoxy resin. The glycidyl ester-type epoxy resin may be, for example, the glycidyl ester of phthalic acid or dimer acid. The glycidylamine type epoxy resin may be, for example, triglycidyl-p-aminophenol, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmetadiaminodiphenylmethane, or triglycidyl isocyanurate.

[0032] The curing agent for the epoxy resin may include, for example, an aromatic amine, a phenolic compound, or a combination thereof. Examples of aromatic amines that can be used as curing agents include diethyltoluenediamine, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,5,3',5'-tetramethyl-4,4'-diaminodiphenylmethane, and dimethylthiotoluenediamine. Examples of phenolic compounds that can be used as curing agents include various novolac resins.

[0033] The thermosetting component contained in the encapsulant may include an epoxy resin and its curing agent, examples of which include those similar to those exemplified for the thermosetting component of the underfill material.

[0034] The encapsulant may contain an acrylic copolymer. An encapsulant containing an acrylic copolymer is likely to form a cured product having an appropriate flexural modulus. The acrylic copolymer is a copolymer of two or more monomers, including a monomer having an acryloyl group, a monomer having a methacryloyl group, or a combination thereof.

[0035] The acrylic copolymer may have a radically polymerizable functional group. The acrylic copolymer having the radically polymerizable functional group is considered to be a component constituting the thermosetting component. The radically polymerizable functional group may be, for example, an acryloyl group, a methacryloyl group, an allyl group, a vinyl group, or a maleimide group. The thermosetting component may include a radical polymerization initiator together with the acrylic copolymer having the radically polymerizable functional group.

[0036] The acrylic copolymer that can be contained in the encapsulant may contain, as a monomer unit, an alkyl(meth)acrylate having a linear or branched alkyl group having 6 to 9 carbon atoms, and the proportion of the alkyl(meth)acrylate having a linear or branched alkyl group having 6 to 9 carbon atoms may be 10% by mass or more and 40% by mass or less based on the amount of all monomer units in the acrylic copolymer. The alkyl(meth)acrylate having a linear or branched alkyl group having 6 to 9 carbon atoms may be one or more selected from n-hexyl(meth)acrylate, n-heptyl(meth)acrylate, n-octyl(meth)acrylate, n-nonyl(meth)acrylate, 2-methyloctyl(meth)acrylate, 2-ethylheptyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isooctyl(meth)acrylate, and isononyl(meth)acrylate.

[0037] The encapsulant may contain an elastomer. An encapsulant containing an elastomer is likely to form a cured product having an appropriate flexural modulus. The elastomer may be, for example, polyisoprene, polybutadiene, 1,2-polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene rubber, polychloroprene, poly(oxypropylene), poly(oxytetramethylene) glycol, polyolefin glycol, poly-ε-caprolactone, silicone rubber, polysulfide rubber, fluororubber, or a combination of two or more selected from these. The elastomer may have a functional group capable of reacting with the thermosetting component. An elastomer having such a functional group is considered to be a component constituting the thermosetting component.

[0038] The elastomer may be a thermoplastic elastomer, such as a polyester-based thermoplastic elastomer, a polybutadiene-based thermoplastic elastomer, an acrylic-based thermoplastic elastomer, or a combination of two or more selected from these.

[0039] The underfill material and the encapsulant may further contain other components as needed, such as a surfactant, a coupling agent, a curing accelerator, and an ion trapping agent.

[0040] As the materials used to form the underfill 30 and the sealing layer 40, a resin set composed of a sealing material and an underfill material may be prepared in advance.

[0041] After the sealing layer 40 and the sealing body 200W are formed, a portion of the sealing layer 40 is removed from the side opposite the semiconductor wafer substrate W. This forms a flat surface S3 on which the semiconductor chip components 20A, 20B are exposed. The portion of the sealing layer 40 can be removed by a conventional method such as chemical mechanical polishing. A flat surface S3 on which the semiconductor chip components 20A, 20B are not exposed may also be formed. The underfill 30 may not be exposed on the flat surface S3, and the entire underfill 30 may be embedded inside the sealing layer 40.

