JP6806112B2 - Semiconductor package and its manufacturing method - Google Patents

Description

The present disclosure relates to a semiconductor package and a method for manufacturing the same.

Conventionally, inventions relating to a sealing liquid resin composition used for sealing a semiconductor element mounting body, particularly a flip chip mounting body, have been known (see Patent Document 1 below). An object of the invention described in Patent Document 1 is to provide a liquid resin composition for sealing which suppresses bleeding and has good pot life and fluidity (see the same document, paragraph 0008, etc.).

In order to achieve this object, Patent Document 1 is a composition containing (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D) a silicone-based copolymer, which is a component. Disclosed is a liquid resin composition for encapsulation, wherein (D) is a copolymer of an alkylpropenoic acid ester and an alkylpropenic acid polysiloxane ester (see the same document, claim 1 and the like).

Further, in Patent Document 1, the above-mentioned component (C) contains nanosilica particles having an average particle size of 10 to 750 nm (see the same document, claim 6 and the like), and the above-mentioned component (A) is 100 parts by mass. It discloses that the component (C) is contained in an amount of 200 to 350 parts by mass (see the same document, claim 7 and the like).

Since this liquid resin composition for encapsulation suppresses bleeding and has good pot life and fluidity, it is suitable as an encapsulant for semiconductor devices, particularly as an encapsulant for a flip chip mount. , Patent Document 1 (see paragraph 0065 of the same document).

Japanese Unexamined Patent Publication No. 2011-006618

Due to the demand for miniaturization, weight reduction, and high performance of electronic devices, for example, in a semiconductor package in which a semiconductor element is mounted on a substrate, further high integration and high density of the semiconductor element are required. In order to satisfy the requirement, it is conceivable to use the above-mentioned conventional resin composition as a sealing material. However, the conventional resin composition has a problem that the silicone-based copolymer is limited to the specific component (D) in order to suppress bleeding.

The present disclosure provides a semiconductor package capable of suppressing bleeding by the action of an inorganic filler contained in the encapsulant, and a method for producing the same.

One aspect of the present disclosure is a semiconductor package including a substrate, a semiconductor element mounted on the substrate, and a sealing portion for sealing between the semiconductor element and the substrate, and the sealing. The portion is a semiconductor package containing a nanofiller which is an inorganic material particle having a particle size of 100 nm or less, and having a nanofiller collecting portion in which the nanofiller is gathered at an outer edge portion of the sealing portion. ..

Further, one aspect of the present disclosure is a method for manufacturing a semiconductor package, comprising a mounting step of mounting a semiconductor element on a substrate and a sealing step of sealing between the substrate and the semiconductor element by a sealing portion. The sealing step is characterized by including a nanofiller collecting step of collecting nanofillers which are inorganic material particles having a particle size of 100 nm or less on the peripheral edge of a region sealed by the sealing portion. This is a method for manufacturing a semiconductor package.

According to the above aspect of the present disclosure, it is possible to provide a semiconductor package capable of suppressing bleeding by the action of an inorganic filler contained in the sealing portion and a method for producing the same.

A schematic cross-sectional view of the semiconductor package according to the first embodiment. FIG. 3 is an enlarged cross-sectional view of an outer edge portion of a sealing portion of the semiconductor package shown in FIG. The flow chart which shows each process of the manufacturing method of the semiconductor package shown in FIG. The flow chart which shows an example of each process of the sealing process shown in FIG. FIG. 6 is a schematic cross-sectional view illustrating an example of the nanofiller collecting step shown in FIG. Schematic cross-sectional view illustrating an example of the filling process shown in FIG. FIG. 5 is an enlarged cross-sectional view of a peripheral edge of a sealing portion of the semiconductor package according to the second embodiment. An enlarged cross-sectional view of the outer edge of the sealing portion of a conventional semiconductor package.

Hereinafter, embodiments of the semiconductor package and its manufacturing method of the present disclosure will be described with reference to the drawings. The ratio of the dimensions of each part shown in each drawing may differ from drawing to drawing.

[Embodiment 1]
FIG. 1 is a schematic cross-sectional view of the semiconductor package 100 according to the first embodiment of the present disclosure. FIG. 2 is an enlarged cross-sectional view of the outer edge portion 31 of the sealing portion 30 of the semiconductor package 100 shown in FIG. Hereinafter, the configuration of the semiconductor package 100 of the present embodiment will be described first, and then the method of manufacturing the semiconductor package 100 will be described.

The semiconductor package 100 of the present embodiment is, for example, an electronic component for constituting an electronic device indispensable in an advanced information society, and is mainly characterized by having the following configuration. The semiconductor package 100 includes a substrate 10, a semiconductor element 20 mounted on the substrate 10, and a sealing portion 30 that seals between the semiconductor element 20 and the substrate 10. The sealing portion 30 includes a nanofiller 40 which is an inorganic material particle having a particle size of 100 nm or less, and has a nanofiller collecting portion 32 in which the nanofiller 40 is gathered on the outer edge portion 31.

The board 10 is a wiring board such as a printed circuit board. Further, the substrate 10 is a multilayer circuit board including a plurality of inner layer conductors made of, for example, copper, alumina, tungsten, molybdenum, or the like. The surface 11 of the substrate 10 facing the semiconductor element 20 is composed of, for example, a glass-based material, a protective layer such as a silicon nitride film, or a resin layer such as a polyimide-based resin. Further, the electrode 12 is exposed on a part of the surface 11 of the substrate 10.