[0042] The main surface S2 of the wafer body 10W constituting the sealed body 200W, opposite the semiconductor chip components 20A and 20B, is further processed as necessary. For example, as shown in FIG. 4B, multiple third electrodes 50 may be formed on the main surface S2. In the example of FIG. 4, the third electrodes 50 are composed of conductive columnar portions 50a and solder bumps 50b. The third electrodes 50 are formed, for example, by a method including polishing the main surface S2 of the wafer body 10W to planarize it, forming columnar portions 50a including electroplating patterned by photolithography, and providing solder bumps 50b on the columnar portions 50a. The solder bumps 50b may be provided after the sealed body 200W is singulated. A small warpage of the sealed body 200W allows the sealed body 200W to be appropriately mounted in a device for polishing semiconductor wafer substrates W.

[0043] As shown in FIGS. 5A and 5B , the sealed body 200W is cut along dicing lines DL to separate the sealed body 200W. This separation yields multiple semiconductor components 200 from a single sealed body 200W. Each semiconductor component 200 includes a wiring member 1, which is a separated semiconductor wafer substrate W, semiconductor chip components 20A and 20B, an underfill 30, a sealing layer 40, and a third electrode 50. The wiring member 1 includes a wiring substrate 10 cut from the wafer main body 10W and a first electrode 15. The wiring member 1 may be an interposer including wiring that connects multiple semiconductor chip components. The method for separating the sealed body 200W is not particularly limited and can be a conventional method such as blade dicing.

[0044] The semiconductor component 200 itself may be used as a semiconductor package, or the semiconductor component 200 may be combined with other members to form a semiconductor package. FIG. 6 is a cross-sectional view showing an example of a semiconductor package having a package substrate on which a semiconductor component is mounted. The semiconductor package 300 shown in FIG. 6 includes a semiconductor package substrate 250 including wiring, a semiconductor component 200 mounted on the semiconductor package substrate 250, an underfill 60, and a heat diffusion plate 70. The semiconductor component 200 is mounted on the semiconductor package substrate 250 with the third electrode 50 facing the semiconductor package substrate 250. The underfill 60 fills the gap between the third electrode 50 and the semiconductor package substrate 250. The heat diffusion plate 70 is provided on the semiconductor package substrate 250 so as to contact the semiconductor component 200 and cover the entire semiconductor component 200. The semiconductor package 300 can be mounted on various motherboards. When the wiring member 1 is an interposer, two or more semiconductor members 20A, 20B are electrically connected to each other via the wiring of the wiring member (interposer) 1. The configuration of the semiconductor package is not limited to the form shown in FIG.

[0045] [Examples] The present invention is not limited to the following examples.

[0046] 1. Underfill Materials and Encapsulants Two types of underfill materials (CUF-A and CUF-B), which are liquid thermosetting compositions, and five types of encapsulating materials (EMC-A, EMC-B, EMC-C, EMC-D, and EMC-E), which are powders, were prepared. The coefficient of linear expansion (CTE) and flexural modulus of the cured products formed by curing the underfill materials and encapsulating materials were measured using the following procedure.

[0047] 1-1. Coefficient of Linear Expansion Underfill Material The underfill material was cured by heating at 150°C for 2 hours to form a cured product. Cylindrical test pieces with a diameter of 8 mm and a height of 20 mm were cut from the cured product. The dimensional change in the longitudinal direction of this test piece was measured using a thermomechanical analyzer (product name: TMA2940, manufactured by TA Instruments) by the compression method, with a heating rate of 5°C / min from 0°C to 300°C. In the thermal expansion curve showing the relationship between the dimensions of the test piece and temperature, the slope of the line connecting the 10°C point and the 30°C point was taken as the coefficient of linear expansion (CTE). The glass transition region, where the slope of the thermal expansion curve changes significantly, was observed around 130°C.

[0048] The encapsulant was injection molded at a mold temperature of 175°C and a molding time of 150 seconds to obtain a rectangular parallelepiped test piece measuring 20 mm x 4 mm x 4 mm. The dimensional change in the longitudinal direction of this test piece was measured using a thermomechanical analyzer (TAS-1000S) manufactured by Rigaku Denki at a heating rate of 5°C / min from 25°C to 260°C. The coefficient of linear expansion (CTE) was determined as the slope of the line connecting the 50°C point and the 70°C point in the thermal expansion curve showing the relationship between the dimensions of the test piece and the temperature. The glass transition region, where the slope of the thermal expansion curve changes significantly, was observed in a temperature range above 150°C for all three encapsulants.

[0049] 1-2. Flexural Modulus Underfill Material The underfill material was cured by heating at 150°C for 2 hours to form a sheet-like cured product. A rectangular test piece measuring 50 mm in length, 10 mm in width, and 3 mm in thickness was cut from the cured product. The viscoelasticity of the test piece was measured by a three-point bending method using a viscoelasticity measuring device (product name: RS AIII, manufactured by TA Instruments) under conditions of a span distance of 40 mm, a frequency of 1 Hz, and a heating rate of 5°C / min from 20°C to 300°C. In the measurement results, the storage modulus at 25°C was taken as the flexural modulus.

[0050] The encapsulant was injection molded at a mold temperature of 175°C for a molding time of 150 seconds to obtain a rectangular test piece measuring 80 mm in length, 10 mm in width, and 4 mm in thickness. The resulting test piece was post-cured by heating at 175°C for 5 hours. A three-point support bending test of the test piece was then performed using a TENSILON (manufactured by A&D Corporation) with a support distance of 64 mm under conditions conforming to JIS-K-6911. The head speed was 3.0 mm / min and the measurement temperature was 25°C. The flexural modulus E (unit: Pa) was calculated according to the following formula, and the obtained value was converted to a value in units of GPa. In the formula, P is the load value (N) detected by the load cell, y is the displacement (mm), l is the support distance (64 mm), w is the width of the test piece (10 mm), and h is the thickness of the test piece (4 mm).

[0051]

[0052] The measurement results are shown in Table 1. Table 1 shows the amount of inorganic filler (silica particles) in the underfill material and the encapsulant, and the average particle size of the inorganic filler. The amount of inorganic filler is a ratio based on the total mass of each material. The cured product of CUF-B exhibited a linear expansion coefficient in the range of 6 ppm / °C to 30 ppm / °C. The cured products of EMC-B, EMC-C, and EMC-D exhibited a linear expansion coefficient in the range of 5 ppm / °C to 14 ppm / °C, and a flexural modulus in the range of 5.0 GPa to 20 GPa.

[0053]

[0054] 2. Verification Test 2-1. Formation of Sealed Body A disk-shaped sealed body including a silicon wafer, a first silicon chip, a second silicon chip, an underfill, and a sealing layer was obtained using the underfill material and sealing material combinations shown in Table 2 by the following procedure.

[0055] A silicon wafer was prepared, having a wafer body with a thickness of 775 μm and a diameter of 300 mm, and Cu bumps (5 μm thick, first electrodes) arranged in a grid pattern with a pitch of 15 μm on the wafer body. A first silicon chip with a rectangular main surface of 20 mm x 15 mm and a thickness of 775 μm, and a second silicon chip with a rectangular main surface of 10 mm x 5 mm and a thickness of 775 μm were prepared. Bumps (second electrodes) arranged in a grid pattern with a pitch of 15 μm were provided on the main surfaces of the first silicon chip and the second silicon chip. The bumps on the first and second silicon chips were composed of copper (3 μm thick), Ni (2 μm thick), and Sn-Ag solder (5 μm thick). 52 first silicon chips and 208 second silicon chips were mounted on a single silicon wafer via bump connection to obtain a connection assembly.

[0056] An underfill material (CUF-A or B) was injected between the silicon wafer and the first or second silicon chip using a jet dispenser (Musashi Engineering, product name: FAD2500). The injected underfill material was cured by heating at 165°C for 2 hours to form an underfill.

[0057] Next, the connector was adsorbed onto a molding device (Apic Yamada Corporation, WCM330MS (product name)), and an 895 μm thick sealing layer that collectively sealed the first silicon chip and the second silicon chip on the silicon wafer was formed by compression molding with a sealing material (EMC-A, B, C, D, or E). The sealing layer was cured by heating at 130°C for 15 minutes. In the case of the connector of Comparative Example 1, in which underfill was formed using underfill material CUF-A, the warpage was so great that it could not be properly adsorbed onto the molding device, and a sealed body with a sealing layer could not be formed.

[0058] 2-2. Evaluation The amount of warpage of the connector and the sealed body at room temperature before the formation of the sealing layer was measured using a warpage measurement device Thermoire (manufactured by AKROMETRIX, product name: Thermoire AXP). The amount of warpage when the end of the connector or the sealed body warped toward the silicon wafer was taken as a positive value. The amount of warpage when the end of the connector or the sealed body was aligned with the sealing layer was taken as a negative value.

[0059] It was confirmed whether the encapsulated body could be properly adsorbed to a grinding device for polishing the sealing layer. If the encapsulated body could be properly adsorbed to the grinding device, it was judged as "OK", and if the encapsulated body could not be adsorbed to the grinding device, it was judged as "NG".