The semiconductor element 20 is, for example, a semiconductor chip, and includes a plurality of terminals 21 and bumps 22 bonded to the terminals 21. The surface of the semiconductor element 20 facing the substrate 10 is covered with a protective layer such as a silicon nitride film or an oxide film, or a resin layer made of a polyimide resin or the like. The semiconductor element 20 is mounted on the substrate 10 by joining the terminal 21 to the electrode 12 of the substrate 10 via the bump 22. That is, the semiconductor element 20 is mounted on the substrate 10 by, for example, flip chip bonding.

The sealing portion 30 is formed by, for example, a CUF (capillary underfill) method in which an underfill, which is a fluid sealing material 30P (see FIG. 6), is filled between the substrate 10 and the semiconductor element 20 by a capillary phenomenon. , The gap between the substrate 10 and the semiconductor element 20 is sealed. As shown in FIG. 2, the sealing portion 30 contains a nanofiller 40 which is an inorganic material particle having a particle size of 100 nm or less. Further, the sealing portion 30 may contain, for example, a microfiller 50 which is an inorganic material particle having a particle size of 0.3 μm or more and 10 μm or less. The nanofiller 40 and the microfiller 50 are, for example, spherical particles of silicon oxide.

The nanofiller 40 and the microfiller 50 suppress thermal expansion and contraction of the sealing portion 30, adjust the viscosity of the sealing material 30P (see FIG. 6) for forming the sealing portion 30, and improve the fluidity. And, for the purpose of suppressing voids and the like, it is contained in the sealing portion 30 in an appropriate ratio. The method for measuring the particle size of the nanofiller 40 and the microfiller 50 is not particularly limited. For example, the average particle size can be determined based on an electron microscope image, or the particle size distribution can be measured by an optical method such as a dynamic light scattering method or a laser diffraction method.

As described above, the semiconductor package 100 is characterized in that the outer edge portion 31 of the sealing portion 30 has a nanofiller collecting portion 32 in which the nanofiller 40 is gathered. That is, the number density of the nanofiller 40 in the nanofiller collecting portion 32 is higher than the number density of the nanofiller 40 in the sealing portion 30 excluding the nanofiller collecting portion 32. In other words, the number of nanofillers 40 contained in the unit volume of the nanofiller collecting portion 32 is larger than the number of nanofillers 40 contained in the unit volume of the sealing portion 30 excluding the nanofiller collecting portion 32.

Further, the total surface area of the nanofiller 40 contained in the unit volume of the nanofiller collecting portion 32 is larger than the total surface area of the nanofiller 40 contained in the unit volume of the sealing portion 30 excluding the nanofiller collecting portion 32. Larger is preferred. The total surface area of the nanofiller 40 contained in a unit volume can be obtained by, for example, the following procedure.

First, assuming that the particle shape of the nanofiller 40 is spherical, the surface area and volume of one particle are obtained from the average particle size of the nanofiller 40. Next, based on the mass of the nanofiller 40 contained per unit volume, the density of the materials constituting the nanofiller 40, and the volume of one particle of the nanofiller 40, the nanofiller 40 contained per unit volume Find the number of particles. Then, based on the obtained number of particles of the nanofiller 40 and the surface area of one particle, the total surface area of the nanofiller 40 contained per unit volume is obtained.

Further, the total volume of the nanofiller 40 contained in the unit volume of the nanofiller collecting portion 32 is larger than the total volume of the nanofiller 40 contained in the unit volume of the sealing portion 30 excluding the nanofiller collecting portion 32. Larger is preferred. As described above, the total volume of the nanofiller 40 contained per unit volume is based on the volume of one particle of the nanofiller 40 and the number of particles of the nanofiller 40 contained per unit volume. Can be sought.

Even if the nanofiller 40 contained in the nanofiller collecting portion 32 and the nanofiller 40 contained in the sealing portion 30 excluding the nanofiller collecting portion 32 have the same material, particle size distribution, and average particle size. It may have different materials, particle size distributions, and average particle sizes.

In the example shown in FIG. 2, the nanofiller 40 contained in the nanofiller collecting portion 32 and the nanofiller 40 contained in the sealing portion 30 excluding the nanofiller collecting portion 32 have the same material, particle size distribution, and average grain. It is assumed to be a diameter. In this case, the weight percentage of the nanofiller 40 contained in the unit weight of the nanofiller collecting portion 32 is larger than the weight percentage of the nanofiller 40 contained in the unit weight of the sealing portion 30 excluding the nanofiller collecting portion 32. Is preferable.

More specifically, the weight percentage of the nanofiller 40 contained in the unit weight of the nanofiller collecting portion 32 is the weight percentage of the nanofiller 40 contained in the unit weight of the sealing portion 30 excluding the nanofiller collecting portion 32. It is desirable that it is 0.5% or more larger than that. For example, when a nanofiller 40 having a relatively large particle size having an average particle size of about 50 nm is used, the amount of the nanofiller 40 can be increased as compared with the case where the particle size is small, and the weight percentage can be increased. Differences can be easily made. This difference in weight percentage is more preferably, for example, 5% or more.