[0060] The state of underfill filling between the silicon wafer and silicon chip was confirmed by observation using a scanning electron microscope. Regarding the filling ability of the underfill material, if no defects such as voids were found, it was judged as "OK", and if defects such as voids were found, it was judged as "NG".

[0061] As shown in Table 2, in Examples 1 and 2, the underfill easily filled the gap between the silicon wafer and the silicon chip, and warping of the connection body and sealing body having the silicon wafer was sufficiently suppressed.

[0062]

[0063] 1...wiring member, 10...wiring board, 10W...wafer body, 15...first electrode, 20A, 20B...semiconductor chip component, 25...second electrode, 30...underfill, 40...sealing layer, 50...third electrode, 60...underfill, 70...heat diffusion plate, 100W...connector, 200...semiconductor component, 200W...sealing body, 250...semiconductor package substrate, 300...semiconductor package, p...pitch, S1, S2...main surface of wafer body, S3...flat surface, W...semiconductor wafer substrate.

Claims

1. A method for manufacturing a semiconductor package, comprising: preparing a connecting body comprising a semiconductor wafer substrate having a wafer body and a plurality of first electrodes, and a plurality of semiconductor chip components having a plurality of second electrodes arranged opposite the first electrodes, the first electrodes and the second electrodes being electrically connected; forming an underfill including a portion that fills the gap between the semiconductor chip components and the semiconductor wafer substrate; forming a sealing layer on the semiconductor wafer substrate that collectively seals the plurality of semiconductor chip components, thereby forming a sealing body comprising the semiconductor wafer substrate, the plurality of semiconductor chip components, the underfill, and the sealing layer; and singulating the sealing body to obtain a plurality of semiconductor components comprising wiring members that are the singulated semiconductor wafer substrates and one or more of the semiconductor chip components, wherein the plurality of first electrodes are arranged on the wafer body at a minimum pitch of 40 μm or less; the underfill is a cured product of an underfill material; the sealing layer is a cured product of a sealing material; and the cured product of the underfill material has a linear expansion coefficient of 6 ppm / °C or more and 30 ppm / °C or less. the linear expansion coefficient of the cured product of the encapsulant is 5 ppm / °C or more and 14 ppm / °C or less, the linear expansion coefficient of the cured product of the underfill material is greater than the linear expansion coefficient of the cured product of the encapsulant, and the flexural modulus of the cured product of the encapsulant is 5.0 GPa or more and 20 GPa or less at 25°C.

2. The method according to claim 1, wherein the semiconductor chip component further has a chip body, the second electrode is provided on the outer surface of the chip body, the underfill is formed so as to further have a protruding portion that protrudes from between the wafer body and the chip body, and in the encapsulant, the protruding portion located between two adjacent semiconductor chip components on the semiconductor wafer substrate does not form a trench having a depth greater than the minimum distance between the wafer body and the chip body.

3. The method according to claim 1, wherein the flexural modulus of the cured sealant is 5.0 GPa or more and 18 GPa or less at 25°C.

4. The method of claim 1, wherein the underfill material is a liquid.

5. The method of claim 2, wherein the sealing material is a powder.

6. The method of claim 1, further comprising removing a portion of the encapsulation layer from a side opposite the semiconductor wafer substrate, thereby forming a flat surface on which the semiconductor chip component is exposed.

7. The method according to claim 1, wherein the plurality of first electrodes are arranged on the wafer body at a minimum pitch of 20 μm or less.

8. The method according to any one of claims 1 to 7, wherein the wiring member is an interposer, and the semiconductor component includes two or more of the semiconductor chip components electrically connected to each other via the wiring member.

9. A resin set for sealing and underfilling semiconductor chip components, comprising: an encapsulating material; and an underfill material, wherein the cured product of the underfill material has a linear expansion coefficient of 6 ppm / °C or more and 30 ppm / °C or less, the cured product of the encapsulating material has a linear expansion coefficient of 5 ppm / °C or more and 14 ppm / °C or less, the cured product of the underfill material has a linear expansion coefficient greater than the linear expansion coefficient of the cured product of the encapsulating material, and the cured product of the encapsulating material has a flexural modulus of 5.0 GPa or more and 20 GPa or less at 25°C.

10. The resin set according to claim 9, wherein the flexural modulus of the cured sealant is 5.0 GPa or more and 18 GPa or less at 25°C.

11. The resin set of claim 9, wherein the underfill material is a liquid.

12. The resin set according to any one of claims 9 to 11, wherein the sealing material is a powder.

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