Compared with the case of using the nanofiller 40 having a large particle size, the increase in the total surface area, which is the surface area per unit mass, is large when the nanofiller 40 having a small particle size is used. Therefore, for example, it is preferable to use a nanofiller 40 having a relatively small particle size having an average particle size of less than 50 nm.

Further, in the semiconductor package 100 of the present embodiment, the nanofiller collecting portion 32 is provided outside the outer edge 23 of the semiconductor element 20. More specifically, the inner edge 32a of the nanofiller gathering portion 32, that is, the edge on the semiconductor element 20 side is located outside the outer edge 23 of the semiconductor element 20. In other words, a gap is provided between the semiconductor element 20 and the nanofiller collecting portion 32 in a direction parallel to the surface 11 of the substrate 10 and perpendicular to the outer edge 23 of the semiconductor element 20.

The semiconductor package 100 is not limited to the configuration shown in FIGS. 1 and 2. For example, the inner edge 32a of the nanofiller collecting portion 32 may be arranged at a position overlapping the outer edge 23 of the semiconductor element 20 in a direction perpendicular to the surface 11 of the substrate 10. Further, a part of the nanofiller collecting portion 32 may be inserted between the substrate 10 and the semiconductor element 20.

Further, in the semiconductor package 100 of the present embodiment, the nanofiller collecting portion 32 is provided on the surface 11 of the substrate 10. Further, in the semiconductor package 100 of the present embodiment, as shown in FIGS. 1 and 2, the nanofiller collecting portion 32 is a surface of the substrate 10 in a cross section orthogonal to the outer edge 23 of the semiconductor element 20 and the surface 11 of the substrate 10. It is provided in a convex shape having a height in a direction perpendicular to 11.

More specifically, in the cross section orthogonal to the outer edge 23 of the semiconductor element 20 and the surface 11 of the substrate 10, the nanofiller collecting portion 32 has a semicircular, semi-elliptical, and mountain shape in which the height of the central portion is higher than that of the peripheral portion. It has a mold, trapezoidal, or triangular cross-sectional shape. The nanofiller collecting portion 32 may be provided in a continuous frame shape over the entire circumference of the outer edge 23 of the semiconductor element 20, and the plurality of nanofiller collecting portions 32 may be provided in the circumferential direction along the outer edge 23 of the semiconductor element 20. It may be provided at intervals. In either case, the nanofiller collecting portion 32 can be formed so as to surround the outer edge 23 of the semiconductor element 20.

In the direction perpendicular to the surface 11 of the substrate 10, the height of the nanofiller collecting portion 32 is preferably, for example, equal to or less than the height of the upper surface of the semiconductor element 20, that is, the height of the end surface opposite to the substrate 10. Further, in the same direction, the height of the nanofiller gathering portion 32 is lower than, for example, the height of the lower surface of the semiconductor element 20, that is, the end surface facing the substrate 10. Further, a gap is formed between the semiconductor element 20 and the nanofiller collecting portion 32, for example, for passing the sealing material 30P (see FIG. 6) having fluidity when forming the sealing portion 30. ..

Hereinafter, the operation of each part of the semiconductor package 100 of the present embodiment will be described while explaining the method of manufacturing the semiconductor package of the present embodiment. FIG. 3 is a flow chart showing each process of the semiconductor package manufacturing method M100 of the present embodiment. FIG. 4 is a flow chart showing an example of each step of the sealing step S20 shown in FIG.

The semiconductor package manufacturing method M100 of the present embodiment includes a mounting step S10 for mounting the semiconductor element 20 on the substrate 10 and a sealing step S20 for sealing between the substrate 10 and the semiconductor element 20 by a sealing portion 30. The sealing step S20 includes a nanofiller collecting step S21. The nanofiller collecting step S21 is a step of collecting nanofillers 40, which are inorganic material particles having a particle size of 100 nm or less, on the peripheral edge of the region sealed by the sealing portion 30. Hereinafter, each step of the semiconductor package manufacturing method M100 will be described in detail.

The mounting step S10 is a step of mounting the semiconductor element 20 on the substrate 10. More specifically, the terminal 21 of the semiconductor element 20 is electrically connected to the electrode 12 of the substrate 10. For example, as described above, the bumps 22 connected to the terminals 21 of the semiconductor element 20 are placed on the electrodes 12 of the substrate 10, heated and melted, and then cooled and solidified to solidify the electrodes 12 of the substrate 10. And the terminal 21 of the semiconductor element 20 are electrically connected via the bump 22. A bump may be provided on the electrode 12 of the substrate 10.

The mounting step S10 may include a cleaning step of cleaning the surface 11 of the substrate 10 and the end face of the semiconductor element 20 facing the substrate 10 after the joining step of joining the semiconductor element 20 to the substrate 10. The cleaning step is performed, for example, for the purpose of removing the flux residue remaining on the surface 11 of the substrate 10 and the end face of the semiconductor element 20 facing the substrate 10 after the joining step. The cleaning step can be performed, for example, by plasma cleaning. If it is not necessary to clean the flux residue or if the flux residue is not generated, the cleaning step can be omitted. The mounting step S10 and the sealing step S20 can be performed in parallel.

The sealing step S20 includes, for example, a filling step S22 and a curing step S23 in addition to the nanofiller collecting step S21 described above. Hereinafter, each step of the sealing step S20 will be described.

FIG. 5 is a schematic cross-sectional view illustrating an example of the nanofiller collecting step S21 shown in FIG. As described above, the nanofiller collecting step S21 is a step of collecting the nanofiller 40, which is an inorganic material particle having a particle size of 100 nm or less, on the peripheral edge of the region sealed by the sealing portion 30.

The nanofiller collecting step S21 includes, for example, a step of arranging the medium 32P containing the nanofiller 40 on the surface 11 of the substrate 10 outside the outer edge 23 of the semiconductor element 20. In this step, for example, the total surface area of the nanofiller 40 contained in the unit volume of the medium 32P is calculated from the total surface area of the nanofiller 40 contained in the unit volume of the encapsulant 30P (see FIG. 6) described later. The medium 32P is prepared so as to be large.

The medium 32P is, for example, a thermosetting resin containing a matrix resin similar to the sealing material 30P for forming the sealing portion 30, a nanofiller 40, and a curing agent. Further, the medium 32P may contain, for example, the above-mentioned microfiller 50 or only the nanofiller 40 as a filler of the inorganic material. The ratio of the nanofiller 40 to the microfiller 50 contained in the medium 32P is such that, for example, the thermal expansion and contraction of the nanofiller collecting portion 32, the viscosity and fluidity of the medium 32P, and the effect of suppressing bleeding are in a preferable range. Prepared for.

Further, the medium 32P is adjusted to, for example, the content and viscosity of the nanofiller 40 capable of maintaining a convex shape having a height in the direction perpendicular to the surface 11 of the substrate 10 when arranged on the surface 11 of the substrate 10. To. When the medium 32P is a thermosetting resin, the medium 32P arranged on the surface 11 of the substrate 10 may be uncured or completely cured before the filling step S22, or may be incompletely half-cured. It may be cured. For example, by completely curing the medium 32P, the nanofiller collecting portion 32 is formed on the surface 11 of the substrate 10.

The medium 32P is not limited to the thermosetting resin, and may be composed of, for example, a solvent having a lower viscosity than the epoxy resin, a solvent that evaporates by heating, or a volatile solvent that evaporates at room temperature. In this case, the solvent constituting the medium 32P preferably has an organic polarity, for example, from the viewpoint of improving the compatibility with the nanofiller 40 and enhancing the dispersibility of the particles.

In the nanofiller collecting step S21, the medium 32P can be arranged on the surface 11 of the substrate 10 by dropping it on the outside of the outer edge 23 of the semiconductor element 20, for example. The medium 32P can be dropped onto the surface 11 of the substrate 10 on the outside of the outer edge 23 of the semiconductor element 20 by, for example, the dispenser D1. As the dispenser D1, for example, a jet dispenser having high dropping accuracy is suitable.

The medium 32P may be arranged in a continuous frame shape over the entire circumference of the outer edge 23 of the semiconductor element 20, or may be arranged at intervals in the circumferential direction along the outer edge 23 of the semiconductor element 20. In either case, the medium 32P can be arranged so as to surround the outer edge 23 of the semiconductor element 20. The amount of the nanofiller 40 arranged on the surface 11 of the substrate 10 in the nanofiller collecting step S21 is preferably as small as possible within the range in which bleeding can be effectively suppressed in the filling step S22 described later. ..

FIG. 6 is a schematic cross-sectional view illustrating an example of the filling step S22 shown in FIG. As described above, in the semiconductor package manufacturing method M100 of the present embodiment, the sealing step S20 includes a filling step S22 after the nanofiller collecting step S21. The filling step S22 is a step of filling the sealing material 30P between the substrate 10 and the semiconductor element 20. The sealing material 30P contains the nanofiller 40 and is cured to form the sealing portion 30.

As described above, the sealing material 30P is a thermosetting resin containing, for example, an epoxy resin which is a matrix resin, nanofillers 40 which are particles of an inorganic material such as silica, and a curing agent. Further, the sealing material 30P may contain, for example, a microfiller 50 which is an inorganic material particle having a particle size of 0.3 μm or more and 10 μm or less. As the epoxy resin constituting the sealing material 30P, for example, a bisphenol-based epoxy resin can be used, and as the curing agent, for example, an imidazole-based curing agent, an amine-based curing agent, or the like can be used. Further, the sealing material 30P may contain, for example, a silicon compound or a curing accelerator.

In the filling step S22, the encapsulant 30P is, for example, a medium 32P which is a thermosetting resin in an uncured or semi-cured state outside the outer edge 23 of the semiconductor element 20, or a nanofiller which is a cured thermosetting resin. It is dropped inside the gathering portion 32. The dropped sealing material 30P penetrates between the substrate 10 and the semiconductor element 20 due to the capillary phenomenon and is filled. The sealing material 30P may be filled from a plurality of directions of the outer edge 23 of the semiconductor element 20, for example, two adjacent sides of the semiconductor element 20 having a rectangular plan view.

The sealing material 30P can be dropped by, for example, the dispenser D2. As the dispenser D2, for example, a jet dispenser having high dropping accuracy is suitable. The dispenser D1 that discharges the medium 32P in the nanofiller collecting step S21 and the dispenser D2 that discharges the sealing material 30P in the filling step S22 may be the same dispenser.

FIG. 8 is an enlarged cross-sectional view of the outer edge portion 931 of the sealing portion 930 of the conventional semiconductor package 900. The sealing portion 930 of the conventional semiconductor package 900 is formed by the CUF method like the sealing portion 30 of the semiconductor package 100 of the present embodiment, and seals the gap between the substrate 910 and the semiconductor element 920. .. Further, the sealing portion 930 of the conventional semiconductor package 900 contains a nanofiller 940 and a microfiller 950, similarly to the sealing portion 30 of the semiconductor package 100 of the present embodiment.

However, unlike the semiconductor package 100 of the present embodiment, the sealing portion 930 of the conventional semiconductor package 900 does not have the nanofiller collecting portion 32 at the outer edge portion 931 of the sealing portion 930. That is, in the conventional semiconductor package 900, the total surface area of the nanofiller 940 contained in the unit volume of the sealing portion 930 is almost the same between the outer edge portion 931 of the sealing portion 930 and the other portions. , The entire sealing portion 930 is approximately equal. That is, the nanofiller 940 is not concentrated on the outer edge portion 931 of the sealing portion 930, but is dispersed substantially uniformly.

In this case, when a sealing material for forming the sealing portion 930 of the conventional semiconductor package 900 is filled between the substrate 910 and the semiconductor element 920, a fillet-shaped portion inclined to the outside of the outer edge 923 of the semiconductor element 920. Is formed. Further, bleed B is generated on the outside of the fillet-like portion of the encapsulant, from which the liquid component derived from the encapsulant leaks out. Bleed B not only causes poor appearance, defects due to contact with peripheral surface mount components, poor conductivity due to contact with electrodes around the semiconductor element 920, and further increases the integration of the semiconductor element 920. It becomes a factor that hinders high density. In order to suppress this bleed B, the conventional resin composition described in Patent Document 1 limits the silicone-based copolymer to a specific component.

On the other hand, the semiconductor package 100 of the present embodiment includes a substrate 10, a semiconductor element 20 mounted on the substrate 10, and a sealing portion 30 for sealing between the semiconductor element 20 and the substrate 10. I have. The sealing portion 30 includes a nanofiller 40 which is an inorganic material particle having a particle size of 100 nm or less, and has a nanofiller collecting portion 32 in which the nanofiller 40 is gathered at the outer edge portion 31 of the sealing portion 30. ing.

Further, in the semiconductor package manufacturing method M100 of the present embodiment, the mounting step S10 for mounting the semiconductor element 20 on the substrate 10 and the sealing step S20 for sealing between the substrate 10 and the semiconductor element 20 by the sealing portion 30. And have. The sealing step S20 includes a nanofiller collecting step S21 for collecting the nanofiller 40, which is an inorganic material particle having a particle size of 100 nm or less, on the peripheral edge of the region sealed by the sealing portion 30.

With such a configuration, the nanofiller 40 contained in the nanofiller collecting portion 32, that is, the nanofiller 40 gathered at the peripheral edge of the region sealed by the sealing portion 30 in the sealing step S20, provides a sealing material. It can retain 30P of liquid component. As a result, bleed B in which the liquid component derived from the sealing material 30P leaks to the outside of the fillet-like portion can be suppressed.

Further, by concentrating the nanofiller 40 only on the nanofiller collecting portion 32, the amount of the nanofiller 40 used is reduced rather than increasing the content of the nanofiller collecting portion 32 in the entire sealing portion 30. be able to. Therefore, according to the semiconductor package 100 of the present embodiment and the semiconductor package manufacturing method M100, the bleed B can be suppressed by a small amount of the nanofiller 40, and the increase in the amount of the relatively expensive nanofiller 40 used can be suppressed. However, the increase in cost can be suppressed.

Further, by causing the nanofiller collecting portion 32 to bear the effect of suppressing the bleed B, it is not necessary to increase the content of the nanofiller 40 in the sealing material 30P for the purpose of suppressing the bleed B. Thereby, the performance such as thermal expansion, heat conduction, and adhesion of the sealing portion 30 and the viscosity and fluidity of the sealing material 30P can be more easily adjusted to the optimum state, and the sealing portion 30 can be adjusted to the optimum state. And it becomes possible to improve the performance of the sealing material 30P.

Further, as a result of diligent studies, the inventors of the present application have found that the larger the total surface area of the nanofiller 40 contained in the unit volume of the encapsulant 30P, the greater the effect of suppressing bleed B. The mechanism by which bleed B is suppressed by the nanofiller 40 includes the following. First, by increasing the contact area between the nanofiller 40 and the liquid component containing the resin component of the encapsulant 30P, more liquid component can be retained on the surface of the nanofiller 40. Further, the resin is held by the capillary effect between the nanofillers 40 or in the minute gaps formed by the nanofillers 40 and the microfillers 50. Further, the nanofiller 40 also functions as a barrier against the outflow of the resin. The details will be described below.

In the semiconductor package 100 of the present embodiment, as described above, the total surface area of the nanofiller 40 contained in the unit volume of the nanofiller collecting portion 32 is per unit volume of the sealing portion 30 excluding the nanofiller collecting portion 32. It is larger than the total surface area of the nanofiller 40 contained in. In other words, in the semiconductor package 100 of the present embodiment, as described above, the total volume of the nanofillers 40 contained in the unit volume of the nanofiller collecting portion 32 is the total volume of the sealing portion 30 excluding the nanofiller collecting portion 32. It is larger than the total volume of the nanofillers 40 contained per unit volume. That is, in the semiconductor package 100 of the present embodiment, the number density of the nanofillers 40 in the nanofiller collecting portion 32 is higher than the number density of the nanofillers 40 in the sealing portion 30 excluding the nanofiller collecting portion 32.

With such a configuration, the nanofiller 40 collected in the nanofiller collecting portion 32 can retain the liquid component of the sealing material 30P and suppress the bleed B. Further, the bleed B is suppressed by holding the liquid component including the resin component of the sealing material 30P in the minute gaps between the particles of the nanofiller 40 by the capillary phenomenon.

Further, since the liquid component that generates the bleed B spreads in the form of a thin film, the surface area is large but the volume is often small as compared with the fillet-like portion of the outer edge portion of the sealing material 30P. Therefore, the total surface area of the nanofiller 40 contained in the unit volume of the nanofiller collecting portion 32 and the total surface area of the nanofiller 40 contained in the unit volume of the sealing portion 30 excluding the nanofiller collecting portion 32. Even if the difference is as small as about 0.5%, it is possible to obtain a sufficient bleed B suppressing effect.

Such an effect of suppressing bleed B is particularly remarkable at the interface between the medium 32P and air. In other words, the effect of suppressing bleed B is remarkable in the portion where the nanofiller 40 is locally concentrated and the portion where the nanofiller 40 is exposed to the surrounding atmosphere of the medium 32P.

Here, in the nanofiller collecting step S21 shown in FIG. 5, the thermosetting resin medium 32P arranged on the surface 11 of the substrate 10 was completely cured to form the nanofiller collecting portion 32 on the surface 11 of the substrate 10. And. In this case, in the filling step S22 shown in FIG. 6, the encapsulant 30P and the medium 32P are hardly mixed, but the encapsulant 30P is formed by the nanofiller 40 exposed at the interface between the nanofiller collecting portion 32 and the air. The liquid component is retained and bleed B is suppressed.

Further, in the nanofiller collecting step S21 shown in FIG. 5, when the filling step S22 shown in FIG. 6 is performed while the thermosetting resin medium 32P arranged on the surface 11 of the substrate 10 is uncured or semi-cured. There is a region where the sealing material 30P and the medium 32P are mixed. In this case, not only the nanofiller 40 exposed at the interface between the medium 32P and the air, but also the nanofiller 40 in which the medium 32P is arranged and gathered retains the liquid component of the sealing material 30P, and the bleed B is suppressed. ..

Further, in the nanofiller collecting step S21 shown in FIG. 5, the medium 32P arranged on the surface 11 of the substrate 10 is not a thermosetting resin but a solvent that evaporates by heating with a lower viscosity than the epoxy resin or a volatile solvent. It is assumed that the nanofiller 40 is contained in the solvent. In this case, in the nanofiller collecting step S21, the solvent of the medium 32P is evaporated, and the nanofiller 40 is arranged in a state of being collected on the peripheral edge of the region sealed by the sealing portion 30 on the surface 11 of the substrate 10. The solvent of the medium 32P may be completely evaporated or partially evaporated.

After that, by performing the filling step S22, the thermosetting resin of the sealing material 30P is in a state of being inserted between the particles of the nanofiller 40 of the nanofiller collecting portion 32. As a result, the liquid component of the sealing material 30P can be retained by the nanofiller 40 gathered at the peripheral edge of the region sealed by the sealing portion 30 on the surface 11 of the substrate 10, and the bleed B can be suppressed. When a solvent having an organic polarity is used as the solvent for the medium 32P, the dispersibility of the nanofiller 40 can be improved, so that the total surface area of the particles is increased and the liquid component of the encapsulant 30P is used. It can be held more effectively and the effect of suppressing bleed B can be further improved.

Further, in the semiconductor package 100 of the present embodiment and the method M100 for manufacturing the semiconductor package, the sealing portion 30 contains, for example, a microfiller 50 which is an inorganic material particle having a particle size of 0.3 μm or more and 10 μm or less. Since the particles of the nanofiller 40 gathered at the peripheral edge of the region sealed by the sealing portion 30 on the surface 11 of the substrate 10 are filled between the particles of the microfiller 50, the liquid component of the sealing material 30P is contained. It functions as a barrier against flowing outward, and bleed B is suppressed. Further, the same effect can be obtained even when the medium 32P contains the microfiller 50.

Further, in the semiconductor package 100 of the present embodiment, the nanofiller collecting portion 32 is provided outside the outer edge of the semiconductor element 20. Further, the nanofiller collecting portion 32 is provided on the surface of the substrate 10. That is, in the semiconductor package manufacturing method M100 of the present embodiment, the nanofiller collecting step S21 includes a step of arranging the medium 32P containing the nanofiller 40 on the surface 11 of the substrate 10 outside the outer edge 23 of the semiconductor element 20. .. The total surface area of the nanofiller 40 contained in the unit volume of the medium 32P is larger than the total surface area of the nanofiller 40 contained in the unit volume of the encapsulant 30P.

With such a configuration, the nanofiller 40 can be concentrated on the peripheral edge of the region sealed by the sealing portion 30. Then, the liquid component of the sealing material 30P filled in the region sealed by the sealing portion 30 is held by the nanofiller 40 gathered at the peripheral edge of the region, and the generation of bleed B can be suppressed. ..

Further, in the semiconductor package 100 of the present embodiment, the nanofiller collecting portion 32 has a height in a direction perpendicular to the surface 11 of the substrate 10 in a cross section orthogonal to the outer edge 23 of the semiconductor element 20 and the surface 11 of the substrate 10. It is provided in a convex shape. With this configuration, in the filling step S22, the nanofiller 40 contained in the nanofiller collecting portion 32 or the medium 32P functions as a barrier to prevent the outflow of the liquid component of the sealing portion 30 or the sealing material 30P, and the bleed B is further formed. It becomes possible to suppress it effectively.

Next, the curing step S23 shown in FIG. 4 is performed. The curing step S23 included in the sealing step S20 of the semiconductor package manufacturing method M100 of the present embodiment is, for example, a step of curing the sealing material 30P containing an epoxy resin and a curing agent. More specifically, in the filling step S22 shown in FIG. 6, the sealing material 30P dropped on the outside of one outer edge 23 of the semiconductor element 20 penetrates between the substrate 10 and the semiconductor element 20 due to the capillary phenomenon. , Reach the other outer edge 23 of the semiconductor element 20. At that time, the curing step S23 is started, and the sealing material 30P is cured by, for example, thermosetting or photocuring to form the sealing portion 30.

Thermosetting is, for example, a step of curing the sealing material 30P, which is a thermosetting resin, by heating the sealing material 30P with a heater. The photocuring is, for example, a step of irradiating the sealing material 30P with light from a spot light source to cure the sealing material 30P which is a photocurable resin. The light to be applied to the sealing material 30P is selected according to the type and amount of the photopolymerization initiator used in the sealing material 30P. As an example, the sealing material 30P can be cured by irradiating the sealing material 30P with visible light or ultraviolet light having a wavelength of 240 nm or more and 700 nm or less and an intensity of 1000 mW / cm ² or more and 6000 mW / cm ² or less.

As described above, according to the present embodiment, the semiconductor package 100 and the method for manufacturing the semiconductor package can suppress the bleed B by the action of the nanofiller 40, which is an inorganic filler contained in the sealing material 30P. M100 can be provided.

In the semiconductor package manufacturing method M100 of the present embodiment, an example in which the filling step S22 is performed after the nanofiller collecting step S21 and an example in which these are performed in parallel have been described, but the nanofiller collecting step S21 is described after the filling step S22. May be done. In this case, the nanofiller collecting step S21 may be performed after the filling step S22 is completed and before the bleed B is generated. Further, the nanofiller collecting step S21, the filling step S22, and the curing step S23 can be performed in parallel at least two or more of these steps.

Further, the medium 32P may not be used in the nanofiller collecting step S21. For example, the nanofiller 40 may be deposited or sprayed directly on the peripheral edge of the region sealed by the sealing portion 30 on the surface 11 of the substrate 10. Further, in the semiconductor package 100 of the present embodiment, the nanofiller collecting portion 32 is formed in the fillet-shaped portion of the sealing portion 30, but the nanofiller collecting portion 32 is larger than the fillet-shaped portion of the sealing portion 30. It may be formed on the outside.

[Embodiment 2]
Next, the semiconductor package according to the second embodiment of the present disclosure and the manufacturing method thereof will be described with reference to FIGS. 1 and 3 to 6. FIG. 7 is an enlarged cross-sectional view of the outer edge portion 31 of the sealing portion 30 of the semiconductor package 200 of the present embodiment corresponding to FIG. 2 of the first embodiment.

The semiconductor package 200 of the present embodiment is different from the semiconductor package 100 of the above-described first embodiment in that the nanofiller collecting portion 32 is provided in a layered manner along the outer peripheral surface of the sealing portion 30. Since the other points of the semiconductor package 200 of the present embodiment are the same as those of the semiconductor package 100 of the first embodiment, the same reference numerals are given to the same parts and the description thereof will be omitted.

Further, in the method for manufacturing the semiconductor package of the present embodiment, the nanofiller collecting step S21 and the filling step S22 shown in FIG. 4 are simultaneously performed. More specifically, in the present embodiment, the nanofiller collecting step S21 does not have a step of arranging the medium 32P containing the nanofiller 40 as shown in FIG.

Instead, in the method for manufacturing a semiconductor package of the present embodiment, in the filling step S22 that also serves as the nanofiller collecting step S21, the sealing portion 30 is contained and cured by containing and curing the nanofiller 40 that has been subjected to a liquid-repellent surface treatment. As shown in FIG. 6, the sealing material 30P forming the above is filled between the substrate 10 and the semiconductor element 20 and allowed to flow. As a result, the nanofiller 40 is concentrated on the surface layer portion of the outer edge portion of the sealing material 30P.

More specifically, the surface treatment of the nanofiller 40 is, for example, a surface treatment using a vinyl-based coupling agent. When the sealing material 30P contains the microfiller 50, it is preferable to apply a liquid-friendly surface treatment to the microfiller 50. Examples of the surface treatment of the microfiller 50 include a surface treatment using an epoxy-based coupling agent.

By such a surface treatment, the liquid repellency of the nanofiller 40 with respect to the liquid component of the sealing material 30P can be improved as compared with the liquid repellency of the microfiller 50. The surface energy may be changed by increasing or decreasing the covering area of the nanofiller 40 and the microfiller 50 by the surface treatment.

By the above-mentioned surface treatment, the interaction between the nanofiller 40 and the liquid component of the sealing material 30P can be weakened, and the nanofiller 40 can easily move when the sealing material 30P flows. As a result, the nanofiller 40 stays at the interface between the sealing material 30P and the air, which is more stable in energy state, and the nanofiller 40 can be concentrated on the surface layer portion of the outer edge portion of the sealing material 30P.

On the other hand, by applying a liquid-friendly surface treatment to the liquid component of the encapsulant 30P on the microfiller 50, the interaction between the microfiller 50 and the liquid component of the encapsulant 30P is strengthened, and the encapsulant 30P The microfiller 50 becomes difficult to move during flow. As a result, the microfiller 50 is prevented from concentrating on the surface layer portion of the outer edge portion of the sealing material 30P.

As described above, in the present embodiment, in the filling step S22 that also serves as the nanofiller collecting step S21, the nanofiller 40 is gathered on the surface layer portion of the outer edge portion of the sealing material 30P, and the outer edge portion of the sealing portion 30 of the semiconductor package 200 is gathered. The nanofiller gathering portion 32 can be formed at 31. The affinity between the nanofiller 40 and the liquid component of the encapsulant 30P is relatively lower than the affinity between the microfiller 50 and the liquid component of the encapsulant 30P, while maintaining a relatively high affinity. By doing so, it is preferable that the nanofiller 40 can be easily concentrated on the surface layer portion of the outer edge portion of the sealing material 30P.

Therefore, according to the semiconductor package 200 of the present embodiment and the manufacturing method thereof, the liquid component of the sealing material 30P is retained by the nanofiller 40 in the same manner as the semiconductor package 100 of the above-described first embodiment and the semiconductor package manufacturing method M100. However, bleed B can be suppressed. After that, by performing the curing step S23 in the same manner as in the first embodiment, as shown in FIG. 7, a semiconductor package 200 in which the nanofiller collecting portion 32 is provided in a layer along the outer peripheral surface of the sealing portion 30 is manufactured. be able to.

Although the embodiments of the present disclosure have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and even if there is a design change or the like within a range not deviating from the gist of the present disclosure. , They are included in this disclosure. For example, a plurality of different types of nanofillers or microfillers may be used.

10 Substrate 11 Surface 20 Semiconductor element 23 Outer edge 30 Encapsulating part 30P Encapsulant 31 Outer edge part 32 Nanofiller collecting part 32P Medium 40 Nanofiller 50 Microfiller 100 Semiconductor package 200 Semiconductor package M100 Semiconductor package manufacturing method S10 Mounting process S20 Sealing Stopping step S21 Nanofiller collecting step S22 Filling step S23 Curing step

Claims (8)

A semiconductor package including a substrate, a semiconductor element mounted on the substrate, and a sealing portion for sealing between the semiconductor element and the substrate.
The sealing portion contains nanofillers which are inorganic material particles having a particle size of 100 nm or less.
The outer edge of the sealing portion, have a nano filler gathered portion massed the nanofiller,
A semiconductor package characterized in that the nanofiller collecting portion is provided outside the outer edge of the semiconductor element, and is provided in a layer along the outer peripheral surface of the sealing portion . The total surface area of the nanofiller contained in the unit volume of the nanofiller collecting portion is larger than the total surface area of the nanofiller contained in the unit volume of the sealing portion excluding the nanofiller collecting portion. The semiconductor package according to claim 1. The total volume of the nanofiller contained per unit volume of the nanofiller collecting portion is larger than the total volume of the nanofiller contained per unit volume of the sealing portion excluding the nanofiller collecting portion. The semiconductor package according to claim 1. The semiconductor package according to claim 1, wherein the number density of the nanofillers in the nanofiller collecting portion is higher than the number density of the nanofillers in the sealing portion excluding the nanofiller collecting portion. The semiconductor package according to claim 1, wherein the sealing portion contains a microfiller which is an inorganic material particle having a particle size of 0.3 μm or more and 10 μm or less. A method for manufacturing a semiconductor package, comprising a mounting step of mounting a semiconductor element on a substrate and a sealing step of sealing between the substrate and the semiconductor element by a sealing portion.
The sealing step, viewed contains a nanofiller gathered step is a particle size in the peripheral portion of the area to be sealed will assemble nanofiller or less of an inorganic material particles 100nm by the sealing portion,
In the nanofiller collecting step, the substrate and the semiconductor element are filled with a sealing material that contains the nanofiller that has undergone a liquid-repellent surface treatment and is cured to form the sealing portion. A method for manufacturing a semiconductor package, characterized in that the nanofiller is concentrated on a surface layer portion of an outer edge portion of the encapsulant by flowing . The method for manufacturing a semiconductor package according to claim 6 , wherein the encapsulant contains microfillers which are inorganic material particles having a particle size of 0.3 μm or more and 10 μm or less. The method for manufacturing a semiconductor package according to claim 6 , wherein the sealing step includes a curing step of curing the sealing material containing an epoxy resin and a curing agent.

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